116 resultados para phylogenetic community structure


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Foraminifera scientific studies became, historically, of your apply in relative dating of rocks, stratigraphic correlations and paleoenvironmental reconstruction. In the last decades, they have been applied on the studies of modern ecosystems, with or without antrhopic influence. Both aspects are interest of petroleum industry. Among other approaches, foraminífera are used as good indicators of the fluctuation of relative sea level. This study aimed to survey and taxonomic study of the community structure of foraminifera in surface samples of a core, 60 cm, collected in mangrove located in Itapanhaú river in Bertioga (SP).It also aims to contribute to the discussion about typical patterns of community structure of mangrove margins and provide elements for discussion on the relative sea level behavior in this area in almost modern times. It was been collected 6 samples along the core of 60 cm of length, each one 10 cm depth. They were made in laboratory and in each sample sought to find at least 100 foraminifera per ml. The species identification was made with reference specified material and collection available on IGCE-UNESPetro, Rio Claro. The community structure was studied in terms of richness, diversity and species composition and was made the results comparison from similar areas to interpret the depositional environment. Were found 21 species within them 13 calcareous and 8 binders, being the most abundant and frequent species Ammonia tepida, Ammonia parkinsoniana e Elphidium spp. Essentially there wasn’t change in the community structure within the period covered by the core which reflects an environment of outer margin of mangrove without noticeable change in relative sea level at the respective time of deposition of muddy sediments. The community structure here recognized its similar to estuarine environment well maintained which indicates a low human impact in the area over the time interval. The agreement of the results...

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To understand how biological phenomena emerge, the nonlinear interactions among the components envolved in these and the correspondent connected elements, like genes, proteins, etc., can be represented by a mathematical object called graph or network, where interacting elements are represented by edges connecting pairs of nodes. The analysis of various graph-related properties of biological networks has revealed many clues about biological processes. Among these properties, the community structure, i.e. groups of nodes densely connected among themselves, but sparsely connected to other groups, are important for identifying separable functional modules within biological systems for the comprehension of the high-level organization of the cell. Communities' detection can be performed by many algorithms, but most of them are based on the density of interactions among nodes of the same community. So far, the detection and analysis of network communities in biological networks have only been pursued for networks composed by one type of interaction (e.g. protein-protein interactions or metabolic interactions). Since a real biological network is simultaneously composed by protein-protein, metabolic and transcriptional regulatory interactions, it would be interesting to investigate how communities are organized in this type of network. For this purpose, we detected the communities in an integrated biological network of the Escherichia coli and Saccharomyces cerevisiae by using the Clique Percolation Method and we veri ed, by calculating the frequency of each type of interaction and its related entropy, if components of communities... (Complete abstract click electronic access below)

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Chrysomya megacephala (Fabricius), has considerable medical, veterinary and forensic importance. In insects in general, the ability to track the food substrate is due to highly sensitive organs adapted for detecting odors, particularly in the case of blowflies, which is one of carcass main consumers. Eggs of blowflies are usually aggregated in function of the behavior of other pheromone mediated by females laying eggs in place on the same substrate. One of the main reasons for studying oviposition behavior is because it may indirectly affect individual qualification, population dynamics and community structure. It has been suggested that female blowflies can evaluate the number of eggs on a substrate, decreasing the size of oviposition in very saturated substrates with larvae or eggs leading to a lower intraspecific competition. The present study investigated the oviposition behavior of females of C. megacephala, and wished to consider whether they are able to distinguish quantitatively (size of the mass) eggs previously put into a place of posture and hence indicate whether there is a limit beneficial (to avoid competition among larvae) for its oviposition on the same substrate or if that place would already be saturated, requiring find another substrate without eggs or less for futures ovipositions. With 20 females and five males, five treatments were applied, repeated ten times and analyzed using the Mann-Whitney test. Each treatment consists in placing, inside the cage, a flask with 50g of ground beef and another one in the other side, with the same amount of substrate with a certain amount of prior oviposition for a period of 5 hours. The masses prior eggs were used 0.03 g, 0.05 g, 0.1 g, 0.2 g and 0.3 g (respectively, T1, T2, T3, T4 and T5). The other part of the work consisted in the use of a “Y” olfactometer, a device used to determine the choice of an invertebrate against... (Complete abstract click electronic access below)

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In this paper, data on the fauna of Ephemeroptera and Trichoptera (ET) from a Cerrado stream was analysed in order to test the hypothesis that the high seasonality of this biome can influence the composition of ET between the wet and dry seasons. The community structure was evaluated using Detrended Correspondence Analysis and Cluster Analysis (Morisita Horn-UPGMA). Environmental factors were analyzed using the Principal Components Analysis. In order to test the effect of abiotic variables on the fauna, It was applied the Procrustean Randomization Test (Protest) and Mantel Test. The environmental factors recorded for this study had a significant effect on the ET fauna from Córrego do Pedregulho. Faunal similarity was high throughout the year, indicating that although there was density of fluctuation, due to rainfall variation, the faunal composition showed little temporal variability. On the other hand, it was possible to observe that the genus Lachlania (Ephemeroptera) occurred preferably during the rainy months and that the faunal composition during the dry season was less variable than those from other seasons. Therefore, environmental seasonality had a partial effect on the faunal composition of ET from Córrego do Pedregulho.

