974 resultados para Raleigh, Walter, Sir, approximately 1552-1618.
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The objective of this paper was to verify the ideal moment of application of desiccants on the soybeans crop, to obtain seeds with maximum physiological and sanitary quality. The cultivar IAC-15 was sowed at the experimental area of FE/UNESP - Campus of Ilha Solteira, located in the district of Selvíria, State of Mato Grosso do Sul (20° 22′S, 51° 22′W at approximately 335 m of altitude). The experimental design was a randomized block, with treatments in a factorial scheme of 3×3 and 4×4 (dessicant x application time), in 1996/97 and 1997/98, respectively. The desiccants applied during the season agricultural year 1996/97 were: paraquat, diquat, paraquat+diquat mix at the doses 400; 300; 200+150 e 400 g a.i.ha -1, respectively. In 1997/98 the same desiccants were used, at the same doses, with additional treatment application of ammonium glufosinate at the dose of 400 g a.i.ha -1. The desiccants were applied three times in 1996/97 and four times in 1997/98 with 5 days intervals starting at the R 6 stage. According to the environmental conditions of this research the best desiccation time was when soybean plants had 80% to 90% of pods with yellow and brown coloration and seeds with 45% to 60% of water content. There were no effects of any of the desiccants tested in the physiological and sanitary potential required for commercialization of the seeds.
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The known diversity of dart-poison frog species has grown from 70 in the 1960s to 247 at present, with no sign that the discovery of new species will wane in the foreseeable future. Although this growth in knowledge of the diversity of this group has been accompanied by detailed investigations of many aspects of the biology of dendrobatids, their phylogenetic relationships remain poorly understood. This study was designed to test hypotheses of dendrobatid diversification by combining new and prior genotypic and phenotypic evidence in a total evidence analysis. DNA sequences were sampled for five mitochondrial and six nuclear loci (approximately 6,100 base pairs [bp]; x=3,740 bp per terminal; total dataset composed of approximately 1.55 million bp), and 174 phenotypic characters were scored from adult and larval morphology, alkaloid profiles, and behavior. These data were combined with relevant published DNA sequences. Ingroup sampling targeted several previously unsampled species, including Aromobates nocturnus, which was hypothesized previously to be the sister of all other dendrobatids. Undescribed and problematic species were sampled from multiple localities when possible. The final dataset consisted of 414 terminals: 367 ingroup terminals of 156 species and 47 outgroup terminals of 46 species. Direct optimization parsimony analysis of the equally weighted evidence resulted in 25,872 optimal trees. Forty nodes collapse in the strict consensus, with all conflict restricted to conspecific terminals. Dendrobatids were recovered as monophyletic, and their sister group consisted of Crossodactylus, Hylodes, and Megaelosia, recognized herein as Hylodidae. Among outgroup taxa, Centrolenidae was found to be the sister group of all athesphatanurans except Hylidae, Leptodactyidae was polyphyletic, Thoropa was nested within Cycloramphidae, and Ceratophryinae was paraphyletic with respect to Telmatobiinae. Among dendrobatids, the monophyly and content of Mannophryne and Phyllobates were corroborated. Aromobates nocturnus and Colostethus saltuensis were found to be nested within Nephelobates, and Minyobates was paraphyletic and nested within Dendrobates. Colostethus was shown to be rampantly nonmonophyletic, with most species falling into two unrelated cis- and trans-Andean clades. A morphologically and behaviorally diverse clade of median lingual process-possessing species was discovered. In light of these findings and the growth in knowledge of the diversity of this large clade over the past 40 years, we propose a new, monophyletic taxonomy for dendrobatids, recognizing the inclusive clade as a superfamily (Dendrobatoidea) composed of two families (one of which is new), six subfamilies (three new), and 16 genera (four new). Although poisonous frogs did not form a monophyletic group, the three poisonous lineages are all confined to the revised family Dendrobatidae, in keeping with the traditional application of this name. We also propose changes to achieve a monophyletic higher-level taxonomy for the athesphatanuran outgroup taxa. Analysis of character evolution revealed multiple origins of phytotelm-breeding, parental provisioning of nutritive oocytes for larval consumption (larval oophagy), and endotrophy. Available evidence indicates that transport of tadpoles on the dorsum of parent nurse frogs-a dendrobatid synapomorphy-is carried out primitively by male nurse frogs, with three independent origins of female transport and five independent origins of biparental transport. Reproductive amplexus is optimally explained as having been lost in the most recent common ancestor of Dendrobatoidea, with cephalic amplexus arising independently three times. © American Museum of Natural History 2006.
