Does core strength training influence running kinetics, lower-extremity stability, and 5000-M performance in runners?

PubMed

Sato, Kimitake; Mokha, Monique

2009-01-01

Although strong core muscles are believed to help athletic performance, few scientific studies have been conducted to identify the effectiveness of core strength training (CST) on improving athletic performance. The aim of this study was to determine the effects of 6 weeks of CST on ground reaction forces (GRFs), stability of the lower extremity, and overall running performance in recreational and competitive runners. After a screening process, 28 healthy adults (age, 36.9 +/- 9.4 years; height, 168.4 +/- 9.6 cm; mass, 70.1 +/- 15.3 kg) volunteered and were divided randomly into 2 groups (n = 14 in each group). A test-retest design was used to assess the differences between CST (experimental) and no CST (control) on GRF measures, lower-extremity stability scores, and running performance. The GRF variables were determined by calculating peak impact, active vertical GRFs (vGRFs), and duration of the 2 horizontal GRFs (hGRFs), as measured while running across a force plate. Lower-extremity stability was assessed using the Star Excursion Balance Test. Running performance was determined by 5000-m run time measured on outdoor tracks. Six 2 (pre, post) x 2 (CST, control) mixed-design analyses of variance were used to determine the influence of CST on each dependent variable, p < 0.05. Twenty subjects completed the study (nexp = 12 and ncon = 8). A significant interaction occurred, with the CST group showing faster times in the 5000-m run after 6 weeks. However, CST did not significantly influence GRF variables and lower-leg stability. Core strength training may be an effective training method for improving performance in runners.

Intrarater reliability of hand held dynamometry in measuring lower extremity isometric strength using a portable stabilization device.

PubMed

Jackson, Steven M; Cheng, M Samuel; Smith, A Russell; Kolber, Morey J

2017-02-01

Hand held dynamometry (HHD) is a more objective way to quantify muscle force production (MP) compared to traditional manual muscle testing. HHD reliability can be negatively impacted by both the strength of the tester and the subject particularly in the lower extremities due to larger muscle groups. The primary aim of this investigation was to assess intrarater reliability of HHD with use of a portable stabilization device for lower extremity MP in an athletic population. Isometric lower extremity strength was measured for bilateral lower extremities including hip abductors, external rotators, adductors, knee extensors, and ankle plantar flexors was measured in a sample of healthy recreational runners (8 male, 7 females, = 30 limbs) training for a marathon. These measurements were assessed using an intrasession intrarater reliability design. Intraclass correlation coefficients (ICC) were calculated using 3,1 model based on the single rater design. The standard error of measurement (SEM) for each muscle group was also calculated. ICC were excellent ranging from ICC (3,1) = 0.93-0.98 with standard error of measurements ranging from 0.58 to 17.2 N. This study establishes the use of a HHD with a portable stabilization device as demonstrating good reliability within testers for measuring lower extremity muscle performance in an active healthy population. Copyright © 2016 Elsevier Ltd. All rights reserved.

Applying the partitioned multiobjective risk method (PMRM) to portfolio selection.

PubMed

Reyes Santos, Joost; Haimes, Yacov Y

2004-06-01

The analysis of risk-return tradeoffs and their practical applications to portfolio analysis paved the way for Modern Portfolio Theory (MPT), which won Harry Markowitz a 1992 Nobel Prize in Economics. A typical approach in measuring a portfolio's expected return is based on the historical returns of the assets included in a portfolio. On the other hand, portfolio risk is usually measured using volatility, which is derived from the historical variance-covariance relationships among the portfolio assets. This article focuses on assessing portfolio risk, with emphasis on extreme risks. To date, volatility is a major measure of risk owing to its simplicity and validity for relatively small asset price fluctuations. Volatility is a justified measure for stable market performance, but it is weak in addressing portfolio risk under aberrant market fluctuations. Extreme market crashes such as that on October 19, 1987 ("Black Monday") and catastrophic events such as the terrorist attack of September 11, 2001 that led to a four-day suspension of trading on the New York Stock Exchange (NYSE) are a few examples where measuring risk via volatility can lead to inaccurate predictions. Thus, there is a need for a more robust metric of risk. By invoking the principles of the extreme-risk-analysis method through the partitioned multiobjective risk method (PMRM), this article contributes to the modeling of extreme risks in portfolio performance. A measure of an extreme portfolio risk, denoted by f(4), is defined as the conditional expectation for a lower-tail region of the distribution of the possible portfolio returns. This article presents a multiobjective problem formulation consisting of optimizing expected return and f(4), whose solution is determined using Evolver-a software that implements a genetic algorithm. Under business-as-usual market scenarios, the results of the proposed PMRM portfolio selection model are found to be compatible with those of the volatility-based model. However, under extremely unfavorable market conditions, results indicate that f(4) can be a more valid measure of risk than volatility.

Vitamin D-deficiency and post-fracture changes in lower extremity function and falls in women with hip fractures

PubMed Central

Hawkes, W. G.; Glowacki, J.; Yu-Yahiro, J.; Hurwitz, S.; Magaziner, J.

2008-01-01

Summary We determined the prevalence of vitamin D deficiency and lower extremity function in women with hip fractures. Women with extremely low vitamin D levels had reduced lower extremity muscle function and increased falls 1 year later. Ensuring vitamin D sufficiency after a hip fracture may improve function and reduce falls. Introduction Hip fractures are the most devastating of fractures, commonly leading to loss of independent ambulation and living. In this retrospective analysis we determined the prevalence of vitamin D deficiency in women with hip fractures and the association between 25-hydroxyvitamin D [25(OH)D] levels and functional impairment one year later. Methods One hundred ten community-dwelling women with hip fractures were recruited from Boston, MA (n= 30) and Baltimore, MD (n=80) before 1998 and 25(OH)D levels were measured by radioimmunoassay. In a subset of women from Baltimore, a performance measure of the lower extremities using the lower extremity gain scale (LEGS) was measured at 2, 6, and 12 months. Falls, grip strength, chair rise time, walking speed, and balance were also determined. Results Vitamin D insufficiency defined as a 25(OH)D ≤32 ng/mL was present in 96% of the women with hip fractures and 38% had extremely low levels ≤9 ng/mL. At 1 year post-fracture, compared to women with a 25(OH) D >9 ng/mL, those with 25(OH)D ≤9 ng/mL had poorer LEGS performance (p<0.0001) and higher fall rates, without group differences in grip strength or balance. Conclusion Vitamin D sufficiency may have important effects on lower extremity function following hip fractures, without excessive healthcare costs. PMID:18373057

Changes in Upper-Extremity Functional Capacity and Daily Performance During Outpatient Occupational Therapy for People With Stroke

PubMed Central

Doman, Caitlin A.; Waddell, Kimberly J.; Bailey, Ryan R.; Moore, Jennifer L.

2016-01-01

OBJECTIVE. This study explored how upper-extremity (UE) functional capacity and daily performance change during the course of outpatient rehabilitation in people with stroke. METHOD. Fifteen participants receiving outpatient occupational therapy services for UE paresis poststroke were enrolled. UE motor capacity was measured with the Action Research Arm Test (ARAT), and UE performance was measured using bilateral, wrist-worn accelerometers. Measurements were taken at or near the start of therapy, at every 10th visit or every 30 days throughout the duration of services, and at discharge. RESULTS. Three patterns were observed: (1) increase in ARAT scores and more normalized accelerometry profiles, (2) increase in ARAT scores but no change in accelerometry profiles, and (3) no change in ARAT scores or in accelerometry profiles. CONCLUSION. UE performance in daily life was highly variable, with inconsistencies between change in UE capacity and change in UE performance. UE capacity and performance are important constructs to assess separately during rehabilitation. PMID:27089298

Estimating the impact of extreme climatic events on riverine sediment transport: new tools and methods

NASA Astrophysics Data System (ADS)

Lajeunesse, E.; Delacourt, C.; Allemand, P.; Limare, A.; Dessert, C.; Ammann, J.; Grandjean, P.

2010-12-01

A series of recent works have underlined that the flux of material exported outside of a watershed is dramatically increased during extreme climatic events, such as storms, tropical cyclones and hurricanes [Dadson et al., 2003 and 2004; Hilton et al., 2008]. Indeed the exceptionally high rainfall rates reached during these events trigger runoff and landsliding which destabilize slopes and accumulate a significant amount of sediments in flooded rivers. This observation raises the question of the control that extreme climatic events might exert on the denudation rate and the morphology of watersheds. Addressing this questions requires to measure sediment transport in flooded rivers. However most conventional sediment monitoring technics rely on manned operated measurements which cannot be performed during extreme climatic events. Monitoring riverine sediment transport during extreme climatic events remains therefore a challenging issue because of the lack of instruments and methodologies adapted to such extreme conditions. In this paper, we present a new methodology aimed at estimating the impact of extreme events on sediment transport in rivers. Our approach relies on the development of two instruments. The first one is an in-situ optical instrument, based on a LISST-25X sensor, capable of measuring both the water level and the concentration of suspended matter in rivers with a time step going from one measurement every hour at low flow to one measurement every 2 minutes during a flood. The second instrument is a remote controlled drone helicopter used to acquire high resolution stereophotogrammetric images of river beds used to compute DEMs and to estimate how flash floods impact the granulometry and the morphology of the river. These two instruments were developed and tested during a 1.5 years field survey performed from june 2007 to january 2009 on the Capesterre river located on Basse-Terre island (Guadeloupe archipelago, Lesser Antilles Arc).

Assessing functional mobility in survivors of lower-extremity sarcoma: reliability and validity of a new assessment tool.

PubMed

Marchese, Victoria G; Rai, Shesh N; Carlson, Claire A; Hinds, Pamela S; Spearing, Elena M; Zhang, Lijun; Callaway, Lulie; Neel, Michael D; Rao, Bhaskar N; Ginsberg, Jill P

2007-08-01

Reliability and validity of a new tool, Functional Mobility Assessment (FMA), were examined in patients with lower-extremity sarcoma. FMA requires the patients to physically perform the functional mobility measures, unlike patient self-report or clinician administered measures. A sample of 114 subjects participated, 20 healthy volunteers and 94 patients with lower-extremity sarcoma after amputation, limb-sparing, or rotationplasty surgery. Reliability of the FMA was examined by three raters testing 20 healthy volunteers and 23 subjects with lower-extremity sarcoma. Concurrent validity was examined using data from 94 subjects with lower-extremity sarcoma who completed the FMA, Musculoskeletal Tumor Society (MSTS), Short-Form 36 (SF-36v2), and Toronto Extremity Salvage Scale (TESS) scores. Construct validity was measured by the ability of the FMA to discriminate between subjects with and without functional mobility deficits. FMA demonstrated excellent reliability (ICC [2,1] >or=0.97). Moderate correlations were found between FMA and SF-36v2 (r = 0.60, P < 0.01), FMA and MSTS (r = 0.68, P < 0.01), and FMA and TESS (r = 0.62, P < 0.01). The patients with lower-extremity sarcoma scored lower on the FMA as compared to healthy controls (P < 0.01). The FMA is a reliable and valid functional outcome measure for patients with lower-extremity sarcoma. This study supports the ability of the FMA to discriminate between patients with varying functional abilities and supports the need to include measures of objective functional mobility in examination of patients with lower-extremity sarcoma.

The effect of mirror therapy on upper-extremity function and activities of daily living in stroke patients.

PubMed

Park, Jin-Young; Chang, Moonyoung; Kim, Kyeong-Mi; Kim, Hee-Jung

2015-06-01

The purpose of this study was to examine the effects of mirror therapy on upper-extremity function and activities of daily living in chronic stroke patients. [Subjects and Methods] Fifteen subjects were each assigned to a mirror therapy group and a sham therapy group. The Fugl-Meyer Motor Function Assessment and the Box and Block Test were performed to compare paretic upper-extremity function and hand coordination abilities. The functional independence measurement was conducted to compare abilities to perform activities of daily living. [Results] Paretic upper-extremity function and hand coordination abilities were significantly different between the mirror therapy and sham therapy groups. Intervention in the mirror therapy group was more effective than in the sham therapy group for improving the ability to perform activities of daily living. Self-care showed statistically significant differences between the two groups. [Conclusion] Mirror therapy is effective in improving paretic upper-extremity function and activities of daily living in chronic stroke patients.

The effect of mirror therapy on upper-extremity function and activities of daily living in stroke patients

PubMed Central

Park, Jin-Young; Chang, Moonyoung; Kim, Kyeong-Mi; Kim, Hee-Jung

2015-01-01

The purpose of this study was to examine the effects of mirror therapy on upper-extremity function and activities of daily living in chronic stroke patients. [Subjects and Methods] Fifteen subjects were each assigned to a mirror therapy group and a sham therapy group. The Fugl-Meyer Motor Function Assessment and the Box and Block Test were performed to compare paretic upper-extremity function and hand coordination abilities. The functional independence measurement was conducted to compare abilities to perform activities of daily living. [Results] Paretic upper-extremity function and hand coordination abilities were significantly different between the mirror therapy and sham therapy groups. Intervention in the mirror therapy group was more effective than in the sham therapy group for improving the ability to perform activities of daily living. Self-care showed statistically significant differences between the two groups. [Conclusion] Mirror therapy is effective in improving paretic upper-extremity function and activities of daily living in chronic stroke patients. PMID:26180297

Perceptions of Heat Risk to Health: A Qualitative Study of Professional Bus Drivers and Their Managers in Jinan, China

PubMed Central

Zhou, Lin; Xin, Zheng; Bai, Li; Wan, Fangjun; Wang, Yongming; Sang, Shaowei; Liu, Shouqin; Zhang, Ji; Liu, Qiyong

2014-01-01

Summer extreme heat threatens the health of individuals, especially persons who are involved in outdoor activities. Ensuring the normal function of a city, bus drivers are among those who participate in outdoor physical activities and are exposed to excessive heat in hot summer weather. This qualitative study was performed to explore professional bus drivers’ in-depth views of extreme heat risks to their health, and ultimately develop targeted advice and policy interventions for city bus drivers. An interview-based study was performed among professional bus drivers in Jinan, China, including four focus groups with professional bus drivers (n = 37) and three interviews with their managers (n = 14). Five central themes or categories from the bus driver interviews were found: concerns about summer heat; health effects related to extreme heat; adaptive measures; barriers in implementing these adaptive measures; and suggested interventions. The beneficial role of cooling facilities (particularly air-conditioning) during extreme heat are addressed. The barriers not only impede the implementation of behavioral adaptive measures but also enhance the negative attitudes of bus drivers towards their effectiveness. The responsibilities of managers in promoting preventive actions are addressed. PMID:24477213

Direct index of refraction measurements at extreme-ultraviolet and soft-x-ray wavelengths.

PubMed

Rosfjord, Kristine; Chang, Chang; Miyakawa, Ryan; Barth, Holly; Attwood, David

2006-03-10

Coherent radiation from undulator beamlines has been used to directly measure the real and imaginary parts of the index of refraction of several materials at both extreme-ultraviolet and soft-x-ray wavelengths. Using the XOR interferometer, we measure the refractive indices of silicon and ruthenium, essential materials for extreme-ultraviolet lithography. Both materials are tested at wavelength (13.4 nm) and across silicon's L2 (99.8 eV) and L3 (99.2 eV) absorption edges. We further extend this direct phase measurement method into the soft-x-ray region, where measurements of chromium and vanadium are performed around their L3 absorption edges at 574.1 and 512.1 eV, respectively. These are the first direct measurements, to our knowledge, of the real part of the index of refraction made in the soft-x-ray region.

Effect of whole-body vibration exercise in a sitting position prior to therapy on muscle tone and upper extremity function in stroke patients.

PubMed

Boo, Jung-A; Moon, Sang-Hyun; Lee, Sun-Min; Choi, Jung-Hyun; Park, Si-Eun

2016-01-01

[Purpose] The purpose of this study was to determine the effect of whole-body vibration exercise in a sitting position prior to therapy in stroke patients. [Subjects and Methods] Fourteen chronic stroke patients were included in this study. Prior to occupational therapy, whole-body exercise was performed for 10 minutes, 5 times per week, for a total of 8 weeks. Muscle tone and upper extremity function were measured. The Modified Ashworth Scale (MAS) was used to measure muscle tone, and the Manual Function Test (MFT) and Fugl-Meyer Assessment scale (FugM) were used to measure upper extremity function. [Results] MAS score was significantly decreased, and MFT and FugM were significantly increased. [Conclusion] These results indicate that whole-body vibration exercise in a sitting position prior to therapy had a positive effect on muscle tone, and upper extremity function in stroke patients.

Effect of Virtual Reality-based Bilateral Upper Extremity Training on Upper Extremity Function after Stroke: A Randomized Controlled Clinical Trial.

PubMed

Lee, Suhyun; Kim, Yumi; Lee, Byoung-Hee

2016-12-01

In the present study, we aimed to investigate the effect of virtual reality-based bilateral upper extremity training (VRBT) on paretic upper limb function and muscle strength in patients with stroke. Eighteen stroke survivors were assigned to either the VRBT group (n = 10) or the bilateral upper limb training group (BT, n = 8). Patients in the VRBT group performed bilateral upper extremity exercises in a virtual reality environment, whereas those in the BT group performed conventional bilateral upper extremity exercises. All training was conducted for 30 minutes day -1 , 3 days a week, for a period of 6 weeks. Patients were assessed for upper extremity function and hand strength. Compared with the BT group, the VRBT group exhibited significant improvements in upper extremity function and muscle strength (p < 0.05) after the 6-week training programme. The Box and Block test results revealed that upper extremity function and elbow flexion in hand strength were significantly improved in terms of group, time and interaction effect of group by time. Furthermore, the VRBT group demonstrated significant improvements in upper extremity function, as measured by the Jebsen Hand Function Test and Grooved Pegboard test, and in the hand strength test, as measured by elbow extension, grip, palmar pinch, lateral pinch and tip pinch, in both time and the interaction effect of group by time. These results suggest that VRBT is a feasible and beneficial means of improving upper extremity function and muscle strength in individuals following stroke. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Rasch validation of the Arabic version of the lower extremity functional scale.

PubMed

Alnahdi, Ali H

2018-02-01

The purpose of this study was to examine the internal construct validity of the Arabic version of the Lower Extremity Functional Scale (20-item Arabic LEFS) using Rasch analysis. Patients (n = 170) with lower extremity musculoskeletal dysfunction were recruited. Rasch analysis of 20-item Arabic LEFS was performed. Once the initial Rasch analysis indicated that the 20-item Arabic LEFS did not fit the Rasch model, follow-up analyses were conducted to improve the fit of the scale to the Rasch measurement model. These modifications included removing misfitting individuals, changing item scoring structure, removing misfitting items, addressing bias caused by response dependency between items and differential item functioning (DIF). Initial analysis indicated deviation of the 20-item Arabic LEFS from the Rasch model. Disordered thresholds in eight items and response dependency between six items were detected with the scale as a whole did not meet the requirement of unidimensionality. Refinements led to a 15-item Arabic LEFS that demonstrated excellent internal consistency (person separation index [PSI] = 0.92) and satisfied all the requirement of the Rasch model. Rasch analysis did not support the 20-item Arabic LEFS as a unidimensional measure of lower extremity function. The refined 15-item Arabic LEFS met all the requirement of the Rasch model and hence is a valid objective measure of lower extremity function. The Rasch-validated 15-item Arabic LEFS needs to be further tested in an independent sample to confirm its fit to the Rasch measurement model. Implications for Rehabilitation The validity of the 20-item Arabic Lower Extremity Functional Scale to measure lower extremity function is not supported. The 15-item Arabic version of the LEFS is a valid measure of lower extremity function and can be used to quantify lower extremity function in patients with lower extremity musculoskeletal disorders.

Methods of Constructing a Blended Performance Function Suitable for Formation Flight

NASA Technical Reports Server (NTRS)

Ryan, Jack

2017-01-01

Two methods for constructing performance functions for formation fight-for-drag-reduction suitable for use with an extreme-seeking control system are presented. The first method approximates an a prior measured or estimated drag-reduction performance function by combining real-time measurements of readily available parameters. The parameters are combined with weightings determined from a minimum squares optimization to form a blended performance function.

A Rasch-validated version of the upper extremity functional index for interval-level measurement of upper extremity function.

PubMed

Hamilton, Clayon B; Chesworth, Bert M

2013-11-01

The original 20-item Upper Extremity Functional Index (UEFI) has not undergone Rasch validation. The purpose of this study was to determine whether Rasch analysis supports the UEFI as a measure of a single construct (ie, upper extremity function) and whether a Rasch-validated UEFI has adequate reproducibility for individual-level patient evaluation. This was a secondary analysis of data from a repeated-measures study designed to evaluate the measurement properties of the UEFI over a 3-week period. Patients (n=239) with musculoskeletal upper extremity disorders were recruited from 17 physical therapy clinics across 4 Canadian provinces. Rasch analysis of the UEFI measurement properties was performed. If the UEFI did not fit the Rasch model, misfitting patients were deleted, items with poor response structure were corrected, and misfitting items and redundant items were deleted. The impact of differential item functioning on the ability estimate of patients was investigated. A 15-item modified UEFI was derived to achieve fit to the Rasch model where the total score was supported as a measure of upper extremity function only. The resultant UEFI-15 interval-level scale (0-100, worst to best state) demonstrated excellent internal consistency (person separation index=0.94) and test-retest reliability (intraclass correlation coefficient [2,1]=.95). The minimal detectable change at the 90% confidence interval was 8.1. Patients who were ambidextrous or bilaterally affected were excluded to allow for the analysis of differential item functioning due to limb involvement and arm dominance. Rasch analysis did not support the validity of the 20-item UEFI. However, the UEFI-15 was a valid and reliable interval-level measure of a single dimension: upper extremity function. Rasch analysis supports using the UEFI-15 in physical therapist practice to quantify upper extremity function in patients with musculoskeletal disorders of the upper extremity.

A Rasch-Validated Version of the Upper Extremity Functional Index for Interval-Level Measurement of Upper Extremity Function

PubMed Central

Chesworth, Bert M.

2013-01-01

Background The original 20-item Upper Extremity Functional Index (UEFI) has not undergone Rasch validation. Objective The purpose of this study was to determine whether Rasch analysis supports the UEFI as a measure of a single construct (ie, upper extremity function) and whether a Rasch-validated UEFI has adequate reproducibility for individual-level patient evaluation. Design This was a secondary analysis of data from a repeated-measures study designed to evaluate the measurement properties of the UEFI over a 3-week period. Methods Patients (n=239) with musculoskeletal upper extremity disorders were recruited from 17 physical therapy clinics across 4 Canadian provinces. Rasch analysis of the UEFI measurement properties was performed. If the UEFI did not fit the Rasch model, misfitting patients were deleted, items with poor response structure were corrected, and misfitting items and redundant items were deleted. The impact of differential item functioning on the ability estimate of patients was investigated. Results A 15-item modified UEFI was derived to achieve fit to the Rasch model where the total score was supported as a measure of upper extremity function only. The resultant UEFI-15 interval-level scale (0–100, worst to best state) demonstrated excellent internal consistency (person separation index=0.94) and test-retest reliability (intraclass correlation coefficient [2,1]=.95). The minimal detectable change at the 90% confidence interval was 8.1. Limitations Patients who were ambidextrous or bilaterally affected were excluded to allow for the analysis of differential item functioning due to limb involvement and arm dominance. Conclusion Rasch analysis did not support the validity of the 20-item UEFI. However, the UEFI-15 was a valid and reliable interval-level measure of a single dimension: upper extremity function. Rasch analysis supports using the UEFI-15 in physical therapist practice to quantify upper extremity function in patients with musculoskeletal disorders of the upper extremity. PMID:23813086

Apparatus for measurement of thermal conductivity of insulation systems subjected to extreme temperature differences

NASA Technical Reports Server (NTRS)

Dube, W. P.; Sparks, L. L.; Slifka, A. J.; Bitsy, R. M.

1990-01-01

Advanced aerospace designs require thermal insulation systems which are consistent with cryogenic fluids, high thermal loads, and design restrictions such as weight and volume. To evaluate the thermal performance of these insulating systems, an apparatus capable of measuring thermal conductivity using extreme temperature differences (27 to 1100 K) is being developed. This system is described along with estimates of precision and accuracy in selected operating conditions. Preliminary data are presented.

Apparatus for measurement of thermal conductivity of insulation systems subjected to extreme temperature differences

NASA Astrophysics Data System (ADS)

Dube, W. P.; Sparks, L. L.; Slifka, A. J.; Bitsy, R. M.

Advanced aerospace designs require thermal insulation systems which are consistent with cryogenic fluids, high thermal loads, and design restrictions such as weight and volume. To evaluate the thermal performance of these insulating systems, an apparatus capable of measuring thermal conductivity using extreme temperature differences (27 to 1100 K) is being developed. This system is described along with estimates of precision and accuracy in selected operating conditions. Preliminary data are presented.

Differences in Self-Reported Physical Limitation Among Older Women and Men in Ismailia, Egypt

PubMed Central

2012-01-01

Objectives. This study explores the reasons for gender differences in self-reported physical limitation among older adults in Ismailia, Egypt. Method. 435 women and 448 men, 50 years and older in Ismailia, Egypt, participated in a social survey and tests of physical performance. Ordered logit models were estimated to compare unadjusted gender differences in reported disability with these differences adjusted sequentially for (a) age and objective measures of physical performance, (b) self-reported morbidities and health care use, and (c) social and economic attributes. Results. Compared with men, women more often reported higher levels of limitation in activities of daily living (ADLs), upper-extremity range of motion (ROM), and lower-extremity gross mobility (GM). Adjusting for age and objective measures of physical performance, women and men had similar odds of self-reporting difficulty with ADLs. With sequential adjustments for the remaining variables, women maintained significantly higher odds of self-reported difficulty with upper-extremity ROM and lower-extremity GM. Discussion. Cross-culturally, gender differences in self-reported disability may arise from objective and subjective perceptions of disability. Collectively, these results and those from prior studies in Bangladesh and the United States suggest that gender gaps in self-reported physical limitation may be associated with the degree of gender equality in society. PMID:22929399

Differences in self-reported physical limitation among older women and men in Ismailia, Egypt.

PubMed

Khadr, Zeinab; Yount, Kathryn

2012-09-01

This study explores the reasons for gender differences in self-reported physical limitation among older adults in Ismailia, Egypt. 435 women and 448 men, 50 years and older in Ismailia, Egypt, participated in a social survey and tests of physical performance. Ordered logit models were estimated to compare unadjusted gender differences in reported disability with these differences adjusted sequentially for (a) age and objective measures of physical performance, (b) self-reported morbidities and health care use, and (c) social and economic attributes. Compared with men, women more often reported higher levels of limitation in activities of daily living (ADLs), upper-extremity range of motion (ROM), and lower-extremity gross mobility (GM). Adjusting for age and objective measures of physical performance, women and men had similar odds of self-reporting difficulty with ADLs. With sequential adjustments for the remaining variables, women maintained significantly higher odds of self-reported difficulty with upper-extremity ROM and lower-extremity GM. Cross-culturally, gender differences in self-reported disability may arise from objective and subjective perceptions of disability. Collectively, these results and those from prior studies in Bangladesh and the United States suggest that gender gaps in self-reported physical limitation may be associated with the degree of gender equality in society.

Feasibility of the Precise Energy Calibration for Fast Neutron Spectrometers

NASA Astrophysics Data System (ADS)

Gaganov, V. V.; Usenko, P. L.; Kryzhanovskaja, M. A.

2017-12-01

Computational studies aimed at improving the accuracy of measurements performed using neutron generators with a tritium target were performed. A measurement design yielding an extremely narrow peak in the energy spectrum of DT neutrons was found. The presence of such a peak establishes the conditions for precise energy calibration of fast-neutron spectrometers.

A comparative assessment of statistical methods for extreme weather analysis

NASA Astrophysics Data System (ADS)

Schlögl, Matthias; Laaha, Gregor

2017-04-01

Extreme weather exposure assessment is of major importance for scientists and practitioners alike. We compare different extreme value approaches and fitting methods with respect to their value for assessing extreme precipitation and temperature impacts. Based on an Austrian data set from 25 meteorological stations representing diverse meteorological conditions, we assess the added value of partial duration series over the standardly used annual maxima series in order to give recommendations for performing extreme value statistics of meteorological hazards. Results show the merits of the robust L-moment estimation, which yielded better results than maximum likelihood estimation in 62 % of all cases. At the same time, results question the general assumption of the threshold excess approach (employing partial duration series, PDS) being superior to the block maxima approach (employing annual maxima series, AMS) due to information gain. For low return periods (non-extreme events) the PDS approach tends to overestimate return levels as compared to the AMS approach, whereas an opposite behavior was found for high return levels (extreme events). In extreme cases, an inappropriate threshold was shown to lead to considerable biases that may outperform the possible gain of information from including additional extreme events by far. This effect was neither visible from the square-root criterion, nor from standardly used graphical diagnosis (mean residual life plot), but from a direct comparison of AMS and PDS in synoptic quantile plots. We therefore recommend performing AMS and PDS approaches simultaneously in order to select the best suited approach. This will make the analyses more robust, in cases where threshold selection and dependency introduces biases to the PDS approach, but also in cases where the AMS contains non-extreme events that may introduce similar biases. For assessing the performance of extreme events we recommend conditional performance measures that focus on rare events only in addition to standardly used unconditional indicators. The findings of this study are of relevance for a broad range of environmental variables, including meteorological and hydrological quantities.

Effect of Custom Orthosis and Rehabilitation Program on Outcomes Following Ankle and Subtalar Fusions.

PubMed

Sheean, Andrew J; Tennent, David J; Owens, Johnny G; Wilken, Jason M; Hsu, Joseph R; Stinner, Daniel J

2016-11-01

Fractures of the distal tibia, ankle, and foot sustained through a high-energy mechanism can be extremely debilitating, and ankle and/or subtalar fusion may be indicated if the limb is deemed salvageable. Functional outcomes among this population are often poor. The purposes of this study were to evaluate the effect of an advanced rehabilitation program combined with the use of a custom ankle-foot orthosis for patients with ankle or subtalar fusion on selected physical performance measures and patient-derived outcome measures and to determine if the response to treatment was predicated upon the type of fusion. We conducted a prospective, longitudinal, observational, cohort study composed of 23 active duty Service Members treated for lower extremity trauma. Patients were separated into 2 groups: group 1 was composed of 12 patients who underwent isolated ankle fusion or ankle fusion combined with ipsilateral subtalar fusion, group 2 was composed of 11 patients who underwent subtalar fusion only. Patient-reported outcome (PRO) measures and physical performance measures were recorded at baseline and at the conclusion of the rehabilitation program. Significant improvements in both groups were seen in each of the 4 physical performance measures. Only group 2 showed significant improvements in all domains of the Veteran's Rand 12-Item Health Survey (VR-12) and Short Musculoskeletal Function Assessment (SMFA) at all points during the course of rehabilitation. Among a subset of patients treated for severe lower extremity trauma with ankle and/or subtalar fusion, an integrated orthotic and rehabilitation initiative improved physical performance and PRO measures over an 8-week course. Level III, prospective comparative series. © The Author(s) 2016.

Manual physical therapy combined with high-intensity functional rehabilitation for severe lower extremity musculoskeletal injuries: a case series*

PubMed Central

Crowell, Michael S.; Deyle, Gail D.; Owens, Johnny; Gill, Norman W.

2016-01-01

Objectives Severe lower extremity trauma accounts for large healthcare costs and often results in elective amputation and poor long-term outcomes. The purpose of this case series is to describe an orthopedic manual physical therapy (OMPT) approach combined with a return to run (RTR) clinical pathway consisting of high-intensity functional rehabilitation with a custom energy-storing orthosis. Methods Three consecutive male patients, aged 21–23 years, with severe lower extremity musculoskeletal injuries were treated with a combined intervention that included a mean (SD) of 12 (2·1) OMPT sessions and 24 (8·7) functional rehabilitation sessions over a mean of 6 weeks (1·0). Additional training with a custom energy-storing orthosis consisted of a mean of 15 (1·2) additional sessions over 4 weeks. Patient self-report outcome measures and a variety of physical performance tests captured change in function. Results Baseline lower extremity functional scale (LEFS) and foot and ankle ability measure activities of daily living subscale (FAAM-ADL) scores indicated severe disability. All patients exceeded the minimal clinically important difference (MCID) in at least one self-report outcome or physical performance test without a brace. Two of three patients exceeded the MCID for at least two physical performance tests after training with and utilizing a custom energy-storing orthosis. Discussion Clinically meaningful changes in self-reported function or physical performance were observed in all patients. A multi-modal approach, including manual therapy and functional exercise, may address the entire spectrum of impairments in patients with severe lower extremity trauma, resulting in improvements in both braced and un-braced function. PMID:27252581

Determination of three-dimensional joint loading within the lower extremities in snowboarding.

PubMed

Krüger, Andreas; McAlpine, Paul; Borrani, Fabio; Edelmann-Nusser, Jürgen

2012-02-01

In the biomechanical literature only a few studies are available focusing on the determination of joint loading within the lower extremities in snowboarding. These studies are limited to analysis in a restricted capture volume due to the use of optical video-based systems. To overcome this restriction the aim of the present study was to develop a method to determine net joint moments within the lower extremities in snowboarding for complete measurement runs. An experienced snowboarder performed several runs equipped with two custom-made force plates as well as a full-body inertial measurement system. A rigid, multi-segment model was developed to describe the motion and loads within the lower extremities. This model is based on an existing lower-body model and designed to be run by the OpenSim software package. Measured kinetic and kinematic data were imported into the OpenSim program and inverse dynamic calculations were performed. The results illustrate the potential of the developed method for the determination of joint loadings within the lower extremities for complete measurement runs in a real snowboarding environment. The calculated net joint moments of force are reasonable in comparison to the data presented in the literature. A good reliability of the method seems to be indicated by the low data variation between different turns. Due to the unknown accuracy of this method the application for inter-individual studies as well as studies of injury mechanisms may be limited. For intra-individual studies comparing different snowboarding techniques as well as different snowboard equipment the method seems to be beneficial. The validity of the method needs to be studied further.

Effect of Robot-Assisted Game Training on Upper Extremity Function in Stroke Patients

PubMed Central

2017-01-01

Objective To determine the effects of combining robot-assisted game training with conventional upper extremity rehabilitation training (RCT) on motor and daily functions in comparison with conventional upper extremity rehabilitation training (OCT) in stroke patients. Methods Subjects were eligible if they were able to perform the robot-assisted game training and were divided randomly into a RCT and an OCT group. The RCT group performed one daily session of 30 minutes of robot-assisted game training with a rehabilitation robot, plus one daily session of 30 minutes of conventional rehabilitation training, 5 days a week for 2 weeks. The OCT group performed two daily sessions of 30 minutes of conventional rehabilitation training. The effects of training were measured by a Manual Function Test (MFT), Manual Muscle Test (MMT), Korean version of the Modified Barthel Index (K-MBI) and a questionnaire about satisfaction with training. These measurements were taken before and after the 2-week training. Results Both groups contained 25 subjects. After training, both groups showed significant improvements in motor and daily functions measured by MFT, MMT, and K-MBI compared to the baseline. Both groups demonstrated similar training effects, except motor power of wrist flexion. Patients in the RCT group were more satisfied than those in the OCT group. Conclusion There were no significant differences in changes in most of the motor and daily functions between the two types of training. However, patients in the RCT group were more satisfied than those in the OCT group. Therefore, RCT could be a useful upper extremity rehabilitation training method. PMID:28971037

High-performance multi-channel fiber-based absolute distance measuring interferometer system

NASA Astrophysics Data System (ADS)

Deck, Leslie L.

2009-08-01

I describe the principle of operation and performance of a fiber-based absolute distance measuring interferometer system with 60 independent simultaneous channels. The system was designed for demanding applications requiring passive, electrically immune sensors with an extremely long MTTF. In addition to providing better than 0.3nm measurement repeatability at 5KHz for all channels, the system demonstrated absolute distance uncertainty of less than 5nm over a 500 micron measurement range.

Exercise with vibration dumb-bell enhances neuromuscular excitability measured using TMS.

PubMed

Fowler, D E; Tok, M I; Colakoğlu, M; Bademkiran, F; Colakoğlu, Z

2010-09-01

The purpose of the study was to examine the effects of exercise without vibration and exercise with vibration (27 Hz) on the cortical silent period (CSP) and cortical motor threshold (CMT) measured using transcranial magnetic stimulation (TMS). In 22 university athletes, a circular coil attached to a TMS stimulator was applied over the contralateral motor cortex of the target forearm. Resting cortical motor thresholds for dominant and non-dominant extremities were measured for each participant. Then, 15 biceps curls (15 flexion and 15 extension movements) were performed with the dominant arm using a single vibration dumbbell with the vibration turned off. On a different day, the same biceps curl protocol was performed with the dumbbell vibrating at 27 Hz (2 mm amplitude). A supra-threshold TMS stimulus (1.5x CMT) was delivered while participants were voluntarily contracting the flexor digitorum sublimus muscle (30% MVC grip strength) to determine cortical silent periods before and after each upper extremity exercise protocol. Cortical motor thresholds were measured at rest and after the vibration exercise protocol. All subjects completed the study protocol as designed. After TMS, the CSP in the dominant (exercised) extremities increased after exercise without vibration from a resting (pre-exercise) mean of 57.3 ms to 70.4 ms (P<0.05) and after exercise with vibration, the CSP decreased to a mean of 49.4 ms (P<0.02). The CSP in the non-dominant (unexercised) extremities decreased from resting values of 75.6 ms to 69.3 ms (P=0.935) after the exercise-only protocol and decreased to 49.4 ms (P<0.01) after the vibration exercise protocol. The cortical motor threshold in exercised extremities decreased from a resting mean of 41.4 μV to a postvibration exercise mean of 38.6 μV (P<0.01). In non-exercised extremities, the CMT also decreased, from mean of 43.5 μV to 39.9 μV after the vibration-exercise (P<0.01). Vibration exercise enhances bilateral corticospinal excitability, as demonstrated by a shortened cortical silent period and lower cortical motor threshold in both exercised and non-exercised extremities.

Evaluation of impairment of the upper extremity.

PubMed

Blair, S J; McCormick, E; Bear-Lehman, J; Fess, E E; Rader, E

1987-08-01

Evaluation of impairment of the upper extremity is the product of a team effort by the physician, occupational therapist, physical therapist, and rehabilitation counselor. A careful recording of the anatomic impairment should be made because this is critical in determining the subsequent functional activities of the extremity. The measurement criteria for clinical and functional evaluation includes condition assessment instruments. Some assess the neurovascular system, others assess movements including the monitoring of articular motion and musculotendinous function. Sensibility assessment instruments measure sympathetic response and detect single joint stimulus, discrimination, quantification, and recognition abilities. A detailed description of each assessment is recorded and physical capacity evaluation is only one component of the entire vocational evaluation. This evaluation answers questions regarding the injured worker's ability to return to his previous job. The work simulator is a useful instrument that allows rehabilitation and testing of the injured upper extremity. Job site evaluation includes assessment criteria for work performance, work behavior, and work environment.

The short physical performance battery as a predictor of functional capacity after stroke.

PubMed

Stookey, Alyssa D; Katzel, Leslie I; Steinbrenner, Gregory; Shaughnessy, Marianne; Ivey, Frederick M

2014-01-01

The short physical performance battery is a widely used instrument for quantifying lower extremity function in older adults. However, its utility for predicting endurance-based measures of functional performance that are more difficult to conduct in clinical settings is unknown. An understanding of this could be particularly relevant in mobility impaired stroke survivors, for whom establishing the predictive strength of simpler to perform measures would aid in tracking broader categories of functional disability. This cross-sectional study was conducted to determine whether the short physical performance battery is related to functional measures with a strong endurance component. Functional measures (short physical performance battery, peak aerobic capacity, and 6-minute walk) were obtained and compared for the first time in stroke survivors with hemiparetic gait. Pearson correlation coefficients were used to assess strength of the relationships (α P < .05). Forty-three stroke participants performed a standardized short physical performance battery. Forty-one of the subjects completed a 6-minute walk, and 40 completed a peak treadmill test. Mean short physical performance battery (6.3 ± 2.5 [mean ± SD]), 6-minute walk (242 ± 115 meters), and peak aerobic capacity (17.4 ± 5.4 mL/kg/min) indicated subjects had moderate to severely impaired lower extremity functional performance. The short physical performance battery was related to both 6-minute walk (r = 0.76; P < .0001) and peak fitness (r = 0.52; P < .001). Our results show that the short physical performance battery may be reflective of endurance-based, longer-distance performance measures that would be difficult to perform in standard clinical stroke settings. Additional studies are needed to explore the value of using the short physical performance battery to assess rehabilitation-related functional progression after stroke. Published by Elsevier Inc.

A treatment for a chronic stroke patient with a plegic hand combining CI therapy with conventional rehabilitation procedures: case report.

PubMed

Bowman, Mary H; Taub, Edward; Uswatte, Gitendra; Delgado, Adriana; Bryson, Camille; Morris, David M; McKay, Staci; Mark, Victor W

2006-01-01

Constraint-Induced Movement therapy (CI therapy) is a recognized rehabilitation approach for persons having stroke with mild to moderately severe motor upper extremity deficits. To date, no rehabilitation treatment protocol has been proven effective that addresses both motor performance and spontaneous upper extremity use in the life situation for chronic stroke participants having severe upper extremity impairment with no active finger extension or thumb abduction. This case report describes treatment of a chronic stroke participant with a plegic hand using a CI therapy protocol that combines CI therapy with selected occupational and physical therapy techniques. Treatment consisted of six sessions of adaptive equipment and upper extremity orthotics training followed by a three-week, six-hour daily intervention of CI therapy plus neurodevelopmental treatment. Outcome measures included the Motor Activity Log for very low functioning patients (Grade 5 MAL), upper extremity portion of the Fugl-Meyer Motor Assessment, Graded Wolf Motor Function Test - for very low functioning patients (gWMFT- Grade 5), and Modified Ashworth Scale. The participant showed improvement on each outcome measure with the largest improvement on the Grade 5 MAL. In follow-up, the participant had good retention of his gains in motor performance and use of his more affected arm for real world activities after 3 months; after a one-week brush-up at 3 months, and at one year post-treatment.

Transcranial Doppler and Lower Extremity Function in Older Adults: Einstein Aging Study.

PubMed

Ezzati, Ali; Rundek, Tatjana; Verghese, Joe; Derby, Carol A

2017-12-01

To determine whether transcranial Doppler ultrasound (TCD) measures of mean blood flow velocity (MBFV) in the major cerebral arteries are associated with measures of lower extremity function in community-dwelling older adults. Cross-sectional study. Community sample. Individuals aged 70 and older (mean 79.5, 54% female) without dementia participating in the Einstein Aging Study (N = 200). All participants underwent TCD assessments and tests of lower extremity function at an annual clinic visit. Average MBFV for anterior (left and right anterior and middle cerebral arteries (MCAs)) and posterior (vertebral (VA) and basilar (BA) artery) circulation was measured using a standardized TCD protocol. Lower extremity function was characterized according to gait speed (cm/s) measured using an instrumented walkway, balance according to unipedal stance time (UPST, seconds), and lower extremity strength according to timed repeated chair rise (seconds). Multiple regression models adjusted for age, sex, race, education, and medical comorbidities showed that lower MBFV in the MCA was associated with slower gait speed and chair rise time but not with UPST. Ordinal regression models showed that lower MBFV in the VA and BA is associated with shorter UPST. Low MBFV in the anterior and posterior cerebral circulation was associated with worse lower extremity function and balance in older adults. This might be indicative of the importance of age-related changes in cerebral hemodynamics in the function of brain regions involved in specific aspects of physical performance. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

Performance Analysis, Design Considerations, and Applications of Extreme-Scale In Situ Infrastructures

DOE PAGES

Ayachit, Utkarsh; Bauer, Andrew; Duque, Earl P. N.; ...

2016-11-01

A key trend facing extreme-scale computational science is the widening gap between computational and I/O rates, and the challenge that follows is how to best gain insight from simulation data when it is increasingly impractical to save it to persistent storage for subsequent visual exploration and analysis. One approach to this challenge is centered around the idea of in situ processing, where visualization and analysis processing is performed while data is still resident in memory. Our paper examines several key design and performance issues related to the idea of in situ processing at extreme scale on modern platforms: Scalability, overhead,more » performance measurement and analysis, comparison and contrast with a traditional post hoc approach, and interfacing with simulation codes. We illustrate these principles in practice with studies, conducted on large-scale HPC platforms, that include a miniapplication and multiple science application codes, one of which demonstrates in situ methods in use at greater than 1M-way concurrency.« less

Effects of body position and extension of the neck and extremities on lung volume measured via computed tomography in red-eared slider turtles (Trachemys scripta elegans).

PubMed

Mans, Christoph; Drees, Randi; Sladky, Kurt K; Hatt, Jean-Michel; Kircher, Patrick R

2013-10-15

To determine the effects of body position and extension of the neck and extremities on CT measurements of ventilated lung volume in red-eared slider turtles (Trachemys scripta elegans). Prospective crossover-design study. 14 adult red-eared slider turtles. CT was performed on turtles in horizontal ventral recumbent and vertical left lateral recumbent, right lateral recumbent, and caudal recumbent body positions. In sedated turtles, evaluations were performed in horizontal ventral recumbent body position with and without extension of the neck and extremities. Lung volumes were estimated from helical CT images with commercial software. Effects of body position, extremity and neck extension, sedation, body weight, and sex on lung volume were analyzed. Mean ± SD volume of dependent lung tissue was significantly decreased in vertical left lateral (18.97 ± 14.65 mL), right lateral (24.59 ± 19.16 mL), and caudal (9.23 ± 12.13 mL) recumbent positions, compared with the same region for turtles in horizontal ventral recumbency (48.52 ± 20.08 mL, 50.66 ± 18.08 mL, and 31.95 ± 15.69 mL, respectively). Total lung volume did not differ among positions because of compensatory increases in nondependent lung tissue. Extension of the extremities and neck significantly increased total lung volume (127.94 ± 35.53 mL), compared with that in turtles with the head, neck, and extremities withdrawn into the shell (103.24 ± 40.13 mL). Vertical positioning of red-eared sliders significantly affected lung volumes and could potentially affect interpretation of radiographs obtained in these positions. Extension of the extremities and neck resulted in the greatest total lung volume.

Extreme weather exposure identification for road networks - a comparative assessment of statistical methods

NASA Astrophysics Data System (ADS)

Schlögl, Matthias; Laaha, Gregor

2017-04-01

The assessment of road infrastructure exposure to extreme weather events is of major importance for scientists and practitioners alike. In this study, we compare the different extreme value approaches and fitting methods with respect to their value for assessing the exposure of transport networks to extreme precipitation and temperature impacts. Based on an Austrian data set from 25 meteorological stations representing diverse meteorological conditions, we assess the added value of partial duration series (PDS) over the standardly used annual maxima series (AMS) in order to give recommendations for performing extreme value statistics of meteorological hazards. Results show the merits of the robust L-moment estimation, which yielded better results than maximum likelihood estimation in 62 % of all cases. At the same time, results question the general assumption of the threshold excess approach (employing PDS) being superior to the block maxima approach (employing AMS) due to information gain. For low return periods (non-extreme events) the PDS approach tends to overestimate return levels as compared to the AMS approach, whereas an opposite behavior was found for high return levels (extreme events). In extreme cases, an inappropriate threshold was shown to lead to considerable biases that may outperform the possible gain of information from including additional extreme events by far. This effect was visible from neither the square-root criterion nor standardly used graphical diagnosis (mean residual life plot) but rather from a direct comparison of AMS and PDS in combined quantile plots. We therefore recommend performing AMS and PDS approaches simultaneously in order to select the best-suited approach. This will make the analyses more robust, not only in cases where threshold selection and dependency introduces biases to the PDS approach but also in cases where the AMS contains non-extreme events that may introduce similar biases. For assessing the performance of extreme events we recommend the use of conditional performance measures that focus on rare events only in addition to standardly used unconditional indicators. The findings of the study directly address road and traffic management but can be transferred to a range of other environmental variables including meteorological and hydrological quantities.

Modified constraint-induced movement therapy for clients with chronic stroke: interrupted time series (ITS) design.

PubMed

Park, JuHyung; Lee, NaYun; Cho, YongHo; Yang, YeongAe

2015-03-01

[Purpose] The purpose of this study was to investigate the impact that modified constraint-induced movement therapy has on upper extremity function and the daily life of chronic stroke patients. [Subjects and Methods] Modified constraint-induced movement therapy was conduct for 2 stroke patients with hemiplegia. It was performed 5 days a week for 2 weeks, and the participants performed their daily living activities wearing mittens for 6 hours a day, including the 2 hours of the therapy program. The assessment was conducted 5 times in 3 weeks before and after intervention. The upper extremity function was measured using the box and block test and a dynamometer, and performance daily of living activities was assessed using the modified Barthel index. The results were analyzed using a scatterplot and linear regression. [Results] All the upper extremity functions of the participants all improved after the modified constraint-induced movement therapy. Performance of daily living activities by participant 1 showed no change, but the results of participant 2 had improved after the intervention. [Conclusion] Through the results of this research, it was identified that modified constraint-induced movement therapy is effective at improving the upper extremity functions and the performance of daily living activities of chronic stroke patients.

Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source

DOE PAGES

Doppner, T.; LePape, S.; Ma, T.; ...

2014-08-11

Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatterx-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. Furthermore, the combination of experiments fully demonstratesmore » the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.« less

Extreme Performance Scalable Operating Systems Final Progress Report (July 1, 2008 - October 31, 2011)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malony, Allen D; Shende, Sameer

This is the final progress report for the FastOS (Phase 2) (FastOS-2) project with Argonne National Laboratory and the University of Oregon (UO). The project started at UO on July 1, 2008 and ran until April 30, 2010, at which time a six-month no-cost extension began. The FastOS-2 work at UO delivered excellent results in all research work areas: * scalable parallel monitoring * kernel-level performance measurement * parallel I/0 system measurement * large-scale and hybrid application performance measurement * onlne scalable performance data reduction and analysis * binary instrumentation

Mining Formative Evaluation Rules Using Web-Based Learning Portfolios for Web-Based Learning Systems

ERIC Educational Resources Information Center

Chen, Chih-Ming; Hong, Chin-Ming; Chen, Shyuan-Yi; Liu, Chao-Yu

2006-01-01

Learning performance assessment aims to evaluate what knowledge learners have acquired from teaching activities. Objective technical measures of learning performance are difficult to develop, but are extremely important for both teachers and learners. Learning performance assessment using learning portfolios or web server log data is becoming an…

Quantitative assessment based on kinematic measures of functional impairments during upper extremity movements: A review.

PubMed

de los Reyes-Guzmán, Ana; Dimbwadyo-Terrer, Iris; Trincado-Alonso, Fernando; Monasterio-Huelin, Félix; Torricelli, Diego; Gil-Agudo, Angel

2014-08-01

Quantitative measures of human movement quality are important for discriminating healthy and pathological conditions and for expressing the outcomes and clinically important changes in subjects' functional state. However the most frequently used instruments for the upper extremity functional assessment are clinical scales, that previously have been standardized and validated, but have a high subjective component depending on the observer who scores the test. But they are not enough to assess motor strategies used during movements, and their use in combination with other more objective measures is necessary. The objective of the present review is to provide an overview on objective metrics found in literature with the aim of quantifying the upper extremity performance during functional tasks, regardless of the equipment or system used for registering kinematic data. A search in Medline, Google Scholar and IEEE Xplore databases was performed following a combination of a series of keywords. The full scientific papers that fulfilled the inclusion criteria were included in the review. A set of kinematic metrics was found in literature in relation to joint displacements, analysis of hand trajectories and velocity profiles. These metrics were classified into different categories according to the movement characteristic that was being measured. These kinematic metrics provide the starting point for a proposed objective metrics for the functional assessment of the upper extremity in people with movement disorders as a consequence of neurological injuries. Potential areas of future and further research are presented in the Discussion section. Copyright © 2014 Elsevier Ltd. All rights reserved.

A laboratory evaluation of the influence of weighing gauges performance on extreme events statistics

NASA Astrophysics Data System (ADS)

Colli, Matteo; Lanza, Luca

2014-05-01

The effects of inaccurate ground based rainfall measurements on the information derived from rain records is yet not much documented in the literature. La Barbera et al. (2002) investigated the propagation of the systematic mechanic errors of tipping bucket type rain gauges (TBR) into the most common statistics of rainfall extremes, e.g. in the assessment of the return period T (or the related non-exceedance probability) of short-duration/high intensity events. Colli et al. (2012) and Lanza et al. (2012) extended the analysis to a 22-years long precipitation data set obtained from a virtual weighing type gauge (WG). The artificial WG time series was obtained basing on real precipitation data measured at the meteo-station of the University of Genova and modelling the weighing gauge output as a linear dynamic system. This approximation was previously validated with dedicated laboratory experiments and is based on the evidence that the accuracy of WG measurements under real world/time varying rainfall conditions is mainly affected by the dynamic response of the gauge (as revealed during the last WMO Field Intercomparison of Rainfall Intensity Gauges). The investigation is now completed by analyzing actual measurements performed by two common weighing gauges, the OTT Pluvio2 load-cell gauge and the GEONOR T-200 vibrating-wire gauge, since both these instruments demonstrated very good performance under previous constant flow rate calibration efforts. A laboratory dynamic rainfall generation system has been arranged and validated in order to simulate a number of precipitation events with variable reference intensities. Such artificial events were generated basing on real world rainfall intensity (RI) records obtained from the meteo-station of the University of Genova so that the statistical structure of the time series is preserved. The influence of the WG RI measurements accuracy on the associated extreme events statistics is analyzed by comparing the original intensity-duration-frequency (IDF) curves with those obtained from the measuring of the simulated rain events. References: Colli, M., L.G. Lanza, and P. La Barbera, (2012). Weighing gauges measurement errors and the design rainfall for urban scale applications, 9th International Workshop On Precipitation In Urban Areas, 6-9 December, 2012, St. Moritz, Switzerland Lanza, L.G., M. Colli, and P. La Barbera (2012). On the influence of rain gauge performance on extreme events statistics: the case of weighing gauges, EGU General Assembly 2012, April 22th, Wien, Austria La Barbera, P., L.G. Lanza, and L. Stagi, (2002). Influence of systematic mechanical errors of tipping-bucket rain gauges on the statistics of rainfall extremes. Water Sci. Techn., 45(2), 1-9.

Biomechanical Analysis of the Closed Kinetic Chain Upper-Extremity Stability Test.

PubMed

Tucci, Helga T; Felicio, Lilian R; McQuade, Kevin J; Bevilaqua-Grossi, Debora; Camarini, Paula Maria Ferreira; Oliveira, Anamaria S

2017-01-01

The closed kinetic chain upper-extremity stability (CKCUES) test is a functional test for the upper extremity performed in the push-up position, where individuals support their body weight on 1 hand placed on the ground and swing the opposite hand until touching the hand on the ground, then switch hands and repeat the process as fast as possible for 15 s. To study scapular kinematic and kinetic measures during the CKCUES test for 3 different distances between hands. Experimental. Laboratory. 30 healthy individuals (15 male, 15 female). Participants performed 3 repetitions of the test at 3 distance conditions: original (36 in), interacromial, and 150% interacromial distance between hands. Participants completed a questionnaire on pain intensity and perceived exertion before and after the procedures. Scapular internal/external rotation, upward/downward rotation, and posterior/anterior tilting kinematics and kinetic data on maximum force and time to maximum force were measured bilaterally in all participants. Percentage of body weight on upper extremities was calculated. Data analyses were based on the total numbers of hand touches performed for each distance condition, and scapular kinematics and kinetic values were averaged over the 3 trials. Scapular kinematics, maximum force, and time to maximum force were compared for the 3 distance conditions within each gender. Significance level was set at α = .05. Scapular internal rotation, posterior tilting, and upward rotation were significantly greater in the dominant side for both genders. Scapular upward rotation was significantly greater in original distance than interacromial distance in swing phase. Time to maximum force in women was significantly greater in the dominant side. CKCUES test kinematic and kinetic measures were not different among 3 conditions based on distance between hands. However, the test might not be suitable for initial or mild-level rehabilitation due to its challenging requirements.

Asymmetrical Pedaling Patterns in Parkinson's Disease Patients

PubMed Central

Penko, Amanda L.; Hirsch, Joshua R.; Voelcker-Rehage, Claudia; Martin, Philip E.; Blackburn, Gordon; Alberts, Jay L.

2015-01-01

Background Approximately 1.5 million Americans are affected by Parkinson's disease [1] which includes the symptoms of postural instability and gait dysfunction. Currently, clinical evaluations of postural instability and gait dysfunction consist of a subjective rater assessment of gait patterns using items from the Unified Parkinson's Disease Rating Scale, and assessments can be insensitive to the effectiveness of medical interventions. Current research suggests the importance of cycling for Parkinson's disease patients, and while Parkinson's gait has been evaluated in previous studies, little is known about lower extremity control during cycling. The purpose of this study is to examine the lower extremity coordination patterns of Parkinson's patients during cycling. Methods Twenty five participants, ages 44-72, with a clinical diagnosis of idiopathic Parkinson's disease participated in an exercise test on a cycle ergometer that was equipped with pedal force measurements. Crank torque, crank angle and power produced by right and left leg were measured throughout the test to calculate Symmetry Index at three stages of exercise (20 Watt, 60 Watt, maximum performance). Findings Decreases in Symmetry Index were observed for average power output in Parkinson's patients as workload increased. Maximum power Symmetry Index showed a significant difference in symmetry between performance at both the 20 Watt and 60 Watt stage and the maximal resistance stage. Minimum power Symmetry Index did not show significant differences across the stages of the test. While lower extremity asymmetries were present in Parkinson's patients during pedaling, these asymmetries did not correlate to postural instability and gait dysfunction Unified Parkinson's Disease Rating Scale scores. Interpretation This pedaling analysis allows for a more sensitive measure of lower extremity function than the Unified Parkinson's Disease Rating Scale and may help to provide unique insight into current and future lower extremity function. PMID:25467810

Pediatric post-thrombotic syndrome in children: Toward the development of a new diagnostic and evaluative measurement tool.

PubMed

Avila, M L; Brandão, L R; Williams, S; Ward, L C; Montoya, M I; Stinson, J; Kiss, A; Lara-Corrales, I; Feldman, B M

2016-08-01

Our goal was to conduct the item generation and piloting phases of a new discriminative and evaluative tool for pediatric post-thrombotic syndrome. We followed a formative model for the development of the tool, focusing on the signs/symptoms (items) that define post-thrombotic syndrome. For item generation, pediatric thrombosis experts and subjects diagnosed with extremity post-thrombotic syndrome during childhood nominated items. In the piloting phase, items were cross-sectionally measured in children with limb deep vein thrombosis to examine item performance. Twenty-three experts and 16 subjects listed 34 items, which were then measured in 140 subjects with previous diagnosis of limb deep vein thrombosis (70 upper extremity and 70 lower extremity). The items with strongest correlation with post-thrombotic syndrome severity and largest area under the curve were pain (in older children), paresthesia, and swollen limb for the upper extremity group, and pain (in older children), tired limb, heaviness, tightness and paresthesia for the lower extremity group. The diagnostic properties of the items and their correlations with post-thrombotic syndrome severity varied according to the assessed venous territory. The information gathered in this study will help experts decide which item should be considered for inclusion in the new tool. Copyright © 2016 Elsevier Ltd. All rights reserved.

SALGOT - Stroke Arm Longitudinal study at the University of Gothenburg, prospective cohort study protocol

PubMed Central

2011-01-01

Background Recovery patterns of upper extremity motor function have been described in several longitudinal studies, but most of these studies have had selected samples, short follow up times or insufficient outcomes on motor function. The general understanding is that improvements in upper extremity occur mainly during the first month after the stroke incident and little if any, significant recovery can be gained after 3-6 months. The purpose of this study is to describe the recovery of upper extremity function longitudinally in a non-selected sample initially admitted to a stroke unit with first ever stroke, living in Gothenburg urban area. Methods/Design A sample of 120 participants with a first-ever stroke and impaired upper extremity function will be consecutively included from an acute stroke unit and followed longitudinally for one year. Assessments are performed at eight occasions: at day 3 and 10, week 3, 4 and 6, month 3, 6 and 12 after onset of stroke. The primary clinical outcome measures are Action Research Arm Test and Fugl-Meyer Assessment for Upper Extremity. As additional measures, two new computer based objective methods with kinematic analysis of arm movements are used. The ABILHAND questionnaire of manual ability, Stroke Impact Scale, grip strength, spasticity, pain, passive range of motion and cognitive function will be assessed as well. At one year follow up, two patient reported outcomes, Impact on Participation and Autonomy and EuroQol Quality of Life Scale, will be added to cover the status of participation and aspects of health related quality of life. Discussion This study comprises a non-selected population with first ever stroke and impaired arm function. Measurements are performed both using traditional clinical assessments as well as computer based measurement systems providing objective kinematic data. The ICF classification of functioning, disability and health is used as framework for the selection of assessment measures. The study design with several repeated measurements on motor function will give us more confident information about the recovery patterns after stroke. This knowledge is essential both for optimizing rehabilitation planning as well as providing important information to the patient about the recovery perspectives. Trial registration ClinicalTrials.gov: NCT01115348 PMID:21612620

Effects of precision demands and mental pressure on muscle activation and hand forces in computer mouse tasks.

PubMed

Visser, Bart; De Looze, Michiel; De Graaff, Matthijs; Van Dieën, Jaap

2004-02-05

The objective of the present study was to gain insight into the effects of precision demands and mental pressure on the load of the upper extremity. Two computer mouse tasks were used: an aiming and a tracking task. Upper extremity loading was operationalized as the myo-electric activity of the wrist flexor and extensor and of the trapezius descendens muscles and the applied grip- and click-forces on the computer mouse. Performance measures, reflecting the accuracy in both tasks and the clicking rate in the aiming task, indicated that the levels of the independent variables resulted in distinguishable levels of accuracy and work pace. Precision demands had a small effect on upper extremity loading with a significant increase in the EMG-amplitudes (21%) of the wrist flexors during the aiming tasks. Precision had large effects on performance. Mental pressure had substantial effects on EMG-amplitudes with an increase of 22% in the trapezius when tracking and increases of 41% in the trapezius and 45% and 140% in the wrist extensors and flexors, respectively, when aiming. During aiming, grip- and click-forces increased by 51% and 40% respectively. Mental pressure had small effects on accuracy but large effects on tempo during aiming. Precision demands and mental pressure in aiming and tracking tasks with a computer mouse were found to coincide with increased muscle activity in some upper extremity muscles and increased force exertion on the computer mouse. Mental pressure caused significant effects on these parameters more often than precision demands. Precision and mental pressure were found to have effects on performance, with precision effects being significant for all performance measures studied and mental pressure effects for some of them. The results of this study suggest that precision demands and mental pressure increase upper extremity load, with mental pressure effects being larger than precision effects. The possible role of precision demands as an indirect mental stressor in working conditions is discussed.

Better Glycemic Control Is Associated With Maintenance of Lower-Extremity Function Over Time in Mexican American and European American Older Adults With Diabetes

PubMed Central

Wang, Chen-Pin; Hazuda, Helen P.

2011-01-01

OBJECTIVE Diabetes is a major cause of functional decline among older adults, but the role of glycemic control remains unclear. This article assesses whether better glycemic control is associated with better maintenance of lower-extremity function over time in older adults with diabetes. RESEARCH DESIGN AND METHODS Participants (n = 119) in the San Antonio Longitudinal Study of Aging, ages 71–85, who met American Diabetes Association diabetes criteria were followed over a 36-month period. Seven measures of A1C (HbA1c) were obtained at 6-month intervals; three measures of lower-extremity function were obtained at 18-month intervals using the Short Physical Performance Battery (SPPB). A two-step analytic approach was used, first, to identify distinct glycemic control classes using latent growth mixture modeling and, second, to examine trajectories of lower-extremity function based on these classes using path analysis. RESULTS Two glycemic control classes were identified: a poorer control class with higher means (all >7%) and higher within-subject variability in HbA1c and a better control class with lower means (all <7%) and lower within-subject variability. The short-term and long-term maintenance of lower-extremity function, assessed by the association between the first and second SPPB measures and the first and third SPPB measures, were both greater in the better control class than in the poorer control class. CONCLUSIONS Among older adults with diabetes, better glycemic control may improve both short-term and long-term maintenance of lower-extremity function. PMID:21216857

Better glycemic control is associated with maintenance of lower-extremity function over time in Mexican American and European American older adults with diabetes.

PubMed

Wang, Chen-Pin; Hazuda, Helen P

2011-02-01

Diabetes is a major cause of functional decline among older adults, but the role of glycemic control remains unclear. This article assesses whether better glycemic control is associated with better maintenance of lower-extremity function over time in older adults with diabetes. Participants (n = 119) in the San Antonio Longitudinal Study of Aging, ages 71-85, who met American Diabetes Association diabetes criteria were followed over a 36-month period. Seven measures of A1C (HbA(1c)) were obtained at 6-month intervals; three measures of lower-extremity function were obtained at 18-month intervals using the Short Physical Performance Battery (SPPB). A two-step analytic approach was used, first, to identify distinct glycemic control classes using latent growth mixture modeling and, second, to examine trajectories of lower-extremity function based on these classes using path analysis. Two glycemic control classes were identified: a poorer control class with higher means (all >7%) and higher within-subject variability in HbA(1c) and a better control class with lower means (all <7%) and lower within-subject variability. The short-term and long-term maintenance of lower-extremity function, assessed by the association between the first and second SPPB measures and the first and third SPPB measures, were both greater in the better control class than in the poorer control class. Among older adults with diabetes, better glycemic control may improve both short-term and long-term maintenance of lower-extremity function.

The effect of the action observation physical training on the upper extremity function in children with cerebral palsy

PubMed Central

Kim, Jin-young; Kim, Jong-man; Ko, Eun-young

2014-01-01

The purpose this study was to investigate the effect of action observation physical training (AOPT) on the functioning of the upper extremities in children with cerebral palsy (CP), using an evaluation framework based on that of the International Classification of Functioning, Disability and Health (ICF). The subjects were divided into an AOPT group and a physical training (PT) group. AOPT group practiced repeatedly the actions they observed on video clips, in which normal child performed an action with their upper extremities. PT group performed the same actions as the AOPT group did after observing landscape photographs. The subjects participated in twelve 30-min sessions, 3 days a week, for 4 weeks. Evaluation of upper extremity function using the following: the power of grasp and Modified Ashworth Scale for body functions and structures, a Box and Block test, an ABILHAND-Kids questionnaire, and the WeeFIM scale for activity and participation. Measurements were performed before and after the training, and 2 weeks after the end of training. The results of this study showed that, in comparison with the PT group, the functioning of the upper extremities in the AOPT group was significantly improved in body functions and activity and participation according to the ICF framework. This study demonstrates that AOPT has a positive influence on the functioning of the upper extremities in children with CP. It is suggested that this alternative approach for functioning of the upper extremities could be an effective method for rehabilitation in children with CP. PMID:25061598

Predictors of Behavior and Performance in Extreme Environments: The Antarctic Space Analogue Program

NASA Technical Reports Server (NTRS)

Palinkas, Lawrence A.; Gunderson, E K. Eric; Holland, A. W.; Miller, Christopher; Johnson, Jeffrey C.

2000-01-01

To determine which, if any, characteristics should be incorporated into a select-in approach to screening personnel for long-duration spaceflight, we examined the influence of crewmember social/ demographic characteristics, personality traits, interpersonal needs, and characteristics of station physical environments on performance measures in 657 American men who spent an austral winter in Antarctica between 1963 and 1974. During screening, subjects completed a Personal History Questionnaire which obtained information on social and demographic characteristics, the Deep Freeze Opinion Survey which assessed 5 different personality traits, and the Fundamental Interpersonal Relations Orientation-Behavior (FIRO-B) Scale which measured 6 dimensions of interpersonal needs. Station environment included measures of crew size and severity of physical environment. Performance was assessed on the basis of combined peer-supervisor evaluations of overall performance, peer nominations of fellow crewmembers who made ideal winter-over candidates, and self-reported depressive symptoms. Social/demographic characteristics, personality traits, interpersonal needs, and characteristics of station environments collectively accounted for 9-17% of the variance in performance measures. The following characteristics were significant independent predictors of more than one performance measure: military service, low levels of neuroticism, extraversion and conscientiousness, and a low desire for affection from others. These results represent an important first step in the development of select-in criteria for personnel on long-duration missions in space and other extreme environments. These criteria must take into consideration the characteristics of the environment and the limitations they place on meeting needs for interpersonal relations and task performance, as well as the characteristics of the individuals and groups who live and work in these environments.

Proof of concept of the ability of the kinect to quantify upper extremity function in dystrophinopathy.

PubMed

Lowes, Linda P; Alfano, Lindsay N; Yetter, Brent A; Worthen-Chaudhari, Lise; Hinchman, William; Savage, Jordan; Samona, Patrick; Flanigan, Kevin M; Mendell, Jerry R

2013-03-14

Individuals with dystrophinopathy lose upper extremity strength in proximal muscles followed by those more distal. Current upper extremity evaluation tools fail to fully capture changes in upper extremity strength and function across the disease spectrum as they tend to focus solely on distal ability. The Kinect by Microsoft is a gaming interface that can gather positional information about an individual's upper extremity movement which can be used to determine functional reaching volume, velocity of movement, and rate of fatigue while playing an engaging video game. The purpose of this study was to determine the feasibility of using the Kinect platform to assess upper extremity function in individuals with dystrophinopathy across the spectrum of abilities. Investigators developed a proof-of-concept device, ACTIVE (Abilities Captured Through Interactive Video Evaluation), to measure functional reaching volume, movement velocity, and rate of fatigue. Five subjects with dystrophinopathy and 5 normal controls were tested using ACTIVE during one testing session. A single subject with dystrophinopathy was simultaneously tested with ACTIVE and a marker-based motion analysis system to establish preliminary validity of measurements. ACTIVE proof-of-concept ranked the upper extremity abilities of subjects with dystrophinopathy by Brooke score, and also differentiated them from performance of normal controls for the functional reaching volume and velocity tests. Preliminary test-retest reliability of the ACTIVE for 2 sequential trials was excellent for functional reaching volume (ICC=0.986, p<0.001) and velocity trials (ICC=0.963, p<0.001). The data from our pilot study with ACTIVE proof-of-concept demonstrates that newly available gaming technology has potential to be used to create a low-cost, widely-accessible and functional upper extremity outcome measure for use with children and adults with dystrophinopathy.

Altered lower extremity joint mechanics occur during the star excursion balance test and single leg hop after ACL-reconstruction in a collegiate athlete.

PubMed

Samaan, Michael A; Ringleb, Stacie I; Bawab, Sebastian Y; Greska, Eric K; Weinhandl, Joshua T

2018-03-01

The effects of ACL-reconstruction on lower extremity joint mechanics during performance of the Star Excursion Balance Test (SEBT) and Single Leg Hop (SLH) are limited. The purpose of this study was to determine if altered lower extremity mechanics occur during the SEBT and SLH after ACL-reconstruction. One female Division I collegiate athlete performed the SEBT and SLH tasks, bilaterally, both before ACL injury and 27 months after ACL-reconstruction. Maximal reach, hop distances, lower extremity joint kinematics and moments were compared between both time points. Musculoskeletal simulations were used to assess muscle force production during the SEBT and SLH at both time points. Compared to the pre-injury time point, SEBT reach distances were similar in both limbs after ACL-reconstruction except for the max anterior reach distance in the ipsilateral limb. The athlete demonstrated similar hop distances, bilaterally, after ACL-reconstruction compared to the pre-injury time point. Despite normal functional performance during the SEBT and SLH, the athlete exhibited altered lower extremity joint mechanics during both of these tasks. These results suggest that measuring the maximal reach and hop distances for these tasks, in combination with an analysis of the lower extremity joint mechanics that occur after ACL-reconstruction, may help clinicians and researchers to better understand the effects of ACL-reconstruction on the neuromuscular system during the SEBT and SLH.

Peripheral Quantitative CT (pQCT) Using a Dedicated Extremity Cone-Beam CT Scanner

PubMed Central

Muhit, A. A.; Arora, S.; Ogawa, M.; Ding, Y.; Zbijewski, W.; Stayman, J. W.; Thawait, G.; Packard, N.; Senn, R.; Yang, D.; Yorkston, J.; Bingham, C.O.; Means, K.; Carrino, J. A.; Siewerdsen, J. H.

2014-01-01

Purpose We describe the initial assessment of the peripheral quantitative CT (pQCT) imaging capabilities of a cone-beam CT (CBCT) scanner dedicated to musculoskeletal extremity imaging. The aim is to accurately measure and quantify bone and joint morphology using information automatically acquired with each CBCT scan, thereby reducing the need for a separate pQCT exam. Methods A prototype CBCT scanner providing isotropic, sub-millimeter spatial resolution and soft-tissue contrast resolution comparable or superior to standard multi-detector CT (MDCT) has been developed for extremity imaging, including the capability for weight-bearing exams and multi-mode (radiography, fluoroscopy, and volumetric) imaging. Assessment of pQCT performance included measurement of bone mineral density (BMD), morphometric parameters of subchondral bone architecture, and joint space analysis. Measurements employed phantoms, cadavers, and patients from an ongoing pilot study imaged with the CBCT prototype (at various acquisition, calibration, and reconstruction techniques) in comparison to MDCT (using pQCT protocols for analysis of BMD) and micro-CT (for analysis of subchondral morphometry). Results The CBCT extremity scanner yielded BMD measurement within ±2–3% error in both phantom studies and cadaver extremity specimens. Subchondral bone architecture (bone volume fraction, trabecular thickness, degree of anisotropy, and structure model index) exhibited good correlation with gold standard micro-CT (error ~5%), surpassing the conventional limitations of spatial resolution in clinical MDCT scanners. Joint space analysis demonstrated the potential for sensitive 3D joint space mapping beyond that of qualitative radiographic scores in application to non-weight-bearing versus weight-bearing lower extremities and assessment of phalangeal joint space integrity in the upper extremities. Conclusion The CBCT extremity scanner demonstrated promising initial results in accurate pQCT analysis from images acquired with each CBCT scan. Future studies will include improved x-ray scatter correction and image reconstruction techniques to further improve accuracy and to correlate pQCT metrics with known pathology. PMID:25076823

Upper-Extremity Dual-Task Function: An Innovative Method to Assess Cognitive Impairment in Older Adults.

PubMed

Toosizadeh, Nima; Najafi, Bijan; Reiman, Eric M; Mager, Reine M; Veldhuizen, Jaimeson K; O'Connor, Kathy; Zamrini, Edward; Mohler, Jane

2016-01-01

Difficulties in orchestrating simultaneous tasks (i.e., dual-tasking) have been associated with cognitive impairments in older adults. Gait tests have been commonly used as the motor task component for dual-task assessments; however, many older adults have mobility impairments or there is a lack of space in busy clinical settings. We assessed an upper-extremity function (UEF) test as an alternative motor task to study the dual-task motor performance in older adults. Older adults (≥65 years) were recruited, and cognitive ability was measured using the Montreal cognitive assessment (MoCA). Participants performed repetitive elbow flexion with their maximum pace, once single-task, and once while counting backward by one (dual-task). Single- and dual-task gait tests were also performed with normal speed. Three-dimensional kinematics was measured both from upper-extremity and lower-extremity using wearable sensors to determine UEF and gait parameters. Parameters were compared between the cognitively impaired and healthy groups using analysis of variance tests, while controlling for age, gender, and body mass index (BMI). Correlations between UEF and gait parameters for dual-task and dual-task cost were assessed using linear regression models. Sixty-seven older adults were recruited (age = 83 ± 10 years). Based on MoCA, 10 (15%) were cognitively impaired. While no significant differences were observed in the single-task condition, within the dual-task condition, the cognitively impaired group showed significantly less arm flexion speed (62%, d = 1.51, p = 0.02) and range of motion (27%, d = 0.93, p = 0.04), and higher speed variability (88%, d = 1.82, p < 0.0001) compared to the cognitively intact group, when adjusted with age, gender, and BMI. Significant correlations were observed between UEF speed parameters and gait stride velocity for dual-task condition (r = 0.55, p < 0.0001) and dual-task cost (r = 0.28, p = 0.03). We introduced a novel test for assessing dual-task performance in older adults that lasts 20 s and is based on upper-extremity function. Our results confirm significant associations between upper-extremity speed, range of motion, and speed variability with both the MoCA score and the gait performance within the dual-task condition.

Upper-Extremity Dual-Task Function: An Innovative Method to Assess Cognitive Impairment in Older Adults

PubMed Central

Toosizadeh, Nima; Najafi, Bijan; Reiman, Eric M.; Mager, Reine M.; Veldhuizen, Jaimeson K.; O’Connor, Kathy; Zamrini, Edward; Mohler, Jane

2016-01-01

Background: Difficulties in orchestrating simultaneous tasks (i.e., dual-tasking) have been associated with cognitive impairments in older adults. Gait tests have been commonly used as the motor task component for dual-task assessments; however, many older adults have mobility impairments or there is a lack of space in busy clinical settings. We assessed an upper-extremity function (UEF) test as an alternative motor task to study the dual-task motor performance in older adults. Methods: Older adults (≥65 years) were recruited, and cognitive ability was measured using the Montreal cognitive assessment (MoCA). Participants performed repetitive elbow flexion with their maximum pace, once single-task, and once while counting backward by one (dual-task). Single- and dual-task gait tests were also performed with normal speed. Three-dimensional kinematics was measured both from upper-extremity and lower-extremity using wearable sensors to determine UEF and gait parameters. Parameters were compared between the cognitively impaired and healthy groups using analysis of variance tests, while controlling for age, gender, and body mass index (BMI). Correlations between UEF and gait parameters for dual-task and dual-task cost were assessed using linear regression models. Results: Sixty-seven older adults were recruited (age = 83 ± 10 years). Based on MoCA, 10 (15%) were cognitively impaired. While no significant differences were observed in the single-task condition, within the dual-task condition, the cognitively impaired group showed significantly less arm flexion speed (62%, d = 1.51, p = 0.02) and range of motion (27%, d = 0.93, p = 0.04), and higher speed variability (88%, d = 1.82, p < 0.0001) compared to the cognitively intact group, when adjusted with age, gender, and BMI. Significant correlations were observed between UEF speed parameters and gait stride velocity for dual-task condition (r = 0.55, p < 0.0001) and dual-task cost (r = 0.28, p = 0.03). Conclusion: We introduced a novel test for assessing dual-task performance in older adults that lasts 20 s and is based on upper-extremity function. Our results confirm significant associations between upper-extremity speed, range of motion, and speed variability with both the MoCA score and the gait performance within the dual-task condition. PMID:27458374

Performance of an SOI Boot-Strapped Full-Bridge MOSFET Driver, Type CHT-FBDR, under Extreme Temperatures

NASA Technical Reports Server (NTRS)

Patterson, Richard; Hammoud, Ahmad

2009-01-01

Electronic systems designed for use in deep space and planetary exploration missions are expected to encounter extreme temperatures and wide thermal swings. Silicon-based devices are limited in their wide-temperature capability and usually require extra measures, such as cooling or heating mechanisms, to provide adequate ambient temperature for proper operation. Silicon-On-Insulator (SOI) technology, on the other hand, lately has been gaining wide spread use in applications where high temperatures are encountered. Due to their inherent design, SOI-based integrated circuit chips are able to operate at temperatures higher than those of the silicon devices by virtue of reducing leakage currents, eliminating parasitic junctions, and limiting internal heating. In addition, SOI devices provide faster switching, consume less power, and offer improved radiation-tolerance. Very little data, however, exist on the performance of such devices and circuits under cryogenic temperatures. In this work, the performance of an SOI bootstrapped, full-bridge driver integrated circuit was evaluated under extreme temperatures and thermal cycling. The investigations were carried out to establish a baseline on the functionality and to determine suitability of this device for use in space exploration missions under extreme temperature conditions.

Bidirectional reflectance distribution function of diffuse extreme ultraviolet scatterers and extreme ultraviolet baffle materials.

PubMed

Newell, M P; Keski-Kuha, R A

1997-08-01

Bidirectional reflectance distribution function (BRDF) measurements of a number of diffuse extreme ultraviolet (EUV) scatterers and EUV baffle materials have been performed with the Goddard EUV scatterometer. BRDF data are presented for white Spectralon SRS-99 at 121.6 nm; the data exhibit a non-Lambertian nature and a total hemispherical reflectance lower than 0.15. Data are also presented for an evaporated Cu black sample, a black Spectralon SRS-02 sample, and a Martin Optical Black sample at wavelengths of 58.4 and 121.6 nm and for angles of incidence of 15 degrees and 45 degrees. Overall Martin Optical Black exhibited the lowest BRDF characteristic, with a total hemispherical reflectance of the order of 0.01 and measured BRDF values as low as 2 x 10(-3) sr(-1).

