2,291 research outputs found

    Taking individual heterogeneity in mortality risks into account in demographic studies of wild animal populations: development and use of statistical models.

    Get PDF
    The Cormarck-Jolly-Seber model incorporating frailty implemented in WinBUGS, using the 9000 kittiwake’s dataset monitorized during 22 years, showed that the convergence is very low over computational view. We developed different kind of multistate model, considering independence/dependence between random effect of breeding and survival probability. The last part of the work was dedicated to model selection with Bayesian framework

    A genome-wide investigation of the worldwide invader Sargassum muticum shows high success albeit (almost) no genetic diversity

    Get PDF
    Twenty years of genetic studies of marine invaders have shown that successful invaders are often characterized by native and introduced populations displaying similar levels of genetic diversity. This pattern is presumably due to high propagule pressure and repeated introductions. The opposite pattern is reported in this study of the brown seaweed, Sargassum muticum, an emblematic species for circumglobal invasions. Albeit demonstrating polymorphism in the native range, microsatellites failed to detect any genetic variation over 1,269 individuals sampled from 46 locations over the Pacific-Atlantic introduction range. Single-nucleotide polymorphisms (SNPs) obtained from ddRAD sequencing revealed some genetic variation, but confirmed severe founder events in both the Pacific and Atlantic introduction ranges. Our study thus exemplifies the need for extreme caution in interpreting neutral genetic diversity as a proxy for invasive potential. Our results confirm a previously hypothesized transoceanic secondary introduction from NE Pacific to Europe. However, the SNP panel unexpectedly revealed two additional distinct genetic origins of introductions. Also, conversely to scenarios based on historical records, southern rather than northern NE Pacific populations could have seeded most of the European populations. Finally, the most recently introduced populations showed the lowest selfing rates, suggesting higher levels of recombination might be beneficial at the early stage of the introduction process (i.e., facilitating evolutionary novelties), whereas uniparental reproduction might be favored later in sustainably established populations (i.e., sustaining local adaptation).Agence Nationale de la Recherche - ANR-10-BTBR-04; European Regional Development Fund; Fundacao para a Ciencia e a Tecnologia - SFRH/BPD/107878/2015, UID/Multi/04326/2016, UID/Multi/04326/2019; Brittany Region;info:eu-repo/semantics/publishedVersio

    Initial Validation of a Brief Pictorial Measure of Caregiver Aggression: The Family Aggression Screening Tool

    Get PDF
    In the present study, we report on the development and initial psychometric properties of the Family Aggression Screening Tool (FAST). The FAST is a brief, self-report tool that makes use of pictorial representations to assess experiences of caregiver aggression, including direct victimization and exposure to intimate partner violence. It is freely available on request and takes under 5 minutes to complete. Psychometric properties of the FAST were investigated in a sample of 168 high-risk youth aged 16 to 24 years. For validation purposes, maltreatment history was assessed using the Childhood Trauma Questionnaire; levels of current psychiatric symptoms were also assessed. Internal consistency of the FAST was good. Convergent validity was supported by strong and discriminative associations with corresponding Childhood Trauma Questionnaire subscales. The FAST also correlated significantly with multi-informant reports of psychiatric symptomatology. Initial findings provide support for the reliability and validity of the FAST as a brief, pictorial screening tool of caregiver aggression

    Sports Data Science Job Requirements

    Get PDF
    Data science is an extremely fast growing field in which job opportunities are opening in every industry related to data science. Within the data science field is the sports data science industry which has it\u27s own requirements and specificities that may not be present in other industries. In this paper, research is done using multiple job posting websites such as LinkedIn, Indeed, Sportstek jobs, and TeamworkOnline to explore the job descriptions of many different sports data science jobs. These job descriptions are then examined using Python coding to find the frequencies of specific data science skills in the various job postings to see which skills are most important for aspiring sports data scientists to learn

    Combinatorics of BB-orbits and Bruhat--Chevalley order on involutions

    Full text link
    Let BB be the group of invertible upper-triangular complex n×nn\times n matrices, u\mathfrak{u} the space of upper-triangular complex matrices with zeroes on the diagonal and u\mathfrak{u}^* its dual space. The group BB acts on u\mathfrak{u}^* by (g.f)(x)=f(gxg1)(g.f)(x)=f(gxg^{-1}), gBg\in B, fuf\in\mathfrak{u}^*, xux\in\mathfrak{u}. To each involution σ\sigma in SnS_n, the symmetric group on nn letters, one can assign the BB-orbit Ωσu\Omega_{\sigma}\in\mathfrak{u}^*. We present a combinatorial description of the partial order on the set of involutions induced by the orbit closures. The answer is given in terms of rook placements and is dual to A. Melnikov's results on BB-orbits on u\mathfrak{u}. Using results of F. Incitti, we also prove that this partial order coincides with the restriction of the Bruhat--Chevalley order to the set of involutions.Comment: 27 page

    Promotion and provision of colorectal cancer screening: a comparison of colorectal cancer control program grantees and nongrantees, 2011-2012.

