986 resultados para Cryptococcus neoformans var. gattii
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2008
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As sementes de guaraná (Paullinia cupana var.sorbilis (Mart.)Ducke) perdem a viabilidade de germinação rapidamente após a colheita, e apresentam um processo de germinação lento e desuniforme, contribuindo para uma baixa eficácia para produção de mudas. Por isto, há interesse na obtenção de cultivares com germinação mais rápida e uniforme. Neste trabalho estimaram-se parâmetros genéticos para a capacidade e velocidade de emergência em progênies do banco de germoplasma da Embrapa Amazônia Oriental. Tomaram-se 100 sementes de cada 28 progênies de polinização livre e instalou-se um experimento em blocos ao acaso com duas repetições em condições naturais de canteiro. Com os dados de germinação, estimaram-se a percentagem e o índice médio de velocidade de mergência (IVE). As estimativas de variâncias genéticas e ambientais, herdabilidade e índice b mostraram que a maior parte da variabilidade presente entre as progênies foi devido aos efeitos genéticos. Pelas estimativas de ganho genético esperado entre progênies, é possível obter-se ganho de seleção para capacidade e velocidade de emergência, sendo que o ganho foi mais expressivo quando se considerou o Índice de Velocidade de Emergência.
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O aumento da variabilidade genética em flores e plantas ornamentais pode ser obtido pela duplicação cromossômica via indução de poliploidia, fator importante no desenvolvimento de variedades comerciais para manter a competição nesse segmento produtivo. Neste sentido, o presente trabalho relata o projeto de pesquisa que está sendo desenvolvido com o objetivo de avaliar plantas de Heliconia chartacea var. Sexy Pink obtidas por poliploidização induzida in vitro quanto às características morfológicas, fisiológicas, citogenéticas e produtivas.
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2016
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A reincorporação de áreas alteradas ao processo produtivo por meio de plantios florestais é uma alternativa de uso do solo uma vez que contribui para a minimização de impactos ambientais, conservação da biodiversidade e diminuição da pressão sobre as florestas nativas. Portanto, o objetivo desse trabalho foi projetar cenário produtivo para um cultivo de paricá (Schizolobium parahyba var. amazonicum (Huber x Ducke) Barneby a fim de analisar o desempenho econômico e a viabilidade deste. O experimento foi conduzido em área no município de Santa Maria das Barreiras, Pará, onde o modelo homogêneo de paricá está sob delineamento inteiramente casualizado e espaçamento 3x 3 m. O plantio foi feito no ano de 2012 e em seguida foram feitas medições de altura (m) e DAP (cm) ainda no ano 0 e nos três anos seguintes (2013, 2014, 2015). A análise econômica foi feita a partir dos dados da área na planilha AmazonSAF, na qual os parâmetros de valor presente líquido (VPL), taxa interna de retorno (TIR) e relação benefício-custo (RB/C) indicaram que o modelo proposto apresenta desempenho satisfatório e é viável economicamente.
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1980
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A presente pesquisa visa analisar a diversidade genética De F. decemcellulare isolado de mudas e plantas adultas de guaranazeiro com sintomas de superbrotamento, hipertrofia floral ou galhas por meio do marcador molecular ERIC-PCR.
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Guarana seeds have the highest caffeine concentration among plants accumulating purine alkaloids, but in contrast with coffee and tea, practically nothing is known about caffeine metabolism in this Amazonian plant. In this study, the levels of purine alkaloids in tissues of five guarana cultivars were determined. Theobromine was the main alkaloid that accumulated in leaves, stems, inflorescences and pericarps of fruit, while caffeine accumulated in the seeds and reached levels from 3.3% to 5.8%. In all tissues analysed, the alkaloid concentration, whether theobromine or caffeine, was higher in young/immature tissues, then decreasing with plant development/maturation. Caffeine synthase activity was highest in seeds of immature fruit. A nucleotide sequence (PcCS) was assembled with sequences retrieved from the EST database REALGENE using sequences of caffeine synthase from coffee and tea, whose expression was also highest in seeds from immature fruit. The PcCS has 1083bp and the protein sequence has greater similarity and identity with the caffeine synthase from cocoa (BTS1) and tea (TCS1). A recombinant PcCS allowed functional characterization of the enzyme as a bifunctional CS, able to catalyse the methylation of 7-methylxanthine to theobromine (3,7-dimethylxanthine), and theobromine to caffeine (1,3,7-trimethylxanthine), respectively. Among several substrates tested, PcCS showed higher affinity for theobromine, differing from all other caffeine synthases described so far, which have higher affinity for paraxanthine. When compared to previous knowledge on the protein structure of coffee caffeine synthase, the unique substrate affinity of PcCS is probably explained by the amino acid residues found in the active site of the predicted protein.
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In the Amazon Region, there is a virtual absence of severe malaria and few fatal cases of naturally occurring Plasmodium falciparum infections; this presents an intriguing and underexplored area of research. In addition to the rapid access of infected persons to effective treatment, one cause of this phenomenon might be the recognition of cytoadherent variant proteins on the infected red blood cell (IRBC) surface, including the var gene encoded P. falciparum erythrocyte membrane protein 1. In order to establish a link between cytoadherence, IRBC surface antibody recognition and the presence or absence of malaria symptoms, we phenotype-selected four Amazonian P. falciparum isolates and the laboratory strain 3D7 for their cytoadherence to CD36 and ICAM1 expressed on CHO cells. We then mapped the dominantly expressed var transcripts and tested whether antibodies from symptomatic or asymptomatic infections showed a differential recognition of the IRBC surface. As controls, the 3D7 lineages expressing severe disease-associated phenotypes were used. We showed that there was no profound difference between the frequency and intensity of antibody recognition of the IRBC-exposed P. falciparum proteins in symptomatic vs. asymptomatic infections. The 3D7 lineages, which expressed severe malaria-associated phenotypes, were strongly recognised by most, but not all plasmas, meaning that the recognition of these phenotypes is frequent in asymptomatic carriers, but is not necessarily a prerequisite to staying free of symptoms.
