949 resultados para density of adults
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Background : Femoral shaft fracture incidence increases in older adults and is associated with low-energy trauma. Apart from bone density, the distribution and size of bone contributes to its strength. Aim : To examine if bone geometry and density of the femoral mid-shaft in older adults differs by sex and race, we studied 197 White women, 225 Black women, 242 White men, and 148 Black men aged 70-79 years participating in the Health, Aging, and Body Composition study; a prospective cohort study in the USA. A secondary purpose of the study was to examine the association of site-specific muscle and fat to bone geometry and density. Subjects and methods : Subjects were community-dwelling and reported no difficulty walking one-quarter of a mile or climbing stairs. Mid-femoral volumetric bone mineral density (vBMD, mg cm -3 ), total area (TA), cortical area (CA), medullary area (MA), cross-sectional moments of inertia (CSMI: I x , I y , J ), and muscle and fat areas (cm 2 ) were determined by computed tomography (CT; GE CT-9800, 10 mm slice thickness). Results : vBMD was greater in men than women with no difference by race ( p < 0.001). Bone areas and area moments of inertia were also greater in men than women ( p < 0.001), with Black women having higher values than White women for TA and CA. Standardizing geometric parameters for body size differences by dividing by powers of femur length did not negate the sex difference for TA and MA. Significant differences ( p < 0.05) among the four groups also remained for I x and J . Mid-thigh muscle area was an independent contributor to TA in all groups (Std beta = 0.181-0.351, p < 0.05) as well as CA in women (Std beta = 0.246-0.254, p < 0.01) and CSMI in White women (Std beta = 0.175-0.185, p < 0.05). Further, muscle area was a significant contributor to vBMD in Black women. Conclusion : These results indicate that bone geometry and density of the femoral diaphysis differs primarily by sex, rather than race, in older well-functioning adults. In addition, site-specific muscle area appears to have a potential contributory role to bone geometry parameters, especially in women.
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We studied for the first time the occurrence of multiple paternity, male reproductive success, and neonate survival in wild, low-density adder (Vipera berus) populations using 13 microsatellite loci. Paternity was assigned for 15 clutches, collected during 3 years. Our data demonstrated that multiple paternity can occur at a high level (69%) in natural populations of V. berus, even if the density of adults is low. The high proportion of multiple sired clutches was comparable to the proportion observed in captive populations. Male reproductive success significantly increased with body length, and only the largest males successfully sired entire clutches. Finally, no relationship was detected between the number of fathers per clutch and neonate survival. These results suggest that multiple matings could be beneficial in populations with high level of inbreeding or low male fecundity.
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Bionomic data and larval density of Scarabaeidae (Pleurosticti) in sugarcane in the central region of Mato Grosso do Sul, Brazil. Phytophagous larvae of Scarabaeidae cause damage to diverse crops. Information on these pests is scarce; therefore, the objective of this study was to determine biological aspects and larval density of species occurring in an area of sugarcane. The studies were developed in Sidrolândia from April 2009 to March 2010. Scarab beetle larvae were collected in sugarcane roots every fifteen days, taken to the laboratory and reared to obtain the adults and determine biological parameters. A total of 2,656 larvae were collected, being 162 Liogenys fuscus, 120 Cyclocephala verticalis, 37 Cyclocephala forsteri, and 2337 Anomonyx sp. In January, 53.65 larvae m-2 were obtained, and the most abundant species was Anomonyx sp, representing 87.99% of the total larvae collected. From November to March, the greatest densities of Anomonyx were observed in the field. The adults of this species occurred from May to September, and egg laying from September to November. Eggs measured 1.1 x 1.7 mm, and incubation period last 15.4 days. First instar larvae were observed mainly in October; second instar larvae from November to April; and third instar from January to July. Pupae were observed from May to August. The most abundant scarab beetle, Anomonyx sp. in roots of sugarcane presents one generation per year in Sidrolândia, MS.