205 research outputs found

    Followup Observations of SDSS and CRTS Candidate Cataclysmic Variables

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    We present photometry of 11 and spectroscopy of 35 potential cataclysmic variables from the Sloan Digital Sky Survey, the Catalina Real-Time Transient Survey and vsnet-alerts. The photometry results include quasi-periodic oscillations during the decline of V1363 Cyg, nightly accretion changes in the likely Polar (AM Herculis binary) SDSS J1344+20, eclipses in SDSS J2141+05 with an orbital period of 76+/-2 min, and possible eclipses in SDSS J2158+09 at an orbital period near 100 min. Time-resolved spectra reveal short orbital periods near 80 min for SDSS J0206+20, 85 min for SDSS J1502+33, and near 100 min for CSS J0015+26, RXS J0150+37, SDSS J1132+62, SDSS J2154+15 and SDSS J2158+09. The prominent HeII line and velocity amplitude of SDSS J2154+15 are consistent with a Polar nature for this object, while the lack of this line and a low velocity amplitude argue against this classification for RXS J0150+37. Single spectra of 10 objects were obtained near outburst and the rest near quiescence, confirming the dwarf novae nature of these objects.Comment: 34 pages, 14 figures, in press at A

    THE IMPACT OF HOME AVAILABILITY OF THE RELATIONSHIP BETWEEN NEIGHBORHOOD AVAILABILITY AND FRUIT AND VEGETABLE CONUMPTION IN LOW-INCOME ETHNIC MINORITIES

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    Purpose: High availability of grocery stores and supermarkets has been positively associated with increased fruit and vegetable consumption, yet some studies have reported that the relationship between availability and consumption is equivocal or inconclusive indicating that availability does not directly translate to increased consumption. The purpose of this study was to investigate the mediating effect of home availability of fruits and vegetables on the relationship between neighborhood availability of supermarkets and grocery stores and fruit and vegetable consumption in low-income, ethnic minority neighborhoods. Methods: Data used in this study was taken from the Healthful Options Using Streets and Transportation in Our Neighborhoods (HOUSTON) study, which aimed to identify and assess relationships between environmental factors and dietary habits in African Americans (N=216) residing in 12 public housing developments in Houston. Participating residents completed the National Institute of Health fruit and vegetable screener to measure consumption. Neighborhood availability of grocery stores and supermarkets was assessed using the Goods and Services Inventory (GASI). Home availability of fruits and vegetables were measured using a survey. Results: Participants averaged 4.76 (SD= 5.52) servings of fruits and vegetables, total servings of fruit and vegetables available in the home averaged 21.12 (SD= 7.09), and the mean total of grocery stores and supermarkets was .04 (SD= .03). Bivariate correlations found that fruit and vegetable consumption was correlated with home availability (r= .352, p\u3c .01). Neighborhood availability was not associated with consumption (r= -.036, p\u3c .01) or home availability (r= -0.027, p\u3c .01). Linear regression analyses showed that neighborhood availability of grocery stores and supermarkets was not associated with home availability or fruit and vegetable consumption (p\u3c .05). Conclusions: Home availability is an important predictor of consumption in low-income neighborhoods, but does not mediate the relationship between neighborhood availability and consumption of fruits and vegetables. A limitation to this study was the use of a mean number of grocery and supermarket stores for each housing development limiting our ability to observe the impact of neighborhood availability on home availability or consumption

    Solving the Obesity Epidemic in African American and Hispanic Communities: Voices from the Community

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    Purpose: Science & Community: Ending Obesity Improving Health (Science & Community) aimed at reducing obesity in Houston by developing partnerships and collaborating with community organizations to identify community research priorities and develop an obesity reduction program. Method: Partnership members were recruited from Science & Community events and invited to participate in in-depth interviews to gain insight on obesity prevalence, causes, and solutions. Partnership and community members (N=22) completed a 60-90 minute in-depth interview with a trained Science & Community team member. The interview guide consisted of 30 questions about pressing health problems in the community, potential solutions to health problems and obesity, and how the environment has impacted obesity and health behaviors in the community. Interviews were led by trained researchers and were transcribed by an external medical transcription company. Transcribed interviews were coded independently by two coders in ATLAS.ti version 6.2. Results: Interviewees (n=12 women and 10 men) were mostly Hispanic or Latino (n=9) and African American (n=7). Common problems identified by interviewees were childhood obesity, balancing a healthy diet, and physical inactivity. Interviewees identified obesity as a major problem in their communities and cited access to quality food and physical activity resources as both the problem and a solution. Additional emergent themes focused on solutions and included increasing awareness and education, coordinated efforts among organizations and using an ecologic approach to combat obesity. Conclusions: Community insight gleaned from this study be used to enhance relevance and sustainability of programs developed to reduce obesity and suggests possible avenues for participatory research and intervention

