3,683 research outputs found

    Runner-up entry for 2018

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    Rapid changes in the vegetation of a shallow pond in Epping Forest, related to recent droughts

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    Over much of Britain, 1995 and 1996 have been perceived as drought years. To evaluate the impact that local climatic conditions are having upon successional changes in higher vegetation (macrophytes), Speakmans Pond in Epping Forest was surveyed and mapped in 1996. The results are related to previous vegetation surveys carried out in 1989 and 1991. In 1989 the dominant marginal vegetation was floating sweet-grass Glyceria fluitans, which also covered a major part of the main body of the pond. Other abundant species included soft rush Juncus effusus, reed mace Typha latifolia and yellow flag Iris pseudocorus. A small (central) area of open water contained bladderwort Utricularia vulgaris and white water-lily Nymphaea alba. A similar plant coverage was found in 1991, with a dominance of floating sweet-grass along the shallow eastern edge. A marked change in the pond was found during the 1996 survey of vegetation in July, when the pool was dry. The major plant cover now consisted of creeping bent Agrostis stolonifera, with isolated clumps of Yorkshire fog Holcus lanatus around the edges; both are terrestrial grasses found on land surrounding the pond. Rushes (Juncus) had increased their distribution round the margins of the pond, and the patch of yellow flag noted in 1989 and 1991 was not found in 1996. The deeper trenches were also dry, but a small patch of white water-lily remained adjacent to one of the trenches

    The Mass Function of the Stellar Component of Galaxies in the Sloan Digital Sky Survey

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    Using the MOPED algorithm we determine non-parametrically the Stellar Mass Function of 96,545 galaxies from the Sloan Digital Sky Survey data release one. By using the reconstructed spectrum due to starlight we can eliminate contamination from either emission lines or AGN components. Our results give excellent agreement with previous works, but extend their range by more than two decades in mass to 10^{7.5} < M_s/h^{-2}M_\odot < 10^{12}. We present both a standard Schechter fit and a fit modified to include an extra, high-mass contribution, possibly from cluster cD galaxies. The Schechter fit parameters are ϕ∗=(7.7±0.8)×10−3h3Mpc−3\phi^*=(7.7\pm 0.8)\times 10^{-3} h^3 Mpc^{-3}, M∗=(7.53±0.04)×1010h−2M⊙M^*=(7.53 \pm 0.04) \times 10^{10} h^{-2}M_\odot and α=−1.167±0.004\alpha=-1.167\pm 0.004. Our sample also yields an estimate for the contribution from baryons in stars to the critical density of Ωb∗h=(2.40±0.04)×10−3\Omega_{b*}h=(2.40 \pm 0.04) \times 10^{-3}, in good agreement with other indicators. Error bars are statistical and a Salpeter IMF is assumed throughout. We find no evolution of the mass function in the redshift range 0.05<z<0.340.05 < z < 0.34 indicating that almost all present day stars were already formed at z∌0.34z \sim 0.34 with little or no star formation activity since then and that the evolution seen in the luminosity function must be largely due to stellar fading.Comment: submitted to MNRA

    The biodiversity audit approach challenges regional priorities and identifies a mismatch in conservation

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    1. Despite a strong uptake of evidence-based approaches, conservation often proceeds from a grossly incomplete understanding of species priorities. To optimize conservation impact within a biogeographical region, quantitative knowledge is needed of the species present, which should be prioritized, and the management interventions these require. The next challenge is to avoid a proliferation of competing species plans, or conversely, a lack of detail within generic habitat-based approaches. 2. We present a methodology for biodiversity auditing. We quantified regional biodiversity by systematically collating available species records, allowing objective prioritization. We collated autecological information to integrate multiple species into management guilds with shared requirements, providing evidence-based guidance for regional conservation. 3. For two regions of Eastern England, Breckland (2300 km^2 ) and The Broads (2000 km^2 ), we collated 083 and 15-million records, respectively. Numbers of species (12 845 and 11 067) and priority species (rare, threatened, designated or regionally restricted: 2097 and 1519, respectively) were orders of magnitude greater than previously recognized. Regional specialists, with a UK range largely or entirely restricted to the region, were poorly recognized posing a risk of regional homogenization. 4. A large body of autecological information existed for priority species and collating this allowed us to define cross-taxa management guilds. Numbers of priority species requiring different combinations of ecological processes and conditions were not matched by current conservation practice in Breckland. For example, the current agri-environment agreements for designated grass heaths potentially catered for only 15% of the 542 priority species and 21% of 47 regional specialists that could potentially benefit from evidence-based management. A focus on vegetation composition rather than the ecological requirements of priority species underpinned this failure. 5. Synthesis and applications. The biodiversity audit approach provides an objective model for prioritization and cost-effective conservation, applicable to regions of Europe where biodiversity has been well characterized. By using this approach to collate available information, management guilds with similar requirements can be defined across taxa, providing evidence-based guidance for regional conservatio

    Homeless street children in Nepal : use of allostatic load to assess the burden of childhood adversity.

