Time-series Modelling, Stationarity and Bayesian Nonparametric Methods

In this paper we introduce two general non-parametric first-order stationary time-series models for which marginal (invariant) and transition distributions are expressed as infinite-dimensional mixtures. That feature makes them the first Bayesian stationary fully non-parametric models developed so far. We draw on the discussion of using stationary models in practice, as a motivation, and advocate the view that flexible (non-parametric) stationary models might be a source for reliable inferences and predictions. It will be noticed that our models adequately fit in the Bayesian inference framework due to a suitable representation theorem. A stationary scale-mixture model is developed as a particular case along with a computational strategy for posterior inference and predictions. The usefulness of that model is illustrated with the analysis of Euro/USD exchange rate log-returns.Stationarity, Markov processes, Dynamic mixture models, Random probability measures, Conditional random probability measures, Latent processes.

A quasi-experimental evaluation of parents as sexual health educators resulting in delayed sexual initiation and increased access to condoms.

OBJECTIVE: To evaluate the effectiveness of an educational intervention for parents of first year high school students in the State of Morelos, Mexico, whose aim was to impact adolescents' sexual behavior, knowledge and access to contraception. MATERIAL AND METHODS: Quasi-experimental prospective study with eleven control and eleven intervention schools using self-administered questionnaires for parents and adolescents pre- and post-intervention. Parent-child dyads in the control and intervention schools were matched according to parents' propensity score; the average treatment effect (ATE) was estimated for adolescent's outcome variables. RESULTS: At follow-up, we found significant differences for adolescents in the intervention schools: 6.8% delayed initiation of sexual intercourse, 14.4% had correct knowledge about emergency contraception (EC), and 164% reported having received condoms from their parents, when comparing with students in control schools. CONCLUSIONS: Our results suggest that parent-focused interventions could be an innovative and effective strategy to promote adolescents sexual health

Young Citizens of the World Unite! A Case for the Model United Nations in Middle School Classrooms

In this manuscript, the authors describe the benefits and theoretical connections the Junior Model United Nations (JMUN) program has with middle school classrooms. The lens used to view the JMUN program is informed by literature on the needs of young adolescents, inquiry learning, and global citizenship. Findings from this literature illuminate nuances in the interaction between inquiry learning through the C3 Framework and active learning participation. Implications for middle school students, in-service teachers, and teacher candidates are discussed

HIV prevention in Mexican schools: prospective randomised evaluation of intervention.

OBJECTIVE: To assess effects on condom use and other sexual behaviour of an HIV prevention programme at school that promotes the use of condoms with and without emergency contraception. DESIGN: Cluster randomised controlled trial. SETTING: 40 public high schools in the state of Morelos, Mexico. PARTICIPANTS: 10 954 first year high school students. INTERVENTION: Schools were randomised to one of three arms: an HIV prevention course that promoted condom use, the same course with emergency contraception as back-up, or the existing sex education course. Self administered anonymous questionnaires were completed at baseline, four months, and 16 months. Students at intervention schools received a 30 hour course (over 15 weeks) on HIV prevention and life skills, designed in accordance with guidelines of the joint United Nations programme on HIV/AIDS. Two extra hours of education on emergency contraception were given to students in the condom promotion with contraception arm. MAIN OUTCOME MEASURES: Primary outcome measure was reported condom use. Other outcomes were reported sexual activity; knowledge and attitudes about HIV and emergency contraception; and attitudes and confidence about condom use. RESULTS: Intervention did not affect reported condom use. Knowledge of HIV improved in both intervention arms and knowledge of emergency contraception improved in the condom promotion with contraception arm. Reported sexual behaviour was similar in the intervention arms and the control group. CONCLUSION: A rigorously designed, implemented, and evaluated HIV education course based in public high schools did not reduce risk behaviour, so such courses need to be redesigned and evaluated. Addition of emergency contraception did not decrease reported condom use or increase risky sexual behaviour but did increase reported use of emergency contraception

Automatic Metro Map Layout Using Multicriteria Optimization

This paper describes an automatic mechanism for drawing metro maps. We apply multicriteria optimization to find effective placement of stations with a good line layout and to label the map unambiguously. A number of metrics are defined, which are used in a weighted sum to find a fitness value for a layout of the map. A hill climbing optimizer is used to reduce the fitness value, and find improved map layouts. To avoid local minima, we apply clustering techniques to the map the hill climber moves both stations and clusters when finding improved layouts. We show the method applied to a number of metro maps, and describe an empirical study that provides some quantitative evidence that automatically-drawn metro maps can help users to find routes more efficiently than either published maps or undistorted maps. Moreover, we found that, in these cases, study subjects indicate a preference for automatically-drawn maps over the alternatives

