2,531 research outputs found
Exploring syndemic vulnerability across generations:A case study of a former fishing village in the Netherlands
This qualitative case study uses a life-course approach to explore syndemic vulnerability in a former fishing village in the Netherlands. Building on four years of fieldwork in a low-income neighborhood, we explored salient themes between and across families and generations. Elderly community members (> 65 years) were interviewed to map village history and explore how contextual factors have affected family life, health, and wellbeing since the 1940s. We systematically traced and compared processes leading to or from syndemic vulnerability by studying seven families across three generations. Adults with at least one of clustering diseases, their parents (when possible), and their children participated in semi-structured life-course interviews. A complex interaction of endemic social conditions, sociocultural normative processes, learned health be-haviors, and disheartening life events shaped families' predispositions for a syndemic of psychological distress, cardiometabolic conditions, and musculoskeletal pain. Educational attainment, continued social support, and aspirational capabilities emerged as themes related to decreasing syndemic vulnerability. This study demonstrates that syndemic vulnerability is potentially intergenerational and reveals the need for culturally sensitive and family-focused syndemic interventions. Future longitudinal research should focus on unravelling the pathogenesis of the clustering of psychological distress, cardiometabolic conditions, and musculoskeletal pain among young people
Disappearing Plants: Why They Hide and How They Return
Prolonged dormancy is a life-history stage in which mature plants fail to resprout for one or more growing seasons and instead remain alive belowground. Prolonged dormancy is relatively common, but the proximate causes and consequences of this intriguing strategy have remained elusive. In this study we tested whether stored resources are associated with remaining belowground, and investigated the resource costs of remaining belowground during the growing season. We measured stored resources at the beginning and end of the growing season in Astragalus scaphoides, an herbaceous perennial in southwest Montana, USA. At the beginning of the growing season, dormant plants had lower concentrations of stored mobile carbon (nonstructural carbohydrates, NSC) than did emergent plants. Surprisingly, during the growing season, dormant plants gained as much NSC as photosynthetically active plants, an increase most likely due to remobilization of structural carbon. Thus, low levels of stored NSC were associated with remaining belowground, and remobilization of structural carbon may allow for dormant plants to emerge in later seasons. The dynamics of NSC in relation to dormancy highlights the ability of plants to change their own resource status somewhat independently of resource assimilation, as well as the importance of considering stored resources in understanding plant responses to the environment
Early detection of children at risk for antisocial behaviour using data from routine preventive child healthcare
BACKGROUND: Youth antisocial behaviour is highly prevalent. Young people are usually not willing to disclose such behaviour to professionals and parents. Our aim was to assess whether child health professionals (CHP) working in preventive child healthcare could identify pre-adolescents at risk for antisocial behaviour through using data that they obtain in routine practice. METHODS: CHPs examined a national sample of 974 pre-adolescents aged 8-12 years (response 79.1%), and interviewed parents and children during routine well-child assessments. We obtained data on family background and current health of the child from the CHP; on developmental concerns from parents, and on social and emotional well-being, injuries, and substance use from the children. Antisocial behaviour concerned the adolescent-reported 15 item International Self-Reported Delinquency study questionnaire, among which are 5 items on violence against people. RESULTS: The prevalence of 2+acts of any antisocial behaviour was 21.8%, and 33.9% for 1+acts of violence (10.5% for 2+). Children who were male, had a young mother, no parent employed, recent injuries, poor performance at school or who were bored by school, and who had parental concerns more often reported 2+antisocial acts and 1+violence against people. Detection algorithms on the basis of these variables were moderately able to classify outcomes, with Areas-Under-the-Curves ranging from 0.66 to 0.71. CONCLUSIONS: Data from routine well-child assessment can help CHPs to detect pre-adolescents at risk for antisocial behaviour, but detection algorithms need to be further improved. This could be done by obtaining additional information on factors that are associated with antisocial behaviour
Morphology Effectively Controls Singlet-Triplet Exciton Relaxation and Charge Transport in Organic Semiconductors
We present a comparative study of ultrafast photo-conversion dynamics in