    Get PDF
    IntroductionSince 2009, the Centers for Disease Control and Prevention (CDC) has awarded nearly $95 million to 29 states and tribes through the Colorectal Cancer Control Program (CRCCP) to fund 2 program components: 1) providing colorectal cancer (CRC) screening to uninsured and underinsured low-income adults and 2) promoting population-wide CRC screening through evidence-based interventions identified in the Guide to Community Preventive Services (Community Guide). CRCCP is a new model for disseminating and promoting use of evidence-based interventions. If the program proves successful, CDC may adopt the model for future cancer control programs. The objective of our study was to compare the colorectal cancer screening practices of recipients of CRCCP funding (grantees) with those of nonrecipients (nongrantees).MethodsWe conducted parallel Web-based surveys in 2012 with CRCCP grantees (N = 29) and nongrantees (N = 24) to assess promotion and provision of CRC screening, including the use of evidence-based interventions.ResultsCRCCP grantees were significantly more likely than nongrantees to use Community Guide-recommended evidence-based interventions (mean, 3.14 interventions vs 1.25 interventions, P < .001) and to use patient navigation services (eg, transportion or language translation services) (72% vs 17%, P < .001) for promoting CRC screening. Both groups were equally likely to use other strategies. CRCCP grantees were significantly more likely to provide CRC screening than were nongrantees (100% versus 50%, P < .001).ConclusionResults suggest that CRCCP funding and support increases use of evidence-based interventions to promote CRC screening, indicating the program's potential to increase population-wide CRC screening rates

    Fisher information and asymptotic normality in system identification for quantum Markov chains

    Full text link
    This paper deals with the problem of estimating the coupling constant θ\theta of a mixing quantum Markov chain. For a repeated measurement on the chain's output we show that the outcomes' time average has an asymptotically normal (Gaussian) distribution, and we give the explicit expressions of its mean and variance. In particular we obtain a simple estimator of θ\theta whose classical Fisher information can be optimized over different choices of measured observables. We then show that the quantum state of the output together with the system, is itself asymptotically Gaussian and compute its quantum Fisher information which sets an absolute bound to the estimation error. The classical and quantum Fisher informations are compared in a simple example. In the vicinity of θ=0\theta=0 we find that the quantum Fisher information has a quadratic rather than linear scaling in output size, and asymptotically the Fisher information is localised in the system, while the output is independent of the parameter.Comment: 10 pages, 2 figures. final versio

    Characterising youth with callous-unemotional traits and concurrent anxiety: evidence for a high-risk clinical group

    Get PDF
    Growing evidence supports the existence of two variants of youth with high callous-unemotional (CU) traits who present with markedly different risk profiles and outcomes, with potential implications for risk assessment and treatment formulation. So far, studies have identified variants of CU youth mainly using data-driven cluster approaches based on levels of CU traits and co-occurring anxiety. Yet, the extent to which this knowledge may be translated into clinical practice is unclear. To this end, the present study employed a severity-based, cut-off approach to systematically characterise CU groups across a range of clinically informative domains, including trauma history, psychiatric symptomatology, affective functioning, attachment style and behavioural risk. Analyses were based on multi-rated data from a community sample of high-risk youths (n = 155, M = 18 years). Consistent with previous studies, we found that, whereas variants show comparable levels of antisocial behaviour, those who present with both high CU and high anxiety report more severe childhood maltreatment, psychological distress, ADHD symptomatology and behavioural risk-including substance use, suicidal ideation and unsafe sex. In addition, these youth show greater attachment insecurity and affective dysregulation, as indexed by levels of irritability and alexithymia. Together, findings indicate that (1) trauma history is a key factor that differentiates variants of CU youth high vs. low on anxiety, and (2) differences in individual functioning across variants point to the need for tailored clinical assessment tools and intervention strategies. Importantly, the present findings indicate that variants of CU youth can be meaningfully differentiated using cut-off based approaches that parallel methods used in clinical assessments

    Optimization of Process-Control Parameters for the Diameter of Electrospun Hydrophilic Polymeric Composite Nanofibers

    Get PDF
    A composite nanofiber composed of three polymers, namely polyvinyl alcohol/polyvinyl pyrrolidone/polyethylene oxide, is produced. The experiments are constructed using three design of experiment techniques, Taguchi L9, Taguchi L27, and Screening method. The experiments are verified using the analysis of variance (ANOVA) method and later a mathematical model is developed using the regression method. The impact of electrospun processing parameters, namely applied voltage, flow rate, and working distance, on nanofibers' diameter is measured. The working distance is a significant factor in controlling the size of the fiber diameter, while the applied voltage has the lowest effect on it. As a result of the regression equation, a Genetic algorithm is used to find the optimum variables for the required fiber diameter, which is 156 nm for flow rate = 0.001 mL h−1, voltage = 30 kV, and distance = 200 mm with a 3% difference from the experimental fiber diameter
    corecore