Population Structure and Cryptic Relatedness in Genetic Association Studies

We review the problem of confounding in genetic association studies, which arises principally because of population structure and cryptic relatedness. Many treatments of the problem consider only a simple ``island'' model of population structure. We take a broader approach, which views population structure and cryptic relatedness as different aspects of a single confounder: the unobserved pedigree defining the (often distant) relationships among the study subjects. Kinship is therefore a central concept, and we review methods of defining and estimating kinship coefficients, both pedigree-based and marker-based. In this unified framework we review solutions to the problem of population structure, including family-based study designs, genomic control, structured association, regression control, principal components adjustment and linear mixed models. The last solution makes the most explicit use of the kinships among the study subjects, and has an established role in the analysis of animal and plant breeding studies. Recent computational developments mean that analyses of human genetic association data are beginning to benefit from its powerful tests for association, which protect against population structure and cryptic kinship, as well as intermediate levels of confounding by the pedigree.Comment: Published in at http://dx.doi.org/10.1214/09-STS307 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Community Orientation and Involvement Patterns of University Professors

Sociolog

Beyond Checklists: A Nursing Informatics Education Strategy for Undergraduate Nursing Students Appraising Health Information on Social Networking Sites (SNS) / Au-delà des listes de vérification : Une stratégie de formation infirmière au numérique pour l’évaluation, par les étudiantes de premier cycle, des informations sur la santé présentes sur les sites des réseaux sociaux (SRS)

Increasingly internet social networking sites are used in healthcare to support, communicate and offer information platforms between healthcare providers, users, and the public. Undergraduate nursing students draw on various sources of evidence to inform best-practice decisions in collaboration with patients and the healthcare team. Student or patient-initiated access of information from social networking sites necessitates high levels of informatics literacy. While students may reveal adept social networking site navigation skills, their capacity to appraise and apply information from these sites to their nursing practice, in ways that demonstrate informatics competence, requires further exploration. The purpose of this education project was to describe how students’ informatics competence was enriched through the development and implementation of a Credibility, Argument, Purpose and Evidence guide, compared to a previously implemented checklist as part of a digital health assignment. The Constructivist Online Learning Environment Survey evaluated student-learning perceptions using the new guide as well as the previously utilized checklist. The developed guide improved students’ perceptions of their ability to appraise social networking sites. Results revealed an improvement in students’ appreciation of the significance of moving beyond the use of checklists when appraising and evaluating social networking sites. Educational institutions assume a prominent role as stakeholders in curriculum development, to equip nursing students with informatics skills to critically appraise and evaluate information from various social networking sites and technologies, alongside other health knowledge, for ethical evidence informed nursing practice. Résumé Les intervenants du secteur de la santé utilisent de plus en plus les sites de réseautage social en ligne pour soutenir, communiquer et offrir une plateforme d’information permettant des échanges entre les professionnels de la santé, les utilisateurs des services de santé et le public. Les étudiantes en sciences infirmières de premier cycle s’appuient sur diverses sources de résultats probants pour prendre des décisions éclairées basées sur les pratiques exemplaires, en collaboration avec les patients et les membres de l’équipe des soins. L’accès aux informations par les étudiantes ou les patients à partir des sites de réseautage social nécessite un niveau élevé de maîtrise du numérique. Bien que les étudiantes puissent détenir des habiletés de navigation sur de tels sites, leur capacité à évaluer et à mettre en application des informations tirées de ces sites dans leur pratique infirmière, de manière à démontrer une compétence numérique, nécessite une exploration plus poussée. Le but de ce projet de formation était de décrire comment la compétence numérique des étudiantes a été enrichie grâce à l’élaboration et à la mise en œuvre d’un guide portant sur la Crédibilité, l’Argumentation, le But, et les Résultats probants, pour remplacer une liste de vérification précédemment utilisée dans le cadre d’un travail en santé numérique. Le Constructivist Online Learning Environment Survey (sondage sur un environnement constructiviste d’apprentissage en ligne) a permis d’évaluer les perceptions d’apprentissage des étudiantes à l’aide du nouveau guide et de la liste de vérification utilisée précédemment. Le guide élaboré a amélioré la perception de ces dernières quant à leur capacité à évaluer les sites de réseautage social et les résultats ont révélé qu’elles comprennent davantage la nécessité d’aller au-delà des listes de vérification pour évaluer de tels sites. Les établissements d’enseignement jouent un rôle de premier plan dans l’élaboration des programmes de formation qui poussent les étudiantes en sciences infirmières à développer leur compétence numérique, leur permettant d’évaluer de manière critique les informations provenant de divers sites de réseaux sociaux et de technologies , en plus d’autres connaissances en matière de santé, pour une pratique infirmière éclairée par une analyse éthique des résultats probants

The Effect of Aging on Crowded Letter Recognition in the Peripheral Visual Field

PURPOSE. Crowding describes the increased difficulty in identifying a target object when it is surrounded by nearby objects (flankers). A recent study investigated the effect of age on visual crowding and found equivocal results: Although crowded visual acuity was worse in older participants, crowding expressed as a ratio did not change with age. However, the spatial extent of crowding is a better index of crowding effects and remains unknown. In the present study, we used established psychophysical methods to characterize the effect of age on visual crowding (magnitude and extent) in a letter recognition task. METHODS. Letter recognition thresholds were determined for three different flanker separations in 54 adults (aged 18-76 years) with normal vision. Additionally, the spatial extent of crowding was established by measuring spacing thresholds: the flanker-to-target separation required to produce a given reduction in performance. Uncrowded visual acuity, crowded visual acuity, and spacing thresholds were expressed as a function of age, avoiding arbitrary categorization of young and old participants. RESULTS. Our results showed that uncrowded and crowded visual acuities do not change significantly as a function of age. Furthermore, spacing thresholds did not change with age and approximated Bouma's law (half eccentricity). CONCLUSIONS. These data show that crowding in adults is unaffected by senescence and provide additional evidence for distinct neural mechanisms mediating surround suppression and visual crowding, since the former shows a significant age effect. Finally, our data suggest that the well-documented age-related decline in peripheral reading ability is not due to agerelated changes in visual crowding

