3,440 research outputs found

    Nutrigenomics and immune function in fish : new insights from omics technologies

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    This study was funded by BBSRC grant BB/M026604/1.Peer reviewedPublisher PD

    McSCIA: application of the Equivalence Theorem in a Monte Carlo radiative transfer model for spherical shell atmospheres

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    A new multiple-scattering Monte Carlo 3-D radiative transfer model named McSCIA (Monte Carlo for SCIAmachy) is presented. The backward technique is used to efficiently simulate narrow field of view instruments. The McSCIA algorithm has been formulated as a function of the Earth&apos;s radius, and can thus perform simulations for both plane-parallel and spherical atmospheres. The latter geometry is essential for the interpretation of limb satellite measurements, as performed by SCIAMACHY on board of ESA&apos;s Envisat. The model can simulate UV-vis-NIR radiation. <br><br> First the ray-tracing algorithm is presented in detail, and then successfully validated against literature references, both in plane-parallel and in spherical geometry. A simple 1-D model is used to explain two different ways of treating absorption. One method uses the single scattering albedo while the other uses the equivalence theorem. The equivalence theorem is based on a separation of absorption and scattering. It is shown that both methods give, in a statistical way, identical results for a wide variety of scenarios. Both absorption methods are included in McSCIA, and it is shown that also for a 3-D case both formulations give identical results. McSCIA limb profiles for atmospheres with and without absorption compare well with the one of the state of the art Monte Carlo radiative transfer model MCC++. <br><br> A simplification of the photon statistics may lead to very fast calculations of absorption features in the atmosphere. However, these simplifications potentially introduce biases in the results. McSCIA does not use simplifications and is therefore a relatively slow implementation of the equivalence theorem

    Handling missing data by re-approaching non-respondents

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    When handling missing data, a researcher should be aware of the mechanism underlying the missingness. In the presence of non-randomly missing data, a model of the missing data mechanism should be included in the analyses to prevent the analyses based on the data from becoming biased. Modeling the missing data mechanism, however, is a difficult task. One way in which knowledge about the missing data mechanism may be obtained is by collecting additional data from non-respondents. In this paper the method of re-approaching respondents who did not answer all questions of a questionnaire is described. New answers were obtained from a sample of these non-respondents and the reason(s) for skipping questions was (were) probed for. The additional data resulted in a larger sample and was used to investigate the differences between respondents and non-respondents, whereas probing for the causes of missingness resulted in more knowledge about the nature of the missing data patterns

    Providing Preventive Oral Health Care to Infants and Young Children in Women, Infants, and Children (WIC), Early Head Start, and Primary Care Settings

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    This report focuses on seven oral health programs that provide preventive oral health care to young children (infants, toddlers, and children up to 5 years old) in Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), Early Head Start (EHS), and primary care settings. All of the programs strive to increase access to preventive oral health care by integrating dental services into primary care settings, WIC clinics, or EHS centers. These programs also rely on primary care providers (physicians, nurses, medical assistants, etc.) or new types of dental hygienists who can practice in community settings to deliver preventive oral health services. Two additional reports in this series describe the remaining programs that provide care in non-dental settings and programs designed to specifically address socioeconomic, cultural, and geographic barriers to preventive oral health care.The findings from the EAs of these programs are synthesized to highlight diverse and innovative strategies that are utilized to provide preventive oral health care in primary care settings, WIC clinics, or EHS centers. These strategies have potential for rigorous evaluation and could emerge as best practices. If proven effective, these innovative program elements could then be disseminated and replicated to increase access for populations in need of preventive oral health care

    Epigenetic modification of the oxytocin receptor gene is associated with emotion processing in the infant brain

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    The neural capacity to discriminate between emotions emerges early in development, though little is known about specific factors that contribute to variability in this vital skill during infancy. In adults, DNA methylation of the oxytocin receptor gene (OXTRm) is an epigenetic modification that is variable, predictive of gene expression, and has been linked to autism spectrum disorder and the neural response to social cues. It is unknown whether OXTRm is variable in infants, and whether it is predictive of early social function. Implementing a developmental neuroimaging epigenetics approach in a large sample of infants (N = 98), we examined whether OXTRm is associated with neural responses to emotional expressions. OXTRm was assessed at 5 months of age. At 7 months of age, infants viewed happy, angry, and fearful faces while functional near-infrared spectroscopy was recorded. We observed that OXTRm shows considerable variability among infants. Critically, infants with higher OXTRm show enhanced responses to anger and fear and attenuated responses to happiness in right inferior frontal cortex, a region implicated in emotion processing through action-perception coupling. Findings support models emphasizing oxytocin's role in modulating neural response to emotion and identify OXTRm as an epigenetic mark contributing to early brain function
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