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  • Wiley-Blackwell  (504,004)
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  • 1
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    Wiley-Blackwell
    Publication Date: 2018-01-03
    Description: Transparent, durable coating materials that show excellent liquid repellency, both water and oil, have multiple applications in science and technology. In this perspective, herein, a simple aqueous chemical formulation is developed that provides a transparent slippery coating without any lubricating fluids, on various substrates extended over large areas. The coatings repel liquids having a range of polarity (solvents) as well as viscosity (oils and emulsions) and withstand mechanical strains. Exceptional optical transparency of 99% in the range of 350–900 nm along with high stability even after cyclic temperature, frost, exposure to sunlight, and corrosive liquids like aqua regia treatments, makes this material unique and widens its applicability in different fields. Besides, being a liquid, it can be coated on an array of substrates independent of their underlying topography, by various easily available techniques. Aside from these interesting properties, the coating is demonstrated as a potential solution contributing to the remediation of one of the biggest global issues of tomorrow: affordable drinking water. The coated surface can capture 5 L of water per day per m 2 at 27 °C when exposed to an atmosphere of 63% relative humidity. An inexpensive aqueous coating material , providing robust, transparent, and liquid repellent properties without any lubricating fluid once cured, is demonstrated. It is stable over extreme mechano-thermochemical perturbations and can be coated on a variety of substrates. Being a liquid, it enables the creation of large surfaces, which makes this material unique for different applications, including atmospheric water harvesting.
    Electronic ISSN: 2056-6646
    Topics: General, Interdisciplinary , Energy, Environment Protection, Nuclear Power Engineering
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  • 2
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    Wiley-Blackwell
    Publication Date: 2018-01-03
    Description: Precise quantification of extracellular glutamate concentrations upon neuronal activation is crucial for the understanding of brain function and neurological disorders. While optogenetics is an outstanding method for the correlation between distinct neurons and their role in circuitry and behavior, the electrochemically inactive nature of glutamate has proven challenging for recording upon optogenetic stimulations. This difficulty is due to the necessity for using enzyme-coated microelectrodes and the risk for light-induced artifacts. In this study, we establish a method for the combination of in vivo optogenetic stimulation with selective measurement of glutamate concentrations using enzyme-coated multielectrode arrays and amperometry. The glutamatergic subthalamic nucleus (STN), which is the main electrode target site in deep brain stimulation treatment of advanced Parkinson′s disease, has recently proven opotogenetically targetable in Pitx2-Cre-transgenic mice and was here used as model system. Upon stereotactic injection of viral Channelrhodopsin2-eYFP constructs into the STN, amperometric recordings were performed at a range of optogenetic stimulation frequencies in the globus pallidus, the main STN target area, in anaesthetized mice. Accurate quantification was enabled through a multi-step analysis approach based on self-referencing microelectrodes and repetition of the experimental protocol at two holding potentials, which allowed for the identification, isolation and removal of photoelectric and photoelectrochemical artifacts. This study advances the field of in vivo glutamate detection with combined optogenetics and amperometric recordings by providing a validated analysis framework for application in a wide variety of glutamate-based approaches in neuroscience. This article is protected by copyright. All rights reserved.
    Print ISSN: 0022-3042
    Electronic ISSN: 1471-4159
    Topics: Medicine
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  • 3
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    Wiley-Blackwell
    Publication Date: 2018-01-04
    Description: The transport phase of the animal-mediated plant dispersal process is critical to dispersal effectiveness as it determines the spatial distribution of the diaspores released and their chance for further recruitment. Assessing this specific phase of the dispersal process generally requires combining diaspore retention times with the associated distances covered. Here, we specifically tested the effect of grooming behavior, interindividual contacts and ungulate fur on diaspore retention times and associated dispersal distances for the hooked diaspores of Xanthium strumarium L. experimentally attached to tamed individuals of three ungulate species. We used a comparative approach based on differing fur quality on different body zones of these three ungulates. During 6-hr sessions, we monitored for grooming and social interactions that may induce intended or inadvertent diaspore detachment. Additionally, we proposed innovative approaches to directly assessing diaspore dispersal distances by red deer in situ. Fat-tailed functions fitted diaspore retention time, highlighting the potential for long-distance dispersal events. The longer the hair, the higher the retention capacity of diaspores in the animal's fur. As predicted, donkey retained diaspores longer than red deer and dwarf goat; and we also confirmed that diaspores attached to the short hair of the head fell off more quickly than did those on the other body zones. Dwarf goat groomed more often than both red deer and donkey, but also when it carried diaspores. Up to 14% of the diaspores detached from animal fur after specific grooming behavior. We observed, in controlled conditions, for the first time and for each ungulate species, interindividual transfers of diaspores, representing 5% of the diaspores attached to animals’ fur. Our results militate for incorporating animal behavior into plant dispersal modeling approaches. We present important methodological updates stressing the potential for long-distance animal-mediated diaspore dispersal events using short monitoring sessions and a trait-based cross-comparative approach. We highlight the interest of coupling diaspore fate monitoring with behavioral census. This helped us describing for the first time unsuspected diaspore transfers among conspecifics.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 4
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    Wiley-Blackwell
    Publication Date: 2018-01-03
    Description: In 2008, a new species for the French bee fauna was recorded in Allauch near Marseille: the giant resin bee, Megachile sculpturalis (Smith, 1853). This was the first European record of this species that is native to East Asia. To our knowledge, it is the first introduced bee species in Europe. Here, we provide an overview of the current distribution of M. sculpturalis in France and we describe the history of its range expansion. Besides our own observations, information was compiled from literature and Internet websites, and by contacting naturalist networks. We collected a total of 117 records ( locality  ×  year combinations) for the 2008–2016 period. The geographical range of M. sculpturalis has extended remarkably, now occupying a third of continental France, with the most northern and western records located 335 and 520 km from Allauch, respectively. Information on its phenology, feeding, and nesting behavior is also provided. We report several events of nest occupation or eviction of Osmia sp. and Xylocopa sp. individuals by M. sculpturalis . Our results show that M. sculpturalis is now well established in France. Given its capacity to adapt and rapidly expand its range, we recommend amplifying the monitoring of this species to better anticipate the changes in its geographical range and its potential impacts on native bees. In 2008, a new species for the French bee fauna was recorded in Allauch near Marseille: the giant resin bee, Megachile sculpturalis (Smith, 1853). This was the first European record of this species native from East Asia. Here, we provide an overview of the current distribution of M. sculpturalis in France and we describe its expansion history.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 5
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    Wiley-Blackwell
    Publication Date: 2018-01-03
    Description: Severe heart pathology upon virus infection is closely associated with the immunological equipment of the host. Since there is no specific treatment available, current research focuses on identifying new drug targets to positively modulate predisposing immune factors. Utilizing a murine model with high susceptibility to coxsackievirus B3-induced myocarditis, this study describes ONX 0914—an immunoproteasome-specific inhibitor—as highly protective during severe heart disease. Represented by reduced heart infiltration of monocytes/macrophages and diminished organ damage, ONX 0914 treatment reversed fulminant pathology. Virus-induced immune response features like overwhelming pro-inflammatory cytokine and chemokine production as well as a progressive loss of lymphocytes all being reminiscent of a sepsis-like disease course were prevented by ONX 0914. Although the viral burden was only minimally affected in highly susceptible mice, resulting maintenance of immune homeostasis improved the cardiac output, and saved animals from severe illness as well as high mortality. Altogether, this could make ONX 0914 a potent drug for the treatment of severe virus-mediated inflammation of the heart and might rank immunoproteasome inhibitors among drugs for preventing pathogen-induced immunopathology. Resembling disease course in patients pre-disposed for severe pathogen-induced cardiac pathology, A/J mice exhibit high susceptibility for virus-induced adverse immune response activation. Systemic application of the LMP7-specific immunoproteasome inhibitor ONX 0914 inversed this hereditary predisposition.
    Print ISSN: 1757-4676
    Electronic ISSN: 1757-4684
    Topics: Medicine
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  • 6
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    Wiley-Blackwell
    Publication Date: 2018-01-03
    Description: Many species are shifting their ranges in response to the changing climate. In cases where such shifts lead to the colonization of a new ecosystem, it is critical to establish how the shifting species itself is impacted by novel environmental and biological interactions. Anthropogenic habitats that are analogous to the historic habitat of a shifting species may play a crucial role in the ability of that species to expand or persist in suboptimal colonized ecosystems. We tested if the anthropogenic habitat of docks, a likely mangrove analog, provides improved conditions for the range-shifting mangrove tree crab Aratus pisonii within the colonized suboptimal salt marsh ecosystem. To test if docks provided an improved habitat, we compared the impact of the salt marsh and dock habitats on ecological and life history traits that influence the ability of this species to persist and expand into the salt marsh and compared these back to baselines in the historic mangrove ecosystem. Specifically, we examined behavior, physiology, foraging, and the thermal conditions of A. pisonii in each habitat. We found that docks provide a more favorable thermal and foraging habitat than the surrounding salt marsh, while their ability to provide conditions which improved behavior and physiology was mixed. Our study shows that anthropogenic habitats can act as analogs to historic ecosystems and enhance the habitat quality for range-shifting species in colonized suboptimal ecosystems. If the patterns that we document are general across systems, then anthropogenic habitats may play an important facilitative role in the range shifts of species with continued climate change. Many species are shifting their ranges in response to the changing climate, and in cases where such shifts lead to the colonization of a new ecosystem, it is critical to establish how the shifting species itself is impacted by novel environmental and biological interactions. We tested if the anthropogenic analogous habitat of docks provides improved conditions for the range-shifting mangrove tree crab Aratus pisonii within the suboptimal colonized salt marsh ecosystem. We found that docks provide a more favorable thermal and foraging habitat than the surrounding salt marsh, while their ability to provide improved behavioral and physiological conditions was mixed.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 7
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    Wiley-Blackwell
    Publication Date: 2018-01-05
    Description: The Horn of Africa forms one of the two main historical entry points of domestics into the continent and Ethiopia is particularly important in this regard. Through the analysis of mitochondrial DNA (mtDNA) d -loop region in 309 individuals from 13 populations, we reveal the maternal genetic variation and demographic dynamics of Ethiopian indigenous goats. A total of 174 variable sites that generated 231 haplotypes were observed. They defined two haplogroups that were present in all the 13 study populations. Reference haplotypes from the six globally defined goat mtDNA haplogroups show the two haplogroups present in Ethiopia to be A and G, the former being the most predominant. Although both haplogroups are characterized by an increase in effective population sizes ( N e ) predating domestication, they also have experienced a decline in N e at different time periods, suggesting different demographic histories. We observed seven haplotypes, six were directly linked to the central haplotypes of the two haplogroups and one was central to haplogroup G. The seven haplotypes were common between Ethiopia, Kenya, Egypt, and Saudi Arabia populations, suggesting common maternal history and the introduction of goats into East Africa via Egypt and the Arabian Peninsula, respectively. While providing new mtDNA data from a historically important region, our results suggest extensive intermixing of goats mediated by human socio-cultural and economic interactions. These have led to the coexistence of the two haplogroups in different geographic regions in Ethiopia resulting in a large caprine genetic diversity that can be exploited for genetic improvement. The complete control region analysis of mtDNA of Ethiopian goats uncovers the maternal genetic variation and historical demographic profiles. In the result, we observed high genetic diversity but no clear phylogeographic structure. This suggests extensive past and present gene flow amongst indigenous goats mediated by human socio-cultural and economic interactions.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 8
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    Wiley-Blackwell
    Publication Date: 2018-01-05
    Description: High resolution Atmosphere General Circulation Models (AGCMs) are capable of directly simulating realistic tropical cyclone (TC) statistics, providing a promising approach for TC-climate studies. Active air-sea coupling in a coupled model framework is essential to capturing TC-ocean interactions, which can influence TC-climate connections on interannual to decadal time scales. Here we investigate how the choices of ocean coupling can affect the directly simulated TCs using high resolution configurations of the Community Earth System Model (CESM). We performed a suite of high resolution, multi-decadal, global scale CESM simulations in which the atmosphere (∼0.25˚ grid spacing) is configured with three different levels of ocean coupling: prescribed climatological sea surface temperature (SST) (ATM), mixed layer ocean (SLAB), and dynamic ocean (CPL). We find that different levels of ocean coupling can influence simulated TC frequency, geographical distributions, and storm intensity. ATM simulates more storms and higher overall storm intensity than the coupled simulations. It also simulates higher TC track density over the eastern Pacific and the North Atlantic, while TC tracks are relatively sparse within CPL and SLAB for these regions. Storm intensification and the maximum wind speed are sensitive to the representations of local surface flux feedbacks in different coupling configurations. Key differences in storm number and distribution can be attributed to variations in the modeled large-scale climate mean state and variability that arise from the combined effect of intrinsic model biases and air-sea interactions. Results help to improve our understanding about the representation of TCs in high resolution coupled Earth system models, with important implications for TC-climate applications.
