Salud Pública

La unidad de aprendizaje de Salud Pública, tiene la finalidad que los dicentes adquieran los conocimientos y habilidades necesarios para la atención de la problemática de la salud pública encaminada a promoción de la salud, prevención y control de los riesgos sanitarios en la población humana, considerando la magnitud, trascendencia y vulnerabilidad de las enfermedades que comparten el hombre y los animales. La capacitación en el manejo de métodos y técnicas de estudio aplicadas a determinar los estimadores en salud, permite analizar y resolver problemas epidemiológicos, quedando en la posición de poder elaborar y aplicar los programas operativos en Salud pública. La Salud Pública Veterinaria es la aplicación de aquellos campos en los que la Medicina Veterinaria comparte un interés común con la Salud Pública. Incluye actividades, en el que las técnicas veterinarias se aplican para la solución de los problemas de salud y enfermedades que afectan a las poblaciones. En la actualidad se ha propuesto la convergencia de estas dos vertientes por el de una salud. La Medicina Veterinaria incrementa la productividad de los animales domésticos, actúa en la prevención de la desnutrición en el hombre al ofrecer productos de origen animal inocuos para la alimentación. La identificación, prevención y el control de las zoonosis, además de las situaciones de emergencia sanitaria y desastres naturales que impactan la Salud Pública. Los conocimientos anteriores en la formación del Médico Veterinario Zootecnista, para su práctica profesional, juega un papel de suma importancia en el enfoque de la Salud Pública. La relevancia de este curso se adquiere una vez que los dicentes adquieren los conocimientos y las estrategias de atención sanitaria para integrarse a los programas sectoriales de interés en la Salud de la comunidad, además de proponer su intervención en la Salud con un espíritu innovador a lo puesto en práctica

Can we ignore trait-dependent colonization and diversification in island biogeography?

The application of state-dependent speciation and extinction (SSE) models to phylogenetic trees has shown an important role for traits in diversification. However, this role remains comparatively unexplored on islands, which can include multiple independent clades resulting from different colonization events. To explore whether assuming no dependence on traits leads to bias in inference on island dynamics, we extend an island biodiversity model, DAISIE (Dynamic Assembly of Islands through Speciation, Immigration and Extinction) to include trait-dependent diversification simulations, and evaluate the robustness of the inference model which ignores this trait-dependence. Our results indicate that when the differences between colonization, extinction and speciation rates between trait states are moderate, the model shows negligible error for a variety of island diversity metrics, suggesting that island diversity dynamics can be accurately estimated without the need to explicitly model trait dependence. We conclude that for many biologically realistic scenarios with trait-dependent diversification and colonization, this simple trait-less inference model is informative and robust to trait effects on colonization, speciation and extinction. Nonetheless, our new simulation model may provide a useful tool for studying patterns of trait variation

Using molecular phylogenies in island biogeography: It's about time

Island biogeography aims at inferring the processes that govern the assembly of communities in space and time. Molecular phylogenies can tell us about the timings of island colonisations and diversification, but have rarely been used for the estimation of colonisation, speciation and extinction rates on islands. In this study we illustrate the effects of including phylogenetic information with the Galapagos avifauna. We find that by including colonisation times we obtain much more precise and accurate parameter estimates than if we rely solely on species richness and endemicity status. Inclusion of branching times improves estimates even further. As molecular phylogenies become increasingly available, we urge biogeographers to start using more of the information they contain

Inferring state-dependent diversification rates using approximate Bayesian computation (ABC)

