412 research outputs found

    Family and parenting characteristics associated with marijuana use by Chilean adolescents

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    OBJECTIVE: Family involvement and several characteristics of parenting have been suggested to be protective factors for adolescent substance use. Some parenting behaviors may have stronger relationships with adolescent behavior while others may have associations with undesirable behavior among youth. Although it is generally acknowledged that families play an important role in the lives of Chilean adolescents, scant research exists on how different family and parenting factors may be associated with marijuana use and related problems in this population which has one of the highest rates of drug use in Latin America. METHODS: Using logistic regression and negative binomial regression, we examined whether a large number of family and parenting variables were associated with the possibility of Chilean adolescents ever using marijuana, and with marijuana-related problems. Analyses controlled for a number of demographic and peer-related variables. RESULTS: Controlling for other parenting and family variables, adolescent reports of parental marijuana use showed a significant and positive association with adolescent marijuana use. The multivariate models also revealed that harsh parenting by fathers was the only family variable associated with the number of marijuana-related problems youth experienced. CONCLUSION: Of all the family and parenting variables studied, perceptions of parental use of marijuana and harsh parenting by fathers were predictors for marijuana use, and the experience of marijuana-related problems. Prevention interventions need to continue emphasizing the critical socializing role that parental behavior plays in their children's development and potential use of marijuana.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3109755/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3109755/Accepted manuscrip

    Time and frequency transfer with a microwave link in the ACES/PHARAO mission

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    The Atomic Clocks Ensemble in Space (ACES/PHARAO mission), which will be installed on board the International Space Station (ISS), uses a dedicated two-way Micro-Wave Link (MWL) in order to compare the timescale generated on board with those provided by many ground stations disseminated on the Earth. Phase accuracy and stability of this long range link will have a key role in the success of the ACES/PHARAO experiment. SYRTE laboratory is heavily involved in the design and development of the data processing software : from theoretical modelling and numerical simulations to the development of a software prototype. Our team is working on a wide range of problems that need to be solved in order to achieve high accuracy in (almost) real time. In this article we present some key aspects of the measurement, as well as current status of the software's development.Comment: Proceedings of the European Frequency and Time Forum (EFTF) 2012 held in Gothenburg, Sweden, April 201

    Open-loop recycling of PET-PE post-industrial multi-layered plastic waste

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    La observación sistemática de vecindarios: el caso de Chile y sus perspectivas para trabajo social

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    El estudio acerca de las características de los vecindarios y sus efectos sobre las personas ha llegado a ser un área de creciente atención por parte de investigadores de diversas disciplinas en países desarrollados. Aunque actualmente existen diversas metodologías para estudiar efectos del vecindario, una de las más utilizadas es la Observación Sistemática de Vecindarios –Systematic Social Observation SSO, en inglés—porque permite recolectar información acerca de diversas características del entorno físico, social, ambiental y económico de los vecindarios donde se aplica. El objetivo de este artículo es (i) dar a conocer sumariamente algunas investigaciones influyentes sobre efectos del vecindario en Estados Unidos, ii) describir cómo se diseñó e implementó la Observación Sistemática de Vecindarios en la ciudad de Santiago de Chile, iii) señalar algunos facilitadores y obstaculizadores de la implementación del proyecto y, finalmente iv) enunciar posibles contribuciones y limitaciones que esta metodología ofrecería al trabajo social en Chile.The study of neighborhood characteristics and their effects on individuals has become an area of increasing attention by scholars from various disciplines in developed countries. Although there are various methods to study neighborhoods and their impact on human populations, one of the most used is the Systematic Social Observation –Observación Sistemática de Vecindarios (OSV), in Spanish—because it allows the collection of information about various features of the physical, social, environmental and economic characteristics of neighborhoods. The purpose of this article is to (i) briefly present some research on neighborhood effects influential in the U.S., ii) describe how they Systematic Social Observation was designed and implemented in the city of Santiago, Chile, iii) discuss some facilitators and obstacles of the implementation process and, finally iv) list possible contributions and limitations this approach would offer the profession of social work in Chile.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004073/Accepted manuscrip

    Prevalence of sexually transmitted infections in women attending antenatal care in Tete province, Mozambique

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    Objective. To determine the prevalence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and syphilis in pregnant women. Methods. A cross-sectional study was conducted among women attending antenatal care clinics (ANCs). Blood samples were tested for syphilis using the rapid plasma reagin (RPR) and treponemal haemagglutination (TPHA) tests; CT and NG were diagnosed using a manual polymerase chain reaction assay on first-void urine samples. A socio-demographic questionnaire was completed. Results were compared with previous published data on sexually transmitted infection (STI) prevalence in Mozambique. Results. Blood and urine samples were collected from 1 119 and 835 women, respectively. The prevalence of CT was 4.1%, and that of NG 2.5%. The RPR test was positive in 5.2% of the women, and 7.1% had a positive TPHA test. Active syphilis was found in 4.7%. In univariate analysis, CT was associated with having had any level of education (

