905 research outputs found

    Development of a scale to assess avoidance behavior due to a fear of falling: the fear of falling avoidance behavior questionnaire

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    Journal ArticleBackground. A history of falls or imbalance may lead to a fear of falling, which may lead to self-imposed avoidance of activity; this avoidance may stimulate a vicious cycle of deconditioning and subsequent falls. Objective. The purpose of this study was to develop a questionnaire that would quantify avoidance behavior due to a fear of falling. Design. This study consisted of 2 parts: questionnaire development and psychometric testing. Questionnaire development involved an expert panel and 39 residents of an assisted living facility. Sixty-three community-dwelling individuals with various health conditions participated in psychometric testing. Method. Questionnaire development included the evaluation of face and content validity and factor analysis of the initial questionnaire. The final result of questionnaire development was the Fear of Falling Avoidance Behavior Questionnaire (FFABQ). In order to determine its psychometric properties, reliability and construct validity were assessed through administration of the FFABQ to participants twice, 1 week apart, and comparison of the FFABQ with other questionnaires related to fear of falling, functional measures of balance and mobility, and daily activity levels using an activity monitor. Results. The FFABQ had good overall test-retest reliability (intraclass correlation coefficient=.812) and was found to differentiate between participants who were considered ?fallers? (ie, at least one fall in the previous year) and those who were considered ?nonfallers.? The FFABQ predicted time spent sitting or lying and endurance. Limitations. A relatively small number of people with a fear of falling were willing to participate. Conclusion. Results from this study offer evidence for the reliability and validity of the FFABQ and support the notion that the FFABQ measures avoidance behavior rather than balance confidence, self-efficacy, or fear

    Total Laparoscopic Hysterectomy: Evaluation of an Evidence-Based Educational Strategy Using a Novel Simulated Suture and Knot-Tying Challenge, the “Holiotomy”

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    Objective. The purpose of this study was to evaluate perceptions of skills and practice patterns of gynecologists attending a course on total laparoscopic hysterectomy (TLH). This course employed extensive use of pelvic trainer boxes to accomplish the Holiotomy Challenge. The “Holiotomy Challenge” entailed suturing two plastic pieces with six figure-of-N sutures tied with four square knots each. Methods. A survey was administered before the course and 3 months later. Data were analyzed by paired t-tests, McNemar's Chi Squares, and ANCOVAs with significance set P < .05. Results. At baseline, 216 surgeons and at 3 months 102 surgeons returned the survey. Surgeons' self-perceptions of their skills significantly increased from 6.24 to 7.28. Their reports of their surgical practice at home revealed significantly increased rates of minimally invasive procedures, from 42% to 54%. Significantly more surgeons reported having the ability to close the vagina, or a small cystotomy or enterotomy. Participation in the cadaver lab and presence of their practice partner did not impact these rates. Conclusions. A comprehensive course employing laparoscopic surgical simulation focused on basic surgical skills essential to TLH has a positive impact on attendees' self-rated skill level and rate of laparoscopic approaches. Many had begun performing TLH after the course

    Structure and dynamics of colloidal depletion gels: coincidence of transitions and heterogeneity

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    Transitions in structural heterogeneity of colloidal depletion gels formed through short-range attractive interactions are correlated with their dynamical arrest. The system is a density and refractive index matched suspension of 0.20 volume fraction poly(methyl methacyrlate) colloids with the non-adsorbing depletant polystyrene added at a size ratio of depletant to colloid of 0.043. As the strength of the short-range attractive interaction is increased, clusters become increasingly structurally heterogeneous, as characterized by number-density fluctuations, and dynamically immobilized, as characterized by the single-particle mean-squared displacement. The number of free colloids in the suspension also progressively declines. As an immobile cluster to gel transition is traversed, structural heterogeneity abruptly decreases. Simultaneously, the mean single-particle dynamics saturates at a localization length on the order of the short-range attractive potential range. Both immobile cluster and gel regimes show dynamical heterogeneity. Non-Gaussian distributions of single particle displacements reveal enhanced populations of dynamical trajectories localized on two different length scales. Similar dependencies of number density fluctuations, free particle number and dynamical length scales on the order of the range of short-range attraction suggests a collective structural origin of dynamic heterogeneity in colloidal gels.Comment: 14 pages, 10 figure

    Position indicating, rotating boom

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    Universal multiplanar position indicating, rotating boom for mounting various instruments or sensors is described. Boom is telescoping, and apparatus is capable of 3 types of rotation controlled by electric motors. Movement may be continuous or incremental

