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  • 1
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    Wiley-Blackwell ; PubMed Central
    Publication Date: 2017-10-24
    Description: The effect of pressure and temperature on microbial communities of marine environments contaminated with petroleum hydrocarbons is understudied. This study aims to reveal the responses of marine bacterial communities to low temperature, high pressure, and contamination with petroleum hydrocarbons using seawater samples collected near an offshore Brazilian platform. Microcosms containing only seawater and those containing seawater contaminated with 1% crude oil were subjected to three different treatments of temperature and pressure as follows: (1) 22°C/0.1 MPa; (2) 4°C/0.1 MPa; and (3) 4°C/22 MPa. The effect of depressurization followed by repressurization on bacterial communities was also evaluated (4°C/22 MPaD). The structure and composition of the bacterial communities in the different microcosms were analyzed by PCR-DGGE and DNA sequencing, respectively. Contamination with oil influenced the structure of the bacterial communities in microcosms incubated either at 4°C or 22°C and at low pressure. Incubation at low temperature and high pressure greatly influenced the structure of bacterial communities even in the absence of oil contamination. The 4°C/22 MPa and 4°C/22 MPaD treatments resulted in similar DGGE profiles. DNA sequencing (after 40 days of incubation) revealed that the diversity and relative abundance of bacterial genera were related to the presence or absence of oil contamination in the nonpressurized treatments. In contrast, the variation in the relative abundances of bacterial genera in the 4°C/22 MPa-microcosms either contaminated or not with crude oil was less evident. The highest relative abundance of the phylum Bacteroidetes was observed in the 4°C/22 MPa treatment. Responses of marine bacterial communities to low temperature, high pressure and contamination with petroleum hydrocarbons using seawater samples collected near an offshore Brazilian platform are revealed in this study. The highest relative abundance of the phylum Bacteroidetes was observed in the 4°C/22 MPa treatment.
    Electronic ISSN: 2045-8827
    Topics: Biology , Medicine
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  • 2
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    Wiley-Blackwell
    Publication Date: 2017-07-22
    Description: It is believed that climate change will influence most of interactions that sustain life on Earth. Among these, the recruitment exerted by plants in their roots vicinity can change, leading to differential assemblages of microbiomes in the rhizosphere. We approached this issue analyzing the variations in the composition of bacterial communities in the rhizosphere of sugarcane cultivated under two concentrations of atmospheric CO 2 (350 or 700 ppm). In addition to the analysis of bacterial community, the use of DNA-SIP allowed the comparison of bacterial groups assimilating roots exudates (based on 13 C-labeled DNA) in both conditions, in a period of 8 days after the CO 2 pulse. The separation of 13 C-DNA indicated the low but increasing frequency of labeling in the rhizosphere, as averages of 0.6, 2.4 and 5.0% of total DNA was labeled after 2, 4 and 8 days after the 13 CO 2 pulse, respectively. Based on large-scale sequencing of the V6 region in the gene 16S rRNA, we found an increase in the bacterial diversity in the 13 C-DNA along the sampling period. We also describe the occurrence of distinct bacterial groups assimilating roots exudates from sugarcane cultivated under each CO 2 concentration. Bacilli, Gammaproteobacteria and Clostridia showed high affinity for the C-sources released by sugarcane under 350 ppm of CO 2 , while under elevated concentration of CO 2 , the assimilation of roots exudates was prevalently made by members of Bacilli and Betaproteobacteria. The communities became more similar along time (4 and 8 days after CO 2 pulse), in both concentrations of CO 2 , electing Actinobacteria, Sphingobacteriia and Alphaproteobacteria as the major cross-feeders on sugarcane exudates. In summary, we described the bacterial groups with higher affinity to assimilate roots exudates in the rhizosphere of sugarcane, and also demonstrated that the rhizosphere community can be differentially assembled in a future scenario with increased contents of CO 2 . This article is protected by copyright. All rights reserved.
