Implicações biológicas da plasticidade fenotípica no modelo Schistosoma mansoni - Nectomys squamipes

The water-rat Nectomys squamipes is mostly important non-human host in schistosomiasis mansoni transmission in Brazil, due to its susceptibility, high abundance and water-contact pattern. During experimental infection of N. squamipes with Schistosoma mansoni, adult worms show phenotypic plasticity. This finding led us to investigate whether biological behavior is also affected. This was assessed comparing the biological characteristics of four S. mansoni strains: BE (State of Belém do Pará), CE (State of Pernambuco), CMO (State of Rio Grande do Norte) and SJ (State of São Paulo) using laboratory-bred N. squamipes. The infection was monitored by determination of the pre-patent period, fecal egg output, egg viability, intestinal egg count and, infectivity rate. No biological modification was observed in these parameters. Overall results highlight that N. squamipes was susceptible to several S. mansoni strains, suggesting that it might contribute to the maintenance of schistosomiasis mansoni in Brazil.O rato d´água Nectomys squamipes é importante transmissor não-humano da esquistossomose. Durante a infecção experimental em N. squamipes, os vermes adultos apresentam plasticidade fenotípica. Esses achados levaram-nos a investigar se os aspectos biológicos também são afetados. Foram comparadas as características biológicas de quatro cepas de S. mansoni: BE (Estado de Belém do Pará), CM (Estado de Pernambuco), CMO (Estado do Rio Grande do Norte) e SJ (Estado de São Paulo), utilizando como modelo experimental N. squamipes criados e mantidos em laboratório. A infecção foi monitorada para a determinação do período pré-patente, eliminação de ovos nas fezes, viabilidade dos ovos, contagem de ovos retidos no intestino e infectividade. Nenhuma modificação biológica foi observada nesses parâmetros. Os resultados sugerem que o N. squamipes é susceptível a várias cepas de S. mansoni, contribuindo para a manutenção da esquistossomose no Brasil

STABILITY AND ADAPTABILITY OF EXPERIMENTAL DOUBLE HYBRIDS IN CORN

The interaction genotype-environment represent one of the most important complications in genetic improvement programs, difficulting the evaluation and advise of genetics materials with good phenotypical stability. The objective of this work was to study the phenotypical stability of double experimental corn hybrids by means of the Additive Main Effects and Multiplicative Interaction Analysis (AMMI) models. For this purpose 124 double experimental hybrids were evaluated plus 5 double commercial hybrids as controls. These hybrids were divided in 4 essay groups (6x6) with 3 repeats and installed in three different environments of the State of São Paulo (Brazil): JAB-1 and JAB-2 in Jaboticabal, during the months of December in 1995 and January in 1996, respectively, and BAR-1 in Barretos in December, 1995. We were able to conclude that the model was usefull for to detect significant differences in the behaviour of the genetics materials, even using a small number of environments. These environments were, quite different, and contributed a lot for the significance of the scores. In a situation where there are only few environments, the AMMI model seems to be very adequate for this kind of studies.A interação de genótipos com ambientes é um dos principais complicadores dos programas de melhoramento genético, pois dificulta a etapa de avaliação e recomendação de materiais genéticos de boa estabilidade fenotípica. Procurou-se nesse trabalho, estudar a estabilidade fenotípica de híbridos duplos experimentais de milho por meio do modelo dos efeitos principais aditivos e interação multiplicativa (AMMI). Avaliaram-se para esse objetivo 124 híbridos duplos experimentais mais cinco híbridos duplos comerciais como testemunhas, divididos em quatro grupos de ensaios delineados em látice 6x6 com três repetições e instalados em três ambientes distintos do estado de São Paulo: JAB-1 e JAB-2 em Jaboticabal nos meses de dezembro de 1995 e janeiro de 1996, respectivamente, e BAR-1 em Barretos em dezembro de 1995. Constatouse que o modelo em estudo mostrou diferenças significativas no comportamento dos materiais genéticos, mesmo empregando pequeno número de ambientes. Esses ambientes foram bastante contrastantes e contribuíram de maneira preponderante para a significância dos escores. Numa situação em que se tem restrições quanto ao número de ambientes para se inferir sobre a estabilidade de materiais genéticos, o emprego da metodologia AMMI mostra-se bastante adequada

The taxonomic status of the endangered thin-spined porcupine, Chaetomys subspinosus (Olfers, 1818), based on molecular and karyologic data

