Comments about some species abundance patterns: classic, neutral, and niche partitioning models

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Associations of Forest Cover, Fragment Area, and Connectivity with Neotropical Understory Bird Species Richness and Abundance

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Microhabitat selection and daily movements of two rodents (Necromys lasiurus and Oryzomys scotti) in Brazilian Cerrado, as revealed by a spool-and-line device

Studies on patterns of habitat use by mammals are necessary for understanding the mechanisms involved in their distribution and abundance. In this study, we used the spool-and-line method to investigate habitat utilization by two sigmodontine rodents from Brazilian Cerrado, Necromys lasiurus and Oryzomys scotti. We conducted the study in a Cerrado area in central Brazil (15 degrees 56'S and e 47 degrees 56'W) where the animals were caught in an area of 7.68 ha of Cerrado sensu stricto. Captured individuals were marked, equipped with a spool-and-Line device, and released at the same capture point. The next day we followed the thread to record their daily movements and find their nests. To investigate microhabitat selection we compared habitat characteristics along traits of each studied species with general habitat characteristics of the study area. Although the mean 24-h distance was greater for N. lasiurus (mean +/- SE: 41.9 +/- 42.2 m, N=3) than for O. scotti (28.7 +/- 14.2 m, N=6) this difference was not significant (Mann-Whitney test, U=26, P>0.6). We detected significant differences among observed microhabitats variables of both species and available microhabitat characteristics as determined by discriminant analysis (Wilks's lambda F=3.001; df=14, 116; P<0.001). Both species were associated to microhabitat characteristics whose values differed markedly from the overall available habitat. Along the first canonical discriminant function of the DFA both them were associated with greater grass height than the mean height available and along the second axis N. lasiurus selected areas with higher fruit availability and more shelters than those selected by 0. scotti. For stronger inferences regarding differential patterns of habitat utilization by Cerrado rodents we suggest the simultaneous use of both spool-and-line and standard trapping methods. (c) 2005 Deutsche Geseltschaft fur Saugetierkunde. Published by Elsevier GmbH. ALL rights reserved.

Diet of the rattlesnake Crotalus durissus in southeastern Brazil (Serpentes, Viperidae)

Gut contents of 633 live rattlesnakes from southeastern Brazil received at the Instituto Butantanitute, SP, Brazil between 1993 and 1995 were studied. The snakes were weighed, measured and sexed. Two hundred and fifty-nine rattlesnakes had stomach and/or intestinal contents. Prey size was estimated by comparison of prey items with specimens from museum collections. Rodents and small marsupials were the main prey eaten by the rattlesnakes, and only 1% of the items were found in the stomach, whereas 41% of the individuals in the sample had feces in the intestine. There was low correlation between size of snake and prey size. No seasonal difference in frequency was found between fed and not fed males, but the occurrence of fed females was significantly lower during summer than winter months (28.9% and 51.8%, respectively). Fed newborn rattlesnakes had the lowest frequency, and also fed on rodents.

Short-Term Antiandrogen Flutamide Treatment Causes Structural Alterations in Somatic Cells Associated with Premature Detachment of Spermatids in the Testis of Pubertal and Adult Guinea Pigs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Importância da vegetação ripária em região intensamente desmatada no sudeste do Brasil: um estudo com peixes de riacho

e investigated whether the presence of degraded riparian forests along streams influences the fish communities' composition in comparison with environments completely deforested. Stream stretches (1st to 3rd order) with degraded riparian forest (n = 20) and without riparian forest (n = 20) in the micro-basins of Aguape and Tiete (downstream portion) rivers, northwest of São Paulo, Brazil, were selected for ichthyofauna sampling. Overall, 6,695 individuals, representing six orders, 17 families and 55 species were registered. Forested streams presented higher observed and estimated richness than deforested streams. However, forested streams, on average, had lower total richness and richness of tolerant species than deforested streams, indicating higher beta diversity among forested streams. A difference on the species composition between streams groups was also registered. Most of the unique species to deforested streams, and of those caught in greater abundance and frequency in these streams, are tolerant to structural degradation of the habitat. In contrast, most species that occurred exclusively or preferentially in forested streams have specialized habits and are more dependent on micro-habitats associated with the presence of riparian vegetation. Our results indicate that streams with riparian vegetation, though degraded, are able to maintain distinct communities when compared to those found in completely deforested streams, allowing the occurrence of species with more specialized habits and contributing to the maintenance of communities regionally more diverse.