Magnetic resonance imaging of the proximal upper extremity musculature in boys with Duchenne muscular dystrophy

PubMed Central

Willcocks, RJ; Triplett, WT; Forbes, SC; Arora, H; Senesac, CR; Lott, DJ; Nicholson, TR; Rooney, WD; Walter, GA; Vandenborne, K

2016-01-01

There is a pressing need for biomarkers and outcomes that can be used across disease stages in Duchenne muscular dystrophy (DMD), to facilitate the inclusion of a wider range of participants in clinical trials and to improve our understanding of the natural history of DMD. Quantitative magnetic resonance imaging (qMRI) and spectroscopy (MRS) biomarkers show considerable promise in both the legs and forearms of individuals with DMD, but have not yet been examined in functionally important proximal upper extremity muscles such as the biceps brachii and deltoid. The primary objective of this study was to examine the feasibility of implementing qMRI and MRS biomarkers in the proximal upper extremity musculature, and the secondary objective was to examine the relationship between MR measures of arm muscle pathology and upper extremity functional endpoints. Biomarkers included MRS and MRI measures of fat fraction and transverse relaxation time (T2). The MR exam was well tolerated in both ambulatory and nonambulatory boys. qMR biomarkers differentiated affected and unaffected participants and correlated strongly with upper extremity function (r=0.91 for biceps brachii T2 versus Performance of Upper Limb score). These qMR outcome measures could be highly beneficial to the neuromuscular disease community, allowing measurement of the quality of functionally important muscles across disease stages to understand the natural history of DMD and particularly to broaden the opportunity for clinical trial participation. PMID:27778157

Cook and Chill: Effect of Temperature on the Performance of Nonequilibrated Blood Glucose Meters.

PubMed

Deakin, Sherine; Steele, Dominic; Clarke, Sarah; Gribben, Cathryn; Bexley, Anne-Marie; Laan, Remmert; Kerr, David

2015-08-20

Exposure to extreme temperature can affect the performance of blood glucose monitoring systems. The aim was to determine the non-equilibrated performance of these systems at extreme high and low temperatures that can occur in daily life. The performances of 5 test systems, (1) Abbott FreeStyle Freedom Lite, (2) Roche AccuChek Aviva, (3) Bayer Contour, (4) LifeScan OneTouch Verio, and (5) Sanofi BG Star, were compared after "cooking" (50°C for 1 hour) or "chilling" (-5°C for 1 hour) with room temperature controls (23°C) using whole blood with glucose concentrations of 50, 100, and 200 mg/dl. The equilibration period (time from the end of incubation to when the test system is operational) was between 1 and 8 minutes, and each test system took between 15 and 30 minutes after incubation to obtain stable measurements at room temperature. Incubating the strips at -5°C or 50°C had little effect on the glucose measurement, whereas incubating the meters introduced bias in performance between 0 and 15 minutes but not subsequently, compared to room temperature controls and at all 3 glucose levels. Compensating technologies embedded within blood glucose monitoring systems studied here perform well at extreme temperatures. People with diabetes need to be alerted to this feature to avoid perceptions of malperformance of their devices and the possible inability to get blood glucose readings on short notice (eg, during time of suspected rapid change or before an unplanned meal). © 2015 Diabetes Technology Society.

Unexpected extreme events drive the inter-annual variabilty in carbon exchange at the Pine forest in Netherlands.

NASA Astrophysics Data System (ADS)

Sethi, Sanjna; Moors, Eddy; Jamir, Chubamenla

2017-04-01

The carbon exchange between vegetation and the atmosphere tends to vary on an annual basis. This change is a continuous process its trend emerging over a period of years can be analysed. In any such trend over a prolonged period, some years stand out more than the others on account of extreme events. Explaining deviations from the expected average emissions may help to understand the drivers behind these interannual deviations. Such noticeable deviations in trend maybe on account of extreme events and need to be analysed in overall context of the ecosystem. This research's focus is to identify the main drivers responsible for the deviations, and how extreme events impact the variability over a prolonged period of time. The hypothesis being that extreme events are driving these deviations. Carbon flux data done for multiple years (1997-2015) for a site at the Loobos Pine Forest is used and compared with an ecosystem model, LPJ-GUESS (Lund-Potsdam-Jena General Ecosystem Simulator) to understand if the deviation of measured data from the simulated data is on account of extreme events on a monthly and daily basis. A Principal Component Analysis is performed on the identified deviations between measured and simulated carbon exchange to pin point the main cause behind their occurrence.​

Developing Home-Based Virtual Reality Therapy Interventions.

PubMed

Lin, Janice; Kelleher, Caitlin L; Engsberg, Jack R

2013-02-01

Stroke is one of the leading causes of serious long-term disability. However, home exercise programs given at rehabilitation often lack in motivational aspects. The purposes of this pilot study were (1) create individualized virtual reality (VR) games and (2) determine the effectiveness of VR games for improving movement in upper extremities in a 6-week home therapy intervention for persons with stroke. Participants were two individuals with upper extremity hemiparesis following a stroke. VR games were created using the Looking Glass programming language and modified based on personal interests, goals, and abilities. Participants were asked to play 1 hour each day for 6 weeks. Assessments measured upper extremity movement (range of motion and Action Research Arm Test [ARAT]) and performance in functional skills (Canadian Occupational Performance Measure [COPM] and Motor Activity Log [MAL]). Three VR games were created by a supervised occupational therapist student. The participants played approximately four to six times a week and performed over 100 repetitions of movements each day. Participants showed improvement in upper extremity movement and participation in functional tasks based on results from the COPM, ARAT, and MAL. Further development in the programming environment is needed to be plausible in a rehabilitation setting. Suggestions include graded-level support and continuation of creating a natural programming language, which will increase the ability to use the program in a rehabilitation setting. However, the VR games were shown to be effective as a home therapy intervention for persons with stroke. VR has the potential to advance therapy services by creating a more motivating home-based therapy service.

Reliability of the Inverse Water Volumetry Method to Measure the Volume of the Upper Limb.

PubMed

Beek, Martinus A; te Slaa, Alexander; van der Laan, Lijckle; Mulder, Paul G H; Rutten, Harm J T; Voogd, Adri C; Luiten, Ernest J T; Gobardhan, Paul D

2015-06-01

Lymphedema of the upper extremity is a common side effect of lymph node dissection or irradiation of the axilla. Several techniques are being applied in order to examine the presence and severity of lymphedema. Measurement of circumference of the upper extremity is most frequently performed. An alternative is the water-displacement method. The aim of this study was to determine the reliability and the reproducibility of the "Inverse Water Volumetry apparatus" (IWV-apparatus) for the measurement of arm volumes. The IWV-apparatus is based on the water-displacement method. Measurements were performed by three breast cancer nurse practitioners on ten healthy volunteers in three weekly sessions. The intra-class correlation coefficient, defined as the ratio of the subject component to the total variance, equaled 0.99. The reliability index is calculated as 0.14 kg. This indicates that only changes in a patient's arm volume measurement of more than 0.14 kg would represent a true change in arm volume, which is about 6% of the mean arm volume of 2.3 kg. The IWV-apparatus proved to be a reliable and reproducible method to measure arm volume.

Combined Cognitive-Strategy and Task-Specific Training Affects Cognition and Upper-Extremity Function in Subacute Stroke: An Exploratory Randomized Controlled Trial

PubMed Central

Polatajko, Helene; Baum, Carolyn; Rios, Jorge; Cirone, Dianne; Doherty, Meghan; McEwen, Sara

2016-01-01

The purpose of this study was to estimate the effect of Cognitive Orientation to Daily Occupational Performance (CO–OP) compared with usual occupational therapy on upper-extremity movement, cognitive flexibility, and stroke impact in people less than 3 mo after stroke. An exploratory, single-blind randomized controlled trial was conducted with people referred to outpatient occupational therapy services at two rehabilitation centers. Arm movement was measured with the Action Research Arm Test, cognitive flexibility with the Delis–Kaplan Executive Function System Trail Making subtest, and stroke impact with subscales of the Stroke Impact Scale. A total of 35 participants were randomized, and 26 completed the intervention. CO–OP demonstrated measurable effects over usual care on all measures. These data provide early support for the use of CO–OP to improve performance and remediate cognitive and arm movement impairments after stroke over usual care; however, future study is warranted to confirm the effects observed in this trial. PMID:26943113

Asymmetries in functional hop tests, lower extremity kinematics, and isokinetic strength persist 6 to 9 months following anterior cruciate ligament reconstruction.

PubMed

Xergia, Sofia A; Pappas, Evangelos; Zampeli, Franceska; Georgiou, Spyros; Georgoulis, Anastasios D

2013-03-01

Within-subject and between-subject cross-sectional study. To investigate symmetry in hop-test performance, strength, and lower extremity kinematics 6 to 9 months following anterior cruciate ligament reconstruction (ACLR). Despite the extensive body of literature involving persons following ACLR, no study has comprehensively evaluated measures of strength, lower extremity kinematics, and functional performance of functional hop tests in this population. The subjects were 22 men (mean ± SD age, 28.8 ± 11.2 years) who had ACLR using a bone-patellar tendon-bone autograft 6 to 9 (7.01 ± 0.93) months previously and 22 healthy male controls (age, 24.8 ± 9.1 years). Participants completed a self-report questionnaire and underwent isokinetic strength testing and functional and kinematic assessment of the single-, triple-, and crossover-hop tests. Two-way analyses of variance were used to test for differences between the ACLR group and the control group, and between the 2 lower extremities of the ACLR group. Compared to the control group, the ACLR group had greater isokinetic knee extension torque deficits at all speeds (P ≤.001) and greater performance asymmetry for all 3 hop tests (P<.001). Compared to the noninvolved lower extremity, the involved lower extremity of the ACLR group exhibited less ankle dorsiflexion and knee flexion in the phases of propulsion (P ≤.014) and landing (P ≤.032). When compared to the control group, the involved lower extremity exhibited less ankle dorsiflexion in the propulsion phase (P<.001) but higher hip flexion in the landing phase (P = .014). Six to 9 months following ACLR, patients continue to demonstrate functional hop and isokinetic knee extension deficits, as well as kinematic differences, during the propulsion and landing phases of the hop tests.

Trunk position influences the kinematics, kinetics, and muscle activity of the lead lower extremity during the forward lunge exercise.

PubMed

Farrokhi, Shawn; Pollard, Christine D; Souza, Richard B; Chen, Yu-Jen; Reischl, Stephen; Powers, Christopher M

2008-07-01

Experimental laboratory study. To examine how a change in trunk position influences the kinematics, kinetics, and muscle activity of the lead lower extremity during the forward lunge exercise. Altering the position of the trunk during the forward lunge exercise is thought to affect the muscular actions of the lead lower extremity. However, no studies have compared the biomechanical differences between the traditional forward lunge and its variations. Ten healthy adults (5 males, 5 females; mean age +/- SD, 26.7 +/- 3.2 years) participated. Lower extremity kinematics, kinetics, and surface electromyographic (EMG) data were obtained while subjects performed 3 lunge exercises: normal lunge with the trunk erect (NL), lunge with the trunk forward (LTF), and lunge with trunk extension (LTE). A 1-way analysis of variance with repeated measures was used to compare lower extremity kinematics, joint impulse (area under the moment-time curve), and normalized EMG (highest 1-second window of activity for selected lower extremity muscles) among the 3 lunge conditions. During the LTF condition, significant increases were noted in peak hip flexion angle, hip extensor and ankle plantar flexor impulse, as well as gluteus maximus and biceps femoris EMG (P<.015) when compared to the NL condition. During the LTE condition, a significant increase was noted in peak ankle dorsiflexion and a significant decrease was noted in peak hip flexion angle (P<.015) compared to the NL condition. Performing a lunge with the trunk forward increased the hip extensor impulse and the recruitment of the hip extensors. In contrast, performing a forward lunge with the trunk extended did not alter joint impulse or activation of the lower extremity musculature. Therapy, level 5.

High-resolution crystal spectrometer for the 10-60 A extreme ultraviolet region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beiersdorfer, P.; Brown, G.V.; Goddard, R.

2004-10-01

A vacuum crystal spectrometer with nominal resolving power approaching 1000 is described for measuring emission lines with wavelength in the extreme ultraviolet region up to 60 A. The instrument utilizes a flat octadecyl hydrogen maleate crystal and a thin-window 1D position-sensitive gas proportional detector. This detector employs a 1-{mu}m-thick 100x8 mm{sup 2} aluminized polyimide window and operates at one atmosphere pressure. The spectrometer has been implemented on the Livermore electron beam ion traps. The performance of the instrument is illustrated in measurements of the newly discovered magnetic field-sensitive line in Ar{sup 8+}.

Hip strength assessment using handheld dynamometry is subject to intertester bias when testers are of different sex and strength.

PubMed

Thorborg, K; Bandholm, T; Schick, M; Jensen, J; Hölmich, P

2013-08-01

Handheld dynamometry (HHD) is a promising tool for obtaining reliable hip strength measurements in the clinical setting, but intertester reliability has been questioned, especially in situations where testers exhibit differences in upper-extremity muscle strength (male vs female). The purpose of this study was to examine the intertester reliability concerning strength assessments of hip abduction, adduction, external and internal rotation, flexion and extension using HHD, and to test whether systematic differences in test values exist between testers of different upper-extremity strength. Fifty healthy individuals (29 women), aged 25 ± 5 years were included. Two physiotherapist students (one female, one male) of different upper-extremity strength performed the measurements. The tester order and strength test order were randomized. Intraclass correlation coefficients were used to quantify reliability, and ranged from 0.82 to 0.91 for the six strength test. The female tester systematically measured lower strength values for all isometric strength tests (P < 0.05). In hip strength assessments using HHD, systematic bias exists between testers of different sex, which is likely explained by differences in upper-extremity strength. Hence, to improve intertester reliability, the dynamometer likely needs external fixation, as this will eliminate the influence of differences in upper-extremity strength between testers. © 2011 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Quantitative measures with WREX usage.

PubMed

Shank, Tracy M; Wee, Jinyong; Ty, Jennifer; Rahman, Tariq

2017-07-01

This paper presents the results of two surveys conducted with users of a functional upper extremity orthosis called the Wilmington Robotic EXoskeleton (WREX). The WREX is a passive anti-gravity arm orthosis that allows people with neuromuscular disabilities to move their arms in three dimensions. An online user survey with 55 patients was conducted to determine the benefits of the WREX. The survey asked 10 questions related to upper extremity function with and without the WREX as well as subjective impressions of the device. A second survey used a phone interview based on the Canadian Occupational Performance Measure (COPM). Parents rated their child's performance and satisfaction while partaking in important activities both with and without the exoskeleton device. Scores were assessed for change between the two conditions. Twenty-five families responded to this survey. Twenty-four out of 25 subjects reported greater levels of performance and satisfaction when they were wearing the WREX. The mean change in performance score was 3.61 points, and the mean change in satisfaction score was 4.44 points. Results show a statistically significant improvement in arm function for everyday tasks with the WREX.

Crew workload-management strategies - A critical factor in system performance

NASA Technical Reports Server (NTRS)

Hart, Sandra G.

1989-01-01

This paper reviews the philosophy and goals of the NASA/USAF Strategic Behavior/Workload Management Program. The philosophical foundation of the program is based on the assumption that an improved understanding of pilot strategies will clarify the complex and inconsistent relationships observed among objective task demands and measures of system performance and pilot workload. The goals are to: (1) develop operationally relevant figures of merit for performance, (2) quantify the effects of strategic behaviors on system performance and pilot workload, (3) identify evaluation criteria for workload measures, and (4) develop methods of improving pilots' abilities to manage workload extremes.

The Fear-Avoidance Components Scale (FACS): Responsiveness to Functional Restoration Treatment in a Chronic Musculoskeletal Pain Disorder (CMPD) Population.

PubMed

Neblett, Randy; Mayer, Tom G; Williams, Mark J; Asih, Sali; Cuesta-Vargas, Antonio I; Hartzell, Meredith M; Gatchel, Robert J

2017-12-01

To assess the clinical validity and factor structure of the Fear-Avoidance Components Scale (FACS), a new fear-avoidance measure. In this study, 426 chronic musculoskeletal pain disorder patients were admitted to a Functional Restoration Program (FRP). They were categorized into 5 FACS severity levels, from subclinical to extreme, at admission, and again at discharge. Associations with objective lifting performance and other patient-reported psychosocial measures were determined at admission and discharge, and objective work outcomes for this predominantly disabled cohort, were assessed 1 year later. Those patients in the severe and extreme FACS severity groups at admission were more likely to "drop out" of treatment than those in the lower severity groups (P=0.05). At both admission and discharge, the FACS severity groups were highly and inversely correlated with objective lifting performance and patient-reported fear-avoidance-related psychosocial variables, including kinesiophobia, pain intensity, depressive symptoms, perceived disability, perceived injustice, and insomnia (Ps<0.001). All variables showed improvement at FRP discharge. Patients in the extreme FACS severity group at discharge were less likely to return to, or retain, work 1 year later (P≤0.02). A factor analysis identified a 2-factor solution. Strong associations were found among FACS scores and other patient-reported psychosocial and objective lifting performance variables at both admission and discharge. High discharge-FACS scores were associated with worse work outcomes 1 year after discharge. The FACS seems to be a valid and clinically useful measure for predicting attendance, physical performance, distress, and relevant work outcomes in FRP treatment of chronic musculoskeletal pain disorder patients.

Unique thermocouple to measure the temperatures of squibs, igniters, propellants, and rocket nozzles

NASA Astrophysics Data System (ADS)

Nanigian, Jacob; Nanigian, Dan

2006-05-01

The temperatures produced by the various components in the propulsion system of rockets and missiles determine the performance of the rocket. Since these temperatures occur very rapidly and under extreme conditions, standard thermocouples fail before any meaningful temperatures are measured. This paper describes the features of a special family of high performance thermocouples, which can measure these transient temperatures with millisecond response times and under the most severe conditions of erosion. Examples of igniter, propellant and rocket nozzle temperatures are included in this paper. Also included is heat flux measurements made by these sensors in rocket applications.

Projected changes to short- and long-duration precipitation extremes over the Canadian Prairie Provinces

NASA Astrophysics Data System (ADS)

Masud, M. B.; Khaliq, M. N.; Wheater, H. S.

2017-09-01

The effects of climate change on April-October short- and long-duration precipitation extremes over the Canadian Prairie Provinces were evaluated using a multi-Regional Climate Model (RCM) ensemble available through the North American Regional Climate Change Assessment Program. Simulations considered include those performed with six RCMs driven by the National Centre for Environmental Prediction (NCEP) reanalysis II product for the 1981-2000 period and those driven by four Atmosphere-Ocean General Circulation Models (AOGCMs) for the current 1971-2000 and future 2041-2070 periods (i.e. a total of 11 current-to-future period simulation pairs). A regional frequency analysis approach was used to develop 2-, 5-, 10-, 25-, and 50-year return values of precipitation extremes from NCEP and AOGCM-driven current and future period simulations that respectively were used to study the performance of RCMs and projected changes for selected return values at regional, grid-cell and local scales. Performance errors due to internal dynamics and physics of RCMs studied for the 1981-2000 period reveal considerable variation in the performance of the RCMs. However, the performance errors were found to be much smaller for RCM ensemble averages than for individual RCMs. Projected changes in future climate to selected regional return values of short-duration (e.g. 15- and 30-min) precipitation extremes and for longer return periods (e.g. 50-year) were found to be mostly larger than those to the longer duration (e.g. 24- and 48-h) extremes and short return periods (e.g. 2-year). Overall, projected changes in precipitation extremes were larger for southeastern regions followed by southern and northern regions and smaller for southwestern and western regions of the study area. The changes to return values were also found to be statistically significant for the majority of the RCM-AOGCM simulation pairs. These projections might be useful as a key input for the future planning of urban drainage infrastructure and development of strategic climate change adaptation measures.

The effects of mirror therapy with tasks on upper extremity function and self-care in stroke patients.

PubMed

Park, Youngju; Chang, Moonyoung; Kim, Kyeong-Mi; An, Duk-Hyun

2015-05-01

[Purpose] The purpose of this study was to determine the effects of mirror therapy with tasks on upper extremity unction and self-care in stroke patients. [Subjects] Thirty participants were randomly assigned to either an experimental group (n=15) or a control group (n=15). [Methods] Subjects in the experimental group received mirror therapy with tasks, and those in the control group received a sham therapy; both therapies were administered, five times per week for six weeks. The main outcome measures were the Manual Function Test for the paralyzed upper limb and the Functional Independence Measure for self-care performance. [Results] The experimental group had more significant gains in change scores compared with the control group after the intervention. [Conclusion] We consider mirror therapy with tasks to be an effective form of intervention for upper extremity function and self-care in stroke patients.

Absolute sensitivity calibration of an extreme ultraviolet spectrometer for tokamak measurements

NASA Astrophysics Data System (ADS)

Guirlet, R.; Schwob, J. L.; Meyer, O.; Vartanian, S.

2017-01-01

An extreme ultraviolet spectrometer installed on the Tore Supra tokamak has been calibrated in absolute units of brightness in the range 10-340 Å. This has been performed by means of a combination of techniques. The range 10-113 Å was absolutely calibrated by using an ultrasoft-X ray source emitting six spectral lines in this range. The calibration transfer to the range 113-182 Å was performed using the spectral line intensity branching ratio method. The range 182-340 Å was calibrated thanks to radiative-collisional modelling of spectral line intensity ratios. The maximum sensitivity of the spectrometer was found to lie around 100 Å. Around this wavelength, the sensitivity is fairly flat in a 80 Å wide interval. The spatial variations of sensitivity along the detector assembly were also measured. The observed trend is related to the quantum efficiency decrease as the angle of the incoming photon trajectories becomes more grazing.

Quantitative assessment of upper extremities motor function in multiple sclerosis.

PubMed

Daunoraviciene, Kristina; Ziziene, Jurgita; Griskevicius, Julius; Pauk, Jolanta; Ovcinikova, Agne; Kizlaitiene, Rasa; Kaubrys, Gintaras

2018-05-18

Upper extremity (UE) motor function deficits are commonly noted in multiple sclerosis (MS) patients and assessing it is challenging because of the lack of consensus regarding its definition. Instrumented biomechanical analysis of upper extremity movements can quantify coordination with different spatiotemporal measures and facilitate disability rating in MS patients. To identify objective quantitative parameters for more accurate evaluation of UE disability and relate it to existing clinical scores. Thirty-four MS patients and 24 healthy controls (CG) performed a finger-to-nose test as fast as possible and, in addition, clinical evaluation kinematic parameters of UE were measured by using inertial sensors. Generally, a higher disability score was associated with an increase of several temporal parameters, like slower task performance. The time taken to touch their nose was longer when the task was fulfilled with eyes closed. Time to peak angular velocity significantly changed in MS patients (EDSS > 5.0). The inter-joint coordination significantly decreases in MS patients (EDSS 3.0-5.5). Spatial parameters indicated that maximal ROM changes were in elbow flexion. Our findings have revealed that spatiotemporal parameters are related to the UE motor function and MS disability level. Moreover, they facilitate clinical rating by supporting clinical decisions with quantitative data.

Measurement Properties of the Lower Extremity Functional Scale: A Systematic Review.

PubMed

Mehta, Saurabh P; Fulton, Allison; Quach, Cedric; Thistle, Megan; Toledo, Cesar; Evans, Neil A

2016-03-01

Systematic review of measurement properties. Many primary studies have examined the measurement properties, such as reliability, validity, and sensitivity to change, of the Lower Extremity Functional Scale (LEFS) in different clinical populations. A systematic review summarizing these properties for the LEFS may provide an important resource. To locate and synthesize evidence on the measurement properties of the LEFS and to discuss the clinical implications of the evidence. A literature search was conducted in 4 databases (PubMed, MEDLINE, Embase, and CINAHL), using predefined search terms. Two reviewers performed a critical appraisal of the included studies using a standardized assessment form. A total of 27 studies were included in the review, of which 18 achieved a very good to excellent methodological quality level. The LEFS scores demonstrated excellent test-retest reliability (intraclass correlation coefficients ranging between 0.85 and 0.99) and demonstrated the expected relationships with measures assessing similar constructs (Pearson correlation coefficient values of greater than 0.7). The responsiveness of the LEFS scores was excellent, as suggested by consistently high effect sizes (greater than 0.8) in patients with different lower extremity conditions. Minimal detectable change at the 90% confidence level (MDC90) for the LEFS scores varied between 8.1 and 15.3 across different reassessment intervals in a wide range of patient populations. The pooled estimate of the MDC90 was 6 points and the minimal clinically important difference was 9 points in patients with lower extremity musculoskeletal conditions, which are indicative of true change and clinically meaningful change, respectively. The results of this review support the reliability, validity, and responsiveness of the LEFS scores for assessing functional impairment in a wide array of patient groups with lower extremity musculoskeletal conditions.

Advanced optical blade tip clearance measurement system

NASA Technical Reports Server (NTRS)

Ford, M. J.; Honeycutt, R. E.; Nordlund, R. E.; Robinson, W. W.

1978-01-01

An advanced electro-optical system was developed to measure single blade tip clearances and average blade tip clearances between a rotor and its gas path seal in an operating gas turbine engine. This system is applicable to fan, compressor, and turbine blade tip clearance measurement requirements, and the system probe is particularly suitable for operation in the extreme turbine environment. A study of optical properties of blade tips was conducted to establish measurement system application limitations. A series of laboratory tests was conducted to determine the measurement system's operational performance characteristics and to demonstrate system capability under simulated operating gas turbine environmental conditions. Operational and environmental performance test data are presented.

Oswestry Disability Index is a better indicator of lumbar motion than the Visual Analogue Scale.

PubMed

Ruiz, Ferrin K; Bohl, Daniel D; Webb, Matthew L; Russo, Glenn S; Grauer, Jonathan N

2014-09-01

Lumbar pathology is often associated with axial pain or neurologic complaints. It is often presumed that such pain is associated with decreased lumbar motion; however, this correlation is not well established. The utility of various outcome measures that are used in both research and clinical practice have been studied, but the connection with range of motion (ROM) has not been well documented. The current study was performed to assess objectively the postulated correlation of lumbar complaints (based on standardized outcome measures) with extremes of lumbar ROM and functional ROM (fROM) with activities of daily living (ADLs) as assessed with an electrogoniometer. This study was a clinical cohort study. Subjects slated to undergo a lumbar intervention (injection, decompression, and/or fusion) were enrolled voluntarily in the study. The two outcome measures used in the study were the Visual Analogue Scale (VAS) for axial extremity, lower extremity, and combined axial and lower extremity, as well as the Oswestry Disability Index (ODI). Pain and disability scores were assessed with the VAS score and ODI. A previously validated electrogoniometer was used to measure ROM (extremes of motion in three planes) and fROM (functional motion during 15 simulated activities of daily living). Pain and disability scores were analyzed for statistically significant association with the motion assessments using linear regression analyses. Twenty-eight men and 39 women were enrolled, with an average age of 55.6 years (range, 18-79 years). The ODI and VAS were associated positively (p<.001). Combined axial and lower extremity VAS scores were associated with lateral and rotational ROM (p<.05), but not with flexion/extension or any fROM. Similar findings were noted for separately analyzed axial and lower extremity VAS scores. On the other hand, the ODI correlated inversely with ROM in all planes, and fROM in at least one plane for 10 of 15 ADLs (p<.05). Extremes of lumbar motion and motions associated with ADLs are of increasing clinical interest. Although the ODI and VAS are associated with each other, the ODI appears to be a better predictor of these motion parameters than the VAS (axial extremity, lower extremity, or combined) and may be more useful in the clinical setting when considering functional movement parameters. Copyright © 2014 Elsevier Inc. All rights reserved.

Performance of the IRI-2007 Model for Equatorial Topside Ion Density in the African Sector for Low and Extremely Low Solar Activity

NASA Technical Reports Server (NTRS)

Klenzing, J.; Simoes, F.; Ivanov, S.; Bilitza, D.; Heelis, R. A.; Rowland, D.

2012-01-01

The recent availability of new data sets during the recent extreme solar minimum provides an opportunity for testing the performance of the International Reference Ionosphere in historically under-sampled regions. This study will present averages and variability of topside ionospheric densities over Africa as a function of season, local time, altitude, and magnetic dip latitude as measured by the Coupled Ion-Neutral Dynamics Investigation (CINDI) Mission of Opportunity on the C/NOFS satellite. The results will be compared to the three topside model options available in IRI-2007. Overall, the NeQuick model is found to have the best performance, though during the deepest part of the solar minimum all three options significantly overestimate density.

Study on Temperature and Synthetic Compensation of Piezo-Resistive Differential Pressure Sensors by Coupled Simulated Annealing and Simplex Optimized Kernel Extreme Learning Machine

PubMed Central

Li, Ji; Hu, Guoqing; Zhou, Yonghong; Zou, Chong; Peng, Wei; Alam SM, Jahangir

2017-01-01

As a high performance-cost ratio solution for differential pressure measurement, piezo-resistive differential pressure sensors are widely used in engineering processes. However, their performance is severely affected by the environmental temperature and the static pressure applied to them. In order to modify the non-linear measuring characteristics of the piezo-resistive differential pressure sensor, compensation actions should synthetically consider these two aspects. Advantages such as nonlinear approximation capability, highly desirable generalization ability and computational efficiency make the kernel extreme learning machine (KELM) a practical approach for this critical task. Since the KELM model is intrinsically sensitive to the regularization parameter and the kernel parameter, a searching scheme combining the coupled simulated annealing (CSA) algorithm and the Nelder-Mead simplex algorithm is adopted to find an optimal KLEM parameter set. A calibration experiment at different working pressure levels was conducted within the temperature range to assess the proposed method. In comparison with other compensation models such as the back-propagation neural network (BP), radius basis neural network (RBF), particle swarm optimization optimized support vector machine (PSO-SVM), particle swarm optimization optimized least squares support vector machine (PSO-LSSVM) and extreme learning machine (ELM), the compensation results show that the presented compensation algorithm exhibits a more satisfactory performance with respect to temperature compensation and synthetic compensation problems. PMID:28422080

Study on Temperature and Synthetic Compensation of Piezo-Resistive Differential Pressure Sensors by Coupled Simulated Annealing and Simplex Optimized Kernel Extreme Learning Machine.

PubMed

Li, Ji; Hu, Guoqing; Zhou, Yonghong; Zou, Chong; Peng, Wei; Alam Sm, Jahangir

2017-04-19

As a high performance-cost ratio solution for differential pressure measurement, piezo-resistive differential pressure sensors are widely used in engineering processes. However, their performance is severely affected by the environmental temperature and the static pressure applied to them. In order to modify the non-linear measuring characteristics of the piezo-resistive differential pressure sensor, compensation actions should synthetically consider these two aspects. Advantages such as nonlinear approximation capability, highly desirable generalization ability and computational efficiency make the kernel extreme learning machine (KELM) a practical approach for this critical task. Since the KELM model is intrinsically sensitive to the regularization parameter and the kernel parameter, a searching scheme combining the coupled simulated annealing (CSA) algorithm and the Nelder-Mead simplex algorithm is adopted to find an optimal KLEM parameter set. A calibration experiment at different working pressure levels was conducted within the temperature range to assess the proposed method. In comparison with other compensation models such as the back-propagation neural network (BP), radius basis neural network (RBF), particle swarm optimization optimized support vector machine (PSO-SVM), particle swarm optimization optimized least squares support vector machine (PSO-LSSVM) and extreme learning machine (ELM), the compensation results show that the presented compensation algorithm exhibits a more satisfactory performance with respect to temperature compensation and synthetic compensation problems.

Unilateral and bilateral upper extremity weight-bearing effect on upper extremity impairment and functional performance after brain injury

PubMed Central

REISTETTER, TIMOTHY; ABREU, BEATRIZ C.; BEAR-LEHMAN, JANE; OTTENBACHER, KENNETH J.

2010-01-01

The purpose of the study was to investigate the effect of upper extremity (UE) weight bearing on UE impairment functional performance of persons with acquired brain injury (BI). A quasi-experimental design was used to examine a convenience sample of 99 persons with acquired BI and 22 without BI (WBI) living in a community re-entry centre. A computerized force-sensing array pressure map system was used to determine the UE pressure during unilateral and bilateral conditions. Differences between groups were examined using t-tests. Correlations were computed between UE weight bearing and hand function, and functional performance as measured by the Fugl-Meyer scale and functional independence measure (FIM) scale. The group of people with BI exerted significantly lower UE weight bearing during unilateral conditions as compared with persons WBI [left: t (119) = 2.34, p = 0.021; right: t (119) = 4.79, p = 0.043). UE weight-bearing measures correlated strongly with FIM motor scores with bilateral UE conditions yielded the highest significant correlation (bilateral left r = 0.487, p < 0.001; bilateral right r = 0.469, p < 0.01). The results indicated that UE weight-bearing pressure differs in unilateral and bilateral conditions, between persons with and WBI and between persons with stroke and traumatic brain injury. These findings may have implications for occupational therapists that use unilateral versus bilateral motor training for rehabilitation. There is a need to replicate the study design with a randomized and stratified sample of persons with BI. PMID:19551694

On-sky performance evaluation and calibration of a polarization-sensitive focal plane array

NASA Astrophysics Data System (ADS)

Vorobiev, Dmitry; Ninkov, Zoran; Brock, Neal; West, Ray

2016-07-01

The advent of pixelated micropolarizer arrays (MPAs) has facilitated the development of polarization-sensitive focal plane arrays (FPAs) based on charge-coupled devices (CCDs) and active pixel sensors (APSs), which are otherwise only able to measure the intensity of light. Polarization sensors based on MPAs are extremely compact, light-weight, mechanically robust devices with no moving parts, capable of measuring the degree and angle of polarization of light in a single snapshot. Furthermore, micropolarizer arrays based on wire grid polarizers (so called micro-grid polarizers) offer extremely broadband performance, across the optical and infrared regimes. These devices have potential for a wide array of commercial and research applications, where measurements of polarization can provide critical information, but where conventional polarimeters could be practically implemented. To date, the most successful commercial applications of these devices are 4D Technology's PhaseCam laser interferometers and PolarCam imaging polarimeters. Recently, MPA-based polarimeters have been identified as a potential solution for space-based telescopes, where the small size, snapshot capability and low power consumption (offered by these devices) are extremely desirable. In this work, we investigated the performance of MPA-based polarimeters designed for astronomical polarimetry using the Rochester Institute of Technology Polarization Imaging Camera (RITPIC). We deployed RITPIC on the 0.9 meter SMARTS telescope at the Cerro Tololo Inter-American Observatory and observed a variety of astronomical objects (calibration stars, variable stars, reflection nebulae and planetary nebulae). We use our observations to develop calibration procedures that are unique to these devices and provide an estimate for polarimetric precision that is achievable.

The spatial return level of aggregated hourly extreme rainfall in Peninsular Malaysia

NASA Astrophysics Data System (ADS)

Shaffie, Mardhiyyah; Eli, Annazirin; Wan Zin, Wan Zawiah; Jemain, Abdul Aziz

2015-07-01

This paper is intended to ascertain the spatial pattern of extreme rainfall distribution in Peninsular Malaysia at several short time intervals, i.e., on hourly basis. Motivation of this research is due to historical records of extreme rainfall in Peninsular Malaysia, whereby many hydrological disasters at this region occur within a short time period. The hourly periods considered are 1, 2, 3, 6, 12, and 24 h. Many previous hydrological studies dealt with daily rainfall data; thus, this study enables comparison to be made on the estimated performances between daily and hourly rainfall data analyses so as to identify the impact of extreme rainfall at a shorter time scale. Return levels based on the time aggregate considered are also computed. Parameter estimation using L-moment method for four probability distributions, namely, the generalized extreme value (GEV), generalized logistic (GLO), generalized Pareto (GPA), and Pearson type III (PE3) distributions were conducted. Aided with the L-moment diagram test and mean square error (MSE) test, GLO was found to be the most appropriate distribution to represent the extreme rainfall data. At most time intervals (10, 50, and 100 years), the spatial patterns revealed that the rainfall distribution across the peninsula differ for 1- and 24-h extreme rainfalls. The outcomes of this study would provide additional information regarding patterns of extreme rainfall in Malaysia which may not be detected when considering only a higher time scale such as daily; thus, appropriate measures for shorter time scales of extreme rainfall can be planned. The implementation of such measures would be beneficial to the authorities to reduce the impact of any disastrous natural event.

Proton Tolerance of SiGe Precision Voltage References for Extreme Temperature Range Electronics

NASA Astrophysics Data System (ADS)

Najafizadeh, Laleh; Bellini, Marco; Prakash, A. P. Gnana; Espinel, Gustavo A.; Cressler, John D.; Marshall, Paul W.; Marshall, Cheryl J.

2006-12-01

A comprehensive investigation of the effects of proton irradiation on the performance of SiGe BiCMOS precision voltage references intended for extreme environment operational conditions is presented. The voltage reference circuits were designed in two distinct SiGe BiCMOS technology platforms (first generation (50 GHz) and third generation (200 GHz)) in order to investigate the effect of technology scaling. The circuits were irradiated at both room temperature and at 77 K. Measurement results from the experiments indicate that the proton-induced changes in the SiGe bandgap references are minor, even down to cryogenic temperatures, clearly good news for the potential application of SiGe mixed-signal circuits in emerging extreme environments

The WISTAH hand study: A prospective cohort study of distal upper extremity musculoskeletal disorders

PubMed Central

2012-01-01

Background Few prospective cohort studies of distal upper extremity musculoskeletal disorders have been performed. Past studies have provided somewhat conflicting evidence for occupational risk factors and have largely reported data without adjustments for many personal and psychosocial factors. Methods/design A multi-center prospective cohort study was incepted to quantify risk factors for distal upper extremity musculoskeletal disorders and potentially develop improved methods for analyzing jobs. Disorders to analyze included carpal tunnel syndrome, lateral epicondylalgia, medial epicondylalgia, trigger digit, deQuervain’s stenosing tenosynovitis and other tendinoses. Workers have thus far been enrolled from 17 different employment settings in 3 diverse US states and performed widely varying work. At baseline, workers undergo laptop administered questionnaires, structured interviews, two standardized physical examinations and nerve conduction studies to ascertain demographic, medical history, psychosocial factors and current musculoskeletal disorders. All workers’ jobs are individually measured for physical factors and are videotaped. Workers are followed monthly for the development of musculoskeletal disorders. Repeat nerve conduction studies are performed for those with symptoms of tingling and numbness in the prior six months. Changes in jobs necessitate re-measure and re-videotaping of job physical factors. Case definitions have been established. Point prevalence of carpal tunnel syndrome is a combination of paraesthesias in at least two median nerve-served digits plus an abnormal nerve conduction study at baseline. The lifetime cumulative incidence of carpal tunnel syndrome will also include those with a past history of carpal tunnel syndrome. Incident cases will exclude those with either a past history or prevalent cases at baseline. Statistical methods planned include survival analyses and logistic regression. Discussion A prospective cohort study of distal upper extremity musculoskeletal disorders is underway and has successfully enrolled over 1,000 workers to date. PMID:22672216

The WISTAH hand study: a prospective cohort study of distal upper extremity musculoskeletal disorders.

PubMed

Garg, Arun; Hegmann, Kurt T; Wertsch, Jacqueline J; Kapellusch, Jay; Thiese, Matthew S; Bloswick, Donald; Merryweather, Andrew; Sesek, Richard; Deckow-Schaefer, Gwen; Foster, James; Wood, Eric; Kendall, Richard; Sheng, Xiaoming; Holubkov, Richard

2012-06-06

Few prospective cohort studies of distal upper extremity musculoskeletal disorders have been performed. Past studies have provided somewhat conflicting evidence for occupational risk factors and have largely reported data without adjustments for many personal and psychosocial factors. A multi-center prospective cohort study was incepted to quantify risk factors for distal upper extremity musculoskeletal disorders and potentially develop improved methods for analyzing jobs. Disorders to analyze included carpal tunnel syndrome, lateral epicondylalgia, medial epicondylalgia, trigger digit, deQuervain's stenosing tenosynovitis and other tendinoses. Workers have thus far been enrolled from 17 different employment settings in 3 diverse US states and performed widely varying work. At baseline, workers undergo laptop administered questionnaires, structured interviews, two standardized physical examinations and nerve conduction studies to ascertain demographic, medical history, psychosocial factors and current musculoskeletal disorders. All workers' jobs are individually measured for physical factors and are videotaped. Workers are followed monthly for the development of musculoskeletal disorders. Repeat nerve conduction studies are performed for those with symptoms of tingling and numbness in the prior six months. Changes in jobs necessitate re-measure and re-videotaping of job physical factors. Case definitions have been established. Point prevalence of carpal tunnel syndrome is a combination of paraesthesias in at least two median nerve-served digits plus an abnormal nerve conduction study at baseline. The lifetime cumulative incidence of carpal tunnel syndrome will also include those with a past history of carpal tunnel syndrome. Incident cases will exclude those with either a past history or prevalent cases at baseline. Statistical methods planned include survival analyses and logistic regression. A prospective cohort study of distal upper extremity musculoskeletal disorders is underway and has successfully enrolled over 1,000 workers to date.

The effects of isolated and integrated 'core stability' training on athletic performance measures: a systematic review.

PubMed

Reed, Casey A; Ford, Kevin R; Myer, Gregory D; Hewett, Timothy E

2012-08-01

Core stability training, operationally defined as training focused to improve trunk and hip control, is an integral part of athletic development, yet little is known about its direct relation to athletic performance. This systematic review focuses on identification of the association between core stability and sports-related performance measures. A secondary objective was to identify difficulties encountered when trying to train core stability with the goal of improving athletic performance. A systematic search was employed to capture all articles related to athletic performance and core stability training that were identified using the electronic databases MEDLINE, CINAHL and SPORTDiscus™ (1982-June 2011). A systematic approach was used to evaluate 179 articles identified for initial review. Studies that performed an intervention targeted toward the core and measured an outcome related to athletic or sport performances were included, while studies with a participant population aged 65 years or older were excluded. Twenty-four in total met the inclusionary criteria for review. Studies were evaluated using the Physical Therapy Evidence Database (PEDro) scale. The 24 articles were separated into three groups, general performance (n = 8), lower extremity (n = 10) and upper extremity (n = 6), for ease of discussion. In the majority of studies, core stability training was utilized in conjunction with more comprehensive exercise programmes. As such, many studies saw improvements in skills of general strengths such as maximum squat load and vertical leap. Surprisingly, not all studies reported measurable increases in specific core strength and stability measures following training. Additionally, investigations that targeted the core as the primary goal for improved outcome of training had mixed results. Core stability is rarely the sole component of an athletic development programme, making it difficult to directly isolate its affect on athletic performance. The population biases of some studies of athletic performance also confound the results. Targeted core stability training provides marginal benefits to athletic performance. Conflicting findings and the lack of a standardization for measurement of outcomes and training focused to improve core strength and stability pose difficulties. Because of this, further research targeted to determine this relationship is necessary to better understand how core strength and stability affect athletic performance.

Optical characterization of extremely small volumes of liquid in sub-micro-holes by simultaneous reflectivity, ellipsometry and spectrometry.

PubMed

Holgado, M; Casquel, R; Sánchez, B; Molpeceres, C; Morales, M; Ocaña, J L

2007-10-01

We have fabricated and characterized a lattice of submicron cone-shaped holes on a SiO(2)/Si wafer. Reflectivity profiles as a function of angle of incidence and polarization, phase shift and spectrometry are obtained for several fluids with different refractive indexes filling the holes. The optical setup allows measuring in the center of a single hole and collecting all data simultaneously, which can be applied for measuring extremely low volumes of fluid (in the order of 0.1 femtolitres) and label-free immunoassays, as it works as a refractive index sensor. A three layer film stack model is defined to perform theoretical calculations.

Analysis of extreme rain and flood events using a regional hydrologically enhanced hydrometeorological system

NASA Astrophysics Data System (ADS)

Yucel, Ismail; Onen, Alper

2013-04-01

Evidence is showing that global warming or climate change has a direct influence on changes in precipitation and the hydrological cycle. Extreme weather events such as heavy rainfall and flooding are projected to become much more frequent as climate warms. Regional hydrometeorological system model which couples the atmosphere with physical and gridded based surface hydrology provide efficient predictions for extreme hydrological events. This modeling system can be used for flood forecasting and warning issues as they provide continuous monitoring of precipitation over large areas at high spatial resolution. This study examines the performance of the Weather Research and Forecasting (WRF-Hydro) model that performs the terrain, sub-terrain, and channel routing in producing streamflow from WRF-derived forcing of extreme precipitation events. The capability of the system with different options such as data assimilation is tested for number of flood events observed in basins of western Black Sea Region in Turkey. Rainfall event structures and associated flood responses are evaluated with gauge and satellite-derived precipitation and measured streamflow values. The modeling system shows skills in capturing the spatial and temporal structure of extreme rainfall events and resulted flood hydrographs. High-resolution routing modules activated in the model enhance the simulated discharges.

Effects of Seated Postural Stability and Trunk and Upper Extremity Strength on Performance during Manual Wheelchair Propulsion Tests in Individuals with Spinal Cord Injury: An Exploratory Study.

PubMed

Gagnon, Dany H; Roy, Audrey; Gabison, Sharon; Duclos, Cyril; Verrier, Molly C; Nadeau, Sylvie

2016-01-01

Objectives. To quantify the association between performance-based manual wheelchair propulsion tests (20 m propulsion test, slalom test, and 6 min propulsion test), trunk and upper extremity (U/E) strength, and seated reaching capability and to establish which ones of these variables best predict performance at these tests. Methods. 15 individuals with a spinal cord injury (SCI) performed the three wheelchair propulsion tests prior to discharge from inpatient SCI rehabilitation. Trunk and U/E strength and seated reaching capability with unilateral hand support were also measured. Bivariate correlation and multiple linear regression analyses allowed determining the best determinants and predictors, respectively. Results. The performance at the three tests was moderately or strongly correlated with anterior and lateral flexion trunk strength, anterior seated reaching distance, and the shoulder, elbow, and handgrip strength measures. Shoulder adductor strength-weakest side explained 53% of the variance on the 20-meter propulsion test-maximum velocity. Shoulder adductor strength-strongest side and forward seated reaching distance explained 71% of the variance on the slalom test. Handgrip strength explained 52% of the variance on the 6-minute propulsion test. Conclusion. Performance at the manual wheelchair propulsion tests is explained by a combination of factors that should be considered in rehabilitation.

The advantage of a decreasing right-hand superiority: the influence of laterality on a selected musical skill (sight reading achievement).

PubMed

Kopiez, Reinhard; Galley, Niels; Lee, Ji In

2006-01-01

In this study, the unrehearsed performance of music, known as 'sight reading', is used as a model to examine the influence of motoric laterality on highly challenging musical performance skills. As expertise research has shown, differences in this skill can be partially explained by factors such as accumulated practise and an early start to training. However, up until now, neurobiological factors that may influence highly demanding instrumental performance have been widely neglected. In an experiment with 52 piano students at a German university music department, we could show that the most challenging musical skill, sight reading (which is characterized by extreme demands on the performer's real time information processing), is positively correlated with decreasing right-hand superiority of performers. Laterality was measured by the differences between left and right-hand performance in a speed tapping task. SR achievement was measured using an accompanying task paradigm. An overall superiority of 22% for non-right-handed pianists was found. This effect is gender-related and stronger in non-right-handed males (r(24) = -0.49, p<0.05) than in non-right-handed females (r(28) = -0.16, p>0.05). We conclude that non-right-handed motoric laterality is associated with neurobiological advantages required for sight reading, an extremely demanding musical subskill.

Lower-extremity peripheral nerve blocks in the perioperative pain management of orthopaedic patients: AAOS exhibit selection.

PubMed

Stein, Benjamin E; Srikumaran, Umasuthan; Tan, Eric W; Freehill, Michael T; Wilckens, John H

2012-11-21

The utilization of peripheral nerve blocks in orthopaedic surgery has paralleled the rise in the number of ambulatory surgical procedures performed. Optimization of pain control in the perioperative orthopaedic patient contributes to improved patient satisfaction, early mobilization, decreased length of hospitalization, and decreased associated hospital and patient costs. Our purpose was to provide a concise, pertinent review of the use of peripheral nerve blocks in various orthopaedic procedures of the lower extremity, with specific focus on procedural anatomy, indications, patient outcome measures, and complications. We reviewed the literature and reference textbooks on commonly performed lower-extremity peripheral nerve block procedures in orthopaedic surgery, focusing on those most commonly used. The use of lower-extremity peripheral nerve blocks is a safe and effective approach to perioperative pain management. Different techniques and timing can have an important impact on patient satisfaction, and each technique has specific indications and complications. For major hip surgery, one of the most commonly used is the lumbar plexus block, which can result in early mobilization, reduced postoperative pain, and decreased opioid-associated adverse events. Associated complications include epidural spread of anesthesia, retroperitoneal hematoma formation, and postoperative falls. For arthroscopic and open knee procedures, the femoral nerve block is frequently used adjunctively. It provides improved early postoperative pain control, early mobilization with therapy, and increased patient satisfaction compared with intra-articular or intravenous opioids alone; it also provides cost savings. However, some studies have shown no significant difference in outcome measures compared with intra-articular opioids alone for arthroscopic anterior cruciate ligament reconstruction. Associated complications include nerve injury, intravascular injection, and postoperative falls. The use of peripheral nerve blocks in lower-extremity surgery is becoming a mainstay of perioperative pain management strategy.

Nerve conduction velocity in human limbs with late sequelae after local cold injury.

PubMed

Arvesen, A; Wilson, J; Rosén, L

1996-06-01

Cold-induced neuropathy may play a dominant role in the long-term sequelae with cold sensitivity after local cold injuries (LCIs). Somatosensory functions were assessed and nerve conduction velocity (NCV) and motor distal delay (MDD) were measured in the limbs of 31 Norwegian former soldiers with persistent cold intolerance 3-4 years after the primary LCI. NCV measurements were performed in 24 lower and 16 upper extremities. NCV was related to degree of overall subjective complaints quantified by means of a visual analogue scale (VAS). Motor (MNCV) and sensory conduction velocity (SNCV) in the lower extremities and SNCV in the hands were significantly decreased compared with controls. MDD was pathologically increased in the feet. NCV of the forearms ranged from normal to significant reduction. The more pronounced effect on the lower extremities may be caused by deeper cooling of the calves compared with forearms for several reasons. No significant associations were found between VAS and NCV except for the right median nerve. NCV measurements may provide objective findings in cold-injured patients and in those with few or no conspicuous clinical signs.

TOTAL KNEE REPLACEMENT IN PATIENTS WITH BELOW-KNEE AMPUTATION

PubMed Central

Karam, Matthew D; Willey, Michael; Shurr, Donald G

2010-01-01

Total knee replacement (TKR) is reserved for patients with severe and disabling arthritis that is non-responsive to conservative measures. Based on existing data, total knee replacement is a safe and cost-effective treatment for alleviating pain and improving physical function in patients who do not respond to conservative therapy. Despite the large variation in health status of patients and types of prosthesis implanted, total knee replacement has proven to be a relatively low risk and successful operation. Each year in the United States surgeons perform approximately 300,000 TKR.1 Likewise, lower extremity amputation is commonly performed in the United States with an annual incidence of 110,000 per year.2 Nearly 70% of all lower extremity amputations are performed as the result of chronic vascular disease, followed by trauma (22%), congenital etiology and tumor (4% each).3 Approximately 50% of all lower extremity amputations are performed secondary to complications from Diabetes Mellitus. Norvell et al. demonstrated that patients who have previously undergone transtibial amputation and ambulate with a prosthesis are more likely to develop degenerative joint disease in the con-tralateral extremity than the ipsilateral extremity.4 Further, radiographic changes consistent with osteoporosis have been demonstrated in up to 88% of limbs that have undergone transtibial amputation.8 To our knowledge, there have been only three reported cases of total knee replacement in patients with ipsilateral transtibial amputation.5,7 The purpose of the present study is to review the existing data on total knee replacement in patients who have undergone transtibial amputation. Further we present a patient with a transtibial amputation who underwent contralateral total knee replacement. PMID:21045987

Laboratory calibration of density-dependent lines in the extreme ultraviolet spectral region

NASA Astrophysics Data System (ADS)

Lepson, J. K.; Beiersdorfer, P.; Gu, M. F.; Desai, P.; Bitter, M.; Roquemore, L.; Reinke, M. L.

2012-05-01

We have been making spectral measurements in the extreme ultraviolet (EUV) from different laboratory sources in order to investigate the electron density dependence of various astrophysically important emission lines and to test the atomic models underlying the diagnostic line ratios. The measurement are being performed at the Livermore EBIT-I electron beam ion trap, the National Spherical Torus Experiment (NSTX) at Princeton, and the Alcator C-Mod tokamak at the Massachusetts Institute of Technology, which together span an electron density of four orders of magnitude and which allow us to test the various models at high and low density limits. Here we present measurements of Fe XXII and Ar XIV, which include new data from an ultra high resolution (λ/Δλ >4000) spectrometer at the EBIT-I facility. We found good agreement between the measurements and modeling calculations for Fe XXII, but poorer agreement for Ar XIV.

Assessing Upper Extremity Motor Function in Practice of Virtual Activities of Daily Living

PubMed Central

Adams, Richard J.; Lichter, Matthew D.; Krepkovich, Eileen T.; Ellington, Allison; White, Marga; Diamond, Paul T.

2015-01-01

A study was conducted to investigate the criterion validity of measures of upper extremity (UE) motor function derived during practice of virtual activities of daily living (ADLs). Fourteen hemiparetic stroke patients employed a Virtual Occupational Therapy Assistant (VOTA), consisting of a high-fidelity virtual world and a Kinect™ sensor, in four sessions of approximately one hour in duration. An Unscented Kalman Filter-based human motion tracking algorithm estimated UE joint kinematics in real-time during performance of virtual ADL activities, enabling both animation of the user’s avatar and automated generation of metrics related to speed and smoothness of motion. These metrics, aggregated over discrete sub-task elements during performance of virtual ADLs, were compared to scores from an established assessment of UE motor performance, the Wolf Motor Function Test (WMFT). Spearman’s rank correlation analysis indicates a moderate correlation between VOTA-derived metrics and the time-based WMFT assessments, supporting the criterion validity of VOTA measures as a means of tracking patient progress during an UE rehabilitation program that includes practice of virtual ADLs. PMID:25265612

Assessing upper extremity motor function in practice of virtual activities of daily living.

PubMed

Adams, Richard J; Lichter, Matthew D; Krepkovich, Eileen T; Ellington, Allison; White, Marga; Diamond, Paul T

2015-03-01

A study was conducted to investigate the criterion validity of measures of upper extremity (UE) motor function derived during practice of virtual activities of daily living (ADLs). Fourteen hemiparetic stroke patients employed a Virtual Occupational Therapy Assistant (VOTA), consisting of a high-fidelity virtual world and a Kinect™ sensor, in four sessions of approximately one hour in duration. An unscented Kalman Filter-based human motion tracking algorithm estimated UE joint kinematics in real-time during performance of virtual ADL activities, enabling both animation of the user's avatar and automated generation of metrics related to speed and smoothness of motion. These metrics, aggregated over discrete sub-task elements during performance of virtual ADLs, were compared to scores from an established assessment of UE motor performance, the Wolf Motor Function Test (WMFT). Spearman's rank correlation analysis indicates a moderate correlation between VOTA-derived metrics and the time-based WMFT assessments, supporting the criterion validity of VOTA measures as a means of tracking patient progress during an UE rehabilitation program that includes practice of virtual ADLs.

A new hydrological model for estimating extreme floods in the Alps

NASA Astrophysics Data System (ADS)

Receanu, R. G.; Hertig, J.-A.; Fallot, J.-M.

2012-04-01

Protection against flooding is very important for a country like Switzerland with a varied topography and many rivers and lakes. Because of the potential danger caused by extreme precipitation, structural and functional safety of large dams must be guaranteed to withstand the passage of an extreme flood. We introduce a new distributed hydrological model to calculate the PMF from a PMP which is spatially and temporally distributed using clouds. This model has permitted the estimation of extreme floods based on the distributed PMP and the taking into account of the specifics of alpine catchments, in particular the small size of the basins, the complex topography, the large lakes, snowmelt and glaciers. This is an important evolution compared to other models described in the literature, as they mainly use a uniform distribution of extreme precipitation all over the watershed. This paper presents the results of calculation with the developed rainfall-runoff model, taking into account measured rainfall and comparing results to observed flood events. This model includes three parts: surface runoff, underground flow and melting snow. Two Swiss watersheds are studied, for which rainfall data and flow rates are available for a considerably long period, including several episodes of heavy rainfall with high flow events. From these events, several simulations are performed to estimate the input model parameters such as soil roughness and average width of rivers in case of surface runoff. Following the same procedure, the parameters used in the underground flow simulation are also estimated indirectly, since direct underground flow and exfiltration measurements are difficult to obtain. A sensitivity analysis of the parameters is performed at the first step to define more precisely the boundary and initial conditions. The results for the two alpine basins, validated with the Nash equation, show a good correlation between the simulated and observed flows. This good correlation shows that the model is valid and gives us the confidence that the results can be extrapolated to phenomena of extreme rainfall of PMP type.

Testing Devices Garner Data on Insulation Performance

NASA Technical Reports Server (NTRS)

2014-01-01

To develop a test instrument that could garner measurements of the thermal performance of insulation under extreme conditions, researchers at Kennedy Space Center devised the Cryostat 1 and then Cryostat 2. McLean, Virginia-based QinetiQ North America licensed the technology and plans to market it to organizations developing materials for things like piping and storage tank insulation, refrigeration, appliances, and consumer goods.

Thermal Evaluation of Fiber Bragg Gratings at Extreme Temperatures

NASA Technical Reports Server (NTRS)

Juergens, Jeffrey; Adamovsky, Grigory; Bhatt, Ramakrishna; Morscher, Gregory; Floyd, Bertram

2005-01-01

The development of integrated fiber optic sensors for use in aerospace health monitoring systems demands that the sensors be able to perform in extreme environments. In order to use fiber optic sensors effectively in an extreme environment one must have a thorough understanding of the sensor's capabilities, limitations, and performance under extreme environmental conditions. This paper reports on our current sensor evaluation examining the performance of freestanding fiber Bragg gratings (FBG) at extreme temperatures. While the ability of FBGs to survive at extreme temperatures has been established, their performance and long term survivability is not well documented. At extreme temperatures the grating structure would be expected to dissipate, degrading the sensors performance and eventually ceasing to return a detectable signal. The fiber jacket will dissipate leaving a brittle, unprotected fiber. For FBGs to be used in aerospace systems their performance and limitations need to be thoroughly understood at extreme temperatures. As the limits of the FBGs performance are pushed the long term survivability and performance of the sensor comes into question. We will not only examine the ability of FBGs to survive extreme temperatures but also look at their performance during many thermal cycles. This paper reports on test results of the performance of thermal cycling commercially available FBGs, at temperatures up to 1000 C, seen in aerospace applications. Additionally this paper will report on the performance of commercially available FBGs held at 1000 C for hundreds of hours. Throughout the evaluation process, various parameters of the FBGs performance were monitored and recorded. Several test samples were subjected to identical test conditions to allow for statistical analysis of the data. Test procedures, calibrations, referencing techniques, performance data, and interpretations and explanations of results are presented in the paper along with directions for future research.

Total and Lower Extremity Lean Mass Percentage Positively Correlates With Jump Performance.

PubMed

Stephenson, Mitchell L; Smith, Derek T; Heinbaugh, Erika M; Moynes, Rebecca C; Rockey, Shawn S; Thomas, Joi J; Dai, Boyi

2015-08-01

Strength and power have been identified as valuable components in both athletic performance and daily function. A major component of strength and power is the muscle mass, which can be assessed with dual-energy x-ray absorptiometry (DXA). The primary purpose of this study was to quantify the relationship between total body lean mass percentage (TBLM%) and lower extremity lean mass percentage (LELM%) and lower extremity force/power production during a countermovement jump (CMJ) in a general population. Researchers performed a DXA analysis on 40 younger participants aged 18-35 years, 28 middle-aged participants aged 36-55 years, and 34 older participants aged 56-75 years. Participants performed 3 CMJ on force platforms. Correlations revealed significant and strong relationships between TBLM% and LELM% compared with CMJ normalized peak vertical ground reaction force (p < 0.001, r = 0.59), normalized peak vertical power (p < 0.001, r = 0.73), and jump height (p < 0.001, r = 0.74) for the combined age groups. Most relationships were also strong within each age group, with some relationships being relatively weaker in the middle-aged and older groups. Minimal difference was found between correlation coefficients of TBLM% and LELM%. Coefficients of determination were all below 0.6 for the combined group, indicating that between-participant variability in CMJ measures cannot be completely explained by lean mass percentages. The findings have implications in including DXA-assessed lean mass percentage as a component for evaluating lower extremity strength and power. A paired DXA analysis and CMJ jump test may be useful for identifying neuromuscular deficits that limit performance.

Measurements of density dependent intensity ratios of extreme ultraviolet line emission from Fe X, XI, and XII

NASA Astrophysics Data System (ADS)

Shimizu, Erina; Ali, Safdar; Tsuda, Takashi; Sakaue, Hiroyuki A.; Kato, Daiji; Murakami, Izumi; Hara, Hirohisa; Watanabe, Tetsuya; Nakamura, Nobuyuki

2017-05-01

We report high-resolution density dependent intensity ratio measurements for middle charge states of iron in the extreme ultraviolet (EUV) spectral wavelength range of 160-200 Å. The measurements were performed at the Tokyo EBIT laboratory by employing a flat-field grazing incidence spectrometer installed on a low energy compact electron beam ion trap. The intensity ratios for several line pairs stemming from Fe X, Fe XI and Fe XII were extracted from spectra collected at the electron beam energies of 340 and 400 eV by varying the beam current between 7.5 and 12 mA at each energy. In addition, the effective electron densities were obtained experimentally by imaging the electron beam profile and ion cloud size with a pinhole camera and visible spectrometer, respectively. In this paper, the experimental results are compared with previous data from the literature and with the present calculations performed using a collisional-radiative model. Our experimental results show a rather good agreement with the calculations and previous reported results.

Reference values for physical performance measures in the aging working population.

PubMed

Cote, Mark P; Kenny, Anne; Dussetschleger, Jeffrey; Farr, Dana; Chaurasia, Ashok; Cherniack, Martin

2014-02-01

The aim of this study was to determine reference physical performance values in older aging workers. Cross-sectional physical performance measures were collected for 736 manufacturing workers to assess effects of work and nonwork factors on age-related changes in musculoskeletal function and health. Participants underwent surveys and physical testing that included bioelectrical impedance analysis, range-of-motion measures, exercise testing, and dynamic assessment. Physical characteristics, such as blood pressure and body fat percentage, were comparable to published values. Dynamic and range-of-motion measurements differed from published normative results. Women had age-related decreases in cervical extension and lateral rotation. Older men had better spinal flexion than expected. Predicted age-related decline in lower-extremity strength and shoulder strength in women was not seen. Men declined in handgrip, lower-extremity strength, and knee extension strength, but not trunk strength, across age groups. There was no appreciable decline in muscle fatigue at the trunk, shoulder, and knee with aging for either gender, except for the youngest age group of women. Normative values may underestimate physical performance in "healthy" older workers, thereby underappreciating declines in less healthy older workers. Work may be preservative of function for a large group of selected individuals. A "healthy worker effect" may be greater for musculoskeletal disease and function than for heart disease and mortality. Clinicians and researchers studying musculoskeletal function in older workers can use a more specific set of reference values.

The effect of extremity strength training on fibromyalgia symptoms and disease impact in an existing multidisciplinary treatment program.

PubMed

Kas, Tamara; Colby, Megan; Case, Maureen; Vaughn, Dan

2016-10-01

The purpose of this study was to examine the effect of upper and lower body extremity strengthening exercise in patients with Fibromyalgia (FM) within an existing multidisciplinary treatment program. Patients between the ages of 18-65 with the medical diagnosis of FM. Comparative study design. The control and experimental group received the same multidisciplinary treatment except that the experimental group performed upper and lower extremity strengthening exercises. The Fibromyalgia Impact Questionnaire (FIQ) was administered at evaluation and discharge from the program in order to measure change in quality of life (QOL). Statistically significant changes in FIQ scores were found for both groups. The addition of extremity strengthening in the experimental group produced an average 4 points greater reduction in FIQ score, however, these results are not considered statistically significant. This study appears to validate the success of a multidisciplinary approach in treating patients with FM, with the possibility for further benefit with the addition of extremity strengthening. Copyright © 2016 Elsevier Ltd. All rights reserved.

Association of lower extremity range of motion and muscle strength with physical performance of community-dwelling older women.

PubMed

Jung, Hungu; Yamasaki, Masahiro

2016-12-08

Reduced lower extremity range of motion (ROM) and muscle strength are related to functional disability in older adults who cannot perform one or more activities of daily living (ADL) independently. The purpose of this study was to determine which factors of seven lower extremity ROMs and two muscle strengths play dominant roles in the physical performance of community-dwelling older women. Ninety-five community-dwelling older women (mean age ± SD, 70.7 ± 4.7 years; age range, 65-83 years) were enrolled in this study. Seven lower extremity ROMs (hip flexion, hip extension, knee flexion, internal and external hip rotation, ankle dorsiflexion, and ankle plantar flexion) and two muscle strengths (knee extension and flexion) were measured. Physical performance tests, including functional reach test (FRT), 5 m gait test, four square step test (FSST), timed up and go test (TUGT), and five times sit-to-stand test (FTSST) were performed. Stepwise regression models for each of the physical performance tests revealed that hip extension ROM and knee flexion strength were important explanatory variables for FRT, FSST, and FTSST. Furthermore, ankle plantar flexion ROM and knee extension strength were significant explanatory variables for the 5 m gait test and TUGT. However, ankle dorsiflexion ROM was a significant explanatory variable for FRT alone. The amount of variance on stepwise multiple regression for the five physical performance tests ranged from 25 (FSST) to 47% (TUGT). Hip extension, ankle dorsiflexion, and ankle plantar flexion ROMs, as well as knee extension and flexion strengths may play primary roles in the physical performance of community-dwelling older women. Further studies should assess whether specific intervention programs targeting older women may achieve improvements in lower extremity ROM and muscle strength, and thereby play an important role in the prevention of dependence on daily activities and loss of physical function, particularly focusing on hip extension, ankle dorsiflexion, and ankle plantar flexion ROMs as well as knee extension and flexion strength.

Video Games as Psychological Tests.

ERIC Educational Resources Information Center

Jones, Marshall B.

1984-01-01

Briefly describes the characteristics of video games and discusses some advantages and disadvantages of their use to measure individual abilities. Relevant research is cited in the areas of stabilization with practice, predictive testing, performance testing, testing under extreme conditions, testing brain-injured persons, and differential…

A functional agility short-term fatigue protocol changes lower extremity mechanics

PubMed Central

Cortes, Nelson; Quammen, David; Lucci, Shawn; Greska, Eric; Onate, James

2012-01-01

The purpose of this study was to evaluate the effects of a functional agility fatigue protocol on lower extremity biomechanics between two unanticipated tasks (stop-jump and sidestep). The subjects consisted of fifteen female collegiate soccer athletes (19 ± 0.7 years, 1.67 ± 0.1 m, 61.7 ± 8 kg) free of lower extremity injury. Participants performed five trials of stop-jump and sidestep tasks. A functional short-term agility protocol was performed, and immediately following participants repeated the unanticipated running tasks. Lower extremity kinematic and kinetic values were obtained pre and post fatigue. Repeated measures analyses of variance were conducted for each dependent variable with an alpha level set at 0.05. Knee position post-fatigue had increased knee internal rotation (11.4 ± 7.5° vs. 7.9 ± 6.5° p = 0.011) than pre-fatigue, and a decreased knee flexion angle (−36.6 ± 6.2° vs.−40.0 ± 6.3°, p = 0.003), as well as hip position post-fatigue had decreased hip flexion angle (35.5 ± 8.7° vs. 43.2 ± 9.5°, p = 0.002). A quick functional fatigue protocol altered lower extremity mechanics of Division I collegiate soccer athletes during landing tasks. Proper mechanics should be emphasized from the beginning of practice/game to aid in potentially minimizing the effects of fatigue in lower extremity mechanics. PMID:22424559

The effects of floor incline on lower extremity biomechanics during unilateral landing from a jump in dancers.

PubMed

Pappas, Evangelos; Orishimo, Karl F; Kremenic, Ian; Liederbach, Marijeanne; Hagins, Marshall

2012-05-01

Retrospective studies have suggested that dancers performing on inclined ("raked") stages have increased injury risk. One study suggests that biomechanical differences exist between flat and inclined surfaces during bilateral landings; however, no studies have examined whether such differences exist during unilateral landings. In addition, little is known regarding potential gender differences in landing mechanics of dancers. Professional dancers (N = 41; 14 male, 27 female) performed unilateral drop jumps from a 30 cm platform onto flat and inclined surfaces while extremity joint angles and moments were identified and analyzed. There were significant joint angle and moment effects due to the inclined flooring. Women had significantly decreased peak ankle dorsiflexion and hip adduction moment compared with men. Findings of the current study suggest that unilateral landings on inclined stages create measurable changes in lower extremity biomechanical variables. These findings provide a preliminary biomechanical rationale for differences in injury rates found in observational studies of raked stages.

Mirror Therapy and Task-Oriented Training for People With a Paretic Upper Extremity.

PubMed

Bondoc, Salvador; Booth, Julie; Budde, Grace; Caruso, Katelyn; DeSousa, Michelle; Earl, Brittany; Hammerton, Kaitlynn; Humphreys, Jill

This study investigates the effect of mirror therapy and task-oriented training on the paretic upper extremity function and occupational performance of people with stroke. This study used a repeated-measures, case-series design in which 4 participants completed a 4-wk intervention consisting of mirror therapy and task-specific training. The intervention was conducted 2×/wk in the clinic and 4×/wk at home. All participants displayed clinically meaningful improvements in self-identified goals at the end of the intervention and at follow-up. Three participants showed clinically meaningful changes in motor function. Although only 1 participant improved in his reported amount of use, all participants showed clinically meaningful improvements in perceived movement quality at varying points of assessment. Mirror therapy, when used as priming for task-oriented training, can produce clinical improvements in upper extremity function and occupational performance in people with hemiparesis. Copyright © 2018 by the American Occupational Therapy Association, Inc.

Anthropometric and computerized tomographic measurements of lower extremity lean body mass.

PubMed

Buckley, D C; Kudsk, K A; Rose, B S; Fatzinger, P; Koetting, C A; Schlatter, M

1987-02-01

The loss of lean muscle mass is one of the hallmarks of protein-calorie malnutrition. Anthropometry is a standardized technique used to assess the response of muscle mass to nutrition therapy by quantifying the muscle and fat compartments. That technique does not accurately reflect actual limb composition, whereas computerized tomography does. Twenty lower extremities on randomly chosen men and women patients were evaluated by anthropometry and computerized tomography. Total area, muscle plus bone area, total volume, and muscle plus bone volume were correlated, using Heymsfield's equation and computerized tomography-generated areas. Anthropometrics overestimated total and muscle plus bone cross-sectional areas at almost every level. Anthropometry overestimated total area and total volume by 5% to 10% but overestimated muscle plus bone area and muscle plus bone volume by as much as 40%. Anthropometry, while easily performed and useful in large population groups for epidemiological studies, offers a poor assessment of lower extremity composition. On the other hand, computerized tomography is also easily performed and, while impractical for large population groups, does offer an accurate assessment of the lower extremity tissue compartments and is an instrument that might be used in research on lean muscle mass.

Fatigue influences lower extremity angular velocities during a single-leg drop vertical jump.

PubMed

Tamura, Akihiro; Akasaka, Kiyokazu; Otsudo, Takahiro; Shiozawa, Junya; Toda, Yuka; Yamada, Kaori

2017-03-01

[Purpose] Fatigue alters lower extremity landing strategies and decreases the ability to attenuate impact during landing. The purpose of this study was to reveal the influence of fatigue on dynamic alignment and joint angular velocities in the lower extremities during a single leg landing. [Subjects and Methods] The 34 female college students were randomly assigned to either the fatigue or control group. The fatigue group performed single-leg drop vertical jumps before, and after, the fatigue protocol, which was performed using a bike ergometer. Lower extremity kinematic data were acquired using a three-dimensional motion analysis system. The ratio of each variable (%), for the pre-fatigue to post-fatigue protocols, were calculated to compare differences between each group. [Results] Peak hip and knee flexion angular velocities increased significantly in the fatigue group compared with the control group. Furthermore, hip flexion angular velocity increased significantly between each group at 40 milliseconds after initial ground contact. [Conclusion] Fatigue reduced the ability to attenuate impact by increasing angular velocities in the direction of hip and knee flexion during landings. These findings indicate a requirement to evaluate movement quality over time by measuring hip and knee flexion angular velocities in landings during fatigue conditions.

Principal components analysis of the hypomanic attitudes and positive predictions inventory and associations with measures of personality, cognitive style and analogue symptoms in a student sample.

PubMed

Dodd, Alyson L; Mansell, Warren; Sadhnani, Vaneeta; Morrison, Anthony P; Tai, Sara

2010-01-01

An integrative cognitive model proposed that ascribing extreme personal appraisals to changes in internal state is key to the development of the symptoms of bipolar disorder. The Hypomanic Attitudes and Positive Predictions Inventory (HAPPI) was developed to measure these appraisals. The aim of the current study was to validate an expanded 61-item version of the HAPPI. In a largely female student sample (N = 134), principal components analysis (PCA) was performed on the HAPPI. Associations between the HAPPI and analogue bipolar symptoms after 3 months were examined. PCA of the HAPPI revealed six categories of belief: Self Activation, Self-and-Other Critical, Catastrophic, Extreme Appraisals of Social Approval, Appraisals of Extreme Agitation, and Loss of Control. The HAPPI predicted all analogue measures of hypomanic symptoms after 3 months when controlling for baseline symptoms. In a more stringent test incorporating other psychological measures, the HAPPI was independently associated only with activation (e.g. thoughts racing) at 3 months. Dependent dysfunctional attitudes predicted greater conflict (e.g. irritability), depression and reduced well-being, hypomanic personality predicted self-reported diagnostic bipolar symptoms, and behavioural dysregulation predicted depression. Extreme beliefs about internal states show a modest independent association with prospective analogue bipolar symptoms, alongside other psychological factors. Further work will be required to improve the factor structure of the HAPPI and study its validity in clinical samples.

Summary of Research Issues in Behavior and Performance in Isolated and Confined Extreme (ICE) Environments

NASA Technical Reports Server (NTRS)

Palinkas, Lawrence A.

2000-01-01

The papers presented in this section describe changes in behavior and performance in various isolated and confined extreme (ICE) environments, including Antarctic expeditions and research stations, space simulators and isolation chambers, and submarines. Each of these environments possesses characteristics that are in some way analogous to those found on long-duration space missions. Despite differences in length of mission, characteristics of mission personnel or crew, and characteristics in the physical environment, the various ICE environments described in this collection of papers appear to produce similar changes in behavior and performance. These changes include increased disturbances of mood, increased rates of psychiatric disorder, increased interpersonal tension, and a disruption of circadian rhythms. However, these environments do not inherently produce decrements in performance. Palinkas and colleagues suggest that prolonged exposure to the isolation and confinement in the Antarctic can actually have positive or "salutogenic" effects as well, evidenced by a decrease in mood disturbances and increase in performance measures.

Extreme Ultraviolet Variability Experiment (EVE) Multiple EUV Grating Spectrographs (MEGS): Radiometric Calibrations and Results

NASA Technical Reports Server (NTRS)

Hock, R. A.; Woods, T. N.; Crotser, D.; Eparvier, F. G.; Woodraska, D. L.; Chamberlin, P. C.; Woods, E. C.

2010-01-01

The NASA Solar Dynamics Observatory (SDO), scheduled for launch in early 2010, incorporates a suite of instruments including the Extreme Ultraviolet Variability Experiment (EVE). EVE has multiple instruments including the Multiple Extreme ultraviolet Grating Spectrographs (MEGS) A, B, and P instruments, the Solar Aspect Monitor (SAM), and the Extreme ultraviolet SpectroPhotometer (ESP). The radiometric calibration of EVE, necessary to convert the instrument counts to physical units, was performed at the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF III) located in Gaithersburg, Maryland. This paper presents the results and derived accuracy of this radiometric calibration for the MEGS A, B, P, and SAM instruments, while the calibration of the ESP instrument is addressed by Didkovsky et al. . In addition, solar measurements that were taken on 14 April 2008, during the NASA 36.240 sounding-rocket flight, are shown for the prototype EVE instruments.

Dynamics of molecules in extreme rotational states

PubMed Central

Yuan, Liwei; Teitelbaum, Samuel W.; Robinson, Allison; Mullin, Amy S.

2011-01-01

We have constructed an optical centrifuge with a pulse energy that is more than 2 orders of magnitude larger than previously reported instruments. This high pulse energy enables us to create large enough number densities of molecules in extreme rotational states to perform high-resolution state-resolved transient IR absorption measurements. Here we report the first studies of energy transfer dynamics involving molecules in extreme rotational states. In these studies, the optical centrifuge drives CO2 molecules into states with J ∼ 220 and we use transient IR probing to monitor the subsequent rotational, translational, and vibrational energy flow dynamics. The results reported here provide the first molecular insights into the relaxation of molecules with rotational energy that is comparable to that of a chemical bond.

Brine organisms and the question of habitat-specific adaptation

NASA Technical Reports Server (NTRS)

Siegel, B. Z.; Siegel, S. M.; Speitel, T.; Waber, J.; Stoecker, R.

1984-01-01

The question of adaptivity to extremely saline water environments is discussed, with attention given to the evolutionary performance of four common organisms including Cladonia skottsbergii, Penicillium notatum, Nostoc, and Dunaliella salina. Samples of each organism were collected and subjected to experimental conditions similar to extreme marine and limnetic environments in the Dead Sea and Don Juan Pond in the upper Wright valley of Antarctica. Measurements were made of isotope uptake and carbon dioxide production, and photoautotrophs were taken. It is found that all of the organisms responded quickly to the need to adapt to the extreme environments. It is concluded that a degree of uncertainty exists in the perception that the abundance of bulk water on the earth is in itself essential for life.

Musculoskeletal symptoms of the upper extremities and the neck: A cross-sectional study on prevalence and symptom-predicting factors at visual display terminal (VDT) workstations

PubMed Central

Klussmann, André; Gebhardt, Hansjuergen; Liebers, Falk; Rieger, Monika A

2008-01-01

Background The aim of this study was to determine the prevalence and the predictors of musculoskeletal symptoms in the upper extremities and neck at visual display terminal (VDT) workstations. Methods In a cross-sectional study 1,065 employees working at VDT > 1 h/d completed a standardised questionnaire. Workstation conditions were documented in a standardised checklist, and a subgroup of 82 employees underwent a physical examination. Results Using the Nordic Questionnaire, the 12-month prevalence of symptoms of the neck, shoulder region, hand/wrist, or elbow/lower arm was 55%, 38%, 21%, and 15% respectively. The duration of VDT work had a significant impact on the frequency of neck symptoms in employees performing such work > 6 h/d. Conclusion With regard to musculoskeletal symptoms of the upper extremities, preventive measures at VDT workstations should be focused on neck and shoulder symptoms (e.g. ergonomic measures, breaks to avoid sitting over long periods). PMID:18588677

Association of unipedal standing time and bone mineral density in community-dwelling Japanese women.

PubMed

Sakai, A; Toba, N; Takeda, M; Suzuki, M; Abe, Y; Aoyagi, K; Nakamura, T

2009-05-01

Bone mineral density (BMD) and physical performance of the lower extremities decrease with age. In community-dwelling Japanese women, unipedal standing time, timed up and go test, and age are associated with BMD while in women aged 70 years and over, unipedal standing time is associated with BMD. The aim of this study was to clarify whether unipedal standing time is significantly associated with BMD in community-dwelling women. The subjects were 90 community-dwelling Japanese women aged 54.7 years. BMD of the second metacarpal bone was measured by computed X-ray densitometry. We measured unipedal standing time as well as timed up and go test to assess physical performance of the lower extremities. Unipedal standing time decreased with increased age. Timed up and go test significantly correlated with age. Low BMD was significantly associated with old age, short unipedal standing time, and long timed up and go test. Stepwise regression analysis revealed that age, unipedal standing time, and timed up and go test were significant factors associated with BMD. In 21 participants aged 70 years and over, body weight and unipedal standing time, but not age, were significantly associated with BMD. BMD and physical performance of the lower extremities decrease with older age. Unipedal standing time, timed up and go test, and age are associated with BMD in community-dwelling Japanese women. In women aged 70 years and over, unipedal standing time is significantly associated with BMD.

Mapping snow depth return levels: smooth spatial modeling versus station interpolation

NASA Astrophysics Data System (ADS)

Blanchet, J.; Lehning, M.

2010-12-01

For adequate risk management in mountainous countries, hazard maps for extreme snow events are needed. This requires the computation of spatial estimates of return levels. In this article we use recent developments in extreme value theory and compare two main approaches for mapping snow depth return levels from in situ measurements. The first one is based on the spatial interpolation of pointwise extremal distributions (the so-called Generalized Extreme Value distribution, GEV henceforth) computed at station locations. The second one is new and based on the direct estimation of a spatially smooth GEV distribution with the joint use of all stations. We compare and validate the different approaches for modeling annual maximum snow depth measured at 100 sites in Switzerland during winters 1965-1966 to 2007-2008. The results show a better performance of the smooth GEV distribution fitting, in particular where the station network is sparser. Smooth return level maps can be computed from the fitted model without any further interpolation. Their regional variability can be revealed by removing the altitudinal dependent covariates in the model. We show how return levels and their regional variability are linked to the main climatological patterns of Switzerland.

