280 research outputs found

    A review of techniques for spatial modeling in geographical, conservation and landscape genetics

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    Most evolutionary processes occur in a spatial context and several spatial analysis techniques have been employed in an exploratory context. However, the existence of autocorrelation can also perturb significance tests when data is analyzed using standard correlation and regression techniques on modeling genetic data as a function of explanatory variables. In this case, more complex models incorporating the effects of autocorrelation must be used. Here we review those models and compared their relative performances in a simple simulation, in which spatial patterns in allele frequencies were generated by a balance between random variation within populations and spatially-structured gene flow. Notwithstanding the somewhat idiosyncratic behavior of the techniques evaluated, it is clear that spatial autocorrelation affects Type I errors and that standard linear regression does not provide minimum variance estimators. Due to its flexibility, we stress that principal coordinate of neighbor matrices (PCNM) and related eigenvector mapping techniques seem to be the best approaches to spatial regression. In general, we hope that our review of commonly used spatial regression techniques in biology and ecology may aid population geneticists towards providing better explanations for population structures dealing with more complex regression problems throughout geographic space

    Estudo da curva de ganho de peso como parâmetro do desenvolvimento físico de ratas expostas ao herbicida sulfentrazona.

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    Foram realizados estudos sobre o efeito do sulfentrazona no ganho de peso de ratas Wistar expostas a doses distintas do herbicida, durante períodos distintos de prenhez. As técnicas utilizadas para avaliar os efeitos dos fatores (fase de prenhez e dose de fungicida) e de suas interações na resposta foram modelo de medidas repetidas, LSD (Least Squares Difference) e técnicas de Comparações Múltiplas.Relatório Técnico do Departamento de Estatística

    Complicações neurológicas em transplantes cardíacos

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    OBJECTIVE: Neurologic complications are known as important cause of morbidity and mortality in orthotopic heart transplantation. Our aim was to identify the frequency and outcome of neurologic complications after heart transplantation in a prospective observational study. METHOD: From September 93 to September 99, as part of our routine heart transplantation protocol all patients with end-stage cardiac failure were evaluated by the same neurologist before and at the time of any neurologic event (symptom or complaint) after transplantation. RESULTS: Out of 120 candidates evaluated, 62 were successfully transplanted (53 male; median age 45.5 years, median follow-up 26.8 months). Fifteen patients (24%) had ischemic, 22 (35%) idiopathic, 24 (39%) Chagas' disease and 1 (2%) had congenital cardiomyopathy. Neurologic complications occurred in 19 patients (31%): tremor, severe headache, transient encephalopathy and seizures related to drug toxicity or metabolic changes in 13; peripheral neuropathy in 4; and spinal cord compression in two (metastatic prostate cancer and epidural abscess). No symptomatic postoperative stroke was observed. CONCLUSIONS: Although frequent, neurologic complications were seldom related to persistent neurologic disability or death. Most of the complications resulted from immunosuppression, however, CNS infection was rare. The absence of symptomatic stroke in our series may be related to the lower frequency of ischemic cardiomyopathy.OBJETIVO: Complicações neurológicas são frequentemente descritas como causa de morbidade e mortalidade em transplantes cardíacos. Nosso objetivo foi avaliar a frequência de complicações neurológicas em pacientes submetidos a transplantes cardíacos, bem como sua evolução, através de um estudo prospectivo observacional. MÉTODO: Todos os candidatos a transplantes cardíacos foram avaliados pelo mesmo neurologista, como parte do protocolo de rotina de avaliação pré-transplante no período de 9/93 a 9/99. Após a cirurgia, os pacientes foram reavaliados sempre que houvesse qualquer sintoma ou queixa neurológica. RESULTADOS: Entre 120 pacientes avaliados no período pré-operatório, 62 foram transplantados (53 sexo masculino; idade mediana de 45.5 anos; tempo de seguimento mediano 26.8 meses). A etiologia da miocardiopatia foi isquêmica em 15 pacientes (24%), idiopática em 22 (35%), chagásica em 24 (39%) e congênita em 1 (2%). Complicações neurológicas ocorreram em 19 pacientes (31%): tremor, cefaléia intensa, encefalopatia transitória ou crises relacionados com toxicidade medicamentosa ou alterações metabólicas em 13; neuropatia periférica em 4; compressão medular em 2 (metástase epidural de carcinoma de próstata e abscesso epidural). Nenhum paciente apresentou acidente vascular cerebral (AVC) sintomático no período pós-operatório. CONCLUSÕES: Apesar de frequentes, as complicações neurológicas raramente provocaram seqüelas permanentes ou óbito. A maior parte das complicações foi relacionada com imunossupressão, entretanto, infecções foram raras. A ausência de pacientes com AVC sintomático pode estar associada com a baixa frequência de miocardiopatia isquêmica na presente série.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of NeurologyUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of CardiologyUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of Infectious DiseasesUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of Cardiovascular SurgeryUNIFESP, EPM, Department of NeurologyUNIFESP, EPM, Department of CardiologyUNIFESP, EPM, Department of Infectious DiseasesUNIFESP, EPM, Department of Cardiovascular SurgerySciEL