    Electronic ISSN: 1942-2466
    Topics: Geography , Geosciences
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  • 9
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    Wiley-Blackwell
    Publication Date: 2018-01-05
    Description: Shell damage and parasitic infections are frequent in gastropods, influencing key snail host life-history traits such as survival, growth, and reproduction. However, their interactions and potential effects on hosts and parasites have never been tested. Host–parasite interactions are particularly interesting in the context of the recently discovered division of labor in trematodes infecting marine snails. Some species have colonies consisting of two different castes present at varying ratios; reproductive members and nonreproductive soldiers specialized in defending the colony. We assessed snail host survival, growth, and shell regeneration in interaction with infections by two trematode species, Philophthalmu s sp. and Maritrema novaezealandense , following damage to the shell in the New Zealand mud snail Zeacumantus subcarinatus . We concomitantly assessed caste-ratio adjustment between nonreproductive soldiers and reproductive members in colonies of the trematode Philophthalmu s sp. in response to interspecific competition and shell damage to its snail host. Shell damage, but not parasitic infection, significantly increased snail mortality, likely due to secondary infections by pathogens. However, trematode infection and shell damage did not negatively affect shell regeneration or growth in Z. subcarinatus ; infected snails actually produced more new shell than their uninfected counterparts. Both interspecific competition and shell damage to the snail host induced caste-ratio adjustment in Philophthalmu s sp. colonies. The proportion of nonreproductive soldiers increased in response to interspecific competition and host shell damage, likely to defend the parasite colony and potentially the snail host against increasing threats. These results indicate that secondary infections by pathogens following shell damage to snails both significantly increased snail mortality and induced caste-ratio adjustments in parasites. This is the first evidence that parasites with a division of labor may be able to produce nonreproductive soldiers according to environmental factors other than interspecific competition with other parasites. We assessed snail host survival, growth, and shell regeneration in interaction with infections by two trematode species following damage to the shell. We concomitantly assessed caste-ratio adjustment between nonreproductive soldiers and reproductive members in colonies of the trematode Philophthalmus sp. in response to interspecific competition and shell damage to its snail host. Shell damage, but not parasitic infection, significantly increased snail mortality, likely due to secondary infections by pathogens. The proportion of nonreproductive soldiers increased in response to interspecific competition and host shell damage. This is the first evidence that parasites with a division of labor may be able to produce nonreproductive soldiers according to environmental factors other than interspecific competition with other parasites.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 10
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    Wiley-Blackwell
    Publication Date: 2018-01-06
    Description: Carrion beetles, Nicrophorus vespilloides, are reared on decomposing carrion where larvae are exposed to high populations of carcass-derived bacteria. Larvae do not become colonized with these bacteria but instead are colonized with the gut microbiome of their parents, suggesting that bacteria in the beetle microbiome outcompete the carcass-derived species for larval colonization. Here, we test this hypothesis and quantify the fitness consequences of colonization with different bacterial symbionts. First, we show that beetles colonized by their endogenous microbiome produce heavier broods than those colonized with carcass-bacteria. Next, we show that bacteria from the endogenous microbiome, including Providencia rettgeri and Morganella morganii , are better colonizers of the beetle gut and can outcompete nonendogenous species, including Serratia marcescens and Escherichia coli , during in vivo competition. Finally, we find that Providencia and Morganella provide beetles with colonization resistance against Serratia and thereby reduce Serratia -induced larval mortality. This effect is eliminated in larvae first colonized by Serratia , suggesting that while competition within the larval gut is determined by priority effects, these effects are less important for Serratia -induced mortality. Our work suggests that an unappreciated benefit of parental care in N. vespilloides is the social transmission of the microbiome from parents to offspring. Our work supports the idea that bacterial gut symbionts provide direct fitness benefits to Nicrophorus larvae by outcompeting potential bacterial pathogens. They further suggest that one benefit of parental care in Nicrophorus vespilloides is the social transmission of the microbiome from caring parents to their offspring.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 11
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    Wiley-Blackwell
    Publication Date: 2018-01-06
    Description: In the southwestern USA, recent large-scale die-offs of conifers raise the question of their resilience and mortality under droughts. To date, little is known about the interannual structural response to droughts. We hypothesized that piñon pines ( Pinus edulis ) respond to drought by reducing the drop of leaf water potential in branches from year to year through needle morphological adjustments. We tested our hypothesis using a 7-year experiment in central New Mexico with three watering treatments (irrigated, normal, and rain exclusion). We analyzed how variation in “evaporative structure” (needle length, stomatal diameter, stomatal density, stomatal conductance) responded to watering treatment and interannual climate variability. We further analyzed annual functional adjustments by comparing yearly addition of needle area (LA) with yearly addition of sapwood area (SA) and distance to tip ( d ), defining the yearly ratios SA:LA and SA:LA/ d . Needle length ( l ) increased with increasing winter and monsoon water supply, and showed more interannual variability when the soil was drier. Stomatal density increased with dryness, while stomatal diameter was reduced. As a result, anatomical maximal stomatal conductance was relatively invariant across treatments. SA:LA and SA:LA/ d showed significant differences across treatments and contrary to our expectation were lower with reduced water input. Within average precipitation ranges, the response of these ratios to soil moisture was similar across treatments. However, when extreme soil drought was combined with high VPD, needle length, SA:LA and SA:LA/ d became highly nonlinear, emphasizing the existence of a response threshold of combined high VPD and dry soil conditions. In new branch tissues, the response of annual functional ratios to water stress was immediate (same year) and does not attempt to reduce the drop of water potential. We suggest that unfavorable evaporative structural response to drought is compensated by dynamic stomatal control to maximize photosynthesis rates. The leaf and sapwood structures determine the design of the hydraulic system of a tree and affect the water exchanges between the plant and the atmosphere. We investigated the effect of drought on the yearly addition of sapwood area, leaf area, and elongation in branches, as well as their interannual variability. Using two functional ratios, we showed that during drought, new tissues added in branches do not support a reduction in the leaf water potential.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 12
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-06
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 13
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    Wiley-Blackwell
    Publication Date: 2018-01-06
    Description: Rothstein (Behavioral Ecology and Sociobiology, 11, 1982, 229) was one of the first comprehensive studies to examine how different egg features influence egg rejection behaviors of avian brood parasite–hosts. The methods and conclusions of Rothstein (1982) laid the foundation for subsequent experimental brood parasitism studies over the past thirty years, but its results have never been evaluated with replication. Here, we partially replicated Rothstein's (1982) experiments using parallel artificial model egg treatments to simulate cowbird ( Molothrus ater ) parasitism in American robin ( Turdus migratorius ) nests. We compared our data with those of Rothstein (1982) and confirmed most of its original findings: (1) robins reject model eggs that differ from the appearance of a natural robin egg toward that of a natural cowbird egg in background color, size, and maculation; (2) rejection responses were best predicted by model egg background color; and (3) model eggs differing by two or more features from natural robin eggs were more likely to be rejected than model eggs differing by one feature alone. In contrast with Rothstein's (1982) conclusion that American robin egg recognition is not specifically tuned toward rejection of brown-headed cowbird eggs, we argue that our results and those of other recent studies of robin egg rejection suggest a discrimination bias toward rejection of cowbird eggs. Future work on egg recognition will benefit from utilizing a range of model eggs varying continuously in background color, maculation patterning, and size in combination with avian visual modeling, rather than using model eggs which vary only discretely. Avian brood parasite–hosts may recognize and remove brood parasite eggs from their nests as a defense mechanism. Here, we replicated egg recognition experiments using artificial eggs placed in American robin ( Turdus migratorius ) nests. Our results confirm many of S.I. Rothstein’s (Behavioral Ecology and Sociobiology, 11, 1982, 229) original findings and also reveal that American robins’ recognition of their own versus foreign eggs is likely driven by a discrimination bias toward rejection of brown-headed cowbird ( Molothrus ater ) eggs.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 14
    Publication Date: 2018-01-09
    Description: Proteostasis imbalance is emerging as a major hallmark of cancer, driving tumor aggressiveness. Evidence suggests that the endoplasmic reticulum (ER), a major site for protein folding and quality control, plays a critical role in cancer development. This concept is valid in glioblastoma multiform (GBM), the most lethal primary brain cancer with no effective treatment. We previously demonstrated that the ER stress sensor IRE1α (referred to as IRE1) contributes to GBM progression, through XBP1 mRNA splicing and regulated IRE1-dependent decay (RIDD) of RNA. Here, we first demonstrated IRE1 signaling significance to human GBM and defined specific IRE1-dependent gene expression signatures that were confronted to human GBM transcriptomes. This approach allowed us to demonstrate the antagonistic roles of XBP1 mRNA splicing and RIDD on tumor outcomes, mainly through selective remodeling of the tumor stroma. This study provides the first demonstration of a dual role of IRE1 downstream signaling in cancer and opens a new therapeutic window to abrogate tumor progression. The IRE1 arm of the Unfolded Protein Response (UPR) plays a major role in cancer development. Dissecting IRE1 signals in human glioblastoma tumors, primary and established cell lines reveals the dual role of XBP1 mRNA splicing and RIDD in tumor aggressiveness.
    Print ISSN: 1757-4676
    Electronic ISSN: 1757-4684
    Topics: Medicine
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  • 15
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    Wiley-Blackwell
    Publication Date: 2018-01-09
    Description: Inherited CTPS1, CD27, and CD70 deficiencies in humans have revealed key factors of T-lymphocyte expansion, a critical prerequisite for an efficient immunity to Epstein–Barr virus (EBV) infection. RASGRP1 is a T-lymphocyte-specific nucleotide exchange factor known to activate the pathway of MAP kinases (MAPK). A deleterious homozygous mutation in RASGRP1 leading to the loss RASGRP1 expression was identified in two siblings who both developed a persistent EBV infection leading to Hodgkin lymphoma. RASGRP1-deficient T cells exhibited defective MAPK activation and impaired proliferation that was restored by expression of wild-type RASGRP1. Similar defects were observed in T cells from healthy individuals when RASGRP1 was downregulated. RASGRP1-deficient T cells also exhibited decreased CD27-dependent proliferation toward CD70-expressing EBV-transformed B cells, a crucial pathway required for expansion of antigen-specific T cells during anti-EBV immunity. Furthermore, RASGRP1-deficient T cells failed to upregulate CTPS1, an important enzyme involved in DNA synthesis. These results show that RASGRP1 deficiency leads to susceptibility to EBV infection and demonstrate the key role of RASGRP1 at the crossroad of pathways required for the expansion of activated T lymphocytes. RASGRP1 deficiency is characterized by a high susceptibility to develop Epstein-Barr virus (EBV)-driven B-cell lymphoproliferative disorders such as B-cell lymphoma like Hodgkin lymphoma. This is caused by defective expansion of activated T cells required for an efficient immune response to EBV.
    Print ISSN: 1757-4676
    Electronic ISSN: 1757-4684
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  • 16
    Publication Date: 2018-01-09
    Description: Deposition of amyloid-β (Aβ) as senile plaques is one of the pathological hallmarks in the brains of Alzheimer's disease (AD) patients. In addition, glial activation has been found in AD brains, although the precise pathological role of astrocytes remains unclear. Here, we identified kallikrein-related peptidase 7 (KLK7) as an astrocyte-derived Aβ degrading enzyme. Expression of KLK7 mRNA was significantly decreased in the brains of AD patients. Ablation of Klk7 exacerbated the thioflavin S-positive Aβ pathology in AD model mice. The expression of Klk7 was upregulated by Aβ treatment in the primary astrocyte, suggesting that Klk7 is homeostatically modulated by Aβ-induced responses. Finally, we found that the Food and Drug Administration-approved anti-dementia drug memantine can increase the expression of Klk7 and Aβ degradation activity specifically in the astrocytes. These data suggest that KLK7 is an important enzyme in the degradation and clearance of deposited Aβ species by astrocytes involved in the pathogenesis of AD. Decreased clearance of Aβ from the brain is related to the pathogenesis of Alzheimer's disease (AD). Kallikrein-related peptidase 7 (KLK7) is an astrocyte-derived Aβ degrading enzyme that affects the amyloid pathology. Thus, astrocytes could be an effective cellular target for AD.
