Extended working hours and health.

PubMed

Raediker, Britta; Janssen, Daniela; Schomann, Carsten; Nachreiner, Friedhelm

2006-01-01

Statistical analyses of the relation between the amount of working hours and impairments to health, based on data from a European survey on working conditions in 2000, clearly reveal that there is a substantial correlation between the number of working hours per week and the frequencies of health complaints. This applies to both musculo-skeletal disorders as well as to psycho-vegetative complaints. The relationship of the duration of the exposure to working conditions to health impairments is moderated by a great number of individual (e.g., age) and situational (e.g., shift-work) variables, showing additive or interactive effects for which selected examples have been presented. In general, however, there is a consistent functional relationship between the number or working hours and their effects on the workers that holds over a great variety of conditions. It is argued that requests for extending working hours should thus be handled with care.

Direct oral anticoagulants for extended thromboprophylaxis in medically ill patients: meta-analysis and risk/benefit assessment.

PubMed

Al Yami, Majed S; Kurdi, Sawsan; Abraham, Ivo

2018-01-01

Standard-duration (7-10 days) thromboprophylaxis with low molecular weight heparin, low dose unfractionated heparin, or fondaparinux in hospitalized medically ill patients is associated with ~50% reduction in venous thromboembolism (VTE) risk. However, these patients remain at high risk for VTE post-discharge. The direct oral anticoagulants (DOACs) apixaban, rivaroxaban and betrixaban have been evaluated for extended-duration (30-42 days) thromboprophylaxis in this population. We review the efficacy and safety results from the 3 pivotal trials of extended-duration DOAC thromboprophylaxis in medically ill patients. We performed a meta-analysis of these pivotal trials focusing on 6 VTE (efficacy) and three bleeding outcomes (safety). These results were integrated into a quantitative risk/benefit assessment. The trials evaluating extended-duration DOAC thromboprophylaxis in medically ill patients failed to establish clear efficacy and/or safety signals for each agent. Our meta-analysis shows that, as a class, DOACs have selective and partial extended-duration prophylactic activity in preventing VTE events. However, this is associated with a marked increase in the risk of various bleeding events. The risk/benefit analyses fail to show a consistent net clinical benefit of extended-duration DOAC prophylaxis in medically ill patients. At this time, the evidence of safe and effective extended-duration thromboprophylaxis with DOACs in this population is inconclusive.

Extended-duration versus short-duration pharmacological thromboprophylaxis in acutely Ill hospitalized medical patients: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Liew, Aaron Y L; Piran, Siavash; Eikelboom, John W; Douketis, James D

2017-04-01

Extended-duration pharmacological thromboprophylaxis, for at least 28 days, is effective for the prevention of symptomatic venous thromboembolism (VTE) in high-risk surgical patients but is of uncertain benefit in hospitalized medical patients. We aimed to evaluate the efficacy and safety of extended-duration thromboprophylaxis in hospitalized medical patients. We conducted a systematic PubMed, Medline and EMBASE literature search until June 2016 and a meta-analysis of randomized controlled trials which compared extended-duration with short-duration thromboprophylaxis in hospitalized medical patients. Four randomized controlled trials comparing extended-duration prophylaxis (24-47 days) with short-duration prophylaxis (6-14 days) in a total of 34,068 acutely ill hospitalized medical patients were included. When compared with short-duration prophylaxis, extended-duration prophylaxis was associated with a decrease in symptomatic proximal or distal deep vein thrombosis (DVT) [relative risk (RR) = 0.52; 95% confidence interval (Cl): 0.35-0.77: p = 0.001; absolute risk reduction (ARR) = 0.32%, number needed to treat (NNT) = 313], and symptomatic non-fatal pulmonary embolism (RR = 0.61; 95% Cl 0.38-0.99: p = 0.04; ARR = 0.16%; NNT = 625), an increase in major bleeding (RR = 2.08; 95% Cl 1.50-2.90: p < 0.0001, absolute risk increase = 0.41%, number needed to harm = 244), and no significant reduction in VTE-related mortality (RR = 0.69; 95% Cl 0.45-1.06: p = 0.09) or all-cause mortality (RR = 1.00; 95% CI 0.89-1.12; p = 0.95). There was heterogeneity for major bleeding due to results from the APEX trial (no difference between betrixaban and enoxaparin). Compared with short-duration thromboprophylaxis, extended-duration treatment reduces the risk for symptomatic DVT and non-fatal pulmonary embolism. Extended treatment with apixaban, enoxaparin and rivaroxaban but not betrixaban increases the risk for major bleeding.

Duration of sleep inertia after napping during simulated night work and in extended operations.

PubMed

Signal, Tracey Leigh; van den Berg, Margo J; Mulrine, Hannah M; Gander, Philippa H

2012-07-01

Due to the mixed findings of previous studies, it is still difficult to provide guidance on how to best manage sleep inertia after waking from naps in operational settings. One of the few factors that can be manipulated is the duration of the nap opportunity. The aim of the present study was to investigate the magnitude and time course of sleep inertia after waking from short (20-, 40- or 60-min) naps during simulated night work and extended operations. In addition, the effect of sleep stage on awakening and duration of slow wave sleep (SWS) on sleep inertia was assessed. Two within-subject protocols were conducted in a controlled laboratory setting. Twenty-four healthy young men (Protocol 1: n = 12, mean age = 25.1 yrs; Protocol 2: n = 12, mean age = 23.2 yrs) were provided with nap opportunities of 20-, 40-, and 60-min (and a control condition of no nap) ending at 02:00 h after ∼20 h of wakefulness (Protocol 1 [P1]: simulated night work) or ending at 12:00 h after ∼30 h of wakefulness (Protocol 2 [P2]: simulated extended operations). A 6-min test battery, including the Karolinska Sleepiness Scale (KSS) and the 4-min 2-Back Working Memory Task (WMT), was repeated every 15 min the first hour after waking. Nap sleep was recorded polysomnographically, and in all nap opportunities sleep onset latency was short and sleep efficiency high. Mixed-model analyses of variance (ANOVA) for repeated measures were calculated and included the factors time (time post-nap), nap opportunity (duration of nap provided), order (order in which the four protocols were completed), and the interaction of these terms. Results showed no test x nap opportunity effect (i.e., no effect of sleep inertia) on KSS. However, WMT performance was impaired (slower reaction time, fewer correct responses, and increased omissions) on the first test post-nap, primarily after a 40- or 60-min nap. In P2 only, performance improvement was evident 45 min post-awakening for naps of 40 min or more. In ANOVAs where sleep stage on awakening was included, the test x nap opportunity interaction was significant, but differences were between wake and non-REM Stage 1/Stage 2 or wake and SWS. A further series of ANOVAs showed no effect of the duration of SWS on sleep inertia. The results of this study demonstrate that no more than 15 min is required for performance decrements due to sleep inertia to dissipate after nap opportunities of 60 min or less, but subjective sleepiness is not a reliable indicator of this effect. Under conditions where sleep is short, these findings also suggest that SWS, per se, does not contribute to more severe sleep inertia. When wakefulness is extended and napping occurs at midday (i.e., P2), nap opportunities of 40- and 60-min have the advantage over shorter duration sleep periods, as they result in performance benefits ∼45 min after waking.

A retrospective cohort study of shift work and risk of cancer-specific mortality in German male chemical workers.

PubMed

Yong, Mei; Nasterlack, Michael; Messerer, Peter; Oberlinner, Christoph; Lang, Stefan

2014-02-01

Human evidence of carcinogenicity concerning shift work is inconsistent. In a previous study, we observed no elevated risk of total mortality in shift workers followed up until the end of 2006. The present study aimed to investigate cancer-specific mortality, relative to shift work. The cohort consisted of male production workers (14,038 shift work and 17,105 day work), employed at BASF Ludwigshafen for at least 1 year between 1995 and 2005. Vital status was followed from 2000 to 2009. Cause-specific mortality was obtained from death certificates. Exposure to shift work was measured both as a dichotomous and continuous variable. While lifetime job history was not available, job duration in the company was derived from personal data, which was then categorized at the quartiles. Cox proportional hazard model was used to adjust for potential confounders, in which job duration was treated as a time-dependent covariate. Between 2000 and 2009, there were 513 and 549 deaths among rotating shift and day work employees, respectively. Risks of total and cancer-specific mortalities were marginally lower among shift workers when taking age at entry and job level into consideration and were statistically significantly lower when cigarette smoking, alcohol intake, job duration, and chronic disease prevalence at entry to follow-up were included as explanatory factors. With respect to mortality risks in relation to exposure duration, no increased risks were found in any of the exposure groups after full adjustment and there was no apparent trend suggesting an exposure-response relation with duration of shift work. The present analysis extends and confirms our previous finding of no excess risk of mortality associated with work in the shift system employed at BASF Ludwigshafen. More specifically, there is also no indication of an increased risk of mortality due to cancer.

When policy meets physiology: the challenge of reducing resident work hours.

PubMed

Lockley, Steven W; Landrigan, Christopher P; Barger, Laura K; Czeisler, Charles A

2006-08-01

Considerable controversy exists regarding optimal work hours for physicians and surgeons in training. In a series of studies, we assessed the effect of extended work hours on resident sleep and health as well as patient safety. In a validated nationwide survey, we found that residents who had worked 24 hours or longer were 2.3 times more likely to have a motor vehicle crash following that shift than when they worked < 24 hours, and that the monthly risk of a crash increased by 16.2% after each extended duration shift. We also found in a randomized trial that interns working a traditional on-call schedule slept 5.8 hours less per week, had twice as many attentional failures on duty overnight, and made 36% more serious medical errors and nearly six times more serious diagnostic errors than when working on a schedule that limited continuous duty to 16 hours. While numerous opinions have been published opposing reductions in extended work hours due to concerns regarding continuity of patient care, reduced educational opportunities, and traditionally-defined professionalism, there are remarkably few objective data in support of continuing to schedule medical trainees to work shifts > 24 hours. An evidence-based approach is needed to minimize the well-documented risk that current work hour practices confer on resident health and patient safety while optimizing education and continuity of care.

Relevance of immobility and importance of risk assessment management for medically ill patients.

PubMed

Hull, Russell D

2013-06-01

Recent or continued immobility is a significant risk factor for venous thromboembolism (VTE) in acutely ill medical patients. Patients may benefit from thromboprophylaxis; however, its optimal duration remains unclear. The Extended Clinical Prophylaxis in Acutely Ill Medical Patients (EXCLAIM) study was the first trial to systematically investigate how the degree of immobilization relates to the risk of developing VTE. EXCLAIM offers insights into the duration of VTE risk associated with reduced mobility and helps identify which patients would benefit most from extended-duration thromboprophylaxis. Further recent studies suggest that extended-duration thromboprophylaxis may be in order in certain high-risk patients to protect the patients from the risk of VTE events occurring, particularly in the posthospitalization period. Baseline d-dimer data and level of mobility could be included in risk assessment. Physicians are recommended to consider the use of extended-duration thromboprophylaxis based on individual risk assessment management (RAM) and balance of benefit and harm.

Bio-psychosocial determinants of time lost from work following non life threatening acute orthopaedic trauma

PubMed Central

2010-01-01

Background To determine factors predicting the duration of time away from work following acute orthopaedic non life threatening trauma Methods Prospective cohort study conducted at four hospitals in Victoria, Australia. The cohort comprised 168 patients aged 18-64 years who were working prior to the injury and sustained a range of acute unintentional orthopaedic injuries resulting in hospitalization. Baseline data was obtained by survey and medical record review. Multivariate Cox proportional hazards regression analysis was used to examine the association between potential predictors and the duration of time away from work during the six month study. The study achieved 89% follow-up. Results Of the 168 participants recruited to the study, 68% returned to work during the six month study. Multivariate Cox proportional hazards regression analysis identified that blue collar work, negative pain attitudes with respect to work, high initial pain intensity, injury severity, older age, initial need for surgery, the presence of co-morbid health conditions at study entry and an orthopaedic injury to more than one region were associated with extended duration away from work following the injury. Participants in receipt of compensation who reported high social functioning at two weeks were 2.58 times more likely to have returned to work than similar participants reporting low social functioning. When only those who had returned to work were considered, the participant reported reason for return to work " to fill the day" was a significant predictor of earlier RTW [RR 2.41 (95% C.I 1.35-4.30)] whereas "financial security" and "because they felt able to" did not achieve significance. Conclusions Many injury-related and psycho social factors affect the duration of time away from work following orthopaedic injury. Some of these are potentially modifiable and may be amenable to intervention. Further consideration of the reasons provided by participants for returning to work may provide important opportunities for social marketing approaches designed to alleviate the financial and social burden associated with work disability. PMID:20051124

Bio-psychosocial determinants of time lost from work following non life threatening acute orthopaedic trauma.

PubMed

Clay, Fiona J; Newstead, Stuart V; Watson, Wendy L; Ozanne-Smith, Joan; McClure, Roderick J

2010-01-05

To determine factors predicting the duration of time away from work following acute orthopaedic non life threatening trauma Prospective cohort study conducted at four hospitals in Victoria, Australia. The cohort comprised 168 patients aged 18-64 years who were working prior to the injury and sustained a range of acute unintentional orthopaedic injuries resulting in hospitalization. Baseline data was obtained by survey and medical record review. Multivariate Cox proportional hazards regression analysis was used to examine the association between potential predictors and the duration of time away from work during the six month study. The study achieved 89% follow-up. Of the 168 participants recruited to the study, 68% returned to work during the six month study. Multivariate Cox proportional hazards regression analysis identified that blue collar work, negative pain attitudes with respect to work, high initial pain intensity, injury severity, older age, initial need for surgery, the presence of co-morbid health conditions at study entry and an orthopaedic injury to more than one region were associated with extended duration away from work following the injury. Participants in receipt of compensation who reported high social functioning at two weeks were 2.58 times more likely to have returned to work than similar participants reporting low social functioning. When only those who had returned to work were considered, the participant reported reason for return to work " to fill the day" was a significant predictor of earlier RTW [RR 2.41 (95% C.I 1.35-4.30)] whereas "financial security" and "because they felt able to" did not achieve significance. Many injury-related and psycho social factors affect the duration of time away from work following orthopaedic injury. Some of these are potentially modifiable and may be amenable to intervention. Further consideration of the reasons provided by participants for returning to work may provide important opportunities for social marketing approaches designed to alleviate the financial and social burden associated with work disability.

Factors Associated With Extended Breastfeeding in India.

PubMed

Mehta, Arpit R; Panneer, Sigamani; Ghosh-Jerath, Suparna; Racine, Elizabeth F

2017-02-01

Extended breastfeeding duration is common in India. Extended breastfeeding protects the infant from infectious disease and promotes child spacing. In the 1990s, the median breastfeeding duration in India was 24 months. Research aim: This study aimed to investigate the median duration of breastfeeding in India and to identify the factors associated with extended breastfeeding to 24 months as recommended by the World Health Organization. This cross-sectional data analysis used nationally representative data from the 2011-2012 Indian Human Development Survey II. The outcome in this study was extended breastfeeding defined as breastfeeding to 24 months or more. Multivariate logistic regression was used to identify the factors associated with extended breastfeeding. The median duration of breastfeeding was 12 months; approximately 25% of women breastfed 24 months or more. Women were at greater odds of breastfeeding 24 months or more if the infant was a boy compared with a girl, if the women lived in a rural area compared with an urban area, if the women were married at a young age (< 17 vs. 20 years or older at marriage), and if the delivery was assisted by a friend or relative compared with a doctor. The median duration of breastfeeding has decreased by 50% from 1992-1993 to 2011-2012. The women who continue to breastfeed 24 months or more tend to be more traditional (i.e., living in rural areas, marrying young, and having family/friends as birth attendants). Further research to study the health effect of decreased breastfeeding duration is warranted.

Extended release of high molecular weight hydroxypropyl methylcellulose from molecularly imprinted, extended wear silicone hydrogel contact lenses.

PubMed

White, Charles J; McBride, Matthew K; Pate, Kayla M; Tieppo, Arianna; Byrne, Mark E

2011-08-01

Symptoms of contact lenses induced dry eye (CLIDE) are typically treated through application of macromolecular re-wetting agents via eye drops. Therapeutic soft contact lenses can be formulated to alleviate CLIDE symptoms by slowly releasing comfort agent from the lens. In this paper, we present an extended wear silicone hydrogel contact lens with extended, controllable release of 120 kDa hydroxypropyl methylcellulose (HPMC) using a molecular imprinting strategy. A commercial silicone hydrogel lens was tailored to release approximately 1000 μg of HPMC over a period of up to 60 days in a constant manner at a rate of 16 μg/day under physiological flowrates, releasing over the entire range of continuous wear. Release rates could be significantly varied by the imprinting effect and functional monomer to template ratio (M/T) with M/T values 0, 0.2, 2.8, 3.4 corresponding to HPMC release durations of 10, 13, 23, and 53 days, respectively. Lenses had high optical quality and adequate mechanical properties for contact lens use. This work highlights the potential of imprinting in the design and engineering of silicone hydrogel lenses to release macromolecules for the duration of wear, which may lead to decreased CLIDE symptoms and more comfortable contact lenses. Copyright © 2011 Elsevier Ltd. All rights reserved.

Daily Positive Spillover and Crossover from Mothers’ Work to Youth Health

PubMed Central

Lawson, Katie M.; Davis, Kelly D.; McHale, Susan M.; Hammer, Leslie B.; Buxton, Orfeu M.

2016-01-01

Prior research shows that employees’ work experiences can “spill over” into their family lives and “cross over” to affect family members. Expanding on studies that emphasize negative implications of work for family life, this study examined positive work-to-family spillover and positive and negative crossover between mothers and their children. Participants were 174 mothers in the extended care (nursing home) industry and their children (ages 9-17), both of whom completed daily diaries on the same, eight, consecutive evenings. On each workday, mothers reported whether they had a positive experience at work, youth reported on their mothers’ positive and negative mood after work, and youth rated their own mental (positive and negative affect) and physical health (physical health symptoms, sleep quality, sleep duration). Results of two-level models showed that mothers’ positive mood after work, on average, was directly related to youth reports of more positive affect, better sleep quality, and longer sleep duration. In addition, mothers with more positive work experiences, on average, displayed less negative mood after work, and in turn, adolescents reported less negative affect and fewer physical health symptoms. Results are discussed in terms of daily family system dynamics. PMID:25243577

Daily positive spillover and crossover from mothers' work to youth health.

PubMed

Lawson, Katie M; Davis, Kelly D; McHale, Susan M; Hammer, Leslie B; Buxton, Orfeu M

2014-12-01

Prior research shows that employees' work experiences can "spill over" into their family lives and "cross over" to affect family members. Expanding on studies that emphasize negative implications of work for family life, this study examined positive work-to-family spillover and positive and negative crossover between mothers and their children. Participants were 174 mothers in the extended care (nursing home) industry and their children (ages 9-17), both of whom completed daily diaries on the same 8 consecutive evenings. On each workday, mothers reported whether they had a positive experience at work, youth reported on their mothers' positive and negative mood after work, and youth rated their own mental (positive and negative affect) and physical health (physical health symptoms, sleep quality, sleep duration). Results of 2-level models showed that mothers' positive mood after work, on average, was directly related to youth reports of more positive affect, better sleep quality, and longer sleep duration. In addition, mothers with more positive work experiences, on average, displayed less negative mood after work, and in turn, adolescents reported less negative affect and fewer physical health symptoms. Results are discussed in terms of daily family system dynamics.

Walking on ballast impacts balance.

PubMed

Wade, Chip; Garner, John C; Redfern, Mark S; Andres, Robert O

2014-01-01

Railroad workers often perform daily work activities on irregular surfaces, specifically on ballast rock. Previous research and injury epidemiology have suggested a relationship between working on irregular surfaces and postural instability. The purpose of this study was to examine the impact of walking on ballast for an extended duration on standing balance. A total of 16 healthy adult males walked on a 7.62 m × 4.57 m (25 ft × 15 ft) walking surface of no ballast (NB) or covered with ballast (B) of an average rock size of about 1 inch for 4 h. Balance was evaluated using dynamic posturography with the NeuroCom(®) Equitest System(™) prior to experiencing the NB or B surface and again every 30 min during the 4 h of ballast exposure. Dependent variables were the sway velocity and root-mean-square (RMS) sway components in the medial-lateral and anterior-posterior directions. Repeated measures ANOVA revealed statistically significant differences in RMS and sway velocity between ballast surface conditions and across exposure times. Overall, the ballast surface condition induced greater sway in all of the dynamic posturography conditions. Walking on irregular surfaces for extended durations has a deleterious effect on balance compared to walking on a surface without ballast. These findings of changes in balance during ballast exposure suggest that working on an irregular surface may impact postural control.

Group structure and group process for effective space station astronaut teams

NASA Technical Reports Server (NTRS)

Nicholas, J. M.; Kagan, R. S.

1985-01-01

Space Station crews will encounter new problems, many derived from the social interaction of groups working in space for extended durations. Solutions to these problems must focus on the structure of groups and the interaction of individuals. A model of intervention is proposed to address problems of interpersonal relationships and emotional stress, and improve the morale, cohesiveness, and productivity of astronaut teams.

Juggling work and breastfeeding: effects of maternity leave and occupational characteristics.

PubMed

Guendelman, Sylvia; Kosa, Jessica Lang; Pearl, Michelle; Graham, Steve; Goodman, Julia; Kharrazi, Martin

2009-01-01

Juggling breastfeeding and paid work can challenge breastfeeding success. We examined the relationship between breastfeeding and maternity leave before and after delivery among working mothers in Southern California. California is 1 of only 5 states in the United States providing paid pregnancy leave that can be extended for infant bonding. Drawing from a case-control study of preterm birth and low birth weight, 770 full-time working mothers were compared on whether they established breastfeeding in the first month. For those who established breastfeeding, we examined duration. Eligible women participated in California's Prenatal Screening Program; delivered live births between July 2002 and December 2003; were > or =18 years old; had a singleton birth without congenital anomalies; and had a US mailing address. We assessed whether maternity leave and other occupational characteristics predicted breastfeeding cessation and used multivariate regression models weighted for probability of sampling to calculate odds ratios for breastfeeding establishment and hazards ratios for breastfeeding cessation. A maternity leave of < or =6 weeks or 6 to 12 weeks after delivery was associated, respectively, with a fourfold and twofold higher odds of failure to establish breastfeeding and an increased probability of cessation after successful establishment, relative to women not returning to work, after adjusting for covariates. The impact of short postpartum leave on breastfeeding cessation was stronger among nonmanagers, women with inflexible jobs, and with high psychosocial distress. Antenatal leave in the last month of pregnancy was not associated with breastfeeding establishment or duration. Postpartum maternity leave may have a positive effect on breastfeeding among full-time workers, particularly those who hold nonmanagerial positions, lack job flexibility, or experience psychosocial distress. Pediatricians should encourage patients to take maternity leave and advocate for extending paid postpartum leave and flexibility in working conditions for breastfeeding women.

Design and Optimization of a Stationary Electrode in a Vertically-Driven MEMS Inertial Switch for Extending Contact Duration

PubMed Central

Xu, Qiu; Yang, Zhuo-Qing; Fu, Bo; Bao, Yan-Ping; Wu, Hao; Sun, Yun-Na; Zhao, Meng-Yuan; Li, Jian; Ding, Gui-Fu; Zhao, Xiao-Lin

2017-01-01

A novel micro-electro-mechanical systems (MEMS) inertial microswitch with a flexible contact-enhanced structure to extend the contact duration has been proposed in the present work. In order to investigate the stiffness k of the stationary electrodes, the stationary electrodes with different shapes, thickness h, width b, and length l were designed, analyzed, and simulated using ANSYS software. Both the analytical and the simulated results indicate that the stiffness k increases with thickness h and width b, while decreasing with an increase of length l, and it is related to the shape. The inertial micro-switches with different kinds of stationary electrodes were simulated using ANSYS software and fabricated using surface micromachining technology. The dynamic simulation indicates that the contact time will decrease with the increase of thickness h and width b, but increase with the length l, and it is related to the shape. As a result, the contact time decreases with the stiffness k of the stationary electrode. Furthermore, the simulated results reveal that the stiffness k changes more rapidly with h and l compared to b. However, overlarge dimension of the whole microswitch is contradicted with small footprint area expectation in the structure design. Therefore, it is unreasonable to extend the contact duration by increasing the length l excessively. Thus, the best and most convenient way to prolong the contact time is to reduce the thickness h of the stationary electrode while keeping the plane geometric structure of the inertial micro-switch unchanged. Finally, the fabricated micro-switches with different shapes of stationary electrodes have been evaluated by a standard dropping hammer system. The test maximum contact time under 288 g acceleration can reach 125 µs. It is shown that the test results are in accordance with the simulated results. The conclusions obtained in this work can provide guidance for the future design and fabrication of inertial microswitches. PMID:28272330

Design and Optimization of a Stationary Electrode in a Vertically-Driven MEMS Inertial Switch for Extending Contact Duration.

PubMed

Xu, Qiu; Yang, Zhuo-Qing; Fu, Bo; Bao, Yan-Ping; Wu, Hao; Sun, Yun-Na; Zhao, Meng-Yuan; Li, Jian; Ding, Gui-Fu; Zhao, Xiao-Lin

2017-03-07

A novel micro-electro-mechanical systems (MEMS) inertial microswitch with a flexible contact-enhanced structure to extend the contact duration has been proposed in the present work. In order to investigate the stiffness k of the stationary electrodes, the stationary electrodes with different shapes, thickness h , width b , and length l were designed, analyzed, and simulated using ANSYS software. Both the analytical and the simulated results indicate that the stiffness k increases with thickness h and width b , while decreasing with an increase of length l , and it is related to the shape. The inertial micro-switches with different kinds of stationary electrodes were simulated using ANSYS software and fabricated using surface micromachining technology. The dynamic simulation indicates that the contact time will decrease with the increase of thickness h and width b , but increase with the length l , and it is related to the shape. As a result, the contact time decreases with the stiffness k of the stationary electrode. Furthermore, the simulated results reveal that the stiffness k changes more rapidly with h and l compared to b . However, overlarge dimension of the whole microswitch is contradicted with small footprint area expectation in the structure design. Therefore, it is unreasonable to extend the contact duration by increasing the length l excessively. Thus, the best and most convenient way to prolong the contact time is to reduce the thickness h of the stationary electrode while keeping the plane geometric structure of the inertial micro-switch unchanged. Finally, the fabricated micro-switches with different shapes of stationary electrodes have been evaluated by a standard dropping hammer system. The test maximum contact time under 288 g acceleration can reach 125 µs. It is shown that the test results are in accordance with the simulated results. The conclusions obtained in this work can provide guidance for the future design and fabrication of inertial microswitches.

Rescaling of temporal expectations during extinction

PubMed Central

Drew, Michael R.; Walsh, Carolyn; Balsam, Peter D

2016-01-01

Previous research suggests that extinction learning is temporally specific. Changing the CS duration between training and extinction can facilitate the loss of the CR within the extinction session but impairs long-term retention of extinction. In two experiments using conditioned magazine approach with rats, we examined the relation between temporal specificity of extinction and CR timing. In Experiment 1 rats were trained on a 12-s, fixed CS-US interval and then extinguished with CS presentations that were 6, 12, or 24 s in duration. The design of Experiment 2 was the same except rats were trained using partial rather than continuous reinforcement. In both experiments, extending the CS duration in extinction facilitated the diminution of CRs during the extinction session, but shortening the CS duration failed to slow extinction. In addition, extending (but not shortening) the CS duration caused temporal rescaling of the CR, in that the peak CR rate migrated later into the trial over the course of extinction training. This migration partially accounted for the faster loss of the CR when the CS duration was extended. Results are incompatible with the hypothesis that extinction is driven by cumulative CS exposure and suggest that temporally extended nonreinforced CS exposure reduces conditioned responding via temporal displacement rather than through extinction per se. PMID:28045291

Muscle metabolic responses during high-intensity intermittent exercise measured by 31P-MRS: relationship to the critical power concept

PubMed Central

Chidnok, Weerapong; DiMenna, Fred J.; Fulford, Jonathan; Bailey, Stephen J.; Skiba, Philip F.; Vanhatalo, Anni

2013-01-01

We investigated the responses of intramuscular phosphate-linked metabolites and pH (as assessed by 31P-MRS) during intermittent high-intensity exercise protocols performed with different recovery-interval durations. Following estimation of the parameters of the power-duration relationship, i.e., the critical power (CP) and curvature constant (W′), for severe-intensity constant-power exercise, nine male subjects completed three intermittent exercise protocols to exhaustion where periods of high-intensity constant-power exercise (60 s) were separated by different durations of passive recovery (18 s, 30 s and 48 s). The tolerable duration of exercise was 304 ± 68 s, 516 ± 142 s, and 847 ± 240 s for the 18-s, 30-s, and 48-s recovery protocols, respectively (P < 0.05). The work done >CP (W>CP) was significantly greater for all intermittent protocols compared with the subjects' W′, and this difference became progressively greater as recovery-interval duration was increased. The restoration of intramuscular phosphocreatine concentration during recovery was greatest, intermediate, and least for 48 s, 30 s, and 18 s of recovery, respectively (P < 0.05). The W>CP in excess of W′ increased with greater durations of recovery, and this was correlated with the mean magnitude of muscle phosphocreatine reconstitution between work intervals (r = 0.61; P < 0.01). The results of this study show that during intermittent high-intensity exercise, recovery intervals allow intramuscular homeostasis to be restored, with the degree of restoration being related to the duration of the recovery interval. Consequently, and consistent with the intermittent CP model, the ability to perform W>CP during intermittent high-intensity exercise and, therefore, exercise tolerance, increases when recovery-interval duration is extended. PMID:24068048

Transforming from Traditional to Collaborative Collective Bargaining: A Case Study of Successful Contract Negotiations and Leadership Styles in Three Pennsylvania School Districts

ERIC Educational Resources Information Center

Dill, Robert W.

2017-01-01

Since 1970, with the passage of Act 195 of 1970, collective bargaining in Pennsylvania has been an integral process in public schools (PSBA Bulletin, 2010). The success or failure of that process extends beyond the contract's duration; it becomes engrained in the school's culture and is noticeable to those who work, study, and live within the…

Managers’ Practices Related to Work–Family Balance Predict Employee Cardiovascular Risk and Sleep Duration in Extended Care Settings

PubMed Central

Berkman, Lisa F.; Buxton, Orfeu; Ertel, Karen; Okechukwu, Cassandra

2012-01-01

An increasing proportion of U.S. workers have family caregiving responsibilities. The purpose of this study was to determine whether employees in extended care settings whose managers are supportive, open, and creative about work–family needs, such as flexibility with work schedules, have lower cardiovascular disease (CVD) risk and longer sleep than their less supported counterparts. From semistructured interviews with managers, we constructed a work–family balance score of manager openness and creativity in dealing with employee work–family needs. Trained interviewers collected survey and physiologic outcome data from 393 employees whose managers had a work–family score. Employee outcomes are sleep duration (actigraphy) and CVD risk assessed by blood cholesterol, high glycosylated hemoglobin/diabetes, blood pressure/hypertension, body-mass index, and tobacco consumption. Employees whose managers were less supportive slept less (29 min/day) and were over twice as likely to have 2 or more CVD risk factors (ORs = 2.1 and 2.03 for low and middle manager work–family scores, respectively) than employees whose managers were most open and creative. Employees who provide direct patient care exhibited particularly elevated CVD risk associated with low manager work–family score. Managers’ attitudes and practices may affect employee health, including sleep duration and CVD risk. PMID:20604637

The behaviour of extended duties dental nurses and the acceptance of fluoride varnish application in preschool children.

PubMed

Zhou, Y; Forbes, G M; Macpherson, L M D; Ball, G E; Humphris, G M

2012-12-01

Extended duties dental nurses (EDDNs) have been trained to deliver fluoride varnish applications to preschool children as part of the Childsmile initiative in Scotland. To determine a detailed behavioural profile of the EDDNs during the administration of the fluoride varnish to confirm professional manner and identify differences in nurse behaviours between successful and unsuccessful application sessions. Nurse-child interactions were video recorded and nurse behaviours coded and analysed using a specially developed coding scheme (SABICS). Behaviour frequency and duration were measured and correlations were calculated. Differences in behaviour were examined between successful and unsuccessful application sessions. Three hundred and three interactions were coded out of 456 recorded application sessions. No incident occurred where nurses threatened or placed undue stress on a child. In unsuccessful, compared with successful, application sessions, nurses demonstrated higher frequency and duration of the following behaviours: 'permission seeking', 'offer of task alternative', 'information seeking' and 'reassurance', controlling for length of procedure. Whereas with successful applications, 'praise', 'instruction' and 'information-giving' were used more frequently and for a longer duration, compared with unsuccessful applications. The EDDNs demonstrated a professional manner working with preschool children. They behaved differently between successful and unsuccessful application sessions. Sequential analysis is needed to examine causal effects of behaviours and its effects on delivery outcomes.

Chronic sleep curtailment, even without extended (>16-h) wakefulness, degrades human vigilance performance.

PubMed

McHill, Andrew W; Hull, Joseph T; Wang, Wei; Czeisler, Charles A; Klerman, Elizabeth B

2018-06-05

Millions of individuals routinely remain awake for more than 18 h daily, which causes performance decrements. It is unknown if these functional impairments are the result of that extended wakefulness or from the associated shortened sleep durations. We therefore examined changes in objective reaction time performance and subjective alertness in a 32-d inpatient protocol in which participants were scheduled to wakefulness durations below 16 h while on a 20-h "day," with randomization into standard sleep:wake ratio (1:2) or chronic sleep restriction (CSR) ratio (1:3.3) conditions. This protocol allowed determination of the contribution of sleep deficiency independent of extended wakefulness, since individual episodes of wakefulness in the CSR condition were only 15.33 h in duration (less than the usual 16 h of wakefulness in a 24-h day) and sleep episodes were 4.67 h in duration each cycle. We found that chronic short sleep duration, even without extended wakefulness, doubled neurobehavioral reaction time performance and increased lapses of attention fivefold, yet did not uniformly decrease self-reported alertness. Further, these impairments in neurobehavioral performance were worsened during the circadian night and were not recovered during the circadian day, indicating that the deleterious effect from the homeostatic buildup of CSR is expressed even during the circadian promotion of daytime arousal. These findings reveal a fundamental aspect of human biology: Chronic insufficient sleep duration equivalent to 5.6 h of sleep opportunity per 24 h impairs neurobehavioral performance and self-assessment of alertness, even without extended wakefulness.

78 FR 12336 - Draft Program Comment for Extending the Duration of Programmatic Agreements Based on the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-22

... ADVISORY COUNCIL ON HISTORIC PRESERVATION Draft Program Comment for Extending the Duration of... AGENCY: Advisory Council on Historic Preservation. ACTION: Notice of Intent to Issue Program Comments for... Efficiency and Conservation Block Grant (EECBG). SUMMARY: The Advisory Council on Historic Preservation (ACHP...

77 FR 31366 - Medicare Program; Semi-Annual Meeting of the Advisory Panel on Hospital Outpatient Payment (HOP...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-25

.... Submission Instructions for Presentations and Comments Because of staffing and resource limitations, we... as nonsurgical extended duration therapeutic services. All presentations will be considered public... recommend that services be designated as nonsurgical extended duration therapeutic services. The Panel may...

Countermeasures to Neurobehavioral Deficits from Cumulative Partial Sleep Deprivation During Space Flight

NASA Technical Reports Server (NTRS)

Dinges, David F.

1999-01-01

This project is concerned with identifying ways to prevent neurobehavioral and physical deterioration due to inadequate sleep in astronauts during long-duration manned space flight. The performance capability of astronauts during extended-duration space flight depends heavily on achieving recovery through adequate sleep. Even with appropriate circadian alignment, sleep loss can erode fundamental elements of human performance capability including vigilance, cognitive speed and accuracy, working memory, reaction time, and physiological alertness. Adequate sleep is essential during manned space flight not only to ensure high levels of safe and effective human performance, but also as a basic regulatory biology critical to healthy human functioning. There is now extensive objective evidence that astronaut sleep is frequently restricted in space flight to averages between 4 hr and 6.5 hr/day. Chronic sleep restriction during manned space flight can occur in response to endogenous disturbances of sleep (motion sickness, stress, circadian rhythms), environmental disruptions of sleep (noise, temperature, light), and curtailment of sleep due to the work demands and other activities that accompany extended space flight operations. The mechanism through which this risk emerges is the development of cumulative homeostatic pressure for sleep across consecutive days of inadequate sleep. Research has shown that the physiological sleepiness and performance deficits engendered by sleep debt can progressively worsen (i.e., accumulate) over consecutive days of sleep restriction, and that sleep limited to levels commonly experienced by astronauts (i.e., 4 - 6 hr per night) for as little as 1 week, can result in increased lapses of attention, degradation of response times, deficits in complex problem solving, reduced learning, mood disturbance, disruption of essential neuroendocrine, metabolic, and neuroimmune responses, and in some vulnerable persons, the emergence of uncontrolled sleep attacks. The prevention of cumulative performance deficits and neuroendocrine disruption from sleep restriction during extended duration space flight involves finding the most effective ways to obtain sleep in order to maintain the high-level cognitive and physical performance functions required for manned space flight. There is currently a critical deficiency in knowledge of the effects of how variations in sleep duration and timing relate to the most efficient return of performance per unit time invested in sleep during long-duration missions, and how the nature of sleep physiology (i.e., sleep stages, sleep electroencephalographic [EEG] power spectral analyses) change as a function of sleep restriction and performance degradation. The primary aim of this project is to meet these critical deficiencies through utilization of a response surface experimental paradigm, testing in a dose-response manner, varying combinations of sleep duration and timing, for the purpose of establishing how to most effectively limit the cumulative adverse effects on human performance and physiology of chronic sleep restriction in space operations.

Flexibility in Postgraduate Medical Training in the Netherlands.

PubMed

Hoff, Reinier G; Frenkel, Joost; Imhof, Saskia M; Ten Cate, Olle

2018-03-01

Postgraduate medical training in the Netherlands has become increasingly individualized. In this article, the authors describe current practices for three residency programs at the University Medical Center Utrecht: anesthesiology, pediatrics, and ophthalmology. These programs are diverse yet share characteristics allowing for individualized residency training. New residents enter each program throughout the year, avoiding a large simultaneous influx of inexperienced doctors. The usual duration of each is five years. However, the actual duration of rotations or of the program as a whole can be reduced because of residents' previous medical experience or demonstration of early mastery of relevant competencies. If necessary, the duration of training can also increase.Although working hours are already restricted by the European Working Time Directive, most residents choose to train on a part-time basis. The length of their program then is extended proportionally. The extension period added for those residents training part-time can be used to develop specific competencies, complete an elective rotation or research, or explore a focus area. If the resident meets all training objectives before the extension period is completed, the program director can choose to shorten the program length. Recently, entrustable professional activities have been introduced to strengthen workplace-based assessment. The effects on program duration have yet to be demonstrated.Flexible postgraduate training is feasible. Although improving work-life balance for residents is a necessity, attention must be paid to ensuring that they gain the necessary experience and competencies and maintain continuity of care to ensure that high-quality patient care is provided.

Human area MT+ shows load-dependent activation during working memory maintenance with continuously morphing stimulation.

PubMed

Galashan, Daniela; Fehr, Thorsten; Kreiter, Andreas K; Herrmann, Manfred

2014-07-11

Initially, human area MT+ was considered a visual area solely processing motion information but further research has shown that it is also involved in various different cognitive operations, such as working memory tasks requiring motion-related information to be maintained or cognitive tasks with implied or expected motion.In the present fMRI study in humans, we focused on MT+ modulation during working memory maintenance using a dynamic shape-tracking working memory task with no motion-related working memory content. Working memory load was systematically varied using complex and simple stimulus material and parametrically increasing retention periods. Activation patterns for the difference between retention of complex and simple memorized stimuli were examined in order to preclude that the reported effects are caused by differences in retrieval. Conjunction analysis over all delay durations for the maintenance of complex versus simple stimuli demonstrated a wide-spread activation pattern. Percent signal change (PSC) in area MT+ revealed a pattern with higher values for the maintenance of complex shapes compared to the retention of a simple circle and with higher values for increasing delay durations. The present data extend previous knowledge by demonstrating that visual area MT+ presents a brain activity pattern usually found in brain regions that are actively involved in working memory maintenance.

Higher Education as an Extended Duration Service: An Investigation of the Determinants of Vietnamese Overseas Student Loyalty

ERIC Educational Resources Information Center

Pham, Hiep-Hung; Lai, Sue Ling

2016-01-01

Regarding higher education as a type of extended duration service, this article proposes a framework considering adjusted expectation, disconfirmation, satisfaction, and commitment in a conceptual model to explain international student loyalty. Employing a structure equation model to the sample data collected from 252 Vietnam overseas students…

20 CFR 336.15 - How to claim extended benefits.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false How to claim extended benefits. 336.15... INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.15 How to claim extended... unemployment or normal sickness benefits and who wishes to claim extended unemployment or extended sickness...

20 CFR 336.15 - How to claim extended benefits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false How to claim extended benefits. 336.15... INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.15 How to claim extended... unemployment or normal sickness benefits and who wishes to claim extended unemployment or extended sickness...

20 CFR 336.15 - How to claim extended benefits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false How to claim extended benefits. 336.15... INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.15 How to claim extended... unemployment or normal sickness benefits and who wishes to claim extended unemployment or extended sickness...

Extended-duration venous thromboembolism prophylaxis in acutely ill medical patients with recently reduced mobility: a randomized trial.

PubMed

Hull, Russell D; Schellong, Sebastian M; Tapson, Victor F; Monreal, Manuel; Samama, Meyer-Michel; Nicol, Philippe; Vicaut, Eric; Turpie, Alexander G G; Yusen, Roger D

2010-07-06

Extended-duration low-molecular-weight heparin has been shown to prevent venous thromboembolism (VTE) in high-risk surgical patients. To evaluate the efficacy and safety of extended-duration enoxaparin thromboprophylaxis in acutely ill medical patients. Randomized, parallel, placebo-controlled trial. Randomization was computer-generated. Allocation was centralized. Patients, caregivers, and outcome assessors were blinded to group assignment. (ClinicalTrials.gov registration number: NCT00077753) SETTING: 370 sites in 20 countries across North and South America, Europe, and Asia. Acutely ill medical patients 40 years or older with recently reduced mobility (bed rest or sedentary without [level 1] or with [level 2] bathroom privileges). Eligibility criteria for patients with level 2 immobility were amended to include only those who had additional VTE risk factors (age >75 years, history of VTE, or active or previous cancer) after interim analyses suggested lower-than-expected VTE rates. Enoxaparin, 40 mg/d subcutaneously (2975 patients), or placebo (2988 patients), for 28 +/- 4 days after receiving open-label enoxaparin for an initial 10 +/- 4 days. Incidence of VTE up to day 28 and of major bleeding events up to 48 hours after the last study treatment dose. Extended-duration enoxaparin reduced VTE incidence compared with placebo (2.5% vs. 4%; absolute risk difference favoring enoxaparin, -1.53% [95.8% CI, -2.54% to -0.52%]). Enoxaparin increased major bleeding events (0.8% vs. 0.3%; absolute risk difference favoring placebo, 0.51% [95% CI, 0.12% to 0.89%]). The benefits of extended-duration enoxaparin seemed to be restricted to women, patients older than 75 years, and those with level 1 immobility. Estimates of efficacy and safety for the overall trial population are difficult to interpret because of the change in eligibility criteria during the trial. Use of extended-duration enoxaparin reduces VTE more than it increases major bleeding events in acutely ill medical patients with level 1 immobility, those older than 75 years, and women. Sanofi-aventis.

Extended duration Orbiter life support definition

NASA Technical Reports Server (NTRS)

Kleiner, G. N.; Thompson, C. D.

1978-01-01

Extending the baseline seven-day Orbiter mission to 30 days or longer and operating with a solar power module as the primary source for electrical power requires changes to the existing environmental control and life support (ECLS) system. The existing ECLS system imposes penalties on longer missions which limit the Orbiter capabilities and changes are required to enhance overall mission objectives. Some of these penalties are: large quantities of expendables, the need to dump or store large quantities of waste material, the need to schedule fuel cell operation, and a high landing weight penalty. This paper presents the study ground rules and examines the limitations of the present ECLS system against Extended Duration Orbiter mission requirements. Alternate methods of accomplishing ECLS functions for the Extended Duration Orbiter are discussed. The overall impact of integrating these options into the Orbiter are evaluated and significant Orbiter weight and volume savings with the recommended approaches are described.

20 CFR 336.15 - How to claim extended benefits.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true How to claim extended benefits. 336.15 Section... INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.15 How to claim extended... unemployment or normal sickness benefits and who wishes to claim extended unemployment or extended sickness...

20 CFR 336.15 - How to claim extended benefits.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true How to claim extended benefits. 336.15 Section... INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.15 How to claim extended... unemployment or normal sickness benefits and who wishes to claim extended unemployment or extended sickness...

20 CFR 336.14 - Extended benefit period.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Extended benefit period. 336.14 Section 336... INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.14 Extended benefit period. (a) Defined. An extended benefit period consists of seven consecutive 14-day registration periods. (b...

20 CFR 336.14 - Extended benefit period.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Extended benefit period. 336.14 Section 336... INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.14 Extended benefit period. (a) Defined. An extended benefit period consists of seven consecutive 14-day registration periods. (b...

20 CFR 336.14 - Extended benefit period.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Extended benefit period. 336.14 Section 336.14... DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.14 Extended benefit period. (a) Defined. An extended benefit period consists of seven consecutive 14-day registration periods. (b) Beginning...

20 CFR 336.14 - Extended benefit period.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Extended benefit period. 336.14 Section 336.14... DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.14 Extended benefit period. (a) Defined. An extended benefit period consists of seven consecutive 14-day registration periods. (b) Beginning...

20 CFR 336.14 - Extended benefit period.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Extended benefit period. 336.14 Section 336.14 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.14 Extended benefit period...

Medical leave granted to psychiatric inpatients--a one-year retrospective review.

PubMed

Koh, K G; Ang, A W

2000-09-01

Of the 676 patients warded in 1998 at the National University Hospital (NUH) Department of Psychological Medicine, over a third (n = 268) required certification of absence from work. Duration of inpatient stay and immediate post-discharge medical leave were examined for this group. These durations were correlated against the patients' diagnoses and their demographic variables. The mental health morbidity of teachers was specifically studied. In this retrospective study, we used medical certificate counterfoils to determine the lengths of admission and post-discharge medical leave duration. ANOVA and Kruskal-Wallis tests of the SPSS computer package were used for statistical analysis. The sex and marital status of these patients did not affect either duration significantly. However, those 45 years and older were granted longer outpatient medical leave. Patients diagnosed with mood and psychotic disorders required longer inpatient stay and were granted longer outpatient medical leave, as compared with other diagnostic groups. It was found that the teachers admitted were largely 45 years and older, had a diagnosis of depression and required extended periods of outpatient medical leave compared to other occupational groups. The mean number of days of inpatient stay and outpatient medical leave may serve as a helpful guideline of current practice. As introduced in this paper, the use of medical certificate counterfoils is a simple yet effective way of measuring days off-work. With the inclusion of those psychiatric patients not working and the medical leave granted long after discharge, calculations of the economic costs of specific mental disorders to Singapore can then be attempted.

