Avaliação dos impactos econômicos, sociais e ambientais de tecnologias da Embrapa Pecuária Sudeste. 4. Técnicas de produção intensiva aplicadas a propriedades familiares produtoras de leite.

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High genetic diversity but low population structure in the frog Pseudopaludicola falcipes (Hensel, 1867) (Amphibia, Anura) from the Pampas of South America

Relative to South America’s ecoregions, the temperate grasslands of the Pampas have been poorly studied from a phylogeographic perspective. Based on an intermediate biogeographic setting between subtropical forest (Atlantic Forest) and arid ecosystems (Chaco and Patagonia), Pampean species are expected to show unstable demographic histories due to the Quaternary climatic oscillations. Herein, we investigate the phylogenetic relatedness and phylogeographic history of Pseudopaludicola falcipes, a small and common frog that is widely distributed across the Pampean grasslands. First, we use molecular data to assess if P. falcipes represents a single or multiple, separately evolving cryptic lineages. Because P. falcipes is a small-size species (\u3c20 mm) with extensive coloration and morphological variation, we suspected that it might represent a complex of cryptic species. In addition, we expected strong genetic and geographic structuring within Pseudopaludicola falcipes due to its large geographic distribution, potentially short dis- persal distances, and multiple riverine barriers. We found that P. falcipes is a single evolutionary lineage with poor geographic structuring. Furthermore, current populations of P. falcipes have a large effective population size, maintain ancestral polymorphisms, and have a complex network of gene flow. We conclude that the demographic history of P. falcipes, combined with its ecological attributes and the landscape features of the Pampas, favored a unique combination among anurans of small body size, large population size, high genetic variability, but high cohesiveness of populations over a wide geographic distribution

ARE Leptodactylus didymus AND L. mystaceus PHYLOGENETICALLY SIBLING SPECIES (AMPHIBIA, ANURA, LEPTODACTYLIDAE)?

The Leptodactylus fuscus species group consists of 25 currently recognized species; within this species group and distributed throughout the Amazon Basin, Atlantic Forests, Gran Chaco, and cerrados is the L. mystaceus species complex. This species complex consists of L. didymus, L. elenae, L. mystaceus, L. notoaktites, and L. spixi. Adult morphologies have been used to distinguish these species from each other except for L. didymus and L. mystaceus (Heyer, 1978; Heyer et al., 1996). Leptodactylus didymus and L. mystaceus are morphologically indistinguishable; the species are recognizable only by the characteristics of their advertisement calls: non-pulsed in L. didymus and pulsed in L. mystaceus (Heyer et al., 1996). Traditionally, L. mystaceus and L. didymus have been considered sibling species. The concept of sibling species was originally introduced by Mayr (1942: 151) to describe pairs or groups of morphologically identical or nearly identical species; however, in subsequent work Mayr (1976) interchangeably used the terms sibling and cryptic species to describe morphologically similar species. Mayr (1942: 151) considered sibling species to be important in understanding the full complexity of animal speciation. In order to differentiate these two terms, herein we take a narrow cladistic methodological approach (i.e., dichotomous speciation) by which we restrict the term sibling species to two taxa that share a most recent common ancestor; whereas, the term cryptic (derived from the Greek Kruptos, meaning \u27hidden\u27; Allaby, 1991) species refers to hidden diversity and does not necessarily imply close phylogenetic relationship. Thus, the sibling species pair of L. didymus and L. mystaceus assumes two postulates: (1) the taxa shared a most recent common ancestor not shared with other species in the L. mystaceus species complex and (2) the two taxa could represent a recent speciation event (i.e., not enough time has passed to reach morphological differentiation, although this is not a requisite). Herein, we analyze the genetic diversity among taxa in this species complex to determine if the sibling species L. didymus and L. mystaceus are sister taxa. If the assumptions about sibling species are correct, then we would expect that the two taxa involved would be genetically closer between themselves than with any other closely related species

Are \u3cem\u3eLeptodactylus didymus\u3c/em\u3e and \u3cem\u3eL. mystaceus\u3c/em\u3e Phylogenetically Sibling Species (Amphibia, Anura, Leptodactylidae)?

The Leptodactylus fuscus species group consists of 25 currently recognized species; within this species group and distributed throughout the Amazon Basin, Atlantic Forests, Gran Chaco, and cerrados is the L. mystaceus species complex. This species complex consists of L. didymus, L. elenae, L. mystaceus, L. notoaktites, and L. spixi. Adult morphologies have been used to distinguish these species from each other except for L. didymus and L. mystaceus (Heyer, 1978; Heyer et al., 1996). Leptodactylus didymus and L. mystaceus are morphologically indistinguishable; the species are recognizable only by the characteristics of their advertisement calls: non-pulsed in L. didymus and pulsed in L. mystaceus (Heyer et al., 1996). Traditionally, L. mystaceus and L. didymus have been considered sibling species. The concept of sibling species was originally introduced by Mayr (1942: 151) to describe pairs or groups of morphologically identical or nearly identical species; however, in subsequent work Mayr (1976) interchangeably used the terms sibling and cryptic species to describe morphologically similar species. Mayr (1942: 151) considered sibling species to be important in understanding the full complexity of animal speciation. In order to differentiate these two terms, herein we take a narrow cladistic methodological approach (i.e., dichotomous speciation) by which we restrict the term sibling species to two taxa that share a most recent common ancestor; whereas, the term cryptic (derived from the Greek Kruptos, meaning \u27hidden\u27; Allaby, 1991) species refers to hidden diversity and does not necessarily imply close phylogenetic relationship. Thus, the sibling species pair of L. didymus and L. mystaceus assumes two postulates: (1) the taxa shared a most recent common ancestor not shared with other species in the L. mystaceus species complex and (2) the two taxa could represent a recent speciation event (i.e., not enough time has passed to reach morphological differentiation, although this is not a requisite). Herein, we analyze the genetic diversity among taxa in this species complex to determine if the sibling species L. didymus and L. mystaceus are sister taxa. If the assumptions about sibling species are correct, then we would expect that the two taxa involved would be genetically closer between themselves than with any other closely related species