    Print ISSN: 1757-4676
    Electronic ISSN: 1757-4684
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  • 17
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    Wiley-Blackwell
    Publication Date: 2018-01-08
    Description: Genotyping of classical major histocompatibility complex (MHC) genes is challenging when they are hypervariable and occur in multiple copies. In this study, we used several different approaches to genotype the moderately variable MHC class I exon 3 (MHCIe3) and the highly polymorphic MHC class II exon 2 (MHCIIβe2) in the bluethroat ( Luscinia svecica ). Two family groups (eight individuals) were sequenced in replicates at both markers using Ion Torrent technology with both a single- and a dual-indexed primer structure. Additionally, MHCIIβe2 was sequenced on Illumina MiSeq. Allele calling was conducted by modifications of the pipeline developed by Sommer et al. (BMC Genomics, 14, 2013, 542) and the software AmpliSAS. While the different genotyping strategies gave largely consistent results for MHCIe3, with a maximum of eight alleles per individual, MHCIIβe2 was remarkably complex with a maximum of 56 MHCIIβe2 alleles called for one individual. Each genotyping strategy detected on average 50%–82% of all MHCIIβe2 alleles per individual, but dropouts were largely allele-specific and consistent within families for each strategy. The discrepancies among approaches indicate PCR biases caused by the platform-specific primer tails. Further, AmpliSAS called fewer alleles than the modified Sommer pipeline. Our results demonstrate that allelic dropout is a significant problem when genotyping the hypervariable MHCIIβe2. As these genotyping errors are largely nonrandom and method-specific, we caution against comparing genotypes across different genotyping strategies. Nevertheless, we conclude that high-throughput approaches provide a major advance in the challenging task of genotyping hypervariable MHC loci, even though they may not reveal the complete allelic repertoire. Several different approaches were used to genotype the moderately variable MHC class I exon 3 (MHCIe3) and the highly polymorphic MHC class II exon 2 (MHCIIβe2) in the bluethroat, using replicates and family data. While the results were largely consistent for MHCIe3 among strategies, the different strategies rendered different results for MHCIIβe2.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 18
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    Wiley-Blackwell
    Publication Date: 2018-01-09
    Description: With increasing attention being paid to the consequences of global biodiversity losses, several recent studies have demonstrated that realistic species losses can have larger impacts than random species losses on community productivity and resilience. However, little is known about the effects of the order in which species are lost on biodiversity–disease relationships. Using a multiyear nitrogen addition and artificial warming experiment in natural assemblages of alpine meadow vegetation on the Qinghai-Tibetan Plateau, we inferred the sequence of plant species losses under fertilization/warming. Then the sequence of species losses under fertilization/warming was used to simulate the species loss orders (both realistic and random) in an adjacently novel removal experiment manipulating plot-level plant diversity. We explicitly compared the effect sizes of random versus realistic species losses simulated from fertilization/warming on plant foliar fungal diseases. We found that realistic species losses simulated from fertilization had greater effects than random losses on fungal diseases, and that species identity drove the diversity–disease relationship. Moreover, the plant species most prone to foliar fungal diseases were also the least vulnerable to extinction under fertilization, demonstrating the importance of protecting low competence species (the ability to maintain and transmit fungal infections was low) to impede the spread of infectious disease. In contrast, there was no difference between random and realistic species loss scenarios simulated from experimental warming (or the combination of warming and fertilization) on the diversity–disease relationship, indicating that the functional consequences of species losses may vary under different drivers. Most manipulative biodiversity–ecosystem function (BEF) experiments use randomly constructed species assemblages. We took a novel approach to explicitly compare dilution effects on foliar fungal infections for random versus realistic species losses simulated from nitrogen addition and warming treatments. We found that realistic species losses under fertilization had greater effects than random losses on fungal diseases.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 19
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    Wiley-Blackwell
    Publication Date: 2018-01-09
    Description: Underground community assemblies have not been studied well compared with aboveground communities, despite their importance for our understanding of whole ecosystems. To investigate underground community assembly over evolutionary timescales, we examined terrestrial earthworm communities (Oligochaeta: Haplotaxida) in conserved mountainous primary forests in Japan as a model system. We collected 553 earthworms mostly from two dominant families, the Megascolecidae and the Lumbricidae, from 12 sites. We constructed a molecular taxonomic unit tree based on the analysis of three genes to examine the effects of a biogeographic factor (dispersal ability) and an evolutionary factor (habitat adaptation) on the earthworm community assembly process. The phylogenetic distance of the earthworm communities among sites was positively correlated with geographic distance when intraspecific variation was included, indicating that the divergence within species was affected by biogeographic factors. The community assembly process in the Megascolecidae has also been affected by environmental conditions in relation to an evolutionary relationship between habitat environment and intestinal cecum type, a trait closely related to habitat depth and diet, whereas that in the Lumbricidae has not been affected as such. Intestinal cecum type showed a pattern of niche conservatism in the Megascolecidae lineage. Our results suggest that investigating the evolution of a key trait related to life history can lead to the clear description of community assembly process over a long timescale and that the community assembly process can differ greatly among related lineages even though they live sympatrically. To investigate underground community assembly over evolutionary time scales, we examined terrestrial earthworm communities (Oligochaeta: Haplotaxida) in conserved mountainous primary forests in Japan. Our study shows that the community assembly process in the Megascolecidae, which is one of the two dominant families in Japan, has been affected by environmental factors in relation to an evolutionary relationship between habitat environment and intestinal cecum type, a trait closely related to habitat depth and diet, whereas that in the Lumbricidae has not been affected as such. Our results suggest that investigating the evolution of a key trait related to life history can lead to the clear description of community assembly process and that the community assembly process can differ greatly among related lineages even though they live sympatrically.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 20
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    Wiley-Blackwell
    Publication Date: 2018-01-09
    Description: Understanding local adaptation of tree populations to climate allows the development of assisted migration guidelines as a tool for forest managers to address climate change. Here, we study the relationship among climate, a wide range of physiological traits, and field performance of selected white spruce provenances originating from throughout the species range. Tree height, survival, cold hardiness, hydraulic, and wood anatomical traits were measured in a 32-year-old common garden trial, located in the center of the species range. Provenance performance included all combinations of high versus low survival and growth, with the most prevalent population differentiation for adaptive traits observed in cold hardiness. Cold hardiness showed a strong association with survival and was associated with cold winter temperatures at the site of seed origin. Tree height was mostly explained by the length of the growing season at the origin of the seed source. Although population differentiation was generally weak in wood anatomical and hydraulic traits, within-population variation was substantial in some traits, and a boundary analysis revealed that efficient water transport was associated with vulnerable xylem and low wood density, indicating that an optimal combination of high water transport efficiency and high cavitation resistance is not possible. Our results suggest that assisted migration prescriptions may be advantageous under warming climate, but pronounced trade-offs between survival and cold hardiness require a careful consideration of the distances of these transfers. In this study, we study relationships between climate, a wide range of physiological traits, and field performance of selected white spruce provenances in a common garden. We observed a strong influence of fall hardiness in tree mortality while tree growth was mostly explained by growing season length. These results will help develop assisted migration prescriptions to mitigate the climate change impact in our forests.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 21
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    Wiley-Blackwell
    Publication Date: 2018-01-09
    Description: Despite the advantage of plant clonality in patchy environments, studies focusing on genet demography in relation to spatially heterogeneous environments remain scarce. Regeneration of bamboos in forest understoreys after synchronous die-off provides an opportunity for assessing how they come to proliferate across heterogeneous light environments. In a Japanese forest, we examined genet demography of a population of Sasa kurilensis over a 7-year period starting 10 years after die-off, shortly after which some genets began spreading horizontally by rhizomes. The aboveground biomass was estimated, and genets were discriminated in 9-m 2 plots placed under both canopy gaps and closed canopies. Overall, the results suggest that the survival and spread of more productive genets and the spatial expansion of genets into closed canopies underlie the proliferation of S. kurilensis . Compared to canopy gaps, the recovery rate of biomass was much slower under closed canopies for the first 10 years after the die-off, but became accelerated during the next 7 years. Genet survival was greater for more productive genets (with greater initial number of culms), and the spaces occupied by genets that died were often colonized afterward by clonal growth of surviving genets. The number of genets decreased under canopy gaps due to greater mortality, but increased under closed canopies where greater number of genets colonized clonally from outside the plots than genets died. The colonizing genets were more productive (having larger culms) than those originally germinated within the plots, and the contribution of colonizing genets to the biomass was greater under closed canopies. Our study emphasizes the importance of investigating genet dynamics over relevant spatiotemporal scales to reveal processes underlying the success of clonal plants in heterogeneous habitats. Despite the advantage of plant clonality in patchy environments, studies focusing on genet demography in relation to spatially heterogeneous environments remain scarce. Regeneration of bamboos in forest understoreys after synchronous die-off provides an opportunity for assessing how they come to proliferate across heterogeneous light environments. We studied the long-term genet demography of a dwarf bamboo, Sasa kurilensis , after synchronous flowering and die-off, and found that the survival and spread of more productive genets and the clonal expansion of genets into closed canopies likely underlie the proliferation of S. kurilensis .
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 22
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    Wiley-Blackwell
    Publication Date: 2018-01-09
    Description: Rare species can play important functional roles, but human-induced changes to disturbance regimes, such as fire, can inadvertently affect these species. We examined the influence of prescribed burns on the recruitment and diversity of plant species within a temperate forest in southeastern Australia, with a focus on species that were rare prior to burning. Floristic composition was compared among plots in landscapes before and after treatment with prescribed burns differing in the extent of area burnt and season of burn (before–after, control-impact design). Floristic surveys were conducted before burns, at the end of a decade of drought, and 3 years postburn. We quantified the effect of prescribed burns on species grouped by their frequency within the landscape before burning (common, less common, and rare) and their life-form attributes (woody perennials, perennial herbs or geophytes, and annual herbs). Burn treatment influenced the response of rare species. In spring-burn plots, the recruitment of rare annual herbs was promoted, differentiating this treatment from both autumn-burn and unburnt plots. In autumn-burn plots, richness of rare species increased across all life-form groups, although composition remained statistically similar to control plots. Richness of rare woody perennials increased in control plots. For all other life-form and frequency groups, the floristic composition of landscapes changed between survey years, but there was no effect of burn treatment, suggesting a likely effect of rainfall on species recruitment. A prescribed burn can increase the occurrence of rare species in a landscape, but burn characteristics can affect the promotion of different life-form groups and thus affect functional diversity. Drought-breaking rain likely had an overarching effect on floristic composition during our study, highlighting that weather can play a greater role in influencing recruitment and diversity in plant communities than a prescribed burn. Prescribed burning can inadvertently affect plant rarity. We examined the influence of prescribed fire on plants in a temperate forest and found that prescribed burns can positively influence the presence of rare species. Burn characteristics, such as season and extent, can influence the type of life-form promoted, for example, extensive spring burns favoring rare annual herbs. Managing disturbance to promote heterogeneous landscapes may help maintain rare species diversity on a landscape scale.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 23
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    Wiley-Blackwell
    Publication Date: 2018-01-10
    Description: Ground penetrating radar (GPR) has emerged as an effective tool for estimating active layer thickness (ALT) and volumetric water content (VWC) within the active layer. In August 2013, we conducted a series of GPR and probing surveys using a 500 MHz antenna and metallic probe around Barrow, Alaska. We collected about 15 km of GPR data and 1.5 km of probing data. Here, we describe the GPR data processing workflow from raw GPR data to the estimated ALT and VWC. We include the corresponding uncertainties for each measured and estimated parameter. The estimated average GPR-derived ALT was 41 cm, with a standard deviation of 9 cm. The average probed ALT was 40 cm, with a standard deviation of 12 cm. The average GPR-derived VWC was 0.65, with a standard deviation of 0.14.
    Electronic ISSN: 2049-6060
    Topics: Geosciences
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  • 24
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-11
    Description: Fire is a dominant, and well-studied, structuring force in many temperate and semi-arid communities; yet, few studies have investigated the effects of fire on multi-trophic interactions. Here, we ask how fire-induced changes in flowering affect the abundance of bumble bee foragers ( Bombus vosnesenskii ) and whether differences in floral resource availability are due to changes in plant species composition or lengthened bloom of a consistent set of species within burned and unburned grasslands. Following fire, burned and unburned sites had similar early spring bee and floral abundances. However, after the early bloom, forager activity remained high only in burned sites, where floral abundance persisted for longer. Importantly, the increased floral abundance following fire was due to a lengthening of within-species flowering phenology, as burned areas later in the season retained floral abundance and composition similar to that of unburned areas early in the season. Furthermore, density of flower patches chosen by bumble bee foragers was significantly higher at burned sites, suggesting an increase in patch quality for foragers in post-fire communities. Our results suggest positive effects of fire for bumble bee foragers and forb communities in California grassland ecosystems in the year following disturbance, namely through differences in plant phenology and floral density. We conclude that fire-induced changes in flowering phenology can alter interspecific interactions and benefit pollinators.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 25
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-11
    Description: Transferring plant material during ecological restoration has inherent risk. The use of seed transfer guidelines minimizes the possibility of introducing maladapted genotypes. We delineated biogeographic regions relevant to the distribution of Cercocarpus montanus for the purpose of creating provisional seed transfer zones for ecological restoration. We also modeled seed transfer guidelines using quantitative estimates of environmental tolerance and thresholds. Analyses identified broadscale environmental patterns relevant for seed transfer success. First, a species distribution model was used to identify the distribution of C. montanus . Next, we used non-metric multidimensional scaling to investigate the structure of environmental data, and hierarchical cluster analysis to delineate biogeographic regions (i.e., environmental discontinuities) using species distribution data. Finally, we calculated measures of environmental tolerance and thresholds for C. montanus to model the probability of seed transfer success with multiple logistic regression. Biogeographic regionalization of C. montanus resulted in four major clusters, which agreed with ordination methods. Logistic regression was implemented using estimates of environmental tolerance and threshold data to model seed transfer success. We compared our species-specific seed transfer zones and guidelines with other provisional seed transfer zone methods and found that our species-specific methods performed better at explaining phenotypic variation of C. montanus in four out of six cases. Seed transfer zones are useful for restoration planning; however, zonal models fail to reflect much of the environmental heterogeneity present across the range of C. montanus . Continuous models for seed transfer success using environmental tolerance and thresholds enhance the development and use of seed transfer guidelines because they reflect landscape heterogeneity at a fine scale, and the results are relative to restoration sites of interest. Herein, we describe a methodology to construct provisional seed transfer zones and continuous seed transfer guidelines using species-specific distribution models and multivariate analyses.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 26
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-11
    Description: Whether interactions between wildlife and livestock are competitive or facilitative is context dependent. Intermediary factors that explain how context (seasonal or regional characteristics of the ecological community) affects these interactions are rarely reported. We compared activity time and density in vicuñas ( Vicugna vicugna ) introduced into the Chimborazo Faunal Production Reserve (CFPR), Ecuador, to describe how they interact with livestock. We compared vicuña density in wetlands and uplands (two landscape structures) with and without livestock (two conditions) using an isodar approach. We measured, over two seasons, vicuña forage abundance, composition, preference and accessibility, time vicuñas spent vigilant, and their flight distances on approach. We tested optimal foraging theory relating to the hypothesis that time mediates behavior, and found that vicuñas were no less frequently vigilant, nor were flight distances greater, during a wet season or in habitats of greater forage abundance and accessibility. We also found no evidence that vicuña behavior was density dependent; instead, we found that more time was spent vigilant by vicuñas when they foraged near livestock in rainy regions during the dry season. Although forage abundance was similar throughout CFPR during a dry season, better forage quality in areas occupied by livestock may constitute an effect of their facilitating vicuñas. A puzzling finding, because it was not explained by any of the other variables we measured, was that at low densities vicuñas selected habitat irrespective of livestock, and where their density was higher, it was doubly so adjacent to livestock. We conclude that in the CFPR, spatial heterogeneity in habitat quality determines the interactions between livestock and vicuñas. To support recommendations that minimize competition between wildlife and livestock, and to expand on descriptions of the contexts that determine the direction of species interactions, future study may require a wider sampling of the densities of sympatric large herbivores in general, and, in the CFPR, a closer resolution of spatial heterogeneity in forage plant quality.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 27
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-11
    Description: Compositional changes in Himalayan vegetation in response to the major drivers of biodiversity loss, climate change and land-use change, are barely documented. We quantify temporal changes in the alpine vegetation of central Nepal and attribute these changes to temporally varying climatic and land-use factors. We re-surveyed the alpine vegetation of two locations within Langtang National Park, central Nepal, after 25 yr using 127 plots of 100 m 2 . Using ordination, regression, and weighted average regression and calibration techniques, we analyzed the changes in terms of species abundance, frequency, and elevational shift in relation to changing atmospheric temperature, precipitation, and livestock grazing. We found a significant increase in the frequency and relative abundance of the majority of species, which was significantly related to the temporal trends in climatic factors and grazing intensity. Out of 12 species with unimodal responses along the elevation gradient during both surveys, the optima of eight species decreased over the time period. The observed elevations of 62 out of 92 sample plots (hence, species composition) in 2014 were lower than the elevations calibrated from species composition and elevation of 1990, indicating an overall downward shift of species assemblages. However, an upward shift of assemblages was also observed at higher elevations. These results indicate that the observed temporal changes in alpine vegetation, largely contrasting the expected upslope shift of species due to climate warming, are driven most likely by interactions of contemporary climate and land-use changes, especially reduced grazing. The complex interactions and feedback mechanisms between warmer winters, increased precipitation, reduced grazing pressure, and thereby altered species interactions most likely facilitated the downslope shift of alpine species assemblages. Climatic and land-use responses of plant species assemblages should therefore be studied focusing on the potential interactions between both the climatic and the land-use factors because such interactions and feedback mechanisms have potential to mask or modify the expected climatic or land-use response of biodiversity.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 28
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-11
    Description: In studies of community assembly, species are often assumed to have similar spatial distributions and responses to the environment regardless of age or size. Under this assumption, it is possible to use species and species-level traits in community composition studies. Here, we test this assumption for two species of soil-living arthropods (springtails: Collembola) with direct development but assumed differences in self-organizing behavior. We expected that the species with more pronounced social interactions ( Hypogastrura tullbergi ) should be less influenced by environmental factors and species interactions across all age classes, than Folsomia quadrioculata that is not known to exhibit social behavior. We used variance partitioning to examine the relative contributions of soil variables, vegetation composition, and other Collembola, vs. spatial variables (as a proxy for intraspecific interactions, i.e., self-organization), on the distribution of the two species and three of their age classes. We show that two coexisting species with clear aggregation patterns greatly differ in how much the environment contributes to affecting the species’ spatial structure. Local F. quadrioculata abundance was explained by different spatial and environmental variables depending on age class. In contrast, for H. tullbergi, spatial variables explained more of the abundance variation in all age classes. These differences have implications for the general predictability of changes in spatial structuring of species, as self-organized species may be less likely to respond to changes in environmental factors. Our results show that because age classes may be differentially affected by environmental conditions, caution should be taken when assuming that species traits can be applied to all developmental stages in a species.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 29
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-11
    Description: Variations in water level profoundly affect functional stability of freshwater ecosystems, as well as macrophyte growth and reproduction. Although the trade-off between allocation to clonal and sexual reproduction in clonal plants can be influenced by a variety of environmental factors, whether variations of reproductive allocation (RA) in response to different environments are driven only by a size-dependent effect (apparent plasticity) or whether RA can also change independently of plant size (true plasticity) is uncertain. We conducted an experiment in nine outdoor mesocosms (6400 L) to investigate the response of clonal and sexual reproduction and vegetative growth of a perennial submerged macrophyte Vallisneria spinulosa at water depths of 50, 100, or 150 cm. We evaluated size-dependent and size-independent effects of water depth on sexual and clonal RA. Deep water reduced vegetative size and sexual output (mass of fruits produced), but increased tuber production of V. spinulosa . There was an apparent trade-off between reproductive modes in terms of biomass investment; plants in deep water allocated more resources into clonal propagation and reduced investment in sexual reproduction compared to plants in shallow or intermediate water. Slopes of allometric relationships (sexual vs. vegetative biomass and clonal vs. vegetative biomass) were significantly affected by water depth. Shifts in sexual RA in response to varying water depths were largely size-dependent, but there were also size-independent effects. In contrast, size-independent effects were more important than effects of size changes in determining clonal RA. We concluded that V. spinulosa adapted to a water-depth gradient by plastic trade-offs between clonal propagation and sexual reproduction. Furthermore, a size-independent effect on RA suggests a flexible reproductive strategy that could be critical for plant performance in changing aquatic environments.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 30
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    Wiley-Blackwell
    Publication Date: 2018-01-12
    Description: Air masses in the convective outflows of four large convective systems near Borneo Island in Malaysia were sampled in the height range 11–13 km within the frame of the SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere) FP7 European project in November and December 2011. Correlated enhancements of CO, CH 4 and the short-lived halogen species (CH 3 I and CHBr 3 ) were detected when the aircraft crossed the anvils of the four systems. These enhancements were interpreted as the fingerprint of vertical transport from the boundary layer by the convective updraft and then horizontal advection in the outflow. For the four observations, the fraction f of air from the boundary layer ranged between 15 and 67%, showing the variability in transport efficiency depending on the dynamics of the convective system. Convective outflows were sampled in the tropical West Pacific in November and December 2011 during SHIVA project. Correlated enhancements of CO, CH 4 and the short-lived halogen species volume mixing ratios were detected when the aircraft crossed the outflow of the convective systems. Using these observations, the fraction of boundary layer air contained in fresh convective outflow was calculated.