Work environment, overtime and sleep among offshore personnel.

PubMed

Parkes, Katharine R

2017-02-01

Personnel working on North Sea oil/gas installations are exposed to remote and potentially hazardous environments, and to extended work schedules (typically, 14×12h shifts). Moreover, overtime (additional to the standard 84-h week) is not uncommon among offshore personnel. Evidence from onshore research suggests that long work hours and adverse environmental characteristics are associated with sleep impairments, and consequently with health and safety risks, including accidents and injuries. However, little is known about the extent to which long hours and a demanding work environment combine synergistically in relation to sleep. The present study sought to address this issue, using survey data collected from offshore day-shift personnel (N=551). The multivariate analysis examined the additive and interactive effects of overtime and measures of the psychosocial/physical work environment (job demands, job control, supervisor support, and physical stressors) as predictors of sleep outcomes during offshore work weeks. Control variables, including age and sleep during leave weeks, were also included in the analysis model. Sleep duration and quality were significantly impaired among those who worked overtime (54% of the participants) relative to those who worked only 12-h shifts. A linear relationship was found between long overtime hours and short sleep duration; personnel who worked >33h/week overtime reported <6h/day sleep. Significant interactions were also found; sleep duration was negatively related to job demands, and positively related to supervisor support, only among personnel who worked overtime. Poor sleep quality was predicted by the additive effects of overtime, low support and an adverse physical environment. These findings highlight the need to further examine the potential health and safety consequences of impaired sleep associated with high overtime rates offshore, and to identify the extent to which adverse effects of overtime can be mitigated by favourable physical and psychosocial work environment characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Judgments of duration, figure-ground contrast, and size for words and nonwords.

PubMed

Reber, Rolf; Zimmermann, Thomas D; Wurtz, Pascal

2004-10-01

Does the word-superiority effect on letter discrimination result in a word-superiority effect on duration judgments? We examined this question in five experiments. In the first four experiments, we have demonstrated that (1) words shown for 32-80 msec were judged as presented longer than non-words shown for the same duration; (2) this word-superiority effect persists if the stimuli are shown for an objective duration of up to 250 msec; and (3) these effects can be extended to judgments of figure-ground contrast and letter size. These findings extend existing data on effects of processing fluency on perceptual judgments. In Experiment 5, we found that duration judgments were higher for words than for pronounceable nonwords, and duration judgments were higher for pronounceable non-words than for nonpronounceable nonwords. We discuss the implications of this finding for the discrepancy-attribution hypothesis.

20 CFR 336.2 - Duration of normal unemployment benefits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the waiting...

20 CFR 336.2 - Duration of normal unemployment benefits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the waiting...

20 CFR 336.2 - Duration of normal unemployment benefits.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the waiting...

20 CFR 336.2 - Duration of normal unemployment benefits.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the waiting...

20 CFR 336.2 - Duration of normal unemployment benefits.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the waiting...

38 CFR 21.74 - Extended evaluation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Extended evaluation. 21... Duration of Rehabilitation Programs § 21.74 Extended evaluation. (a) General. An extended evaluation may be... reasonably feasible for the veteran. The services which may be provided during the period of extended...

38 CFR 21.74 - Extended evaluation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Extended evaluation. 21... Duration of Rehabilitation Programs § 21.74 Extended evaluation. (a) General. An extended evaluation may be... reasonably feasible for the veteran. The services which may be provided during the period of extended...

38 CFR 21.74 - Extended evaluation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Extended evaluation. 21... Duration of Rehabilitation Programs § 21.74 Extended evaluation. (a) General. An extended evaluation may be... reasonably feasible for the veteran. The services which may be provided during the period of extended...

38 CFR 21.74 - Extended evaluation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Extended evaluation. 21... Duration of Rehabilitation Programs § 21.74 Extended evaluation. (a) General. An extended evaluation may be... reasonably feasible for the veteran. The services which may be provided during the period of extended...

38 CFR 21.74 - Extended evaluation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Extended evaluation. 21... Duration of Rehabilitation Programs § 21.74 Extended evaluation. (a) General. An extended evaluation may be... reasonably feasible for the veteran. The services which may be provided during the period of extended...

Work-leave rotation pattern and incidence of offshore workplace injury.

PubMed

Massey, S

2018-05-17

Studies on work-leave rotation pattern and work place injuries among offshore oil and gas workers have been few and limited to a 2- or 3-week rotation schedule. To examine incidence of workplace injury in relation to the duration of time into work rotation for extended work schedules up to 24 weeks. Six-year injury data on four offshore installations were extracted. Data were analysed for incidence of injury over time and relative risk using linear trend lines and regression. In total, 311 injuries for 1302 workers were analysed, 39% with rotation schedule of 4 weeks work and 4 weeks rest, 27% 8 weeks work and 4 weeks rest, 23% 16 weeks work and 4 weeks rest and 10% 24 weeks work and 4 weeks rest. Incidence of injury decreased as duration of time into the work rotation increased, corrected for exposure, and this was statistically significant for all rotations in first 4 weeks (P < 0.01). Negative correlation between time offshore and injury was observed in all schedules and consistent for age groups, categories of work, shifts and severity of injury. There was no difference in relative risk of injuries between the four schedules, when corrected for exposure and occupational risk of injury. These results are at variance with previous studies, although no prior study has looked beyond 3-week rotation schedule. Longer offshore schedules are safely possible and this could help decrease manpower and logistics costs for oil and gas companies coping with unprecedented low oil prices.

Comparison of limb kinematics between collected and lengthened (medium/extended) trot in two groups of dressage horses on two different surfaces.

PubMed

Walker, V A; Tranquille, C A; Newton, J R; Dyson, S J; Brandham, J; Northrop, A J; Murray, R C

2017-09-01

Dressage horses are often asked to work in lengthened paces during training and competition, but to date there is limited information about the biomechanics of dressage-specific paces. Preliminary work has shown increased fetlock extension in extended compared with collected paces, but further investigation of the kinematic differences between collected, medium and extended trot in dressage horses is warranted. Investigation of the effect of collected vs. medium/extended trot on limb kinematics of dressage horses. Prospective kinematic evaluation. Twenty clinically sound horses in active dressage training were used. Group 1: Ten young horses (≤6 years) were assessed at collected and medium trot and Group 2: Ten mature horses (≥9 years) were assessed at collected and extended trot. All horses were evaluated on two different surfaces. High speed motion capture (240 Hz) was used to determine kinematic variables. Fore- and hindlimb angles were measured at mid-stance. Descriptive statistics and mixed effect multilevel regression analyses were performed. Speed and stride length were reduced and stride duration increased at collected compared with medium/extended trot. Lengthened trot (medium/extended trot) was associated with increased fetlock extension in both the fore- and hindlimbs in both groups of horses. Changes were greater in mature horses compared with young horses. Shoulder and carpus angles were associated with forelimb fetlock angle. Hock angle was not significantly influenced by pace. Surface had no effect on fetlock or hock angles. Only 2D motion analysis was carried out. Results may have differed in horses with more extreme gait characteristics. Medium/extended trot increases extension of the fore- and hindlimb fetlock joints compared with collected trot in both young and mature dressage horses, respectively. © 2017 EVJ Ltd.

NASA's extended duration orbiter medical program

NASA Technical Reports Server (NTRS)

Pool, Sam Lee; Sawin, Charles F.

1992-01-01

The physiological issues involved in safely extending Shuttle flights from 10 to 16 days have been viewed by some as academic. After all, they reasoned, humans already have lived and worked in space for periods exceeding even 28 days in the United States Skylab Program and onboard the Russian space stations. The difference in the Shuttle program is in the physical position of the astronauts as they reenter the Earth's atmosphere. Crewmembers in the earlier Apollo, Skylab, and Russian programs were returned to Earth in the supine position. Space Shuttle crewmembers, in contrast, are seated upright during reentry and landing; reexperiencing the Earth's g forces in this position has far more pronounced effects on the crewmember's physiological functions. The goal of the Extended Duration Orbiter (EDO) Medical Project (EDOMP) has been to ensure that crewmembers maintain physiological reserves sufficient to perform entry, landing, and egress safely. Early in the Shuttle Program, it became clear that physiological deconditioning during space flight could produce significant symptoms upon return to Earth. The signs and symptoms observed during the entry, landing, and egress after Shuttle missions have included very high heart rates and low blood pressures upon standing. Dizziness, 'graying out,' and fainting have occurred on ambulation or shortly thereafter. Other symptoms at landing have included headache, light-headedness, nausea and vomitting, leg cramping, inability to stand for several minutes after wheel-stop, and unsteadiness of gait.

Prophylactic surgery prior to extended-duration space flight: Is the benefit worth the risk?

PubMed Central

Ball, Chad G.; Kirkpatrick, Andrew W.; Williams, David R.; Jones, Jeffrey A.; Polk, J.D.; Vanderploeg, James M.; Talamini, Mark A.; Campbell, Mark R.; Broderick, Timothy J.

2012-01-01

This article explores the potential benefits and defined risks associated with prophylactic surgical procedures for astronauts before extended-duration space flight. This includes, but is not limited to, appendectomy and cholecystesctomy. Furthermore, discussion of treatment during space flight, potential impact of an acute illness on a defined mission and the ethical issues surrounding this concept are debated in detail. PMID:22564516

A Proposed Change to ITU-R Recommendation 681

NASA Technical Reports Server (NTRS)

Davarian, F.

1996-01-01

Recommendation 681 of the International Telecommunications Union (ITU) provides five models for the prediction of propagation effects on land mobile satellite links: empirical roadside shadowing (ERS), attenuation frequency scaling, fade duration distribution, non-fade duration distribution, and fading due to multipath. Because the above prediction models have been empirically derived using a limited amount of data, these schemes work only for restricted ranges of link parameters. With the first two models, for example, the frequency and elevation angle parameters are restricted to 0.8 to 2.7 GHz and 20 to 60 degrees, respectively. Recently measured data have enabled us to enhance the range of the first two schemes. Moreover, for convenience, they have been combined into a single scheme named the extended empirical roadside shadowing (EERS) model.

The human cardiovascular system during space flight

NASA Astrophysics Data System (ADS)

Grigoriev, A. I.; Kotovskaya, A. R.; Fomina, G. A.

2011-05-01

Purpose of the work is to analyze and to summarize the data of investigations into human hemodynamics performed over 20 years aboard orbital stations Salyut-7 and Mir with participation of 26 cosmonauts on space flights (SF) from 8 to 438 days in duration. The ultrasonic techniques and occlusive plethysmography demonstrated dynamics of changes in the cardiovascular system during SF of various durations. The parameters of general hemodynamics, the pumping function of the heart and arterial circulation in the brain remained stable in all the space flights; however, there were alterations in peripheral circulation associated with blood redistribution and hypovolemie in microgravity. The anti-gravity distribution of the vascular tone decayed gradually as unneeded. The most considerable changes were observed in leg vessels, equally in arteries (decrease in resistance) and veins (increase in maximum capacity). The lower body negative pressure test (LBNP) revealed deterioration of the gravity-dependent reactions that changed for the worse as SF duration extended. The cardiovascular deconditioning showed itself as loss of descent acceleration tolerance and orthostatic instability in the postflight period.

Domestic dog roaming patterns in remote northern Australian indigenous communities and implications for disease modelling.

PubMed

Hudson, Emily G; Brookes, Victoria J; Dürr, Salome; Ward, Michael P

2017-10-01

Although Australia is canine rabies free, the Northern Peninsula Area (NPA), Queensland and other northern Australian communities are at risk of an incursion due to proximity to rabies infected islands of Indonesia and existing disease spread pathways. Northern Australia also has large populations of free-roaming domestic dogs, presenting a risk of rabies establishment and maintenance should an incursion occur. Agent-based rabies spread models are being used to predict potential outbreak size and identify effective control strategies to aid incursion preparedness. A key component of these models is knowledge of dog roaming patterns to inform contact rates. However, a comprehensive understanding of how dogs utilise their environment and the heterogeneity of their movements to estimate contact rates is lacking. Using a novel simulation approach - and GPS data collected from 21 free-roaming domestic dogs in the NPA in 2014 and 2016 - we characterised the roaming patterns within this dog population. Multiple subsets from each individual dog's GPS dataset were selected representing different monitoring durations and a utilisation distribution (UD) and derived core (50%) and extended (95%) home ranges (HR) were estimated for each duration. Three roaming patterns were identified, based on changes in mean HR over increased monitoring durations, supported by assessment of maps of daily UDs of each dog. Stay-at-home dogs consolidated their HR around their owner's residence, resulting in a decrease in mean HR (both core and extended) as monitoring duration increased (median peak core and extended HR 0.336 and 3.696ha, respectively). Roamer dogs consolidated their core HR but their extended HR increased with longer monitoring durations, suggesting that their roaming patterns based on place of residence were more variable (median peak core and extended HR 0.391 and 6.049ha, respectively). Explorer dogs demonstrated large variability in their roaming patterns, with both core and extended HR increasing as monitoring duration increased (median peak core and extended HR 0.650 and 9.520ha, respectively). These findings are likely driven by multiple factors that have not been further investigated within this study. Different roaming patterns suggest heterogeneous contact rates between dogs in this population. These findings will be incorporated into disease-spread modelling to more realistically represent roaming patterns and improve model predictions. Copyright © 2017 Elsevier B.V. All rights reserved.

Mathematical modeling of acute and chronic cardiovascular changes during Extended Duration Orbiter (EDO) flights

NASA Technical Reports Server (NTRS)

White, Ronald J.; Leonard, Joel I.; Srinivasan, R. Srini; Charles, John B.

1991-01-01

The purpose of NASA's Extended Duration Orbiter program is a gradual extension of the capabilities of the Space Shuttle Orbiter beyond its current 7-10 day limit on mission duration, as warranted by deepening understanding of the long-term physiological effects of weightlessness. Attention is being given to the cardiovascular problem of orthostatic tolerance loss due to its adverse effects on crew performance and health during reentry and initial readaptation to earth gravity. An account is given of the results of the application of proven mathematical models of circulatory and cardiovascular systems under microgravity conditions.

Extended Duration Nocturnal Hemodialysis and Changes in Plasma Metabolite Profiles.

PubMed

Kalim, Sahir; Wald, Ron; Yan, Andrew T; Goldstein, Marc B; Kiaii, Mercedeh; Xu, Dihua; Berg, Anders H; Clish, Clary; Thadhani, Ravi; Rhee, Eugene P; Perl, Jeffrey

2018-03-07

In-center, extended duration nocturnal hemodialysis has been associated with variable clinical benefits, but the effect of extended duration hemodialysis on many established uremic solutes and other components of the metabolome is unknown. We determined the magnitude of change in metabolite profiles for patients on extended duration nocturnal hemodialysis. In a 52-week prospective, observational study, we followed 33 patients receiving conventional thrice weekly hemodialysis who converted to nocturnal hemodialysis (7-8 hours per session, three times per week). A separate group of 20 patients who remained on conventional hemodialysis (3-4 hours per session, three times per week) served as a control group. For both groups, we applied liquid chromatography-mass spectrometry-based metabolite profiling on stored plasma samples collected from all participants at baseline and after 1 year. We examined longitudinal changes in 164 metabolites among those who remained on conventional hemodialysis and those who converted to nocturnal hemodialysis using Wilcoxon rank sum tests adjusted for multiple comparisons (false discovery rate <0.05). On average, the nocturnal group had 9.6 hours more dialysis per week than the conventional group. Among 164 metabolites, none changed significantly from baseline to study end in the conventional group. Twenty-nine metabolites changed in the nocturnal group, 21 of which increased from baseline to study end (including all branched-chain amino acids). Eight metabolites decreased after conversion to nocturnal dialysis, including l-carnitine and acetylcarnitine. By contrast, several established uremic retention solutes, including p -cresol sulfate, indoxyl sulfate, and trimethylamine N -oxide, did not change with extended dialysis. Across a wide array of metabolites examined, extended duration hemodialysis was associated with modest changes in the plasma metabolome, with most differences relating to metabolite increases, despite increased dialysis time. Few metabolites showed reduction with more dialysis, and no change in several established uremic toxins was observed. Copyright © 2018 by the American Society of Nephrology.

Extended Duration Orbiter (EDO) Improved Waste Collection System (IWCS)

NASA Technical Reports Server (NTRS)

1992-01-01

This overall front view shows the Extended Duration Orbiter (EDO) Waste Collection System (WCS) scheduled to fly aboard NASA's Endeavour, Orbiter Vehicle (OV) 105, for the STS-54 mission. Detailed Test Objective 662, Extended duration orbiter WCS evaluation, will verify the design of the new EDO WCS under microgravity conditions for a prolonged period. OV-105 has been modified with additional structures in the waste management compartment (WMC) and additional avionics to support/restrain the EDO WCS. Among the advantages the new IWCS is hoped to have over the currect WCS are greater dependability, better hygiene, virtually unlimited capacity, and more efficient preparation between shuttle missions. Unlike the previous WCS, the improved version will not have to be removed from the spacecraft to be readied for the next flight. The WCS was documented in JSC's Crew Systems Laboratory Bldg 7.

Feasibility of an Extended-Duration Aerial Platform Using Autonomous Multi-Rotor Vehicle Swapping and Battery Management

DTIC Science & Technology

2017-12-01

AN EXTENDED-DURATION AERIAL PLATFORM USING AUTONOMOUS MULTI-ROTOR VEHICLE SWAPPING AND BATTERY MANAGEMENT by Alexander G. Williams December...Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time...of information . Send comments regarding this burden estimate or any other aspect of this collection of information , including suggestions for

Array Receivers and Sound Sources for Three Dimensional Shallow Water Acoustic Field Experiments

DTIC Science & Technology

2016-12-06

upgrade included improving the SHRU clocks by utilizing chip- scale atomic clocks (CSAC), enlarging battery packs to extend the operation duration, and...instrument upgrade included improving the SHRU clocks by utilizing chip-scale atomic clocks (CSAC), enlarging battery packs to extend the operation...Changing the deployment configuration to use dual pressure housings to augment the alkaline primary battery payload to achieve the one-year duration

Modeling magnetization transfer effects of Q2TIPS bolus saturation in multi-TI pulsed arterial spin labeling.

PubMed

Petr, Jan; Schramm, Georg; Hofheinz, Frank; Langner, Jens; van den Hoff, Jörg

2014-10-01

To estimate the relaxation time changes during Q2TIPS bolus saturation caused by magnetization transfer effects and to propose and evaluate an extended model for perfusion quantification which takes this into account. Three multi inversion-time pulsed arterial spin labeling sequences with different bolus saturation duration were acquired for five healthy volunteers. Magnetization transfer exchange rates in tissue and blood were obtained from control image saturation recovery. Cerebral blood flow (CBF) obtained using the extended model and the standard model was compared. A decrease of obtained CBF of 6% (10%) was observed in grey matter when the duration of bolus saturation increased from 600 to 900 ms (1200 ms). This decrease was reduced to 1.6% (2.8%) when the extended quantification model was used. Compared with the extended model, the standard model underestimated CBF in grey matter by 9.7, 15.0, and 18.7% for saturation durations 600, 900, and 1200 ms, respectively. Results for simulated single inversion-time data showed 5-16% CBF underestimation depending on blood arrival time and bolus saturation duration. Magnetization transfer effects caused by bolus saturation pulses should not be ignored when performing quantification as they can cause appreciable underestimation of the CBF. Copyright © 2013 Wiley Periodicals, Inc.

32 CFR 2103.13 - Duration of original classification.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Duration of original classification. 2103.13... DECLASSIFIED Original Classification § 2103.13 Duration of original classification. Original classification may be extended beyond six years only by officials with Top Secret classification authority. This...

Work shift duration: a review comparing eight hour and 12 hour shift systems.

PubMed

Smith, L; Folkard, S; Tucker, P; Macdonald, I

1998-04-01

Shiftwork is now a major feature of working life across a broad range of industries. The features of the shift systems operated can impact on the wellbeing, performance, and sleep of shiftworkers. This paper reviews the current state of knowledge on one major characteristic of shift rotas-namely, shift duration. Evidence comparing the relative effects of eight hour and 12 hour shifts on fatigue and job performance, safety, sleep, and physical and psychological health are considered. At the organisational level, factors such as the mode of system implementation, attitudes towards shift rotas, sickness absence and turnover, overtime, and moonlighting are discussed. Manual and electronic searches of the shiftwork research literature were conducted to obtain information on comparisons between eight hour and 12 hour shifts. The research findings are largely equivocal. The bulk of the evidence suggests few differences between eight and 12 hour shifts in the way they affect people. There may even be advantages to 12 hour shifts in terms of lower stress levels, better physical and psychological wellbeing, improved durations and quality of off duty sleep as well as improvements in family relations. On the negative side, the main concerns are fatigue and safety. It is noted that a 12 hour shift does not equate with being active for only 12 hours. There can be considerable extension of the person's time awake either side of the shift. However, the effects of longer term exposure to extended work days have been relatively uncharted in any systematic way. Longitudinal comparative research into the chronic impact of the compressed working week is needed.

Maximizing MST's inductive capability with a Bp programmable power supply

NASA Astrophysics Data System (ADS)

Chapman, B. E.; Holly, D. J.; Jacobson, C. M.; McCollam, K. J.; Morin, J. C.; Sarff, J. S.; Squitieri, A.

2016-10-01

A major goal of the MST program is the advancement of inductive control for the development of both the RFP's fusion potential and, synergistically, the predictive capability of fusion science. This entails programmable power supplies (PPS's) for the Bt and Bp circuits. A Bt PPS is already in place, allowing advanced RFP operation and the production of tokamak plasmas, and a Bp PPS prototype is under construction. To explore some of the new capabilities to be provided by the Bp PPS, the existing Bt PPS has been temporarily connected to the Bp circuit. One key result is new-found access to very low Ip (20 kA) and very low Lundquist number, S (104). At this low S, simulation of RFP plasmas with the MHD code NIMROD is readily achievable, and work toward validation of extended MHD models using NIMROD is underway with direct comparisons to these MST plasmas. The full Bp PPS will also provide higher Ip and S than presently possible, allowing MST to produce plasmas with S spanning as much as five orders of magnitude, a dramatic extension of MST's capability. In these initial tests, the PPS has also increased five-fold MST's Ip flattop duration, to about 100 ms. This, coupled with the recently demonstrated PPS ability to drive large-amplitude sinusoidal oscillations in Ip, will allow tests of extended-duration oscillating field current drive, the goal of which is ac sustainment of a quasi-dc plasma current. Work supported by US DOE.

40 CFR 122.46 - Duration of permits (applicable to State programs, see § 123.25).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Duration of permits (applicable to... ELIMINATION SYSTEM Permit Conditions § 122.46 Duration of permits (applicable to State programs, see § 123.25... in § 122.6, the term of a permit shall not be extended by modification beyond the maximum duration...

Investigation of Supercritical Water Phenomena for Space and Extraterrestrial Application

NASA Technical Reports Server (NTRS)

Hicks, Michael C.; Hegde, Uday G.; Fisher, John W.

2012-01-01

The cost of carrying or resupplying life support resources for long duration manned space exploration missions such as a mission to Mars is prohibitive and requires the development of suitable recycling technologies. Supercritical Water Oxidation (SCWO) has been identified as an attractive candidate for these extended missions because (i) pre-drying of wet waste streams is not required, (ii) product streams are relatively benign, microbially inert, and easily reclaimed, (iii) waste conversion is complete and relatively fast, and (iv) with proper design and operation, reactions can be self-sustaining. Initial work in this area at NASA was carried out at the Ames Research Center in the 1990 s with a focus on understanding the linkages between feed stock preparation (i.e., particle size and distribution) of cellulosic based waste streams and destruction rates under a range of operating temperatures and pressures. More recently, work in SCWO research for space and extra-terrestrial application has been performed at NASA s Glenn Research Center where various investigations, with a particular focus in the gravitational effects on the thermo-physical processes occurring in the bulk medium, have been pursued. In 2010 a collaborative NASA/CNES (the French Space Agency) experiment on the critical transition of pure water was conducted in the long duration microgravity environment on the International Space Station (ISS). A follow-on experiment, to study the precipitation of salt in sub-critical, trans-critical and supercritical water is scheduled to be conducted on the ISS in 2013. This paper provides a brief history of NASA s earlier work in SCWO, discusses the potential for application of SCWO technology in extended space and extraterrestrial missions, describes related research conducted on the ISS, and provides a list of future research activities to advance this technology in both terrestrial and extra-terrestrial applications.

Manned orbital systems concepts study. Book 3: Configurations for extended duration missions. [mission planning and project planning for space missions

NASA Technical Reports Server (NTRS)

1975-01-01

Mission planning, systems analysis, and design concepts for the Space Shuttle/Spacelab system for extended manned operations are described. Topics discussed are: (1) payloads, (2) spacecraft docking, (3) structural design criteria, (4) life support systems, (5) power supplies, and (6) the role of man in long duration orbital operations. Also discussed are the assembling of large structures in space. Engineering drawings are included.

Extended duration orbiter study: CO2 removal and water recovery

NASA Technical Reports Server (NTRS)

Marshall, R. D.; Ellis, G. S.; Schubert, F. H.; Wynveen, R. A.

1979-01-01

Two electrochemical depolarized carbon dioxide concentrator subsystems were evaluated against baseline lithium hydroxide for (1) the baseline orbiter when expanded to accommodate a crew of seven (mission option one), (2) an extended duration orbiter with a power extension package to reduce fuel cell expendables (mission option two), and (3) an extended duration orbiter with a full capability power module to eliminate fuel cell expendables (mission option three). The electrochemical depolarized carbon dioxide concentrator was also compared to the solid amine regenerable carbon dioxide removal concept. Water recovery is not required for Mission Option One since sufficient water is generated by the fuel cells. The vapor compression distillation subsystem was evaluated for mission option two and three only. Weight savings attainable using the vapor compression distillation subsystem for water recovery versus on-board water storage were determined. Combined carbon dioxide removal and water recovery was evaluated to determine the effect on regenerable carbon dioxide removal subsystem selection.

Extended Duration Orbiter (EDO) Improved Waste Collection System (IWCS)

NASA Technical Reports Server (NTRS)

1992-01-01

This high angle overall view shows the top side components of the Extended Duration Orbiter (EDO) Waste Collection System (WCS) scheduled to fly aboard NASA's Endeavour, Orbiter Vehicle (OV) 105, for the STS-54 mission. Detailed Test Objective 662, Extended duration orbiter WCS evaluation, will verify the design of the new EDO WCS under microgravity conditions for a prolonged period. OV-105 has been modified with additional structures in the waste management compartment (WMC) and additional avionics to support/restrain the EDO WCS. Among the advantages the new IWCS is hoped to have over the currect WCS are greater dependability, better hygiene, virtually unlimited capacity, and more efficient preparation between shuttle missions. Unlike the previous WCS, the improved version will not have to be removed from the spacecraft to be readied for the next flight. The WCS was documented in JSC's Crew Systems Laboratory Bldg 7.

21 CFR 526.1810 - Pirlimycin.

Code of Federal Regulations, 2011 CFR

2011-04-01

... be used for food regardless of treatment duration. Following infusion twice at a 24-hour interval, treated animals must not be slaughtered for 9 days. Following any extended duration of therapy (infusion...

Patient compliance with extended low molecular weight heparin injections following hip and knee arthroplasty.

PubMed

Deakin, Dan E; Mishreki, Andrew; Aslam, Nadim; Docker, Charles

2010-01-01

The use of extended duration thromboprophylaxis following hip and knee arthroplasty is becoming widespread. The aim of our study was to determine patient compliance with extended duration thromboprophylaxis using low molecular weight (LMWH) injections following hip and knee arthroplasty. 42 consecutive patients undergoing hip and knee arthroplasty were prospectively contacted during their fifth post operative week. A fully anonymised questionnaire was completed by each patient. All patients responded. One was excluded having been prescribed warfarin for pre existing atrial fibrillation. Twenty nine (71%) patients were discharged with the intention of self administering LMWH injections. Eight (20%) and four (9%) patients were discharged with the intention of administration by a relative or district nurse respectively. No patient required the person administering the injections to be changed after discharge from hospital. 90% (n=37) of patients reported not missing any doses. 10% (n=2) of patients missed one dose and 10% (n=2) missed two doses. Patient compliance with extended duration thromboprophylaxis using LMWH injections is extremely high. Oral thromboprophylaxis may be useful in the minority of patients requiring daily visits by a nurse to administer injections.

The LDEF ultra heavy cosmic ray experiment

NASA Technical Reports Server (NTRS)

Osullivan, D.; Thompson, A.; Bosch, J.; Keegan, R.; Wenzel, K.-P.; Smit, A.; Domingo, C.

1991-01-01

The Long Duration Exposure Facility (LDEF) Ultra Heavy Cosmic Ray Experiment (UHCRE) used 16 side viewing LDEF trays giving a total geometry factor for high energy cosmic rays of 30 sq m sr. The total exposure factor was 170 sq m sr y. The experiment is based on a modular array of 192 solid state nuclear track detector stacks, mounted in sets of 4 pressure vessels (3 experiment tray). The extended duration of the LDEF mission has resulted in a greatly enhanced potential scientific yield from the UHCRE. Initial scanning results indicate that at least 2000 cosmic ray nuclei with Z greater than 65 were collected, including the world's first statistically significant sample of actinides. Postflight work to date and the current status of the experiment are reviewed. Provisional results from analysis of preflight and postflight calibrations are presented.

Workshop on Exercise Prescription for Long-Duration Space Flight

NASA Technical Reports Server (NTRS)

Harris, Bernard A., Jr. (Editor); Stewart, Donald F. (Editor)

1989-01-01

The National Aeronautics and Space Administration has a dedicated history of ensuring human safety and productivity in flight. Working and living in space long term represents the challenge of the future. Our concern is in determining the effects on the human body of living in space. Space flight provides a powerful stimulus for adaptation, such as cardiovascular and musculoskeletal deconditioning. Extended-duration space flight will influence a great many systems in the human body. We must understand the process by which this adaptation occurs. The NASA is agressively involved in developing programs which will act as a foundation for this new field of space medicine. The hallmark of these programs deals with prevention of deconditioning, currently referred to as countermeasures to zero g. Exercise appears to be most effective in preventing the cardiovascular and musculoskeletal degradation of microgravity.

Resource limitation and responses to rivals in males of the fruit fly Drosophila melanogaster.

PubMed

Mason, J S; Rostant, W G; Chapman, T

2016-10-01

Diet has a profound direct and indirect effect on reproductive success in both sexes. Variation in diet quality and quantity can significantly alter the capacity of females to lay eggs and of males to deliver courtship. Here, we tested the effect of dietary resource limitation on the ability of male Drosophila melanogaster to respond adaptively to rivals by extending their mating duration. Previous work carried out under ad libitum diet conditions showed that males exposed to rivals prior to mating significantly extend mating duration, transfer more ejaculate proteins and achieve higher reproductive success. Such adaptive responses are predicted to occur because male ejaculate production may be limited. Hence, ejaculate resources require allocation across different reproductive bouts, to balance current vs. future reproductive success. However, when males suffer dietary limitation, and potentially have fewer reproductive resources to apportion, we expect adaptive allocation of responses to rivals to be minimized. We tested this prediction and found that males held on agar-only diets for 5-7 days lost the ability to extend mating following exposure to rivals. Interestingly, extended mating was retained in males held on low yeast/sugar: no sugar/yeast diet treatments, but was mostly lost when males were maintained on 'imbalanced' diets in which there was high yeast: no sugar and vice versa. Overall, the results show that males exhibit adaptive responses to rivals according to the degree of dietary resource limitation and to the ratio of individual diet components. © 2016 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.

Space station analysis study. Part 2, Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1977-01-01

Objectives of the space station program requiring the support of man in space, either in the shuttle sortie mode or in extended duration facilities are identified and analyzed. A set of functional requirements was derived to identify specific technology advancement needs, tests to be conducted, and processes to be developed. Program options are summarized for: (1) satellite power system; (2) earth services; (3) space cosmological research and development; (4) space processing and manufacturing; (5) multidiscipline science laboratory; (6) sensor development facility; (7) living and working in space; and (8) orbital depot.

Experimental Results of the EU ITER Prototype Gyrotrons

NASA Astrophysics Data System (ADS)

Gantenbein, G.; Albajar, F.; Alberti, S.; Avramidis, K.; Bin, W.; Bonicelli, T.; Bruschi, A.; Chelis, J.; Fanale, F.; Legrand, F.; Hermann, V.; Hogge, J.-P.; Illy, S.; Ioannidis, Z. C.; Jin, J.; Jelonnek, J.; Kasparek, W.; Latsas, G. P.; Lechte, C.; Lontano, M.; Pagonakis, I. G.; Rzesnicki, T.; Schlatter, C.; Schmid, M.; Tigelis, I. G.; Thumm, M.; Tran, M. Q.; Vomvoridis, J. L.; Zein, A.; Zisis, A.

2017-10-01

The European 1 MW, 170 GHz CW industrial prototype gyrotron for ECRH&CD on ITER was under test at the KIT test facility during 2016. In order to optimize the gyrotron operation, the tube was thoroughly tested in the short-pulse regime, with pulse lengths below 10 ms, for a wide range of operational parameters. The operation was extended to longer pulses with a duration of up to 180 s. In this work we present in detail the achievements and the challenges that were faced during the long-pulse experimental campaign.

21 CFR 526.1810 - Pirlimycin.

Code of Federal Regulations, 2010 CFR

2010-04-01

... regardless of treatment duration. Following infusion twice at a 24-hour interval, treated animals must not be slaughtered for 9 days. Following any extended duration of therapy (infusion longer than twice at a 24-hour...

Extending the authority for sickness certification beyond the medical profession: the importance of 'boundary work'.

PubMed

Welsh, Victoria K; Sanders, Tom; Richardson, Jane C; Wynne-Jones, Gwenllian; Jinks, Clare; Mallen, Christian D

2014-05-17

The study aimed to explore the views of general practitioners (GPs), nurses and physiotherapists towards extending the role of sickness certification beyond the medical profession in primary care. Fifteen GPs, seven nurses and six physiotherapists were selected to achieve varied respondent characteristics including sex, geographical location, service duration and post-graduate specialist training. Constant-comparative qualitative analysis of data from 28 semi-structured telephone interviews was undertaken. The majority of respondents supported the extended role concept; however members of each professional group also rejected the notion. Respondents employed four different legitimacy claims to justify their views and define their occupational boundaries in relation to sickness certification practice. Condition-specific legitimacy, the ability to adopt a holistic approach to sickness certification, system efficiency and control-related arguments were used to different degrees by each occupation. Practical suggestions for the extension of the sickness certification role beyond the medical profession are underpinned by the sociological theory of professional identity. Extending the authority to certify sickness absence beyond the medical profession is not simply a matter of addressing practical and organisational obstacles. There is also a need to consider the impact on, and preferences of, the specific occupations and their respective boundary claims. This paper explores the implications of extending the sick certification role beyond general practice. We conclude that the main policy challenge of such a move is to a) persuade GPs to relinquish this role (or to share it with other professions), and b) to understand the 'boundary work' involved.

Valuation of opportunity costs by rats working for rewarding electrical brain stimulation.

PubMed

Solomon, Rebecca Brana; Conover, Kent; Shizgal, Peter

2017-01-01

Pursuit of one goal typically precludes simultaneous pursuit of another. Thus, each exclusive activity entails an "opportunity cost:" the forgone benefits from the next-best activity eschewed. The present experiment estimates, in laboratory rats, the function that maps objective opportunity costs into subjective ones. In an operant chamber, rewarding electrical brain stimulation was delivered when the cumulative time a lever had been depressed reached a criterion duration. The value of the activities forgone during this duration is the opportunity cost of the electrical reward. We determined which of four functions best describes how objective opportunity costs, expressed as the required duration of lever depression, are translated into their subjective equivalents. The simplest account is the identity function, which equates subjective and objective opportunity costs. A variant of this function called the "sigmoidal-slope function," converges on the identity function at longer durations but deviates from it at shorter durations. The sigmoidal-slope function has the form of a hockey stick. The flat "blade" denotes a range over which opportunity costs are subjectively equivalent; these durations are too short to allow substitution of more beneficial activities. The blade extends into an upward-curving portion over which costs become discriminable and finally into the straight "handle," over which objective and subjective costs match. The two remaining functions are based on hyperbolic and exponential temporal discounting, respectively. The results are best described by the sigmoidal-slope function. That this is so suggests that different principles of intertemporal choice are involved in the evaluation of time spent working for a reward or waiting for its delivery. The subjective opportunity-cost function plays a key role in the evaluation and selection of goals. An accurate description of its form and parameters is essential to successful modeling and prediction of instrumental performance and reward-related decision making.

Passivity-based Robust Control of Aerospace Systems

NASA Technical Reports Server (NTRS)

Kelkar, Atul G.; Joshi, Suresh M. (Technical Monitor)

2000-01-01

This report provides a brief summary of the research work performed over the duration of the cooperative research agreement between NASA Langley Research Center and Kansas State University. The cooperative agreement which was originally for the duration the three years was extended by another year through no-cost extension in order to accomplish the goals of the project. The main objective of the research was to develop passivity-based robust control methodology for passive and non-passive aerospace systems. The focus of the first-year's research was limited to the investigation of passivity-based methods for the robust control of Linear Time-Invariant (LTI) single-input single-output (SISO), open-loop stable, minimum-phase non-passive systems. The second year's focus was mainly on extending the passivity-based methodology to a larger class of non-passive LTI systems which includes unstable and nonminimum phase SISO systems. For LTI non-passive systems, five different passification. methods were developed. The primary effort during the years three and four was on the development of passification methodology for MIMO systems, development of methods for checking robustness of passification, and developing synthesis techniques for passifying compensators. For passive LTI systems optimal synthesis procedure was also developed for the design of constant-gain positive real controllers. For nonlinear passive systems, numerical optimization-based technique was developed for the synthesis of constant as well as time-varying gain positive-real controllers. The passivity-based control design methodology developed during the duration of this project was demonstrated by its application to various benchmark examples. These example systems included longitudinal model of an F-18 High Alpha Research Vehicle (HARV) for pitch axis control, NASA's supersonic transport wind tunnel model, ACC benchmark model, 1-D acoustic duct model, piezo-actuated flexible link model, and NASA's Benchmark Active Controls Technology (BACT) Wing model. Some of the stability results for linear passive systems were also extended to nonlinear passive systems. Several publications and conference presentations resulted from this research.

Work shift duration: a review comparing eight hour and 12 hour shift systems

PubMed Central

Smith, L.; Folkard, S.; Tucker, P.; Macdonald, I.

1998-01-01

OBJECTIVES: Shiftwork is now a major feature of working life across a broad range of industries. The features of the shift systems operated can impact on the wellbeing, performance, and sleep of shiftworkers. This paper reviews the current state of knowledge on one major characteristic of shift rotas-namely, shift duration. Evidence comparing the relative effects of eight hour and 12 hour shifts on fatigue and job performance, safety, sleep, and physical and psychological health are considered. At the organisational level, factors such as the mode of system implementation, attitudes towards shift rotas, sickness absence and turnover, overtime, and moonlighting are discussed. METHODS: Manual and electronic searches of the shiftwork research literature were conducted to obtain information on comparisons between eight hour and 12 hour shifts. RESULTS: The research findings are largely equivocal. The bulk of the evidence suggests few differences between eight and 12 hour shifts in the way they affect people. There may even be advantages to 12 hour shifts in terms of lower stress levels, better physical and psychological wellbeing, improved durations and quality of off duty sleep as well as improvements in family relations. On the negative side, the main concerns are fatigue and safety. It is noted that a 12 hour shift does not equate with being active for only 12 hours. CONCLUSIONS: There can be considerable extension of the person's time awake either side of the shift. However, the effects of longer term exposure to extended work days have been relatively uncharted in any systematic way. Longitudinal comparative research into the chronic impact of the compressed working week is needed.   PMID:9624275

Excessive work and risk of haemorrhagic stroke: a nationwide case-control study.

PubMed

Kim, Beom Joon; Lee, Seung-Hoon; Ryu, Wi-Sun; Kim, Chi Kyung; Chung, Jong-Won; Kim, Dohoung; Park, Hong-Kyun; Bae, Hee-Joon; Park, Byung-Joo; Yoon, Byung-Woo

2013-10-01

Adverse effect of excessive work on health has been suggested previously, but it was not documented in cerebrovascular diseases. The authors investigated whether excessive working conditions would associate with increased risk of haemorrhagic stroke. A nationwide matched case-control study database, which contains 940 cases of incident haemorrhagic stroke (498 intracerebral haemorrhages and 442 sub-arachnoid haemorrhages) with 1880 gender- and age- (± 5-year) matched controls, was analysed. Work-related information based on the regular job situation, including type of occupation, regular working time, duration of strenuous activity during regular work and shift work, was gathered through face-to-face interviews. Conditional logistic regression analyses were used for the multivariable analyses. Compared with white-collar workers, blue-collar workers had a higher risk for haemorrhagic stroke (odds ratio, 1.33 [95% confidence interval, 1.06-1.66]). Longer regular working time was associated with increased risk of haemorrhagic stroke [odds ratio, 1.38 (95% confidence interval, 1.05-1.81) for 8-12 h/day; odds ratio, 1.95 (95% confidence interval, 1.33-2.86) for ≥ 13 h/day; compared with ≤ 4 h/day]. Exposure to ≥ 8 h/week of strenuous activity also associated haemorrhagic stroke risk [odds ratio, 1.61 (95% confidence interval, 1.26-2.05); compared with no strenuous activity]. Shift work was not associated with haemorrhagic stroke (P = 0.98). Positive associations between working condition indices and haemorrhagic stroke risk were consistent regardless of haemorrhagic stroke sub-types and current employment status. Blue-collar occupation, longer regular working time and extended duration of strenuous activity during work may relate to an increased risk of haemorrhagic stroke. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Development of conditioning programs for dressage horses based on time-motion analysis of competitions.

PubMed

Clayton, H M

1993-05-01

The time-motion characteristics of Canadian basic- and medium-level dressage competitions are described, and the results are applied in formulating sport-specific conditioning programs. One competition was analyzed at the six levels from basic 1 to medium 3. Each test was divided into a series of sequences based on the type and speed of activity. The durations of the sequences were measured from videotapes. The basic-level tests had fewer sequences, and they were shorter in distance and duration than the medium tests (P < 0.10), but the average speed did not differ between the two levels. It is recommended that horses competing at the basic levels be conditioned using 5-min exercise periods, with short (10-s) bursts of lengthened trot and canter included at basic 2 and above. In preparation for medium-level competitions, the duration of the work periods increases to 7 min, 10- to 12-s bursts of medium or extended trot and canter are included, and transitions are performed frequently to simulate the energy expenditure in overcoming inertia.

Extended Duration Vascular Endothelial Growth Factor Inhibition in the Eye: Failures, Successes, and Future Possibilities.

PubMed

Stewart, Michael W

2018-01-27

Vascular endothelial growth factor (VEGF) plays a pivotal role in the development of neovascularization and edema from several common chorioretinal vascular conditions. The intravitreally injected drugs (aflibercept, bevacizumab, conbercept, pegaptanib, and ranibizumab) used to treat these conditions improve the visual acuity and macular morphology in most patients. Monthly or bimonthly injections were administered in the phase III pivotal trials but physicians usually individualize therapy with pro re nata (PRN) or treat and extend regimens. Despite these lower frequency treatment regimens, frequent injections and clinic visits are still needed to produce satisfactory outcomes. Newly developed drugs and refillable reservoirs with favorable pharmacokinetic profiles may extend durations of action and require fewer office visits. However, we have learned from previous experiences that the longer durations of action seen in strategically designed phase III trials often do not translate to less frequent injections in real-life clinical practice. Unfortunately, long-acting therapies that produce soluble VEGF receptors (encapsulated cell technology and adenovirus injected DNA) have failed in phase II trials. The development of longer duration therapies remains a difficult and frustrating process, and frequent drug injections are likely to remain the standard-of-care for years to come.

Sexual conflict over the duration of copulation in Drosophila montana: why is longer better?

PubMed Central

Mazzi, Dominique; Kesäniemi, Jenni; Hoikkala, Anneli; Klappert, Kirsten

2009-01-01

Background Conflicts of interest between the sexes are increasingly recognized as an engine driving the (co-)evolution of reproductive traits. The reproductive behaviour of Drosophila montana suggests the occurrence of sexual conflict over the duration of copulation. During the last stages of copulation, females vigorously attempt to dislodge the mounting male, while males struggle to maintain genital contact and often successfully extend copulations far beyond the females' preferred duration. Results By preventing female resistance, we show that females make a substantial contribution towards shortening copulations. We staged matings under different sex ratio conditions, and provide evidence that copulation duration is a form of male reproductive investment that responds to the perceived intensity of sperm competition as predicted by game theoretical models. Further, we investigated potential benefits to persistent males, and costs to females coerced into longer matings. While males did not benefit in terms of increased progeny production by protracting copulation, female remating was delayed after long first copulations. Conclusion Copulation time is a trait subject to sexual conflict. Mating durations exceeding female optima serve males as a form of 'extended mate guarding': by inducing mating refractoriness in the female, a male extends the time over which its sperm is exclusively used to sire progeny and reduces the likelihood of the female being reinseminated by a competitor. PMID:19523190

The Effects of Extended Bedtimes on Sleep Duration and Food Desire in Overweight Young Adults: A Home-Based Intervention

PubMed Central

Tasali, Esra; Chapotot, Florian; Wroblewski, Kristen; Schoeller, Dale

2014-01-01

Introduction Sleep curtailment is an endemic behavior in modern society. Well-controlled laboratory studies have shown that sleep loss in young adults is associated with increased desire for high-calorie food and obesity risk. However, the relevance of these laboratory findings to real life is uncertain. We conducted a 3 week, within-participant, intervention study to assess the effects of extended bedtimes on sleep duration and food desire under real life conditions in individuals who are at risk for obesity. Methods Ten overweight young adults reporting average habitual sleep duration of less than 6.5 hours were studied in the home environment. Habitual bedtimes for 1-week (baseline) were followed by bedtimes extended to 8.5 hours for 2-weeks (intervention). Participants were unaware of the intervention until after the baseline period. Participants received individualized behavioural counselling on sleep hygiene on the first day of the intervention period. Sleep duration was recorded by wrist actigraphy throughout the study. Participants rated their sleepiness, vigor and desire for various foods using visual analog scales at the end of baseline and intervention periods. Results On average, participants obtained 1.6 hours more sleep with extended bedtimes (5.6 vs. 7.1; p<0.001) and reported being less sleepy (p=0.004) and more vigorous (p=0.034). Additional sleep was associated with a 14% decrease in overall appetite (p=0.030) and a 62% decrease in desire for sweet and salty foods (p=0.017). Desire for fruits, vegetables and protein-rich nutrients was not affected by added sleep. Conclusions Sleep duration can be successfully increased in real life settings and obtaining adequate sleep is associated with less desire for high calorie foods in overweight young adults who habitually curtail their sleep. PMID:24858836

Maternal pre-pregnancy obesity and risk for inattention and negative emotionality in children.

