880 resultados para POPULATION DISTRIBUTION


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This study describes the spatio-temporal distribution, population biology, and diet of the puffer fish Lagocephalus laevigatus in Caraguatatuba Bay, south-eastern Brazil. Monthly samples were taken between August 2003 and October 2004 by trawls in two areas, south and north, at depths of 1 to 4 m. The fish were measured and their sex and reproductive stage determined. The abundance of this species was compared between areas and among months, and the items in the diet were identified and quantified. Lagocephalus laevigatus was rare in Caraguatatuba Bay, where only 199 small individuals (4.8 to 15.4 cm) were obtained in the entire study period, suggesting that this species uses the estuary as a nursery. None of the specimens of L. laevigatus captured in Caraguatatuba Bay were sexually mature. Higher densities of L. laevigatus in the bay were recorded in the south area and between October and December 2003, i.e. in the spring, suggesting that spawning may occur from late winter to spring (August through to November). The diet items consumed by L. laevigatus in Caraguatatuba Bay were, as expected from the current literature, crustaceans, mainly amphipods, and fish. However, the most-consumed item was the sea whip Leptogorgia setacea (Cnidaria). This feeding habit may be related to the presence of toxins (tetrodotoxin and saxitoxin) that are frequently found in the skin and viscera of L. laevigatus, which may be sequestered from the sea whip, which possibility still needs to be specifically evaluated.

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This study evaluated the spatio-temporal distribution, population biology and diet of Menticirrhus americanus in Caraguatatuba Bay. Samples were taken monthly between August 2003 and October 2004, by trawling in two previously selected areas. The northern area is more exposed to wave activity and is influenced by a river, functioning as a small estuary. In contrast, the southern area is relatively sheltered from wave energy and influenced to a lesser degree by smaller rivers. The fishes' length was measured, and the sex and gonadal stage macroscopically identified. The abundance of this species was compared between areas and among months. The diet was identified and quantified. M. americanus occurred in equal proportions in the two study areas, being most abundant in April 2004, followed by December 2003 and January 2004. The population was dominated by small immature individuals. The few individuals in maturation or mature that were captured showed no seasonal pattern of distribution. This species had a varied diet, feeding on worms (nemerteans, sipunculans and echiurans), mollusks (bivalves and cephalopods), polychaetes, crustaceans and fish. The presence of intact nematodes in the intestine suggests that these are parasites. The results demonstrated that M. americanus has a homogeneous spatial and temporal distribution in Caraguatatuba Bay, being uniformly distributed between the south and north areas as well as across the months. This species can be considered a carnivorous predator, showing a preference for consuming benthic sandy-beach species such as glycerids and other polychaetes, crustaceans, and bivalve siphons.

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Ecosystems may reflect environmental changes in many respects, from the debilitation of individuals to alterations in community composition. Equally, population parameters may provide reliable indications of environmental changes. Members of the sciaenid fish genus Stellifer are usually very abundant where they occur, often with two or more species living in sympatry. Here, the population dynamics of three Stellifer species from southeastern Brazil were assessed. Sampling was carried out in shallow marine areas of Caraguatatuba Bay, from August 2003 to October 2004. The species evaluated were Stellifer rastrifer (n=3183), S. brasiliensis (n=357) and S. stellifer (n=116). The area under greater continental influence tended to support more, but smaller individuals. Size variations over time were similar among species and negatively correlated with Krel, which showed smooth fluctuations. The general length-frequency distribution was concentrated between 6.0 and 9.0 cm, and the great majority of females did not present mature gonads during the sampling period. The findings support the existence of a stratification by size for these species, indicating that the area is essential for the development of younger fish. Failure to consider these characteristics for the management of similar areas may have serious implications for these environments.

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We present results from an analysis of stellar population parameters for 7132 galaxies in the 6dF Galaxy Survey Fundamental Plane (FP) sample. We bin the galaxies along the axes, v1, v2 and v3, of the tri-variate Gaussian to which we have fitted the galaxy distribution in effective radius, surface brightness and central velocity dispersion (FP space), and compute median values of stellar age, [Fe/H], [Z/H] and [a/Fe]. We determine the directions of the vectors in FP space along which each of the binned stellar population parameters vary most strongly. In contrast to previous work, we find stellar population trends not just with velocity dispersion and FP residual, but with radius and surface brightness as well. The most remarkable finding is that the stellar population parameters vary through the plane (v1 direction) and across the plane (v3 direction), but show no variation at all along the plane (v2 direction). The v2 direction in FP space roughly corresponds to luminosity density. We interpret a galaxys position along this vector as being closely tied to its merger history, such that early-type galaxies with lower luminosity density are more likely to have undergone major mergers. This conclusion is reinforced by an examination of the simulations of Kobayashi, which show clear trends of merger history with v2.