<p>Abstract</p> <p>Background</p> <p>The thin-spined porcupine, also known as the bristle-spined rat, <it>Chaetomys subspinosus </it>(Olfers, 1818), the only member of its genus, figures among Brazilian endangered species. In addition to being threatened, it is poorly known, and even its taxonomic status at the family level has long been controversial. The genus <it>Chaetomys </it>was originally regarded as a porcupine in the family Erethizontidae, but some authors classified it as a spiny-rat in the family Echimyidae. Although the dispute seems to be settled in favor of the erethizontid advocates, further discussion of its affinities should be based on a phylogenetic framework. In the present study, we used nucleotide-sequence data from the complete mitochondrial cytochrome <it>b </it>gene and karyotypic information to address this issue. Our molecular analyses included one individual of <it>Chaetomys subspinosus </it>from the state of Bahia in northeastern Brazil, and other hystricognaths.</p> <p>Results</p> <p>All topologies recovered in our molecular phylogenetic analyses strongly supported <it>Chaetomys subspinosus </it>as a sister clade of the erethizontids. Cytogenetically, <it>Chaetomys subspinosus </it>showed 2n = 52 and FN = 76. Although the sexual pair could not be identified, we assumed that the X chromosome is biarmed. The karyotype included 13 large to medium metacentric and submetacentric chromosome pairs, one small subtelocentric pair, and 12 small acrocentric pairs. The subtelocentric pair 14 had a terminal secondary constriction in the short arm, corresponding to the nucleolar organizer region (Ag-NOR), similar to the erethizontid <it>Sphiggurus villosus</it>, 2n = 42 and FN = 76, and different from the echimyids, in which the secondary constriction is interstitial.</p> <p>Conclusion</p> <p>Both molecular phylogenies and karyotypical evidence indicated that <it>Chaetomys </it>is closely related to the Erethizontidae rather than to the Echimyidae, although in a basal position relative to the rest of the Erethizontidae. The high levels of molecular and morphological divergence suggest that <it>Chaetomys </it>belongs to an early radiation of the Erethizontidae that may have occurred in the Early Miocene, and should be assigned to its own subfamily, the Chaetomyinae.</p

Parasitological and morphological study of Schistosoma mansoni and diabetes mellitus in mice

AbstractSchistosomes are blood-dwelling flukes which are highly dependent on the host metabolism. The aim of this study was to investigate possible relationship between streptozotocin-induced diabetes and the outcome of acute murine schistosomiasis mansoni. Male and female SW mice were treated by a single intraperitoneally injected dose of streptozotocin (180mg/kg). Seven days after induction, both control and diabetic animals were infected with 70 Schistosoma mansoni cercariae (BH strain). Diabetics and their controls were weighed 45days after birth and for the last time prior to killing. Susceptibility to infection was evaluated twice a week by quantifying fecal egg excretion 7–9weeks post-infection by the Kato–Katz’ thick smear method. Mice were euthanized the day after the last fecal examination was performed. Adult worms were recovered from the portal system and mesenteric veins, whereas liver and intestine were removed for enumeration of egg load. No differences in worm length or in measurements of the reproductive organs, tegument, and suckers were detected. Also oviposition was unaffected as the total number of eggs per female worm from the liver, the small and the large intestine was the same in both groups. An oogram evaluation revealed a lower percentage of mature (23.0% vs. 40.7%) and a higher percentage of immature (69.1% vs. 51.7%) eggs in the small intestine of the diabetic mice. We suggest that principally a hampered egg passage through the intestine tissue caused this reduction and that probably both the eggs and the impaired host response play a role

O paradigma Estrutura-Conduta-Desempenho: um estudo nas empresas das indústrias de jóias de Guaporé - RS