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This research studied the effect of low density polyethylene packaging and storage temperature on the preservation of fresh-cut (minimally processed) cabbage. The cabbages, previously cooled to a temperature of 10 ºC, were selected, washed, cut in four parts (with the central stalk removed), sanitized, cut in strips, rinsed, put in the centrifuge, weighed and stored in plastic packaging of low density polyethylene (70 µm), and then stored in cold chambers at temperatures of 1 and 10 ºC for 20 days. The following aspects were evaluated: carbon dioxide, oxygen and ethylene in the internal atmosphere of the package as well as, pH, titratable acidity, total soluble solids, vitamin C, loss of fresh mass and the total soluble solids/acidity in the fresh-cut cabbage ratio. The experimental design was entirely casual, with three repetitions. The analysis parameters, except for the vitamin C, loss of fresh mass and ethylene, presented significant variation between the temperatures and days of storage. The cabbage stored at a temperature of 1 ºC presented a shelf life of around 15 days, significantly higher than that stored at 10 ºC. At this temperature, on the 8th day of storage, the product was completely decayed, unfit for commercialization or consumption.
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Chromosome numbers of 11 South-Brazilian species of Adesmia were determined. The cytological preparations were obtained by squashing cells of root tips, using the acetic-orcein method. The chromosome number for all the species studied was 2n=20, excepting A. incana var. incana with 2n=ca.40. The counts are new for nine species, and the other two agree with the literature. It is suggested x=10 as the basic number for the genus. Up to the present only four species were cited as polyploid.
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The taxonomy of the genus Heliotropium L. in Brazil was studied, revealing nine species and two varieties: H. amplexicaule Vahl, H. angiospermum Murray, H. curassavicum L., H. curassavicum var. argentinum I.M. Johnst., H. elongatum (Lehm.) I.M. Johnst., H. elongatum var. burchellii I.M. Johnst., H. indicum L., H. leiocarpum Morong, H. nicotianaefolium Poir., H. phylicoides Cham. and H. transalpinum Vell. Descriptions, illustrations, comments on relationships based on morphology and data on species distribution are presented.
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The spouted and fluidized bed technologies are usually employed in operations of drying, coating and granulation of particles by the chemical and pharmaceutical industries. The use of these techniques in agronomy is limited to the treatment of some species of seeds. In this work, the objective was to analyse the fluid-dynamics of fluidized and spouted beds when broccoli (Brassica oleracea L. var. Italica) seeds are used and also to verify the influence on seed germination after 60 min of seed exposition to spouting or fluidization, at room temperature. The fluid-dynamics was defined by the measurements of the bed pressure drop as a function of the air flow rate for different seeds loads. The experimental conditions were based on the physical properties of the seeds and were limited by the apparatus dimensions. The cone-cylindrical bed was constructed in plexyglass to permit flow visualization. The values of the parameters: maximum pressure drop, minimum spouting flow rate and pressure drop, and stable spout pressure drop were experimentally obtained from the fluid-dynamic analysis and were compared with the values calculated by empirical equations found in the literature. The same procedure was carried out with the fluidized bed and the important parameters for this regime were the air velocity and the bed pressure drop at minimum fluidization. The analysis of seed germination indicated that no damage was caused to the seeds by the spout or fluidization processes.
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PURPOSE: This study evaluated the inflammatory reaction caused by the implantation of iodoform and calcium hydroxide in the back of rats. These drugs may be used as intracanal dressings to eliminate residual bacteria of the root canal system. METHODS: Twenty albinic rats (Rattus norvegicus, var Wistar) were divided into four groups: control group 1 (CG1) had normal skin; control group 2 (CG2) had wounded tissue without drugs; in groups 3 and 4, iodoform (IG) and calcium hydroxide (CHG) were inserted into the wounds, respectively. After 3, 5 and 11 days, slices of the implanted areas were macroscopically and microscopically observed regarding to their qualitative and quantitative aspects. RESULTS: In the macroscopical analysis, the CHG showed a large area of necrosis and swelling, which progressively decreased; in the IG the presence of iodoform surrounded by normal tissue was observed. The qualitative and quantitative histological analysis showed that IG promoted a shorter delay in the inflammatory response than the CHG. CONCLUSION: The inflammatory reaction for iodoform had a peak period five days after the drug insertion. By comparison, calcium hydroxide showed a very large area of necrosis that could only be partially eliminated after eleven days.
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This paper describes 2D-QSAR and 3D-QSAR studies against Candida albicans and Cryptococcus neofarmans for a set of 20 bisbenzamidines. In the studies of 2D-QSAR with C. albicans it was obtained a correlation between log MIC-1 and lipolo component-Z (r² = 0.68; Q² = 0.51). In the case of C. neofarmans a correlation between log MIC-1 and lipolo component-Z and of Balaban index (r² = 0.85; Q² = 0.6) was obtained. 3D-QSAR studies using CoMFA showed that the steric fields contributed more to the predicted activities for Candida albicans (94.9%) and Cryptococcus neofarmans (97.9%).