State-dependent speciation and extinction (SSE) models provide a framework for quantifying whether species traits have an impact on evolutionary rates and how this shapes the variation in species richness among clades in a phylogeny. However, SSE models are becoming increasingly complex, limiting the application of likelihood-based inference methods. Approximate Bayesian computation (ABC), a likelihood-free approach, is a potentially powerful alternative for estimating parameters. One of the key challenges in using ABC is the selection of efficient summary statistics, which can greatly affect the accuracy and precision of the parameter estimates. In state-dependent diversification models, summary statistics need to capture the complex relationships between rates of diversification and species traits. Here, we develop an ABC framework to estimate state-dependent speciation, extinction and transition rates in the BiSSE (binary state dependent speciation and extinction) model. Using different sets of candidate summary statistics, we then compare the inference ability of ABC with that of using likelihood-based maximum likelihood (ML) and Markov chain Monte Carlo (MCMC) methods. Our results show the ABC algorithm can accurately estimate state-dependent diversification rates for most of the model parameter sets we explored. The inference error of the parameters associated with the species-poor state is larger with ABC than in the likelihood estimations only when the speciation rate is highly asymmetric between the two states (λ1 / λ0 = 5). Furthermore, we find that the combination of normalized lineage-through-time (nLTT) statistics and phylogenetic signal in binary traits (Fitz and Purvis’s D) constitute efficient summary statistics for the ABC method. By providing insights into the selection of suitable summary statistics, our work aims to contribute to the use of the ABC approach in the development of complex state-dependent diversification models, for which a likelihood is not available.Competing Interest StatementThe authors have declared no competing interest

Identifying summary statistics for approximate Bayesian computation in a phylogenetic island biogeography model

Estimation of parameters of evolutionary island biogeography models, such as colonization and diversification rates, is important for a better understanding of island systems. A popular statistical inference framework is likelihood-based estimation of parameters using island species richness and phylogenetic data. Likelihood approaches require that the likelihood can be computed analytically or numerically, but with the increasing complexity of island biogeography models, this is often unfeasible. Simulation-based estimation methods may then be a promising alternative. One such method is approximate Bayesian computation (ABC), which compares summary statistics of the empirical data with the output of model simulations. However, ABC demands the definition of summary statistics that sufficiently describe the data, which is yet to be explored in island biogeography. Here, we propose a set of summary statistics and use it in an ABC framework for the estimation of parameters of an island biogeography model, DAISIE (Dynamic Assembly of Island biota through Speciation, Immigration and Extinction). For this model, likelihood-based inference is possible, which gives us the opportunity to assess the performance of the summary statistics. DAISIE currently only allows maximum likelihood estimation (MLE), so we additionally develop a likelihood-based Bayesian inference framework using Markov Chain Monte Carlo (MCMC) to enable comparison with the ABC results (i.e., making the same assumptions on prior distributions). We simulated phylogenies of island communities subject to colonization, speciation, and extinction using the DAISIE simulation model and compared the estimated parameters using the three inference approaches (MLE, MCMC and ABC). Our results show that the ABC algorithm performs well in estimating colonization and diversification rates, except when the species richness or amount of phylogenetic information from an island are low. We find that compared to island species diversity statistics, summary statistics that make use of phylogenetic and temporal patterns (e.g., the number of species through time) significantly improve ABC inference accuracy, especially in estimating colonization and anagenesis rates, as well as making inference converge considerably faster and perform better under the same number of iterations. Island biogeography is rapidly developing new simulation models that can explain the complexity of island biodiversity, and our study provides a set of informative summary statistics that can be used in island biogeography studies for which likelihood-based inference methods are not an option.Competing Interest StatementThe authors have declared no competing interest

Dietary lipid level affects growth performance and nutrient utilisation of Senegalese sole (Solea senegalensis) juveniles

Over the last few years, several aspects of Senegalese sole (Solea senegalensis) culture have been developed and optimised but the dietary lipid level for optimal growth has never been determined. Hence, five isonitrogenous diets (56 % dietary protein) with increasing dietary lipid levels (4, 8, 12, 16 and 20 % DM) were fed to satiation to triplicate groups of twenty fish (mean initial weight 10 g). Fifteen tanks were randomly assigned one of the five diets. Feed was distributed using automatic feeders, and fish were fed over a 16-week period. At the end of the experiment the fish fed on diets containing the two lowest dietary lipid levels (4 and 8 %) showed a 3-fold body-weight increase with a significantly higher daily growth index than fish fed higher lipid levels (1-2 v. 0-8). Moreover, these fish displayed a significantly lower dry feed intake (12g/kg per d) and feed conversion ratio (1-0) compared with fish fed higher lipids levels (16-19 g/kg per d; feed conversion ratio 2-0). Low dietary lipid levels (< 12 %) significantly improved nutrient retention and gain and hence growth, without major effects on whole-body composition. Despite the slight alteration in n-3 PUFA muscle content in the fish fed low-fat-diets, this fish fed low dietary lipid still remains a rich n-3 PUFA product and generally maintained its nutritional value. These results evidenced a low lipid tolerance of Senegalese sole juveniles and suggest a maximal dietary inclusion level of 8 % lipids for both optimal growth and nutrient utilisation without compromising flesh quality.IDEIA; European fund FEDERinfo:eu-repo/semantics/publishedVersio