Landing Technique and Performance in Youth Athletes After a Single Injury-Prevention Program Session

PubMed Central

Root, Hayley; Trojian, Thomas; Martinez, Jessica; Kraemer, William; DiStefano, Lindsay J.

2015-01-01

Context Injury-prevention programs (IPPs) performed as season-long warm-ups improve injury rates, performance outcomes, and jump-landing technique. However, concerns regarding program adoption exist. Identifying the acute benefits of using an IPP compared with other warm-ups may encourage IPP adoption. Objective To examine the immediate effects of 3 warm-up protocols (IPP, static warm-up [SWU], or dynamic warm-up [DWU]) on jump-landing technique and performance measures in youth athletes. Design Randomized controlled clinical trial. Setting Gymnasiums. Patients or Other Participants Sixty male and 29 female athletes (age = 13 ± 2 years, height = 162.8 ± 12.6 cm, mass = 37.1 ± 13.5 kg) volunteered to participate in a single session. Intervention(s) Participants were stratified by age, sex, and sport and then were randomized into 1 protocol: IPP, SWU, or DWU. The IPP consisted of dynamic flexibility, strengthening, plyometric, and balance exercises and emphasized proper technique. The SWU consisted of jogging and lower extremity static stretching. The DWU consisted of dynamic lower extremity flexibility exercises. Participants were assessed for landing technique and performance measures immediately before (PRE) and after (POST) completing their warm-ups. Main Outcome Measure(s) One rater graded each jump-landing trial using the Landing Error Scoring System. Participants performed a vertical jump, long jump, shuttle run, and jump-landing task in randomized order. The averages of all jump-landing trials and performance variables were used to calculate 1 composite score for each variable at PRE and POST. Change scores were calculated (POST − PRE) for all measures. Separate 1-way (group) analyses of variance were conducted for each dependent variable (α < .05). Results No differences were observed among groups for any performance measures (P > .05). The Landing Error Scoring System scores improved after the IPP (change = −0.40 ± 1.24 errors) compared with the DWU (0.27 ± 1.09 errors) and SWU (0.43 ± 1.35 errors; P = .04). Conclusions An IPP did not impair sport performance and may have reduced injury risk, which supports the use of these programs before sport activity. PMID:26523663

Measurement of absolute laser energy absorption by nano-structured targets

NASA Astrophysics Data System (ADS)

Park, Jaebum; Tommasini, R.; London, R.; Bargsten, C.; Hollinger, R.; Capeluto, M. G.; Shlyaptsev, V. N.; Rocca, J. J.

2017-10-01

Nano-structured targets have been reported to allow the realization of extreme plasma conditions using table top lasers, and have gained much interest as a platform to investigate the ultra-high energy density plasmas (>100 MJ/cm3) . One reason for these targets to achieve extreme conditions is increased laser energy absorption (LEA). The absolute LEA by nano-structured targets has been measured for the first time and compared to that by foil targets. The experimental results, including the effects of target parameters on the LEA, will be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52097NA27344, and funded by LDRD (#15-ERD-054).

Multiresolution modeling with a JMASS-JWARS HLA Federation

NASA Astrophysics Data System (ADS)

Prince, John D.; Painter, Ron D.; Pendell, Brian; Richert, Walt; Wolcott, Christopher

2002-07-01

CACI, Inc.-Federal has built, tested, and demonstrated the use of a JMASS-JWARS HLA Federation that supports multi- resolution modeling of a weapon system and its subsystems in a JMASS engineering and engagement model environment, while providing a realistic JWARS theater campaign-level synthetic battle space and operational context to assess the weapon system's value added and deployment/employment supportability in a multi-day, combined force-on-force scenario. Traditionally, acquisition analyses require a hierarchical suite of simulation models to address engineering, engagement, mission and theater/campaign measures of performance, measures of effectiveness and measures of merit. Configuring and running this suite of simulations and transferring the appropriate data between each model is both time consuming and error prone. The ideal solution would be a single simulation with the requisite resolution and fidelity to perform all four levels of acquisition analysis. However, current computer hardware technologies cannot deliver the runtime performance necessary to support the resulting extremely large simulation. One viable alternative is to integrate the current hierarchical suite of simulation models using the DoD's High Level Architecture in order to support multi- resolution modeling. An HLA integration eliminates the extremely large model problem, provides a well-defined and manageable mixed resolution simulation and minimizes VV&A issues.

Core stability: implications for dance injuries.

PubMed

Rickman, Ashley M; Ambegaonkar, Jatin P; Cortes, Nelson

2012-09-01

Dancers experience a high incidence of injury due to the extreme physical demands of dancing. The majority of dance injuries are chronic in nature and occur in the lower extremities and low back. Researchers have indicated decreased core stability (CS) as a risk factor for these injuries. Although decreased CS is suggested to negatively affect lower extremity joint motion and lumbar control during activity, this relationship has not been extensively discussed in previous dance literature. Understanding the relationship between CS and injury risk is important to help reduce dance injury incidence and improve performance. The purposes of this review were to discuss: 1. the core and components of CS, 2. the relationship between CS and injury, 3. CS assessment techniques, and 4. future dance CS research areas. CS is the integration of passive (non-contractile), active (contractile), and neural structures to minimize the effects of external forces and maintain stability. CS is maintained by a combination of muscle power, strength, endurance, and sensory-motor control of the lumbopelvic-hip complex. CS assessments include measuring muscle strength and power using maximal voluntary isometric and isokinetic contractions and measuring endurance using the Biering-Sorensen, plank, and lateral plank tests. Measuring sensory-motor control requires specialized equipment (e.g., balance platforms). Overall, limited research has comprehensively examined all components of CS together and their relationships to injury. Rather, previous researchers have separately examined core power, strength, endurance, or sensory-motor control. Future researchers should explore the multifactorial role of CS in reducing injury risk and enhancing performance in dancers.

Outcomes and Disability After Massive Proximal Upper Extremity Reconstruction in a Resource-Limited Setting.

PubMed

Giladi, Aviram M; Shanmugakrishnan, R Raja; Venkatramani, Hari; Raja Sekaran, S; Chung, Kevin C; Sabapathy, S Raja

2017-06-01

At Ganga Hospital in Coimbatore, India, a unique approach is applied to treat massive upper limb injuries. However, long-term outcomes of complex reconstruction performed in the resource-limited setting are not known. This hinders understanding of outcomes and disability from these injuries and prevents systematically addressing care delivery around upper extremity trauma in the developing world. This project aims to analyze the details of the unique Ganga Hospital reconstruction experience and use patient-reported outcome measures for the first time in this patient population to evaluate post-injury recovery and disability . Forty-six patients were evaluated 6 months or more after massive proximal upper extremity reconstruction at Ganga Hospital. Patients completed functional tests, Jebsen-Taylor test (JTT), and patient-reported outcomes (PROs)-Michigan Hand Questionnaire (MHQ), Disability of Arm, Shoulder, and Hand questionnaire (DASH), and Short-Form 36 (SF-36). Correlations between metrics were assessed with Pearson's correlation coefficients. Linear regression modeling evaluated associations between severity, reconstruction, and outcomes. MHQ and DASH results correlated with functional test performance, JTT performance, and SF-36 scores (Pearson's coefficients all ≥0.33, p ≤ 0.05). In this cohort, mean MHQ score was 79 ± 15 and mean DASH score was 13 ± 15, which are not significantly different than scores for long-term outcomes after other complex upper extremity procedures. The following factors predicted PROs and functional performance after reconstruction: extent of soft tissue reconstruction, multi-segmental ulna fractures, median nerve injury, and ability for patients to return to work and maintain their job after injury. Complex proximal upper extremity salvage can be performed in the resource-limited setting with excellent long-term functional and patient-reported outcomes. PRO questionnaires are useful for reporting outcomes that correlate to functional and sensory testing and may be used to assess post-traumatic disability.

Upper Ocean Boundary Layer Studies

DTIC Science & Technology

1991-10-16

of this study has been the demonstration of the extreme sensitivity of our acoustic current meter / vorticity sensor . The instrument performance has... Tiltmeters on the Arctic Ocean were used to measure flexure of the ice forced by an energetic packet of internal waves riding the crest of diurnal

Descriptive Statistics and Cluster Analysis for Extreme Rainfall in Java Island

NASA Astrophysics Data System (ADS)

E Komalasari, K.; Pawitan, H.; Faqih, A.

2017-03-01

This study aims to describe regional pattern of extreme rainfall based on maximum daily rainfall for period 1983 to 2012 in Java Island. Descriptive statistics analysis was performed to obtain centralization, variation and distribution of maximum precipitation data. Mean and median are utilized to measure central tendency data while Inter Quartile Range (IQR) and standard deviation are utilized to measure variation of data. In addition, skewness and kurtosis used to obtain shape the distribution of rainfall data. Cluster analysis using squared euclidean distance and ward method is applied to perform regional grouping. Result of this study show that mean (average) of maximum daily rainfall in Java Region during period 1983-2012 is around 80-181mm with median between 75-160mm and standard deviation between 17 to 82. Cluster analysis produces four clusters and show that western area of Java tent to have a higher annual maxima of daily rainfall than northern area, and have more variety of annual maximum value.

Deficits of Visuospatial Attention with Reflexive Orienting Induced by Eye-Gazed Cues in Children with Developmental Coordination Disorder in the Lower Extremities: An Event-Related Potential Study

ERIC Educational Resources Information Center

Tsai, Chia-Liang; Pan, Chien-Yu; Chang, Yu-Kai; Wang, Chun-Hao; Tseng, Ko-Da

2010-01-01

The present study aims to investigate and compare the behavioral performance and event-related potentials (ERPs) measures in children with developmental coordination disorder (DCD) and typically developing (TD) children when performing the visuospatial attention task with reflexive orienting. Thirty children with DCD and 30 TD children were…

Expertise on Cognitive Workloads and Performance During Navigation and Target Detection

DTIC Science & Technology

2012-03-01

requiring little or no attention 1. Little confusion, risk, frustration, or anxiety exists and can be easily accomodated 2. Occasionally have spare...to confusion, frustration, or anxiety noticeably adds to workload. Significant compensation is required to maintain adequate performance. 3... anxiety . High to extreme determination and self- control required 59 Field Description elapsedTime (sec) Continuous measurement of time from the

Physical Function in Older Men With Hyperkyphosis

PubMed Central

Harrison, Stephanie L.; Fink, Howard A.; Marshall, Lynn M.; Orwoll, Eric; Barrett-Connor, Elizabeth; Cawthon, Peggy M.; Kado, Deborah M.

2015-01-01

Background. Age-related hyperkyphosis has been associated with poor physical function and is a well-established predictor of adverse health outcomes in older women, but its impact on health in older men is less well understood. Methods. We conducted a cross-sectional study to evaluate the association of hyperkyphosis and physical function in 2,363 men, aged 71–98 (M = 79) from the Osteoporotic Fractures in Men Study. Kyphosis was measured using the Rancho Bernardo Study block method. Measurements of grip strength and lower extremity function, including gait speed over 6 m, narrow walk (measure of dynamic balance), repeated chair stands ability and time, and lower extremity power (Nottingham Power Rig) were included separately as primary outcomes. We investigated associations of kyphosis and each outcome in age-adjusted and multivariable linear or logistic regression models, controlling for age, clinic, education, race, bone mineral density, height, weight, diabetes, and physical activity. Results. In multivariate linear regression, we observed a dose-related response of worse scores on each lower extremity physical function test as number of blocks increased, p for trend ≤.001. Using a cutoff of ≥4 blocks, 20% (N = 469) of men were characterized with hyperkyphosis. In multivariate logistic regression, men with hyperkyphosis had increased odds (range 1.5–1.8) of being in the worst quartile of performing lower extremity physical function tasks (p < .001 for each outcome). Kyphosis was not associated with grip strength in any multivariate analysis. Conclusions. Hyperkyphosis is associated with impaired lower extremity physical function in older men. Further studies are needed to determine the direction of causality. PMID:25431353

Modeling the Performance of Direct-Detection Doppler Lidar Systems in Real Atmospheres

NASA Technical Reports Server (NTRS)

McGill, Matthew J.; Hart, William D.; McKay, Jack A.; Spinhirne, James D.

1999-01-01

Previous modeling of the performance of spaceborne direct-detection Doppler lidar systems has assumed extremely idealized atmospheric models. Here we develop a technique for modeling the performance of these systems in a more realistic atmosphere, based on actual airborne lidar observations. The resulting atmospheric model contains cloud and aerosol variability that is absent in other simulations of spaceborne Doppler lidar instruments. To produce a realistic simulation of daytime performance, we include solar radiance values that are based on actual measurements and are allowed to vary as the viewing scene changes. Simulations are performed for two types of direct-detection Doppler lidar systems: the double-edge and the multi-channel techniques. Both systems were optimized to measure winds from Rayleigh backscatter at 355 nm. Simulations show that the measurement uncertainty during daytime is degraded by only about 10-20% compared to nighttime performance, provided a proper solar filter is included in the instrument design.

Modeling the performance of direct-detection Doppler lidar systems including cloud and solar background variability.

PubMed

McGill, M J; Hart, W D; McKay, J A; Spinhirne, J D

1999-10-20

Previous modeling of the performance of spaceborne direct-detection Doppler lidar systems assumed extremely idealized atmospheric models. Here we develop a technique for modeling the performance of these systems in a more realistic atmosphere, based on actual airborne lidar observations. The resulting atmospheric model contains cloud and aerosol variability that is absent in other simulations of spaceborne Doppler lidar instruments. To produce a realistic simulation of daytime performance, we include solar radiance values that are based on actual measurements and are allowed to vary as the viewing scene changes. Simulations are performed for two types of direct-detection Doppler lidar system: the double-edge and the multichannel techniques. Both systems were optimized to measure winds from Rayleigh backscatter at 355 nm. Simulations show that the measurement uncertainty during daytime is degraded by only approximately 10-20% compared with nighttime performance, provided that a proper solar filter is included in the instrument design.

Kinematic determinants of weapon velocity during the fencing lunge in experienced épée fencers.

PubMed

Bottoms, Lindsay; Greenhalgh, Andrew; Sinclair, Jonathan

2013-01-01

The lunge is the most common attack in fencing, however there is currently a paucity of published research investigating the kinematics of this movement. The aim of this study was to investigate if kinematics measured during the épée fencing lunge had a significant effect on sword velocity at touch and whether there were any key movement tactics that produced the maximum velocity. Lower extremity kinematic data were obtained from fourteen right handed club épée fencers using a 3D motion capture system as they completed simulated lunges. A forward stepwise multiple linear regression was performed on the data. The overall regression model yielded an Adj R2 of 0.74, p ≤ 0.01. The results show that the rear lower extremity's knee range of motion, peak hip flexion and the fore lower extremity's peak hip flexion all in the sagittal plane were significant predictors of sword velocity. The results indicate that flexion of the rear extremity's knee is an important predictor, suggesting that the fencer sits low in their stance to produce power during the lunge. Furthermore it would appear that the magnitude of peak flexion of the fore extremity's hip was a significant indicator of sword velocity suggesting movement of fore limbs should also be considered in lunge performance.

Effects of pelvic compression belts on the kinematics and kinetics of the lower extremities during sit-to-stand maneuvers

PubMed Central

Kim, Jong Moon; Je, Hyun Dong; Kim, Hyeong-Dong

2017-01-01

[Purpose] To investigate the effects of a pelvic compression belt (PCB) and chair height on the kinematics and kinetics of the lower extremity during sit-to-stand (STS) maneuvers in healthy people. [Subjects and Methods] Twenty-two people participated in this study. They were required to perform STS maneuvers under four conditions. Hip joint moment and angular displacement of the hip, knee, and ankle were measured. A PCB was also applied below the anterior superior iliac spine. [Results] The angular displacement of the ankle joint increased while performing STS maneuvers from a normal chair with a PCB in phase 1, and decreased during phase 2 when performing STS maneuvers from a high chair. The overall angular displacement in phase 3 was decreased while rising from a chair with a PCB and rising from a high chair. When performed STS maneuvers from a high chair, the angular displacement of the hip, knee, and ankle joint decreased considerably in phase 3. This decreased lower extremity motion in phase 3 indicated that participants required less momentum to complete the maneuver. [Conclusion] The results of this study suggest that a PCB might be appropriate for patients with pelvic girdle pain and lower back pain related to pregnancy. PMID:28878454

Effects of pelvic compression belts on the kinematics and kinetics of the lower extremities during sit-to-stand maneuvers.

PubMed

Kim, Jong Moon; Je, Hyun Dong; Kim, Hyeong-Dong

2017-08-01

[Purpose] To investigate the effects of a pelvic compression belt (PCB) and chair height on the kinematics and kinetics of the lower extremity during sit-to-stand (STS) maneuvers in healthy people. [Subjects and Methods] Twenty-two people participated in this study. They were required to perform STS maneuvers under four conditions. Hip joint moment and angular displacement of the hip, knee, and ankle were measured. A PCB was also applied below the anterior superior iliac spine. [Results] The angular displacement of the ankle joint increased while performing STS maneuvers from a normal chair with a PCB in phase 1, and decreased during phase 2 when performing STS maneuvers from a high chair. The overall angular displacement in phase 3 was decreased while rising from a chair with a PCB and rising from a high chair. When performed STS maneuvers from a high chair, the angular displacement of the hip, knee, and ankle joint decreased considerably in phase 3. This decreased lower extremity motion in phase 3 indicated that participants required less momentum to complete the maneuver. [Conclusion] The results of this study suggest that a PCB might be appropriate for patients with pelvic girdle pain and lower back pain related to pregnancy.

Effects of Seated Postural Stability and Trunk and Upper Extremity Strength on Performance during Manual Wheelchair Propulsion Tests in Individuals with Spinal Cord Injury: An Exploratory Study

PubMed Central

Roy, Audrey; Gabison, Sharon; Verrier, Molly C.

2016-01-01

Objectives. To quantify the association between performance-based manual wheelchair propulsion tests (20 m propulsion test, slalom test, and 6 min propulsion test), trunk and upper extremity (U/E) strength, and seated reaching capability and to establish which ones of these variables best predict performance at these tests. Methods. 15 individuals with a spinal cord injury (SCI) performed the three wheelchair propulsion tests prior to discharge from inpatient SCI rehabilitation. Trunk and U/E strength and seated reaching capability with unilateral hand support were also measured. Bivariate correlation and multiple linear regression analyses allowed determining the best determinants and predictors, respectively. Results. The performance at the three tests was moderately or strongly correlated with anterior and lateral flexion trunk strength, anterior seated reaching distance, and the shoulder, elbow, and handgrip strength measures. Shoulder adductor strength-weakest side explained 53% of the variance on the 20-meter propulsion test-maximum velocity. Shoulder adductor strength-strongest side and forward seated reaching distance explained 71% of the variance on the slalom test. Handgrip strength explained 52% of the variance on the 6-minute propulsion test. Conclusion. Performance at the manual wheelchair propulsion tests is explained by a combination of factors that should be considered in rehabilitation. PMID:27635262

New scramblers for precision radial velocity: square and octagonal fibers

NASA Astrophysics Data System (ADS)

Chazelas, Bruno; Pepe, Francesco; Wildi, François; Bouchy, Francois; Perruchot, Sandrine; Avila, Gerardo

2010-07-01

One of the remaining limitation of the precise radial velocity instruments is the imperfect scrambling produced by the circular fibers. We present here experimental studies on new optical fibers aiming at an improvement of the scrambling they provide. New fibers shapes were tested: square and octagonal. Measurements have been performed of the scrambling performances of these fibers in the near field as well FRD measurements. These fibers show extremely promising performances in the near field scrambling: an improvement of a factor 5 to 10 compared to the circular fiber. They however show some strange behavior in the far field that need to be understood.

Responsiveness of SF-36 and Lower Extremity Functional Scale for assessing outcomes in traumatic injuries of lower extremities.

PubMed

Pan, Shin-Liang; Liang, Huey-Wen; Hou, Wen-Hsuan; Yeh, Tian-Shin

2014-11-01

To assess the responsiveness of one generic questionnaire, Medical Outcomes Study Short Form-36 (SF-36), and one region-specific outcome measure, Lower Extremity Functional Scale (LEFS), in patients with traumatic injuries of lower extremities. A prospective and observational study of patients after traumatic injuries of lower extremities. Assessments were performed at baseline and 3 months later. In-patients and out-patients in two university hospitals in Taiwan. A convenience sample of 109 subjects were evaluated and 94 (86%) were followed. Not applicable. Assessments of responsiveness with distribution-based approach (effect size, standardized response mean [SRM], minimal detectable change) and anchor-based approach (receiver's operating curve analysis, ROC analysis). LEFS and physical component score (PCS) of SF-36 were all responsive to global improvement, with fair-to-good accuracy in discriminating between participants with and without improvement. The area under curve gained by ROC analysis for LEFS and SF-36 PCS was similar (0.65 vs. 0.70, p=0.26). Our findings revealed comparable responsiveness of LEFS and PCS of SF-36 in a sample of subjects with traumatic injuries of lower limbs. Either type of functional measure would be suitable for use in clinical trials where improvement in function was an endpoint of interest. Copyright © 2014 Elsevier Ltd. All rights reserved.

Functional Multijoint Position Reproduction Acuity in Overhead-Throwing Athletes

PubMed Central

Tripp, Brady L; Uhl, Timothy L; Mattacola, Carl G; Srinivasan, Cidambi; Shapiro, Robert

2006-01-01

Context: Baseball players rely on the sensorimotor system to uphold the balance between upper extremity stability and mobility while maintaining athletic performance. However, few researchers have studied functional multijoint measures of sensorimotor acuity in overhead-throwing athletes. Objective: To compare sensorimotor acuity between 2 high-demand functional positions and among planes of motion within individual joints and to describe a novel method of measuring sensorimotor function. Design: Single-session, repeated-measures design. Setting: University musculoskeletal research laboratory. Patients or Other Participants: Twenty-one National Collegiate Athletic Association Division I baseball players (age = 20.8 ± 1.5 years, height = 181.3 ± 5.1 cm, mass = 87.8 ± 9.1 kg) with no history of upper extremity injury or central nervous system disorder. Main Outcome Measure(s): We measured active multijoint position reproduction acuity in multiple planes using an electromagnetic tracking device. Subjects reproduced 2 positions: arm cock and ball release. We calculated absolute and variable error for individual motions at the scapulothoracic, glenohumeral, elbow, and wrist joints and calculated overall joint acuity with 3-dimensional variable error. Results: Acuity was significantly better in the arm-cock position compared with ball release at the scapulothoracic and glenohumeral joints. We observed significant differences among planes of motion within the scapulothoracic and glenohumeral joints at ball release. Scapulothoracic internal rotation and glenohumeral horizontal abduction and rotation displayed less acuity than other motions. Conclusions: We established the reliability of a functional measure of upper extremity sensorimotor system acuity in baseball players. Using this technique, we observed differences in acuity between 2 test positions and among planes of motion within the glenohumeral and scapulothoracic joints. Clinicians may consider these differences when designing and implementing sensorimotor system training. Our error scores are similar in magnitude to those reported using single-joint and single-plane measures. However, 3-dimensional, multijoint measures allow practical, unconstrained test positions and offer additional insight into the upper extremity as a functional unit. PMID:16791298

Do Associations Between Perceived Environmental and Individual Characteristics and Walking Limitations Depend on Lower Extremity Performance Level?

PubMed

Sakari, Ritva; Rantakokko, Merja; Portegijs, Erja; Iwarsson, Susanne; Sipilä, Sarianna; Viljanen, Anne; Rantanen, Taina

2017-06-01

The aim of this study was to analyze whether the associations between perceived environmental and individual characteristics and perceived walking limitations in older people differ between those with intact and those with poorer lower extremity performance. Persons aged 75 to 90 ( N = 834) participated in interviews and performance tests in their homes. Standard questionnaires were used to obtain walking difficulties; environmental barriers to and, facilitators of, mobility; and perceived individual hindrances to outdoor mobility. Lower extremity performance was tested using Short Physical Performance Battery (SPPB). Among those with poorer lower extremity performance, the likelihood for advanced walking limitations was, in particular, related to perceived poor safety in the environment, and among those with intact performance to perceived social issues, such as lack of company, as well as to long distances. The environmental correlates of walking limitations seem to depend on the level of lower extremity performance.

Field Performance of Photovoltaic Systems in the Tucson Desert

NASA Astrophysics Data System (ADS)

Orsburn, Sean; Brooks, Adria; Cormode, Daniel; Greenberg, James; Hardesty, Garrett; Lonij, Vincent; Salhab, Anas; St. Germaine, Tyler; Torres, Gabe; Cronin, Alexander

2011-10-01

At the Tucson Electric Power (TEP) solar test yard, over 20 different grid-connected photovoltaic (PV) systems are being tested. The goal at the TEP solar test yard is to measure and model real-world performance of PV systems and to benchmark new technologies such as holographic concentrators. By studying voltage and current produced by the PV systems as a function of incident irradiance, and module temperature, we can compare our measurements of field-performance (in a harsh desert environment) to manufacturer specifications (determined under laboratory conditions). In order to measure high-voltage and high-current signals, we designed and built reliable, accurate sensors that can handle extreme desert temperatures. We will present several benchmarks of sensors in a controlled environment, including shunt resistors and Hall-effect current sensors, to determine temperature drift and accuracy. Finally we will present preliminary field measurements of PV performance for several different PV technologies.

Health related quality of life and return to work after minor extremity injuries: A longitudinal study comparing upper versus lower extremity injuries.

PubMed

Sluys, Kerstin Prignitz; Shults, Justine; Richmond, Therese S

2016-04-01

To investigate the impact on health related quality of life (HRQL) during the first year after minor extremity injury and to determine whether there is a difference in recovery patterns and return to work between upper extremity injuries (UEI) and lower extremity injuries (LEI). A total of 181 adults' age 18 years or older randomly selected from patients admitted to an emergency department with minor injuries were studied. HRQL was measured using the Functional Status Questionnaire (FSQ) at 1-2 weeks, 3, 6, and 12-months post-injury. Pre-injury FSQ scores were measured retrospectively at admission. A quasi-least square (QLS) model was constructed to examine differences of FSQ scores at each measuring point for UEI and LEI. Fractures of the knee/lower leg (25%) were the most frequently injured body area. Slips or falls (57%) and traffic-related events (22%) were the most common injury causes. The mean ISS was 4.2 (SD 0.86). Both groups had significant declines in the FSQ scores physical and social functioning at 1-2 weeks after injury. Patients with UEI made larger improvements in the first 3 months post-injury versus patients with LEI whose improvements extended over the first 6 months. None of the groups reached the pre-injury FSQ scores during the first post-injury year except in the subscale work performance where UEI exceeded the pre-injury scores. At 12 months post-injury, significant lower FSQ scores remained in the LEI group compared to the UEI group in intermediate activities of daily living (p=0.036, d 0.4) and work performance (p=0.004, d 0.7). The return to work at 3 months and 12 months were 76% and 88% for UEI and 58% and 77% for LEI. No significant differences were found between groups in the FSQ scale mental health and social interaction. LEI had the highest impact on HRQL and return to work during the first year which exceeded the consequences of UEI. These findings contribute to the information about the consequences of injury in order to give sufficient prognostic information to patients and different stakeholders. Future investigations should aim to investigate specific minor extremity injuries and identify factors that facilitate recovery and return to work. Copyright © 2016 Elsevier Ltd. All rights reserved.

Health related quality of life and return to work after minor extremity injuries: A longitudinal study comparing upper versus lower extremity injuries

PubMed Central

Sluys, Kerstin Prignitz; Shults, Justine; Richmond, Therese S.

2016-01-01

Purpose To investigate the impact on health related quality of life (HRQL) during the first year after minor extremity injury and to determine whether there is a difference in recovery patterns and return to work between upper extremity injuries (UEI) and lower extremity injuries (LEI). Method A total of 181 adults’ age 18 years or older randomly selected from patients admitted to an emergency department with minor injuries were studied. HRQL was measured using the Functional Status Questionnaire (FSQ) at 1–2 weeks, 3, 6, and 12-months post-injury. Pre-injury FSQ scores were measured retrospectively at admission. A quasi-least square (QLS) model was constructed to examine differences of FSQ scores at each measuring point for UEI and LEI. Results Fractures of the knee/lower leg (25%) were the most frequently injured body area. Slips or falls (57%) and traffic-related events (22%) were the most common injury causes. The mean ISS was 4.2 (SD 0.86). Both groups had significant declines in the FSQ scores physical and social functioning at 1–2 weeks after injury. Patients with UEI made larger improvements in the first 3 months post-injury versus patients with LEI whose improvements extended over the first 6 months. None of the groups reached the pre-injury FSQ scores during the first post-injury year except in the subscale work performance where UEI exceeded the pre-injury scores. At 12 months post-injury, significant lower FSQ scores remained in the LEI group compared to the UEI group in intermediate activities of daily living (p=0.036, d 0.4) and work performance (p=0.004, d 0.7). The return to work at 3 months and 12 months were 76% and 88% for UEI and 58% and 77% for LEI. No significant differences were found between groups in the FSQ scale mental health and social interaction. Conclusions LEI had the highest impact on HRQL and return to work during the first year which exceeded the consequences of UEI. These findings contribute to the information about the consequences of injury in order to give sufficient prognostic information to patients and different stakeholders. Future investigations should aim to investigate specific minor extremity injuries and identify factors that facilitate recovery and return to work. PMID:26965363

Diabetic Driving Studies-Part 1: Brake Response Time in Diabetic Drivers With Lower Extremity Neuropathy.

PubMed

Meyr, Andrew J; Spiess, Kerianne E

Although the effect of lower extremity pathology and surgical intervention on automobile driving function has been a topic of contemporary interest, we are unaware of any analysis of the effect of lower extremity diabetic sensorimotor neuropathy on driving performance. The objective of the present case-control investigation was to assess the mean brake response time in diabetic drivers with lower extremity neuropathy compared with that of a control group and a brake response safety threshold. The driving performances of participants were evaluated using a computerized driving simulator with specific measurement of the mean brake response time and frequency of abnormally delayed brake responses. We analyzed a control group of 25 active drivers with neither diabetes nor lower extremity neuropathy and an experimental group of 25 active drivers with type 2 diabetes and lower extremity neuropathy. The experimental group demonstrated a 37.89% slower mean brake response time (0.757 ± 0.180 versus 0.549 ± 0.076 second; p < .001), with abnormally delayed responses occurring at a greater frequency (57.5% versus 3.5%; p < .001). Independent of a comparative statistical analysis, the observed mean brake response time in the experimental group was slower than the reported safety brake response threshold of 0.70 second. The results of the present investigation provide original data with respect to abnormally delayed brake responses in diabetic patients with lower extremity neuropathy and might raise the potential for impaired driving function in this population. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Upper-extremity functional electric stimulation-assisted exercises on a workstation in the subacute phase of stroke recovery.

PubMed

Kowalczewski, Jan; Gritsenko, Valeriya; Ashworth, Nigel; Ellaway, Peter; Prochazka, Arthur

2007-07-01

To test the efficacy of functional electric stimulation (FES)-assisted exercise therapy (FES-ET) on a workstation in the subacute phase of recovery from a stroke. Single-blind, randomly controlled comparison of high- and low-intensity treatment. Laboratory in a rehabilitation hospital. Nineteen stroke survivors (10 men, 9 women; mean age +/- standard deviation, 60.6+/-5.8y), with upper-extremity hemiplegia (mean poststroke time, 48+/-17d). The main inclusion criteria were: stroke occurred within 3 months of onset of trial and resulted in severe upper-limb dysfunction, and FES produced adequate hand opening. An FES stimulator and an exercise workstation with instrumented objects were used by 2 groups to perform specific motor tasks with their affected upper extremity. Ten subjects in the high-intensity FES-ET group received FES-ET for 1 hour a day on 15 to 20 consecutive workdays. Nine subjects in the low-intensity FES-ET group received 15 minutes of sensory electric stimulation 4 days a week and on the fifth day they received 1 hour of FES-ET. Primary outcome measure included the Wolf Motor Function Test (WMFT). Secondary outcome measures included the Motor Activity Log (MAL), the upper-extremity portion of the Fugl-Meyer Assessment (FMA), and the combined kinematic score (CKS) derived from workstation measurements. The WMFT, MAL, and FMA were used to assess function in the absence of FES whereas CKS was used to evaluate function assisted by FES. Improvements in the WMFT and CKS were significantly greater in the high-intensity group (post-treatment effect size, .95) than the low-intensity group (post-treatment effect size, 1.3). The differences in MAL and FMA were not statistically significant. Subjects performing high-intensity FES-ET showed significantly greater improvements on the WMFT than those performing low-intensity FES-ET. However, this was not reflected in subjects' self-assessments (MAL) or in their FMA scores, so the clinical significance of the result is open to debate. The CKS data suggest that high-intensity FES-ET may be advantageous in neuroprosthetic applications.

Photosynthetic response of Persian Gulf acroporid corals to summer versus winter temperature deviations

PubMed Central

Saleh, Abolfazl; Mehdinia, Ali; Shirvani, Arash; Kayal, Mohsen

2015-01-01

With on-going climate change, coral susceptibility to thermal stress constitutes a central concern in reefconservation. In the Persian Gulf, coral reefs are confronted with a high seasonal variability in water temperature, and both hot and cold extremes have been associated with episodes of coral bleaching and mortality. Using physiological performance as a measure of coral health, we investigated the thermal susceptibility of the common acroporid, Acropora downingi, near Hengam Island where the temperature oscillates seasonally in the range 20.2–34.2 °C. In a series of two short-term experiments comparing coral response in summer versus winter conditions, we exposed corals during each season (1) to the corresponding seasonal average and extreme temperature levels in a static thermal environment, and (2) to a progressive temperature deviation from the annual mean toward the corresponding extreme seasonal value and beyond in a dynamic thermal environment. We monitored four indictors of coral physiological performance: net photosynthesis (Pn), dark respiration (R), autotrophic capability (Pn/R), and survival. Corals exposed to warming during summer showed a decrease in net photosynthesis and ultimately died, while corals exposed to cooling during winter were not affected in their photosynthetic performance and survival. Coral autotrophic capability Pn/R was lower at the warmer thermal level within eachseason, and during summer compared to winter. Corals exposed to the maximum temperature of summer displayed Pn/R < 1, inferring that photosynthetic performance could not support basal metabolic needs under this environment. Our results suggest that the autotrophic performance of the Persian Gulf A. downingi is sensitive to the extreme temperatures endured in summer, and therefore its populations may be impacted by future increases in water temperature. PMID:26157627

Photosynthetic response of Persian Gulf acroporid corals to summer versus winter temperature deviations.

PubMed

Vajed Samiei, Jahangir; Saleh, Abolfazl; Mehdinia, Ali; Shirvani, Arash; Kayal, Mohsen

2015-01-01

With on-going climate change, coral susceptibility to thermal stress constitutes a central concern in reefconservation. In the Persian Gulf, coral reefs are confronted with a high seasonal variability in water temperature, and both hot and cold extremes have been associated with episodes of coral bleaching and mortality. Using physiological performance as a measure of coral health, we investigated the thermal susceptibility of the common acroporid, Acropora downingi, near Hengam Island where the temperature oscillates seasonally in the range 20.2-34.2 °C. In a series of two short-term experiments comparing coral response in summer versus winter conditions, we exposed corals during each season (1) to the corresponding seasonal average and extreme temperature levels in a static thermal environment, and (2) to a progressive temperature deviation from the annual mean toward the corresponding extreme seasonal value and beyond in a dynamic thermal environment. We monitored four indictors of coral physiological performance: net photosynthesis (Pn), dark respiration (R), autotrophic capability (Pn/R), and survival. Corals exposed to warming during summer showed a decrease in net photosynthesis and ultimately died, while corals exposed to cooling during winter were not affected in their photosynthetic performance and survival. Coral autotrophic capability Pn/R was lower at the warmer thermal level within eachseason, and during summer compared to winter. Corals exposed to the maximum temperature of summer displayed Pn/R < 1, inferring that photosynthetic performance could not support basal metabolic needs under this environment. Our results suggest that the autotrophic performance of the Persian Gulf A. downingi is sensitive to the extreme temperatures endured in summer, and therefore its populations may be impacted by future increases in water temperature.

LEVELS OF EXTREMELY LOW-FREQUENCY ELECTRIC AND MAGNETIC FIELDS FROM OVERHEAD POWER LINES IN THE OUTDOOR ENVIRONMENT OF RAMALLAH CITY-PALESTINE.

PubMed

Abuasbi, Falastine; Lahham, Adnan; Abdel-Raziq, Issam Rashid

2018-05-01

In this study, levels of extremely low-frequency electric and magnetic fields originated from overhead power lines were investigated in the outdoor environment in Ramallah city, Palestine. Spot measurements were applied to record fields intensities over 6-min period. The Spectrum Analyzer NF-5035 was used to perform measurements at 1 m above ground level and directly underneath 40 randomly selected power lines distributed fairly within the city. Levels of electric fields varied depending on the line's category (power line, transformer or distributor), a minimum mean electric field of 3.9 V/m was found under a distributor line, and a maximum of 769.4 V/m under a high-voltage power line (66 kV). However, results of electric fields showed a log-normal distribution with the geometric mean and the geometric standard deviation of 35.9 and 2.8 V/m, respectively. Magnetic fields measured at power lines, on contrast, were not log-normally distributed; the minimum and maximum mean magnetic fields under power lines were 0.89 and 3.5 μT, respectively. As a result, none of the measured fields exceeded the ICNIRP's guidelines recommended for general public exposures to extremely low-frequency fields.

The Effects of Isolated and Integrated ‘Core Stability’ Training on Athletic Performance Measures

PubMed Central

Reed, Casey A.; Ford, Kevin R.; Myer, Gregory D.; Hewett, Timothy E.

2014-01-01

Background Core stability training, operationally defined as training focused to improve trunk and hip control, is an integral part of athletic development, yet little is known about its direct relation to athletic performance. Objective This systematic review focuses on identification of the association between core stability and sports-related performance measures. A secondary objective was to identify difficulties encountered when trying to train core stability with the goal of improving athletic performance. Data sources A systematic search was employed to capture all articles related to athletic performance and core stability training that were identified using the electronic databases MEDLINE, CINAHL and SPORTDiscus™ (1982-June2011). Study selection A systematic approach was used to evaluate 179 articles identified for initial review. Studies that performed an intervention targeted toward the core and measured an outcome related to athletic or sport performances were included, while studies with a participant population aged 65 years or older were excluded. Twenty-four in total met the inclusionary criteria for review. Study appraisal and synthesis methods Studies were evaluated using the Physical Therapy Evidence Database (PEDro) scale. The 24 articles were separated into three groups, general performance (n = 8), lower extremity (n = 10) and upper extremity (n = 6), for ease of discussion. Results In the majority of studies, core stability training was utilized in conjunction with more comprehensive exercise programmes. As such, many studies saw improvements in skills of general strengths such as maximum squat load and vertical leap. Surprisingly, not all studies reported measurable increases in specific core strength and stability measures following training. Additionally, investigations that targeted the core as the primary goal for improved outcome of training had mixed results. Limitations Core stability is rarely the sole component of an athletic development programme, making it difficult to directly isolate its affect on athletic performance. The population biases of some studies of athletic performance also confound the results. Conclusions Targeted core stability training provides marginal benefits to athletic performance. Conflicting findings and the lack of a standardization for measurement of outcomes and training focused to improve core strength and stability pose difficulties. Because of this, further research targeted to determine this relationship is necessary to better understand how core strength and stability affect athletic performance. PMID:22784233

THE IMMEDIATE AND LONG-TERM EFFECTS OF KINESIOTAPE® ON BALANCE AND FUNCTIONAL PERFORMANCE.

PubMed

Wilson, Victoria; Douris, Peter; Fukuroku, Taryn; Kuzniewski, Michael; Dias, Joe; Figueiredo, Patrick

2016-04-01

The application of Kinesio Tex® tape (KT) results, in theory, in the improvement of muscle contractibility by supporting weakened muscles. The effect of KT on muscle strength has been investigated by numerous researchers who have theorized that KT facilitates an immediate increase in muscle strength by generating a concentric pull on the fascia. The effect of KT on balance and functional performance has been controversial because of the inconsistencies of tension and direction of pull required during application of KT and whether its use on healthy individuals provides therapeutic benefits. The purpose of the present study was to investigate the immediate and long-term effects of the prescribed application (for facilitation) of KT when applied to the dominant lower extremity of healthy individuals. The hypothesis was that balance and functional performance would improve with the prescribed application of KT versus the sham application. Pretest-posttest repeated measures control group design. Seventeen healthy subjects (9 males; 8 females) ranging from 18-35 years of age (mean age 23.3 ± 0.72), volunteered to participate in this study. KT was applied to the gastrocnemius of the participant's dominant leg using a prescribed application to facilitate muscle performance for the experimental group versus a sham application for the control group. The Biodex Balance System and four hop tests were utilized to assess balance, proprioception, and functional performance beginning on the first day including pre- and immediately post-KT application measurements. Subsequent measurements were performed 24, 72, and 120 hours after tape application. Repeated measures ANOVA's were performed for each individual dependent variable. There were no significant differences for main and interaction effects between KT and sham groups for the balance and four hop tests. The results of the present study did not indicate any significant differences in balance and functional performance when KT was applied to the gastrocnemius muscle of the lower extremity. Level 1- Randomized Clinical Trial.

Biomechanical and Performance Differences Between Female Soccer Athletes in National Collegiate Athletic Association Divisions I and III

PubMed Central

Smith, Rose; Ford, Kevin R; Myer, Gregory D; Holleran, Adam; Treadway, Erin; Hewett, Timothy E

2007-01-01

Context: The recent increase in women's varsity soccer participation has been accompanied by a lower extremity injury rate that is 2 to 6 times that of their male counterparts. Objective: To define the differences between lower extremity biomechanics (knee abduction and knee flexion measures) and performance (maximal vertical jump height) between National Collegiate Athletic Association Division I and III female soccer athletes during a drop vertical jump. Design: Mixed 2 × 2 design. Setting: Research laboratory. Patients or Other Participants: Thirty-four female collegiate soccer players (Division I: n = 19; Division III: n = 15) participated in the study. The groups were similar in height and mass. Intervention(s): Each subject performed a maximal vertical jump, followed by 3 drop vertical jumps. Main Outcome Measure(s): Kinematics (knee abduction and flexion angles) and kinetics (knee abduction and flexion moments) were measured with a motion analysis system and 2 force platforms during the drop vertical jumps. Results: Knee abduction angular range of motion and knee abduction external moments were not different between groups (P > .05). However, Division I athletes demonstrated decreased knee flexion range of motion (P = .038) and greater peak external knee flexion moment (P = .009) compared with Division III athletes. Division I athletes demonstrated increased vertical jump height compared with Division III (P = .008). Conclusions: Division I athletes demonstrated different sagittal-plane mechanics than Division III athletes, which may facilitate improved performance. The similarities in anterior cruciate ligament injury risk factors (knee abduction torques and angles) may correlate with the consistent incidence of anterior cruciate ligament injury across divisions. PMID:18174935

Measuring daily Value-at-Risk of SSEC index: A new approach based on multifractal analysis and extreme value theory

NASA Astrophysics Data System (ADS)

Wei, Yu; Chen, Wang; Lin, Yu

2013-05-01

Recent studies in the econophysics literature reveal that price variability has fractal and multifractal characteristics not only in developed financial markets, but also in emerging markets. Taking high-frequency intraday quotes of the Shanghai Stock Exchange Component (SSEC) Index as example, this paper proposes a new method to measure daily Value-at-Risk (VaR) by combining the newly introduced multifractal volatility (MFV) model and the extreme value theory (EVT) method. Two VaR backtesting techniques are then employed to compare the performance of the model with that of a group of linear and nonlinear generalized autoregressive conditional heteroskedasticity (GARCH) models. The empirical results show the multifractal nature of price volatility in Chinese stock market. VaR measures based on the multifractal volatility model and EVT method outperform many GARCH-type models at high-risk levels.

Forecasting Financial Extremes: A Network Degree Measure of Super-Exponential Growth.

PubMed

Yan, Wanfeng; van Tuyll van Serooskerken, Edgar

2015-01-01

Investors in stock market are usually greedy during bull markets and scared during bear markets. The greed or fear spreads across investors quickly. This is known as the herding effect, and often leads to a fast movement of stock prices. During such market regimes, stock prices change at a super-exponential rate and are normally followed by a trend reversal that corrects the previous overreaction. In this paper, we construct an indicator to measure the magnitude of the super-exponential growth of stock prices, by measuring the degree of the price network, generated from the price time series. Twelve major international stock indices have been investigated. Error diagram tests show that this new indicator has strong predictive power for financial extremes, both peaks and troughs. By varying the parameters used to construct the error diagram, we show the predictive power is very robust. The new indicator has a better performance than the LPPL pattern recognition indicator.

Maintaining physical fitness and function in Alzheimer's disease: a pilot study.

PubMed

Yu, Fang; Savik, Kay; Wyman, Jean F; Bronas, Ulf G

2011-08-01

Little is known about how aerobic exercise affects physical functioning in persons with Alzheimer's disease (AD). This pilot study used a 1-group repeated measures design to examine the feasibility and impact of a 6-month individualized moderate intensity cycling intervention on cardiorespiratory fitness and lower extremity function in 8 participants aged 81.4 ± 3.58. Cardiorespiratory fitness was measured using the shuttle walk and modified YMCA cycle ergometer tests, and lower extremity function was measured using the Short Physical Performance Battery (SPPB) at baseline, 3 months and 6 months. The YMCA test showed a significant reduction in heart rate at stage 2 (103.4 vs 90.9 vs 91.6; P = .01), while no significant changes were observed in the shuttle walk and SPPB tests. Persons with AD are able to improve cardiorespiratory conditioning from aerobic exercise. Randomized, controlled trials are needed to confirm these findings. Implications for future research are detailed.

The influence of lower limb impairments on RaceRunning performance in athletes with hypertonia, ataxia or athetosis.

PubMed

van der Linden, Marietta L; Jahed, Sadaf; Tennant, Nicola; Verheul, Martine H G

2018-03-01

RaceRunning enables athletes with limited or no walking ability to propel themselves independently using a three-wheeled running bike that has a saddle and a chest plate for support but no pedals. For RaceRunning to be included as a Para athletics event, an evidence-based classification system is required. Therefore, the aim of this study was to assess the association between a range of impairment measures and RaceRunning performance. The following impairment measures were recorded: lower limb muscle strength assessed using Manual Muscle Testing (MMT), selective voluntary motor control assessed using the Selective Control Assessment of the Lower Extremity (SCALE), spasticity recorded using both the Australian Spasticity Assessment Score (ASAS) and Modified Ashworth Scale (MAS), passive range of motion (ROM) of the lower extremities and the maximum static step length achieved on a stationary bike (MSSL). Associations between impairment measures and 100-meter race speed were assessed using Spearman's correlation coefficients. Sixteen male and fifteen female athletes (27 with cerebral palsy), aged 23 (SD = 7) years, Gross Motor Function Classification System levels ranging from II to V, participated. The MSSL averaged over both legs and the ASAS, MAS, SCALE, and MMT summed over all joints and both legs, significantly correlated with 100 m race performance (rho: 0.40-0.54). Passive knee extension was the only ROM measure that was significantly associated with race speed (rho = 0.48). These results suggest that lower limb spasticity, isometric leg strength, selective voluntary motor control and passive knee extension impact performance in RaceRunning athletes. This supports the potential use of these measures in a future evidence-based classification system. Copyright © 2018 Elsevier B.V. All rights reserved.

Game-Based Virtual Reality Canoe Paddling Training to Improve Postural Balance and Upper Extremity Function: A Preliminary Randomized Controlled Study of 30 Patients with Subacute Stroke.

PubMed

Lee, Myung Mo; Lee, Kyeong Jin; Song, Chang Ho

2018-04-27

BACKGROUND Virtual reality (VR) training with motion-controlled console games can be incorporated into stroke rehabilitation programs. The use of a variety of gaming software can provide the patient with an opportunity to perform activities that are exciting, entertaining, and that may not be feasible in clinical environments. The aim of this preliminary randomized controlled study was to investigate the effects of game-based VR canoe paddling training, when combined with conventional physical rehabilitation programs, on postural balance and upper extremity function in 30 patients with subacute stroke. MATERIAL AND METHODS Thirty patients, who were within six months following the diagnosis of stroke, were randomly allocated to either the experimental group (n=15) or the control group (n=15). All participants participated in a conventional rehabilitation program. Also, the experimental group (n=15) performed the VR canoe paddling training for 30 minutes each day, three times per week, for five weeks. After five weeks, outcomes of changes in postural balance and upper extremity function were evaluated and compared between the two groups. RESULTS At five weeks, postural balance and upper extremity function showed significant improvements in both patients groups when compared with the baseline measurements (p<0.05). However, postural balance and upper extremity function were significantly improved in the experimental group when compared with the control group (p<0.05). CONCLUSIONS Game-based VR canoe paddling training is an effective rehabilitation therapy that enhances postural balance and upper extremity function in patients with subacute stroke when combined with conventional physical rehabilitation programs.

A Neuroscience Approach to Optimizing Brain Resources for Human Performance in Extreme Environments

PubMed Central

Paulus, Martin P.; Potterat, Eric G.; Taylor, Marcus K.; Van Orden, Karl F.; Bauman, James; Momen, Nausheen; Padilla, Genieleah A.; Swain, Judith L.

2009-01-01

Extreme environments requiring optimal cognitive and behavioral performance occur in a wide variety of situations ranging from complex combat operations to elite athletic competitions. Although a large literature characterizes psychological and other aspects of individual differences in performances in extreme environments, virtually nothing is known about the underlying neural basis for these differences. This review summarizes the cognitive, emotional, and behavioral consequences of exposure to extreme environments, discusses predictors of performance, and builds a case for the use of neuroscience approaches to quantify and understand optimal cognitive and behavioral performance. Extreme environments are defined as an external context that exposes individuals to demanding psychological and/or physical conditions, and which may have profound effects on cognitive and behavioral performance. Examples of these types of environments include combat situations, Olympic-level competition, and expeditions in extreme cold, at high altitudes, or in space. Optimal performance is defined as the degree to which individuals achieve a desired outcome when completing goal-oriented tasks. It is hypothesized that individual variability with respect to optimal performance in extreme environments depends on a well “contextualized” internal body state that is associated with an appropriate potential to act. This hypothesis can be translated into an experimental approach that may be useful for quantifying the degree to which individuals are particularly suited to performing optimally in demanding environments. PMID:19447132

A Systematic Approach for Engagement Analysis Under Multitasking Environments

NASA Technical Reports Server (NTRS)

Zhang, Guangfan; Leddo, John; Xu, Roger; Richey, Carl; Schnell, Tom; McKenzie, Frederick; Li, Jiang

2011-01-01

An overload condition can lead to high stress for an operator and further cause substantial drops in performance. On the other extreme, in automated systems, an operator may become underloaded; in which case, it is difficult for the operator to maintain sustained attention. When an unexpected event occurs, either internal or external to the automated system, a disengaged operation may neglect, misunderstand, or respond slowly/inappropriately to the situation. In this paper, we discuss a systematic approach monitor for extremes of cognitive workload and engagement in multitasking environments. Inferences of cognitive workload ar engagement are based on subjective evaluations, objective performance measures, physiological signals, and task analysis results. The systematic approach developed In this paper aggregates these types of information collected under the multitasking environment and can provide a real-time assessment or engagement.

High-Achieving High School Students and Not so High-Achieving College Students: A Look at Lack of Self-Control, Academic Ability, and Performance in College

ERIC Educational Resources Information Center

Honken, Nora B.; Ralston, Patricia A. S.

2013-01-01

This study investigated the relationship among lack of self-control, academic ability, and academic performance for a cohort of freshman engineering students who were, with a few exceptions, extremely high achievers in high school. Structural equation modeling analysis led to the conclusion that lack of self-control in high school, as measured by…

Improving balance, mobility, and dual-task performance in an adolescent with cerebral palsy: A case report.

PubMed

Fisher-Pipher, Sarah; Kenyon, Lisa K; Westman, Marci

2017-07-01

Improving functional mobility is often a desired outcome for adolescents with cerebral palsy (CP). Traditional neurorehabilitation approaches are frequently directed at impairments; however, improvements may not be carried over into functional mobility. The purpose of this case report was to describe the examination, intervention, and outcomes of a task-oriented physical therapy intervention program to improve dynamic balance, functional mobility, and dual-task performance in an adolescent with CP. The participant was a 15-year-old girl with spastic triplegic CP (Gross Motor Classification System Level II). Examination procedures included the Canadian Occupational Performance Measure, 6-minute walk test, Muscle Power Sprint Test, 10 x 5-meter sprint test, Timed Up and Down Stairs Test, Gross Motor Function Measure, Gillette Functional Assessment Questionnaire, and functional lower extremity strength tests. Intervention focused on task-oriented dynamic balance and mobility tasks that incorporated coordination and speed demands as well as task-specific lower extremity and trunk strengthening activities. Dual task demands were integrated into all intervention activities. Post-intervention testing revealed improvements in cardiovascular endurance, anaerobic power, agility, stair climbing, gross motor skills, and mobility. The participant appeared to benefit from a task-oriented program to improve dynamic balance, functional mobility, and dual-task performance.

Functional measures developed for clinical populations identified impairment among active workers with upper extremity disorders

PubMed Central

Gardner, Bethany T.; Dale, Ann Marie; Buckner-Petty, Skye; Rachford, Robert; Strickland, Jaime; Kaskutas, Vicki; Evanoff, Bradley

2017-01-01

Purpose Few studies have explored measures of function across a range of health outcomes in a general working population. Using four upper extremity (UE) case definitions from the scientific literature, we described the performance of functional measures of work, activities of daily living, and overall health. Methods A sample of 573 workers completed several functional measures: modified recall versions of the QuickDASH, Levine Functional Status Scale (FSS), DASH Work module (DASH-W), and standard SF-8 physical component score. We determined case status based on four UE case definitions: 1) UE symptoms, 2) UE musculoskeletal disorders (MSD), 3) carpal tunnel syndrome (CTS), and 4) work limitations due to UE symptoms. We calculated effect sizes for each case definition to show the magnitude of the differences that were detected between cases and non-cases for each case definition on each functional measure. Sensitivity and specificity analyses showed how well each measure identified functional impairments across the UE case definitions. Results All measures discriminated between cases and non-cases for each case definition with the largest effect sizes for CTS and work limitations, particularly for the modified FSS and DASH-W measures. Specificity was high and sensitivity was low for outcomes of UE symptoms and UE MSD in all measures. Sensitivity was high for CTS and work limitations. Conclusions Functional measures developed specifically for use in clinical, treatment-seeking populations may identify mild levels of impairment in relatively healthy, active working populations, but measures performed better among workers with CTS or those reporting limitations at work. PMID:26091980

Operation of SOI P-Channel Field Effect Transistors, CHT-PMOS30, under Extreme Temperatures

NASA Technical Reports Server (NTRS)

Patterson, Richard; Hammoud, Ahmad

2009-01-01

Electronic systems are required to operate under extreme temperatures in NASA planetary exploration and deep space missions. Electronics on-board spacecraft must also tolerate thermal cycling between extreme temperatures. Thermal management means are usually included in today s spacecraft systems to provide adequate temperature for proper operation of the electronics. These measures, which may include heating elements, heat pipes, radiators, etc., however add to the complexity in the design of the system, increases its cost and weight, and affects its performance and reliability. Electronic parts and circuits capable of withstanding and operating under extreme temperatures would reflect in improvement in system s efficiency, reducing cost, and improving overall reliability. Semiconductor chips based on silicon-on-insulator (SOI) technology are designed mainly for high temperature applications and find extensive use in terrestrial well-logging fields. Their inherent design offers advantages over silicon devices in terms of reduced leakage currents, less power consumption, faster switching speeds, and good radiation tolerance. Little is known, however, about their performance at cryogenic temperatures and under wide thermal swings. Experimental investigation on the operation of SOI, N-channel field effect transistors under wide temperature range was reported earlier [1]. This work examines the performance of P-channel devices of these SOI transistors. The electronic part investigated in this work comprised of a Cissoid s CHT-PMOS30, high temperature P-channel MOSFET (metal-oxide semiconductor field-effect transistor) device [2]. This high voltage, medium-power transistor is designed for geothermal well logging applications, aerospace and avionics, and automotive industry, and is specified for operation in the temperature range of -55 C to +225 C. Table I shows some specifications of this transistor [2]. The CHT-PMOS30 device was characterized at various temperatures over the range of -190 C to +225 C in terms of its voltage/current characteristic curves. The test temperatures included +22, -50, -100, -150, -175, -190, +50, +100, +150, +175, +200, and +225 C. Limited thermal cycling testing was also performed on the device. These tests consisted of subjecting the transistor to a total of twelve thermal cycles between -190 C and +225 C. A temperature rate of change of 10 C/min and a soak time at the test temperature of 10 minutes were used throughout this work. Post-cycling measurements were also performed at selected temperatures. In addition, re-start capability at extreme temperatures, i.e. power switched on while the device was soaking for a period of 20 minutes at the test temperatures of -190 C and +225 C, was investigated.

An empirical evaluation of genetic distance statistics using microsatellite data from bear (Ursidae) populations.

PubMed

Paetkau, D; Waits, L P; Clarkson, P L; Craighead, L; Strobeck, C

1997-12-01

A large microsatellite data set from three species of bear (Ursidae) was used to empirically test the performance of six genetic distance measures in resolving relationships at a variety of scales ranging from adjacent areas in a continuous distribution to species that diverged several million years ago. At the finest scale, while some distance measures performed extremely well, statistics developed specifically to accommodate the mutational processes of microsatellites performed relatively poorly, presumably because of the relatively higher variance of these statistics. At the other extreme, no statistic was able to resolve the close sister relationship of polar bears and brown bears from more distantly related pairs of species. This failure is most likely due to constraints on allele distributions at microsatellite loci. At intermediate scales, both within continuous distributions and in comparisons to insular populations of late Pleistocene origin, it was not possible to define the point where linearity was lost for each of the statistics, except that it is clearly lost after relatively short periods of independent evolution. All of the statistics were affected by the amount of genetic diversity within the populations being compared, significantly complicating the interpretation of genetic distance data.

An Empirical Evaluation of Genetic Distance Statistics Using Microsatellite Data from Bear (Ursidae) Populations

PubMed Central

Paetkau, D.; Waits, L. P.; Clarkson, P. L.; Craighead, L.; Strobeck, C.

1997-01-01

A large microsatellite data set from three species of bear (Ursidae) was used to empirically test the performance of six genetic distance measures in resolving relationships at a variety of scales ranging from adjacent areas in a continuous distribution to species that diverged several million years ago. At the finest scale, while some distance measures performed extremely well, statistics developed specifically to accommodate the mutational processes of microsatellites performed relatively poorly, presumably because of the relatively higher variance of these statistics. At the other extreme, no statistic was able to resolve the close sister relationship of polar bears and brown bears from more distantly related pairs of species. This failure is most likely due to constraints on allele distributions at microsatellite loci. At intermediate scales, both within continuous distributions and in comparisons to insular populations of late Pleistocene origin, it was not possible to define the point where linearity was lost for each of the statistics, except that it is clearly lost after relatively short periods of independent evolution. All of the statistics were affected by the amount of genetic diversity within the populations being compared, significantly complicating the interpretation of genetic distance data. PMID:9409849

Air Pollution Potential from Electroplating Operations.

ERIC Educational Resources Information Center

Diamond, Philip

Measurements were made of emission rates from electroplating operations considered to have maximum air pollution potential. Sampling was performed at McClellan and additional data from a previous survey at Hill Air Force Base was used. Values obtained were extremely low. Based on existing Federal standards, no collectors are specifically required…

CT measurement of range of motion of ankle and subtalar joints following two lateral column lengthening procedures.

PubMed

Beimers, Lijkele; Louwerens, Jan W K; Tuijthof, Gabrielle Josephine Maria; Jonges, Remmet; van Dijk, C N Niek; Blankevoort, Leendert

2012-05-01

Lateral column lengthening (LCL) has become an accepted procedure for the operative treatment of the flexible flatfoot deformity. Hindfoot arthrodesis via a calcaneocuboid distraction arthrodesis (CCDA) has been considered a less favourable surgical option than the anterior open wedge calcaneal distraction osteotomy (ACDO), as CCDA has been associated with reduced hindfoot joint motion postoperatively. The ankle and subtalar joint ranges of motion were measured in patients who underwent an ACDO or CCDA procedure for flatfoot deformity. CT scanning was performed with the foot in extreme positions in five ACDO and five CCDA patients. A bone segmentation and registration technique for the tibia, talus and calcaneus was applied to the CT images. Finite helical axis (FHA) rotations representing the range of motion of the joints were calculated for the motion between opposite extreme foot positions of the tibia and the calcaneus relative to the talus. The maximum mean FHA rotation of the ankle joint (for extreme dorsiflexion to extreme plantarflexion) after ACDO was 52.2 degrees ± 12.4 degrees and after CCDA 49.0 degrees ± 12.0 degrees. Subtalar joint maximum mean FHA rotation (for extreme eversion to extreme inversion) following ACDO was 22.8 degrees ± 8.6 degrees, and following CCDA 24.4 degrees ± 7.6 degrees. An accurate CT-based technique was used to assess the range of motion of the ankle and subtalar joints following two lateral column lengthening procedures for flatfoot deformity. Comparable results with a considerable amount of variance were found for the range of motion following the ACDO and CCDA procedures.

Effect of reconstruction of the anterior cruciate ligament on proprioception of the knee and the heel strike transient.

PubMed

Co, F H; Skinner, H B; Cannon, W D

1993-09-01

Abnormal proprioception of the knee joint has been documented after rupture of the anterior cruciate ligament (ACL) and may result in the loss of muscular reflexes. Excessive loading from the lack of muscular control may predispose the joint to osteoarthrosis. To investigate this problem, 10 patients were studied at an average of 31.6 months after ACL reconstruction. Three tests of joint proprioception and measurements of the vertical component of heel strike force during normal gait were used. A normal control group also was studied. For two of the proprioception tests (reproduction of passive motion and relative reproduction), there were no statistical differences among the uninjured (control) limbs, the normal contralateral limb of patients with a reconstructed ACL, and the extremity with a reconstructed ACL. In the third test (threshold of detection of motion), which previously has been shown to be adversely affected by ACL injury, the measurements for both extremities of patients with a reconstructed ACL were more accurate than those for the control group. The reconstructed extremity performed less accurately than the contralateral extremity (p < 0.05). The heel strike transient (vertical component of ground reaction force at heel strike) for uninjured and ACL-reconstructed limbs was not significantly different. In fact, the extremity with the reconstructed ACL had a lower transient than the uninjured extremity. Heel strike transients in patients with a reconstructed ACL were higher than those in the controls, but the differences were significant only when corrected for velocity of gait.(ABSTRACT TRUNCATED AT 250 WORDS)

Can physiological engineering/programming increase multi-generational thermal tolerance to extreme temperature events?

PubMed

Sorby, Kris L; Green, Mark P; Dempster, Tim D; Jessop, Tim S

2018-05-29

Organisms increasingly encounter higher frequencies of extreme weather events as a consequence of global climate change. Currently, few strategies are available to mitigate climate change effects on animals arising from acute extreme high temperature events. We tested the capacity of physiological engineering to influence the intra- and multi-generational upper thermal tolerance capacity of a model organism Artemia , subjected to extreme high temperatures. Enhancement of specific physiological regulators during development could affect thermal tolerances or life-history attributes affecting subsequent fitness. Using experimental Artemia populations we exposed F0 individuals to one of four treatments; heat hardening (28°C to 36°C, 1°C per 10 minutes), heat hardening plus serotonin (0.056 µg ml -1 ), heat hardening plus methionine (0.79 mg ml -1 ), and a control treatment. Regulator concentrations were based on previous literature. Serotonin may promote thermotolerance, acting upon metabolism and life-history. Methionine acts as a methylation agent across generations. For all groups, measurements were collected for three performance traits of individual thermal tolerance (upper sublethal thermal limit, lethal limit, and dysregulation range) over two generations. Results showed no treatment increased upper thermal limit during acute thermal stress, although serotonin-treated and methionine-treated individuals outperformed controls across multiple thermal performance traits. Additionally, some effects were evident across generations. Together these results suggest phenotypic engineering provides complex outcomes; and if implemented with heat hardening can further influence performance in multiple thermal tolerance traits, within and across generations. Potentially, such techniques could be up-scaled to provide resilience and stability in populations susceptible to extreme temperature events. © 2018. Published by The Company of Biologists Ltd.

The effects of therapeutic instrumental music performance on endurance level, self-perceived fatigue level, and self-perceived exertion of inpatients in physical rehabilitation.

PubMed

Lim, Hayoung A; Miller, Karen; Fabian, Chuck

2011-01-01

The present study investigated the effects of a Neurologic Music Therapy (NMT) sensory-motor rehabilitation technique, Therapeutic Instrumental Music Performance (TIMP) as compared to Traditional Occupational Therapy (TOT), on endurance, self-perceived fatigue, and self-perceived exertion of 35 hospitalized patients in physical rehabilitation. The present study attempted to examine whether an active musical experience such as TIMP with musical cueing (i.e., rhythmic auditory cueing) during physical exercises influences one's perception of pain, fatigue, and exertion. All participants were diagnosed with a neurologic disorder or had recently undergone orthopedic surgery. Investigators measured the effects of TOT and TIMP during upper extremity exercise of the less affected or stronger upper extremity. Results showed no significant difference on endurance measures between the 2 treatment conditions (TIMP and TOT). Statistically significant differences were found between TIMP and TOT when measuring their effects on perceived exertion and perceived fatigue. TIMP resulted in significantly less perception of fatigue and exertion levels than TOT. TIMP can be used foran effective sensory-motor rehabilitation technique to decrease perceived exertion and fatigue level of inpatients in physical rehabilitation.

Solution electrostatic levitator for measuring surface properties and bulk structures of an extremely supersaturated solution drop above metastable zone width limit.

PubMed

Lee, Sooheyong; Jo, Wonhyuk; Cho, Yong Chan; Lee, Hyun Hwi; Lee, Geun Woo

2017-05-01

We report on the first integrated apparatus for measuring surface and thermophysical properties and bulk structures of a highly supersaturated solution by combining electrostatic levitation with real-time laser/x-ray scattering. Even today, a proper characterization of supersaturated solutions far above their solubility limits is extremely challenging because heterogeneous nucleation sites such as container walls or impurities readily initiate crystallization before the measurements can be performed. In this work, we demonstrate simultaneous measurements of drying kinetics and surface tension of a potassium dihydrogen phosphate (KH 2 PO 4 ) aqueous solution droplet and its bulk structural evolution beyond the metastable zone width limit. Our experimental finding shows that the noticeable changes of the surface properties are accompanied by polymerizations of hydrated monomer clusters. The novel electrostatic levitation apparatus presented here provides an effective means for studying a wide range of highly concentrated solutions and liquids in deep metastable states.

Optimal regionalization of extreme value distributions for flood estimation

NASA Astrophysics Data System (ADS)

Asadi, Peiman; Engelke, Sebastian; Davison, Anthony C.

2018-01-01

Regionalization methods have long been used to estimate high return levels of river discharges at ungauged locations on a river network. In these methods, discharge measurements from a homogeneous group of similar, gauged, stations are used to estimate high quantiles at a target location that has no observations. The similarity of this group to the ungauged location is measured in terms of a hydrological distance measuring differences in physical and meteorological catchment attributes. We develop a statistical method for estimation of high return levels based on regionalizing the parameters of a generalized extreme value distribution. The group of stations is chosen by optimizing over the attribute weights of the hydrological distance, ensuring similarity and in-group homogeneity. Our method is applied to discharge data from the Rhine basin in Switzerland, and its performance at ungauged locations is compared to that of other regionalization methods. For gauged locations we show how our approach improves the estimation uncertainty for long return periods by combining local measurements with those from the chosen group.

Influence of Whole-Body Vibration Training Without Visual Feedback on Balance and Lower-Extremity Muscle Strength of the Elderly: A Randomized Controlled Trial.

PubMed

Tseng, Shiuan-Yu; Lai, Chung-Liang; Chang, Kai-Ling; Hsu, Pi-Shan; Lee, Meng-Chih; Wang, Chun-Hou

2016-02-01

The purpose of this study was to investigate the influence of whole-body vibration (WBV) training without visual feedback on balance and lower-extremity muscle strength in the elderly.Elderly subjects who did not exercise regularly participated in this study. Subjects were randomly divided into a WBV with eyes open group, a visual feedback-deprived plus WBV (VFDWBV) group, and a control group (0 Hz, eyes open). WBV training was provided over a 3-month period, 3 times per week for 5 min each session. Balance performance was measured with the limits of stability test, and muscle strength was measured with an isokinetic dynamometer.A total of 45 elderly subjects with an average age of 69.22  ±  3.97 years, divided into a WBV group (n = 14), a VFDWBV group (n = 17), and a control group (n = 14), completed the trial. Statistically significant differences were found in the balance performance of the 3 groups at different time points (time × group interaction: F = 13.213, P < 0.001), and the VFDWBV group had more improvement in balance than the WBV and control groups. The strength of the knee extensor and flexor muscles had time × group interactions: F = 29.604, P < 0.001 and F = 4.684, P = 0.015, respectively; the VFDWBV group had more improvement on lower-extremity muscle strength than the WBV and control groups. The 6-month follow-up showed that the rates of hospital visits for medical services due to falls were 0% in the WBV group (0/14), 0% in the VFDWBV group (0/17), and 28.57% in the control group (4/14).Results showed that WBV training at 20  Hz without visual feedback can significantly improve the balance performance and lower-extremity muscle strength of the elderly.

Assessing Individual Weather Risk-Taking and Its Role in Modeling Likelihood of Hurricane Evacuation

NASA Astrophysics Data System (ADS)

Stewart, A. E.

2017-12-01

This research focuses upon measuring an individual's level of perceived risk of different severe and extreme weather conditions using a new self-report measure, the Weather Risk-Taking Scale (WRTS). For 32 severe and extreme situations in which people could perform an unsafe behavior (e. g., remaining outside with lightning striking close by, driving over roadways covered with water, not evacuating ahead of an approaching hurricane, etc.), people rated: 1.their likelihood of performing the behavior, 2. The perceived risk of performing the behavior, 3. the expected benefits of performing the behavior, and 4. whether the behavior has actually been performed in the past. Initial development research with the measure using 246 undergraduate students examined its psychometric properties and found that it was internally consistent (Cronbach's a ranged from .87 to .93 for the four scales) and that the scales possessed good temporal (test-retest) reliability (r's ranged from .84 to .91). A second regression study involving 86 undergraduate students found that taking weather risks was associated with having taken similar risks in one's past and with the personality trait of sensation-seeking. Being more attentive to the weather and perceiving its risks when it became extreme was associated with lower likelihoods of taking weather risks (overall regression model, R2adj = 0.60). A third study involving 334 people examined the contributions of weather risk perceptions and risk-taking in modeling the self-reported likelihood of complying with a recommended evacuation ahead of a hurricane. Here, higher perceptions of hurricane risks and lower perceived benefits of risk-taking along with fear of severe weather and hurricane personal self-efficacy ratings were all statistically significant contributors to the likelihood of evacuating ahead of a hurricane. Psychological rootedness and attachment to one's home also tend to predict lack of evacuation. This research highlights the contributions that a psychological approach can offer in understanding preparations for severe weather. This approach also suggests that a great deal of individual variation exists in weather-protective behaviors, which may explain in part why some people take weather-related risks despite receiving warnings for severe weather.

Design of a complex virtual reality simulation to train finger motion for persons with hemiparesis: a proof of concept study.

PubMed

Adamovich, Sergei V; Fluet, Gerard G; Mathai, Abraham; Qiu, Qinyin; Lewis, Jeffrey; Merians, Alma S

2009-07-17

Current neuroscience has identified rehabilitation approaches with the potential to stimulate adaptive changes in the brains of persons with hemiparesis. These approaches include, intensive task-oriented training, bimanual activities and balancing proximal and distal upper extremity interventions to reduce competition between these segments for neural territory. This paper describes the design and feasibility testing of a robotic/virtual environment system designed to train the hand and arm of persons with hemiparesis. The system employs a simulated piano that presents visual, auditory and tactile feedback comparable to an actual piano. Arm tracking allows patients to train both the arm and hand as a coordinated unit, emphasizing the integration of both transport and manipulation phases. The piano trainer includes songs and scales that can be performed with one or both hands. Adaptable haptic assistance is available for more involved subjects. An algorithm adjusts task difficulty in proportion to subject performance. A proof of concept study was performed on four subjects with upper extremity hemiparesis secondary to chronic stroke to establish: a) the safety and feasibility of this system and b) the concurrent validity of robotically measured kinematic and performance measures to behavioral measures of upper extremity function. None of the subjects experienced adverse events or responses during or after training. As a group, the subjects improved in both performance time and key press accuracy. Three of the four subjects demonstrated improvements in fractionation, the ability to move each finger individually. Two subjects improved their aggregate time on the Jebsen Test of Hand Function and three of the four subjects improved in Wolf Motor Function Test aggregate time. The system designed in this paper has proven to be safe and feasible for the training of hand function for persons with hemiparesis. It features a flexible design that allows for the use and further study of adjustments in point of view, bilateral and unimanual treatment modes, adaptive training algorithms and haptically rendered collisions in the context of rehabilitation of the hemiparetic hand.

Design of a complex virtual reality simulation to train finger motion for persons with hemiparesis: a proof of concept study

PubMed Central

Adamovich, Sergei V; Fluet, Gerard G; Mathai, Abraham; Qiu, Qinyin; Lewis, Jeffrey; Merians, Alma S

2009-01-01

Background Current neuroscience has identified rehabilitation approaches with the potential to stimulate adaptive changes in the brains of persons with hemiparesis. These approaches include, intensive task-oriented training, bimanual activities and balancing proximal and distal upper extremity interventions to reduce competition between these segments for neural territory. Methods This paper describes the design and feasibility testing of a robotic/virtual environment system designed to train the hand and arm of persons with hemiparesis. The system employs a simulated piano that presents visual, auditory and tactile feedback comparable to an actual piano. Arm tracking allows patients to train both the arm and hand as a coordinated unit, emphasizing the integration of both transport and manipulation phases. The piano trainer includes songs and scales that can be performed with one or both hands. Adaptable haptic assistance is available for more involved subjects. An algorithm adjusts task difficulty in proportion to subject performance. A proof of concept study was performed on four subjects with upper extremity hemiparesis secondary to chronic stroke to establish: a) the safety and feasibility of this system and b) the concurrent validity of robotically measured kinematic and performance measures to behavioral measures of upper extremity function. Results None of the subjects experienced adverse events or responses during or after training. As a group, the subjects improved in both performance time and key press accuracy. Three of the four subjects demonstrated improvements in fractionation, the ability to move each finger individually. Two subjects improved their aggregate time on the Jebsen Test of Hand Function and three of the four subjects improved in Wolf Motor Function Test aggregate time. Conclusion The system designed in this paper has proven to be safe and feasible for the training of hand function for persons with hemiparesis. It features a flexible design that allows for the use and further study of adjustments in point of view, bilateral and unimanual treatment modes, adaptive training algorithms and haptically rendered collisions in the context of rehabilitation of the hemiparetic hand. PMID:19615045

Effect of a lateral step-up exercise protocol on quadriceps and lower extremity performance.

PubMed

Worrell, T W; Borchert, B; Erner, K; Fritz, J; Leerar, P

1993-12-01

Closed kinetic chain exercises have been promoted as more functional and more appropriate than open kinetic chain exercises. Limited research exists demonstrating the effect of closed kinetic chain exercise on quadriceps and lower extremity performance. The purpose of this study was to determine the effect of a lateral step-up exercise protocol on isokinetic quadriceps peak torque and the following lower extremity activities: 1) leg press, 2) maximal step-up repetitions with body weight plus 25%, 3) hop for distance, and 4) 6-m timed hop. Twenty subjects participated in a 4-week training period, and 18 subjects served as controls. For the experimental group, a repeated measure ANOVA comparing pretest and posttest values revealed significant improvements in the leg press (p < or = .05), step-ups (p < or = .05), hop for distance (p < or = .05), and hop for time (p < or = .05) and no significant increase in isokinetic quadriceps peak torque (p > or = .05). Over the course of the training period, weight used for the step-up exercise increased (p < or = .05), repetitions decreased (p < or = .05), and step-up work did not change (p > or = .05). For the control group, no significant change (p > or = .05) occurred in any variable. The inability of the isokinetic dynamometer to detect increases in quadriceps performance is important because the isokinetic values are frequently used as criteria for return to functional activities. We conclude that closed kinetic chain testing and exercise provide additional means to assess and rehabilitate the lower extremity.

Use of computer games as an intervention for stroke.

PubMed

Proffitt, Rachel M; Alankus, Gazihan; Kelleher, Caitlin L; Engsberg, Jack R

2011-01-01

Current rehabilitation for persons with hemiparesis after stroke requires high numbers of repetitions to be in accordance with contemporary motor learning principles. The motivational characteristics of computer games can be harnessed to create engaging interventions for persons with hemiparesis after stroke that incorporate this high number of repetitions. The purpose of this case report was to test the feasibility of using computer games as a 6-week home therapy intervention to improve upper extremity function for a person with stroke. One person with left upper extremity hemiparesis after stroke participated in a 6-week home therapy computer game intervention. The games were customized to her preferences and abilities and modified weekly. Her performance was tracked and analyzed. Data from pre-, mid-, and postintervention testing using standard upper extremity measures and the Reaching Performance Scale (RPS) were analyzed. After 3 weeks, the participant demonstrated increased upper extremity range of motion at the shoulder and decreased compensatory trunk movements during reaching tasks. After 6 weeks, she showed functional gains in activities of daily living (ADLs) and instrumental ADLs despite no further improvements on the RPS. Results indicate that computer games have the potential to be a useful intervention for people with stroke. Future work will add additional support to quantify the effectiveness of the games as a home therapy intervention for persons with stroke.

Normal and Extreme Wind Conditions for Power at Coastal Locations in China

PubMed Central

Gao, Meng; Ning, Jicai; Wu, Xiaoqing

2015-01-01

In this paper, the normal and extreme wind conditions for power at 12 coastal locations along China’s coastline were investigated. For this purpose, the daily meteorological data measured at the standard 10-m height above ground for periods of 40–62 years are statistically analyzed. The East Asian Monsoon that affects almost China’s entire coastal region is considered as the leading factor determining wind energy resources. For most stations, the mean wind speed is higher in winter and lower in summer. Meanwhile, the wind direction analysis indicates that the prevalent winds in summer are southerly, while those in winter are northerly. The air densities at different coastal locations differ significantly, resulting in the difference in wind power density. The Weibull and lognormal distributions are applied to fit the yearly wind speeds. The lognormal distribution performs better than the Weibull distribution at 8 coastal stations according to two judgement criteria, the Kolmogorov–Smirnov test and absolute error (AE). Regarding the annual maximum extreme wind speed, the generalized extreme value (GEV) distribution performs better than the commonly-used Gumbel distribution. At these southeastern coastal locations, strong winds usually occur in typhoon season. These 4 coastal provinces, that is, Guangdong, Fujian, Hainan, and Zhejiang, which have abundant wind resources, are also prone to typhoon disasters. PMID:26313256

Normal and Extreme Wind Conditions for Power at Coastal Locations in China.

PubMed

Gao, Meng; Ning, Jicai; Wu, Xiaoqing

2015-01-01

In this paper, the normal and extreme wind conditions for power at 12 coastal locations along China's coastline were investigated. For this purpose, the daily meteorological data measured at the standard 10-m height above ground for periods of 40-62 years are statistically analyzed. The East Asian Monsoon that affects almost China's entire coastal region is considered as the leading factor determining wind energy resources. For most stations, the mean wind speed is higher in winter and lower in summer. Meanwhile, the wind direction analysis indicates that the prevalent winds in summer are southerly, while those in winter are northerly. The air densities at different coastal locations differ significantly, resulting in the difference in wind power density. The Weibull and lognormal distributions are applied to fit the yearly wind speeds. The lognormal distribution performs better than the Weibull distribution at 8 coastal stations according to two judgement criteria, the Kolmogorov-Smirnov test and absolute error (AE). Regarding the annual maximum extreme wind speed, the generalized extreme value (GEV) distribution performs better than the commonly-used Gumbel distribution. At these southeastern coastal locations, strong winds usually occur in typhoon season. These 4 coastal provinces, that is, Guangdong, Fujian, Hainan, and Zhejiang, which have abundant wind resources, are also prone to typhoon disasters.

Effects of whole body vibration exercise on neuromuscular function for individuals with knee osteoarthritis: study protocol for a randomized controlled trial.