Objective of the study: This study aimed to understand how the structure of the industry and the conduct of the business organization influence the performance of companies that composes the jewelry industry in Guaporé-RS. Methodology: The authors carried out an exploratory research, with a qualitative and quantitative approach, characterized as a study of multiple cases. A structured script was used as a data collection instrument, elaborated from analysis categories that emerged from the literature review.Originality: This is an unprecedented study of the application of the ECD theoretical model to the jewelry industry in Guaporé-RS. Main results: As a main result, the authors highlight that, in the perception of the study participants, the structure of the jewelry industry in Guaporé has an influence on the conduct of its members and this, in turn, has influenced the performance of companies and the industry as a whole. It was possible to understand how the processes of choice and implementation of the adopted strategy are carried out, in addition to identifying the influences on the definition of how to compete and the results obtained from these choices. Theoretical / methodological contributions: As the ECD model has not been applied in this sector, his theoretical proposal broadens the understanding of the complexity of the behavior of industry actors, the understanding of the strategies that companies use and, especially, the performance they achieve from their performance in scenarios of extreme competition. Social / management contributions: It results from the data obtained from the studied industry, since it will be able to expand the knowledge of the participants and enable the projection of future scenarios, strengthening the industry as a whole.Objetivo do estudo: Este estudo objetivou compreender como a estrutura da indústria e a conduta da organização empresarial influenciam o desempenho das empresas que integram a indústria de joias de Guaporé-RS. Método: Realizou-se uma pesquisa de caráter exploratório, com abordagem qualitativa e quantitativa, caracterizando-se como um estudo de casos múltiplos. Utilizou-se como instrumento de coleta de dados um roteiro estruturado, elaborado a partir de categorias de análise que emergiram da revisão de literatura. Originalidade: Trata-se de um estudo inédito da aplicação do modelo teórico ECD à indústria de joias de Guaporé-RS. Principais resultados: Como principal resultado, destaca-se que na percepção dos participantes do estudo, a estrutura da indústria de joias de Guaporé tem influência sobre a conduta de seus integrantes e esta, por sua vez, tem influenciado o desempenho das empresas e da indústria como um todo. Foi possível compreender como os processos de escolha e implementação da estratégia adotada são realizados, além de identificar as influências na definição da maneira como competir e os resultados obtidos a partir dessas escolhas. Contribuições teóricas/metodológicas: A proposta teórica do modelo ECD, por não ter sido aplicada neste setor, amplia o entendimento da complexidade do comportamento dos atores da indústria, o entendimento das estratégias que as empresas utilizam e, especialmente, o desempenho que elas alcançam a partir de sua atuação em cenários de extrema competição. Contribuições sociais/de gestão: Decorre dos dados obtidos junto à indústria estudada, uma vez que poderá ampliar o conhecimento dos participantes e possibilitar a projeção de cenários futuros, fortalecendo a indústria como um todo

Spatial disaggregation of multi-component soil map units using legacy data and a tree-based algorithm in southern Brazil

Soil surveys often contain multi-component map units comprising two or more soil classes, whose spatial distribution within the map unit is not represented. Digital Soil Mapping tools supported by information from soil surveys make it possible to predict where these classes are located. The aim of this study was to develop a methodology to increase the detail of conventional soil maps by means of spatial disaggregation of multi-component map units and to predict the spatial location of the derived soil classes. Three digital maps of terrain variables - slope, landforms, and topographic wetness index - were correlated with the soil map and 72 georeferenced profiles from the Porto Alegre soil survey. Explicit rules that expressed regional soil-landscape relationships were formulated based on the resulting combinations. These rules were used to select typical areas of occurrence of each soil class and to train a decision tree model to predict the occurrence of individualized soil classes. Validation of the soil map predictions was conducted by comparison with available soil profiles. The soil map produced showed high agreement (80.5 % accuracy) with the soil classes observed in the soil profiles; Ultisols and Lithic Udorthents were predicted with greater accuracy. The soil variables selected in this study were suitable to represent the soil-landscape relationships, suggesting potential use in future studies. This approach developed a more detailed soil map relevant to current demands for soil information and has potential to be replicated in other areas in which data availability is similar

Revalidação do painel sorológico empregado na avaliação dos kits de diagnóstico da doença de Chagas