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    As challenges to child well-being through economic disadvantage, family disruption, and migration or displacement escalate world wide, the need for cross-culturally robust understanding of childhood adversity proportionately increases. Toward this end, developmental risk was assessed in four contrasting groups of 107 Nepali children ages 10–14 years that represent distinctive, common conditions in which contemporary children grow up. Relative cumulative burden (allostatic load) indexed by multiple dimensions of physical and psychosocial stress was ascertained among homeless street boys and three family-based groups, from poor urban squatter settlements, urban middle class, and a remote rural village. Biomarkers of stress and vulnerability to stress included growth status, salivary cortisol, antibodies to Epstein–Barr virus, acute phase inflammatory responses (alpha1-antichymotrypsin), and cardiovascular fitness and reactivity (flex heart rate and pressor response). Individual biomarkers of risk and allostatic load differed markedly among groups, were highest in villagers, and varied by components of allostatic load. Such data suggest a need for critical appraisal of homelessness and migration as a risk factor to youth, given prevailing local conditions such as rural poverty, and represents the only multidimensional study of childhood allostatic load and developmental risk in non-Western settings

    Impact of changes in mode of travel to work on changes in body mass index: evidence from the British Household Panel Survey

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    BACKGROUND Active commuting is associated with various health benefits, but little is known about its causal relationship with body mass index (BMI). METHODS We used cohort data from three consecutive annual waves of the British Household Panel Survey, a longitudinal study of nationally representative households, in 2004/05 (n=15,791), 2005/06 and 2006/07. Participants selected for the analyses (n=4,056) reported their usual main mode of travel to work at each time point. Self-reported height and weight were used to derive BMI at baseline and after two years. Multivariable linear regression analyses were used to assess associations between switching to and from active modes of travel (over one and two years) and change in BMI (over two years) and to assess dose-response relationships. RESULTS After adjustment for socioeconomic and health-related covariates, the first analysis (n=3,269) showed that switching from private motor transport to active travel or public transport (n=179) was associated with a significant reduction in BMI compared to continued private motor vehicle use (n=3,090) (-0.32kg/m2, 95% CI: -0.60 to -0.05). Larger adjusted effect sizes were associated with switching to active travel (n=109) (-0.45kg/m2, -0.78 to -0.11), particularly among those who switched within the first year and those with the longest journeys. The second analysis (n=787) showed that switching from active travel or public transport to private motor transport was associated with a significant increase in BMI (0.34kg/m2, 0.05 to 0.64). CONCLUSION Interventions to enable commuters to switch from private motor transport to more active modes of travel could contribute to reducing population mean BMI

    A closer look at the Test of Personal Intelligence (TOPI)

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    Personal intelligence involves the capacity to reason about personality and personality-related information. Studying ability-based measures of personal intelligence creates a virtuous cycle of better measurement and better theoretical understanding. In Study 1 (N = 10,318), we conduct an item-level analysis of the Test of Personal Intelligence (TOPI) to explore people\u27s problem-solving abilities in the area. Personal intelligence divided into a Consistency-Congruency factor that concerned understanding traits and their associated behaviors, and a Dynamic-Analytic factor that involved understanding personality processes and goals. The finding cross-validated in Study 2 (N = 8,459). In Study 3 (N = 384), we examined correlates of the two factors. Understanding the abilities involved in personal intelligence may help us to educate people about how to better solve problems about personality

    Technical Report for “When People Estimate their Personal Intelligence Who Is Overconfident? Who is Accurate?”

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    The Technical Supplement includes additional information about the article “Who Believes they are High in Personal Intelligence.” The Supplement is organized such that material follows the organization of the article, with the exception that group-wise analyses—i.e., analyses based on median splits of the archival samples on the Test of Personal Intelligence and Self-Estimated Personal Intelligence, are in their own Appendix owing to the considerable length of that material

    TEST OF PERSONAL INTELLIGENCE 1.4 (TOPI 1.4) MANUAL

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    Personal intelligence involves the capacity to reason about personality and personality-relevant information. People high in personal intelligence are good at understanding themselves and others. The UNH Personality Lab developed a series of ability-based tests that assess this skill, under the name of the Test of Personal Intelligence (TOPI)

    A Closer Look at the Test of Personal Intelligence Presentation

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    Personal intelligence is the capacity to reason about personality and personality-related information. To understand more about the structure of the mental abilities involved in personal intelligence, we fit several factor models to an ability based test of personal intelligence. A two-factor oblique simple structure model fit the data well. The findings inform us about the nature of abilities people use to understand personality in themselves and others
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