PubMed

Lai, Zhangqi; Wang, Xueqiang; Lee, Seullee; Hou, Xihe; Wang, Lin

2017-09-20

Knee osteoarthritis (KOA) is a leading cause of public disability. Neuromuscular function contributes to the development and/or progression of KOA. Whole body vibration (WBV) exercise improve the neuromuscular function of patients with neurological disorders and even that of older patients with limited exercise options. Therefore, WBV exercise may offer an efficient and alternative treatment for individuals with KOA. However, the effects of WBV training on the neuromuscular function of individuals with KOA remain unclear. Therefore, this study attempts to investigate the effect of a 12-week WBV exercise on the neuromuscular function of individuals with KOA. We will conduct a prospective, single-blind randomized controlled trial on 180 KOA patients. Participants will be randomly assigned to the WBV exercise, lower extremity resistance training, and health education groups. The WBV exercise group will participate in a 12-week WBV training. The lower extremity resistance training group will undergo a 12-week lower extremity resistance training of both lower limbs. The control group will receive health education for 12 weeks. After the intervention, the participants will be followed up for 3 months with no active intervention. Primary outcome measures will include anthropometric measurements, gait analysis during walking and stair climbing, muscle strength test of the knee and ankle, proprioception test of the knee and ankle, and neuromuscular response of the leg muscles. Secondary outcome measures will include self-reported pain and physical functional capacity, and physical performance measures. Furthermore, adverse events will be recorded and analyzed. If any participant withdraws from the trial, intention-to-treat analysis will be performed. Important features of this trial mainly include intervention setting, outcome measure selection, and study duration. This study is intended for estimating the effect of WBV intervention on neuromuscular control outcomes. Study results may provide evidence to support the beneficial effects of WBV exercise on the physical performance and neuromuscular control of individuals with KOA to fill the research gap on the efficacy of WBV. Chinese Clinical Trial Registry, ID: ChiCTR-IOR-16009234 . Registered on 21 September 2016.

Physical function in older men with hyperkyphosis.

PubMed

Katzman, Wendy B; Harrison, Stephanie L; Fink, Howard A; Marshall, Lynn M; Orwoll, Eric; Barrett-Connor, Elizabeth; Cawthon, Peggy M; Kado, Deborah M

2015-05-01

Age-related hyperkyphosis has been associated with poor physical function and is a well-established predictor of adverse health outcomes in older women, but its impact on health in older men is less well understood. We conducted a cross-sectional study to evaluate the association of hyperkyphosis and physical function in 2,363 men, aged 71-98 (M = 79) from the Osteoporotic Fractures in Men Study. Kyphosis was measured using the Rancho Bernardo Study block method. Measurements of grip strength and lower extremity function, including gait speed over 6 m, narrow walk (measure of dynamic balance), repeated chair stands ability and time, and lower extremity power (Nottingham Power Rig) were included separately as primary outcomes. We investigated associations of kyphosis and each outcome in age-adjusted and multivariable linear or logistic regression models, controlling for age, clinic, education, race, bone mineral density, height, weight, diabetes, and physical activity. In multivariate linear regression, we observed a dose-related response of worse scores on each lower extremity physical function test as number of blocks increased, p for trend ≤.001. Using a cutoff of ≥4 blocks, 20% (N = 469) of men were characterized with hyperkyphosis. In multivariate logistic regression, men with hyperkyphosis had increased odds (range 1.5-1.8) of being in the worst quartile of performing lower extremity physical function tasks (p < .001 for each outcome). Kyphosis was not associated with grip strength in any multivariate analysis. Hyperkyphosis is associated with impaired lower extremity physical function in older men. Further studies are needed to determine the direction of causality. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Electronics for Extreme Environments

NASA Astrophysics Data System (ADS)

Patel, J. U.; Cressler, J.; Li, Y.; Niu, G.

2001-01-01

Most of the NASA missions involve extreme environments comprising radiation and low or high temperatures. Current practice of providing friendly ambient operating environment to electronics costs considerable power and mass (for shielding). Immediate missions such as the Europa orbiter and lander and Mars landers require the electronics to perform reliably in extreme conditions during the most critical part of the mission. Some other missions planned in the future also involve substantial surface activity in terms of measurements, sample collection, penetration through ice and crust and the analysis of samples. Thus it is extremely critical to develop electronics that could reliably operate under extreme space environments. Silicon On Insulator (SOI) technology is an extremely attractive candidate for NASA's future low power and high speed electronic systems because it offers increased transconductance, decreased sub-threshold slope, reduced short channel effects, elimination of kink effect, enhanced low field mobility, and immunity from radiation induced latch-up. A common belief that semiconductor devices function better at low temperatures is generally true for bulk devices but it does not hold true for deep sub-micron SOI CMOS devices with microscopic device features of 0.25 micrometers and smaller. Various temperature sensitive device parameters and device characteristics have recently been reported in the literature. Behavior of state of the art technology devices under such conditions needs to be evaluated in order to determine possible modifications in the device design for better performance and survivability under extreme environments. Here, we present a unique approach of developing electronics for extreme environments to benefit future NASA missions as described above. This will also benefit other long transit/life time missions such as the solar sail and planetary outposts in which electronics is out open in the unshielded space at the ambient space temperatures and always exposed to radiation. Additional information is contained in the original extended abstract.

Leisure-time sport and overuse injuries of extremities in children age 6–13, a 2.5 years prospective cohort study: the CHAMPS-study DK

PubMed Central

Chéron, Charlène; Leboeuf-Yde, Charlotte; Le Scanff, Christine; Jespersen, Eva; Rexen, Christina Trifonov; Franz, Claudia; Wedderkopp, Niels

2017-01-01

Objectives It is not known which sports are most likely to cause overuse injuries of the extremities in children. In this study, we report on the incidence of overuse injuries of the upper and lower extremities in children who participate in various leisure-time sports and relate this to the frequency of sport sessions. Design Natural experiment including a prospective cohort study. Setting 10 state schools in 1 Danish municipality: Svendborg. Participants 1270 children aged 6–13 years participating in the Childhood Health, Activity, and Motor Performance School Study Denmark. Outcomes measures Over 2.5 years, parents answered weekly SMS-track messages (a) on type and frequency of leisure-time sports undertaken by their child, and (b) reporting if their child had experienced any musculoskeletal pain. Children with reported pain were examined by a clinician and diagnosed as having an overuse injury of an extremity or not. The incidence of diagnosed overuse injury was calculated for each of the 9 most common sports in relation to 5-week periods. Incidence by frequency of sessions was calculated, and multivariable analysis was performed taking into account age, sex and frequency of physical education classes at school. Results Incidence of overuse injuries of the lower extremity ranged from 0.2 to 3.3 for the 9 sports, but was near 0 for overuse injuries of the upper extremities. There was no obvious dose–response. The multivariate analysis showed soccer and handball to be the sports most likely to result in an overuse injury. Conclusions Among a general population of schoolchildren, overuse injuries of the lower extremities were not common and overuse injuries of the upper extremities were rare. Organised leisure-time sport, as practised in Denmark, can be considered a safe activity for children. PMID:28087543

Risk of Lower Extremity Injury in a Military Cadet Population After a Supervised Injury-Prevention Program

PubMed Central

Carow, Scott D.; Haniuk, Eric M.; Cameron, Kenneth L.; Padua, Darin A.; Marshall, Stephen W.; DiStefano, Lindsay J.; de la Motte, Sarah J.; Beutler, Anthony I.; Gerber, John P.

2016-01-01

Context: Specific movement patterns have been identified as possible risk factors for noncontact lower extremity injuries. The Dynamic Integrated Movement Enhancement (DIME) was developed to modify these movement patterns to decrease injury risk. Objective: To determine if the DIME is effective for preventing lower extremity injuries in US Military Academy (USMA) cadets. Design: Cluster-randomized controlled trial. Setting: Cadet Basic Training at USMA. Patients or Other Participants: Participants were 1313 cadets (1070 men, 243 women). Intervention(s): Participants were cluster randomized to 3 groups. The active warm-up (AWU) group performed standard Army warm-up exercises. The DIME groups were assigned to a DIME cadre-supervised (DCS) group or a DIME expert-supervised (DES) group; the former consisted of cadet supervision and the latter combined cadet and health professional supervision. Groups performed exercises 3 times weekly for 6 weeks. Main Outcome Measure(s): Cumulative risk of lower extremity injury was the primary outcome. We gathered data during Cadet Basic Training and for 9 months during the subsequent academic year. Risk ratios and 95% confidence intervals (CIs) were calculated to compare groups. Results: No differences were seen between the AWU and the combined DIME (DCS and DES) groups during Cadet Basic Training or the academic year. During the academic year, lower extremity injury risk in the DES group decreased 41% (relative risk [RR] = 0.59; 95% CI = 0.38, 0.93; P = .02) compared with the DCS group; a nonsignificant 25% (RR = 0.75; 95% CI = 0.49, 1.14; P = .18) decrease occurred in the DES group compared with the AWU group. Finally, there was a nonsignificant 27% (RR = 1.27; 95% CI = 0.90, 1.78; P = .17) increase in injury risk during the academic year in the DCS group compared with the AWU group. Conclusions: We observed no differences in lower extremity injury risk between the AWU and combined DIME groups. However, the magnitude and direction of the risk ratios in the DES group compared with the AWU group, although not statistically significant, indicate that professional supervision may be a factor in the success of injury-prevention programs. PMID:25117875

Factors Influencing Obstacle Crossing Performance in Patients with Parkinson's Disease

PubMed Central

Liao, Ying-Yi; Yang, Yea-Ru; Wu, Yih-Ru; Wang, Ray-Yau

2014-01-01

Background Tripping over obstacles is the major cause of falls in community-dwelling patients with Parkinson's disease (PD). Understanding the factors associated with the obstacle crossing behavior may help to develop possible training programs for crossing performance. This study aimed to identify the relationships and important factors determining obstacle crossing performance in patients with PD. Methods Forty-two idiopathic patients with PD (Hoehn and Yahr stages I to III) participated in this study. Obstacle crossing performance was recorded by the Liberty system, a three-dimensional motion capture device. Maximal isometric strength of the lower extremity was measured by a handheld dynamometer. Dynamic balance and sensory integration ability were assessed using the Balance Master system. Movement velocity (MV), maximal excursion (ME), and directional control (DC) were obtained during the limits of stability test to quantify dynamic balance. The sum of sensory organization test (SOT) scores was used to quantify sensory organization ability. Results Both crossing stride length and stride velocity correlated significantly with lower extremity muscle strength, dynamic balance control (forward and sideward), and sum of SOT scores. From the regression model, forward DC and ankle dorsiflexor strength were identified as two major determinants for crossing performance (R2 = .37 to.41 for the crossing stride length, R2 = .43 to.44 for the crossing stride velocity). Conclusions Lower extremity muscle strength, dynamic balance control and sensory integration ability significantly influence obstacle crossing performance. We suggest an emphasis on muscle strengthening exercises (especially ankle dorsiflexors), balance training (especially forward DC), and sensory integration training to improve obstacle crossing performance in patients with PD. PMID:24454723

Test-retest and interrater reliability of the functional lower extremity evaluation.

PubMed

Haitz, Karyn; Shultz, Rebecca; Hodgins, Melissa; Matheson, Gordon O

2014-12-01

Repeated-measures clinical measurement reliability study. To establish the reliability and face validity of the Functional Lower Extremity Evaluation (FLEE). The FLEE is a 45-minute battery of 8 standardized functional performance tests that measures 3 components of lower extremity function: control, power, and endurance. The reliability and normative values for the FLEE in healthy athletes are unknown. A face validity survey for the FLEE was sent to sports medicine personnel to evaluate the level of importance and frequency of clinical usage of each test included in the FLEE. The FLEE was then administered and rated for 40 uninjured athletes. To assess test-retest reliability, each athlete was tested twice, 1 week apart, by the same rater. To assess interrater reliability, 3 raters scored each athlete during 1 of the testing sessions. Intraclass correlation coefficients were used to assess the test-retest and interrater reliability of each of the FLEE tests. In the face validity survey, the FLEE tests were rated as highly important by 58% to 71% of respondents but frequently used by only 26% to 45% of respondents. Interrater reliability intraclass correlation coefficients ranged from 0.83 to 1.00, and test-retest reliability ranged from 0.71 to 0.95. The FLEE tests are considered clinically important for assessing lower extremity function by sports medicine personnel but are underused. The FLEE also is a reliable assessment tool. Future studies are required to determine if use of the FLEE to make return-to-play decisions may reduce reinjury rates.

Added Value of Physical Performance Measures in Predicting Adverse Health-Related Events: Results from the Health, Aging, and Body Composition Study

PubMed Central

Cesari, Matteo; Kritchevsky, Stephen B; Newman, Anne B; Simonsick, Eleanor M; Harris, Tamara B; Penninx, Brenda W; Brach, Jennifer S; Tylavsky, Frances A; Satterfield, Suzanne; Bauer, Doug C; Rubin, Susan M; Visser, Marjolein; Pahor, Marco

2009-01-01

Objectives To determine how three different physical performance measures (PPM) combine for added utility in predicting adverse health events in elders. Design Prospective cohort study. Setting Health, Aging, and Body Composition Study. Participants 3,024 well-functioning older persons (mean age 73.6 years). Measurements Timed gait, repeated chair stands and balance (semi- and full-tandem, and single leg stands each held for 30 seconds) tests were administered at baseline. Usual gait speed was categorized to distinguish high and low risk participants using the previously established 1 m/sec cut-point. The same population-percentile (21.3%) was used to identify cut-points for repeated chair stands (17.05 sec) and balance (53 sec) tests. Cox proportional hazard analyses were performed to evaluate the added value of PPM in predicting mortality, hospitalization, and (severe) mobility limitation events over 6.9 years of follow-up. Results Risk estimates for developing adverse health-related events were similarly large for each of the three high risk groups considered separately. A greater number of PPM scores at the high risk level was associated with a greater risk of developing adverse health-related events. When all three PPMs were considered, having only one poor performance was sufficient to indicate a highly significant higher risk of (severe) lower extremity and mortality events. Conclusion Although gait speed is considered the most important predictor of adverse health events, these findings demonstrate that poor performance on other tests of lower extremity function are equally prognostic. This suggests that chair stand and standing balance performance may be adequate substitutes when gait speed is unavailable. PMID:19207142

Fabrication of diamond based sensors for use in extreme environments

DOE PAGES

Samudrala, Gopi K.; Moore, Samuel L.; Vohra, Yogesh K.

2015-04-23

Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This methodmore » can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. Here, we demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.« less

Fabrication of diamond based sensors for use in extreme environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samudrala, Gopi K.; Moore, Samuel L.; Vohra, Yogesh K.

Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This methodmore » can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. Here, we demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.« less

Changes in seasonal streamflow extremes experienced in rivers of Northwestern South America (Colombia)

NASA Astrophysics Data System (ADS)

Pierini, J. O.; Restrepo, J. C.; Aguirre, J.; Bustamante, A. M.; Velásquez, G. J.

2017-04-01

A measure of the variability in seasonal extreme streamflow was estimated for the Colombian Caribbean coast, using monthly time series of freshwater discharge from ten watersheds. The aim was to detect modifications in the streamflow monthly distribution, seasonal trends, variance and extreme monthly values. A 20-year length time moving window, with 1-year successive shiftments, was applied to the monthly series to analyze the seasonal variability of streamflow. The seasonal-windowed data were statistically fitted through the Gamma distribution function. Scale and shape parameters were computed using the Maximum Likelihood Estimation (MLE) and the bootstrap method for 1000 resample. A trend analysis was performed for each windowed-serie, allowing to detect the window of maximum absolute values for trends. Significant temporal shifts in seasonal streamflow distribution and quantiles (QT), were obtained for different frequencies. Wet and dry extremes periods increased significantly in the last decades. Such increase did not occur simultaneously through the region. Some locations exhibited continuous increases only at minimum QT.

Winter storms drive rapid phenotypic, regulatory, and genomic shifts in the green anole lizard.

PubMed

Campbell-Staton, Shane C; Cheviron, Zachary A; Rochette, Nicholas; Catchen, Julian; Losos, Jonathan B; Edwards, Scott V

2017-08-04

Extreme environmental perturbations offer opportunities to observe the effects of natural selection in wild populations. During the winter of 2013-2014, the southeastern United States endured an extreme cold event. We used thermal performance, transcriptomics, and genome scans to measure responses of lizard populations to storm-induced selection. We found significant increases in cold tolerance at the species' southern limit. Gene expression in southern survivors shifted toward patterns characteristic of northern populations. Comparing samples before and after the extreme winter, 14 genomic regions were differentiated in the surviving southern population; four also exhibited signatures of local adaptation across the latitudinal gradient and implicate genes involved in nervous system function. Together, our results suggest that extreme winter events can rapidly produce strong selection on natural populations at multiple biological levels that recapitulate geographic patterns of local adaptation. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

DANCE, BALANCE AND CORE MUSCLE PERFORMANCE MEASURES ARE IMPROVED FOLLOWING A 9-WEEK CORE STABILIZATION TRAINING PROGRAM AMONG COMPETITIVE COLLEGIATE Dancers.

PubMed

Watson, Todd; Graning, Jessica; McPherson, Sue; Carter, Elizabeth; Edwards, Joshuah; Melcher, Isaac; Burgess, Taylor

2017-02-01

Dance performance requires not only lower extremity muscle strength and endurance, but also sufficient core stabilization during dynamic dance movements. While previous studies have identified a link between core muscle performance and lower extremity injury risk, what has not been determined is if an extended core stabilization training program will improve specific measures of dance performance. This study examined the impact of a nine-week core stabilization program on indices of dance performance, balance measures, and core muscle performance in competitive collegiate dancers. Within-subject repeated measures design. A convenience sample of 24 female collegiate dance team members (age = 19.7 ± 1.1 years, height = 164.3 ± 5.3 cm, weight 60.3 ± 6.2 kg, BMI = 22.5 ± 3.0) participated. The intervention consisted of a supervised and non-supervised core (trunk musculature) exercise training program designed specifically for dance team participants performed three days/week for nine weeks in addition to routine dance practice. Prior to the program implementation and following initial testing, transversus abdominis (TrA) activation training was completed using the abdominal draw-in maneuver (ADIM) including ultrasound imaging (USI) verification and instructor feedback. Paired t tests were conducted regarding the nine-week core stabilization program on dance performance and balance measures (pirouettes, single leg balance in passe' releve position, and star excursion balance test [SEBT]) and on tests of muscle performance. A repeated measures (RM) ANOVA examined four TrA instruction conditions of activation: resting baseline, self-selected activation, immediately following ADIM training and four days after completion of the core stabilization training program. Alpha was set at 0.05 for all analysis. Statistically significant improvements were seen on single leg balance in passe' releve and bilateral anterior reach for the SEBT (both p ≤ 0.01), number of pirouettes (p = 0.011), and all measures of strength (p ≤ 0.05) except single leg heel raise. The RM ANOVA on mean percentage of change in TrA was significant; post hoc paired t tests demonstrated significant improvements in dancers' TrA activations across the four instruction conditions. This core stabilization training program improves pirouette ability, balance (static and dynamic), and measures of muscle performance. Additionally, ADIM training resulted in immediate and short-term (nine-week) improvements in TrA activation in a functional dance position. 2b.

DANCE, BALANCE AND CORE MUSCLE PERFORMANCE MEASURES ARE IMPROVED FOLLOWING A 9-WEEK CORE STABILIZATION TRAINING PROGRAM AMONG COMPETITIVE COLLEGIATE Dancers

PubMed Central

Graning, Jessica; McPherson, Sue; Carter, Elizabeth; Edwards, Joshuah; Melcher, Isaac; Burgess, Taylor

2017-01-01

Background Dance performance requires not only lower extremity muscle strength and endurance, but also sufficient core stabilization during dynamic dance movements. While previous studies have identified a link between core muscle performance and lower extremity injury risk, what has not been determined is if an extended core stabilization training program will improve specific measures of dance performance. Hypothesis/Purpose This study examined the impact of a nine-week core stabilization program on indices of dance performance, balance measures, and core muscle performance in competitive collegiate dancers. Study Design Within-subject repeated measures design. Methods A convenience sample of 24 female collegiate dance team members (age = 19.7 ± 1.1 years, height = 164.3 ± 5.3 cm, weight 60.3 ± 6.2 kg, BMI = 22.5 ± 3.0) participated. The intervention consisted of a supervised and non-supervised core (trunk musculature) exercise training program designed specifically for dance team participants performed three days/week for nine weeks in addition to routine dance practice. Prior to the program implementation and following initial testing, transversus abdominis (TrA) activation training was completed using the abdominal draw-in maneuver (ADIM) including ultrasound imaging (USI) verification and instructor feedback. Paired t tests were conducted regarding the nine-week core stabilization program on dance performance and balance measures (pirouettes, single leg balance in passe’ releve position, and star excursion balance test [SEBT]) and on tests of muscle performance. A repeated measures (RM) ANOVA examined four TrA instruction conditions of activation: resting baseline, self-selected activation, immediately following ADIM training and four days after completion of the core stabilization training program. Alpha was set at 0.05 for all analysis. Results Statistically significant improvements were seen on single leg balance in passe’ releve and bilateral anterior reach for the SEBT (both p ≤ 0.01), number of pirouettes (p = 0.011), and all measures of strength (p ≤ 0.05) except single leg heel raise. The RM ANOVA on mean percentage of change in TrA was significant; post hoc paired t tests demonstrated significant improvements in dancers’ TrA activations across the four instruction conditions Conclusion This core stabilization training program improves pirouette ability, balance (static and dynamic), and measures of muscle performance. Additionally, ADIM training resulted in immediate and short-term (nine-week) improvements in TrA activation in a functional dance position. Level of Evidence 2b PMID:28217414

Lower- extremity biomechanics and maintenance of vertical-jump height during prolonged intermittent exercise.

PubMed

Schmitz, Randy J; Cone, John C; Copple, Timothy J; Henson, Robert A; Shultz, Sandra J

2014-11-01

Potential biomechanical compensations allowing for maintenance of maximal explosive performance during prolonged intermittent exercise, with respect to the corresponding rise in injury rates during the later stages of exercise or competition, are relatively unknown. To identify lower-extremity countermovement-jump (CMJ) biomechanical factors using a principal-components approach and then examine how these factors changed during a 90-min intermittent-exercise protocol (IEP) while maintaining maximal jump height. Mixed-model design. Laboratory. Fifty-nine intermittent-sport athletes (30 male, 29 female) participated in experimental and control conditions. Before and after a dynamic warm-up and every 15 min during the 1st and 2nd halves of an individually prescribed 90-min IEP, participants were assessed on rating of perceived exertion, sprint/cut speed, and 3-dimensional CMJ biomechanics (experimental). On a separate day, the same measures were obtained every 15 min during 90 min of quiet rest (control). Univariate piecewise growth models analyzed progressive changes in CMJ performance and biomechanical factors extracted from a principal-components analysis of the individual biomechanical dependent variables. While CMJ height was maintained during the 1st and 2nd halves, the body descended less and knee kinetic and energetic magnitudes decreased as the IEP progressed. The results indicate that vertical-jump performance is maintained along with progressive biomechanical changes commonly associated with decreased performance. A better understanding of lower-extremity biomechanics during explosive actions in response to IEP allows us to further develop and individualize performance training programs.

Construction of a ratiometric fluorescent probe with an extremely large emission shift for imaging hypochlorite in living cells

NASA Astrophysics Data System (ADS)

Song, Xuezhen; Dong, Baoli; Kong, Xiuqi; Wang, Chao; Zhang, Nan; Lin, Weiying

2018-01-01

Hypochlorite is one of the important reactive oxygen species (ROS) and plays critical roles in many biologically vital processes. Herein, we present a unique ratiometric fluorescent probe (CBP) with an extremely large emission shift for detecting hypochlorite in living cells. Utilizing positively charged α,β-unsaturated carbonyl group as the reaction site, the probe CBP itself exhibited near-infrared (NIR) fluorescence at 662 nm, and can display strong blue fluorescence at 456 nm when responded to hypochlorite. Notably, the extremely large emission shift of 206 nm could enable the precise measurement of the fluorescence peak intensities and ratios. CBP showed high sensitivity, excellent selectivity, desirable performance at physiological pH, and low cytotoxicity. The bioimaging experiments demonstrate the biological application of CBP for the ratiometric imaging of hypochlorite in living cells.

Calibration of a microchannel plate based extreme ultraviolet grazing incident spectrometer at the Advanced Light Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bakeman, M. S.; Lawrence Berkeley National Laboratory, Berkeley, California 94720; Tilborg, J. van

We present the design and calibration of a microchannel plate based extreme ultraviolet spectrometer. Calibration was performed at the Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL). This spectrometer will be used to record the single shot spectrum of radiation emitted by the tapered hybrid undulator (THUNDER) undulator installed at the LOASIS GeV-class laser-plasma-accelerator. The spectrometer uses an aberration-corrected concave grating with 1200 lines/mm covering 11-62 nm and a microchannel plate detector with a CsI coated photocathode for increased quantum efficiency in the extreme ultraviolet. A touch screen interface controls the grating angle, aperture size, and placementmore » of the detector in vacuum, allowing for high-resolution measurements over the entire spectral range.« less

Solar Probe Cup: Laboratory Performance

NASA Astrophysics Data System (ADS)

Case, A. W.; Kasper, J. C.; Korreck, K. E.; Stevens, M. L.; Larson, D. E.; Wright, K. H., Jr.; Gallagher, D. L.; Whittlesey, P. L.

2017-12-01

The Solar Probe Cup (SPC) is a Faraday Cup instrument that will fly on the Paker Solar Probe (PSP) spacecraft, orbiting the Sun at as close as 9.86 solar radii. The SPC instrument is designed to measure the thermal solar wind plasma (protons, alphas, and electrons) that will be encountered throughout its close encounter with the Sun. Due to the solar wind flow being primarily radial, the SPC instrument is pointed directly at the Sun, resulting in an extreme thermal environment that must be tolerated throughout the primary data collection phase. Laboratory testing has been performed over the past 6 months to demonstrate the instrument's performance relative to its requirements, and to characterize the measurements over the expected thermal range. This presentation will demonstrate the performance of the instrument as measured in the lab, describe the operational configurations planned for flight, and discuss the data products that will be created.

Rapid, high-resolution measurement of leaf area and leaf orientation using terrestrial LiDAR scanning data

USDA-ARS?s Scientific Manuscript database

The rapid evolution of high performance computing technology has allowed for the development of extremely detailed models of the urban and natural environment. Although models can now represent sub-meter-scale variability in environmental geometry, model users are often unable to specify the geometr...

The Dual Economy of Schooling and Teacher Morale in South Africa

ERIC Educational Resources Information Center

Shalem, Yael; Hoadley, Ursula

2009-01-01

Low teacher morale, coupled with extremely poor schooling outcomes for students as measured on standardized tests have increasingly been reported in the media in South Africa. As elsewhere, there is growing demand for the reorganisation of teachers' work in order to enhance school performance. The paper investigates the ways in which current…

Climate change vulnerability assessment in Georgia

Treesearch

Binita KC; J. Marshall Shepherd; Cassandra Johnson Gaither

2015-01-01

Climate change is occurring in the Southeastern United States, and one manifestation is changes in frequency and intensity of extreme events. A vulnerability assessment is performed in the state of Georgia (United States) at the county level from 1975 to 2012 in decadal increments. Climate change vulnerability is typically measured as a function of exposure to physical...

Gender Differences in Mathematical Achievement at the Norwegian Elementary-School Level.

ERIC Educational Resources Information Center

Manger, Terje

1995-01-01

The relationship between gender and mathematical achievement was investigated in 440 female and 480 male Norwegian third graders. Boys had higher test scores, but the effect size was small. Boys performed better in numeracy, mental arithmetic, and measurement problems. Marked gender differences were found at extreme tails of the distribution.…

Effects of robotic-aided rehabilitation on recovery of upper extremity function in chronic stroke: a single case study.

PubMed

Flinn, Nancy A; Smith, Jennifer L; Tripp, Christopher J; White, Matthew W

2009-01-01

The objective of the study was to examine the results of robotic therapy in a single client. A 48-year-old female client 15 months post-stroke, with right hemiparesis, received robotic therapy as an outpatient in a large Midwestern rehabilitation hospital. Robotic therapy was provided three times a week for 6 weeks. Robotic therapy consisted of goal-directed, robotic-aided reaching tasks to exercise the hemiparetic shoulder and elbow. No other therapeutic intervention for the affected upper extremity was provided during the study or 3 months follow-up period. The outcome measures included the Fugl-Meyer, graded Wolf motor function test (GWMFT), motor activity log, active range of motion and Canadian occupational performance measure. The participant made gains in active movement; performance; and satisfaction of functional tasks, GWMFT and functional use. Limitations involved in this study relate to the generalizability of the sample size, effect of medications, expense of robotic technologies and the impact of aphasia. Future research should incorporate functional use training along with robotic therapy.

Application of High Speed Digital Image Correlation in Rocket Engine Hot Fire Testing

NASA Technical Reports Server (NTRS)

Gradl, Paul R.; Schmidt, Tim

2016-01-01

Hot fire testing of rocket engine components and rocket engine systems is a critical aspect of the development process to understand performance, reliability and system interactions. Ground testing provides the opportunity for highly instrumented development testing to validate analytical model predictions and determine necessary design changes and process improvements. To properly obtain discrete measurements for model validation, instrumentation must survive in the highly dynamic and extreme temperature application of hot fire testing. Digital Image Correlation has been investigated and being evaluated as a technique to augment traditional instrumentation during component and engine testing providing further data for additional performance improvements and cost savings. The feasibility of digital image correlation techniques were demonstrated in subscale and full scale hotfire testing. This incorporated a pair of high speed cameras to measure three-dimensional, real-time displacements and strains installed and operated under the extreme environments present on the test stand. The development process, setup and calibrations, data collection, hotfire test data collection and post-test analysis and results are presented in this paper.

Selected Performance Measurements of the F-15 Active Axisymmetric Thrust-vectoring Nozzle

NASA Technical Reports Server (NTRS)

Orme, John S.; Sims, Robert L.

1998-01-01

Flight tests recently completed at the NASA Dryden Flight Research Center evaluated performance of a hydromechanically vectored axisymmetric nozzle onboard the F-15 ACTIVE. A flight-test technique whereby strain gages installed onto engine mounts provided for the direct measurement of thrust and vector forces has proven to be extremely valuable. Flow turning and thrust efficiency, as well as nozzle static pressure distributions were measured and analyzed. This report presents results from testing at an altitude of 30,000 ft and a speed of Mach 0.9. Flow turning and thrust efficiency were found to be significantly different than predicted, and moreover, varied substantially with power setting and pitch vector angle. Results of an in-flight comparison of the direct thrust measurement technique and an engine simulation fell within the expected uncertainty bands. Overall nozzle performance at this flight condition demonstrated the F100-PW-229 thrust-vectoring nozzles to be highly capable and efficient.

Selected Performance Measurements of the F-15 ACTIVE Axisymmetric Thrust-Vectoring Nozzle

NASA Technical Reports Server (NTRS)

Orme, John S.; Sims, Robert L.

1999-01-01

Flight tests recently completed at the NASA Dryden Flight Research Center evaluated performance of a hydromechanically vectored axisymmetric nozzle onboard the F-15 ACTIVE. A flight-test technique whereby strain gages installed onto engine mounts provided for the direct measurement of thrust and vector forces has proven to be extremely valuable. Flow turning and thrust efficiency, as well as nozzle static pressure distributions were measured and analyzed. This report presents results from testing at an altitude of 30,000 ft and a speed of Mach 0.9. Flow turning and thrust efficiency were found to be significantly different than predicted, and moreover, varied substantially with power setting and pitch vector angle. Results of an in-flight comparison of the direct thrust measurement technique and an engine simulation fell within the expected uncertainty bands. Overall nozzle performance at this flight condition demonstrated the F100-PW-229 thrust-vectoring nozzles to be highly capable and efficient.

Temperature extremes in Alaska: temporal variability and circulation background

NASA Astrophysics Data System (ADS)

Sulikowska, Agnieszka; Walawender, Jakub P.; Walawender, Ewelina

2018-06-01

The aims of this study are to characterize the spatial and temporal variability of extremely warm days (WDs) and warm spells (WSs) in summer as well as extremely cold days (CDs) and cold spells (CSs) in winter in Alaska in the years 1951-2015 and to determine the role of atmospheric circulation in their occurrence. The analysis is performed using daily temperature maxima (T MAX) and minima (T MIN) measured at 10 weather stations in Alaska as well as mean daily values of sea level pressure and wind direction at the 850 hPa isobaric level. WD (CD) is defined as a day with T MAX above the 95th (T MIN below the 5th) percentile of a probability density function calculated from observations, and WS (CS) equals at least three consecutive WDs (CDs). Frequency of the occurrence and severity of warm and cold extremes as well as duration of WSs and CSs is analyzed. In order to characterize synoptic conditions during temperature extremes, the objective classification scheme of advection types considering jointly the direction of the air influx and type of pressure system is employed. The results show that the general trend is towards the warmer temperatures, and the warming is greater in the winter than summer and for T MAX as opposed to T MIN. This is reflected in changes in the frequency of occurrence and intensity of temperature extremes which are much more pronounced in the case of winter cold extremes (decreasing tendencies) than summer warm extremes (increasing tendencies). The occurrence of temperature extremes is generally favored by anticyclonic weather with advection direction indicating air mass flows from the interior of the North American continent as well as the south (warm extremes in summer) and north (cold extremes in winter).

Game-Based Virtual Reality Canoe Paddling Training to Improve Postural Balance and Upper Extremity Function: A Preliminary Randomized Controlled Study of 30 Patients with Subacute Stroke

PubMed Central

Lee, Myung Mo; Lee, Kyeong Jin

2018-01-01

Background Virtual reality (VR) training with motion-controlled console games can be incorporated into stroke rehabilitation programs. The use of a variety of gaming software can provide the patient with an opportunity to perform activities that are exciting, entertaining, and that may not be feasible in clinical environments. The aim of this preliminary randomized controlled study was to investigate the effects of game-based VR canoe paddling training, when combined with conventional physical rehabilitation programs, on postural balance and upper extremity function in 30 patients with subacute stroke. Material/Methods Thirty patients, who were within six months following the diagnosis of stroke, were randomly allocated to either the experimental group (n=15) or the control group (n=15). All participants participated in a conventional rehabilitation program. Also, the experimental group (n=15) performed the VR canoe paddling training for 30 minutes each day, three times per week, for five weeks. After five weeks, outcomes of changes in postural balance and upper extremity function were evaluated and compared between the two groups. Results At five weeks, postural balance and upper extremity function showed significant improvements in both patients groups when compared with the baseline measurements (p<0.05). However, postural balance and upper extremity function were significantly improved in the experimental group when compared with the control group (p<0.05). Conclusions Game-based VR canoe paddling training is an effective rehabilitation therapy that enhances postural balance and upper extremity function in patients with subacute stroke when combined with conventional physical rehabilitation programs. PMID:29702630

Classifying Lower Extremity Muscle Fatigue during Walking using Machine Learning and Inertial Sensors

PubMed Central

Zhang, Jian; Lockhart, Thurmon E.; Soangra, Rahul

2013-01-01

Fatigue in lower extremity musculature is associated with decline in postural stability, motor performance and alters normal walking patterns in human subjects. Automated recognition of lower extremity muscle fatigue condition may be advantageous in early detection of fall and injury risks. Supervised machine learning methods such as Support Vector Machines (SVM) have been previously used for classifying healthy and pathological gait patterns and also for separating old and young gait patterns. In this study we explore the classification potential of SVM in recognition of gait patterns utilizing an inertial measurement unit associated with lower extremity muscular fatigue. Both kinematic and kinetic gait patterns of 17 participants (29±11 years) were recorded and analyzed in normal and fatigued state of walking. Lower extremities were fatigued by performance of a squatting exercise until the participants reached 60% of their baseline maximal voluntary exertion level. Feature selection methods were used to classify fatigue and no-fatigue conditions based on temporal and frequency information of the signals. Additionally, influences of three different kernel schemes (i.e., linear, polynomial, and radial basis function) were investigated for SVM classification. The results indicated that lower extremity muscle fatigue condition influenced gait and loading responses. In terms of the SVM classification results, an accuracy of 96% was reached in distinguishing the two gait patterns (fatigue and no-fatigue) within the same subject using the kinematic, time and frequency domain features. It is also found that linear kernel and RBF kernel were equally good to identify intra-individual fatigue characteristics. These results suggest that intra-subject fatigue classification using gait patterns from an inertial sensor holds considerable potential in identifying “at-risk” gait due to muscle fatigue. PMID:24081829

Neuromuscular training improves performance and lower-extremity biomechanics in female athletes.

PubMed

Myer, Gregory D; Ford, Kevin R; Palumbo, Joseph P; Hewett, Timothy E

2005-02-01

The purpose of this study was to examine the effects of a comprehensive neuromuscular training program on measures of performance and lower-extremity movement biomechanics in female athletes. The hypothesis was that significant improvements in measures of performance would be demonstrated concomitant with improved biomechanical measures related to anterior cruciate ligament injury risk. Forty-one female basketball, soccer, and volleyball players (age, 15.3 +/- 0.9 years; weight, 64.8 +/- 9.96 kg; height, 171.2 +/- 7.21 cm) underwent 6 weeks of training that included 4 main components (plyometric and movement, core strengthening and balance, resistance training, and speed training). Twelve age-, height-, and weight-matched controls underwent the same testing protocol twice 6 weeks apart. Trained athletes demonstrated increased predicted 1 repetition maximum squat (92%) and bench press (20%). Right and left single-leg hop distance increased 10.39 cm and 8.53 cm, respectively, and vertical jump also increased from 39.9 +/- 0.9 cm to 43.2 +/- 1.1 cm with training. Speed in a 9.1-m sprint improved from 1.80 +/- 0.02 seconds to 1.73 +/- 0.01 seconds. Pre- and posttest 3-dimensional motion analysis demonstrated increased knee flexion-extension range of motion during the landing phase of a vertical jump (right, 71.9 +/- 1.4 degrees to 76.9 +/- 1.4 degrees ; left, 71.3 +/- 1.5 degrees to 77.3 +/- 1.4 degrees ). Training decreased knee valgus (28%) and varus (38%) torques. Control subjects did not demonstrate significant alterations during the 6-week interval. The results of this study support the hypothesis that the combination of multiple-injury prevention-training components into a comprehensive program improves measures of performance and movement biomechanics.

Improved motor performance in chronic spinal cord injury following upper-limb robotic training.

PubMed

Cortes, Mar; Elder, Jessica; Rykman, Avrielle; Murray, Lynda; Avedissian, Manuel; Stampas, Argyrios; Thickbroom, Gary W; Pascual-Leone, Alvaro; Krebs, Hermano Igo; Valls-Sole, Josep; Edwards, Dylan J

2013-01-01

Recovering upper-limb motor function has important implications for improving independence of patients with tetraplegia after traumatic spinal cord injury (SCI). To evaluate the feasibility, safety and effectiveness of robotic-assisted training of upper limb in a chronic SCI population. A total of 10 chronic tetraplegic SCI patients (C4 to C6 level of injury, American Spinal Injury Association Impairment Scale, A to D) participated in a 6-week wrist-robot training protocol (1 hour/day 3 times/week). The following outcome measures were recorded at baseline and after the robotic training: a) motor performance, assessed by robot-measured kinematics, b) corticospinal excitability measured by transcranial magnetic stimulation (TMS), and c) changes in clinical scales: motor strength (Upper extremity motor score), pain level (Visual Analog Scale) and spasticity (Modified Ashworth scale). No adverse effects were observed during or after the robotic training. Statistically significant improvements were found in motor performance kinematics: aim (pre 1.17 ± 0.11 raduans, post 1.03 ± 0.08 raduans, p = 0.03) and smoothness of movement (pre 0.26 ± 0.03, post 0.31 ± 0.02, p = 0.03). These changes were not accompanied by changes in upper-extremity muscle strength or corticospinal excitability. No changes in pain or spasticity were found. Robotic-assisted training of the upper limb over six weeks is a feasible and safe intervention that can enhance movement kinematics without negatively affecting pain or spasticity in chronic SCI. In addition, robot-assisted devices are an excellent tool to quantify motor performance (kinematics) and can be used to sensitively measure changes after a given rehabilitative intervention.

Extreme learning machines: a new approach for modeling dissolved oxygen (DO) concentration with and without water quality variables as predictors.

PubMed

Heddam, Salim; Kisi, Ozgur

2017-07-01

In this paper, several extreme learning machine (ELM) models, including standard extreme learning machine with sigmoid activation function (S-ELM), extreme learning machine with radial basis activation function (R-ELM), online sequential extreme learning machine (OS-ELM), and optimally pruned extreme learning machine (OP-ELM), are newly applied for predicting dissolved oxygen concentration with and without water quality variables as predictors. Firstly, using data from eight United States Geological Survey (USGS) stations located in different rivers basins, USA, the S-ELM, R-ELM, OS-ELM, and OP-ELM were compared against the measured dissolved oxygen (DO) using four water quality variables, water temperature, specific conductance, turbidity, and pH, as predictors. For each station, we used data measured at an hourly time step for a period of 4 years. The dataset was divided into a training set (70%) and a validation set (30%). We selected several combinations of the water quality variables as inputs for each ELM model and six different scenarios were compared. Secondly, an attempt was made to predict DO concentration without water quality variables. To achieve this goal, we used the year numbers, 2008, 2009, etc., month numbers from (1) to (12), day numbers from (1) to (31) and hour numbers from (00:00) to (24:00) as predictors. Thirdly, the best ELM models were trained using validation dataset and tested with the training dataset. The performances of the four ELM models were evaluated using four statistical indices: the coefficient of correlation (R), the Nash-Sutcliffe efficiency (NSE), the root mean squared error (RMSE), and the mean absolute error (MAE). Results obtained from the eight stations indicated that: (i) the best results were obtained by the S-ELM, R-ELM, OS-ELM, and OP-ELM models having four water quality variables as predictors; (ii) out of eight stations, the OP-ELM performed better than the other three ELM models at seven stations while the R-ELM performed the best at one station. The OS-ELM models performed the worst and provided the lowest accuracy; (iii) for predicting DO without water quality variables, the R-ELM performed the best at seven stations followed by the S-ELM in the second place and the OP-ELM performed the worst with low accuracy; (iv) for the final application where training ELM models with validation dataset and testing with training dataset, the OP-ELM provided the best accuracy using water quality variables and the R-ELM performed the best at all eight stations without water quality variables. Fourthly, and finally, we compared the results obtained from different ELM models with those obtained using multiple linear regression (MLR) and multilayer perceptron neural network (MLPNN). Results obtained using MLPNN and MLR models reveal that: (i) using water quality variables as predictors, the MLR performed the worst and provided the lowest accuracy in all stations; (ii) MLPNN was ranked in the second place at two stations, in the third place at four stations, and finally, in the fourth place at two stations, (iii) for predicting DO without water quality variables, MLPNN is ranked in the second place at five stations, and ranked in the third, fourth, and fifth places in the remaining three stations, while MLR was ranked in the last place with very low accuracy at all stations. Overall, the results suggest that the ELM is more effective than the MLPNN and MLR for modelling DO concentration in river ecosystems.

A comparison between measured surface microtopography and observed scattering in the extreme ultraviolet

NASA Technical Reports Server (NTRS)

Green, James; Jelinsky, Sharon; Bowyer, Stuart; Malina, Roger F.

1988-01-01

The paper presents comparative measurements of surface roughness on prepared samples. These measurements have been made with both Talystep profilometers and WYKO interferometers. In addition, the scattering distribution from these samples was measured at extreme ultraviolet wavelengths. The utility of the WYKO interferometer and Talystep device for specifying extreme ultraviolet mirror surface quality is discussed.

Acoustic properties and density of polyurea at pressure up to 13.5 GPa through Brillouin scattering spectroscopy

NASA Astrophysics Data System (ADS)

Ransom, T. C.; Ahart, Muhtar; Hemley, Russell J.; Roland, C. M.

2018-05-01

Brillouin scattering was performed on an elastomeric polyurea, an important technological polymer. Being widely used for impact modification, of particular interest is its response to extreme pressure conditions. We applied pressures up to 13.5 GPa using a diamond anvil cell and measured the longitudinal and transverse sound velocities via Brillouin light scattering. From these data, the equation of state, the elastic moduli, and Poisson's ratio were obtained. By comparison with previous dilatometry measurements up to 1 GPa, we show how viscoelastic effects can be accounted for in order to obtain an accurate equation of state. Because of the extreme strain-rate hardening of vitrifying polyurea, the property changes associated with its solidification are more subtle in the high frequency Brillouin data than observed in conventional mechanical testing and dilatometry.

The influences of obesity and age on functional performance during intermittent upper extremity tasks.

PubMed

Cavuoto, Lora A; Nussbaum, Maury A

2014-01-01

In this study, the main and interactive effects of obesity and age on functional performance were assessed during intermittent exertions involving the upper extremity. The prevalence of obesity has doubled over the past 30 years and this increase is associated with higher health care costs, rates of workplace injury, and lost workdays. Obesity and aging can modify job demands and affect worker capacity in terms of muscular and psychomotor function. However, there is a lack of empirical studies quantifying the work-relevant (or ergonomic) impacts related to task demands, capacities, and their potential imbalance. Eight obese and eight non-obese participants from each of two age groups (18-25 and 50-65 years) completed three endurance tasks involving fixed levels of task demands: hand grip, shoulder flexion, and a simulated assembly task using the upper extremity. Measures of functional performance including endurance, discomfort, motor control, and task performance were recorded for each of the task conditions. Endurance times were ∼60% longer for the non-obese group, and older participants had longer endurance times; however there was no evidence of interactive effects of obesity and age. Obesity also impaired functional performance, as indicated by higher rates of strength loss, increases in discomfort, and declines in task performance. These observed impairments may reflect underlying physiological differences among individuals who are obese, but that are independent of age. Obesity-related impairments may have implications for the design of work duration and demand level to prevent fatigue development for workers who are obese.

Within-summer variation in out-of-hospital cardiac arrest due to extremely long sunshine duration.

PubMed

Onozuka, Daisuke; Hagihara, Akihito

2017-03-15

Although several studies have reported the impacts of extremely high temperatures on cardiovascular diseases, no studies have examined whether variation in out-of-hospital cardiac arrest (OHCA) due to extremely long sunshine duration changes during the summer. We obtained daily data on all cases of OHCA and weather variations for all 47 prefectures of Japan during the summer (June to September) between 2005 and 2014. A distributed lag non-linear model combined with a quasi-Poisson regression model was used to estimate within-summer variation in OHCA due to extremely long sunshine duration for each prefecture. Then, multivariate random-effects meta-analysis was performed to derive overall effect estimates of sunshine duration at the national level. A total of 166,496 OHCAs of presumed cardiac origin met the inclusion criteria. The minimum morbidity percentile (MMP) was the 0th percentile of sunshine duration at the national level. The overall cumulative relative risk (RR) at the 99th percentile vs. the MMP was 1.15 (95% CI: 1.05-1.27) during the summer. The effect of extremely long sunshine duration on OHCA in early summer was acute and did not persist, whereas an identical effect was observed in late summer, but it was delayed and lasted for several days. During summer periods, excessive sunshine duration could increase the risk of OHCA. Timely preventive measures to reduce the OHCA risk due to extremely long sunshine duration are important in early summer, whereas these measures could include a wider time window of several days to reduce the risk in late summer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Monitoring Changes of Tropical Extreme Rainfall Events Using Differential Absorption Barometric Radar (DiBAR)

NASA Technical Reports Server (NTRS)

Lin, Bing; Harrah, Steven; Lawrence, R. Wes; Hu, Yongxiang; Min, Qilong

2015-01-01

This work studies the potential of monitoring changes in tropical extreme rainfall events such as tropical storms from space using a Differential-absorption BArometric Radar (DiBAR) operating at 50-55 gigahertz O2 absorption band to remotely measure sea surface air pressure. Air pressure is among the most important variables that affect atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Analyses show that with the proposed radar the errors in instantaneous (averaged) pressure estimates can be as low as approximately 5 millibars (approximately 1 millibar) under all weather conditions. With these sea level pressure measurements, the forecasts, analyses and understanding of these extreme events in both short and long time scales can be improved. Severe weathers, especially hurricanes, are listed as one of core areas that need improved observations and predictions in WCRP (World Climate Research Program) and NASA Decadal Survey (DS) and have major impacts on public safety and national security through disaster mitigation. Since the development of the DiBAR concept about a decade ago, our team has made substantial progress in advancing the concept. Our feasibility assessment clearly shows the potential of sea surface barometry using existing radar technologies. We have developed a DiBAR system design, fabricated a Prototype-DiBAR (P-DiBAR) for proof-of-concept, conducted lab, ground and airborne P-DiBAR tests. The flight test results are consistent with our instrumentation goals. Observational system simulation experiments for space DiBAR performance show substantial improvements in tropical storm predictions, not only for the hurricane track and position but also for the hurricane intensity. DiBAR measurements will lead us to an unprecedented level of the prediction and knowledge on tropical extreme rainfall weather and climate conditions.

Monitoring Cellular Events in Living Mast Cells Stimulated with an Extremely Small Amount of Fluid on a Microchip

NASA Astrophysics Data System (ADS)

Munaka, Tatsuya; Abe, Hirohisa; Kanai, Masaki; Sakamoto, Takashi; Nakanishi, Hiroaki; Yamaoka, Tetsuji; Shoji, Shuichi; Murakami, Akira

2006-07-01

We successfully developed a measurement system for real-time analysis of cellular function using a newly designed microchip. This microchip was equipped with a micro cell incubation chamber (240 nl) and was stimulated by a very small amount of stimuli (as small as 24 nl). Using the microchip system, cultivation of mast cells was successfully carried out. Monitoring of the cellular events after stimulation with an extremely small amount of fluid on a microchip was performed. This system could be applicable for various types of cellular analysis including real-time monitoring of cellular response by stimulation.

75 FR 2796 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-19

... noted that the limit for baked extreme performance coatings in the rule is less stringent than the limit... the VOC limit for baked extreme performance coatings and the exemption for repair and touch-up operations. As to the emission limit for baked extreme performance coatings, the VOC limit in Rule 4603 is...

Time-of-flight Extreme Environment Diffractometer at the Helmholtz-Zentrum Berlin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prokhnenko, Oleksandr, E-mail: prokhnenko@helmholtz-berlin.de; Stein, Wolf-Dieter; Bleif, Hans-Jürgen

2015-03-15

The Extreme Environment Diffractometer (EXED) is a new neutron time-of-flight instrument at the BER II research reactor at the Helmholtz-Zentrum Berlin, Germany. Although EXED is a special-purpose instrument, its early construction made it available for users as a general-purpose diffractometer. In this respect, EXED became one of the rare examples, where the performance of a time-of-flight diffractometer at a continuous source can be characterized. In this paper, we report on the design and performance of EXED with an emphasis on the unique instrument capabilities. The latter comprise variable wavelength resolution and wavelength band, control of the incoming beam divergence, themore » possibility to change the angular positions of detectors and their distance to the sample, and use of event recording and offline histogramming. These features combined make EXED easily tunable to the requirements of a particular problem, from conventional diffraction to small angle neutron scattering. The instrument performance is demonstrated by several reference measurements and user experiments.« less

Real-time turbulence profiling with a pair of laser guide star Shack-Hartmann wavefront sensors for wide-field adaptive optics systems on large to extremely large telescopes.

PubMed

Gilles, L; Ellerbroek, B L

2010-11-01

Real-time turbulence profiling is necessary to tune tomographic wavefront reconstruction algorithms for wide-field adaptive optics (AO) systems on large to extremely large telescopes, and to perform a variety of image post-processing tasks involving point-spread function reconstruction. This paper describes a computationally efficient and accurate numerical technique inspired by the slope detection and ranging (SLODAR) method to perform this task in real time from properly selected Shack-Hartmann wavefront sensor measurements accumulated over a few hundred frames from a pair of laser guide stars, thus eliminating the need for an additional instrument. The algorithm is introduced, followed by a theoretical influence function analysis illustrating its impulse response to high-resolution turbulence profiles. Finally, its performance is assessed in the context of the Thirty Meter Telescope multi-conjugate adaptive optics system via end-to-end wave optics Monte Carlo simulations.

Combining agreement and frequency rating scales to optimize psychometrics in measuring behavioral health functioning.

PubMed

Marfeo, Elizabeth E; Ni, Pengsheng; Chan, Leighton; Rasch, Elizabeth K; Jette, Alan M

2014-07-01

The goal of this article was to investigate optimal functioning of using frequency vs. agreement rating scales in two subdomains of the newly developed Work Disability Functional Assessment Battery: the Mood & Emotions and Behavioral Control scales. A psychometric study comparing rating scale performance embedded in a cross-sectional survey used for developing a new instrument to measure behavioral health functioning among adults applying for disability benefits in the United States was performed. Within the sample of 1,017 respondents, the range of response category endorsement was similar for both frequency and agreement item types for both scales. There were fewer missing values in the frequency items than the agreement items. Both frequency and agreement items showed acceptable reliability. The frequency items demonstrated optimal effectiveness around the mean ± 1-2 standard deviation score range; the agreement items performed better at the extreme score ranges. Findings suggest an optimal response format requires a mix of both agreement-based and frequency-based items. Frequency items perform better in the normal range of responses, capturing specific behaviors, reactions, or situations that may elicit a specific response. Agreement items do better for those whose scores are more extreme and capture subjective content related to general attitudes, behaviors, or feelings of work-related behavioral health functioning. Copyright © 2014 Elsevier Inc. All rights reserved.

Validity and interobserver agreement of lower extremity local tissue water measurements in healthy women using tissue dielectric constant.

PubMed

Jensen, Mads R; Birkballe, Susanne; Nørregaard, Susan; Karlsmark, Tonny

2012-07-01

Tissue dielectric constant (TDC) measurement may become an important tool in the clinical evaluation of chronic lower extremity swelling in women; however, several factors are known to influence TDC measurements, and comparative data on healthy lower extremities are few. Thirty-four healthy women volunteered. Age, BMI, moisturizer use and hair removal were registered. Three blinded investigators performed TDC measurements in a randomized sequence on clearly marked locations on the foot, the ankle and the lower leg. The effective measuring depth was 2.5 mm. The mean TDC was 37.8 ± 5.5 (mean ± SD) on the foot, 29.0 ± 3.1 on the ankle and 30.5 ± 3.9 on the lower leg. TDC was highly dependent on measuring site (P<0.001) but did not vary significantly between investigators (P=0.127). Neither age, BMI, hair removal nor moisturizer use had any significant effect on the lower leg TDC. Intraclass correlation coefficients were 0.77 for the foot, 0.94 for the ankle and 0.94 for the lower leg. The TDC on the foot was significantly higher compared with ankle and lower leg values. Foot measurements should be interpreted cautiously because of questionable interobserver agreement. The interobserver agreement was high on lower leg and ankle measurements. Neither age, BMI, hair removal nor moisturizer use had any significant on effect on the lower leg TDC. TDC values of 35.2 for the ankle and 38.3 for the lower leg are suggested as upper normal reference limits in women. © 2012 The Authors Clinical Physiology and Functional Imaging © 2012 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Novel Sensor Technology To Assess Independence and Limb-Use Laterality in Cervical Spinal Cord Injury.

PubMed

Brogioli, Michael; Popp, Werner L; Albisser, Urs; Brust, Anne K; Frotzler, Angela; Gassert, Roger; Curt, Armin; Starkey, Michelle L

2016-11-01

After spinal cord injury (SCI), levels of independence are commonly assessed with standardized clinical assessments. However, such tests do not provide information about the actual extent of upper limb activities or the impact on independence of bi- versus unilateral usage throughout daily life following cervical SCI. The objective of this study was to correlate activity intensity and laterality of upper extremity activity measured by body-fixed inertial measurement units (IMUs) with clinical assessment scores of independence. Limb-use intensity and laterality of activities performed by the upper extremities was measured in 12 subjects with cervical SCI using four IMUs (positioned on both wrists, on the chest, and on one wheel of the wheelchair). Algorithms capable of reliably detecting self-propulsion and arm activity in a clinical environment were applied to rate functional outcome levels, and were related to clinical independence measures during inpatient rehabilitation. Measures of intensity of upper extremity activity during self-propulsion positively correlated (p < 0.05, r = 0.643) with independence measures related to mobility. Clinical measures of laterality were positively correlated (p < 0.01, r = 0.900) with laterality as measured by IMUs during "daily life," and increased laterality was negatively correlated (p < 0.01, r = -0.739) with independence. IMU sensor technology is sensitive in assessing and quantifying upper limb-use intensity and laterality in human cervical SCI. Continuous and objective movement data of distinct daily activities (i.e., mobility and day-to-day activities) can be related to levels of independence. Therefore, IMU sensor technology is suitable not only for monitoring activity levels during rehabilitation (including during clinical trials) but could also be used to assess levels of participation after discharge.

Serratia marcescens meningitis following spinal anaesthesia and arthroscopy.

PubMed

Hadzic, Amir; Koluder-Cimic, Nada; Hadzovic-Cengic, Meliha; Gojak, Refet; Gavrankapetanovic, Ismet; Becirbegovic, Semin

2012-01-01

We present case of nosocomial bacterial meningitis, caused by Serratia marcescens (ESBL), occurred following spinal anaesthesia. Although very rare bacterial meningitis is serious complication of spinal anaesthesia and early diagnosis as well as effective treatment is extremely important. Previously healthy individual, admitted to Orthopaedic Department for routine arthroscopy, approximately within 24 hours after operation was performed complained of headache and fever. Infectious Diseases physician was consulted, lumbar puncture was performed and purulent meningitis was confirmed. Cerebrospinal fluid and blood cultures of patient confirmed Serratia marcescens (ESBL), resistant pathogen and important nosocomial agent. Patient was successfully treated. Cases of spinal meningitis caused by Serratia marcescens are rare. Local resistance pattern is important and should be always considered when starting therapy. Infection control team was appointed because of similar case of meningitis one month before in the same Department, and after investigation discovered Serratia in anaesthetic vial used in procedures. New measures and recommendations regarding infection control were implemented at Orthopaedic Department. Meningitis as a complication should always be considered as a possible differential diagnosis with patients after spinal anaesthesia complaining on headache and fever. Early diagnosis and early treatment is extremely important. Knowledge and practice of infection control measures is mandatory and should be always emphasized to performing staff.

Efficient universal blind quantum computation.

PubMed

Giovannetti, Vittorio; Maccone, Lorenzo; Morimae, Tomoyuki; Rudolph, Terry G

2013-12-06

We give a cheat sensitive protocol for blind universal quantum computation that is efficient in terms of computational and communication resources: it allows one party to perform an arbitrary computation on a second party's quantum computer without revealing either which computation is performed, or its input and output. The first party's computational capabilities can be extremely limited: she must only be able to create and measure single-qubit superposition states. The second party is not required to use measurement-based quantum computation. The protocol requires the (optimal) exchange of O(Jlog2(N)) single-qubit states, where J is the computational depth and N is the number of qubits needed for the computation.

The effects of gas mixtures on ion engine erosion and performance

NASA Technical Reports Server (NTRS)

Garner, Charles E.; Brophy, John R.; Aston, Graeme

1987-01-01

Erosion measurements were performed on a modified J-series 30 cm ion engine operating on xenon propellant. Erosion data was obtained by measuring the trench depth etched into masked polished metal samples for test durations of up to 24 hours. The data indicates that erosion is greatest at the cathode side of the baffle, with tantalum being the material with the least erosion of all materials tested. There is a clear indication of a significant reduction in erosion of all materials tested when nitrogen is added to the propellant. The technique used in these experiments requires test samples which are extremely smooth and flat.

PRESEASON JUMP AND HOP MEASURES IN MALE COLLEGIATE BASKETBALL PLAYERS: AN EPIDEMIOLOGIC REPORT.

PubMed

Brumitt, Jason; Engilis, Amy; Isaak, Dale; Briggs, Amy; Mattocks, Alma

2016-12-01

Injuries are inherent in basketball with lower extremity (LE) injury rates reported as high as 11.6 per 1000 athletic exposures (AEs); many of these injuries result in time loss from sport participation. A recent trend in sports medicine research has been the attempt to identify athletes who may be at risk for injury based on measures of preseason fitness. The purpose of this prospective cohort study was to determine if the standing long jump (SLJ) and/or the single-leg hop (SLH) for distance functional performance tests (FPT) are associated with non-contact time loss lower quadrant (LQ, defined as lower extremities or low back) injury in collegiate male basketball players. It was hypothesized that basketball players with shorter SLJ or SLH measures would be at an increased risk for LQ injury. Seventy-one male collegiate basketball players from five teams completed a demographic questionnaire and performed three SLJ and six SLH (three per lower extremity) tests. Team athletic trainers tracked non-contact LQ time loss injuries during the season. Prospective cohort. Mean SLJ distance (normalized to height) was 0.99 (± 0.11) and mean SLH distances for the right and left were 0.85 ± 0.11 and 0.87 ± 0.10, respectively. A total of 29 (18 initial, 11 subsequent) non-contact time loss LQ injuries occurred during the study. At risk athletes (e.g., those with shorter SLJ and/or SLH) were no more likely to experience a non-contact time loss injury than their counterparts [OR associated with each FPT below cut scores = 0.9 (95% CI: 0.2, 4.9)]. The results from this study indicate that preseason performance of the SLJ and the SLH were not associated with future risk of LQ injury in this population. Preseason SLJ and SLH measures were not associated with non-contact time loss injuries in male collegiate basketball players. However, the descriptive data presented in this study can help sports medicine professionals evaluate athletic readiness prior to discharging an athlete back to sport after a LQ injury. 2.

Materials Properties and Solvated Electron Dynamics of Isolated Nanoparticles and Nanodroplets Probed with Ultrafast Extreme Ultraviolet Beams.

PubMed

Ellis, Jennifer L; Hickstein, Daniel D; Xiong, Wei; Dollar, Franklin; Palm, Brett B; Keister, K Ellen; Dorney, Kevin M; Ding, Chengyuan; Fan, Tingting; Wilker, Molly B; Schnitzenbaumer, Kyle J; Dukovic, Gordana; Jimenez, Jose L; Kapteyn, Henry C; Murnane, Margaret M

2016-02-18

We present ultrafast photoemission measurements of isolated nanoparticles in vacuum using extreme ultraviolet (EUV) light produced through high harmonic generation. Surface-selective static EUV photoemission measurements were performed on nanoparticles with a wide array of compositions, ranging from ionic crystals to nanodroplets of organic material. We find that the total photoelectron yield varies greatly with nanoparticle composition and provides insight into material properties such as the electron mean free path and effective mass. Additionally, we conduct time-resolved photoelectron yield measurements of isolated oleylamine nanodroplets, observing that EUV photons can create solvated electrons in liquid nanodroplets. Using photoemission from a time-delayed 790 nm pulse, we observe that a solvated electron is produced in an excited state and subsequently relaxes to its ground state with a lifetime of 151 ± 31 fs. This work demonstrates that femotosecond EUV photoemission is a versatile surface-sensitive probe of the properties and ultrafast dynamics of isolated nanoparticles.

Smartphone assessment of knee flexion compared to radiographic standards.

PubMed

Dietz, Matthew J; Sprando, Daniel; Hanselman, Andrew E; Regier, Michael D; Frye, Benjamin M

2017-03-01

Measuring knee range of motion (ROM) is an important assessment for the outcomes of total knee arthroplasty. Recent technological advances have led to the development and use of accelerometer-based smartphone applications to measure knee ROM. The purpose of this study was to develop, standardize, and validate methods of utilizing smartphone accelerometer technology compared to radiographic standards, visual estimation, and goniometric evaluation. Participants used visual estimation, a long-arm goniometer, and a smartphone accelerometer to determine range of motion of a cadaveric lower extremity; these results were compared to radiographs taken at the same angles. The optimal smartphone position was determined to be on top of the leg at the distal femur and proximal tibia location. Between methods, it was found that the smartphone and goniometer were comparably reliable in measuring knee flexion (ICC=0.94; 95% CI: 0.91-0.96). Visual estimation was found to be the least reliable method of measurement. The results suggested that the smartphone accelerometer was non-inferior when compared to the other measurement techniques, demonstrated similar deviations from radiographic standards, and did not appear to be influenced by the person performing the measurements or the girth of the extremity. Copyright © 2016 Elsevier B.V. All rights reserved.

Smartphone Assessment of Knee Flexion Compared to Radiographic Standards

PubMed Central

Dietz, Matthew J.; Sprando, Daniel; Hanselman, Andrew E.; Regier, Michael D.; Frye, Benjamin M.

2017-01-01

Purpose Measuring knee range of motion (ROM) is an important assessment for the outcomes of total knee arthroplasty. Recent technological advances have led to the development and use of accelerometer-based smartphone applications to measure knee ROM. The purpose of this study was to develop, standardize, and validate methods of utilizing smartphone accelerometer technology compared to radiographic standards, visual estimation, and goniometric evaluation. Methods Participants used visual estimation, a long-arm goniometer, and a smartphone accelerometer to determine range of motion of a cadaveric lower extremity; these results were compared to radiographs taken at the same angles. Results The optimal smartphone position was determined to be on top of the leg at the distal femur and proximal tibia location. Between methods, it was found that the smartphone and goniometer were comparably reliable in measuring knee flexion (ICC = 0.94; 95% CI: 0.91–0.96). Visual estimation was found to be the least reliable method of measurement. Conclusions The results suggested that the smartphone accelerometer was non-inferior when compared to the other measurement techniques, demonstrated similar deviations from radiographic standards, and did not appear to be influenced by the person performing the measurements or the girth of the extremity. PMID:28179062

Neural predictors of evaluative attitudes toward celebrities

PubMed Central

Shibata, Kazuhisa; Matsumoto, Kenji; Adolphs, Ralph

2017-01-01

Abstract Our attitudes toward others influence a wide range of everyday behaviors and have been the most extensively studied concept in the history of social psychology. Yet they remain difficult to measure reliably and objectively, since both explicit and implicit measures are typically confounded by other psychological processes. We here address the feasibility of decoding incidental attitudes based on brain activations. Participants were presented with pictures of members of a Japanese idol group inside an functional magnetic resonance imaging scanner while performing an unrelated detection task, and subsequently (outside the scanner) performed an incentive-compatible choice task that revealed their attitude toward each celebrity. We used a real-world election scheme that exists for this idol group, which confirmed both strongly negative and strongly positive attitudes toward specific individuals. Whole-brain multivariate analyses (searchlight-based support vector regression) showed that activation patterns in the anterior striatum predicted each participant’s revealed attitudes (choice behavior) using leave-one-out (as well as 4-fold) cross-validation across participants. In contrast, attitude extremity (unsigned magnitude) could be decoded from a distinct region in the posterior striatum. The findings demonstrate dissociable striatal representations of valenced attitude and attitude extremity and constitute a first step toward an objective and process-pure neural measure of attitudes. PMID:27651542

Crystallized verbal skills in schizophrenia: relationship to neurocognition, symptoms, and functional status.

PubMed

Kurtz, Matthew M; Donato, Jad; Rose, Jennifer

2011-11-01

To study the relationship of superior (i.e., ≥ 90th percentile), average (11th-89th percentile) or extremely low (i.e., ≤ 10th percentile) crystallized verbal skills to neurocognitive profiles, symptoms and everyday life function in schizophrenia. Crystallized verbal skill was derived from Vocabulary subtest scores from the Wechsler Adult Intelligence Scale (WAIS). Out of a sample of 165 stable outpatients with schizophrenia we identified 25 participants with superior crystallized verbal skill, 104 participants with average verbal skill, and 36 participants with extremely low crystallized verbal skill. Each participant was administered measures of attention, working memory, verbal learning and memory, problem-solving and processing speed, as well as symptom and performance-based adaptive life skill assessments. The magnitude of neuropsychological impairment across the three groups was different, after adjusting for group differences in education and duration of illness. Working memory, and verbal learning and memory skills were different across all three groups, while processing speed differentiated the extremely low verbal skill group from the other two groups and problem-solving differentiated the very low verbal skill group from the superior verbal skill group. There were no group differences in sustained attention. Capacity measures of everyday life skills were different across each of the three groups. Crystallized verbal skill in schizophrenia is related to the magnitude of impairment in neurocognitive function and performance-based skills in everyday life function. Patterns of neuropsychological impairment were similar across different levels of crystallized verbal skill.

Robots integrated with virtual reality simulations for customized motor training in a person with upper extremity hemiparesis: a case report

PubMed Central

Fluet, Gerard G.; Merians, Alma S.; Qiu, Qinyin; Lafond, Ian; Saleh, Soha; Ruano, Viviana; Delmonico, Andrea R.; Adamovich, Sergei V.

2014-01-01

Background and Purpose A majority of studies examining repetitive task practice facilitated by robots for the treatment of upper extremity paresis utilize standardized protocols applied to large groups. Others utilize interventions tailored to patients but don't describe the clinical decision making process utilized to develop and modify interventions. This case report will describe a robot-based intervention customized to match the goals and clinical presentation of a gentleman with upper extremity hemiparesis secondary to stroke. Methods PM is an 85 year-old man with left hemiparesis secondary to an intracerebral hemorrhage five years prior to examination. Outcomes were measured before and after a one month period of home therapy and after a one month robotic intervention. The intervention was designed to address specific impairments identified during his PT examination. When necessary, activities were modified based on the patient's response to his first week of treatment. Outcomes PM trained twelve sessions using six virtually simulated activities. Modifications to original configurations of these activities resulted in performance improvements in five of these activities. PM demonstrated a 35 second improvement in Jebsen Test of Hand Function time and a 44 second improvement in Wolf Motor Function Test time subsequent to the robotic training intervention. Reaching kinematics, 24 hour activity measurement and the Hand and Activities of Daily Living scales of the Stroke Impact Scale all improved as well. Discussion A customized program of robotically facilitated rehabilitation resulted in large short-term improvements in several measurements of upper extremity function in a patient with chronic hemiparesis. PMID:22592063

The Relationship between Behavior Ratings and Concurrent and Subsequent Mental and Motor Performance in Toddlers Born at Extremely Low Birth Weight

ERIC Educational Resources Information Center

Messinger, Daniel; Lambert, Brittany; Bauer, Charles R.; Bann, Carla M.; Hamlin-Smith, Kasey; Das, Abhik

2010-01-01

When predicting child developmental outcomes, reliance on children's scores on measures of developmental functioning alone might mask more subtle behavioral difficulties, especially in children with developmental risk factors. The current study examined predictors and stability of examiner behavior ratings and their association with concurrent and…

THE IMMEDIATE AND LONG-TERM EFFECTS OF KINESIOTAPE® ON BALANCE AND FUNCTIONAL PERFORMANCE

PubMed Central

Douris, Peter; Fukuroku, Taryn; Kuzniewski, Michael; Dias, Joe; Figueiredo, Patrick

2016-01-01

Background The application of Kinesio Tex® tape (KT) results, in theory, in the improvement of muscle contractibility by supporting weakened muscles. The effect of KT on muscle strength has been investigated by numerous researchers who have theorized that KT facilitates an immediate increase in muscle strength by generating a concentric pull on the fascia. The effect of KT on balance and functional performance has been controversial because of the inconsistencies of tension and direction of pull required during application of KT and whether its use on healthy individuals provides therapeutic benefits. Hypotheses/Purpose The purpose of the present study was to investigate the immediate and long-term effects of the prescribed application (for facilitation) of KT when applied to the dominant lower extremity of healthy individuals. The hypothesis was that balance and functional performance would improve with the prescribed application of KT versus the sham application. Study Design Pretest-posttest repeated measures control group design. Methods Seventeen healthy subjects (9 males; 8 females) ranging from 18-35 years of age (mean age 23.3 ± 0.72), volunteered to participate in this study. KT was applied to the gastrocnemius of the participant's dominant leg using a prescribed application to facilitate muscle performance for the experimental group versus a sham application for the control group. The Biodex Balance System and four hop tests were utilized to assess balance, proprioception, and functional performance beginning on the first day including pre- and immediately post-KT application measurements. Subsequent measurements were performed 24, 72, and 120 hours after tape application. Repeated measures ANOVA's were performed for each individual dependent variable. Results There were no significant differences for main and interaction effects between KT and sham groups for the balance and four hop tests. Conclusion The results of the present study did not indicate any significant differences in balance and functional performance when KT was applied to the gastrocnemius muscle of the lower extremity. Level of evidence Level 1- Randomized Clinical Trial PMID:27104058

The relationship between lower extremity alignment and Medial Tibial Stress Syndrome among non-professional athletes

PubMed Central

Raissi, Golam Reza D; Cherati, Afsaneh D Safar; Mansoori, Kourosh D; Razi, Mohammad D

2009-01-01

Objective To determine the relationship between lower extremity alignment and MTSS amongst non-professional athletes Design In a prospective Study, sixty six subjects were evaluated. Bilateral navicular drop test, Q angle, Achilles angle, tibial angle, intermalleolar and intercondylar distance were measured. In addition, runner's height, body mass, history of previous running injury, running experience was recorded. Runners were followed for 17 weeks to determine occurrence of MTSS. Results The overall injury rate for MTSS was 19.7%. The MTSS injury rate in girls (22%) was not significantly different from the rate in boys (14.3%). Most MTSS injuries were induced after 60 hours of exercise, which did not differ between boys and girls. There was a significant difference in right and left navicular drop (ND) in athletes with MTSS. MTSS had no significant correlation with other variables including Quadriceps, Tibia and Achilles angles, intercondylar and intermaleolar lengths and lower extremity lengths. Limitation All measurements performed in this study were uniplanar and static. The small sample size deemed our main limitation. The accurate assessment of participants with previous history of anterior leg pain for MTSS was another limitation. Conclusion Although a significant relationship between navicular drop and MTSS was found in this study; there was not any significant relationship between lower extremity alignment and MTSS in our sample study. PMID:19519909

Cardiac and Vascular Responses to Thigh Cuffs and Respiratory Maneuvers on Crewmembers of the International Space Station

NASA Technical Reports Server (NTRS)

Hamilton, Douglas; Sargsyan, Ashot E.; Garcia, Kathleen; Ebert, Douglas; Whitson, Peggy A.; Feiveson, Alan; Alferova, Irina V.; Dulchavsky, Scott A.; Matveev, Vladimir P.; Bogomolov, Valery V.;

An Examination of Lower Extremity Function and its Correlates in Older African American and White Men.

PubMed

Clay, Olivio J; Thorpe, Roland J; Wilkinson, Larrell L; Plaisance, Eric P; Crowe, Michael; Sawyer, Patricia; Brown, Cynthia J

2015-08-07

Maintaining functional status and reducing/eliminating health disparities in late life are key priorities. Older African Americans have been found to have worse lower extremity functioning than Whites, but little is known about potential differences in correlates between African American and White men. The goal of this investigation was to examine measures that could explain this racial difference and to identify race-specific correlates of lower extremity function. Data were analyzed for a sample of community-dwelling men. Linear regression models examined demographics, medical conditions, health behaviors, and perceived discrimination and mental health as correlates of an objective measure of lower extremity function, the Short Physical Performance Battery (SPPB). Scores on the SPPB have a potential range of 0 to 12 with higher scores corresponding to better functioning. The mean age of all men was 74.9 years (SD=6.5), and the sample was 50% African American and 53% rural. African American men had scores on the SPPB that were significantly lower than White men after adjusting for age, rural residence, marital status, education, and income difficulty (P<.01). Racial differences in cognitive functioning accounted for approximately 41% of the race effect on physical function. Additional models stratified by race revealed a pattern of similar correlates of the SPPB among African American and White men. The results of this investigation can be helpful for researchers and clinicians to aid in identifying older men who are at-risk for poor lower extremity function and in planning targeted interventions to help reduce disparities.

A hybrid joint based controller for an upper extremity exoskeleton

NASA Astrophysics Data System (ADS)

Mohd Khairuddin, Ismail; Taha, Zahari; Majeed, Anwar P. P. Abdul; Hakeem Deboucha, Abdel; Azraai Mohd Razman, Mohd; Aziz Jaafar, Abdul; Mohamed, Zulkifli

2016-02-01

This paper presents the modelling and control of a two degree of freedom upper extremity exoskeleton. The Euler-Lagrange formulation was used in deriving the dynamic modelling of both the human upper limb as well as the exoskeleton that consists of the upper arm and the forearm. The human model is based on anthropometrical measurements of the upper limb. The proportional-derivative (PD) computed torque control (CTC) architecture is employed in this study to investigate its efficacy performing joint-space control objectives specifically in rehabilitating the elbow and shoulder joints along the sagittal plane. An active force control (AFC) algorithm is also incorporated into the PD-CTC to investigate the effectiveness of this hybrid system in compensating disturbances. It was found that the AFC- PD-CTC performs well against the disturbances introduced into the system whilst achieving acceptable trajectory tracking as compared to the conventional PD-CTC control architecture.

Morphology Development in Solution-Processed Functional Organic Blend Films: An In Situ Viewpoint.

PubMed

Richter, Lee J; DeLongchamp, Dean M; Amassian, Aram

2017-05-10

Solution-processed organic films are a facile route to high-speed, low cost, large-area deposition of electrically functional components (transistors, solar cells, emitters, etc.) that can enable a diversity of emerging technologies, from Industry 4.0, to the Internet of things, to point-of-use heath care and elder care. The extreme sensitivity of the functional performance of organic films to structure and the general nonequilibrium nature of solution drying result in extreme processing-performance correlations. In this Review, we highlight insights into the fundamentals of solution-based film deposition afforded by recent state-of-the-art in situ measurements of functional film drying. Emphasis is placed on multimodal studies that combine surface-sensitive X-ray scattering (GIWAXS or GISAXS) with optical characterization to clearly define the evolution of solute structure (aggregation, crystallinity, and morphology) with film thickness.

Performance of Vascular Exposure and Fasciotomy Among Surgical Residents Before and After Training Compared With Experts.

PubMed

Mackenzie, Colin F; Garofalo, Evan; Puche, Adam; Chen, Hegang; Pugh, Kristy; Shackelford, Stacy; Tisherman, Samuel; Henry, Sharon; Bowyer, Mark W

2017-06-01

Surgical patient outcomes are related to surgeon skills. To measure resident surgeon technical and nontechnical skills for trauma core competencies before and after training and up to 18 months later and to compare resident performance with the performance of expert traumatologists. This longitudinal study performed from May 1, 2013, through February 29, 2016, at Maryland State Anatomy Board cadaver laboratories included 40 surgical residents and 10 expert traumatologists. Performance was measured during extremity vascular exposures and lower extremity fasciotomy in fresh cadavers before and after taking the Advanced Surgical Skills for Exposure in Trauma (ASSET) course. The primary outcome variable was individual procedure score (IPS), with secondary outcomes of IPSs on 5 components of technical and nontechnical skills, Global Rating Scale scores, errors, and time to complete the procedure. Two trained evaluators located in the same laboratory evaluated performance with a standardized script and mobile touch-screen data collection. Thirty-eight (95%) of 40 surgical residents (mean [SD] age, 31 [2.9] years) who were evaluated before and within 4 weeks of ASSET training completed follow-up evaluations 12 to 18 months later (mean [SD], 14 [2.7] months). The experts (mean [SD] age, 52 [10.0] years) were significantly older and had a longer (mean [SD], 46 [16.3] months) interval since taking the ASSET course (both P < .001). Overall resident cohort performance improved with increased anatomy knowledge, correct procedural steps, and decreased errors from 60% to 19% after the ASSET course regardless of clinical year of training (P < .001). For 21 of 40 residents (52%), correct vascular procedural steps plotted against anatomy knowledge (the 2 IPS components most improved with training) indicates the resident's performance was within 1 nearest-neighbor classifier of experts after ASSET training. Five residents had no improvement with training. The Trauma Readiness Index for experts (mean [SD], 74 [4]) was significantly different compared with the trained residents (mean [SD], 48 [7] before training vs 63 [7] after training [P = .004] and vs 64 [6] 14 months later [P = .002]). Critical errors that might lead to patient death were identified by pretraining IPS decile of less than 0.5. At follow-up, frequency of resident critical errors was no different from experts. The IPSs ranged from 31.6% to 76.9% among residents for core trauma competency procedures. Modeling revealed that interval experience, rather than time since training, affected skill retention up to 18 months later. Only 4 experts and 16 residents (40%) adequately decompressed and confirmed entry into all 4 lower extremity compartments. This study found that ASSET training improved resident procedural skills for up to 18 months. Performance was highly variable. Interval experience after training affected performance. Pretraining skill identified competency of residents vs experts. Extremity vascular and fasciotomy performance evaluations suggest the need for specific anatomical training interventions in residents with IPS deciles less than 0.5.

Safety of elective hand surgery following axillary lymph node dissection for breast cancer.