PubMed

Rodriguez, Alina

2010-02-01

This study aimed to replicate and extend previous work showing an association between maternal pre-pregnancy adiposity and risk for attention deficit hyperactivity disorder (ADHD) symptoms in children. A Swedish population-based prospective pregnancy-offspring cohort was followed up when children were 5 years old (N = 1,714). Mothers and kindergarten teachers rated children's ADHD symptoms, presence and duration of problems, and emotionality. Dichotomized outcomes examined difficulties of clinical relevance (top 15% of the distribution). Analyses adjusted for pregnancy (maternal smoking, depressive symptoms, life events, education, age, family structure), birth outcomes (birth weight, gestational age, infant sex) and concurrent variables (family structure, maternal depressive symptoms, parental ADHD symptoms, and child overweight) in an attempt to rule out confounding. Maternal pre-pregnancy overweight and obesity predicted high inattention symptom scores and obesity was associated with a two-fold increase in risk of difficulties with emotion intensity and emotion regulation according to teacher reports. Means of maternal ratings were unrelated to pre-pregnancy body mass index (BMI). Presence and duration of problems were associated with both maternal over and underweight according to teachers. Despite discrepancies between maternal and teacher reports, these results provide further evidence that maternal pre-pregnancy overweight and obesity are associated with child inattention symptoms and extend previous work by establishing a link between obesity and emotional difficulties. Maternal adiposity at the time of conception may be instrumental in programming child mental health, as prenatal brain development depends on maternal energy supply. Possible mechanisms include disturbed maternal metabolic function. If maternal pre-pregnancy obesity is a causal risk factor, the potential for prevention is great.

[Factors associated with duration of breastfeeding for children of low-income families from southern Curitiba, Paraná State, Brazil].

PubMed

Baptista, Gerson Henrique; Andrade, Adriano Herbert H K Gonçalves de; Giolo, Suely Ruiz

2009-03-01

Various studies have focused on breastfeeding and the possible factors associated with early weaning. This study aimed to identify risk factors and protective factors for duration of breastfeeding in low-income families in southern Curitiba, Paraná State, Brazil. A cohort study from November 2006 to March 2007 included 118 mothers of children less than two years of age and enrolled in the TC Health Unit (USTC) located in the southern area of Curitiba. Statistical analyses using the Kaplan-Meier method and Cox regression model identified the following protective factors for breastfeeding: mother's awareness of the benefits of extended breastfeeding, exclusive feeding with mother's breast milk while in the maternity ward, and rooming-in. Factors contributing to early weaning were low birth weight, mother's work outside the home, and difficulties experienced by the mother in breastfeeding during the first days postpartum.

Lowering social security's duration-of-marriage requirement: distributional effects for future female retirees.

PubMed

Tamborini, Christopher R; Whitman, Kevin

2010-01-01

A number of alternatives to Social Security's auxiliary benefit system have been proposed in the context of changes in American family and work patterns. This article focuses on one modification therein-lowering the 10-year duration-of-marriage requirement for divorced spouses. Using a powerful microsimulation model (MINT), we examine the distributional effects of extending spouse and survivor benefit eligibility to 5- and 7-year marriages ending in divorce among female retirees in 2030, a population largely comprised of baby boomers. Results show that the options would increase benefits for a small share of female retirees, around 2 to 4%, and would not affect the vast majority of low-income divorced older women. However, of those affected, the options would substantially increase benefits and lower incidence of poverty and near poor. Low-income divorced retirees with marriages between 5 and 9 years in length and a deceased former spouse face the greatest potential gains.

Skylab: Program Description

NASA Technical Reports Server (NTRS)

1971-01-01

In 1973 three Americans will embark on the first of a series of Earth orbiting missions using Skylab, the first United States vehicle created specifically to enable man to live and work in space for extended periods. Sky lab is a program dedicated to the use of space and its unique environment and vantage point to increase our knowledge and understanding of the Earth's importance to man's well-being and man's influence on Earth's ecology. Sky lab will also be a major step in manned space flight. Habitation by the first crew will double our previous man-in-space duration (Gemini VII) and the second visit will redouble that duration. It will, in effect, create a bridge between the development flights of the 60s and the long duration operational space flights of the future. To accomplish its mission, Sky lab will be placed in Earth orbit and will be visited and inhabited by three different crews during an eight-month period. While successfully inhabiting and operating the vehicle for one- and two-month continuous periods, these crews will obtain data in areas pertinent to the man/Earth relationship and to long duration space flight. Data will be acquired by Skylab primarily through the conduct of "experiments." Four categories of investigation are planned. These are summarized in the following paragraphs.

40 CFR 86.1705-99 - General provisions; opt-in.

Code of Federal Regulations, 2011 CFR

2011-07-01

... National LEV extends only until model year 2004, except as provided in 40 CFR 86.1707. For the duration of... above. STATE's participation in National LEV extends until model year 2006, except as provided in 40 CFR... vehicles in model year 2004, 2005 or 2006, STATE's participation in National LEV extends only until model...

Extending the Precipitation Map Offshore Using Daily and 3-Hourly Combined Precipitation Estimates

NASA Technical Reports Server (NTRS)

Huffman, George J.; Adler, Robert F.; Bolvin, David T.; Curtis, Scott; Einaudi, Franco (Technical Monitor)

2001-01-01

One of the difficulties in studying landfalling extratropical cyclones along the Pacific Coast is the lack of antecedent data over the ocean, including precipitation. Recent research on combining various satellite-based precipitation estimates opens the possibility of realistic precipitation estimates on a global 1 deg. x 1 deg. latitude-longitude grid at the daily or even 3-hourly interval. The goal in this work is to provide quantitative precipitation estimates that correctly represent the precipitation- related variables in the hydrological cycle: surface accumulations (fresh-water flux into oceans), frequency and duration statistics, net latent heating, etc.

In-Situ Propellant Production on Mars: A Sabatier/Electrolysis Demonstration Plant

NASA Astrophysics Data System (ADS)

Clark, David L.

1997-01-01

An efficient, reliable propellant production plant has been developed for use on Mars. Using a Sabatier reactor in conjunction with a water electrolysis system, a complete demonstration plant has produced methane and liquid oxygen from simulated Martian atmosphere. The production plant has demonstrated high efficiency, extended duration production and autonomous operations. This paper presents the results and conclusions relating to eventual use in a Mars sample return mission. This work was funded by the Jet Propulsion Laboratory (JPL). The production plant was built and tested at the Propulsion Center of Lockheed Martin at the Denver Colorado facility.

Strategies for managing work/life interaction among women and men with variable and unpredictable work hours in retail sales in Québec, Canada.

PubMed

Messing, Karen; Tissot, France; Couture, Vanessa; Bernstein, Stephanie

2014-01-01

Increasingly, work schedules in retail sales are generated by software that takes into account variations in predicted sales. The resulting variable and unpredictable schedules require employees to be available, unpaid, over extended periods. At the request of a union, we studied schedule preferences in a retail chain in Québec using observations, interviews, and questionnaires. Shift start times had varied on average by four hours over the previous week; 83 percent had worked at least one day the previous weekend. Difficulties with work/life balance were associated with schedules and, among women, with family responsibilities. Most workers wanted: more advance notice; early shifts; regular schedules; two days off in sequence; and weekends off. Choices varied, so software could be adapted to take preferences into account. Also, employers could give better advance notice and establish systems for shift exchanges. Governments could limit store hours and schedule variability while prolonging the minimum sequential duration of leave per week.

Elaborated Odor Test for Extended Exposure

NASA Technical Reports Server (NTRS)

Buchanan, Vanessa D.; Henry, Emily J.; Mast, Dion J.; Harper, Susana A.; Beeson, Harold D.; Tapia, Alma S.

2016-01-01

Concerns were raised when incidental exposure to a proprietary bonding material revealed the material had an irritating odor. The NASA-STD-6001B document describes a supplemental test method option for programs to evaluate materials with odor concerns (Test 6, Odor Assessment). In addition to the supplemental standard odor assessment with less than 10 seconds of exposure, the NASA White Sands Test Facility (WSTF) Materials Flight Acceptance Testing section was requested to perform an odor test with an extended duration to evaluate effects of an extended exposure and to more closely simulate realistic exposure scenarios. With approval from the NASA Johnson Space Center Industrial Hygienist, WSTF developed a 15-minute odor test method. WSTF performed this extended-duration odor test to evaluate the odor and physical effects of the bonding material configured between two aluminum plates, after the safety of the gas was verified via toxicity analysis per NASA-STD-6001B Test 7, Determination of Offgassed Products. During extended-duration testing, odor panel members were arranged near the test material in a small room with the air handlers and doors closed to minimize dilution. The odor panel members wafted gas toward themselves and recorded their individual assessments of odor and physical effects at various intervals during the 15-minute exposure and posttest. A posttest interview was conducted to obtain further information. Testing was effective in providing data for comparison and selection of an optimal offgassing and odor containment configuration. The developed test method for extended exposure is proposed as a useful tool for further evaluating materials with identified odors of concern if continued use of the material is anticipated.

[Sleep, work, and study: sleep duration in working and non-working students].

PubMed

Pereira, Erico Felden; Bernardo, Maria Perpeto Socorro Leite; D'Almeida, Vânia; Louzada, Fernando Mazzilli

2011-05-01

The aim of this study was to investigate the duration of sleep and associated factors in working and non-working students. Data were analyzed on the sleep-wake cycle in 863 teenage students in São Paulo, Brazil. Adjusted analyses were performed to compare sleep duration in working and non-working students. 18.4% of the group worked, and 52% of the working students slept eight hours or less per night. Prevalence of short sleep duration was higher in working students of both sexes (males, p = 0.017; females, p < 0.001). Working students showed short sleep duration in the analysis adjusted for socioeconomic status, but short sleep was more frequent in older adolescents (p = 0.004) and in lower (p = 0.001) and middle (p = 0.011) socioeconomic classes. Although more working students were in night school, in the model adjusted for gender and socioeconomic status, working students in afternoon courses showed higher prevalence of short sleep duration (PR = 2.53; 95%CI: 1.68-4.12).

The effect of work shift configurations on emergency medical dispatch center response.

PubMed

Montassier, Emmanuel; Labady, Julien; Andre, Antoine; Potel, Gilles; Berthier, Frederic; Jenvrin, Joel; Penverne, Yann

2015-01-01

It has been proved that emergency medical dispatch centers (EMDC) save lives by promoting an appropriate allocation of emergency medical service resources. Indeed, optimal dispatcher call duration is pivotal to reduce the time gap between the time a call is placed and the delivery of medical care. However, little is known about the impact of work shift configurations (i.e., work shift duration and work shift rotation throughout the day) and dispatcher call duration. Thus, the objective of our study was to assess the effect of work shift configurations on dispatcher call duration. During a 1-year study period, we analyzed the dispatcher call durations for medical and trauma calls during the 4 different work shift rotations (day, morning, evening, and night) and during the 10-hour work shift of each dispatcher in the EMDC of Nantes. We extracted dispatcher call durations from our advanced telephone system, configured with CC Pulse + (Genesys, Alcatel Lucent), and collected them in a custom designed database (Excel, Microsoft). Afterward, we analyzed these data using linear mixed effects models. During the study period, our EMDC received 408,077 calls. Globally, the mean dispatcher call duration was 107 ± 45 seconds. Based on multivariate linear mixed effects models, the dispatcher call duration was affected by night work shift and work shift duration greater than 8 hours, increasing it by about 10 ± 1 seconds and 4 ± 1 seconds, respectively (both p < 0.001). Our study showed that there was a statistically significant difference in dispatcher call duration over work shift rotation and duration, with longer durations seen over night shifts and shifts over 8 hours. While these differences are small and may not have clinical significance, they may have implications for EMDC efficiency.

Associations between insomnia, sleep duration and poor work ability.

PubMed

Lian, Yulong; Xiao, Jing; Liu, Yan; Ning, Li; Guan, Suzhen; Ge, Hua; Li, Fuye; Liu, Jiwen

2015-01-01

The aim of this study was to examine the independent and joint effect of insomnia and objective sleep duration on poor work ability. In this cross-sectional study, a total of 2820 Chinese manufacturing workers were categorized as insomnia patients and individuals with normal sleeping pattern by interview according to DSM-IV criteria. Sleep duration was classified into four categories: ≥7h, 6-7h, 5-6h, and <5h according to objective sleep duration of Watch-PAT-200 test. Work ability was assessed using the Chinese Work Ability Index (WAI) questionnaire. Regression analysis examined the independent and joint association of sleep duration and insomnia with poor work ability, after adjusting for various confounding factors. Insomnia and objective short sleep duration were both independently associated with poor work ability. Compared with the normal sleeping and ≥7h sleep duration group, the highest risk of poor work ability was in the insomnia patients with <5h sleep duration [odds ratio (OR) 3.43, 95% confidence interval (CI) 1.87-5.23], followed by the individuals with insomnia who slept 5-6h (OR 2.03, 95% CI 1.42-2.67). Insomnia and sleep duration in workers are both separately and together associated with increased risk of poor work ability. Objective sleep duration should be taken into consideration when assessing the work ability of people with insomnia. Copyright © 2014 Elsevier Inc. All rights reserved.

Anticoagulants (extended duration) for prevention of venous thromboembolism following total hip or knee replacement or hip fracture repair.

PubMed

Forster, Rachel; Stewart, Marlene

2016-03-30

The optimal duration of thromboprophylaxis after total hip or knee replacement, or hip fracture repair remains controversial. It is common practice to administer prophylaxis using low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) until discharge from hospital, usually seven to 14 days after surgery. International guidelines recommend extending thromboprophylaxis for up to 35 days following major orthopaedic surgery but the recommendation is weak due to moderate quality evidence. In addition, recent oral anticoagulants that exert effect by direct inhibition of thrombin or activated factor X lack the need for monitoring and have few known drug interactions. Interest in this topic remains high. To assess the effects of extended-duration anticoagulant thromboprophylaxis for the prevention of venous thromboembolism (VTE) in people undergoing elective hip or knee replacement surgery, or hip fracture repair. The Cochrane Vascular Information Specialist searched the Specialised Register (last searched May 2015) and CENTRAL (2015, Issue 4). Clinical trials databases were searched for ongoing or unpublished studies. Randomised controlled trials assessing extended-duration thromboprophylaxis (five to seven weeks) using accepted prophylactic doses of LMWH, UFH, vitamin K antagonists (VKA) or direct oral anticoagulants (DOAC) compared with short-duration thromboprophylaxis (seven to 14 days) followed by placebo, no treatment or similar extended-duration thromboprophylaxis with LMWH, UFH, VKA or DOACs in participants undergoing hip or knee replacement or hip fracture repair. We independently selected trials and extracted data. Disagreements were resolved by discussion. We performed fixed-effect model meta-analyses with odds ratios (ORs) and 95% confidence intervals (CIs). We used a random-effects model when there was heterogeneity. We included 16 studies (24,930 participants); six compared heparin with placebo, one compared VKA with placebo, two compared DOAC with placebo, one compared VKA with heparin, five compared DOAC with heparin and one compared anticoagulants chosen at investigators' discretion with placebo. Three trials included participants undergoing knee replacement. No studies assessed hip fracture repair.Trials were generally of good methodological quality. The main reason for unclear risk of bias was insufficient reporting. The quality of evidence according to GRADE was generally moderate, as some comparisons included a single study, low number of events or heterogeneity between studies leading to wide CIs.We showed no difference between extended-duration heparin and placebo in symptomatic VTE (OR 0.59, 95% CI 0.35 to 1.01; 2329 participants; 5 studies; high quality evidence), symptomatic deep vein thrombosis (DVT) (OR 0.73, 95% CI 0.39 to 1.38; 2019 participants; 4 studies; moderate quality evidence), symptomatic pulmonary embolism (PE) (OR 0.61, 95% CI 0.16 to 2.33; 1595 participants; 3 studies; low quality evidence) and major bleeding (OR 0.59, 95% CI 0.14 to 2.46; 2500 participants; 5 studies; moderate quality evidence). Minor bleeding was increased in the heparin group (OR 2.01, 95% CI 1.43 to 2.81; 2500 participants; 5 studies; high quality evidence). Clinically relevant non-major bleeding was not reported.We showed no difference between extended-duration VKA and placebo (one study, 360 participants) for symptomatic VTE (OR 0.10, 95% CI 0.01 to 1.94; moderate quality evidence), symptomatic DVT (OR 0.13, 95% CI 0.01 to 2.62; moderate quality evidence), symptomatic PE (OR 0.32, 95% CI 0.01 to 7.84; moderate quality evidence) and major bleeding (OR 2.89, 95% CI 0.12 to 71.31; low quality evidence). Clinically relevant non-major bleeding and minor bleeding were not reported.Extended-duration DOAC showed reduced symptomatic VTE (OR 0.20, 95% CI 0.06 to 0.68; 2419 participants; 1 study; moderate quality evidence) and symptomatic DVT (OR 0.18, 95% CI 0.04 to 0.81; 2459 participants; 2 studies; high quality evidence) compared to placebo. No differences were found for symptomatic PE (OR 0.25, 95% CI 0.03 to 2.25; 1733 participants; 1 study; low quality evidence), major bleeding (OR 1.00, 95% CI 0.06 to 16.02; 2457 participants; 1 study; low quality evidence), clinically relevant non-major bleeding (OR 1.22, 95% CI 0.76 to 1.95; 2457 participants; 1 study; moderate quality evidence) and minor bleeding (OR 1.18, 95% CI 0.74 to 1.88; 2457 participants; 1 study; moderate quality evidence).We showed no difference between extended-duration anticoagulants chosen at investigators' discretion and placebo (one study, 557 participants, low quality evidence) for symptomatic VTE (OR 0.50, 95% CI 0.09 to 2.74), symptomatic DVT (OR 0.33, 95% CI 0.03 to 3.21), symptomatic PE (OR 1.00, 95% CI 0.06 to 16.13), and major bleeding (OR 5.05, 95% CI 0.24 to 105.76). Clinically relevant non-major bleeding and minor bleeding were not reported.We showed no difference between extended-duration VKA and heparin (one study, low quality evidence) for symptomatic VTE (OR 1.64, 95% CI 0.85 to 3.16; 1279 participants), symptomatic DVT (OR 1.36, 95% CI 0.69 to 2.68; 1279 participants), symptomatic PE (OR 9.16, 95% CI 0.49 to 170.42; 1279 participants), major bleeding (OR 3.87, 95% CI 1.91 to 7.85; 1272 participants) and minor bleeding (OR 1.33, 95% CI 0.64 to 2.76; 1279 participants). Clinically relevant non-major bleeding was not reported.We showed no difference between extended-duration DOAC and heparin for symptomatic VTE (OR 0.70, 95% CI 0.28 to 1.70; 15,977 participants; 5 studies; low quality evidence), symptomatic DVT (OR 0.60, 95% CI 0.11 to 3.27; 15,977 participants; 5 studies; low quality evidence), symptomatic PE (OR 0.91, 95% CI 0.43 to 1.94; 14,731 participants; 5 studies; moderate quality evidence), major bleeding (OR 1.11, 95% CI 0.79 to 1.54; 16,199 participants; 5 studies; high quality evidence), clinically relevant non-major bleeding (OR 1.08, 95% CI 0.90 to 1.28; 15,241 participants; 4 studies; high quality evidence) and minor bleeding (OR 0.95, 95% CI 0.82 to 1.10; 11,766 participants; 4 studies; high quality evidence). Moderate quality evidence suggests extended-duration anticoagulants to prevent VTE should be considered for people undergoing hip replacement surgery, although the benefit should be weighed against the increased risk of minor bleeding. Further studies are needed to better understand the association between VTE and extended-duration oral anticoagulants in relation to knee replacement and hip fracture repair, as well as outcomes such as distal and proximal DVT, reoperation, wound infection and healing.

Work life after psychosis: A detailed examination.

PubMed

Turner, Niall; O'Mahony, Paul; Hill, Michelle; Fanning, Felicity; Larkin, Conall; Waddington, John; O'Callaghan, Eadbhard; Clarke, Mary

2015-01-01

Conducting research on the work outcomes of first episode psychosis (FEP) samples may extend our understanding of the factors associated with the work outcome of people with schizophrenia and other psychotic illnesses. To conduct a detailed study of the work outcome of an FEP sample. Members of a FEP cohort, who had completed a 12-year clinical outcome assessment, were invited to participate in an adjunctive work outcome study. Engagement in paid and non-paid work was first established and the relationship with potentially influential baseline characteristics investigated. Subsequently the influence of work outcome to participants' level of quality of life, mental health, recovery, and social inclusion were examined. Among the 38 participants the mean percentage of time spent in work was 62% of which 50% was in paid work and 12% was in non-paid work. Being employed at inception was the only independent predictor of the duration of the follow-up period spent in work. Relationships between work outcome and all measures of wellbeing were found. The paid and non-paid work attained by people affected by a psychotic illness played an important role in the extent of their wellbeing, recovery, and social inclusion.

Adolescents' Sleep Behaviors and Perceptions of Sleep

ERIC Educational Resources Information Center

Noland, Heather; Price, James H.; Dake, Joseph; Telljohann, Susan K.

2009-01-01

Background: Sleep duration affects the health of children and adolescents. Shorter sleep durations have been associated with poorer academic performance, unintentional injuries, and obesity in adolescents. This study extends our understanding of how adolescents perceive and deal with their sleep issues. Methods: General education classes were…

Long working hours directly and indirectly (via short sleep duration) induce headache even in healthy white-collar men: cross-sectional and 1-year follow-up analyses.

PubMed

Nagaya, Teruo; Hibino, Minoru; Kondo, Yasuaki

2018-01-01

Headache in employees may be linked with both overwork and sleep restriction induced by long working hours. Inter-relationships among working hours, sleep duration and headache were investigated. Cross-sectional analyses for prevalent headache (n = 35,908) and 1-year follow-up analyses for incident headache (n = 19,788) were conducted in apparently healthy white-collar men aged 25-59 years. Headache (yes/no), working hours and sleep duration were based on self-administered questionnaire. After determination of relationships between working hours and sleep duration, logistic regression analysis estimated odds ratio (OR) and 95% confidence interval for prevalent and incident headache according to working hours (35-44, 45-49, 50-59 and ≥60 h/week) and sleep duration (≥7, 6-6.9, 5-5.9 and <5 h/day), and tested linear trends in OR. Additionally, interactive effects of working hours and sleep duration on OR were checked. Covariates in the analyses were age, body mass index, drinking, smoking and exercise. Prevalent and incident headache was found in 1979 (5.5%) men and 707 (3.6%) men, respectively. Working hours were inversely associated with sleep duration. OR for prevalent and incident headache rose with increasing working hours and with reducing sleep duration, regardless of influences of the covariates. Working hours and sleep duration had no interactive effects on OR for prevalent or incident headache. The results indicate that long working hours directly and indirectly (via short sleep duration) induce headache even in apparently healthy white-collar men. Headache in employees may be useful for early detection of adverse health effects by long working hours.

Calcium Kinetics During Space Flight

NASA Technical Reports Server (NTRS)

Smith, Scott M.; Wastney, Meryl E.; OBrien, Kimberly O.; Lane, Helen W.

1999-01-01

Bone loss is one of the most detrimental effects of space flight, threatening to limit the duration of human space missions. The ability to understand and counteract this loss will be critical for crew health and safety during and after extended-duration missions. The hypotheses to be tested in this project are that space flight alters calcium homeostasis and bone mineral metabolism, and that calcium homeostasis and bone mineral metabolism will return to baseline within days to weeks of return to Earth. These hypotheses will be evidenced by elevated rates of bone mineral resorption and decreased bone mineral deposition, decreased absorption of dietary calcium, altered calcitropic endocrine profiles, elevated excretion of calcium in urine and feces, and elevated excretion of markers of bone resorption. The second hypothesis will be evidenced by return of indices of calcium homeostasis and bone metabolism to preflight levels within days to weeks of return to Earth. Studies will be conducted on International Space Station astronauts before, during, and after extended-duration flights. Measurements of calcium kinetics, bone mass, and endocrine/biochemical markers of bone and calcium homeostasis will be conducted. Kinetic studies utilizing dual isotope tracer kinetic studies and mathematical modeling techniques will allow for determination of bone calcium deposition, bone calcium resorption, dietary calcium absorption and calcium excretion (both urinary and endogenous fecal excretion). These studies will build upon preliminary work conducted on the Russian Mir space station. The results from this project will be critical for clarifying how microgravity affects bone and calcium homeostasis, and will provide an important control point for assessment of countermeasure efficacy. These results are expected to aid in developing countermeasures for bone loss, both for space crews and for individuals on Earth who have metabolic bone diseases.

Working multiple jobs over a day or a week: Short-term effects on sleep duration

PubMed Central

Marucci-Wellman, Helen R.; Lombardi, David A.; Willetts, Joanna L.

2016-01-01

ABSTRACT Approximately 10% of the employed population in the United States works in multiple jobs. They are more likely to work long hours and in nonstandard work schedules, factors known to impact sleep duration and quality, and increase the risk of injury. In this study we used multivariate regression models to compare the duration of sleep in a 24-hour period between workers working in multiple jobs (MJHs) with single job holders (SJHs) controlling for other work schedule and demographic factors. We used data from the Bureau of Labor Statistics US American Time Use Survey (ATUS) pooled over a 9-year period (2003–2011). We found that MJHs had significantly reduced sleep duration compared with SJHs due to a number of independent factors, such as working longer hours and more often late at night. Male MJHs, working in their primary job or more than one job on the diary day, also had significantly shorter sleep durations (up to 40 minutes less on a weekend day) than male SJHs, even after controlling for all other factors. Therefore, duration of work hours, time of day working and duration of travel for work may not be the only factors to consider when understanding if male MJHs are able to fit in enough recuperative rest from their busy schedule. Work at night had the greatest impact on sleep duration for females, reducing sleep time by almost an hour compared with females who did not work at night. We also hypothesize that the high frequency or fragmentation of non-leisure activities (e.g. work and travel for work) throughout the day and between jobs may have an additional impact on the duration and quality of sleep for MJHs. PMID:27092404

Working multiple jobs over a day or a week: Short-term effects on sleep duration.

PubMed

Marucci-Wellman, Helen R; Lombardi, David A; Willetts, Joanna L

Approximately 10% of the employed population in the United States works in multiple jobs. They are more likely to work long hours and in nonstandard work schedules, factors known to impact sleep duration and quality, and increase the risk of injury. In this study we used multivariate regression models to compare the duration of sleep in a 24-hour period between workers working in multiple jobs (MJHs) with single job holders (SJHs) controlling for other work schedule and demographic factors. We used data from the Bureau of Labor Statistics US American Time Use Survey (ATUS) pooled over a 9-year period (2003-2011). We found that MJHs had significantly reduced sleep duration compared with SJHs due to a number of independent factors, such as working longer hours and more often late at night. Male MJHs, working in their primary job or more than one job on the diary day, also had significantly shorter sleep durations (up to 40 minutes less on a weekend day) than male SJHs, even after controlling for all other factors. Therefore, duration of work hours, time of day working and duration of travel for work may not be the only factors to consider when understanding if male MJHs are able to fit in enough recuperative rest from their busy schedule. Work at night had the greatest impact on sleep duration for females, reducing sleep time by almost an hour compared with females who did not work at night. We also hypothesize that the high frequency or fragmentation of non-leisure activities (e.g. work and travel for work) throughout the day and between jobs may have an additional impact on the duration and quality of sleep for MJHs.

A unique, fast-forwards rotating schedule with 12-h long shifts prevents chronic sleep debt.

PubMed

Fischer, Dorothee; Vetter, Céline; Oberlinner, Christoph; Wegener, Sven; Roenneberg, Till

2016-01-01

Sleep debt--together with circadian misalignment--is considered a central factor for adverse health outcomes associated with shift work. Here, we describe in detail sleep-wake behavior in a fast-forward rotating 12-h shift schedule, which involves at least 24 hours off after each shift and thus allows examining the role of immediate recovery after shift-specific sleep debt. Thirty-five participants at two chemical plants in Germany were chronotyped using the Munich ChronoType Questionnaire for Shift-Workers (MCTQ(Shift)) and wore actimeters throughout the two-week study period. From these actimetry recordings, we computed sleep and nap duration, social jetlag (a measure of circadian misalignment), and the daily timing of activity and sleep (center of gravity and mid-sleep, respectively). We observed that the long off-work periods between each shift create a fast alternation between shortened (mean ± standard deviation, 5h 17min ± 56min) and extended (8h 25min ± 72min) sleep episodes resulting in immanent reductions of sleep debt. Additionally, extensive napping of early chronotypes (up to 3 hours before the night shift) statistically compensated short sleep durations after the night shift. Partial rank correlations showed chronotype-dependent patterns of sleep and activity that were similar to those previously described in 8-h schedules; however, sleep before the day shift did not differ between chronotypes. Our findings indicate that schedules preventing a build-up of chronic sleep debt may reduce detrimental effects of shift work irrespective of shift duration. Prospective studies are needed to further elucidate the relationship between sleep, the circadian system, and health and safety hazards.

The relationship between length of vocational disability, psychiatric illness, life stressors and sociodemographic variables.

PubMed

Chandarana, P; Jackson, T; Kohr, R; Iezzi, T

1997-01-01

The primary objective of this study was to examine the relationship between vocational disability, psychiatric illness, life stressors and sociodemographic factors. Information on a variety of variables was obtained from insurance files of 147 subjects who had submitted claims for monetary compensation on grounds of psychiatric symptoms. The majority of subjects received a diagnosis of mood disorder or anxiety disorder. Extended vocational disability was associated with longer duration of psychiatric illness, rating of poorer prognosis by the treating physician, and lower income and occupational levels. Individuals with recent onset of disability reported more stressors than those experiencing extended disability. Although longer duration of psychiatric illness was associated with vocational disability, other variables play an important role in accounting for extended vocational disability.

HyPlane for Space Tourism and Business Transportation

NASA Astrophysics Data System (ADS)

Savino, R.

In the present work a preliminary study on a small hypersonic airplane for a long duration space tourism mission is presented. It is also consistent with a point-to-point medium range (5000-6000 km) hypersonic trip, in the frame of the "urgent business travel" market segment. The main ideas is to transfer technological solutions developed for aeronautical and space atmospheric re-entry systems to the design of such a hypersonic airplane. A winged vehicle characterized by high aerodynamic efficiency and able to manoeuvre along the flight path, in all aerodynamic regimes encountered, is taken into consideration. Rocket-Based Combined Cycle and Turbine-Based Combined Cycle engines are investigated to ensure higher performances in terms of flight duration and range. Different flight-paths are also considered, including sub-orbital parabolic trajectories and steady state hypersonic cruise. The former, in particular, takes advantage of the high aerodynamic efficiency during the unpowered phase, in combination with a periodic engine actuation, to guarantee a long duration oscillating flight path. These trajectories offer Space tourists the opportunity of extended missions, characterized by repeated periods of low-gravity at altitudes high enough to ensure a wide view of the Earth from Space.

[Associations of the work duration, sleep duration and number of holidays with an exaggerated blood pressure response during an exercise stress test among workers].

PubMed

Michishita, Ryoma; Ohta, Masanori; Ikeda, Masaharu; Jiang, Ying; Yamato, Hiroshi

2016-01-01

It has been reported that an exaggerated systolic blood pressure (ESBP) response during exercise, even if resting blood pressure is normal, is associated with an increased risk of future hypertension and cardiovascular disease (CVD). This study was designed to investigate the relationships of work duration, sleep duration and number of holidays with blood pressure response during an exercise stress test among normotensive workers. The subjects were 362 normotensive workers (79 males and 283 females; age, 49.1 years). A multi-stage graded submaximal exercise stress test was performed on each subject using an electric bicycle ergometer. The workload was increased every 3 minutes, and blood pressure was measured at rest and during the last 1 minute of each stage. In this study, an ESBP response during exercise was defined according to the criteria of the Framingham Study (peak systolic blood pressure ≥210 mmHg in males, or ≥190 mmHg in females). Working environments, work duration, sleep duration, number of holidays, and physical activity during commuting and work, and leisure time exercise duration were evaluated using a questionnaire. An ESBP response during exercise was observed in 94 (26.0%) workers. The adjusted odds ratio for the prevalence of an ESBP response during exercise was found to be significantly higher with an increase in work duration, decreases in sleep duration and number of holidays (p<0.05, respectively). Moreover, the highest work duration with lowest sleep duration and number of holidays groups had significantly higher adjusted odds ratio for the prevalence of an ESBP response during exercise than the lowest work duration with highest sleep duration and number of holidays groups (p<0.05, respectively). Based on our results, we consider that the assessment of blood pressure response during exercise and daily life are necessary to prevent the incidence of future hypertension, CVD and death due to overwork in workers with long-work duration, short sleep duration and small number of holidays.

Man in space: The use of animal models

NASA Astrophysics Data System (ADS)

Ballard, Rodney W.; Souza, Kenneth A.

Animals have traditionally preceded man into space. During animal and human travels in space over the past almost 30 years, numerous anatomical, physiological, and biochemical changes have been observed. In order to safely qualify humans for extended duration space missions, scientific research needs to be performed. It may be possible to achieve many of these research goals with flight crews serving as experimental subjects; however, to do this with human subjects alone is impractical. Therefore, the use of animal surrogates as experimental subjects is essential to provide the missing information on the effects of spaceflights, to validate countermeasures, and to test medical treatment techniques which will be necessary for long duration missions. This research to assure human health, safety, and productivity in future extended duration space flights will include flights on NASA's Space Shuttle, unmanned biosatellites, and the Space Station Freedom.

Man in space: the use of animal models.

PubMed

Ballard, R W; Souza, K A

1991-01-01

Animals have traditionally preceded man into space. During animal and human travels in space over the past almost 30 years, numerous anatomical, physiological, and biochemical changes have been observed. In order to safely qualify humans for extended duration space missions, scientific research needs to be performed. It may be possible to achieve many of these research goals with flight crews serving as experimental subjects; however, to do this with human subjects alone is impractical. Therefore, the use of animal surrogates as experimental subjects is essential to provide the missing information on the effects of spaceflights, to validate countermeasures, and to test medical treatment techniques which will be necessary for long duration missions. This research to assure human health, safety, and productivity in future extended duration space flights will include flights on NASA's Space Shuttle, unmanned biosatellites, and the Space Station Freedom.

Circadian Entrainment, Sleep-Wake Regulation and Neurobehavioral Performance During Extended Duration Space Flight

NASA Technical Reports Server (NTRS)

Czeisler, Charles A.

1999-01-01

Long-duration manned space flight requires crew members to maintain a high level of cognitive performance and vigilance while operating and monitoring sophisticated instrumentation. However, the reduction in the strength of environmental synchronizers in the space environment leads to misalignment of circadian phase among crew members, coupled with restricted time available to sleep, results in sleep deprivation and consequent deterioration of neurobehavioral function. Crew members are provided, and presently use, long-acting benzodiazepine hypnotics on board the current, relatively brief space shuttle missions to counteract such sleep disruption, a situation that is only likely to worsen during extended duration missions. Given the known carry-over effects of such compounds on daytime performance, together with the reduction in emergency readiness associated with their use at night, NASA has recognized the need to develop effective but safe countermeasures to allow crew members to obtain an adequate amount of sleep. Over the past eight years, we have successfully implemented a new technology for shuttle crew members involving bright light exposure during the pre-launch period to facilitate adaptation of the circadian timing system to the inversions of the sleep-wake schedule often required during dual shift missions. However for long duration space station missions it will be necessary to develop effective and attainable countermeasures that can be used chronically to optimize circadian entrainment. Our current research effort is to study the effects of light-dark cycles with reduced zeitgeber strength, such as are anticipated during long-duration space flight, on the entrainment of the endogenous circadian timing system and to study the effects of a countermeasure that consists of scheduled brief exposures to bright light on the human circadian timing system. The proposed studies are designed to address the following Specific Aims: (1) test the hypothesis that synchronization of the human circadian pacemaker will be disturbed in men and women by the reduction in LD cycle strength. (2) test the hypothesis that this disturbed circadian synchronization will result in the secretion of the sleep-promoting hormone melatonin during the waking day, disturbed sleep, reduced growth hormone secretion, and impaired performance and daytime alertness; (3) as a countermeasure, test the hypothesis that brief daily exposures to bright light (10,000 lux) will reestablish normal entrained circadian phase, resulting in improved sleep consolidation, normalized sleep structure and endogenous growth hormone secretion and enhanced daytime performance. To date, we have carried out twelve experiments to address Hypotheses I and 2 and data analyses are in progress. The results of the current research may have important implications for the treatment of circadian rhythm sleep disorders, such as delayed sleep phase syndrome and shift-work dyssomnia, which are anticipated to have a high incidence and prevalence during extended duration space flight such as planned for the International Space Station and manned missions to Mars.

Differentiating Behavior Initiation and Maintenance: Theoretical Framework and Proof of Concept

ERIC Educational Resources Information Center

Voils, Corrine I.; Gierisch, Jennifer M.; Yancy, William S., Jr.; Sandelowski, Margarete; Smith, Rose; Bolton, Jamiyla; Strauss, Jennifer L.

2014-01-01

Although many interventions are effective for health behavior initiation, maintenance has proven elusive. Interventions targeting maintenance often extend the duration with which initiation content is delivered or the duration of follow-up without intervention. We posit that health behavior initiation and maintenance require separate psychological…

Bending creep and load duration of Douglas-fir 2 by 4s under constant load for up to 12-plus years

Treesearch

Charles C. Gerhards

2000-01-01

This paper finalizes research on graded Douglas-fir 2 by 4 beams subjected to constant bending loads of various levels and durations. Compared to results for testing in a controlled environment, results confirm that load duration did not appear to be shortened by tests in an uncontrolled environment, at least extending out to 12-plus years. By the same comparison,...

Skylab: A beginning. [astronaut performance in extended space exploration

NASA Technical Reports Server (NTRS)

Dietlein, L. F.

1974-01-01

Skylab biomedical experience indicates that man adapts well to and functions effectively in the space environment for time periods approaching three months. Appropriate dietary intake coupled with adequate, programmed exercise, sleep, work and recreation periods are essential to crew health and well being. No untoward physiological responses have been noted that would preclude longer duration space flights, but more research is required in order to understand the mechanisms involved in the observed responses. Remedial or preventive measures may be required for Mars-type missions, and further study of man in earth orbit for an uninterrupted six-month period should ideally precede this Mars-type mission.

Generalizing the flash technique in the front-face configuration to measure the thermal diffusivity of semitransparent solids

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

Pech-May, Nelson Wilbur; Department of Applied Physics, CINVESTAV Unidad Mérida, carretera Antigua a Progreso km6, A.P. 73 Cordemex, Mérida Yucatán 97310, México; Mendioroz, Arantza

2014-10-15

In this work, we have extended the front-face flash method to retrieve simultaneously the thermal diffusivity and the optical absorption coefficient of semitransparent plates. A complete theoretical model that allows calculating the front surface temperature rise of the sample has been developed. It takes into consideration additional effects, such as multiple reflections of the heating light beam inside the sample, heat losses by convection and radiation, transparency of the sample to infrared wavelengths, and heating pulse duration. Measurements performed on calibrated solids, covering a wide range of absorption coefficients (from transparent to opaque) and thermal diffusivities, validate the proposed method.

Long term evolution of distant retrograde orbits in the Earth-Moon system

NASA Astrophysics Data System (ADS)

Bezrouk, Collin; Parker, Jeffrey S.

2017-09-01

This work studies the evolution of several Distant Retrograde Orbits (DROs) of varying size in the Earth-Moon system over durations up to tens of millennia. This analysis is relevant for missions requiring a completely hands off, long duration quarantine orbit, such as a Mars Sample Return mission or the Asteroid Redirect Mission. Four DROs are selected from four stable size regions and are propagated for up to 30,000 years with an integrator that uses extended precision arithmetic techniques and a high fidelity dynamical model. The evolution of the orbit's size, shape, orientation, period, out-of-plane amplitude, and Jacobi constant are tracked. It has been found that small DROs, with minor axis amplitudes of approximately 45,000 km or less decay in size and period largely due to the Moon's solid tides. Larger DROs (62,000 km and up) are more influenced by the gravity of bodies external to the Earth-Moon system, and remain bound to the Moon for significantly less time.

Main medical results of extended flights on space station Mir in 1986-1990

NASA Astrophysics Data System (ADS)

Grigoriev, A. I.; Bugrov, S. A.; Bogomolov, V. V.; Egorov, A. D.; Polyakov, V. V.; Tarasov, I. K.; Shulzhenko, E. B.

During 1986-1990 seven prime spacecrews (16 cosmonauts) have flow on-board the Mir orbital complex. The longest space mission duration was 366 days. The principal objectives of the medical tasks were the maintenance of good health and performance of the spacecrews and conducting medical research programs which included study of the cardiovascular, motor, endocrine, blood, immune, and metabolic systems. Results obtained point to the ability of humans to readily adapt to a year-long stay in space and maintain good health and performance. Readaptation had a similar course as after other previous long-term space flights of up to 8 months in duration. Primary body system changes were not qualitatively different from findings after flights aboard the Salyut 6 and 7 space stations. In this case, during and after an 11-12 month flight, body system alterations were even less severe which was a result of adequate countermeasure use, their systematic and creative employment and maintenance of required environments to support life and work in space.

78 FR 41481 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-10

... Effectiveness of a Proposed Rule Change Relating to Extending FLEX AIM Pilot Program Until July 18, 2014 July 5... Pilot Period expiring on July 18, 201[3]4, there will be no minimum size requirement for orders to be... change merely extends the duration of the pilot program until July 18, 2014. Extending the pilot for an...

Social influences on the duration of antibiotic treatment of clinical mastitis in dairy cows.

PubMed

Swinkels, J M; Hilkens, A; Zoche-Golob, V; Krömker, V; Buddiger, M; Jansen, J; Lam, T J G M

2015-04-01

Clinical mastitis of dairy cows is a visible inflammation of the udder, which is usually caused by bacteria and treated with antibiotics. Although pressure is increasing to reduce antibiotic usage in livestock in the European Union, feedback from the field suggests that clinical mastitis treatment is frequently repeated after the initial per-label treatment, thereby extending treatment duration. The aim of this study was to explore the social factors influencing farmers' decision-making on the duration of antibiotic treatment of clinical mastitis. In total, 38 dairy farmers in the Netherlands (n=17) and Germany (n=21) were interviewed in a qualitative semi-structured way. Extended treatment was defined as any treatment longer than that given in label directions. Of the 38 farmers, 30 reported routine and 7 occasional extended antibiotic treatment. The interviewed farmers were sensitive toward social norms of other farmers and recognition for good stockmanship. Extended treatment is perceived as part of the social norm of "being a good farmer." The participants' perception was that mastitis is not treated "thoroughly" if clinical symptoms were still visible at the time of cessation of treatment, because it may persist or recur. As a result, treatment was frequently extended by repeating the initial label treatment. Farmers, specifically the more "cow-oriented" farmers, expressed insecurity on how to treat mastitis effectively. This insecurity made them more sensitive to comply with other farmers' injunctive ("what ought to be") and descriptive ("what is done") norms and the perceived veterinarians' informational norm that extended treatment is better, resulting in an approved social norm. Social approval reduces the insecurity of being perceived as a poor farmer; thus, extended treatment is emotionally rewarded. This social reward apparently outweighs the higher costs of more waste milk and more antibiotic usage. Perceived positive reference groups with whom the farmer identifies and regularly communicates face to face, such as other farmers, the herd veterinarian, and other farm advisors, confirm the farmer's judgment on extending treatment and influences him or her toward socially accepted behavior. Society was the most negative reference group, barely influencing farmers' decision-making on treatment. The emotional gap between farmers and society is large and probably difficult to overcome. Legislation may reduce antibiotic usage, if doable and controllable. Evidence-based information on treatment efficacy or practical on-farm decision support indicating when to end treatment may be able to change social norms of "thorough" treatment, especially when communicated by a positive reference group such as veterinarians. Because prudent antibiotic use is hindered by perceived subjective norms on optimal duration of antibiotic treatment, more research is needed, particularly on the optimal duration of antibiotic treatment of specific pathogens as related to cure and recurrence of clinical mastitis. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

41 CFR 302-8.203 - What is the authorized time period for extended storage of my HHG?

Code of Federal Regulations, 2010 CFR

2010-07-01

... HHG? Time limitations for extended storage of your HHG will be determined by your agency as follows: (a) For the duration of the OCONUS assignment plus 30 days prior to the time the tour begins and plus...

Hazardous Gas Detection Sensor Using Broadband Light-Emitting Diode-Based Absorption Spectroscopy for Space Applications

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

Terracciano, Anthony; Thurmond, Kyle; Villar, Michael

As space travel matures and extended duration voyages become increasingly common, it will be necessary to include arrays of early fire detection systems aboard spacefaring vessels, space habitats, and in spacesuits. As gasses that are relevant to combustion and pyrolysis have absorption features in the midinfrared range, it is possible to utilize absorption spectroscopy as a means of detecting and quantifying the concentration of these hazardous compounds. Within this work, a sensor for detecting carbon dioxide has been designed and tested autonomously on a high-altitude balloon flight. The sensor utilizes a 4.2-mm lightemitting diode source, amplitude modulation to characterize speciesmore » concentrations, and frequency modulation to characterize ambient temperature. Future work will include expanding the sensor design to detect other gases, and demonstrating suborbital flight capability.« less

Hazardous Gas Detection Sensor Using Broadband Light-Emitting Diode-Based Absorption Spectroscopy for Space Applications

DOE PAGES

Terracciano, Anthony; Thurmond, Kyle; Villar, Michael; ...

2018-03-12

As space travel matures and extended duration voyages become increasingly common, it will be necessary to include arrays of early fire detection systems aboard spacefaring vessels, space habitats, and in spacesuits. As gasses that are relevant to combustion and pyrolysis have absorption features in the midinfrared range, it is possible to utilize absorption spectroscopy as a means of detecting and quantifying the concentration of these hazardous compounds. Within this work, a sensor for detecting carbon dioxide has been designed and tested autonomously on a high-altitude balloon flight. The sensor utilizes a 4.2-mm lightemitting diode source, amplitude modulation to characterize speciesmore » concentrations, and frequency modulation to characterize ambient temperature. Future work will include expanding the sensor design to detect other gases, and demonstrating suborbital flight capability.« less

Thorium-Free Versus Thoriated Plasma Gun Electrodes: Statistical Evaluation of Coating Properties

NASA Astrophysics Data System (ADS)

Colmenares-Angulo, Jose; Molz, Ronald; Hawley, David; Seshadri, Ramachandran Chidambaram

2016-04-01

Industries throughout the world today have an increased awareness of environmental, health, and safety issues. This, together with recent Nuclear Regulatory Commission changes concerning source material (e.g., thorium) has added complexity in the supply chain of thoriated tungsten commonly used in plasma spray gun spares. In the interest of a safer and more sustainable work environment, Oerlikon Metco has developed thorium-free material solutions proven to have longer service life than conventional thoriated spares. This work reports on the effect, if any, caused by tungsten compositional changes and extended service life in coating properties. Microstructure, coating efficiency parameters, hardness, particle state, in situ coating stress, and ex situ modulus are evaluated over the service life duration of the nozzle, comparing coatings with thoriated and non-thoriated nozzles and electrodes with the same spray parameters.

