220 research outputs found

    Probing the Multiple Structures of Vaterite through Combined Computational and Experimental Raman Spectroscopy

    Get PDF
    First-principles Raman spectra have been computed for several new vaterite structural models that have been recently proposed, and compared with spectra recorded on a set of biogenic, geological and synthetic samples. This set includes new measurements collected on Herdamania momus spicules (Great Barrier Reef, Queensland, Australia), which are known to have purity and crystallinity that are higher than for other biogenic samples. Overall, due to the close structural connection between the various models, the computed Raman spectra are found to be broadly similar. However, the spectra obtained for the two most stable models (monoclinic C2 and trigonal P3221, corresponding to two different polytypes of vaterite) exhibit features that are in excellent agreement with the experimental spectra, whereas the other theoretical structures show minor peaks that are not observed experimentally. When comparing the spectra for the two lowest energy structural models (C2 and P3221), the differences are too small to discriminate between these candidates. The Raman spectrum of Herdamania momus is of higher quality with respect to spectra obtained in previous studies on other biogenic samples. However, there is no significant and systematic difference with respect to samples of geological and synthetic origin

    Characterisation of pulmonary function trajectories: results from a Brazilian cohort.

    Get PDF
    Background: Pulmonary function (PF) trajectories are determined by different exposures throughout the life course. The aim of this study was to investigate characteristics related to PF trajectories from 15 to 22 years in a Brazilian cohort. Methods: A birth cohort study (1993 Pelotas Birth Cohort) was conducted with spirometry at 15, 18 and 22 years. PF trajectories were built based on z-score of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and their ratio using a group-based trajectory model. Associations with exposures reported from perinatal to 22 years were described. Results: Three trajectories, low (LT), average (AT) and high (HT) were identified in 2917 individuals. Wealthiest individuals belonged to the HT of FEV1 (p=0.023). Lower maternal pregestational body mass index (BMI) (22.4±0.2; p<0.001 and 22.1±0.14; p<0.001) and lower birth weight (3164.8±25.4; p=0.029 and 3132.3±19.4; p=0.005) were related to the LT of FEV1 and FVC. Mother's smoking exposure during pregnancy (37.7%; p=0.002), active smoking at ages 18 and 22 years (20.1% and 25.8%; p<0.001) and family history of asthma (44.8%; p<0.001) were related to the LT of FEV1/FVC. Wheezing, asthma and hospitalisations due to respiratory diseases in childhood were related to the LT of both FEV1 and FEV1/FVC. Higher BMIs were related to the HT of FEV1 and FVC at all ages. Conclusions: PF trajectories were mainly related to income, pregestational BMI, birth weight, hospitalisation due to respiratory diseases in childhood, participant's BMI, report of wheezing, medical diagnosis and family history of asthma, gestational exposure to tobacco and current smoking status in adolescence and young adult age

    Multiethnic meta-analysis identifies ancestry-specific and cross-ancestry loci for pulmonary function

    Get PDF
    Nearly 100 loci have been identified for pulmonary function, almost exclusively in studies of European ancestry populations. We extend previous research by meta-analyzing genome-wide association studies of 1000 Genomes imputed variants in relation to pulmonary function in a multiethnic population of 90,715 individuals of European (N = 60,552), African (N = 8429), Asian (N = 9959), and Hispanic/Latino (N = 11,775) ethnicities. We identify over 50 additional loci at genome-wide significance in ancestry-specific or multiethnic meta-analyses. Using recent fine-mapping methods incorporating functional annotation, gene expression, and differences in linkage disequilibrium between ethnicities, we further shed light on potential causal variants and genes at known and newly identified loci. Several of the novel genes encode proteins with predicted or established drug targets, including KCNK2 and CDK12. Our study highlights the utility of multiethnic and integrative genomics approaches to extend existing knowledge of the genetics of l

    Tendencia temporal de asma en niños y adolescentes en Brasil en el período de 1998 a 2008