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The central and western portion of the S̃ao Paulo State has large areas of sugar cane plantations, and due to the growing demand for biofuels, the production is increasing every year. During the harvest period some plantation areas are burnt a few hours before the manual cutting, causing significant quantities of biomass burning aerosol to be injected into the atmosphere. During August 2010, a field campaign has been carried out in Ourinhos, situated in the south-western region of S̃ao Paulo State. A 2-channel Raman Lidar system and two meteorological S-Band Doppler Radars are used to indentify and quantify the biomass burning plumes. In addiction, CALIPSO Satellite observations were used to compare the aerosol optical properties detected in that region with those retrieved by Raman Lidar system. Although the campaign yielded 30 days of measurements, this paper will be focusing only one case study, when aerosols released from nearby sugar cane fires were detected by the Lidar system during a CALIPSO overpass. The meteorological radar, installed in Bauru, approximately 110 km northeast from the experimental site, had recorded echoes (dense smoke comprising aerosols) from several fires occurring close to the Raman Lidar system, which also detected an intense load of aerosol in the atmosphere. HYSPLIT model forward trajectories presented a strong indication that both instruments have measured the same air masss parcels, corroborated with the Lidar Ratio values from the 532 nm elastic and 607 nm Raman N2 channel analyses and data retrieved from CALIPSO have indicated the predominance of aerosol from biomass burning sources. © 2011 SPIE.
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Faunal impoverishment and distorted species compositions are common phenomena in oceanic islands; however, many land-bridge islands are poorly inventoried, especially in the Neotropics. We sampled a small mammal community on a land-bridge island (Anchieta Island) along the Brazilian coast. We found only one marsupial Didelphis aurita (Wied-Neuwied, 1826) and two rodent species Oligoryzomys nigripes (Olfers, 1818) and Trinomys iheringi (Thomas, 1911) during 12 months of live trapping and 9195 trap-nights. The diversity of rodents and marsupials was not explained by species-area relations, indicating possible past extinctions. The abundance of D. aurita and O. nigripes was approximately three times higher, while the abundance of T. iheringi was approximately four times lower than abundances reported from other Brazilian Atlantic Forest sites. The population of D. aurita exhibited many phenotypic changes; males were on average 8 % smaller and females produced 30 % less litters than those from the mainland and other land-bridge islands. The long history of forest disturbance, habitat loss, reduction in forest productivity, and the recent introduction of mesopredators may be the major drivers that explain the small mammal community composition on this island. © 2013 Walter de Gruyter GmbH, Berlin/Boston.
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Inappropriate reference limits increase the risks of unnecessary investigations and diagnostic failures. Species, breed, environment, handling, and physiologic stage can influence serum biochemical variables. This study aimed to establish serum biochemical reference intervals of Pêga donkeys and the influence of age and sex on these variables. Samples were taken from 110 donkeys (79 females and 31 males; 8 under 1 year, 33 between 1 and 3 years, and 69 over 3 years old). There were no differences for creatine kinase (CK), albumin, urea, and magnesium among age groups. Animals under 1 year old had the lowest aspartate aminotransferase (AST), creatinine, triglycerides, total calcium, and chloride means; lower indirect bilirubin, gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), and sodium levels than over 3-year-old group and the highest phosphorus, glucose, cholesterol, ionized calcium, and alkaline phosphatase (AP) values. Total protein increased with age. The group from 1 to 3 years had higher potassium than up to 1-year-old group. Animals over 3 years old had the highest means of direct and total bilirubin. ALT, CK, GGT, direct and total bilirubin, urea, triglycerides, sodium, potassium, and chloride levels did not differ between genders. Females had higher AST, total protein, total calcium, and indirect bilirubin levels. Males showed greater AP, albumin, phosphorus, glucose, creatinine, cholesterol, magnesium, and ionized calcium values. Discrepancies among present results and previous studies show influencing factors on biochemical profile of donkeys and reinforce the importance of establishment of specific reference intervals. This study is useful in clinical routine and as basis to other scientific researches with Pêga donkeys. © 2013 Springer-Verlag London.