Long term trend and interannual variability of land carbon uptake — the attribution and processes

NASA Astrophysics Data System (ADS)

Fu, Zheng

2017-04-01

Ecosystem carbon (C) uptake in terrestrial ecosystems has increased over the past five decades, but with large interannual variability (IAV). However, we are not clear on the attribution and the processes that control the long-term trend and IAV of land C uptake. Using atmospheric inversion net ecosystem exchange (NEE) data, we quantified the trend and IAV of NEE across the globe, the Northern Hemisphere (NH), and the Southern Hemisphere (SH), and decomposed NEE into carbon uptake amplitude and duration during each year from 1979-2013. We found the NH rather than the SH determined the IAV, while both hemispheres contributed equivalently to the global NEE trend. Different ecosystems in the NH and SH had differential relative contributions to their trend and IAV. The long-term trends of increased C uptake across the globe and the SH were attributed to both extended duration and increasing amplitude of C uptake. The shortened duration of uptake in the NH partly offsets the effects of increased NEE amplitude, making the net C uptake trend the same as that of the SH. The change in NEE IAV was also linked to changes in the amplitude and duration of uptake, but they worked in different ways in the NH, SH and globe. The fundamental attributions of amplitude and duration of C uptake revealed in this study are helpful to better understand the mechanisms underlying the trend and IAV of land C uptake. Our findings also suggest the critical roles of grassland and croplands in the NH in contributing to the trend and IAV of land C uptake.

Long term trend and interannual variability of land carbon uptake—the attribution and processes

NASA Astrophysics Data System (ADS)

Fu, Zheng; Dong, Jinwei; Zhou, Yuke; Stoy, Paul C.; Niu, Shuli

2017-01-01

Ecosystem carbon (C) uptake in terrestrial ecosystems has increased over the past five decades, but with large interannual variability (IAV). However, we are not clear on the attribution and the processes that control the long-term trend and IAV of land C uptake. Using atmospheric inversion net ecosystem exchange (NEE) data, we quantified the trend and IAV of NEE across the globe, the Northern Hemisphere (NH), and the Southern Hemisphere (SH), and decomposed NEE into carbon uptake amplitude and duration during each year from 1979-2013. We found the NH rather than the SH determined the IAV, while both hemispheres contributed equivalently to the global NEE trend. Different ecosystems in the NH and SH had differential relative contributions to their trend and IAV. The long-term trends of increased C uptake across the globe and the SH were attributed to both extended duration and increasing amplitude of C uptake. The shortened duration of uptake in the NH partly offsets the effects of increased NEE amplitude, making the net C uptake trend the same as that of the SH. The change in NEE IAV was also linked to changes in the amplitude and duration of uptake, but they worked in different ways in the NH, SH and globe. The fundamental attributions of amplitude and duration of C uptake revealed in this study are helpful to better understand the mechanisms underlying the trend and IAV of land C uptake. Our findings also suggest the critical roles of grassland and croplands in the NH in contributing to the trend and IAV of land C uptake.

Space flight rehabilitation.

PubMed

Payne, Michael W C; Williams, David R; Trudel, Guy

2007-07-01

The weightless environment of space imposes specific physiologic adaptations on healthy astronauts. On return to Earth, these adaptations manifest as physical impairments that necessitate a period of rehabilitation. Physiologic changes result from unloading in microgravity and highly correlate with those seen in relatively immobile terrestrial patient populations such as spinal cord, geriatric, or deconditioned bed-rest patients. Major postflight impairments requiring rehabilitation intervention include orthostatic intolerance, bone demineralization, muscular atrophy, and neurovestibular symptoms. Space agencies are preparing for extended-duration missions, including colonization of the moon and interplanetary exploration of Mars. These longer-duration flights will result in more severe and more prolonged disability, potentially beyond the point of safe return to Earth. This paper will review and discuss existing space rehabilitation plans for major postflight impairments. Evidence-based rehabilitation interventions are imperative not only to facilitate return to Earth but also to extend the safe duration of exposure to a physiologically hostile microgravity environment.

Introduction

NASA Astrophysics Data System (ADS)

Gaskin, J. A.; Smith, I. S.; Jones, W. V.

In 1783, the Montgolfier brothers ushered in a new era of transportation and exploration when they used hot air to drive an un-tethered balloon to an altitude of 2 km. Made of sackcloth and held together with cords, this balloon challenged the way we thought about human travel, and it has since evolved into a robust platform for performing novel science and testing new technologies. Today, high-altitude balloons regularly reach altitudes of 40 km, and they can support payloads that weigh more than 3000 kg. Long-duration balloons can currently support mission durations lasting 55 days, and developing balloon technologies (i.e. Super-Pressure Balloons) are expected to extend that duration to 100 days or longer; competing with satellite payloads. This relatively inexpensive platform supports a broad range of science payloads, spanning multiple disciplines (astrophysics, heliophysics, planetary and earth science). Applications extending beyond traditional science include testing new technologies for eventual space-based application and stratospheric airships for planetary applications.

Rotating night shift work, sleep, and colorectal adenoma in women.

PubMed

Devore, Elizabeth E; Massa, Jennifer; Papantoniou, Kyriaki; Schernhammer, Eva S; Wu, Kana; Zhang, Xuehong; Willett, Walter C; Fuchs, Charles S; Chan, Andrew T; Ogino, Shuji; Giovannucci, Edward; Wei, Esther K

2017-07-01

This study aims to investigate the associations of rotating night shift work history and sleep duration with risk of colorectal adenoma. We evaluated 56,275 cancer-free participants of the Nurses' Health Study II, who had their first colonoscopy or sigmoidoscopy between 1991 and 2011; rotating night shift work and sleep duration were reported by mailed questionnaire. Multivariable-adjusted logistic regression was used to estimate relative risks (RR) of colorectal adenoma, with 95% confidence intervals (CI), across categories of rotating night shift work history (none, 1-4, 5-9, and ≥10 years) and sleep duration (≤5, 6, 7, 8, and ≥9 h/day). We found no association between duration of rotating night shift work and occurrence of colorectal adenoma (p-trend across shift work categories = 0.5). Women with the longest durations of rotating night shift work (≥10 years) had a similar risk of adenoma compared to women without a history of rotating night shift work (multivariable-adjusted RR = 0.96, 95% CI = 0.83-1.11). Similarly, there were no associations of shorter or longer sleep durations with adenoma risk (p-trend = 0.2 across sleep durations of ≤5 through 7 h/day and p-trend = 0.5 across sleep durations of 7 through ≥9 h/day). Results were similar when we examined associations according to adenoma location and subtype. Our results do not support an association between rotating night shift work or sleep duration and risk of colorectal adenoma in women.

Extended Duration of Transgene Expression from Pegylated POD Nanoparticles Enables Attenuation of Photoreceptor Degeneration

PubMed Central

Binder, Christina; Cashman, Siobhan M.; Kumar-Singh, Rajendra

2013-01-01

Retinitis pigmentosa (RP) is the most genetically heterogeneous disorder known to cause blindness, involving over 50 different genes. Previously, we have described nanoparticles (NPs) 150 nm in size, comprised of a 3.5 kD peptide (POD) complexed to PEG and DNA (PEGPOD DNA). These NPs expressing GDNF enabled rescue of photoreceptor degeneration in mice up to 11 days post injection. In the current study we examine use of scaffold/ matrix attachment regions (S/MARs), CpG depletion and titration of DNA content of PEGPOD DNA NPs to extend the duration of transgene expression. S/MARs and CpGs did not significantly influence the duration of transgene expression, but did influence its stability. These parameters enabled us to extend transgene expression from 48 hours to 10 weeks. At 77 days post injection, we observed a 76% rescue of the thickness of the retinal outer nuclear layer (ONL) and at 37 days post injection we observed 53% and 55% rescue of the A and B wave ERG amplitudes respectively and 60% rescue of the ONL. Our studies suggest that PEGPOD DNA NPs have potential as gene delivery vectors for the retina. PMID:24278479

Sleep and Alertness in Medical Interns and Residents: An Observational Study on the Role of Extended Shifts.

PubMed

Basner, Mathias; Dinges, David F; Shea, Judy A; Small, Dylan S; Zhu, Jingsan; Norton, Laurie; Ecker, Adrian J; Novak, Cristina; Bellini, Lisa M; Volpp, Kevin G

2017-04-01

Fatigue from sleep loss is a risk to physician and patient safety, but objective data on physician sleep and alertness on different duty hour schedules is scarce. This study objectively quantified differences in sleep duration and alertness between medical interns working extended overnight shifts and residents not or rarely working extended overnight shifts. Sleep-wake activity of 137 interns and 87 PGY-2/3 residents on 2-week Internal Medicine and Oncology rotations was assessed with wrist-actigraphy. Alertness was assessed daily with a brief Psychomotor Vigilance Test (PVT) and the Karolinska Sleepiness Scale. Interns averaged 6.93 hours (95% confidence interval [CI] 6.84-7.03 hours) sleep per 24 hours across shifts, significantly less than residents not working overnight shifts (7.18 hours, 95% CI 7.06-7.30 hours, p = .007). Interns obtained on average 2.19 hours (95% CI 2.02-2.36 hours) sleep during on-call nights (17.5% obtained no sleep). Alertness was significantly lower on mornings after on-call nights compared to regular shifts (p < .001). Naps between 9 am and 6 pm on the first day post-call were frequent (90.8%) and averaged 2.84 hours (95% CI 2.69-3.00 hours), but interns still slept 1.66 hours less per 24 hours (95% CI 1.56-1.76 hours) compared to regular shift days (p < .001). Sleep inertia significantly affected alertness in the 60 minutes after waking on-call. Extended overnight shifts increase the likelihood of chronic sleep restriction in interns. Reduced levels of alertness after on-call nights need to be mitigated. A systematic comparison of sleep, alertness, and safety outcomes under current and past duty hour rules is encouraged. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Sleep and Alertness in Medical Interns and Residents: An Observational Study on the Role of Extended Shifts

PubMed Central

Dinges, David F.; Shea, Judy A.; Small, Dylan S.; Zhu, Jingsan; Norton, Laurie; Ecker, Adrian J.; Novak, Cristina; Bellini, Lisa M.; Volpp, Kevin G.

2017-01-01

Abstract Study Objectives: Fatigue from sleep loss is a risk to physician and patient safety, but objective data on physician sleep and alertness on different duty hour schedules is scarce. This study objectively quantified differences in sleep duration and alertness between medical interns working extended overnight shifts and residents not or rarely working extended overnight shifts. Methods: Sleep–wake activity of 137 interns and 87 PGY-2/3 residents on 2-week Internal Medicine and Oncology rotations was assessed with wrist-actigraphy. Alertness was assessed daily with a brief Psychomotor Vigilance Test (PVT) and the Karolinska Sleepiness Scale. Results: Interns averaged 6.93 hours (95% confidence interval [CI] 6.84–7.03 hours) sleep per 24 hours across shifts, significantly less than residents not working overnight shifts (7.18 hours, 95% CI 7.06–7.30 hours, p = .007). Interns obtained on average 2.19 hours (95% CI 2.02–2.36 hours) sleep during on-call nights (17.5% obtained no sleep). Alertness was significantly lower on mornings after on-call nights compared to regular shifts (p < .001). Naps between 9 am and 6 pm on the first day post‐call were frequent (90.8%) and averaged 2.84 hours (95% CI 2.69–3.00 hours), but interns still slept 1.66 hours less per 24 hours (95% CI 1.56–1.76 hours) compared to regular shift days (p < .001). Sleep inertia significantly affected alertness in the 60 minutes after waking on-call. Conclusions: Extended overnight shifts increase the likelihood of chronic sleep restriction in interns. Reduced levels of alertness after on-call nights need to be mitigated. A systematic comparison of sleep, alertness, and safety outcomes under current and past duty hour rules is encouraged. PMID:28329124

Regional muscle loss after short duration spaceflight.

PubMed

LeBlanc, A; Rowe, R; Schneider, V; Evans, H; Hedrick, T

1995-12-01

Muscle strength and limb girth measurements during Skylab and Apollo missions suggested that loss of muscle mass may occur as a result of spaceflight. Extended duration spaceflight is important for the economical and practical use of space. The loss of muscle mass during spaceflight is a medical concern for long duration flights to the planets or extended stays aboard space stations. Understanding the extent and temporal relationships of muscle loss is important for the development of effective spaceflight countermeasures. We hypothesized that significant and measurable changes in muscle volume would occur in Shuttle crewmembers following 8 d of weightlessness. MRI was used to obtain the muscle volumes of the calf, thigh and lower back before and after the STS-47 Shuttle mission. Statistical analyses demonstrated that the soleus-gastrocnemius (-6.3%), anterior calf (-3.9%), hamstrings (-8.3%), quadriceps (-6.0%) and intrinsic back (-10.3%) muscles were decreased, p < 0.05, compared to baseline, 24 h after landing. At 2 weeks post recovery, the hamstrings and intrinsic lower back muscles were still below baseline, p < 0.05. These results demonstrate that even short duration spaceflight can result in significant muscle atrophy.

Computer work duration and its dependence on the used pause definition.

PubMed

Richter, Janneke M; Slijper, Harm P; Over, Eelco A B; Frens, Maarten A

2008-11-01

Several ergonomic studies have estimated computer work duration using registration software. In these studies, an arbitrary pause definition (Pd; the minimal time between two computer events to constitute a pause) is chosen and the resulting duration of computer work is estimated. In order to uncover the relationship between the used pause definition and the computer work duration (PWT), we used registration software to record usage patterns of 571 computer users across almost 60,000 working days. For a large range of Pds (1-120 s), we found a shallow, log-linear relationship between PWT and Pds. For keyboard and mouse use, a second-order function fitted the data best. We found that these relationships were dependent on the amount of computer work and subject characteristics. Comparison of exposure duration from studies using different pause definitions should take this into account, since it could lead to misclassification. Software manufacturers and ergonomists assessing computer work duration could use the found relationships for software design and study comparison.

Maternal return to paid work and breastfeeding practices in Bangkok, Thailand.

PubMed

Aikawa, Tomomi; Pavadhgul, Patcharanee; Chongsuwat, Rewadee; Sawasdivorn, Siraporn; Boonshuyar, Chaweewon

2015-03-01

This study explored the association between mothers' work-related factors and breastfeeding practices in Bangkok, Thailand. Data were collected from 84 working mothers with a child aged 6 to 24 months who visited the breastfeeding mobile clinic at a nursery goods exhibition. Thai interviewers collected data using a structured questionnaire. Analysis of the data showed that exclusive breastfeeding for 3 months was 78.6%, and for 6 months it was 38.1%. Mothers who returned to work 3 months or more after giving birth exclusively breastfed more than the mothers who returned to work in less than 3 months (crude odds ratio [OR] = 4.26, 95% confidence interval [CI] = 1.39-13.05; adjusted OR = 4.15, 95% CI = 1.15-14.95). Moreover, mothers who worked at self-employed or family-owned businesses and some mothers working at private companies showed tendencies of returning to work in less than 3 months. Results suggest that longer maternity leave would help extend the duration of exclusive breastfeeding. In addition, the improvement of a breastfeeding supportive environment in the workplace would be valuable and may be an effective means to improve breastfeeding practices and infant health. © 2011 APJPH.

20 CFR 336.5 - Notice to employee.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.5 Notice to employee. The Board will notify... will be exhausted. Such notice will include information about the availability of extended benefits... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Notice to employee. 336.5 Section 336.5...

20 CFR 336.12 - Exhaustion of rights to normal sickness benefits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... benefits. 336.12 Section 336.12 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.12... employee received sickness benefits for 130 days of sickness in the benefit year; or (b) The employee...

Environmental Health

NASA Technical Reports Server (NTRS)

Pierson, Duane; James, John; Russo, Dane; Limero, Thomas; Beck, Steve; Groves, Theron

1999-01-01

The Environmental Health activity for the Extended Duration Orbiter Medical Project (EDOMP) was formed to develop an overall strategy for safeguarding crew members from potential airborne hazards anticipated on missions of extended duration. These efforts were necessary because of major modifications to the air revitalization system of the U.S. Space Shuttle and an increased potential for environmental health risks associated with longer space flights. Degradation of air quality in the Shuttle during a space flight mission has the potential to affect the performance of the crew not only during piloting, landing, or egress, but also during space flight. It was anticipated that the risk of significant deterioration in air quality would increase with extended mission lengths and could result from: (1) a major chemical contamination incident, such as a thermodegradation event or toxic leak, (2) continual accumulation of volatile organic compounds to unacceptable levels, (3) excessive levels of airborne particles, (4) excessive levels of microorganisms, or (5) accumulation of airborne pathogens.

An interactive media program for managing psychosocial problems on long-duration spaceflights.

PubMed

Carter, James A; Buckey, Jay C; Greenhalgh, Leonard; Holland, Albert W; Hegel, Mark T

2005-06-01

Space crews must be self-reliant to complete long-duration missions successfully. This project involves the development and evaluation of a network of self-guided interactive multimedia programs to train and assist long-duration flyers in the prevention, assessment, and management of psychosocial problems that can arise on extended missions. The system is currently under development and is intended for use both during training and on orbit. A virtual space station 3-dimensional graphic was created to serve as a portal to multimedia-based training, assessment, and intervention resources. Additionally, original content on interpersonal conflict and depression is being developed for the system. Input on the best practices for managing conflict and depression on extended missions was obtained from 13 veteran long-duration flyers, as well as from clinical experts. Formative evaluation of a prototype of the system will be conducted with 10 members of the astronaut corps. Subsequently, the content on conflict and depression will be completed, and the depression self-treatment portion will be evaluated in a randomized controlled trial. Although this study involves developing countermeasures to assist long-duration flyers, it also provides a model that could be applied in many Earthbound settings, both in operational environments and in everyday life.

Response terminated displays unload selective attention

PubMed Central

Roper, Zachary J. J.; Vecera, Shaun P.

2013-01-01

Perceptual load theory successfully replaced the early vs. late selection debate by appealing to adaptive control over the efficiency of selective attention. Early selection is observed unless perceptual load (p-Load) is sufficiently low to grant attentional “spill-over” to task-irrelevant stimuli. Many studies exploring load theory have used limited display durations that perhaps impose artificial limits on encoding processes. We extended the exposure duration in a classic p-Load task to alleviate temporal encoding demands that may otherwise tax mnemonic consolidation processes. If the load effect arises from perceptual demands alone, then freeing-up available mnemonic resources by extending the exposure duration should have little effect. The results of Experiment 1 falsify this prediction. We observed a reliable flanker effect under high p-Load, response-terminated displays. Next, we orthogonally manipulated exposure duration and task-relevance. Counter-intuitively, we found that the likelihood of observing the flanker effect under high p-Load resides with the duration of the task-relevant array, not the flanker itself. We propose that stimulus and encoding demands interact to produce the load effect. Our account clarifies how task parameters differentially impinge upon cognitive processes to produce attentional “spill-over” by appealing to visual short-term memory as an additional processing bottleneck when stimuli are briefly presented. PMID:24399983

Response terminated displays unload selective attention.

PubMed

Roper, Zachary J J; Vecera, Shaun P

2013-01-01

Perceptual load theory successfully replaced the early vs. late selection debate by appealing to adaptive control over the efficiency of selective attention. Early selection is observed unless perceptual load (p-Load) is sufficiently low to grant attentional "spill-over" to task-irrelevant stimuli. Many studies exploring load theory have used limited display durations that perhaps impose artificial limits on encoding processes. We extended the exposure duration in a classic p-Load task to alleviate temporal encoding demands that may otherwise tax mnemonic consolidation processes. If the load effect arises from perceptual demands alone, then freeing-up available mnemonic resources by extending the exposure duration should have little effect. The results of Experiment 1 falsify this prediction. We observed a reliable flanker effect under high p-Load, response-terminated displays. Next, we orthogonally manipulated exposure duration and task-relevance. Counter-intuitively, we found that the likelihood of observing the flanker effect under high p-Load resides with the duration of the task-relevant array, not the flanker itself. We propose that stimulus and encoding demands interact to produce the load effect. Our account clarifies how task parameters differentially impinge upon cognitive processes to produce attentional "spill-over" by appealing to visual short-term memory as an additional processing bottleneck when stimuli are briefly presented.

A cross-sectional study of the association between working hours and sleep duration among the Japanese working population.

PubMed

Ohtsu, Tadahiro; Kaneita, Yoshitaka; Aritake, Sayaka; Mishima, Kazuo; Uchiyama, Makoto; Akashiba, Tsuneto; Uchimura, Naohisa; Nakaji, Shigeyuki; Munezawa, Takeshi; Kokaze, Akatsuki; Ohida, Takashi

2013-01-01

This study aimed to clarify the association between long working hours and short sleep duration among Japanese workers. We selected 4,000 households from across Japan by stratified random sampling and conducted an interview survey of a total of 662 participants (372 men; 290 women) in November 2009. Logistic regression analyses were performed using "sleep duration <6 hours per day" as a dependent variable to examine the association between working hours/overtime hours and short sleep duration. When male participants who worked for ≥7 but <9 hours per day were used as a reference, the odds ratio (OR) for short sleep duration in those who worked for ≥ 11 hours was 8.62 (95% confidence interval [CI]: 3.94-18.86). With regard to overtime hours among men, when participants without overtime were used as a reference, the OR for those whose period of overtime was ≥ 3 hours but <4 hours was 3.59 (95% CI: 1.42-9.08). For both men and women, those with long weekday working hours tended to have a short sleep duration during weekdays and holidays. It is essential to avoid working long hours in order to prevent short sleep duration.

Improving Signal Detection using Allan and Theo Variances

NASA Astrophysics Data System (ADS)

Hardy, Andrew; Broering, Mark; Korsch, Wolfgang

2017-09-01

Precision measurements often deal with small signals buried within electronic noise. Extracting these signals can be enhanced through digital signal processing. Improving these techniques provide signal to noise ratios. Studies presently performed at the University of Kentucky are utilizing the electro-optic Kerr effect to understand cell charging effects within ultra-cold neutron storage cells. This work is relevant for the neutron electric dipole moment (nEDM) experiment at Oak Ridge National Laboratory. These investigations, and future investigations in general, will benefit from the illustrated improved analysis techniques. This project will showcase various methods for determining the optimum duration that data should be gathered for. Typically, extending the measuring time of an experimental run reduces the averaged noise. However, experiments also encounter drift due to fluctuations which mitigate the benefits of extended data gathering. Through comparing FFT averaging techniques, along with Allan and Theo variance measurements, quantifiable differences in signal detection will be presented. This research is supported by DOE Grants: DE-FG02-99ER411001, DE-AC05-00OR22725.

High-Heat-Flux Cyclic Durability of Thermal and Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Ghosn, Louis L.; Miller, Robert A.

2007-01-01

Advanced ceramic thermal and environmental barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to protect the engine components and further raise engine temperatures. For the supersonic vehicles currently envisioned in the NASA fundamental aeronautics program, advanced gas turbine engines will be used to provide high power density thrust during the extended supersonic flight of the aircraft, while meeting stringent low emission requirements. Advanced ceramic coating systems are critical to the performance, life and durability of the hot-section components of the engine systems. In this work, the laser and burner rig based high-heat-flux testing approaches were developed to investigate the coating cyclic response and failure mechanisms under simulated supersonic long-duration cruise mission. The accelerated coating cracking and delamination mechanism under the engine high-heat-flux, and extended supersonic cruise time conditions will be addressed. A coating life prediction framework may be realized by examining the crack initiation and propagation in conjunction with environmental degradation under high-heat-flux test conditions.

Synthesis of Nanosecond Ultrawideband Radiation Pulses

NASA Astrophysics Data System (ADS)

Koshelev, V. I.; Plisko, V. V.; Sevostyanov, E. A.

2017-12-01

The synthesis of electromagnetic pulses with an extended spectrum by summing pulses of different duration in free space has been studied. The radiation spectrum has been estimated analytically for a 4-element array of combined antennas excited by bipolar voltage pulses of duration 0.5, 1, 2, and 3 ns. It has been shown experimentally that radiation with a spectral width of more than three octaves can be produced using a 2×2 array of combined antennas excited by bipolar pulses of duration 2 and 3 ns.

Sleep duration as a mediator between an alternating day and night shift work schedule and metabolic syndrome among female hospital employees.

PubMed

Korsiak, Jill; Tranmer, Joan; Day, Andrew; Aronson, Kristan J

2018-02-01

The main objective was to determine whether sleep duration on work shifts mediates the relationship between a current alternating day and night shift work schedule and metabolic syndrome among female hospital employees. The secondary objective was to assess whether cumulative lifetime shift work exposure was associated with metabolic syndrome. In this cross-sectional study of 294 female hospital employees, sleep duration was measured with the ActiGraph GT3X+. Shift work status was determined through self-report. Investigation of the total, direct and indirect effects between shift work, sleep duration on work shifts and metabolic syndrome was conducted using regression path analysis. Logistic regression was used to determine the association between cumulative shift work exposure and metabolic syndrome. Shift work is strongly associated with metabolic syndrome (OR Total =2.72, 95% CI 1.38 to 5.36), and the relationship is attenuated when work shift sleep duration is added to the model (OR Direct =1.18, 95% CI 0.49 to 2.89). Sleep duration is an important intermediate between shift work and metabolic syndrome (OR Indirect =2.25, 95% CI 1.27 to 4.26). Cumulative shift work exposure is not associated with metabolic syndrome in this population. Sleep duration mediates the association between a current alternating day-night shift work pattern and metabolic syndrome. © 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.

Measures of Working Memory Span and Verbal Rehearsal Speed in Deaf Children after Cochlear Implantation

PubMed Central

Pisoni, David B.; Cleary, Miranda

2012-01-01

Large individual differences in spoken word recognition performance have been found in deaf children after cochlear implantation. Recently, Pisoni and Geers (2000) reported that simple forward digit span measures of verbal working memory were significantly correlated with spoken word recognition scores even after potentially confounding variables were statistically controlled for. The present study replicates and extends these initial findings to the full set of 176 participants in the CID cochlear implant study. The pooled data indicate that despite statistical “partialling-out” of differences in chronological age, communication mode, duration of deafness, duration of device use, age at onset of deafness, number of active electrodes, and speech feature discrimination, significant correlations still remain between digit span and several measures of spoken word recognition. Strong correlations were also observed between speaking rate and both forward and backward digit span, a result that is similar to previously reported findings in normalhearing adults and children. The results suggest that perhaps as much as 20% of the currently unexplained variance in spoken word recognition scores may be independently accounted for by individual differences in cognitive factors related to the speed and efficiency with which phonological and lexical representations of spoken words are maintained in and retrieved from working memory. A smaller percentage, perhaps about 7% of the currently unexplained variance in spoken word recognition scores, may be accounted for in terms of working memory capacity. We discuss how these relationships may arise and their contribution to subsequent speech and language development in prelingually deaf children who use cochlear implants. PMID:12612485

Meterwavelength Single-pulse Polarimetric Emission Survey. III. The Phenomenon of Nulling in Pulsars

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

Basu, Rahul; Mitra, Dipanjan; Melikidze, George I., E-mail: rahulbasu.astro@gmail.com

A detailed analysis of nulling was conducted for the pulsars studied in the Meterwavelength Single-pulse Polarimetric Emission Survey. We characterized nulling in 36 pulsars including 17 pulsars where the phenomenon was reported for the first time. The most dominant nulls lasted for a short duration, less than five periods. Longer duration nulls extending to hundreds of periods were also seen in some cases. A careful analysis showed the presence of periodicities in the transition from the null to the burst states in 11 pulsars. In our earlier work, fluctuation spectrum analysis showed multiple periodicities in 6 of these 11 pulsars.more » We demonstrate that the longer periodicity in each case was associated with nulling. The shorter periodicities usually originate from subpulse drifting. The nulling periodicities were more aligned with the periodic amplitude modulation, indicating a possible common origin for both. The most prevalent nulls last for a single period and can be potentially explained using random variations affecting the plasma processes in the pulsar magnetosphere. On the other hand, longer-duration nulls require changes in the pair-production processes, which need an external triggering mechanism for the changes. The presence of periodic nulling puts an added constraint on the triggering mechanism, which also needs to be periodic.« less

Extended RF shimming: Sequence‐level parallel transmission optimization applied to steady‐state free precession MRI of the heart

PubMed Central

Price, Anthony N.; Padormo, Francesco; Hajnal, Joseph V.; Malik, Shaihan J.

2017-01-01

Cardiac magnetic resonance imaging (MRI) at high field presents challenges because of the high specific absorption rate and significant transmit field (B 1 +) inhomogeneities. Parallel transmission MRI offers the ability to correct for both issues at the level of individual radiofrequency (RF) pulses, but must operate within strict hardware and safety constraints. The constraints are themselves affected by sequence parameters, such as the RF pulse duration and TR, meaning that an overall optimal operating point exists for a given sequence. This work seeks to obtain optimal performance by performing a ‘sequence‐level’ optimization in which pulse sequence parameters are included as part of an RF shimming calculation. The method is applied to balanced steady‐state free precession cardiac MRI with the objective of minimizing TR, hence reducing the imaging duration. Results are demonstrated using an eight‐channel parallel transmit system operating at 3 T, with an in vivo study carried out on seven male subjects of varying body mass index (BMI). Compared with single‐channel operation, a mean‐squared‐error shimming approach leads to reduced imaging durations of 32 ± 3% with simultaneous improvement in flip angle homogeneity of 32 ± 8% within the myocardium. PMID:28195684

Extended RF shimming: Sequence-level parallel transmission optimization applied to steady-state free precession MRI of the heart.

PubMed

Beqiri, Arian; Price, Anthony N; Padormo, Francesco; Hajnal, Joseph V; Malik, Shaihan J

2017-06-01

Cardiac magnetic resonance imaging (MRI) at high field presents challenges because of the high specific absorption rate and significant transmit field (B 1 + ) inhomogeneities. Parallel transmission MRI offers the ability to correct for both issues at the level of individual radiofrequency (RF) pulses, but must operate within strict hardware and safety constraints. The constraints are themselves affected by sequence parameters, such as the RF pulse duration and TR, meaning that an overall optimal operating point exists for a given sequence. This work seeks to obtain optimal performance by performing a 'sequence-level' optimization in which pulse sequence parameters are included as part of an RF shimming calculation. The method is applied to balanced steady-state free precession cardiac MRI with the objective of minimizing TR, hence reducing the imaging duration. Results are demonstrated using an eight-channel parallel transmit system operating at 3 T, with an in vivo study carried out on seven male subjects of varying body mass index (BMI). Compared with single-channel operation, a mean-squared-error shimming approach leads to reduced imaging durations of 32 ± 3% with simultaneous improvement in flip angle homogeneity of 32 ± 8% within the myocardium. © 2017 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.

Impact of extended stun duration and voltage on the recovery of consciousness in broilers

USDA-ARS?s Scientific Manuscript database

Typical electrical stun duration for broilers in the United States is from 5 to 15 s (depending on voltage), but would be considerably longer if and when the kill-line stopped. The welfare and conscious/unconscious status of broilers within the stunner cabinet is a concern while the line is stopped...

The Impact of Target, Wording, and Duration on Rating Accuracy for Direct Behavior Rating

ERIC Educational Resources Information Center

Chafouleas, Sandra M.; Jaffery, Rose; Riley-Tillman, T. Chris; Christ, Theodore J.; Sen, Rohini

2013-01-01

The purpose of this study was to extend evaluation of rater accuracy using "Direct Behavior Rating--Single-Item Scales" (DBR-SIS). Extension of prior research was accomplished through use of criterion ratings derived from both systematic direct observation and expert DBR-SIS scores, and also through control of the durations over which…

Manned orbital systems concepts study. Book 2: Requirements for extended-duration missions

NASA Technical Reports Server (NTRS)

1975-01-01

In order to provide essential data needed in long-range program planning, the Manned Orbital Systems Concepts (MOSC) study attempted to define, evaluate, and compare concepts for manned orbital systems that provide extended experiment mission capabilities in space, flexibility of operation, and growth potential. Specific areas discussed include roles and requirements for man in future space missions, requirements for extended capability, mission/payload concepts, and preliminary design and operational requirements.

Mothers' Concerns for Personal Safety and Privacy While Breastfeeding: An Unexplored Phenomenon.

PubMed

Rosen-Carole, Casey; Allen, Katherine; Fagnano, Maria; Dozier, Ann; Halterman, Jill

2018-04-01

Preliminary qualitative research in upstate NY shows new mothers are worried about safety while breastfeeding. Little is known regarding prevalence of these concerns and their effect on breastfeeding outcomes. (1) Determine frequency of breastfeeding safety and privacy concerns; (2) Explore their association with breastfeeding outcomes. Mothers were surveyed immediately and 1-month postpartum about breastfeeding goals; both surveys addressed privacy and safety concerns at home, work, and in public. Outcome data included breastfeeding intent, exclusivity, and duration. Breastfeeding/non-breastfeeding mothers were compared using Chi-square and multivariate analyses. A total of 279 women enrolled. Of these 82.8% initiated breastfeeding; at 1-month 72% provided any breast milk, and 44% were exclusively breastfeeding. About 99% felt safe breastfeeding at home; 25% reported privacy concerns; and 5% felt "vulnerable or unsafe" while breastfeeding. At 1-month, 49% agreed there was a safe place to breastfeed/express milk at work (20% unsure). Non-breastfeeding mothers expressed more safety concerns outside home/at work: 18% breastfeeding versus 28% non-breastfeeding outside home; 27% breastfeeding versus 40% non-breastfeeding at work. Nearly 54% who reported feeling vulnerable/unsafe with breastfeeding initiated breastfeeding, compared with 86% not reporting this concern (p = 0.008). Fewer women initiating breastfeeding reported vulnerability/safety (3% breastfeeding versus 14% non-breastfeeding, p = 0.008) or privacy (22% breastfeeding versus 40% non-breastfeeding, p = 0.19) concerns. Associations held after controlling for age, race, parity, insurance, geography, and marital-status. Significant associations between initiation, privacy, and safety concerns did not extend to duration or exclusivity. Many breastfeeding women reported safety and privacy concerns, especially outside the home and at work, which may influence breastfeeding initiation. Further study may identify methods to address these issues, potentially increasing breastfeeding rates.

Relationship Between Age, Tenure, and Disability Duration in Persons With Compensated Work-Related Conditions

PubMed Central

Besen, Elyssa; Young, Amanda E.; Gaines, Brittany; Pransky, Glenn

2016-01-01

Objective: The aim of the study was to examine the relationships among age, tenure, and the length of disability following a work-related injury/illness. Methods: This study utilized 361,754 administrative workers’ compensation claims. The relationships between age, tenure, and disability duration was estimated with random-effects models. Results: The age-disability duration relationship was stronger than the tenure-disability duration relationship. An interaction was observed between age and tenure. At younger ages, disability duration varied little based on tenure. In midlife, disability duration was greater for workers with lower tenure than for workers with higher tenure. At the oldest ages, disability duration increased as tenure increased. Conclusions: Findings indicate that age is a more important factor in disability duration than tenure; however, the relationship between age and disability duration varies based on tenure, suggesting that both age and tenure are important influences in the work-disability process. PMID:26645384

Relationship Between Age, Tenure, and Disability Duration in Persons With Compensated Work-Related Conditions.

PubMed

Besen, Elyssa; Young, Amanda E; Gaines, Brittany; Pransky, Glenn

2016-02-01

The aim of the study was to examine the relationships among age, tenure, and the length of disability following a work-related injury/illness. This study utilized 361,754 administrative workers' compensation claims. The relationships between age, tenure, and disability duration was estimated with random-effects models. The age-disability duration relationship was stronger than the tenure-disability duration relationship. An interaction was observed between age and tenure. At younger ages, disability duration varied little based on tenure. In midlife, disability duration was greater for workers with lower tenure than for workers with higher tenure. At the oldest ages, disability duration increased as tenure increased. Findings indicate that age is a more important factor in disability duration than tenure; however, the relationship between age and disability duration varies based on tenure, suggesting that both age and tenure are important influences in the work-disability process.

20 CFR 336.11 - Exhaustion of rights to normal unemployment benefits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Exhaustion of rights to normal unemployment... RAILROAD UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.11 Exhaustion of rights to normal unemployment benefits. For the purposes of this part, the Board considers that...

20 CFR 336.11 - Exhaustion of rights to normal unemployment benefits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Exhaustion of rights to normal unemployment... RAILROAD UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.11 Exhaustion of rights to normal unemployment benefits. For the purposes of this part, the Board considers that...

20 CFR 336.11 - Exhaustion of rights to normal unemployment benefits.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Exhaustion of rights to normal unemployment... RAILROAD UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.11 Exhaustion of rights to normal unemployment benefits. For the purposes of this part, the Board considers that...

20 CFR 336.11 - Exhaustion of rights to normal unemployment benefits.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Exhaustion of rights to normal unemployment... RAILROAD UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.11 Exhaustion of rights to normal unemployment benefits. For the purposes of this part, the Board considers that...

20 CFR 336.11 - Exhaustion of rights to normal unemployment benefits.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Exhaustion of rights to normal unemployment... RAILROAD UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Extended Benefits § 336.11 Exhaustion of rights to normal unemployment benefits. For the purposes of this part, the Board considers that...

Does time off work after injury vary by jurisdiction? A comparative study of eight Australian workers' compensation systems

PubMed Central

Collie, Alex; Lane, Tyler J; Hassani-Mahmooei, Behrooz; Thompson, Jason; McLeod, Chris

2016-01-01

Objectives To determine whether the jurisdiction in which a work-related injury compensation claim is made is an independent predictor of duration of time off work following work injury, and if so, the magnitude of the effect. Setting Eight Australian state and territory workers' compensation systems, providing coverage for more than 90% of the Australian labour force. Administrative claims data from these systems were provided by government regulatory authorities for the study. Participants 95 976 Australian workers with workers' compensation claims accepted in 2010 and with at least 2 weeks of compensated time off work. Primary outcome measure Duration of time lost from work in weeks, censored at 104 weeks. Results After controlling for demographic, worker, injury and employer factors in a Cox regression model, significant differences in duration of time loss between state and territory of claim were observed. Compared with New South Wales, workers in Victoria, South Australia and Comcare had significantly longer durations of time off work and were more likely to be receiving income benefits at 104 weeks postinjury, while workers in Tasmania and Queensland had significantly shorter durations of time off work. Conclusions The jurisdiction in which an injured worker makes a compensation claim has a significant and independent impact on duration of time loss. Further research is necessary to identify specific compensation system policies and practices that promote timely and appropriate return to work and reduce duration of time off work. PMID:27150186

An interventional approach for patient and nurse safety: a fatigue countermeasures feasibility study.

PubMed

Scott, Linda D; Hofmeister, Nancee; Rogness, Neal; Rogers, Ann E

2010-01-01

Studies indicate that extended shifts worked by hospital staff nurses are associated with higher risk of errors. Long work hours coupled with insufficient sleep and fatigue are even riskier. Although other industries have developed programs to reduce fatigue-related errors and injury, fatigue countermeasures program for nurses (FCMPN) are lacking. The objective of this study was to evaluate the feasibility of an FCMPN for improving sleep duration and quality while reducing daytime sleepiness and patient care errors. Selected sleep variables, errors and drowsy driving, were evaluated among hospital staff nurses (n = 47) before and after FCMPN implementation. A one-group pretest-posttest repeated-measures approach was used. Participants provided data 2 weeks before the FCMPN, 4 weeks after receiving the intervention, and again at 3 months after intervention. Most of the nurses experienced poor sleep quality, severe daytime sleepiness, and decreased alertness at work and while operating a motor vehicle. After the FCMPN, significant improvements were noted in sleep duration, sleep quality, alertness, and error prevention. Although significant improvements were not found in daytime sleepiness scores, severity of daytime sleepiness appeared to decrease. Despite improvements in fatigue management, nurses reported feelings of guilt when engaging in FCMPN activities, especially strategic naps and relieved breaks. Initial findings support the feasibility of using an FCMPN for mitigating fatigue, improving sleep, and reducing errors among hospital staff nurses. In future investigations, the acceptability, efficacy, and effectiveness of FCMPNs can be examined.

Growth behavior of carbon nanotubes on multilayered metal catalyst film in chemical vapor deposition

NASA Astrophysics Data System (ADS)

Cui, H.; Eres, G.; Howe, J. Y.; Puretkzy, A.; Varela, M.; Geohegan, D. B.; Lowndes, D. H.

2003-06-01

The temperature and time dependences of carbon nanotube (CNT) growth by chemical vapor deposition are studied using a multilayered Al/Fe/Mo catalyst on silicon substrates. Within the 600-1100 °C temperature range of these studies, narrower temperature ranges were determined for the growth of distinct types of aligned multi-walled CNTs and single-walled CNTs by using high-resolution transmission electron microscopy and Raman spectroscopy. At 900 °C, in contrast to earlier work, double-walled CNTs are found more abundant than single-walled CNTs. Defects also are found to accumulate faster than the ordered graphitic structure if the growth of CNTs is extended to long durations.

Online analysis and process control in recombinant protein production (review).

PubMed

Palmer, Shane M; Kunji, Edmund R S

2012-01-01

Online analysis and control is essential for efficient and reproducible bioprocesses. A key factor in real-time control is the ability to measure critical variables rapidly. Online in situ measurements are the preferred option and minimize the potential loss of sterility. The challenge is to provide sensors with a good lifespan that withstand harsh bioprocess conditions, remain stable for the duration of a process without the need for recalibration, and offer a suitable working range. In recent decades, many new techniques that promise to extend the possibilities of analysis and control, not only by providing new parameters for analysis, but also through the improvement of accepted, well practiced, measurements have arisen.

Processing and Preparation of Advanced Stirling Convertors for Extended Operation

NASA Technical Reports Server (NTRS)

Oriti, Salvatore M.; Cornell, Paggy A.

2008-01-01

The U.S. Department of Energy (DOE), Lockheed Martin Space Company (LMSC), Sunpower Inc., and NASA Glenn Research Center (GRC) have been developing an Advanced Stirling Radioisotope Generator (ASRG) for use as a power system on space science missions. This generator will make use of the free-piston Stirling convertors to achieve higher conversion efficiency than currently available alternatives. NASA GRC is supporting the development of the ASRG by providing extended operation of several Sunpower Inc. Advanced Stirling Convertors (ASCs). In the past year and a half, eight ASCs have operated in continuous, unattended mode in both air and thermal vacuum environments. Hardware, software, and procedures were developed to prepare each convertor for extended operation with intended durations on the order of tens of thousands of hours. Steps taken to prepare a convertor for long-term operation included geometry measurements, thermocouple instrumentation, evaluation of working fluid purity, evacuation with bakeout, and high purity charge. Actions were also taken to ensure the reliability of support systems, such as data acquisition and automated shutdown checkouts. Once a convertor completed these steps, it underwent short-term testing to gather baseline performance data before initiating extended operation. These tests included insulation thermal loss characterization, low-temperature checkout, and full-temperature and power demonstration. This paper discusses the facilities developed to support continuous, unattended operation, and the processing results of the eight ASCs currently on test.

Processing and Preparation of Advanced Stirling Convertors for Extended Operation at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Oriti, Salvatore M.; Cornell, Peggy A.

2008-01-01

The U.S. Department of Energy (DOE), Lockheed Martin Space Company (LMSC), Sunpower Inc., and NASA Glenn Research Center (GRC) have been developing an Advanced Stirling Radioisotope Generator (ASRG) for use as a power system on space science missions. This generator will make use of the free-piston Stirling convertors to achieve higher conversion efficiency than currently available alternatives. NASA GRC is supporting the development of the ASRG by providing extended operation of several Sunpower Inc. Advanced Stirling Convertors (ASCs). In the past year and a half, eight ASCs have operated in continuous, unattended mode in both air and thermal vacuum environments. Hardware, software, and procedures were developed to prepare each convertor for extended operation with intended durations on the order of tens of thousands of hours. Steps taken to prepare a convertor for long-term operation included geometry measurements, thermocouple instrumentation, evaluation of working fluid purity, evacuation with bakeout, and high purity charge. Actions were also taken to ensure the reliability of support systems, such as data acquisition and automated shutdown checkouts. Once a convertor completed these steps, it underwent short-term testing to gather baseline performance data before initiating extended operation. These tests included insulation thermal loss characterization, low-temperature checkout, and full-temperature and power demonstration. This paper discusses the facilities developed to support continuous, unattended operation, and the processing results of the eight ASCs currently on test.

The 120-S minute: using analysis of work activity to prevent psychological distress among elementary school teachers.

PubMed

Messing, K; Seifert, A M; Escalona, E

1997-01-01

Primary school teachers in Québec suffer psychological distress, as shown by the Québec Health Survey (M. Gervais, 1993; Santè Québec, 1995). The authors applied and extended the French model (F. Guérin, A. Laville, F. Daniellou, J. Duraffourg, & A. Kerguelen, 1991) of analysis of work activity to observing classroom teaching (14 women in 10 classrooms for a total of 48 hr 24 min) to identify stressful elements. The authors observed a rapid sequence of actions, eye fixations of short duration, little physical or mental relaxation, multiple simultaneous activities, and uncomfortable temperature and humidity levels. Teachers use many strategies to teach, to create a learning environment, and to maintain attention in classrooms under adverse conditions. Examination of these strategies led to recommendations to improve relations between the teachers and their supervisors and to make the classroom an easier place to teach.

Venous Thromboembolism Requiring Extended Anticoagulation Among HIV-Infected Patients in a Rural, Resource-Constrained Setting in Western Kenya.

PubMed

Kanyi, John; Karwa, Rakhi; Pastakia, Sonak Dinesh; Manji, Imran; Manyara, Simon; Saina, Collins

2017-05-01

HIV-infected patients are at an increased risk of developing venous thromboembolism (VTE), and minimal data are available to describe the need for extended treatment. To evaluate the frequency of and determine predictive risk factors for extended anticoagulation of VTE in HIV-infected patients in rural, western Kenya. A retrospective chart review was conducted at the Anticoagulation Monitoring Service affiliated with Moi Teaching and Referral Hospital and the Academic Model Providing Access to Healthcare. Data were collected on patients who were HIV-infected and receiving anticoagulation for lower-limb deep vein thrombosis. The need for extended anticoagulation, defined as receiving ≥7 months of warfarin therapy, was established based on patient symptoms or Doppler ultrasound-confirmed diagnosis. Evaluation of the secondary outcomes utilized a univariate analysis to identify risk factors associated with extended anticoagulation. A total of 71 patients were included in the analysis; 27 patients (38%) required extended anticoagulation. The univariate analysis showed a statistically significant association between the need for extended anticoagulation and achieving a therapeutic international normalized ratio within 21 days in both the unadjusted and adjusted analysis. Patients with a history of opportunistic infections required an extended duration of anticoagulation in the adjusted analysis: odds ratio = 3.42; 95% CI = 1.04-11.32; P = 0.04. This study shows that there may be a need for increased duration of anticoagulation in HIV-infected patients, with a need to address the issue of long-term management. Guideline recommendations are needed to address the complexity of treatment issues in this population.

Cohort mortality study of garment industry workers exposed to formaldehyde: update and internal comparisons.