    Print ISSN: 1757-1693
    Electronic ISSN: 1757-1707
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Wiley-Blackwell
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  • 3
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    Wiley-Blackwell
    Publication Date: 2017-10-05
    Description: Internal organs of ectotherms have melanin-containing cells that confer different degrees of coloration to them. Previous experimental studies analyzed their developmental origin, role in immunity, and hormonal regulation. For example, melanin increases with ultraviolet radiation (UV) and temperature in frogs and fish. However, little is known about how environmental variables influence the amount of coloration on organs among amphibian species over a large spatial extent. Here, we tested how climatic variables (temperature, UV, and photoperiod) influence the coloration of internal organs of anurans. We recorded the level of melanin pigmentation using four categories on 12 internal organs and structures of 388 specimens from 43 species belonging to six anuran families. Then, we tested which climatic variables had the highest covariation with the pigmentation on each organ after controlling for spatial autocorrelation in climatic variables and phylogenetic signal in organ coloration using the extended version of the RLQ ordination. Coloration in all organs was correlated with the phylogeny. However, the coloration of different organs was affected by different variables. Specifically, the coloration of the heart, kidneys, and rectum of hylids, Rhinella schneideri , some Leptodactylus , and Proceratophrys strongly covaried with temperature and photoperiod, whereas that of the testicle, lumbar parietal peritoneum, lungs, and mesenterium of Leiuperinae, Hylodidae, Adenomera , and most Leptodactylus had highest covariation with UV-B and temperature. Our results support the notion that melanin pigmentation on the surface of organs of amphibians has an adaptive function conferred by the protective functions of the pigment. But most importantly, internal melanin seems to respond differently to climatic variables depending on the lineage and locality in which species occur. We tested the influence of UV, temperature, and photoperiod on the degree of coloration of internal organs in anurans. The melanin coloration of each organ is influenced by distinct environmental variables depending on the species and geographical distribution.
    Electronic ISSN: 2045-7758
    Topics: Biology
    Published by Wiley-Blackwell
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  • 4
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    Wiley-Blackwell
    Publication Date: 2018-02-25
    Description: The effectiveness of conservation plans depends on environmental, ecological, and socioeconomic factors. Global change makes conservation decisions even more challenging. Among others, the components of most concern in modern-day conservation assessments are as follows: the magnitude of climate and land-use changes; species dispersal abilities; competition with harmful socioeconomic activities for land use; the number of threatened species to consider; and, relatedly, the available budget to act. Here, we provide a unified framework that quantifies the relative effects of those factors on conservation. We conducted an area-scheduling work plan in order to identify sets of areas along time in which the persistence expectancies of species are optimized. The approach was illustrated using data of potential distribution of ten nonvolant mammal species in Iberia Peninsula from current time up to 2080. Analyses were conducted considering possible setups among the factors that are likely to critically impact conservation success: three climate/land-use scenarios; four species’ dispersal kernel curves; six land-use layer types; and two planning designs, in which assessments were made independently for each species, or joining all species in a single plan. We identified areas for an array of investments levels capable to circumvent the spatial conflicts with socioeconomic activities. The effect of each factor on the estimated species persistence scores was assessed using linear mixed models. Our results evidence that conservation success is highly reliant on the resources available to abate land-use conflicts. Nonetheless, under the same investment levels, planning design and climate change were the factors that most shaped species persistence scores. The persistence of five species was especially affected by the sole effect of planning design and consequently, larger conservation investments may retard climatic debts. For three species, the negative effects of a changing climate and of multiple-species planning designs added up, making these species especially at risk. Integrated assessments of the factors most likely to limit species persistence are pivotal to achieve effectiveness. There are several factors impinging the effectiveness of biodiversity conservation. In this analysis, we made a contrasting whole-integrated evaluation on the individual effects of planning design, climate, species dispersal ability, land use, and budget available for area acquisition over the persistence of ten conservation-concerning mammal species in Iberia Peninsula up to 2080 within optimal sets of areas enabling species to rearrange their distributions when following their changing suitable climate locations in future times. The effect of budget and planning designs presented the largest effects. The synergestic effects of climate with these ones are detrimental to maintain the persistence of some of the species at a secure level against extinction debts.