PubMed

Hershko, Dan D; Stahl, Shalom

2007-01-01

The development of lymphedema is the most feared complication shared by breast cancer survivors undergoing hand surgery after prior axillary lymph node dissection (ALND). Traditionally, these patients are advised to avoid any interventional procedures in the ipsilateral upper extremity. However, the appropriateness of some of these precautions was recently challenged by some surgeons claiming that elective hand operations can be safely performed in these patients. The purpose of this study was to evaluate our experience and determine the safety of elective hand operations in breast cancer survivors. The medical records of patients operated for different hand conditions after prior breast surgery and ALND at our institution between 1983 and 2002 were reviewed. The techniques and preventive measures performed, use of antibiotics, and upper extremity complications associated with the operations were analyzed. Overall, we operated on 27 patients after prior ALND performed for breast cancer. Follow-up was available for 25 patients. Four patients had pre-existing lymphedema. The surgical technique used was similar to that performed in patients without prior ALND and antibiotic prophylaxis was not given. Delayed wound healing was observed in one patient and finger joint stiffness in another. Two patients with pre-existing lymphedema developed temporary worsening of their condition. None of the patients developed new lymphedema. The results of the present study support the few previous studies, suggesting that hand surgery can be safely performed in patients with prior ALND. Based on these findings, the appropriateness of the rigorous precautions and prohibitions regarding the care and use of the ipsilateral upper extremity may need to be reconsidered.

Impact of a joint labor-management ergonomics program on upper extremity musculoskeletal symptoms among garment workers.

PubMed

Herbert, R; Dropkin, J; Warren, N; Sivin, D; Doucette, J; Kellogg, L; Bardin, J; Kass, D; Zoloth, S

2001-10-01

This study evaluated the effect of an ergonomics intervention program on the prevalence and intensity of symptoms of upper extremity work-related musculoskeletal disorders among 36 garment workers performing an operation called spooling. Adjustable chairs were introduced and workers were trained in their use. Symptom surveys were administered prior to and 6 months after introduction of adjustable chairs. Quantitative pre- and post-intervention measurement of joint position was performed utilizing videotapes among a subgroup of nineteen. Eighty nine percent of the cohort reported pain in either the neck or at least one upper extremity anatomic site prior to the adjustable chair intervention. Among subjects reporting pain at baseline, there were significantly decreased pain levels in 10 of 11 anatomic sites after the intervention. Among all subjects, the proportion reporting pain decreased for each anatomic site following the intervention, with statistically significant decreases in 3 sites. However, there were only modest declines in awkward posture among the videotaped subgroup. This study suggests that introduction of an ergonomics program focused on education and introduction of an adjustable chair may diminish musculoskeletal symptomatology in apparel manufacturing workers.

Materials and noncoplanar mesh designs for integrated circuits with linear elastic responses to extreme mechanical deformations.

PubMed

Kim, Dae-Hyeong; Song, Jizhou; Choi, Won Mook; Kim, Hoon-Sik; Kim, Rak-Hwan; Liu, Zhuangjian; Huang, Yonggang Y; Hwang, Keh-Chih; Zhang, Yong-wei; Rogers, John A

2008-12-02

Electronic systems that offer elastic mechanical responses to high-strain deformations are of growing interest because of their ability to enable new biomedical devices and other applications whose requirements are impossible to satisfy with conventional wafer-based technologies or even with those that offer simple bendability. This article introduces materials and mechanical design strategies for classes of electronic circuits that offer extremely high stretchability, enabling them to accommodate even demanding configurations such as corkscrew twists with tight pitch (e.g., 90 degrees in approximately 1 cm) and linear stretching to "rubber-band" levels of strain (e.g., up to approximately 140%). The use of single crystalline silicon nanomaterials for the semiconductor provides performance in stretchable complementary metal-oxide-semiconductor (CMOS) integrated circuits approaching that of conventional devices with comparable feature sizes formed on silicon wafers. Comprehensive theoretical studies of the mechanics reveal the way in which the structural designs enable these extreme mechanical properties without fracturing the intrinsically brittle active materials or even inducing significant changes in their electrical properties. The results, as demonstrated through electrical measurements of arrays of transistors, CMOS inverters, ring oscillators, and differential amplifiers, suggest a valuable route to high-performance stretchable electronics.

Foale performs FOOT experiment OPS in the U.S. Lab during Expedition 8

NASA Image and Video Library

2004-04-07

ISS008-E-20901 (7 April 2004) --- Astronaut C. Michael Foale, Expedition 8 commander and NASA ISS science officer, balances on the footplate of a special track attached to the Human Research Facility (HRF) rack in the Destiny laboratory on the International Space Station (ISS) to perform Foot/Ground Reaction Forces During Spaceflight (FOOT) / Electromyography (EMG) calibration operations. Foale is wearing the Lower Extremity Monitoring Suit (LEMS), the cycling tights outfitted with 20 sensors, which measures forces on joints and muscle activity.

Extreme ultraviolet and soft x-ray diagnostics of high-temperature plasmas. Annual progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moos, H W; Armstrong, L Jr

1980-01-01

The work performed from mid-January 1979 through 1980 is described. EUV diagnostic studies have been performed at the Alcator A and C Tokamaks, and on TMX. A toroidal asymmetry has been found in the low density phase of Alcator A. The confinement time of impurities has been measured on Alcator A. Impurity concentrations in the center cell of TMX have been studied using EUV spectroscopic techniques. A time resolving spectrograph with 1024 detector elements is essentially complete.

Self-Reported Disability: Association With Lower Extremity Performance and Other Determinants in Older Adults Attending Primary Care.

PubMed

Silva, Anabela G; Queirós, Alexandra; Sa-Couto, Pedro; Rocha, Nelson P

2015-12-01

Measurement of function usually involves the use of both performance-based and self-report instruments. However, the relationship between both types of measures is not yet completely understood, in particular for older adults attending primary care. The main objective of the study was to investigate the association between the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) and the Short Physical Performance Battery (SPPB) for older adults at primary care. A secondary objective was to determine the influence of sociodemographic and health-related variables on this relationship. This was a cross-sectional study. A total of 504 participants aged 60 years and older from 18 different primary care centers underwent a one-session assessment including: sociodemographic variables, comorbidities, performance, self-reported disability, pain, depressive symptoms, and physical activity. Performance was assessed using the SPPB, and self-reported disability was assessed using the WHODAS 2.0. The correlation between WHODAS 2.0 and SPPB scores was strong (r=.65). Regression analysis showed that the SPPB total score explained 41.7% of the variance in WHODAS 2.0 scores (adjusted R(2)=41.6%). A second model including the SPPB subtests (balance, gait, and sit-to-stand), depressive symptoms, number of pain sites, pain intensity, and level of physical activity explained 61.7% of the variance in WHODAS 2.0 scores (adjusted R(2)=60.4%). No model improvement was found when considering the 6 WHODAS 2.0 individual domains. The cross-sectional nature of the study does not allow inferences on causal relationships. This study's findings confirm that self-report and performance-based measures relate to different aspects of functioning. Further study is needed to determine if primary care interventions targeting lower extremity performance and depressive symptoms improve self-reported disability. © 2015 American Physical Therapy Association.

The opposite end of the attention deficit hyperactivity disorder continuum: genetic and environmental aetiologies of extremely low ADHD traits.

PubMed

Greven, Corina U; Merwood, Andrew; van der Meer, Jolanda M J; Haworth, Claire M A; Rommelse, Nanda; Buitelaar, Jan K

2016-04-01

Although attention deficit hyperactivity disorder (ADHD) is thought to reflect a continuously distributed quantitative trait, it is assessed through binary diagnosis or skewed measures biased towards its high, symptomatic extreme. A growing trend is to study the positive tail of normally distributed traits, a promising avenue, for example, to study high intelligence to increase power for gene-hunting for intelligence. However, the emergence of such a 'positive genetics' model has been tempered for ADHD due to poor phenotypic resolution at the low extreme. Overcoming this methodological limitation, we conduct the first study to assess the aetiologies of low extreme ADHD traits. In a population-representative sample of 2,143 twins, the Strength and Weaknesses of ADHD Symptoms and Normal behaviour (SWAN) questionnaire was used to assess ADHD traits on a continuum from low to high. Aetiological influences on extreme ADHD traits were estimated using DeFries-Fulker extremes analysis. ADHD traits were related to behavioural, cognitive and home environmental outcomes using regression. Low extreme ADHD traits were significantly influenced by shared environmental factors (23-35%) but were not significantly heritable. In contrast, high-extreme ADHD traits showed significant heritability (39-51%) but no shared environmental influences. Compared to individuals with high extreme or with average levels of ADHD traits, individuals with low extreme ADHD traits showed fewer internalizing and externalizing behaviour problems, better cognitive performance and more positive behaviours and positive home environmental outcomes. Shared environmental influences on low extreme ADHD traits may reflect passive gene-environment correlation, which arises because parents provide environments as well as passing on genes. Studying the low extreme opens new avenues to study mechanisms underlying previously neglected positive behaviours. This is different from the current deficit-based model of intervention, but congruent with a population-level approach to improving youth wellbeing. © 2015 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.

A Comprehensive Radial Velocity Error Budget for Next Generation Doppler Spectrometers

NASA Technical Reports Server (NTRS)

Halverson, Samuel; Ryan, Terrien; Mahadevan, Suvrath; Roy, Arpita; Bender, Chad; Stefansson, Guomundur Kari; Monson, Andrew; Levi, Eric; Hearty, Fred; Blake, Cullen;

Development of laser interferometric high-precision geometry monitor for JASMINE

NASA Astrophysics Data System (ADS)

Niwa, Yoshito; Arai, Koji; Ueda, Akitoshi; Sakagami, Masaaki; Gouda, Naoteru; Kobayashi, Yukiyasu; Yamada, Yoshiyuki; Yano, Taihei

2008-07-01

The telescope geometry of JASMINE should be stabilized and monitored with the accuracy of about 10 to 100 picometer or 10 to 100 picoradian in root-mean-square over about 10 hours. For this purpose, a high-precision interferometric laser metrology system is employed. One of useful techniques for measuring displacements in extremely minute scales is the heterodyne interferometrical method. Experiment for verification of multi degree of freedom measurement was performed and mirror motions were successfully monitored with three degree of freedom.

Extremely high frequency RF effects on electronics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale

The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit boardmore » traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.« less

Th/U/Pu/Cm dating of galactic cosmic rays with the extremely heavy cosmic ray composition observer

NASA Astrophysics Data System (ADS)

Westphal, Andrew J.; Weaver, Benjamin A.; Tarlé, Gregory

The principal goal of ECCO, the Extremely-heavy Cosmic-ray Composition Observer, is the measurement of the age of heavy galactic cosmic-ray nuclei using the extremely rare actinides (Th, U, Pu, Cm) as clocks. ECCO is one of two cosmic-ray instruments comprising the Heavy Nuclei Explorer (HNX), which was recently selected as one of several missions for Phase A study under NASA's Small class Explorer (SMEX) program. ECCO is based on the flight heritage of Trek, an array of barium-phosphate glass tracketch detectors deployed on the Russian space station Mir from 1991-1995. Using Trek, we measured the abundances of elements with Z > 70 in the galactic cosmic rays (GCRs). Trek consisted of a 1 m 2 array of stacks of individually polished thin BP-1 glass detectors. ECCO will be a much larger instrument, but will achieve both excellent resolution and low cost through use of a novel detector configuration. Here we report the results of recent accelerator tests of the ECCO detectors that verify detector performance. We also show the expected charge and energy resolution of ECCO as a function of energy.

Cardiovascular consequences of extreme prematurity: the EPICure study.

PubMed

McEniery, Carmel M; Bolton, Charlotte E; Fawke, Joseph; Hennessy, Enid; Stocks, Janet; Wilkinson, Ian B; Cockcroft, John R; Marlow, Neil

2011-07-01

The long-term consequences of extreme prematurity are becoming increasingly important, given recent improvements in neonatal intensive care. The aim of the current study was to examine the cardiovascular consequences of extreme prematurity in 11-year-olds born at or before 25 completed weeks of gestation. Age and sex-matched classmates were recruited as controls. Information concerning perinatal and maternal history was collected, and current anthropometric characteristics were measured in 219 children born extremely preterm and 153 classmates. A subset of the extremely preterm children (n = 68) and classmates (n = 90) then underwent detailed haemodynamic investigations, including measurement of supine blood pressure (BP), aortic pulse wave velocity (aPWV, a measure of aortic stiffness) and augmentation index (AIx, a measure of arterial pressure wave reflections). Seated brachial systolic and diastolic BP were not different between extremely preterm children and classmates (P = 0.3 for both), although there was a small, significant elevation in supine mean and diastolic BP in the extremely preterm children (P < 0.05 for both). Arterial pressure wave reflections were significantly elevated in the extremely preterm children (P < 0.001) and this persisted after adjusting for confounding variables. However, aortic stiffness was not different between the groups (P = 0.1). These data suggest that extreme prematurity is associated with altered arterial haemodynamics in children, not evident from the examination of brachial BP alone. Moreover, the smaller, preresistance and resistance vessels rather than large elastic arteries appear to be most affected. Children born extremely preterm may be at increased future cardiovascular risk.

Muscle Strength and Changes in Physical Function in Women With Systemic Lupus Erythematosus.

PubMed

Andrews, James S; Trupin, Laura; Schmajuk, Gabriela; Barton, Jennifer; Margaretten, Mary; Yazdany, Jinoos; Yelin, Edward H; Katz, Patricia P

2015-08-01

Cross-sectional studies have observed that muscle weakness is associated with worse physical function among women with systemic lupus erythematosus (SLE). The present study examines whether reduced upper and lower extremity muscle strength predict declines in function over time among adult women with SLE. One hundred forty-six women from a longitudinal SLE cohort participated in the study. All measures were collected during in-person research visits approximately 2 years apart. Upper extremity muscle strength was assessed by grip strength. Lower extremity muscle strength was assessed by peak knee torque of extension and flexion. Physical function was assessed using the Short Physical Performance Battery (SPPB). Regression analyses modeled associations of baseline upper and lower extremity muscle strength with followup SPPB scores controlling for baseline SPPB, age, SLE duration, SLE disease activity (Systemic Lupus Activity Questionnaire), physical activity level, prednisone use, body composition, and depression. Secondary analyses tested whether associations of baseline muscle strength with followup in SPPB scores differed between intervals of varying baseline muscle strength. Lower extremity muscle strength strongly predicted changes over 2 years in physical function even when controlling for covariates. The association of reduced lower extremity muscle strength with reduced physical function in the future was greatest among the weakest women. Reduced lower extremity muscle strength predicted clinically significant declines in physical function, especially among the weakest women. Future studies should test whether therapies that promote preservation of lower extremity muscle strength may prevent declines in function among women with SLE. © 2015, American College of Rheumatology.

INTERSESSION RELIABILITY OF UPPER EXTREMITY ISOKINETIC PUSH-PULL TESTING.

PubMed

Riemann, Bryan L; Davis, Sarah E; Huet, Kevin; Davies, George J

2016-02-01

Based on the frequency pushing and pulling patterns are used in functional activities, there is a need to establish an objective method of quantifying the muscle performance characteristics associated with these motions, particularly during the later stages of rehabilitation as criteria for discharge. While isokinetic assessment offers an approach to quantifying muscle performance, little is known about closed kinetic chain (CKC) isokinetic testing of the upper extremity (UE). To determine the intersession reliability of isokinetic upper extremity measurement of pushing and pulling peak force and average power at slow (0.24 m/s), medium (0.43 m/s) and fast (0.61 m/s) velocities in healthy young adults. The secondary purpose was to compare pushing and pulling peak force (PF) and average power (AP) between the upper extremity limbs (dominant, non-dominant) across the three velocities. Twenty-four physically active men and women completed a test-retest (>96 hours) protocol in order to establish isokinetic UE CKC reliability of PF and AP during five maximal push and pull repetitions at three velocities. Both limb and speed orders were randomized between subjects. High test-retest relative reliability using intraclass correlation coefficients (ICC2, 1) were revealed for PF (.91-.97) and AP (.85-.95) across velocities, limbs and directions. PF typical error (% coefficient of variation) ranged from 6.1% to 11.3% while AP ranged from 9.9% to 26.7%. PF decreased significantly (p < .05) as velocity increased whereas AP increased as velocity increased. PF and AP during pushing were significantly greater than pulling at all velocities, however the push-pull differences in PF became less as velocity increased. There were no significant differences identified between the dominant and nondominant limbs. Isokinetically derived UE CKC push-pull PF and AP are reliable measures. The lack of limb differences in healthy normal participants suggests that clinicians can consider bilateral comparisons when interpreting test performance. The increase in pushing PF and AP compared to pulling can be attributed to the muscles involved and the frequency that pushing patterns are used during functional activities. 3.

Investigating skin-to-skin care patterns with extremely preterm infants in the NICU and their effect on early cognitive and communication performance: a retrospective cohort study.

PubMed

Gonya, Jenn; Ray, William C; Rumpf, R Wolfgang; Brock, Guy

2017-03-20

The primary objective of the study was to investigate how patterns of skin-to-skin care might impact infant early cognitive and communication performance. This was a retrospective cohort study. This study took place in a level-IV all-referral neonatal intensive care unit in the Midwest USA specialising in the care of extremely preterm infants. Data were collected from the electronic medical records of all extremely preterm infants (gestational age <27 weeks) admitted to the unit during 2010-2011 and who completed 6-month and 12-month developmental assessments in the follow-up clinic (n=97). Outcome measures included the cognitive and communication subscales of the Bayley Scales of Infant Development, Third Edition (Bayley-III); and skin-to-skin patterns including: total hours of maternal and paternal participation throughout hospitalisation, total duration in weeks and frequency (hours per week). Extracted data were analysed through a multistep process of logistic regressions, t-tests, χ 2 tests and Fisher's exact tests followed with exploratory network analysis using novel visual analytic software. Infants who received above the sample median in total hours, weekly frequency and total hours from mothers and fathers of skin-to-skin care were more likely to score ≥80 on the cognitive and communication scales of the Bayley-III. However, the results were not statistically significant (p>0.05). Mothers provided the majority of skin-to-skin care with a sharp decline at 30 weeks corrected age, regardless of when extremely preterm infants were admitted. Additional exploratory network analysis suggests that medical and skin-to-skin factors play a parallel, non-synergistic role in contributing to early cognitive and communication performance as assessed through the Bayley-III. This study suggests an association between early and frequent skin-to-skin care with extremely preterm infants and early cognitive and communication performance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

SOI N-Channel Field Effect Transistors, CHT-NMOS80, for Extreme Temperatures

NASA Technical Reports Server (NTRS)

Patterson, Richard L.; Hammoud, Almad

2009-01-01

Extreme temperatures, both hot and cold, are anticipated in many of NASA space exploration missions as well as in terrestrial applications. One can seldom find electronics that are capable of operation under both regimes. Even for operation under one (hot or cold) temperature extreme, some thermal controls need to be introduced to provide appropriate ambient temperatures so that spacecraft on-board or field on-site electronic systems work properly. The inclusion of these controls, which comprise of heating elements and radiators along with their associated structures, adds to the complexity in the design of the system, increases cost and weight, and affects overall reliability. Thus, it would be highly desirable and very beneficial to eliminate these thermal measures in order to simplify system's design, improve efficiency, reduce development and launch costs, and improve reliability. These requirements can only be met through the development of electronic parts that are designed for proper and efficient operation under extreme temperature conditions. Silicon-on-insulator (SOI) based devices are finding more use in harsh environments due to the benefits that their inherent design offers in terms of reduced leakage currents, less power consumption, faster switching speeds, good radiation tolerance, and extreme temperature operability. Little is known, however, about their performance at cryogenic temperatures and under wide thermal swings. The objective of this work was to evaluate the performance of a new commercial-off-the-shelf (COTS) SOI parts over an extended temperature range and to determine the effects of thermal cycling on their performance. The results will establish a baseline on the suitability of such devices for use in space exploration missions under extreme temperatures, and will aid mission planners and circuit designers in the proper selection of electronic parts and circuits. The electronic part investigated in this work comprised of a CHT-NMOS80 high temperature N-channel MOSFET (metal-oxide semiconductor field-effect transistor) device that was manufactured by CISSOID. This high voltage, medium-power transistor is fabricated using SOI processes and is designed for extreme wide temperature applications such as geothermal well logging, aerospace and avionics, and automotive industry. It has a high DC current capability and is specified for operation in the temperature range of -55 C to +225 C

Temperature Effect of Low Velocity Impact Resistance of Glass/epoxy Laminates

NASA Astrophysics Data System (ADS)

Kang, Ki-Weon; Kim, Heung-Seob; Chung, Tae-Jin; Koh, Seung-Kee

This paper aims to evaluate the effect of temperature on impact damage resistance of glass/epoxy laminates. A series of impact tests were performed using an instrumented impact-testing machine at temperature ranging from -40°C to +80°C. The resulting impact damage was measured using back light method. The impact resistance parameters were employed to understand the damage resistance. It was observed that temperature has a little effect on the impact responses of composite laminates. The damage resistance of glass/epoxy laminates is somewhat deteriorated at two opposite extremes of the studied temperature range and this behavior is likely due to the property change of glass/epoxy laminates under extreme temperatures

Generating circularly polarized radiation in the extreme ultraviolet spectral range at the free-electron laser FLASH

NASA Astrophysics Data System (ADS)

von Korff Schmising, Clemens; Weder, David; Noll, Tino; Pfau, Bastian; Hennecke, Martin; Strüber, Christian; Radu, Ilie; Schneider, Michael; Staeck, Steffen; Günther, Christian M.; Lüning, Jan; Merhe, Alaa el dine; Buck, Jens; Hartmann, Gregor; Viefhaus, Jens; Treusch, Rolf; Eisebitt, Stefan

2017-05-01

A new device for polarization control at the free electron laser facility FLASH1 at DESY has been commissioned for user operation. The polarizer is based on phase retardation upon reflection off metallic mirrors. Its performance is characterized in three independent measurements and confirms the theoretical predictions of efficient and broadband generation of circularly polarized radiation in the extreme ultraviolet spectral range from 35 eV to 90 eV. The degree of circular polarization reaches up to 90% while maintaining high total transmission values exceeding 30%. The simple design of the device allows straightforward alignment for user operation and rapid switching between left and right circularly polarized radiation.

Shear-Wave Elastography Assessments of Quadriceps Stiffness Changes prior to, during and after Prolonged Exercise: A Longitudinal Study during an Extreme Mountain Ultra-Marathon.

PubMed

Andonian, Pierre; Viallon, Magalie; Le Goff, Caroline; de Bourguignon, Charles; Tourel, Charline; Morel, Jérome; Giardini, Guido; Gergelé, Laurent; Millet, Grégoire P; Croisille, Pierre

2016-01-01

In sports medicine, there is increasing interest in quantifying the elastic properties of skeletal muscle, especially during extreme muscular stimulation, to improve our understanding of the impact of alterations in skeletal muscle stiffness on resulting pain or injuries, as well as the mechanisms underlying the relationships between these parameters. Our main objective was to determine whether real-time shear-wave elastography (SWE) can monitor changes in quadriceps muscle elasticity during an extreme mountain ultra-marathon, a powerful mechanical stress model. Our study involved 50 volunteers participating in an extreme mountain marathon (distance: 330 km, elevation: +24,000 m). Quantitative SWE velocity and shear modulus measurements were performed in most superficial quadriceps muscle heads at the following 4 time points: before the race, halfway through the race, upon finishing the race and after recovery (+48 h). Blood biomarker levels were also measured. A significant decrease in the quadriceps shear modulus was observed upon finishing the race (3.31±0.61 kPa) (p<0.001) compared to baseline (3.56±0.63 kPa), followed by a partial recovery +48 h after the race (3.45±0.6 kPa) (p = 0.002) across all muscle heads, as well as for each of the following three muscle heads: the rectus femoris (p = 0.003), the vastus medialis (p = 0.033) and the vastus lateralis (p = 0.001). Our study is the first to assess changes in muscle stiffness during prolonged extreme physical endurance exercises based on shear modulus measurements using non-invasive SWE. We concluded that decreases in stiffness, which may have resulted from quadriceps overuse in the setting of supra-physiological stress caused by the extreme distance and unique elevation of the race, may have been responsible for the development of inflammation and muscle swelling. SWE may hence represent a promising tool for monitoring physiologic or pathological variations in muscle stiffness and may be useful for diagnosing and monitoring muscle changes.

Shear-Wave Elastography Assessments of Quadriceps Stiffness Changes prior to, during and after Prolonged Exercise: A Longitudinal Study during an Extreme Mountain Ultra-Marathon

PubMed Central

Andonian, Pierre; Viallon, Magalie; Le Goff, Caroline; de Bourguignon, Charles; Tourel, Charline; Morel, Jérome; Giardini, Guido; Gergelé, Laurent; Millet, Grégoire P.; Croisille, Pierre

2016-01-01

In sports medicine, there is increasing interest in quantifying the elastic properties of skeletal muscle, especially during extreme muscular stimulation, to improve our understanding of the impact of alterations in skeletal muscle stiffness on resulting pain or injuries, as well as the mechanisms underlying the relationships between these parameters. Our main objective was to determine whether real-time shear-wave elastography (SWE) can monitor changes in quadriceps muscle elasticity during an extreme mountain ultra-marathon, a powerful mechanical stress model. Our study involved 50 volunteers participating in an extreme mountain marathon (distance: 330 km, elevation: +24,000 m). Quantitative SWE velocity and shear modulus measurements were performed in most superficial quadriceps muscle heads at the following 4 time points: before the race, halfway through the race, upon finishing the race and after recovery (+48 h). Blood biomarker levels were also measured. A significant decrease in the quadriceps shear modulus was observed upon finishing the race (3.31±0.61 kPa) (p<0.001) compared to baseline (3.56±0.63 kPa), followed by a partial recovery +48 h after the race (3.45±0.6 kPa) (p = 0.002) across all muscle heads, as well as for each of the following three muscle heads: the rectus femoris (p = 0.003), the vastus medialis (p = 0.033) and the vastus lateralis (p = 0.001). Our study is the first to assess changes in muscle stiffness during prolonged extreme physical endurance exercises based on shear modulus measurements using non-invasive SWE. We concluded that decreases in stiffness, which may have resulted from quadriceps overuse in the setting of supra-physiological stress caused by the extreme distance and unique elevation of the race, may have been responsible for the development of inflammation and muscle swelling. SWE may hence represent a promising tool for monitoring physiologic or pathological variations in muscle stiffness and may be useful for diagnosing and monitoring muscle changes. PMID:27579699

Comparison of disease activity measures for anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis.

PubMed

Merkel, P A; Cuthbertson, D D; Hellmich, B; Hoffman, G S; Jayne, D R W; Kallenberg, C G M; Krischer, J P; Luqmani, R; Mahr, A D; Matteson, E L; Specks, U; Stone, J H

2009-01-01

Currently, several different instruments are used to measure disease activity and extent in clinical trials of anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, leading to division among investigative groups and difficulty comparing study results. An exercise comparing six different vasculitis instruments was performed. A total of 10 experienced vasculitis investigators from 5 countries scored 20 cases in the literature of Wegener granulomatosis or microscopic polyangiitis using 6 disease assessment tools: the Birmingham Vasculitis Activity Score (BVAS), The BVAS for Wegener granulomatosis (BVAS/WG), BVAS 2003, a Physician Global Assessment (PGA), the Disease Extent Index (DEI) and the Five Factor Score (FFS). Five cases were rescored by all raters. Reliability of the measures was extremely high (intraclass correlations for the six measures all = 0.98). Within each instrument, there were no significant differences or outliers among the scores from the 10 investigators. Test/retest reliability was high for each measure: range = 0.77 to 0.95. The scores of the five acute activity measures correlated extremely well with one another. Currently available tools for measuring disease extent and activity in ANCA-associated vasculitis are highly correlated and reliable. These results provide investigators with confidence to compare different clinical trial data and helps form common ground as international research groups develop new, improved and universally accepted vasculitis disease assessment instruments.

Advanced Ultrasonic Diagnosis of Extremity Trauma: The Faster Exam

NASA Technical Reports Server (NTRS)

Dulchavsky, S. A.; Henry, S. E.; Moed, B. R.; Diebel, L. N.; Marshburn, T.; Hamilton, D. R.; Logan, J.; Kirkpatrick, A. W.; Williams, D. R.

2002-01-01

Ultrasound is of prO)len accuracy in abdominal and thoracic trauma and may be useful to diagnose extremity injury in situations where radiography is not available such as military and space applications. We prospectively evaluated the utility of extremity , ultrasound performed by trained, non-physician personnel in patients with extremity trauma, to simulate remote aerospace or military applications . Methods: Patients with extremity trauma were identified by history, physical examination, and radiographic studies. Ultrasound examination was performed bilaterally by nonphysician personnel with a portable ultrasound device using a 10-5 MHz linear probe, Images were video-recorded for later analysis against radiography by Fisher's exact test. The average time of examination was 4 minutes. Ultrasound accurately diagnosed extremity, injury in 94% of patients with no false positive exams; accuracy was greater in mid-shaft locations and least in the metacarpa/metatarsals. Soft tissue/tendon injury was readily visualized . Extremity ultrasound can be performed quickly and accurately by nonphysician personnel with excellent accuracy. Blinded verification of the utility of ultrasound in patients with extremity injury should be done to determine if Extremity and Respiratory evaluation should be added to the FAST examination (the FASTER exam) and verify the technique in remote locations such as military and aerospace applications.

Development of a Sheathed Miniature Aerothermal Reentry Thermocouple for Thermal Protection System Materials

NASA Technical Reports Server (NTRS)

Martinez, Edward R.; Weber, Carissa Tudryn; Oishi, Tomo; Santos, Jose; Mach, Joseph

2011-01-01

The Sheathed Miniature Aerothermal Reentry Thermocouple is a micro-miniature thermocouple for high temperature measurement in extreme environments. It is available for use in Thermal Protection System materials for ground testing and flight. This paper discusses the heritage, and design of the instrument. Experimental and analytical methods used to verify its performance and limitations are described.

Language Testing: An Overview and Language Testing in Educational Institutions of Bangladesh

ERIC Educational Resources Information Center

Hossain, Md. Mahroof; Ahmed, Md. Kawser

2015-01-01

Test is procedures for measuring ability, knowledge or performance. Testing can be defined as a method of assessment and improvement of the students. Language testing in any point is an extremely multifarious task that ought to be based on method as well as exercise. The results of assessments are used for one or more purposes. So they have an…

No effects of power line frequency extremely low frequency electromagnetic field exposure on selected neurobehavior tests of workers inspecting transformers and distribution line stations versus controls.

PubMed

Li, Li; Xiong, De-fu; Liu, Jia-wen; Li, Zi-xin; Zeng, Guang-cheng; Li, Hua-liang

2014-03-01

We aimed to evaluate the interference of 50 Hz extremely low frequency electromagnetic field (ELF-EMF) occupational exposure on the neurobehavior tests of workers performing tour-inspection close to transformers and distribution power lines. Occupational short-term "spot" measurements were carried out. 310 inspection workers and 300 logistics staff were selected as exposure and control. The neurobehavior tests were performed through computer-based neurobehavior evaluation system, including mental arithmetic, curve coincide, simple visual reaction time, visual retention, auditory digit span and pursuit aiming. In 500 kV areas electric field intensity at 71.98% of total measured 590 spots were above 5 kV/m (national occupational standard), while in 220 kV areas electric field intensity at 15.69% of total 701 spots were above 5 kV/m. Magnetic field flux density at all the spots was below 1,000 μT (ICNIRP occupational standard). The neurobehavior score changes showed no statistical significance. Results of neurobehavior tests among different age, seniority groups showed no significant changes. Neurobehavior changes caused by daily repeated ELF-EMF exposure were not observed in the current study.

How NOAA/DSCOVR Will Perform during Extreme Space Weather and Why Lead Time Exceeds Expectations

NASA Astrophysics Data System (ADS)

Biesecker, D. A.

2014-12-01

The NOAA/DSCOVR satellite is expected to launch in January, 2015 and replace the NASA/ACE satellite as the L1 Sentinel in early Summer, 2015. Having relied on ACE to provide critical warnings of geomagnetic storms since 1998, it is important for the space weather community to understand how DSCOVR will perform relative to ACE in real-time operations. The WIND/SWE instrument is sufficiently similar to the DSCOVR Faraday Cup that it can be used as a proxy for DSCOVR, with some caveats. We compare the ACE/SWEPAM and WIND/SWE observations for all geomagnetic storm events meeting the criteria of severe or extreme. We also examine time periods where ACE data were compromised by solar energetic particles. We find that DSCOVR will provide a more robust data stream than was provided by ACE during solar cycle 23. We will briefly address the magnetometer, supra-thermal particle measurements, and relativistic proton measurements provided by ACE, of which only the magnetometer is retained on DSCOVR. We also demonstrate that lead time for geomagnetic storm notifications to customers far exceeds the L1 to Earth delay time.

Analysis of buried interfaces in multilayer mirrors using grazing incidence extreme ultraviolet reflectometry near resonance edges.

PubMed

Sertsu, M G; Nardello, M; Giglia, A; Corso, A J; Maurizio, C; Juschkin, L; Nicolosi, P

2015-12-10

Accurate measurements of optical properties of multilayer (ML) mirrors and chemical compositions of interdiffusion layers are particularly challenging to date. In this work, an innovative and nondestructive experimental characterization method for multilayers is discussed. The method is based on extreme ultraviolet (EUV) reflectivity measurements performed on a wide grazing incidence angular range at an energy near the absorption resonance edge of low-Z elements in the ML components. This experimental method combined with the underlying physical phenomenon of abrupt changes of optical constants near EUV resonance edges enables us to characterize optical and structural properties of multilayers with high sensitivity. A major advantage of the method is to perform detailed quantitative analysis of buried interfaces of multilayer structures in a nondestructive and nonimaging setup. Coatings of Si/Mo multilayers on a Si substrate with period d=16.4  nm, number of bilayers N=25, and different capping structures are investigated. Stoichiometric compositions of Si-on-Mo and Mo-on-Si interface diffusion layers are derived. Effects of surface oxidation reactions and carbon contaminations on the optical constants of capping layers and the impact of neighboring atoms' interactions on optical responses of Si and Mo layers are discussed.

Adaptive mixed reality rehabilitation improves quality of reaching movements more than traditional reaching therapy following stroke.

PubMed

Duff, Margaret; Chen, Yinpeng; Cheng, Long; Liu, Sheng-Min; Blake, Paul; Wolf, Steven L; Rikakis, Thanassis

2013-05-01

Adaptive mixed reality rehabilitation (AMRR) is a novel integration of motion capture technology and high-level media computing that provides precise kinematic measurements and engaging multimodal feedback for self-assessment during a therapeutic task. We describe the first proof-of-concept study to compare outcomes of AMRR and traditional upper-extremity physical therapy. Two groups of participants with chronic stroke received either a month of AMRR therapy (n = 11) or matched dosing of traditional repetitive task therapy (n = 10). Participants were right handed, between 35 and 85 years old, and could independently reach to and at least partially grasp an object in front of them. Upper-extremity clinical scale scores and kinematic performances were measured before and after treatment. Both groups showed increased function after therapy, demonstrated by statistically significant improvements in Wolf Motor Function Test and upper-extremity Fugl-Meyer Assessment (FMA) scores, with the traditional therapy group improving significantly more on the FMA. However, only participants who received AMRR therapy showed a consistent improvement in kinematic measurements, both for the trained task of reaching to grasp a cone and the untrained task of reaching to push a lighted button. AMRR may be useful in improving both functionality and the kinematics of reaching. Further study is needed to determine if AMRR therapy induces long-term changes in movement quality that foster better functional recovery.

Work activities and musculoskeletal complaints among preschool workers.

PubMed

Grant, K A; Habes, D J; Tepper, A L

1995-12-01

The potential for musculoskeletal trauma among preschool workers has been largely unexplored in the United States. This case report describes an investigation conducted to identify and evaluate possible causes of back and lower extremity pain among 22 workers at a Montessori day care facility. Investigators met with and distributed a questionnaire to school employees, and made measurements of workstation and furniture dimensions. Investigators also recorded the normal work activities of school employees on videotape, and performed a work sampling study to estimate the percentage of time employees spend performing various tasks and in certain postures. Questionnaire results from 18 employees indicated that back pain/discomfort was a common musculoskeletal complaint, reported by 61% of respondents. Neck/shoulder pain, lower extremity pain and hand/wrist pain were reported by 33, 33 and 11% of respondents, respectively. Observation and analysis of work activities indicated that employees spend significant periods of time kneeling, sitting on the floor, squatting, or bending at the waist. Furthermore, staff members who work with smaller children (i.e. six weeks to 18 months of age) performed more lifts and assumed more awkward lower extremity postures than employees who work with older children (3-4 years of age). Analysis of two lifting tasks using the revised NIOSH lifting equation indicated that employees who handle small children may be at increased risk of lifting-related low back pain. Investigators concluded that day care employees at this facility are at increased risk of low back pain and lower extremity (i.e. knee) injury due to work activities that require awkward or heavy lifts, and static working postures. Recommendations for reducing or eliminating these risks by modifying the workplace and changing the organization and methods of work are presented.

Performance of the upgraded LTP-II at the ALS Optical Metrology Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Advanced Light Source; Yashchuk, Valeriy V; Kirschman, Jonathan L.

2008-07-14

The next generation of synchrotrons and free electron laser facilities requires x-ray optical systems with extremely high performance, generally of diffraction limited quality. Fabrication and use of such optics requires adequate, highly accurate metrology and dedicated instrumentation. Previously, we suggested ways to improve the performance of the Long Trace Profiler (LTP), a slope measuring instrument widely used to characterize x-ray optics at long spatial wavelengths. The main way is use of a CCD detector and corresponding technique for calibration of photo-response non-uniformity [J. L. Kirschman, et al., Proceedings of SPIE 6704, 67040J (2007)]. The present work focuses on the performancemore » and characteristics of the upgraded LTP-II at the ALS Optical Metrology Laboratory. This includes a review of the overall aspects of the design, control system, the movement and measurement regimes for the stage, and analysis of the performance by a slope measurement of a highly curved super-quality substrate with less than 0.3 microradian (rms)slope variation.« less

How well do the GCMs replicate the historical precipitation variability in the Colorado River Basin?

NASA Astrophysics Data System (ADS)

Guentchev, G.; Barsugli, J. J.; Eischeid, J.; Raff, D. A.; Brekke, L.

2009-12-01

Observed precipitation variability measures are compared to measures obtained using the World Climate Research Programme (WCRP) Coupled Model Intercomparison Project (CMIP3) General Circulation Models (GCM) data from 36 model projections downscaled by Brekke at al. (2007) and 30 model projections downscaled by Jon Eischeid. Three groups of variability measures are considered in this historical period (1951-1999) comparison: a) basic variability measures, such as standard deviation, interdecadal standard deviation; b) exceedance probability values, i.e., 10% (extreme wet years) and 90% (extreme dry years) exceedance probability values of series of n-year running mean annual amounts, where n=1,12; 10% exceedance probability values of annual maximum monthly precipitation (extreme wet months); and c) runs variability measures, e.g., frequency of negative and positive runs of annual precipitation amounts, total number of the negative and positive runs. Two gridded precipitation data sets produced from observations are used: the Maurer et al. (2002) and the Daly et al. (1994) Precipitation Regression on Independent Slopes Method (PRISM) data sets. The data consist of monthly grid-point precipitation averaged on a United States Geological Survey (USGS) hydrological sub-region scale. The statistical significance of the obtained model minus observed measure differences is assessed using a block bootstrapping approach. The analyses were performed on annual, seasonal and monthly scale. The results indicate that the interdecadal standard deviation is underestimated, in general, on all time scales by the downscaled model data. The differences are statistically significant at a 0.05 significance level for several Lower Colorado Basin sub-regions on annual and seasonal scale, and for several sub-regions located mostly in the Upper Colorado River Basin for the months of March, June, July and November. Although the models simulate drier extreme wet years, wetter extreme dry years and drier extreme wet months for the Upper Colorado basin, the differences are mostly not-significant. Exceptions are the results about the extreme wet years for n=3 for sub-region White-Yampa, for n=6, 7, and 8 for sub-region Upper Colorado-Dolores, and about the extreme dry years for n=11 for sub-region Great Divide-Upper Green. None of the results for the sub-regions in the Lower Colorado Basin were significant. For most of the Upper Colorado sub-regions the models simulate significantly lower frequency of negative and positive 4-6 year runs, while for several sub-regions a significantly higher frequency of 2-year negative runs is evident in the model versus the Maurer data comparisons. The model projections versus the PRISM data comparison reveals similar results for the negative runs, while for the positive runs the results indicate that the models simulate higher frequency of the 2-6 year runs. The results for the Lower Colorado basin sub-regions are similar, in general, to these for the Upper Colorado sub-regions. The differences between the simulated and the observed total number of negative or positive runs were not significant for almost all of the sub-regions within the Colorado River Basin.

Lifetime Estimation of a Time Projection Chamber X-ray Polarimeter

NASA Technical Reports Server (NTRS)

Hill, Joanne E.; Black, J. Kevin; Brieda, Lubos; Dickens, Patsy L.; deGarcia, Kristina Montt; Hawk, Douglas L.; Hayato, Asami; Jahoda, Keith; Mohammed, Jelila

2013-01-01

The Gravity and Extreme Magnetism Small Explorer (GEMS) X-ray polarimeter Instrument (XPI) was designed to measure the polarization of 23 sources over the course of its 9 month mission. The XPI design consists of two telescopes each with a polarimeter assembly at the focus of a grazing incidence mirror. To make sensitive polarization measurements the GEMS Polarimeter Assembly (PA) employed a gas detection system based on a Time Projection Chamber (TPC) technique. Gas detectors are inherently at risk of degraded performance arising from contamination from outgassing of internal detector components or due to loss of gas. This paper describes the design and the materials used to build a prototype of the flight polarimeter with the required GEMS lifetime. We report the results from outgassing measurements of the polarimeter subassemblies and assemblies, enclosure seal tests, life tests, and performance tests that demonstrate that the GEMS lifetime is achievable. Finally we report performance measurements and the lifetime enhancement from the use of a getter.

High-Performance Sensors Based on Resistance Fluctuations of Single-Layer-Graphene Transistors.

PubMed

Amin, Kazi Rafsanjani; Bid, Aveek

2015-09-09

One of the most interesting predicted applications of graphene-monolayer-based devices is as high-quality sensors. In this article, we show, through systematic experiments, a chemical vapor sensor based on the measurement of low-frequency resistance fluctuations of single-layer-graphene field-effect-transistor devices. The sensor has extremely high sensitivity, very high specificity, high fidelity, and fast response times. The performance of the device using this scheme of measurement (which uses resistance fluctuations as the detection parameter) is more than 2 orders of magnitude better than a detection scheme in which changes in the average value of the resistance is monitored. We propose a number-density-fluctuation-based model to explain the superior characteristics of a noise-measurement-based detection scheme presented in this article.

Pressure distribution on mattresses.

PubMed

Nicol, K; Rusteberg, D

1993-12-01

Measurements of pressure distribution are usually performed on a hard base, such as those in gait analysis or tire research; measurements on soft surfaces are avoided because of technical problems. A sensor mat was developed which consists of 512 pressure sensors, glued to arbitrary locations of a fabric. The mat can be bent to spherical and saddle shapes so that it can be utilised on soft and flexible surfaces like chairs and beds. Performance of eight hospital mattresses concerning decubitus prophylactics and support in supine and side position was studied in four subjects representing extreme body build. It was found that one particular mattress served well for three subjects, whereas no mattress was suitable for the high and heavy type. It was concluded that measurement of pressure distribution is a valuable tool for designing and selecting.

Low noise buffer amplifiers and buffered phase comparators for precise time and frequency measurement and distribution

NASA Technical Reports Server (NTRS)

Eichinger, R. A.; Dachel, P.; Miller, W. H.; Ingold, J. S.

1982-01-01

Extremely low noise, high performance, wideband buffer amplifiers and buffered phase comparators were developed. These buffer amplifiers are designed to distribute reference frequencies from 30 KHz to 45 MHz from a hydrogen maser without degrading the hydrogen maser's performance. The buffered phase comparators are designed to intercompare the phase of state of the art hydrogen masers without adding any significant measurement system noise. These devices have a 27 femtosecond phase stability floor and are stable to better than one picosecond for long periods of time. Their temperature coefficient is less than one picosecond per degree C, and they have shown virtually no voltage coefficients.

Chaotic patterns of autonomic activity during hypnotic recall.

PubMed

Bob, Petr; Siroka, Ivana; Susta, Marek

2009-01-01

Chaotic neural dynamics likely emerge in cognitive processes and may present time periods that are extremely sensitive to influences affecting the neural system. Recent findings suggest that this sensitivity may increase during retrieval of stressful emotional experiences reflecting underlying mechanism related to consolidation of traumatic memories. In this context, hypnotic recall of anxiety memories in 10 patients, simultaneously with ECG measurement was performed. The same measurement was performed during control cognitive task in 8 anxiety patients and 22 healthy controls. Nonlinear data analysis of ECG records indicates significant increase in the degree of chaos during retrieval of stressful memory in all the patients. The results suggest a role of chaotic neural dynamics during processing of anxiety-related stressful memories.

Effects of helicopter noise and vibration on pilot performance (as measured in a fixed-base flight simulator)

NASA Technical Reports Server (NTRS)

Stave, A. M.

1973-01-01

The effects of noise and vibration on pilot performance are described. Pilot subjects were required to fly VTOL commercial IFR schedules using the computer simulation facilities. The routes flown simulated closely metropolitan routes flown currently by a helicopter airline. The duration of simulator flights ranged from 3 to 8 hours. Subjects were exposed to noise sound pressure levels ranging from 74dB (ambient) to 100dB and 17 Hz vibration stimuli ranging from .1 g to .3 g measured at the floor directly beneath the pilot's seat. Despite subject reports of extreme fatigue in these long flights, performance did not degrade. A curve of performance shows a slow improvement for the first three hours of exposure and a slight loss in performance during the remainder of the flight. As environmental stress conditions (noise, vibration, and time in the simulator) increased, subject performance improved. Within the limits of this study, the higher the stress the better the performance.

Observer reliability of the Gross Motor Performance Measure and the Quality of Upper Extremity Skills Test, based on video recordings.

PubMed

Sorsdahl, Anne Brit; Moe-Nilssen, Rolf; Strand, Liv Inger

2008-02-01

The aim of this study was to examine observer reliability of the Gross Motor Performance Measure (GMPM) and the Quality of Upper Extremity Skills Test (QUEST) based on video clips. The tests were administered to 26 children with cerebral palsy (CP; 14 males, 12 females; range 2-13y, mean 7y 6mo), 24 with spastic CP, and two with dyskinesia. Respectively, five, six, five, four, and six children were classified in Gross Motor Function Classification System Levels I to V; and four, nine, five, five, and three children were classified in Manual Ability Classification System levels I to V. The children's performances were recorded and edited. Two experienced paediatric physical therapists assessed the children from watching the video clips. Intraobserver and interobserver reliability values of the total scores were mostly high, intraclass correlation coefficient (ICC)(1,1) varying from 0.69 to 0.97 with only one coefficient below 0.89. The ICCs of subscores varied from 0.36 to 0.95, finding'Alignment'and'Weight shift'in GMPM and'Protective extension'in QUEST highly reliable. The subscores'Dissociated movements'in GMPM and QUEST, and'Grasp'in QUEST were the least reliable, and recommendations are made to increase reliability of these subscores. Video scoring was time consuming, but was found to offer many advantages; the possibility to review performance, to use special trained observers for scoring and less demanding assessment for the children.

Magnetic field measurements near stand-alone transformer stations.

PubMed

Kandel, Shaiela; Hareuveny, Ronen; Yitzhak, Nir-Mordechay; Ruppin, Raphael

2013-12-01

Extremely low-frequency (ELF) magnetic field (MF) measurements around and above three stand-alone 22/0.4-kV transformer stations have been performed. The low-voltage (LV) cables between the transformer and the LV switchgear were found to be the major source of strong ELF MFs of limited spatial extent. The strong fields measured above the transformer stations support the assessment method, to be used in future epidemiological studies, of classifying apartments located right above the transformer stations as highly exposed to MFs. The results of the MF measurements above the ground around the transformer stations provide a basis for the assessment of the option of implementing precautionary procedures.

Measuring Skew in Average Surface Roughness as a Function of Surface Preparation

NASA Technical Reports Server (NTRS)

Stahl, Mark

2015-01-01

Characterizing surface roughness is important for predicting optical performance. Better measurement of surface roughness reduces polishing time, saves money and allows the science requirements to be better defined. This study characterized statistics of average surface roughness as a function of polishing time. Average surface roughness was measured at 81 locations using a Zygo white light interferometer at regular intervals during the polishing process. Each data set was fit to a normal and Largest Extreme Value (LEV) distribution; then tested for goodness of fit. We show that the skew in the average data changes as a function of polishing time.

[Effect of disease severity on upper extremity muscle strength, exercise capacity, and activities of daily living in individuals with pulmonary arterial hypertension].

PubMed

Özcan Kahraman, Buse; Özsoy, İsmail; Acar, Serap; Özpelit, Ebru; Akdeniz, Bahri; Sevinç, Can; Savcı, Sema

2017-07-01

Pulmonary arterial hypertension (PAH) is a rare disease. Although muscle strength, exercise capacity, quality of life, and activities of daily living of patients with PAH are affected, it is not known how they are affected by disease severity. The purpose of the present study was to investigate effects of disease severity on upper extremity muscle strength, exercise capacity, and performance of activities of daily living in patients with PAH. Twenty-five patients with disease severity classified according to the New York Heart Association (NYHA) as functional class II (n=14) or class III (n=11) were included in the study. Upper-extremity exercise capacity and limitations in performing activities of daily living were assessed with 6-minute pegboard and ring test (6PBRT) and the Milliken activities of daily living scale (MAS), respectively. Shoulder flexion, elbow extension, elbow flexion muscle strength, and handgrip strength were measured with dynamometer. There were no significant differences in age, gender, body mass index, or mean pulmonary artery pressure between groups (p>0.05). The 6PBRT, MAS, and elbow flexion (right) and grip strength (right and left) results were significantly lower in NYHA III group than in NYHA II group (p=0.004, p=0.002, p=0.043, p=0.002 and p=0.003, respectively). There was no significant difference in shoulder flexion, elbow flexion (left), or elbow extension between groups (p>0.05). Results suggest that upper extremity exercise capacity, elbow flexion muscle strength (right), and handgrip strength decrease and that limitations in activities of daily living grow as disease severity increases in patients with PAH. When planning rehabilitation programs, disease severity should be considered and evaluations and treatments for the upper extremities should be included.

Temporal Wind Pairs for Space Launch Vehicle Capability Assessment and Risk Mitigation

NASA Technical Reports Server (NTRS)

Decker, Ryan K.; Barbre, Robert E., Jr.

2015-01-01

Space launch vehicles incorporate upper-level wind assessments to determine wind effects on the vehicle and for a commit to launch decision. These assessments make use of wind profiles measured hours prior to launch and may not represent the actual wind the vehicle will fly through. Uncertainty in the winds over the time period between the assessment and launch introduces uncertainty in assessment of vehicle controllability and structural integrity that must be accounted for to ensure launch safety. Temporal wind pairs are used in engineering development of allowances to mitigate uncertainty. Five sets of temporal wind pairs at various times (0.75, 1.5, 2, 3 and 4-hrs) at the United States Air Force Eastern Range and Western Range, as well as the National Aeronautics and Space Administration's Wallops Flight Facility are developed for use in upper-level wind assessments on vehicle performance. Historical databases are compiled from balloon-based and vertically pointing Doppler radar wind profiler systems. Various automated and manual quality control procedures are used to remove unacceptable profiles. Statistical analyses on the resultant wind pairs from each site are performed to determine if the observed extreme wind changes in the sample pairs are representative of extreme temporal wind change. Wind change samples in the Eastern Range and Western Range databases characterize extreme wind change. However, the small sample sizes in the Wallops Flight Facility databases yield low confidence that the sample population characterizes extreme wind change that could occur.

Temporal Wind Pairs for Space Launch Vehicle Capability Assessment and Risk Mitigation

NASA Technical Reports Server (NTRS)

Decker, Ryan K.; Barbre, Robert E., Jr.

2014-01-01

Space launch vehicles incorporate upper-level wind assessments to determine wind effects on the vehicle and for a commit to launch decision. These assessments make use of wind profiles measured hours prior to launch and may not represent the actual wind the vehicle will fly through. Uncertainty in the winds over the time period between the assessment and launch introduces uncertainty in assessment of vehicle controllability and structural integrity that must be accounted for to ensure launch safety. Temporal wind pairs are used in engineering development of allowances to mitigate uncertainty. Five sets of temporal wind pairs at various times (0.75, 1.5, 2, 3 and 4-hrs) at the United States Air Force Eastern Range and Western Range, as well as the National Aeronautics and Space Administration's Wallops Flight Facility are developed for use in upper-level wind assessments on vehicle performance. Historical databases are compiled from balloon-based and vertically pointing Doppler radar wind profiler systems. Various automated and manual quality control procedures are used to remove unacceptable profiles. Statistical analyses on the resultant wind pairs from each site are performed to determine if the observed extreme wind changes in the sample pairs are representative of extreme temporal wind change. Wind change samples in the Eastern Range and Western Range databases characterize extreme wind change. However, the small sample sizes in the Wallops Flight Facility databases yield low confidence that the sample population characterizes extreme wind change that could occur.

Kinematic and neuromuscular relationships between lower extremity clinical movement assessments.

PubMed

Mauntel, Timothy C; Cram, Tyler R; Frank, Barnett S; Begalle, Rebecca L; Norcross, Marc F; Blackburn, J Troy; Padua, Darin A

2018-06-01

Lower extremity injuries have immediate and long-term consequences. Lower extremity movement assessments can assist with identifying individuals at greater injury risk and guide injury prevention interventions. Movement assessments identify similar movement characteristics and evidence suggests large magnitude kinematic relationships exist between movement patterns observed across assessments; however, the magnitude of the relationships for electromyographic (EMG) measures across movement assessments remains largely unknown. This study examined relationships between lower extremity kinematic and EMG measures during jump landings and single leg squats. Lower extremity three-dimensional kinematic and EMG data were sampled from healthy adults (males = 20, females = 20) during the movement assessments. Pearson correlations examined the relationships of the kinematic and EMG measures and paired samples t-tests compared mean kinematic and EMG measures between the assessments. Overall, significant moderate correlations were observed for lower extremity kinematic (r avg  = 0.41, r range  = 0.10-0.61) and EMG (r avg  = 0.47, r range  = 0.32-0.80) measures across assessments. Kinematic and EMG measures were greater during the jump landings. Jump landings and single leg squats place different demands on the body and necessitate different kinematic and EMG patterns, such that these measures are not highly correlated between assessments. Clinicians should, therefore, use multiple assessments to identify aberrant movement and neuromuscular control patterns so that comprehensive interventions can be implemented.

Predicting the effects of muscle activation on knee, thigh, and hip injuries in frontal crashes using a finite-element model with muscle forces from subject testing and musculoskeletal modeling.

PubMed

Chang, Chia-Yuan; Rupp, Jonathan D; Reed, Matthew P; Hughes, Richard E; Schneider, Lawrence W

2009-11-01

In a previous study, the authors reported on the development of a finite-element model of the midsize male pelvis and lower extremities with lower-extremity musculature that was validated using PMHS knee-impact response data. Knee-impact simulations with this model were performed using forces from four muscles in the lower extremities associated with two-foot bracing reported in the literature to provide preliminary estimates of the effects of lower-extremity muscle activation on knee-thigh-hip injury potential in frontal impacts. The current study addresses a major limitation of these preliminary simulations by using the AnyBody three-dimensional musculoskeletal model to estimate muscle forces produced in 35 muscles in each lower extremity during emergency one-foot braking. To check the predictions of the AnyBody Model, activation levels of twelve major muscles in the hip and lower extremities were measured using surface EMG electrodes on 12 midsize-male subjects performing simulated maximum and 50% of maximum braking in a laboratory seating buck. Comparisons between test results and the predictions of the AnyBody Model when it was used to simulate these same braking tests suggest that the AnyBody model appropriately predicts agonistic muscle activations but under predicts antagonistic muscle activations. Simulations of knee-to-knee-bolster impacts were performed by impacting the knees of the lower-extremity finite element model with and without the muscle forces predicted by the validated AnyBody Model. Results of these simulations confirm previous findings that muscle tension increases knee-impact force by increasing the effective mass of the KTH complex due to tighter coupling of muscle mass to bone. They also indicate that muscle activation preferentially couples mass distal to the hip, thereby accentuating the decrease in femur force from the knee to the hip. However, the reduction in force transmitted from the knee to the hip is offset by the increased force at the knee and by increased compressive forces at the hip due to activation of lower-extremity muscles. As a result, approximately 45% to 60% and 50% to 65% of the force applied to the knee is applied to the hip in the simulations without and with muscle tension, respectively. The simulation results suggest that lower-extremity muscle tension has little effect on the risk of hip injuries, but it increases the bending moments in the femoral shaft, thereby increasing the risk of femoral shaft fractures by 20%-40%. However, these findings may be affected by the inability of the AnyBody Model to appropriately predict antagonistic muscle forces.

Pre-Kidney Transplant Lower Extremity Impairment and Post-Kidney Transplant Mortality.

PubMed

Nastasi, A J; McAdams-DeMarco, M A; Schrack, J; Ying, H; Olorundare, I; Warsame, F; Mountford, A; Haugen, C E; González Fernández, M; Norman, S P; Segev, D L

2018-01-01

Prediction models for post-kidney transplantation mortality have had limited success (C-statistics ≤0.70). Adding objective measures of potentially modifiable factors may improve prediction and, consequently, kidney transplant (KT) survival through intervention. The Short Physical Performance Battery (SPPB) is an easily administered objective test of lower extremity function consisting of three parts (balance, walking speed, chair stands), each with scores of 0-4, for a composite score of 0-12, with higher scores indicating better function. SPPB performance and frailty (Fried frailty phenotype) were assessed at admission for KT in a prospective cohort of 719 KT recipients at Johns Hopkins Hospital (8/2009 to 6/2016) and University of Michigan (2/2013 to 12/2016). The independent associations between SPPB impairment (SPPB composite score ≤10) and composite score with post-KT mortality were tested using adjusted competing risks models treating graft failure as a competing risk. The 5-year posttransplantation mortality for impaired recipients was 20.6% compared to 4.5% for unimpaired recipients (p < 0.001). Impaired recipients had a 2.30-fold (adjusted hazard ratio [aHR] 2.30, 95% confidence interval [CI] 1.12-4.74, p = 0.02) increased risk of postkidney transplantation mortality compared to unimpaired recipients. Each one-point decrease in SPPB score was independently associated with a 1.19-fold (95% CI 1.09-1.30, p < 0.001) higher risk of post-KT mortality. SPPB-derived lower extremity function is a potentially highly useful and modifiable objective measure for pre-KT risk prediction. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

Statistical analysis and ANN modeling for predicting hydrological extremes under climate change scenarios: the example of a small Mediterranean agro-watershed.

PubMed

Kourgialas, Nektarios N; Dokou, Zoi; Karatzas, George P

2015-05-01

The purpose of this study was to create a modeling management tool for the simulation of extreme flow events under current and future climatic conditions. This tool is a combination of different components and can be applied in complex hydrogeological river basins, where frequent flood and drought phenomena occur. The first component is the statistical analysis of the available hydro-meteorological data. Specifically, principal components analysis was performed in order to quantify the importance of the hydro-meteorological parameters that affect the generation of extreme events. The second component is a prediction-forecasting artificial neural network (ANN) model that simulates, accurately and efficiently, river flow on an hourly basis. This model is based on a methodology that attempts to resolve a very difficult problem related to the accurate estimation of extreme flows. For this purpose, the available measurements (5 years of hourly data) were divided in two subsets: one for the dry and one for the wet periods of the hydrological year. This way, two ANNs were created, trained, tested and validated for a complex Mediterranean river basin in Crete, Greece. As part of the second management component a statistical downscaling tool was used for the creation of meteorological data according to the higher and lower emission climate change scenarios A2 and B1. These data are used as input in the ANN for the forecasting of river flow for the next two decades. The final component is the application of a meteorological index on the measured and forecasted precipitation and flow data, in order to assess the severity and duration of extreme events. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of a Lower Extremity Preventive Training Program on Physical Performance Scores in Military Recruits.

PubMed

Peck, Karen Y; DiStefano, Lindsay J; Marshall, Stephen W; Padua, Darin A; Beutler, Anthony I; de la Motte, Sarah J; Frank, Barnett S; Martinez, Jessica C; Cameron, Kenneth L

2017-11-01

Peck, KY, DiStefano, LJ, Marshall, SW, Padua, DA, Beutler, AI, de la Motte, SJ, Frank, BS, Martinez, JC, and Cameron, KL. Effect of a lower extremity preventive training program on physical performance scores in military recruits. J Strength Cond Res 31(11): 3146-3157, 2017-Exercise-based preventive training programs are designed to improve movement patterns associated with lower extremity injury risk; however, the impact of these programs on general physical fitness has not been evaluated. The purpose of this study was to compare fitness scores between participants in a preventive training program and a control group. One thousand sixty-eight freshmen from a U.S. Service Academy were cluster-randomized into either the intervention or control group during 6 weeks of summer training. The intervention group performed a preventive training program, specifically the Dynamic Integrated Movement Enhancement (DIME), which is designed to improve lower extremity movement patterns. The control group performed the Army Preparation Drill (PD), a warm-up designed to prepare soldiers for training. Main outcome measures were the Army Physical Fitness Test (APFT) raw and scaled (for age and sex) scores. Independent t tests were used to assess between-group differences. Multivariable logistic regression models were used to control for the influence of confounding variables. Dynamic Integrated Movement Enhancement group participants completed the APFT 2-mile run 20 seconds faster compared with the PD group (p < 0.001), which corresponded with significantly higher scaled scores (p < 0.001). Army Physical Fitness Test push-up scores were significantly higher in the DIME group (p = 0.041), but there were no significant differences in APFT sit-up scores. The DIME group had significantly higher total APFT scores compared with the PD group (p < 0.001). Similar results were observed in multivariable models after controlling for sex and body mass index (BMI). Committing time to the implementation of a preventive training program does not appear to negatively affect fitness test scores.

Short-term effects of upper extremity circuit resistance training on muscle strength and functional independence in patients with paraplegia.

PubMed

Yildirim, Adem; Sürücü, Gülseren Dost; Karamercan, Ayşe; Gedik, Dilay Eken; Atci, Nermin; Dülgeroǧlu, Deniz; Özgirgin, Neşe

2016-11-21

A number of exercises to strengthen the upper extremities are recommended to increase functional independence and quality of life (QoL) in patients with paraplegia. Circuit resistance training (CRT) is a type of progressive resistive exercise performed repeatedly at fixed mechanical exercise stations. The aim of this study was to investigate the potential benefits of CRT for upper extremity muscle strength, functional independence, and QoL in patients with paraplegia. Twenty-six patients with paraplegia who were participating in a conventional rehabilitation program at a tertiary education and research hospital were enrolled in this study. The participants were randomly assigned to two groups. The exercise group participated in the CRT program, which consisted of repetitive exercises for the upper extremities performed at fixed mechanical stations 5 sessions per week for 6 weeks, in addition to conventional rehabilitation. Participants in the control group received only conventional rehabilitation over the same period. We compared the groups with respect to QoL, as well as isokinetic muscle test outcomes in the upper extremities, using the Functional Independence Measure (FIM) and Borg's scale. We observed significant increases in scores on the physical component of the FIM, Borg's scale, and QoL in both the exercise and control groups. Furthermore, the large majority of isokinetic values were significantly more improved in the exercise group compared to the control group. When post-treatment outcomes were compared between the groups, improvements in scores on the physical component of the FIM and in most isokinetic values were significantly greater in the exercise group. This study showed that CRT has positive effects on muscle strength in the upper extremities and the physical disability components of the FIM when added to conventional rehabilitation programs for paraplegic patients. However, we observed no significant improvement in QoL scores after adding CRT to a conventional treatment regime. Randomized trial (Level II).

Footwear traction and lower extremity noncontact injury.

PubMed

Wannop, John W; Luo, Geng; Stefanyshyn, Darren J

2013-11-01

Football is the most popular high school sport; however, it has the highest rate of injury. Speculation has been prevalent that foot fixation due to high footwear traction contributes to injury risk. Therefore, the purpose of the study was to determine whether a relationship exists between the athlete's specific footwear traction (measured with their own shoes on the field of play) and lower extremity noncontact injury in high school football. For 3 yr, 555 high school football athletes had their footwear traction measured on the actual field of play at the start of the season, and any injury the athletes suffered during a game was recorded. Lower extremity noncontact injury rates, grouped based on the athlete's specific footwear traction (both translational and rotational), were compared. For translational traction, injury rate reached a peak of 23.3 injuries/1000 game exposures within the midrange of translational traction, before decreasing to 5.0 injuries/1000 game exposures in the high range of traction. For rotational traction, there was a steady increase in injury rate as footwear traction increased, starting at 4.2 injuries/1000 game exposures at low traction and reaching 19.2 injuries/1000 game exposures at high traction. A relationship exists between footwear traction and noncontact lower extremity injury, with increases in rotational traction leading to a greater injury rate and increases in translational traction leading to a decrease in injury. It is recommended that athletes consider selecting footwear with the lowest rotational traction values for which no detriment in performance results.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Divis, Kristin; Anderson-Bergman, Clifford; Abbott, Robert

Exposure to extreme environments is both mentally and physically taxing, leading to suboptimal performance and even life-threatening emergencies. Physiological and cognitive monitoring could provide the earliest indicator of performance decline and inform appropriate therapeutic intervention, yet little research has explored the relationship between these markers in strenuous settings. The Rim-to-Rim Wearables at the Canyon for Health (R2RWATCH) study is a research project at Sandia National Laboratories funded by the Defense Threat Reduction Agency to identify which physiological and cognitive phenomena collected by non-invasive wearable devices are the most related to performance in extreme environments. In a pilot study, data weremore » collected from civilians and military warfighters hiking the Rim-to-Rim trail at the Grand Canyon. Each participant wore a set of devices collecting physiological, cognitive, and environmental data such as heart rate, memory, ambient temperature, etc. Promising preliminary results found correlates between physiological markers recorded by the wearable devices and decline in cognitive abilities, although further work is required to refine those measurements. Planned follow-up studies will validate these findings and further explore outstanding questions.« less

Rate of muscle contraction is associated with cognition in women, not in men.

PubMed

Tian, Qu; Osawa, Yusuke; Resnick, Susan M; Ferrucci, Luigi; Studenski, Stephanie A

2018-05-08

In older persons, lower hand grip strength is associated with poorer cognition. Little is known about how the rate of muscle contraction relates to cognition and upper extremity motor function, and sex differences are understudied. Linear regression, adjusting for age, race, education, body mass index, appendicular lean mass, and knee pain assessed sex-specific cross-sectional associations of peak torque, rate of torque development (RTD) and rate of velocity development (RVD) with cognition and upper extremity motor function. In men (n=447), higher rate-adjusted peak torque and a greater RVD were associated with faster simple finger tapping speed, and a greater RVD was associated with higher nondominant pegboard performance. In women (n=447), higher peak torque was not associated with any measures, but a greater RTD was associated with faster simple tapping speed and higher language performance, and a greater RVD was associated with higher executive function, attention, memory, and nondominant pegboard performance. In women with low isokinetic peak torque, RVD was associated with attention and memory. RVD capacity may reflect neural health, especially in women with low muscle strength.

Effect of trotting speed on kinematic variables measured by use of extremity-mounted inertial measurement units in nonlame horses performing controlled treadmill exercise.

PubMed

Cruz, Antonio M; Vidondo, Beatriz; Ramseyer, Alessandra A; Maninchedda, Ugo E

2018-02-01

OBJECTIVE To assess effects of speed on kinematic variables measured by use of extremity-mounted inertial measurement units (IMUs) in nonlame horses performing controlled exercise on a treadmill. ANIMALS 10 nonlame horses. PROCEDURES 6 IMUs were attached at predetermined locations on 10 nonlame Franches Montagnes horses. Data were collected in triplicate during trotting at 3.33 and 3.88 m/s on a high-speed treadmill. Thirty-three selected kinematic variables were analyzed. Repeated-measures ANOVA was used to assess the effect of speed. RESULTS Significant differences between the 2 speeds were detected for most temporal (11/14) and spatial (12/19) variables. The observed spatial and temporal changes would translate into a gait for the higher speed characterized by increased stride length, protraction and retraction, flexion and extension, mediolateral movement of the tibia, and symmetry, but with similar temporal variables and a reduction in stride duration. However, even though the tibia coronal range of motion was significantly different between speeds, the high degree of variability raised concerns about whether these changes were clinically relevant. For some variables, the lower trotting speed apparently was associated with more variability than was the higher trotting speed. CONCLUSIONS AND CLINICAL RELEVANCE At a higher trotting speed, horses moved in the same manner (eg, the temporal events investigated occurred at the same relative time within the stride). However, from a spatial perspective, horses moved with greater action of the segments evaluated. The detected changes in kinematic variables indicated that trotting speed should be controlled or kept constant during gait evaluation.

Accuracy of Handheld Blood Glucose Meters at High Altitude

PubMed Central

de Vries, Suzanna T.; Fokkert, Marion J.; Dikkeschei, Bert D.; Rienks, Rienk; Bilo, Karin M.; Bilo, Henk J. G.

2010-01-01

Background Due to increasing numbers of people with diabetes taking part in extreme sports (e.g., high-altitude trekking), reliable handheld blood glucose meters (BGMs) are necessary. Accurate blood glucose measurement under extreme conditions is paramount for safe recreation at altitude. Prior studies reported bias in blood glucose measurements using different BGMs at high altitude. We hypothesized that glucose-oxidase based BGMs are more influenced by the lower atmospheric oxygen pressure at altitude than glucose dehydrogenase based BGMs. Methodology/Principal Findings Glucose measurements at simulated altitude of nine BGMs (six glucose dehydrogenase and three glucose oxidase BGMs) were compared to glucose measurement on a similar BGM at sea level and to a laboratory glucose reference method. Venous blood samples of four different glucose levels were used. Moreover, two glucose oxidase and two glucose dehydrogenase based BGMs were evaluated at different altitudes on Mount Kilimanjaro. Accuracy criteria were set at a bias <15% from reference glucose (when >6.5 mmol/L) and <1 mmol/L from reference glucose (when <6.5 mmol/L). No significant difference was observed between measurements at simulated altitude and sea level for either glucose oxidase based BGMs or glucose dehydrogenase based BGMs as a group phenomenon. Two GDH based BGMs did not meet set performance criteria. Most BGMs are generally overestimating true glucose concentration at high altitude. Conclusion At simulated high altitude all tested BGMs, including glucose oxidase based BGMs, did not show influence of low atmospheric oxygen pressure. All BGMs, except for two GDH based BGMs, performed within predefined criteria. At true high altitude one GDH based BGM had best precision and accuracy. PMID:21103399

Physiological and Cognitive Factors Related to Human Performance During the Grand Canyon Rim-to-Rim Hike

DOE PAGES

Divis, Kristin; Anderson-Bergman, Clifford; Abbott, Robert; ...

2018-01-24

Exposure to extreme environments is both mentally and physically taxing, leading to suboptimal performance and even life-threatening emergencies. Physiological and cognitive monitoring could provide the earliest indicator of performance decline and inform appropriate therapeutic intervention, yet little research has explored the relationship between these markers in strenuous settings. The Rim-to-Rim Wearables at the Canyon for Health (R2RWATCH) study is a research project at Sandia National Laboratories funded by the Defense Threat Reduction Agency to identify which physiological and cognitive phenomena collected by non-invasive wearable devices are the most related to performance in extreme environments. In a pilot study, data weremore » collected from civilians and military warfighters hiking the Rim-to-Rim trail at the Grand Canyon. Each participant wore a set of devices collecting physiological, cognitive, and environmental data such as heart rate, memory, ambient temperature, etc. Promising preliminary results found correlates between physiological markers recorded by the wearable devices and decline in cognitive abilities, although further work is required to refine those measurements. Planned follow-up studies will validate these findings and further explore outstanding questions.« less

Examining Associations between Psychosis Risk, Social Anhedonia, and Performance of Striatum-Related Behavioral Tasks

PubMed Central

Karcher, Nicole R.; Martin, Elizabeth A.; Kerns, John G.

2015-01-01

Both psychosis and anhedonia have been associated to some extent with striatal functioning. The current study examined whether either psychosis risk or social anhedonia was associated with performance on three tasks related to striatal functioning. Psychosis risk participants had extremely elevated Perceptual Aberration/Magical Ideation (PerMag) scores (n=69), with 43% of psychosis risk participants also having semi-structured interview-assessed psychotic-like experiences which further heightens their risk of psychotic disorder (Chapman, Chapman, Kwapil, Eckblad, & Zinser, 1994). Compared to both extremely elevated Social Anhedonia (n=60) and control (n=68) groups, the PerMag group exhibited poorer performance on two of the striatum-related tasks, the Weather Prediction Task (WPT) and the Learned Irrelevance Paradigm, but not on Finger Tapping. In addition, PerMag participants with psychotic-like experiences were especially impaired on the WPT. Overall, this study arguably provides the first evidence that psychosis risk but not social anhedonia is associated with performance on the WPT, a task thought to be strongly associated with activation in the associative striatum, and also suggests that the WPT might be especially useful as a behavioral measure of psychosis risk. PMID:26075968

Examining associations between psychosis risk, social anhedonia, and performance of striatum-related behavioral tasks.

PubMed

Karcher, Nicole R; Martin, Elizabeth A; Kerns, John G

2015-08-01

Both psychosis and anhedonia have been associated to some extent with striatal functioning. The current study examined whether either psychosis risk or social anhedonia was associated with performance on 3 tasks related to striatal functioning. Psychosis risk participants had extremely elevated Perceptual Aberration/Magical Ideation (PerMag) scores (n = 69), with 43% of psychosis risk participants also having semistructured interview-assessed psychotic-like experiences which further heightens their risk of psychotic disorder (Chapman, Chapman, Kwapil, Eckblad, & Zinser, 1994). Compared with both extremely elevated social anhedonia (n = 60) and control (n = 68) groups, the PerMag group exhibited poorer performance on 2 of the striatum-related tasks, the Weather Prediction Task (WPT) and the Learned Irrelevance Paradigm, but not on Finger Tapping. In addition, PerMag participants with psychotic-like experiences were especially impaired on the WPT. Overall, this study arguably provides the first evidence that psychosis risk but not social anhedonia is associated with performance on the WPT, a task thought to be strongly associated with activation in the associative striatum, and also suggests that the WPT might be especially useful as a behavioral measure of psychosis risk. (c) 2015 APA, all rights reserved).

Evaluation of different time domain peak models using extreme learning machine-based peak detection for EEG signal.

PubMed

Adam, Asrul; Ibrahim, Zuwairie; Mokhtar, Norrima; Shapiai, Mohd Ibrahim; Cumming, Paul; Mubin, Marizan

2016-01-01

Various peak models have been introduced to detect and analyze peaks in the time domain analysis of electroencephalogram (EEG) signals. In general, peak model in the time domain analysis consists of a set of signal parameters, such as amplitude, width, and slope. Models including those proposed by Dumpala, Acir, Liu, and Dingle are routinely used to detect peaks in EEG signals acquired in clinical studies of epilepsy or eye blink. The optimal peak model is the most reliable peak detection performance in a particular application. A fair measure of performance of different models requires a common and unbiased platform. In this study, we evaluate the performance of the four different peak models using the extreme learning machine (ELM)-based peak detection algorithm. We found that the Dingle model gave the best performance, with 72 % accuracy in the analysis of real EEG data. Statistical analysis conferred that the Dingle model afforded significantly better mean testing accuracy than did the Acir and Liu models, which were in the range 37-52 %. Meanwhile, the Dingle model has no significant difference compared to Dumpala model.

Physiological and Cognitive Factors Related to Human Performance During the Grand Canyon Rim-to-Rim Hike

DOE Office of Scientific and Technical Information (OSTI.GOV)

Divis, Kristin; Anderson-Bergman, Clifford; Abbott, Robert

Exposure to extreme environments is both mentally and physically taxing, leading to suboptimal performance and even life-threatening emergencies. Physiological and cognitive monitoring could provide the earliest indicator of performance decline and inform appropriate therapeutic intervention, yet little research has explored the relationship between these markers in strenuous settings. The Rim-to-Rim Wearables at the Canyon for Health (R2RWATCH) study is a research project at Sandia National Laboratories funded by the Defense Threat Reduction Agency to identify which physiological and cognitive phenomena collected by non-invasive wearable devices are the most related to performance in extreme environments. In a pilot study, data weremore » collected from civilians and military warfighters hiking the Rim-to-Rim trail at the Grand Canyon. Each participant wore a set of devices collecting physiological, cognitive, and environmental data such as heart rate, memory, ambient temperature, etc. Promising preliminary results found correlates between physiological markers recorded by the wearable devices and decline in cognitive abilities, although further work is required to refine those measurements. Planned follow-up studies will validate these findings and further explore outstanding questions.« less

Peak-discharge frequency and potential extreme peak discharge for natural streams in the Brazos River basin, Texas

USGS Publications Warehouse

Raines, Timothy H.

1998-01-01

The potential extreme peak-discharge curves as related to contributing drainage area were estimated for each of the three hydrologic regions from measured extreme peaks of record at 186 sites with streamflow-gaging stations and from measured extreme peaks at 37 sites without streamflow-gaging stations in and near the Brazos River Basin. The potential extreme peak-discharge curves generally are similar for hydrologic regions 1 and 2, and the curve for region 3 consistently is below the curves for regions 1 and 2, which indicates smaller peak discharges.

Low energy cyclotron for radiocarbon dating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Welch, J.J.

1984-12-01

The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer.more » These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity /sup 14/C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate /sup 14/C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect /sup 14/C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible.« less

Neural predictors of evaluative attitudes toward celebrities.

PubMed

Izuma, Keise; Shibata, Kazuhisa; Matsumoto, Kenji; Adolphs, Ralph

2017-03-01

Our attitudes toward others influence a wide range of everyday behaviors and have been the most extensively studied concept in the history of social psychology. Yet they remain difficult to measure reliably and objectively, since both explicit and implicit measures are typically confounded by other psychological processes. We here address the feasibility of decoding incidental attitudes based on brain activations. Participants were presented with pictures of members of a Japanese idol group inside an functional magnetic resonance imaging scanner while performing an unrelated detection task, and subsequently (outside the scanner) performed an incentive-compatible choice task that revealed their attitude toward each celebrity. We used a real-world election scheme that exists for this idol group, which confirmed both strongly negative and strongly positive attitudes toward specific individuals. Whole-brain multivariate analyses (searchlight-based support vector regression) showed that activation patterns in the anterior striatum predicted each participant's revealed attitudes (choice behavior) using leave-one-out (as well as 4-fold) cross-validation across participants. In contrast, attitude extremity (unsigned magnitude) could be decoded from a distinct region in the posterior striatum. The findings demonstrate dissociable striatal representations of valenced attitude and attitude extremity and constitute a first step toward an objective and process-pure neural measure of attitudes. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Measures of Functional Performance and Their Association With Hip and Thigh Strength

PubMed Central

Kollock, Roger; Van Lunen, Bonnie L.; Ringleb, Stacie I.; Oñate, James A.

2015-01-01

Context: Insufficient hip and thigh strength may increase an athlete's susceptibility to injury. However, screening for strength deficits using isometric and isokinetic instrumentation may not be practical in all clinical scenarios. Objective: To determine if functional performance tests are valid indicators of hip and thigh strength. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Sixty-two recreationally athletic men (n = 30, age = 21.07 years, height = 173.84 cm, mass = 81.47 kg) and women (n = 32, age = 21.03 years, height = 168.77 cm, mass = 68.22 kg) participants were recruited. Intervention(s): During session 1, we measured isometric peak force and rate of force development for 8 lower extremity muscle groups, followed by an isometric endurance test. During session 2, participants performed functional performance tests. Main Outcome Measure(s): Peak force, rate of force development, fatigue index, hop distance (or height), work (joules), and number of hops performed during the 30-second lateral-hop test were assessed. The r values were squared to calculate r 2. We used Pearson correlations to evaluate the associations between functional performance and strength. Results: In men, the strongest relationship was observed between triple-hop work and hip-adductor peak force (r2 = 50, P ≤ .001). Triple-hop work also was related to hip-adductor (r2 = 38, P ≤ .01) and hip-flexor (r2 = 37, P ≤ .01) rate of force development. For women, the strongest relationships were between single-legged vertical-jump work and knee-flexor peak force (r2 = 0.44, P ≤ .01) and single-legged vertical-jump height and knee-flexor peak force (r2 = 0.42, P ≤ .01). Single-legged vertical-jump height also was related to knee-flexor rate of force development (r2 = 0.49, P ≤ .001). The 30-second lateral-hop test did not account for a significant portion of the variance in strength endurance. Conclusions: Hop tests alone did not provide clinicians with enough information to make evidence-based decisions about lower extremity strength in isolated muscle groups. PMID:25347236

Movement-Based VR Gameplay Therapy For A Child With Cerebral Palsy.