tetracene (Tc) and pentacene (Pc) single crystals and Pc films using optical
pump-probe spectroscopy. Photo-induced absorption in Tc and Pc crystals is
activated and temperature-independent respectively, demonstrating dominant
singlet-triplet exciton fission. In Pc films (as well as C-doped films)
this decay channel is suppressed by electron trapping. These results
demonstrate the central role of crystallinity and purity in photogeneration
processes and will constrain the design of future photovoltaic devices.Comment:
The Correlation Dimension of Young Stars in Dwarf Galaxies
We present the correlation dimension of resolved young stars in four actively
star-forming dwarf galaxies that are sufficiently resolved and transparent to
be modeled as projections of three-dimensional point distributions. We use data
in the Hubble Space Telescope archive; photometry for one of them, UGCA 292, is
presented here for the first time. We find that there are statistically
distinguishable differences in the nature of stellar clustering among the
sample galaxies. The young stars of VII Zw 403, the brightest galaxy in the
sample, have the highest value for the correlation dimension and also the most
dramatic decrease with logarithmic scale, falling from to
over less than a factor of ten in . This decrease is
consistent with the edge effect produced by a projected Poisson distribution
within a 2:2:1 ellipsoid. The young stars in UGC 4483, the faintest galaxy in
the sample, exhibit very different behavior, with a constant value of about 0.5
over this same range in , extending nearly to the edge of the distribution.
This behavior may indicate either a scale-free distribution with an unusually
low correlation dimension, or a two-component (not scale-free) combination of
cluster and field stars.Comment: 25 pages, 10 figures, accepted by A
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Effects of sampling design, estimators, and variability on groundfish management in Oregon
Sampling error associated with estimates of species composition and age composition
of commercial groundfish landings in Oregon from 1989 to 1991 is documented to evaluate
the impact of variable landing data on fisheries management and monitoring programs. The
statistical reliability and bias associated with two multistage sampling designs are
investigated on the bases of the practical suitability of field procedures and accuracy and
precision of the derived estimates. Additionally, the variability associated with landing
estimates of age composition for five groundfish species is used to examine critically the
ability of age-structured stock assessment models to describe adequately the stochastic
properties of actual catch-at-age data. Finally, the spatial similarity of reproductive
parameters derived from sampling data for Dover sole inhabiting marine waters off the coast
of Oregon is examined in statistical and practical terms to provide management additional
analyses that can be used to adopt harvest strategies that minimize detrimental effects to the
exploited fish stock(s).
A two-stage random sampling design combined with stratification components
generated relatively reliable landing statistics. At least two-thirds of the total landings of
rockfish in each port/quarter stratum consisted of estimates of species composition that had small coefficients of variation (CVs <10%). For each species sampled for age composition, at least three-fourths of the total landings included estimates for individual ages with CVs <25%. For the majority of the landings, the variation at the first stage of sampling contributed at least 63% and 90% to the variance of the landing estimates for the species and age compositions, respectively.
An abbreviated version of a multistage sampling design, which incorporated a single sampling unit at the second stage, produced generally similar results to those generated by the 'complete' two-stage approach discussed above. However, results indicated that there was likely a substantial risk in using this design for species-composition sampling, given the biased variance measures associated with its application. For all practical purposes, the bias was not as problematic in age-composition sampling; however, caution and additional monitoring procedures are recommended to ensure that inferences reflect the actual statistical properties of the sampling design.
An analysis of the variability in catch-at-age data clearly indicated that a multinomial probability error structure, included in models that are based on maximum likelihood estimation, more closely follows the estimated variances associated with the sampled landing data than does a lognormal error structure used in models based on least squares estimation. An analysis of maturity data from commercial landings provided some statistical evidence that spatial differences may exist in sexual maturity schedules of Dover sole inhabiting Oregon waters; however, it does not appear that the statistical findings from the maturity assessments are of magnitudes that reflect dramatic implications for management
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