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This study was accomplished in existing Cerrado's relicts at State Park Guartelá, Tibagi, PR (24°39'10S and 50°15'25W), which represent one of the last extreme-meridional remanescents of this type of formation. Fifty plots with dimensions of 5x5m were allocated for phyto-sociological analysis, including in the sample individuals with height ≥ 1 m, divided into two samples to evaluate the following strata: a) upper-plants with DAS ≥ 3 cm, and b) intermediate - plants with DAS <3cm. Moreover, in each plot, there were established sub-plots with dimensions of 1x1m for sampling the lower stratum, comprised by individuals with height <1m and >10cm. The complete survey found 1340 individuals distributed in 28 families, 66 genera and 115 species. The diversity index was higher for the mean component (H'=3.30), followed by the superior component (H'=3.09) and the inferior (H'=2.91). The frequent occurrence of bushes is a remarkable characteristic of the physiognomy of the areas inside the park and 82 % of the populations studied are distributed in aggregated standard. Because it is a marginal region of occurrence of cerrado vegetation, now under the influence of a subtropical climate, more humid and cold, compared to the core area of this biome, it is noted that these areas are characterized by a decrease in stature, richness and diversity of its flora. Nevertheless, they preserve typical species of the Brazilian Savannah; but, due to their distribution in relicts and been, in part, devastated, some are included in the red list of endangered plants in Parana state, which evidences the importance of conservation and management of these areas.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Amphibian populations worldwide have been suffering declines generated by habitat degradation, loss, fragmentation and habitat split. With habitat loss and fragmentation in the landscape comes habitat split, which is the separation between the adult anuran habitat and breeding sites, forcing individuals to move through matrix during breeding seasons. Thus, habitat split increases the chance of extinction of amphibians with aquatic larval development and acts as a filter in the selection of species having great influence on species richness and community structure. The use of functional diversity allows us to consider the identity and characteristics of each species to understand the effects of fragmentation processes. The objective of this study was to estimate the effects of habitat split, as well as habitat loss in the landscape, on amphibians functional diversity (FD) and species richness (S). We selected 26 landscapes from a database with anuran surveys of Brazilian Atlantic Forest. For each landscape we calculated DF, S and landscape metrics at multiple scales. To calculate the DF we considered traits that influenced species use and persistence in the landscape. We refined maps of forest remnants and water bodies for metrics calculation. To relate DF and S (response variables) to landscape variables (explanatory variables), we used a model selection approach, fitting generalized linear models (GLMS) and making your selection with AICc. We compared the effect of model absence and models with habitat split, habitat amount and habitat connectivity effects, as well as their interaction. The most plausible models for S were the sum and interaction between habitat split in 7.5 km scale. For anurans with terrestrial development, habitat amount was the only plausible explanatory variable, in the 5 km scale. For anurans with aquatic larvae habitat amount in larger scales and the addition of habitat amount and habitat split were plausible...

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edge effect. Thus, under the influence of the adjacent matrix, fragments undergo microclimatic alterations that accentuate changes in species composition and community structure. In order to better understand edge and matrix effects on the richness and abundance of edaphic arthropods, this study assessed: (a) the difference between habitat (fragment) and non-habitat (matrix); (b) whether there is a continuous interior-edge-matrix gradient; and (c) the difference between matrices for arthropod orders richness and abundance. We selected 15 landscapes, 5 of which contained a cerrado fragment surrounded by sugarcane cultivation, 5 with a cerrado fragment within eucalyptus and 5 with a cerrado fragment within pasture. In each landscape the soil fauna was collected along with the soil and then extracted with the aid of the modified Berlese-Tullgren funnel. We chose the orders Coleoptera, Collembola, Mesostigmata and Oribatida for analysis, and after separation of the individuals we used model selection analysis via AIC. The model type fragment x matrix was the most likely to explain richness, total and relative abundances of the four orders (wAICc between 0,6623 and 1,0). The model of edge distance (edge effect) was plausible to total abundance and relative abundance of Mesostigmata order (wAICc=0,2717 and 0,186). Local environmental variables (soil texture, temperature and relative humidity), and fragment size were also measured to avoid confounding factors and were not presented as plausible models to explain the patterns. So edaphic arthropods, despite protecting themselves under the ground, are extremely sensitive to fragmentation, even with the replacement of natural habitat by agricultural use, such as sugarcane, pasture and eucalyptus. This group should be studied environmental impact assessments because provides important ecosystem se ravincde s inacnludd eisd ainn efficient bio-indicator