    Nitric Oxide Pathways in Surface-Flame Radiant Burners

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    Nitrogen oxide (NOx) formation in surface-flame burners is studied. Surface-flame burners are typically made of metal fibers, ceramic fibers, or ceramic foam and provide radiant flux with low pollutant emissions. A one-dimensional model represents combustion on and within the porous medium using multistep chemistry, separate gas and energy equations, and a radiatively participating porous medium. We describe experimental measurements of NOx profiles above a surface-flame burner and compare them to model predictions. The model predicts NOx concentration with reasonable success. Deviations between model and experiment are primarily the result of heat loss in the experiment that is not considered in the model. Reaction rate analysis is performed to identify the chemical kinetic source of NO in the flame. Zeldovich NO is significant only at the highest firing rate studied (600 kW/m2, ϕ = 0.9), where it is responsible for 50-60% of the total NO. At the lower firing rates (200 and 300 kW/m2, ϕ = 0.9), where total NO is low, nearly all of the NO is formed in the flame front. Zeldovich NO accounts for 20-30% percent of the total NO, the Fenimore pathway accounts for less than 10% of the NO, and 50-75% percent of the NO is formed through the NNH, N2O and other paths. Sensitivity analysis shows that NO production in the flame front is most sensitive to NNH+O = NH+NO, with CH+N2 = HCN+N having the second highest sensitivity coefficient. At the lower firing rates NO emission is insensitive to porous medium properties, while at the high firing rate NO emission is slightly sensitive to porous medium properties

    Non-Catalytic NOx Removal from Gas Turbine Exhaust with Cyanuric Acid in a Recirculating Reactor; Small Scale Evaluation and Industrial Application

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    A novel SNC technique to remove oxides of nitrogen (NOx) from stationary gas turbine exhaust has been investigated and applied. The technique employs the use of cyanuric acid (CYA), a non-toxic, dry powder, combined with the injection of auxiliary turbine fuel and recirculation. During the initial investigation, exhaust, generated by a 150 kW gas turbine, was treated in an insulated recirculation reactor, with a mean residence time of 0.65 to 0.71 seconds and a pressure drop of 660 Pa. In the reactor, autoignition of injected auxiliary gas turbine fuel raises the flue gas temperature to between 700 and 800 ºC. CYA slurry is injected. Temperature rise and NOx reduction occur simultaneously. Load following has been achieved. At all temperatures, significant NOx reduction from initial concentrations of 106 to 124 ppm to as low as 18 ppm at 15% O2 have been observed. However, The process generates N2O emissions, which vary from 45 to 163 ppm, increasing with increasing CYA/NOx ratio. The ratio of N2O formed to NO removed was found to be between 1 to 1.5 to 1. The performance of CYA ((HNCO)3) is compared to that of ammonia (NH3) and urea ((NH2)2CO). A numerical model, which combines a detailed chemical kinetic mechanism with recirculation, has been developed. The model captures all observed trends well and is an invaluable guide to improved understanding of the interactive NOx removal process. The process was then successfully scaled up and applied to a variety of industrial 3.7 MW gas turbines and similarly significant NOx reduction has been achieved

    Note and Comment

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    The Law School; Unauthorized Operation by Physician; The Kansas Oil Refinery Bill; Garnishment of Public Corporations; The rule in Wild\u27s Case Today; Effect of a complicated Form of Ballot on the Elector\u27s Freedom of Choice; Situs of Debts for Garnishment; Malicious Interference With the Contract of Employmen

    Improved Dynamic Postural Task Performance without Improvements in Postural Responses: The Blessing and the Curse of Dopamine Replacement

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    Introduction. Dopamine-replacement medications may improve mobility while not improving responses to postural challenges and could therefore increase fall risk. The purpose of this study was to measure reactive postural responses and gait-related mobility of patients with PD during ON and OFF medication conditions. Methods. Reactive postural responses to the Pull Test and performance of the Functional Gait Assessment (FGA) were recorded from 15 persons with PD during ON and OFF medication conditions. Results. Persons with PD demonstrated no significant difference in the reactive postural responses between medication conditions but demonstrated significantly better performance on the FGA when ON medications compared to OFF. Discussion/Conclusion. Dopamine-replacement medications alone may improve gait-related mobility without improvements in reactive postural responses and therefore could result in iatrogenic increases in fall risk. Rehabilitation providers should be aware of the side effects and limitations of medication treatment and implement interventions to improve postural responses
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