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Since around 1723, on the occasion of its initial colonization by Europeans, Rondonia has received successive waves of immigrants. This has been further swelled by individuals from northeastern Brazil, who began entering at the beginning of the twentieth century. The ethnic composition varies across the state according to the various sites of settlement of each wave of immigrants. We analyzed the frequency of the CCR5 Delta 32 allele of the CCR5 chemokine receptor, which is considered a Caucasian marker, in five sample sets from the population. Four were collected in Porto Velho, the state capital and the site of several waves of migration. Of these, two, from the Hospital de Base were comprised of HB Mothers and HB Newborns presenting allele frequencies of 3.5% and 3.1%, respectively, a third from the peri-urban neighborhoods of Candelaria/Bate-Estaca (1.8%), whereas a fourth, from the Research Center on Tropical Medicine/CEPEM (0.6%), was composed of malaria patients under treament. The fifth sample (3.4%) came from the inland Quilombola village of Pedras Negras. Two homozygous individuals (CCR5 Delta 32/CCR5 Delta 32) were detected among the HB Mother samples. The frequency of this allele was heterogeneous and higher where the European inflow was more pronounced. The presence of the allele in Pedras Negras revealed European miscegenation in a community largely comprising Quilombolas.

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OBJECTIVE: To describe the regional and socioeconomic distribution of household food availability in Brazil. METHODS: Data from the 2008-2009 Household Budget Survey on food and beverage acquisition for household consumption, conducted by the Instituto Brasileiro de Geografia e Estatistica (Brazilian Institute of Geography and Statistics), were analyzed. The amounts of foods, recorded during seven consecutive days in the 55,970 sample households, were converted into calories and nutrients. Food quality indicators were constructed and analyzed according to the regional and socioeconomic strata of the Brazilian population. RESULTS: The amount of energy from protein was adequate in all regional and socioeconomic strata. On the other hand, an excess of free sugars and fats was observed in all regions of the country, especially in the Southern and Southeastern regions. The proportion of saturated fats was high in urban areas and consistent with the greater contribution of animal-derived products. Limited availability of fruits and vegetables was found in all regions. An increase in the fat content and reduction in carbohydrate content of the diet were observed with the increase in income. CONCLUSIONS: The negative characteristics of the Brazilian diet observed at the end of the first decade of the 21(st) century indicate the need to prioritize public policies for the promotion of healthy eating.

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The frequency distribution of SNPs and haplotypes in the ABCB1, SLCO1B1 and SLCO1B3 genes varies largely among continental populations. This variation can lead to biases in pharmacogenetic studies conducted in admixed populations such as those from Brazil and other Latin American countries. The aim of this study was to evaluate the influence of self-reported colour, geographical origin and genomic ancestry on distributions of the ABCB1, SLCO1B1 and SLCO1B3 polymorphisms and derived haplotypes in admixed Brazilian populations. A total of 1039 healthy adults from the north, north-east, south-east and south of Brazil were recruited for this investigation. The c.388A>G (rs2306283), c.463C>A (rs11045819) and c.521T>C (rs4149056) SNPs in the SLCO1B1 gene and c.334T>G (rs4149117) and c.699G>A (rs7311358) SNPs in the SLCO1B3 gene were determined by Taqman 5'-nuclease assays. The ABCB1 c.1236C>T (rs1128503), c.2677G>T/A (rs2032582) and c.3435C>T (rs1045642) polymorphisms were genotyped using a previously described single-base extension/termination method. The results showed that genotype and haplotype distributions are highly variable among populations of the same self-reported colour and geographical region. However, genomic ancestry showed that these associations are better explained by a continuous variable. The influence of ancestry on the distribution of alleles and haplotype frequencies was more evident in variants with large differences in allele frequencies between European and African populations. Design and interpretation of pharmacogenetic studies using these transporter genes should include genomic controls to avoid spurious conclusions based on improper matching of study cohorts from Brazilian populations and other highly admixed populations.

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The activity of natural killer cells depends on the balance between activating and inhibitory signals coming from their receptors. Among these are the killer cell immunoglobulin-like receptors (KIR) that recognize specific HLA class I allotypes. Here we characterized KIR genetic diversity and their HLA ligands in the population of Curitiba, Parana State (n = 164), and compared it with other worldwide populations. The distribution of 2DL4 alleles was also analyzed. The Curitiba population did not differ significantly from European and Euro-descendant populations, but as an admixed population showed higher genetic diversity. We found 27 KIR profiles, many of them uncommon in European populations, in agreement with the elevated historically recent gene flow in the study population. The frequencies of KIR genes and their respective HLA ligands were distributed independently and none of the analyzed individuals lacked functional KIR-HLA ligand combinations. KIR gene frequencies of 33 worldwide populations were consistent with geographic and ethnic distribution, in agreement with demography being the major factor shaping the observed gene content diversity of the KIR locus.