PubMed

Meyers, Alysha R; Pinkerton, Lynne E; Hein, Misty J

2013-09-01

To further evaluate the association between formaldehyde and leukemia, we extended follow-up through 2008 for a cohort mortality study of 11,043 US formaldehyde-exposed garment workers. We computed standardized mortality ratios and standardized rate ratios stratified by year of first exposure, exposure duration, and time since first exposure. Associations between exposure duration and rates of leukemia and myeloid leukemia were further examined using Poisson regression models. Compared to the US population, myeloid leukemia mortality was elevated but overall leukemia mortality was not. In internal analyses, overall leukemia mortality increased with increasing exposure duration and this trend was statistically significant. We continue to see limited evidence of an association between formaldehyde and leukemia. However, the extended follow-up did not strengthen previously observed associations. In addition to continued epidemiologic research, we recommend further research to evaluate the biological plausibility of a causal relation between formaldehyde and leukemia. Copyright © 2013 Wiley Periodicals, Inc.

Introduction (Special Issue on Scientific Balloon Capabilities and Instrumentation)

NASA Technical Reports Server (NTRS)

Gaskin, Jessica A.; Smith, I. S.; Jones, W. V.

2014-01-01

In 1783, the Montgolfier brothers ushered in a new era of transportation and exploration when they used hot air to drive an un-tethered balloon to an altitude of 2 km. Made of sackcloth and held together with cords, this balloon challenged the way we thought about human travel, and it has since evolved into a robust platform for performing novel science and testing new technologies. Today, high-altitude balloons regularly reach altitudes of 40 km, and they can support payloads that weigh more than 3,000 kg. Long-duration balloons can currently support mission durations lasting 55 days, and developing balloon technologies (i.e. Super-Pressure Balloons) are expected to extend that duration to 100 days or longer; competing with satellite payloads. This relatively inexpensive platform supports a broad range of science payloads, spanning multiple disciplines (astrophysics, heliophysics, planetary and earth science.) Applications extending beyond traditional science include testing new technologies for eventual space-based application and stratospheric airships for planetary applications.

Responses of the crab Heterozius rotundifrons to heterospecific chemical alarm cues: phylogeny vs. ecological overlap.

PubMed

Hazlett, Brian A; McLay, Colin

2005-03-01

The big-handed brachyuran crab Heterozius rotundifrons extends the time spent in its anti-predator posture, limb extended posture, if exposed to chemical cues from crushed conspecifics. In this study, we tested whether crabs also respond to chemical cues from crushed heterospecific crabs, and if so, whether phylogenetic relations or ecological overlap is more important in influencing the duration of the anti-predator posture. Chemical cues from two other brachyuran crabs (Cyclograpsus lavauxi and Hemigrapsus sexdentatus), which do not overlap directly in ecological distribution with H. rotundifrons, elicited a duration of the anti-predator posture that was indistinguishable from that produced by conspecific chemical cues. In contrast, chemical cues from two anomuran crabs (Petrolisthes elongatus and Pagurus novizealandiae) that overlap in ecological distribution with H. rotundifrons, elicited durations of the antipredator posture that were significantly shorter than those of either conspecifics or more closely related crab species. Thus, phylogenetic relationship seems to be more important than ecological overlap in influencing anti-predator behavior in H. rotundifrons.

75 FR 78786 - Self-Regulatory Organizations; National Stock Exchange, Inc.; Notice of Filing and Immediate...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-16

... program will expire on December 10, 2010. The instant rule filing proposes to extend the pilot program... that the duration of this pilot program should be extended. Accordingly, pursuant to the instant rule... respect to the proposed rule change that are filed with the Commission, and all written communications...

Photometric and spectroscopic gamma-ray observations of solar transient phenomena using long duration balloons

NASA Technical Reports Server (NTRS)

Pelling, M. R.; Duttweiler, F.; Lin, R. F.; Levedahl, W. K.; Primbach, H.; Curtis, D. W.; Burley, K. C.

1985-01-01

A program currently in progress to conduct extended duration spectroscopic and photometric observation of solar X-ray phenomena from balloons is described. High photometric sensitivity to weak hard X-ray bursts is attained using a 600 sq cm array of phoswich scintillators. High spectral resolution for stronger bursts is available from an array of planar germanium detectors. These instruments are carried in a novel balloon gondola dssigned for the 15 to 20 day float durations available through using conventional zero pressure balloons in the radiation controlled (RACOON) mode.

Photometric and spectroscopic gamma-ray observations of solar transient phenomena using long duration balloons

NASA Astrophysics Data System (ADS)

Pelling, M. R.; Duttweiler, F.; Lin, R. F.; Levedahl, W. K.; Primbach, H.; Curtis, D. W.; Burley, K. C.

1985-08-01

A program currently in progress to conduct extended duration spectroscopic and photometric observation of solar X-ray phenomena from balloons is described. High photometric sensitivity to weak hard X-ray bursts is attained using a 600 sq cm array of phoswich scintillators. High spectral resolution for stronger bursts is available from an array of planar germanium detectors. These instruments are carried in a novel balloon gondola dssigned for the 15 to 20 day float durations available through using conventional zero pressure balloons in the radiation controlled (RACOON) mode.

Measurement of the permeability, perfusion, and histogram characteristics in relapsing-remitting multiple sclerosis using dynamic contrast-enhanced MRI with extended Tofts linear model.

PubMed

Yin, Ping; Xiong, Hua; Liu, Yi; Sah, Shambhu K; Zeng, Chun; Wang, Jingjie; Li, Yongmei; Hong, Nan

2018-01-01

To investigate the application value of using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with extended Tofts linear model for relapsing-remitting multiple sclerosis (RRMS) and its correlation with expanded disability status scale (EDSS) scores and disease duration. Thirty patients with multiple sclerosis (MS) underwent conventional magnetic resonance imaging (MRI) and DCE-MRI with a 3.0 Tesla MR scanner. An extended Tofts linear model was used to quantitatively measure MR imaging biomarkers. The histogram parameters and correlation among imaging biomarkers, EDSS scores, and disease duration were also analyzed. The MR imaging biomarkers volume transfer constant (K trans ), volume of the extravascular extracellular space per unit volume of tissue (Ve), fractional plasma volume (V p ), cerebral blood flow (CBF), and cerebral blood volume (CBV) of contrast-enhancing (CE) lesions were significantly higher (P < 0.05) than those of nonenhancing (NE) lesions and normal-appearing white matter (NAWM) regions. The skewness of Ve value in CE lesions was more close to normal distribution. There was no significant correlation among the biomarkers with the EDSS scores and disease duration (P > 0.05). Our study demonstrates that the DCE-MRI with the extended Tofts linear model can measure the permeability and perfusion characteristic in MS lesions and in NAWM regions. The K trans , Ve, Vp, CBF, and CBV of CE lesions were significantly higher than that of NE lesions. The skewness of Ve value in CE lesions was more close to normal distribution, indicating that the histogram can be helpful to distinguish the pathology of MS lesions.

An Examination of Alternate Assessment Durations when Assessing Multiple-Skill Computational Fluency: The Generalizability and Dependability of Curriculum-Based Outcomes within the Context of Educational Decisions

ERIC Educational Resources Information Center

Christ, Theodore J.; Johnson-Gros, Kristin H.

2005-01-01

The current study extended previous research on curriculum-based measurement in mathematics (M-CBM) assessments. The purpose was to examine the generalizability and dependability of multiple-skill M-CBM computation assessments across various assessment durations (1, 2, 3, 4, 5, and 6 minutes). Results of generalizability and dependability studies…

[Predictors of the duration of non-work-related sick leave due to anxiety disorders].

PubMed

Catalina-Romero, Carlos; Martínez-Muñoz, Paloma; Quevedo-Aguado, Luis; Ruiz-Moraga, Montserrat; Fernández-Labandera, Carlos; Calvo-Bonacho, Eva

2013-01-01

To analyze the duration of non-work-related sick leave due to anxiety disorders and to identify demographic, occupational and clinical variables that may contribute to its prediction. We performed a prospective cohort study of 1,161 workers with an episode of non-work-related sick leave due to an anxiety disorder, belonging to the insured population of a mutual insurance company. We assessed the duration of non-work-related sick leave episodes and the main potentially related demographic, occupational and clinical variables. All non-work-related sick leave processes were followed-up until discharge. Cox regression analyses were conducted to establish the predictors of non-work-related sick leave duration. The median duration of non-work-related sick leave due to anxiety disorders was 83 days. In a multivariate analysis, the following factors were identified as being significantly associated with increases in the duration of sick leave (p <0.05): age of over 35 years, lower educational level (primary school studies, secondary school studies or high-school diploma vs. university degree), and the existence of comorbidity and unemployment occurring during the sick leave. In contrast, being separated or divorced was associated with an earlier return to work (p <0.05). Anxiety disorders are associated with long periods of non-work-related sick leave compared with other disorders and standard time duration. Demographic, occupational and clinical variables collected at the initial assessment of the sick leave episode would help to identify groups with an increased risk of prolonged sick leave, requiring strategies to facilitate return to work. Copyright © 2011 SESPAS. Published by Elsevier Espana. All rights reserved.

Space transportation system options for extended duration and power

NASA Technical Reports Server (NTRS)

Loftus, J. P., Jr.

1979-01-01

A modification kit for the Space Transportation System (STS) Orbiter is proposed to provide more power and mission duration for payloads. The power extension package (PEP) - a flexible-substrate solar array deployed on the Space Shuttle Orbiter remote manipulator system - can provide as much as 29 kW total power for durations of 10 to 48 days. The kit is installed only for those flights which require enhanced power or duration. Modifications to the Orbiter thermal control and life support systems to improve heat balance and to reduce consumables are proposed. The changes consist of repositioning the Orbiter forward radiators and replacing the lithium hydroxide scrubber with a regenerable solid amine.

Evaluation of SAMe-TT2R2 Score on Predicting Success With Extended-Interval Warfarin Monitoring.

PubMed

Hwang, Andrew Y; Carris, Nicholas W; Dietrich, Eric A; Gums, John G; Smith, Steven M

2018-06-01

In patients with stable international normalized ratios, 12-week extended-interval warfarin monitoring can be considered; however, predictors of success with this strategy are unknown. The previously validated SAMe-TT 2 R 2 score (considering sex, age, medical history, treatment, tobacco, and race) predicts anticoagulation control during standard follow-up (every 4 weeks), with lower scores associated with greater time in therapeutic range. To evaluate the ability of the SAMe-TT 2 R 2 score in predicting success with extended-interval warfarin follow-up in patients with previously stable warfarin doses. In this post hoc analysis of a single-arm feasibility study, baseline SAMe-TT 2 R 2 scores were calculated for patients with ≥1 extended-interval follow-up visit. The primary analysis assessed achieved weeks of extended-interval follow-up according to baseline SAMe-TT 2 R 2 scores. A total of 47 patients receiving chronic anticoagulation completed a median of 36 weeks of extended-interval follow-up. The median baseline SAMe-TT 2 R 2 score was 1 (range 0-5). Lower SAMe-TT 2 R 2 scores appeared to be associated with greater duration of extended-interval follow-up achieved, though the differences between scores were not statistically significant. No individual variable of the SAMe-TT 2 R 2 score was associated with achieved weeks of extended-interval follow-up. Analysis of additional patient factors found that longer duration (≥24 weeks) of prior stable treatment was significantly associated with greater weeks of extended-interval follow-up completed ( P = 0.04). Conclusion and Relevance: This pilot study provides limited evidence that the SAMe-TT 2 R 2 score predicts success with extended-interval warfarin follow-up but requires confirmation in a larger study. Further research is also necessary to establish additional predictors of successful extended-interval warfarin follow-up.

A Review of Training Methods and Instructional Techniques: Implications for Behavioral Skills Training in U.S. Astronauts (DRAFT)

NASA Technical Reports Server (NTRS)

Hysong, Sylvia J.; Galarza, Laura; Holland, Albert W.

2007-01-01

Long-duration space missions (LDM) place unique physical, environmental and psychological demands on crewmembers that directly affect their ability to live and work in space. A growing body of research on crews working for extended periods in isolated, confined environments reveals the existence of psychological and performance problems in varying degrees of magnitude. The research has also demonstrated that although the environment plays a cathartic role, many of these problems are due to interpersonal frictions (Wood, Lugg, Hysong, & Harm, 1999), and affect each individual differently. Consequently, crewmembers often turn to maladaptive behaviors as coping mechanisms, resulting in decreased productivity and psychological discomfort. From this body of research, critical skills have been identified that can help a crewmember better navigate the psychological challenges of long duration space flight. Although most people lack several of these skills, most of them can be learned; thus, a training program can be designed to teach crewmembers effective leadership, teamwork, and self-care strategies that will help minimize the emergence of maladaptive behaviors. Thus, it is the purpose of this report is twofold: 1) To review the training literature to help determine the optimal instructional methods to use in delivering psychological skill training to the U.S. Astronaut Expedition Corps, and 2) To detail the structure and content of the proposed Astronaut Expedition Corps Psychological Training Program.

Sampling considerations for modal analysis with damping

NASA Astrophysics Data System (ADS)

Park, Jae Young; Wakin, Michael B.; Gilbert, Anna C.

2015-03-01

Structural health monitoring (SHM) systems are critical for monitoring aging infrastructure (such as buildings or bridges) in a cost-effective manner. Wireless sensor networks that sample vibration data over time are particularly appealing for SHM applications due to their flexibility and low cost. However, in order to extend the battery life of wireless sensor nodes, it is essential to minimize the amount of vibration data these sensors must collect and transmit. In recent work, we have studied the performance of the Singular Value Decomposition (SVD) applied to the collection of data and provided new finite sample analysis characterizing conditions under which this simple technique{also known as the Proper Orthogonal Decomposition (POD){can correctly estimate the mode shapes of the structure. Specifically, we provided theoretical guarantees on the number and duration of samples required in order to estimate a structure's mode shapes to a desired level of accuracy. In that previous work, however, we considered simplified Multiple-Degree-Of-Freedom (MDOF) systems with no damping. In this paper we consider MDOF systems with proportional damping and show that, with sufficiently light damping, the POD can continue to provide accurate estimates of a structure's mode shapes. We support our discussion with new analytical insight and experimental demonstrations. In particular, we study the tradeoffs between the level of damping, the sampling rate and duration, and the accuracy to which the structure's mode shapes can be estimated.

Time-Extended Payoffs for Collectives of Autonomous Agents

NASA Technical Reports Server (NTRS)

Tumer, Kagan; Agogino, Adrian K.

2002-01-01

A collective is a set of self-interested agents which try to maximize their own utilities, along with a a well-defined, time-extended world utility function which rates the performance of the entire system. In this paper, we use theory of collectives to design time-extended payoff utilities for agents that are both aligned with the world utility, and are "learnable", i.e., the agents can readily see how their behavior affects their utility. We show that in systems where each agent aims to optimize such payoff functions, coordination arises as a byproduct of the agents selfishly pursuing their own goals. A game theoretic analysis shows that such payoff functions have the net effect of aligning the Nash equilibrium, Pareto optimal solution and world utility optimum, thus eliminating undesirable behavior such as agents working at cross-purposes. We then apply collective-based payoff functions to the token collection in a gridworld problem where agents need to optimize the aggregate value of tokens collected across an episode of finite duration (i.e., an abstracted version of rovers on Mars collecting scientifically interesting rock samples, subject to power limitations). We show that, regardless of the initial token distribution, reinforcement learning agents using collective-based payoff functions significantly outperform both natural extensions of single agent algorithms and global reinforcement learning solutions based on "team games".

Association between shift work and obesity among female nurses: Korean Nurses’ Survey

PubMed Central

2013-01-01

Background Shift work has been hypothesized as a risk factor for obesity. In this study, we investigated the association between current shift work and body mass index (BMI) among female nurses in Korea. The relationship between duration of shift work and BMI of the participants was also evaluated. Methods This cross-sectional survey evaluated participants in the Korean Nurses’ Survey, conducted from October to December 2011, using web-based self-administered questionnaires. A total of 9,989 nurses were included among 10,000 who registered on the survey web site (5,287 shift workers and 4,702 non-shift workers). Current shift workers were divided into tertiles of shift work duration (0.08–3.00 years, n = 1,732; 3.08–6.75 years, n = 1,731; and 6.83–38.00 years, n = 1,686). The BMI thresholds of overweight and obesity were ≥23 kg/m2 and ≥25 kg/m2, respectively. Data were analyzed using SPSS software. Results Mean participant age was 33.2 ± 8.6 years and the mean BMI was 20.9 ± 2.5 kg/m2. There were statistically significant differences in current smoking status, regular drinking habit, dietary habits, regular exercise, sleep problems and self-perceived health status according to duration of shift work. The overall prevalence of overweight/obesity (18.6%) and obesity (7.4%) increased significantly as shift work duration increased from the lowest to highest tertile (P for trend <0.001). Multivariate logistic regression analysis revealed no association between current shift work and BMI. However, after adjusting for potential confounders, the participants with the longest duration of shift work were 1.63 (95% CI, 1.22–2.17) times more likely to be overweight or obese than those with the shortest duration. There was a significant positive association between obesity and shift work duration in the unadjusted analysis; however, it was attenuated and no longer significant in the multivariate model. Conclusions The duration of shift work was positively associated with prevalence of overweight/obesity in nurses in Korea. Although these findings need to be confirmed in prospective studies, they suggest that special attention should be paid to female nurses with a long duration of shift work. PMID:24354395

Software-recorded and self-reported duration of computer use in relation to the onset of severe arm-wrist-hand pain and neck-shoulder pain.

PubMed

Ijmker, Stefan; Huysmans, Maaike A; van der Beek, Allard J; Knol, Dirk L; van Mechelen, Willem; Bongers, Paulien M; Blatter, Birgitte M

2011-07-01

In both science and media, the adverse effects of a long duration of computer use at work on musculoskeletal health have long been debated. Until recently, the duration of computer use was mainly measured by self-reports, and studies using more objective measures, such as software-recorded computer duration, were lacking. The objective of this study was to examine the association between duration of computer use at work, measured with software and self-reports, and the onset of severe arm-wrist-hand and neck-shoulder symptoms. A 2-year follow-up study was conducted between 2004 and 2006 among 1951 office workers in The Netherlands. Self-reported computer duration and other risk factors were collected at baseline and at 1-year follow-up. Computer use at work was recorded continuously with computer software for 1009 participants. Outcome questionnaires were obtained at baseline and every 3 months during follow-up. Cases were identified based on the transition within 3 months of no or minor symptoms to severe symptoms. Self-reported duration of computer use was positively associated with the onset of both arm-wrist-hand (RR 1.9, 95% CI 1.1 to 3.1 for more than 4 h/day of total computer use at work) and neck-shoulder symptoms (RR 1.5, 95% CI 1.1 to 2.0 for more than 4 h/day of mouse use at work). The recorded duration of computer use did not show any statistically significant association with the outcomes. In the present study, no association was found between the software-recorded duration of computer use at work and the onset of severe arm-wrist-hand and neck-shoulder symptoms using an exposure window of 3 months. In contrast, a positive association was found between the self-reported duration of computer use at work and the onset of severe arm-wrist-hand and neck-shoulder symptoms. The different findings for recorded and self-reported computer duration could not be explained satisfactorily.

Effects of health care provider work hours and sleep deprivation on safety and performance.

PubMed

Lockley, Steven W; Barger, Laura K; Ayas, Najib T; Rothschild, Jeffrey M; Czeisler, Charles A; Landrigan, Christopher P

2007-11-01

There has been increasing interest in the impact of resident-physician and nurse work hours on patient safety. The evidence demonstrates that work schedules have a profound effect on providers' sleep and performance, as well as on their safety and that of their patients. Nurses working shifts greater than 12.5 hours are at significantly increased risk of experiencing decreased vigilance on the job, suffering an occupational injury, or making a medical error. Physicians-in-training working traditional > 24-hour on-call shifts are at greatly increased risk of experiencing an occupational sharps injury or a motor vehicle crash on the drive home from work and of making a serious or even fatal medical error. As compared to when working 16-hours shifts, on-call residents have twice as many attentional failures when working overnight and commit 36% more serious medical errors. They also report making 300% more fatigue-related medical errors that lead to a patient's death. The weight of evidence strongly suggests that extended-duration work shifts significantly increase fatigue and impair performance and safety. From the standpoint of both providers and patients, the hours routinely worked by health care providers in the United States are unsafe. To reduce the unacceptably high rate of preventable fatigue-related medical error and injuries among health care workers, the United States must establish and enforce safe work-hour limits.

Relevant factors for the optimal duration of extended endocrine therapy in early breast cancer.

PubMed

Blok, Erik J; Kroep, Judith R; Meershoek-Klein Kranenbarg, Elma; Duijm-de Carpentier, Marjolijn; Putter, Hein; Liefers, Gerrit-Jan; Nortier, Johan W R; Rutgers, Emiel J Th; Seynaeve, Caroline M; van de Velde, Cornelis J H

2018-04-01

For postmenopausal patients with hormone receptor-positive early breast cancer, the optimal subgroup and duration of extended endocrine therapy is not clear yet. The aim of this study using the IDEAL patient cohort was to identify a subgroup for which longer (5 years) extended therapy is beneficial over shorter (2.5 years) extended endocrine therapy. In the IDEAL trial, 1824 patients who completed 5 years of adjuvant endocrine therapy (either 5 years of tamoxifen (12%), 5 years of an AI (29%), or a sequential strategy of both (59%)) were randomized between either 2.5 or 5 years of extended letrozole. For each prior therapy subgroup, the value of longer therapy was assessed for both node-negative and node-positive patients using Kaplan Meier and Cox regression survival analyses. In node-positive patients, there was a significant benefit of 5 years (over 2.5 years) of extended therapy (disease-free survival (DFS) HR 0.67, p = 0.03, 95% CI 0.47-0.96). This effect was only observed in patients who were treated initially with a sequential scheme (DFS HR 0.60, p = 0.03, 95% CI 0.38-0.95). In all other subgroups, there was no significant benefit of longer extended therapy. Similar results were found in patients who were randomized for their initial adjuvant therapy in the TEAM trial (DFS HR 0.37, p = 0.07, 95% CI 0.13-1.06), although this additional analysis was underpowered for definite conclusions. This study suggests that node-positive patients could benefit from longer extended endocrine therapy, although this effect appears isolated to patients treated with sequential endocrine therapy during the first 5 years and needs validation and long-term follow-up.

Antarctic Space Analog Program

NASA Technical Reports Server (NTRS)

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

1998-01-01

The primary aim of this project was to examine group dynamics and individual performance in extreme, isolated environments and identify human factors requirements for long-duration space missions using data collected in an analog environment. Specifically, we wished to determine: 1) the characteristics of social relations in small groups of individuals living and working together in extreme, isolated environments, and 2) the environmental, social and psychological determinants of performance effectiveness in such groups. These two issues were examined in six interrelated studies using data collected in small, isolated research stations in Antarctica from 1963 to the present. Results from these six studies indicated that behavior and performance on long-duration space flights is likely to be seasonal or cyclical, situational, social, and salutogenic in nature. The project responded to two NASA program emphases for FY 1997 as described in the NRA: 1) the primary emphasis of the Behavior and Performance Program on determining long-term individual and group performance responses to space, identifying critical factors affecting those responses and understanding underlying mechanisms involved in behavior and performance, and developing and using ground-based models and analogs for studying space-related behavior and performance; and 2) the emphasis of the Data Analysis Program on extended data analysis. Results from the study were used to develop recommendations for the design and development of pre-flight crew training and in-flight psychological countermeasures for long-duration manned space missions.

A climatological study of the duration of Northern Hemisphere Cut-off low systems

NASA Astrophysics Data System (ADS)

Nieto, R.; Gimeno, L.; de La Torre, L.; Tesouro, M.; Añel, J. A.; Ribera, P.

2003-04-01

Cut-off low-pressure systems-COLS- are usually closed circulations at middle and upper troposphere developed from a deep trough in the westerlies. The importance of their study is due to both the convective severe events that can occur if they are over warm ocean and because they are important mechanisms of Stratosphere-troposphere exchange- STE-. A COL system would last about a couple of days before being destroyed by diabatic heating if there were not injection of new air into the COL with high potential vorticity. In the practice their duration range from 1 day to 17 days. There are previous climatological studies about the duration of COLs, but limited to five years. In this work we extended the study to a period of 41-year period (1958 to 1998). The identification of COLs were done using an approach based in imposing the three main physical characteristics of the conceptual model of COL (a. closed circulation and minimum of geopotential, minimum of equivalent thickness, and two baroclinic zones, one in front of the low and the other behind the low). Data from NCAR-NCEP reanalysis were used. Results confirmed previous studies that most of COL systems have a short time of life. The majority of COLs lasted 2-3 days and very few lasted more than 10 days.

Application of virtual reality for crew mental health in extended-duration space missions

NASA Astrophysics Data System (ADS)

Salamon, Nick; Grimm, Jonathan M.; Horack, John M.; Newton, Elizabeth K.

2018-05-01

Human exploration of the solar system brings a host of environmental and engineering challenges. Among the most important factors in crew health and human performance is the preservation of mental health. The mental well-being of astronaut crews is a significant issue affecting the success of long-duration space missions, such as habitation on or around the Moon, Mars exploration, and eventual colonization of the solar system. If mental health is not properly addressed, these missions will be at risk. Upkeep of mental health will be especially difficult on long duration missions because many of the support systems available to crews on shorter missions will not be available. In this paper, we examine the use of immersive virtual reality (VR) simulations to maintain healthy mental states in astronaut crews who are removed from the essential comforts typically associated with terrestrial life. Various methods of simulations and their administration are analyzed in the context of current research and knowledge in the fields of psychology, medicine, and space sciences, with a specific focus on the environment faced by astronauts on long-term missions. The results of this investigation show that virtual reality should be considered a plausible measure in preventing mental state deterioration in astronauts, though more work is needed to provide a comprehensive view of the effectiveness and administration of VR methods.

Effect of semen extender supplementation with cysteine on postthaw sperm quality, DNA damage, and fertilizing ability in the common carp (Cyprinus carpio).

PubMed

Öğretmen, Fatih; İnanan, Burak Evren; Kutluyer, Filiz; Kayim, Murathan

2015-06-01

Amino acids have an important biological role for prevention of cell damage during cryopreservation. The objective of this study is to determine the effects of cysteine on postthaw sperm motility, duration of sperm motility, DNA damage, and fertility in the common carp (Cyprinus carpio). Sperm collected from 10 individuals was cryopreserved in extenders containing different cysteine concentrations (2.5, 5, 10, and 20 mM). Semen samples diluted at the ratio of 1:9 by the extenders were subjected to cryopreservation. After dilution, the semen was aspirated into 0.25-mL straws; the straws were placed on the tray, frozen in nitrogen vapor, and plunged into liquid nitrogen. DNA damage was evaluated by comet assay after cryopreservation. Our results indicated that an increase in the concentration of cysteine caused a significant increase in the motility rate and duration of sperm in the common carp (C carpio; P < 0.05). Comparing all concentrations of cysteine, the best concentration of cysteine was 20 mM. Higher postthaw motility (76.00 ± 1.00%) and fertilization (97.00 ± 1.73%) rates were obtained with the extender at the concentration of 20 mM. Supplementation of the extender with cysteine was increased the fertilization and hatching rate and decreased DNA damage. Consequently, cysteine affected the motility, fertilization, and DNA damage positively, and extenders could be supplemented with cysteine. Copyright © 2015 Elsevier Inc. All rights reserved.

The LDEF ultra heavy cosmic ray experiment

NASA Technical Reports Server (NTRS)

Osullivan, D.; Thompson, A.; Bosch, J.; Keegan, R.; Wenzel, K.-P.; Smit, A.; Domingo, C.

1992-01-01

The LDEF Ultra Heavy Cosmic Ray Experiment (UHCRE) used 16 side viewing LDEF trays giving a total geometry factor for high energy cosmic rays of 30 sq m sr. The total exposure factor was 170 sq m sr y. The experiment is based on a modular array of 192 solid state nuclear track detector stacks, mounted in sets of four in 48 pressure vessels. The extended duration of the LDEF mission has resulted in a greatly enhanced potential scientific yield from the UHCRE. Initial scanning results indicate that at least 1800 cosmic ray nuclei with Z greater than 65 were collected, including the world's first statistically significant sample of actinides. Post flight work to date and the current status of the experiment are reviewed.

Screening protocols for the prevention of occupational noise-induced hearing loss: the role of conventional and extended high frequency audiometry may vary according to the years of employment.

PubMed

Riga, Maria; Korres, George; Balatsouras, Dimitrios; Korres, Stavros

2010-07-01

Although occupational noise-induced hearing loss (NIHL) has become a major problem in industrialized societies, there is a notable lack of effective screening protocols to ensure its early diagnosis. The aim of this study was to detect a potential role of extended high frequency (EHF) audiometry in industrial hearing screening protocols. The population consisted of 151 persons, working for 8 hours daily in a noisy environment (90-110 dBA). The changes of hearing thresholds in industrial workers were analyzed, not only with respect to their age, as has been presented by previous studies, but also with respect to the duration of their previous employment. During the first 10 years of employment, the frequencies 12500, 14000 and 16000Hz were the only ones significantly affected. For the second decade of employment, thresholds were significantly elevated only at 2000 and 4000Hz. After exceeding 20 years of employment, the affected frequencies were 250, 500 and 1000Hz. The effects of age on hearing acuity were significant at all frequencies for the first 2 groups. EHF audiometry seems able to identify the first signs of NIHL, much earlier than conventional audiometry, and therefore may need to be implemented in the screening examinations especially of workers with less than 1 decade of employment. Hearing screening protocols could become more efficient by adjusting their frequency ranges according to the frequencies "at risk", which correspond to the duration of the workers' previous employment.

Timing of insolation forcing, CO2 and sea level changes around the current and last four interglacial periods

NASA Astrophysics Data System (ADS)

Kawamura, K.; Aoki, S.; Nakazawa, T.; Abe-Ouchi, A.; Saito, F.

2013-12-01

Investigation of the roles of different forcings (e.g. orbital variations and greenhouse gases) on climate and sea level requires a paleoclimate chronology with high accuracy. Such a chronology for the past 360 ky was constructed through orbital tuning of O2/N2 ratio of trapped air in the Dome Fuji and Vostok ice cores with local summer insolation (Kawamura et al., 2007). We extend the O2/N2 chronology back to ~500 kyr by analyzing the second Dome Fuji ice core, and find the duration of 11 ka, 5 ka, 9 ka, and 20 ka for MIS 5e, 7e, 9e and 11c interglacial periods in Antarctica, with similar variations in atmospheric CO2. The termination timings are consistent with the rising phase of Northern Hemisphere summer insolation. Marine sediment cores from northern North Atlantic contain millennial-scale signatures in various proxy records (e.g. SST, IRD), including abrupt climatic shifts and bipolar seesaw. Based on the bipolar correlation of millennial-scale events, it is possible to transfer our accurate chronology to marine cores from the North Atlantic. As a first attempt, we correlate the planktonic δ18O and IRD records from the marine core ODP 980 with the ice-core δ18O and CH4 around MIS 11. We find that the durations of interglacial plateaus of planktonic δ18O (proxy for sea surface environments) and benthic δ18O (proxy for ice volume and deep-sea temperature) for MIS 11c are 20 and 15 ka, respectively, which are significantly shorter than originally suggested. These durations are similar to that of Antarctic climate and atmospheric CO2. However, the onsets of interglacial levels in ODP980 for MIS 11 are significantly later than those in Antarctic δ18O and atmospheric CO2 (by as much as ~10 ka), suggesting very long duration (more than one precession cycle) for the complete deglaciation and northern high-latitude warming for Termination V. Atmospheric CO2 may have been the critical forcing for this termination. The long duration of Termination V is consistent with our new ice sheet simulations (extended from the work of Abe-Ouchi et al., 2013) in which an ice-sheet/climate model is forced by insolation and CO2 variations. In the presentation, comparisons for other interglacial periods will also be reported.

Afternoon Napping and Cognition in Chinese Older Adults: Findings from the China Health and Retirement Longitudinal Study Baseline Assessment.

PubMed

Li, Junxin; Cacchione, Pamela Z; Hodgson, Nancy; Riegel, Barbara; Keenan, Brendan T; Scharf, Mathew T; Richards, Kathy C; Gooneratne, Nalaka S

2017-02-01

To examine the cross-sectional associations between self-reported postlunch napping and structured cognitive assessments in Chinese older adults. Cross-sectional cohort study. China. Individuals aged 65 and older from the baseline national wave of the China Health and Retirement Longitudinal Study (CHARLS) (N = 2,974). Interview-based cognitive assessments of orientation and attention, episodic memory, visuospatial abilities, and a combined global cognition score incorporating these assessments. Other self-reported or interview-based assessments included postlunch napping duration, nighttime sleep duration, demographic characteristics, health habits, comorbidities, functional status and social activities. According to reported napping duration, older adults were categorized as non-nappers (0 minutes), short nappers (<30 minutes), moderate nappers (30-90 minutes), and extended nappers (>90 minutes). Postlunch napping was reporting in 57.7% of participants for a mean of 63 minutes. Cognitive function was significantly associated with napping (P < .001). Between-group comparisons showed that moderate nappers had better overall cognition than nonnappers (P < .001) or extended nappers (P = .01). Nonnappers also had significantly poorer cognition than short nappers (P = .03). In multiple regression analysis, moderate napping was significantly associated with better cognition than non- (P = .004), short (P = .04), and extended napping (P = .002), after controlling for demographic characteristics, body mass index, depression, instrumental activities of daily living, social activities, and nighttime sleep duration. A cross-sectional association was found between moderate postlunch napping and better cognition in Chinese older adults. The cross-sectional design and self-reported measures of sleep limited the findings. Longitudinal studies with objective napping measures are needed to further test this hypothesis. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

Applying mathematical models to predict resident physician performance and alertness on traditional and novel work schedules.

PubMed

Klerman, Elizabeth B; Beckett, Scott A; Landrigan, Christopher P

2016-09-13

In 2011 the U.S. Accreditation Council for Graduate Medical Education began limiting first year resident physicians (interns) to shifts of ≤16 consecutive hours. Controversy persists regarding the effectiveness of this policy for reducing errors and accidents while promoting education and patient care. Using a mathematical model of the effects of circadian rhythms and length of time awake on objective performance and subjective alertness, we quantitatively compared predictions for traditional intern schedules to those that limit work to ≤ 16 consecutive hours. We simulated two traditional schedules and three novel schedules using the mathematical model. The traditional schedules had extended duration work shifts (≥24 h) with overnight work shifts every second shift (including every third night, Q3) or every third shift (including every fourth night, Q4) night; the novel schedules had two different cross-cover (XC) night team schedules (XC-V1 and XC-V2) and a Rapid Cycle Rotation (RCR) schedule. Predicted objective performance and subjective alertness for each work shift were computed for each individual's schedule within a team and then combined for the team as a whole. Our primary outcome was the amount of time within a work shift during which a team's model-predicted objective performance and subjective alertness were lower than that expected after 16 or 24 h of continuous wake in an otherwise rested individual. The model predicted fewer hours with poor performance and alertness, especially during night-time work hours, for all three novel schedules than for either the traditional Q3 or Q4 schedules. Three proposed schedules that eliminate extended shifts may improve performance and alertness compared with traditional Q3 or Q4 schedules. Predicted times of worse performance and alertness were at night, which is also a time when supervision of trainees is lower. Mathematical modeling provides a quantitative comparison approach with potential to aid residency programs in schedule analysis and redesign.

Sex-Related Differences in the Effects of Sleep Habits on Verbal and Visuospatial Working Memory

PubMed Central

Nakagawa, Seishu; Takeuchi, Hikaru; Taki, Yasuyuki; Nouchi, Rui; Sekiguchi, Atsushi; Kotozaki, Yuka; Miyauchi, Carlos M.; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

2016-01-01

Poor sleep quality negatively affects memory performance, and working memory in particular. We investigated sleep habits related to sleep quality including sleep duration, daytime nap duration, nap frequency, and dream content recall frequency (DCRF). Declarative working memory can be subdivided into verbal working memory (VWM) and visuospatial working memory (VSWM). We hypothesized that sleep habits would have different effects on VWM and VSWM. To our knowledge, our study is the first to investigate differences between VWM and VSWM related to daytime nap duration, nap frequency, and DCRF. Furthermore, we tested the hypothesis that the effects of duration and frequency of daytime naps and DCRF on VWM and VSWM differed according to sex. We assessed 779 healthy right-handed individuals (434 males and 345 females; mean age: 20.7 ± 1.8 years) using a digit span forward and backward VWM task, a forward and backward VSWM task, and sleep habits scales. A correlation analysis was used to test the relationships between VWM capacity (VWMC) and VSWM capacity (VSWMC) scores and sleep duration, nap duration, nap frequency, and DCRF. Furthermore, multiple regression analyses were conducted to identify factors associated with VWMC and VSWMC scores and to identify sex-related differences. We found significant positive correlations between VSWMC and nap duration and DCRF, and between VWMC and sleep duration in all subjects. Furthermore, we found that working memory capacity (WMC) was positively correlated with nap duration in males and with sleep duration in females, and DCRF was positively correlated with VSWMC in females. Our finding of sex-related differences in the effects of sleep habits on WMC has not been reported previously. The associations between WMC and sleep habits differed according to sex because of differences in the underlying neural correlates of VWM and VSWM, and effectiveness of the sleep habits in males and females. PMID:27516751

Sex-Related Differences in the Effects of Sleep Habits on Verbal and Visuospatial Working Memory.

PubMed

Nakagawa, Seishu; Takeuchi, Hikaru; Taki, Yasuyuki; Nouchi, Rui; Sekiguchi, Atsushi; Kotozaki, Yuka; Miyauchi, Carlos M; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

2016-01-01

Poor sleep quality negatively affects memory performance, and working memory in particular. We investigated sleep habits related to sleep quality including sleep duration, daytime nap duration, nap frequency, and dream content recall frequency (DCRF). Declarative working memory can be subdivided into verbal working memory (VWM) and visuospatial working memory (VSWM). We hypothesized that sleep habits would have different effects on VWM and VSWM. To our knowledge, our study is the first to investigate differences between VWM and VSWM related to daytime nap duration, nap frequency, and DCRF. Furthermore, we tested the hypothesis that the effects of duration and frequency of daytime naps and DCRF on VWM and VSWM differed according to sex. We assessed 779 healthy right-handed individuals (434 males and 345 females; mean age: 20.7 ± 1.8 years) using a digit span forward and backward VWM task, a forward and backward VSWM task, and sleep habits scales. A correlation analysis was used to test the relationships between VWM capacity (VWMC) and VSWM capacity (VSWMC) scores and sleep duration, nap duration, nap frequency, and DCRF. Furthermore, multiple regression analyses were conducted to identify factors associated with VWMC and VSWMC scores and to identify sex-related differences. We found significant positive correlations between VSWMC and nap duration and DCRF, and between VWMC and sleep duration in all subjects. Furthermore, we found that working memory capacity (WMC) was positively correlated with nap duration in males and with sleep duration in females, and DCRF was positively correlated with VSWMC in females. Our finding of sex-related differences in the effects of sleep habits on WMC has not been reported previously. The associations between WMC and sleep habits differed according to sex because of differences in the underlying neural correlates of VWM and VSWM, and effectiveness of the sleep habits in males and females.

Evaluation of three ergonomic measures on productivity, physical work demands, and workload in gypsum bricklayers.

PubMed

van der Molen, Henk F; Kuijer, P Paul F M; Formanoy, Margriet; Bron, Lennart; Hoozemans, Marco J M; Visser, Bart; Frings-Dresen, Monique H W

2010-06-01

This study evaluated the effects of a combination of three ergonomic measures designed to reduce the risk of low back complaints among gypsum bricklayers. The measures focused on optimizing working height and reducing carrying distances. A within-subjects (N = 10) controlled field study was used to compare the effects of working with the ergonomic measures with those of working with conventional working methods at the worksite during the course of a full working day. Productivity, work demands, and workload were assessed. No effects were found on productivity, total work time, duration of tasks, duration of carrying, or energetic or biomechanical workload. However, the duration and frequency of working between knee and hip height during a working day increased by 25% and 15%, respectively, due to the ergonomic measures. During the finishing task, the duration and frequency of working below knee level decreased significantly by 4 min and 71 times, respectively. The limited impact of the ergonomic measures argues for additional measures to reduce the risk of low back complaints. 2010 Wiley-Liss, Inc.

The interpretation of optical light variations of Centaurus X-3

NASA Technical Reports Server (NTRS)

Mauder, H.

1976-01-01

The interpretation of optical light variations of X-ray binaries is discussed for the case of negligible reflection effect. The limiting cases of synchronous rotation of the visible star (Roche configuration) and of no rotation (pure tidal deformation) are considered. The theoretical results are compared with the available light curves of Cen X-3. X-ray data of the Copernicus satellite are used to get an impression of the atmospheric structure of the outer layers of the visible component. It is shown, that the X-ray eclipse duration is in good agreement with the mass ration derived from the optical variations. The X-ray eclipse duration is discussed with respect to the extended low states, and a possible correlation of the extended lows with the appearance of the optical light curves is considered.

A randomized clinical trial comparing an extended-use hygroscopic condenser humidifier with heated-water humidification in mechanically ventilated patients.

PubMed

Kollef, M H; Shapiro, S D; Boyd, V; Silver, P; Von Harz, B; Trovillion, E; Prentice, D

1998-03-01

To determine the safety and cost-effectiveness of mechanical ventilation with an extended-use hygroscopic condenser humidifier (Duration; Nellcor Puritan-Bennett; Eden Prairie, Minn) compared with mechanical ventilation with heated-water humidification. Prospective randomized clinical trial. Medical and surgical ICUs of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. Three hundred ten consecutive qualified patients undergoing mechanical ventilation. Patients requiring mechanical ventilation were randomly assigned to receive humidification with either an extended-use hygroscopic condenser humidifier (for up to the first 7 days of mechanical ventilation) or heated-water humidification. Occurrence of ventilator-associated pneumonia, endotracheal tube occlusion, duration of mechanical ventilation, lengths of intensive care and hospitalization, acquired multiorgan dysfunction, and hospital mortality. One hundred sixty-three patients were randomly assigned to receive humidification with an extended-use hygroscopic condenser humidifier, and 147 patients were randomly assigned to receive heated-water humidification. The two groups were similar at the time of randomization with regard to demographic characteristics, ICU admission diagnoses, and severity of illness. Risk factors for the development of ventilator-associated pneumonia were also similar during the study period for both treatment groups. Ventilator-associated pneumonia was seen in 15 (9.2%) patients receiving humidification with an extended-use hygroscopic condenser humidifier and in 15 (10.2%) patients receiving heated-water humidification (relative risk, 0.90; 95% confidence interval=0.46 to 1.78; p=0.766). No statistically significant differences for hospital mortality, duration of mechanical ventilation, lengths of stay in the hospital ICU, or acquired organ system derangements were found between the two treatment groups. No episode of endotracheal tube occlusion occurred during the study period in either treatment group. The total cost of providing humidification was $2,605 for patients receiving a hygroscopic condenser humidifier compared with $5,625 for patients receiving heated-water humidification. Our findings suggest that the initial application of an extended-use hygroscopic condenser humidifier is a safe and more cost-effective method of providing humidification to patients requiring mechanical ventilation compared with heated-water humidification.

Short sleep mediates the association between long work hours and increased body mass index.

PubMed

Magee, Christopher A; Caputi, Peter; Iverson, Don C

2011-04-01

This study examined whether short sleep duration, physical activity and time spent sitting each day mediated the association between long work hours and body mass index (BMI). Participants included 16,951 middle aged Australian adults who were employed in full time work (i.e. ≥35 h a week). Data on BMI, sleep duration, work hours and other health and demographic variables were obtained through a self-report questionnaire. A multiple mediation model was tested whereby sleep duration, physical activity and amount of time spent sitting were entered as potential mediators between work hours and BMI. The results demonstrated that short sleep partially mediated the association between long work hours and increased BMI in males. In females, long work hours were indirectly related to higher BMI through short sleep. The results provide some support for the hypothesis that long work hours could contribute to obesity via a reduction in sleep duration; this warrants further investigation in prospective studies.

The extended Theory of Planned Behavior in explaining exclusive breastfeeding intention and behavior among women in Kelantan, Malaysia.

PubMed

Tengku Ismail, Tengku Alina; Wan Muda, Wan Abdul Manan; Bakar, Mohd Isa

2016-02-01

The purpose of this study is to utilize an extended Theory of Planned Behavior in identifying predictors of exclusive breastfeeding intention and behavior among women in Kelantan, Malaysia. A prospective cohort study was conducted, recruiting pregnant womenthrough two-stage cluster sampling. Their exclusive breastfeeding intention, attitude, perceived norm, perceived behavioral control and past behavior were obtained at baseline through interviewer-guided questionnaire. At one month after delivery, another interview was conducted to determine the two additional variables in the extended theory, which were their postpartum support and breastfeeding difficulty. The behavior, which was the actual duration of exclusive breastfeeding, was obtained from the second follow-up at six months. Pearson correlation and two hierarchical regression analyses were conducted. A total of 200 women completed the study follow-up. Their median intended exclusive breastfeeding duration was 4.0 (IQR 5) months, and the median actual duration was 1.0 (IQR 4) month. The Theory of Planned Behavior explained 51.0% of the variance in intention, with perceived behavioral control and attitude were the significant predictors. It also explained 10.0% of the variance in behavior, but the addition of postpartum support and breastfeeding difficulty increased the amount of explained variance in behavior by 6.0%. The significant predictors of exclusive breastfeeding behavior were intention, postpartum support and breastfeeding difficulty. The extended Theory of Planned Behaviorhad a good predictive ability in explaining exclusive breastfeedingintention and behavior. The women's intention to practice exclusive breastfeeding may be improved by improving their perceived behavioral control and attitude. Providing correct postpartum support and skills to handle breastfeeding difficulties after delivery will improve their exclusive breastfeeding behavior.

The extended Theory of Planned Behavior in explaining exclusive breastfeeding intention and behavior among women in Kelantan, Malaysia

PubMed Central

Wan Muda, Wan Abdul Manan; Bakar, Mohd Isa

2016-01-01

BACKGROUND/OBJECTIVES The purpose of this study is to utilize an extended Theory of Planned Behavior in identifying predictors of exclusive breastfeeding intention and behavior among women in Kelantan, Malaysia. SUBJECTS/METHODS A prospective cohort study was conducted, recruiting pregnant womenthrough two-stage cluster sampling. Their exclusive breastfeeding intention, attitude, perceived norm, perceived behavioral control and past behavior were obtained at baseline through interviewer-guided questionnaire. At one month after delivery, another interview was conducted to determine the two additional variables in the extended theory, which were their postpartum support and breastfeeding difficulty. The behavior, which was the actual duration of exclusive breastfeeding, was obtained from the second follow-up at six months. Pearson correlation and two hierarchical regression analyses were conducted. RESULTS A total of 200 women completed the study follow-up. Their median intended exclusive breastfeeding duration was 4.0 (IQR 5) months, and the median actual duration was 1.0 (IQR 4) month. The Theory of Planned Behavior explained 51.0% of the variance in intention, with perceived behavioral control and attitude were the significant predictors. It also explained 10.0% of the variance in behavior, but the addition of postpartum support and breastfeeding difficulty increased the amount of explained variance in behavior by 6.0%. The significant predictors of exclusive breastfeeding behavior were intention, postpartum support and breastfeeding difficulty. CONCLUSION The extended Theory of Planned Behaviorhad a good predictive ability in explaining exclusive breastfeedingintention and behavior. The women's intention to practice exclusive breastfeeding may be improved by improving their perceived behavioral control and attitude. Providing correct postpartum support and skills to handle breastfeeding difficulties after delivery will improve their exclusive breastfeeding behavior. PMID:26865916

Short Sleep Duration is Associated with Obesity in Hispanic Manufacturing Workers.

