24 research outputs found

    Retrieval validation during the European aqua thermodynamic experiment

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    Atmospheric and surface thermodynamic parameters retrieved with advanced hyperspectral remote sensors aboard Earth observing satellites are critical to weather prediction and scientific research. The retrieval algorithms and retrieved parameters from satellite sounders must be validated to demonstrate the capability and accuracy of both observation and data processing systems. The European Aqua Thermodynamic Experiment (EAQUATE) was conducted not only for validation of the Atmospheric InfraRed Sounder on the Aqua satellite, but also for assessment of validation systems of both ground-based and aircraft-based instruments that will be used for other satellite systems, such as the Infrared Atmospheric Sounding Interferometer on the European MetOp satellite, the Cross-track Infrared Sounder from the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project and the continuing series of NPOESS satellites. Detailed intercomparisons were conducted and presented using different retrieval methodologies: measurements from airborne ultraspectral Fourier transform spectrometers, aircraft in situ instruments, dedicated dropsondes and radiosondes, ground-based Raman lidar, as well as the European Centre for Medium-range Weather Forecasting modelled thermal structures. The results of this study not only illustrate the quality of the measurements and retrieval products, but also demonstrate the capability of the validation systems put in place to validate current and future hyperspectral sounding instruments and their scientific products

    Attachment to Conventional Institutions and Adolescent Rapid Repeat Pregnancy: A Longitudinal National Study Among Adolescents in the United States

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    INTRODUCTION: There is limited research on rapid repeat pregnancies (RRP) among adolescents, especially using nationally representative samples. We examine distal factors—school, family, peers, and public/private religious ties—and their associations with RRP among adolescent mothers. METHODS: Guided by social development theory, we conducted multivariate logistic regression analyses, adjusted for sociodemographic characteristics, to examine associations between RRP and attachment to school, family, peers, and religion among 1,158 female respondents from the National Longitudinal Study of Adolescent to Adult Health (Add Health) who reported at least one live birth before age 20. RESULTS: Attachments to conventional institutions were associated with lower likelihood of RRP. Adolescent mothers who had a stronger relationship with their parents had reduced odds of RRP (adjusted odds ratio [aOR] 0.83, 95% CI 0.71-0.99). Increased odds of RRP were associated with anticipating fewer negative social consequences of sex (aOR 1.18, 95% CI 1.02-1.35), never praying (versus praying daily; aOR 1.47, 95% CI 1.10-1.96), and never participating in church-related youth activities (versus participating once a week; 1.04, 95% CI 1.01-1.07). DISCUSSION: After an adolescent birth, social support from family, peers, and the community can benefit young mothers. Private aspects of religiosity may be especially important. Understanding the processes by which these distal factors are linked to the likelihood of RRP is needed to create multifaceted intervention programs that provide diverse methods of support customized to specific circumstances of adolescent mothers

    Potencial evocado auditivo de longa latĂȘncia para estĂ­mulo de fala apresentado com diferentes transdutores em crianças ouvintes

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    Objetivo: analisar, de forma comparativa, a influĂȘncia do transdutor no registro dos componentes P1, N1 e P2 eliciados por estĂ­mulo de fala, quanto Ă  latĂȘncia e Ă  amplitude, em crianças ouvintes. MĂ©todo: 30 crianças ouvintes de quatro a 12 anos de idade, de ambos os sexos. Os potenciais evocados auditivos de longa latĂȘncia foram pesquisados por meio dos transdutores, fone de inserção e caixa acĂșstica, eliciados por estĂ­mulo de fala /da/, sendo o intervalo interestĂ­mulos de 526ms, a intensidade de 70dBNA e a taxa de apresentação de 1,9 estĂ­mulos por segundo. Foram analisados os componentes P1, N1 e P2 quando presentes, quanto Ă  latĂȘncia e Ă  amplitude. Resultados: constatou-se um nĂ­vel de concordĂąncia forte entre a pesquisadora e o juiz. NĂŁo houve diferença estatisticamente significante ao comparar os valores de latĂȘncia e amplitude dos componentes P1, N1 e P2, ao considerar sexo e orelha, assim como para a latĂȘncia dos componentes quando analisado os tipos de transdutores. Entretanto, houve diferença estatisticamente significante para a amplitude dos componentes P1 e N1, com maior amplitude para o transdutor caixa acĂșstica. ConclusĂŁo: os valores de latĂȘncia dos componentes P1, N1 e P2 e amplitude de P2 obtidos com fone de inserção podem ser utilizados como referĂȘncia de normalidade independente do transdutor utilizado para a pesquisa dos potenciais evocados auditivos de longa latĂȘncia

    Grouping facilitates avoidance of parasites by fish

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    Background. Parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. We studied the role of fish behaviour in avoiding microhabitats with a high infection risk using Oncorhynchus mykiss and cercariae of Diplostomum pseudospathaceum as a model. Spatial distribution of parasites in experimental tanks was highly heterogeneous. We hypothesized that fish in groups are better at recognizing a parasitized area and avoiding it than solitary fish. Methods. Number of fish, either solitary or in groups of 5, was recorded in different compartments of a shuttle tank where fish could make a choice between areas with different risk of being infected. Intensity of infection was assessed and compared with the number of fish recorded in the compartment with parasites and level of fish motility. Results. Both solitary fish and fish in groups avoided parasitized areas, but fish in groups avoided it more strongly and thus acquired significantly fewer parasites than solitary fish. Prevalence of infection among grouped and solitary fish was 66 and 92 %, respectively, with the mean abundance two times higher in the solitary fish. Between-individual variation in the number of parasites per fish was higher in the “groups” treatment (across all individuals) than in the “solitary” treatment. Avoidance behaviour was more efficient when fish were allowed to explore the experimental arena prior to parasite exposure. High motility of fish was shown to increase the acquisition of D. pseudospathaceum. Conclusion. Fish in groups better avoided parasitized habitat, and acquired significantly fewer parasites than solitary fish. We suggest that fish in groups benefit from information about parasites gained from other members of a group. Grouping behaviour may be an efficient mechanism of parasite avoidance, together with individual behaviour and immune responses of fishes. Avoidance of habitats with a high parasite risk can be an important factor contributing to the evolution and maintenance of grouping behaviour in fish.peerReviewe
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