PubMed

Stansfield, Sharon; Dennis, Carole; Larin, Hélène; Gallagher, Courtney

2015-01-01

This paper presents a single-subject feasibility study of a motion-based VR game designed to provide benefits similar to constraint-induced movement therapy for children with cerebral palsy, while providing a more enjoyable experience. The game was designed to encourage the child to perform the desired therapeutic movements by allowing him to interact with the game using only his more-affected arm. The study used an AB design: Performance across baseline and intervention phases was assessed to determine whether the intervention resulted in changes to repeated measures. Results of the study showed that compared with baseline measurements done prior to his game experience, the participant's post-intervention performance showed improvement in speed of reach, dissociated movement, and bilateral integration of upper extremities in functional tasks. The child's mother, as well as one of his therapists, reported better performance outside of the study environment as well.

Embedded Sensors and Controls to Improve Component Performance and Reliability -- Loop-scale Testbed Design Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melin, Alexander M.; Kisner, Roger A.

2016-09-01

Embedded instrumentation and control systems that can operate in extreme environments are challenging to design and operate. Extreme environments limit the options for sensors and actuators and degrade their performance. Because sensors and actuators are necessary for feedback control, these limitations mean that designing embedded instrumentation and control systems for the challenging environments of nuclear reactors requires advanced technical solutions that are not available commercially. This report details the development of testbed that will be used for cross-cutting embedded instrumentation and control research for nuclear power applications. This research is funded by the Department of Energy's Nuclear Energy Enabling Technologymore » program's Advanced Sensors and Instrumentation topic. The design goal of the loop-scale testbed is to build a low temperature pump that utilizes magnetic bearing that will be incorporated into a water loop to test control system performance and self-sensing techniques. Specifically, this testbed will be used to analyze control system performance in response to nonlinear and cross-coupling fluid effects between the shaft axes of motion, rotordynamics and gyroscopic effects, and impeller disturbances. This testbed will also be used to characterize the performance losses when using self-sensing position measurement techniques. Active magnetic bearings are a technology that can reduce failures and maintenance costs in nuclear power plants. They are particularly relevant to liquid salt reactors that operate at high temperatures (700 C). Pumps used in the extreme environment of liquid salt reactors provide many engineering challenges that can be overcome with magnetic bearings and their associated embedded instrumentation and control. This report will give details of the mechanical design and electromagnetic design of the loop-scale embedded instrumentation and control testbed.« less

Body composition and military performance--many things to many people.

PubMed

Friedl, Karl E

2012-07-01

Soldiers are expected to maintain the highest possible level of physical readiness because they must be ready to mobilize and perform their duties anywhere in the world at any time. The objective of Army body composition standards is to motivate physical training and good nutrition habits to ensure a high state of readiness. Establishment of enforceable and rational standards to support this objective has been challenging even at extremes of body size. Morbidly obese individuals are clearly not suited to military service, but very large muscular individuals may be superbly qualified for soldier performance demands. For this reason, large individuals are measured for body fat using a waist circumference-based equation (female soldiers are also measured for hip circumference). The main challenge comes in setting appropriate fat standards to support the full range of Army requirements. Military appearance ideals dictate the most stringent body fat standards, whereas health risk thresholds anchor the most liberal standards, and physical performance associations fall on a spectrum between these 2 poles. Standards should not exclude or penalize specialized performance capabilities such as endurance running or power lifting across a spectrum of body sizes and fat. The full integration of women into the military further complicates the issue because of sexually dimorphic characteristics that make gender-appropriate standards essential and where inappropriately stringent standards can compromise both health and performance of this segment of the force. Other associations with body composition such as stress effects on intraabdominal fat distribution patterns and metabolic implications of a fat reserve for survival in extreme environments are also relevant considerations. This is a review of the science that underpins the U.S. Army body composition standards.

Improving simulated long-term responses of vegetation to temperature and precipitation extremes using the ACME land model

NASA Astrophysics Data System (ADS)

Ricciuto, D. M.; Warren, J.; Guha, A.

2017-12-01

While carbon and energy fluxes in current Earth system models generally have reasonable instantaneous responses to extreme temperature and precipitation events, they often do not adequately represent the long-term impacts of these events. For example, simulated net primary productivity (NPP) may decrease during an extreme heat wave or drought, but may recover rapidly to pre-event levels following the conclusion of the extreme event. However, field measurements indicate that long-lasting damage to leaves and other plant components often occur, potentially affecting the carbon and energy balance for months after the extreme event. The duration and frequency of such extreme conditions is likely to shift in the future, and therefore it is critical for Earth system models to better represent these processes for more accurate predictions of future vegetation productivity and land-atmosphere feedbacks. Here we modify the structure of the Accelerated Climate Model for Energy (ACME) land surface model to represent long-term impacts and test the improved model against observations from experiments that applied extreme conditions in growth chambers. Additionally, we test the model against eddy covariance measurements that followed extreme conditions at selected locations in North America, and against satellite-measured vegetation indices following regional extreme events.

Effects of Experimental Anterior Knee Pain on Muscle Activation During Landing and Jumping Performed at Various Intensities.

PubMed

Park, Jihong; Denning, W Matt; Pitt, Jordan D; Francom, Devin; Hopkins, J Ty; Seeley, Matthew K

2017-01-01

Although knee pain is common, some facets of this pain are unclear. The independent effects (ie, independent from other knee injury or pathology) of knee pain on neural activation of lower-extremity muscles during landing and jumping have not been observed. To investigate the independent effects of knee pain on lower-extremity muscle (gastrocnemius, vastus medialis, medial hamstrings, gluteus medius, and gluteus maximus) activation amplitude during landing and jumping, performed at 2 different intensities. Laboratory-based, pretest, posttest, repeated-measures design, where all subjects performed both data-collection sessions. Thirteen able-bodied subjects performed 2 different land and jump tasks (forward and lateral) under 2 different conditions (control and pain), at 2 different intensities (high and low). For the pain condition, experimental knee pain was induced via a hypertonic saline injection into the right infrapatellar fat pad. Functional linear models were used to evaluate the influence of experimental knee pain on muscle-activation amplitude throughout the 2 land and jump tasks. Experimental knee pain independently altered activation for all of the observed muscles during various parts of the 2 different land and jump tasks. These activation alterations were not consistently influenced by task intensity. Experimental knee pain alters activation amplitude of various lower-extremity muscles during landing and jumping. The nature of the alteration varies between muscles, intensities, and phases of the movement (ie, landing and jumping). Generally, experimental knee pain inhibits the gastrocnemius, medial hamstring, and gluteus medius during landing while independently increasing activation of the same muscles during jumping.

Factors affecting the 7Be surface concentration and its extremely high occurrences over the Scandinavian Peninsula during autumn and winter.

PubMed

Ajtić, J; Brattich, E; Sarvan, D; Djurdjevic, V; Hernández-Ceballos, M A

2018-05-01

Relationships between the beryllium-7 activity concentrations in surface air and meteorological parameters (temperature, atmospheric pressure, and precipitation), teleconnection indices (Arctic Oscillation, North Atlantic Oscillation, and Scandinavian pattern) and number of sunspots are investigated using two multivariate statistical techniques: hierarchical cluster and factor analysis. The beryllium-7 surface measurements over 1995-2011, at four sampling sites located in the Scandinavian Peninsula, are obtained from the Radioactivity Environmental Monitoring Database. In all sites, the statistical analyses show that the beryllium-7 concentrations are strongly linked to temperature. Although the beryllium-7 surface concentration exhibits the well-characterised spring/summer maximum, our study shows that extremely high beryllium-7 concentrations, defined as the values exceeding the 90 th percentile in the data records for each site, also occur over the October-March period. Two types of autumn/winter extremes are distinguished: type-1 when the number of extremes in a given month is less than three, and type-2 when at least three extremes occur in a month. Factor analysis performed for these autumn/winter events shows a weaker effect of temperature and a stronger impact of the transport and production signal on the beryllium-7 concentrations. Further, the majority of the type-2 extremes are associated with a very high monthly Scandinavian teleconnection index. The type-2 extremes that occurred in January, February and March are also linked to sudden stratospheric warmings of the Arctic vortex. Our results indicate that the Scandinavian teleconnection index might be a good indicator of the meteorological conditions facilitating extremely high beryllium-7 surface concentrations over Scandinavia during autumn and winter. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assisting Hand Assessment and Children's Hand-Use Experience Questionnaire -Observed Versus Perceived Bimanual Performance in Children with Unilateral Cerebral Palsy.

PubMed

Ryll, Ulrike C; Bastiaenen, Carolien H G; Eliasson, Ann-Christin

2017-05-01

To explore the differences, relationship, and extent of agreement between the Assisting Hand Assessment (AHA), measuring observed ability to perform bimanual tasks, and the Children's Hand-Use Experience Questionnaire (CHEQ), assessing experienced bimanual performance. This study investigates a convenience sample of 34 children (16 girls) with unilateral cerebral palsy aged 6-18 years (mean 12.1, SD 3.9) in a cross-sectional design. The AHA and CHEQ subscales share 8-25% of their variance (R 2 ). Bland-Altman plots for AHA and all three CHEQ subscales indicate good average agreement, with a mean difference approaching zero but large 95% confidence intervals. Limits of agreement were extremely wide, indicating considerable disagreement between AHA and CHEQ subscales. AHA and CHEQ seem to measure different though somewhat related constructs of bimanual performance. Results of this investigation reinforce the recommendation to use both instruments to obtain complementary information about bimanual performance including observed and perceived performance of children with unilateral cerebral palsy.

Epidemiology and Impact on Performance of Lower Extremity Stress Injuries in Professional Basketball Players.

PubMed

Khan, Moin; Madden, Kim; Burrus, M Tyrrell; Rogowski, Joseph P; Stotts, Jeff; Samani, Marisa J; Sikka, Robby; Bedi, Asheesh

Professional basketball players in the National Basketball Association (NBA) subject their lower extremities to significant repetitive loading during both regular-season and off-season training. Little is known about the incidence of lower extremity bony stress injuries and their impact on return to play and performance in these athletes. Stress injuries of the lower extremity will have significant impact on performance. Case series. Level 4. All bony stress injuries from 2005 to 2015 were identified from the NBA. Number of games missed due to injury and performance statistics were collected from 2 years prior to injury to 2 years after the injury. A linear regression analysis was performed to determine the impact of injury for players who returned to sport. A total of 76 lower extremity bony stress injuries involving 75 NBA players (mean age, 25.4 ± 4.1 years) were identified. Fifty-five percent (42/76) involved the foot, and most injuries occurred during the regular season (82.9%, 63/76), with half occurring within the first 6 weeks. Among players who sustained a fifth metatarsal stress fracture, 42.9% were unable to return to professional play. Players who sustained stress injuries had reduced play performance, specifically related to number of games played ( P = 0.014) and number of steals per game ( P = 0.004). Players who had surgery had significantly better performance at 2 years than those who were managed nonoperatively, independent of the type of injury (β = 4.561; 95% CI, 1.255-7.868). Lower extremity bony stress injuries may significantly affect both short- and long-term player performance and career length. Stress injuries result in decreased player performance, and surgical intervention results in improved performance metrics compared with those treated using conservative methods. Stress injuries result in decreased player performance, and surgical intervention results in improved performance metrics.

GPS in dynamic monitoring of long-period structures

USGS Publications Warehouse

Celebi, M.

2000-01-01

Global Positioning System (GPS) technology with high sampling rates (??? 10 samples per second) allows scientifically justified and economically feasible dynamic measurements of relative displacements of long-period structures-otherwise difficult to measure directly by other means, such as the most commonly used accelerometers that require post-processing including double integration. We describe an experiment whereby the displacement responses of a simulated tall building are measured clearly and accurately in real-time. Such measurements can be used to assess average drift ratios and changes in dynamic characteristics, and therefore can be used by engineers and building owners or managers to assess the building performance during extreme motions caused by earthquakes and strong winds. By establishing threshold displacements or drift ratios and identifying changing dynamic characteristics, procedures can be developed to use such information to secure public safety and/or take steps to improve the performance of the building. Published by Elsevier Science Ltd.

Honing the accuracy of extreme-ultraviolet optical system testing: at-wavelength and visible-light measurements of the ETS Set-2 projection optic

NASA Astrophysics Data System (ADS)

Goldberg, Kenneth A.; Naulleau, Patrick P.; Bokor, Jeffrey; Chapman, Henry N.

2002-07-01

As the quality of optical systems for extreme ultraviolet lithography improves, high-accuracy wavefront metrology for alignment and qualification becomes ever more important. To enable the development of diffraction-limited EUV projection optics, visible-light and EUV interferometries must work in close collaboration. We present a detailed comparison of EUV and visible-light wavefront measurements performed across the field of view of a lithographic-quality EUV projection optical system designed for use in the Engineering Test Stand developed by the Virtual National Laboratory and the EUV Limited Liability Company. The comparisons reveal that the present level of RMS agreement lies in the 0.3-0.4-nm range. Astigmatism is the most significant aberration component for the alignment of this optical system; it is also the dominant term in the discrepancy, and the aberration with the highest measurement uncertainty. With EUV optical systems requiring total wavefront quality in the (lambda) EUV/50 range, and even higher surface-figure quality for the individual mirror elements, improved accuracy through future comparisons, and additional studies, are required.

Energy transport in short-pulse-laser-heated targets measured using extreme ultraviolet laser backlighting.

PubMed

Wilson, L A; Tallents, G J; Pasley, J; Whittaker, D S; Rose, S J; Guilbaud, O; Cassou, K; Kazamias, S; Daboussi, S; Pittman, M; Delmas, O; Demailly, J; Neveu, O; Ros, D

2012-08-01

The accurate characterization of thermal electron transport and the determination of heating by suprathermal electrons in laser driven solid targets are both issues of great importance to the current experiments being performed at the National Ignition Facility, which aims to achieve thermonuclear fusion ignition using lasers. Ionization, induced by electronic heat conduction, can cause the opacity of a material to drop significantly once bound-free photoionization is no longer energetically possible. We show that this drop in opacity enables measurements of the transmission of extreme ultraviolet (EUV) laser pulses at 13.9 nm to act as a signature of the heating of thin (50 nm) iron layers with a 50-nm thick parylene-N (CH) overlay irradiated by 35-fs pulses at irradiance 3×10(16) Wcm(-2). Comparing EUV transmission measurements at different times after irradiation to fluid code simulations shows that the target is instantaneously heated by hot electrons (with approximately 10% of the laser energy), followed by thermal conduction with a flux limiter of ≈0.05.

Ultrasonic High-Temperature Sensors: Past Experiments and Prospects for Future Use

NASA Astrophysics Data System (ADS)

Laurie, M.; Magallon, D.; Rempe, J.; Wilkins, C.; Pierre, J.; Marquié, C.; Eymery, S.; Morice, R.

2010-09-01

Ultrasonic thermometry sensors (UTS) have been intensively studied in the past to measure temperatures from 2080 K to 3380 K. This sensor, which uses the temperature dependence of the acoustic velocity in materials, was developed for experiments in extreme environments. Its major advantages, which are (a) capability of measuring a temperature profile from multiple sensors on a single probe and (b) measurement near the sensor material melting point, can be of great interest when dealing with on-line monitoring of high-temperature safety tests. Ultrasonic techniques were successfully applied in several severe accident related experiments. With new developments of alternative materials, this instrument may be used in a wide range of experimental areas where robustness and compactness are required. Long-term irradiation experiments of nuclear fuel to extremely high burn-ups could benefit from this previous experience. After an overview of UTS technology, this article summarizes experimental work performed to improve the reliability of these sensors. The various designs, advantages, and drawbacks are outlined and future prospects for long-term high-temperature irradiation experiments are discussed.

Psychometrics of the wrist stability and hand mobility subscales of the Fugl-Meyer assessment in moderately impaired stroke.

PubMed

Page, Stephen J; Hade, Erinn; Persch, Andrew

2015-01-01

There remains a need for a quickly administered, stroke-specific, bedside measure of active wrist and finger movement for the expanding stroke population. The wrist stability and hand mobility scales of the upper extremity Fugl-Meyer Assessment (w/h UE FM) constitute a valid, reliable measure of paretic UE impairment in patients with active wrist and finger movement. The aim of this study was to determine performance on the w/h UE FM in a stable cohort of survivors of stroke with only palpable movement in their paretic wrist flexors. A single-center cohort study was conducted. Thirty-two individuals exhibiting stable, moderate upper extremity hemiparesis (15 male, 17 female; mean age=56.6 years, SD=10.1; mean time since stroke=4.6 years, SD=5.8) participated in the study, which was conducted at an outpatient rehabilitation clinic in the midwestern United States. The w/h UE FM and Action Research Arm Test (ARAT) were administered twice. Intraclass correlation coefficients (ICCs), Cronbach alpha, and ordinal alpha were computed to determine reliability, and Spearman rank correlation coefficients and Bland-Altman plots were computed to establish validity. Intraclass correlation coefficients for the w/h UE FM and ARAT were .95 and .99, respectively. The w/h UE FM intrarater reliability and internal consistency were greater than .80, and concurrent validity was greater than .70. This also was the first stroke rehabilitative study to apply ordinal alpha to examine internal consistency values, revealing w/h UE FM levels greater than .85. Concurrent validity findings were corroborated by Bland-Altman plots. It appears that the w/h UE FM is a promising tool to measure distal upper extremity movement in patients with little active paretic wrist and finger movement. This finding widens the segment of patients on whom the w/h UE FM can be effectively used and addresses a gap, as commonly used measures necessitate active distal upper extremity movement. © 2015 American Physical Therapy Association.

Using Publicly Available Data to Construct a Transparent Measure of Health Care Value: A Method and Initial Results.

PubMed

Weeks, William B; Kotzbauer, Gregory R; Weinstein, James N

2016-06-01

Using publicly available Hospital Compare and Medicare data, we found a substantial range of hospital-level performance on quality, expenditure, and value measures for 4 common reasons for admission. Hospitals' ability to consistently deliver high-quality, low-cost care varied across the different reasons for admission. With the exception of coronary artery bypass grafting, hospitals that provided the highest-value care had more beds and a larger average daily census than those providing the lowest-value care. Transparent data like those we present can empower patients to compare hospital performance, make better-informed treatment decisions, and decide where to obtain care for particular health care problems. In the United States, the transition from volume to value dominates discussions of health care reform. While shared decision making might help patients determine whether to get care, transparency in procedure- and hospital-specific value measures would help them determine where to get care. Using Hospital Compare and Medicare expenditure data, we constructed a hospital-level measure of value from a numerator composed of quality-of-care measures (satisfaction, use of timely and effective care, and avoidance of harms) and a denominator composed of risk-adjusted 30-day episode-of-care expenditures for acute myocardial infarction (1,900 hospitals), coronary artery bypass grafting (884 hospitals), colectomy (1,252 hospitals), and hip replacement surgery (1,243 hospitals). We found substantial variation in aggregate measures of quality, cost, and value at the hospital level. Value calculation provided additional richness when compared to assessment based on quality or cost alone: about 50% of hospitals in an extreme quality- (and about 65% more in an extreme cost-) quintile were in the same extreme value quintile. With the exception of coronary artery bypass grafting, higher-value hospitals were larger and had a higher average daily census than lower-value hospitals, but were no more likely to be accredited by the Joint Commission or to have a residency program accredited by the American Council of Graduate Medical Education. While future efforts to compose value measures will certainly be modified and expanded to examine other reasons for admission, the construct that we present could allow patients to transparently compare procedure- and hospital-specific quality, spending, and value and empower them to decide where to obtain care. © 2016 Milbank Memorial Fund.

Digital Holographic Demonstration Systems by Stanford University and Siros Technologies

NASA Astrophysics Data System (ADS)

Hesselink, L.

Its useful capacity, transfer rate and access time measure the performance of a holographic data storage system (HDSS). Data should never be lost, requiring a corrected bit error rate (BER) of 10-12 to 10-15. To compete successfully in the large storage marketplace, an HDS drive should be cost-competitive with improved performance over other drives. The exception could be certain niche markets, where unique HDS attributes — all-solid-state implementation with extremely short access times or associative retrieval — are attractive or required.

A laboratory investigation into microwave backscattering from sea ice. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Bredow, Jonathan W.

1989-01-01

The sources of scattering of artificial sea ice were determined, backscatter measurements semi-quantitatively were compared with theoretical predictions, and inexpensive polarimetric radars were developed for sea ice backscatter studies. A brief review of the dielectric properties of sea ice and of commonly used surface and volume scattering theories is presented. A description is provided of the backscatter measurements performed and experimental techniques used. The development of inexpensive short-range polarimetric radars is discussed. The steps taken to add polarimetric capability to a simple FM-W radar are considered as are sample polarimetric phase measurements of the radar. Ice surface characterization data and techniques are discussed, including computation of surface rms height and correlation length and air bubble distribution statistics. A method is also presented of estimating the standard deviation of rms height and correlation length for cases of few data points. Comparisons were made of backscatter measurements and theory. It was determined that backscatter from an extremely smooth saline ice surface at C band cannot be attributed only to surface scatter. It was found that snow cover had a significant influence on backscatter from extremely smooth saline ice at C band.

The ankle brachial index and change in lower extremity functioning over time: the Women's Health and Aging Study.

PubMed

McDermott, Mary McGrae; Ferrucci, Luigi; Simonsick, Eleanor M; Balfour, Jennifer; Fried, Linda; Ling, Shari; Gibson, Daniel; Guralnik, Jack M

2002-02-01

To define the association between baseline ankle brachial index (ABI) level and subsequent onset of severe disability. Prospective cohort study. Baltimore community. Eight hundred forty-seven disabled women aged 65 and older participating in the Women's Health and Aging Study. At baseline, participants underwent measurement of ABI and lower extremity functioning. Measures of lower extremity functioning included patient's report of their ability to walk one-quarter of a mile, number of city blocks walked last week, number of stair flights climbed last week, and performance-based measures including walking speed over 4 meters, five repeated chair stands, and a summary performance score. Functioning was remeasured every 6 months for 3 years. Definitions of severe disability were developed a priori, and participants who met these definitions at baseline were excluded from subsequent analyses. Participants with an ABI of less than 0.60 at baseline had significantly higher cumulative probabilities of developing severe disability than participants with a baseline ABI of 0.90 to 1.50 for walking-specific outcomes (ability to walk a quarter of a mile, number of city blocks walked last week, and walking velocity) but not for the remaining functional outcomes. In age-adjusted Cox proportional hazards analyses, hazard ratios for participants with a baseline ABI of less than 0.60 were 1.63 for becoming unable to walk a quarter of a mile (P = .044), 2.00 for developing severe disability in the number of blocks walked last week (P = .004), and 1.61 for developing severe disability in walking speed (P = .041), compared with participants with a baseline ABI of 0.90 to 1.50. Adjusting for age, race, baseline performance, and comorbidities, an ABI of less than 0.60 remained associated with becoming severely disabled in the number of blocks walked last week (hazard ratio = 1.97, P = .009) and nearly significantly associated with becoming unable to walk a quarter of a mile (hazard ratio = 1.54, P = .09). In fully adjusted random effects models, a baseline ABI of less than 0.60 was associated with significantly greater decline in walking speed per year (P = .019) and nearly significantly greater decline in number of blocks walked last week per year (P = .053) compared with a baseline ABI of 0.90 to 1.50. In community-dwelling disabled older women, a low ABI is associated with a greater incidence of severe disability in walking-specific but not other lower extremity functional outcomes, compared with persons with a normal ABI over 3 years.

Validation of Questionnaire-Assessed Physical Activity in Comparison With Objective Measures Using Accelerometers and Physical Performance Measures Among Community-Dwelling Adults Aged ≥85 Years in Tokyo, Japan.

PubMed

Oguma, Yuko; Osawa, Yusuke; Takayama, Michiyo; Abe, Yukiko; Tanaka, Shigeho; Lee, I-Min; Arai, Yasumichi

2017-04-01

To date, there is no physical activity (PA) questionnaire with convergent and construct validity for the oldest-old. The aim of the current study was to investigate the validity of questionnaire-assessed PA in comparison with objective measures determined by uniaxial and triaxial accelerometers and physical performance measures in the oldest-old. Participants were 155 elderly (mean age 90 years) who were examined at the university and agreed to wear an accelerometer for 7 days in the 3-year-follow-up survey of the Tokyo Oldest-Old Survey of Total Health. Fifty-nine participants wore a uniaxial and triaxial accelerometer simultaneously. Self-rated walking, exercise, and household PA were measured using a modified Zutphen PA Questionnaire (PAQ). Several physical performance tests were done, and the associations among PAQ, accelerometer-assessed PA, and physical performances were compared by Spearman's correlation coefficients. Significant, low to moderate correlations between PA measures were seen on questionnaire and accelerometer assessments (ρ = 0.19 to 0.34). Questionnaireassessed PA measure were correlated with a range of lower extremity performance (ρ = 0.21 to 0.29). This PAQ demonstrated convergent and construct validity. Our findings suggest that the PAQ can reasonably be used in this oldest-old population to rank their PA level.

Modeling and evaluation of a high-resolution CMOS detector for cone-beam CT of the extremities.

PubMed

Cao, Qian; Sisniega, Alejandro; Brehler, Michael; Stayman, J Webster; Yorkston, John; Siewerdsen, Jeffrey H; Zbijewski, Wojciech

2018-01-01

Quantitative assessment of trabecular bone microarchitecture in extremity cone-beam CT (CBCT) would benefit from the high spatial resolution, low electronic noise, and fast scan time provided by complementary metal-oxide semiconductor (CMOS) x-ray detectors. We investigate the performance of CMOS sensors in extremity CBCT, in particular with respect to potential advantages of thin (<0.7 mm) scintillators offering higher spatial resolution. A cascaded systems model of a CMOS x-ray detector incorporating the effects of CsI:Tl scintillator thickness was developed. Simulation studies were performed using nominal extremity CBCT acquisition protocols (90 kVp, 0.126 mAs/projection). A range of scintillator thickness (0.35-0.75 mm), pixel size (0.05-0.4 mm), focal spot size (0.05-0.7 mm), magnification (1.1-2.1), and dose (15-40 mGy) was considered. The detectability index was evaluated for both CMOS and a-Si:H flat-panel detector (FPD) configurations for a range of imaging tasks emphasizing spatial frequencies associated with feature size aobj. Experimental validation was performed on a CBCT test bench in the geometry of a compact orthopedic CBCT system (SAD = 43.1 cm, SDD = 56.0 cm, matching that of the Carestream OnSight 3D system). The test-bench studies involved a 0.3 mm focal spot x-ray source and two CMOS detectors (Dalsa Xineos-3030HR, 0.099 mm pixel pitch) - one with the standard CsI:Tl thickness of 0.7 mm (C700) and one with a custom 0.4 mm thick scintillator (C400). Measurements of modulation transfer function (MTF), detective quantum efficiency (DQE), and CBCT scans of a cadaveric knee (15 mGy) were obtained for each detector. Optimal detectability for high-frequency tasks (feature size of ~0.06 mm, consistent with the size of trabeculae) was ~4× for the C700 CMOS detector compared to the a-Si:H FPD at nominal system geometry of extremity CBCT. This is due to ~5× lower electronic noise of a CMOS sensor, which enables input quantum-limited imaging at smaller pixel size. Optimal pixel size for high-frequency tasks was <0.1 mm for a CMOS, compared to ~0.14 mm for an a-Si:H FPD. For this fine pixel pitch, detectability of fine features could be improved by using a thinner scintillator to reduce light spread blur. A 22% increase in detectability of 0.06 mm features was found for the C400 configuration compared to C700. An improvement in the frequency at 50% modulation (f 50 ) of MTF was measured, increasing from 1.8 lp/mm for C700 to 2.5 lp/mm for C400. The C400 configuration also achieved equivalent or better DQE as C700 for frequencies above ~2 mm -1 . Images of cadaver specimens confirmed improved visualization of trabeculae with the C400 sensor. The small pixel size of CMOS detectors yields improved performance in high-resolution extremity CBCT compared to a-Si:H FPDs, particularly when coupled with a custom 0.4 mm thick scintillator. The results indicate that adoption of a CMOS detector in extremity CBCT can benefit applications in quantitative imaging of trabecular microstructure in humans. © 2017 American Association of Physicists in Medicine.

Results of the AEROS satellite program: Summary

NASA Technical Reports Server (NTRS)

Lammerzahl, P.; Rawer, K.; Roemer, N.

1980-01-01

Published literature reporting aeronomic data collected on two AEROS missions is summarized. The extreme ultraviolet solar radiation and other significant parameters of the thermosphere/ionosphere were investigated. Kinetic pressure, the quantity of atomic nitrogen, and partial densities of helium, oxygen, nitrogen, argon, and atomic nitrogen were determined. The thermal electron population, superthermal energy distribution, plasma density, ion temperature, and composition according to ion types were measured. The chief energy supply in the thermosphere was calculated. Aeronomic calculations showing that variations in the parameters of the ionosphere cannot be correlated with fluctuations of extreme ultraviolet solar radiation were performed. The AEROS data were compared with data from S3-1, ISIS, and AE-C satellites. Models of the thermosphere and ionosphere were developed.

Perceived ability to perform daily hand activities after stroke and associated factors: a cross-sectional study.

PubMed

Ekstrand, Elisabeth; Rylander, Lars; Lexell, Jan; Brogårdh, Christina

2016-11-02

Despite that disability of the upper extremity is common after stroke, there is limited knowledge how it influences self-perceived ability to perform daily hand activities. The aim of this study was to describe which daily hand activities that persons with mild to moderate impairments of the upper extremity after stroke perceive difficult to perform and to evaluate how several potential factors are associated with the self-perceived performance. Seventy-five persons (72 % male) with mild to moderate impairments of the upper extremity after stroke (4 to 116 months) participated. Self-perceived ability to perform daily hand activities was rated with the ABILHAND Questionnaire. The perceived ability to perform daily hand activities and the potentially associated factors (age, gender, social and vocational situation, affected hand, upper extremity pain, spasticity, grip strength, somatosensation of the hand, manual dexterity, perceived participation and life satisfaction) were evaluated by linear regression models. The activities that were perceived difficult or impossible for a majority of the participants were bimanual tasks that required fine manual dexterity of the more affected hand. The factor that had the strongest association with perceived ability to perform daily hand activities was dexterity (p < 0.001), which together with perceived participation (p = 0.002) explained 48 % of the variance in the final multivariate model. Persons with mild to moderate impairments of the upper extremity after stroke perceive that bimanual activities requiring fine manual dexterity are the most difficult to perform. Dexterity and perceived participation are factors specifically important to consider in the rehabilitation of the upper extremity after stroke in order to improve the ability to use the hands in daily life.

Hybrid photonic signal processing

NASA Astrophysics Data System (ADS)

Ghauri, Farzan Naseer

This thesis proposes research of novel hybrid photonic signal processing systems in the areas of optical communications, test and measurement, RF signal processing and extreme environment optical sensors. It will be shown that use of innovative hybrid techniques allows design of photonic signal processing systems with superior performance parameters and enhanced capabilities. These applications can be divided into domains of analog-digital hybrid signal processing applications and free-space---fiber-coupled hybrid optical sensors. The analog-digital hybrid signal processing applications include a high-performance analog-digital hybrid MEMS variable optical attenuator that can simultaneously provide high dynamic range as well as high resolution attenuation controls; an analog-digital hybrid MEMS beam profiler that allows high-power watt-level laser beam profiling and also provides both submicron-level high resolution and wide area profiling coverage; and all optical transversal RF filters that operate on the principle of broadband optical spectral control using MEMS and/or Acousto-Optic tunable Filters (AOTF) devices which can provide continuous, digital or hybrid signal time delay and weight selection. The hybrid optical sensors presented in the thesis are extreme environment pressure sensors and dual temperature-pressure sensors. The sensors employ hybrid free-space and fiber-coupled techniques for remotely monitoring a system under simultaneous extremely high temperatures and pressures.

Materials and noncoplanar mesh designs for integrated circuits with linear elastic responses to extreme mechanical deformations

PubMed Central

Kim, Dae-Hyeong; Song, Jizhou; Choi, Won Mook; Kim, Hoon-Sik; Kim, Rak-Hwan; Liu, Zhuangjian; Huang, Yonggang Y.; Hwang, Keh-Chih; Zhang, Yong-wei; Rogers, John A.

2008-01-01

Electronic systems that offer elastic mechanical responses to high-strain deformations are of growing interest because of their ability to enable new biomedical devices and other applications whose requirements are impossible to satisfy with conventional wafer-based technologies or even with those that offer simple bendability. This article introduces materials and mechanical design strategies for classes of electronic circuits that offer extremely high stretchability, enabling them to accommodate even demanding configurations such as corkscrew twists with tight pitch (e.g., 90° in ≈1 cm) and linear stretching to “rubber-band” levels of strain (e.g., up to ≈140%). The use of single crystalline silicon nanomaterials for the semiconductor provides performance in stretchable complementary metal-oxide-semiconductor (CMOS) integrated circuits approaching that of conventional devices with comparable feature sizes formed on silicon wafers. Comprehensive theoretical studies of the mechanics reveal the way in which the structural designs enable these extreme mechanical properties without fracturing the intrinsically brittle active materials or even inducing significant changes in their electrical properties. The results, as demonstrated through electrical measurements of arrays of transistors, CMOS inverters, ring oscillators, and differential amplifiers, suggest a valuable route to high-performance stretchable electronics. PMID:19015528

Early working memory as a racially and ethnically neutral measure of outcome in extremely preterm children at 18-22 months

PubMed Central

Lowe, Jean R.; Duncan, Andrea Freeman; Bann, Carla M.; Fuller, Janell; Hintz, Susan R.; Das, Abhik; Higgins, Rosemary D.; Watterberg, Kristi L.

2013-01-01

Background Difficulties with executive function has been found in preterm children, resulting in difficulties with learning and school performance. Aim This study evaluated the relationship of early working memory as measured by object permanence items to the cognitive and language scores on the Bayley Scales-III in a cohort of children born extremely preterm. Study Design Logistic regression models were conducted to compare object permanence scores derived from the Bayley Scales-III by race/ethnicity and maternal education, controlling for medical covariates. Subjects Extremely preterm toddlers (526), who were part of a Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's multi-center study, were evaluated at 18-22 months corrected age. Outcome Measures Object permanence scores derived from the Bayley Developmental Scales were compared by race/ethnicity and maternal education, controlling for medical covariates. Results There were no significant differences in object permanence mastery and scores among the treatment groups after controlling for medical and social variables, including maternal education and race/ethnicity. Males and children with intraventricular hemorrhage, retinopathy of prematurity, and bronchopulmonary dysplasia were less likely to demonstrate object permanence mastery and had lower object permanence scores. Children who attained object permanence mastery had significantly higher Bayley Scales-III cognitive and language scores after controlling for medical and socio-economic factors. Conclusions Our measure of object permanence is free of influence from race, ethnic and socio-economic factors. Adding this simple task to current clinical practice could help detect early executive function difficulties in young children. PMID:23993309

Broad-band flared horn with low sidelobes. [applicable to cosmic background radiation measurement

NASA Technical Reports Server (NTRS)

Mather, J. C.

1981-01-01

A circular horn antenna flared like a trumpet is analyzed with the geometrical theory of diffraction and then tested experimentally. Sidelobes are found to be extremely low (-75 dB), in agreement with theory. Low sidelobe performance is predicted to be broad-band and to improve at higher frequencies. The full aperture of the tested horn is approximately 50 wavelengths. Suggestions for even better low sidelobe antennas are made. The applicability of this horn to the measurement of cosmic background radiation is noted.

An evaluation of the state of time synchronization on leadership class supercomputers

DOE PAGES

Jones, Terry; Ostrouchov, George; Koenig, Gregory A.; ...

2017-10-09

We present a detailed examination of time agreement characteristics for nodes within extreme-scale parallel computers. Using a software tool we introduce in this paper, we quantify attributes of clock skew among nodes in three representative high-performance computers sited at three national laboratories. Our measurements detail the statistical properties of time agreement among nodes and how time agreement drifts over typical application execution durations. We discuss the implications of our measurements, why the current state of the field is inadequate, and propose strategies to address observed shortcomings.

Time-resolved experiments in the frequency domain using synchrotron radiation (invited)

NASA Astrophysics Data System (ADS)

De Stasio, Gelsomina; Giusti, A. M.; Parasassi, T.; Ravagnan, G.; Sapora, O.

1992-01-01

PLASTIQUE is the only synchrotron radiation beam line in the world that performs time-resolved fluorescence experiments in frequency domain. These experiments are extremely valuable sources of information on the structure and the dynamics of molecules. This technique measures fluorescence lifetimes with picosecond resolution in the near UV spectral range. Such accurate measurements are rendered possible by taking phase and modulation data, and by the advantages of the cross-correlation technique. A successful experiment demonstrated the radiation damage induced by low doses of radiation on rabbit blood cell membranes.

An evaluation of the state of time synchronization on leadership class supercomputers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Terry; Ostrouchov, George; Koenig, Gregory A.

We present a detailed examination of time agreement characteristics for nodes within extreme-scale parallel computers. Using a software tool we introduce in this paper, we quantify attributes of clock skew among nodes in three representative high-performance computers sited at three national laboratories. Our measurements detail the statistical properties of time agreement among nodes and how time agreement drifts over typical application execution durations. We discuss the implications of our measurements, why the current state of the field is inadequate, and propose strategies to address observed shortcomings.

Sensory-Challenge Balance Exercises Improve Multisensory Reweighting in Fall-Prone Older Adults.

PubMed

Allison, Leslie K; Kiemel, Tim; Jeka, John J

2018-04-01

Multisensory reweighting (MSR) deficits in older adults contribute to fall risk. Sensory-challenge balance exercises may have value for addressing the MSR deficits in fall-prone older adults. The purpose of this study was to examine the effect of sensory-challenge balance exercises on MSR and clinical balance measures in fall-prone older adults. We used a quasi-experimental, repeated-measures, within-subjects design. Older adults with a history of falls underwent an 8-week baseline (control) period. This was followed by an 8-week intervention period that included 16 sensory-challenge balance exercise sessions performed with computerized balance training equipment. Measurements, taken twice before and once after intervention, included laboratory measures of MSR (center of mass gain and phase, position, and velocity variability) and clinical tests (Activities-specific Balance Confidence Scale, Berg Balance Scale, Sensory Organization Test, Limits of Stability test, and lower extremity strength and range of motion). Twenty adults 70 years of age and older with a history of falls completed all 16 sessions. Significant improvements were observed in laboratory-based MSR measures of touch gain (P = 0.006) and phase (P = 0.05), Berg Balance Scale (P = 0.002), Sensory Organization Test (P = 0.002), Limits of Stability Test (P = 0.001), and lower extremity strength scores (P = 0.005). Mean values of vision gain increased more than those for touch gain, but did not reach significance. A balance exercise program specifically targeting multisensory integration mechanisms improved MSR, balance, and lower extremity strength in this mechanistic study. These valuable findings provide the scientific rationale for sensory-challenge balance exercise to improve perception of body position and motion in space and potential reduction in fall risk.

Effects of virtual reality-based bilateral upper-extremity training on brain activity in post-stroke patients.

PubMed

Lee, Su-Hyun; Kim, Yu-Mi; Lee, Byoung-Hee

2015-07-01

[Purpose] This study investigated the therapeutic effects of virtual reality-based bilateral upper-extremity training on brain activity in patients with stroke. [Subjects and Methods] Eighteen chronic stroke patients were divided into two groups: the virtual reality-based bilateral upper-extremity training group (n = 10) and the bilateral upper-limb training group (n = 8). The virtual reality-based bilateral upper-extremity training group performed bilateral upper-extremity exercises in a virtual reality environment, while the bilateral upper-limb training group performed only bilateral upper-extremity exercise. All training was conducted 30 minutes per day, three times per week for six weeks, followed by brain activity evaluation. [Results] Electroencephalography showed significant increases in concentration in the frontopolar 2 and frontal 4 areas, and significant increases in brain activity in the frontopolar 1 and frontal 3 areas in the virtual reality-based bilateral upper-extremity training group. [Conclusion] Virtual reality-based bilateral upper-extremity training can improve the brain activity of stroke patients. Thus, virtual reality-based bilateral upper-extremity training is feasible and beneficial for improving brain activation in stroke patients.

Characteristic changes in heat extremes over India in response to global warming using CMIP5 model simulations

NASA Astrophysics Data System (ADS)

Kundeti, K.; Chang, H. H.; T V, L. K.; Desamsetti, S.; Dandi, A. R.

2017-12-01

A critical aspect of human-induced climate change is how it will affect climatological mean and extremes around the world. Summer season surface climate of the Indian sub continent is characterized by hot and humid conditions. The global warming can have profound impact on the mean climate as well as extreme weather events over India that may affect both natural and human systems significantly. In this study we examine very direct measure of the impact of climate change on human health and comfort. The Heat stress Index is the measure of combined effects of temperature and atmospheric moisture on the ability of the human body to dissipate heat. It is important to assess the future changes in the seasonal mean of heat stress index, it is also desirable to know how the future holds when it comes to extremes in temperature for a country like India where so much of outdoor activities happen both in the onshore/offshore energy sectors, extensive construction activities. This study assesses the performance of the Coupled Model Inter comparison Project Phase 5 (CMIP5) simulations in the present and develops future climate scenarios. The changes in heat extremes are assessed for three future periods 2016-2035, 2046-2065 and 2080-2099 with respect to 1986-2005 (base line) under two RCP's (Representative Concentrate Pathways) - RCP4.5 and RCP8.5. In view of this, we provide the expected future changes in the seasonal mean heat stress indices and also the frequency of heat stress exceeding a certain threshold relevant to Inida. Besides, we provide spatial maps of expected future changes in the heat stress index derived as a function of daily mean temperature and relative humidity and representative of human comfort having a direct bearing on the human activities. The observations show an increase in heat extremes over many parts in this region that are generally well captured by the models. The results indicate a significant change in frequency and intensity of heat extremes over many parts of this region which may have serious implications on agriculture,human health, management of urban infrastructure and water resources.

Muscle power is an important measure to detect deficits in muscle function in hip osteoarthritis: a cross-sectional study.

PubMed

Bieler, Theresa; Magnusson, Stig Peter; Christensen, Helle Elisabeth; Kjaer, Michael; Beyer, Nina

2017-07-01

To investigate between-leg differences in hip and thigh muscle strength and leg extensor power in patients with unilateral hip osteoarthritis. Further, to compare between-leg differences in knee extensor strength and leg extensor power between patients and healthy peers. Seventy-two patients (60-87 years) with radiographic and symptomatic hip osteoarthritis not awaiting hip replacement and 35 healthy peers (63-82 years) were included. Hip and thigh muscle strength and leg extensor power were measured in patients and knee extensor strength and leg extensor power in healthy. The symptomatic extremity in patients was significantly (p < 0.05, paired t-test) weaker compared with the non-symptomatic extremity for five hip muscles (8-17%), knee extensors (11%) and leg extensor power (19%). Healthy older adults had asymmetry in knee extensor strength (6%, p < 0.05) comparable to that found in patients, but had no asymmetry in leg extensor power. Patients had generalized weakening of the affected lower extremity and numerically the largest asymmetry was evident for leg extensor power. In contrast, healthy peers had no asymmetry in leg extensor power. These results indicate that exercise interventions focusing on improving leg extensor power of the symptomatic lower extremity and reducing asymmetry may be beneficial for patients with hip osteoarthritis. Implications for Rehabilitation Even in patients with mild symptoms not awaiting hip replacement a generalized muscle weakening of the symptomatic lower extremity seems to be present. Between-leg differences in leg extensor power (force × velocity) appears to be relatively large (19%) in patients with unilateral hip osteoarthritis in contrast to healthy peers who show no asymmetry. Compared to muscle strength the relationship between functional performance and leg extensor power seems to be stronger, and more strongly related to power of the symptomatic lower extremity. Our results indicate that exercise interventions focusing on improving leg extensor power of the symptomatic lower extremity and reducing asymmetry may be beneficial for patients with mild symptoms not awaiting hip replacement.

Consistency of extreme flood estimation approaches

NASA Astrophysics Data System (ADS)

Felder, Guido; Paquet, Emmanuel; Penot, David; Zischg, Andreas; Weingartner, Rolf

2017-04-01

Estimations of low-probability flood events are frequently used for the planning of infrastructure as well as for determining the dimensions of flood protection measures. There are several well-established methodical procedures to estimate low-probability floods. However, a global assessment of the consistency of these methods is difficult to achieve, the "true value" of an extreme flood being not observable. Anyway, a detailed comparison performed on a given case study brings useful information about the statistical and hydrological processes involved in different methods. In this study, the following three different approaches for estimating low-probability floods are compared: a purely statistical approach (ordinary extreme value statistics), a statistical approach based on stochastic rainfall-runoff simulation (SCHADEX method), and a deterministic approach (physically based PMF estimation). These methods are tested for two different Swiss catchments. The results and some intermediate variables are used for assessing potential strengths and weaknesses of each method, as well as for evaluating the consistency of these methods.

The effects of music on pain perception of stroke patients during upper extremity joint exercises.

PubMed

Kim, Soo Ji; Koh, Iljoo

2005-01-01

The purpose of this study was to determine the effects of music therapy on pain perception of stroke patients during upper extremity joint exercises. Ten stroke patients (1 male and 9 females) ranging in age from 61 to 73 participated in the study. Music conditions used in the study consisted of: (a) song, (b) karaoke accompaniment (same music to condition A except singers' voices), and (c) no music. Exercise movements in this study included hand, wrist, and shoulder joints. During the 8-week period music therapy sessions, subjects repeated 3 conditions according to the randomized orders and subjects rated their perceived pain on a scale immediately after each condition. The General Linear Model (GLM) Repeated Measures ANOVA revealed that there were no significant differences in pain rating across the three music conditions. However, positive affects and verbal responses, while performing upper extremity exercises with both music and karaoke accompaniment music, were observed using video observations.

TECA: Petascale pattern recognition for climate science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prabhat, .; Byna, Surendra; Vishwanath, Venkatram

Climate Change is one of the most pressing challenges facing humanity in the 21st century. Climate simulations provide us with a unique opportunity to examine effects of anthropogenic emissions. Highresolution climate simulations produce “Big Data”: contemporary climate archives are ≈ 5PB in size and we expect future archives to measure on the order of Exa-Bytes. In this work, we present the successful application of TECA (Toolkit for Extreme Climate Analysis) framework, for extracting extreme weather patterns such as Tropical Cyclones, Atmospheric Rivers and Extra-Tropical Cyclones from TB-sized simulation datasets. TECA has been run at full-scale on Cray XE6 and IBMmore » BG/Q systems, and has reduced the runtime for pattern detection tasks from years to hours. TECA has been utilized to evaluate the performance of various computational models in reproducing the statistics of extreme weather events, and for characterizing the change in frequency of storm systems in the future.« less

Extreme-scale Algorithms and Solver Resilience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dongarra, Jack

A widening gap exists between the peak performance of high-performance computers and the performance achieved by complex applications running on these platforms. Over the next decade, extreme-scale systems will present major new challenges to algorithm development that could amplify this mismatch in such a way that it prevents the productive use of future DOE Leadership computers due to the following; Extreme levels of parallelism due to multicore processors; An increase in system fault rates requiring algorithms to be resilient beyond just checkpoint/restart; Complex memory hierarchies and costly data movement in both energy and performance; Heterogeneous system architectures (mixing CPUs, GPUs,more » etc.); and Conflicting goals of performance, resilience, and power requirements.« less

Data and software tools for gamma radiation spectral threat detection and nuclide identification algorithm development and evaluation

NASA Astrophysics Data System (ADS)

Portnoy, David; Fisher, Brian; Phifer, Daniel

2015-06-01

The detection of radiological and nuclear threats is extremely important to national security. The federal government is spending significant resources developing new detection systems and attempting to increase the performance of existing ones. The detection of illicit radionuclides that may pose a radiological or nuclear threat is a challenging problem complicated by benign radiation sources (e.g., cat litter and medical treatments), shielding, and large variations in background radiation. Although there is a growing acceptance within the community that concentrating efforts on algorithm development (independent of the specifics of fully assembled systems) has the potential for significant overall system performance gains, there are two major hindrances to advancements in gamma spectral analysis algorithms under the current paradigm: access to data and common performance metrics along with baseline performance measures. Because many of the signatures collected during performance measurement campaigns are classified, dissemination to algorithm developers is extremely limited. This leaves developers no choice but to collect their own data if they are lucky enough to have access to material and sensors. This is often combined with their own definition of metrics for measuring performance. These two conditions make it all but impossible for developers and external reviewers to make meaningful comparisons between algorithms. Without meaningful comparisons, performance advancements become very hard to achieve and (more importantly) recognize. The objective of this work is to overcome these obstacles by developing and freely distributing real and synthetically generated gamma-spectra data sets as well as software tools for performance evaluation with associated performance baselines to national labs, academic institutions, government agencies, and industry. At present, datasets for two tracks, or application domains, have been developed: one that includes temporal spectral data at 1 s time intervals, which represents data collected by a mobile system operating in a dynamic radiation background environment; and one that represents static measurements with a foreground spectrum (background plus source) and a background spectrum. These data include controlled variations in both Source Related Factors (nuclide, nuclide combinations, activities, distances, collection times, shielding configurations, and background spectra) and Detector Related Factors (currently only gain shifts, but resolution changes and non-linear energy calibration errors will be added soon). The software tools will allow the developer to evaluate the performance impact of each of these factors. Although this first implementation is somewhat limited in scope, considering only NaI-based detection systems and two application domains, it is hoped that (with community feedback) a wider range of detector types and applications will be included in the future. This article describes the methods used for dataset creation, the software validation/performance measurement tools, the performance metrics used, and examples of baseline performance.

Effects of interactive metronome training on postural stability and upper extremity function in Parkinson's disease: a case study.

PubMed

Kim, Arim; Lee, Hye-Sun; Song, Chiang-Soon

2017-01-01

[Purpose] The purpose of this study was to examine the effects of interactive metronome training on the postural stability and upper extremity function of an individual with Parkinson's disease. [Subject and Methods] The participant of this case study was a 75-year-old female with Parkinson's disease diagnosed 7 years prior. This study was a single-subject research with an A-B-A design. She received IM training during the treatment phase (B phase) for 40 minutes per session. She was assessed pretest and posttest using the Berg balance scale and Wolf motor function test, and at baseline and the treatment phase using the measured box-and-block test and a Tetrax system. [Results] After training, the patient's static and dynamic balance, functional activity, and performance time of the upper extremity improved. Interactive metronome therapy improved the manual dexterity of both hands. Interactive metronome therapy also improved the limit of stability of the Parkinson's disease. [Conclusion] Though a case study, the results of this study suggest that IM therapy is effective at restoring the postural stability and upper extremity function of patients with Parkinson's disease.

Effects of interactive metronome training on postural stability and upper extremity function in Parkinson’s disease: a case study

PubMed Central

Kim, Arim; Lee, Hye-Sun; Song, Chiang-Soon

2017-01-01

[Purpose] The purpose of this study was to examine the effects of interactive metronome training on the postural stability and upper extremity function of an individual with Parkinson’s disease. [Subject and Methods] The participant of this case study was a 75-year-old female with Parkinson’s disease diagnosed 7 years prior. This study was a single-subject research with an A-B-A design. She received IM training during the treatment phase (B phase) for 40 minutes per session. She was assessed pretest and posttest using the Berg balance scale and Wolf motor function test, and at baseline and the treatment phase using the measured box-and-block test and a Tetrax system. [Results] After training, the patient’s static and dynamic balance, functional activity, and performance time of the upper extremity improved. Interactive metronome therapy improved the manual dexterity of both hands. Interactive metronome therapy also improved the limit of stability of the Parkinson’s disease. [Conclusion] Though a case study, the results of this study suggest that IM therapy is effective at restoring the postural stability and upper extremity function of patients with Parkinson’s disease. PMID:28210066

Reliability and validity of a low load endurance strength test for upper and lower extremities in patients with fibromyalgia.

PubMed

Munguía-Izquierdo, Diego; Legaz-Arrese, Alejandro

2012-11-01

To evaluate the reliability, standard error of the mean (SEM), clinical significant change, and known group validity of 2 assessments of endurance strength to low loads in patients with fibromyalgia syndrome (FS). Cross-sectional reliability and comparative study. University Pablo de Olavide, Seville, Spain. Middle-aged women with FS (n=95) and healthy women (n=64) matched for age, weight, and body mass index (BMI) were recruited for the study. Not applicable. The endurance strength to low loads tests of the upper and lower extremities and anthropometric measures (BMI) were used for the evaluations. The differences between the readings (tests 1 and 2) and the SDs of the differences, intraclass correlation coefficient (ICC) model (2,1), 95% confidence interval for the ICC, coefficient of repeatability, intrapatient SD, SEM, Wilcoxon signed-rank test, and Bland-Altman plots were used to examine reliability. A Mann-Whitney U test was used to analyze the differences in test values between the patient group and the control group. We hypothesized that patients with FS would have an endurance strength to low loads performance in lower and upper extremities at least twice as low as that of the healthy controls. Satisfactory test-retest reliability and SEMs were found for the lower extremity, dominant arm, and nondominant arm tests (ICC=.973-.979; P<.001; SEMs=1.44-1.66 repetitions). The differences in the mean between the test and retest were lower than the SEM for all performed tests, varying from -.10 to .29 repetitions. No significant differences were found between the test and retest (P>.05 for all). The Bland-Altman plots showed 95% limits of agreement for the lower extremity (4.7 to -4.5), dominant arm (3.8 to -4.4), and nondominant arm (3.9 to -4.1) tests. The endurance strength to low loads test scores for the patients with FS were 4-fold lower than for the controls in all performed tests (P<.001 for all). The endurance strength to low loads tests showed good reliability and known group validity and can be recommended for evaluating endurance strength to low loads in patients with FS. For individual evaluation, however, an improved score of at least 4 and 5 repetitions for the upper and lower extremities, respectively, was required for the differences to be considered as substantial clinical change. Patients with FS showed impaired endurance strength to low loads performance when compared with the general population. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Objective measurement of complex multimodal and multidimensional display formats: a common metric for predicting format effectiveness

NASA Astrophysics Data System (ADS)

Marshak, William P.; Darkow, David J.; Wesler, Mary M.; Fix, Edward L.

2000-08-01

Computer-based display designers have more sensory modes and more dimensions within sensory modality with which to encode information in a user interface than ever before. This elaboration of information presentation has made measurement of display/format effectiveness and predicting display/format performance extremely difficult. A multivariate method has been devised which isolates critical information, physically measures its signal strength, and compares it with other elements of the display, which act like background noise. This common Metric relates signal-to-noise ratios (SNRs) within each stimulus dimension, then combines SNRs among display modes, dimensions and cognitive factors can predict display format effectiveness. Examples with their Common Metric assessment and validation in performance will be presented along with the derivation of the metric. Implications of the Common Metric in display design and evaluation will be discussed.

Sequences of upper and lower extremity motions in javelin throwing.

PubMed

Liu, Hui; Leigh, Steve; Yu, Bing

2010-11-01

Javelin throwing is technically demanding. Sequences of upper and lower extremity motions are important for javelin throwing performance. The purpose of this study was to determine the general sequences of upper and lower extremity motions of elite male and female javelin throwers. Three-dimensional kinematic data were collected for 32 female and 30 male elite javelin throwers during competitions. Shoulder, elbow, wrist, hip, knee, ankle, lower trunk, and upper trunk joint and segment angles were reduced for the best trial of each participant. Beginning times of 6 upper extremity and 10 lower extremity joint and segment angular motions were identified. Sequences of the upper and lower extremity motions were determined through statistical analyses. Upper and lower extremity motions of the male and female elite javelin throwers followed specific sequences (P ≤ 0.050). Upper extremity motions of the male and female elite javelin throwers did not follow a proximal-to-distal sequence as suggested in the literature. Male and female elite javelin throwers apparently employed different sequences for upper and lower extremity motions (P < 0.001). Further studies are needed to determine the effects of sequences of upper and lower extremity motions on javelin throwing performance.

A Cross-sectional Examination of Vitamin D, Obesity, and Measures of Pain and Function in Middle-aged and Older Adults With Knee Osteoarthritis.

PubMed

Glover, Toni L; Goodin, Burel R; King, Christopher D; Sibille, Kimberly T; Herbert, Matthew S; Sotolongo, Adriana S; Cruz-Almeida, Yenisel; Bartley, Emily J; Bulls, Hailey W; Horgas, Ann L; Redden, David T; Riley, Joseph L; Staud, Roland; Fessler, Barri J; Bradley, Laurence A; Fillingim, Roger B

2015-12-01

The prevalence of knee osteoarthritis (OA) is increasing with the aging population and is exacerbated by the growing numbers of obese older adults. Low levels of vitamin D, measured by serum 25-hydroxyvitamin D (25(OH)D), in older adults and obese individuals are correlated with several negative health conditions, including chronic pain. This cross-sectional study sought to examine the interactive influence of 25(OH)D levels and obesity on knee OA pain and functional performance measures. The sample consisted of 256 (63% female) racially diverse (55% black/African Americans) middle-aged and older adults (mean age 56.8 y). Blood was collected for analysis of 25(OH)D by high-performance liquid chromatography. Participants provided self-report regarding knee OA pain and underwent a lower extremity functional performance test. Results demonstrated that obesity was associated with lower levels of 25(OH)D. Participants with adequate 25(OH)D levels reported significantly less knee OA pain compared with participants with deficient or insufficient levels, regardless of obesity status. Furthermore, there was a significant interaction between obesity and 25(OH)D levels for lower extremity functional performance, such that obese individuals with adequate 25(OH)D levels demonstrated better performance than those obese participants with deficient or insufficient 25(OH)D levels. The mechanisms by which adequate 25(OH)D levels are associated with pain severity and improved function have not been completely elucidated. It may be that the pleiotropic role of biologically active 25(OH)D influences pain and pain processing through peripheral and central mechanisms. Alternatively, higher levels of pain may lead to reduced outdoor activity, which may contribute to both obesity and decreased vitamin D. Thus, investigating vitamin D status in obese and nonobese individuals with knee OA warrants further study.

A Cross-Sectional Examination of Vitamin D, Obesity, and Measures of Pain and Function in Middle-Aged and Older Adults with Knee Osteoarthritis

PubMed Central

Glover, Toni L.; Goodin, Burel R.; King, Christopher D.; Sibille, Kimberly T.; Herbert, Matthew S.; Sotolongo, Adriana S.; Cruz-Almeida, Yenisel; Bartley, Emily J.; Bulls, Hailey W.; Horgas, Ann L.; Redden, David T.; Riley, Joseph L.; Staud, Roland; Fessler, Barri J.; Bradley, Laurence A.; Fillingim, Roger B.

2015-01-01

Objectives The prevalence of knee osteoarthritis is increasing with the aging population and is exacerbated by the growing numbers of obese older adults. Low levels of vitamin D, measured by serum 25-hydroxyvitamin D (25(OH)D), in older adults and obese individuals are correlated with several negative health conditions, including chronic pain. This cross-sectional study sought to examine the interactive influence of 25(OH)D levels and obesity on knee osteoarthritis pain and functional performance measures. Methods The sample consisted of 256 (63% female) racially-diverse (55% Black/African Americans) middle-aged and older adults (mean age 56.8 years). Blood was collected for analysis of 25(OH)D by high performance liquid chromatography. Participants provided self-report regarding knee osteoarthritis pain and underwent a lower extremity functional performance test. Results Results demonstrated that obesity was associated with lower levels of 25(OH)D. Participants with adequate 25(OH)D levels reported significantly less knee osteoarthritis pain compared to participants with deficient or insufficient levels, regardless of obesity status. Furthermore, there was a significant interaction between obesity and 25(OH)D levels for lower extremity functional performance, such that obese individuals with adequate 25(OH)D levels demonstrated better performance than those obese participants with deficient or insufficient 25(OH)D levels. Discussion The mechanisms by which adequate 25(OH)D levels are associated with pain severity and improved function have not been completely elucidated. It may be that the pleiotropic role of biologically active 25(OH)D influences pain and pain processing via peripheral and central mechanisms. Alternatively, higher levels of pain may lead to reduced outdoor activity, which may contribute to both obesity and decreased vitamin D. Thus, investigating vitamin D status in obese and non-obese individuals with knee osteoarthritis warrants further study. PMID:25569220

Functional outcomes following the prosthetic training phase of rehabilitation after dysvascular lower extremity amputation

PubMed Central

Christiansen, Cory; Fields, Thomas; Lev, Guy; Stephenson, Ryan O.; Stevens-Lapsley, Jennifer E.

2015-01-01

Objective To describe physical function outcomes and modes of physical therapy intervention for a cohort of patients with dysvascular lower extremity amputation (LEA) during the prosthetic training phase of rehabilitation. Design A retrospective cohort study. Setting Physical rehabilitation clinics at a Veterans Affairs Medical Center and a University Hospital. Patients Forty-two patients (38 men, 4 women, age 60.2±8.4 years) who completed outpatient physical therapy rehabilitation with prosthetic training after dysvascular LEA. Methods All patients underwent a prosthetic training phase of rehabilitation, with standardized outcome measures performed at initiation and discharge. Main Outcome Measures Performance-based physical function measures included: Two-Minute Walk (2MW), Timed-Up and Go (TUG), and 5-meter gait speed. Self-report physical function measures included: the Prosthesis Evaluation Questionnaire – Mobility Section (PEQ-MS) and the Patient-Specific Functional Scale (PSFS). Rehabilitation dose was tracked as total number of clinic visits, rehabilitation duration, and specific intervention modes. Results There were significant improvements in 2MW (mean±SD) [67.5±29.9 m (initial) and 103.3±45.8 m (discharge) (p<0.001)], gait speed [0.58±0.27 m/s (initial) and 0.88±0.39 m/s (discharge) (p<0.001)], TUG [34.8±21.3 s (initial) and 18.6±13.9 s (discharge) (p<0.001)], PEQ-MS [2.2±0.9 (initial) and 2.8±0.8 (discharge) (p<0.001)], and PSFS [3.2±2.0 (initial) and 5.9±2.3 (discharge) (p<0.001)]. Performance-based (TUG) and self-report (PEQ-MS) changes in functional mobility from initial exam to discharge had low or no correlations with rehabilitation dose measures. Number of clinic visits was 12.7±13.1 and rehabilitation duration was 13.7±16.8 weeks. Conclusions Significant improvements in performance-based and self-report measures of physical function occurred during the prosthetic training phase of physical rehabilitation following dysvascular major LEA. Despite improvements in function, gait speed and TUG outcomes remained below clinically important thresholds, indicating patients were limited in community ambulation and at risk for falls. Lack of moderate or higher correlation between rehabilitation dose and outcome measures may indicate need for more specific rehabilitation dose measures. PMID:25978948

A longitudinal study of ice hockey in boys aged 8--12.

PubMed

MacNab, R B

1979-03-01

A group of fifteen boys (experimental or competitive) were studied over a five year period of competitive ice hockey beginning at age 8. The subjects were members of a team which averaged 66 games per year, ranging from 50 at age 8 to 78 at age 12. In addition, they practiced twice a week with heavy stress on skating and individual puck handling skills. A second group of eleven boys (control or less competitive) were studied from age 10 to 12. The latter subjects played an average of 25 games per year and practiced once a week. All subjects were measured each year on skating and puck control skills, fitness-performance tests, grip strength, physical work capacity as well as height and weight. The results demonstrate learning curves for skating and puck control tests which, while typical in nature, show extremely high levels of achievement. Fitness-Performance, grip strength and physical work capacity levels of the competitive group are extremely high in comparison with data from other countries.

Identification of a novel FAM83H mutation and microhardness of an affected molar in autosomal dominant hypocalcified amelogenesis imperfecta.

PubMed

Hyun, H-K; Lee, S-K; Lee, K-E; Kang, H-Y; Kim, E-J; Choung, P-H; Kim, J-W

2009-11-01

To determine the underlying molecular genetic aetiology of a family with the hypocalcified form of amelogenesis imperfecta and to investigate the hardness of the enamel and dentine of a known FAM83H mutation. Mutational screening of the FAM83H on the basis of candidate gene approach was performed. All exons and exon-intron boundaries was amplified and sequenced. A microhardness test was performed to measure the Vickers microhardness value. A novel nonsense mutation (c.1354C>T, p.Q452X) was identified in the last exon of FAM83H, which resulted in soft, uncalcified enamel. The affected enamel was extremely soft (about 17% of the normal control), but the underlying dentine was as hard as the normal control. Mutational analysis revealed a novel mutation in FAM83H gene. Hardness of dentine was not affected by the mutation, whilst the enamel was extremely soft.

Classification accuracy of claims-based methods for identifying providers failing to meet performance targets.

PubMed

Hubbard, Rebecca A; Benjamin-Johnson, Rhondee; Onega, Tracy; Smith-Bindman, Rebecca; Zhu, Weiwei; Fenton, Joshua J

2015-01-15

Quality assessment is critical for healthcare reform, but data sources are lacking for measurement of many important healthcare outcomes. With over 49 million people covered by Medicare as of 2010, Medicare claims data offer a potentially valuable source that could be used in targeted health care quality improvement efforts. However, little is known about the operating characteristics of provider profiling methods using claims-based outcome measures that may estimate provider performance with error. Motivated by the example of screening mammography performance, we compared approaches to identifying providers failing to meet guideline targets using Medicare claims data. We used data from the Breast Cancer Surveillance Consortium and linked Medicare claims to compare claims-based and clinical estimates of cancer detection rate. We then demonstrated the performance of claim-based estimates across a broad range of operating characteristics using simulation studies. We found that identification of poor performing providers was extremely sensitive to algorithm specificity, with no approach identifying more than 65% of poor performing providers when claims-based measures had specificity of 0.995 or less. We conclude that claims have the potential to contribute important information on healthcare outcomes to quality improvement efforts. However, to achieve this potential, development of highly accurate claims-based outcome measures should remain a priority. Copyright © 2014 John Wiley & Sons, Ltd.

Evaluation of a home-based exercise program in the treatment of Alzheimer's disease: the Maximizing Independence in Dementia (MIND) study.

PubMed

Steinberg, Martin; Leoutsakos, Jeannie-Marie Sheppard; Podewils, Laura Jean; Lyketsos, C G

2009-07-01

To determine the feasibility and efficacy of a home-based exercise intervention program to improve the functional performance of patients with Alzheimer's Disease (AD). Twenty-seven home-dwelling patients with AD were randomized to either an exercise intervention program delivered by their caregivers or a home safety assessment control. Measures of functional performance (primary), cognition, neuropsychiatric symptoms, quality of life and caregiver burden (secondary) were obtained at baseline and at 6 and 12 weeks following randomization. For each outcome measure, intent-to-treat analyses using linear random effects models were performed. Feasibility and adverse events were also assessed. Adherence to the exercise program was good. On the primary outcomes (functional performance) patients in the exercise group demonstrated a trend for improved performance on measures of hand function and lower extremity strength. On secondary outcome measures, trends toward worse depression and lower quality of life ratings were noted. The physical exercise intervention developed for the study, delivered by caregivers to home-dwelling patients with AD, was feasible and was associated with a trend for improved functional performance in this group of frail patients. Given the limited efficacy to date of pharmacotherapies for AD, further study of exercise intervention, in a variety of care setting, is warranted.

Children’s Personal Exposure Measurements to Extremely Low Frequency Magnetic Fields in Italy

PubMed Central

Liorni, Ilaria; Parazzini, Marta; Struchen, Benjamin; Fiocchi, Serena; Röösli, Martin; Ravazzani, Paolo

2016-01-01

Extremely low frequency magnetic fields (ELF-MFs) exposure is still a topic of concern due to their possible impact on children’s health. Although epidemiological studies claimed an evidence of a possible association between ELF-MF above 0.4 μT and childhood leukemia, biological mechanisms able to support a causal relationship between ELF-MF and this disease were not found yet. To provide further knowledge about children’s ELF-MF exposure correlated to children’s daily activities, a measurement study was conducted in Milan (Italy). Eighty-six children were recruited, 52 of whom were specifically chosen with respect to the distance to power lines and built-in transformers to oversample potentially highly exposed children. Personal and bedroom measurements were performed for each child in two different seasons. The major outcomes of this study are: (1) median values over 24-h personal and bedroom measurements were <3 μT established by the Italian law as the quality target; (2) geometric mean values over 24-h bedroom measurements were mostly <0.4 μT; (3) seasonal variations did not significantly influence personal and bedroom measurements; (4) the highest average MF levels were mostly found at home during the day and outdoors; (5) no significant differences were found in the median and geometric mean values between personal and bedroom measurements, but were found in the arithmetic mean. PMID:27258295

Compression ultrasonography of the lower extremity with portable vascular ultrasonography can accurately detect deep venous thrombosis in the emergency department.

PubMed

Crisp, Jonathan G; Lovato, Luis M; Jang, Timothy B

2010-12-01

Compression ultrasonography of the lower extremity is an established method of detecting proximal lower extremity deep venous thrombosis when performed by a certified operator in a vascular laboratory. Our objective is to determine the sensitivity and specificity of bedside 2-point compression ultrasonography performed in the emergency department (ED) with portable vascular ultrasonography for the detection of proximal lower extremity deep venous thrombosis. We did this by directly comparing emergency physician-performed ultrasonography to lower extremity duplex ultrasonography performed by the Department of Radiology. This was a prospective, cross-sectional study and diagnostic test assessment of a convenience sample of ED patients with a suspected lower extremity deep venous thrombosis, conducted at a single-center, urban, academic ED. All physicians had a 10-minute training session before enrolling patients. ED compression ultrasonography occurred before Department of Radiology ultrasonography and involved identification of 2 specific points: the common femoral and popliteal vessels, with subsequent compression of the common femoral and popliteal veins. The study result was considered positive for proximal lower extremity deep venous thrombosis if either vein was incompressible or a thrombus was visualized. Sensitivity and specificity were calculated with the final radiologist interpretation of the Department of Radiology ultrasonography as the criterion standard. A total of 47 physicians performed 199 2-point compression ultrasonographic examinations in the ED. Median number of examinations per physician was 2 (range 1 to 29 examinations; interquartile range 1 to 5 examinations). There were 45 proximal lower extremity deep venous thromboses observed on Department of Radiology evaluation, all correctly identified by ED 2-point compression ultrasonography. The 153 patients without proximal lower extremity deep venous thrombosis all had a negative ED compression ultrasonographic result. One patient with a negative Department of Radiology ultrasonographic result was found to have decreased compression of the popliteal vein on ED compression ultrasonography, giving a single false-positive result, yet repeated ultrasonography by the Department of Radiology 1 week later showed a popliteal deep venous thrombosis. The sensitivity and specificity of ED 2-point compression ultrasonography for deep venous thrombosis were 100% (95% confidence interval 92% to 100%) and 99% (95% confidence interval 96% to 100%), respectively. Emergency physician-performed 2-point compression ultrasonography of the lower extremity with a portable vascular ultrasonographic machine, conducted in the ED by this physician group and in this patient sample, accurately identified the presence and absence of proximal lower extremity deep venous thrombosis. Copyright © 2010 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

The kinematics of upper extremity reaching: a reliability study on people with and without shoulder impingement syndrome

PubMed Central

2010-01-01

Background Tasks chosen to evaluate motor performance should reflect the movement deficits characteristic of the target population and present an appropriate challenge for the patients who would be evaluated. A reaching task that evaluates impairment characteristics of people with shoulder impingement syndrome (SIS) was developed to evaluate the motor performance of this population. The objectives of this study were to characterize the reproducibility of this reaching task in people with and without SIS and to evaluate the impact of the number of trials on reproducibility. Methods Thirty subjects with SIS and twenty healthy subjects participated in the first measurement session to evaluate intrasession reliability. Ten healthy subjects were retested within 2 to 7 days to assess intersession reliability. At each measurement session, upper extremity kinematic patterns were evaluated during a reaching task. Ten trials were recorded. Thereafter, the upper extremity position at the end of reaching and total joint excursion that occurred during reaching were calculated. Intraclass correlation coefficient (ICC) and minimal detectable change (MDC) were used to estimate intra and intersession reliability. Results Intrasession reliability for total joint excursion was good to very good when based on the first two trials (0.770.92). As for end-reach position, intrasession reliability was very good when using either the first two, first five or last five trials (ICC>0.82). Globally, MDC were smaller for the last five trials. Intersession reliability of total joint excursion and position at the end of reaching was good to very good when using the mean of the first two or five trials (0.690.82). For most joints, MDC were smaller when using all ten trials. Conclusions The reaching task proposed to evaluate the upper limb motor performance was found reliable in people with and without SIS. Furthermore, the minimal difference necessary to infer a meaningful change in motor performance was determined, indicating that relatively small changes in task performance can be interpreted as a change in motor performance. PMID:20331889

The Kinematics of Trunk and Upper Extremities in One-Handed and Two-Handed Backhand Stroke

PubMed Central

Stępień, Adam; Bober, Tadeusz; Zawadzki, Jerzy

2011-01-01

The aim of this study was to present kinematics of trunk and upper extremities in tennis players who perform one-handed and two-handed backhand strokes. The study aimed to address the question of whether one of those techniques has some important advantage over the other. If so, what makes it superior? The study included 10 tennis coaches with average coaching experience of 9 years. The coaches were asked to hit 15 one-handed and two-handed backhands. The tests were carried out in a laboratory. A sponge ball was used in order to protect the measurement equipment. Video motion analysis was carried out using BTS SMART system; images were recorded with 6 cameras with a rate of 120 frames per second. The analysis of both backhand strokes focused on the second phase of the stroke (acceleration). The use of an eight-element model of human body for description of upper body motion in both techniques revealed kinematic differences in how both backhands are performed. The two-handed backhand was performed in closed kinetic chain with 8 degrees of freedom, whereas the one-handed backhand involved an open kinetic chain with 7 degrees of freedom. Higher rigidity of upper extremities which are connected with trunk in the two-handed backhand, contributes to an elevated trunk effect in this stroke. This is confirmed by higher component velocities for racket handle, which result from trunk rotation in the two-handed backhand and a negative separation angle in the two-handed backhand at the moment of contact of the racket with the ball. The study does not provide a clear-cut answer to the question of advantages of one technique over the other; however, it reveals dissimilar patterns of driving the racket in both techniques, which suggests the need for extending the analysis of techniques of both backhands with additional kinematics of tennis racket in consideration of measurements of ball velocities. PMID:23486650

The Usability of a Pressure-Indicating Film to Measure the Teat Load Caused by a Collapsing Liner

PubMed Central

Demba, Susanne; Elsholz, Sabrina; Ammon, Christian; Rose-Meierhöfer, Sandra

2016-01-01

Prevention of damage to the teat and mastitis requires determination of the teat load caused by a collapsing liner. The aim of this study was to test a pressure-indicating film designed to measure the pressure between a collapsing liner and artificial teats. The Ultra Super Low and the Extreme Low pressure-indicating films were tested on two types of artificial teat. The experiments were performed with a conventional milking cluster equipped with round silicone liners. For each teat and film type, 30 repetitions were performed. Each repetition was performed with a new piece of film. Kruskal-Wallis tests were performed to detect differences between the pressure values for the different teats. The area of regions where pressure-indication color developed was calculated to determine the most suitable film type. Both film types measured the pressure applied to both artificial teats by the teat cup liner. Thus, the pressure-indicating films can be used to measure the pressure between a collapsing liner and an artificial teat. Based on the results of the present investigation, a pressure-indicating film with the measurement ranges of both film types combined would be an optimal tool to measure the overall pressure between an artificial teat and a collapsing liner. PMID:27690033

A dynamic method for magnetic torque measurement

NASA Technical Reports Server (NTRS)

Lin, C. E.; Jou, H. L.

1994-01-01

In a magnetic suspension system, accurate force measurement will result in better control performance in the test section, especially when a wider range of operation is required. Although many useful methods were developed to obtain the desired model, however, significant error is inevitable since the magnetic field distribution of the large-gap magnetic suspension system is extremely nonlinear. This paper proposed an easy approach to measure the magnetic torque of a magnetic suspension system using an angular photo encoder. Through the measurement of the velocity change data, the magnetic torque is converted. The proposed idea is described and implemented to obtain the desired data. It is useful to the calculation of a magnetic force in the magnetic suspension system.

Significance of Environmental Variables on Flight Electronics and Design Concerns for Extreme Environments

NASA Astrophysics Data System (ADS)

Hazeli, K.; Kingstedt, O. T.

2017-05-01

It is critical to investigate the performance of electronic systems and their components under the environments experienced during proposed missions to improve spacecraft and robotic vehicle functionality and performance in extreme environments.

Facilitating Co-Design for Extreme-Scale Systems Through Lightweight Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelmann, Christian; Lauer, Frank

This work focuses on tools for investigating algorithm performance at extreme scale with millions of concurrent threads and for evaluating the impact of future architecture choices to facilitate the co-design of high-performance computing (HPC) architectures and applications. The approach focuses on lightweight simulation of extreme-scale HPC systems with the needed amount of accuracy. The prototype presented in this paper is able to provide this capability using a parallel discrete event simulation (PDES), such that a Message Passing Interface (MPI) application can be executed at extreme scale, and its performance properties can be evaluated. The results of an initial prototype aremore » encouraging as a simple 'hello world' MPI program could be scaled up to 1,048,576 virtual MPI processes on a four-node cluster, and the performance properties of two MPI programs could be evaluated at up to 16,384 virtual MPI processes on the same system.« less

Forecasting seasonal hydrologic response in major river basins

NASA Astrophysics Data System (ADS)

Bhuiyan, A. M.

2014-05-01

Seasonal precipitation variation due to natural climate variation influences stream flow and the apparent frequency and severity of extreme hydrological conditions such as flood and drought. To study hydrologic response and understand the occurrence of extreme hydrological events, the relevant forcing variables must be identified. This study attempts to assess and quantify the historical occurrence and context of extreme hydrologic flow events and quantify the relation between relevant climate variables. Once identified, the flow data and climate variables are evaluated to identify the primary relationship indicators of hydrologic extreme event occurrence. Existing studies focus on developing basin-scale forecasting techniques based on climate anomalies in El Nino/La Nina episodes linked to global climate. Building on earlier work, the goal of this research is to quantify variations in historical river flows at seasonal temporal-scale, and regional to continental spatial-scale. The work identifies and quantifies runoff variability of major river basins and correlates flow with environmental forcing variables such as El Nino, La Nina, sunspot cycle. These variables are expected to be the primary external natural indicators of inter-annual and inter-seasonal patterns of regional precipitation and river flow. Relations between continental-scale hydrologic flows and external climate variables are evaluated through direct correlations in a seasonal context with environmental phenomenon such as sun spot numbers (SSN), Southern Oscillation Index (SOI), and Pacific Decadal Oscillation (PDO). Methods including stochastic time series analysis and artificial neural networks are developed to represent the seasonal variability evident in the historical records of river flows. River flows are categorized into low, average and high flow levels to evaluate and simulate flow variations under associated climate variable variations. Results demonstrated not any particular method is suited to represent scenarios leading to extreme flow conditions. For selected flow scenarios, the persistence model performance may be comparable to more complex multivariate approaches, and complex methods did not always improve flow estimation. Overall model performance indicates inclusion of river flows and forcing variables on average improve model extreme event forecasting skills. As a means to further refine the flow estimation, an ensemble forecast method is implemented to provide a likelihood-based indication of expected river flow magnitude and variability. Results indicate seasonal flow variations are well-captured in the ensemble range, therefore the ensemble approach can often prove efficient in estimating extreme river flow conditions. The discriminant prediction approach, a probabilistic measure to forecast streamflow, is also adopted to derive model performance. Results show the efficiency of the method in terms of representing uncertainties in the forecasts.

Estimating chlorophyll content and bathymetry of Lake Tahoe using AVIRIS data

NASA Technical Reports Server (NTRS)

Hamilton, Michael K.; Davis, Curtiss O.; Rhea, W. J.; Pilorz, Stuart H.; Carder, Kendall L.

1993-01-01

Data on chlorophyll content and bathymetry of Lake Tahoe obtained on August 9, 1990 by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) are compared to concurrent in situ surface and in-water measurements. Measured parameters included profiles of percent transmission of monochromatic light, stimulated chlorophyll fluorescence, photosynthetically available radiation, spectral upwelling and downwelling irradiance, and upwelling radiance. Several analyses were performed illustrating the utility of the AVIRIS over a dark water scene. Image-derived chlorophyll concentration compared extremely well with that measured with bottle samples. A bathymetry map of the shallow parts of the lake was constructed which compares favorably with published lake soundings.

Measuring skew in average surface roughness as a function of surface preparation

NASA Astrophysics Data System (ADS)

Stahl, Mark T.

2015-08-01

Characterizing surface roughness is important for predicting optical performance. Better measurement of surface roughness reduces polishing time, saves money and allows the science requirements to be better defined. This study characterized statistics of average surface roughness as a function of polishing time. Average surface roughness was measured at 81 locations using a Zygo® white light interferometer at regular intervals during the polishing process. Each data set was fit to a normal and Largest Extreme Value (LEV) distribution; then tested for goodness of fit. We show that the skew in the average data changes as a function of polishing time.

Clock Agreement Among Parallel Supercomputer Nodes

DOE Data Explorer

Jones, Terry R.; Koenig, Gregory A.

