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| Registros recuperados: 15 | |
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| Diniz-Filho,José Alexandre Felizola; Oliveira,Guilherme de; Lobo,Fábio; Ferreira,Laerte Guimarães; Bini,Luis Mauricio; Rangel,Thiago Fernando Lopes Valle Brito. |
| The Cerrado biome, the second largest biome in Neotropical region, consists of a mosaic of different habitat types, ranging from open grasslands to dense woodlands and dry forests. An intensive recent occupation process has transformed it into the most important region for cattle ranching and intensive commodity crops in Brazil. In this study, a macroecological approach was used to evaluate broad-scale spatial patterns of habitat loss in the Brazilian Cerrado, applying a series of spatial autocorrelation and partial regression analyses to understand how the proportion of remaining natural habitats is correlated with socio-economic variables, expressing different dimensions of human occupation and climatic variation. On average, 59% of the area is occupied... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: MODIS; Brazilian Cerrado; Spatial autocorrelation. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000600007 |
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| Cunha,Hélida Ferreira da; Diniz-Filho,José Alexandre Felizola; Brandão,Divino. |
| Abundace and body size distribution of invertebrates of leaf litter in Amazonian forest, Brazil. Based on 605 invertebrates sampled of the litter in an Amazonian Forest, some basic macroecological patterns for this assemblage were described. The relationship between abundance and body size, at logarithmic scale, was triangular, and the distribution of species was constrained in an asymmetric triangular envelope, that was tested using null model procedures in ECOSIM (P= 0,0002). The most abundant species were at an intermediated body size. The relationship between maximum abundance with different mean body size classes confirmed the Energetic Equivalent Rule (b = -1,069; t-0,75 = -2,13; P = 0.079). This way, species tend to consume energy from the community... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Abundance; Body size; Energetic Equivalence Rule; Invertebrates; Triangular pattern. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0085-56262003000100009 |
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| Soares,Thannya Nascimento; Chaves,Lázaro José; Telles,Mariana Pires de Campos; Diniz-Filho,José Alexandre Felizola; Resende,Lucileide Vilela. |
| O objetivo deste trabalho foi avaliar o padrão espacial da variabilidade genética entre plantas, dentro de três populações naturais de barueiro (Dipteryx alata Vogel), pela genotipagem por RAPD e técnicas de autocorrelação espacial. Os cinco iniciadores RAPD permitiram a codificação de 45 locos, utilizados nas análises de diversidade, estrutura e distribuição espacial da variabilidade genética entre populações. As populações apresentaram diversidade genética (Hs) com valor médio 0,314. Verificou-se que 12% da variação total se encontra entre as populações, o que indica que estas mantêm um considerável nível de variabilidade genética. Foi observada tendência de autocorrelação espacial positiva nas primeiras classes de distâncias, nas três populações, o que... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Autocorrelação espacial; Baru; Conservação; Estrutura familiar; Fluxo gênico; RAPD. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2008000900008 |
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| Rodrigues,Flávia Melo; Diniz-Filho,José Alexandre Felizola. |
| Geographic structure of genetic distances among local populations within species, based on allozyme data, has usually been evaluated by estimating genetic distances clustered with hierarchical algorithms, such as the unweighted pair-group method by arithmetic averages (UPGMA). The distortion produced in the clustering process is estimated by the cophenetic correlation coefficient. This hierarchical approach, however, can fail to produce an accurate representation of genetic distances among populations in a low dimensional space, especially when continuous (clinal) or reticulate patterns of variation exist. In the present study, we analyzed 50 genetic distance matrices from the literature, for animal taxa ranging from Platyhelminthes to Mammalia, in order... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571998000200010 |
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| Telles,Mariana Pires de Campos; Diniz-Filho,José Alexandre Felizola. |
| An Ornstein-Uhlenbeck process was used to simulate the exponential relationship between genetic divergence and geographic distances, as predicted by stochastic processes of population differentiation, such as isolation-by-distance, stepping-stone or coalescence models. These simulations were based only on the spatial coordinates of the local populations that defined a spatial unweighted pair-group method using arithmetic averages (UPGMA) link among them. The simulated gene frequency surfaces were then analyzed using spatial autocorrelation procedures and Nei's genetic distances, constructed with different numbers of variables (gene frequencies). Stochastic divergence in space produced strong spatial patterns at univariate and mutivariate levels. Using a... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400007 |
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| Diniz-Filho,José Alexandre Felizola; Sant'Ana,Carlos Eduardo Ramos de. |
| During the last few years, many models have been proposed to link microevolutionary processes to macroevolutionary patterns, defined by comparative data analysis. Among these, Brownian motion and Ornstein-Uhlenbeck (O-U) processes have been used to model, respectively, genetic drift or directional selection and stabilizing selection. These models produce different curves of pairwise variance between species against time since divergence, in such a way that different profiles appear in phylogenetic correlograms. We analyzed variation in body length among 19 species of South American owls, by means of phylogenetic correlograms constructed using Moran's I coefficient in four distance classes. Phylogeny among species was based on DNA hybridization. The... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000200008 |
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| Registros recuperados: 15 | |
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