    Electronic ISSN: 1530-261X
    Topics: Geosciences , Physics
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  • 31
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    Wiley-Blackwell
    Publication Date: 2018-01-12
    Description: One of the central goals of the field of population ecology is to identify the drivers of population dynamics, particularly in the context of predator–prey relationships. Understanding the relative role of top-down versus bottom-up drivers is of particular interest in understanding ecosystem dynamics. Our goal was to explore predator–prey relationships in a boreal ecosystem in interior Alaska through the use of multispecies long-term monitoring data. We used 29 years of field data and a dynamic multistate site occupancy modeling approach to explore the trophic relationships between an apex predator, the golden eagle, and cyclic populations of the two primary prey species available to eagles early in the breeding season, snowshoe hare and willow ptarmigan. We found that golden eagle reproductive success was reliant on prey numbers, but also responded prior to changes in the phase of the snowshoe hare population cycle and failed to respond to variation in hare cycle amplitude. There was no lagged response to ptarmigan populations, and ptarmigan populations recovered quickly from the low phase. Together, these results suggested that eagle reproduction is largely driven by bottom-up processes, with little evidence of top-down control of either ptarmigan or hare populations. Although the relationship between golden eagle reproductive success and prey abundance had been previously established, here we established prey populations are likely driving eagle dynamics through bottom-up processes. The key to this insight was our focus on golden eagle reproductive parameters rather than overall abundance. Although our inference is limited to the golden eagle–hare–ptarmigan relationships we studied, our results suggest caution in interpreting predator–prey abundance patterns among other species as strong evidence for top-down control. Reproductive success in golden eagles is linked to ptarmigan and snowshoe hare abundance. The characteristics of these linkages strongly suggest bottom-up limitation of eagles by their prey.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 32
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    Wiley-Blackwell
    Publication Date: 2018-01-12
    Description: The freshwater–marine transition that characterizes an estuarine system can provide multiple entry options for invading species, yet the relative importance of this gradient in determining the functional contribution of invading species has received little attention. The ecological consequences of species invasion are routinely evaluated within a freshwater versus marine context, even though many invasive species can inhabit a wide range of salinities. We investigate the functional consequences of different sizes of Corbicula fluminea —an invasive species able to adapt to a wide range of temperatures and salinity—across the freshwater–marine transition in the presence versus absence of warming. Specifically, we characterize how C. fluminea affect fluid and particle transport, important processes in mediating nutrient cycling (NH 4 -N, NO 3 -N, PO 4 -P). Results showed that sediment particle reworking (bioturbation) tends to be influenced by size and to a lesser extent, temperature and salinity; nutrient concentrations are influenced by different interactions between all variables (salinity, temperature, and size class). Our findings demonstrate the highly context-dependent nature of the ecosystem consequences of invasion and highlight the potential for species to simultaneously occupy multiple components of an ecosystem. Recognizing of this aspect of invasibility is fundamental to management and conservation efforts, particularly as freshwater and marine systems tend to be compartmentalized rather than be treated as a contiguous unit. We conclude that more comprehensive appreciation of the distribution of invasive species across adjacent habitats and different seasons is urgently needed to allow the true extent of biological introductions, and their ecological consequences, to be fully realized. The functional consequences of different sizes of Corbicula fluminea —an invasive species able to adapt to a wide range of temperatures and salinity—across the freshwater–marine transition in the presence versus absence of warming were investigated.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 33
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    Wiley-Blackwell
    Publication Date: 2018-01-12
    Description: Despite the importance of coral microbiomes for holobiont persistence, the interactions among these are not well understood. In particular, knowledge of the co-occurrence and taxonomic importance of specific members of the microbial core, as well as patterns of specific mobile genetic elements (MGEs), is lacking. We used seawater and mucus samples collected from Mussismilia hispida colonies on two reefs located in Bahia, Brazil, to disentangle their associated bacterial communities, intertaxa correlations, and plasmid patterns. Proxies for two broad-host-range (BHR) plasmid groups, IncP-1β and PromA, were screened. Both groups were significantly (up to 252 and 100%, respectively) more abundant in coral mucus than in seawater. Notably, the PromA plasmid group was detected only in coral mucus samples. The core bacteriome of M. hispida  mucus was composed primarily of members of the Proteobacteria, followed by those of Firmicutes. Significant host specificity and co-occurrences among different groups of the dominant phyla (e.g., Bacillaceae and Pseudoalteromonadaceae and the genera Pseudomonas , Bacillus, and Vibrio ) were detected. These relationships were observed for both the most abundant phyla and the bacteriome core, in which most of the operational taxonomic units showed intertaxa correlations. The observed evidence of host-specific bacteriome and co-occurrence (and potential symbioses or niche space co-dominance) among the most dominant members indicates a taxonomic selection of members of the stable bacterial community. In parallel, host-specific plasmid patterns could also be, independently, related to the assembly of members of the coral microbiome. Significant host specificity and co-occurrences among different groups of the dominant phyla (e.g., Bacillaceae and Pseudoalteromonadaceae and the genera Pseudomonas, Bacillus, and Vibrio), and host-specific plasmids patterns were detected associated with Mussismilia hispida . This was true considering both the most abundant phyla and the bacteriome core, in which most of the operational taxonomic units presented intertaxa correlations. The observed evidence of host-specific bacteriome and co-occurrence (and potential symbioses or niche space codominance) among the most dominant members indicates a taxonomic selection of members of the stable bacterial community.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 34
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-12
    Description: Large regulated rivers often require fisheries and water managers to make management decisions involving resident fish population dynamics that have many ecological drivers. Because of the large scale of the system and often competing interests and demands for water, there is a critical need for decision support tools (DSTs) that allow examination of alternative management scenarios while considering key ecological interactions. Spatially explicit individual-based models (IBMs) can serve as effective DSTs by providing information on fish population dynamics while accounting for, and providing extensive, spatially explicit information on, the numerous ecological drivers. Spatially explicit IBMs are often difficult to implement owing to the numerous and often complex inputs the models require. Here, I demonstrate how a suite of free, graphical user interface equipped programs, along with three custom-built and publicly available plugins, can streamline the modeling process and serve as a IBM-based DST for fisheries management on large regulated rivers. The main program is a spatially explicit IBM of juvenile salmonid dynamics, inSALMO, with two other programs that generate the key input data in the required spatially explicit formats. I then use this proposed DST to simulate a Chinook salmon population on a portion of California's Sacramento River to determine whether an IBM-based DST is appropriate to evaluate management impacts on a large regulated river. The Sacramento is a large river of major concern in California and is representative of many rivers in the United States and worldwide in that it is dammed, has a resident fish population, and is heavily used for water supply. The proposed DTS results compare favorably with the predictive power of a general additive model, while providing a much fuller and richer data set that could significantly aid and inform management decisions.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 35
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-12
    Description: Over the last 100 yr, anthropogenic stressors have decimated the assemblage of deepwater coregonines that once underpinned the food webs of the Laurentian Great Lakes. As a part of ongoing restoration efforts, fisheries managers are interested in reintroducing deepwater coregonines from remnant populations to reestablish historical food web connections. However, little is known about historical trophic position and niche partitioning among deepwater coregonines in the Great Lakes. We used nitrogen stable isotope analysis of amino acids to compare trophic position of museum-preserved (1920s) and present-day forage fishes in Lakes Michigan and Superior. In the 1920s, deepwater coregonines exhibited clear trophic niche partitioning, with trophic positions spanning a full trophic level. Additionally, species trophic positions were tightly conserved between lakes. In Lake Superior, trophic niche partitioning has been maintained over the last 100 yr, but trophic position has shifted downward by ~0.5 trophic level. The more dramatic species loss in Lake Michigan corresponds with a sharp reduction in trophic niche breadth over time. Our study reveals remarkable trophic niche breadth among deepwater coregonines prior to the major anthropogenic impacts on the Laurentian Great Lakes and provides a food web benchmark for restoring the historical trophic diversity of this iconic species flock.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 36
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-12
    Description: Color polymorphisms offer unique opportunities for testing the role of ecological adaptation and natural selection in the origin of species. However, the ecological conditions that facilitate the coexistence and speciation of color morphs in nature remain poorly understood. In this study, we investigate the ecological mechanisms maintaining the color polymorphism in the arc-eye hawkfish ( Paracirrhites arcatus ), which consists of two common morphs (pink white-striped [PWS] and melanistic [MEL]) and less common intermediates that all coexist on shallow coral reefs throughout the Indo-Pacific. Our approach was to test whether ecologically based disruptive selection on color could explain the maintenance of and possible incipient divergence between sympatric color morphs. We compared patterns of spatial distribution, abundance, habitat use and preference, and niche overlap among color morphs at nine sites along the leeward coast of Hawaii Island. We demonstrate that despite co-occurring at all sites, sympatric color morphs show significant niche divergence along a steep ecological gradient. Morph frequencies correlate strongly with a multivariate gradient in coral community and reef topography, which explained 81% of the variability in relative abundance of the two main color morphs. Melanistic morphs were more frequent in shallow, steep surge zones dominated by Pocillopora corals. In contrast, PWS morphs were more frequent in deeper, sub-surge zones with higher coral cover dominated by Porites corals. Niche overlap analyses highlight how the two main morphs are partitioned on opposite ends of this continuous ecological gradient, while phenotypic intermediates are mostly restricted to intermediate habitats. The strong correlation between phenotype and environment suggests that morphs have fitness advantages in their respective habitats. We speculate that disruptive natural selection on color pattern to increase crypsis in heterogeneous visual environments has led to divergence in habitat preferences. The resulting ecological isolation provides a plausible mechanism for the persistence of multiple coexisting color phenotypes in P. arcatus . If divergence in color also affects mate choice, the evolution of reproductive isolation is likely to be promoted.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 37
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    Wiley-Blackwell
    Publication Date: 2018-01-12
    Description: During the recent 50 years, in response to global warming, nearly all of the rivers in the arid region of northwest China have shown significant increasing trends in runoff. However, runoff in the Hotan River has shown a slight decreasing trend that corresponded to a rate of −0.18 × 10 8  m 3 /decade for the same period. Here, based on an analysis of runoff from mountain pass hydrologic stations and precipitation during 1960–2009, as well as measurements of upper-air temperature (UAT) from the Hotan sounding station (1960–2011) and MODIS land surface temperature (LST) of the mountainous area (2001–2011), we found that the annual runoff in the Hotan River was mainly determined (75%) by summer runoff. We also determined that the summer runoff was strongly associated (correlation coefficient: R  = 0.78, P  〈 0.001) with summer UAT at 500 hPa and mountain LST ( R  = 0.69, P  〈 0.001) during 1960–2009. Because the largest proportion of runoff in the Hotan River stems from glacial meltwater, we suggest that the decreasing trends exhibited by the UAT in the mid-lower troposphere and the LST within the mountainous area in summer are the main reasons why runoff shows a slight decreasing trend over the past half century. Location map in the study and mountainous area of Hotan River.
    Electronic ISSN: 1530-261X
    Topics: Geosciences , Physics
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  • 38
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    Wiley-Blackwell
    Publication Date: 2018-01-12
    Description: Using six flights observations in September 2015 over Hebei, China, this study shows a robust negative aerosol-cloud droplet effective radius (r e ) relationship for liquid clouds, which is different from previous studies that found positive aerosol-cloud r e relationship over east China using satellite observations. Total of 27 cloud samples were analyzed with the classification of clean and polluted conditions using lower and upper 1/3 rd aerosol concentration at 200 m below the cloud bases. By normalizing the profiles of cloud droplet r e , we found significant smaller values under polluted than under clean condition at most heights. Moreover, the averaged profiles of cloud LWC show larger values under polluted than clean conditions, indicating even stronger negative aerosol-cloud r e relationship if LWC is kept constant. The droplet size distributions further demonstrate that more droplets concentrate within smaller size ranges under polluted conditions. Quantitatively, the aerosol-cloud interaction is found around 0.10-0.19 for the study region.