2014-04-30

This dataset presents measurements that quantify the clock synchronization time-agreement characteristics among several high performance computers including the current world's most powerful machine for open science, the U.S. Department of Energy's Titan machine sited at Oak Ridge National Laboratory. These ultra-fast machines derive much of their computational capability from extreme node counts (over 18000 nodes in the case of the Titan machine). Time-agreement is commonly utilized by parallel programming applications and tools, distributed programming application and tools, and system software. Our time-agreement measurements detail the degree of time variance between nodes and how that variance changes over time. The dataset includes empirical measurements and the accompanying spreadsheets.

Changes in the Width of the Tibiofibular Syndesmosis Related to Lower Extremity Joint Dynamics and Neuromuscular Coordination on Drop Landing During the Menstrual Cycle.

PubMed

Okazaki, Michie; Kaneko, Masaaki; Ishida, Yukisato; Murase, Norio; Katsumura, Toshihito

2017-09-01

Many injuries of the lower extremities, especially the knee and ankle, occur during sports activity, and the incidence rate is higher in women than in men. The hypothesis was that phases of the menstrual cycle affect the width of the tibiofibular syndesmosis during drop landing in healthy young women and that such changes at the tibiofibular joint also affect the dynamics and neuromuscular coordination of the lower extremities. Descriptive laboratory study. Participants included 28 healthy young women (mean age, 21.0 ± 0.8 years). Blood samples were collected to determine plasma levels of estradiol and progesterone immediately before the performance of the task: drop landing on a single leg from a 30-cm platform. Using ultrasonography, the distance between the tibia and the distal end of the fibula, regarded as the width of the tibiofibular syndesmosis, was measured in an upright position without flexion of the ankle. The peak ground-reaction force (GRF) on landing was measured using a force platform. The time to peak GRF (Tp-GRF) was measured as the time from initial ground contact to the peak GRF. Hip, knee, and ankle joint angles during the single-leg landing were calculated using a 3-dimensional motion analysis system. Muscle activities of the lower extremities were measured using surface electromyography. The width of the tibiofibular syndesmosis was significantly greater in the luteal phase when compared with the menstrual, follicular, and ovulation phases (by 5%-8% of control). Also, during the luteal phase, the Tp-GRF was significantly shorter than in the follicular phase (by 6%); hip internal rotation and knee valgus were significantly greater than in the menstrual phase (by 43% and 34%, respectively); knee flexion was significantly less than in the menstrual and follicular phases (by 7%-9%); ankle dorsiflection was significantly less than in the follicular phase (by 11%); ankle adduction and eversion were significantly greater than in the menstrual and follicular phases (by 26%-46%, and 27%-33%, respectively); and activation of the gluteus maximus before landing was significantly lower than in the menstrual and follicular phases (by 20%-22%). The luteal phase appears to be associated with decreased strength and laxity of the ankle as well as lower extremity muscle activity in women. The changes presumably represent a greater risk for sports injuries. The results of this study suggest that the luteal phase may be related to the greater incidence of lower extremity injuries in women.

Effects of Progressive Body Weight Support Treadmill Forward and Backward Walking Training on Stroke Patients' Affected Side Lower Extremity's Walking Ability.

PubMed

Kim, Kyunghoon; Lee, Sukmin; Lee, Kyoungbo

2014-12-01

[Purpose] The purpose of the present study was to examine the effects of progressive body weight supported treadmill forward and backward walking training (PBWSTFBWT), progressive body weight supported treadmill forward walking training (PBWSTFWT), progressive body weight supported treadmill backward walking training (PBWSTBWT), on stroke patients' affected side lower extremity's walking ability. [Subjects and Methods] A total of 36 chronic stroke patients were divided into three groups with 12 subjects in each group. Each of the groups performed one of the progressive body weight supported treadmill training methods for 30 minute, six times per week for three weeks, and then received general physical therapy without any other intervention until the follow-up tests. For the assessment of the affected side lower extremity's walking ability, step length of the affected side, stance phase of the affected side, swing phase of the affected side, single support of the affected side, and step time of the affected side were measured using optogait and the symmetry index. [Results] In the within group comparisons, all the three groups showed significant differences between before and after the intervention and in the comparison of the three groups, the PBWSTFBWT group showed more significant differences in all of the assessed items than the other two groups. [Conclusion] In the present study progressive body weight supported treadmill training was performed in an environment in which the subjects were actually walked, and PBWSTFBWT was more effective at efficiently training stroke patients' affected side lower extremity's walking ability.

Effect of task-based mirror therapy on motor recovery of the upper extremity in chronic stroke patients: a pilot study.

PubMed

Arya, Kamal Narayan; Pandian, Shanta

2013-01-01

Mirror therapy (MT) is an alternative therapeutic intervention that uses the interaction of visuomotor-proprioception inputs to enhance movement performance of the impaired limb. Despite strong evidence for task-specific training in stroke, MT has been investigated using nontask movements. The aim of this pilot study was to assess the effectiveness of task-based MT on motor recovery of the upper extremity in chronic stroke patients. In a pretest-posttest single-group design, a convenience sample of 13 chronic stroke patients at an occupational therapy department of a rehabilitation institute was assessed on a task-based MT intervention. Participants received a task-based MT program, performing various tasks by the less affected upper extremity and observing in the mirror box along with conventional management, 4 days per week for 4 weeks. Fugl-Meyer Assessment (FMA), which includes subsection upper extremity (FMA-UE) and subpart upper arm (FMA-UA) and hand (FMA-WH), was used as an outcome measure. Participants showed no significant improvement for FMA-UE and FMA-UA at postassessment. FMA-UE changed from 43% to 51%. Post FMA-UA score showed only 2% improvement. However, there was statistically significant improvement on mean scores of FMA-WH at postassessment (16.21 ± 3.06) as compared with the prescores (12.29 ± 3.1; P < .05). FMA-WH improved from 41% to 54%. The preliminary findings suggest that task-based MT is effective in improving wrist and hand motor recovery in chronic stroke patients. Further studies in the form of randomized trials are needed to validate its effectiveness.

Earth Scanner Bearing Accelerated Life Test

NASA Technical Reports Server (NTRS)

Dietz, Brian J.; VanDyk, Steven G.; Predmore, Roamer E.

2000-01-01

The Moderate Resolution Imaging Spectrometer (MODIS) optical instrument for NASA Goddard will measure biological and physical processes on the Earth's surface and in the lower atmosphere. A key component of the instrument is an extremely accurate scan mirror motor/encoder assembly. Of prime concern in the performance and reliability of the scan motor/encoder is bearing selection and lubrication. This paper describes life testing of the bearings and lubrication selected for the program.

Fabry-Perot Interferometer for Column CO2

NASA Technical Reports Server (NTRS)

Heaps, William S.; Kawa, Randolph; Bhartia, P. K. (Technical Monitor)

2002-01-01

Global atmospheric CO2 measurements are essential to resolving significant discrepancies in our understanding of the global carbon budget and, hence, humankind's role in global climate change. The science measurement requirements for CO2 are extremely demanding (precision approx. 0.3%). No atmospheric chemical species has ever been measured from space with this precision. We are developing a novel application of a Fabry-Perot interferometer to detect spectral absorption of reflected sunlight by CO2 and O2 in the atmosphere. Preliminary design studies indicate that the method will be able to achieve the sensitivity and signal-to-noise detection required to measure column CO2 at the target specification. The objective of this program is to construct a prototype instrument for deployment on an aircraft to test the instrument performance and our ability to retrieve the data in the real atmosphere. To date we have assembled a laboratory bench system to begin testing the optical and electronic components. We are also measuring signal and noise levels in actual sunlight to evaluate component performance.

Abdominal Circumference Versus Body Mass Index as Predictors of Lower Extremity Overuse Injury Risk.

PubMed

Nye, Nathaniel S; Kafer, Drew S; Olsen, Cara; Carnahan, David H; Crawford, Paul F

2018-02-01

Abdominal circumference (AC) is superior to body mass index (BMI) as a measure of risk for various health outcomes. Our objective was to compare AC and BMI as predictors of lower extremity overuse injury (LEOI) risk. Retrospective review of electronic medical records of 79,868 US Air Force personnel over a 7-year period (2005-2011) for incidence of new LEOI. Subjects were stratified by BMI and AC. Injury risk for BMI/AC subgroups was calculated using Kaplan-Meier curves and Cox proportional-hazards regression. Receiver operating characteristic curves with area under the curve were used to compare each model's predictive value. Cox proportional-hazards regression showed significant risk association between elevated BMI, AC, and all injury types, with hazard ratios ranging 1.230-3.415 for obese versus normal BMI and 1.665-3.893 for high-risk versus low-risk AC (P < .05 for all measures). Receiver operating characteristic curves with area under the curve showed equivalent performance between BMI and AC for predicting all injury types. However, the combined model (AC and BMI) showed improved predictive ability over either model alone for joint injury, overall LEOI, and most strongly for osteoarthritis. Although AC and BMI alone performed similarly well, a combined approach using BMI and AC together improved risk estimation for LEOI.

Innovative STRoke Interactive Virtual thErapy (STRIVE) online platform for community-dwelling stroke survivors: a randomised controlled trial protocol.

PubMed

Johnson, Liam; Bird, Marie-Louise; Muthalib, Makii; Teo, Wei-Peng

2018-01-09

The STRoke Interactive Virtual thErapy (STRIVE) intervention provides community-dwelling stroke survivors access to individualised, remotely supervised progressive exercise training via an online platform. This trial aims to determine the clinical efficacy of the STRIVE intervention and its effect on brain activity in community-dwelling stroke survivors. In a multisite, assessor-blinded randomised controlled trial, 60 stroke survivors >3 months poststroke with mild-to-moderate upper extremity impairment will be recruited and equally randomised by location (Melbourne, Victoria or Launceston, Tasmania) to receive 8 weeks of virtual therapy (VT) at a local exercise training facility or usual care. Participants allocated to VT will perform 3-5 upper limb exercises individualised to their impairment severity and preference, while participants allocated to usual care will be asked to maintain their usual daily activities. The primary outcome measures will be upper limb motor function and impairment, which will be assessed using the Action Research Arm Test and Upper Extremity Fugl-Meyer, respectively. Secondary outcome measures include upper extremity function and spasticity, as measured by the box and block test and Modified AshworthScale, respectively, and task-related changes in bilateral sensorimotor cortex haemodynamics during hand reaching and wrist extension movements as measured by functional near-infrared spectroscopy. Quality of life will be measured using the Euro-Quality of Life-5 Dimension-5 Level Scale, and the Motor Activity Log-28 will be used to measure use of the hemiparetic arm. All measures will be assessed at baseline and immediately postintervention. The study was approved by the Deakin University Human Research Ethics Committee in May 2017 (No. 2017-087). The results will be disseminated in peer-reviewed journals and presented at major international stroke meetings. ACTRN12617000745347; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Innovative STRoke Interactive Virtual thErapy (STRIVE) online platform for community-dwelling stroke survivors: a randomised controlled trial protocol

PubMed Central

Bird, Marie-Louise; Muthalib, Makii

2018-01-01

Introduction The STRoke Interactive Virtual thErapy (STRIVE) intervention provides community-dwelling stroke survivors access to individualised, remotely supervised progressive exercise training via an online platform. This trial aims to determine the clinical efficacy of the STRIVE intervention and its effect on brain activity in community-dwelling stroke survivors. Methods and analysis In a multisite, assessor-blinded randomised controlled trial, 60 stroke survivors >3 months poststroke with mild-to-moderate upper extremity impairment will be recruited and equally randomised by location (Melbourne, Victoria or Launceston, Tasmania) to receive 8 weeks of virtual therapy (VT) at a local exercise training facility or usual care. Participants allocated to VT will perform 3–5 upper limb exercises individualised to their impairment severity and preference, while participants allocated to usual care will be asked to maintain their usual daily activities. The primary outcome measures will be upper limb motor function and impairment, which will be assessed using the Action Research Arm Test and Upper Extremity Fugl-Meyer, respectively. Secondary outcome measures include upper extremity function and spasticity, as measured by the box and block test and Modified AshworthScale, respectively, and task-related changes in bilateral sensorimotor cortex haemodynamics during hand reaching and wrist extension movements as measured by functional near-infrared spectroscopy. Quality of life will be measured using the Euro-Quality of Life-5 Dimension-5 Level Scale, and the Motor Activity Log-28 will be used to measure use of the hemiparetic arm. All measures will be assessed at baseline and immediately postintervention. Ethics and dissemination The study was approved by the Deakin University Human Research Ethics Committee in May 2017 (No. 2017–087). The results will be disseminated in peer-reviewed journals and presented at major international stroke meetings. Trial registration number ACTRN12617000745347; Pre-results. PMID:29317414

Trunk Muscle Attributes are Associated with Balance and Mobility in Older Adults: A Pilot Study

PubMed Central

Suri, Pradeep; Kiely, Dan K.; Leveille, Suzanne G.; Frontera, Walter R.; Bean, Jonathan. F.

2010-01-01

Objective To determine if trunk muscle attributes are associated with balance and mobility performance among mobility-limited older adults. Design Cross-sectional analysis of data from a randomized clinical trial. Setting Outpatient rehabilitation research center. Participants Community-dwelling older adults (N=70; mean age 75.9 y) with mobility limitations as defined by the Short Physical Performance Battery (SPPB). Methods Independent variables included physiologic measures of trunk extension strength, trunk flexion strength, trunk extension endurance, trunk extension endurance and leg press strength. All measures were well tolerated by the study subjects without the occurrence of any associated injuries or adverse events. The association of each physiologic measure with each outcome was examined, using separate multivariate models to calculate the partial variance (R2) of each trunk and extremity measure. Main Outcome Measurements Balance measured by the Berg Balance Scale (BBS) and Unipedal Stance Test (UST), and mobility performance as measured by the SPPB. Results Trunk extension endurance (partial R2=.14, p=.02), and leg press strength (partial R2=.14, p=.003) accounted for the greatest amount of the variance in SPPB performance. Trunk extension endurance (partial R2=.17, p=.007), accounted for the greatest amount of the variance in BBS performance. Trunk extension strength (R2=.09, p=.03), accounted for the greatest amount of the variance in UST performance. The variance explained by trunk extension endurance equaled or exceeded the variance explained by limb strength across all three performance outcomes. Conclusions Trunk endurance and strength can be safely measured in mobility-limited older adults, and are associated with both balance and mobility performance. Trunk endurance and trunk strength are physiologic attributes worthy of targeting in the rehabilitative care of mobility-limited older adults. PMID:19854420

The influence of personal qualities on performance and progression in a pre-registration nursing programme.

PubMed

Pitt, Victoria; Powis, David; Levett-Jones, Tracy; Hunter, Sharyn

2014-05-01

Research conducted primarily with psychology and medical students has highlighted that personal qualities play an important role in students' academic performance. In nursing there has been limited investigation of the relationship between personal qualities and performance. Yet, reports of student incivility and a lack of compassion have prompted appeals to integrate the assessment of personal qualities into pre-registration nursing student selection. Before this can be done research is needed to explore the influence of students' personal qualities on programme performance and progression. This study explores the relationships between students' personal qualities and their academic and clinical performance, behaviours and progression through a pre-registration nursing programme in Australia. This longitudinal descriptive correlational study was undertaken with a sample of Australian pre-registration nursing students (n=138). Students' personal qualities were assessed using three personal qualities assessment (PQA) instruments. Outcome measures included grades in nursing theory and clinical courses, yearly grade point average, final clinical competency, progression (completion), class attendance and levels of life event stress. Significant correlations were found between academic performance and PQA scores for self-control, resilience and traits of aloofness, confidence and involvement. Final clinical competence was predicted by confidence and self-control scores. Students with higher empathy had higher levels of life event stress in their first year and class attendance had a positive correlation with self-control. Completing the programme in three years was weakly predicted by the measure of resilience. No difference was noted between extreme or non-extreme scorers on the PQA scales with respect to performance or progression. This sample of students' personal qualities was found to influence their academic and clinical performance and their ability to complete a pre-registration programme in three years. However, further research is required with larger cohorts to confirm the use of personal qualities assessment during selection. © 2013.

Generalist genes and high cognitive abilities.

PubMed

Haworth, Claire M A; Dale, Philip S; Plomin, Robert

2009-07-01

The concept of generalist genes operating across diverse domains of cognitive abilities is now widely accepted. Much less is known about the etiology of the high extreme of performance. Is there more specialization at the high extreme? Using a representative sample of 4,000 12-year-old twin pairs from the UK Twins Early Development Study, we investigated the genetic and environmental overlap between web-based tests of general cognitive ability, reading, mathematics and language performance for the top 15% of the distribution using DF extremes analysis. Generalist genes are just as evident at the high extremes of performance as they are for the entire distribution of abilities and for cognitive disabilities. However, a smaller proportion of the phenotypic intercorrelations appears to be explained by genetic influences for high abilities.

Generalist genes and high cognitive abilities

PubMed Central

Haworth, Claire M.A.; Dale, Philip S.; Plomin, Robert

2014-01-01

The concept of generalist genes operating across diverse domains of cognitive abilities is now widely accepted. Much less is known about the etiology of the high extreme of performance. Is there more specialization at the high extreme? Using a representative sample of 4000 12-year-old twin pairs from the UK Twins Early Development Study, we investigated the genetic and environmental overlap between web-based tests of general cognitive ability, reading, mathematics and language performance for the top 15% of the distribution using DF extremes analysis. Generalist genes are just as evident at the high extremes of performance as they are for the entire distribution of abilities and for cognitive disabilities. However, a smaller proportion of the phenotypic intercorrelations appears to be explained by genetic influences for high abilities. PMID:19377870

CAN UPPER EXTREMITY FUNCTIONAL TESTS PREDICT THE SOFTBALL THROW FOR DISTANCE: A PREDICTIVE VALIDITY INVESTIGATION

PubMed Central

Hanney, William J.; Kolber, Morey J.; Davies, George J.; Riemann, Bryan

2011-01-01

Introduction: Understanding the relationships between performance tests and sport activity is important to the rehabilitation specialist. The purpose of this study was two- fold: 1) To identify if relationships exist between tests of upper body strength and power (Single Arm Seated Shot Put, Timed Push-Up, Timed Modified Pull-Up, and The Davies Closed Kinetic Chain Upper Extremity Stability Test, and the softball throw for distance), 2) To determine which variable or group of variables best predicts the performance of a sport specific task (the softball throw for distance). Methods: One hundred eighty subjects (111 females and 69 males, aged 18-45 years) performed the 5 upper extremity tests. The Pearson product moment correlation and a stepwise regression were used to determine whether relationships existed between performance on the tests and which upper extremity test result best explained the performance on the softball throw for distance. Results: There were significant correlations (r=.33 to r=.70, p=0.001) between performance on all of the tests. The modified pull-up test was the best predictor of the performance on the softball throw for distance (r2= 48.7), explaining 48.7% of variation in performance. When weight, height, and age were added to the regression equation the r2 values increased to 64.5, 66.2, and 67.5 respectively. Conclusion: The results of this study indicate that several upper extremity tests demonstrate significant relationships with one another and with the softball throw for distance. The modified pull up test was the best predictor of performance on the softball throw for distance. PMID:21712942

Using Extreme Groups Strategy When Measures Are Not Normally Distributed.

ERIC Educational Resources Information Center

Fowler, Robert L.

1992-01-01

A Monte Carlo simulation explored how to optimize power in the extreme groups strategy when sampling from nonnormal distributions. Results show that the optimum percent for the extreme group selection was approximately the same for all population shapes, except the extremely platykurtic (uniform) distribution. (SLD)

Therapeutic riding followed by rhythmic auditory stimulation to improve balance and gait in a subject with orthopedic pathologies.

PubMed

Ungermann, Cathryn M; Gras, Laura Z

2011-12-01

The study objectives were to investigate the effect of therapeutic riding with a subject who had an orthopedic diagnosis. This is a single-subject case report. The study was conducted at an equestrian facility with an indoor riding arena. The subject was a 59-year-old woman with grade I spondylolisthesis at L4/L5 and multilevel lumbar spinal stenosis in central and foraminal canals. The subject had an anterior cervical fusion of C3-C7. The subject has been ambulating with a straight cane due to her history of frequent falls. Gait, agility, strength, range of motion, and balance testing were performed. The subject had impairments of bilateral lower extremities with an ataxic gait pattern and was at risk for continued falls according to the balance measures. The intervention comprised therapeutic riding sessions 3 times a week for 20 minutes for 4 weeks. Each riding session was immediately followed by a 10-minute independent walking program with a metronome for rhythmic auditory stimulation. The outcome measures were as follows: Manual muscle testing and range of motion of the lower extremities, Gait Speed Test, Dynamic Gait Index, Four-Square Step Test, Chair Stand Test, Single Leg Stance. Improvements were seen in lower extremity strength and range of motion and balance. The subject improved on balance scores, placing her out of the risk for falls category. Therapeutic riding followed by rhythmic auditory stimulation improved lower extremity range of motion, strength, and balance with this subject.

An exploratory analysis of the self-reported goals of individuals with chronic upper-extremity paresis following stroke.

PubMed

Waddell, Kimberly J; Birkenmeier, Rebecca L; Bland, Marghuretta D; Lang, Catherine E

2016-01-01

To classify the self-identified goals of individuals post-stroke with chronic upper extremity (UE) paresis, and determine if age, UE functional capacity and pre-stroke hand dominance influence overall goal selection. Sixty-five subjects participated. Using the Canadian Occupational Performance Measure (COPM) to establish treatment goals, the top five goals were categorized using the Occupational Therapy Practice Framework into five categories: activities of daily living (ADLs), instrumental activities of daily living (IADLs), leisure, work and general UE movement. A Chi-square analysis determined if age, UE functional capacity (measured by the Action Research Arm Test) and UE hand dominance influenced individual goal selection. The majority of goals were in the ADL (37%) and IADL (40%) categories. A small percentage (12%) was related to general UE movement. Individuals with moderate UE functional capacity identified more ADL goals than those with higher UE functional capacity. There was not a difference between age and UE dominance across all five goal areas. Individuals with chronic UE paresis had specific goals that were not influenced by age or hand dominance, but partially influenced by severity. General UE movement goals were identified less than goals related to specific activities. Considering the specificity of individual goals following stroke, it is recommended that clinicians regularly utilize a goal setting tool to help establish client goals. It is recommended that clinicians further inquire about general goals in order to link upper extremity deficits to functional activity limitations. Age, upper extremity functional capacity and hand dominance have little influence on the rehabilitation goals for individuals with chronic paresis after stroke.

Spectro-Temporal Electrocardiogram Analysis for Noise-Robust Heart Rate and Heart Rate Variability Measurement

PubMed Central

Tobón, Diana P.; Jayaraman, Srinivasan

2017-01-01

The last few years has seen a proliferation of wearable electrocardiogram (ECG) devices in the market with applications in fitness tracking, patient monitoring, athletic performance assessment, stress and fatigue detection, and biometrics, to name a few. The majority of these applications rely on the computation of the heart rate (HR) and the so-called heart rate variability (HRV) index via time-, frequency-, or non-linear-domain approaches. Wearable/portable devices, however, are highly susceptible to artifacts, particularly those resultant from movement. These artifacts can hamper HR/HRV measurement, thus pose a serious threat to cardiac monitoring applications. While current solutions rely on ECG enhancement as a pre-processing step prior to HR/HRV calculation, existing artifact removal algorithms still perform poorly under extremely noisy scenarios. To overcome this limitation, we take an alternate approach and propose the use of a spectro-temporal ECG signal representation that we show separates cardiac components from artifacts. More specifically, by quantifying the rate-of-change of ECG spectral components over time, we show that heart rate estimates can be reliably obtained even in extremely noisy signals, thus bypassing the need for ECG enhancement. With such HR measurements in hands, we then propose a new noise-robust HRV index termed MD-HRV (modulation-domain HRV) computed as the standard deviation of the obtained HR values. Experiments with synthetic ECG signals corrupted at various different signal-to-noise levels, as well as recorded noisy signals show the proposed measure outperforming several HRV benchmark parameters computed post wavelet-based enhancement. These findings suggest that the proposed HR measures and derived MD-HRV metric are well-suited for ambulant cardiac monitoring applications, particularly those involving intense movement (e.g., elite athletic training). PMID:29255653

Worse self-reported outcomes but no limitations in performance-based measures in patients with long-standing hip and groin pain compared with healthy controls.

PubMed

Wörner, Tobias; Sigurðsson, Haraldur B; Pålsson, Anders; Kostogiannis, Ioannis; Ageberg, Eva

2017-01-01

This study aimed to evaluate patient-reported outcomes as well as lower extremity and trunk muscle function in patients with long-standing hip and groin pain, in comparison with matched, healthy controls. It was hypothesized that patients with long-standing hip and groin pain would report more deficiency on the Copenhagen Hip and Groin Outcome Score (HAGOS) and have worse outcomes on performance-based measures than healthy controls. Nineteen patients with long-standing hip and groin pain and 19 healthy, activity level-, age-, gender-, and weight-matched controls were assessed with the HAGOS for self-reported outcomes, and a parallel squat (w/kg), single-leg triple jump (cm), single-leg rise (n), barbell roll-out (% of height), and plank test (s) for performance-based measures. Independent sample t test was performed to assess between-group differences. The paired t test was used to analyse between-limb differences in unilateral performance tasks. The patients had worse scores than the controls in all HAGOS subscales (p ≤ 0.001), while no statistically significant differences were observed for any performance measure between groups or between symptomatic and non-symptomatic limbs. Despite significant self-reported functional limitations on the HAGOS, there were no significant differences between groups in performance-based strength or power measures. The results of this study highlight the need to identify performance-based measures, sensitive to functional deficiencies in patients with long-standing hip and groin pain in order to complement the clinical picture obtained by patient-reported outcomes such as the HAGOS. III.

Projected changes to precipitation extremes over the Canadian Prairies using multi-RCM ensemble

NASA Astrophysics Data System (ADS)

Masud, M. B.; Khaliq, M. N.; Wheater, H. S.

2016-12-01

Information on projected changes to precipitation extremes is needed for future planning of urban drainage infrastructure and storm water management systems and to sustain socio-economic activities and ecosystems at local, regional and other scales of interest. This study explores the projected changes to seasonal (April-October) precipitation extremes at daily, hourly and sub-hourly scales over the Canadian Prairie Provinces of Alberta, Saskatchewan, and Manitoba, based on the North American Regional Climate Change Assessment Program multi-Regional Climate Model (RCM) ensemble and regional frequency analysis. The performance of each RCM is evaluated regarding boundary and performance errors to study various sources of uncertainties and the impact of large-scale driving fields. In the absence of RCM-simulated short-duration extremes, a framework is developed to derive changes to extremes of these durations. Results from this research reveal that the relative changes in sub-hourly extremes are higher than those in the hourly and daily extremes. Overall, projected changes in precipitation extremes are larger for southeastern parts of this region than southern and northern areas, and smaller for southwestern and western parts of the study area. Keywords: climate change, precipitation extremes, regional frequency analysis, NARCCAP, Canadian Prairie provinces

Associations of occupational standing with musculoskeletal symptoms: a systematic review with meta-analysis.

PubMed

Coenen, Pieter; Willenberg, Lisa; Parry, Sharon; Shi, Joyce W; Romero, Lorena; Blackwood, Diana M; Maher, Christopher G; Healy, Genevieve N; Dunstan, David W; Straker, Leon M

2018-02-01

Given the high exposure to occupational standing in specific occupations, and recent initiatives to encourage intermittent standing among white-collar workers, a better understanding of the potential health consequences of occupational standing is required. We aimed to review and quantify the epidemiological evidence on associations of occupational standing with musculoskeletal symptoms. A systematic review was performed. Data from included articles were extracted and described, and meta-analyses conducted when data were sufficiently homogeneous. Electronic databases were systematically searched. Peer-reviewed articles on occupational standing and musculoskeletal symptoms from epidemiological studies were identified. Of the 11 750 articles screened, 50 articles reporting 49 studies were included (45 cross-sectional and 5 longitudinal; n=88 158 participants) describing the associations of occupational standing with musculoskeletal symptoms, including low-back (39 articles), lower extremity (14 articles) and upper extremity (18 articles) symptoms. In the meta-analysis, 'substantial' (>4 hours/workday) occupational standing was associated with the occurrence of low-back symptoms (pooled OR (95% CI) 1.31 (1.10 to 1.56)). Evidence on lower and upper extremity symptoms was too heterogeneous for meta-analyses. The majority of included studies reported statistically significant detrimental associations of occupational standing with lower extremity, but not with upper extremity symptoms. The evidence suggests that substantial occupational standing is associated with the occurrence of low-back and (inconclusively) lower extremity symptoms, but there may not be such an association with upper extremity symptoms. However, these conclusions are tentative as only limited evidence was found from high-quality, longitudinal studies with fully adjusted models using objective measures of standing. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Silicon-On-Insulator (SOI) Devices and Mixed-Signal Circuits for Extreme Temperature Applications

NASA Technical Reports Server (NTRS)

Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik

2008-01-01

Electronic systems in planetary exploration missions and in aerospace applications are expected to encounter extreme temperatures and wide thermal swings in their operational environments. Electronics designed for such applications must, therefore, be able to withstand exposure to extreme temperatures and to perform properly for the duration of the missions. Electronic parts based on silicon-on-insulator (SOI) technology are known, based on device structure, to provide faster switching, consume less power, and offer better radiation-tolerance compared to their silicon counterparts. They also exhibit reduced current leakage and are often tailored for high temperature operation. However, little is known about their performance at low temperature. The performance of several SOI devices and mixed-signal circuits was determined under extreme temperatures, cold-restart, and thermal cycling. The investigations were carried out to establish a baseline on the functionality and to determine suitability of these devices for use in space exploration missions under extreme temperatures. The experimental results obtained on selected SOI devices are presented and discussed in this paper.

Censored rainfall modelling for estimation of fine-scale extremes

NASA Astrophysics Data System (ADS)

Cross, David; Onof, Christian; Winter, Hugo; Bernardara, Pietro

2018-01-01

Reliable estimation of rainfall extremes is essential for drainage system design, flood mitigation, and risk quantification. However, traditional techniques lack physical realism and extrapolation can be highly uncertain. In this study, we improve the physical basis for short-duration extreme rainfall estimation by simulating the heavy portion of the rainfall record mechanistically using the Bartlett-Lewis rectangular pulse (BLRP) model. Mechanistic rainfall models have had a tendency to underestimate rainfall extremes at fine temporal scales. Despite this, the simple process representation of rectangular pulse models is appealing in the context of extreme rainfall estimation because it emulates the known phenomenology of rainfall generation. A censored approach to Bartlett-Lewis model calibration is proposed and performed for single-site rainfall from two gauges in the UK and Germany. Extreme rainfall estimation is performed for each gauge at the 5, 15, and 60 min resolutions, and considerations for censor selection discussed.

Effect of Reduced Stiffness Dance Flooring on Lower Extremity Joint Angular Trajectories During a Ballet Jump.

PubMed

Hackney, James; Brummel, Sara; Newman, Mary; Scott, Shannon; Reinagel, Matthew; Smith, Jennifer

2015-09-01

We carried out a study to investigate how low stiffness flooring may help prevent overuse injuries of the lower extremity in dancers. It was hypothesized that performing a ballet jump (sauté) on a reduced stiffness dance floor would decrease maximum joint flexion angles and negative angular velocities at the hips, knees, or ankles compared to performing the same jump on a harder floor. The participants were 15 young adult female dancers (age range 18 to 28, mean = 20.89 ± 2.93 years) with at least 5 years of continuous ballet experience and without history of serious lower body injury, surgery, or recent pain. They performed sautés on a (low stiffness) Harlequin ® WoodSpring Floor and on a vinyl-covered hardwood on concrete floor. Maximum joint flexion angles and negative velocities at bilateral hips, knees, and ankles were measured with the "Ariel Performance Analysis System" (APAS). Paired one-tailed t-tests yielded significant decreases in maximum knee angle (average decrease = 3.4° ± 4.2°, p = 0.026) and angular negative velocity of the ankles (average decrease = 18.7°/sec ± 27.9°/sec, p = 0.009) with low stiffness flooring. If the knee angle is less acute, then the length of the external knee flexion moment arm will also be shorter and result in a smaller external knee flexion moment, given an equal landing force. Also, high velocities of eccentric muscle contraction, which are necessary to control negative angular velocity of the ankle joint, are associated with higher risk of musculotendinous injury. Hence, our findings indicate that reduced floor stiffness may indeed help decrease the likelihood of lower extremity injuries.

Performance verification of the Gravity and Extreme Magnetism Small explorer (GEMS) x-ray polarimeter

NASA Astrophysics Data System (ADS)

Enoto, Teruaki; Black, J. Kevin; Kitaguchi, Takao; Hayato, Asami; Hill, Joanne E.; Jahoda, Keith; Tamagawa, Toru; Kaneko, Kenta; Takeuchi, Yoko; Yoshikawa, Akifumi; Marlowe, Hannah; Griffiths, Scott; Kaaret, Philip E.; Kenward, David; Khalid, Syed

2014-07-01

Polarimetry is a powerful tool for astrophysical observations that has yet to be exploited in the X-ray band. For satellite-borne and sounding rocket experiments, we have developed a photoelectric gas polarimeter to measure X-ray polarization in the 2-10 keV range utilizing a time projection chamber (TPC) and advanced micro-pattern gas electron multiplier (GEM) techniques. We carried out performance verification of a flight equivalent unit (1/4 model) which was planned to be launched on the NASA Gravity and Extreme Magnetism Small Explorer (GEMS) satellite. The test was performed at Brookhaven National Laboratory, National Synchrotron Light Source (NSLS) facility in April 2013. The polarimeter was irradiated with linearly-polarized monochromatic X-rays between 2.3 and 10.0 keV and scanned with a collimated beam at 5 different detector positions. After a systematic investigation of the detector response, a modulation factor >=35% above 4 keV was obtained with the expected polarization angle. At energies below 4 keV where the photoelectron track becomes short, diffusion in the region between the GEM and readout strips leaves an asymmetric photoelectron image. A correction method retrieves an expected modulation angle, and the expected modulation factor, ~20% at 2.7 keV. Folding the measured values of modulation through an instrument model gives sensitivity, parameterized by minimum detectable polarization (MDP), nearly identical to that assumed at the preliminary design review (PDR).

Relationship of Hip and Trunk Muscle Function with Single Leg Step-Down Performance: Implications for Return to Play Screening and Rehabilitation.

PubMed

Burnham, Jeremy M; Yonz, Michael C; Robertson, Kaley E; McKinley, Rachelle; Wilson, Benjamin R; Johnson, Darren L; Ireland, Mary Lloyd; Noehren, Brian

2016-11-01

Evaluate the relationship of hip and trunk muscle function with the Single Leg Step-Down test (SLSD). Laboratory study. Biomechanics Laboratory. 71 healthy participants with no history of anterior cruciate ligament (ACL) or lower extremity injury in the last 3 months completed this study (38 males, 33 females; mean 25.49 ± 0.62 years). Hip abduction (HABD), external rotation (HER), and extension (HEXT) peak isometric force were measured. Trunk endurance was measured with plank (PL) and side plank (SPL) tests. SLSD repetitions in 60-s and dynamic knee valgus (VAL) were recorded. PL, SPL, HABD, HER, and HEXT were positively correlated with SLSD repetitions. PL (r = 0.598, p < 0.001) was most correlated with SLSD repetitions, and regression demonstrated that PL (p = 0.001, R 2  = 0.469) was a predictor of SLSD repetitions. VAL trended toward negative correlation with PL and SPL. Sex-specific differences were present, with PL, SPL, HABD, and HER showing stronger relationships with SLSD in females. Hip and trunk muscle function were positively correlated with SLSD performance, and these relationships were strongest in females. PL predicted performance on the SLSD. Further research is needed to investigate the utility of SLSD as a screening or return-to-play test for lower extremity conditions such as ACL injury and patellofemoral pain. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effects of modified constraint-induced movement therapy and mirror therapy on upper extremity function and its influence on activities of daily living.

PubMed

Ju, Yumi; Yoon, In-Jin

2018-01-01

[Purpose] Modified constraint-induced movement therapy and mirror therapy are recognized as stroke rehabilitation methods. The aim of the present study was to determine whether these therapies influence upper extremity function and whether upper extremity function influences the ability to perform activities of daily living in further. [Subjects and Methods] Twenty-eight stroke patients participated in the study. Interventions were administered five times per week for 3 weeks. Activities of daily living or self-exercise were performed after modified constraint-induced movement therapy or mirror therapy, respectively. Analyses were performed on the results of the Manual Function Test and the Korean version of the Modified Barthel Index to determine the factors influencing activities of daily living. [Results] Both groups showed improvement in upper extremity function, but only the modified constraint-induced movement therapy group showed a correlation between upper extremity function and performance in the hygiene, eating, and dressing. The improved hand manipulation function found in the modified constraint-induced movement therapy had statistically significant influences on eating and dressing. [Conclusion] Our results suggest that a patient's attempts to move the affected side result in improved performance in activities of daily living as well as physical function.

The effects of modified constraint-induced movement therapy and mirror therapy on upper extremity function and its influence on activities of daily living

PubMed Central

Ju, Yumi; Yoon, In-Jin

2018-01-01

[Purpose] Modified constraint-induced movement therapy and mirror therapy are recognized as stroke rehabilitation methods. The aim of the present study was to determine whether these therapies influence upper extremity function and whether upper extremity function influences the ability to perform activities of daily living in further. [Subjects and Methods] Twenty-eight stroke patients participated in the study. Interventions were administered five times per week for 3 weeks. Activities of daily living or self-exercise were performed after modified constraint-induced movement therapy or mirror therapy, respectively. Analyses were performed on the results of the Manual Function Test and the Korean version of the Modified Barthel Index to determine the factors influencing activities of daily living. [Results] Both groups showed improvement in upper extremity function, but only the modified constraint-induced movement therapy group showed a correlation between upper extremity function and performance in the hygiene, eating, and dressing. The improved hand manipulation function found in the modified constraint-induced movement therapy had statistically significant influences on eating and dressing. [Conclusion] Our results suggest that a patient’s attempts to move the affected side result in improved performance in activities of daily living as well as physical function. PMID:29410571

Is goniometry suitable for measuring ankle range of motion in female ballet dancers? An initial comparison with radiographic measurement.

PubMed

Russell, Jeffrey A; Shave, Ruth M; Kruse, David W; Nevill, Alan M; Koutedakis, Yiannis; Wyon, Matthew A

2011-06-01

Female ballet dancers require extreme ankle motion to attain the demi-plié (weight-bearing full dorsiflexion [DF]) and en pointe (weight-bearing full plantar flexion [PF]) positions of ballet. However, techniques for assessing this amount of motion have not yet received sufficient scientific scrutiny. Therefore, the purpose of this study was to examine possible differences between weight-bearing goniometric and radiographic ankle range of motion measurements in female ballet dancers. Ankle range of motion in 8 experienced female ballet dancers was assessed by goniometry and 2 radiographic measurement methods. The latter were performed on 3 mediolateral x-rays, in demi-plié, neutral, and en pointe positions; one of them used the same landmarks as goniometry. DF values were not significantly different among the methods, but PF values were (P < .05). Not only was PF of the talocrural joint significantly less than the other 2 measurements (P < .001), PF from the goniometric method applied to the x-rays was significantly less than PF obtained from clinical goniometry (P < .05). These data provide insight into the extreme ankle and foot motion, particularly PF, required in female ballet dancers and suggest that goniometry may not be ideal for assessing ankle range of motion in these individuals. Therefore, further research is needed to standardize how DF and PF are measured in ballet dancers. Diagnostic, Level I.

Measurements of the optical performance of bolometers for SPICA/SAFARI

NASA Astrophysics Data System (ADS)

Audley, Michael D.; de Lange, Gert; Gao, Jian-Rong; Khosropanah, Pourya; Ridder, Marcel; Ferrari, Lorenza; Laauwen, Wouter M.; Ranjan, Manisha; Mauskopf, Philip D.; Morozov, Dmitry; Trappe, Neil A.

2012-09-01

We have measured the optical response of detectors designed for SAFARI, the far-infrared imaging spectrometer for the SPICA satellite. To take advantage of SPICA's cooled optics, SAFARI’s three bolometer arrays are populated with extremely sensitive (NEP~2×10-19 W/√Hz) transition edge sensors with a transition temperature close to 100 mK. The extreme sensitivity and low saturation power (~4 fW) of SAFARI’s detectors present challenges to characterizing them. We have therefore built up an ultra-low background test facility with a cryogen-free high-capacity dilution refrigerator, paying careful attention to stray-light exclusion. Our use of a pulse-tube cooler to pre-cool the dilution refrigerator required that the SAFARI Detector System Test Facility provide a high degree electrical, magnetic, and mechanical isolation for the detectors. We have carefully characterized the performance of the test facility in terms of background power loading. The test facility has been designed to be flexible and easily reconfigurable with internal illuminators that allow us to characterize the optical response of the detectors. We describe the test facility and some of the steps we took to create an ultra-low background test environment. We have measured the optical response of two detectors designed for SAFARI’s short-wave wavelength band in combination with a spherical backshort and conical feedhorn. We find an overall optical efficiency of 40% for both, compared with an ideal-case predicted optical efficiency of 66%.

Detection of Stress Levels from Biosignals Measured in Virtual Reality Environments Using a Kernel-Based Extreme Learning Machine.

PubMed

Cho, Dongrae; Ham, Jinsil; Oh, Jooyoung; Park, Jeanho; Kim, Sayup; Lee, Nak-Kyu; Lee, Boreom

2017-10-24

Virtual reality (VR) is a computer technique that creates an artificial environment composed of realistic images, sounds, and other sensations. Many researchers have used VR devices to generate various stimuli, and have utilized them to perform experiments or to provide treatment. In this study, the participants performed mental tasks using a VR device while physiological signals were measured: a photoplethysmogram (PPG), electrodermal activity (EDA), and skin temperature (SKT). In general, stress is an important factor that can influence the autonomic nervous system (ANS). Heart-rate variability (HRV) is known to be related to ANS activity, so we used an HRV derived from the PPG peak interval. In addition, the peak characteristics of the skin conductance (SC) from EDA and SKT variation can also reflect ANS activity; we utilized them as well. Then, we applied a kernel-based extreme-learning machine (K-ELM) to correctly classify the stress levels induced by the VR task to reflect five different levels of stress situations: baseline, mild stress, moderate stress, severe stress, and recovery. Twelve healthy subjects voluntarily participated in the study. Three physiological signals were measured in stress environment generated by VR device. As a result, the average classification accuracy was over 95% using K-ELM and the integrated feature (IT = HRV + SC + SKT). In addition, the proposed algorithm can embed a microcontroller chip since K-ELM algorithm have very short computation time. Therefore, a compact wearable device classifying stress levels using physiological signals can be developed.

Climatic extremes improve predictions of spatial patterns of tree species

USGS Publications Warehouse

Zimmermann, N.E.; Yoccoz, N.G.; Edwards, T.C.; Meier, E.S.; Thuiller, W.; Guisan, Antoine; Schmatz, D.R.; Pearman, P.B.

2009-01-01

Understanding niche evolution, dynamics, and the response of species to climate change requires knowledge of the determinants of the environmental niche and species range limits. Mean values of climatic variables are often used in such analyses. In contrast, the increasing frequency of climate extremes suggests the importance of understanding their additional influence on range limits. Here, we assess how measures representing climate extremes (i.e., interannual variability in climate parameters) explain and predict spatial patterns of 11 tree species in Switzerland. We find clear, although comparably small, improvement (+20% in adjusted D2, +8% and +3% in cross-validated True Skill Statistic and area under the receiver operating characteristics curve values) in models that use measures of extremes in addition to means. The primary effect of including information on climate extremes is a correction of local overprediction and underprediction. Our results demonstrate that measures of climate extremes are important for understanding the climatic limits of tree species and assessing species niche characteristics. The inclusion of climate variability likely will improve models of species range limits under future conditions, where changes in mean climate and increased variability are expected.

A study of the stress wave factor technique for nondestructive evaluation of composite materials

NASA Technical Reports Server (NTRS)

Sarrafzadeh-Khoee, A.; Kiernan, M. T.; Duke, J. C., Jr.; Henneke, E. G., II

1986-01-01

The acousto-ultrasonic method of nondestructive evaluation is an extremely sensitive means of assessing material response. Efforts continue to complete the understanding of this method. In order to achieve the full sensitivity of the technique, extreme care must be taken in its performance. This report provides an update of the efforts to advance the understanding of this method and to increase its application to the nondestructive evaluation of composite materials. Included are descriptions of a novel optical system that is capable of measuring in-plane and out-of-plane displacements, an IBM PC-based data acquisition system, an extensive data analysis software package, the azimuthal variation of acousto-ultrasonic behavior in graphite/epoxy laminates, and preliminary examination of processing variation in graphite-aluminum tubes.

Element Selectivity in Second-Harmonic Generation of GaFeO3 by a Soft-X-Ray Free-Electron Laser

NASA Astrophysics Data System (ADS)

Yamamoto, Sh.; Omi, T.; Akai, H.; Kubota, Y.; Takahashi, Y.; Suzuki, Y.; Hirata, Y.; Yamamoto, K.; Yukawa, R.; Horiba, K.; Yumoto, H.; Koyama, T.; Ohashi, H.; Owada, S.; Tono, K.; Yabashi, M.; Shigemasa, E.; Yamamoto, S.; Kotsugi, M.; Wadati, H.; Kumigashira, H.; Arima, T.; Shin, S.; Matsuda, I.

2018-06-01

Nonlinear optical frequency conversion has been challenged to move down to the extreme ultraviolet and x-ray region. However, the extremely low signals have allowed researchers to only perform transmission experiments of the gas phase or ultrathin films. Here, we report second harmonic generation (SHG) of the reflected beam of a soft x-ray free-electron laser from a solid, which is enhanced by the resonant effect. The observation revealed that the double resonance condition can be met by absorption edges for transition metal oxides in the soft x-ray range, and this suggests that the resonant SHG technique can be applicable to a wide range of materials. We discuss the possibility of element-selective SHG spectroscopy measurements in the soft x-ray range.

Predicting Material Performance in the Space Environment from Laboratory Test Data, Static Design Environments, and Space Weather Models

NASA Technical Reports Server (NTRS)

Minow, Josep I.; Edwards, David L.

2008-01-01

Qualifying materials for use in the space environment is typically accomplished with laboratory exposures to simulated UV/EUV, atomic oxygen, and charged particle radiation environments with in-situ or subsequent measurements of material properties of interest to the particular application. Choice of environment exposure levels are derived from static design environments intended to represent either mean or extreme conditions that are anticipated to be encountered during a mission. The real space environment however is quite variable. Predictions of the on orbit performance of a material qualified to laboratory environments can be done using information on 'space weather' variations in the real environment. This presentation will first review the variability of space environments of concern for material degradation and then demonstrate techniques for using test data to predict material performance in a variety of space environments from low Earth orbit to interplanetary space using historical measurements and space weather models.

Measurements of observables during detonator function

NASA Astrophysics Data System (ADS)

Smilowitz, Laura; Henson, Bryan; Remelius, Dennis

Thermal explosion and detonation are two phenomena which can both occur as the response of explosives to thermal or mechanical insults. Thermal explosion is typically considered in the safety envelope and detonation is considered in the performance regime of explosive behavior. However, the two regimes are tied together by a phenomenon called deflagration to detonation transition (DDT). In this talk, I will discuss experiments on commercial detonators aimed at understanding the mechanism for energy release during detonator function. Diagnostic development towards measuring temperature, pressure, and density during the extreme conditions and time scales of detonation will be discussed. Our current ability to perform table-top dynamic radiography on functioning detonators will be described. Dynamic measurements of temperature, pressure, and density will be shown and discussion of the function of a detonator will be given in terms of our current understanding of deflagration, detonation, and the transition between the two.

Handwriting capacity in children newly diagnosed with Attention Deficit Hyperactivity Disorder.

PubMed

Brossard-Racine, Marie; Majnemer, Annette; Shevell, Michael; Snider, Laurie; Bélanger, Stacey Ageranioti

2011-01-01

Preliminary evidence suggests that children with Attention Deficit Hyperactivity Disorder (ADHD) may exhibit handwriting difficulties. However, the exact nature of these difficulties and the extent to which they may relate to motor or behavioural difficulties remains unclear. The aim of this study was to describe handwriting capacity in children newly diagnosed with ADHD and identify predictors of performance. Forty medication-naïve children with ADHD (mean age 8.1 years) were evaluated with the Evaluation Tool of Children's Handwriting-Manuscript, the Movement Assessment Battery for Children (M-ABC), the Developmental Test of Visual Motor Integration (VMI) and the Conner Global Index. An important subset (85.0%) exhibited manual dexterity difficulties. Handwriting performance was extremely variable in terms of speed and legibility. VMI was the most important predictor of legibility. Upper extremity coordination, as measured by the M-ABC ball skills subtest, was also a good predictor of word legibility. Poor handwriting legibility and slow writing speed were common in children newly diagnosed with ADHD and were associated with motor abilities. Future studies are needed to determine whether interventions, including stimulant medications, can improve handwriting performance and related motor functioning. Copyright © 2011 Elsevier Ltd. All rights reserved.

Content range and precision of a computer adaptive test of upper extremity function for children with cerebral palsy.

PubMed

Montpetit, Kathleen; Haley, Stephen; Bilodeau, Nathalie; Ni, Pengsheng; Tian, Feng; Gorton, George; Mulcahey, M J

2011-02-01

This article reports on the content range and measurement precision of an upper extremity (UE) computer adaptive testing (CAT) platform of physical function in children with cerebral palsy. Upper extremity items representing skills of all abilities were administered to 305 parents. These responses were compared with two traditional standardized measures: Pediatric Outcomes Data Collection Instrument and Functional Independence Measure for Children. The UE CAT correlated strongly with the upper extremity component of these measures and had greater precision when describing individual functional ability. The UE item bank has wider range with items populating the lower end of the ability spectrum. This new UE item bank and CAT have the capability to quickly assess children of all ages and abilities with good precision and, most importantly, with items that are meaningful and appropriate for their age and level of physical function.

Trunk muscle attributes are associated with balance and mobility in older adults: a pilot study.

PubMed

Suri, Pradeep; Kiely, Dan K; Leveille, Suzanne G; Frontera, Walter R; Bean, Jonathan F

2009-10-01

To determine whether trunk muscle attributes are associated with balance and mobility performance among mobility-limited older adults. Cross-sectional analysis of data from a randomized clinical trial. Outpatient rehabilitation research center. Community-dwelling older adults (N = 70; mean age 75.9 years) with mobility limitations as defined by the Short Physical Performance Battery (SPPB). Independent variables included physiologic measures of trunk extension strength, trunk flexion strength, trunk extension endurance, trunk extension endurance, and leg press strength. All measures were well tolerated by the study subjects without the occurrence of any associated injuries or adverse events. The association of each physiologic measure with each outcome was examined by the use of separate multivariate models to calculate the partial variance (R(2)) of each trunk and extremity measure. Balance measured by the Berg Balance Scale and Unipedal Stance Test and mobility performance as measured by the SPPB. Trunk extension endurance (partial R(2) = .14, P = .02), and leg press strength (partial R(2) = .14, P = .003) accounted for the greatest amount of the variance in SPPB performance. Trunk extension endurance (partial R(2) = .17, P = .007), accounted for the greatest amount of the variance in BBS performance. Trunk extension strength (R(2) = .09, P = .03), accounted for the greatest amount of the variance in UST performance. The variance explained by trunk extension endurance equaled or exceeded the variance explained by limb strength across all three performance outcomes. Trunk endurance and strength can be safely measured in mobility-limited older adults and are associated with both balance and mobility performance. Trunk endurance and trunk strength are physiologic attributes worthy of targeting in the rehabilitative care of mobility-limited older adults.

Sensitivity to change of mobility measures in musculoskeletal conditions on lower extremities in outpatient rehabilitation settings.

PubMed

Navarro-Pujalte, Esther; Gacto-Sánchez, Mariano; Montilla-Herrador, Joaquina; Escolar-Reina, Pilar; Ángeles Franco-Sierra, María; Medina-Mirapeix, Francesc

2018-01-12

Prospective longitudinal study. To examine the sensitivity of the Mobility Activities Measure for lower extremities and to compare it to the sensitivity of the Physical Functioning Scale (PF-10) and the Patient-Specific Functional Scale (PSFS) at week 4 and week 8 post-hospitalization in outpatient rehabilitation settings. Mobility Activities Measure is a set of short mobility measures to track outpatient rehabilitation progress: its scales have shown good properties but its sensitivity to change has not been reported. Patients with musculoskeletal conditions were recruited at admission in three outpatient rehabilitation settings in Spain. Data were collected at admission, week 4 and week 8 from an initial sample of 236 patients (mean age ± SD = 36.7 ± 11.1). Mobility Activities Measure scales for lower extremity; PF-10; and PSFS. All the Mobility Activities Measure scales were sensitive to both positive and negative changes (the Standardized Response Means (SRMs) ranged between 1.05 and 1.53 at week 4, and between 0.63 and 1.47 at week 8). The summary measure encompassing the three Mobility Activities Measure scales detected a higher proportion of participants who had improved beyond the minimal detectable change (MDC) than detected by the PSFS and the PF-10 both at week 4 (86.64% vs. 69.81% and 42.23%, respectively) and week 8 (71.14% vs. 55.65% and 60.81%, respectively). The three Mobility Activities Measure scales assessing the lower extremity can be used across outpatient rehabilitation settings to provide consistent and sensitive measures of changes in patients' mobility. Implications for rehabilitation All the scales of the Mobility Activities Measure for the lower extremity were sensitive to both positive and negative change across the follow-up periods. Overall, the summary measure encompassing the three Mobility Activities Measure scales for the lower extremity appeared more sensitive to positive changes than the Physical Functioning Scale, especially during the first four weeks of treatment. The summary measure also detected a higher percentage of participants with positive change that exceeded the minimal detectable change than the Patient-Specific Functional Scale and the Physical Functioning Scale at the first follow-up period. By demonstrating their consistency and sensitivity to change, the three Mobility Activities Measures scales can now be considered in order to track patients' functional progress. Mobility Activities Measure can be therefore used in patients with musculoskeletal conditions across outpatient rehabilitation settings to provide estimates of change in mobility activities focusing on the lower extremity.

Effects of foot orthotics on running economy: methodological considerations.

PubMed

Burke, Jeanmarie R; Papuga, M Owen

2012-05-01

The purpose of the study was to collect preliminary data to address methodological considerations that may impact subject-specific reactions to foot orthotics during running. Six endurance-trained recreational runners recruited from a chiropractic college campus wore their preferred running shoes and then inserted either their custom-made orthotics during 1 testing session or their shoe-fitted insoles during the other testing session. Comfort perception was measured for each footwear condition. Measurements of oxygen consumption (VO2) at several moderate exercise intensities, to mimic recreational running, generated an individual's economy-of-running line. Predicted running velocity at VO(2max) (vVO2max) was calculated as an index of endurance performance. Lower extremity muscle activity was recorded. Descriptive statistics, a repeated-measures analysis of variance model, and a paired t test were used to document any systematic changes in running economy, lower extremity muscle activities, and vVO2max within and across subjects as a function of footwear conditions. Decreases in VO2 at several moderate exercise intensities (F((1,5)footwear) = 10.37, P = .023) and increases in vVO2max (t(5) = 4.20, P = .008) occurred in all 6 subjects while wearing their orthotic intervention vs their shoe-fitted insoles. There were no consistent changes in lower extremity muscle activity. Methodological decisions to use a sustained incremental exercise protocol at several moderate exercise intensities and to measure comfort perception of a custom-molded foot orthosis were effective at documenting systematic improvements in running economy among the 6 recreational runners tested. The development of a less physically demanding sustained exercise protocol is necessary to determine underlying neuromuscular mechanisms and/or clinical effectiveness of orthotic interventions. Copyright © 2012 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

Upper-arm anthropometry: an alternative indicator of nutritional health to body mass index in unilateral lower-extremity amputees?

PubMed

Miller, Michelle; Wong, Wing Ki; Wu, Jing; Cavenett, Sally; Daniels, Lynne; Crotty, Maria

2008-10-01

To evaluate the utility of body mass index (BMI) and corrected-arm-muscle area (CAMA) as measures of nutritional health for lower-limb amputees attending prosthetics clinics. Cross-sectional study. Prosthetics clinic in Australia. Unilateral lower-extremity amputees (N=58; age range, 21-91y; 37 transtibial, 21 transfemoral) attending a regional prosthetics clinic between May and November 2003. Not applicable. Weight (without prosthesis), corrected and uncorrected for the amputated limb was used with height estimated from knee height to calculate corrected BMI (cBMI) and uncorrected BMI (uBMI). CAMA was calculated using the mean of triplicate mid-upper-arm circumference (MUAC) and triceps skinfold thickness (TST) measurements. The Mini Nutritional Assessment (MNA) and Assessment of Quality of Life were administered according to recommended protocols. The Pearson correlation was used to determine the strength and significance of associations between variables, and bivariate regression analyses were performed to determine whether an association existed between the nutritional variables (BMI, CAMA, MNA) and quality of life (QOL). There were no statistically significant differences in the measures of nutritional health according to site (transtibial, transfemoral) of amputation. MUAC, TST, and CAMA all showed moderate to high positive correlations (r range, .541-.782) with both cBMI and uBMI. The strength of the relationship between the MNA and cBMI/uBMI was weaker (r=.383, r=.380, respectively) but remained positive and statistically significant (P=.003). QOL was not associated with cBMI or uBMI but was related to CAMA (beta=-.132; P=.030) and MNA (beta=-.561; P=.017). For persons with unilateral lower-extremity amputation, measurement of upper-arm anthropometry may be a more useful indicator of nutritional health and its consequences than BMI.

Novel immunoassay formats for integrated microfluidic circuits: diffusion immunoassays (DIA)

NASA Astrophysics Data System (ADS)

Weigl, Bernhard H.; Hatch, Anson; Kamholz, Andrew E.; Yager, Paul

2000-03-01

Novel designs of integrated fluidic microchips allow separations, chemical reactions, and calibration-free analytical measurements to be performed directly in very small quantities of complex samples such as whole blood and contaminated environmental samples. This technology lends itself to applications such as clinical diagnostics, including tumor marker screening, and environmental sensing in remote locations. Lab-on-a-Chip based systems offer many *advantages over traditional analytical devices: They consume extremely low volumes of both samples and reagents. Each chip is inexpensive and small. The sampling-to-result time is extremely short. They perform all analytical functions, including sampling, sample pretreatment, separation, dilution, and mixing steps, chemical reactions, and detection in an integrated microfluidic circuit. Lab-on-a-Chip systems enable the design of small, portable, rugged, low-cost, easy to use, yet extremely versatile and capable diagnostic instruments. In addition, fluids flowing in microchannels exhibit unique characteristics ('microfluidics'), which allow the design of analytical devices and assay formats that would not function on a macroscale. Existing Lab-on-a-chip technologies work very well for highly predictable and homogeneous samples common in genetic testing and drug discovery processes. One of the biggest challenges for current Labs-on-a-chip, however, is to perform analysis in the presence of the complexity and heterogeneity of actual samples such as whole blood or contaminated environmental samples. Micronics has developed a variety of Lab-on-a-Chip assays that can overcome those shortcomings. We will now present various types of novel Lab- on-a-Chip-based immunoassays, including the so-called Diffusion Immunoassays (DIA) that are based on the competitive laminar diffusion of analyte molecules and tracer molecules into a region of the chip containing antibodies that target the analyte molecules. Advantages of this technique are a reduction in reagents, higher sensitivity, minimal preparation of complex samples such as blood, real-time calibration, and extremely rapid analysis.

Validation of China-wide interpolated daily climate variables from 1960 to 2011

NASA Astrophysics Data System (ADS)

Yuan, Wenping; Xu, Bing; Chen, Zhuoqi; Xia, Jiangzhou; Xu, Wenfang; Chen, Yang; Wu, Xiaoxu; Fu, Yang

2015-02-01

Temporally and spatially continuous meteorological variables are increasingly in demand to support many different types of applications related to climate studies. Using measurements from 600 climate stations, a thin-plate spline method was applied to generate daily gridded climate datasets for mean air temperature, maximum temperature, minimum temperature, relative humidity, sunshine duration, wind speed, atmospheric pressure, and precipitation over China for the period 1961-2011. A comprehensive evaluation of interpolated climate was conducted at 150 independent validation sites. The results showed superior performance for most of the estimated variables. Except for wind speed, determination coefficients ( R 2) varied from 0.65 to 0.90, and interpolations showed high consistency with observations. Most of the estimated climate variables showed relatively consistent accuracy among all seasons according to the root mean square error, R 2, and relative predictive error. The interpolated data correctly predicted the occurrence of daily precipitation at validation sites with an accuracy of 83 %. Moreover, the interpolation data successfully explained the interannual variability trend for the eight meteorological variables at most validation sites. Consistent interannual variability trends were observed at 66-95 % of the sites for the eight meteorological variables. Accuracy in distinguishing extreme weather events differed substantially among the meteorological variables. The interpolated data identified extreme events for the three temperature variables, relative humidity, and sunshine duration with an accuracy ranging from 63 to 77 %. However, for wind speed, air pressure, and precipitation, the interpolation model correctly identified only 41, 48, and 58 % of extreme events, respectively. The validation indicates that the interpolations can be applied with high confidence for the three temperatures variables, as well as relative humidity and sunshine duration based on the performance of these variables in estimating daily variations, interannual variability, and extreme events. Although longitude, latitude, and elevation data are included in the model, additional information, such as topography and cloud cover, should be integrated into the interpolation algorithm to improve performance in estimating wind speed, atmospheric pressure, and precipitation.

The effects of below-elbow immobilization on driving performance.

PubMed

Jones, Evan M; Barrow, Aaron E; Skordas, Nic J; Green, David P; Cho, Mickey S

2017-02-01

There is limited research to guide physicians and patients in deciding whether it is safe to drive while wearing various forms of upper extremity immobilization. The purpose of this study is to evaluate the effect of below-elbow removable splints and fiberglass casts on automobile driving performance. 20 healthy subjects completed 10 runs through a closed, cone-marked driving course while wearing a randomized sequence of four different types of immobilization on each extremity (short arm thumb spica fiberglass cast, short arm fiberglass cast, short arm thumb spica splint, and short arm wrist splint). The first and last driving runs were without immobilization and served as controls. Performance was measured based on evaluation by a certified driving instructor (pass/fail scoring), cones hit, run time, and subject-perceived driving difficulty (1-10 analogue scoring). The greatest number of instructor-scored failures occurred while immobilized in right arm spica casts (n=6; p=0.02) and left arm spica casts (n=5; p=0.049). The right arm spica cast had the highest subject-perceived difficulty (5.2±1.9; p<0.001). All forms of immobilization had significantly increased perceived difficulty compared to control, except for the left short arm splint (2.5±1.6; p>0.05). There was no significant difference in number of cones hit or driving time between control runs and runs with any type of immobilization. Drivers should use caution when wearing any of the forms of upper extremity immobilization tested in this study. All forms of immobilization, with exception of the left short arm splint significantly increased perceived driving difficulty. However, only the fiberglass spica casts (both left and right arm), significantly increased drive run failures due to loss of vehicle control. We recommend against driving when wearing a below-elbow fiberglass spica cast on either extremity. Copyright © 2016. Published by Elsevier Ltd.

Longitudinal evaluation of Patient Reported Outcomes Measurement Information Systems (PROMIS) measures in pediatric chronic pain

PubMed Central

Kashikar-Zuck, Susmita; Carle, Adam; Barnett, Kimberly; Goldschneider, Kenneth R.; Sherry, David D.; Mara, Constance A.; Cunningham, Natoshia; Farrell, Jennifer; Tress, Jenna; DeWitt, Esi Morgan

2015-01-01

The Patient Reported Outcomes Measurement Information System (PROMIS) initiative is a comprehensive strategy by the National Institutes of Health to support the development and validation of precise instruments to assess self-reported health domains across healthy and disease-specific populations. Much progress has been made in instrument development but there remains a gap in the validation of PROMIS measures for pediatric chronic pain. The purpose of this study was to investigate the construct validity and responsiveness to change of seven PROMIS domains for the assessment of children (ages 8-18) with chronic pain – Pain Interference, Fatigue, Anxiety, Depression, Mobility, Upper Extremity Function and Peer Relationships. PROMIS measures were administered at the initial visit and two follow-up visits at an outpatient chronic pain clinic (CPC; N=82) and at an intensive amplified pain day-treatment program (AMP; N= 63). Aim 1 examined construct validity of PROMIS measures by comparing them with corresponding “legacy” measures administered as part of usual care in the CPC sample. Aim 2 examined sensitivity to change in both CPC and AMP samples. Longitudinal growth models showed that PROMIS Pain Interference, Anxiety, Depression, Mobility, Upper Extremity and Peer Relationship measures and legacy instruments generally performed similarly with slightly steeper slopes of improvement in legacy measures. All seven PROMIS domains showed responsiveness to change. Results offered initial support for the validity of PROMIS measures in pediatric chronic pain. Further validation with larger and more diverse pediatric pain samples and additional legacy measures would broaden the scope of use of PROMIS in clinical research. PMID:26447704

Time resolved 3D momentum imaging of ultrafast dynamics by coherent VUV-XUV radiation

DOE PAGES

Sturm, F. P.; Wright, T. W.; Ray, D.; ...

2016-06-14

Have we present a new experimental setup for measuring ultrafast nuclear and electron dynamics of molecules after photo-excitation and ionization. We combine a high flux femtosecond vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) source with an internally cold molecular beam and a 3D momentum imaging particle spectrometer to measure electrons and ions in coincidence. We describe a variety of tools developed to perform pump-probe studies in the VUV-XUV spectrum and to modify and characterize the photon beam. First benchmark experiments are presented to demonstrate the capabilities of the system.

Upper extremity outcome measures for collagen VI-related myopathy and LAMA2-related muscular dystrophy

PubMed Central

Bendixen, Roxanna M.; Butrum, Jocelyn; Jain, Mina S.; Parks, Rebecca; Hodsdon, Bonnie; Nichols, Carmel; Hsia, Michelle; Nelson, Leslie; Keller, Katherine C.; McGuire, Michelle; Elliott, Jeffrey S.; Linton, Melody M.; Arveson, Irene C.; Tounkara, Fatou; Vasavada, Ruhi; Harnett, Elizabeth; Punjabi, Monal; Donkervoort, Sandra; Dastgir, Jahannaz; Leach, Meganne E.; Rutkowski, Anne; Waite, Melissa; Collins, James; Bönnemann, Carsten G.; Meilleur, Katherine G.

2017-01-01

Purpose Congenital muscular dystrophy (CMD) comprises a rare group of genetic muscle diseases that present at birth or early during infancy. Two common subtypes of CMD are collagen VI-related muscular dystrophy (COL6-RD) and laminin alpha 2-related dystrophy (LAMA2-RD). Traditional outcome measures in CMD include gross motor and mobility assessments, yet significant motor declines underscore the need for valid upper extremity (UE) motor assessments as a clinical endpoint. This study validated a battery of UE measures in these two CMD subtypes for future clinical trials. Methods For this cross-sectional study, 42 participants were assessed over the same 2–5 day period at the National Institutes of Health Clinical Center (CC). All UE measures were correlated with the Motor Function Measure 32 (MFM32). The battery of UE assessments included the Jebsen Taylor Hand Function Test, Quality of Upper Extremity Skills Test (QUEST), hand held dynamometry, goniometry, and MyoSet Tools. Spearman Rho was used for correlations to the MFM32. Pearson was performed to correlate the Jebsen, QUEST, hand-held dynamometry, goniometry and the MyoSet Tools. Correlations were considered significant at the 0.01 level (2-tailed). Results Significant correlations were found between both the MFM32 and MFM Dimension 3 only (Distal Motor function) and the Jebsen, QUEST, MyoGrip and MyoPinch, elbow flexion/extension ROM and myometry. Additional correlations between the assessments are reported. Conclusions The Jebsen, the Grasp and Dissociated Movements domains of the QUEST, the MyoGrip and the MyoPinch tools, as well as elbow ROM and myometry were determined to be valid and feasible in this population, provided variation in test items, and assessed a range of difficulty in CMD. To move forward, it will be of utmost importance to determine whether these UE measures are reproducible and sensitive to change over time. PMID:28087121

An Investigation of Three Extremity Armor Systems: Determination of Physiological, Biomechanical, and Physical Performance Effects and Quantification of Body Area Coverage

DTIC Science & Technology

2012-03-19

THREE EXTREMITY ARMOR SYSTEMS: DETERMINATION OF PHYSIOLOGICAL, BIOMECHANICAL, AND PHYSICAL PERFORMANCE EFFECTS AND QUANTIFICATION OF BODY AREA...PHYSICAL PERFORMANCE EFFECTS AND QUANTIFICATION OF BODY AREA COVERAGE 5a. CONTRACT NUMBER MIPR #M9545006MPR6CC7 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER NATICK/TR-12/014 9

Statistical Modeling of Natural Backgrounds in Hyperspectral LWIR Data

DTIC Science & Technology

2016-09-06

extremely important for studying performance trades. First, we study the validity of this model using real hyperspectral data, and compare the relative...difficult to validate any statistical model created for a target of interest. However, since background measurements are plentiful, it is reasonable to...Golden, S., Less, D., Jin, X., and Rynes, P., “ Modeling and analysis of LWIR signature variability associated with 3d and BRDF effects,” 98400P (May 2016

Skylab vectorcardiograph: System description and in flight operation

NASA Technical Reports Server (NTRS)

Lintott, J.; Costello, M. J.

1975-01-01

A vectorcardiograph system was used to measure cardiac electrical activity of Skylab crewmen. This system was chosen because of its data-quantification advantages. The vectorcardiograph was required to meet recommended American Heart Association specifications, to withstand space environmental extremes, and to facilitate data gathering in the weightless environment. The vectorcardiograph system performed without failure, and all projected data were acquired. The appendix lists the design specifications used for the Skylab vectorcardiograph system.

Counter tube window and X-ray fluorescence analyzer study

NASA Technical Reports Server (NTRS)

Hertel, R.; Holm, M.

1973-01-01

A study was performed to determine the best design tube window and X-ray fluorescence analyzer for quantitative analysis of Venusian dust and condensates. The principal objective of the project was to develop the best counter tube window geometry for the sensing element of the instrument. This included formulation of a mathematical model of the window and optimization of its parameters. The proposed detector and instrument has several important features. The instrument will perform a near real-time analysis of dust in the Venusian atmosphere, and is capable of measuring dust layers less than 1 micron thick. In addition, wide dynamic measurement range will be provided to compensate for extreme variations in count rates. An integral pulse-height analyzer and memory accumulate data and read out spectra for detail computer analysis on the ground.

Co-Phasing the Large Binocular Telescope:. [Status and Performance of LBTI-PHASECam

NASA Technical Reports Server (NTRS)

Defrere, D.; Hinz, P.; Downey, E.; Ashby, D.; Bailey, V.; Brusa, G.; Christou, J.; Danchi, W. C.; Grenz, P.; Hill, J. M.;

Comparability of item quality indices from sparse data matrices with random and non-random missing data patterns.

PubMed

Wolfe, Edward W; McGill, Michael T

2011-01-01

This article summarizes a simulation study of the performance of five item quality indicators (the weighted and unweighted versions of the mean square and standardized mean square fit indices and the point-measure correlation) under conditions of relatively high and low amounts of missing data under both random and conditional patterns of missing data for testing contexts such as those encountered in operational administrations of a computerized adaptive certification or licensure examination. The results suggest that weighted fit indices, particularly the standardized mean square index, and the point-measure correlation provide the most consistent information between random and conditional missing data patterns and that these indices perform more comparably for items near the passing score than for items with extreme difficulty values.

Time-Resolved K-shell Photoabsorption Edge Measurement in a Strongly Coupled Matter Driven by Laser-converted Radiation

NASA Astrophysics Data System (ADS)

Zhao, Yang; Yang, Jia-Min; Zhang, Ji-Yan; Yang, Guo-Hong; Xiong, Gang; Wei, Min-Xi; Song, Tian-Ming; Zhang, Zhi-Yu

2013-06-01

A time-resolved K edge absorption measurement of warm dense KCl was performed on Shenguang II laser facility. The x-ray radiation driven shocks were adopted to take colliding shocks compression. By using Dog bone hohlraum the CH/KCl/CH sample was shielded from the laser hitting point to suppress the M band preheating and enhance the compressibility. Thus, an unexplored and extreme region of the plasma state with the maximum 5 times solid density and temperature lower than 3 eV (with coupling constant Γii around 100) was first obtained. The photoabsorption spectra of chlorine near the K-shell edge have been measured with a crystal spectrometer using a short x-ray backlighter. The K edge red shift up to 11.7 eV and broadening of 15.2 eV were obtained for the maximum compression. The electron temperature, inferred by Fermi-Dirac fit of the measured K-edge broadening, was consistent with the hydrodynamic predictions. The comparison of the K edge shift with a plasma model, in which the ionization effect, continuum lowering and partial degeneracy are considered, shows that more improvements are desired to describe in details the variation of K edge shift. This work might extend future study of WDM in extreme conditions of high compression.

A 77-118 GHz RESONANCE-FREE SEPTUM POLARIZER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yen-Lin; Chiueh, Tzihong; Teng, Hsiao-Feng, E-mail: chiuehth@phys.ntu.edu.tw

2014-03-01

Measurements of polarized radiation often reveal specific physical properties of emission sources, such as the strengths and orientations of magnetic fields offered by synchrotron radiation and Zeeman line emission, and the electron density distribution caused by free-free emission. Polarization-capable, millimeter/sub-millimeter telescopes are normally equipped with either septum polarizers or ortho-mode transducers (OMT) to detect polarized radiation. Though the septum polarizer is limited to a significantly narrower bandwidth than the OMT, it possesses advantageous features unparalleled by the OMT when it comes to determining astronomical polarization measurements. We design an extremely wide-band circular waveguide septum polarizer, covering 42% bandwidth, from 77more » GHz to 118 GHz, without any undesired resonance, challenging the conventional bandwidth limit. Stokes parameters, constructed from the measured data between 77 GHz and 115 GHz, show that the leakage from I to Q and U is below ±2%, and the Q – U mutual leakage is below ±1%. Such a performance is comparable to other modern polarizers, but the bandwidth of this polarizer can be at least twice as wide. This extremely wide-band design removes the major weakness of the septum polarizer and opens up a new window for future astronomical polarization measurements.« less

Assessment of dynamic balance via measurement of lower extremities tortuosity.

PubMed

Eltoukhy, Moataz; Kuenze, Christopher; Jun, Hyung-Pil; Asfour, Shihab; Travascio, Francesco

2015-03-01

Tortuosity describes how twisted or how much curvature is present in an observed movement or path. The purpose of this study was to investigate the differences in segmental tortuosity between Star Excursion Balance Test (SEBT) reach directions. Fifteen healthy participants completed this study. Participants completed the modified three direction (anterior, posteromedial, posterolateral) SEBT with three-dimensional motion analysis using an 8 camera BTS Smart 7000DX motion analysis system. The tortuosity of stance limb retro-reflective markers was then calculated and compared between reach directions using a 1 × 3 ANOVA with repeated measures, while the relationship between SEBT performance and tortuosity was established using Pearson product moment correlations. Anterior superior iliac spine tortuosity was significantly greater (p < 0.001) and lateral knee tortuosity was lesser (p = 0.018) in the anterior direction compared to the posteromedial and posterolateral directions. In addition, second metatarsal tortuosity was greater in the anterior reach direction when compared to posteromedial direction (p = 0.024). Tortuosity is a novel biomechanical measurement technique that provides an assessment of segmental movement during common dynamic tasks such as the SEBT. This enhanced level of detail compared to more global measures of joint kinematic may provide insight into compensatory movement strategies adopted following lower extremity joint injury.

Integrative rehabilitation of elderly stroke survivors: the design and evaluation of the BrightArm™.

PubMed

Rabin, Bryan A; Burdea, Grigore C; Roll, Doru T; Hundal, Jasdeep S; Damiani, Frank; Pollack, Simcha

2012-07-01

To describe the development of the BrightArm upper extremity rehabilitation system, and to determine its clinical feasibility with older hemiplegic patients. The BrightArm adjusted arm gravity loading through table tilting. Patients wore an arm support that sensed grasp strength and communicated wirelessly with a personal computer. Games were written to improve cognitive, psychosocial and the upper extremity motor function and adapted automatically to each patient. The system underwent feasibility trials spanning 6 weeks. Participants were evaluated pre-therapy, post-therapy, and at 6 weeks follow-up using standardized clinical measures. Computerized measures of supported arm reach and game performance were stored on a remote server. Five participants had clinically significant improvements in their active range of shoulder movement, shoulder strength, grasp strength, and their ability to focus. Several participants demonstrated substantially higher arm function (measured with the Fugl-Meyer test) and two were less-depressed (measured with the Becks Depression Inventory, Second Edition). The BrightArm technology was well-accepted by the participants, who gave it an overall subjective rating of 4.1 on a 5 point Likert scale. Given these preliminary findings, it will be beneficial to evaluate the BrightArm through controlled clinical trials and to investigate its application to other clinical populations.

Integrative rehabilitation of elderly stroke survivors: The design and evaluation of the BrightArm™

PubMed Central

Rabin, Bryan A.; Burdea, Grigore C.; Roll, Doru T.; Hundal, Jasdeep S.; Damiani, Frank; Pollack, Simcha

2011-01-01

Purpose To describe the development of the BrightArm upper extremity rehabilitation system, and to determine its clinical feasibility with older hemiplegic patients. Method The BrightArm adjusted arm gravity loading through table tilting. Patients wore an arm support that sensed grasp strength and communicated wirelessly with a personal computer. Games were written to improve cognitive, psychosocial and the upper extremity motor function and adapted automatically to each patient. The system underwent feasibility trials spanning 6 weeks. Participants were evaluated pre-therapy, post-therapy, and at 6 weeks follow-up using standardized clinical measures. Computerized measures of supported arm reach and game performance were stored on a remote server. Results Five participants had clinically significant improvements in their active range of shoulder movement, shoulder strength, grasp strength, and their ability to focus. Several participants demonstrated substantially higher arm function (measured with the Fugl-Meyer test) and two were less-depressed (measured with the Becks Depression Inventory, Second Edition). The BrightArm technology was well-accepted by the participants, who gave it an overall subjective rating of 4.1 on a 5 point Likert scale. Conclusions Given these preliminary findings, it will be beneficial to evaluate the BrightArm through controlled clinical trials and to investigate its application to other clinical populations. PMID:22107353

Effects of Pump-turbine S-shaped Characteristics on Transient Behaviours: Experimental Investigation

NASA Astrophysics Data System (ADS)

Zeng, Wei; Yang, Jiandong; Hu, Jinhong; Tang, Renbo

2017-05-01

A pumped storage stations model was set up and introduced in the previous paper. In the model station, the S-shaped characteristic curves was measured at the load rejection condition with the guide vanes stalling. Load rejection tests where guide-vane closed linearly were performed to validate the effect of the S-shaped characteristics on hydraulic transients. Load rejection experiments with different guide vane closing schemes were also performed to determine a suitable scheme considering the S-shaped characteristics. The condition of one pump turbine rejecting its load after another defined as one-after-another (OAA) load rejection was performed to validate the possibility of S-induced extreme draft tube pressure.

Capturing the dynamics of response variability in the brain in ADHD.

PubMed

van Belle, Janna; van Raalten, Tamar; Bos, Dienke J; Zandbelt, Bram B; Oranje, Bob; Durston, Sarah

2015-01-01

ADHD is characterized by increased intra-individual variability in response times during the performance of cognitive tasks. However, little is known about developmental changes in intra-individual variability, and how these changes relate to cognitive performance. Twenty subjects with ADHD aged 7-24 years and 20 age-matched, typically developing controls participated in an fMRI-scan while they performed a go-no-go task. We fit an ex-Gaussian distribution on the response distribution to objectively separate extremely slow responses, related to lapses of attention, from variability on fast responses. We assessed developmental changes in these intra-individual variability measures, and investigated their relation to no-go performance. Results show that the ex-Gaussian measures were better predictors of no-go performance than traditional measures of reaction time. Furthermore, we found between-group differences in the change in ex-Gaussian parameters with age, and their relation to task performance: subjects with ADHD showed age-related decreases in their variability on fast responses (sigma), but not in lapses of attention (tau), whereas control subjects showed a decrease in both measures of variability. For control subjects, but not subjects with ADHD, this age-related reduction in variability was predictive of task performance. This group difference was reflected in neural activation: for typically developing subjects, the age-related decrease in intra-individual variability on fast responses (sigma) predicted activity in the dorsal anterior cingulate gyrus (dACG), whereas for subjects with ADHD, activity in this region was related to improved no-go performance with age, but not to intra-individual variability. These data show that using more sophisticated measures of intra-individual variability allows the capturing of the dynamics of task performance and associated neural changes not permitted by more traditional measures.

