7 resultados para 430104 History - North American
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
Tribe Pogonieae (Orchidaceae), as Currently known, comprises live genera distributed from South to North America and Eastern Asia. Phylogenetic inferences within Cleistes and among genera of tribe Pogonieae were made based oil nrDNA (ITS) and cpDNA (trnL-F, rps16, rbcL, and psaB) Sequence data and maximum parsimony. Eighteen species of Cleistes, members of all other genera of Pogonieae, and outgroups were sampled. Analyses based oil individual DNA regions provided similar topologies. All evidence indicates that Cleistes is paraphyletic. The North American C. divaricata and C bifaria are more closely related to the temperate genera Isotria and Pogonia than to their Central and South American congeners, the latter Constituting a monophyletic group characterized by the production of nectar as reward, tuberous roots, and their distribution in Central and South America. The Amazonian Duckeella is sister to the remainder of Pogonieae. Taxonomic and biogeographic implications are discussed, and morphological synapomorphies are given For clades obtained in the inferred molecular phylogeny. (C) 2008 Gesellschaft fur Biologische Systematik. Published by Elsevier GmbH. All rights reserved.
Resumo:
Objective: The aim of this study was to investigate the effects of exercise training on cardiovascular autonomic dysfunction in ovariectomized rats submitted to myocardial infarction. Methods: Female Wistar rats were divided into the following ovariectomized groups: sedentary ovariectomized (SO), trained ovariectomized (TO), sedentary ovariectomized infarcted (SOI), and trained ovariectomized infarcted (TOI). Trained groups were submitted to an exercise training protocol on a treadmill (8 wk). Arterial baroreflex sensitivity was evaluated by heart rate responses to arterial pressure changes, and cardiopulmonary baroreflex sensitivity was tested by bradycardic and hypotension responses to serotonin injection. Vagal and sympathetic effects were calculated by pharmacological blockade. Results: Arterial pressure was reduced in the TO in comparison with the SO group and increased in the TOI in relation to the SOI group. Exercise training improved the baroreflex sensitivity in both the TO and TOI groups. The TOI group displayed improvement in cardiopulmonary reflex sensitivity compared with the SOI group at the 16 mu g/kg serotonin dose. Exercise training enhanced the vagal effect in both the TO (45%) and TOI (46%) animals compared with the SO and SOI animals and reduced the sympathetic effect in the TOI (38%) in comparison with the SOI animals. Significant correlations were obtained between bradycardic baroreflex responses and vagal (r = -0.7, P < 0.005) and sympathetic (r = 0.7, P < 0.001) effects. Conclusions: These results indicate that exercise training in ovariectomized rats submitted to myocardial infarction improves resting hemodynamic status and reflex control of the circulation, which may be due to an increase in the vagal component. This suggests a homeostatic role for exercise training in reducing the autonomic impairment of myocardial infarction in postmenopausal women.
Resumo:
Krameria plants are found in arid regions of the Americas and present a floral system that attracts oil-collecting bees. Niche modeling and multivariate tools were applied to examine ecological and geographical aspects of the 18 species of this genus, using occurrence data obtained from herbaria and literature. Niche modeling showed the potential areas of occurrence for each species and the analysis of climatic variables suggested that North American species occur mostly in deserted or xeric ecoregions with monthly precipitation below 140 mm and large temperature ranges. South American species are mainly found in deserted ecoregions and subtropical savannas where monthly precipitation often exceeds 150 mm and temperature ranges are smaller. Principal Component Analysis (PCA) performed with values of temperature and precipitation showed that the distribution limits of Krameria species are primarily associated with maximum and minimum temperatures. Modeling of Krameria species proved to be a useful tool for analyzing the influence of the ecological niche variables in the geographical distribution of species, providing new information to guide future investigations. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
A new genus and species of Cyphophthalmi, Canga renatae gen. nov., sp. nov., is described in the family Neogoveidae from a system of caves in the Serra de Carajas, Para State, Brazil. Canga can be easily distinguished from other neogoveid genera by the presence of a dentate claw on leg I, a unique character among known cyphophthalmid species, and by the free coxa II, which is fused to coxae III and IV in all the other neogoveid species except for the North American Metasiro. The new genus also differs from other Neotropical neogoveids in the lack of a dorsal crest on the chelicerae and in the lack of opisthosomal glands. The finding of a neogoveid in the Para State greatly increases the known distribution of South American cyphophtalmids into the Eastern Brazilian Amazon forest.
Resumo:
A new species of Amphisbaena is described from Fazenda Caraibas, municipality of Mucuge, state of Bahia, Brazil, in the northern portion of the Serra do Espinhaco. The new species is a small amphisbaenian without precloacal pores, 210-213 body annuli, 12-13 tail annuli without evident autotomic site, and 14 dorsal and 14-15 ventral segments per annuli at midbody. The striking difference of this form is the presence of small tubercles on the dorsal region of its tail. This feature is unique among its congeners, although Rhineura floridana, a North American amphisbaenian, has tubercles on its tail. We suggest that the presence of tubercles on the tail of Amphisbaena sp. nov. and Rhineura floridana has arisen independently.
Resumo:
The gene SNRNP200 is composed of 45 exons and encodes a protein essential for pre-mRNA splicing, the 200 kDa helicase hBrr2. Two mutations in SNRNP200 have recently been associated with autosomal dominant retinitis pigmentosa (adRP), a retinal degenerative disease, in two families from China. In this work we analyzed the entire 35-Kb SNRNP200 genomic region in a cohort of 96 unrelated North American patients with adRP. To complete this large-scale sequencing project, we performed ultra high-throughput sequencing of pooled, untagged PCR products. We then validated the detected DNA changes by Sanger sequencing of individual samples from this cohort and from an additional one of 95 patients. One of the two previously known mutations (p.S1087L) was identified in 3 patients, while 4 new missense changes (p.R681C, p.R681H, p.V683L, p.Y689C) affecting highly conserved codons were identified in 6 unrelated individuals, indicating that the prevalence of SNRNP200-associated adRP is relatively high. We also took advantage of this research to evaluate the pool-and-sequence method, especially with respect to the generation of false positive and negative results. We conclude that, although this strategy can be adopted for rapid discovery of new disease-associated variants, it still requires extensive validation to be used in routine DNA screenings. (C) 2011 Wiley-Liss, Inc.
Resumo:
Purpose: The aim of this study was investigate the association between complement Factor H polymorphism (Y402H) and age-related macular degeneration (AMD) in Brazilian patients. Methods: Patients with AMD aged 50 or more and age-matched healthy controls were enrolled in the study. Genomic DNA was isolated from leucocytes of patients and controls; the Y402H polymorphism of complement Factor H gene (CFH) was determined by polymerase chain reaction directed sequencing. Results: The frequency of 1277C allele of Factor H was 56.30% in patients with AMD compared with 36.51% in controls (p-value = 0.001). The genotypic distribution differed significantly between the two groups (1277CC 36.98%, 1277CT 38.65% and 1277TT 24.37% for AMD group; 1277CC 13.16%, 1277CT 46.71% and 1277TT 40.13% for controls, p-value = 0.001). The odds ratio for patients with AMD carrying only one 1277C allele was 1.36 and for those carrying two 1277C alleles was 4.63, when compared to the control group. Conclusions: These results suggest the Y402H polymorphism of CFH is a risk factor to the development of AMD in Brazilian patients. This is in accordance with findings from the majority of previous study population in Europe and North American.