516 research outputs found

    Role of Hellenic Range and Pasture Society in Technology Interaction and Policy Evolution

    Get PDF
    The Hellenic Range and Pasture Society (HRPS) was founded in 1992 and is a non-profit scientific association. It is composed of 74 members with a common interest in the study, management, and rational use of rangelands and related ecosystems (e.g. pasturelands). The objectives for which the corporation was established are: a) to develop an understanding of rangeland ecosystems and of the principles applicable to the management of rangeland resources (soil, plants, water, and animals), b) to assist all who work with rangelands and pasturelands to keep abreast of new findings and techniques in the science and art of rangeland and pasture management, c) to create a public appreciation of the economic and social benefits to be obtained from the rangeland environment, and d) to promote professional development of its members

    Prenatal and childhood adversity and inflammation in children: A population-based longitudinal study

    Get PDF
    BACKGROUND: Stressful life events experienced during childhood and early prenatal development have been associated with inflammation during childhood. However, no study has considered these two exposures jointly, or has investigated the effect of their interaction. METHODS: In the Avon Longitudinal Study of Parents and Children, a general-population birth cohort, we explored if inflammatory markers [serum C-reactive protein (CRP) and interleukin 6 (IL-6)] at age 9 years were related to early prenatal events (at 18 weeks pregnancy), childhood events (measured on seven occasions at ages 0-9 years) and their interaction (n=3,915). Latent growth curve modelling estimated trajectories of childhood events, and linear regression explored associations of prenatal and childhood events with inflammatory markers. Models controlled for ethnicity, socioeconomic status and body mass index, were stratified by gender and considered both unweighted and weighted (by impact) event exposures. RESULTS: Even after adjustment for confounders and prenatal events, both the intercept and the slope of number of childhood events were associated with IL-6, but only in females. The significant effect of the slope held for both weighted (by impact) and unweighted event specifications. Prenatal events were not associated with either inflammatory marker when childhood events were controlled. There was no evidence for synergistic effects of prenatal and childhood events. CONCLUSION: Independently of prenatal adverse life events, the number and increase in number of adverse life events experienced in childhood were associated positively with plasma levels of inflammatory markers, such as IL-6, in girls. This gender specificity warrants further research

    Ability-grouping and problem behavior trajectories in childhood and adolescence: Results from a U.K. population-based sample

    Get PDF
    Ability-grouping has been studied extensively in relation to children's academic, but not emotional and behavioral outcomes. The sample comprised 7259 U.K. children (50% male) with data on between-class and within-class ability-grouping at age 7. Peer, emotional, hyperactivity, and conduct problems were measured at ages 7, 11, and 14 years. Children in low within-class ability groups showed more hyperactivity and emotional problems across the study period compared to non-grouped children, after adjustments for the different types of ability grouping and confounding. Additionally, children in the middle within-class ability groups showed more, and those in the top within-class groups less, hyperactivity compared to non-grouped children, after adjustment. Children in lower within-class groups should be monitored closely to ensure that their well-being is not compromised

    The Role of Primary School Composition in the Trajectories of Internalising and Externalising Problems across Childhood and Adolescence

    Get PDF
    There is little research on the role of school and its composition in explaining individual children's psychological outcomes. This study examined for the first time the role of several primary-school compositional characteristics, and their interactions with individual level characteristics, in the development of two such outcomes, internalising and externalising problems, at ages 7, 11 and 14 years in 4794 children in England participating in the Millennium Cohort Study. Using hierarchical (multilevel) linear models, we found that, even after adjusting for individual and family characteristics, children in schools with higher proportions of pupils eligible for free school meals had more externalising problems. In general, children with special educational needs, lower academic performance, more distressed mothers, and those in non-intact families had more internalising and externalising problems. Our results underline the importance of targeting schools with less affluent overall intakes, but also highlight the key role of individual and family characteristics in the development of their pupils' psychological functioning

    A nonlinear classical model for the decay widths of Isoscalar Giant Monopole Resonances

    Full text link
    The decay of the Isoscalar Giant Monopole Resonance (ISGMR) in nuclei is studied by means of a nonlinear classical model consisting of several noninteracting nucleons (particles) moving in a potential well with an oscillating nuclear surface (wall). The motion of the nuclear surface is described by means of a collective variable which appears explicitly in the Hamiltonian as an additional degree of freedom. The total energy of the system is therefore conserved. Although the particles do not directly interact with each other, their motions are indirectly coupled by means of their interaction with the moving nuclear surface. We consider as free parameters in this model the degree of collectivity and the fraction of nucleons that participate to the decay of the collective excitation. Specifically, we have calculated the decay width of the ISGMR in the spherical nuclei 208Pb^{208}\rm{Pb}, 144Sm^{144}\rm{Sm}, 116Sn^{116}\rm{Sn} and 90Zr^{90}\rm{Zr}. Despite its simplicity and its purely classical nature, the model reproduces the trend of the experimental data which show that with increasing mass number the decay width decreases. Moreover the experimental results (with the exception of 90Zr^{90}\rm{Zr}) can be well fitted using appropriate values for the free parameters mentioned above. It is also found that these values allow for a good description of the experimentally measured 112Sn^{112}\rm{Sn} and 124Sn^{124}\rm{Sn} decay widths. In addition, we give a prediction for the decay width of the exotic isotope 132Sn^{132}Sn for which there is experimental interest. The agreement of our results with the corresponding experimental data for medium-heavy nuclei is dictated by the underlying classical mechanics i.e. the behaviour of the maximum Lyapunov exponent as a function of the system size