    Get PDF
    OBJECTIVE: To analyze the trends in asthma prevalence in children and adolescents between 1998 and 2008 in Brazil. METHODS: Data on asthma prevalence from the 1998, 2003 and 2008 National Household Sample Surveys were analyzed. The sample was comprised of 141,402, 144,443 and 134,032 individuals in 1998, 2003 and 2008, respectively, and the analysis was adjusted for the sample design. Trends in asthma prevalence were described for sex, Brazilian regions and place of residence of children (zero to nine years of age) and adolescents (ten to 19 years of age). RESULTS: The prevalence of asthma in children was 7.7% in 1998, 8.1% in 2003 and 8.5% in 2008, with an annual increase of 1%. The highest annual increase was observed in the Southeast and North regions (1.4%). Among adolescents, the prevalence of asthma was 4.4% in 1998, 5.0% in 2003 and 5.5% in 2008, with an increase of 2.2% per year. In the Northeast region, the annual increase in the prevalence of asthma was 3.5%. The greatest increases were observed in boys and in residents of rural areas. CONCLUSIONS: Although asthma has decreased in some developing countries, the results found in Brazil point to an increase in this disease in children and adolescents between 1998 and 2008, especially in rural areas.OBJETIVO: Analisar as tendências de asma em crianças e adolescentes entre 1998 e 2008 no Brasil. MÉTODOS: Foram analisados os dados de prevalência de asma da Pesquisa Nacional por Amostra de Domicílios, dos anos de 1998, 2003 e 2008. A amostra foi constituída por 141.402, 144.443 e 134.032 indivíduos em 1998, 2003 e 2008, respectivamente, e a análise foi ajustada pelo desenho amostral. As tendências de asma foram descritas por sexo, regiões do Brasil e local de residência, em crianças (zero a nove anos) e adolescentes (dez a 19 anos). RESULTADOS: A prevalência de asma entre crianças foi 7,7% em 1998, 8,1% em 2003 e 8,5% em 2008, com um incremento anual de 1%. O maior aumento anual foi observado nas regiões Sudeste e Norte (1,4%). Entre o grupo de adolescentes, a prevalência de asma foi de 4,4% em 1998, 5,0% em 2003 e 5,5% em 2008, com aumento de 2,2% ao ano. Na região Nordeste, o aumento anual na prevalência de asma foi de 3,5%. Os maiores incrementos foram observados entre os meninos e entre moradores da zona rural. CONCLUSÕES: Apesar de a asma apresentar um decréscimo em países emergentes, no Brasil os resultados apontam um incremento da asma entre crianças e adolescentes no período de 1998 e 2008, especialmente na zona rural.OBJETIVO: Analizar las tendencias de asma en niños y adolescentes entre 1998 y 2008 en Brasil. MÉTODOS: Se analizaron los datos de prevalencia de asma de la Investigación Nacional por Muestra de Domicilios, de los años de 1998, 2003 y 2008. La muestra fue constituida por 141.402, 144.443 y 134.032 individuos en 1998, 2003 y 2008, respectivamente y el análisis fue ajustado por el diseño muestral. Las tendencias de asma fueron descritas por sexo, regiones de Brasil y lugar de residencia, en niños (cero a nueve años) y adolescentes (diez a 19 años). RESULTADOS: La prevalencia de asma entre niños fue de 7,7% en 1998, 8,1% en 2003 y 8,5% en 2008, con un incremento anual de 1%. El mayor aumento anual fue observado en la región Sureste y Norte (1,4%). Entre el grupo de adolescentes, la prevalencia de asma fue de 4,4% en 1998, 5,0% en 2003 y 5,5% en 2008, con aumento de 2,2% al año. En la región Noreste, el aumento anual en la prevalencia de asma fue de 3,5%. Los mayores incrementos fueron observados entre los varones y entre habitantes de la zona rural. CONCLUSIONES: A pesar de el asma presentar una disminución en países en desarrollo, en Brasil, los resultados señalan un incremento del asma entre niños y adolescentes en el período de 1998 y 2008, especialmente en la zona rural

    Low Maternal Capital Predicts Life History Trade-Offs in Daughters: Why Adverse Outcomes Cluster in Individuals.

