1,693 research outputs found

    Development of Fuses for Protection of Geiger-Mode Avalanche Photodiode Arrays

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    Current-limiting fuses composed of Ti/Al/Ni were developed for use in Geiger-mode avalanche photodiode arrays for each individual pixel in the array. The fuses were designed to burn out at ∼4.5 × 10[superscript −3] A and maintain post-burnout leakage currents less than 10[superscript −7] A at 70 V sustained for several minutes. Experimental fuse data are presented and successful incorporation of the fuses into a 256 × 64 pixel InP-based Geiger-mode avalanche photodiode array is reported

    Private Food Assistance in a Small Metropolitan Area: Urban Resources and Rural Needs

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    Food banks and other private feeding programs have become an institutionalized component of the social welfare system in over 190 urban areas in the U.S. More recently, private food assistance has gained importance in rural areas as well. The density and capacity of agencies to serve the poor is higher in urban areas than in sparsely populated rural locales where distance and dispersal tend to be barriers to supplying and accessing donated food. Rural food distribution strategies thus must be qualitatively different than those in larger communities, because of the smaller-scale, more informal distributional system. Little is known about how urban-based nonprofit services stimulate and support food assistance in surrounding rural locales. Based on intensive interviews with food bank stafffood pan try directors, and food pantry clientele, we examine obstacles affecting the use of food pantries and the amelioration of food insecurity. We also provide an assessment of how changes in federal welfare provisions may be affecting the need for private food assistance

    Integrating Glenohumeral Range of Motion with Dynamic Postural Control for Early Detection of Elbow Injury Risk in Collegiate Baseball Pitchers: A Preliminary Prospective Case Series

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    Introduction: Medial elbow ulnar collateral ligament (UCL) injuries are common in baseball with increased surgical incidence in pitchers. There is no consensus on which modifiable injury risk metrics or performance screening tools to use to identify at risk collegiate baseball pitchers. Current literature on UCL injury risk has focused on local passive glenohumeral rotational motion with limited forays into more global movement patterns. The aim of this study was to assess possible relationships involving UCL injuries and modifiable local and global motor control performance risk factors. Material and Methods: An observational single cohort case series involving 15 collegiate baseball pitchers aimed to elucidate disparitites in glenohumeral active and passive range of motion alongside an assessment of general movement competency and dynamic motor control performance to identify injury risk for the UCL. Preseaon baseline metrics, including the Functional Movement Screen, Upper and Lower Quarter Y Balance Test, and glenohumaral internal and external rotation active, passive, and total arc range of motion were examined. Results: The two pitchers with UCL injury demonstrated less ability to actively move into their available passive rotational range with decreased lower extremity dynamic postural control, but no difference with general movement competency. The pitcher requiring UCL surgical intervention demonstrated even greater excessive passive range compared to the other injured pitcher and a decreased ability to control base of support during the dynamic single-leg balance performance test. Discussion: Participants with UCL injuries exibited noticable deficiencies in baseline active and passive mobility, suggestive of a potential motor control deficit and a compromised ability to fully access available range of motion. Furthermore, diminished performance on the Lower Quarter Y Balance Test identified potential motor control limitations involving a decreased ability to dynamically maintain a base of support. Conclusions: This is the first study designed to identify motor control issues in the both the local shoulder region and global body movement to identify modifiable risk factors for UCL injuries in baseball pitchers. This study may begin to address the gap in the literature by combining modifiable local shoulder range of motion and global balance metrics to identify pitchers at risk for UCL injuries. It underscores the significance of comparing active and passive range of motion in tandem with dynamic postural control assessments to better evaluate the risk of injuries in baseball pitchers. This case series lays the groundwork for future randomized clinical trials to evaluate the utiliity of combining this information

    Spectral-domain optical coherence tomography as a noninvasive method to assess damaged and regenerating adult zebrafish retinas.

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    These experiments assessed the ability of spectral-domain optical coherence tomography (SD-OCT) to accurately represent the structural organization of the adult zebrafish retina and reveal the dynamic morphologic changes during either light-induced damage and regeneration of photoreceptors or ouabain-induced inner retinal damage. Retinas of control dark-adapted adult albino zebrafish were compared with retinas subjected to 24 hours of constant intense light and recovered for up to 8 weeks or ouabain-damaged retinas that recovered for up to 3 weeks. Images were captured and the measurements of retinal morphology were made by SD-OCT, and then compared with those obtained by histology of the same eyes. Measurements between SD-OCT and histology were very similar for the undamaged, damaged, and regenerating retinas. Axial measurements of SD-OCT also revealed vitreal morphology that was not readily visualized by histology. SD-OCT accurately represented retinal lamination and photoreceptor loss and recovery during light-induced damage and subsequent regeneration. SD-OCT was less accurate at detecting the inner nuclear layer in ouabain-damaged retinas, but accurately detected the undamaged outer nuclear layer. Thus, SD-OCT provides a noninvasive and quantitative method to assess the morphology and the extent of damage and repair in the zebrafish retina

    Polyproline is a minimal antifreeze protein mimetic and enhances the cryopreservation of cell monolayers

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    Tissue engineering, gene therapy, drug screening and emerging regenerative medicine therapies are fundamentally reliant on high-quality adherent cell culture, but current methods to cryopreserve cells in this format can give low cell yields and requires large volumes of solvent 'antifreezes'. Herein we report polyproline is a minimum (bio)synthetic mimic of antifreeze proteins, which is accessible by solution, solid phase and recombinant methods. We demonstrate that polyproline has ice recrystallization inhibition activity linked to its amphipathic helix and that it enhances the DMSO- cryopreservation of adherent cell lines. Polyproline may be a versatile additive in the emerging field of macromolecular cryoprotectants

    The Development and Evaluation of a Combined Infection–Rheumatology Assessment Service in Response to the Chikungunya Fever Epidemic

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    The chikungunya virus is an arthritogenic alphavirus. Acute infection may be followed by persistent arthralgia, often causing significant functional impairment. The 2014–2015 chikungunya fever (CHIKF) epidemic resulted in a marked increase in cases presenting to rheumatology and tropical diseases services. A combined multidisciplinary rheumatology–tropical diseases service for assessment, management, and follow-up of patients with proven CHIKF and persistent (≥ 4 weeks) arthralgia was proposed and rapidly developed at The Hospital for Tropical Diseases in London. Rapid set up of a multidisciplinary clinic in response to the epidemic was achieved. Of a total of 54 patients, 21 (38.9%) patients with CHIKF developed persistent arthralgia and were reviewed by the multidisciplinary service. A combined assessment approach enabled comprehensive multidisciplinary assessment of CHIKF, assessment of joint pathology through ultrasound, and appropriate follow-up. A combined rheumatology–tropical diseases service was successfully used to identify and assess CHIKF-associated morbidity. Future outbreaks may be approached by establishing tailored multidisciplinary clinics

    Food Security of Low-Income Single Parents in East Alabama: Use of Private and Public Programs in the Age of Welfare Reform

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    Despite a strong economy, the use of private, nonprofit food assistance is increasing. To determine how single parenthood affects the use of both public and private food assistance, a sample of food bank clients and low-income, food-needy non-clients in East Alabama was interviewed. Overall, single-parent food-pantry clients indicated higher levels of food insecurity than other groups, but the non-clients who were not single parents also indicated high levels of need. Although 42 percent of food bank clients were single parents, results showed that married couples with children were more highly represented among the food bank clients than among food-needy individuals who do not use the pantry. Single parents were more likely than others to receive food stamp and Temporary Assistance to Needy Families (TANF) benefits, a finding that corresponds to this group\u27s lower incomes and larger family sizes
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