509 research outputs found
The association of at-risk, problem, and pathological gambling with substance use, depression, and arrest history
We examined at-risk, problem, or pathological gambling co-occurrence with frequency of past-year alcohol, tobacco, and marijuana use; depressive symptoms; and arrest history. Data included the responses of over 3,000 individuals who participated in a 2006 telephone survey designed to understand the extent of at-risk, problem, and pathological gambling; comorbidity levels with substance use; mental health; and social problems among Southwestern U.S. residents. Data were analyzed with multinomial and bivariate logistic regression. Respondents at risk for problem gambling were more likely to use alcohol, tobacco, and marijuana than those respondents not at risk. Pathological gamblers were no more or less likely to consume alcohol or tobacco than were non-gamblers or those not at risk. A dose-response relationship existed between degree of gambling problems and depressive symptoms and arrest history. Interventions for at-risk or problem gamblers need to include substance use treatment, and the phenomenon of low levels of substance use among pathological gamblers needs further exploration
Proton cyclotron wave generation mechanisms upstream of Venus
[1] Long-term observations of proton cyclotron waves in the upstream region of Venus raise the question of under which general solar wind conditions these waves are generated and maintained. The waves are characterized by their occurrence at the local proton cyclotron frequency and left-hand polarization, both in the spacecraft frame. Magnetometer data of the Venus Express spacecraft for two Venus years of observations are analyzed before, during, and after the occurrence of these waves. The configuration of the upstream magnetic field and the solar wind velocity is investigated, to study if the waves are generated from a ring distribution of pickup ions in velocity space or from a parallel pickup ion beam, i.e., for quasi-parallel conditions of solar wind velocity and magnetic field when the solar wind motional electric field is weak. It is found that stable and mainly quasi-parallel magnetic field conditions for up to ∼20 min prior to wave observation are present, enabling sufficient ion pickup and wave growth to obtain observable waves in the magnetometer data. Persistent waves occur mainly under quasi-parallel conditions. This is in agreement with linear theory, which predicts efficient wave growth for instabilities driven by field-aligned planetary ion beams, already for low pickup ion density. The occurrence of highly coherent waves at 4 RV upstream toward the Sun implies that planetary neutral hydrogen is initially picked up at least 5 RV toward the Sun from a sufficiently dense Venus hydrogen exosphere.Fil: Delva, M.. Austrian Academy of Sciences; AustriaFil: Mazelle, C.. Universitá Paul Sabatier; FranciaFil: 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: Volwerk, M.. Austrian Academy of Sciences; AustriaFil: Vörös, Z.. University of Innsbruck; AustriaFil: Zhang, T. L.. Austrian Academy of Sciences; Austri
Astrophysics datamining in the classroom: Exploring real data with new software tools and robotic telescopes
Within the efforts to bring frontline interactive astrophysics and astronomy
to the classroom, the Hands on Universe (HOU) developed a set of exercises and
platform using real data obtained by some of the most advanced ground and space
observatories. The backbone of this endeavour is a new free software Web tool -
Such a Lovely Software for Astronomy based on Image J (Salsa J). It is
student-friendly and developed specifically for the HOU project and targets
middle and high schools. It allows students to display, analyze, and explore
professionally obtained astronomical images, while learning concepts on
gravitational dynamics, kinematics, nuclear fusion, electromagnetism. The
continuous evolving set of exercises and tutorials is being completed with real
(professionally obtained) data to download and detailed tutorials. The
flexibility of the Salsa J platform tool enables students and teachers to
extend the exercises with their own observations. The software developed for
the HOU program has been designed to be a multi-platform, multi-lingual
experience for image manipulation and analysis in the classroom. Its design
enables easy implementation of new facilities (extensions and plugins), minimal
in-situ maintenance and flexibility for exercise plugin. Here, we describe some
of the most advanced exercises about astrophysics in the classroom, addressing
particular examples on gravitational dynamics, concepts currently introduced in
most sciences curricula in middle and high schools.Comment: 10 pages, 12 images, submitted to the special theme issue Using
Astronomy and Space Science Research in Physics Courses of the American
Journal of Physic
Impact of early initiation versus national standard of care of antiretroviral therapy in Swaziland's public sector health system : study protocol for a stepped-wedge randomized trial
Background: There is robust clinical evidence to support offering early access to antiretroviral treatment (ART) to all HIV-positive individuals, irrespective of disease stage, to both improve patient health outcomes and reduce HIV incidence. However, as the global treatment guidelines shift to meet this evidence, it is still largely unknown if early access to ART for all (also referred to as "treatment as prevention" or " universal test and treat") is a feasible intervention in the resource-limited countries where this approach could have the biggest impact on the course of the HIV epidemics. The MaxART Early Access to ART for All (EAAA) implementation study was designed to determine the feasibility, acceptability, clinical outcomes, affordability, and scalability of offering early antiretroviral treatment to all HIV-positive individuals in Swaziland's public sector health system.