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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O trabalho teve por objetivo determinar, em casa-de-vegetação, a densidade adequada de adultos, a idade ideal das plantas e a distribuição vertical de ovos nas diferentes partes da planta, visando à realização de estudos de resistência e à melhoria das práticas de manejo de Spodoptera frugiperda em algodoeiro. Os experimentos de oviposição de S. frugiperda em relação à densidade de adultos, relação entre plantas de algodoeiro e oviposição de S. frugiperda e não preferência para oviposição de S. frugiperda em variedades de algodoeiro foram realizados com plantas da variedade de algodoeiro BRS Ita 90. A não preferência (antixenose) para oviposição foi acompanhada nas variedades FiberMax 966, FiberMax 977, DeltaOpal, DeltaPenta, Acala 90, Coodetec 408, Coodetec 409, Coodetec 410, BRS Cedro, BRS Ipê, BRS Aroeira, IPR 96, IPR 20, BRS Araçá, IAC 24 e BRS Ita 90. Concluiu-se que S. frugiperda prefere ovipositar em plantas com cerca de 60 dias de idade, na superfície inferior das folhas situadas no terço superior dos testes de plantas sob condições de estufa. Uma densidade de, pelo menos, três pares de adultos S. frugiperda por planta foi suficiente para realizar testes de não preferência para oviposição em casa de vegetação. As variedades Coodetec 408, BRS Aroeira, BRS Araçá, BRS Ita 90 e DeltaPenta apresentaram resistência do tipo não preferência para oviposição de S. frugiperda. Em regiões com altas infestações de S. frugiperda, seria prudente para o cultivo utilizar a variedade de algodão BRS Ita 90.
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We estimated the population density of the Helmeted Curassow (Pauxi pauxi) in Tama National Park (TNP) Colombia, using visual counts between December 2006 and December 2008. We used six line transects (1 km each) equitably distributed in a natural forest between 800 and 1,200 m asl in the southern part of the park. The sampling effort was 588 hrs with a total distance of 490 km, a detection rate of 0.06 records/hr, and an encounter rate of 0.08 individuals/km. Only solitary individuals were recorded (n = 40); the estimated density was 4.8 individuals/km(2). Most detections occurred in the lower strata of the forest (floor and sub-canopy) where hunters take advantage of curassows in the lower strata for successful harvest. The southern sector of TNP becomes important in the dry season. Our study suggests a large population is in TNP, but harvesting activities including removal of eggs, chicks, and juveniles, and hunting adults are affecting the reproductive rate and population of the species. Received 6 June 2011. Accepted 2 February 2012.
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This study aimed to evaluate the relationship between the cost and energy density of diet consumed in Brazilian households. Data from the Brazilian Household Budget Survey (POF 200812009) were used to identify the main foods and their prices. Similar items were grouped, resulting in a basket of 67 products. Linear programming was applied for the composition of isoenergetic baskets, minimizing the deviation from the average household diet. Restrictions were imposed on the inclusion of items and the energy contribution of the various food groups. A reduction in average cost of diet was applied at intervals of R$0.15 to the lowest possible cost. We identified an inverse association between energy density and cost of diet (p < 0.05), and at the lowest possible cost we obtained the maximum value of energy density Restrictions on the diet's cost resulted in the selection of diets with higher energy density, indicating that cost of diet may lead to the adoption of inadequate diets in Brazil.
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UV-absorbing covers reduce the incidence of injurious insect pests and viruses in protected crops. In the present study, the effect of a UV-absorbing net (Bionet) on the spatio-temporal dynamics of the potato aphid on lettuce plants was evaluated. A field experiment was conducted during three seasons in two identical tunnels divided in four plots. A set of lettuce plants were artificially infested with Macrosiphum euphorbiae adults and the population was estimated by counting aphids on every plant over 7 to 9 weeks. Insect population grew exponentially but a significantly lower aphid density was present on plants grown under the UV-absorbing cover compared to a standard 50 mesh net. Similarly, in laboratory conditions, life table parameters were significantly reduced under the Bionet. Moreover, SADIE analysis showed that the spatial distribution of aphids was effectively limited under the UV-absorbing nets. Our results indicate that UV-absorbing nets should be considered as an important component of lettuce indoor cropping systems preventing pesticide applications and reducing the risk of spread of aphid-borne virus diseases.