TESTING THE EFFICIENCY-CAPM JOINT HYPOTHESIS IN THE BOVESPA

Market efficiency implies stock prices fully reflect all publicly available information instantaneously and, thus, no investment strategies can systematically earn abnormal returns. However, market efficiency per se is not testable. In order to analyze whether a stock market is efficient we have to test the joint hypothesis which refers fact that testing for market efficiency necessary involves asset pricing models. Then, we can compare real returns with expected returns predicted by a specific pricing model. In this context, the purpose of this study is to analyze whether the BOVESPA is an efficient market or, by contrast, it is possible to obtain abnormal returns employing the Capital Asset Pricing Model. To that end, we employ an intuitive trading rule based on purchasing exclusively those shares that are considered undervalued by the CAPM and compare it with the passive strategy of purchasing all shares that are members of the selective market index. Finally, our results are consistent with market efficiency as well as with the CAPM

Profitability of technical trading rules in the Brazilian stock market

Objetivo: El objetivo de este trabajo ha sido analizar las diferentes estrategias comerciales para el mercado de valores brasileño. Este análisis se centra en la comparación y combinación de diferentes reglas activas contra la regla pasiva de compra y retención. Antecedentes: El papel de líder regional del mercado de valores brasileño ha atraído la atención de los inversores, que ahora lo consideran una alternativa válida cuando buscan diversificar sus carteras. Por consiguiente, un uso adecuado de las Reglas Técnicas de Comercio (RTC) podría ayudar a los inversores a obtener los beneficios deseados de sus inversiones. Método: Se compara el rendimiento de las estrategias activas basadas en las TTR clásicas con una propuesta basada en el indicador de momentum, y luego todas ellas con las obtenidas de la estrategia pasiva de compra y retención. Se emplean pruebas de comprobación de la realidad y de capacidad de predicción superior para tener en cuenta el posible sesgo de fisgoneo de los datos. Los resultados: Se muestra que las reglas clásicas tienen un peor rendimiento que una regla propuesta basada en la Tasa de Cambio. Además, cuando empleamos una ETF que rastrea las compañías más pequeñas, obtenemos rendimientos más altos que los obtenidos para las compañías más grandes. Contribuciones: Este análisis es especialmente interesante porque, hasta donde sabemos, no hay evidencia empírica en ese sentido para el mercado de valores brasileño. Además, ampliamos la evidencia anterior centrándonos en tres ETF que rastrean las empresas grandes, medianas y pequeñas del mercado de valores brasileño y, por lo tanto, los resultados obtenidos de nuestro análisis proporcionarán una mejor visión de las oportunidades de inversión que la evidencia empírica anterior ha mostrado.Objective: The objective of this paper has been to analyze different trading strategies for the Brazilian stock market. This analysis is focused on the comparison and combination of different active rules against the passive rule of buy-and-hold. Background: The role of regional leader of the Brazilian stock market has attracted the attention of the investors, who now consider it a valid alternative when seeking to diversify their portfolios. Consequently, an adequate use of the Technical Trading Rules (TTR) could help investors obtain the desired profits on their investments. Method: We compare the performance of active strategies based on classical TTRs with a proposal based on the momentum indicator, and then all of them with those obtained from the passive strategy of buy-and-hold. Reality Check and Superior Predictive Ability tests are employed to account for possible data snooping bias. Results: It is shown that the classical rules perform worse than a proposed rule based on the Rate of Change. Additionally, when we employ an ETF which tracks the smaller companies, we obtain higher performances than those obtained for larger companies. Contributions: This analysis is especially interesting because, to our knowledge, there is no empirical evidence in that sense for the Brazilian stock market. Additionally, we extend the previous evidence by focusing on three ETFs that track large, medium and small companies of the Brazilian stock market and, therefore, the results obtained from our analysis will provide a better vision of the investment opportunities than what the previous empirical evidence has shown.• Junta de Extremadura. V Plan Regional de Investigación y Desarrollo. Ayuda GR15027peerReviewe