998 resultados para Population expansions


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The mantis shrimp Squilla biformis is the most conspicuous and abundant stomatopod captured during benthic trawling operations off the Pacific coast of Costa Rica. Due to its abundance, this species is considered a potential fisheries resource for the region. Nevertheless, its life history is practically unknown. The present study describes the population demography, spatial distribution and behaviour of S. biformis from Pacific Costa Rica. The population was principally composed of individuals between 20 and 32 mm carapace length (CL), forming 2 age groups. Individuals of 35 to 45 mm CL and > 45 mm CL were poorly represented. We assume that larger individuals are more frequent at greater depths (probably on the continental slope), thus out of the reach of the fishing vessels used in our study. Males outnumbered females, as observed in other stomatopods. Visual evidence of their behaviour demonstrates that the adults in this species possess a benthic and pelagic life style. Largest numbers of individuals (50% of the total) were found between 240 to 260 m, the same bathymetric range that was historically occupied by commercial shrimps. This shift may be related to intense fishing activities. We observed a synchronized moulting of females and males during less luminous (third and fourth) lunar phases. The evolutionary development of a group moulting system could confer advantages to S. biformis in comparison to other stomatopods whose moulting process is individual and asynchronous.

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The squat lobster Pleuroncodes monodon is one of the most common and abundant galatheid species in the deepwater fishery of Pacific coast of America. In contrast with Peru and Chile, the red squat lobster is not commercially exploited in Costa Rica. Here we estimated the size of sexual maturity and analysed egg production in P. monodon from the Pacific of Costa Rica; the results might be important for an adequate management strategy when initiating a sustainable fishery of this resource in Costa Rica. Analyses of allometric growth revealed that females and males reached their morphological sexual maturity at 26.9 and 30.4 mm CL. respectively. The percentage of immature females captured in the present study (54%) suggests that almost half of females are able to reproduce before they are caught. Egg production was positively correlated with body size; females that measured between 24.1 and 29.0 mm CL contributed roughly 90% to the offspring production of the population. Females from Costa Rica had a considerably lower average egg volume (0.039 mm(3)) and higher fecundity (9810) than females from Chile. In comparison to other American galatheids P. monodon from Costa Rica produces numerous but small eggs, a typical strategy of species with a prolonged larval development. An analysis between our results and information published about P. monodon from Chile also revealed differences in the size-frequency distribution shape of both populations. The non-exploited character of the Costa Rican P. monodon population and a latitudinal (temperature-related) cline in body size might be associated with these differences. (C) 2010 Elsevier B.V. All rights reserved.

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The striped-legged hermit Crab Clibanarius vittatus, with a geographical distribution covering a wide range Of latitudes in the western Atlantic, was selected for a comparative study on population features between two different areas of the Brazilian coast that are separated by approximately 3000 km. The two populations Were sampled concurrently for nine months. The populations in northern and southeastern Brazil showed different profiles in terms of size of specimens, sex ratio, and shell occupation. The observed plasticity of these life-cycle traits of C. vittatus in relation to local environmental conditions is discussed. (C) 2009 Elsevier Masson SAS. All rights reserved

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This study has calculated the potential impact of hormone replacement therapy (HRT) on breast cancer incidence in Australia and has estimated how changes in prescribing HRT to women could affect this risk. The effects of HRT on breast cancer incidence was estimated using the attributable fraction technique with prevalence data derived from the 2001 Australian Health Survey and published rates of breast cancer relative risks from HRT use. In Australia, 12% of adult women were current HRT users and in 2001, 11783 breast cancers were reported. Of these, 1066 (9%) were potentially attributable to HRT. Restricting HRT use to women aged less than 65 years, ceasing HRT prescribing after 10 years or limiting combined oestrogen and progesterone HRT to five years (but otherwise keeping prescription levels to 2001 levels) may reduce the annual breast cancer caseload by 280 (2.4%), 555 (4.7%) or 674 (5.7%), respectively. In conclusion, this study has demonstrated that when HRT prevalence is relatively high, the effect on breast cancer incidence in the population will be significant. A small modification in HRT prescribing practices may impact breast cancer incidence in Australia with associated financial and health care provision implications. (C) 2005 Elsevier Ltd. All rights reserved.

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Background: Studies investigating the association between alcohol use and cognitive disorders in the elderly population have produced divergent results. Moreover, the role of alcohol in cognitive dysfunction is not clear. The aims of this study were to estimate the prevalence of alcohol-related problems in an elderly population from Brazil and to investigate their association with cognitive and functional impairment (CFI) and dementia. Methods: A community-based cross-sectional study was performed. A sample of 1,145 elderly people was examined in 2 phases. Several instruments were utilized in the first phase: the CAGE questionnaire was used to identify potential cases of alcohol-related problems, and a screening test for dementia was used to estimate CFI. The CAMDEX interview (Cambridge Examination) and DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition) criteria were used for the clinical diagnosis of dementia in the second phase. Results: ""Heavy alcohol use"" (CAGE >= 2) was found in 92 subjects (prevalence: 8.2%). It was associated with gender (males, p < 0.001), low education (only in females, p = 0.002), and low socioeconomic level (p = 0.001, in females; p = 0.002, in males). The Mini Mental State Examination exhibited a nonlinear relationship with alcohol-related problems in females; ""mild-moderate alcohol use"" (CAGE < 2) presented the highest score. A significant association between alcohol-related problems and cognitive dysfunction was found only in females. ""Heavy alcohol use"" was associated with higher CFI and dementia rates compared to ""mild-moderate alcohol use"" (p = 0.003 and p < 0.001, respectively). ""Mild-moderate alcohol use"" had a tendency of association with lower CFI and dementia rates when compared to ""no alcohol use"" (p = 0.063 and 0.050, respectively). Conclusion: Our findings suggest that alcohol use does not have a linear relationship with cognitive decline.

