605 research outputs found

    Preparing Youth for College and Career: A Process Evaluation of Urban Alliance

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    Urban Alliance, headquartered in Washington, DC, serves at-risk youth through its high school internship program, which provides training, mentoring, and work experience to high school seniors from distressed communities in Washington, DC; Baltimore; Northern Virginia; and Chicago. The program serves youth before they become disconnected, helping them successfully transition to higher education or employment after graduation. Urban Alliance has commissioned the Urban Institute to conduct a six-year, randomized controlled trial impact and process evaluation of its high school internship program. This report provides a process analysis of the program; the analysis is informed by extensive evaluator observation and interviews with staff, stakeholders, and youth. It also presents baseline information about Urban Alliance and the youth participating in its high school internship program in Washington, DC, and Baltimore in the 2011ā€“12 and 2012ā€“13 program years. Subsequent reports as part of the impact study will describe the early-adulthood impacts of the Urban Alliance internship program on the youth it serves. Below is a summary of the findings in this first of three reports

    The comprehensive cohort model in a pilot trial in orthopaedic trauma

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    Background: The primary aim of this study was to provide an estimate of effect size for the functional outcome of operative versus non-operative treatment for patients with an acute rupture of the Achilles tendon using accelerated rehabilitation for both groups of patients. The secondary aim was to assess the use of a comprehensive cohort research design (i.e. a parallel patient-preference group alongside a randomised group) in improving the accuracy of this estimate within an orthopaedic trauma setting. Methods: Pragmatic randomised controlled trial and comprehensive cohort study within a level 1 trauma centre. Twenty randomised participants (10 operative and 10 non-operative) and 29 preference participants (3 operative and 26 non-operative). The ge range was 22-72 years and 37 of the 52 patients were men. All participants had an acute rupture of their Achilles tendon and no other injuries. All of the patients in the operative group had a simple end-to-end repair of the tendon with no augmentation. Both groups then followed the same eight-week immediate weight-bearing rehabilitation programme using an off-the-shelf orthotic. The disability rating index (DRI; primary outcome), EQ-5D, Achilles Total Rupture Score and complications were assessed ed at two weeks, six weeks, three months, six months and nine months after initial injury. Results: At nine months, there was no significant difference in DRI between patients randomised to operative or non-operative management. There was no difference in DRI between the randomised group and the parallel patient preference group. The use of a comprehensive cohort of patients did not provide useful additional information as to the treatment effect size because the majority of patients chose non-operative management. Conclusions: Recruitment to clinical trials that compare operative and non-operative interventions is notoriously difficult; especially within the trauma setting. Including a parallel patient preference group to create a comprehensive cohort of patients has been suggested as a way of increasing the power of such trials. In our study, the comprehensive cohort model doubled the number of patients involved in the study. However, a strong preference for non-operative treatment meant that the increased number of patients did not significantly increase the ability of the trial to detect a difference between the two interventions

    Immigration Enforcement and Fairness to Would-Be Immigrants

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    This chapter argues that governments have a duty to take reasonably effective and humane steps to minimize the occurrence of unauthorized migration and stay. While the effects of unauthorized migration on a countryā€™s citizens and institutions have been vigorously debated, the literature has largely ignored duties of fairness to would-be immigrants. It is argued here that failing to take reasonable steps to prevent unauthorized migration and stay is deeply unfair to would-be immigrants who are not in a position to bypass visa regulations. Importantly, the argument here is orthogonal to the debate as to how much and what kinds of immigration ought to be allowed

    Processing Bi-Pb-Sr-Ca-Cu-O superconductors from amorphous state

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    The bismuth based high T sub c superconductors can be processed via an amorphous Bi-Pb-Sr-Ca-Cu oxide. The amorphous oxides were prepared by melting the constituent powders in an alumina crucible at 1200 C in air followed by pouring the liquid onto an aluminum plate, and rapidly pressing with a second plate. In the amorphous state, no crystalline phase was identified in the powder x ray diffraction pattern of the quenched materials. After heat treatment at high temperature the amorphous materials crystallized into a glass ceramic containing a large fraction of the Bi2Sr2Ca2Cu3O(x) phase T sub c = 110 K. The processing method, crystallization, and results of dc electrical resistivity and ac magnetic susceptibility measurements are discussed

    Tuning of Collagen Scaffold Properties Modulates Embedded Endothelial Cell Regulatory Phenotype in Repair of Vascular Injuries In Vivo

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    Perivascularly implanted matrix embedded endothelial cells (MEECs) are potent regulators of inflammation and intimal hyperplasia following vascular injuries. Endothelial cells (ECs) in collagen scaffolds adopt a reparative phenotype with significant therapeutic potential. Although the biology of MEECs is increasingly understood, tuning of scaffold properties to control cell-substrate interactions is less well-studied. It is hypothesized that modulating scaffold degradation would change EC phenotype. Scaffolds with differential degradation are prepared by cross-linking and predegradation. Vascular injury increases degradation and the presence of MEECs retards injury-mediated degradation. MEECs respond to differential scaffold properties with altered viability in vivo, suppressed smooth muscle cell (SMC) proliferation in vitro, and altered interleukin-6 and matrix metalloproteinase-9 expression. When implanted perivascularly to a murine carotid wire injury, tuned scaffolds change MEEC effects on vascular repair and inflammation. Live animal imaging enables real-time tracking of cell viability, inflammation, and scaffold degradation, affording an unprecedented understanding of interactions between cells, substrate, and tissue. MEEC-treated injuries improve endothelialization and reduce SMC hyperplasia over 14 d. These data demonstrate the potent role material design plays in tuning MEEC efficacy in vivo, with implications for the design of clinical therapies.National Institutes of Health (U.S.) (Grant R01 GM 49039

    A non trivial extension of the two-dimensional Ising model: the d-dimensional "molecular" model

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    A recently proposed molecular model is discussed as a non-trivial extension of the Ising model. For d=2 the two models are shown to be equivalent, while for d>2 the molecular model describes a peculiar second order transition from an isotropic high temperature phase to a low-dimensional anisotropic low temperature state. The general mean field analysis is compared with the results achieved by a variational Migdal-Kadanoff real space renormalization group method and by standard Monte Carlo sampling for d=3. By finite size scaling the critical exponent has been found to be 0.44\pm 0.02 thus establishing that the molecular model does not belong to the universality class of the Ising model for d>2.Comment: 25 pages, 5 figure

    GLOBAL REFINEMENT OF TERRESTRIAL LASER SCANNER DATA REGISTRATION USING WEIGHTED SENSOR POSES

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    Terrestrial laser scanner (TLS) sensor captures highly dense and accurate point clouds quite useful for indoor and outdoor mapping, navigation, 3D reconstruction, surveillance, industrial projects, infrastructure management, and others. In this paper, we present a global registration method that weights the sensor poses for refinement of TLS data registration. Our global refinement method assumes that the variance-covariance matrix that describes the uncertainty of sensor poses is available to refine the registration errors. The effectiveness of the proposed method is demonstrated with TLS dataset obtained into outdoor environment. Our results show that the weighting the sensor poses obtained in registration task improves the positional accuracy of TLS sensor
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