Subjective SES is Associated with Children's Neurophysiological Response to Auditory Oddballs

Language and reading acquisitions are strongly associated with a child’s socioeconomic status (SES). There are a number of potential explanations for this relationship. We explore one potential explanation—a child’s SES is associated with how children discriminate word-like sounds (i.e., phonological processing), a foundational skill for reading acquisition. Magnetoencephalography data from a sample of 71 children (aged 6 years and 11 months–12 years and 3 months), during a passive auditory oddball task containing word and nonword deviants, were used to test “where” (which sensors) and “when” (at what time) any association may occur. We also investigated associations between cognition, education, and this neurophysiological response. We report differences in the neural processing of word and nonword deviant tones at an early N200 component (likely representing early sensory processing) and a later P300 component (likely representing attentional and/or semantic processing). More interestingly we found “parental subjective” SES (the parents rating of their own relative affluence) was convincingly associated with later responses, but there were no significant associations with equivalized income. This suggests that the SES as rated by their parents is associated with underlying phonological detection skills. Furthermore, this correlation likely occurs at a later time point in information processing, associated with semantic and attentional processes. In contrast, household income is not significantly associated with these skills. One possibility is that the subjective assessment of SES is more impactful on neural mechanisms of phonological processing than the less complex and more objective measure of household income

Molybdenum dioxide in carbon nanoreactors as a catalytic nanosponge for the efficient desulfurization of liquid fuels

The principle of a “catalytic nanosponge” that combines the catalysis of organosulfur oxidation and sequestration of the products from reaction mixtures is demonstrated. Group VI metal oxide nanoparticles (CrOx, MoOx, WOx) are embedded within hollow graphitized carbon nanofibers (GNFs), which act as nanoscale reaction vessels for oxidation reactions used in the decontamination of fuel. When immersed in a model liquid alkane fuel contaminated with organosulfur compounds (benzothiophene, dibenzothiophene, dimethyldibenzothiophene), it is found that MoO2@GNF nanoreactors, comprising 30 nm molybdenum dioxide nanoparticles grown within the channel of GNFs, show superior abilities toward oxidative desulfurization (ODS), affording over 98% sulfur removal at only 5.9 mol% catalyst loading. The role of the carbon nanoreactor in MoO2@GNF is to enhance the activity and stability of catalytic centers over at least 5 cycles. Surprisingly, the nanotube cavity can selectively absorb and remove the ODS products (sulfoxides and sulfones) from several model fuel systems. This effect is related to an adsorptive desulfurization (ADS) mechanism, which in combination with ODS within the same material, yields a “catalytic nanosponge” MoO2@GNF. This innovative ODS and ADS synergistic functionality negates the need for a solvent extraction step in fuel desulfurization and produces ultralow sulfur fuel

Learning from an Electronic Chart Testbed

Over the past five years, the Canadian Hydrographic Service’s Electronic Chart Testbed has provided insights into the way an electronic chart (EC) will handle chart data — and from this the appropriate form for the Hydrographic Office to provide and electronic chart database; it has stimulated suggestions about how the display should be designed; it has provided a practical model for use in planning IHO specifications — and followed on to test these by implementing them; and it has shared in giving mariners demonstrations of some of the eventual capabilities of ECDIS, so that they can start thinking about what they need from it. This paper describes planning the Testbed; lessons from early tests; initial ideas on electronic chart data and on display design; and the reactions from mariners who saw the Testbed among six electronic charts on board the Norwegian ship LANCE during the 1988 North Sea Project

Sexual dimorphism of brown adipose tissue function

ObjectiveTo determine whether brown adipose tissue (BAT) activity in school-age children differs between the sexes and to explore the impact of dietary intake, sedentary behavior, and picky/fussy eating.Study designChildren aged 8.5-11.8 years of age (n = 36) underwent infrared thermography to determine the temperature of the skin overlying the main superficial BAT depot in the supraclavicular region before and after 5 minutes of mild cold exposure (single-hand immersion in cool tap water at about 20°C). The relationships between the supraclavicular region temperature and parental reports of food consumption, eating behavior, and inactivity were explored.ResultsThe supraclavicular region temperature was higher in boys (n = 16) at baseline, and after cold exposure. Boys displayed a greater thermogenic response to cold. Strong negative correlations were observed between the supraclavicular region temperature and body mass index percentile, and differences in supraclavicular region temperature between girls and boys persisted after adjustment for body mass index percentile. A negative linear relationship was observed between protein and vegetable intake and supraclavicular region temperature in girls only, but did not persist after adjustment for multiple comparisons. There was no difference in the adjusted supraclavicular region temperature between active or inactive children, or picky and nonpicky eaters.ConclusionsThese findings indicate sexual dimorphism in BAT thermogenic activity and a sex-specific impact of diet. Future studies should aim to quantify the contribution of BAT to childhood energy expenditure, energy imbalance, and any role in the origins of childhood obesity