Ahstract-Optimal operation of hydrothermal systems is very complex hecause it corresponds to a mnltiperiod, stochastic, large scale and characterized hy a nonseparable objective function optimization problem As a result it is traditionally carried out without taking into account transmission constraints or considering them in n very simplified wny. This approach is not adequate lo address certain kind of problems such as cost-benefit studies of transmission interconnections in hydro systems or the study of spatial distributions of spot prices ("zones" identification) through the electric network, due to hydro and power flow constraints. In this paper we address the problem of stochastic optimization of large scale transmission constrained hydrothermal systems with applications to the Brazilian case.
introduction: The cause of the sudden infant death syndrome (SIDS) is perhaps the oldest of unsolved mysteries of medicine, possibly dating back to Exodus in Biblical times when Egyptian children died in their sleep as if from a plague. It occurs when infants die unexpectedly with no sufficient cause of death found in a forensic autopsy, including death scene investigation and review of medical history. That SIDS is an X-linked recessive death from infectious respiratory disease of a physiologically anemic infant and not a simple anomalous cardiac or neurological condition is an extraordinary claim that requires extraordinary evidence. If it were by a simple cause, it would have already been solved, with over 11,000 papers on SIDS listed now in PubMed. Our aim is to use mathematical models of SIDS to explain: (1) its 50% excess male death rate; (2) its 4-parameter lognormal distribution of ages at death; (3) its winter maxima and summer minima; and (4) its increasing rate with live-birth order.Methods: From extensive SIDS vital statistics data and published epidemiologic studies, we developed probability models to explain the mathematical behavior of SIDS meeting the four constraints mentioned above. We, then, compare these SIDS properties to infant death from acute respiratory infection (ARI), and infant death from encephalopathy, unspecified (EU).results: Comparisons show that SIDS are congruent with ARI and are not consistent with EU and that these probability models not only fit the SIDS data but they also predict and fit the male fraction of all infant and child mortality from birth through the first 5 years of their life.conclusion: SIDS are not rejected as an X-linked disease involving ARI and are not explained by a triple risk model that has been commonly accepted by the SIDS medical community, as implicating a neurological causation process in a subset of SIDS.
Although the association between acculturation and substance use among Latino groups is important, it is often understudied, especially within specific Latino groups living in geographically distinct communities, such as the Mexican American population in South Texas. The researchers of this study aimed to better understand the effect of acculturation on substance use and alcohol dependence in a Mexican American college student population. This survey study investigated the correlation between acculturation and substance use and dependence by using the Vancouver Index of Acculturation (VIA), items related to substance use (nicotine, marijuana, and cocaine) in a Mexican American college student sample (N = 1,494), and the Short Alcohol Dependence Data Questionnaire (SADD; N = 715). The study was conducted in the Texas-Mexico border region. The results suggest that higher levels of acculturation do not predict increased drug use or alcohol dependence in the Mexican American college students. However, acculturation was found to be associated with lower use of cocaine and marijuana. The discussion examines commonalities and differences in drug use and dependence. Specifically, acculturation seems to have an inverse relationship to substance use and may serve as a protective factor to licit and illicit drug use among Mexican American college students.
El objetivo de la investigación fue analizar las diferencias entre el rendimiento académico y el tipo de práctica artística extracurricular en estudiantes de bachillerato. Participaron 169 estudiantes de la ciudad de Morelia, Michoacán (México). Se recabaron datos sociodemográficos mediante una ficha de identificación; se diseñó y aplicó un Inventario de Actividades Académicas y Extra Académicas (actividad artística entre ellas) y se obtuvo la boleta de calificaciones de cada participante; los datos se analizaron con el programa SPSS 20. Se llevaron a cabo pruebas de diferencia entre las variables: rendimiento académico y tipo de práctica artística. Se encontraron diferencias estadísticamente significativas entre el rendimiento académico y la práctica de las artes, siendo los participantes que practican actividades artísticas los de mejor rendimiento académico, sobre todo en las asignaturas de Español y Literatura.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.