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Mannose-binding lectin (MBL) is a protein able to bind to carbohydrate patterns on pathogen membranes; upon MBL binding, its associated serine protease MBL-associated serine protease type 2 (MASP2) is autoactivated, promoting the activation of complement via the lectin pathway. For both MBL2 and MASP2 genes, the frequencies of polymorphisms are extremely variable between different ethnicities, and this aspect has to be carefully considered when performing genetic studies. While polymorphisms in the MBL-encoding gene (MBL2) have been associated, depending upon ethnicity, with several diseases in different populations, little is known about the distribution of MASP2 gene polymorphisms in human populations. The aim of our study was thus to determine the frequencies of MBL2 (exon 1 and promoter) and MASP2 (p.D371Y) polymorphisms in a Brazilian population from Rio de Janeiro. A total of 294 blood donor samples were genotyped for 27 polymorphisms in the MBL2 gene by direct sequencing of a region spanning from the promoter polymorphism H/L rs11003125 to the rs1800451 polymorphism (at codon 57 in the first exon of the gene). Genotyping for MASP2 p.D371Y was carried out using fluorogenic probes. To our knowledge, this is the first study reporting the prevalence of the MASP2 p.D371Y polymorphism in a Brazilian population. The C allele frequency 39% is something intermediate between the reported 14% in Europeans and 90% in Sub-Saharan Africans. MBL2 polymorphisms frequencies were quite comparable to those previously reported for admixed Brazilians. Both MBL2 and MASP2 polymorphisms frequencies reported in our study for the admixed Brazilian population are somehow intermediate between those reported in Europeans and Africans, reflecting the ethnic composition of the southern Brazilian population, estimated to derive from an admixture of Caucasian (31%), African (34%) and Native American (33%) populations. In conclusion, our population genetic study describes the frequencies of MBL2 and MASP2 functional SNPs in a population from Rio de Janeiro, with the aim of adding new information concerning the distribution of these SNPs in a previously unanalysed Brazilian population, thus providing a new genetic tool for the evaluation of the association of MBL2 and MASP2 functional SNPs with diseases in Brazil, with particular emphasis on the state of Rio de Janeiro.

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The conservation of biodiversity in agricultural landscapes depends on information about the ways in which species are affected by the conversion of native habitats into novel anthropogenic environments and the strategies that the species use to persist in these altered ecosystems. Here, we investigate how small mammals occupy the different agroecosystems of an agricultural landscape in the state of Sao Paulo, Brazil. From August 2003 through January 2005, we surveyed small mammals using Sherman traps at 16 sampling sites in each of the four predominant environments of the local agricultural landscape: remnant fragments of semideciduous forest, Eucalyptus plantations, sugarcane plantations, and pastures. With a total effort of 23,040 trap-nights and a capture success of 0.8%, we captured 177 rodents and marsupials belonging to eight species. The assemblage represented by these mammals is essentially composed of generalist species, which are common in degraded areas. Sugarcane plantations had the highest abundance, whereas pastures had the lowest species richness. Our results suggest that the loss of forest species can be related to the loss of native forest. The results also indicate that to improve the conservation value of agricultural landscapes, native forest fragments should be conserved, extensive monocultures should be avoided and agricultural impacts should be mitigated.

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The known distribution of the harlequin frog, Atelopus nahumae RUIZ-CARRANZA, ARDILA-ROBAYO & HERNANDEZ-CAMACHO, 1994, is reported along with three new locality records in the northwestern Sierra Nevada de Santa Marta (Colombia). In the new localities, observations were made on the frog's mating behavior. This report adds the Cordoba River Basin, another high valley of the Sierra Nevada de Santa Marta, to the known range of A. nahumae. Nevertheless, the general distribution of the species in this region is largely unknown.

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Objectives: To estimate prevalence, age-of-onset, gender distribution and identify correlates of lifetime psychiatric disorders in the Sao Paulo Metropolitan Area (SPMA). Methods: The Sao Paulo Megacity Mental Health Survey assessed psychiatric disorders on a probabilistic sample of 5,037 adult residents in the SPMA, using the World Mental Health Survey Version of the Composite International Diagnostic Interview. Response rate was 81.3%. Results: Lifetime prevalence for any disorder was 44.8%; estimated risk at age 75 was 57.7%; comorbidity was frequent. Major depression, specific phobias and alcohol abuse were the most prevalent across disorders; anxiety disorders were the most frequent class. Early age-of-onset for phobic and impulse-control disorders and later age-of-onset for mood disorders were observed. Women were more likely to have anxiety and mood disorders, whereas men, substance use disorders. Apart from conduct disorders, more frequent in men, there were no gender differences in impulse-control disorders. There was a consistent trend of higher prevalence in the youngest cohorts. Low education level was associated to substance use disorders. Conclusions: Psychiatric disorders are highly prevalent among the general adult population in the SPMA, with frequent comorbidity, early age-of-onset for most disorders, and younger cohorts presenting higher rates of morbidity. Such scenario calls for vigorous public health action.