    Availability of outpatient substance use disorder treatment programs in the United States

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78029/1/41.pd

    Temporal variability of waves at the proton cyclotron frequency upstream from Mars: Implications for Mars distant hydrogen exosphere

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    We report on the temporal variability of the occurrence of waves at the local proton cyclotron frequency upstream from the Martian bow shock from Mars Global Surveyor observations during the first aerobraking and science phasing orbit periods. Observations at high southern latitudes during minimum-to-mean solar activity show that the wave occurrence rate is significantly higher around perihelion/ southern summer solstice than around the spring and autumn equinoxes. A similar trend is observed in the hydrogen (H) exospheric density profiles over the Martian dayside and South Pole obtained from a model including UV thermospheric heating effects. In spite of the complexity in the ion pickup and plasma wave generation and evolution processes, these results support the idea that variations in the occurrence of waves could be used to study the temporal evolution of the distant Martian H corona and its coupling with the thermosphere at altitudes currently inaccessible to direct measurements.Fil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Romanelli, Norberto Julio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Chaufray, J. Y.. LATMOS; FranciaFil: Gomez, Daniel Osvaldo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Mazelle, C.. IRAP; FranciaFil: Delva, M.. IWF-ÖAW; AustriaFil: Modolo, R.. LATMOS; FranciaFil: González Galindo, F.. Instituto de Astrofísica de Andalucía; EspañaFil: Brain, D. A.. University of Colorado Boulder; Estados Unido

    Where are the Uranus Trojans?

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    The area of stable motion for fictitious Trojan asteroids around Uranus' equilateral equilibrium points is investigated with respect to the inclination of the asteroid's orbit to determine the size of the regions and their shape. For this task we used the results of extensive numerical integrations of orbits for a grid of initial conditions around the points L4 and L5, and analyzed the stability of the individual orbits. Our basic dynamical model was the Outer Solar System (Jupiter, Saturn, Uranus and Neptune). We integrated the equations of motion of fictitious Trojans in the vicinity of the stable equilibrium points for selected orbits up to the age of the Solar system of 5 billion years. One experiment has been undertaken for cuts through the Lagrange points for fixed values of the inclinations, while the semimajor axes were varied. The extension of the stable region with respect to the initial semimajor axis lies between 19.05 < a < 19.3 AU but depends on the initial inclination. In another run the inclination of the asteroids' orbit was varied in the range 0 < i < 60 and the semimajor axes were fixed. It turned out that only four 'windows' of stable orbits survive: these are the orbits for the initial inclinations 0 < i < 7, 9 < i < 13, 31 < i < 36 and 38 < i < 50. We postulate the existence of at least some Trojans around the Uranus Lagrange points for the stability window at small and also high inclinations.Comment: 15 pages, 12 figures, submitted to CMD

    Meditenanean rainfull space-time variabili| and its relation with runoff modelling

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    [ES] El objetivo de esta investigación es estudiar el efecto de la variabilidad espacio-temporal de la lluvia en la respuesta hidrológica de la cuenca (caudal pico y volumen del hidrograma de crecida). Para ello se generaron 100 episodios sintéticos con el modelo estocástico multidimensional de lluvia RAINGEN, que sirvieron como entrada al modelo distribuido lluvia-escorrentía TETIS. La aplicación se llevó a cabo en la cuenca de la Rambla del Poyo, ubicada en la costa mediterránea de España. Se consideraron densidades de medición equivalentes a 1, 4, 16 y 64 Km2/pluviómetro e intervalo temporal de 10 minutos, para áreas entre 2 km2 y 421 km2. Se estudió también la respuesta de las cuencas considerando como entraba el hietograma medio de precipitación[EN] The aim of this paper is to study the effecto of the space-time rainfall variability in runoff modelling, specially the peak flow and the runoff volume. The distributed rain-fall-runoff model TETIS has been used for the discharge simulation, while the rainfall input consisted on a family of one hundred synthetics events, generated with the multidimentional stochastic rainfall model RAINGEN. teh study area is the Rambla del Poyo basin, located in the mediterranean coast in Spain. Rain gauge densities of 1, 4, 16 and 64 km2/gauge were considered, and time level of aggregation of 10 minutes considering basins between 2 km2 and 421 km2. The cahtchment's response to the average precipitation hyetograph was also compuetd and compared to the others.Guichard Romero, D.; García Bartual, RL.; Francés, F.; Domínguez Mora, R. (2006). La variabilidad espacio-temporal de la lluvia mediterránea y su influencia en la respuesta hidrológica. Quehacer cientifico en Chiapas. 1(1):9-21. http://hdl.handle.net/10251/99489S9211
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