847 resultados para Big Brown Bats
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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We studied the potential role as seed disperser of the pacu fish (Piaracrus mesopotamicus, Characidae) in the Pantanal of Brazil. The most important food item in the diet of the pacu in the wet season was fruits of the palm Bactris glaucescens found in the guts of 73 percent of all fishes collected (N = 70). We found a positive relationship between fish length, weight, and gape size and the number of intact seeds in their gut. Therefore, large pacus are especially important in dispersing B. glaucescens seeds within the studied system. Since the best seed dispersers are the largest fishes, which are preferred by commercial fisheries, we predict that the ongoing over fishing in freshwater ecosystems will have major impacts on the dispersal system of fish-dependent plants. We suggest that it is paramount to change the attitudes in fisheries management of fruit-eating fishes and urgent to evaluate the impact of fishing on forest regeneration.
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The performance of 36 models (22 ocean color models and 14 biogeochemical ocean circulation models (BOGCMs)) that estimate depth-integrated marine net primary productivity (NPP) was assessed by comparing their output to in situ (14)C data at the Bermuda Atlantic Time series Study (BATS) and the Hawaii Ocean Time series (HOT) over nearly two decades. Specifically, skill was assessed based on the models' ability to estimate the observed mean, variability, and trends of NPP. At both sites, more than 90% of the models underestimated mean NPP, with the average bias of the BOGCMs being nearly twice that of the ocean color models. However, the difference in overall skill between the best BOGCM and the best ocean color model at each site was not significant. Between 1989 and 2007, in situ NPP at BATS and HOT increased by an average of nearly 2% per year and was positively correlated to the North Pacific Gyre Oscillation index. The majority of ocean color models produced in situ NPP trends that were closer to the observed trends when chlorophyll-alpha was derived from high-performance liquid chromatography (HPLC), rather than fluorometric or SeaWiFS data. However, this was a function of time such that average trend magnitude was more accurately estimated over longer time periods. Among BOGCMs, only two individual models successfully produced an increasing NPP trend (one model at each site). We caution against the use of models to assess multiannual changes in NPP over short time periods. Ocean color model estimates of NPP trends could improve if more high quality HPLC chlorophyll-alpha time series were available.
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The karyotypes of 4 species of bats, Artibeus lituratus (Phyllostomatidae), Pipistrellus pipistrellus (Vespertilionidae), Pteropus alecto and P. giganteus (Pteropodidae), were studied after several banding techniques. For A. lituratus, in which an X-autosome translocation was observed, an analysis of the replication pattern in the rearranged chromosome was also made after BrdU incorporation.
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Seasonal variation in growth and yield of cultured brown mussels Perna perna was studied in Ubatuba, south-east Brazilian coastline. Young mussels were transplanted (seeded) into four groups of 16 polyethylene net tubes 2 m long, suspended from a wooden raft (18 m 2). The first group was set out in April (autumn), the next in July (winter), the next in October (spring) 1984 and the final group in January (summer) 1985. One net tube of each group was sampled monthly and biometric data were collected. Growth was initially faster for the spring group, but at the end of the culture period length and weight were not statistically different between groups. L(∞) and W(∞) were 73.9, 71.3, 72.7 and 73.8 mm and 26.3, 23.9, 25.7 and 25.7 g for the autumn, winter, spring and summer groups, respectively. Maximum yield was attained 9 months after seeding for groups of autumn, winter and spring (7.2, 5.2 and 6.3 kg x m -1, respectively) and after 10 months for the summer group (6.9 kg X m -1). The conclusion of this study is that, growth and yield were unaffected by the season of seeding at the study site and that it is not commercially worthwhile to farm mussels more than 9 months, due to yield decrease.
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The effect of the continuous emission hypothesis on the two-pion Bose-Einstein correlation function is discussed and compared with the corresponding results based on the usual freeze-out. Sizable differences in the correlation function appear in these different descriptions of the decoupling process. This means that, when extracting properties of the hot matter formed in high-energy heavy-ion collisions from the data, completely different conclusions may be reached according to the description of the particle emission process adopted.