Capturing the dynamics of response variability in the brain in ADHD

PubMed Central

van Belle, Janna; van Raalten, Tamar; Bos, Dienke J.; Zandbelt, Bram B.; Oranje, Bob; Durston, Sarah

2014-01-01

ADHD is characterized by increased intra-individual variability in response times during the performance of cognitive tasks. However, little is known about developmental changes in intra-individual variability, and how these changes relate to cognitive performance. Twenty subjects with ADHD aged 7–24 years and 20 age-matched, typically developing controls participated in an fMRI-scan while they performed a go-no-go task. We fit an ex-Gaussian distribution on the response distribution to objectively separate extremely slow responses, related to lapses of attention, from variability on fast responses. We assessed developmental changes in these intra-individual variability measures, and investigated their relation to no-go performance. Results show that the ex-Gaussian measures were better predictors of no-go performance than traditional measures of reaction time. Furthermore, we found between-group differences in the change in ex-Gaussian parameters with age, and their relation to task performance: subjects with ADHD showed age-related decreases in their variability on fast responses (sigma), but not in lapses of attention (tau), whereas control subjects showed a decrease in both measures of variability. For control subjects, but not subjects with ADHD, this age-related reduction in variability was predictive of task performance. This group difference was reflected in neural activation: for typically developing subjects, the age-related decrease in intra-individual variability on fast responses (sigma) predicted activity in the dorsal anterior cingulate gyrus (dACG), whereas for subjects with ADHD, activity in this region was related to improved no-go performance with age, but not to intra-individual variability. These data show that using more sophisticated measures of intra-individual variability allows the capturing of the dynamics of task performance and associated neural changes not permitted by more traditional measures. PMID:25610775

Gender differences in lower extremity kinematics, kinetics and energy absorption during landing.

PubMed

Decker, Michael J; Torry, Michael R; Wyland, Douglas J; Sterett, William I; Richard Steadman, J

2003-08-01

To determine whether gender differences exist in lower extremity joint motions and energy absorption landing strategies between age and skill matched recreational athletes. Mixed factor, repeated measures design. Compared to males, females execute high demand activities in a more erect posture potentially predisposing the anterior cruciate ligament to greater loads and injury. The preferred energy absorption strategy may provide insight for this performance difference. Inverse dynamic solutions estimated lower extremity joint kinematics, kinetics and energetic profiles for twelve males and nine females performing a 60 cm drop landing. Females demonstrated a more erect landing posture and utilized greater hip and ankle joint range of motions and maximum joint angular velocities compared to males. Females also exhibited greater energy absorption and peak powers from the knee extensors and ankle plantar-flexors compared to the males. Examinations of the energy absorption contributions revealed that the knee was the primary shock absorber for both genders, whereas the ankle plantar-flexors muscles was the second largest contributor to energy absorption for the females and the hip extensors muscles for the males. Females may choose to land in a more erect posture to maximize the energy absorption from the joints most proximal to ground contact. Females may be at a greater risk to anterior cruciate ligament injury during landing due to their energy absorption strategy.

Spinal Cord Injury After Extremity Surgery in Children With Thoracic Kyphosis.

PubMed

Pruszczynski, Blazej; Mackenzie, William G; Rogers, Kenneth; White, Klane K

2015-10-01

Spinal cord injury is a rare complication after lower extremity surgery in children with skeletal dysplasia and thoracic kyphosis. We encountered two patients who had this complication, from among 51 (39 from Nemours/Alfred I. duPont Hospital for Children and 12 from Seattle Children's Hospital) who underwent lower extremity surgery during an 8.5-year period (June 2004 to December 2012). Because spinal cord injury is a devastating complication likely not known to most physicians treating patients with skeletal dysplasias, we sought to examine factors that may contribute to this rare complication. We performed a retrospective review of two patients with skeletal dysplasia who had paraplegia develop after extremity surgery. Outcome measures included operative time, vital signs, and postsurgery recovery of neurologic deficit. MR images were reviewed. Two patients were found-an 8.5-year-old boy with spondyloepiphyseal dysplasia congenita with a 76°-thoracic kyphosis apex at T4 and a 6.5-year-old boy with mucopolysaccharidosis type 1-H with an 80°-thoracic kyphosis apex at T2. Bilateral proximal femoral osteotomies or bilateral innominate and proximal femoral osteotomies had been performed. The spinal cord injuries occurred at the apex of the kyphosis as determined by clinical examination and MRI assessment. In both patients, the mean arterial blood pressure decreased below 50 mm Hg and might be a factor in the etiology of the paralysis. The first patient recovered motor function in 5 months; the second had no recovery. Paraplegia is extremely rare after nonspine operations. Many factors contribute to the risk for a spinal cord event: low mean arterial pressure, duration of the surgery, position on the operating table, the kyphotic spine deformity, or unappreciated vascular disease. Motor-evoked potentials and somatosensory-evoked potentials together potentially provide high sensitivity and specificity for predicting a postoperative neurologic deficit. Based on our two patients with skeletal dysplasia and a literature review of patients with hyperkyphosis undergoing extremity surgery, the surgeon must be aware of the risk of spinal cord injury. Careful preoperative assessment possibly including MRI of the spine is recommended. Mean arterial pressure should be maintained at a safe level; neuromonitoring should be considered.

Severity of vehicle bumper location in vehicle-to-pedestrian impact accidents.

PubMed

Matsui, Yasuhiro; Hitosugi, Masahito; Mizuno, Koji

2011-10-10

Pedestrian protection is one of the key topics for safety measures in traffic accidents all over the world. To analyze the relation between the collision site of the vehicle bumper and the severity of the lower extremity injuries, we performed biomechanical experiments. We compared the applied external force and the risks of subsequent injuries between the impact of the center and side positions of the front bumper. These comparisons were performed by practical impact tests with eight typical different types of cars which were typical of the current vehicle fleets. The tests were made using the TRL legform impactor which was a mechanical substitute of a pedestrian lower extremity. The TRL impactor is used all over the world for assessing the safety of car bumpers. It was found that the risks of lower extremity injuries in the impacts at the side positions, in front of the vehicle's side member, were significantly higher than those at the center. In the tests, we found that foam materials around the rigid front cross member had a significant effect on reducing the lower extremity injury risks and especially tibia fracture risk against vehicle bumper center collisions, but had little effect at the sides of the bumper over the vehicle's side members where the foam was thinner. We also found that the front shape of the vehicle affected the risk of ligaments injuries. According to these results, the information of impact locations of cars in vehicle-to-pedestrian traffic accidents is valuable for clinicians to diagnose patients with lower extremity injuries in traffic accidents and for forensic pathologists to analyze the accident reconstruction. Furthermore, the results suggest that testing of the bumper area in front of the main longitudinal beams should be included in the car safety legislation to require pedestrian safety. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Vertebral deformities and fractures are associated with MRI and pQCT measures obtained at the distal tibia and radius of postmenopausal women

PubMed Central

Rajapakse, C. S.; Phillips, E. A.; Sun, W.; Wald, M. J.; Magland, J. F.; Snyder, P. J.; Wehrli, F. W.

2016-01-01

Summary We investigated the association of postmenopausal vertebral deformities and fractures with bone parameters derived from distal extremities using MRI and pQCT. Distal extremity measures showed variable degrees of association with vertebral deformities and fractures, highlighting the systemic nature of postmenopausal bone loss. Introduction Prevalent vertebral deformities and fractures are known to predict incident further fractures. However, the association of distal extremity measures and vertebral deformities in postmenopausal women has not been fully established. Methods This study involved 98 postmenopausal women (age range 60–88 years, mean 70 years) with DXA BMD T-scores at either the hip or spine in the range of −1.5 to −3.5. Wedge, biconcavity, and crush deformities were computed on the basis of spine MRI. Vertebral fractures were assessed using Eastell's criterion. Distal tibia and radius stiffness was computed using MRI-based finite element analysis. BMD at the distal extremities were obtained using pQCT. Results Several distal extremity MRI and pQCT measures showed negative association with vertebral deformity on the basis of single parameter correlation (r up to 0.67) and two-parameter regression (r up to 0.76) models involving MRI stiffness and pQCT BMD. Subjects who had at least one prevalent vertebral fracture showed decreased MRI stiffness (up to 17.9 %) and pQCT density (up to 34.2 %) at the distal extremities compared to the non-fracture group. DXA lumbar spine BMD T-score was not associated with vertebral deformities. Conclusions The association between vertebral deformities and distal extremity measures supports the notion of postmenopausal osteoporosis as a systemic phenomenon. PMID:24221453

Inertial Sensor Measurements of Upper-Limb Kinematics in Stroke Patients in Clinic and Home Environment.

PubMed

Held, Jeremia P O; Klaassen, Bart; Eenhoorn, Albert; van Beijnum, Bert-Jan F; Buurke, Jaap H; Veltink, Peter H; Luft, Andreas R

2018-01-01

Upper-limb impairments in stroke patients are usually measured in clinical setting using standard clinical assessment. In addition, kinematic analysis using opto-electronic systems has been used in the laboratory setting to map arm recovery. Such kinematic measurements cannot capture the actual function of the upper extremity in daily life. The aim of this study is to longitudinally explore the complementarity of post-stroke upper-limb recovery measured by standard clinical assessments and daily-life recorded kinematics. The study was designed as an observational, single-group study to evaluate rehabilitation progress in a clinical and home environment, with a full-body sensor system in stroke patients. Kinematic data were recorded with a full-body motion capture suit during clinical assessment and self-directed activities of daily living. The measurements were performed at three time points for 3 h: (1) 2 weeks before discharge of the rehabilitation clinic, (2) right after discharge, and (3) 4 weeks after discharge. The kinematic analysis of reaching movements uses the position and orientation of each body segment to derive the joint angles. Newly developed metrics for classifying activity and quality of upper extremity movement were applied. The data of four stroke patients (three mildly impaired, one sever impaired) were included in this study. The arm motor function assessment improved during the inpatient rehabilitation, but declined in the first 4 weeks after discharge. A change in the data (kinematics and new metrics) from the daily-life recording was seen in in all patients. Despite this worsening patients increased the number of reaches they performed during daily life in their home environment. It is feasible to measure arm kinematics using Inertial Measurement Unit sensors during daily life in stroke patients at the different stages of rehabilitation. Our results from the daily-life recordings complemented the data from the clinical assessments and illustrate the potential to identify stroke patient characteristics, based on kinematics, reaching counts, and work area. https://clinicaltrials.gov, identifier NCT02118363.

Comparison of the diagnostic accuracy of FBP, ASiR, and MBIR reconstruction during CT angiography in the evaluation of a vessel phantom with calcified stenosis in a distal superficial femoral artery in a cadaver extremity.

PubMed

Tsukada, Jitsuro; Yamada, Minoru; Yamada, Yoshitake; Yamazaki, Shun; Imanishi, Nobuaki; Tamura, Kentaro; Hashimoto, Masahiro; Nakatsuka, Seishi; Jinzaki, Masahiro

2016-07-01

To investigate whether adaptive statistical iterative reconstruction (ASiR) or model-based iterative reconstruction (MBIR) improves the diagnostic performance of computed tomography angiography (CTA) for small-vessel calcified lesions relative to filtered back projection (FBP) using cadaver extremities and a calcified stenosis phantom. A cadaver was used in accordance with our institutional regulations, and a calcified stenosis phantom simulating 4 grades of stenosis was prepared. The phantom was inserted within the distal superficial femoral artery of the cadaver leg. Ten CT images per reconstruction type and stenosis grade were acquired using a 64-slice multidetector-row CTA.As an objective measurement, the first and second derivatives of the CT value function profiles were calculated. As a subjective measurement, 2 blinded reviewers measured the stenosis ratio using a quantitative scale. The Wilcoxon rank-sum test was used to evaluate the data. Objective measurements of both 25% and 50% stenosis differed significantly (P < 0.01) between MBIR (25/50%: 25.80/50.30 ± 3.88/3.86%) and FBP (25/50%: 35.60/83.80 ± 3.44/26.10%), whereas significant differences were not observed between ASiR and FBP.Reviewer 2's subjective measurements of 25% stenosis differed significantly (P < 0.01) between MBIR (35.13 ± 3.25%) and ASiR (40.89 ± 3.14%), and the measurements of 50% stenosis differed significantly (P < 0.01) between MBIR (reviewers 1/2, 62.36/54.78 ± 2.78/4.96%) and FBP (reviewers 1/2, 62.36/74.84 ± 2.78/18.10%). Significant differences in the subjective measurements were not observed between ASiR and FBP. MBIR improves the diagnostic performance of CTA for small-vessel calcified lesions relative to FBP.

Comparison of the diagnostic accuracy of FBP, ASiR, and MBIR reconstruction during CT angiography in the evaluation of a vessel phantom with calcified stenosis in a distal superficial femoral artery in a cadaver extremity

PubMed Central

Tsukada, Jitsuro; Yamada, Minoru; Yamada, Yoshitake; Yamazaki, Shun; Imanishi, Nobuaki; Tamura, Kentaro; Hashimoto, Masahiro; Nakatsuka, Seishi; Jinzaki, Masahiro

2016-01-01

Abstract Purpose: To investigate whether adaptive statistical iterative reconstruction (ASiR) or model-based iterative reconstruction (MBIR) improves the diagnostic performance of computed tomography angiography (CTA) for small-vessel calcified lesions relative to filtered back projection (FBP) using cadaver extremities and a calcified stenosis phantom. Methods: A cadaver was used in accordance with our institutional regulations, and a calcified stenosis phantom simulating 4 grades of stenosis was prepared. The phantom was inserted within the distal superficial femoral artery of the cadaver leg. Ten CT images per reconstruction type and stenosis grade were acquired using a 64-slice multidetector-row CTA. As an objective measurement, the first and second derivatives of the CT value function profiles were calculated. As a subjective measurement, 2 blinded reviewers measured the stenosis ratio using a quantitative scale. The Wilcoxon rank-sum test was used to evaluate the data. Results: Objective measurements of both 25% and 50% stenosis differed significantly (P < 0.01) between MBIR (25/50%: 25.80/50.30 ± 3.88/3.86%) and FBP (25/50%: 35.60/83.80 ± 3.44/26.10%), whereas significant differences were not observed between ASiR and FBP. Reviewer 2's subjective measurements of 25% stenosis differed significantly (P < 0.01) between MBIR (35.13 ± 3.25%) and ASiR (40.89 ± 3.14%), and the measurements of 50% stenosis differed significantly (P < 0.01) between MBIR (reviewers 1/2, 62.36/54.78 ± 2.78/4.96%) and FBP (reviewers 1/2, 62.36/74.84 ± 2.78/18.10%). Significant differences in the subjective measurements were not observed between ASiR and FBP. Conclusion: MBIR improves the diagnostic performance of CTA for small-vessel calcified lesions relative to FBP. PMID:27399123

Predictive validity of the personal qualities assessment for selection of medical students in Scotland.

PubMed

Dowell, Jon; Lumsden, Mary Ann; Powis, David; Munro, Don; Bore, Miles; Makubate, Boikanyo; Kumwenda, Ben

2011-01-01

The Personal Qualities Assessment (PQA) was developed to enhance medical student selection by measuring a range of non-cognitive attributes in the applicants to medical school. Applicants to the five Scottish medical schools were invited to pilot the test in 2001 and 2002. To evaluate the predictive validity of PQA for selecting medical students. A longitudinal cohort study was conducted in which PQA scores were compared with senior year medical school performance. Consent to access performance markers was obtained from 626 students (61.6% of 1017 entrants in 2002-2003). Linkable Foundation Year (4th) rankings were available for 411 (66%) students and objective structured clinical examination (OSCE) rankings for 335 (54%) of those consenting. Both samples were representative of the original cohort. No significant correlations were detected between separate elements of the PQA assessment and student performance. However, using the algorithm advocated by Powis et al. those defined as 'non-extreme' (<±1.5 SD from the cohort mean scores; SD, standard deviation) character types on the involved-detached and on the libertarian-communitarian moral orientation scales were ranked higher in OSCEs (average of 7.5% or 25 out of 335, p = 0.049). This study was limited by high attrition and basic outcome markers which are insensitive to relevant non-cognitive characteristics. However, it is the largest currently available study of predictive validity for the PQA assessment. There was one finding of significance: that those students who were identified by PQA as 'not extreme' on the two personal characteristics scales performed better in an OSCE measure of professionalism. Futures studies are required since psychometric testing for both cognitive and non-cognitive attributes are increasingly used in admission process and these should include more and better measures of professionalism against which to correlate non-cognitive traits.

Heatshield for Extreme Entry Environment Technology: Results from Acreage and Integrated Seams Arcjet Testing

NASA Technical Reports Server (NTRS)

Venkatapathy, Ethiraj

2016-01-01

This invited talk will give a brief overview of the integrated heat-shield system design that requires seams and the extreme environment conditions that HEEET should be demonstrated to be capable of thermal performance without fail. We have tested HEEET across many different facilities and at conditions that are extreme. The presentation will highlight the performance of both the acreage as well as integrated seam at these conditions. The Invite talks are 10 min and hence this presentation will be short.

Using Upper Extremity Skin Temperatures to Assess Thermal Comfort in Office Buildings in Changsha, China

PubMed Central

Wu, Zhibin; Li, Nianping; Cui, Haijiao; Peng, Jinqing; Chen, Haowen; Liu, Penglong

2017-01-01

Existing thermal comfort field studies are mainly focused on the relationship between the indoor physical environment and the thermal comfort. In numerous chamber experiments, physiological parameters were adopted to assess thermal comfort, but the experiments’ conclusions may not represent a realistic thermal environment due to the highly controlled thermal environment and few occupants. This paper focuses on determining the relationships between upper extremity skin temperatures (i.e., finger, wrist, hand and forearm) and the indoor thermal comfort. Also, the applicability of predicting thermal comfort by using upper extremity skin temperatures was explored. Field studies were performed in office buildings equipped with split air-conditioning (SAC) located in the hot summer and cold winter (HSCW) climate zone of China during the summer of 2016. Psychological responses of occupants were recorded and physical and physiological factors were measured simultaneously. Standard effective temperature (SET*) was used to incorporate the effect of humidity and air velocity on thermal comfort. The results indicate that upper extremity skin temperatures are good indicators for predicting thermal sensation, and could be used to assess the thermal comfort in terms of physiological mechanism. In addition, the neutral temperature was 24.7 °C and the upper limit for 80% acceptability was 28.2 °C in SET*. PMID:28934173

Numerical Analysis of Flood modeling of upper Citarum River under Extreme Flood Condition

NASA Astrophysics Data System (ADS)

Siregar, R. I.

2018-02-01

This paper focuses on how to approach the numerical method and computation to analyse flood parameters. Water level and flood discharge are the flood parameters solved by numerical methods approach. Numerical method performed on this paper for unsteady flow conditions have strengths and weaknesses, among others easily applied to the following cases in which the boundary irregular flow. The study area is in upper Citarum Watershed, Bandung, West Java. This paper uses computation approach with Force2 programming and HEC-RAS to solve the flow problem in upper Citarum River, to investigate and forecast extreme flood condition. Numerical analysis based on extreme flood events that have occurred in the upper Citarum watershed. The result of water level parameter modeling and extreme flood discharge compared with measurement data to analyse validation. The inundation area about flood that happened in 2010 is about 75.26 square kilometres. Comparing two-method show that the FEM analysis with Force2 programs has the best approach to validation data with Nash Index is 0.84 and HEC-RAS that is 0.76 for water level. For discharge data Nash Index obtained the result analysis use Force2 is 0.80 and with use HEC-RAS is 0.79.

Using Upper Extremity Skin Temperatures to Assess Thermal Comfort in Office Buildings in Changsha, China.

PubMed

Wu, Zhibin; Li, Nianping; Cui, Haijiao; Peng, Jinqing; Chen, Haowen; Liu, Penglong

2017-09-21

Existing thermal comfort field studies are mainly focused on the relationship between the indoor physical environment and the thermal comfort. In numerous chamber experiments, physiological parameters were adopted to assess thermal comfort, but the experiments' conclusions may not represent a realistic thermal environment due to the highly controlled thermal environment and few occupants. This paper focuses on determining the relationships between upper extremity skin temperatures (i.e., finger, wrist, hand and forearm) and the indoor thermal comfort. Also, the applicability of predicting thermal comfort by using upper extremity skin temperatures was explored. Field studies were performed in office buildings equipped with split air-conditioning (SAC) located in the hot summer and cold winter (HSCW) climate zone of China during the summer of 2016. Psychological responses of occupants were recorded and physical and physiological factors were measured simultaneously. Standard effective temperature (SET*) was used to incorporate the effect of humidity and air velocity on thermal comfort. The results indicate that upper extremity skin temperatures are good indicators for predicting thermal sensation, and could be used to assess the thermal comfort in terms of physiological mechanism. In addition, the neutral temperature was 24.7 °C and the upper limit for 80% acceptability was 28.2 °C in SET*.

Effect of mirror therapy on upper extremity motor function in stroke patients: a randomized controlled trial.

PubMed

Gurbuz, Nigar; Afsar, Sevgi Ikbali; Ayaş, Sehri; Cosar, Sacide Nur Saracgil

2016-09-01

[Purpose] This study aimed to evaluate the effectiveness of mirror therapy combined with a conventional rehabilitation program on upper extremity motor and functional recovery in stroke patients. [Subjects and Methods] Thirty-one hemiplegic patients were included. The patients were randomly assigned to a mirror (n=16) or conventional group (n=15). The patients in both groups underwent conventional therapy for 4 weeks (60-120 minutes/day, 5 days/week). The mirror group received mirror therapy, consisting of periodic flexion and extension movements of the wrist and fingers on the non-paralyzed side. The patients in the conventional group performed the same exercises against the non-reflecting face of the mirror. The patients were evaluated at the beginning and end of the treatment by a blinded assessor using the Brunnstrom stage, Fugl-Meyer Assessment (FMA) upper extremity score, and the Functional Independence Measure (FIM) self-care score. [Results] There was an improvement in Brunnstrom stage and the FIM self-care score in both groups, but the post-treatment FMA score was significantly higher in the mirror therapy group than in the conventional treatment group. [Conclusion] Mirror therapy in addition to a conventional rehabilitation program was found to provide additional benefit in motor recovery of the upper extremity in stroke patients.

Effect of mirror therapy on upper extremity motor function in stroke patients: a randomized controlled trial

PubMed Central

Gurbuz, Nigar; Afsar, Sevgi Ikbali; Ayaş, Sehri; Cosar, Sacide Nur Saracgil

2016-01-01

[Purpose] This study aimed to evaluate the effectiveness of mirror therapy combined with a conventional rehabilitation program on upper extremity motor and functional recovery in stroke patients. [Subjects and Methods] Thirty-one hemiplegic patients were included. The patients were randomly assigned to a mirror (n=16) or conventional group (n=15). The patients in both groups underwent conventional therapy for 4 weeks (60–120 minutes/day, 5 days/week). The mirror group received mirror therapy, consisting of periodic flexion and extension movements of the wrist and fingers on the non-paralyzed side. The patients in the conventional group performed the same exercises against the non-reflecting face of the mirror. The patients were evaluated at the beginning and end of the treatment by a blinded assessor using the Brunnstrom stage, Fugl-Meyer Assessment (FMA) upper extremity score, and the Functional Independence Measure (FIM) self-care score. [Results] There was an improvement in Brunnstrom stage and the FIM self-care score in both groups, but the post-treatment FMA score was significantly higher in the mirror therapy group than in the conventional treatment group. [Conclusion] Mirror therapy in addition to a conventional rehabilitation program was found to provide additional benefit in motor recovery of the upper extremity in stroke patients. PMID:27799679

UNDERFLIGHT CALIBRATION OF SOHO/CDS AND HINODE/EIS WITH EUNIS-07

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Tongjiang; Brosius, Jeffrey W.; Thomas, Roger J.

2011-12-01

Flights of Goddard Space Flight Center's Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) sounding rocket in 2006 and 2007 provided updated radiometric calibrations for Solar and Heliospheric Observatory/Coronal Diagnostic Spectrometer (SOHO/CDS) and Hinode/Extreme Ultraviolet Imaging Spectrometer (Hinode/EIS). EUNIS carried two independent imaging spectrographs covering wavebands of 300-370 A in first order and 170-205 A in second order. After each flight, end-to-end radiometric calibrations of the rocket payload were carried out in the same facility used for pre-launch calibrations of CDS and EIS. During the 2007 flight, EUNIS, SOHO/CDS, and Hinode/EIS observed the same solar locations, allowing the EUNIS calibrations to bemore » directly applied to both CDS and EIS. The measured CDS NIS 1 line intensities calibrated with the standard (version 4) responsivities with the standard long-term corrections are found to be too low by a factor of 1.5 due to the decrease in responsivity. The EIS calibration update is performed in two ways. One uses the direct calibration transfer of the calibrated EUNIS-07 short wavelength (SW) channel. The other uses the insensitive line pairs, in which one member was observed by the EUNIS-07 long wavelength (LW) channel and the other by EIS in either the LW or SW waveband. Measurements from both methods are in good agreement, and confirm (within the measurement uncertainties) the EIS responsivity measured directly before the instrument's launch. The measurements also suggest that the EIS responsivity decreased by a factor of about 1.2 after the first year of operation (although the size of the measurement uncertainties is comparable to this decrease). The shape of the EIS SW response curve obtained by EUNIS-07 is consistent with the one measured in laboratory prior to launch. The absolute value of the quiet-Sun He II 304 A intensity measured by EUNIS-07 is consistent with the radiance measured by CDS NIS in quiet regions near the disk center and the solar minimum irradiance recently obtained by CDS NIS and the Solar Dynamics Observatory/Extreme Ultraviolet Variability Experiment.« less

Creation and Validation of Sintered PTFE BRDF Targets & Standards

PubMed Central

Durell, Christopher; Scharpf, Dan; McKee, Greg; L’Heureux, Michelle; Georgiev, Georgi; Obein, Gael; Cooksey, Catherine

2016-01-01

Sintered polytetrafluoroethylene (PTFE) is an extremely stable, near-perfect Lambertian reflecting diffuser and calibration standard material that has been used by national labs, space, aerospace and commercial sectors for over two decades. New uncertainty targets of 2 % on-orbit absolute validation in the Earth Observing Systems community have challenged the industry to improve is characterization and knowledge of almost every aspect of radiometric performance (space and ground). Assuming “near perfect” reflectance for angular dependent measurements is no longer going to suffice for many program needs. The total hemispherical spectral reflectance provides a good mark of general performance; but, without the angular characterization of bidirectional reflectance distribution function (BRDF) measurements, critical data is missing from many applications and uncertainty budgets. Therefore, traceable BRDF measurement capability is needed to characterize sintered PTFE’s angular response and provide a full uncertainty profile to users. This paper presents preliminary comparison measurements of the BRDF of sintered PTFE from several laboratories to better quantify the BRDF of sintered PTFE, assess the BRDF measurement comparability between laboratories, and improve estimates of measurement uncertainties under laboratory conditions. PMID:26900206

Creation and Validation of Sintered PTFE BRDF Targets & Standards.

PubMed

Durell, Christopher; Scharpf, Dan; McKee, Greg; L'Heureux, Michelle; Georgiev, Georgi; Obein, Gael; Cooksey, Catherine

2015-09-21

Sintered polytetrafluoroethylene (PTFE) is an extremely stable, near-perfect Lambertian reflecting diffuser and calibration standard material that has been used by national labs, space, aerospace and commercial sectors for over two decades. New uncertainty targets of 2 % on-orbit absolute validation in the Earth Observing Systems community have challenged the industry to improve is characterization and knowledge of almost every aspect of radiometric performance (space and ground). Assuming "near perfect" reflectance for angular dependent measurements is no longer going to suffice for many program needs. The total hemispherical spectral reflectance provides a good mark of general performance; but, without the angular characterization of bidirectional reflectance distribution function (BRDF) measurements, critical data is missing from many applications and uncertainty budgets. Therefore, traceable BRDF measurement capability is needed to characterize sintered PTFE's angular response and provide a full uncertainty profile to users. This paper presents preliminary comparison measurements of the BRDF of sintered PTFE from several laboratories to better quantify the BRDF of sintered PTFE, assess the BRDF measurement comparability between laboratories, and improve estimates of measurement uncertainties under laboratory conditions.

Aircraft Wake RCS Measurement

NASA Technical Reports Server (NTRS)

Gilson, William H.

1994-01-01

A series of multi-frequency radar measurements of aircraft wakes at altitudes of 5,000 to 25,00 ft. were performed at Kwajalein, R.M.I., in May and June of 1990. Two aircraft were tested, a Learjet 35 and a Lockheed C-5A. The cross-section of the wake of the Learjet was too small for detection at Kwajalein. The wake of the C-5A, although also very small, was detected and measured at VHF, UHF, L-, S-, and C-bands, at distances behind the aircraft ranging from about one hundred meters to tens of kilometers. The data suggest that the mechanism by which aircraft wakes have detectable radar signatures is, contrary to previous expectations, unrelated to engine exhaust but instead due to turbulent mixing by the wake vortices of pre-existing index of refraction gradients in the ambient atmosphere. These measurements were of necessity performed with extremely powerful and sensitive instrumentation radars, and the wake cross-section is too small for most practical applications.

Aircraft wake RCS measurement

NASA Astrophysics Data System (ADS)

Gilson, William H.

1994-07-01

A series of multi-frequency radar measurements of aircraft wakes at altitudes of 5,000 to 25,00 ft. were performed at Kwajalein, R.M.I., in May and June of 1990. Two aircraft were tested, a Learjet 35 and a Lockheed C-5A. The cross-section of the wake of the Learjet was too small for detection at Kwajalein. The wake of the C-5A, although also very small, was detected and measured at VHF, UHF, L-, S-, and C-bands, at distances behind the aircraft ranging from about one hundred meters to tens of kilometers. The data suggest that the mechanism by which aircraft wakes have detectable radar signatures is, contrary to previous expectations, unrelated to engine exhaust but instead due to turbulent mixing by the wake vortices of pre-existing index of refraction gradients in the ambient atmosphere. These measurements were of necessity performed with extremely powerful and sensitive instrumentation radars, and the wake cross-section is too small for most practical applications.

Reliability of 3-Dimensional Measures of Single-Leg Drop Landing Across 3 Institutions: Implications for Multicenter Research for Secondary ACL-Injury Prevention.

PubMed

Myer, Gregory D; Bates, Nathaniel A; DiCesare, Christopher A; Barber Foss, Kim D; Thomas, Staci M; Wordeman, Samuel C; Sugimoto, Dai; Roewer, Benjamin D; Medina McKeon, Jennifer M; Di Stasi, Stephanie L; Noehren, Brian W; McNally, Michael; Ford, Kevin R; Kiefer, Adam W; Hewett, Timothy E

2015-05-01

Due to the limitations of single-center studies in achieving appropriate sampling with relatively rare disorders, multicenter collaborations have been proposed to achieve desired sampling levels. However, documented reliability of biomechanical data is necessary for multicenter injury-prevention studies and is currently unavailable. To measure the reliability of 3-dimensional (3D) biomechanical waveforms from kinetic and kinematic variables during a single-leg landing (SLL) performed at 3 separate testing facilities. Multicenter reliability study. 3 laboratories. 25 female junior varsity and varsity high school volleyball players who visited each facility over a 1-mo period. Subjects were instrumented with 43 reflective markers to record 3D motion as they performed SLLs. During the SLL the athlete balanced on 1 leg, dropped down off of a 31-cm-high box, and landed on the same leg. Kinematic and kinetic data from both legs were processed from 2 trials across the 3 laboratories. Coefficients of multiple correlations (CMC) were used to statistically compare each joint angle and moment waveform for the first 500 ms of landing. Average CMC for lower-extremity sagittal-plane motion was excellent between laboratories (hip .98, knee .95, ankle .99). Average CMC for lower-extremity frontal-plane motion was also excellent between laboratories (hip .98, knee .80, ankle .93). Kinetic waveforms were repeatable in each plane of rotation (3-center mean CMC ≥.71), while knee sagittal-plane moments were the most consistent measure across sites (3-center mean CMC ≥.94). CMC waveform comparisons were similar relative to the joint measured to previously published reports of between-sessions reliability of sagittal- and frontal-plane biomechanics performed at a single institution. Continued research is needed to further standardize technology and methods to help ensure that highly reliable results can be achieved with multicenter biomechanical screening models.

Extreme value statistics analysis of fracture strengths of a sintered silicon nitride failing from pores

NASA Technical Reports Server (NTRS)

Chao, Luen-Yuan; Shetty, Dinesh K.

1992-01-01

Statistical analysis and correlation between pore-size distribution and fracture strength distribution using the theory of extreme-value statistics is presented for a sintered silicon nitride. The pore-size distribution on a polished surface of this material was characterized, using an automatic optical image analyzer. The distribution measured on the two-dimensional plane surface was transformed to a population (volume) distribution, using the Schwartz-Saltykov diameter method. The population pore-size distribution and the distribution of the pore size at the fracture origin were correllated by extreme-value statistics. Fracture strength distribution was then predicted from the extreme-value pore-size distribution, usin a linear elastic fracture mechanics model of annular crack around pore and the fracture toughness of the ceramic. The predicted strength distribution was in good agreement with strength measurements in bending. In particular, the extreme-value statistics analysis explained the nonlinear trend in the linearized Weibull plot of measured strengths without postulating a lower-bound strength.

Radiative heat transfer in the extreme near field.

PubMed

Kim, Kyeongtae; Song, Bai; Fernández-Hurtado, Víctor; Lee, Woochul; Jeong, Wonho; Cui, Longji; Thompson, Dakotah; Feist, Johannes; Reid, M T Homer; García-Vidal, Francisco J; Cuevas, Juan Carlos; Meyhofer, Edgar; Reddy, Pramod

2015-12-17

Radiative transfer of energy at the nanometre length scale is of great importance to a variety of technologies including heat-assisted magnetic recording, near-field thermophotovoltaics and lithography. Although experimental advances have enabled elucidation of near-field radiative heat transfer in gaps as small as 20-30 nanometres (refs 4-6), quantitative analysis in the extreme near field (less than 10 nanometres) has been greatly limited by experimental challenges. Moreover, the results of pioneering measurements differed from theoretical predictions by orders of magnitude. Here we use custom-fabricated scanning probes with embedded thermocouples, in conjunction with new microdevices capable of periodic temperature modulation, to measure radiative heat transfer down to gaps as small as two nanometres. For our experiments we deposited suitably chosen metal or dielectric layers on the scanning probes and microdevices, enabling direct study of extreme near-field radiation between silica-silica, silicon nitride-silicon nitride and gold-gold surfaces to reveal marked, gap-size-dependent enhancements of radiative heat transfer. Furthermore, our state-of-the-art calculations of radiative heat transfer, performed within the theoretical framework of fluctuational electrodynamics, are in excellent agreement with our experimental results, providing unambiguous evidence that confirms the validity of this theory for modelling radiative heat transfer in gaps as small as a few nanometres. This work lays the foundations required for the rational design of novel technologies that leverage nanoscale radiative heat transfer.

An operational-oriented approach to the assessment of low probability seismic ground motions for critical infrastructures

NASA Astrophysics Data System (ADS)

Garcia-Fernandez, Mariano; Assatourians, Karen; Jimenez, Maria-Jose

2018-01-01

Extreme natural hazard events have the potential to cause significant disruption to critical infrastructure (CI) networks. Among them, earthquakes represent a major threat as sudden-onset events with limited, if any, capability of forecast, and high damage potential. In recent years, the increased exposure of interdependent systems has heightened concern, motivating the need for a framework for the management of these increased hazards. The seismic performance level and resilience of existing non-nuclear CIs can be analyzed by identifying the ground motion input values leading to failure of selected key elements. Main interest focuses on the ground motions exceeding the original design values, which should correspond to low probability occurrence. A seismic hazard methodology has been specifically developed to consider low-probability ground motions affecting elongated CI networks. The approach is based on Monte Carlo simulation, which allows for building long-duration synthetic earthquake catalogs to derive low-probability amplitudes. This approach does not affect the mean hazard values and allows obtaining a representation of maximum amplitudes that follow a general extreme-value distribution. This facilitates the analysis of the occurrence of extremes, i.e., very low probability of exceedance from unlikely combinations, for the development of, e.g., stress tests, among other applications. Following this methodology, extreme ground-motion scenarios have been developed for selected combinations of modeling inputs including seismic activity models (source model and magnitude-recurrence relationship), ground motion prediction equations (GMPE), hazard levels, and fractiles of extreme ground motion. The different results provide an overview of the effects of different hazard modeling inputs on the generated extreme motion hazard scenarios. This approach to seismic hazard is at the core of the risk analysis procedure developed and applied to European CI transport networks within the framework of the European-funded INFRARISK project. Such an operational seismic hazard framework can be used to provide insight in a timely manner to make informed risk management or regulating further decisions on the required level of detail or on the adoption of measures, the cost of which can be balanced against the benefits of the measures in question.

Robot-assisted upper extremity rehabilitation for cervical spinal cord injuries: a systematic scoping review.

PubMed

Singh, Hardeep; Unger, Janelle; Zariffa, José; Pakosh, Maureen; Jaglal, Susan; Craven, B Catharine; Musselman, Kristin E

2018-01-15

Abstact Purpose: To provide an overview of the feasibility and outcomes of robotic-assisted upper extremity training for individuals with cervical spinal cord injury (SCI), and to identify gaps in current research and articulate future research directions. A systematic search was conducted using Medline, Embase, PsycINFO, CCTR, CDSR, CINAHL and PubMed on June 7, 2017. Search terms included 3 themes: (1) robotics; (2) SCI; (3) upper extremity. Studies using robots for upper extremity rehabilitation among individuals with cervical SCI were included. Identified articles were independently reviewed by two researchers and compared to pre-specified criteria. Disagreements regarding article inclusion were resolved through discussion. The modified Downs and Black checklist was used to assess article quality. Participant characteristics, study and intervention details, training outcomes, robot features, study limitations and recommendations for future studies were abstracted from included articles. Twelve articles (one randomized clinical trial, six case series, five case studies) met the inclusion criteria. Five robots were exoskeletons and three were end-effectors. Sample sizes ranged from 1 to 17 subjects. Articles had variable quality, with quality scores ranging from 8 to 20. Studies had a low internal validity primarily from lack of blinding or a control group. Individuals with mild-moderate impairments showed the greatest improvements on body structure/function and performance-level measures. This review is limited by the small number of articles, low-sample sizes and the diversity of devices and their associated training protocols, and outcome measures. Preliminary evidence suggests robot-assisted interventions are safe, feasible and can reduce active assistance provided by therapists. Implications for rehabilitation Robot-assisted upper extremity training for individuals with cervical spinal cord injury is safe, feasible and can reduce hands-on assistance provided by therapists. Future research in robotics rehabilitation with individuals with spinal cord injury is needed to determine the optimal device and training protocol as well as effectiveness.

Large uncertainties in observed daily precipitation extremes over land

NASA Astrophysics Data System (ADS)

Herold, Nicholas; Behrangi, Ali; Alexander, Lisa V.

2017-01-01

We explore uncertainties in observed daily precipitation extremes over the terrestrial tropics and subtropics (50°S-50°N) based on five commonly used products: the Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) dataset, the Global Precipitation Climatology Centre-Full Data Daily (GPCC-FDD) dataset, the Tropical Rainfall Measuring Mission (TRMM) multi-satellite research product (T3B42 v7), the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR), and the Global Precipitation Climatology Project's One-Degree Daily (GPCP-1DD) dataset. We use the precipitation indices R10mm and Rx1day, developed by the Expert Team on Climate Change Detection and Indices, to explore the behavior of "moderate" and "extreme" extremes, respectively. In order to assess the sensitivity of extreme precipitation to different grid sizes we perform our calculations on four common spatial resolutions (0.25° × 0.25°, 1° × 1°, 2.5° × 2.5°, and 3.75° × 2.5°). The impact of the chosen "order of operation" in calculating these indices is also determined. Our results show that moderate extremes are relatively insensitive to product and resolution choice, while extreme extremes can be very sensitive. For example, at 0.25° × 0.25° quasi-global mean Rx1day values vary from 37 mm in PERSIANN-CDR to 62 mm in T3B42. We find that the interproduct spread becomes prominent at resolutions of 1° × 1° and finer, thus establishing a minimum effective resolution at which observational products agree. Without improvements in interproduct spread, these exceedingly large observational uncertainties at high spatial resolution may limit the usefulness of model evaluations. As has been found previously, resolution sensitivity can be largely eliminated by applying an order of operation where indices are calculated prior to regridding. However, this approach is not appropriate when true area averages are desired (e.g., for model evaluations).

Voice stress analysis

NASA Technical Reports Server (NTRS)

Brenner, Malcolm; Shipp, Thomas

1988-01-01

In a study of the validity of eight candidate voice measures (fundamental frequency, amplitude, speech rate, frequency jitter, amplitude shimmer, Psychological Stress Evaluator scores, energy distribution, and the derived measure of the above measures) for determining psychological stress, 17 males age 21 to 35 were subjected to a tracking task on a microcomputer CRT while parameters of vocal production as well as heart rate were measured. Findings confirm those of earlier studies that increases in fundamental frequency, amplitude, and speech rate are found in speakers involved in extreme levels of stress. In addition, it was found that the same changes appear to occur in a regular fashion within a more subtle level of stress that may be characteristic, for example, of routine flying situations. None of the individual speech measures performed as robustly as did heart rate.

The Effect of Body Weight Support Treadmill Training on Gait Recovery, Proximal Lower Limb Motor Pattern, and Balance in Patients with Subacute Stroke

PubMed Central

Lo, Wai Leung; Lin, Qiang; Xiao, Xiang; Raghavan, Preeti; Huang, Dong-Feng

2015-01-01

Objective. Gait performance is an indicator of mobility impairment after stroke. This study evaluated changes in balance, lower extremity motor function, and spatiotemporal gait parameters after receiving body weight supported treadmill training (BWSTT) and conventional overground walking training (CT) in patients with subacute stroke using 3D motion analysis. Setting. Inpatient department of rehabilitation medicine at a university-affiliated hospital. Participants. 24 subjects with unilateral hemiplegia in the subacute stage were randomized to the BWSTT (n = 12) and CT (n = 12) groups. Parameters were compared between the two groups. Data from twelve age matched healthy subjects were recorded as reference. Interventions. Patients received gait training with BWSTT or CT for an average of 30 minutes/day, 5 days/week, for 3 weeks. Main Outcome Measures. Balance was measured by the Brunel balance assessment. Lower extremity motor function was evaluated by the Fugl-Meyer assessment scale. Kinematic data were collected and analyzed using a gait capture system before and after the interventions. Results. Both groups improved on balance and lower extremity motor function measures (P < 0.05), with no significant difference between the two groups after intervention. However, kinematic data were significantly improved (P < 0.05) after BWSTT but not after CT. Maximum hip extension and flexion angles were significantly improved (P < 0.05) for the BWSTT group during the stance and swing phases compared to baseline. Conclusion. In subacute patients with stroke, BWSTT can lead to improved gait quality when compared with conventional gait training. Both methods can improve balance and motor function. PMID:26649295

Virtual reality for upper extremity rehabilitation in early stroke: a pilot randomized controlled trial.

PubMed

Yin, Chan Wai; Sien, Ng Yee; Ying, Low Ai; Chung, Stephanie Fook-Chong Man; Tan May Leng, Dawn

2014-11-01

To investigate the effect of virtual reality (VR) rehabilitation on upper extremity motor performance of patients with early stroke. Pilot randomized controlled trial. Rehabilitation wards. Twenty three adults with stroke (mean age (SD) = 58.35 (13.45) years and mean time since stroke (SD) = 16.30 (7.44) days). Participants were randomly assigned to VR group (n=11) or control group (n=12). VR group received nine 30 minutes upper extremity VR therapy in standing (five weekdays in two weeks) plus conventional therapy, which included physical and occupational therapy. Control group received only conventional therapy, which was comparable to total training time received by VR group (mean training hours (SD):VR = 17.07 (2.86); control = 15.50 (2.79)). The main outcome measure was the Fugl-Meyer Assessment (FMA). Secondary outcomes included Action Research Arm Test, Motor Activity Log and Functional Independence Measure. Results were taken at baseline, post intervention and 1-month post intervention. Participants' feedback and adverse effects were recorded. All participants improved in FMA scores (mean change (SD) = 11.65 (8.56), P<.001). These effects were sustained at one month after intervention (mean (SD) change from baseline = 18.67 (13.26), P<.001). All other outcome measures showed similar patterns. There were no significant differences in improvement between both groups. Majority of the participants found VR training useful and enjoyable, with no serious adverse effects reported. Although additional VR training was not superior to conventional therapy alone, this study demonstrates the feasibility of VR training in early stroke. © The Author(s) 2014.

Early working memory as a racially and ethnically neutral measure of outcome in extremely preterm children at 18-22 months.

PubMed

Lowe, Jean R; Duncan, Andrea Freeman; Bann, Carla M; Fuller, Janell; Hintz, Susan R; Das, Abhik; Higgins, Rosemary D; Watterberg, Kristi L

2013-12-01

Difficulties with executive function have been found in preterm children, resulting in difficulties with learning and school performance. This study evaluated the relationship of early working memory as measured by object permanence items to the cognitive and language scores on the Bayley Scales-III in a cohort of children born extremely preterm. Logistic regression models were conducted to compare object permanence scores derived from the Bayley Scales-III by race/ethnicity and maternal education, controlling for medical covariates. Extremely preterm toddlers (526), who were part of a Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's multi-center study, were evaluated at 18-22 months corrected age. Object permanence scores derived from the Bayley Developmental Scales were compared by race/ethnicity and maternal education, controlling for medical covariates. There were no significant differences in object permanence mastery and scores among the treatment groups after controlling for medical and social variables, including maternal education and race/ethnicity. Males and children with intraventricular hemorrhage, retinopathy of prematurity, and bronchopulmonary dysplasia were less likely to demonstrate object permanence mastery and had lower object permanence scores. Children who attained object permanence mastery had significantly higher Bayley Scales-III cognitive and language scores after controlling for medical and socio-economic factors. Our measure of object permanence is free of influence from race, ethnic and socio-economic factors. Adding this simple task to current clinical practice could help detect early executive function difficulties in young children. Published by Elsevier Ireland Ltd.

Alignment Measurements of the Microwave Anisotropy Probe (MAP) Instrument in a Thermal/Vacuum Chamber

NASA Technical Reports Server (NTRS)

Hill, Michael D.; Herrera, Acey A.; Crane, J. Allen; Packard, Edward A.; Aviado, Carlos; Sampler, Henry P.

2000-01-01

The Microwave Anisotropy Probe (MAP) Observatory, scheduled for a fall 2000 launch, is designed to measure temperature fluctuations (anisotropy) and produce a high sensitivity and high spatial resolution (approximately 0.2 degree) map of the cosmic microwave background (CMB) radiation over the entire sky between 22 and 90 GHz. MAP utilizes back-to-back Gregorian telescopes to focus the microwave signals into 10 differential microwave receivers, via 20 feed horns. Proper alignment of the telescope reflectors and the feed horns at the operating temperature of 90 K is a critical element to ensure mission success. We describe the hardware and methods used to validate the displacement/deformation predictions of the reflectors and the microwave feed horns during thermal/vacuum testing of the reflectors and the microwave instrument. The smallest deformation predictions to be measured were on the order of +/- 0.030 inches (+/- 0.762 mm). Performance of these alignment measurements inside a thermal/vacuum chamber with conventional alignment equipment posed several limitations. The most troublesome limitation was the inability to send personnel into the chamber to perform the measurements during the test due to vacuum and the temperature extremes. The photogrammetry (PG) system was chosen to perform the measurements since it is a non- contact measurement system, the measurements can be made relatively quickly and accurately, and the photogrammetric camera can be operated remotely. The hardware and methods developed to perform the MAP alignment measurements using PG proved to be highly successful. The measurements met the desired requirements, for the metal structures enabling the desired distortions to be measured resolving deformations an order of magnitude smaller than the imposed requirements. Viable data were provided to the MAP Project for a full analysis of the on-orbit performance of the Instrument's microwave system.

Effect of thermal stresses on the mechanism of tooth pain.

PubMed

Oskui, Iman Z; Ashtiani, Mohammed N; Hashemi, Ata; Jafarzadeh, Hamid

2014-11-01

Daily hot and cold thermal loadings on teeth may result in structural deformation, mechanical stress, and pain signaling. The aim of this study was to compare the adverse effects of hot and cold beverages on an intact tooth and, then, to provide physical evidence to support the hydrodynamic theory of tooth pain sensation mechanism. Three-dimensional finite element analysis was performed on a premolar model subjected to hot and cold thermal loadings. Elapsed times for heat diffusion and stress detection at the pulp-dentin junction were calculated as measures of the pain sensation. Extreme tensile stress within the enamel resulted in damage in cold loadings. Also, extreme values of stress at the pulpal wall occurred 21.6 seconds earlier than extreme temperatures in hot and cold loadings. The intact tooth was remarkably vulnerable to cold loading. Earlier changes in mechanical stress rather than temperature at the pulp-dentin junction indicate that the dental pain caused by hot or cold beverages may be based on the hydrodynamic theory. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

TLEM 2.0 - a comprehensive musculoskeletal geometry dataset for subject-specific modeling of lower extremity.

PubMed

Carbone, V; Fluit, R; Pellikaan, P; van der Krogt, M M; Janssen, D; Damsgaard, M; Vigneron, L; Feilkas, T; Koopman, H F J M; Verdonschot, N

2015-03-18

When analyzing complex biomechanical problems such as predicting the effects of orthopedic surgery, subject-specific musculoskeletal models are essential to achieve reliable predictions. The aim of this paper is to present the Twente Lower Extremity Model 2.0, a new comprehensive dataset of the musculoskeletal geometry of the lower extremity, which is based on medical imaging data and dissection performed on the right lower extremity of a fresh male cadaver. Bone, muscle and subcutaneous fat (including skin) volumes were segmented from computed tomography and magnetic resonance images scans. Inertial parameters were estimated from the image-based segmented volumes. A complete cadaver dissection was performed, in which bony landmarks, attachments sites and lines-of-action of 55 muscle actuators and 12 ligaments, bony wrapping surfaces, and joint geometry were measured. The obtained musculoskeletal geometry dataset was finally implemented in the AnyBody Modeling System (AnyBody Technology A/S, Aalborg, Denmark), resulting in a model consisting of 12 segments, 11 joints and 21 degrees of freedom, and including 166 muscle-tendon elements for each leg. The new TLEM 2.0 dataset was purposely built to be easily combined with novel image-based scaling techniques, such as bone surface morphing, muscle volume registration and muscle-tendon path identification, in order to obtain subject-specific musculoskeletal models in a quick and accurate way. The complete dataset, including CT and MRI scans and segmented volume and surfaces, is made available at http://www.utwente.nl/ctw/bw/research/projects/TLEMsafe for the biomechanical community, in order to accelerate the development and adoption of subject-specific models on large scale. TLEM 2.0 is freely shared for non-commercial use only, under acceptance of the TLEMsafe Research License Agreement. Copyright © 2014 Elsevier Ltd. All rights reserved.

GPS FOM Chimney Analysis using Generalized Extreme Value Distribution

NASA Technical Reports Server (NTRS)

Ott, Rick; Frisbee, Joe; Saha, Kanan

2004-01-01

Many a time an objective of a statistical analysis is to estimate a limit value like 3-sigma 95% confidence upper limit from a data sample. The generalized Extreme Value Distribution method can be profitably employed in many situations for such an estimate. . .. It is well known that according to the Central Limit theorem the mean value of a large data set is normally distributed irrespective of the distribution of the data from which the mean value is derived. In a somewhat similar fashion it is observed that many times the extreme value of a data set has a distribution that can be formulated with a Generalized Distribution. In space shuttle entry with 3-string GPS navigation the Figure Of Merit (FOM) value gives a measure of GPS navigated state accuracy. A GPS navigated state with FOM of 6 or higher is deemed unacceptable and is said to form a FOM 6 or higher chimney. A FOM chimney is a period of time during which the FOM value stays higher than 5. A longer period of FOM of value 6 or higher causes navigated state to accumulate more error for a lack of state update. For an acceptable landing it is imperative that the state error remains low and hence at low altitude during entry GPS data of FOM greater than 5 must not last more than 138 seconds. I To test the GPS performAnce many entry test cases were simulated at the Avionics Development Laboratory. Only high value FoM chimneys are consequential. The extreme value statistical technique is applied to analyze high value FOM chimneys. The Maximum likelihood method is used to determine parameters that characterize the GEV distribution, and then the limit value statistics are estimated.

Extreme-phenotype genome-wide association study (XP-GWAS): a method for identifying trait-associated variants by sequencing pools of individuals selected from a diversity panel.

PubMed

Yang, Jinliang; Jiang, Haiying; Yeh, Cheng-Ting; Yu, Jianming; Jeddeloh, Jeffrey A; Nettleton, Dan; Schnable, Patrick S

2015-11-01

Although approaches for performing genome-wide association studies (GWAS) are well developed, conventional GWAS requires high-density genotyping of large numbers of individuals from a diversity panel. Here we report a method for performing GWAS that does not require genotyping of large numbers of individuals. Instead XP-GWAS (extreme-phenotype GWAS) relies on genotyping pools of individuals from a diversity panel that have extreme phenotypes. This analysis measures allele frequencies in the extreme pools, enabling discovery of associations between genetic variants and traits of interest. This method was evaluated in maize (Zea mays) using the well-characterized kernel row number trait, which was selected to enable comparisons between the results of XP-GWAS and conventional GWAS. An exome-sequencing strategy was used to focus sequencing resources on genes and their flanking regions. A total of 0.94 million variants were identified and served as evaluation markers; comparisons among pools showed that 145 of these variants were statistically associated with the kernel row number phenotype. These trait-associated variants were significantly enriched in regions identified by conventional GWAS. XP-GWAS was able to resolve several linked QTL and detect trait-associated variants within a single gene under a QTL peak. XP-GWAS is expected to be particularly valuable for detecting genes or alleles responsible for quantitative variation in species for which extensive genotyping resources are not available, such as wild progenitors of crops, orphan crops, and other poorly characterized species such as those of ecological interest. © 2015 The Authors The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.

Improving the performance of extreme learning machine for hyperspectral image classification

NASA Astrophysics Data System (ADS)

Li, Jiaojiao; Du, Qian; Li, Wei; Li, Yunsong

2015-05-01

Extreme learning machine (ELM) and kernel ELM (KELM) can offer comparable performance as the standard powerful classifier―support vector machine (SVM), but with much lower computational cost due to extremely simple training step. However, their performance may be sensitive to several parameters, such as the number of hidden neurons. An empirical linear relationship between the number of training samples and the number of hidden neurons is proposed. Such a relationship can be easily estimated with two small training sets and extended to large training sets so as to greatly reduce computational cost. Other parameters, such as the steepness parameter in the sigmodal activation function and regularization parameter in the KELM, are also investigated. The experimental results show that classification performance is sensitive to these parameters; fortunately, simple selections will result in suboptimal performance.

Walking performance and muscle strength in the later stage poststroke: a nonlinear relationship.

PubMed

Carvalho, Cristiane; Sunnerhagen, Katharina S; Willén, Carin

2013-05-01

To evaluate the relation between muscle strength in the lower extremities and walking performance (speed and distance) in subjects in the later stage poststroke and to compare this with normative data. A cross-sectional observational study. University hospital department. Subjects poststroke (n=41; 31 men, 10 women) with a mean age of 59±5.8 years and a time from stroke onset of 52±36 months were evaluated. An urban sample (n=144) of 40- to 79-year-olds (69 men, 75 women) formed the healthy reference group. Not applicable. Muscle strength in the lower extremities was measured with an isokinetic dynamometer and combined into a strength index. Values for the 30-meter walk test for self-selected and maximum speed and the 6-minute walk test were measured. A nonlinear regression model was used. The average strength index was 730±309 in the subjects after stroke compared with 1112±362 in the healthy group. A nonlinear relation between walking performance and muscle strength was evident. The model explained 37% of the variance in self-selected speed in the stroke group and 20% in the healthy group, and 63% and 38%, respectively, in the maximum walking speed. For the 6-minute walk test, the model explained 44% of the variance in the stroke group. Subjects in the later stage poststroke were weaker than the healthy reference group, and their weakness was associated with walking performance. At the same strength index, subjects walked at lower speeds and shorter distances after stroke, indicating that there are multiple impairments that affect walking ability. Treatments focused on increasing muscle strength thus continue to hold promise. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

A high-performance gradient insert for rapid and short-T2 imaging at full duty cycle.

PubMed

Weiger, Markus; Overweg, Johan; Rösler, Manuela Barbara; Froidevaux, Romain; Hennel, Franciszek; Wilm, Bertram Jakob; Penn, Alexander; Sturzenegger, Urs; Schuth, Wout; Mathlener, Menno; Borgo, Martino; Börnert, Peter; Leussler, Christoph; Luechinger, Roger; Dietrich, Benjamin Emanuel; Reber, Jonas; Brunner, David Otto; Schmid, Thomas; Vionnet, Laetitia; Pruessmann, Klaas P

2018-06-01

The goal of this study was to devise a gradient system for MRI in humans that reconciles cutting-edge gradient strength with rapid switching and brings up the duty cycle to 100% at full continuous amplitude. Aiming to advance neuroimaging and short-T 2 techniques, the hardware design focused on the head and the extremities as target anatomies. A boundary element method with minimization of power dissipation and stored magnetic energy was used to design anatomy-targeted gradient coils with maximally relaxed geometry constraints. The design relies on hollow conductors for high-performance cooling and split coils to enable dual-mode gradient amplifier operation. With this approach, strength and slew rate specifications of either 100 mT/m with 1200 mT/m/ms or 200 mT/m with 600 mT/m/ms were reached at 100% duty cycle, assuming a standard gradient amplifier and cooling unit. After manufacturing, the specified values for maximum gradient strength, maximum switching rate, and field geometry were verified experimentally. In temperature measurements, maximum local values of 63°C were observed, confirming that the device can be operated continuously at full amplitude. Testing for peripheral nerve stimulation showed nearly unrestricted applicability in humans at full gradient performance. In measurements of acoustic noise, a maximum average sound pressure level of 132 dB(A) was determined. In vivo capability was demonstrated by head and knee imaging. Full gradient performance was employed with echo planar and zero echo time readouts. Combining extreme gradient strength and switching speed without duty cycle limitations, the described system offers unprecedented options for rapid and short-T 2 imaging. Magn Reson Med 79:3256-3266, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

''Playstation eyetoy games'' improve upper extremity-related motor functioning in subacute stroke: a randomized controlled clinical trial.

PubMed

Yavuzer, G; Senel, A; Atay, M B; Stam, H J

2008-09-01

To evaluate the effects of ''Playstation EyeToy Games'' on upper extremity motor recovery and upper extremity-related motor functioning of patients with subacute stroke. The authors designed a randomized, controlled, assessor-blinded, 4-week trial, with follow-up at 3 months. A total of 20 hemiparetic inpatients (mean age 61.1 years), all within 12 months post-stroke, received 30 minutes of treatment with ''Playstation EyeToy Games'' per day, consisting of flexion and extension of the paretic shoulder, elbow and wrist as well as abduction of the paretic shoulder or placebo therapy (watching the games for the same duration without physical involvement into the games) in addition to conventional program, 5 days a week, 2-5 hours/day for 4 weeks. Brunnstrom's staging and self-care sub-items of the functional independence measure (FIM) were performed at 0 month (baseline), 4 weeks (post-treatment), and 3 months (follow-up) after the treatment. The mean change score (95% confidence interval) of the FIM self-care score (5.5 [2.9-8.0] vs 1.8 [0.1-3.7], P=0.018) showed significantly more improvement in the EyeToy group compared to the control group. No significant differences were found between the groups for the Brunnstrom stages for hand and upper extremity. ''Playstation EyeToy Games'' combined with a conventional stroke rehabilitation program have a potential to enhance upper extremity-related motor functioning in subacute stroke patients.

Biomechanical and psychosocial work exposures and musculoskeletal symptoms among vineyard workers.

PubMed

Bernard, Christophe; Courouve, Laurène; Bouée, Stéphane; Adjémian, Annie; Chrétien, Jean-Claude; Niedhammer, Isabelle

2011-01-01

This study explored the associations between biomechanical and psychosocial work factors and musculoskeletal symptoms in vineyard workers. This cross-sectional study was based on a random sample of 2,824 male and 1,123 female vineyard workers in France. Data were collected using a self-administered questionnaire. Neck/shoulder, back and upper and lower extremity symptoms were evaluated using the Nordic questionnaire. Biomechanical exposures included 15 tasks related to vineyard activities. Psychosocial work factors included effort-reward imbalance and overcommitment, measured using the effort-reward imbalance model, and low job control and insufficient material means. Statistical analysis was performed using logistic regression analysis, and the results were adjusted for age, body mass index, educational level, work status and years in vineyard. Pruning-related factors increased the risk of upper extremity pain for both genders, of back pain for men and of neck/shoulder and lower extremity pain for women. Driving increased the risk of neck/shoulder and back pain among men. Psychosocial work factors, which were insufficient material means, overcommitment (both genders), effort-reward imbalance (men) and low job control (women), were associated with musculoskeletal symptoms, back and upper extremity pain for both genders and neck/shoulder and lower extremity pain for men. These results underlined that both biomechanical and psychosocial work factors may play a role in musculoskeletal pain among vineyard workers. Prevention policies focusing on both biomechanical and psychosocial work exposures may be useful to prevent musculoskeletal symptoms.

‘Leave Your Ego at the Door’: A Narrative Investigation into Effective Wingsuit Flying

PubMed Central

Arijs, Cedric; Chroni, Stiliani; Brymer, Eric; Carless, David

2017-01-01

In recent years there has been a rapid growth in interest in extreme sports. For the most part research has focused on understanding motivations for participation in extreme sports and very little research has attempted to investigate the psychological structure of effective performance. Those few studies that have attempted to explore this issue have tested models designed for traditional sport on adventure sports. However, extreme sports are not the same as adventure sports or traditional sports. This study employed a narrative approach to investigate experiences of effective performance in the extreme sport of proximity wingsuit flying. An overarching theme we labeled ‘leave your ego at the door,’ emerged based on four sub-themes: (1) know thy self, (2) know thy skills, (3) know the environment now, and (4) tame the ‘inner animal.’ These themes are presented and discussed in relation to performance and discovery narratives identified within elite sport, thereby shedding light on how participants’ experiences of the extreme sport of proximity wingsuit flying differ from dominant stories within traditional sports. PMID:29204131

Fourier fringe analysis and its application to metrology of extreme physical phenomena: a review [Invited].

PubMed

Takeda, Mitsuo

2013-01-01

The paper reviews a technique for fringe analysis referred to as Fourier fringe analysis (FFA) or the Fourier transform method, with a particular focus on its application to metrology of extreme physical phenomena. Examples include the measurement of extremely small magnetic fields with subfluxon sensitivity by electron wave interferometry, subnanometer wavefront evaluation of projection optics for extreme UV lithography, the detection of sub-Ångstrom distortion of a crystal lattice, and the measurement of ultrashort optical pulses in the femotsecond to attosecond range, which show how the advantages of FFA are exploited in these cutting edge applications.

Development and initial psychometric evaluation of an item bank created to measure upper extremity function in persons with stroke.

PubMed

Higgins, Johanne; Finch, Lois E; Kopec, Jacek; Mayo, Nancy E

2010-02-01

To create and illustrate the development of a method to parsimoniously and hierarchically assess upper extremity function in persons after stroke. Data were analyzed using Rasch analysis. Re-analysis of data from 8 studies involving persons after stroke. Over 4000 patients with stroke who participated in various studies in Montreal and elsewhere in Canada. Data comprised 17 tests or indices of upper extremity function and health-related quality of life, for a total of 99 items related to upper extremity function. Tests and indices included, among others, the Box and Block Test, the Nine-Hole Peg Test and the Stroke Impact Scale. Data were collected at various times post-stroke from 3 days to 1 year. Once the data fit the model, a bank of items measuring upper extremity function with persons and items organized hierarchically by difficulty and ability in log units was produced. This bank forms the basis for eventual computer adaptive testing. The calibration of the items should be tested further psychometrically, as should the interpretation of the metric arising from using the item calibration to measure the upper extremity of individuals.

MEASUREMENT OF SMALL MECHANICAL VIBRATIONS OF BRAIN TISSUE EXPOSED TO EXTREMELY-LOW-FREQUENCY ELECTRIC FIELDS

EPA Science Inventory

Electromagnetic fields can interact with biological tissue both electrically and mechanically. This study investigated the mechanical interaction between brain tissue and an extremely-low-frequency (ELF) electric field by measuring the resultant vibrational amplitude. The exposur...

Rainy Day: A Remote Sensing-Driven Extreme Rainfall Simulation Approach for Hazard Assessment

NASA Astrophysics Data System (ADS)

Wright, Daniel; Yatheendradas, Soni; Peters-Lidard, Christa; Kirschbaum, Dalia; Ayalew, Tibebu; Mantilla, Ricardo; Krajewski, Witold

2015-04-01

Progress on the assessment of rainfall-driven hazards such as floods and landslides has been hampered by the challenge of characterizing the frequency, intensity, and structure of extreme rainfall at the watershed or hillslope scale. Conventional approaches rely on simplifying assumptions and are strongly dependent on the location, the availability of long-term rain gage measurements, and the subjectivity of the analyst. Regional and global-scale rainfall remote sensing products provide an alternative, but are limited by relatively short (~15-year) observational records. To overcome this, we have coupled these remote sensing products with a space-time resampling framework known as stochastic storm transposition (SST). SST "lengthens" the rainfall record by resampling from a catalog of observed storms from a user-defined region, effectively recreating the regional extreme rainfall hydroclimate. This coupling has been codified in Rainy Day, a Python-based platform for quickly generating large numbers of probabilistic extreme rainfall "scenarios" at any point on the globe. Rainy Day is readily compatible with any gridded rainfall dataset. The user can optionally incorporate regional rain gage or weather radar measurements for bias correction using the Precipitation Uncertainties for Satellite Hydrology (PUSH) framework. Results from Rainy Day using the CMORPH satellite precipitation product are compared with local observations in two examples. The first example is peak discharge estimation in a medium-sized (~4000 square km) watershed in the central United States performed using CUENCAS, a parsimonious physically-based distributed hydrologic model. The second example is rainfall frequency analysis for Saint Lucia, a small volcanic island in the eastern Caribbean that is prone to landslides and flash floods. The distinct rainfall hydroclimates of the two example sites illustrate the flexibility of the approach and its usefulness for hazard analysis in data-poor regions.

From positive psychology to psychopathology: the continuum of attention-deficit hyperactivity disorder.

PubMed

Greven, Corina U; Buitelaar, Jan K; Salum, Giovanni A

2018-03-01

Integration of positive psychology into clinical research and treatment has been slow. This integration can be facilitated by the conceptualisation of mental disorders as the high, symptomatic extreme of continuous normal variation. This assumes that there is also a low, positive extreme, which is, however, unchartered territory. This study aims to examine how well current measures capture the low extreme of mental disorder continua, using attention-deficit hyperactivity disorder (ADHD) as an example. The ability of three validated scales to capture ADHD as a continuous trait was examined using Item Response Theory in a sample of 9,882 adolescents from the UK population-representative Twins Early Development Study. These scales were: the Strengths and Weakness of ADHD Symptoms and Normal behaviour scale (SWAN), Strength and Difficulties Questionnaire (SDQ - hyperactivity subscale), and Conners' Parent Rating Scale (Conners). Only the SWAN reliably differentiated interindividual differences between participants lying at any level of the continuous ADHD latent trait, including the extreme low, positive end (z-scores from -3 to +3). The SDQ showed low reliability across the ADHD latent trait. In contrast, the Conners performed best at differentiating individuals scoring at or above the mean to the high symptomatic range (z-scores from 0 to +3). The SWAN was the only measure to provide indicators of 'positive mental health', endorsed in the presence of particularly good attentive abilities. Scales such as the SWAN that reliably capture ADHD as a continuous trait, including the positive end, are important for not missing meaningful variation in population-based studies. Indicators of positive mental health may be helpful in clinical practice, as positive attributes have been shown to directly influence as well as buffer negative effects of psychiatric symptoms. © 2017 Association for Child and Adolescent Mental Health.

Measures of functional performance and their association with hip and thigh strength.

PubMed

Kollock, Roger; Van Lunen, Bonnie L; Ringleb, Stacie I; Oñate, James A

2015-01-01

Insufficient hip and thigh strength may increase an athlete's susceptibility to injury. However, screening for strength deficits using isometric and isokinetic instrumentation may not be practical in all clinical scenarios. To determine if functional performance tests are valid indicators of hip and thigh strength. Descriptive laboratory study. Research laboratory. Sixty-two recreationally athletic men (n = 30, age = 21.07 years, height = 173.84 cm, mass = 81.47 kg) and women (n = 32, age = 21.03 years, height = 168.77 cm, mass = 68.22 kg) participants were recruited. During session 1, we measured isometric peak force and rate of force development for 8 lower extremity muscle groups, followed by an isometric endurance test. During session 2, participants performed functional performance tests. Peak force, rate of force development, fatigue index, hop distance (or height), work (joules), and number of hops performed during the 30-second lateral-hop test were assessed. The r values were squared to calculate r (2). We used Pearson correlations to evaluate the associations between functional performance and strength. In men, the strongest relationship was observed between triple-hop work and hip-adductor peak force (r(2) = 50, P ≤ .001). Triple-hop work also was related to hip-adductor (r(2) = 38, P ≤ .01) and hip-flexor (r(2) = 37, P ≤ .01) rate of force development. For women, the strongest relationships were between single-legged vertical-jump work and knee-flexor peak force (r(2) = 0.44, P ≤ .01) and single-legged vertical-jump height and knee-flexor peak force (r(2) = 0.42, P ≤ .01). Single-legged vertical-jump height also was related to knee-flexor rate of force development (r(2) = 0.49, P ≤ .001). The 30-second lateral-hop test did not account for a significant portion of the variance in strength endurance. Hop tests alone did not provide clinicians with enough information to make evidence-based decisions about lower extremity strength in isolated muscle groups.

Cortical disconnection of the ipsilesional primary motor cortex is associated with gait speed and upper extremity motor impairment in chronic left hemispheric stroke.

PubMed

Peters, Denise M; Fridriksson, Julius; Stewart, Jill C; Richardson, Jessica D; Rorden, Chris; Bonilha, Leonardo; Middleton, Addie; Gleichgerrcht, Ezequiel; Fritz, Stacy L

2018-01-01

Advances in neuroimaging have enabled the mapping of white matter connections across the entire brain, allowing for a more thorough examination of the extent of white matter disconnection after stroke. To assess how cortical disconnection contributes to motor impairments, we examined the relationship between structural brain connectivity and upper and lower extremity motor function in individuals with chronic stroke. Forty-three participants [mean age: 59.7 (±11.2) years; time poststroke: 64.4 (±58.8) months] underwent clinical motor assessments and MRI scanning. Nonparametric correlation analyses were performed to examine the relationship between structural connectivity amid a subsection of the motor network and upper/lower extremity motor function. Standard multiple linear regression analyses were performed to examine the relationship between cortical necrosis and disconnection of three main cortical areas of motor control [primary motor cortex (M1), premotor cortex (PMC), and supplementary motor area (SMA)] and motor function. Anatomical connectivity between ipsilesional M1/SMA and the (1) cerebral peduncle, (2) thalamus, and (3) red nucleus were significantly correlated with upper and lower extremity motor performance (P ≤ 0.003). M1-M1 interhemispheric connectivity was also significantly correlated with gross manual dexterity of the affected upper extremity (P = 0.001). Regression models with M1 lesion load and M1 disconnection (adjusted for time poststroke) explained a significant amount of variance in upper extremity motor performance (R 2  = 0.36-0.46) and gait speed (R 2  = 0.46), with M1 disconnection an independent predictor of motor performance. Cortical disconnection, especially of ipsilesional M1, could significantly contribute to variability seen in locomotor and upper extremity motor function and recovery in chronic stroke. Hum Brain Mapp 39:120-132, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Technological Advances in Interventions to Enhance Post-Stroke Gait

PubMed Central

Sheffler, Lynne R.; Chae, John

2012-01-01

Synopsis This article provides a comprehensive review of specific rehabilitation interventions used to enhance hemiparetic gait following stroke. Neurologic rehabilitation interventions may be either therapeutic resulting in enhanced motor recovery or compensatory whereby assistance or substitution for neurological deficits results in improved functional performance. Included in this review are lower extremity functional electrical stimulation (FES), body-weight supported treadmill training (BWSTT), and lower extremity robotic-assisted gait training. These post-stroke gait training therapies are predicated on activity-dependent neuroplasticity which is the concept that cortical reorganization following central nervous system injury may be induced by repetitive, skilled, and cognitively engaging active movement. All three interventions have been trialed extensively in both research and clinical settings to demonstrate a positive effect on various gait parameters and measures of walking performance. However, more evidence is necessary to determine if specific technology-enhanced gait training methods are superior to conventional gait training methods. This review provides an overview of evidence-based research which supports the efficacy of these three interventions to improve gait, as well as provide perspective on future developments to enhance post-stroke gait in neurologic rehabilitation. PMID:23598265

Duplex evaluation following femoropopliteal angioplasty and stenting: criteria and utility of surveillance.

PubMed

Baril, Donald T; Marone, Luke K

2012-07-01

Surveillance following lower extremity bypass, carotid endarterectomy, and endovascular aortic aneurysm repair has become the standard of care at most institutions. Conversely, surveillance following lower extremity endovascular interventions is performed somewhat sporadically in part because the duplex criteria for recurrent stenoses have been ill defined. It appears that duplex surveillance after peripheral endovascular interventions, as with conventional bypass, is beneficial in identifying recurrent lesions which may preclude failure and occlusion. In-stent stenosis following superficial femoral artery angioplasty and stenting can be predicted by both peak systolic velocity and velocity ratio data as measured by duplex ultrasound. Duplex criteria have been defined to determine both ≥50% in-stent stenosis and ≥80% in-stent stenosis. Although not yet well studied, it appears that applying these criteria during routine surveillance may assist in preventing failure of endovascular interventions.

Measurement Properties of Instruments for Measuring of Lymphedema: Systematic Review.

PubMed

Hidding, Janine T; Viehoff, Peter B; Beurskens, Carien H G; van Laarhoven, Hanneke W M; Nijhuis-van der Sanden, Maria W G; van der Wees, Philip J

2016-12-01

Lymphedema is a common complication of cancer treatment, resulting in swelling and subjective symptoms. Reliable and valid measurement of this side effect of medical treatment is important. The purpose of this study was to provide best evidence regarding which measurement instruments are most appropriate in measuring lymphedema in its different stages. The PubMed and Web of Science databases were used, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Clinical studies on measurement instruments assessing lymphedema were reviewed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) scoring instrument for quality assessment. Data on reliability, concurrent validity, convergent validity, sensitivity, specificity, applicability, and costs were extracted. Pooled data showed good intrarater intraclass correlation coefficients (ICCs) (.89) for bioimpedance spectroscopy (BIS) in the lower extremities and high intrarater and interrater ICCs for water volumetry, tape measurement, and perometry (.98-.99) in the upper extremities. In the upper extremities, the standard error of measurement was 3.6% (σ=0.7%) for water volumetry, 5.6% (σ=2.1%) for perometry, and 6.6% (σ=2.6%) for tape measurement. Sensitivity of tape measurement in the upper extremities, using different cutoff points, varied from 0.73 to 0.90, and specificity values varied from 0.72 to 0.78. No uniform definition of lymphedema was available, and a gold standard as a reference test was lacking. Items concerning risk of bias were study design, patient selection, description of lymphedema, blinding of test outcomes, and number of included participants. Measurement instruments with evidence for good reliability and validity were BIS, water volumetry, tape measurement, and perometry, where BIS can detect alterations in extracellular fluid in stage 1 lymphedema and the other measurement instruments can detect alterations in volume starting from stage 2. In research, water volumetry is indicated as a reference test for measuring lymphedema in the upper extremities. © 2016 American Physical Therapy Association.

WE-AB-207A-01: BEST IN PHYSICS (IMAGING): High-Resolution Cone-Beam CT of the Extremities and Cancellous Bone Architecture with a CMOS Detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, Q; Brehler, M; Sisniega, A

Purpose: Extremity cone-beam CT (CBCT) with an amorphous silicon (aSi) flat-panel detector (FPD) provides low-dose volumetric imaging with high spatial resolution. We investigate the performance of the newer complementary metal-oxide semiconductor (CMOS) detectors to enhance resolution of extremities CBCT to ∼0.1 mm, enabling morphological analysis of trabecular bone. Quantitative in-vivo imaging of bone microarchitecture could present an important advance for osteoporosis and osteoarthritis diagnosis and therapy assessment. Methods: Cascaded systems models of CMOS- and FPD-based extremities CBCT were implemented. Performance was compared for a range of pixel sizes (0.05–0.4 mm), focal spot sizes (0.3–0.6 FS), and x-ray techniques (0.05–0.8 mAs/projection)more » using detectability of high-, low-, and all-frequency tasks for a nonprewhitening observer. Test-bench implementation of CMOS-based extremity CBCT involved a Teledyne DALSA Xineos3030HR detector with 0.099 mm pixels and a compact rotating anode x-ray source with 0.3 FS (IMD RTM37). Metrics of bone morphology obtained using CMOS-based CBCT were compared in cadaveric specimens to FPD-based system using a Varian PaxScan4030 (0.194 mm pixels). Results: Finer pixel size and reduced electronic noise for CMOS (136 e compared to 2000 e for FPD) resulted in ∼1.9× increase in detectability for high-frequency tasks and ∼1.1× increase for all-frequency tasks. Incorporation of the new x-ray source with reduced focal spot size (0.3 FS vs. 0.5 FS used on current extremities CBCT) improved detectability for CMOS-based CBCT by ∼1.7× for high-frequency tasks. Compared to FPD CBCT, the CMOS detector yielded improved agreement with micro-CT in measurements of trabecular thickness (∼1.7× reduction in relative error), bone volume (∼1.5× reduction), and trabecular spacing (∼3.5× reduction). Conclusion: Imaging performance modelling and experimentation indicate substantial improvements for high-frequency imaging tasks through adoption of the CMOS detector and small FS x-ray source, motivating the use of these components in a new system for quantitative in-vivo imaging of trabecular bone. Financial Support: US NIH grant R01EB018896. Qian Cao is a Howard Hughes Medical Institute International Student Research Fellow. Disclosures: W Zbijewski, J Siewerdsen and A Sisniega receive research funding from Carestream Health.« less

Typhoon generated surface gravity waves measured by NOMAD-type buoys

NASA Astrophysics Data System (ADS)

Collins, Clarence O., III

This study examines wind-generated ocean surface waves as measured by NOMAD-type buoys during the ONR-sponsored Impact of Typhoons on the Ocean in the Pacific (ITOP) field experiment in 2010. 1-D measurements from two new Extreme Air-Sea Interaction (EASI) NOMAD-type buoys were validated against measurements from established Air-Sea Interaction Spar (ASIS) buoys. Also, during ITOP, 3 drifting Miniature Wave Buoys, a wave measuring marine radar on the R/V Roger Revelle, and several overpasses of JASON-1 (C- and Ku-band) and -2 (Ku-band) satellite altimeters were within 100 km of either EASI buoy. These additional measurements were compared against both EASI buoys. Findings are in line with previous wave parameter inter-comparisons. A corroborated measurement of mean wave direction and direction at the peak of the spectrum from the EASI buoy is presented. Consequently, this study is the first published account of directional wave information which has been successfully gathered from a buoy with a 6 m NOMAD-type hull. This result may be applied to improve operational coverage of wave direction. In addition, details for giving a consistent estimate of sea surface elevation from buoys using strapped down accelerometers are given. This was found to be particularly important for accurate measurement of extreme waves. These technical studies established a high level of confidence in the ITOP wave measurements. Detailed frequency-direction spectra were analyzed. Structures in the wave field were described during the close passages of 4 major tropical cyclones (TC) including: severe tropical storm Dianmu, Typhoon Fanapi, Super Typhoon Megi, and Typhoon Chaba. In addition, significant swell was measured from a distant 5th TC, Typhoon Malakas. Changes in storm direction and intensity are found to have a profound impact on the wave field. Measurements of extreme waves were explored. More extreme waves were measured during TCs which coincided with times of increased wave steepness. The largest extreme waves, which are more impressive than the Draupner (aka Newyears) wave in terms of normalized wave height, were found to occur under circumstances which support the theory of modulation instability. It is suggested that swell and wind sea, as generated by complex TCs winds, may merge and/or couple in such a way to produce sea-states which are unstable. The largest extreme wave, which was over 21 m high, appears to have occurred under such circumstances. However, the development of unstable seas, and the possible connection between the occurrence of extreme waves and unstable seas, has yet to be confirmed.

Radiation Assurance for the Space Environment

NASA Technical Reports Server (NTRS)

Barth, Janet L.; LaBel, Kenneth A.; Poivey, Christian

2004-01-01

The space radiation environment can lead to extremely harsh operating conditions for spacecraft electronic systems. A hardness assurance methodology must be followed to assure that the space radiation environment does not compromise the functionality and performance of space-based systems during the mission lifetime. The methodology includes a definition of the radiation environment, assessment of the radiation sensitivity of parts, worst-case analysis of the impact of radiation effects, and part acceptance decisions which are likely to include mitigation measures.