    Electronic ISSN: 2045-7758
    Topics: Biology
    Published by Wiley-Blackwell
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  • 5
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    Wiley-Blackwell
    Publication Date: 2017-05-15
    Description: Seasonality causes fluctuations in resource availability, affecting the presence and abundance of animal species. The impacts of these oscillations on wildlife populations can be exacerbated by habitat fragmentation. We assessed differences in bat species abundance between the wet and dry season in a fragmented landscape in the Central Amazon characterized by primary forest fragments embedded in a secondary forest matrix. We also evaluated whether the relative importance of local vegetation structure versus landscape characteristics (composition and configuration) in shaping bat abundance patterns varied between seasons. Our working hypotheses were that abundance responses are species as well as season specific, and that in the wet season, local vegetation structure is a stronger determinant of bat abundance than landscape-scale attributes. Generalized linear mixed-effects models in combination with hierarchical partitioning revealed that relationships between species abundances and local vegetation structure and landscape characteristics were both season specific and scale dependent. Overall, landscape characteristics were more important than local vegetation characteristics, suggesting that landscape structure is likely to play an even more important role in landscapes with higher fragment-matrix contrast. Responses varied between frugivores and animalivores. In the dry season, frugivores responded more to compositional metrics, whereas during the wet season, local and configurational metrics were more important. Animalivores showed similar patterns in both seasons, responding to the same group of metrics in both seasons. Differences in responses likely reflect seasonal differences in the phenology of flowering and fruiting between primary and secondary forests, which affected the foraging behavior and habitat use of bats. Management actions should encompass multiscale approaches to account for the idiosyncratic responses of species to seasonal variation in resource abundance and consequently to local and landscape scale attributes. Fragmentation is one of the most important drivers of global biodiversity loss. In this article we study the effects of seasonality on the responses of Neotropical bats to local- and landscape-scale attributes in a fragmented landscape.
    Electronic ISSN: 2045-7758
    Topics: Biology
    Published by Wiley-Blackwell
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  • 6
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    Wiley-Blackwell
    Publication Date: 2016-10-26
    Description: Physiological network functioning in the hippocampus is dependent on a balance between glutamatergic cell excitability and the activity of diverse local circuit neurons that release the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Tuners of neuronal communication such as adenosine, an endogenous modulator of synapses, control hippocampal network operations by regulating excitability. Evidence has been recently accumulating on the influence of adenosine on different aspects of GABAergic transmission to shape hippocampal function. This review addresses how adenosine, through its high-affinity A 1 (A 1 R) and A 2A receptors (A 2 A R), interferes with different GABA-mediated forms of inhibition in the hippocampus to regulate neuronal excitability. Adenosine-mediated modulation of phasic/tonic inhibitory transmission, of GABA transport mechanisms and its interference with other modulatory systems are discussed together with the putative implications for neuronal function in physiological and pathological conditions. This article is protected by copyright. All rights reserved.
    Print ISSN: 0022-3042
    Electronic ISSN: 1471-4159
    Topics: Medicine
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  • 7
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    Wiley-Blackwell
    Publication Date: 2016-03-05
    Description: Morphological variation is unevenly distributed within the mammalian skull; some of its parts have diversified more than others. It is commonly thought that this pattern of variation is mainly the result of the structural organization of the skull, as defined by the pattern and magnitude of trait covariation. Patterns of trait covariation can facilitate morphological diversification if they are aligned in the direction of selection, or these patterns can constrain diversification if oriented in a different direction. Within this theoretical framework, it is thought that more variable parts possess patterns of trait covariation that made them more capable of evolutionary change, that is, are more labile. However, differences in the degree of morphological variation among skull traits could arise despite variation in trait lability if, for example, some traits have evolved at a different rate and/or undergone stabilizing selection. Here, we test these hypotheses in the mammalian skull using 2D geometric morphometrics to quantify skull shape and estimating constraint, rates of evolution, and lability. Contrary to the expectations, more variable parts of the skull across mammalian species are less capable of evolutionary change than are less variable skull parts. Our results suggest that patterns of morphological variation in the skull could result from differences in rate of evolution and stabilizing selection. Are more diverse parts of the mammalian skull more labile? Contrary to the expectations, we provide evidence that more variable parts of the skull are less capable of evolutionary change than are less variable skull parts. Our results suggest that patterns of morphological variation in the skull could result from differences in rate of evolution and stabilizing selection.