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Aside from the pervasive effects of body mass, much controversy exists as to what factors account for interspecific variation in basal metabolic rates (BMR) of mammals; however, both diet and phylogeny have been strongly implicated. We examined variation in BMR within the New World bat family Phyllostomidae, which shows the largest diversity of food habits among mammalian families, including frugivorous, nectarivorous, insectivorous, carnivorous and blood-eating species. For 27 species, diet was taken from the literature and BMR was either measured on animals captured in Brazil or extracted from the literature. Conventional (nonphylogenetic) analysis of covariance (ANCOVA), with body mass as the covariate, was first used to test the effects of diet on BMR. In this analysis, which assumes that all species evolved simultaneously from a single ancestor (i.e., a star phylogeny), diet exerted a strong effect on mass-in-dependent BMR: nectarivorous bats showed higher mass-independent BMR than other bats feeding on fruits, insects or blood. In phylogenetic ANCOVAs via Monte Carlo computer simulation, which assume that species are part of a branching hierarchical phylogeny, no statistically significant effect of diet on BMR was observed. Hence, results of the nonphylogenetic analysis were misleading because the critical values for testing the effect of diet were underestimated. However, in this sample of bats, diet is perfectly confounded with phylogeny, because the four dietary categories represent four separate subclades, which greatly reduces statistical power to detect a diet (= subclade) effect. But even if diet did appear to exert an influence on BMR in this sample of bats, it would not be logically possible to separate this effect from the possibility that the dietary categories differ for some other reason (i.e., another synapomorphy of one or more of the subclades). Examples such as this highlight the importance of considering phylogenetic relationships when designing new comparative studies, as well as when analyzing existing data sets. We also discuss some possible reasons why BMR may not coadapt with diet. © by Urban & Fischer Verlag.
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This work objectified the study of sucrose and sorbitol effect in the in vitro conservation for Passiflora giberti N. E. Brown, access. Therefore, an experiment was conducted in a completely randomized design to compare control treatment (standard MS) to MS medium supplemented with three sucrose concentrations (0, 15 and 30 g L -1) combined with three sorbitol concentrations (10, 20 and 40 g L -1), in a total of 10 treatments with 20 replicas. The experiment evaluation was carried out at 30, 60, 90 and 120 days of incubation, whereas the height of shoots (cm), number of roots, number and color of leaves were observed. The results showed the possibility to maintain passion-fruit microplants for a four months period under slow growth in MS medium supplemented with 10 or 20 g L -1 of sorbitol, without sucrose, and kept under 16 hours photoperiod (22 μ E m -2 s -1) and temperature of 27 ± 1°C. Sucrose sustained the longest development of the microplants. Root formation was affected by the sorbitol in the concentration of 40 g L -1 and by the absence of sucrose in the culture medium.
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Captive brown brocket deer (Mazama gouazoubira) were manually restrained to assess tear production by the Schirmer tear test I to measure intraocular pressure by applanation tonometry, to examine ocular conjunctival epithelial cells via cytologic and histologic samples, and to survey ocular conjunctival microflora by microbiologic culture. The mean value for the Schirmer tear test I was 8.9 ± 1.8 mm/min, and the mean intraocular pressure was 15.3 ± 3.1 mm Hg. Conjunctival epithelium contained stratified pavimentous layers of cells, and the microflora consisted of predominantly gram-positive bacteria. Copyright 2007 by American Association of Zoo Veterinarians.
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Lettuce big vein associated virus (LBVaV) and Mirafiori lettuce big vein virus (MLBVV) have been found in mixed infection in Brazil causing the lettuce big vein disease. Analysis of part of the coat protein (CP) gene of Brazilian isolates of LBVaV collected from lettuce, showed at least 93% amino acid sequence identity with other LBVaV isolates. Genetic diversity among MLBVV CP sequences was higher when compared to LBVaV CP sequences, with amino acid sequence identity ranging between 91% to 100%. Brazilian isolates of MLBVV belong to subgroup A, with one RsaI restriction site on the coat protein gene. There is no indication for a possible geografical origin for the Brazilian isolates of LBVaV and MLBVV.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)