Methods: This is a three-year stepped-wedge randomized design with open enrollment for all adults aged 18 years and older across 14 government-managed health facilities in Swaziland's Hhohho Region. Primary endpoints are retention and viral suppression. Secondary endpoints include ART initiation, adherence, drug resistance, tuberculosis, HIV disease progression, patient satisfaction, and cost per patient per year. Sites are grouped to transition two at a time from the control (standard of care) to intervention (EAAA) stage at each four-month step. This design will result in approximately one half of the total observation time to accrue in the intervention arm and the other half in the control arm. Our estimated enrolment number, which is supported by conservative power calculations, is 4501 patients over the course of the 36-month study period. A multidisciplinary, mixed-methods approach will be adopted to supplement the randomized controlled trial and meet the study aims. Additional study components include implementation science, social science, economic evaluation, and predictive HIV incidence modeling.
Discussion: A stepped-wedge randomized design is a causally strong and robust approach to determine if providing antiretroviral treatment for all HIV-positive individuals is a feasible intervention in a resource-limited, public sector health system. We expect our study results to contribute to health policy decisions related to the HIV response in Swaziland and other countries in sub-Saharan Africa
The motion of vibrating systems in Schwarzchild spacetime
Abstract. In this communication, the effects of vibrations at high frequencies onto a freely falling two-body system in Schwarzschild spacetime are investigated. We present these effects for different kinds of reference motions, all of which are placed in regions of weak gravitation: circular orbits, radial free fall (with different initial velocities) and radial free fall with a small tangential velocity. The vibrations induce a change in the motion of the vibrating system, which is characterized by a radial deviation between the vibrating system and the reference motion of the non-vibrating system. For a circular orbit, we show that the maximal radial deviation increases linearly with the initial radius. For a radial free fall, the radial deviation after one oscillation decreases quadratically with respect to the initial radius
Extended Fermi coordinates
We extend the notion of Fermi coordinates to a generalized definition in
which the highest orders are described by arbitrary functions. From this
definition rises a formalism that naturally gives coordinate transformation
formulae. Some examples are developped in which the extended Fermi coordinates
simplify the metric components.Comment: 16 pages, 1 figur
Magnetic Fluctuations and Turbulence in the Venus Magnetosheath and Wake
Recent research has shown that distinct physical regions in the Venusian
induced magnetosphere are recognizable from the variations of strength and of
wave/fluctuation activity of the magnetic field. In this paper the statistical
properties of magnetic fluctuations are investigated in the Venusian
magnetosheath, terminator, and wake regions. The latter two regions were not
visited by previous missions. We found 1/f fluctuations in the magnetosheath,
large-scale structures near the terminator and more developed turbulence
further downstream in the wake. Location independent short-tailed non-Gaussian
statistics was observed.Comment: 16 pages, 4 figure
Low-frequency magnetic field fluctuations in Venus' solar wind interaction region: Venus Express observations
We investigate wave properties of low-frequency magnetic field
fluctuations in Venus' solar wind
interaction region based on the measurements made on board the Venus
Express spacecraft. The orbit geometry is very suitable to
investigate the fluctuations in Venus' low-altitude magnetosheath
and mid-magnetotail and provides an opportunity for a comparative
study of low-frequency waves at Venus and Mars. The
spatial distributions of the wave properties, in particular in the
dayside and nightside magnetosheath as well as in the tail and
mantle region, are similar to observations at Mars. As both planets
do not have a global magnetic field, the interaction process of the
solar wind with both planets is similar and leads to similar
instabilities and wave structures. We focus on the spatial
distribution of the wave intensity of the fluctuating magnetic field and
detect an enhancement of the intensity in the dayside magnetosheath
and a strong decrease towards the terminator. For a detailed
investigation of the intensity distribution we adopt an
analytical streamline model to describe the plasma flow around
Venus. This allows displaying the evolution of the intensity along
different streamlines. It is assumed that the waves are generated
in the vicinity of the bow shock and are convected
downstream with the turbulent magnetosheath flow.
However, neither the different Mach numbers upstream and downstream
of the bow shock, nor the variation of the cross sectional area and
the flow velocity along the streamlines play probably an important role
in order to explain the observed concentration of wave intensity in the
dayside magnetosheath and the decay towards the nightside
magnetosheath. But, the concept of freely evolving or decaying turbulence is in good
qualitative agreement with the observations, as we observe a power law decay
of the intensity along the streamlines. The observations support the assumption of
wave convection through the magnetosheath, but reveal at the same time
that wave sources may not only exist at the bow shock, but also in the magnetosheath
Int J Environ Res Public Health
In 2015, the International Federation of Gynecology and Obstetrics established the prevention of exposures to environmental reprotoxic substances as a priority for health professionals. However, available information about reproductive hazards is voluminous, dispersed, and complex, and this is a severe limitation for physicians to incorporate the prevention of environmental exposure into standard preventive care. One difficulty frequently cited by physicians is the lack of evidence-based information. The objective of our study was to identify a list of environmental chemical hazards to reproduction. We used lists present in relevant regulations or included in scientific reports or databases to identify reproductive hazards. The reproductive hazards were prioritized according to the strength of evidence concerning their impact on fertility or development of the offspring. We identified 1251 reproductive hazards. Our prioritization approach resulted in a high-priority classification for 462 risk factors belonging to the following eight classes: drugs (n = 206), metals (n = 116), pesticides (n = 38), organic solvents (n = 27), synthesizing and/or processing agents in industrial processes (n = 23), phthalates (n = 13), perfluorinated compounds (n = 13), and other compounds (n = 26). Despite the limitations of this work, the generated lists constitute a useful working basis to put in place innovative environmental preventive measures according to the principle of evidence-based medicine
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