Supporting an Inquiry Mindset: Resisting the Lack of Curiosity by Design Model

As we work with students within teacher education and secondary contexts, we face an ever-growing disconnect over what should be taught or valued in the learning environment: Is it the memorization of content or the acquisition of skills related to being better citizens? As professors of social studies and literacy education and a teacher of secondary science, we introduce our students to our respective fields and task them with applying content within real-world contexts. This is not an easy task for teachers in any content area, political and social forces complicate this task. They must strike a balance between competing approaches to content implementation. In social studies these approaches can be as varied as teaching a hero narrative versus a more complex inquiry-based approach to understanding people in historical settings. With this context in mind, the purpose of this article is to advocate for an inquiry approach to teaching social studies and other disciplines in all grades through research and personal experiences

Extended-Household as a Co-Residence Strategy: The Case Of Santiago De Chile

Extended- household, as a social phenomenon, depends on the value of relationships of support and dependence among the members of a community. When this collaborative relationship occurs between residents of the same dwelling, it is then understood as a situation of co-residence. In the case of Santiago de Chile, the Extended - household phenomenon has increased by 610%. Data shows that families prefer to sacrifice conditions of habitability, privacy and security to maintain networks of support, location and access to urban goods, rather than migrating to the periphery as homeowners. It is urgent to generate mechanisms that recognize the needs and preferences of those who make up this “chronic” housing deficit, which is shown today as a form of fragile resistance to socio-spatial segregation

¿Qué están investigando los estudiantes de derecho en Colombia?: Un diagnóstico a propósito del investigando 2005

Las actuales exigencias impuestas por la sociedad a los profesionales del derecho han despertado el interés de docentes y estudiantes por la investigación jurídica y sociojurídica; por tal razón, se han abierto espacios académicos de intercambio y reflexión como el INVESTIGANDO 2005. Este evento, realizado los días 11, 12 y 13 de mayo de 2005 en la Universidad de Antioquia, permitió reflexionar acerca de la función social de la investigación en el derecho, al igual que sobre las políticas públicas de promoción de la misma en las instituciones educativas. Así mismo sirvió de escenario para conocer, por medio de un diagnóstico, los intereses, prácticas y experiencias investigativas jurídicas y sociojurídicas de los estudiantes de derecho en Colombia

Regional genetic structure in the Magellanic penguin (Spheniscus magellanicus) suggests metapopulation dynamics

Using microsatellite markers and mitochondrial DNA (mtDNA) sequences (cytochrome oxidase 1 gene), we estimated levels of genetic structuring among nine Magellanic Penguin (Spheniscus magellanicus) colonies distributed throughout three major reproductive regions of the South Atlantic Ocean. Overall, breeding colonies showed relatively high levels of genetic diversity at both nuclear and mtDNA markers (mean heteorzygosity: He = 0.598; mean allelic diversity: A = 7.11; mtDNA haplotype diversity: h = 0.812). A hierarchical analysis of molecular variance based on microsatellite data showed limited genetic structuring of breeding colonies, with 99% of the variation explained by differences among individuals and 0.7–1.0% attributed to differences among the three regions. The mtDNA analysis revealed higher levels of genetic structuring, with 3.43% of the variation explained by regions and 2.24% explained by colonies within the regions. Furthermore, a Mantel test revealed a significant association between geographic and genetic distances among colonies. The limited genetic structuring we detected is likely a result of (1) population intermixing through natal dispersal and (2) the large effective sizes of the reproductive colonies, both of which prevent genetic differentiation at neutral markers, balanced with (3) the regional association of breeding colonies to distinct feeding grounds and (4) a recent expansion of the population. Our results suggest that the demographic dynamics of breeding colonies of Magellanic Penguins may be framed under a metapopulation model, in which colonies with large numbers of breeding pairs could be considered source populations for maintaining the overall abundance of this species in the Atlantic Ocean

Daily temperature profiles in and around Western Kenyan larval habitats of Anopheles gambiae as related to egg mortality

BACKGROUND: Anopheles gambiae eggs are more frequently found on soil around puddle habitats of the larvae, than on the water surface itself in Western Kenya. Thus, eggs can experience temperatures more wide-ranging and lethal than those experienced by larvae or pupae confined within puddles. METHODS: Small batches of eggs from house-collected An. gambiae as well as from the Kisumu laboratory strain were bathed for defined times in water whose temperature was precisely controlled. Daily temperature profiles were recorded by an infrared thermometer on seven different days in and around three types of typical An. gambiae larval habitats at Kisian. RESULTS: For wild eggs, significant mortality occurred upon brief heating between 42 – 44°C. Few eggs hatched after 10 min at 45°C and none hatched above this temperature. A similar pattern occurred for eggs of the Kisumu strain, except it was shifted downwards by 1°C. Egg mortality was time-dependent above 40°C. Temperatures of water in the three types of larval habitats never exceeded 35°C. Wet or damp mud rarely and only briefly exceeded 40°C; thus, water and mud would be highly conducive to egg survival and development. However, dry soils frequently reached 40 – 50°C for several h. Eggs stranded on dry surfaces would experience substantial mortality on hot, sunny days. CONCLUSION: Moist mud around puddles constitutes suitable habitat for An. gambiae eggs; however, eggs on the surface of dry soil under direct sunlight are unlikely to survive for more than a few hours