    Linear and nonlinear rheology of wormlike micelles

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    Several surfactant molecules self-assemble in solution to form long, cylindrical, flexible wormlike micelles. These micelles can be entangled with each other leading to viscoelastic phases. The rheological properties of such phases are very interesting and have been the subject of a large number of experimental and theoretical studies in recent years. We shall report on our recent work on the macrorheology, microrheology and nonlinear flow behaviour of dilute aqueous solutions of a surfactant CTAT (Cetyltrimethylammonium Tosilate). This system forms elongated micelles and exhibits strong viscoelasticity at low concentrations (\sim 0.9 wt%) without the addition of electrolytes. Microrheology measurements of G(ω)G(\omega) have been done using diffusing wave spectroscopy which will be compared with the conventional frequency sweep measurements done using a cone and plate rheometer. The second part of the paper deals with the nonlinear rheology where the measured shear stress σ\sigma is a nonmonotonic function of the shear rate γ˙\dot{\gamma}. In stress-controlled experiments, the shear stress shows a plateau for γ˙\dot{\gamma} larger than some critical strain rate, similar to the earlier reports on CPyCl/NaSal system. Cates et al have proposed that the plateau is a signature of mechanical instability in the form of shear bands. We have carried out extensive experiments under controlled strain rate conditions, to study the time-dependence of shear stress. The measured time series of shear stress has been analysed in terms of correlation integrals and Lyapunov exponents to show unambiguously that the behaviour is typical of low dimensional dynamical systems.Comment: 15 pages, 10 eps figure

    Using the RE-AIM framework to evaluate physical activity public health programs in México

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    Background: Physical activity (PA) public health programming has been widely used in Mexico; however, few studies have documented individual and organizational factors that might be used to evaluate their public health impact. The RE-AIM framework is an evaluation tool that examines individual and organizational factors of public health programs. The purpose of this study was to use the RE-AIM framework to determine the degree to which PA programs in Mexico reported individual and organizational factors and to investigate whether reporting differed by the program's funding source. Methods: Public health programs promoting PA were systematically identified during 2008-2013 and had to have an active program website. Initial searches produced 23 possible programs with 12 meeting inclusion criteria. A coding sheet was developed to capture behavioral, outcome and RE-AIM indicators from program websites. Results: In addition to targeting PA, five (42%) programs also targeted dietary habits and the most commonly reported outcome was change in body composition (58%). Programs reported an average of 11.1 (±3.9) RE-AIM indicator items (out of 27 total). On average, 45% reported reach indicators, 34% reported efficacy/effectiveness indicators, 60% reported adoption indicators, 40% reported implementation indicators, and 35% reported maintenance indicators. The proportion of RE-AIM indicators reported did not differ significantly for programs that were government supported (M∈=∈10, SD∈=∈3.1) and programs that were partially or wholly privately or corporately supported (M∈=∈12.0, SD∈=∈4.4). Conclusion: While reach and adoption of these programs were most commonly reported, there is a need for stronger evaluation of behavioral and health outcomes before the public health impact of these programs can be established. © 2015 Jauregui et al.; licensee BioMed Central

    Effect of Cold Work on the Tensile Properties of 6061, 2024, and 7075 Al Alloys

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    Aluminum alloys 6061, 2024, and 7075 were heat treated to various tempers and then subjected to a range of plastic strain (stretching) in order to determine their strain limits. Tensile properties, conductivity, hardness, and grain size measurements were evaluated. The effects of the plastic strain on these properties are discussed and strain limits are suggested

    Design and methodology of a cluster-randomized trial in early care and education centers to meet physical activity guidelines: Sustainability via Active Garden Education (SAGE)

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    Strategies are needed to help early care and education centers (ECEC) comply with policies to meet daily physical activity and fruit and vegetable guidelines for young children. This manuscript describes the design and methodology of Sustainability via Active Garden Education (SAGE), a 12-session cluster-randomized controlled crossover design trial using community-based participatory research (CBPR) to test a garden-based ECEC physical activity and fruit and vegetables promotion intervention for young children aged 3–5 years in 20 sites. The SAGE curriculum uses the plant lifecycle as a metaphor for human development. Children learn how to plant, water, weed, harvest, and do simple food preparation involving washing, cleaning, and sampling fruit and vegetables along with active learning songs, games, science experiments, mindful eating exercises, and interactive discussions to reinforce various healthy lifestyle topics. Parents will receive newsletters and text messages linked to the curriculum, describing local resources and events, and to remind them about activities and assessments. Children will be measured on physical activity, height, and weight and observed during meal and snack times to document dietary habits. Parents will complete measures about dietary habits outside of the ECEC, parenting practices, home physical activity resources, and home fruit and vegetable availability. SAGE fills an important void in the policy literature by employing a participatory strategy to produce a carefully crafted and engaging curriculum with the goal of meeting health policy guidelines and educational accreditation standards. If successful, SAGE may inform and inspire widespread dissemination and implementation to reduce health disparities and improve health equity

    Indoor robot gardening: design and implementation

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    This paper describes the architecture and implementation of a distributed autonomous gardening system with applications in urban/indoor precision agriculture. The garden is a mesh network of robots and plants. The gardening robots are mobile manipulators with an eye-in-hand camera. They are capable of locating plants in the garden, watering them, and locating and grasping fruit. The plants are potted cherry tomatoes enhanced with sensors and computation to monitor their well-being (e.g. soil humidity, state of fruits) and with networking to communicate servicing requests to the robots. By embedding sensing, computation, and communication into the pots, task allocation in the system is de-centrally coordinated, which makes the system scalable and robust against the failure of a centralized agent. We describe the architecture of this system and present experimental results for navigation, object recognition, and manipulation as well as challenges that lie ahead toward autonomous precision agriculture with multi-robot teams.Swiss National Science Foundation (contract number PBEL2118737)United States. Army Research Office. Multidisciplinary University Research Initiative (MURI SWARMS project W911NF-05-1-0219)National Science Foundation (U.S.) (NSF IIS-0426838)Intel Corporation (EFRI 0735953 Intel)Massachusetts Institute of Technology (UROP program)Massachusetts Institute of Technology (MSRP program
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