PubMed

Benham, Grant; Ghaddar, Suad F; Talavera-Garza, Liza

2017-01-01

The present study examined the relationship between obesity and sleep duration among Hispanic manufacturing workers. Two hundred and twenty eight Hispanic workers from eight manufacturing plants completed an in-person interview that included measures of demographics, health literacy, and sleep duration. Height and weight were directly assessed. A logistic regression, controlling for gender, education, age, income, physical activity levels, self-reported health status, and health literacy, indicated that workers who slept six hours or less were significantly more likely to be obese than those sleeping seven to nine hours (OR: 1.90, 95% CI: 1.04-3.47). Our results extend previous research on the association between sleep duration and obesity to an understudied population of Hispanic workers.

[Brain Mechanisms for Measuring Time: Population Coding of Durations].

PubMed

Hayashi, Masamichi J

2016-11-01

Temporal processing is crucial in many aspects of our perception and action. While there is mounting evidence for the encoding mechanisms of spatial ("where") and identity ("what") information, those of temporal information ("when") remain largely unknown. Recent studies suggested that, similarly to the basic visual stimulus features such as orientation, motion direction, and numerical quantity, event durations are also represented by a population of neurons that are tuned for specific, preferred durations. This paper first reviews recent psychophysical studies on duration aftereffect. Changes in the three parameters (response gain, shift, and width of tuning curves) are then discussed that may need to be taken into account in the putative duration-channel model. Next, the potential neural basis of the duration channels is examined by overviewing recent neuroimaging and electrophysiological studies on time perception. Finally, this paper proposes a general neural basis of timing that commonly represents time-differences independent of stimulus types (e.g., a single duration v.s. multiple brief events). This extends the idea of the "when pathway" from the perception of temporal order to the general timing mechanisms for the perception of duration, temporal frequency, and synchrony.

Success of strategies for combining employment and breastfeeding.

PubMed

Fein, Sara B; Mandal, Bidisha; Roe, Brian E

2008-10-01

Return to work is associated with diminished breastfeeding intensity and duration. Although more mothers breastfeed after returning to work now than earlier, research has not documented the strategies that mothers use for combining paid work and breastfeeding or their effect on breastfeeding outcomes. This study examined which strategies are associated with smaller decrements in breastfeeding intensity and longer durations. We analyzed 810 mothers from the Infant Feeding Practices Study II who worked and breastfed. We used regression and censored regression models to analyze 4 strategies that mothers used to combine these 2 activities: (1) feed directly from the breast only; (2) both pump and feed directly; (3) pump only; and (4) neither pump nor breastfeed during the work day. Outcomes were the difference in percentage of milk feeds that were breast milk between the month before and after return to work and duration of breastfeeding after return to work. Forty-three percent of mothers pumped milk at work only; 32% fed the infant directly from the breast only. These 2 strategies, along with pumping and feeding directly, were statistically similar and superior to neither pumping nor breastfeeding during the work day for the outcome of change in breastfeeding intensity. For the outcome of breastfeeding duration, the 2 strategies that included directly feeding from the breast were associated with longer duration than pumping only, whereas the strategy of neither pumping nor breastfeeding during the work day was associated with the shortest duration. Feeding the infant from the breast during the work day is the most effective strategy for combining breastfeeding and work. Ways to enable direct feeding include on-site child care, telecommuting, keeping the infant at work, allowing the mother to leave work to go to the infant, and having the infant brought to the work site. Establishing ways for mothers to feed from the breast after return to work is important to meet US breastfeeding goals.

Sleep deprivation in resident physicians, work hour limitations, and related outcomes: a systematic review of the literature.

PubMed

Mansukhani, Meghna P; Kolla, Bhanu Prakash; Surani, Salim; Varon, Joseph; Ramar, Kannan

2012-07-01

Extended work hours, interrupted sleep, and shift work are integral parts of medical training among all specialties. The need for 24-hour patient care coverage and economic factors have resulted in prolonged work hours for resident physicians. This has traditionally been thought to enhance medical educational experience. These long and erratic work hours lead to acute and chronic sleep deprivation and poor sleep quality, resulting in numerous adverse consequences. Impairments may occur in several domains, including attention, cognition, motor skills, and mood. Resident performance, professionalism, safety, and well-being are affected by sleep deprivation, causing potentially adverse implications for patient care. Studies have shown adverse health consequences, motor vehicle accidents, increased alcohol and medication use, and serious medical errors to occur in association with both sleep deprivation and shift work. Resident work hour limitations have been mandated by the Accreditation Council for Graduate Medical Education in response to patient safety concerns. Studies evaluating the impact of these regulations on resident physicians have generated conflicting reports on patient outcomes, demonstrating only a modest increase in sleep duration for resident physicians, along with negative perceptions regarding their education. This literature review summarizes research on the effects of sleep deprivation and shift work, and examines current literature on the impact of recent work hour limitations on resident physicians and patient-related outcomes.

The association between physical medicine and rehabilitation service utilization and disability duration following work-related fracture.

PubMed

Young, Amanda; Muhlner, Stasia; Kurowski, Alicia; Cifuentes, Manuel

2015-06-05

Rural residents with work-related fractures utilize healthcare differently and return to work (RTW) sooner than their similarly-injured urban peers. To elucidate the relationship between physical medicine and rehabilitation (PM&R) service usage and work-disability duration following work-related injury. Retrospective cohort study, employing a two-phase sequential analysis. The project involved a longitudinal analysis of PM&R utilization and work-disability duration of 2,216 people across the U.S. who fractured a bone, received PM&R services, and had at least seven days off work. In the first phase of the analysis each individual was assigned a PM&R utilization score based on how similar his or her usage was to that typical of rural residents. The second phase tested the relationship between assigned PM&R utilization scores and work-disability duration. Differences in urban versus rural PM&R utilization included less total PM&R services and fewer passive services in the first 8 weeks for rural claimants. Among those off work for more than a month, rural residents used more active services just prior to RTW, with a gradual decreasing of services leading up to RTW. Controlling for covariates, aggregate PM&R utilization scores were found to relate to time to first RTW (Hazard Ratio=1.66, p<0.005). Findings suggest that using services in a way that is more consistent with rural patterns is associated with decreased work-disability durations. Consistent with previous studies, results suggest that passive services, prolonged episodes of care, and failure to focus on transitioning to self-management are related to longer work-disability durations.

Retention of movement pattern changes after a lower extremity injury prevention program is affected by program duration.

PubMed

Padua, Darin A; DiStefano, Lindsay J; Marshall, Stephen W; Beutler, Anthony I; de la Motte, Sarah J; DiStefano, Michael J

2012-02-01

Changes in movement patterns have been repeatedly observed immediately after completing a lower extremity injury prevention program. However, it is not known if movement pattern changes are maintained after discontinuing the training program. The ability to maintain movement pattern changes after training has ceased may be influenced by the program's duration. The authors hypothesized that among individuals who completed either a 3-month or 9-month training program and who demonstrated immediate movement pattern changes, only those who completed the 9-month training program would maintain movement pattern changes after a 3-month period of no longer performing the exercises. Cohort study; Level of evidence, 2. A total of 140 youth soccer athletes from 15 separate teams volunteered to participate. Athletes' movement patterns were assessed using the Landing Error Scoring System (LESS) at pretest, posttest, and 3 months after ceasing the program (retention test). Eighty-four of the original 140 participants demonstrated improvements in their LESS scores between pretest and posttest (change in LESS score >0) and were included in the final analyses for this study (n = 84; 20 boys and 64 girls; mean age, 14 ± 2 years; age range, 11-17 years). Teams performed 3-month (short-duration group) and 9-month (extended-duration group) injury prevention programs. The exercises performed were identical for both groups. Teams performed the programs as part of their normal warm-up routine. Although both groups improved their total LESS scores from pretest to posttest, only the extended-duration training group retained their improvements 3 months after ceasing the injury prevention program (F(2,137) = 3.38; P = .04). Results suggest that training duration may be an important factor to consider when designing injury prevention programs that facilitate long-term changes in movement control.

The effects of intimate partner violence duration on individual and partner-related sexual risk factors among women.

PubMed

Fontenot, Holly B; Fantasia, Heidi Collins; Lee-St John, Terrence J; Sutherland, Melissa A

2014-01-01

Intimate partner violence (IPV) is associated with risk of sexually transmitted infections (STIs) and HIV among women, but less is known about mechanisms of this association and if length of relationship violence is a factor. The purpose of this study was to explore the relationship between the duration of IPV and both individual and partner-related sexual risk factors that may increase women's risk for STIs and HIV. This was a secondary analysis of data collected from the medical records of 2000 women. Four distinct categories defined the duration of partner violence: violence in the past year only, past year and during the past 5 years, past year plus extending for greater than 5 years, and no past year violence but a history of partner violence. Logistic regression models were used to examine the associations between the duration of partner violence and individual sexual risk behaviors (eg, number of sexual partners, drug and/or alcohol use, anal sex) and partner-related sexual risk factors (eg, nonmonogamy, STI risk, condom nonuse). Nearly 30% of the women in the study reported a history of partner violence during their lifetime. All of the individual risk factors, as well as partner-related risk factors, were significantly associated (P < .05) with partner violence and duration of violence. The study findings extend the knowledge related to partner violence as a risk factor for STIs/HIV, highlighting the effects of partner violence duration on the health of women. Assessing for lifetime experiences of partner violence may improve outcomes for women and their families. © 2014 by the American College of Nurse-Midwives.

Portable positive protection : a guide for short duration and short term work zones.

DOT National Transportation Integrated Search

2016-06-01

Transportation agencies, contractors, researchers, and private vendors are actively looking for new methods and devices : to help make construction and maintenance work zones safer while maximizing mobility. Short-term and short-duration : work zones...

[Geriatric nursing staff retention. Opportunities, potentials, and strategies].

PubMed

Joost, A

2013-08-01

Retaining geriatric nurses in their line of work could be an important strategy to prevent the shortage of skilled staff in the future. A prerequisite for this is detailed knowledge of the length and structure of professional careers. The IWAK ( Institut für Wirtschaft, Arbeit und Kultur) evaluated data from the German Social Insurance and carried out a structural analysis of the professional careers of geriatric nurses. Results showed that the average duration of professional careers is 20 years, of which 11.7 years constitute the period of employment and 7.8 years account for periods of inactivity. According to these findings, there is a considerable potential in extending professional careers and reducing the periods of inactivity to make better use of the existing skilled staff and to reduce staff shortage in this area. Concrete measures could involve improvement of working conditions (with the aim of avoiding long periods of inactivity and illness-related premature career endings as well as of increasing job satisfaction), creating better conditions for a good balance between work and family life, as well as setting up individual strategies to expand weekly working hours. Key players are businesses but also local authorities and politicians.

Extended Duration Dual Antiplatelet Therapy After Percutaneous Coronary Intervention in Patients With Peripheral Arterial Disease: A Meta-Analysis.

PubMed

Ling, Hua; Andrews, Ebony; Ombengi, David; Li, Fang

2018-06-01

Patients with peripheral arterial disease (PAD) undergoing percutaneous coronary intervention (PCI) are at elevated risk of ischemic and bleeding events. However, the optimal duration of dual antiplatelet therapy (DAPT) after PCI in patients with PAD remains unclear. A systematic literature search was performed through June 2017 using PubMed, EMBASE and Cochrane databases with the following key terms: "dual antiplatelet therapy", "P2Y12 inhibitor", "myocardial infarction", "percutaneous coronary intervention", "stent", "peripheral arterial disease", and "ankle-brachial index". The analysis was restricted to randomized trials published in English in patients with PAD receiving extended DAPT (> 12-month) after PCI. Overall analysis was performed using Review Manager 5.3 with the Mantel-Haenszel method. Two randomized controlled trials involving 895 patients were included in this review. Compared to the placebo group, there was no statistical significance in the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) in patients receiving extended DAPT (odds ratio (OR) 0.76, 95% confidence interval (CI) 0.37 - 1.57; P = 0.46). The results were associated with substantial heterogeneity (I 2 = 71%, P = 0.07). Extended DAPT was not significantly associated with increased moderate/severe bleeding events (OR 1.63, 95% CI 0.84 - 3.18; P = 0.15; I 2 = 0%, P = 0.59). The extended DAPT was associated with 82% relative risk reduction in the events of definite/probably stent thrombosis. Among patients with PAD, extended DAPT after PCI resulted in a non-significant difference in ischemic and bleeding events compared to placebo, respectively. The routine use of extended DAPT in this cohort should be carefully evaluated.

Benchmark duration of work hours for development of fatigue symptoms in Japanese workers with adjustment for job-related stress.

PubMed

Suwazono, Yasushi; Dochi, Mirei; Kobayashi, Etsuko; Oishi, Mitsuhiro; Okubo, Yasushi; Tanaka, Kumihiko; Sakata, Kouichi

2008-12-01

The objective of this study was to calculate benchmark durations and lower 95% confidence limits for benchmark durations of working hours associated with subjective fatigue symptoms by applying the benchmark dose approach while adjusting for job-related stress using multiple logistic regression analyses. A self-administered questionnaire was completed by 3,069 male and 412 female daytime workers (age 18-67 years) in a Japanese steel company. The eight dependent variables in the Cumulative Fatigue Symptoms Index were decreased vitality, general fatigue, physical disorders, irritability, decreased willingness to work, anxiety, depressive feelings, and chronic tiredness. Independent variables were daily working hours, four subscales (job demand, job control, interpersonal relationship, and job suitability) of the Brief Job Stress Questionnaire, and other potential covariates. Using significant parameters for working hours and those for other covariates, the benchmark durations of working hours were calculated for the corresponding Index property. Benchmark response was set at 5% or 10%. Assuming a condition of worst job stress, the benchmark duration/lower 95% confidence limit for benchmark duration of working hours per day with a benchmark response of 5% or 10% were 10.0/9.4 or 11.7/10.7 (irritability) and 9.2/8.9 or 10.4/9.8 (chronic tiredness) in men and 8.9/8.4 or 9.8/8.9 (chronic tiredness) in women. The threshold amounts of working hours for fatigue symptoms under the worst job-related stress were very close to the standard daily working hours in Japan. The results strongly suggest that special attention should be paid to employees whose working hours exceed threshold amounts based on individual levels of job-related stress.

Physiological and psychological impacts of extended work hours in logging operations

Treesearch

Dana Mitchell; Tom Gallagher

2007-01-01

A study was initiated in 2006 to develop an understanding of the considerations of using extended work hours in the logging industry in the southeastern United States. Through semistructured interviews, it was obvious that loggers were individually creating ways of successfully implementing extended working hours without understanding the impacts that extended working...

Pain-related work interference is a key factor in a worker/workplace model of work absence duration due to musculoskeletal conditions in Canadian nurses.

PubMed

Murray, Eleanor; Franche, Renée-Louise; Ibrahim, Selahadin; Smith, Peter; Carnide, Nancy; Côté, Pierre; Gibson, Jane; Guzman, Jaime; Koehoorn, Mieke; Mustard, Cameron

2013-12-01

To examine the role of pain experiences in relation to work absence, within the context of other worker health factors and workplace factors among Canadian nurses with work-related musculoskeletal (MSK) injury. Structural equation modeling was used on a sample of 941 employed, female, direct care nurses with at least one day of work absence due to a work-related MSK injury, from the cross-sectional 2005 National Survey of the Work and Health of Nurses. The final model suggests that pain severity and pain-related work interference mediate the impact of the following worker health and workplace factors on work absence duration: depression, back problems, age, unionization, workplace physical demands and low job control. The model accounted for 14 % of the variance in work absence duration and 46.6 % of the variance in pain-related work interference. Our findings support a key role for pain severity and pain-related work interference in mediating the effects of workplace factors and worker health factors on work absence duration. Future interventions should explore reducing pain-related work interference through addressing workplace issues, such as providing modified work, reducing physical demands, and increasing job control.

Incubation of conditioned fear in the conditioned suppression model in rats: role of food-restriction conditions, length of conditioned stimulus, and generality to conditioned freezing

PubMed Central

Pickens, Charles L.; Navarre, Brittany M.; Nair, Sunila G.

2010-01-01

We recently adapted the conditioned suppression of operant responding method to study fear incubation. We found that food-restricted rats show low fear 2 days after extended (10 d; 100 30-sec tone-shock pairings) fear training and high fear after 1–2 months. Here, we studied a potential mechanism of fear incubation: extended food-restriction stress. We also studied whether fear incubation is observed after fear training with a prolonged-duration (6-min) tone conditioned stimulus (CS), and whether conditioned freezing incubates after extended training in rats with or without a concurrent operant task. Conditioned fear was assessed 2 days and 1 month after training. In the conditioned suppression method, fear incubation was reliably observed in rats under moderate food-restriction conditions (18–20 g food/day) that allowed for weight gain, and after extended (10 d), but not limited (1 d), fear training with the 6-min CS. Incubation of conditioned freezing was observed after extended fear training in rats lever-pressing for food and, to a lesser degree, in rats not performing an operant task. Results indicate that prolonged hunger-related stress does not account for fear incubation in the conditioned suppression method, and that fear incubation occurs to a longer-duration (6-min) fear CS. Extended training also leads to robust fear incubation of conditioned freezing in rats performing an operant task and weaker fear incubation in rats not performing an operant task. PMID:20600654

Incubation of conditioned fear in the conditioned suppression model in rats: role of food-restriction conditions, length of conditioned stimulus, and generality to conditioned freezing.

PubMed

Pickens, C L; Navarre, B M; Nair, S G

2010-09-15

We recently adapted the conditioned suppression of operant responding method to study fear incubation. We found that food-restricted rats show low fear 2 days after extended (10 d; 100 30-s tone-shock pairings) fear training and high fear after 1-2 months. Here, we studied a potential mechanism of fear incubation: extended food-restriction stress. We also studied whether fear incubation is observed after fear training with a prolonged-duration (6-min) tone conditioned stimulus (CS), and whether conditioned freezing incubates after extended training in rats with or without a concurrent operant task. Conditioned fear was assessed 2 days and 1 month after training. In the conditioned suppression method, fear incubation was reliably observed in rats under moderate food-restriction conditions (18-20 g food/day) that allowed for weight gain, and after extended (10 d), but not limited (1 d), fear training with the 6-min CS. Incubation of conditioned freezing was observed after extended fear training in rats lever-pressing for food and, to a lesser degree, in rats not performing an operant task. Results indicate that prolonged hunger-related stress does not account for fear incubation in the conditioned suppression method, and that fear incubation occurs to a longer-duration (6-min) fear CS. Extended training also leads to robust fear incubation of conditioned freezing in rats performing an operant task and weaker fear incubation in rats not performing an operant task. (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Associations Among Rotating Night Shift Work, Sleep, and Skin Cancer in Nurses’ Health Study II Participants

PubMed Central

Heckman, Carolyn J.; Kloss, Jacqueline D.; Feskanich, Diane; Culnan, Elizabeth; Schernhammer, Eva S.

2016-01-01

Background Night shift work and sleep duration have been associated with breast and other cancers. Results from the few prior studies of night shift work and skin cancer risk have been mixed and not fully accounted for other potentially important health-related variables (e.g., sleep characteristics). This study evaluated the relationship between rotating night shift work and skin cancer risk and included additional skin cancer risk factors and sleep-related variables. Methods The current study used data from 74,323 Nurses’ Health Study (NHS) II participants. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for skin cancers across categories of shift work and sleep duration. Results Over 10 years of follow-up, 4308 BCC, 334 SCC and 212 melanoma cases were identified. Longer duration of rotating night shifts was associated with a linear decline in risk of BCC (HR=0.93, 95% CI: 0.90-0.97 per 5-year increase). Shift work was not significantly associated with either melanoma (HR=1.02, 95% CI: 0.86-1.21) or SCC (HR=0.92, 95% CI: 0.80-1.06). A short sleep duration (≤6 hours per day) was associated with lower risks of melanoma (HR=0.68, 95% CI: 0.46-0.98) and BCC (HR=0.93, 95% CI: 0.86-1.00) compared with the most common report of 7 hours. SCC was not associated with duration of sleep (HR=0.94, 95% CI: 0.83-1.06). Conclusions Longer duration of rotating night shift work and shorter sleep duration were associated with lower risk of some skin cancers. Further research is needed to confirm and identify the mechanisms underlying these associations. PMID:27663986

The association of social functioning, social relationships and the receipt of compensation with time to return to work following unintentional injuries to Victorian workers.

PubMed

Clay, Fiona J; Fitzharris, Michael; Kerr, Emily; McClure, Roderick J; Watson, Wendy L

2012-09-01

Understanding individual factors associated with return to work (RTW) post-injury is an important goal of compensation systems research. The aim of the present study was to determine factors associated with time to return to work following acute unintentional injuries. A prospective cohort study was conducted in Victoria, Australia. The cohort comprised 133 persons who were employed at the time they were admitted to one of three study hospitals. Baseline health status data was obtained retrospectively at one-week post-injury and participants were further surveyed at 1, 6, 12, 26 and 52 weeks post-injury to measure recovery. Multivariate Cox proportional hazards regression analysis was used to examine the association between potential prognostic factors and time to RTW during the 12 month study. At the end of 12 months follow-up, 81.2% of the study cohort had returned to work. Older age, increased injury severity, self reported symptomatic pain and poor mental health at 1 week post-injury were associated with extended time to RTW. A significant statistical interaction between the receipt of compensation and high social functioning as measured by the SF-36 or strong social relationships as measured by the Assessment of Quality of Life was associated with earlier RTW. Participants reporting strong social relationships and high social functioning at 1 week post-injury and entitled to injury compensation returned to work 2.05 and 3.66 times earlier respectively, than similar participants with no entitlement to compensation. Both injury-related and psychosocial factors were associated with the duration of time to RTW following acute unintentional injuries. This study replicated previously reported findings on social functioning and compensation from an independent acute trauma sample. Programs or policies to improve social functioning early post-injury may provide opportunities to improve the duration of time to RTW following injury.

A Synoptic- and Planetary-Scale Analysis of Widespread North American Ice Storms

NASA Astrophysics Data System (ADS)

McCray, C.; Gyakum, J. R.; Atallah, E.

2017-12-01

Freezing rain can have devastating impacts, particularly when it persists for many hours. Predicting the precise temperature stratification necessary for long duration freezing rain events remains an important forecast challenge. To better elucidate the conditions responsible for the most severe events, we concentrate on surface observations of long-duration (6 or more hours) freezing rain events over North America from 1979-2016. Furthermore, we analyze cases in which multiple stations observe long-duration events simultaneously. Following these cases over successive days allows us to generate maps of freezing rain "tracks." We then categorize recurring geographic patterns to examine the meteorological conditions leading to these events. While freezing rain is most frequently observed in the northeastern United States and southeastern Canada, long-duration events have affected areas as far south as the Gulf Coast. Notably, a disproportionately large number of very long duration (18 or more hours) events have occurred in the Southern Plains states relative to the climatological annual frequency of freezing rain there. Classification of individual cases shows that most of these very long duration events are associated with a recurring pattern which produces freezing rain along a southwest-northeast swath from Texas/Oklahoma into the northeastern U.S. and eastern Canada. Storms classified within this pattern include the January 1998 and December 2013 ice storms. While this pattern is the most widespread, additional spatially extensive patterns occur. One of these areas extends from the Southern Plains eastward along the Gulf Coast to Georgia and the Carolinas. A third category of events extends from the Upper Midwest into the northeastern U.S. and southeastern Canada. The expansive areal extent and long duration of these events make them especially problematic. An analysis of the planetary- to synoptic-scale settings responsible for these cases and the differences among individual storms is performed to provide forecasters with additional tools/insight towards the prediction of these damaging weather events.

Technology-Assisted Behavioral Intervention to Extend Sleep Duration: Development and Design of the Sleep Bunny Mobile App.

PubMed

Baron, Kelly Glazer; Duffecy, Jennifer; Reid, Kathryn; Begale, Mark; Caccamo, Lauren

2018-01-10

Despite the high prevalence of short sleep duration (29.2% of adults sleep <6 hours on weekdays), there are no existing theory-based behavioral interventions to extend sleep duration. The popularity of wearable sleep trackers provides an opportunity to engage users in interventions. The objective of this study was to outline the theoretical foundation and iterative process of designing the "Sleep Bunny," a technology-assisted sleep extension intervention including a mobile phone app, wearable sleep tracker, and brief telephone coaching. We conducted a two-step process in the development of this intervention, which was as follows: (1) user testing of the app and (2) a field trial that was completed by 2 participants with short sleep duration and a cardiovascular disease risk factor linked to short sleep duration (body mass index [BMI] >25). All participants had habitual sleep duration <6.5 hours verified by 7 days of actigraphy. A total of 6 individuals completed initial user testing in the development phase, and 2 participants completed field testing. Participants in the user testing and field testing responded to open-ended surveys about the design and utility of the app. Participants in the field testing completed the Epworth Sleepiness Scale and also wore an actigraph for a 1-week baseline period and during the 4-week intervention period. The feedback suggests that users enjoyed the wearable sleep tracker and found the app visually pleasing, but they suggested improvements to the notification and reminder features of the app. The 2 participants who completed the field test demonstrated significant improvements in sleep duration and daytime sleepiness. Further testing is needed to determine effects of this intervention in populations at risk for the mental and physical consequences of sleep loss. ©Kelly Glazer Baron, Jennifer Duffecy, Kathryn Reid, Mark Begale, Lauren Caccamo. Originally published in JMIR Mental Health (http://mental.jmir.org), 10.01.2018.

Predictors of work disability after start of anti-TNF therapy in a national cohort of Swedish patients with rheumatoid arthritis: does early anti-TNF therapy bring patients back to work?

PubMed

Olofsson, T; Petersson, I F; Eriksson, J K; Englund, M; Nilsson, J A; Geborek, P; Jacobsson, L T H; Askling, J; Neovius, M

2017-07-01

To examine predictors of work ability gain and loss after anti-tumour necrosis factor (TNF) start, respectively, in working-age patients with rheumatoid arthritis (RA) with a special focus on disease duration. Patients with RA, aged 19-62 years, starting their first TNF inhibitor 2006-2009 with full work ability (0 sick leave/disability pension days during 3 months before bio-start; n=1048) or no work ability (90 days; n=753) were identified in the Swedish biologics register (Anti-Rheumatic Treatment In Sweden, ARTIS) and sick leave/disability pension days retrieved from the Social Insurance Agency. Outcome was defined as work ability gain ≥50% for patients without work ability at bio-start and work ability loss ≥50% for patients with full work ability, and survival analyses conducted. Baseline predictors including disease duration, age, sex, education level, employment, Health Assessment Questionnaire, Disease Activity Score 28 and relevant comorbidities were estimated using Cox regression. During 3 years after anti-TNF start, the probability of regaining work ability for totally work-disabled patients was 35% for those with disease duration <5 years and 14% for disease duration ≥5 years (adjusted HR 2.1 (95% CI 1.4 to 3.2)). For patients with full work ability at bio-start, disease duration did not predict work ability loss. Baseline disability pension was also a strong predictor of work ability gain after treatment start. A substantial proportion of work-disabled patients with RA who start anti-TNF therapy regain work ability. Those initiating treatment within 5 years of symptom onset have a more than doubled 3-year probability of regaining work ability compared with later treatment starts. This effect seems largely due to the impact of disease duration on disability pension status. 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/.

The Cumulative Lifting Index (CULI) for the Revised NIOSH Lifting Equation: Quantifying Risk for Workers With Job Rotation.

PubMed

Garg, Arun; Kapellusch, Jay M

2016-08-01

The objectives were to: (a) develop a continuous frequency multiplier (FM) for the Revised NIOSH Lifting Equation (RNLE) as a function of lifting frequency and duration of a lifting task, and (b) describe the Cumulative Lifting Index (CULI), a methodology for estimating physical exposure to workers with job rotation. The existing FM for the RNLE (FME) does not differentiate between task duration >2 hr and <8 hr, which makes quantifying physical exposure to workers with job rotation difficult and presents challenges to job designers. Using the existing FMs for 1, 2, and 8 hr of task durations, we developed a continuous FM (FMP) that extends to 12 hr per day. We simulated 157,500 jobs consisting of two tasks each and, using different combinations of Frequency Independent Lifting Index, lifting frequency and duration of lifting. Biomechanical stresses were estimated using the CULI, time-weighted average (TWA), and peak exposure. The median difference between FME and FMP was ±1% (range: 0%-15%). Compared to CULI, TWA underestimated risk of low-back pain (LBP) for 18% to 30% of jobs, and peak exposure for an assumed 8-hr work shift overestimated risk of LBP for 20% to 25% of jobs. Peak task exposure showed 90% agreement with CULI but ignored one of two tasks. The CULI partially addressed the underestimation of physical exposure using the TWA approach and overestimation of exposure using the peak-exposure approach. The proposed FM and CULI may provide more accurate physical exposure estimates, and therefore estimated risk of LBP, for workers with job rotation. © 2016, Human Factors and Ergonomics Society.

Medical and Genetic Differences in the Adverse Impact of Sleep Loss on Performance: Ethical Considerations for the Medical Profession

PubMed Central

Czeisler, Charles A.

2009-01-01

The Institute of Medicine recently concluded that-on average-medical residents make more serious medical errors and have more motor vehicle crashes when they are deprived of sleep. In the interest of public safety, society has required limitations on work hours in many other safety sensitive occupations, including transportation and nuclear power generation. Those who argue in favor of traditional extended duration resident work hours often suggest that there are inter- individual differences in response to acute sleep loss or chronic sleep deprivation, implying that physicians may be more resistant than the average person to the detrimental effects of sleep deprivation on performance, although there is no evidence that physicians are particularly resistant to such effects. Indeed, recent investigations have identified genetic polymorphisms that may convey a relative resistance to the effects of prolonged wakefulness on a subset of the healthy population, although there is no evidence that physicians are over-represented in this cohort. Conversely, there are also genetic polymorphisms, sleep disorders and other inter-individual differences that appear to convey an increased vulnerability to the performance-impairing effects of 24 hours of wakefulness. Given the magnitude of inter-individual differences in the effect of sleep loss on cognitive performance, and the sizeable proportion of the population affected by sleep disorders, hospitals face a number of ethical dilemmas. How should the work hours of physicians be limited to protect patient safety optimally? For example, some have argued that, in contrast to other professions, work schedules that repeatedly induce acute and chronic sleep loss are uniquely essential to the training of physicians. If evidence were to prove this premise to be correct, how should such training be ethically accomplished in the quartile of physicians and surgeons who are most vulnerable to the effects of sleep loss on performance without unacceptably compromising patient safety? Moreover, once it is possible to identify reliably those most vulnerable to the adverse effects of sleep loss on performance, will academic medical centers have an obligation to evaluate the proficiency of both residents and staff physicians under conditions of acute and chronic sleep deprivation? Should work-hour policy limits be modified to ensure that they are not hazardous for the patients of the most vulnerable quartile of physicians, or should the limits be personalized to enable the most resistant quartile to work longer hours? Given that the prevalence of sleep disorders has increased in our society overall, and increases markedly with age, how should fitness for extended duration work hours be monitored over a physician's career? In the spirit of the dictum to do no harm, advances in understanding the medical and genetic basis of inter-individual differences in the performance vulnerability to sleep loss should be incorporated into the development of work-hour policy limits for both physicians and surgeons. PMID:19768182

Medical and genetic differences in the adverse impact of sleep loss on performance: ethical considerations for the medical profession.

PubMed

Czeisler, Charles A

2009-01-01

The Institute of Medicine recently concluded that-on average-medical residents make more serious medical errors and have more motor vehicle crashes when they are deprived of sleep. In the interest of public safety, society has required limitations on work hours in many other safety sensitive occupations, including transportation and nuclear power generation. Those who argue in favor of traditional extended duration resident work hours often suggest that there are inter- individual differences in response to acute sleep loss or chronic sleep deprivation, implying that physicians may be more resistant than the average person to the detrimental effects of sleep deprivation on performance, although there is no evidence that physicians are particularly resistant to such effects. Indeed, recent investigations have identified genetic polymorphisms that may convey a relative resistance to the effects of prolonged wakefulness on a subset of the healthy population, although there is no evidence that physicians are over-represented in this cohort. Conversely, there are also genetic polymorphisms, sleep disorders and other inter-individual differences that appear to convey an increased vulnerability to the performance-impairing effects of 24 hours of wakefulness. Given the magnitude of inter-individual differences in the effect of sleep loss on cognitive performance, and the sizeable proportion of the population affected by sleep disorders, hospitals face a number of ethical dilemmas. How should the work hours of physicians be limited to protect patient safety optimally? For example, some have argued that, in contrast to other professions, work schedules that repeatedly induce acute and chronic sleep loss are uniquely essential to the training of physicians. If evidence were to prove this premise to be correct, how should such training be ethically accomplished in the quartile of physicians and surgeons who are most vulnerable to the effects of sleep loss on performance without unacceptably compromising patient safety? Moreover, once it is possible to identify reliably those most vulnerable to the adverse effects of sleep loss on performance, will academic medical centers have an obligation to evaluate the proficiency of both residents and staff physicians under conditions of acute and chronic sleep deprivation? Should work-hour policy limits be modified to ensure that they are not hazardous for the patients of the most vulnerable quartile of physicians, or should the limits be personalized to enable the most resistant quartile to work longer hours? Given that the prevalence of sleep disorders has increased in our society overall, and increases markedly with age, how should fitness for extended duration work hours be monitored over a physician's career? In the spirit of the dictum to do no harm, advances in understanding the medical and genetic basis of inter-individual differences in the performance vulnerability to sleep loss should be incorporated into the development of work-hour policy limits for both physicians and surgeons.

Effect of gradient pulse duration on MRI estimation of the diffusional kurtosis for a two-compartment exchange model

NASA Astrophysics Data System (ADS)

Jensen, Jens H.; Helpern, Joseph A.

2011-06-01

Hardware constraints typically require the use of extended gradient pulse durations for clinical applications of diffusion-weighted magnetic resonance imaging (DW-MRI), which can potentially influence the estimation of diffusion metrics. Prior studies have examined this effect for the apparent diffusion coefficient. This study employs a two-compartment exchange model in order to assess the gradient pulse duration sensitivity of the apparent diffusional kurtosis (ADK), a quantitative index of diffusional non-Gaussianity. An analytic expression is derived and numerically evaluated for parameter ranges relevant to DW-MRI of brain. It is found that the ADK differs from the true diffusional kurtosis by at most a few percent. This suggests that ADK estimates for brain may be robust with respect to changes in pulse gradient duration.

The differential effects of full-time and part-time work status on breastfeeding.

PubMed

Mandal, Bidisha; Roe, Brian Eric; Fein, Sara Beck

2010-09-01

Return to work is associated with diminished breastfeeding. Although more mothers breastfeed after returning to work compared to a decade ago, research has not documented the variations in breastfeeding initiation and duration based on full-time and part-time (less than 35h/week) work status. In this study, we clarify these differences. Longitudinal data from the Infant Feeding Practices Study II, collected between 2005 and 2007, for over 1400 mothers are used. In analyzing initiation, mother's work status was categorized by the expected number of hours she planned to work postpartum. In the duration model, work status was categorized based on the actual number of hours worked upon mother's return to employment after controlling for baby's age when she returned to work. Covariates in logistic and censored regressions included demographics, maternity leave, parity, past breastfeeding experience, hospital experience, and social support. Compared with expecting not to work, expecting to work <35h/week was not associated with breastfeeding initiation while expecting to work full-time decreased breastfeeding initiation. Compared with breastfeeding mothers who did not work, returning to work within 12 weeks regardless of work status and returning to work after 12 weeks while working more than 34h/week were associated with significantly shorter breastfeeding duration. Part-time work and increased amount of leave taken promote breastfeeding initiation and duration.

Cavitation bubble dynamics during thulium fiber laser lithotripsy

NASA Astrophysics Data System (ADS)

Hardy, Luke A.; Kennedy, Joshua D.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

2016-02-01

The Thulium fiber laser (TFL) is being explored for lithotripsy. TFL parameters differ from standard Holmium:YAG laser in several ways, including smaller fiber delivery, more strongly absorbed wavelength, low pulse energy/high pulse rate operation, and more uniform temporal pulse structure. High speed imaging of cavitation bubbles was performed at 105,000 fps and 10 μm spatial resolution to determine influence of these laser parameters on bubble formation. TFL was operated at 1908 nm with pulse energies of 5-75 mJ, and pulse durations of 200-1000 μs, delivered through 100-μm-core fiber. Cavitation bubble dynamics using Holmium laser at 2100 nm with pulse energies of 200-1000 mJ and pulse duration of 350 μs was studied, for comparison. A single, 500 μs TFL pulse produced a bubble stream extending 1090 +/- 110 μm from fiber tip, and maximum bubble diameters averaged 590 +/- 20 μm (n=4). These observations are consistent with previous studies which reported TFL ablation stallout at working distances < 1.0 mm. TFL bubble dimensions were five times smaller than for Holmium laser due to lower pulse energy, higher water absorption coefficient, and smaller fiber diameter used.

Psychological training of NASA astronauts for extended missions

NASA Technical Reports Server (NTRS)

Holland, A. W.

1992-01-01

The success of operational teams working in remote and hostile environments rests in large part on adequate preparation of those teams prior to emplacement in field settings. Psychological training, directed at the maintenance of crew health and performance becomes increasingly important as space missions grow in duration and complexity. Methods: Topics to be discussed include: the conceptual framework of psychological training; needs analysis; content and delivery options; methods of assessing training efficacy; use of testbeds and analogies and the relationship of training to crew selection and real-time support activities. Results and Conclusions: This paper will discuss the psychological training approach being developed at the NASA/JSC Behavior and Performance Laboratory. This approach will be compared and contrasted with those underway in the U.S. Department of Defense and in other space agencies.

From amnesia to dementia: ERP studies of memory and language.

PubMed

Taylor, Jason R; Olichney, John M

2007-01-01

Cognitive event-related potential (ERP) studies of memory and language impairments in amnesia and Alzheimer's disease (AD) are reviewed. Well-circumscribed lesions of the medial temporal lobe (MTL) or diencephalon causing an amnestic syndrome, an inability to encode and retrieve episodic memories beyond the brief duration of working memory, appear to produce altered plasticity of the late positive P600 component, but usually spare P300 and N400 components. The neuropathology of AD affects MTL and extends to neocortical association areas, causing deficits of episodic and semantic memory. In AD dementia, the P300, N400, and P600 all commonly show abnormalities. ERP studies of individuals with mild cognitive impairment may reveal neurophysiological changes prior to the emergence of clinical deficits, which could advance the early detection and diagnosis of AD.

Risks from Solar Particle Events for Long Duration Space Missions Outside Low Earth Orbit

NASA Technical Reports Server (NTRS)

Over, S.; Myers, J.; Ford, J.

2016-01-01

The Integrated Medical Model (IMM) simulates the medical occurrences and mission outcomes for various mission profiles using probabilistic risk assessment techniques. As part of the work with the Integrated Medical Model (IMM), this project focuses on radiation risks from acute events during extended human missions outside low Earth orbit (LEO). Of primary importance in acute risk assessment are solar particle events (SPEs), which are low probability, high consequence events that could adversely affect mission outcomes through acute radiation damage to astronauts. SPEs can be further classified into coronal mass ejections (CMEs) and solar flares/impulsive events (Fig. 1). CMEs are an eruption of solar material and have shock enhancements that contribute to make these types of events higher in total fluence than impulsive events.

F18 Life Support: APECS and EDOX Cockpit Integration

NASA Technical Reports Server (NTRS)

Herrick, Paul

1998-01-01

Two systems are currently being integrated into the F18 Hornet support aircraft at NASA Dryden Flight Research Center (DFRC). The first system is the Aircrew Personal Environmental Control System (APECS). The system is designed to increase aircrew performance by combating heat stress in the cockpit. The second system is the Extended Duration Oxygen System (EDOX). This system will provide additional redundancy and oxygen system duration to the F18 without extensive modification to the current system.

Use of Sequent Peak Algorithm Drought Severity Index and Hydroclimatic Reconstructions from Tree-Rings to Inform Water Supply Reliability Planning

NASA Astrophysics Data System (ADS)

Bray, B. S.; Palhegyi, G.

2015-12-01

California is in the midst of a severe drought with below average runoff since WY 2012. Within this context, many water resource managers are scrutinizing water supply reliability assumptions for planning studies. Severe droughts represent a relatively rare phenomenon, occurring only a handful of times within our limited 100-year period of watershed runoff records. Furthermore, droughts may have different runoff magnitudes and durations that inherently present a challenge for direct comparisons of one drought with another. We use the sequent peak algorithm as a drought severity index (SPADSI) that accounts for both drought magnitude and duration relative to an assumed minimum release policy and fixed level-of-development (LOD) demand modeling framework. The SPADSI allows direct, quantitative evaluation of different policy options for lessening drought severity where, for example, layering a customer rationing policy onto model results reduced the SPADSI for the historical 1976-77 drought from 520 to 450 thousand acre-feet (TAF) and 1987-92 drought from 650 to 415 TAF for 2015 LOD. A strong correlation (R2 = 0.96) between Mokelumne River watershed runoff and tree-ring hydroclimate reconstructions for neighboring American and Stanislaus watersheds from Meko et al. (2014) was the basis for an extended 1100-year historical reconstruction of Mokelumne Watershed annual runoff. The reconstructed runoff timeseries is used to investigate extended historical drought durations for the Mokelumne Watershed where shorter one- to three-year droughts are most probable durations (>90%) whereas longer duration droughts lasting as long as 10 years such as occurred in 1776-85 are also possible, though much less likely. Applying the SPADSI to the reconstructed runoff timeseries showed that recent droughts e.g. 1929-34, 1976-77, and 1987-92 are all relatively severe within this millennial context, falling on the distribution tail of the extended SPADSI dataset. These findings are consistent with Meko et al. (2014) in their analysis of other watersheds in the region. These findings and other insights from the reconstructed runoff timeseries along with the SPADSI provide valuable information for water resource managers evaluating water supply reliability assumptions for future drought planning efforts.

Why are women more likely than men to extend paid work? The impact of work-family life history.

PubMed

Finch, Naomi

2014-03-01

Extending working life beyond the state pension age is a key European Union policy. In the UK, women are more likely to extend paid work than men, indicating that factors other than the state pension age play a role in working longer. Women are less able to build pension income due to their role as carer within the family. It, therefore, follows that gender inequalities over the life course continue into older age to influence need, capacity and desire to undertake paid work after state pension age. This paper explores how work, marital and fertility history impact upon the likelihood of extending employment. It uses the British Household Panel Survey's retrospective data from the first 14 waves to summarise work-family histories, and logistic regression to understand the impact of work and family histories on extending paid work. Findings show that, on the one hand, women are extending paid work for financial reasons to make up for 'opportunity costs' as a result of their caring role within the family, with short breaks due to caring, lengthy marriages, divorcing and remaining single with children all being important. Yet, there is also evidence of 'status maintenance' from working life, with the women most likely to extend paid work, also those with the highest work orientation, prior to state pension age. But lengthy dis-attachment (due to caring) from the labour market makes extending working life more difficult. This has implications for policy strategies to entice women into paid work to make up for low independent financial resources.

Financial incentives to promote extended smoking abstinence in opioid-maintained patients: a randomized trial.

PubMed

Sigmon, Stacey C; Miller, Mollie E; Meyer, Andrew C; Saulsgiver, Kathryn; Badger, Gary J; Heil, Sarah H; Higgins, Stephen T

2016-05-01

Prior studies by our group demonstrated the efficacy of a brief but intensive behavioral intervention for producing initial smoking abstinence among opioid-dependent patients. In the present study, our aim was to promote longer-duration abstinence in this population. Following an initial 2-week incentive intervention for smoking abstinence, we examined whether a 10-week maintenance arm involving continuation of contingent reinforcement will produce greater smoking abstinence than a similar duration of noncontingent reinforcement. Randomized, 12-week, parallel-group study. Out-patient research clinic in Burlington, Vermont, USA. Opioid-maintained smokers (n = 88) who provided breath carbon monoxide and urinary cotinine specimens and received contingent reinforcement for smoking abstinence during weeks 1-2 (phase 1), with 63 randomized on day 14 to an extended contingent (EC; n = 31) or extended noncontingent (EN; n = 32) experimental condition for weeks 3-12 (phase 2). The EC condition consisted of voucher values that escalated across consecutive negative samples until they reached $30, after which they remained at $30 per negative sample. A positive or a missing sample resulted in no vouchers for that day and reset the value of the next negative same to $9. Two consecutive negatives returned the schedule to the pre-reset value. The EN control condition consisted of vouchers delivered for providing scheduled samples, but independent of smoking status. The primary outcome was percentage of biochemically abstinent samples during phase 2. Secondary measures included abstinence status at final study visit, complete abstinence, participants' longest duration of continuous abstinence, cotinine and carbon monoxide (CO) levels and self-reported cigarettes per day. EC participants achieved greater smoking abstinence during phase 2 than EN participants [46.7 versus 23.5% negative samples, respectively; odds ratio (OR) = 2.98, 95% confidence interval (CI) = 1.16-7.65, χ(2) 1  (=)  5.0, P = 0.02]. When longest duration of continuous abstinence was compared between experimental groups, EC participants achieved twice the mean duration of continuous abstinence compared with EN participants (3.31 versus 1.68 weeks; t61  = 1.83, P = 0.07). An effect of experimental condition was also seen on mean cotinine levels (42.5 versus 210.6 ng/ml, respectively; F1,61 =5.9, P = 0.02). Among opioid-maintained smokers receiving an initial period of daily contingent incentives, a contingent reinforcement intervention appears to be more effective at extending smoking abstinence than noncontingent reinforcement over 10 weeks. © 2015 Society for the Study of Addiction.

Maternal Nonstandard Work Schedules and Breastfeeding Behaviors.

PubMed

Zilanawala, Afshin

2017-06-01

Objectives Although maternal employment rates have increased in the last decade in the UK, there is very little research investigating the linkages between maternal nonstandard work schedules (i.e., work schedules outside of the Monday through Friday, 9-5 schedule) and breastfeeding initiation and duration, especially given the wide literature citing the health advantages of breastfeeding for mothers and children. Methods This paper uses a population-based, UK cohort study, the Millennium Cohort Study (n = 17,397), to investigate the association between types of maternal nonstandard work (evening, night, away from home overnight, and weekends) and breastfeeding behaviors. Results In unadjusted models, exposure to evening shifts was associated with greater odds of breastfeeding initiation (OR 1.71, CI 1.50-1.94) and greater odds of short (OR 1.55, CI 1.32-1.81), intermediate (OR 2.01, CI 1.64-2.47), prolonged partial duration (OR 2.20, CI 1.78-2.72), and prolonged exclusive duration (OR 1.53, CI 1.29-1.82), compared with mothers who were unemployed and those who work other types of nonstandard shifts. Socioeconomic advantage of mothers working evening schedules largely explained the higher odds of breastfeeding initiation and duration. Conclusions Socioeconomic characteristics explain more breastfeeding behaviors among mothers working evening shifts. Policy interventions to increase breastfeeding initiation and duration should consider the timing of maternal work schedules.

