3,295 research outputs found
AN ANALYSIS OF THE ECONOMIC EFFICIENCY OF THOROUGHBRED BREEDER/OWNER INCENTIVE POLICIES
Thoroughbred incentive programs are subsidy policies designed to promote regional race horse breeding and ownership. At issue, is an ongoing debate concerning the effectiveness of alternative policies. Empirical results indicate the programs have a positive economic affect, but gains in efficiency can be obtained by reallocating funds to open purses.Livestock Production/Industries,
AN ECONOMIC ANALYSIS OF THE EFFECTIVENESS OF THOROUGHBRED BREEDER/OWNER INCENTIVE POLICIES
Thoroughbred incentive programs are subsidy policies funded from state parimutuel tax revenue designed to promote regional race horse breeding and ownership. At issue is an ongoing debate concerning the effectiveness of alternative policies. Empirical results indicate that incentive programs have a positive economic effect, but gains to Thoroughbred breeders can be obtained by reallocating tax revenue to non-restricted purses. A policy allocating tax revenue ton non-restricted purses shifts yearling demand and increases prices, while breeder subsidies shift only the supply function and therefore lower prices. Consequently, breeder revenues increase in response to a policy that favors non-restricted purses over subsidies.incentive programs, parimutual horse racing, subsidy, tax, Thoroughbred, Agricultural and Food Policy,
PRICE EXPECTATIONS AND SUPPLY RESPONSE IN THE THOROUGHBRED YEARLING MARKET
Limited information is available concerning price determination in the thoroughbred yearling market. A recursive model incorporating price expectations and biological constraints is used to estimate supply and demand functions for thoroughbred horses. Empirical results characterize a market with inelastic supply and elastic demand that converges to equilibrium under static conditions. Purses were identified as the most influential variable impacting price. Comparative statics illustrate the effectiveness of purses as a policy instrument for the thoroughbred industry. Federal tax policy also was found to have a significant impact on the decisions to breed or invest in thoroughbred yearlings.Elasticity, Parimutual horse racing, Price determination, Price flexibility, Purses, Thoroughbred, Yearling, Demand and Price Analysis, Livestock Production/Industries,
The Role of School Counselors in Meeting Students\u27 Mental Health Needs: Examining Issues of Professional Identity
The professional identity of school counselors has evolved over time. This article traces the historical context driving this evolution, and suggests it is time for the profession to conjoin the roles of educational leader and mental health professional. This proposal is prompted by heightened awareness of unmet student mental health needs, referrals that go unmet, school counselors displaced by other mental health providers in schools, the potential loss of the unique school counselor role, and the natural link between the mental health professional role and the array of personal-social factors that impact student achievement. A conjoint professional school counselor identity that includes the roles of both educational leader and mental health professional positions school counselors to better respond to all students, including those with mental health needs. This article discusses potential roadblocks and offers suggestions for action
An Ensemble Model of QSAR Tools for Regulatory Risk Assessment
Quantitative structure activity relationships (QSARs) are theoretical models that relate a quantitative measure of chemical structure to a physical property or a biological effect. QSAR predictions can be used for chemical risk assessment for protection of human and environmental health, which makes them interesting to regulators, especially in the absence of experimental data. For compatibility with regulatory use, QSAR models should be transparent, reproducible and optimized to minimize the number of false negatives. In silico QSAR tools are gaining wide acceptance as a faster alternative to otherwise time-consuming clinical and animal testing methods. However, different QSAR tools often make conflicting predictions for a given chemical and may also vary in their predictive performance across different chemical datasets. In a regulatory context, conflicting predictions raise interpretation, validation and adequacy concerns. To address these concerns, ensemble learning techniques in the machine learning paradigm can be used to integrate predictions from multiple tools. By leveraging various underlying QSAR algorithms and training datasets, the resulting consensus prediction should yield better overall predictive ability. We present a novel ensemble QSAR model using Bayesian classification. The model allows for varying a cut-off parameter that allows for a selection in the desirable trade-off between model sensitivity and specificity. The predictive performance of the ensemble model is compared with four in silico tools (Toxtree, Lazar, OECD Toolbox, and Danish QSAR) to predict carcinogenicity for a dataset of air toxins (332 chemicals) and a subset of the gold carcinogenic potency database (480 chemicals). Leave-one-out cross validation results show that the ensemble model achieves the best trade-off between sensitivity and specificity (accuracy: 83.8 % and 80.4 %, and balanced accuracy: 80.6 % and 80.8 %) and highest inter-rater agreement [kappa (Îş): 0.63 and 0.62] for both the datasets. The ROC curves demonstrate the utility of the cut-off feature in the predictive ability of the ensemble model. This feature provides an additional control to the regulators in grading a chemical based on the severity of the toxic endpoint under study
