175 resultados para Occurrence


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Although the Brazilian sharpnose shark, Rhizoprionodon lalandii (Muller and Henle, 1839), is an inshore species widely distributed in the Western Atlantic from Panama to Uruguay, there is little available information on its biology. During a long-term study of small coastal sharks caught by gill net fisheries in southeastern Brazil (PROJETO CACAO), 3643 specimens of R. lalandii were examined, comprising 61.3% of the total sharks,and including all sizes classes, from 30 to 78,5 cm TL., and weights from 100 to 2950 g. The length-weight relationships were not significantly different between sexes, Overall sex ratio favoured the males slightly at the rate of 1.3: 1. Sex ratios, however, did differ significantly between season and size classes. This species occurred in this area all year long. Three seasonal size-class Occurrence patterns were recognized: (1) between October and March, the juveniles were more frequents (2) from April to July, adults were most common, and (3) from August to September, neonates were most numerically abundant. Such patterns we to associated with reproductive tactics that may reduce intra-specific and inter-specific competition with hammerhead shark neonates (Sphyrna lewini). probably result in reduced natural mortality of the offspring during their first few months. (C) 2005 Elsevier B.V. All rights reserved.

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The ultrastructural aspects of the ileum of Melipona quadrifasciata anthidioides, a stingless bee whose workers obtain their protein requirements from pollen, present morphological evidences of digestion and absorption. These evidences are represented by special relationships between food particles and the bacterial nora present and between their assemblage and the ileum wall, mainly in the ileum three anterior fourths. The apical features of the epithelium also are indicative of organic material absorption.

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The occurrence of natural triploidy in two specimens of Astyanax scabripinnis collected in the Araqua river and in the Corrego das Pedras stream, respectively, is noticed. The triploid specimen from the Araqua river presented one macro B-chromosome and the triploid specimen from Corrego das Pedras stream presented two macro B-chromosomes. The C-banding performed in the specimen from the Araqua river confirmed the triploidy and showed that the macro B-chromosome was entirely heterochromatic. Ag-NOR characterization showed two chromosomes involved in the nucleolar activity in both specimens. Some aspects related to the origin of triploid fishes are described.

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B chromosomes occur in several Neotropical fish species. Cytogenetic analysis of 27 specimens (15 females and 12 males) of Astyanax scabripinnis paranae from the Araqua river (a small headwater tributary of the Tiete river) shows that this population has 2n = 50 chromosomes (4M + 30 SM + 4ST + 12A), two chromosome pairs with NORs and conspicuous C-band positive blocks in the terminal position of the long arm of four chromosome pairs. In this population, eight females presented 2n = 51 chromosomes and the extra chromosome was a large metacentric similar in size and morphology to the first chromosome pair in the karotype. This accessory chromosome is entirely heterochromatic in C-banded metaphases and shows a late replication pattern evidenced by BrdU incorporation. There was no significant correlation between the presence of B chromosomes and increased NOR activity at the P >0.05 level. Some aspects related to these B chromosomes are discussed.

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In the present study spermiogenesis was investigated in Cetopsis coecutiens (Cetopsidae), and Bunocephalus amazonicus (Aspredinidae), while spermatozoa ultrastructure was investigated in C. coecutiens, B. amazonicus, and Nematogenys inermis (Nematogenyidae). Aspredinidae and Cetopsidae share a spermatogenesis of the semicystic type, and a particular type of spermiogenesis process not reported in any fish group. In the three species analyzed, spermatozoa are biflagellate with flagella having the classical axoneme formulae (9 + 2). The analysis of thirteen characters showed the presence of eight characters shared by Cetopsidae and Aspredinidae, and six characters shared by Cetopsidae and Nematogenyidae, which may suggest that these three families may be more related than actually hypothesized, comprising a very primitive siluriform lineage originated after Diplomystidae.

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Objective. - In this study strains of yeasts isolated from the blood of human patients were analyzed taxonomically, their virulence factors were determined and compared, and phenotypic markers were used to compare the samples with respect to phenotypic differences across the range of patients as well as between samples isotated from the same patient.Methods. - the study involved a total of 75 strains of yeast isolated from the blood of in-patients of the Public Hospital, Botucatu, S (a) over tildeo Paulo, Brazil, with a clinical profile of fungemia. The hospital wards with the largest number of fungemias were neonatal intensive care units (ICUs) (32%) followed by gastric surgery (13.4%) and pediatric wards (10.7%). After identification, the samples were analyzed for the production of phospholipase and proteinase enzymes, and biotyped according to their susceptibility to killer toxins.Results. - the most frequent species found was Candida albicans (38.7%) followed by C. parapsilosis (30.7%). In terms of enzyme production, 98.7% of the 75 samples of yeast presented a strongly positive activity for proteinase; however, 78.7% did not present any phospholipasic activity. Six different biotypes were identified, the most frequent being 511 and 888.Conclusion. In association with phenotypic methods, genetic analyses should also be made of the samples under study to help in the rational development of a wider range of preventive measures and better control of hospital-contracted infections. (c) 2005 Published by Elsevier SAS.

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This study aimed at observing aspects of epidemiology in order to investigate the use of alcohol in patients older than 18 with severe and moderate traumatic brain injury, which were attended in the Clinics Hospital of the University of Uberlandia. Positive alcoholemy was found in 39.3% of the patients. of the 33 positive exams alcoholemy was found higher than 60 mg/dL in 28 (84.6%). There was not significant relation between alcoholemy levels and trauma severity. The major prevalence occurred on Saturdays nights. The most frequent types of external causes were transportation accidents (64.74) followed by accidental falls (17.27%) and physical aggression (16.55%). 93.9% of the patients with positive alcoholemy were men aged 20-29. 24.2% of the ones with positive alcoholemy died yet no significant difference was found in the study of the ones with negative alcoholemy (n=51) (p=0.93); RR= 0.9; IC95%=0.40-2.08.