    Electronic ISSN: 2333-5084
    Topics: Geosciences , Physics
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  • 39
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    Wiley-Blackwell
    Publication Date: 2018-01-12
    Description: Most of the global climate models (GCMs) in the Coupled Model Intercomparison Project, phase 5 (CMIP5) do not include precipitating ice (a.k.a. falling snow) in their radiation calculations. We examine the importance of the radiative effects of precipitating ice on simulated surface wind stress and sea surface temperatures (SSTs) in terms of seasonal variation and in the evolution of Central Pacific El Nino (CP-El Nino) events. Using controlled simulations with the CESM1 model, we show that the exclusion of precipitating ice radiative effects generates a persistent excessive upper-level radiative cooling and an increasingly unstable atmosphere over convective regions such as the western Pacific and tropical convergence zones. The invigorated convection leads to persistent anomalous low-level outflows which weaken the easterly trade winds, reducing upper-ocean mixing and leading to a positive SST bias in the model mean state. In CP-El Nino events, this means that outflow from the modeled convection in the central Pacific reduces winds to the east, allowing unrealistic eastward propagation of warm SST anomalies following the peak in CP-El Nino activity. Including the radiative effects of precipitating ice reduces these model biases and improves the simulated life cycle of the CP-El Nino. Improved simulations of present day tropical seasonal variations and CP-El Nino events would increase the confidence in simulating their future behaviour.
    Electronic ISSN: 2333-5084
    Topics: Geosciences , Physics
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  • 40
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    Wiley-Blackwell
    Publication Date: 2018-01-14
    Description: Mating systems have broad impacts on how sexual selection and mate choice operate within a species, but studies of mating behavior in the laboratory may not reflect how these processes occur in the wild. Here, we examined the mating behavior of the neotropical butterfly Heliconius erato in the field by releasing larvae and virgin females and observing how they mated. H. erato is considered a pupal-mating species (i.e., males mate with females as they emerge from the pupal case). However, we observed only two teneral mating events, and experimentally released virgins were almost all mated upon recapture. Our study confirms the presence of some pupal-mating behavior in H. erato , but suggests that adult mating is likely the prevalent mating strategy in this species. These findings have important implications for the role of color pattern and female mate choice in the generation of reproductive isolation in this diverse genus. Heliconius erato is thought to be one of a few species of butterfly which display an unusual mating system known as pupal mating: males wait on the developing pupae of females and mate with them upon emergence. Using experiments and observations with natural populations, we find that while H. erato do engage in pupal mating in the wild, it is rare: adult-mating is likely the prevalent mode of mating. Our finding that most couplings occur between adults suggests that color pattern is likely an important factor driving assortative mating and speciation in this adaptively radiating species.
    Electronic ISSN: 2045-7758
    Topics: Biology
    Published by Wiley-Blackwell
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  • 41
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    Wiley-Blackwell
    Publication Date: 2018-01-14
    Description: Environmental differences influence the evolutionary divergence of mating signals through selection acting either directly on signal transmission (“sensory drive”) or because morphological adaptation to different foraging niches causes divergence in “magic traits” associated with signal production, thus indirectly driving signal evolution. Sensory drive and magic traits both contribute to variation in signal structure, yet we have limited understanding of the relative role of these direct and indirect processes during signal evolution. Using phylogenetic analyses across 276 species of ovenbirds (Aves: Furnariidae), we compared the extent to which song evolution was related to the direct influence of habitat characteristics and the indirect effect of body size and beak size, two potential magic traits in birds. We find that indirect ecological selection, via diversification in putative magic traits, explains variation in temporal, spectral, and performance features of song. Body size influences song frequency, whereas beak size limits temporal and performance components of song. In comparison, direct ecological selection has weaker and more limited effects on song structure. Our results illustrate the importance of considering multiple deterministic processes in the evolution of mating signals. Sensory drive and magic traits both contribute to variation in acoustic signal structure, yet we have limited understanding of the relative role of these direct and indirect processes during signal evolution. Using phylogenetic analyses across 276 species of ovenbirds (Aves: Furnariidae), we compared the extent to which song evolution was related to the direct influence of habitat characteristics and the indirect effect of body size and beak size, two potential magic traits in birds. We find that indirect ecological selection, via diversification in putative magic traits, explains variation in temporal, spectral, and performance features of song, whereas direct ecological selection has weaker and more limited effects on song structure.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 42
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    Wiley-Blackwell
    Publication Date: 2018-01-17
    Description: “Financial toxicity” has now become a familiar term used in the discussion of cancer drugs, and it is gaining traction in the literature given the high price of newer classes of therapies. However, as a phenomenon in the contemporary treatment and care of people with cancer, financial toxicity is not fully understood, with the discussion on mitigation mainly geared toward interventions at the health system level. Although important, health policy prescriptions take time before their intended results manifest, if they are implemented at all. They require corresponding strategies at the individual patient level. In this review, the authors discuss the nature of financial toxicity, defined as the objective financial burden and subjective financial distress of patients with cancer, as a result of treatments using innovative drugs and concomitant health services. They discuss coping with financial toxicity by patients and how maladaptive coping leads to poor health and nonhealth outcomes. They cover management strategies for oncologists, including having the difficult and urgent conversation about the cost and value of cancer treatment, availability of and access to resources, and assessment of financial toxicity as part of supportive care in the provision of comprehensive cancer care. CA Cancer J Clin 2018 . © 2018 American Cancer Society .
    Print ISSN: 0007-9235
    Electronic ISSN: 1542-4863
    Topics: Medicine
    Published by Wiley-Blackwell on behalf of American Cancer Society.
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  • 43
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    Wiley-Blackwell
    Publication Date: 2018-01-17
    Description: Plant ecologists require spatial information on functional soil properties but are often faced with soil classifications that are not directly interpretable or useful for statistical models. Sand and clay content are important soil properties because they indicate soil water-holding capacity and nutrient content, yet these data are not available for much of the landscape. Remotely sensed soil radiometric data offer promise for developing statistical models of functional soil properties applicable over large areas. Here, we build models linking radiometric data for an area of 40,000 km 2 with soil physicochemical data collected over a period of 30 years and demonstrate a strong relationship between gamma radiometric potassium ( 40 K), thorium (²³²Th), and soil sand and clay content. Our models showed predictive performance of 43% with internal cross-validation (to held-out data) and ~30% for external validation to an independent test dataset. This work contributes to broader availability and uptake of remote sensing products for explaining patterns in plant distribution and performance across landscapes. Soil texture and chemistry significantly explained deviation in remote-sensed gamma-radiometric Th and K. Percent sand and clay particles in A Horizon were the most influential variables. Gamma-radiometric Th and and K, with environmental data, moderately predicted sand and clay %.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 44
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    Wiley-Blackwell
    Publication Date: 2018-01-17
    Description: The response of tropical forests to global warming is one of the largest uncertainties in predicting the future carbon balance of Earth. To determine the likely effects of elevated temperatures on tropical forest understory plants and soils, as well as other ecosystems, an infrared (IR) heater system was developed to provide in situ warming for the Tropical Responses to Altered Climate Experiment (TRACE) in the Luquillo Experimental Forest in Puerto Rico. Three replicate heated 4-m-diameter plots were warmed to maintain a 4°C increase in understory vegetation compared to three unheated control plots, as sensed by IR thermometers. The equipment was larger than any used previously and was subjected to challenges different from those of many temperate ecosystem warming systems, including frequent power surges and outages, high humidity, heavy rains, hurricanes, saturated clayey soils, and steep slopes. The system was able to maintain the target 4.0°C increase in hourly average vegetation temperatures to within ± 0.1°C. The vegetation was heterogeneous and on a 21° slope, which decreased uniformity of the warming treatment on the plots; yet, the green leaves were fairly uniformly warmed, and there was little difference among 0–10 cm depth soil temperatures at the plot centers, edges, and midway between. Soil temperatures at the 40–50 cm depth increased about 3°C compared to the controls after a month of warming. As expected, the soil in the heated plots dried faster than that of the control plots, but the average soil moisture remained adequate for the plants. The TRACE heating system produced an adequately uniform warming precisely controlled down to at least 50-cm soil depth, thereby creating a treatment that allows for assessing mechanistic responses of tropical plants and soil to warming, with applicability to other ecosystems. No physical obstacles to scaling the approach to taller vegetation (i.e., trees) and larger plots were observed. An infrared heater system was designed, installed, and tested over tropical forest understory vegetation in Puerto Rico. Larger plots and a higher degree of warming required using 4–8 times larger equipment than used for this application before, and the location involved challenges from power surges and outages, high humidity, steep slope, weak soils, and hurricanes. The system maintained the target 4°C rise in temperature of the heated plots above that of the controls when power was available, the uniformity of the treatment was satisfactory, and significant soil warming of 2.6°C on average to a depth of 50 cm was achieved with minimal soil drying.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 45
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    Wiley-Blackwell
    Publication Date: 2018-01-17
    Description: Fluctuations in marine populations often relate to the supply of recruits by oceanic currents. Variation in these currents is typically driven by large-scale changes in climate, in particular ENSO (El Nino Southern Oscillation). The dependence on large-scale climatic changes may, however, be modified by early life history traits of marine taxa. Based on eight years of annual surveys, along 150 km of coastline, we examined how ENSO influenced abundance of juvenile fish, coral spat, and canopy-forming macroalgae. We then investigated what traits make populations of some fish families more reliant on the ENSO relationship than others. Abundance of juvenile fish and coral recruits was generally positively correlated with the Southern Oscillation Index (SOI), higher densities recorded during La Niña years, when the ENSO-influenced Leeuwin Current is stronger and sea surface temperature higher. The relationship is typically positive and stronger among fish families with shorter pelagic larval durations and stronger swimming abilities. The relationship is also stronger at sites on the coral back reef, although the strongest of all relationships were among the lethrinids ( r  = .9), siganids ( r  = .9), and mullids ( r  = .8), which recruit to macroalgal meadows in the lagoon. ENSO effects on habitat seem to moderate SOI–juvenile abundance relationship. Macroalgal canopies are higher during La Niña years, providing more favorable habitat for juvenile fish and strengthening the SOI effect on juvenile abundance. Conversely, loss of coral following a La Niña-related heat wave may have compromised postsettlement survival of coral dependent species, weakening the influence of SOI on their abundance. This assessment of ENSO effects on tropical fish and habitat-forming biota and how it is mediated by functional ecology improves our ability to predict and manage changes in the replenishment of marine populations. Abundance of juvenile fish and coral recruits was generally positively correlated with the Southern Oscillation Index (SOI), with higher densities recorded during La Niña years. The relationship is typically positive and stronger among fish families with shorter pelagic larval durations and stronger swimming abilities. ENSO effects on habitat seem to moderate SOI–juvenile abundance relationship.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 46
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    Wiley-Blackwell
    Publication Date: 2018-01-17
    Description: Translocations have become an increasingly valuable tool for conservation in recent years, but assessing the successfulness of translocations and identifying factors that contribute to their success continue to challenge biologists. As a unique class of translocation, population reinforcements have received relatively little attention despite representing a substantial portion of translocation programs. Here, we conducted population viability analyses to quantify the effects of 216 reinforcement scenarios on the long-term viability of four populations of Greater Prairie-Chickens ( Tympanuchus cupido pinnatus ) in Wisconsin, USA, and used multiple linear regression to identify factors that had the greatest relative influence on population viability. We considered reinforcements from outside of the study area in addition to translocations among Wisconsin populations. We observed the largest decreases in site-specific extinction probability and the largest increases in the number of sites persisting for 50 years when more vulnerable populations were targeted for reinforcement. Conversely, reinforcing the most stable sites caused the greatest reduction in regional extinction probability. We found that the number of translocated hens was a comparatively poor predictor of changes in long-term population viability, whereas the earlier onset of reinforcement was consistently associated with the greatest increases in viability. Our results highlight the value of evaluating alternative reinforcement strategies a priori and considering the effects of reinforcement on metrics of long-term population persistence. We used a combination of population viability analysis and linear regression techniques to compare 216 reinforcement scenarios for four populations of the threatened Greater Prairie-Chicken ( Tympanuchus cupido pinnatus ) in central Wisconsin, USA. We considered three different metrics of long-term population viability and identified factors that were most strongly associated with population persistence. Early onset of reinforcement efforts was a much stronger predictor of long-term translocation success than release cohort size.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 47
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    Wiley-Blackwell
    Publication Date: 2018-01-16
    Description: Salivary gland acinar cells are routinely destroyed during radiation treatment for head and neck cancer that results in a lifetime of hyposalivation and co-morbidities. A potential regenerative strategy for replacing injured tissue is the reactivation of endogenous stem cells by targeted therapeutics. However, the identity of these cells, whether they are capable of regenerating the tissue, and the mechanisms by which they are regulated are unknown. Using in vivo and ex vivo models, in combination with genetic lineage tracing and human tissue, we discover a SOX2 + stem cell population essential to acinar cell maintenance that is capable of replenishing acini after radiation. Furthermore, we show that acinar cell replacement is nerve dependent and that addition of a muscarinic mimetic is sufficient to drive regeneration. Moreover, we show that SOX2 is diminished in irradiated human salivary gland, along with parasympathetic nerves, suggesting that tissue degeneration is due to loss of progenitors and their regulators. Thus, we establish a new paradigm that salivary glands can regenerate after genotoxic shock and do so through a SOX2 nerve-dependent mechanism. Salivary glands regenerate after radiation injury through SOX2-mediated secretory acinar cell replacement as shown using genetic lineage tracing and ablation methods, in combination with in vivo and ex vivo gamma radiation-induced damage models.
    Print ISSN: 1757-4676
    Electronic ISSN: 1757-4684
    Topics: Medicine
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  • 48
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    Wiley-Blackwell
    Publication Date: 2018-01-16
    Description: Carbon-based sunlight absorbers in solar-driven steam generation have recently attracted much attention due to the possibility of huge applications of low-cost steam for medical sterilization or sanitization, seawater desalination, chemical distillation, and water purification. In this minireview, recent developments in carbon-based sunlight absorbers in solar-driven steam generation systems are reviewed, including graphene, graphite, carbon nanotubes, other carbon materials, and carbon-based composite materials, highlighting important contributions worldwide that promise low-cost, efficient, robust, reusable, chemically stable, and excellent broadband solar absorption. Furthermore, the crucial challenges associated with employing carbon materials in this field are emphasized. Recent developments in carbon-based sunlight absorbers in solar-driven steam generation systems are reviewed, including graphene, graphite, carbon nanotubes, other carbon materials, and carbon-based composites materials. In particular, important contributions worldwide that promise low-cost, efficient, robust, reusable, chemically stable, and excellent broadband solar absorption are highlighted. Furthermore, the crucial challenges associated with employing carbon materials in this field are emphasized.
