468 research outputs found

    Parity-violation in elastic electron scattering: A first measurement of the parity-violating asymmetry at Q2 = 0.631 (GeV/c)2 at backward angle

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    The goal of Experiment E04-115 (the G0 backward angle measurement) at Jefferson Lab is to investigate the contributions of strange quarks to the fundamental properties of the nucleon. The experiment measures parity-violating asymmetries in elastic electron scattering off hydrogen and quasielastic electron scattering off deuterium at backward angles at Q2 = 0.631 (GeV/c)2 and Q 2 = 0.232 (GeV/c)2. The backward angle measurement represents the second phase of the G0 experiment. The first phase, Experiment E00-006 (the G0 forward angle experiment), measured parity-violating asymmetries in elastic electron scattering off hydrogen at forward angles over a Q 2 range of 0.1-1.0 (GeV/c)2. The experiments used a polarized electron beam and unpolarized hydrogen and deuterium liquid targets. From these measurements, along with the electromagnetic form factors, one can extract the contribution of the strange quark to the proton\u27s charge and magnetization distributions.;This thesis represents a first measurement of a parity-violating asymmetry in elastic electron scattering at Q2 = 0.631 (GeV/c) 2 off hydrogen at backward angles. This work is based on data obtained during the first part of the run, beginning in March 2006 and ending in May 2006. During this period, a total of 15 C of beam charge was accumulated. The total accumulated charge represents about 15% of the 110 C which was proposed for this Q2. The measured asymmetry is A = (-47.4 +/- 7.1 +/- 5.9 +/- 11.8) ppm, where the first uncertainty is due to statistics, the second uncertainty is systematic, and the third uncertainty is associated with the blinding factor. This result is consistent with a zero contribution from the strange quarks. The helicity-correlated beam properties and slopes are under adequate control for the final precision of the experiment

    LIHEAP Stabilizes Family Housing and Protects Children's Health

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    The heating and cooling season presents special challenges for our nation's low-income families. With limited resources, many are challenged to manage the seasonal spike in utility expenses, facing decisions about whether to pay the rent, keep the lights and heat on, or buy enough groceries to get through the end of the month. We know that each of these decisions will have significant implications for the health of their youngest children. Unfortunately, these tough choices are all too common this winter as the nation experiences increases in energy prices, unusually cold weather, and continued high unemployment

    Boost to SNAP Benefits Protected Young Children's Health

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    The Great Recession has taken a significant toll on America's children. In 2010, 25 percent of children under age six were living in poverty, up from 21 percent in 2007

    Bridging the ICT4D Design-Actuality Gap: “Human ATMs” and the Provision of Financial Services for “Humble People”

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    Most challenges in ICT for development (ICT4D) projects can be related to differences in perceptions of systems developers and their actual users. Such design-actuality gaps exist both because designers take an uninformed stance towards the user context, and also because problems that ICT4D projects address are nested in systems whose interplay is nearly impossible to predict. Although gaps are inevitable, users are not passive recipients whose only choices are to accept shortfalls in design or reject ICT4D technologies. Rather, users may act to remedy shortfalls through system work-arounds. In this paper we investigate the design use gap in the Brazilian correspondent banking model, an ICT4D project in which local small businesspeople interact with social, financial, government, and technical systems to provide financial services mostly for poor populations. Our findings suggest that correspondents’ acts to alter the financial and social systems proved sufficient to permit success of the project. Our results point to the importance of taking into account user actions and the separate roles of individual systems when designing ICT4D projects and theorizing their performance

    Amish Economic Transformations: New Forms of Income and Wealth Distribution in a Traditionally “Flat” Community