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Abstract Background In this study the effect of myenteric denervation induced by benzalconium chloride (BAC) on distribution of fibrillar components of extracellular matrix (ECM) and inflammatory cells was investigated in gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Rats were divided in four experimental groups: non-denervated (I) and denervated stomach (II) without MNNG treatment; non-denervated (III) and denervated stomachs (IV) treated with MNNG. For histopathological, histochemical and stereological analysis, sections of gastric fragments were stained with Hematoxylin-Eosin, Picrosirius-Hematoxylin, Gomori reticulin, Weigert's Resorcin-Fuchsin, Toluidine Blue and Alcian-Blue/Safranin (AB-SAF). Results BAC denervation causes an increase in the frequency of reticular and elastic fibers in the denervated (group II) compared to the non-denervated stomachs (group I). The treatment of the animals with MNNG induced the development of adenocarcinomas in non-denervated and denervated stomachs (groups III and IV, respectively) with a notable increase in the relative volume of the stroma, the frequency of reticular fibers and the inflammatory infiltrate that was more intense in group IV. An increase in the frequency of elastic fibers was observed in adenocarcinomas of denervated (group IV) compared to the non-denervated stomachs (group III) that showed degradation of these fibers. The development of lesions (groups III and IV) was also associated with an increase in the mast cell population, especially AB and AB-SAF positives, the latter mainly in the denervated group IV. Conclusions The results show a strong association in the morphological alteration of the ECM fibrillar components, the increased density of mast cells and the development of tumors induced by MNNG in the non-denervated rat stomach or denervated by BAC. This suggests that the study of extracellular and intracellular components of tumor microenvironment contributes to understanding of tumor biology by action of myenteric denervation.

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Abstract Background Hepatitis C virus (HCV) is an important human pathogen affecting around 3% of the human population. In Brazil, it is estimated that there are approximately 2 to 3 million HCV chronic carriers. There are few reports of HCV prevalence in Rondônia State (RO), but it was estimated in 9.7% from 1999 to 2005. The aim of this study was to characterize HCV genotypes in 58 chronic HCV infected patients from Porto Velho, Rondônia (RO), Brazil. Methods A fragment of 380 bp of NS5B region was amplified by nested PCR for genotyping analysis. Viral sequences were characterized by phylogenetic analysis using reference sequences obtained from the GenBank (n = 173). Sequences were aligned using Muscle software and edited in the SE-AL software. Phylogenetic analyses were conducted using Bayesian Markov chain Monte Carlo simulation (MCMC) to obtain the MCC tree using BEAST v.1.5.3. Results From 58 anti-HCV positive samples, 22 were positive to the NS5B fragment and successfully sequenced. Genotype 1b was the most prevalent in this population (50%), followed by 1a (27.2%), 2b (13.6%) and 3a (9.0%). Conclusions This study is the first report of HCV genotypes from Rondônia State and subtype 1b was found to be the most prevalent. This subtype is mostly found among people who have a previous history of blood transfusion but more detailed studies with a larger number of patients are necessary to understand the HCV dynamics in the population of Rondônia State, Brazil.

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Abstract Background H. pylori seroprevalence in Brazilians varies and is dependent on socioeconomic status, sanitation conditions and ethnicity; furthermore, H. pylori is not always associated with the incidence of gastric cancer, suggesting the role of more virulent strains. The purpose of this study was to analyze the association of more virulent H. pylori strains with gastric cancer. Methods DNA was extracted from gastric biopsies of thirty-four cases of gastric cancer (11 intestinal-type, 23 diffuse-type), and thirty-four of patients with endoscopic gastritis. The presence of cagPAI genes (cagA, cagA promoter, cagE, cagM, tnpB, tnpA, cagT and the left end of the cagII (LEC)) and babA were analyzed by PCR. Results Comparison of H. pylori isolates from gastric cancer and gastritis patients showed significant associations of tnpA and LEC with gastric cancer (73.5% [OR, 6.66; 95% CI, 2.30-19.25] and 58.8% [OR, 10.71; 95% CI, 3.07-37.28] of cases, respectively). Other cagPAI genes were detected in both groups at similar frequencies. Conclusions tnpA and LEC of H. pylori cagPAI were associated with gastric cancer; nonetheless, these results were restricted within this group of patients and further studies are needed to confirm these results in a larger sample and determine their role in gastric carcinogenesis.