    Electronic ISSN: 2056-6646
    Topics: General, Interdisciplinary , Energy, Environment Protection, Nuclear Power Engineering
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  • 49
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    Wiley-Blackwell
    Publication Date: 2018-01-16
    Description: Lithium extraction from high Mg/Li ratio brine is a key technical problem in the world. Based on the principle of rocking-chair lithium-ion batteries, cathode material LiFePO 4 is applied to extract lithium from brine, and a novel lithium-ion battery system of LiFePO 4 | NaCl solution | anion-exchange membrane | brine | FePO 4 is constructed. In this method, Li + is selectively absorbed from the brine by FePO 4 (Li + + e + FePO 4 = LiFePO 4 ); meanwhile, Li + is desorbed from LiFePO 4 (LiFePO 4 − e = Li + + FePO 4 ) and enriched efficiently. To treat a raw brine solution, the Mg/Li ratio decreases from the initial 134.4 in the brine to 1.2 in the obtained anolyte and 83% lithium is extracted. For the treatment of an old brine solution, the Mg/Li ratio decreases from the initial 48.4 in the brine to 0.5 and the concentration of lithium in the anolyte is accumulated about six times (from the initial 0.51 g L −1 in the brine to 3.2 g L −1 in the anolyte), with the absorption capacity of about 25 mg (Li) g (LiFePO 4 ) −1 . Additionally, it displays a great perspective on the application in light of its high selectively, good cycling performance, effective lithium enrichment, environmental friendliness, low cost, and avoidance of poisonous organic reagents and harmful acid or oxidant. Lithium extraction from high Mg/Li ratio brine is a global technical problem. In this study, cathode material LiFePO 4 is applied to extract lithium from the brine via a novel electrochemical system of LiFePO 4 | NaCl solution | anion-exchange membrane | brine |FePO 4 . It displays a great perspective on the application in light of its high selectively, good cycling performance, effective lithium enrichment, and low cost.
    Electronic ISSN: 2056-6646
    Topics: General, Interdisciplinary , Energy, Environment Protection, Nuclear Power Engineering
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  • 50
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    Wiley-Blackwell
    Publication Date: 2018-01-18
    Electronic ISSN: 1942-2466
    Topics: Geography , Geosciences
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  • 51
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    Wiley-Blackwell
    Publication Date: 2018-01-18
    Description: Parkinson's disease (PD) is a movement disorder with widespread neurodegeneration in the brain. Significant oxidative, reductive, metabolic, and proteotoxic alterations have been observed in PD postmortem brains. The alterations of mitochondrial function resulting in decreased bioenergetic health is important and needs to be further examined to help develop biomarkers for PD severity and prognosis. It is now becoming clear that multiple hits on metabolic and signaling pathways are likely to exacerbate PD pathogenesis. Indeed, data obtained from genetic and genome association studies have implicated interactive contributions of genes controlling protein quality control and metabolism. For example, loss of key proteins that are responsible for clearance of dysfunctional mitochondria through a process called mitophagy has been found to cause PD, and a significant proportion of genes associated with PD encode proteins involved in the autophagy-lysosomal pathway. In this review, we highlight the evidence for the targeting of mitochondria by proteotoxic, redox and metabolic stress and the role autophagic surveillance in maintenance of mitochondrial quality. Furthermore, we summarize the role of α-synuclein, LRRK2, and tau in modulating mitochondrial function and autophagy. Among the stressors that can overwhelm the mitochondrial quality control mechanisms, we will discuss 4-hydroxynonenal (HNE) and nitric oxide. The impact of autophagy is context depend and as such can have both beneficial and detrimental effects. Furthermore, we highlight the potential of targeting mitochondria and autophagic function as an integrated therapeutic strategy and the emerging contribution of the microbiome to PD susceptibility. This article is protected by copyright. All rights reserved.
    Print ISSN: 0022-3042
    Electronic ISSN: 1471-4159
    Topics: Medicine
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  • 52
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    Wiley-Blackwell
    Publication Date: 2018-01-18
    Description: We introduce a new method to determine the anisotropy of reflectance of sea ice and snow at spatial scales from 1 m 2 to 80 m 2 using a multispectral circular fish-eye radiance camera (CE600). The CE600 allows measuring radiance simultaneously in all directions of a hemisphere at a 1°angular resolution. The spectral characteristics of the reflectance and its dependency on illumination conditions obtained from the camera are compared to those obtained with a hyperspectral field spectroradiometer manufactured by Analytical Spectral Device, Inc. (ASD). Results confirm the potential of the CE600, with the suggested measurement set-up and data processing, to measure commensurable sea ice and snow Hemispherical Directional Reflectance Factor, HDRF, values. Compared to the ASD, the reflectance anisotropy measured with the CE600 provides much higher resolution in terms of directional reflectance (N=16020). The hyperangular resolution allows detecting features that were overlooked using the ASD due to its limited number of measurement angles (N = 25). This dataset of HDRF further documents variations in the anisotropy of the reflectance of snow and ice with the geometry of observation and illumination conditions and its spectral and spatial scale dependency. Finally, in order to re-produce the hyperangular CE600 reflectance measurements over the entire 400-900 nm spectral range, a regression based method is proposed to combine the ASD and CE600 measurements. Results confirm that both instruments may be used in synergy to construct a hyperangular and -spectral snow and ice reflectance anisotropy dataset.
    Electronic ISSN: 2333-5084
    Topics: Geosciences , Physics
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  • 53
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    Wiley-Blackwell
    Publication Date: 2018-01-18
    Description: Interspecific variation in life-history traits and physiological limits can be linked to the environmental conditions species experience, including climatic conditions. As alpine environments are particularly vulnerable under climate change, we focus on the montane-alpine fly Drosophila nigrosparsa . Here, we characterized some of its life-history traits and physiological limits and compared these with those of other drosophilids, namely Drosophila hydei , Drosophila melanogaster , and Drosophila obscura . We assayed oviposition rate, longevity, productivity, development time, larval competitiveness, starvation resistance, and heat and cold tolerance. Compared with the other species assayed, D. nigrosparsa is less fecund, relatively long-living, starvation susceptible, cold adapted, and surprisingly well heat adapted. These life-history characteristics provide insights into invertebrate adaptations to alpine conditions which may evolve under ongoing climate change. Life-history traits and physiological limits of the alpine fly Drosophila nigrosparsa were assayed in the laboratory and compared with those of four other Drosophila species. Drosophila nigrosparsa has relatively low fecundity, is long-living, starvation susceptible, cold adapted, and surprisingly heat tolerant.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 54
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    Wiley-Blackwell
    Publication Date: 2018-01-18
    Description: Environmental unpredictability is known to result in the evolution of bet-hedging traits. Variable dormancy enhances survival through harsh conditions, and is widely cited as a diversification bet-hedging trait. The floating aquatic plant, Spirodela polyrhiza (Greater Duckweed), provides an opportunity to study diversification because although partially reliable seasonal cues exist, its growing season is subject to an unpredictable and literally “hard” termination when the surface water freezes, and overwinter survival depends on a switch from production of normal daughter fronds to production of dense, sinking “turions” prior to freeze-over. The problem for S. polyrhiza is that diversified dormancy behavior must be generated among clonally produced, genetically identical offspring. Variation in phenology has been observed in the field, but its sources are unknown. Here, we investigate sources of phenological variation in turion production , and test the hypothesis that diversification in turion phenology is generated within genetic lineages through effects of parental birth order. As expected, phenotypic plasticity to temperature is expressed along a thermal gradient; more interestingly, parental birth order was found to have a significant and strong effect on turion phenology: Turions are produced earlier by late birth-order parents. These results hold regardless of whether turion phenology is measured as first turion birth order, time to first turion, or turion frequency. This study addresses a question of current interest on potential mechanisms generating diversification, and suggests that consistent phenotypic differences across birth orders generate life history variation. There has been considerable recent interest—both from developmental and evolutionary perspectives—in mechanisms that generate differences among genetically identical individuals. Here, we ask how the clonal aquatic plant, Spirodela polyrhiza , generates potentially adaptive behavioural variation among its clonal offspring. This species inhabits ponds susceptible to unpredictable timing of freeze-up events that are fatal to regular offspring. We find that in addition to phenotypic plasticity in response to seasonal cues, phenological diversification in the switch from production of regular offspring to specialized overwintering “turions” is generated by parental birth order.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 55
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    Wiley-Blackwell
    Publication Date: 2018-01-18
    Description: Knowledge about chemical communication in some vertebrates is still relatively limited. Squamates are a glaring example of this, even when recent evidences indicate that scents are involved in social and sexual interactions. In lizards, where our understanding of chemical communication has considerably progressed in the last few years, many questions about chemical interactions remain unanswered. A potential reason for this is the inherent complexity and technical limitations that some methodologies embody when analyzing the compounds used to convey information. We provide here a straightforward procedure to analyze lizard chemical secretions based on gas chromatography coupled to mass spectrometry that uses an internal standard for the semiquantification of compounds. We compare the results of this method with those obtained by the traditional procedure of calculating relative proportions of compounds. For such purpose, we designed two experiments to investigate if these procedures allowed revealing changes in chemical secretions 1) when lizards received previously a vitamin dietary supplementation or 2) when the chemical secretions were exposed to high temperatures. Our results show that the procedure based on relative proportions is useful to describe the overall chemical profile, or changes in it, at population or species levels. On the other hand, the use of the procedure based on semiquantitative determination can be applied when the target of study is the variation in one or more particular compounds of the sample, as it has proved more accurate detecting quantitative variations in the secretions. This method would reveal new aspects produced by, for example, the effects of different physiological and climatic factors that the traditional method does not show. We provide a straightforward procedure to analyze lizard chemical secretions based on gas chromatography coupled to mass spectrometry that uses an internal standard for the semiquantification of compounds.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 56
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    Wiley-Blackwell
    Publication Date: 2018-01-18
    Description: Zooplankton have evolved several mechanisms to deal with environmental threats, such as ultraviolet radiation (UVR), and in order to identify strategies inherent to organisms exposed to different UVR environments, we here examine life-history traits of two lineages of Daphnia pulex . The lineages differed in the UVR dose they had received at their place of origin from extremely high UVR stress at high-altitude Bolivian lakes to low UVR stress near the sea level in temperate Sweden. Nine life-history variables of each lineage were analyzed in laboratory experiments in the presence and the absence of sub-lethal doses of UVR (UV-A band), and we identified trade-offs among variables through structural equation modeling (SEM). The UVR treatment was detrimental to almost all life-history variables of both lineages; however, the Daphnia historically exposed to higher doses of UVR (HighUV) showed a higher overall fecundity than those historically exposed to lower doses of UVR (LowUV). The total offspring and ephippia production, as well as the number of clutches and number of offspring at first reproduction, was directly affected by UVR in both lineages. Main differences between lineages involved indirect effects that affected offspring production as the age at first reproduction. We here show that organisms within the same species have developed different strategies as responses to UVR, although no increased physiological tolerance or plasticity was shown by the HighUV lineage. In addition to known tolerance strategies to UVR, including avoidance, prevention, or repairing of damages, we here propose a population strategy that includes early reproduction and high fertility, which we show compensated for the fitness loss imposed by UVR stress. In order to identify strategies inherent to organisms exposed to different UVR environments, we here examined life-history traits of two lineages of Daphnia pulex through structural equation modeling (SEM). We here show that organisms within the same species have developed different strategies as responses to UVR and propose an evolutionary population strategy that includes early reproduction and high fertility.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 57
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    Wiley-Blackwell
    Publication Date: 2018-01-18
    Description: Invasive alien species (IAS) constitute a major threat to global biological diversity. In order to control their spread, a detailed understanding of the factors influencing their distribution is essential. Although international trade is regarded as a major force structuring spatial patterns of IAS, the role of other social factors remains unclear. Despite studies highlighting the importance of strong governance in slowing drivers of biodiversity loss such as logging, deforestation, and agricultural intensification, no study has yet analyzed its contribution to the issue of IAS. Using estimates of governance quality and comprehensive spatiotemporal IAS data, we performed multiple linear regressions to investigate the effect of governance quality upon the distribution of species listed under “100 of the worst” IAS in 38 Eurasian countries as defined by DASIE. Our model suggested that for countries with higher GDP, stronger governance was associated with a greater number of the worst IAS; in contrast, for the lowest GDP countries under analysis, stronger governance was associated with fewer of these IAS. We elucidate how the quality of governance within a country has implications for trade, tourism, transport, legislation, and economic development, all of which influence the spread of IAS. While our findings support the common assumption that strengthening governance benefits conservation interventions in countries of smaller economy, we find that this effect is not universal. Stronger governance alone cannot adequately address the problem of IAS, and targeted action is required in relatively high-GDP countries in order to stem the influx of IAS associated with high volumes of trade. Multiple linear regressions on data for invasive alien species (IAS) in 38 Eurasian countries have shown that, for countries with higher GDP, stronger governance was associated with a greater number of the worst IAS; in contrast, for the lowest GDP countries under analysis, stronger governance was associated with fewer of these IAS. Accordingly, the assumption that strengthening governance will benefit conservation interventions should not be applied broadly to IAS in all contexts.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 58
    Publication Date: 2018-01-18
    Description: Brown adipose tissue (BAT) activation stimulates energy expenditure in human adults, which makes it an attractive target to combat obesity and related disorders. Recent studies demonstrated a role for G protein-coupled receptor 120 (GPR120) in BAT thermogenesis. Here, we investigated the therapeutic potential of GPR120 agonism and addressed GPR120-mediated signaling in BAT. We found that activation of GPR120 by the selective agonist TUG-891 acutely increases fat oxidation and reduces body weight and fat mass in C57Bl/6J mice. These effects coincided with decreased brown adipocyte lipid content and increased nutrient uptake by BAT, confirming increased BAT activity. Consistent with these observations, GPR120 deficiency reduced expression of genes involved in nutrient handling in BAT. Stimulation of brown adipocytes in vitro with TUG-891 acutely induced O 2 consumption, through GPR120-dependent and GPR120-independent mechanisms. TUG-891 not only stimulated GPR120 signaling resulting in intracellular calcium release, mitochondrial depolarization, and mitochondrial fission, but also activated UCP1. Collectively, these data suggest that activation of brown adipocytes with the GPR120 agonist TUG-891 is a promising strategy to increase lipid combustion and reduce obesity. This study demonstrates that the GPR120 agonist TUG-891 improves metabolic health by activation of brown fat. Mechanistically, TUG-891 promotes respiration in brown adipocytes by stimulating GPR120-dependent Ca 2+ release and mitochondrial fragmentation, thereby activating UCP1.