    A comunidade de insetos endófagos de Asteraceae em Cerrados de São Paulo

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    A survey of the endophagous insects fauna associated to Asteraceae capitula was carried out from 2000 to 2002 in eight cerrado sensu stricto sites located in the Brazilian state of São Paulo. Sixty-four endophagous species of Diptera and Lepidoptera were recorded from 49 asteracean host plants. Approximately half of the species were obtained from a single locality, with a large proportion emerging from a single sample (unicates). Thirty percent of the species were singletons (i.e. only one individual was recorded). The large proportion of rare species suggests a high species turnover among localities. Lepidopteran species were recorded on more host species than dipterans, confirming their more polyphagous food habit, also observed in other Brazilian biomes and in Europe. We conclude that the studied cerrado localities, all within São Paulo State, are isolated with its invertebrate fauna composed of many rare and exclusive species. We suggest that the maintenance of Asteraceae biodiversity and their endophagous insects depend on the conservation of all cerrado remnants in the state.No presente estudo foi realizado um levantamento da fauna de insetos endófagos de capítulos de Asteraceae (Compostas), de 2000 a 2002, em oito localidades de cerrados sensu stricto no estado de São Paulo. Foram obtidas 64 espécies de endófagos (dípteros e lepidópteros) de 49 espécies de hospedeiras. Aproximadamente metade das espécies foi obtida de apenas uma área, e destas uma grande proporção ocorreu em apenas uma amostra (unicatas). Trinta por cento das espécies foram consideradas singletons (apenas um indivíduo foi obtido). A grande quantidade de espécies raras sugere uma forte troca de espécies entre diferentes áreas. Lepidópteros foram registrados em mais espécies hospedeiras que dípteros, confirmando o já observado para o mesmo sistema de insetos e plantas em outros ambientes no Brasil e Europa. As áreas de cerrado sensu stricto estudadas no estado de São Paulo encontram-se isoladas, com uma grande parte da fauna de invertebrados composta por muitas espécies raras e exclusivas. Diante deste quadro, sugere-se que a manutenção da biodiversidade de Asteraceae e seus endófagos em seus níveis atuais depende da conservação de todo o conjunto de remanescentes de cerrado do estado.458468Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Is the expansion of sugarcane over pasturelands a sustainable strategy for Brazil's bioenergy industry?

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    The authors gratefully thank the São Paulo Research Foundation (FAPESP) (grants # 2014/08632-9 # 2015/14122-6, # 2013/17581-6, # 2014/16612-8 and 2018/09845-7) for the scholarship granted while this research was carried out, and CNPq (grants # 402992/2013-0 and # 311661/2014-9) for the financial support of the present research. Anonymous reviewers are also thanked for their valuable criticisms and comments, which led to substantial improvements of this manuscript.Peer reviewedPostprintPostprin

    How important is agriculture and familiar agriculture agribusiness for Brazil and its states: an interregional input-output approach

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    The aim of this paper is estimate how important is agriculture and familiar agriculture agribusiness for Brazil and its states. To do so, the GDP for the agribusiness of these complexes is estimated for Brazil and for its 27 states. The estimation is based on an interregional input-output system constructed for the Brazilian economy. The agribusiness takes into consideration the relations between the agriculture production and the other sectors in the economy (inputs for production, industry, transportation, distribution, and commercialization). The importance of the agribusiness can be evidence for it’s share of about 30% in the total Brazilian GDP, but regional differences will make this average oscillates between 4% and 79% in the Brazilian states. Another distinction will be made between small familiar production and large scale production that will vary according to the product and the state. Some relation between land distribution and the type of agriculture will also be made
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