Effects of living near a new urban motorway on the travel behaviour of local residents in deprived areas: Evidence from a natural experimental study
We evaluated the effects of a new motorway built through deprived neighbourhoods on travel behaviour in residents. This natural experiment comprised a longitudinal cohort (n=365) and two cross-sectional samples (baseline n=980; follow-up n=978) recruited in 2005 and 2013. Adults from one of three study areas - surrounding the new motorway (South), an existing motorway (East), or no motorway (North) - completed a previous day travel record. Adjusted two-part regression models examined associations between exposure and outcome. Compared to the North, cohort participants in the South were more likely to undertake travel by any mode (OR 2.1, 95% CI 1.0–4.2) at follow-up. Within the South study area, cohort participants living closer to a motorway junction were more likely to travel by any mode at follow-up (OR 4.7, 95% CI 1.1–19.7), and cross-sectional participants living closer were more likely to use a car at follow-up (OR 3.4, 95% CI 1.1–10.7), compared to those living further away. Overall, the new motorway appeared to promote travel and car use in those living nearby, but did not influence active travel. This may propagate socioeconomic inequalities in non-car owners
When is a parasite not a parasite? Effects of larval tick burdens on white-footed mouse survival
Many animal species can carry considerable burdens of ectoparasites: parasites living on the outside of a host's body. Ectoparasite infestation can decrease host survival, but the magnitude and even direction of survival effects can vary depending on the type of ectoparasite and the nature and duration of the association. When ectoparasites also serve as vectors of pathogens, the effects of ectoparasite infestation on host survival have the potential to alter disease dynamics by regulating host populations and stabilizing transmission. We quantified the impact of larval Ixodes scapularis tick burdens on both within-season and overwinter survival of white-footed mice (Peromyscus leucopus) using a hierarchical Bayesian capture-mark-recapture model. I. scapularis and P. leucopus are, respectively, vectors and competent reservoirs for the causative agents of Lyme disease, anaplasmosis, and babesiosis. Using a data set of 5587 individual mouse capture histories over sixteen years, we found little evidence for any effect of tick burdens on either within-season or overwinter mouse survival probabilities. In male mice, tick burdens were positively correlated with within-season survival probabilities. Mean maximum tick burdens were also positively correlated with population rates of change during the concurrent breeding season. The apparent indifference of mice to high tick burdens may contribute to their effectiveness as reservoir hosts for several human zoonotic pathogens.Fil: Hersh, Michelle H.. Cary Institute of Ecosystem Studies; Estados Unidos. Bard College. Program in Biology; Estados Unidos. Sarah Lawrence College; Estados UnidosFil: LaDeau, Shannon L.. Cary Institute of Ecosystem Studies; Estados UnidosFil: Previtali, Maria Andrea. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe; ArgentinaFil: Ostfeld, Richard S.. Cary Institute of Ecosystem Studies; Estados Unido
Robust Approximation to Adaptive Control by Use of Representative Parameter Sets with Particular Reference to Type 1 Diabetes
This paper describes an approach to adaptive optimal control in the presence of model parameter calculation difficulties. This has wide application in a variety of biological and biomedical research and clinical problems. To illustrate the techniques, the approach is applied to the development and implementation of a practical adaptive insulin infusion algorithm for use with patients with Type 1 diabetes mellitus
Posthumaniser le programme d’études de McLuhan : Faire des riffs sur La ville en tant que salle de classe (City as Classroom)
Conditions of the posthuman are hastened by the technologies that now fully mediate our brains and nervous systems, a circumstance anticipated by Marshall McLuhan some sixty years ago. In 1977, McLuhan co-developed a media textbook for Canadian high school students. We expand on a selection of the concepts and themes identified in City as Classroom: Understanding Language and Media and query in what ways we might apply a forty-year-old media curriculum to our present-day circumstances. We riff on Marshall McLuhan’s prognostications on education during the electric age as a recalibration of his remarkably prescient work and conceptualize a hypercity in which to explore our considerations. We enmesh City as Classroom with the materiality of city spaces and theorize a posthuman critical pedagogy as a call to action.Les conditions du posthumain sont accélérées par les technologies qui assurent désormais la médiation complète de nos cerveaux et nos systèmes nerveux, une circonstance anticipée par Marshall McLuhan il y a une soixantaine d'années. En 1977, McLuhan a co-développé un manuel des médias pour les élèves canadien(ne)s du secondaire. Nous développons une sélection des concepts et des thèmes identifiés dans « City as Classroom : Understanding Language and Media » et nous nous demandons de quelle manière nous pourrions appliquer un curriculum des médias de quarante ans à notre situation actuelle. Nous faisons des riffs sur les pronostics de Marshall McLuhan sur l'éducation à l'ère électrique comme un recalibrage de son travail remarquablement prémonitoire et nous conceptualisons une hypercité dans laquelle explorer nos considérations. Nous entremêlons « City as Classroom » avec la matérialité des espaces urbains et nous théorisons une pédagogie critique posthumain en tant qu’un appel à l'action
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