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Background: Obesity, a growing epidemic, is a preventable risk factor for cardiometabolic diseases. Obesity and cardiometabolic diseases affect Hispanics and African Americans more than non-Hispanic Caucasians. This study examined the relationship among race/ethnicity, obesity diagnostic measures (body mass index, waist circumference, subscapular and triceps skinfold thickness), and cardiometabolic risk factors (hyperglycemia, high, non-high-density lipoprotein cholesterol, low, high-density lipoprotein cholesterol, and hypertension) for adults across the United States. Methods: Using data from two-cycles of the National Health and Examination Survey (NHANES) 2007-2010, and accounting for the complex sample design, logistic regression models were conducted comparing obesity indicators in Mexican Americans, other Hispanics, and Black non-Hispanics, with White non-Hispanics and their associations with the presence of cardiometabolic diseases. Results: Differences by race/ethnicity were found for subscapular skinfold thickness and hyperglycemia. Waist circumference and subscapular skinfold were positively associated with the presence of hyperglycemia; dyslipidemia, and hypertension across race/ ethnicity, adjusting for age, gender, smoking, physical activity, education, income to poverty index, and health insurance. Race/ ethnicity did not influence the association of any obesity indicators with the tested cardiometabolic diseases. All obesity measures except triceps skinfold were associated with hyperglycemia. Conclusions: We suggest that subscapular skinfold thickness be considered as an inexpensive non-intrusive screening tool for cardiometabolic risk factors in an adult US population
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Hydrodynamism is an environmental stressor on marine communities with effects on populations of intertidal organisms. Microphrys bicornutus is a crab species associated with secondary substrates on rocky shores and little is known about its population dynamics and its relation to the shore hydrodynamics. The aim of this study is to describe the population structure of Microphrys bicornutus on intertidal rocky shores from the north coast of the São Paulo State, Brazil, and the influence of wave exposure on the density of this decorator crab. There was a greater density of M. bicornutus on sheltered than on exposed rocky shores, which is probably due to the hydrodynamic influence on M. bicornutus populations on rocky shores: directly ( by the physical stress caused by wave impact) and indirectly ( by determining the dominance of the secondary substrate) acting on the density of these crabs. Our results also suggest a vertical distribution of juveniles and adults, where the juveniles might be more abundant on the infralittoral fringe and, thus, more influenced by hydrodynamism than adults in the infralittoral.
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We show that carbon nanotubes (CNTs) with high density of defects can present a strong electronic interaction with nanoparticles of Pt-Ru with average particle size of 3.5 +/- 0.8 nm. Depending on the Pt-Ru loading on the CNTs, CO and methanol oxidation reactions suggest there is a charge transfer between Pt-Ru that in turn provokes a decrease in the electronic interaction taking place between Ru and Pt in the PtRu alloy. The CO stripping potentials were observed at about 0.65 and 0.5 V for Pt-Ru/CNT electrodes with Pt-Ru loadings of 10 and 20, and 30 wt %, respectively. (C) 2008 The Electrochemical Society. [DOI: 10.1149/1.2990222] All rights reserved.