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To analyse breast cancer incidence trends in New South Wales (NSW), Australia, in relation to population-based mammography screening targeting women aged 50 to 69 years. Trends in age-specific incidence of invasive breast cancers in NSW women aged >= 40 years were examined in relation to mammography screening rates and screening cancer detection rates. Incidence of invasive breast cancer in NSW women increased in all age-groups over 1972 to 2002. The incidence trend for women aged 50 to 69 years showed that the steepest rise was associated with increased participation in population-based mammography screening, which was implemented from 1988 and achieved state-wide coverage in 1995. The elevated incidence of invasive cancer significantly exceeded pre-screening levels, and persisted after rates of initial screens declined. This elevated incidence was sustained by the contribution of cancers diagnosed through subsequent screening, and resulted from increased cancer detection rates in subsequent screens. The recent increase in invasive breast cancer incidence in NSW is associated with mammography screening, and occurred mostly in the target age-group women. Persistence of higher incidence after 1994 was not explicable by inflation of cancer incidence due to detection of prevalent screen cases, but was associated with a trend of increased cancer detection rates in subsequent screening rounds, probably consequent to quality improvements in mammography screening diagnosis.

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This study investigates the relationship between the number of screening mammograms read by radiologists and the screening breast cancer detection rate. Cancer detection rates for incident screens (all women aged >= 40 years) were compared by increasing categories of reader volume using Poisson regression. Data from New South Wales (NSW) for a 2 year period (2000-2001) were obtained from the BreastScreen NSW programme. Cancer detection rates increased with the number of mammograms read in the programme, reaching a plateau of approximately 40 per 10,000 after 1375 mammograms per year. No significant differences in cancer detection were evident above 875 mammograms (compared to below 875 mammograms) per year (RR = 0.79, 95% CI 0.63-0.99). (c) 2005 Elsevier Ltd. All rights reserved.

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The firefighters are at increased risk of respiratory disease as a result of exposure to smoke and dust. The aim of this study was to determine the prevalence and risk associated with respiratory symptoms among city firefighters in Sao Paulo, Brazil. Methods A cross-sectional study utilizing the European Community Respiratory Health Survey (ECRHS) questionnaire was administered to firefighters and police officers, in order to evaluate their respiratory symptoms. Results Complete respiraton, data were obtained from 1,235 firefighters and 1,839 police officers. Among the firefighters, there were 55.5% never-smokers, 22.4% current smokers and 18.2% former smokers (P < 0.05). Among the police officers, there were 63.4%, 18.6%, and 9.6% who were never-smokers, current smokers and former smokers (P < 0.05), respectively. Compared to police, firefighters experienced an increase in wheezing [OR = 1.63 (95% CI: 1.43-1.87)], wheezing with breathlessness [OR = 1.34 (95% CI: 1.10-1.64)], wheezing without a cold [OR = 1.60 (95% CI: 1.32-1.95)], waking with tightness in the chest [OR = 1.20 (95% CI: 1.02-1.42)], and rhinitis [OR = 1.12 (95% CI: 1.03-1.22)]. The prevalence of adult-onset asthma in never-smokers was 9.3% and 6.7% for firefighters and police officers [OR = 1.23 (95% CI: 1.01-1.56)]. All independent association was observed between years employed, smoking, history of rhinitis, and work as a firefighter and respiratory, and nasal symptoms. We observed a high prevalence of asthma-like symptoms in firefighters who presented respiratory symptoms beginning immediately after firefighting. Conclusion These results suggest that the prevalence of respiratory symptoms and asthma in firefighters is higher than those in police officers. Work-as a firefighter, rhinitis and vears employed were risk factors for respiratory,symptoms of asthma. Am. J. Ind. Med. 52:261 269, 2009. (C) 2008 Wiley-Liss, Inc.