    Electronic ISSN: 2045-7758
    Topics: Biology
    Published by Wiley-Blackwell
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  • 8
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    Wiley-Blackwell ; PubMed Central
    Publication Date: 2016-10-28
    Description: Pine wilt disease (PWD) is one of the most destructive diseases in trees of the genus Pinus and is responsible for environmental and economic losses around the world. The only known causal agent of the disease is the pinewood nematode (PWN) Bursaphelenchus xylophilus . Despite that, bacteria belonging to several different genera have been found associated with PWN and their roles in the development of PWD have been suggested. Molecular methodologies and the new era of genomics have revealed different perspectives to the problem, recognizing the manifold interactions between different organisms involved in the disease. Here, we reviewed the possible roles of nematode-carried bacteria in PWD, what could be the definition of this group of microorganisms and questioned their origin as possible endophytes, discussing their relation within the endophytic community of pine trees. The diversity of the nematode-carried bacteria and the diversity of pine tree endophytes, reported until now, is revised in detail in this review. What could signify a synergetic effect with PWN harming the plant, or what could equip bacteria with functions to control the presence of nematodes inside the tree, is outlined as two possible roles of the microbial community in the etiology of this disease. An emphasis is put on the potential revealed by the genomic data of isolated organisms in their potential activities as effective tools in PWD management. Here, we reviewed the possible roles of nematode-carried bacteria in pine wilt disease, what could be the definition of this group of microorganisms and questioned their origin as possible endophytes, discussing their relation within the endophytic community of pine trees. The diversity of the nematode-carried bacteria and the diversity of pine tree endophytes, reported until now, is revisited in detail in this review. What could signify a synergetic effect with pinewood nematode harming the plant, or what could equip bacteria with functions to control the presence of nematodes inside the tree, is outlined as two possible roles of the microbial community in the etiology of this disease.
    Electronic ISSN: 2045-8827
    Topics: Biology , Medicine
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  • 9
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    Wiley-Blackwell
    Publication Date: 2014-02-24
    Description: Guanosine, a guanine-based purine, is an extracellular signaling molecule that is released from astrocytes and shows neuroprotective effects in several in vivo and in vitro studies. Our group recently showed that guanosine presents antioxidant properties in C6 astroglial cells. The heme oxygenase 1 (HO1) signaling pathway is associated with protection against oxidative stress. Azide, an inhibitor of the respiratory chain, is frequently used in experimental models to induce oxidative and nitrosative stress. Thus, the goal of this study was to investigate the effect of guanosine on azide-induced oxidative damage in C6 astroglial cells. Azide treatment of these cells resulted in several detrimental effects, including induction of cytotoxicity and mitochondrial dysfunction, increased levels of reactive oxygen/nitrogen species, iNOS expression and NADPH oxidase, decreased glutamate uptake and EAAC1 glutamate transporter expression, decreased glutathione (GSH) levels, and decreased activities of glutamine synthetase (GS), superoxide dismutase (SOD) and catalase (CAT). The treatment also increased NFκB activation and the release of proinflammatory cytokines TNF-α and IL-1β. Guanosine strongly prevented these effects, protecting glial cells against azide-induced cytotoxicity and modulating glial, oxidative and inflammatory responses through the activation of the HO1 pathway. These observations reinforce and support the role of guanosine as an antioxidant molecule against oxidative damage. This article is protected by copyright. All rights reserved.
    Print ISSN: 0022-3042
    Electronic ISSN: 1471-4159
    Topics: Medicine
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