    Print ISSN: 1757-4676
    Electronic ISSN: 1757-4684
    Topics: Medicine
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  • 59
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    Wiley-Blackwell
    Publication Date: 2018-01-19
    Description: Plant–soil feedbacks (PSFs) have gained attention for their potential role in explaining plant growth and invasion. While promising, most PSF research has measured plant monoculture growth on different soils in short-term, greenhouse experiments. Here, five soil types were conditioned by growing one native species, three non-native species, or a mixed plant community in different plots in a common-garden experiment. After 4 years, plants were removed and one native and one non-native plant community were planted into replicate plots of each soil type. After three additional years, the percentage cover of each of the three target species in each community was measured. These data were used to parameterize a plant community growth model. Model predictions were compared to native and non-native abundance on the landscape. Native community cover was lowest on soil conditioned by the dominant non-native, Centaurea diffusa , and non-native community cover was lowest on soil cultivated by the dominant native, Pseudoroegneria spicata . Consistent with plant growth on the landscape, the plant growth model predicted that the positive PSFs observed in the common-garden experiment would result in two distinct communities on the landscape: a native plant community on native soils and a non-native plant community on non-native soils. In contrast, when PSF effects were removed, the model predicted that non-native plants would dominate all soils, which was not consistent with plant growth on the landscape. Results provide an example where PSF effects were large enough to change the rank-order abundance of native and non-native plant communities and to explain plant distributions on the landscape. The positive PSFs that contributed to this effect reflected the ability of the two dominant plant species to suppress each other's growth. Results suggest that plant dominance, at least in this system, reflects the ability of a species to suppress the growth of dominant competitors through soil-mediated effects. A native and non-native plant community were grown on different soils during a seven-year plant–soil feedback experiment. Consistent with plant growth on the landscape, the native community grew poorly on soils cultivated by the dominant non-native plant, and the non-native community grew poorly on soils cultivated by the dominant native plant.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 60
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    Wiley-Blackwell
    Publication Date: 2018-01-19
    Description: Senescence is a highly variable process that comprises both age-dependent and state-dependent components and can be greatly affected by environmental conditions. However, few studies have quantified the magnitude of age-dependent and state-dependent senescence in key life-history traits across individuals inhabiting different spatially structured and seasonal environments. We used longitudinal data from wild female yellow-bellied marmots ( Marmota flaviventer ), living in two adjacent environments that differ in elevation and associated phenology, to quantify how age and individual state, measured as “time to death,” affect body mass senescence in different environments. Further, we quantified how patterns of senescence differed between two biologically distinct seasons, spring, and late summer. Body mass senescence had an age-dependent component, expressed as a decrease in mass in old age. Overall, estimated age-dependent senescence was greater in females living in the more favorable lower elevation environment, than in the harsher higher elevation environment, and greater in late summer than in spring. Body mass senescence also had a state-dependent component, captured by effects of time to death, but only in the more favorable lower elevation environment. In spring, body mass gradually decreased from 2 years before death, whereas in late summer, state-dependent effects were expressed as a terminal decrease in body mass in the last year of life. Contrary to expectations, we found that senescence was more likely to be observed under more favorable environmental conditions, rather than under harsher conditions. By further demonstrating that senescence patterns differ among seasons, our results imply that within-year temporal environmental variation must be considered alongside spatial environmental variation in order to characterize and understand the pattern and magnitude of senescence in wild populations. Few studies have quantified the magnitude of age-dependent and state-dependent senescence in key life-history traits across individuals inhabiting different spatially structured and seasonal environments. We show that age-dependent and state-dependent (i.e., time to death) effects on body mass co-occur in wild yellow-bellied marmots, and contrary to most previous studies, we found that senescence was more likely to be observed at lower rather than higher elevation. By further demonstrating that senescence patterns differ among seasons, our results imply that within-year temporal environmental variation must be considered alongside spatial environmental variation in order to characterize and understand the pattern and magnitude of senescence in natural populations.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 61
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-19
    Description: Plant leaf phenology is typically observed either via ground-based visual observations on individuals or via remote sensing of land surface vegetation. To integrate phenological information from both data sources, collected at different spatial scales using different observational protocols, digital cameras were deployed spanning canopy areas with enough spatial resolution to identify temporal changes in individual deciduous tree species with continuous observations. Comparisons of phenology between camera photography and in situ observations have been reported in prior studies; however, it is still unclear that how these camera images relate to field observations at individual and species levels, and how the metrics from those images provide comparable species-specific phenological responses to environmental variation. We set a suite of digital time-lapse cameras to acquire continuous photographs of deciduous tree canopies and conducted ground-based visual observations in Connecticut, USA, from 2012 to 2014. Comparisons between image-derived dates and observed phenological dates showed that both green and red color indices could be matched to ground observations, and red color indices showed good performance in matching autumn phenology across our group of eight tree species that dominate the southern New England forests. Linear mixed-effects models were applied to investigate the relationships between climatic/weather conditions and the timing of peak and of intensity of red color in fall foliage for each species. Model results suggested that temperature, precipitation, drought stress in autumn, and heat stress in summer are all important factors to the timing of peak fall foliage color and that higher minimum temperatures (or lower cold degree-day accumulation) in the autumn are linked to higher intensity of red coloration at least in sugar maples. This study improves our understanding of temporal and spatial variation in the phenology of deciduous trees captured by digital cameras. As well, this provides insights into relating species-specific information on phenology from visual observations in the field to near-surface remote sensing and points to the need for further research on autumn phenology using the change in redness of tree canopies.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 62
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-19
    Description: Species responses to climate change have been shown to vary in both direction and magnitude. Understanding these idiosyncratic responses is crucial if we are to predict extinction risk and set up efficient conservation strategies. The variations observed across species have been related to several species attributes including intrinsic traits such as physiological tolerances or life-history strategies but also to niche characteristics (e.g., niche breadth [NB], niche position [NP]). However, although previous studies have successfully linked species attributes to population dynamics or range shifts, few have considered synergistic effects to explain responses to climate variations. Here, we assessed whether five species attributes (fecundity, thermal safety margin, trophic position [TP], NB, and NP) explained interspecific differences in four parameters influencing population dynamics of 35 stream fish species at the French scale. We used Bayesian N-mixture models to estimate posterior distributions of the growth rate, the strength of density dependence, and the influence of both mean temperature and temperature variability on populations for each species. We then used phylogenetic generalized least squares (PGLS) models to investigate the influence of species attributes and their interactions on interspecific differences in each of the four parameter driving population dynamics. The percentage of variance explained by the PGLS models was relatively high (around 40% on average), indicating that species attributes are good predictors of species population dynamics. Furthermore, we showed that the influence of these single attributes was mediated by other attributes, especially NP and TP. Importantly, we found that models including interaction terms had greater support over simple additive models in explaining interspecific differences in population dynamics. Taken together, these results point to the importance of considering the interplay between species attributes in unraveling the mechanisms involved in population dynamics and understanding the vulnerability of species to global change.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 63
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-19
    Description: Plant functional traits research has revealed many interesting and important patterns among morphological, physiological, and life-history traits and the environment. These are exemplified in trade-offs between groups of traits such as those embodied in the leaf and wood economics spectra. Inferences from empirical studies are often constrained by the correlative nature of the analyses, availability of trait data, and a focus on easily measured traits. However, empirical studies have been fundamental to modeling endeavors aiming to enhance our understanding of how functional traits scale up to affect, for example, community dynamics and ecosystem productivity. Here, we take a complementary approach utilizing an individual-based model of tree growth and mortality (the allometrically constrained growth and carbon allocation [ACGCA] model) to investigate the theoretical trait space (TTS) of North American trees. The model includes 32 parameters representing allometric, physiological, and anatomical traits, some overlapping leaf and wood economics spectra traits. Using a Bayesian approach, we fit the ACGCA model to individual tree heights and diameters from the USFS Forest Inventory and Analysis (FIA) dataset, with further constraints by literature-based priors. Fitting the model to 1.3 million FIA records—aggregated across individuals, species, and sites—produced a posterior distribution of traits leading to realistic growth. We explored this multidimensional posterior distribution (the TTS) to evaluate trait–trait relationships emerging from the ACGCA model, and compare these against empirical patterns reported in the literature. Only three notable bivariate correlations, among 496 possible trait pairs, were contained in the TTS. However, stepwise regressions uncovered a complicated structure; only a subset of traits—related to photosynthesis (e.g., radiation-use efficiency and maintenance respiration)—exhibited strong multivariate trade-offs with each other, while half of the traits—mostly related to allometries and construction costs—varied independently of other traits. Interestingly, specific leaf area was related to several rarely measured root traits. The trade-offs contained in the TTS generally reflect mass-balance (related to carbon allocation) and engineering (mostly related to allometries) trade-offs represented in the ACGCA model and point to potentially important traits that are under-explored in field studies (e.g., root traits and branch senescence rates).
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 64
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    Wiley-Blackwell
    Publication Date: 2018-01-20
    Description: We studied the temperature relations of wild and zoo Aldabra giant tortoises ( Aldabrachelys gigantea ) focusing on (1) the relationship between environmental temperature and tortoise activity patterns ( n  = 8 wild individuals) and (2) on tortoise body temperature fluctuations, including how their core and external body temperatures vary in relation to different environmental temperature ranges (seasons; n  = 4 wild and n  = 5 zoo individuals). In addition, we surveyed the literature to review the effect of body mass on core body temperature range in relation to environmental temperature in the Testudinidae. Diurnal activity of tortoises was bimodally distributed and influenced by environmental temperature and season. The mean air temperature at which activity is maximized was 27.9°C, with a range of 25.8–31.7°C. Furthermore, air temperature explained changes in the core body temperature better than did mass, and only during the coldest trial, did tortoises with higher mass show more stable temperatures. Our results, together with the overall Testudinidae overview, suggest that, once variation in environmental temperature has been taken into account, there is little effect of mass on the temperature stability of tortoises. Moreover, the presence of thermal inertia in an individual tortoise depends on the environmental temperatures, and we found no evidence for inertial homeothermy. Finally, patterns of core and external body temperatures in comparison with environmental temperatures suggest that Aldabra giant tortoises act as mixed conformer–regulators. Our study provides a baseline to manage the thermal environment of wild and rewilded populations of an important island ecosystem engineer species in an era of climate change. According to the patterns of body temperature in relation to environmental temperature, Aldabra giant tortoises act as conformer–regulators. In the wild, tortoises modify their daily and seasonal activity and regulate their body temperature close to 30°C. This study provides a baseline to manage the thermal environment of wild and rewilded populations of an important island ecosystem engineer species in an era of climate change.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 65
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    Wiley-Blackwell
    Publication Date: 2018-01-20
    Description: Little is known about how important social behaviors such as song vary within and among populations for any of the endemic Hawaiian honeycreepers. Habitat loss and non-native diseases (e.g., avian malaria) have resulted in isolation and fragmentation of Hawaiian honeycreepers within primarily high elevation forests. In this study, we examined how isolation of Hawai'i ‘amakihi ( Chlorodrepanis virens ) populations within a fragmented landscape influences acoustic variability in song. In the last decade, small, isolated populations of disease tolerant ‘amakihi have been found within low elevation forests, allowing us to record ‘amakihi songs across a large elevational gradient (10–1800 m) that parallels disease susceptibility on Hawai'i island. To understand underlying differences among populations, we examined the role of geographic distance, elevation, and habitat structure on acoustic characteristics of ‘amakihi songs. We found that the acoustic characteristics of ‘amakihi songs and song-type repertoires varied most strongly across an elevational gradient. Differences in ‘amakihi song types were primarily driven by less complex songs (e.g., fewer frequency changes, shorter songs) of individuals recorded at low elevation sites compared to mid and high elevation populations. The reduced complexity of ‘amakihi songs at low elevation sites is most likely shaped by the effects of habitat fragmentation and a disease-driven population bottleneck associated with avian malaria, and maintained through isolation, localized song learning and sharing, and cultural drift. These results highlight how a non-native disease through its influence on population demographics may have also indirectly played a role in shaping the acoustic characteristics of a species. In songbirds, song is a culturally transmitted trait, and the fragmentation and isolation of populations can inhibit the flow of song among populations. Hawaiian honeycreeper populations have become isolated due to habitat loss and the distribution of non-native diseases that vary across elevations. We found that small, isolated populations of disease tolerant honeycreepers at low elevations had less complex songs than higher elevation disease-susceptible populations, suggesting an indirect role of disease in shaping acoustic variability.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 66
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    Wiley-Blackwell
    Publication Date: 2018-01-20
    Description: Inbreeding depression can have alarming impacts on threatened species with small population sizes. Assessing inbreeding has therefore become an important focus of conservation research. In this study, heterozygosity–fitness correlations (HFCs) were measured by genotyping 7 loci in 83 adult and 184 hatchling Lesser Antillean Iguanas, Iguana delicatissima, at a communal nesting site in Dominica to assess the role of inbreeding depression on hatchling fitness and recruitment to the adult population in this endangered species. We found insignificant correlations between multilocus heterozygosity and multiple fitness proxies in hatchlings and adults. Further, multilocus heterozygosity did not differ significantly between hatchlings and adults, which suggests that the survivorship of homozygous hatchlings does not differ markedly from that of their heterozygous counterparts. However, genotypes at two individual loci were correlated with hatching date, a finding consistent with the linkage between specific marker loci and segregating deleterious recessive alleles. These results provide only modest evidence that inbreeding depression influences the population dynamics of I. delicatissima on Dominica. In this study, heterozygosity-fitness correlations (HFCs) were measured in adult and hatchling Lesser Antillean Iguanas, Iguana delicatissima , at a communal nesting site in Dominica to assess the role of inbreeding depression on hatchling fitness and recruitment to the adult population in this endangered species. Our results provide only modest evidence that inbreeding depression influences the population dynamics of I. delicatissima on Dominica.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 67
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    Wiley-Blackwell
    Publication Date: 2018-01-20
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 68
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    Wiley-Blackwell
    Publication Date: 2018-01-20
    Description: Ocean warming can modify the phytoplankton biomass on decadal scales. Significant increases in sea surface temperature (SST) and rainfall in the northwest of Australia over recent decades are attributed to climate change. Here, we used four biomarker proxies (TEX 86 index, long-chain n -alkanes, brassicasterol, and dinosterol) to reconstruct approximately 60-year variations of SST, terrestrial input, and diatom and dinoflagellate biomass in the coastal waters of the remote Kimberley region. The results showed that the most significant increases in SST and terrestrial input occurred since 1997, accompanied by an abrupt increase in diatom and dinoflagellate biomasses. Compared with the results before 1997, the average temperature during 1997–2011 increased approximately 1°C, rainfall increased 248.2 mm, brassicasterol and dinosterol contents increased 8.5 and 1.7 times. Principal component analysis indicated that the warming SST played a more important role in the phytoplankton increase than increased rainfall and river discharge. An abrupt increase in phytoplankton occurred since the 1990s, accompanied by significant increases in temperature and terrestrial input. Warming temperature played a more important role for the decadal phytoplankton increase than rainfall. Applicability of TEX86H biomarker proxy for SST off northwestern Australia was validated.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 69
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-20
    Description: Increased nutrient inputs can cause shifts in plant community composition and plant functional traits, both of which affect ecosystem function. We studied community- and species-level leaf functional trait changes in a full factorial nitrogen (N), phosphorus (P), and potassium (K) fertilization experiment in a semi-arid grassland. Nitrogen was the only nutrient addition to significantly affect leaf functional traits, and N addition increased community-weighted specific leaf area (SLA) by 19%, leaf chlorophyll content by 34%, height by 26%, and leaf dry matter content (LDMC) decreased by 11% while leaf thickness and toughness did not change significantly. At the species level, most species contributed to the community-weighted trait and increased in SLA, chlorophyll, height, and LDMC with N addition. These intraspecific changes in functional traits account for 51–71% of the community-level changes in SLA, chlorophyll, plant height, and LDMC. The remaining change is due to species abundance changes; the two most abundant species ( Bouteloua gracilis and Carex filifolia ) decreased in abundance with N addition while subdominant species increased in abundance. We also found annual variation in SLA, chlorophyll, plant height, and LDMC to be as important in influencing traits as N addition, likely due to differences in precipitation. Aboveground net primary productivity (ANPP) did not change significantly with N addition. However, N addition caused a 34% increase in leaf area index (LAI) and a 67% increase in canopy chlorophyll density. We demonstrate that nitrogen-induced changes in both functional traits and species abundances magnify ANPP changes in LAI and canopy chlorophyll density. Therefore, ANPP underestimates N addition-induced ecosystem-level changes in the canopy vegetation.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 70
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    Wiley-Blackwell
    Publication Date: 2018-01-20
    Description: Climate change is expected to result in range shifts and habitat fragmentation for many species. In the Arctic, loss of sea ice will reduce barriers to dispersal or eliminate movement corridors, resulting in increased connectivity or geographic isolation with sweeping implications for conservation. We used satellite telemetry, data from individually marked animals (research and harvest), and microsatellite genetic data to examine changes in geographic range, emigration, and interpopulation connectivity of the Baffin Bay (BB) polar bear ( Ursus maritimus ) subpopulation over a 25-year period of sea-ice loss. Satellite telemetry collected from n  = 43 (1991–1995) and 38 (2009–2015) adult females revealed a significant contraction in subpopulation range size (95% bivariate normal kernel range) in most months and seasons, with the most marked reduction being a 70% decline in summer from 716,000 km 2 (SE 58,000) to 211,000 km 2 (SE 23,000) ( p  〈 .001). Between the 1990s and 2000s, there was a significant shift northward during the on-ice seasons (2.6 ° shift in winter median latitude, 1.1 ° shift in spring median latitude) and a significant range contraction in the ice-free summers. Bears in the 2000s were less likely to leave BB, with significant reductions in the numbers of bears moving into Davis Strait (DS) in winter and Lancaster Sound (LS) in summer. Harvest recoveries suggested both short and long-term fidelity to BB remained high over both periods (83–99% of marked bears remained in BB). Genetic analyses using eight polymorphic microsatellites confirmed a previously documented differentiation between BB, DS, and LS; yet weakly differentiated BB from Kane Basin (KB) for the first time. Our results provide the first multiple lines of evidence for an increasingly geographically and functionally isolated subpopulation of polar bears in the context of long-term sea-ice loss. This may be indicative of future patterns for other polar bear subpopulations under climate change. Our results provide the first multiple lines of evidence for an increasingly geographically and functionally isolated subpopulation of polar bears in the context of long-term sea-ice loss. This work is important and timely because large-scale sea-ice loss across the Arctic is predicted to continue and this is expected to have multiple impacts on polar bears.