Acute Effects of Zolpidem Extended-Release on Cognitive Performance and Sleep in Healthy Males After Repeated Nightly Use

PubMed Central

Kleykamp, Bethea A.; Griffiths, Roland R.; McCann, Una D.; Smith, Michael T.; Mintzer, Miriam Z.

2012-01-01

The extended-release formulation of zolpidem (Ambien CR®) is approved for the treatment of insomnia without a treatment duration limit. Acutely zolpidem impairs performance, and no research to date has examined whether tolerance develops to these performance impairments during nighttime awakening. The present double-blind, placebo-controlled study examined whether tolerance develops to zolpidem-induced acute performance impairment after repeated (22–30 days) nightly use. Effects of bedtime administration of zolpidem extended-release (ZOL; 12.5 mg) were tested on a battery of performance measures assessed during a forced nighttime awakening in 15 healthy male volunteers who completed overnight polysomnographic recording sessions in our laboratory at baseline and after approximately a month of at-home ZOL. As expected, bedtime ZOL administration was associated with changes in sleep architecture and impairments across all performance domains during nighttime testing (psychomotor function, attention, working memory, episodic memory, metacognition) with no residual next morning impairment. Tolerance did not develop to the observed ZOL-related impairments on any outcome. Possible evidence of acute abstinence effects following discontinuation of ZOL was observed on some performance and sleep outcomes. Overall, these findings suggest that performance is significantly impaired during nighttime awakening even after a month of nightly ZOL administration and these impairments could significantly impact safety should nighttime awakening require unimpaired functioning (e.g., driving; combat-related activities in the military). PMID:21928913

Factors associated with sleep duration in Brazilian high school students.

PubMed

Gomes Felden, Érico Pereira; Barbosa, Diego Grasel; Junior, Geraldo Jose Ferrari; Santos, Manoella De Oliveira; Pelegrini, Andreia; Silva, Diego Augusto Santos

2017-01-01

The aim of this study was to investigate the factors associated with short sleep duration on southern Brazilian high school students. Our study was comprised of 1,132 adolescents aged 14 to 19 years, enrolled in public high schools in São José, Brazil. The students answered a questionnaire about working (work and workload), health perception, smoking, school schedule, sleep (duration and daytime sleepiness), and socio-demographics data. The results showed that more than two thirds of adolescent workers had short sleep duration (76.7%), and those with a higher workload (more than 20 hours) had a shorter sleep duration (7.07 hours) compared to non-workers (7.83 hours). In the analysis of factors associated with short sleep duration, adolescents who worked (OR = 2.12, 95% CI 1.53 to 2.95) were more likely to have short sleep duration compared to those who did not work. In addition, older adolescents (17-19 years) and students with poor sleep quality were 40% and 55% more likely to have short sleep duration compared to younger adolescents (14-16 years) and students with good sleep quality, respectively. Adolescents with daytime sleepiness were more likely to have short sleep duration (OR = 1.49, 95% CI 1.06 to 2.07) compared to those without excessive daytime sleepiness. In addition students of the morning shift (OR = 6.02, 95% CI 4.23 to 8.57) and evening shift (OR = 2.16, 95% CI 1.45 to 3.22) were more likely to have short sleep duration compared to adolescents of the afternoon shift. Thereby adolescents who are workers, older, attended morning and evening classes and have excessive daytime sleepiness showed risk factors for short sleep duration. In this sense, it is pointed out the importance of raising awareness of these risk factors for short sleep duration of students from public schools from São José, located in southern Brazil.

The soil water characteristic as new class of closed-form parametric expressions for the flow duration curve

NASA Astrophysics Data System (ADS)

Sadegh, M.; Vrugt, J. A.; Gupta, H. V.; Xu, C.

2016-04-01

The flow duration curve is a signature catchment characteristic that depicts graphically the relationship between the exceedance probability of streamflow and its magnitude. This curve is relatively easy to create and interpret, and is used widely for hydrologic analysis, water quality management, and the design of hydroelectric power plants (among others). Several mathematical expressions have been proposed to mimic the FDC. Yet, these efforts have not been particularly successful, in large part because available functions are not flexible enough to portray accurately the functional shape of the FDC for a large range of catchments and contrasting hydrologic behaviors. Here, we extend the work of Vrugt and Sadegh (2013) and introduce several commonly used models of the soil water characteristic as new class of closed-form parametric expressions for the flow duration curve. These soil water retention functions are relatively simple to use, contain between two to three parameters, and mimic closely the empirical FDCs of 430 catchments of the MOPEX data set. We then relate the calibrated parameter values of these models to physical and climatological characteristics of the watershed using multivariate linear regression analysis, and evaluate the regionalization potential of our proposed models against those of the literature. If quality of fit is of main importance then the 3-parameter van Genuchten model is preferred, whereas the 2-parameter lognormal, 3-parameter GEV and generalized Pareto models show greater promise for regionalization.

Local sustained delivery of bupivacaine HCl from a new castor oil-based nanoemulsion system.

PubMed

Rachmawati, Heni; Arvin, Yang Aryani; Asyarie, Sukmadjaja; Anggadiredja, Kusnandar; Tjandrawinata, Raymond Rubianto; Storm, Gert

2018-06-01

Bupivacaine HCl (1-butyl-2',6'-pipecoloxylidide hydrochloride), an amide local anesthetic compound, is a local anesthetic drug utilized for intraoperative local anesthesia, post-operative analgesia and in the treatment of chronic pain. However, its utility is limited by the relative short duration of analgesia after local administration (approximately 9 h after direct injection) and risk for side effects. This work is aimed to develop a nanoemulsion of bupivacaine HCl with sustained local anesthetics release kinetics for improved pain management, by exhibiting extended analgesic action and providing reduced peak levels in the circulation to minimize side effects. Herein, biodegradable oils were evaluated for use in nanoemulsions to enable sustained release kinetics of bupivacaine HCl. Only with castor oil, a clear and stable nanoemulsion was obtained without the occurrence of phase separation over a period of 3 months. High loading of bupivacaine HCl into the castor oil-based nanoemulsion system was achieved with about 98% entrapment efficiency and the resulting formulation showed high stability under stress conditions (accelerated stability test) regarding changes in visual appearance, drug content, and droplet size. We show herein that the in vitro release and in vivo pharmacokinetic profiles as well as pharmacodynamic outcome (pain relief test) after subcutaneous administration in rats correlate well and clearly demonstrate the prolonged release and extended duration of activity of our novel nanoformulation. In addition, the lower C max value achieved in the blood compartment suggests the possibility that the risk for systemic side effects is reduced. We conclude that castor oil-based nanomulsion represents an attractive pain treatment possibility to achieve prolonged local action of bupivacaine HCl.

Extending Galactic Habitable Zone Modeling to Include the Emergence of Intelligent Life.

PubMed

Morrison, Ian S; Gowanlock, Michael G

2015-08-01

Previous studies of the galactic habitable zone have been concerned with identifying those regions of the Galaxy that may favor the emergence of complex life. A planet is deemed habitable if it meets a set of assumed criteria for supporting the emergence of such complex life. In this work, we extend the assessment of habitability to consider the potential for life to further evolve to the point of intelligence--termed the propensity for the emergence of intelligent life, φI. We assume φI is strongly influenced by the time durations available for evolutionary processes to proceed undisturbed by the sterilizing effects of nearby supernovae. The times between supernova events provide windows of opportunity for the evolution of intelligence. We developed a model that allows us to analyze these window times to generate a metric for φI, and we examine here the spatial and temporal variation of this metric. Even under the assumption that long time durations are required between sterilizations to allow for the emergence of intelligence, our model suggests that the inner Galaxy provides the greatest number of opportunities for intelligence to arise. This is due to the substantially higher number density of habitable planets in this region, which outweighs the effects of a higher supernova rate in the region. Our model also shows that φI is increasing with time. Intelligent life emerged at approximately the present time at Earth's galactocentric radius, but a similar level of evolutionary opportunity was available in the inner Galaxy more than 2 Gyr ago. Our findings suggest that the inner Galaxy should logically be a prime target region for searches for extraterrestrial intelligence and that any civilizations that may have emerged there are potentially much older than our own.

Meta-analysis of the effect of road work zones on crash occurrence.

PubMed

Theofilatos, Athanasios; Ziakopoulos, Apostolos; Papadimitriou, Eleonora; Yannis, George; Diamandouros, Konstantinos

2017-11-01

There is strong evidence that work zones pose increased risk of crashes and injuries. The two most common risk factors associated with increased crash frequencies are work zone duration and length. However, relevant research on the topic is relatively limited. For that reason, this paper presents formal meta-analyses of studies that have estimated the relationship between the number of crashes and work zone duration and length, in order to provide overall estimates of those effects on crash frequencies. All studies presented in this paper are crash prediction models with similar specifications. According to the meta-analyses and after correcting for publication bias when it was considered appropriate, the summary estimates of regression coefficients were found to be 0.1703 for duration and 0.862 for length. These effects were significant for length but not for duration. However, the overall estimate of duration was significant before correcting for publication bias. Separate meta-analyses on the studies examining both duration and length was also carried out in order to have rough estimates of the combined effects. The estimate of duration was found to be 0.953, while for length was 0.847. Similar to previous meta-analyses the effect of duration after correcting for publication bias is not significant, while the effect of length was significant at a 95% level. Meta-regression findings indicate that the main factors influencing the overall estimates of the beta coefficients are study year and region for duration and study year and model specification for length. Copyright © 2017 Elsevier Ltd. All rights reserved.

Daily sleep, weekly working hours, and risk of work-related injury: US National Health Interview Survey (2004-2008).

PubMed

Lombardi, David A; Folkard, Simon; Willetts, Joanna L; Smith, Gordon S

2010-07-01

The impact on health and safety of the combination of chronic sleep deficits and extended working hours has received worldwide attention. Using the National Health Interview Survey (NHIS), an in-person household survey using a multistage, stratified, clustered sample design representing the US civilian, non-institutionalized population, the authors estimated the effect of total daily self-reported sleep time and weekly working hours on the risk of a work-related injury. During the survey period 2004-2008, 177,576 persons (ages 18-74) sampled within households reported that they worked at a paid job the previous week and reported their total weekly work hours. A randomly selected adult in each household (n = 75,718) was asked to report his/her usual (average) total daily sleep hours the prior week; complete responses were obtained for 74,415 (98.3%) workers. Weighted annualized work-related injury rates were then estimated across a priori defined categories of both average total daily sleep hours and weekly working hours. To account for the complex sampling design, weighted multiple logistic regression was used to independently estimate the risk of a work-related injury for categories of usual daily sleep duration and weekly working hours, controlling for important covariates and potential confounders of age, sex, race/ethnicity, education, type of pay, industry, occupation (proxy for job risk), body mass index, and the interaction between sleep duration and work hours. Based on the inclusion criteria, there were an estimated 129,950,376 workers annually at risk and 3,634,446 work-related medically treated injury episodes (overall injury rate 2.80/100 workers). Unadjusted annualized injury rates/100 workers across weekly work hours were 2.03 (< or =20 h), 3.01 (20-30 h), 2.45 (31-40 h), 3.45 (40-50 h), 3.71 (50-60 h), and 4.34 (>60 h). With regards to self-reported daily sleep time, the estimated annualized injury rates/100 workers were 7.89 (<5 h sleep), 5.21 (5-5.9 h), 3.62 (6-6.9 h), 2.27 (7-7.9 h), 2.50 (8-8.9 h), 2.22 (9-9.9 h), and 4.72 (>10 h). After controlling for weekly work hours, and aforementioned covariates, significant increases in risk/1 h decrease were observed for several sleep categories. Using 7-7.9 h sleep as reference, the adjusted injury risk (odds ratio [OR] for a worker sleeping a total of <5 h/day was 2.65 (95% confidence interval [CI]: 1.57-4.47), for 5-5.9 h 1.79 (95% CI: 1.22-2.62), and for 6-6.9 h 1.40 (95% CI: 1.10-1.79). No other usual sleep duration categories were significantly different than the reference; however, for >10 h of usual daily sleep, the OR was marginally significantly elevated, 1.82 (95% CI: 0.96-3.47). These results suggest significant increases in work-related injury risk with decreasing usual daily self-reported sleep hours and increasing weekly work hours, independent of industry, occupation, type of pay, sex, age, education, and body mass.

STS-71 hardware assembly view

NASA Technical Reports Server (NTRS)

1994-01-01

Lockheed Space Operations Company workers in the Extended Duration Orbiter (EDO) Facility, located inside the Vehicle Assembly Building (VAB), carefully hoist the Orbiter Docking System (ODS) from its shipping container into a test stand. The ODS was ship

Method for the measurement of media player use

NASA Astrophysics Data System (ADS)

Webb, Graham

There has been ongoing concern that prolonged use of MP3 players can lead to noise-induced hearing loss. Acoustic exposure is the product of intensity and duration of exposure. Previous work has utilised measurements of maximum headphone output and output during listening tests to determine acoustic intensity; whilst duration of use is currently assessed with questionnaires and interviews. The subjective nature of these latter methods has led to a wide variation in figures for device use, restricting the scope of media player risk assessment. A need was therefore identified for an improved method of acquiring data of users' listening habits. This need was addressed with the design of a new data-logging device that discretely measures voltage output from the media player, whilst in use. A calibration method is proposed to implement the headphone transfer function into the data-logger, to relate output voltage to exposed pressure. It is proposed that the headphone transfer function is measured using an acoustic manikin, representative of the population of interest. The real ear measurement is put forward as an appropriate tool for validating results gained using this approach. A data-logger was designed and a proof of concept has been demonstrated in a software program written for this purpose. The proposed method has the advantages that an objective measurement can be made of the user's natural listening habits, over a long period of time, with a resolution comparable to personal acoustic dosimetry. A number of practical steps are required to further this work before data can be collected. A software graphic equaliser was used to implement the transfer function, but the chosen filter topology gave an unsatisfactory response, an investigation is required for further work. The device requires migration to hardware and the experimental calibration and validation of the system are also required. The worldwide population of MP3 player users is in the region of hundreds of millions of people. The relationship between user and device is becoming closer and portable music technology is becoming ubiquitous, permitting extended listening durations. There is therefore a strong need to continue this field of research, to increase understanding of the risks of this aspect of recreational noise.

Mitigation of Electromagnetic Pulse (EMP) Effects from Short-Pulse Lasers and Fusion Neutrons

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

Eder, D C; Throop, A; Brown, Jr., C G

2009-03-06

Our research focused on obtaining a fundamental understanding of the source and properties of EMP at the Titan PW(petawatt)-class laser facility. The project was motivated by data loss and damage to components due to EMP, which can limit diagnostic techniques that can be used reliably at short-pulse PW-class laser facilities. Our measurements of the electromagnetic fields, using a variety of probes, provide information on the strength, time duration, and frequency dependence of the EMP. We measure electric field strengths in the 100's of kV/m range, durations up to 100 ns, and very broad frequency response extending out to 5 GHzmore » and possibly beyond. This information is being used to design shielding to mitigate the effects of EMP on components at various laser facilities. We showed the need for well-shielded cables and oscilloscopes to obtain high quality data. Significant work was invested in data analysis techniques to process this data. This work is now being transferred to data analysis procedures for the EMP diagnostics being fielded on the National Ignition Facility (NIF). In addition to electromagnetic field measurements, we measured the spatial and energy distribution of electrons escaping from targets. This information is used as input into the 3D electromagnetic code, EMSolve, which calculates time dependent electromagnetic fields. The simulation results compare reasonably well with data for both the strength and broad frequency bandwidth of the EMP. This modeling work required significant improvements in EMSolve to model the fields in the Titan chamber generated by electrons escaping the target. During dedicated Titan shots, we studied the effects of varying laser energy, target size, and pulse duration on EMP properties. We also studied the effect of surrounding the target with a thick conducting sphere and cube as a potential mitigation approach. System generated EMP (SGEMP) in coaxial cables does not appear to be a significant at Titan. Our results are directly relevant to planned short-pulse ARC (advanced radiographic capability) operation on NIF.« less

Understanding the role of sleep quality and sleep duration in commercial driving safety.

PubMed

Lemke, Michael K; Apostolopoulos, Yorghos; Hege, Adam; Sönmez, Sevil; Wideman, Laurie

2016-12-01

Long-haul truck drivers in the United States suffer disproportionately high injury rates. Sleep is a critical factor in these outcomes, contributing to fatigue and degrading multiple aspects of safety-relevant performance. Both sleep duration and sleep quality are often compromised among truck drivers; however, much of the efforts to combat fatigue focus on sleep duration rather than sleep quality. Thus, the current study has two objectives: (1) to determine the degree to which sleep impacts safety-relevant performance among long-haul truck drivers; and (2) to evaluate workday and non-workday sleep quality and duration as predictors of drivers' safety-relevant performance. A non-experimental, descriptive, cross-sectional design was employed to collect survey and biometric data from 260 long-haul truck drivers. The Trucker Sleep Disorders Survey was developed to assess sleep duration and quality, the impact of sleep on job performance and accident risk, and other relevant work organization characteristics. Descriptive statistics assessed work organization variables, sleep duration and quality, and frequency of engaging in safety-relevant performance while sleepy. Linear regression analyses were conducted to evaluate relationships between sleep duration, sleep quality, and work organization variables with safety composite variables. Drivers reported long work hours, with over 70% of drivers working more than 11h daily. Drivers also reported a large number of miles driven per week, with an average of 2,812.61 miles per week, and frequent violations of hours-of-service rules, with 43.8% of drivers "sometimes to always" violating the "14-h rule." Sleep duration was longer, and sleep quality was better, on non-workdays compared on workdays. Drivers frequently operated motor vehicles while sleepy, and sleepiness impacted several aspects of safety-relevant performance. Sleep quality was better associated with driving while sleepy and with job performance and concentration than sleep duration. Sleep duration was better associated with accidents and accident risk than sleep quality. Sleep quality appears to be better associated with safety-relevant performance among long-haul truck drivers than sleep duration. Comprehensive and multilevel efforts are needed to meaningfully address sleep quality among drivers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of the long-term stability of retort pouch foods to support extended duration spaceflight.

PubMed

Catauro, Patricia M; Perchonok, Michele H

2012-01-01

To determine the suitability of retort processed foods to support long-duration spaceflight, a series of 36-mo accelerated shelf life studies were performed on 13 representative retort pouch products. Combined sensory evaluations, physical properties assessments, and nutritional analyses were employed to determine shelf life endpoints for these foods, which were either observed during the analysis or extrapolated via mathematical projection. Data obtained through analysis of these 13 products were later used to estimate the shelf life values of all retort-processed spaceflight foods. In general, the major determinants of shelf life appear to be the development of off-flavor and off-color in products over time. These changes were assumed to be the result of Maillard and oxidation reactions, which can be initiated or accelerated as a result of the retort process and product formulation. Meat products and other vegetable entrées are projected to maintain their quality the longest, between 2 and 8 y, without refrigeration. Fruit and dessert products (1.5 to 5 y), dairy products (2.5 to 3.25 y), and starches, vegetable, and soup products (1 to 4 y) follow. Aside from considerable losses in B and C vitamin content, nutritional value of most products was maintained throughout shelf life. Fortification of storage-labile vitamins was proposed as a countermeasure to ensure long-term nutritive value of these products. The use of nonthermal sterilization technologies was also recommended, as a means to improve initial quality of these products and extend their shelf life for use in long-duration missions. Data obtained also emphasize the importance of low temperature storage in maintaining product quality. Retort sterilized pouch products are garnering increased commercial acceptance, largely due to their improved convenience and quality over metal-canned products. Assessment of the long-term stability of these products with ambient storage can identify potential areas for improvement, and ultimately increase consumer satisfaction with these technologies. Journal of Food Science © 2011 Institute of Food Technologists® No claim to original US government works.

Nurses' extended work hours: Patient, nurse and organizational outcomes.

PubMed

Kunaviktikul, W; Wichaikhum, O; Nantsupawat, A; Nantsupawat, R; Chontawan, R; Klunklin, A; Roongruangsri, S; Nantachaipan, P; Supamanee, T; Chitpakdee, B; Akkadechanunt, T; Sirakamon, S

2015-09-01

Nursing shortages have been associated with increased nurse workloads that may result in work errors, thus impacting patient, nurse and organizational outcomes. To examine for the first time in Thailand nurses' extended work hours (working more than 40 h per week) and its relationship to patient, nurse and organizational outcomes. Using multistage sampling, 1524 registered nurses working in 90 hospitals across Thailand completed demographic forms: the Nurses' Extended Work Hours Form; the Patient, Nurse, Organizational Outcomes Form; the Organizational Productivity Questionnaire and the Maslach Burnout Inventory. The data were analysed using descriptive statistics, Spearman's rank correlation and logistic regression. The average extended work hour of respondents was 18.82 h per week. About 80% worked two consecutive shifts. The extended work hours had a positive correlation with patient outcomes, such as patient identification errors, pressure ulcers, communication errors and patient complaints and with nurse outcomes of emotional exhaustion and depersonalization. Furthermore, we found a negative correlation between extended work hours and job satisfaction as a whole, intent to stay and organizational productivity. Nurses who had extended work hours of >16 h per week were significantly more likely to perceive all four adverse patient outcomes than participants working an extended ≤8 h per week. Patient outcomes were measured by respondents' self-reports. This may not always reflect the real occurrence of adverse events. Associations between extended work hours and outcomes for patients, nurses and the organization were found. The findings demonstrate that working two shifts (16 h) more than the regular work hours lead to negative outcomes for patients, nurses and the organization. Our findings add to increasing international evidence that nurses' poor working conditions result in negative outcomes for professionals, patients and health systems. Policymakers need to be aware of the issues regarding nurses' extended work hours, which has been found to contribute to burnout. Urgently, nurse and health administrators need to develop and implement appropriate nursing overtime policies and strategies to help reduce this phenomenon, including measures to overcome the nursing shortage. © 2015 International Council of Nurses.

Deep searches for broadband extended gravitational-wave emission bursts by heterogeneous computing

NASA Astrophysics Data System (ADS)

van Putten, Maurice H. P. M.

2017-09-01

We present a heterogeneous search algorithm for broadband extended gravitational-wave emission, expected from gamma-ray bursts and energetic core-collapse supernovae. It searches the (f,\\dot{f})-plane for long-duration bursts by inner engines slowly exhausting their energy reservoir by matched filtering on a graphics processor unit (GPU) over a template bank of millions of 1 s duration chirps. Parseval's theorem is used to predict the standard deviation σ of the filter output, taking advantage of the near-Gaussian noise in the LIGO S6 data over 350-2000 Hz. Tails exceeding a multiple of σ are communicated back to a central processing unit. This algorithm attains about 65% efficiency overall, normalized to the fast Fourier transform. At about one million correlations per second over data segments of 16 s duration (N=2^{16} samples), better than real-time analysis is achieved on a cluster of about a dozen GPUs. We demonstrate its application to the capture of high-frequency hardware LIGO injections. This algorithm serves as a starting point for deep all-sky searches in both archive data and real-time analysis in current observational runs.

Dietary Support of Extended-Duration Bed Rest Studies

NASA Technical Reports Server (NTRS)

Inniss, A. M.; Rice, B. L.; Smith, S. M.

2006-01-01

Dietary control and nutrient intake are critical aspects of any metabolic study, but this is especially true in the case of bed rest studies. We sought to define nutrient requirements, develop menus, and implement them in a series of three long-duration bed rest studies. With regard to energy intake, the goal was to maintain subject body weight to within 3% of their body weight on day 3 of bed rest (after fluid shift had occurred). For other nutrients, intakes were based on the NASA space flight nutritional requirements (with some adaptations based on the ground-based model used here). A secondary goal was to develop menus with foods similar to those expected to be approved for space flight (however, this was relaxed to attain desired nutrient intakes). This paper also describes the role of the research dietitian as part of the multi-disciplinary team and the importance of the metabolic kitchen staff. It also provides insight into some of the dietary challenges that arise during extended-duration bed rest studies. Regardless of the overall objective of the study, nutrition must be carefully planned, implemented, and monitored for results to be uncompromised.

Effectiveness of an Extended Yoga Treatment for Women with Chronic Posttraumatic Stress Disorder.

PubMed

Price, Maggi; Spinazzola, Joseph; Musicaro, Regina; Turner, Jennifer; Suvak, Michael; Emerson, David; van der Kolk, Bessel

2017-04-01

Yoga has been found to be an effective posttraumatic stress disorder (PTSD) treatment for a variety of trauma survivors, including females with chronic PTSD. Aim/Purpose: The current study builds on extant research by examining an extended trauma-sensitive yoga treatment for women with chronic PTSD. The study sought to optimize the results of a treatment protocol examined in a recent randomized controlled trial with a shorter duration and without assignment or monitoring of home practice. The authors examined a 20-week trauma-sensitive yoga treatment in a non-randomized single-group treatment feasibility study for women with chronic treatment-resistant PTSD (N = 9). The authors examined PTSD and dissociation symptom reduction over several assessment periods. The results indicate that participants experienced significant reductions in PTSD and dissociative symptomatology above and beyond similar treatments of a shorter duration. The findings suggest that more intensive trauma-sensitive yoga treatment characterized by longer duration and intentional assignment and monitoring of home practice may be more advantageous for individuals with severe and chronic PTSD. The implications of the findings for the potentially more substantial role of yoga as an intervention for a subset of adults with chronic treatment-resistant PTSD are discussed.

Drift in Neural Population Activity Causes Working Memory to Deteriorate Over Time.

PubMed

Schneegans, Sebastian; Bays, Paul M

2018-05-23

Short-term memories are thought to be maintained in the form of sustained spiking activity in neural populations. Decreases in recall precision observed with increasing number of memorized items can be accounted for by a limit on total spiking activity, resulting in fewer spikes contributing to the representation of each individual item. Longer retention intervals likewise reduce recall precision, but it is unknown what changes in population activity produce this effect. One possibility is that spiking activity becomes attenuated over time, such that the same mechanism accounts for both effects of set size and retention duration. Alternatively, reduced performance may be caused by drift in the encoded value over time, without a decrease in overall spiking activity. Human participants of either sex performed a variable-delay cued recall task with a saccadic response, providing a precise measure of recall latency. Based on a spike integration model of decision making, if the effects of set size and retention duration are both caused by decreased spiking activity, we would predict a fixed relationship between recall precision and response latency across conditions. In contrast, the drift hypothesis predicts no systematic changes in latency with increasing delays. Our results show both an increase in latency with set size, and a decrease in response precision with longer delays within each set size, but no systematic increase in latency for increasing delay durations. These results were quantitatively reproduced by a model based on a limited neural resource in which working memories drift rather than decay with time. SIGNIFICANCE STATEMENT Rapid deterioration over seconds is a defining feature of short-term memory, but what mechanism drives this degradation of internal representations? Here, we extend a successful population coding model of working memory by introducing possible mechanisms of delay effects. We show that a decay in neural signal over time predicts that the time required for memory retrieval will increase with delay, whereas a random drift in the stored value predicts no effect of delay on retrieval time. Testing these predictions in a multi-item memory task with an eye movement response, we identified drift as a key mechanism of memory decline. These results provide evidence for a dynamic spiking basis for working memory, in contrast to recent proposals of activity-silent storage. Copyright © 2018 Schneegans and Bays.

Work-place predictors of duration of breastfeeding among female physicians.

PubMed

Sattari, Maryam; Serwint, Janet R; Neal, Dan; Chen, Si; Levine, David M

2013-12-01

To identify work-related predictors of breastfeeding duration among female physicians. Data on 238 children were obtained from 50 female physicians, whose main affiliation was with Johns Hopkins University (Baltimore, MD), and 80 female physicians, whose main affiliation was with the University of Florida (Gainesville, FL). We used a mixed linear model to determine which variables were significant predictors of breastfeeding duration when controlling for maternal demographics and taking into account the clustering of observations on study location and mothers. Although female physicians intended to breastfeed 56% of the infants for at least 12 months and 97% of infants were breastfed at birth, only 34% of infants continued to receive breast milk at 12 months. Duration of lactation among female physicians correlated with the following work-related factors: (1) not having to make up missed call/work that occurred as result of pregnancy or maternity leave; (2) longer length of maternity leave; (3) sufficiency of time at work for milk expression; and (4) perceived level of support for breastfeeding efforts at work from colleagues, program director, or division/section chiefs. Our findings support the importance of work-related factors in breastfeeding maintenance among female physicians and suggest that a tailored intervention, providing time and institutional encouragement, might result in significant improvement in their breastfeeding duration. Copyright © 2013 Mosby, Inc. All rights reserved.

Learning and the Spiral Illusion

ERIC Educational Resources Information Center

Houtman, S. D.

1974-01-01

The purpose of the experiment was to ascertain whether the duration of the spiral illusion could be extended by a 'learning procedure' which would distinguish a longer-term learning effect from short-term adaptive changes due to inhibition. (Author)

Thermal Control System for a Small, Extended Duration Lunar Surface Science Platform

NASA Technical Reports Server (NTRS)

Bugby, D.; Farmer, J.; OConnor, B.; Wirzburger, M.; Abel, E.; Stouffer, C.

2010-01-01

The presentation slides include: Introduction: lunar mission definition, Problem: requirements/methodology, Concept: thermal switching options, Analysis: system evaluation, Plans: dual-radiator LHP (loop heat pipe) test bed, and Conclusions: from this study.

Space Station CMIF extended duration metabolic control test

NASA Technical Reports Server (NTRS)

Schunk, Richard G.; Bagdigian, Robert M.; Carrasquillo, Robyn L.; Ogle, Kathryn Y.; Wieland, Paul O.

1989-01-01

The Space Station Extended Duration Metabolic Control Test (EMCT) was conducted at the MSFC Core Module Integration Facility. The primary objective of the EMCT was to gather performance data from a partially-closed regenerative Environmental Control and Life Support (ECLS) system functioning under steady-state conditions. Included is a description of the EMCT configuration, a summary of events, a discussion of anomalies that occurred during the test, and detailed results and analysis from individual measurements of water and gas samples taken during the test. A comparison of the physical, chemical, and microbiological methods used in the post test laboratory analyses of the water samples is included. The preprototype ECLS hardware used in the test, providing an overall process description and theory of operation for each hardware item. Analytical results pertaining to a system level mass balance and selected system power estimates are also included.

Antibiotic prophylaxis and risk of Clostridium difficile infection after coronary artery bypass graft surgery.

PubMed

Poeran, Jashvant; Mazumdar, Madhu; Rasul, Rehana; Meyer, Joanne; Sacks, Henry S; Koll, Brian S; Wallach, Frances R; Moskowitz, Alan; Gelijns, Annetine C

2016-02-01

Antibiotic use, particularly type and duration, is a crucial modifiable risk factor for Clostridium difficile. Cardiac surgery is of particular interest because prophylactic antibiotics are recommended for 48 hours or less (vs ≤24 hours for noncardiac surgery), with increasing vancomycin use. We aimed to study associations between antibiotic prophylaxis (duration/vancomycin use) and C difficile among patients undergoing coronary artery bypass grafting. We extracted data on coronary artery bypass grafting procedures from the national Premier Perspective claims database (2006-2013, n = 154,200, 233 hospitals). Multilevel multivariable logistic regressions measured associations between (1) duration (<2 days, "standard" vs ≥2 days, "extended") and (2) type of antibiotic used ("cephalosporin," "cephalosporin + vancomycin," "vancomycin") and C difficile as outcome. Overall C difficile prevalence was 0.21% (n = 329). Most patients (59.7%) received a cephalosporin only; in 33.1% vancomycin was added, whereas 7.2% received vancomycin only. Extended prophylaxis was used in 20.9%. In adjusted analyses, extended prophylaxis (vs standard) was associated with significantly increased C difficile risk (odds ratio, 1.43; confidence interval, 1.07-1.92), whereas no significant associations existed for vancomycin use as adjuvant or primary prophylactic compared with the use of cephalosporins (odds ratio, 1.21; confidence interval, 0.92-1.60, and odds ratio, 1.39; confidence interval, 0.94-2.05, respectively). Substantial inter-hospital variation exists in the percentage of extended antibiotic prophylaxis (interquartile range, 2.5-35.7), use of adjuvant vancomycin (interquartile range, 4.2-61.1), and vancomycin alone (interquartile range, 2.3-10.4). Although extended use of antibiotic prophylaxis was associated with increased C difficile risk after coronary artery bypass grafting, vancomycin use was not. The observed hospital variation in antibiotic prophylaxis practices suggests great potential for efforts aimed at standardizing practices that subsequently could reduce C difficile risk. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Post-Discharge Care Duration, Charges, and Outcomes Among Medicare Patients After Primary Total Hip and Knee Arthroplasty.

PubMed

Ponnusamy, Karthikeyan E; Naseer, Zan; El Dafrawy, Mostafa H; Okafor, Louis; Alexander, Clayton; Sterling, Robert S; Khanuja, Harpal S; Skolasky, Richard L

2017-06-07

In April 2016, the U.S. Centers for Medicare & Medicaid Services initiated mandatory 90-day bundled payments for total hip and knee arthroplasty for much of the country. Our goal was to determine duration of care, 90-day charges, and readmission rates by discharge disposition and U.S. region after hip or knee arthroplasty. Using the 2008 Medicare Provider Analysis and Review database 100% sample, we identified patients who had undergone elective primary total hip or knee arthroplasty. We collected data on patient age, sex, comorbidities, U.S. Census region, discharge disposition, duration of care, 90-day charges, and readmission. Multivariate regression was used to assess factors associated with readmission (logistic) and charges (linear). Significance was set at p < 0.01. Patients undergoing 138,842 total hip arthroplasties were discharged to home (18%), home health care (34%), extended-care facilities (35%), and inpatient rehabilitation (13%); patients undergoing 329,233 total knee arthroplasties were discharged to home (21%), home health care (38%), extended-care facilities (31%), and inpatient rehabilitation (10%). Patients in the Northeast were more likely to be discharged to extended-care facilities or inpatient rehabilitation than patients in other regions. Patients in the West had the highest 90-day charges. Approximately 70% of patients were discharged home from extended-care facilities, whereas after inpatient rehabilitation, >50% of patients received home health care. Among those discharged to home, 90-day readmission rates were highest in the South (9.6%) for patients undergoing total hip arthroplasty and in the Midwest (8.7%) and the South (8.5%) for patients undergoing total knee arthroplasty. Having ≥4 comorbidities, followed by discharge to inpatient rehabilitation or an extended-care facility, had the strongest associations with readmission, whereas the region of the West and the discharge disposition to inpatient rehabilitation had the strongest association with higher charges. Among Medicare patients, discharge disposition and number of comorbidities were most strongly associated with readmission. Inpatient rehabilitation and the West region had the strongest associations with higher charges. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Associations among rotating night shift work, sleep and skin cancer in Nurses' Health Study II participants.

PubMed

Heckman, Carolyn J; Kloss, Jacqueline D; Feskanich, Diane; Culnan, Elizabeth; Schernhammer, Eva S

2017-03-01

Night shift work and sleep duration have been associated with breast and other cancers. Results from the few prior studies of night shift work and skin cancer risk have been mixed and not fully accounted for other potentially important health-related variables (eg, sleep characteristics). This study evaluated the relationship between rotating night shift work and skin cancer risk and included additional skin cancer risk factors and sleep-related variables. The current study used data from 74 323 Nurses' Health Study (NHS) II participants. Cox proportional hazards models were used to estimate multivariable-adjusted HRs and 95% CIs for skin cancers across categories of shift work and sleep duration. Over 10 years of follow-up, 4308 basal cell carcinoma (BCC), 334 squamous cell carcinoma (SCC) and 212 melanoma cases were identified. Longer duration of rotating night shifts was associated with a linear decline in risk of BCC (HR=0.93, 95% CI 0.90 to 0.97 per 5-year increase). Shift work was not significantly associated with either melanoma (HR=1.02, 95% CI 0.86 to 1.21) or SCC (HR=0.92, 95% CI 0.80 to 1.06). A short sleep duration (≤6 hours per day) was associated with lower risks of melanoma (HR=0.68, 95% CI 0.46 to 0.98) and BCC (HR=0.93, 95% CI 0.86 to 1.00) compared with the most common report of 7 hours. SCC was not associated with duration of sleep (HR=0.94, 95% CI 0.83 to 1.06). Longer duration of rotating night shift work and shorter sleep duration were associated with lower risk of some skin cancers. Further research is needed to confirm and identify the mechanisms underlying these associations. 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/.

Night-shift work, sleep duration, daytime napping, and breast cancer risk.

PubMed

Wang, Pan; Ren, Fang-Mei; Lin, Ying; Su, Feng-Xi; Jia, Wei-Hua; Su, Xue-Fen; Tang, Lu-Ying; Ren, Ze-Fang

2015-04-01

Sleep habits vary among different countries, and sleep problems may cause various health problems. The aim of our study was to evaluate the separate and combined associations of night-shift work, sleep duration, and daytime napping with breast cancer risk among the Chinese population. This study conducted face-to-face interviews with 712 women diagnosed with incident invasive breast cancer before treatment and 742 age-matched controls. Information on sleep habits, demographic characteristics, and suspected or established risk factors of breast cancer were collected from the two groups. Multivariate logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). Night-shift work was associated with an increased risk of breast cancer [OR (95% CI): 1.34 (1.05-1.72)]. Compared to women with a sleep duration of 6.1-8.9 h/day, women who had shorter [(≤6.0 h/day) (OR (95% CI): 1.53 (1.10-2.12)] and longer (≥9.0 h/day) sleep duration [(OR (95% CI): 1.59 (1.17-2.17)] had an increased risk of breast cancer. In addition, daytime napping was associated with a reduced risk of breast cancer among night-shift workers [OR (95% CI): 0.57 (0.36-0.90)], but no association was found among women who never had night-shift work [OR (95% CI): 1.01 (0.75-1.35)] (P for interaction = 0.054). Night-shift work and longer sleep duration also synergistically increased breast cancer risk [OR (95% CI): 3.69 (1.94-7.02)] (P for interaction = 0.009). Sleep problems, including night-shift work, and shorter and longer sleep duration, are associated with an increased breast cancer risk. In particular, the combined effects of night-shift work with no daytime napping or longer sleep duration are greater than the independent effects. Copyright © 2014 Elsevier B.V. All rights reserved.

Is fatigue after work a barrier for leisure-time physical activity? Cross-sectional study among 10,000 adults from the general working population.

PubMed

Bláfoss, Rúni; Micheletti, Jéssica K; Sundstrup, Emil; Jakobsen, Markus D; Bay, Hans; Andersen, Lars L

2018-04-01

In spite of the many health-related benefits of regular physical activity, fatiguing work may be a barrier to performing leisure-time physical activity. This study investigates the association between work-related fatigue and the duration of low- and high-intensity leisure-time physical activity in workers with sedentary and physically demanding jobs. From the 2010 round of the Danish Work Environment Cohort Study, currently employed wage earners from the general working population ( N=10,427) replied to questions about work-related fatigue (predictor) and duration of low- and high-intensity leisure-time physical activity (outcome). Associations were modelled using general linear models controlling for various confounders. Among workers with physically demanding jobs, higher levels of work-related fatigue were associated with gradually lower levels of leisure-time physical activity - for low, moderate and high levels of work-related fatigue the duration of high-intensity leisure-time physical activity was 133 (95% confidence interval (CI) 127-178), 134 (95% CI 109-160) and 113 (95% CI 86-140) min per week, respectively (trend test p<0.001). The duration of high-intensity leisure-time physical activity was lower among older workers (≥50 years) compared to younger workers (<50 years) (132 ± 126 vs 168 ± 150 min per week) ( p<0.0001). The duration of high-intensity leisure-time physical activity gradually decreases with increased work-related fatigue in workers with physically demanding jobs. Older workers perform less high-intensity physical activity than younger workers. Workplaces should consider initiatives to allow workers with physically demanding jobs and older workers to perform physical exercise during working hours and thereby increase physical capacity to meet the job demands.

Theoretical and Experimental Study of Radial Velocity Generation for Extending Bandwidth of Magnetohydrodynamic Angular Rate Sensor at Low Frequency.

PubMed

Ji, Yue; Li, Xingfei; Wu, Tengfei; Chen, Cheng

2015-12-15

The magnetohydrodynamics angular rate sensor (MHD ARS) has received much attention for its ultra-low noise in ultra-broad bandwidth and its impact resistance in harsh environments; however, its poor performance at low frequency hinders its work in long time duration. The paper presents a modified MHD ARS combining Coriolis with MHD effect to extend the measurement scope throughout the whole bandwidth, in which an appropriate radial flow velocity should be provided to satisfy simplified model of the modified MHD ARS. A method that can generate radial velocity by an MHD pump in MHD ARS is proposed. A device is designed to study the radial flow velocity generated by the MHD pump. The influence of structure and physical parameters are studied by numerical simulation and experiment of the device. The analytic expression of the velocity generated by the energized current drawn from simulation and experiment are consistent, which demonstrates the effectiveness of the method generating radial velocity. The study can be applied to generate and control radial velocity in modified MHD ARS, which is essential for the two effects combination throughout the whole bandwidth.

Theoretical and Experimental Study of Radial Velocity Generation for Extending Bandwidth of Magnetohydrodynamic Angular Rate Sensor at Low Frequency

PubMed Central

Ji, Yue; Li, Xingfei; Wu, Tengfei; Chen, Cheng

2015-01-01

The magnetohydrodynamics angular rate sensor (MHD ARS) has received much attention for its ultra-low noise in ultra-broad bandwidth and its impact resistance in harsh environments; however, its poor performance at low frequency hinders its work in long time duration. The paper presents a modified MHD ARS combining Coriolis with MHD effect to extend the measurement scope throughout the whole bandwidth, in which an appropriate radial flow velocity should be provided to satisfy simplified model of the modified MHD ARS. A method that can generate radial velocity by an MHD pump in MHD ARS is proposed. A device is designed to study the radial flow velocity generated by the MHD pump. The influence of structure and physical parameters are studied by numerical simulation and experiment of the device. The analytic expression of the velocity generated by the energized current drawn from simulation and experiment are consistent, which demonstrates the effectiveness of the method generating radial velocity. The study can be applied to generate and control radial velocity in modified MHD ARS, which is essential for the two effects combination throughout the whole bandwidth. PMID:26694393

Impact of implant composition of twin-screw extruded lipid implants on the release behavior.

PubMed

Even, Marie-Paule; Bobbala, Sharan; Kooi, Kok Liang; Hook, Sarah; Winter, Gerhard; Engert, Julia

2015-09-30

The development of vaccine delivery systems that will remove or reduce the need for repeated dosing has led to the investigation of sustained release systems. In this context, the duration of antigen release is of great importance as is the requirement for concomitant adjuvant release. In this work, lipid implants consisting of cholesterol (CHOL), soybean lecithin, Dynasan 114 (D114), the model antigen ovalbumin (OVA) and the adjuvant Quil-A (QA) were produced by twin-screw extrusion. The release of antigen and adjuvant was investigated in vitro and we observed complete OVA release over a period of 7 days while QA was released in a linear fashion over a period of up to 12 days. In order to extend OVA release, lipid implants were subjected to post-extrusion curing at 45-55°C. The OVA release could be extended to up to 14 days. Furthermore the influence of the implant composition on the release of the model antigen was investigated. It was shown that the percentage of cholesterol in particular plays an important role in modulating release. Copyright © 2015 Elsevier B.V. All rights reserved.

Sickness benefit claims due to mental disorders in Brazil: associations in a population-based study.

PubMed

Barbosa-Branco, Anadergh; Bültmann, Ute; Steenstra, Ivan

2012-10-01

This study aims to determine the prevalence and duration of sickness benefit claims due to mental disorders and their association with economic activity, sex, age, work-relatedness and income replacement using a population-based study of sickness benefit claims (> 15 days) due to mental disorders in Brazil carried out in 2008. The prevalence of mental disorders was 45.1 claims per 10,000 workers. Prevalence and duration of sickness benefit claims due to mental disorder were higher and longer in workers aged over 40 years. Prevalence of claims was 73% higher in women but duration of sickness benefit claims was longer in men. Prevalence rates for claims differed widely according to economic activity, with sewage, residential care and programming and broadcasting activities showing the highest rates. Claims were deemed to be work-related in 8.5% of cases with mental disorder showing low work-relatedness in Brazil. A wide variation of prevalence and duration between age, economic activity and work-relatedness was observed, suggesting that working conditions are a more important factor in mental disorder work disability than previously assumed.

Extended driving impairs nocturnal driving performances.

PubMed

Sagaspe, Patricia; Taillard, Jacques; Akerstedt, Torbjorn; Bayon, Virginie; Espié, Stéphane; Chaumet, Guillaume; Bioulac, Bernard; Philip, Pierre

2008-01-01

Though fatigue and sleepiness at the wheel are well-known risk factors for traffic accidents, many drivers combine extended driving and sleep deprivation. Fatigue-related accidents occur mainly at night but there is no experimental data available to determine if the duration of prior driving affects driving performance at night. Participants drove in 3 nocturnal driving sessions (3-5 am, 1-5 am and 9 pm-5 am) on open highway. Fourteen young healthy men (mean age [+/-SD] = 23.4 [+/-1.7] years) participated Inappropriate line crossings (ILC) in the last hour of driving of each session, sleep variables, self-perceived fatigue and sleepiness were measured. Compared to the short (3-5 am) driving session, the incidence rate ratio of inappropriate line crossings increased by 2.6 (95% CI, 1.1 to 6.0; P<.05) for the intermediate (1-5 am) driving session and by 4.0 (CI, 1.7 to 9.4; P<.001) for the long (9 pm-5 am) driving session. Compared to the reference session (9-10 pm), the incidence rate ratio of inappropriate line crossings were 6.0 (95% CI, 2.3 to 15.5; P<.001), 15.4 (CI, 4.6 to 51.5; P<.001) and 24.3 (CI, 7.4 to 79.5; P<.001), respectively, for the three different durations of driving. Self-rated fatigue and sleepiness scores were both positively correlated to driving impairment in the intermediate and long duration sessions (P<.05) and increased significantly during the nocturnal driving sessions compared to the reference session (P<.01). At night, extended driving impairs driving performances and therefore should be limited.

Extended working shifts: are they applicable to the Southeastern United States?

Treesearch

Dana Mitchell; Tom Gallagher

2006-01-01

Logging operations in Scandinavia, Canada and the Lake States of the United States have used non-traditional (extended) working hours to increase their production for many years. However, extended shifts are uncommon in the southeastern United States. A major limitation in implementing extended working hours in the southeastern states is that logging business owners...

Optimal trajectory planning for a UAV glider using atmospheric thermals

NASA Astrophysics Data System (ADS)

Kagabo, Wilson B.