Oral microbial colonization in patients with systemic lupus erythematous: correlation with treatment and disease activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Zooplankton fluctuations in Jurumirim Reservoir (São Paulo, Brazil): a three-year study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Maternal protein restriction affects gene expression and enzyme activity of intestinal disaccharidases in adult rat offspring

This study investigated the consequences of intrauterine protein restriction on the gastrointestinal tract and particularly on the gene expression and activity of intestinal disaccharidases in the adult offspring. Wistar rat dams were fed isocaloric diets containing 6% protein (restricted, n = 8) or 17% protein (control, n = 8) throughout gestation. Male offspring (n = 5-8 in each group) were evaluated at 3 or 16 weeks of age. Maternal protein restriction during pregnancy produced offspring with growth restriction from birth (5.7 ± 0.1 vs 6.3 ± 0.1 g; mean ± SE) to weaning (42.4 ± 1.3 vs 49.1 ± 1.6 g), although at 16 weeks of age their body weight was similar to control (421.7 ± 8.9 and 428.5 ± 8.5 g). Maternal protein restriction also increased lactase activity in the proximal (0.23 ± 0.02 vs 0.15 ± 0.02), medial (0.30 ± 0.06 vs 0.14 ± 0.01) and distal (0.43 ± 0.07 vs 0.07 ± 0.02 U·g-1·min-1) small intestine, and mRNA lactase abundance in the proximal intestine (7.96 ± 1.11 vs 2.38 ± 0.47 relative units) of 3-week-old offspring rats. In addition, maternal protein restriction increased sucrase activity (1.20 ± 0.02 vs 0.91 ± 0.02 U·g-1·min-1) and sucrase mRNA abundance (4.48 ± 0.51 vs 1.95 ± 0.17 relative units) in the duodenum of 16-week-old rats. In conclusion, the present study shows for the first time that intrauterine protein restriction affects gene expression of intestinal enzymes in offspring.

Effects of microhabitat on palm seed predation in two forest fragments in southeast Brazil

The establishment of plants depends crucially on where seeds are deposited in the environment. Some authors suggest that in forest understory seed predation is lower than in gaps, and higher than at the forest edge. However, most studies have been carried out in large forest patches and very little is known about the effects of microhabitat conditions on seed predation in forest fragments. We evaluated the effects of three microhabitats (gaps, forest edge, and understory) on seed predation of two palm species (Euterpe edulis and Syagrus romanzoffiana) in two semi-deciduous forest fragments (230 and 2100 hat in southeast Brazil. Our objective was to test two hypotheses: (1) Low rodent abundance in small fragments as a result of meso-predator action levels leads to lower seed predation in small fragments. (2) Most mammal species in small fragments are generalists with respect to diet and habitat, so that seed predation is similar in different microhabitats (gaps, forest edge and understory) in the small fragment, but not in the larger one. The study community of small fragments is usually composed of generalist species (in diet and habitat aspects), so we expected the same rate of seed predation among microhabitats (gaps, forest edge and understory) in the tested smaller fragment. The experiment was carried out in the dry season (for E. edulis) and in the wet season (for S. romanzoffiana) in 1999. We conclude that post-dispersal seed predation in forest fragments can be directly connected with mammal communities, reflecting their historical and ecological aspects. (C) 2004 Elsevier SAS. All rights reserved.

Efficacy and safety of a soy isoflavone extract in postmenopausal women: A randomized, double-blind, and placebo-controlled study

Objective: To investigate the efficacy of soy isoflavone on climacteric symptoms in postmenopausal women.Design: In this double-blind, randomized, placebo-controlled study, a total of 80 women (mean age =55.1 years), who reported 5 or more hot flush episodes per day, were randomized to receive either 250 mg of standardized soy extract (Glycine max AT) a total of 100 mg/day of isoflavone (n=40) or placebo (n=40). Exclusion criteria included: contra-indication for hormone therapy (HT), chronic gastrointestinal diseases, and users of HT within the preceding 6-months. For 10-months, climacteric symptoms were evaluated using a score card and the menopausal Kupperman index. Compliance and safety were also assessed. At baseline and the end of the study, lipid and hormonal profiles, as well as vaginal, mammographic and ultrasonographic parameters were measured. The t-test, Wilcoxon test and ANOVA were used in the statistical analysis.Results: At baseline, the mean number of hot flushes was 9.6 +/- 3.9 per day in the isoflavone group and 10.1 +/- 4.9 in the placebo group (p>0.05). After 10 months, there was a significant reduction in frequency of hot flushes among isoflavone users when compared to those on placebo (3.1 +/- 2.3 and 5.9 +/- 4.3, respectively) (p<0.001). Kupperman index mean values showed a significant reduction in both groups. However, soy isoflavone was significantly superior to placebo, in reducing hot flush severity (69.9% and 33.7%, respectively) (p<0.001). Endometrial thickness, mammography, vaginal cytology, lipids and hormonal profile did not change in both groups. No serious adverse event related to isoflavone treatment was reported.Conclusions: the soy isoflavone extract exerted favorable effects on vasomotor symptoms and good compliance, providing a safe and effective alternative therapeutic for postmenopausal women. (C) 2007 Elsevier B.V.. All rights reserved.