Phylogenetic analyses of mtDNA sequences reveal three cryptic lineages in the widespread neotropical frog Leptodactylus fuscus (Schneider, 1799) (Anura, Leptodactylidae)

Leptodactylus fuscus is a neotropical frog ranging from Panamá to Argentina, to the east of the Andes mountains, and also inhabiting Margarita, Trinidad, and the Tobago islands. We performed phylogenetic analyses of 12S rRNA, 16S rRNA, tRNA-Leu, and ND1 mitochondrial (mt) DNA sequences from specimens collected across the geographic distribution of L. fuscus to examine two alternative hypotheses: (i) L. fuscus is a single, widely distributed species, or (ii) L. fuscus is a species complex. We tested statistically for geographic association and partitioning of genetic variation among mtDNA clades. The mtDNA data supported the hypothesis of several cryptic species within L. fuscus. Unlinked mtDNA and nuclear markers supported independently the distinctness of a ‘northern’ phylogenetic unit. In addition, the mtDNA data divided the southern populations into two clades that showed no sister relationship to each other, consistent with high differentiation and lack of gene flow among southern populations as suggested by allozyme data. Concordance between mtDNA and allozyme patterns suggests that cryptic speciation has occurred in L. fuscus without morphological or call differentiation. This study illustrates a case in which lineage splitting during the speciation process took place without divergence in reproductive isolation mechanisms (e.g. advertisement call in frogs), contrary to expectations predicted using a biological species framework

Phylogeography of the frog Leptodactylus validus (Amphibia: Anura): Patterns and timing of colonization events in the Lesser Antilles

The frog Leptodactylus validus occurs in northern South America, Trinidad and Tobago, and the southern Lesser Antilles (Grenada and St. Vincent). Mitochondrial DNA sequences were used to perform a nested clade phylogeographic analysis (NCPA), to date colonization events, and to analyze colonization patterns using on a relaxed molecular clock and coalescent simulations. L. validus originated on the mainland and first colonized Trinidad with subsequent independent colonizations of Tobago and the Lesser Antilles from Trinidad. The NCPA suggests a historical vicariant event between populations in Trinidad and Tobago from those in the Lesser Antilles. The colonization of Trinidad occurred 1 million years ago (mya) and the colonization of the Lesser Antillean islands occurred 0.4 mya. The coalescent approach supported the scenario where L. validus dispersed from Trinidad to St. Vincent and from there to Grenada, a dispersal event that could have been mediated by human introduction as recent as 1600 years ago

Eficiência Relativa de Agricultores Familiares na Produção de Leite.

O objetivo deste trabalho foi avaliar a eficiência relativa na produção de leite de uma amostra de agricultores familiares do Estado do Paraná, que estão sob orientação técnica de extensionistas participantes do Projeto Balde Cheio. A avaliação foi feita utilizando-se o Método de Envelopamento de Dados ? DEA. A média da eficiência da amostra analisada foi de 92% evidenciando que o grupo de produtores foi muito eficiente na gestão da tecnologia empregada e a importância do extensionista como agente de transferência de tecnologia

Adsorção e dessorção competitivas de Cd, Cu, Ni, Pb e Zn em amostras de um Latossolo vermelho amarelo distroférrico até 5 m de profundidade

As características químicas e mineralógicas do solo sofrem modificações nos diferentes horizontes do perfil e também dentro de um mesmo horizonte com o aumento da profundidade. Em Latossolos este fato muitas vezes talvez não seja muito intenso. A variação de diferentes atributos ao longo do perfil influencia a mobilidade de metais, uma vez que a interação dos íons com as superfícies reativas é decorrente destes atributos, influenciando assim na adsorção e dessorção dos metais no solo, podendo levar à contaminação da água subterrânea. Neste trabalho são apresentados os resultados de experimentos de adsorção competitiva, e dessorção, de Cd, Cu, Ni, Pb e Zn, em amostras de um Latossolo vermelho amarelo distroférrico, que recebeu lodo de esgoto em superfície, coletadas de 0 a 5 metros de profundidade, e das variações dos principais atributos destas amostras. As amostras foram coletadas nas profundidades 0 (topo); 1; 2; 3; 4 e 5 (base) metros no campo experimental da EMBRAPA Meio Ambiente (Jaguariúna-SP), num Latossolo vermelho amarelo distroférrico, onde está sendo aplicado lodo de esgoto. Todos os ensaios foram realizados com amostras da fração argila. As amostras tiveram suas características químicas (pH, capacidade de troca de cátions-CTC, matéria orgânica-MO, ponto de efeito salino nulo-PESN) e o teor de óxidos de Fe, determinados segundo Camargo et al. (1986). As determinações mineralógicas foram obtidas por difratometria de raios-x