    Electronic ISSN: 2045-7758
    Topics: Biology
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  • 71
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-20
    Description: Management and conservation strategies for endangered species require information on their temporal and spatial behavioral and habitat use relationships. We evaluated activity patterns and resource selection of black bears in northwestern Mexico. We surveyed 29 localities with 1450 camera traps stations from 2009 to 2013 in the states of Sonora and Chihuahua, Mexico. In each locality, we calculated the proportion of diurnal, nocturnal, and crepuscular activity through a kernel density estimator based on the time of independent photographic events, and we built a beta regression between diurnal density and annual temperature, seasonal rainfall (SR), human density, road density, daylight hours, season, and management type. To evaluate resource selection, we built a binomial logistic regression model incorporating Normalized Difference Vegetation Index (NDVI), mean and coefficient of variation of annual temperature, human population density (PD), terrain roughness, and season. Black bear activity was primarily diurnal with a bimodal tendency around sunrise and sunset. Diurnal activity (between sunrise and sunset) was positively influenced by daylight hours, SR, and private reserves and negatively influenced by anthropogenic factors. Resource selection was positively influenced by the coefficient of variation in temperature and NDVI and negatively associated with average annual temperature, PD, and terrain roughness. Activity patterns and resource use were similar to other regions in North America. However, temperature was one of the main factors influencing black bear activity and resource selection in our study areas and should be considered when developing management plans given projected increases in temperature expected under climate change scenarios. We present the first work of its kind for northwestern Mexico and considered it as an important component in future survey and management protocols for the species in the southern portion of its distribution.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 72
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    Wiley-Blackwell
    In: Ecosphere
    Publication Date: 2018-01-20
    Description: Identifying factors determining the performance of individuals is an essential part of resolving what drives population dynamics. For species undergoing ontogenetic shifts in resource and habitat use, this entails assessing individual performance in all habitats used. Whereas survival and growth of anadromous Atlantic salmon, Salmo salar L., in its juvenile, river habitat are known to depend on size-dependent foraging and food availability, individual performance of salmon in the growth habitat out at sea is commonly explained only by abiotic factors. Still, individuals undergo this habitat shift to grow large, suggesting performance should be food-dependent also in the growth habitat. Because fish communities are highly size-structured, the link between predators and their prey may depend on their respective body sizes. Here, we study whether the performance of Baltic Sea salmon in its growth habitat is food- and size-dependent, by combining extensive diet and body size data of Baltic salmon with spatially resolved monitoring data on abundance and size distribution of their main prey, herring, Clupea harengus L., and sprat, Sprattus sprattus L. We found that both the species and size composition of prey in the diet varied with salmon body size. By accounting for this size-dependent predation and the spatially varying size distribution of prey species, we could explain the variation in salmon diet composition among salmon individuals in different Baltic Sea basins and of different length. The proportion of sprat in diet of salmon was better explained by size-specific prey availability (SSP) than total prey biomass, especially for small salmon. Further, salmon body condition increased with SSP, whereas total prey biomass could not explain variation in the condition of salmon. These findings demonstrate that food- and size-dependent processes indeed can influence the performance of anadromous fish also in large marine systems. Thus, we argue that consideration of these processes, stretching across habitats, is important for understanding performance and dynamics of predatory fish in open aquatic systems, as well as for successful management of species such as Atlantic salmon.
    Electronic ISSN: 2150-8925
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 73
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    Wiley-Blackwell
    Publication Date: 2018-01-23
    Description: Conventional pacemaker batteries have limited lifetime and require a major surgery for replacement. To overcome this impediment, a design for piezoelectric energy harvester scavenging energy from blood pressure variation in the patient's body is proposed. This piezoelectric energy harvester converts the force arising from blood pressure variation into electric voltage. The image shows the self-powered pacemaker; the background portrays the campus of the Indian Institute of Technology Mandi, India, where the research was carried out. Further details can be found in article number 1700084 by Rahul Vaish and co-workers.
    Electronic ISSN: 2056-6646
    Topics: General, Interdisciplinary , Energy, Environment Protection, Nuclear Power Engineering
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  • 74
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    Wiley-Blackwell
    Publication Date: 2018-01-23
    Electronic ISSN: 2056-6646
    Topics: General, Interdisciplinary , Energy, Environment Protection, Nuclear Power Engineering
    Published by Wiley-Blackwell
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  • 75
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    Wiley-Blackwell
    Publication Date: 2018-01-23
    Electronic ISSN: 2056-6646
    Topics: General, Interdisciplinary , Energy, Environment Protection, Nuclear Power Engineering
    Published by Wiley-Blackwell
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  • 76
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    Wiley-Blackwell
    Publication Date: 2018-01-23
    Description: [1] Satellite observation and general circulation model (GCM) studies suggest that precipitating ice makes non-negligible contributions to the radiation balance of the Earth. However in most GCMs, precipitating ice is diagnosed and its radiative effects are not taken into account. Here we examine the longwave radiative impact of precipitating ice using a global non-hydrostatic atmospheric model with a double-moment cloud microphysics scheme. An offline radiation model is employed to determine cloud radiative effects according to the amount and altitude of each type of ice hydrometeor. Results show that the snow radiative effect reaches 2 W m −2 in the tropics, which is about half the value estimated by previous studies. This effect is strongly dependent on the vertical separation of ice categories, and is partially generated by differences in terminal velocities, which are not represented in GCMs with diagnostic precipitating ice. Results from sensitivity experiments that artificially change the categories and altitudes of precipitating ice show that the simulated longwave heating profile and longwave radiation field are sensitive to the treatment of precipitating ice in models. This study emphasizes the importance of incorporating appropriate treatments for the radiative effects of precipitating ice in cloud and radiation schemes in GCMs in order to capture the cloud radiative effects of upper-level clouds.
    Electronic ISSN: 1942-2466
    Topics: Geography , Geosciences
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  • 77
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    Wiley-Blackwell
    Publication Date: 2018-01-23
    Description: Low clouds strongly impact the radiation budget of the climate system, but their simulation in most GCMs has remained a challenge, especially over the subtropical stratocumulus region. Assuming a Gaussian distribution for the subgrid-scale total water and liquid water potential temperature, a new statistical cloud scheme is proposed and tested in NCAR Community Atmospheric Model version 5 (CAM5). The subgrid-scale variance is diagnosed from the turbulent and shallow convective processes in CAM5. The approach is able to maintain the consistency between cloud fraction and cloud condensate and thus alleviates the adjustment needed in the default relative humidity based cloud fraction scheme. Short-term forecast simulations indicate that low cloud fraction and liquid water content, including their diurnal cycle, are improved due to a proper consideration of subgrid-scale variance over the southeastern Pacific Ocean region. Compared with the default cloud scheme, the new approach produced the mean climate reasonably well with improved shortwave cloud forcing (SWCF) due to more reasonable low cloud fraction and liquid water path over regions with predominant low clouds. Meanwhile, the SWCF bias over the tropical land regions is also alleviated. Furthermore, the simulated marine boundary layer clouds with the new approach extend further offshore and agree better with observations. The new approach is able to obtain the top of atmosphere (TOA) radiation balance with a slightly alleviated double ITCZ problem in preliminary coupled simulations. This study implies that a close coupling of cloud processes with other subgrid-scale physical processes is a promising approach to improve cloud simulations.
    Electronic ISSN: 1942-2466
    Topics: Geography , Geosciences
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  • 78
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    Wiley-Blackwell
    Publication Date: 2018-01-23
    Description: A recent study revealed that corticotropin-releasing hormone (CRH) in the cerebral cortex (CTX) plays a regulatory role in emotional behaviors in rodents. Given the functional interaction between brain-derived neurotrophic factor (BDNF) and the CRH-signaling pathway in the hypothalamic-pituitary-adrenal (HPA) axis, we hypothesized that BDNF may regulate gene expression of CRH and its related molecules in the CTX. Findings of real-time quantitative PCR (RT-qPCR) indicated that stimulation of cultured rat cortical neurons with BDNF led to marked elevations in the mRNA levels of CRH and CRH-binding protein (CRH-BP). The BDNF-induced upregulation of CRH-BP mRNA was attenuated by inhibitors of tyrosine receptor kinase (Trk) and MEK, but not by an inhibitor for PI3K and PLCγ. The upregulation was partially blocked by an inhibitor of lysine-specific demethylase (KDM) 6B. Fluorescent imaging identified the vesicular pattern of pH-sensitive green fluorescent protein-fused CRH-BP (CRH-BP-pHluorin), which co-localized with mCherry-tagged BDNF in cortical neurons. In addition, live-cell imaging detected drastic increases of pHluorin fluorescence in neurites upon membrane depolarization. Finally, we confirmed that tetrodotoxin (TTX) partially attenuated the BDNF-induced upregulation of CRH-BP mRNA, but not that of the protein. These observations indicate the following: In cortical neurons, BDNF led to gene expression of CRH-BP and CRH. TrkB, MEK, presumably ERK, and KDM6B are involved in the BDNF-induced gene expression of CRH-BP, and BDNF is able to induce the upregulation in a neuronal activity-independent manner. It is suggested that CRH-BP is stored into BDNF-containing secretory granules in cortical neurons, and is secreted in response to membrane depolarization. This article is protected by copyright. All rights reserved.
    Print ISSN: 0022-3042
    Electronic ISSN: 1471-4159
    Topics: Medicine
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  • 79
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    Wiley-Blackwell
    Publication Date: 2018-01-23
    Description: By their ability to shatter quality of life for both patients and caregivers, neurodegenerative diseases are the most devastating of human disorders. Unfortunately, there are no effective or long-terms treatments capable of slowing down the relentless loss of neurons in any of these diseases. One impediment is the lack of detailed knowledge of the molecular mechanisms underlying the processes of neurodegeneration. While some neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease and Amyotrophic lateral sclerosis, are mostly sporadic in nature, driven by both environment and genetic susceptibility, many others, including Huntington's disease, Spinocerebellar ataxias and Spinal-bulbar muscular atrophy, are genetically inherited disorders. Surprisingly, given their different roots and etiologies, both sporadic and genetic neurodegenerative disorders have been linked to disease mechanisms involving histone deacetylase (HDAC) proteins, which consists of 18 family members with diverse functions. While most studies have implicated certain HDAC subtypes in promoting neurodegeneration, a substantial body of literature suggests that other HDAC proteins can preserve neuronal viability. Of particular interest, however, is the recent realization that a single HDAC subtype can have both neuroprotective and neurotoxic effects. Diverse mechanisms, beyond transcriptional regulation have been linked to these effects, including deacetylation of non-histone proteins, protein-protein interactions, post-translational modifications of the HDAC proteins themselves and direct interactions with disease proteins. The roles of these HDACs in both sporadic and genetic neurodegenerative diseases will be discussed in the current review. This article is protected by copyright. All rights reserved.
    Print ISSN: 0022-3042
    Electronic ISSN: 1471-4159
    Topics: Medicine
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