    Early adolescent outcomes of joint developmental trajectories of problem behavior and IQ in childhood

    Get PDF
    General cognitive ability (IQ) and problem behavior (externalizing and internalizing problems) are variable and inter-related in children. However, it is unknown how they co-develop in the general child population and how their patterns of co-development may be related to later outcomes. We carried out this study to explore this. Using data from 16,844 Millennium Cohort Study children, we fitted three-parallel-process growth mixture models to identify joint developmental trajectories of internalizing, externalizing and IQ scores at ages 3-11 years. We then examined their associations with age 11 outcomes. We identified a typically developing group (83%) and three atypical groups, all with worse behavior and ability: children with improving behavior and low (but improving in males) ability (6%); children with persistently high levels of problems and low ability (5%); and children with worsening behavior and low ability (6%). Compared to typically developing children, the latter two groups were more likely to show poor decision-making, be bullies or bully victims, engage in antisocial behaviors, skip and dislike school, be unhappy and have low self-esteem. By contrast, children (especially males) in the improver group had outcomes that were similar to, or even better than, those of their typically developing peers. These findings encourage the development of interventions to target children with both cognitive and behavioral difficulties

    Hyperacceleration in a stochastic Fermi-Ulam model

    Full text link
    Fermi acceleration in a Fermi-Ulam model, consisting of an ensemble of particles bouncing between two, infinitely heavy, stochastically oscillating hard walls, is investigated. It is shown that the widely used approximation, neglecting the displacement of the walls (static wall approximation), leads to a systematic underestimation of particle acceleration. An improved approximative map is introduced, which takes into account the effect of the wall displacement, and in addition allows the analytical estimation of the long term behavior of the particle mean velocity as well as the corresponding probability distribution, in complete agreement with the numerical results of the exact dynamics. This effect accounting for the increased particle acceleration -Fermi hyperacceleration- is also present in higher dimensional systems, such as the driven Lorentz gas.Comment: 4 pages, 3 figures. To be published in Phys. Rev. Let

    Clinical usefulness of scoring systems to predict severe acute pancreatitis: A systematic review and meta-analysis with pre and post-test probability assessment

    Get PDF
    Background: Scoring systems for severe acute pancreatitis (SAP) prediction should be used in conjunction with pre-test probability to establish post-test probability of SAP, but data of this kind are lacking.Objective: To investigate the predictive value of commonly employed scoring systems and their usefulness in modifying the pre-test probability of SAP.Methods: Following PRISMA statement and MOOSE checklists after PROSPERO registration, PubMed was searched from inception until September 2022. Retrospective, prospective, cross-sectional studies or clinical trials on patients with acute pancreatitis defined as Revised Atlanta Criteria, reporting rate of SAP and using at least one score among Bedside Index for Severity in Acute Pancreatitis (BISAP), Acute Physiology and Chronic Health Examination (APACHE)-II, RANSON, and Systemic Inflammatory Response Syndrome (SIRS) with their sensitivity and specificity were included. Random effects model meta-analyses were performed. Pre-test probability and likelihood ratio (LR) were combined to estimate post-test probability on Fagan nomograms. Pooled severity rate was used as pre-test probability of SAP and pooled sensitivity and specificity to calculate LR and generate post-test probability. A priori hypotheses for heterogeneity were developed and sensitivity analyses planned.Results: 43 studies yielding 14,116 acute pancreatitis patients were included: 42 with BISAP, 30 with APACHE-II, 27 with Ranson, 8 with SIRS. Pooled pre-test probability of SAP ranged 16.6%-25.3%. The post-test probability of SAP with positive/negative score was 47%/6% for BISAP, 43%/5% for APACHE-II, 48%/5% for Ranson, 40%/12% for SIRS. In 18 studies comparing BISAP, APACHE-II, and Ranson in 6740 patients with pooled pre-test probability of SAP of 18.7%, post-test probability when scores were positive was 48% for BISAP, 46% for APACHE-II, 50% for Ranson. When scores were negative, post-test probability dropped to 7% for BISAP, 6% for Ranson, 5% for APACHE-II. Quality, design, and country of origin of the studies did not explain the observed high heterogeneity.Conclusions: The most commonly used scoring systems to predict SAP perform poorly and do not aid in decision-making
    • …
    corecore