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A long-standing interest in cactus taxonomy has existed since the Linnaean generation, but an appreciation of the reproductive biology of cacti started early in the 1900s. Numerous studies indicate that plant reproductive traits provide valuable systematic information. Despite the extensive reproductive versatility and specializations in breeding systems coupled with the striking floral shapes, the reproductive biology of the Cactaceae has been investigated in approximately 10% of its species. Hence, the systematic value of architectural design and organization of internal floral parts has remained virtually unexplored in the family. This study represents the most extensive survey of flower and nectary morphology in the Cactaceae focusing on tribes Hylocereeae and Rhipsalideae (subfamily Cactoideae). Our objectives were (1) to conduct comparative morphological analyses of flowers and floral nectaries and (2) to compare nectar solute concentration in these two tribes consisting of holo- and semi-epiphytic species. Flower morphology, nectary types, and sugar concentration of nectar have strong taxonomic implications at the tribal, generic and specific levels. Foremost, three types of nectaries were found, namely chamber nectary (with the open and diffuse subtypes), furrow nectary (including the holder nectary subtype), and annular nectary. All Hylocereeae species possess chamber nectaries, in which the nectarial tissue has both trichomes and stomata. The Rhipsalideae are distinguished by two kinds of floral nectaries: furrow and annular, both nectary types with stomata only. The annular nectary type characterizes the genus Rhipsalis. Nectar concentration is another significant taxonomic indicator separating the Hylocereeae and Rhipsalideae and establishing trends linked to nectar sugar concentration and amount of nectar production in relation to flower size. There is an inverse relationship between flower size and amount of nectar production in the smaller Rhipsalideae flowers, in which nectar concentration is more than two-fold higher despite the smaller volume of nectar produced when compared to the large Hylocereeae flowers. Variability of nectary morphology and nectar concentration was also evaluated as potential synapomorphic characters in recent phylogenies of these tribes. In conclusion, our data provide strong evidence of the systematic value of floral nectaries and nectar sugar concentration in the Cactaceae, particularly at different taxonomic levels in the Hylocereeae and Rhipsalideae. © 2013 Perspectives in Plant Ecology, Evolution and Systematics.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Filosofia - FFC
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Neste trabalho é apresentado o desenvolvimento e os resultados da implementação e testes em campo de um estabilizador de sistema de potência (ESP) projetado com técnica de controle digital para fins de amortecimento de modos de oscilação eletromecânica observáveis em sinais de potência elétrica medido em uma unidade hidro-geradora, de 350 MVA da Usina Hidrelétrica de Tucuruí. É apresentada e aplicada a metodologia de identificação de modelos paramétricos lineares do tipo auto regressivo com entradas exógenas (ARX), para estimação de modelos com capacidade de capturar a informação relevante (amortecimento e freqüência natural) dos modos eletromecânicos dominantes do sistema. De posse do modelo paramétrico ARX, é efetuada então a síntese da lei de controle digital amortecedor para o ESP, através da técnica de deslocamento radial dos pólos da função de transferência de malha fechada. Para a síntese da lei de controle digital, utilizou-se uma estrutura canônica do tipo RST. Para os testes de campo, a lei de controle amortecedor do ESP digital foi codificada em linguagem C e embarcada em um protótipo cujo hardware é baseado em microcontrolador modelo DSPIC 30F3014, o qual incorpora um grande número de periféricos para aquisição e comunicação de dados. Para avaliar o desempenho do ESP digital desenvolvido, testes experimentais foram realizados em uma unidade geradora de 350 MVA da casa de força número 1, da UHE de Tucuruí. O estabilizador desenvolvido atua através da modulação da referência de tensão do regulador automático de tensão da respectiva unidade geradora, de acordo com as oscilações observadas através da medida de potência elétrica no estator do gerador. Os resultados de testes de campo mostraram um excelente desempenho do ESP digital no amortecimento de um modo eletromecânico, de freqüência natural de aproximadamente 1,7 Hz, observado nos teste de campo realizado.
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Neste artigo tratamos da participação de Sir William Thomson na instalação do cabo telegráfico submarino entre Pernambuco e o Pará realizada pela Western and Brazilian Telegraph Company nos meses de agosto e setembro de 1873.
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A partir do século XVII iniciou-se na Amazônia toda uma movimentação de viajantes/naturalistas atraídos pela biossociodiversidade dessa região dominada por uma floresta tropical. Henry Bates (1825-1892), estudioso de história natural, foi um deles, tendo, porém, se deslocado para o Norte do Brasil entre os anos de 1848 e 1859. Nesse contexto, o presente paper tem como objetivo analisar o processo de transferência das informações produzidas por esse viajante naturalista após 11 anos de trabalho de campo. A partir do material bibliográfico reunido para esse fim, verificou-se que tal processo foi bem-sucedido, como evidencia a ampla circulação das obras publicadas por Bates. Transcorridos 156 anos dessa expedição, a produção científica de Bates continua a participar do circuito acadêmico de produção de conhecimento sobre a Amazônia na contemporaneidade, qual seja no campo da biologia, da zoologia, da sociologia, da história ou da antropologia.
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Este artigo é uma iniciativa de destacar alguns elementos a respeito das reflexões de Walter Benjamin sobre o cinema, uma arte que, segundo o próprio autor, responde aos anseios perceptivos do homem moderno, àquele para o qual foi negada qualquer experiência. O cinema, “a obra de arte na era de sua reprodutibilidade técnica”, por excelência, é, para o autor, o marco de uma nova percepção, de uma nova relação entre público e obra de arte: a percepção coletiva. O que a multidão busca não é a contemplação ou o recolhimento diante da obra de arte, mas a sua distração. Fato que o cinema, ao reproduzir em sua forma o conceito benjaminiano de “experiência do choque”, por meio das sucessivas exposições de seus fragmentos, interrompendo constantemente a associação de idéias dos espectadores, insiste em colocar em pauta, (re)afirmando o caráter de diversão da arte moderna. Entretanto, para o autor, o cinema dialeticamente responde à diversão como o instrumento adequado para uma pedagogia das multidões — por meio de uma arte emancipada, as massas também se emancipariam.