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The argasid tick Ornithodoros marinkellei Kohls, Clifford, and Jones, 1969 was described 4 decades ago based on larval specimens collected from bats (Pteronotus spp.) in Colombia and Panama. Thereafter, larval O. marinkellei parasitizing bats were reported from Venezuela, Guyana, and Brazil. Herein, we describe the adults and nymph, and redescribe the larva of O. marinkellei based on specimens recently collected in the western Brazilian Amazon region. In contrast to all other known adult argasids, the idiosoma of both males and females of O. marinkellei is covered with sclerotized plaques. The idiosoma of the nymph of O. marinkellei is entirely micromamillated, and differs from the adults by the absence of plaques. The larva of O. marinkellei is morphologically similar to the larvae of the 2 other species belonging to the subgenus Subparmatus, i.e., Ornithodoros viguerasi Cooley and Kohls, 1941 and Ornithodoros mormoops Kohls, Clifford, and Jones, 1969. Because of the long and narrow dorsal plate, the larva of O. marinkellei is readily distinguished from O. viguerasi and O. mormoops. Comparison of our larvae from Brazil with O. marinkellei paratype specimens from Colombia confirmed their taxonomic identification. However, a few morphological differences, particularly in the size of the gnathosoma, were observed. Further studies are necessary to clarify whether O. marinkellei is a complex of different species, or a single species represented by morphologically polymorphic, and geographically distinct populations. Partial mitochondrial 16S rDNA gene sequences were generated for O. marinkellei specimens from Brazil, and compared with available homologous sequences in GenBank. Phylogenetic analyses revealed O. marinkellei to be distinct from the remaining argasid species available in GenBank, including other bat-associated tick species that are found in sympatry with O. marinkellei in the Neotropical region.
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Introduction: Osteogenic effects of therapeutic fluoride have been reported; however, the impact of exposure to low level water fluoridation on bone density is not clear. We investigated the effect of long-term exposure to fluoridated water from growth to young adulthood on bone mineral density (BMD). Methods: BMD was measured in 24 healthy women from Regina (fluoride 0.1 mg/L) and 33 from Saskatoon (fluoride 1.0 mg/L), with no differences between groups for height, weight, lifestyle or dietary factors. Results: Saskatoon women had significantly higher mean BMD at total anterior-posterior lumbar spine (APS) and estimated volumetric L3 (VLS), with no difference at total body (TB) or proximal femur (PF). Conclusion: Exposure to water fluoridation during the growing years may have a power impact on axial spine bone density in young women.
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Objectives: To evaluate clinical and echocardiographic variables that could be used to predict outcomes in patients with asymptomatic severe aortic valve stenosis. Management of asymptomatic severe aortic stenosis is controversial. Because prophylactic surgery may be protective, independent predictors of events that could justify early surgery have been sought. Methods: Outpatients (n= 133; mean [+/- SD] age, 66.2 +/- 13.6 years) with isolated severe asymptomatic aortic stenosis but normal left ventricular function and no previous myocardial infarction were followed up prospectively at a tertiary care hospital. Interventions: We use a ""wait-for-events"" strategy. Clinical and echocardiographic variables were analyzed. Results: Nineteen patients developed angina; 40, dyspnea; 5, syncope; and 7, sudden death during a mean follow-up period of 3.30 +/- 1.87 years. Event-free survival was 90.2 +/- 2.6% at 1 year, 73.4 +/-.9% at 2 years, 70.7 +/- 4.3% at 3 years, 57.8 +/- 4.7% at 4 years, 40.3 +/- 5.0% at 5 years, and 33.3 +/- 5.2% at 6 years. The mean follow-up period until sudden death (1.32 +/- 1.11 years) was shorter than that for dyspnea (2.44 +/- 1.84 years), syncope (2.87 +/- 1.26 years) and angina (3.03 +/- 1.68 years). Cox regression analysis disclosed only reduced but within normal limits ejection fraction as independent predictor of total events. Conclusions: Management on ""wait-for-events"" strategy is generally safe. Progressive left ventricular ejection fraction reduction even within normal limits identified patients at high risk for events in whom valve replacement surgery should be considered. (c) 2007 Elsevier Ireland Ltd. All rights reserved.