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    The basic contours of the Amish economic transformation over the past few decades have been well documented, including the demographic squeeze that pushed many Amish out of farming, their embrace of cottage industries and, to a lesser extent, factory labor, and the social and cultural dilemmas created by successful entrepreneurship. Yet the effects of increasing market entanglement on the distribution of income and assets in Amish communities are still poorly understood. In this exploratory study, we draw on publicly available data from the U.S. Census, the Ohio Amish Directory, and records from real estate transactions to map out the distribution of income and land wealth in one predominantly Amish-populated Census Tract in Holmes County, OH. Our findings illustrate economic differentiation within the Amish community, as well as the ways in which affiliation and church leadership are associated with land holdings. Our case study raises important questions about growing economic inequalities that merit further exploration

    Amish Economic Transformations: New Forms of Income and Wealth Distribution in a Traditionally “Flat” Community

    Get PDF
    The basic contours of the Amish economic transformation over the past few decades have been well documented, including the demographic squeeze that pushed many Amish out of farming, their embrace of cottage industries and, to a lesser extent, factory labor, and the social and cultural dilemmas created by successful entrepreneurship. Yet the effects of increasing market entanglement on the distribution of income and assets in Amish communities are still poorly understood. In this exploratory study, we draw on publicly available data from the U.S. Census, the Ohio Amish Directory, and records from real estate transactions to map out the distribution of income and land wealth in one predominantly Amish-populated Census Tract in Holmes County, OH. Our findings illustrate economic differentiation within the Amish community, as well as the ways in which affiliation and church leadership are associated with land holdings. Our case study raises important questions about growing economic inequalities that merit further exploration

    Single Wall Carbon Nanotube-polymer Solar Cells

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    Investigation of single wall carbon nanotube (SWNT)-polymer solar cells has been conducted towards developing alternative lightweight, flexible devices for space power applications. Photovoltaic devices were constructed with regioregular poly(3-octylthiophene)-(P3OT) and purified, >95% w/w, laser-generated SWNTs. The P3OT composites were deposited on ITO-coated polyethylene terapthalate (PET) and I-V characterization was performed under simulated AM0 illumination. Fabricated devices for the 1.0% w/w SWNT-P3OT composites showed a photoresponse with an open-circuit voltage (V(sub oc)) of 0.98 V and a short-circuit current density (I(sub sc)) of 0.12 mA/sq cm. Optimization of carrier transport within these novel photovoltaic systems is proposed, specifically development of nanostructure-SWNT complexes to enhance exciton dissociation

    Planning for Detroit's Tax-Reverted Properties: Possibilities fo rthe Wayne County Land Bank

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    http://deepblue.lib.umich.edu/bitstream/2027.42/110958/1/planning_for_detroit_s_tax_reverted_properties2006.pd

    Reducing prolonged sedentary time using a treadmill desk acutely improves cardiometabolic risk markers in male and female adults

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    The objectives of this study were to evaluate the acute effects of interrupting prolonged sitting with an accumulated 2 h of light-intensity walking on postprandial cardiometabolic risk markers. In this randomised crossover trial, 24 participants (twelve males) aged 18-55 years took part in two, 6.5 h conditions: 1) prolonged sitting (SIT) and 2) sitting interrupted hourly with 20 min light-intensity treadmill desk walking at between 1.2-3.5 km/h-1 (INT-SIT). Standardized meals were provided at 0 h and 3 h. Blood samples and blood pressure measures were taken hourly. Statistical analyses were completed using linear mixed models. Postprandial incremental area under the curve responses (mmol/L∙6.5 h) for glucose (4.52 [3.47, 5.56] and 6.66 [5.62, 7.71] for INT-SIT and SIT, respectively) and triglycerides (1.96 [0.96, 2.96] and 2.71 [1.70, 3.71] mmol/L∙6.5 h, for INT-SIT and SIT, respectively) were significantly lower in INT-SIT than SIT. Mean systolic and diastolic blood pressure responses were lower by 3% and 4%, respectively, in INT-SIT than SIT (P0.05). These findings suggest that interrupting sitting with an accumulated 2 h of light-intensity walking acutely improves cardiometabolic risk levels in males and females compared with prolonged sitting
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