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Background: There is a paucity of information describing the real-time 3-dimensional echocardiography (RT3DE) and dyssynchrony indexes (DIs) of a normal population. We evaluate the RT3DE DIs in a population with normal electrocardiograms and 2- and 3-dimensional echocardiographic analyses. This information is relevant for cardiac resynchronization therapy. Methods: We evaluated 131 healthy volunteers (73 were male, aged 46 +/- 14 years) who were referred for routine echocardiography; who presented normal cardiac structure on electrocardiography, 2-dimensional echocardiography, and RT3DE; and who had no history of cardiac diseases. We analyzed 3-dimensional left ventricular ejection fraction, left ventricle end-diastolic volume, left ventricle end-systolic volume, and left ventricular systolic DI% (6-, 12-, and 16-segment models). RT3DE data were analyzed by quantifying the statistical distribution (mean, median, standard deviation [SD], relative SD, coefficient of skewness, coefficient of kurtosis, Kolmogorov-Smirnov test, D`Agostino-Pearson test, percentiles, and 95% confidence interval). Results: Left ventricular ejection fraction ranged from 50% to 80% (66.1% +/- 7.1%); left ventricle end-diastolic volume ranged from 39.8 to 145 mL (79.1 +/- 24.9 mL); left ventricle end-systolic volume ranged from 12.9 to 66 mL (27 +/- 12.1 mL); 6-segment DI% ranged from 0.20% to 3.80% (1.21% +/- 0.66%), median: 1.06, relative SD: 0.5482, coefficient of skewness: 1.2620 (P < .0001), coefficient of Kurtosis: 1.9956 (P = .0039); percentile 2.5%: 0.2900, percentile 97.5%: 2.8300; 12-segment DI% ranged from 0.22% to 4.01% (1.29% +/- 0.71%), median: 1.14, relative SD: 0.95, coefficient of skewness: 1.1089 (P < .0001), coefficient of Kurtosis: 1.6372 (P = .0100), percentile 2.5%: 0.2850, percentile 97.5%: 3.0700; and 16-segment DI% ranged from 0.29% to 4.88% (1.59 +/- 0.99), median: 1.39, relative SD: 0.56, coefficient of skewness: 1.0792 (P < .0001), coefficient of Kurtosis: 0.9248 (P = .07), percentile 2.5%: 0.3750, percentile 97.5%: 3.750. Conclusion: This study allows for the quantification of RT3DE DIs in normal subjects, providing a comparison for patients with heart failure who may be candidates for cardiac resynchronization therapy. (J Am Soc Echocardiogr 2008; 21: 1229-1235)

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Objective: To investigate: 1) the impact of clinical varicocele on reactive oxygen species (ROS) levels in neat and washed semen in a proven fertile population; and 2) the correlation between ROS levels, testicular volume, and varicocele grade in the same population of fertile men. Design: Prospective controlled clinical study. Setting: Andrology laboratory at tertiary-care hospital. Patient(s): One hundred fourteen healthy fertile men (81 normal fertile and 33 fertile with clinical varicocele) and 30 infertile patients (control subjects). Intervention(s): Standard semen analysis and measurement of sperm ROS production. Main Outcome Measure(s): Seminal parameters, seminal ROS levels, seminal leukocyte levels, clinical varicocele, and testis size. Result(s): Thirty-three of the 11.4 (29%) fertile men had clinical varicocele (grade 1, n = 14; grade 2, n = 11; and grade 3, n = 8), and the remaining 81 (71%) had a normal physical examination. Levels of ROS and semen quality did not differ significantly between the fertile men with or without varicocele. No significant differences in ROS levels in neat and washed semen were observed compared with fertile men with grades 2 and 3 varicocele and with fertile men with varicocele grade 1. The ROS levels in neat and washed semen were not significantly correlated with varicocele grade in fertile men. No significant correlations between ROS levels and testis volume were observed between the fertile groups. Conclusion(s): The presence of clinical varicocele in fertile men is not associated with higher seminal ROS levels or abnormal semen parameters. Levels of ROS are not correlated with varicocele grade or testis volume in the same population of fertile men.

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Problem We evaluated associations between a length polymorphism in intron 2 of the gene coding for IL-1ra (gene symbol IL1RN) and pregnancy outcome in a population with a high rate of preterm birth. Method of study Subjects were pregnant women in Maceio, Brazil and their newborns. DNA was tested for IL1RN genotypes and alleles by gene amplification using primer pairs that spanned the polymorphic region. Every subject completed a detailed questionnaire. Results The frequency of allele 2 (IL1RN*2) carriage was elevated in mothers with a spontaneous preterm birth (SPTB) in the current pregnancy (P = 0.02) and also with a prior preterm delivery (P = .01). Both SPTB with intact membranes (P = 0.01) and SPTB preceded by pre-term pre-mature rupture of membranes (P = .03) were associated with IL1RN*2 carriage. A previous fetal demise was more than twice as prevalent in mothers positive for two copies of IL1RN*2. Conclusion Maternal carriage of IL1RN*2 increases susceptibility to inflammation-triggered spontaneous pre-term birth.

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Neutron activation analysis was applied to assess trace elements concentrations in head hair from healthy elderly people living in the Sao Paulo metropolitan area. Concentrations of As, Br, Ca, Cl, Co, Cr, Cu, Fe, K, La, Mn, Na, Sb, Se and, Zn were determined. Comparisons were made between the results obtained for dyed and non-dyed hair as well as for hair from females and males of two different age groups. The results were also compared with range values established by clinical laboratories and published data.