    Get PDF
    Background: Some individuals appear prone to multiple adverse outcomes, including poor health, school dropout, risky behavior and early reproduction. This clustering remains poorly understood. Drawing on evolutionary life history theory, we hypothesized that maternal investment in early life would predict the developmental trajectory and adult phenotype of female offspring. Specifically, we predicted that daughters receiving low investment would prioritize the life history functions of "reproduction" and "defense" over "growth" and "maintenance," increasing the risk of several adverse outcomes. Methods: We investigated 2,091 mother-daughter dyads from a birth cohort in Pelotas, Brazil. We combined data on maternal height, body mass index, income, and education into a composite index of "maternal capital." Daughter outcomes included reproductive status at 18 years, growth, adult anthropometry, body composition, cardio-metabolic risk, educational attainment, work status, and risky behavior. We tested whether daughters' early reproduction (<18 years) and exposure to low maternal capital were associated with adverse outcomes, and whether this accounted for the clustering of adverse outcomes within individuals. Results: Daughters reproducing early were shorter, more centrally adipose, had less education and demonstrated more risky behavior compared to those not reproducing. Low maternal capital was associated with greater likelihood of the daughter reproducing early, smoking and having committed violent crime. High maternal capital was positively associated with the daughter's birth weight and adult size, and the likelihood of being in school. Associations of maternal capital with cardio-metabolic risk were inconsistent. Daughters reproducing early comprised 14.8% of the population, but accounted for 18% of obesity; 20% of violent crime, low birth weight and short stature; 32% of current smoking; and 52% of school dropout. Exposure to low maternal capital contributed similarly to the clustering of adverse outcomes among daughters. Outcomes were worst among daughters characterized by both low maternal capital and early reproduction. Conclusion: Consistent with life history theory, daughters exposed to low maternal capital demonstrate "future discounting" in behavior and physiology, prioritizing early reproduction over growth, education, and health. Trade-offs associated with low maternal capital and early reproduction contribute to clustering of adverse outcomes. Our approach provides new insight into inter-generational cycles of disadvantage

    Tabagismo no Brasil: desigualdades regionais e prevalência segundo características ocupacionais

    Full text link
    O estudo descreveu a prevalência do tabagismo diário segundo sexo, idade, renda domiciliar e ocupação dos moradores de 15 anos ou mais, no Brasil e regiões, baseado nos dados da Pesquisa Nacional por Amostra Domiciliar 2008 (PNAD/IBGE). A análise considerou o desenho da amostra e incluiu 252.768 indivíduos. A prevalência de fumo diário no Brasil foi 15,1%, variando de 12,8% na região Norte a 17,4% na região Sul, sendo 62% maior nos homens que mulheres. A prevalência de fumo foi inversamente proporcional à renda domiciliar, sendo 18,6% entre os 20% mais pobres e 11,5% entre os 20% mais ricos. As mesmas tendências para sexo, idade e renda foram observadas nas diferentes regiões do país. O consumo diário de cigarros foi 3% maior entre os trabalhadores comparados com não trabalhadores. Trabalhadores não manuais apresentaram prevalências de fumo abaixo de 10%, enquanto trabalhadores manuais relataram frequências acima de 20%. A associação entre tabagismo e ocupação permaneceu após ajuste para sexo, idade e renda. As desigualdades encontradas devem ser consideradas no planejamento e direcionamento de ações efetivas para redução do tabagismo. Os grupos ocupacionais mais expostos deveriam ter prioridade nas intervenções.</jats:p
    corecore