Environmental Gradients
Mostrando 13-24 de 107 artigos, teses e dissertações.
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13. Effect of blisters and rims on radial hydride precipitation in fuel elements under dry storage conditions
ABSTRACT Hydrogen enters in Zry clads during fuel element life in service; when hydrogen exceeds the terminal solid solubility, circumferential hydrides are precipitated. In the presence of thermal gradients, produced for instance by oxide spallation, localized concentration of hydrides - known as blisters - can be formed. Due to the fact that zirconium hydr
Matéria (Rio J.). Publicado em: 19/07/2018
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14. Prokaryotic picoplankton distribution within the oxygen minimum zone of the central Mexican Pacific across environmental gradients
Resumo O picophytoplankton marinho tornou-se uma questão importante para compreender a ecologia global das formas fototróficas, devido à sua ampla distribuição e contribuição para a biomassa e a produtividade. Estudamos os pigmentos de abundância, distribuição e assinatura do picofitoplâncton procarionte Prochlorococcus e Synechococcus durante um
Braz. j. oceanogr.. Publicado em: 2018-06
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15. Fish habitat associations along a longitudinal gradient in a preserved coastal Atlantic stream, Brazil
ABSTRACT Habitat conditions at multiple scales are one of the major factors structuring ichthyofauna. Thus, we analyzed the fish habitat associations along the headwater-mouth gradient of a coastal Atlantic stream. We categorized the sampling sites into habitat units, so that in the middle reach these categories were statistically differentiated into riffles
Zoologia (Curitiba). Publicado em: 01/02/2018
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16. Phylogenetic community structure reveals differences in plant community assembly of an oligotrophic white-sand ecosystem from the Brazilian Atlantic Forest
ABSTRACT Mussununga, an oligotrophic sandy savanna ecosystem, comprises distinct physiognomies along fire, water and nutrient availability gradients. Grasslands and woodlands are constrained at the opposite poles of these gradients, with grasslands occurring in areas with poorer soils and higher levels of both water-stress and fire intensity. According to th
Acta Bot. Bras.. Publicado em: 21/09/2017
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17. Patterns of species richness and abundance among cactus communities receiving different rainfall levels in the semiarid region of Brazil
ABSTRACT This study examines the variation in cacti species richness and abundance among sites with different average rainfall and soil types. We assessed a total of 3,660 individuals of six species of Cactaceae: Cereus jamacaru, Melocactus zehntneri, Pilosocereus gounellei, Pilosocereus pachycladus, Tacinga inamoena, and Tacinga palmadora. The greatest spec
Acta Bot. Bras.. Publicado em: 26/10/2016
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18. Distribution of the members of the Pipiens Assemblage in the sympatric area from Argentina: which is where and when?
Given their medical and veterinary relevance, the members of the Pipiens Assemblage are a worldwide target of ecological research. The distribution of Culex pipiens s.s. and Cx. quinquefasciatus converge in Buenos Aires, Argentina, where hybrids have been detected. Each member of the assemblage exhibits a distinct eco-physiological behaviour that can affect
Mem. Inst. Oswaldo Cruz. Publicado em: 24/10/2016
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19. Phenotypic plasticity associated to environmental hypoxia in the neotropical serrasalmid Piaractus mesopotamicus (Holmberg, 1887) (Characiformes: Serrasalmidae)
ABSTRACT Many South American characid fishes develop reversible dermal protuberances in the jaws to optimize aquatic surface respiration (ASR) during hypoxia. To date, basic aspects of this adaptation remain unknown, mainly due to the scarcity of experimental studies. In laboratory experiments, we determined time necessary for the complete formation and reve
Neotrop. ichthyol.. Publicado em: 20/06/2016
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20. Hydraulic architecture of lianas in a semiarid climate: efficiency or safety?
Xylem anatomical traits can provide insights regarding the mechanisms affecting the distribution of vascular plants across environmental gradients. In this study, we aimed to investigate the hypothesis that lianas occurring in semiarid environments have characteristics that maximize the xylem resistance to tension-induced cavitation along the root-stem-branc
Acta Bot. Bras.. Publicado em: 2015-06
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21. Sandfly species diversity in association with human activities in the Kani tribe settlements of the Western Ghats, Thiruvananthapuram, Kerala, India
Sandfly prevalence in the Kani tribe settlements of Western Ghats in India was investigated. A total of 1,279 sandflies comprising 17 species was obtained. Sandfly abundance showed a negative correlation (r = -0.97, p = 0.003) with increase in altitudinal ranges from 0-1,000 m. When sandfly samples were grouped according to landscape characteristics of the l
Mem. Inst. Oswaldo Cruz. Publicado em: 31/03/2015
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22. A COMUNIDADE DE MICROLIQUENS CROSTOSOS SOFRE ALTERAÇÃO AO LONGO DE GRADIENTES AMBIENTAIS NA CAATINGA? / A COMMUNITY OF SUFFERING MICROLIQUENS CROSTOSOS CHANGE ALONG ENVIRONMENTAL GRADIENTS IN CAATINGA?
Lichens are a quite diverse group of organisms and important components of the diversity of tropical forests since they act as pioneer organisms in the colonization of terrestrial environments and play various roles in ecosystems. However, studies on the ecology of lichens only in areas of Caatinga are still lacking. This study, which was held in a conservat
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/02/2012
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23. Reprodução, distribuição e padrões de co-ocorrência em uma comunidade de palmeiras na Amazônia central: Uma abordagem teórica e experimental / Main drivers controlling reproduction, distribution and co-occurrence patterns in a palm community in a terra firme Forest at central Amazonia: A theoretical and experimental approach
One of the main concerns of community ecology is to determine which factors affect species distribution. Starting from the premise that fruit production is the last step of true establishment, we match environmental gradients and the experimental approaches with help from phylogenetic tools to bring light into the mechanisms influencing palm distribution pat
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/02/2012
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24. Editorial
The inventory of fish species of the río Mamoré sub-drainage in the Bolivian Amazon is far from being complete. This article informs about a small scale species inventory in the close vicinity of the town Santa Ana del Yacuma (drained by the río Yacuma, a left side tributary of the río Mamoré). Sampling four habitat types, 615 fish specimens belonging t
Biota Neotrop.. Publicado em: 2012-12