Introduction: Acute phase of Chagas disease is characterised by the presence of blood parasites while in the chronic phase, parasite titres decrease and antibodies increase.  According to RDC nº 36, of August 26, 2015, diagnostic tests for the disease belong to risk class IV, with mandatory registration with the National Health Surveillance Agency. The performance of these products is assessed in the laboratory analysis prior to registration, against serological panels composed of true positive and negative samples. Objective:  Revalidate the serological panel composed of true positive samples for Chagas disease  used in the analysis of in vitro diagnostic kits for the detection of specific antibodies against Trypanosoma cruzi. Method: Revalidation of the Chagas serological panel by retrospective analysis of results obtained in the methodologies: ELISA, Rapid Test, Immunofluorescence, Agglutination, Hemagglutination and Chemiluminescence, meeting the criteria of: positivity in 02 Rapid Tests; 03 Immunofluorescences; 01 Agglutination Test; 05 ELISAS, 02 Hemagglutination Tests, 03 Chemiluminescences and volume ≥ 10 mL. Results: 45 kits with a satisfactory report were selected, being 60.0% ELISA, 16.0% immunofluorescence, 11.0%  chemiluminescence, 7.0%  hemagglutination, 4.0% immunochromatographic test and 2.0% agglutination. 160 records were evaluated, 56.2% of which were destined for ELISA, 14.4% of chemiluminescence, 13.1% of immunoflurescence, 8.1% of hemagglutination, 5.6% of rapid tests and 2.5% of agglutination. A standardized spreadsheet was prepared to insert the data in Excel® and evaluate the samples against the methodologies. A total of 64 samples were revalidated. Conclusions: The revalidated Panel, composed of 64 samples, was characterized and its use guarantees reliable results, expanding the analytical capacity of the Laboratory of Blood and Blood Products in the quality control of diagnostic kits.Introdução: A doença de Chagas apresenta infecção aguda com alta parasitemia e crônica com queda da parasitemia e aumento de anticorpos. Segundo a RDC nº 36, de 26 de agosto de 2015, os testes de diagnóstico da doença pertencem à classe de risco IV, com obrigatoriedade de registro junto a Agência Nacional de Vigilância Sanitária. O desempenho desses produtos é avaliado na análise laboratorial prévia ao registro, frente a painéis sorológicos compostos por amostras verdadeiro-positivas e negativas. Objetivo: Revalidar o painel sorológico composto de amostras verdadeiro-positivas para doença de Chagas utilizado na análise de kits de diagnóstico in vitro destinados à detecção de anticorpos específicos contra Trypanosoma cruzi. Método: Revalidação do painel sorológico de Chagas por análise retrospectiva de resultados obtidos nas metodologias: ELISA, teste imunocromatográfico, imunofluorescência, aglutinação, hemaglutinação e quimioluminescência, atendendo aos critérios de: positividade em dois testes rápidos; três imunofluorescências; um teste de aglutinação; cinco ELISA, dois testes de hemaglutinação; três de quimioluminescências e  volume ≥ 10 mL. Resultados: Foram selecionados 45 kits com laudo satisfatório, sendo 60,0% ELISA, 16,0%  imunofluorescência, 11,0% quimioluminescência, 7,0% hemaglutinação,  4,0% teste imunocromatográfico e 2,0% aglutinação. Foram avaliados 160 registros nos quais, 56,2% destinados a ELISA, 14,4% de quimioluminescência, 13,1% de imunoflurescência,  8,1% de hemaglutinação, 5,6% de testes rápidos e 2,5% de aglutinação. Foi elaborada uma planilha padronizada para inserção dos dados em Excel® e avaliação das amostras frente às metodologias. Um total de 64 amostras foi revalidado. Conclusões: O painel revalidado, composto por 64 amostras, foi caracterizado e seu uso garante resultados confiáveis, ampliando a capacidade analítica do Laboratório de Sangue e Hemoderivados no controle de qualidade de kits para diagnóstico

Individualização de classes de solos por desagregação de polígonos de mapa fisiográfico

The objective of this work was to disaggregate the polygons of physiographic map units in order to individualize the soil classes in each one, representing them as simple soil map units and generating a more detailed soil map than the original one, making these data more useful for future reference. A physiographic map, on a 1:25,000 scale, of the Tarumãzinho watershed, located in the municipality of Águas Frias, in the state of Santa Catarina, Brazil, was used. For disaggregation, three geomorphometric parameters were applied: slope and landforms, both derived from the digital terrain model; and an elevation map. The boundaries of the physiographic units and the elevation, slope, and landform maps were subjected to cross tabulation to identify the existing combinations between the soil classes of each physiographic unit. Based on these combinations, rules were established to select typical areas of occurrence of each soil type in order to train a decision tree model to predict the occurrence of soil classes. The model was trained using the Weka software and was validated with a set of georeferenced soil profiles. Disaggregation enables the individualization and spatialization of soil classes and is useful in producing detailed soil maps.O objetivo deste trabalho foi desagregar os polígonos de mapas de unidades fisiográficas, de modo a individualizar as classes de solos ocorrentes em cada unidade, para representá-las como unidades de mapeamento simples de solos e gerar um mapa de solos com maior detalhe cartográfico que o mapa original, ampliando a utilidade desses dados em demandas futuras. Foi utilizado um mapa fisiográfico, em escala 1:25.000, da microbacia Córrego Tarumãzinho, localizada no Município de Águas Frias, no Estado de Santa Catarina. Para realizar a desagregação, foram utilizados três parâmetros geomorfométricos: declividade e formas do terreno, ambas derivadas do modelo digital do terreno; e mapa de elevação. Os limites das unidades fisiográficas e os mapas de elevação, declividade e formas do terreno foram submetidos à tabulação cruzada para identificar as combinações existentes entre as classes de solos que compõem cada unidade fisiográfica. A partir dessas combinações, foram elaboradas regras para selecionar áreas de ocorrência típica de cada tipo de solo, para treinar um modelo de árvores de decisão para predição da ocorrência das classes de solos. O treinamento do modelo foi realizado no programa Weka, e a sua validação foi feita com um conjunto de perfis de solos georreferenciados. A desagregação possibilita a individualização e a espacialização das classes de solos e é útil para a produção de mapas de solos detalhados