An Unmanned Aerial Vehicle Glider (UAV glider) uses atmospheric energy in its different forms to remain aloft for extended flight durations. This UAV glider's aim is to extract atmospheric thermal energy and use it to supplement its battery energy usage and increase the mission period. Given an infrared camera identified atmospheric thermal of known strength and location; current wind speed and direction; current battery level; altitude and location of the UAV glider; and estimating the expected altitude gain from the thermal, is it possible to make an energy-efficient based motivation to fly to an atmospheric thermal so as to achieve UAV glider extended flight time? For this work, an infrared thermal camera aboard the UAV glider takes continuous forward-looking ground images of "hot spots". Through image processing a candidate atmospheric thermal strength and location is estimated. An Intelligent Decision Model incorporates this information with the current UAV glider status and weather conditions to provide an energy-based recommendation to modify the flight path of the UAV glider. Research, development, and simulation of the Intelligent Decision Model is the primary focus of this work. Three models are developed: (1) Battery Usage Model, (2) Intelligent Decision Model, and (3) Altitude Gain Model. The Battery Usage Model comes from the candidate flight trajectory, wind speed & direction and aircraft dynamic model. Intelligent Decision Model uses a fuzzy logic based approach. The Altitude Gain Model requires the strength and size of the thermal and is found a priori.

Sub- and Quasi-Centurial Cycles in Solar and Geomagnetic Activity Data Series

NASA Astrophysics Data System (ADS)

Komitov, B.; Sello, S.; Duchlev, P.; Dechev, M.; Penev, K.; Koleva, K.

2016-07-01

The subject of this paper is the existence and stability of solar cycles with durations in the range of 20-250 years. Five types of data series are used: 1) the Zurich series (1749-2009 AD), the mean annual International sunspot number Ri, 2) the Group sunspot number series Rh (1610-1995 AD), 3) the simulated extended sunspot number from Extended time series of Solar Activity Indices (ESAI) (1090-2002 AD), 4) the simulated extended geomagnetic aa-index from ESAI (1099-2002 AD), 5) the Meudon filament series (1919-1991 AD). Two principally independent methods of time series analysis are used: the T-R periodogram analysis (both in standard and ``scanning window'' regimes) and the wavelet-analysis. The obtained results are very similar. A strong cycle with a mean duration of 55-60 years is found to exist in all series. On the other hand, a strong and stable quasi 110-120 years and ˜200-year cycles are obtained in all of these series except in the Ri one. The high importance of the long term solar activity dynamics for the aims of solar dynamo modeling and predictions is especially noted.

Extended Culture of Bone Marrow with Granulocyte Macrophage-Colony Stimulating Factor Generates Immunosuppressive Cells

PubMed Central

Na, Hye Young; Sohn, Moah; Ryu, Seul Hye; Choi, Wanho; In, Hyunju; Shin, Hyun Soo

2018-01-01

Bone marrow-derived dendritic cells (BM-DCs) are generated from bone marrow (BM) cells cultured with granulocyte macrophage-colony stimulating factor (GM-CSF) for a week. In this study we investigated the effect of duration on the BM culture with GM-CSF. Within several months, the cells in the BM culture gradually expressed homogeneous levels of CD11c and major histocompatibility complex II on surface, and they became unable to stimulate allogeneic naïve T cells in mixed lymphocyte reaction (MLR). In addition, when the BM culture were sustained for 32 wk or longer, the BM cells acquired ability to suppress the proliferation of allogeneic T cells in MLR as well as the response of ovalbumin-specific OT-I transgenic T cells in antigen-dependent manner. We found that, except for programmed death-ligand 1, most cell surface molecules were expressed lower in the BM cells cultured with GM-CSF for the extended duration. These results indicate that BM cells in the extended culture with GM-CSF undergo 2 distinct steps of functional change; first, they lose the immunostimulatory capacity; and next, they gain the immunosuppressive ability. PMID:29736292

Periodic Fluctuation of Perceived Duration

PubMed Central

Shima, Shuhei; Murai, Yuki; Yuasa, Kenichi; Hashimoto, Yuki

2018-01-01

In recent years, several studies have reported that the allocation of spatial attention fluctuates periodically. This periodic attention was revealed by measuring behavioral performance as a function of cue-to-target interval in the Posner cueing paradigm. Previous studies reported behavioral oscillations using target detection tasks. Whether the influence of periodic attention extends to cognitively demanding tasks remains unclear. To assess this, we examined the effects of periodic attention on the perception of duration. In the experiment, participants performed a temporal bisection task while a cue was presented with various cue-to-target intervals. Perceived duration fluctuated rhythmically as a function of cue-to-target interval at a group level but not at an individual level when the target was presented on the same side as the attentional cue. The results indicate that the perception of duration is influenced by periodic attention. In other words, periodic attention can influence the performance of cognitively demanding tasks such as the perception of duration. PMID:29755719

Immunological Diagnosis

USDA-ARS?s Scientific Manuscript database

Bovine tuberculosis (TB) is generally considered a slowly progressive disease of extended duration (lasting years) and most cattle do not exhibit readily apparent clinical signs of infection until late in the course of disease. Currently, agent-based strategies for the detection of tuberculous cattl...

Return to work following surgery for lumbar radiculopathy: a systematic review.

PubMed

Huysmans, Eva; Goudman, Lisa; Van Belleghem, Griet; De Jaeger, Mats; Moens, Maarten; Nijs, Jo; Ickmans, Kelly; Buyl, Ronald; Vanroelen, Christophe; Putman, Koen

2018-05-22

Informing patients about postoperative return to work (RTW) expectations is of utmost importance because of the influence of realistic expectations on RTW outcomes. We aimed to give an overview of the duration of sick leave and RTW rates after surgery for lumbar radiculopathy and to list predictors of and factors related to RTW. A systematic review was carried out. A systematic literature search was conducted in PubMed, Web of Science, EMBASE, and SCOPUS. Full-text articles on RTW following surgery for lumbar radiculopathy were included through double-blind screening. Risk of bias was assessed using a modified version of the Downs and Black checklist. Sixty-three full-text articles (total sample size: 7,100 patients) were included. Risk of bias was scored low to high. Mean duration of sick leave ranged from 0.8 to 20 weeks. Within 0.1-240 months post surgery, 3%-100% of patients resumed work. Most important predictors for work resumption were preoperative work status, presence of comorbidities, age, sex and duration of preoperative symptoms. Duration of sick leave can be predicted by the preoperative level of pain or disability and presence of symptoms of depression, occupational mental stress, and lateral disc prolapse. Furthermore, less invasive surgical techniques were found to result in better RTW outcomes compared with more invasive techniques. Diverse results were found for RTW rates and duration of sick leave. Preoperative work status, presence of comorbidities, and several demographic factors were retrieved as predictors of RTW and duration of sick leave. Copyright © 2018 Elsevier Inc. All rights reserved.

Work-related lesions of the supraspinatus tendon: a case-control study.

PubMed

Seidler, Andreas; Bolm-Audorff, Ulrich; Petereit-Haack, Gabriela; Ball, Elke; Klupp, Magdalena; Krauss, Noëlle; Elsner, Gine

2011-04-01

To examine the dose-response relationship between cumulative duration of work with highly elevated arms (work above shoulder level) as well as of manual material handling and ruptures of the supraspinatus tendon in a population-based case-control study. In 14 radiologic practices, we recruited 483 male patients aged 25-65 with radiographically confirmed partial (n = 385) or total (n = 98) supraspinatus tears associated with shoulder pain. A total of 300 male control subjects were recruited. Data were gathered in a structured personal interview. To calculate cumulative exposure, the self-reported duration of lifting/carrying of heavy loads (>20 kg) as well as the duration of work with highly elevated arms was added up over the entire working life. The results of our study support a dose-response relationship between cumulative duration of work with highly elevated arms and symptomatic supraspinatus tendon tears. For a cumulative duration of >3,195 h work above shoulder level, the risk of a supraspinatus tendon rupture is elevated to 2.0 (95% CI 1.1-3.5), adjusted for age, region, lifting/carrying of heavy loads, handheld vibration, apparatus gymnastics/shot put/javelin/hammer throwing/wrestling, and tennis. The cumulative duration of carrying/lifting of heavy loads also yields a positive dose-response relation with disease (independent from work above shoulder level and from handheld vibration), with an adjusted odds ratio of 1.8 (95% CI 1.0-3.2) in the highest exposure category (>77 h). We find an increased risk for subjects exposed to handheld vibration with an adjusted OR of 3.2 (95% CI 1.7-5.9) in the highest exposure category (16 years or more in the job with exposure), but a clear dose-response relationship is lacking. This study points to a potential etiologic role of long-term cumulative effects of work with highly elevated arms and heavy lifting/carrying on shoulder tendon disorders.

Dexamethasone as a ropivacaine adjuvant for ultrasound-guided interscalene brachial plexus block: A randomized, double-blinded clinical trial.

PubMed

Sakae, Thiago Mamôru; Marchioro, Patricia; Schuelter-Trevisol, Fabiana; Trevisol, Daisson José

2017-05-01

The purpose of this study was to evaluate the effect of intravenous or perineural dexamethasone added to ropivacaine on the duration of ultrasound-guided interscalene brachial plexus blocks (BPB). Randomized clinical trial. Sixty ASA physical status I-II patients with elective shoulder arthroscopic surgeries under interscalene brachial plexus blocks were randomly allocated to receive 20ml of 0.75% ropivacaine with 1ml of isotonic saline (C group, n=20), 20ml of 0.75% ropivacaine with 1ml (4mg) of perineural dexamethasone (Dpn group, n=20), or 20ml of 0.75% ropivacaine with 1ml of isotonic saline and intravenous 4mg dexamethasone (IV) (Div group, n=20). A nerve stimulation technique with ultrasound was used in all patients. The onset time and duration of sensory blocks were assessed. Secondary outcomes were pain scores (VAS) and postoperative vomiting and nausea (PONV). The duration of the motor and sensory block was extended in group Dpn compared with group Div and group C (P<0.05). In addition, within 24h, group Dpn presented lower levels of VAS and lower incidence of PONV as compared with the other groups. Moreover, there was a significant reduction on onset time between group Dpn and the other groups. Perineural 4mg dexamethasone was more effective than intravenous in extending the duration of ropivacaine in ultrasound-guided interscalene BPB. Moreover, Dpn has significant effects on onset time, PONV, and VAS. Copyright © 2017 Elsevier Inc. All rights reserved.

Does Breast-feeding Relate to Development of Atopic Dermatitis in Young Korean Children?: Based on the Fourth and Fifth Korea National Health and Nutrition Examination Survey 2007–2012

PubMed Central

Lee, Kyung Suk; Rha, Yeong-Ho; Oh, In-Hwan; Choi, Yong Sung; Kim, Young-Eun

2017-01-01

Purpose There have been conflicting reports concerning the relationship between breast-feeding and the development of atopic dermatitis (AD) in early childhood. The objective of this study was to investigate the associations between breast-feeding and the risk of AD in early childhood in Korea. Methods We combined the fourth and fifth Korea National Health and Nutrition Examination Survey data collected from 2007 to 2012 and analyzed 2,015 children at 1 to 3 years old. Regression analysis was used to determine the association of the following variables: AD, feeding types, duration of breast-feeding, and others. Results The annual prevalence of exclusive breast-feeding and AD decreased. Parents with allergic diseases preferred breast-feeding and extended duration of feeding compared with those without. In multiple logistic regression analyses, exclusive breast-feeding in feeding type I (P=0.070; adjusted odds ratio [OR]=1.990), exclusive breast-feeding in feeding type II (P=0.095; adjusted OR=1.495) and breast-feeding duration (P=0.430; adjusted OR=1.013) were not significantly related to AD. Conclusions Breast-feeding was not found to be associated with an occurrence of AD in young children. Rather, parents with histories of allergic diseases tended to prefer breast-feeding and extend its duration. To clarify the role of breast-feeding in the development of AD, a nation-wide prospective study is needed. PMID:28497917

Effects of Heat Stress on Construction Labor Productivity in Hong Kong: A Case Study of Rebar Workers.

PubMed

Yi, Wen; Chan, Albert P C

2017-09-12

Global warming is bringing more frequent and severe heat waves, and the result will be serious for vulnerable populations such as construction workers. Excessive heat stress has profound effects on physiological responses, which cause occupational injuries, fatalities and low productivity. Construction workers are particularly affected by heat stress, because of the body heat production caused by physically demanding tasks, and hot and humid working conditions. Field studies were conducted between August and September 2016 at two construction training grounds in Hong Kong. Onsite wet-bulb globe temperature (WBGT), workers' heart rate (HR), and labor productivity were measured and monitored. Based on the 378 data sets of synchronized environmental, physiological, construction labor productivity (CLP), and personal variables, a CLP-heat stress model was established. It was found that WBGT, percentage of maximum HR, age, work duration, and alcohol drinking habits were determining factors for predicting the CLP (adjusted R ² = 0.68, p < 0.05). The model revealed that heat stress reduces CLP, with the percentage of direct work time decreasing by 0.33% when the WBGT increased by 1 °C. The findings in this study extend the existing practice notes by providing scientific data that may be of benefit to the industry in producing solid guidelines for working in hot weather.

Effects of Heat Stress on Construction Labor Productivity in Hong Kong: A Case Study of Rebar Workers

PubMed Central

Chan, Albert P. C.

2017-01-01

Global warming is bringing more frequent and severe heat waves, and the result will be serious for vulnerable populations such as construction workers. Excessive heat stress has profound effects on physiological responses, which cause occupational injuries, fatalities and low productivity. Construction workers are particularly affected by heat stress, because of the body heat production caused by physically demanding tasks, and hot and humid working conditions. Field studies were conducted between August and September 2016 at two construction training grounds in Hong Kong. Onsite wet-bulb globe temperature (WBGT), workers’ heart rate (HR), and labor productivity were measured and monitored. Based on the 378 data sets of synchronized environmental, physiological, construction labor productivity (CLP), and personal variables, a CLP-heat stress model was established. It was found that WBGT, percentage of maximum HR, age, work duration, and alcohol drinking habits were determining factors for predicting the CLP (adjusted R2 = 0.68, p < 0.05). The model revealed that heat stress reduces CLP, with the percentage of direct work time decreasing by 0.33% when the WBGT increased by 1 °C. The findings in this study extend the existing practice notes by providing scientific data that may be of benefit to the industry in producing solid guidelines for working in hot weather. PMID:28895899

Development of an improved membrane for a vapor diffusion water recovery process. [onboard manned spacecraft

NASA Technical Reports Server (NTRS)

Rich, T. R.; Mix, T. W.

1974-01-01

Recovery of potable water from urine on manned space missions of extended duration was the objective of work aimed at the improvement of membrane performance for the vapor diffusion process (VDR). Kynar, Teflon, PVC, and polysulfone candidate membranes were evaluated from chemical, thermal, mechanical, and fabricating standpoints to determine their suitability for operation in the VDR pervaporation module. Pervaporation rates and other performance characteristics were determined in a breadboard pervaporator test rig. Kynar and Teflon membranes were demonstrated to be chemically stable at pervaporation temperatures in urine pretreated with chromic acid bactericide. The separation of the pervaporator and condenser modules, the use of a recirculating sweep gas to conduct pervaporate to the condenser, and the selection of a hollow fiber membrane configuration for pervaporator module design is recommended as a result of the investigation.

Recognizing suspicious activities in infrared imagery using appearance-based features and the theory of hidden conditional random fields for outdoor perimeter surveillance

NASA Astrophysics Data System (ADS)

Rogotis, Savvas; Palaskas, Christos; Ioannidis, Dimosthenis; Tzovaras, Dimitrios; Likothanassis, Spiros

2015-11-01

This work aims to present an extended framework for automatically recognizing suspicious activities in outdoor perimeter surveilling systems based on infrared video processing. By combining size-, speed-, and appearance-based features, like the local phase quantization and the histograms of oriented gradients, actions of small duration are recognized and used as input, along with spatial information, for modeling target activities using the theory of hidden conditional random fields (HCRFs). HCRFs are used to classify an observation sequence into the most appropriate activity label class, thus discriminating high-risk activities like trespassing from zero risk activities, such as loitering outside the perimeter. The effectiveness of this approach is demonstrated with experimental results in various scenarios that represent suspicious activities in perimeter surveillance systems.

Rhythmic motor entrainment in children with speech and language impairments: tapping to the beat.

PubMed

Corriveau, Kathleen H; Goswami, Usha

2009-01-01

In prior work (Corriveau et al., 2007), we showed that children with speech and language impairments (SLI) were significantly less sensitive than controls to two auditory cues to rhythmic timing, amplitude envelope rise time and duration. Here we explore whether rhythmic problems extend to rhythmic motor entrainment. Tapping in synchrony with a beat has been described as the simplest rhythmic act that humans perform. We explored whether tapping to a beat would be impaired in children for whom auditory rhythmic timing is impaired. Children with SLI were indeed found to be impaired in a range of measures of paced rhythmic tapping, but were not equally impaired in tapping in an unpaced control condition requiring an internally-generated rhythm. The severity of impairment in paced tapping was linked to language and literacy outcomes.

A single sample study of dissociation between expressed and experienced pleasure by gender in mild depression.

PubMed

Brown, S L

Thirty male and thirty female adult subjects were divided equally into three groups on the basis of the Zung Self-Rating Depression Scale; mildly depressed (50-63), normal (40-49), and "low normal" (20-39). Observer ratings of positive affect were made during a one and one-half hour laboratory experiment, and self-ratings of pleasurable experience were collected at the end of the experiment. Results showed no significant differences between groups for self-report of experienced pleasure. However, a significant difference between groups was found for observer ratings of positive affect, with the mildly depressed and "low normal" subjects showing a shorter duration and a lower degree of positive affect than the normals. These results partially replicate and extended previous work. Implications for theory, research, and psychotherapy are discussed.

Person to Person Biological Heat Bypass During EVA Emergencies

NASA Technical Reports Server (NTRS)

Koscheyev, Victor S.; Leon, Gloria R.; Lee, Joo-Young; Kim, Jung-Hyun; Berowiski, Anna; Trevino, Robert C.

2007-01-01

During EVA and other extreme environments, mutual human support is sometimes the last way to survive when there is a failure of the life support equipment. The possibility to transfer a coolant to remove heat or a warming fluid to increase heat from one individual to another to support the thermal balance of the individual with system failure was assessed. The following scenarios were considered: 1. one participant has a cooling system that is not working well and already has a body heat deficit equal to 100-120 kcal and a finger temperature decline to 25 C; 2. one participant has the same status of overcooling and the other mild overheating. Preliminary findings showed promise in using such sharing tactics to extend the time duration of survival in extreme situations when there is a high metabolic rate in the donor.

The Effects of Long Duration Bed Rest as a Spaceflight Analogue on Resting State Sensorimotor Network Functional Connectivity and Neurocognitive Performance

NASA Technical Reports Server (NTRS)

Cassady, K.; Koppelmans, V.; Yuan, P.; Cooke, K.; De Dios, Y.; Stepanyan, V.; Szecsy, D.; Gadd, N.; Wood, S.; Reuter-Lorenz, P.;

The Extended Duration Sounding Rocket (EDSR): Low Cost Science and Technology Missions

NASA Astrophysics Data System (ADS)

Cruddace, R. G.; Chakrabarti, S.; Cash, W.; Eberspeaker, P.; Figer, D.; Figueroa, O.; Harris, W.; Kowalski, M.; Maddox, R.; Martin, C.; McCammon, D.; Nordsieck, K.; Polidan, R.; Sanders, W.; Wilkinson, E.; Asrat

2011-12-01

The 50-year old NASA sounding rocket (SR) program has been successful in launching scientific payloads into space frequently and at low cost with a 85% success rate. In 2008 the NASA Astrophysics Sounding Rocket Assessment Team (ASRAT), set up to review the future course of the SR program, made four major recommendations, one of which now called Extended Duration Sounding Rocket (EDSR). ASRAT recommended a system capable of launching science payloads (up to 420 kg) into low Earth orbit frequently (1/yr) at low cost, with a mission duration of approximately 30 days. Payload selection would be based on meritorious high-value science that can be performed by migrating sub-orbital payloads to orbit. Establishment of this capability is a essential for NASA as it strives to advance technical readiness and lower costs for risk averse Explorers and flagship missions in its pursuit of a balanced and sustainable program and achieve big science goals within a limited fiscal environment. The development of a new generation of small, low-cost launch vehicles (SLV), primarily the SpaceX Falcon 1 and the Orbital Sciences Minotaur I has made this concept conceivable. The NASA Wallops Flight Facility (WFF)conducted a detailed engineering concept study, aimed at defining the technical characteristics of all phases of a mission, from design, procurement, assembly, test, integration and mission operations. The work was led by Dr. Raymond Cruddace, a veteran of the SR program and the prime mover of the EDSR concept. The team investigated details such as, the "FAA licensed contract" for launch service procurement, with WFF and NASA SMD being responsible for mission assurance which results in a factor of two cost savings over the current approach. These and other creative solutions resulted in a proof-of-concept Class D mission design that could have a sustained launch rate of at least 1/yr, a mission duration of up to about 3 months, and a total cost of $25-30 million for each mission. The payload includes a pointing system with arc second precision, a command and data system which can be configured to meet the unique requirements of a particular mission, and a solar cell-battery power system. Anticipating the tremendous need of access to space, Cruddace and his team included a capability of inclusion of a number of smaller secondary instruments, ranging in size from CubeSats to instruments weighing up to 100 lb. These secondary payloads could be ejected as needed by P-PODs. In this talk, we will summarize EDSR, a legacy of Ray Cruddace.

Determinants of Sleep Duration among High School Students in Part-Time Employment

ERIC Educational Resources Information Center

Laberge, Luc; Ledoux, Élise; Auclair, Julie; Gaudreault, Marco

2014-01-01

Adolescents who work while attending school are reported to sleep less than those who do not. This study aimed to identify factors associated with short sleep duration in students who work during the school year. A cross-sectional survey aiming to describe working conditions and occupational safety and health was completed by representative…

Identification of traffic control devices for mobile and short duration work operations

DOT National Transportation Integrated Search

2006-07-01

This report documents and summarizes the study Identification of Traffic Control Devices for Mobile and Short Duration Work Operations, for the New Jersey Department of Transportation. The study was conducted in three tasks: 1. Literature Searc...

Juggling work and motherhood: the impact of employment and maternity leave on breastfeeding duration: a survival analysis on Growing Up in Scotland data.

PubMed

Skafida, Valeria

2012-02-01

In 2005, Scotland became the first nation to make breastfeeding in public a legal right, but current breastfeeding targets and maternity leave allowance do not acknowledge the conflicting demands women face when juggling employment and motherhood. This paper explores how employment and maternity leave relate to breastfeeding duration among mothers in Scotland. The Growing Up in Scotland national longitudinal cohort study of 5,217 babies born in 2004-2005 was used. Multivariate proportional hazards regression models were specified using one cross-sectional wave of data to predict breastfeeding duration. Mothers working as employees, full-time (Hazard Ratio 1.6) or part-time (HR1.3), had a higher risk of earlier breastfeeding cessation than non-working mothers. However, self-employed mothers did not differ significantly from non-working mothers in their breastfeeding patterns. Mothers who took longer maternity leave breastfed for longer. The relationships between employment, maternity leave and breastfeeding duration were significant when controlling for known predictors of breastfeeding. Younger mothers, those with less formal education, single mothers, those of white ethnic background, and first-time mothers were more likely to stop breastfeeding sooner, as has been noted in previous research. Employment and early return to work are both factors associated with a shorter duration of breastfeeding. More flexible working conditions and more generous employment leave could help to prolong breastfeeding among working mothers. Current health and employment policy in Scotland and the UK could be better coordinated so that working mothers have the adequate support to meet the conflicting demands of employment and motherhood.

Intensity and duration of intermittent exercise and recovery during a soccer match.

PubMed

Orendurff, Michael S; Walker, Jason D; Jovanovic, Mladen; Tulchin, Kirsten L; Levy, Morris; Hoffmann, David K

2010-10-01

Soccer is a sport consisting of high-intensity intermittent exercise, with players making forays across their anaerobic threshold for tactical advantage followed by periods of recovery. The intensity and duration of these work and recovery bouts were defined during a men's soccer match using StepWatch Activity Monitors recording step rate for each 3-second period. The data were coded by custom software to separate work bouts (step rate ≥ 4) from recovery bouts (step rate < 4), and a square wave of the pattern of bouts was plotted for 5 players: center forward, central midfielder, wing midfielder, central defender, and wing defender. Four values were calculated for each work and recovery bout identified: duration, and mean, maximum, and minimum step rate (intensity). This novel technique provided detailed graphical information on the duration and exercise intensity of each position throughout the match. The center midfielder was able to sustain work and recovery bout characteristics throughout the match and appeared to recover at higher intensity levels than other players. The forward showed the consequence of accumulated fatigue late in the match and was unable to sustain the duration of high-intensity work bouts observed earlier in the match. The central defender attenuated the intensity of his work and recovery bouts late in the match staying closer to a more moderate work rate with fewer high- or low-intensity bouts. Having objective data qualifying players' work and recovery bout characteristics might prove valuable for tactical decision making, substitution timing, and for planning future training sessions.

Physiological response of wild rainbow trout to angling: Impact of angling duration, fish size, body condition, and temperature

USGS Publications Warehouse

Meka, Julie M.; McCormick, S.D.

2005-01-01

This study evaluated the immediate physiological response of wild rainbow trout to catch-and-release angling in the Alagnak River, southwest Alaska. Information was recorded on individual rainbow trout (n = 415) captured by angling including landing time and the time required to remove hooks (angling duration), the time to anesthetize fish in clove oil and withdraw blood, fish length and weight, and water temperature at capture locations. Plasma cortisol, glucose, ions (sodium, potassium, chloride), and lactate were analyzed to determine the effects of angling duration, fish size, body condition, and temperature. Levels of plasma ions did not change significantly during the observed physiological response and levels of plasma glucose were sometimes influenced by length (2000, 2001), body condition (2001), or temperature (2001). Levels of plasma cortisol and lactate in extended capture fish (angling duration greater than 2 min) were significantly higher than levels in rapid capture fish (angling duration less than 2 min). Rapid capture fish were significantly smaller than extended capture fish, reflecting that fish size influenced landing and handling times. Fish size was related to cortisol and lactate in 2002, which corresponded to the year when larger fish were captured and there were longer landing times. Body condition (i.e., weight/length regression residuals index), was significantly related to lactate in 2000 and 2001. Water temperatures were higher in 2001 (mean temperature ± S.E., 13 ± 2oC) than in 2002 (10 ± 2oC), and fish captured in 2001 had significantly higher cortisol and lactate concentrations than fish captured in 2002. The pattern of increase in plasma cortisol and lactate was due to the amount of time fish were angled, and the upper limit of the response was due to water temperature. The results of this study indicate the importance of minimizing the duration of angling in order to reduce the sublethal physiological disturbances in wild fish subjected to catch-and-release angling, particularly during warmer water temperatures. It is also important to note that factors such as fish size may influence both the duration of angling and subsequent physiological response. 

Working hours and sleep duration in midlife as determinants of health-related quality of life among older businessmen.

PubMed

von Bonsdorff, Mikaela Birgitta; Strandberg, Arto; von Bonsdorff, Monika; Törmäkangas, Timo; Pitkälä, Kaisu H; Strandberg, Timo E

2017-01-25

Long working hours and short sleep duration are associated with a range of adverse health consequences. However, the combined effect of these two exposures on health-related quality of life (HRQoL) has not been investigated. We studied white men born between 1919 and 1934 in the Helsinki Businessmen Study (HBS, initial n = 3,490). Data on clinical variables, self-rated health (SRH), working hours and sleep duration in 1974, and RAND-36 (SF-36) HRQoL survey in the year 2000 were available for 1,527 men. Follow-up time was 26 years. By combining working hours and sleep duration, four categories were formed: (i) normal work (≤50 hours/week) and normal sleep (>47 hours/week); (ii) long work (>50 hours/week) and normal sleep; (iii) normal work and short sleep (≤47 hours/week); and (iv) long work and short sleep. The association with RAND-36 domains was examined using multiple linear regression models adjusted for age, smoking and SRH. Compared to those with normal work and sleep in midlife, men with long work and short sleep had poorer RAND-36 scores for physical functioning, vitality and general health, and those with long work and normal sleep had poorer scores for physical functioning in old age. Adjustment for midlife smoking and SRH attenuated the associations, but the one for long work and short sleep and physical functioning remained significant (difference in mean physical functioning score −4.58, 95% confidence interval −9.00 to −0.15). Businessmen who had long working hours coupled with short sleep duration in midlife had poorer physical health in old age. © The Author 2016. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Dose-response association between leisure time physical activity and work ability: Cross-sectional study among 3000 workers.

PubMed

Calatayud, Joaquin; Jakobsen, Markus D; Sundstrup, Emil; Casaña, Jose; Andersen, Lars L

2015-12-01

Regular physical activity is important for longevity and health, but knowledge about the optimal dose of physical activity for maintaining good work ability is unknown. This study investigates the association between intensity and duration of physical activity during leisure time and work ability in relation to physical demands of the job. From the 2010 round of the Danish Work Environment Cohort Study, currently employed wage earners with physically demanding work (n = 2952) replied to questions about work, lifestyle and health. Excellent (100 points), very good (75 points), good (50 points), fair (25 points) and poor (0 points) work ability in relation to the physical demands of the job was experienced by 18%, 40%, 30%, 10% and 2% of the respondents, respectively. General linear models that controlled for gender, age, physical and psychosocial work factors, lifestyle and chronic disease showed that the duration of high-intensity physical activity during leisure was positively associated with work ability, in a dose-response fashion (p < 0.001). Those performing ⩾ 5 hours of high-intensity physical activity per week had on average 8 points higher work ability than those not performing such activities. The duration of low-intensity leisure-time physical activity was not associated with work ability (p = 0.5668). The duration of high-intensity physical activity during leisure time is associated in a dose-response fashion with work ability, in workers with physically demanding jobs. © 2015 the Nordic Societies of Public Health.

Sunlight Exposure, Work Hours, Caffeine Consumption, and Sleep Duration in the Naval Environment.

PubMed

Shattuck, Nita L; Matsangas, Panagiotis

2017-06-01

Sailors in the U.S. Navy are habitual shiftworkers, often experiencing circadian misalignment due to their irregular work/rest schedules. This study assessed the effect of sunlight exposure, work hours, and caffeinated beverage consumption on the daily sleep duration of crewmembers of a U.S. Navy ship during a 2-wk underway period. Working in an artificially lit area with no access to sunlight during work hours, U.S. Navy crew members (N = 91) used daily logs to report their daily activity, caffeinated beverage consumption, and exposure to sunlight while off-duty; sleep was assessed by wrist-worn actigraphy. Hours of sunlight exposure, work duration, and the amount of coffee/tea/soft drinks were statistically significant predictors of sleep duration. On average, crewmembers who reported more than one half-hour of sunlight each day slept on average ∼40 min (10%) less than their peers working the same shifts who received less than one half-hour of sunlight (on average 6.05 ± 0.90 h vs. 6.71 ± 0.91 h, respectively). Exposure to sunlight, work hours, and consumption of caffeinated beverages are important factors when planning watchstanding schedules at sea. Even though further research is needed, our results suggest that even brief exposure to sunlight may contribute to circadian misalignment that negatively affects sleep in the operational environment. Educating crewmembers about sleep hygiene, especially the important roles played by sunlight and caffeine, could potentially improve the sleep and fatigue levels of this population of maritime shiftworkers.Shattuck NL, Matsangas P. Sunlight exposure, work hours, caffeine consumption, and sleep duration in the naval environment. Aerosp Med Hum Perform. 2017; 88(6):579-585.

Sleep disturbances and reduced work functioning in depressive or anxiety disorders.

PubMed

van Mill, Josine G; Vogelzangs, Nicole; Hoogendijk, Witte J G; Penninx, Brenda W J H

2013-11-01

We aimed to examine the associations between sleep disturbances and work functioning in an epidemiologic cohort study in subjects with or without depressive or anxiety disorders. There were 707 subjects included in our analyses with depressive or anxiety disorders and 728 subjects without current depressive or anxiety disorders. Insomnia was defined as a score ≥9 using the Insomnia Rating Scale. Self-reported sleep duration was categorized in short, normal, and long (≤6, 7-9, and ≥10 h, respectively). Work absenteeism was defined as none, short (≤2 weeks), or long (>2 weeks). Work performance was defined as not impaired, reduced, or impaired. Logistic regression analyses were performed to examine the associations of sleep disturbances with work functioning. In subjects with psychopathology, insomnia and short sleep duration were significantly associated with impaired work performance (odds ratio [OR] for insomnia, 2.20; [95% confidence interval {CI}, 1.50-3.22]; OR for short sleep, 2.54 [95% CI, 1.66-3.88] compared to normal sleep duration). Insomnia (OR, 2.48 [95% CI, 1.67-3.69]) and short sleep duration (OR, 1.85 [95% CI, 1.23-2.78]) also were associated with long-term absenteeism. These findings remained the same after considering clinical characteristics including medication use and symptom severity. In subjects without psychopathology, no significant associations were found between insomnia and short sleep duration on work functioning after considering subthreshold depression symptoms. In subjects with psychopathology, sleep disturbances were negatively associated with work functioning, independent of disorder severity and use of psychotropic medication. Further research is needed to determine if treatment of sleep disturbances in subjects with psychopathology improves work functioning. Copyright © 2013 Elsevier B.V. All rights reserved.

Association between depressive symptoms and morningness-eveningness, sleep duration and rotating shift work in Japanese nurses.

PubMed

Togo, Fumiharu; Yoshizaki, Takahiro; Komatsu, Taiki

2017-01-01

Higher depressive symptoms have been reported in rotating shift workers compared with day workers. Depressive symptoms in adults who do not engage in night work have also been shown to be associated with chronotype and sleep duration. This study examines associations between depressive symptoms, morningness-eveningness (i.e. the degree to which people prefer to be active in the morning or the evening), sleep duration and rotating shift work. Japanese nurses (1252 day workers and 1780 rotating shift workers, aged 20-59) were studied using a self-administered questionnaire. The questionnaire covered depressive symptoms, morningness-eveningness, sleep habits and demographic characteristics of the participants. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to determine the levels of depressive symptoms. A Japanese version of the Morningness-Eveningness Questionnaire (MEQ) was used to measure morningness-eveningness. The CES-D score of shift workers was significantly (p < 0.05) higher than that of day workers. The MEQ score was significantly (p < 0.05) lower (i.e. greater eveningness) in shift workers than in day workers. Sleep duration on the day shift was significantly (p < 0.05) shorter in shift workers than in day workers. Simple linear regression revealed that the MEQ score, sleep duration on the day shift and current work shift (i.e. rotating shift work) were significantly (p < 0.05) associated with the CES-D score. Multivariate linear regression indicated that greater eveningness and shorter sleep duration were independently associated with higher CES-D scores, while rotating shift work was not. These associations between the MEQ score, the sleep duration and the CES-D score were also confirmed in both day workers and shift workers when the groups were analyzed separately. These results suggest that greater eveningness and shorter sleep duration on the day shift were independently associated with higher levels of depressive symptoms, which may explain associations between rotating shift workers and depressive symptoms. These findings have important implications for the development of novel strategies for preventing poor mental health in day workers and rotating shift workers.

The effects of delay duration on visual working memory for orientation.

PubMed

Shin, Hongsup; Zou, Qijia; Ma, Wei Ji

2017-12-01

We used a delayed-estimation paradigm to characterize the joint effects of set size (one, two, four, or six) and delay duration (1, 2, 3, or 6 s) on visual working memory for orientation. We conducted two experiments: one with delay durations blocked, another with delay durations interleaved. As dependent variables, we examined four model-free metrics of dispersion as well as precision estimates in four simple models. We tested for effects of delay time using analyses of variance, linear regressions, and nested model comparisons. We found significant effects of set size and delay duration on both model-free and model-based measures of dispersion. However, the effect of delay duration was much weaker than that of set size, dependent on the analysis method, and apparent in only a minority of subjects. The highest forgetting slope found in either experiment at any set size was a modest 1.14°/s. As secondary results, we found a low rate of nontarget reports, and significant estimation biases towards oblique orientations (but no dependence of their magnitude on either set size or delay duration). Relative stability of working memory even at higher set sizes is consistent with earlier results for motion direction and spatial frequency. We compare with a recent study that performed a very similar experiment.

A health care system for the Space Station

NASA Technical Reports Server (NTRS)

1992-01-01

Life science will be one of the pacing technologies for long duration manned spaceflight. The ability to effectively deliver state-of-the-art inflight medical care will have a major impact on crew health and mission success. The future Space Station crews will participate in missions of extended duration with limited capability for emergency return. This factor alone places great responsibility on program designers to ensure the health, safety, and well-being of the crews. The Health Maintenance Facility (HMF) under development at the Johnson Space Center is described.

Subjective expansion of extended time-spans in experienced meditators.

PubMed

Wittmann, Marc; Otten, Simone; Schötz, Eva; Sarikaya, Anna; Lehnen, Hanna; Jo, Han-Gue; Kohls, Niko; Schmidt, Stefan; Meissner, Karin

2014-01-01

Experienced meditators typically report that they experience time slowing down in meditation practice as well as in everyday life. Conceptually this phenomenon may be understood through functional states of mindfulness, i.e., by attention regulation, body awareness, emotion regulation, and enhanced memory. However, hardly any systematic empirical work exists regarding the experience of time in meditators. In the current cross-sectional study, we investigated whether 42 experienced mindfulness meditation practitioners (with on average 10 years of experience) showed differences in the experience of time as compared to 42 controls without any meditation experience matched for age, sex, and education. The perception of time was assessed with a battery of psychophysical tasks assessing the accuracy of prospective time judgments in duration discrimination, duration reproduction, and time estimation in the milliseconds to minutes range as well with several psychometric instruments related to subjective time such as the Zimbardo Time Perspective Inventory, the Barratt Impulsivity Scale and the Freiburg Mindfulness Inventory. In addition, subjective time judgments on the current passage of time and retrospective time ranges were assessed. While subjective judgements of time were found to be significantly different between the two groups on several scales, no differences in duration estimates in the psychophysical tasks were detected. Regarding subjective time, mindfulness meditators experienced less time pressure, more time dilation, and a general slower passage of time. Moreover, they felt that the last week and the last month passed more slowly. Overall, although no intergroup differences in psychophysical tasks were detected, the reported findings demonstrate a close association between mindfulness meditation and the subjective feeling of the passage of time captured by psychometric instruments.

Is Customization in Antidepressant Prescribing Associated with Acute-Phase Treatment Adherence?

PubMed

Merrick, Elizabeth L; Hodgkin, Dominic; Panas, Lee; Soumerai, Stephen B; Ritter, Grant

2012-03-01

OBJECTIVES: The objective was to explore whether prescribing variation is associated with duration of antidepressant use during the acute phase of treatment. Improving quality of care and increasing the extent to which treatment is patient-centered and customized are interrelated goals. Prescribing variation may be considered a marker of customization, and could be associated with better antidepressant treatment adherence. METHODS: A cross-sectional secondary data analysis examining the association between providers' antidepressant prescribing variation and patient continuity of antidepressant treatment. The data source was two states' Medicaid claims for dual-eligible Medicaid/Medicare patients. The sample included 383 patients with new episodes of antidepressant treatment, representing 70 providers with at least four patients in the sample. We tested two alternate measures of prescribing concentration: 1) share of prescriber's initial antidepressant prescribing accounted for by the two most common regimens, and 2) Herfindahl index. The HEDIS performance measure of effective acute-phase treatment (at least 84 out of 114 days with antidepressant) was the dependent variable. KEY FINDINGS: In multivariate analyses, the concentration measure based on the top two regimens was significant and inversely related to duration adequacy (p <.05). The Herfindahl index measure showed a trend towards a similar inverse relationship (p<.10). CONCLUSIONS: The findings provide some support for the hypothesized relationship between prescribing variation and adequate antidepressant treatment duration during the acute phase of treatment. Future work with more detailed, clinical longitudinal data could extend this inquiry to better understand the causal mechanisms using a more direct measure of customized care.

Is Customization in Antidepressant Prescribing Associated with Acute-Phase Treatment Adherence?

PubMed Central

Merrick, Elizabeth L.; Hodgkin, Dominic; Panas, Lee; Soumerai, Stephen B.; Ritter, Grant

2012-01-01

Objectives The objective was to explore whether prescribing variation is associated with duration of antidepressant use during the acute phase of treatment. Improving quality of care and increasing the extent to which treatment is patient-centered and customized are interrelated goals. Prescribing variation may be considered a marker of customization, and could be associated with better antidepressant treatment adherence. Methods A cross-sectional secondary data analysis examining the association between providers' antidepressant prescribing variation and patient continuity of antidepressant treatment. The data source was two states' Medicaid claims for dual-eligible Medicaid/Medicare patients. The sample included 383 patients with new episodes of antidepressant treatment, representing 70 providers with at least four patients in the sample. We tested two alternate measures of prescribing concentration: 1) share of prescriber's initial antidepressant prescribing accounted for by the two most common regimens, and 2) Herfindahl index. The HEDIS performance measure of effective acute-phase treatment (at least 84 out of 114 days with antidepressant) was the dependent variable. Key Findings In multivariate analyses, the concentration measure based on the top two regimens was significant and inversely related to duration adequacy (p <.05). The Herfindahl index measure showed a trend towards a similar inverse relationship (p<.10). Conclusions The findings provide some support for the hypothesized relationship between prescribing variation and adequate antidepressant treatment duration during the acute phase of treatment. Future work with more detailed, clinical longitudinal data could extend this inquiry to better understand the causal mechanisms using a more direct measure of customized care. PMID:22707982

Self-calibrating d-scan: measuring ultrashort laser pulses on-target using an arbitrary pulse compressor.

PubMed

Alonso, Benjamín; Sola, Íñigo J; Crespo, Helder

2018-02-19

In most applications of ultrashort pulse lasers, temporal compressors are used to achieve a desired pulse duration in a target or sample, and precise temporal characterization is important. The dispersion-scan (d-scan) pulse characterization technique usually involves using glass wedges to impart variable, well-defined amounts of dispersion to the pulses, while measuring the spectrum of a nonlinear signal produced by those pulses. This works very well for broadband few-cycle pulses, but longer, narrower bandwidth pulses are much more difficult to measure this way. Here we demonstrate the concept of self-calibrating d-scan, which extends the applicability of the d-scan technique to pulses of arbitrary duration, enabling their complete measurement without prior knowledge of the introduced dispersion. In particular, we show that the pulse compressors already employed in chirped pulse amplification (CPA) systems can be used to simultaneously compress and measure the temporal profile of the output pulses on-target in a simple way, without the need of additional diagnostics or calibrations, while at the same time calibrating the often-unknown differential dispersion of the compressor itself. We demonstrate the technique through simulations and experiments under known conditions. Finally, we apply it to the measurement and compression of 27.5 fs pulses from a CPA laser.

Relative time sharing: new findings and an extension of the resource allocation model of temporal processing.

PubMed

Buhusi, Catalin V; Meck, Warren H

2009-07-12

Individuals time as if using a stopwatch that can be stopped or reset on command. Here, we review behavioural and neurobiological data supporting the time-sharing hypothesis that perceived time depends on the attentional and memory resources allocated to the timing process. Neuroimaging studies in humans suggest that timekeeping tasks engage brain circuits typically involved in attention and working memory. Behavioural, pharmacological, lesion and electrophysiological studies in lower animals support this time-sharing hypothesis. When subjects attend to a second task, or when intruder events are presented, estimated durations are shorter, presumably due to resources being taken away from timing. Here, we extend the time-sharing hypothesis by proposing that resource reallocation is proportional to the perceived contrast, both in temporal and non-temporal features, between intruders and the timed events. New findings support this extension by showing that the effect of an intruder event is dependent on the relative duration of the intruder to the intertrial interval. The conclusion is that the brain circuits engaged by timekeeping comprise not only those primarily involved in time accumulation, but also those involved in the maintenance of attentional and memory resources for timing, and in the monitoring and reallocation of those resources among tasks.

Bi-photon spectral correlation measurements from a silicon nanowire in the quantum and classical regimes

PubMed Central

Jizan, Iman; Helt, L. G.; Xiong, Chunle; Collins, Matthew J.; Choi, Duk-Yong; Joon Chae, Chang; Liscidini, Marco; Steel, M. J.; Eggleton, Benjamin J.; Clark, Alex S.

2015-01-01

The growing requirement for photon pairs with specific spectral correlations in quantum optics experiments has created a demand for fast, high resolution and accurate source characterisation. A promising tool for such characterisation uses classical stimulated processes, in which an additional seed laser stimulates photon generation yielding much higher count rates, as recently demonstrated for a χ(2) integrated source in A. Eckstein et al. Laser Photon. Rev. 8, L76 (2014). In this work we extend these results to χ(3) integrated sources, directly measuring for the first time the relation between spectral correlation measurements via stimulated and spontaneous four wave mixing in an integrated optical waveguide, a silicon nanowire. We directly confirm the speed-up due to higher count rates and demonstrate that this allows additional resolution to be gained when compared to traditional coincidence measurements without any increase in measurement time. As the pump pulse duration can influence the degree of spectral correlation, all of our measurements are taken for two different pump pulse widths. This allows us to confirm that the classical stimulated process correctly captures the degree of spectral correlation regardless of pump pulse duration, and cements its place as an essential characterisation method for the development of future quantum integrated devices. PMID:26218609

Dramatic dwindling of the power spectrum of high order harmonics by shrinking of the gap size in bowtie nanostructures

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

Hosseinzadeh, F.; Batebi, S., E-mail: s-batebi@guilan.ac.ir; Soofi, M. Q.

2017-03-15

Our work is based on high harmonic generation in a gaseous medium (helium ion), by exploiting gold bowtie nanostructures as laser field amplifiers. As the result of emission of a laser pulse, the wave function of the atom varies with time; so, it is necessary to solve 1D time-dependent Schrödinger equation by means of split operator method. By illumination of a short duration, long wavelength three color laser pulse inside the gap, the enhanced field not only changes with time, but also varies in space. In this work we considered this space inhomogeneity in linear and nonlinear schemes. We showmore » that in nonlinear case, the plateau region is more extended. We also show that in larger gaps, cutoff occurs on higher frequencies. But limitation of electron motion in bowtie nanostructures leads to the choice of an optimum 16 nm gap size in our case. We predict that, by the superposition of supercontinuum harmonics, a 26 attosecond pulse can be generated.« less

Managing neurobehavioral capability when social expediency trumps biological imperatives

PubMed Central

Spaeth, Andrea M.; Goel, Namni; Dinges, David F.

2013-01-01

Sleep, which is evolutionarily conserved across species, is a biological imperative that cannot be ignored or replaced. However, the percentage of habitually sleep-restricted adults has increased in recent decades. Extended work hours and commutes, shift work schedules, and television viewing are particularly potent social factors that influence sleep duration. Chronic partial sleep restriction, a product of these social expediencies, leads to the accumulation of sleep debt over time and consequently increases sleep propensity, decreases alertness, and impairs critical aspects of cognitive functioning. Significant interindividual variability in the neurobehavioral responses to sleep restriction exists—this variability is stable and phenotypic—suggesting a genetic basis. Identifying vulnerability to sleep loss is essential as many adults cannot accurately judge their level of impairment in response to sleep restriction. Indeed, the consequences of impaired performance and the lack of insight due to sleep loss can be catastrophic. In order to cope with the effects of social expediencies on biological imperatives, identification of biological (including genetic) and behavioral markers of sleep loss vulnerability as well as development of technological approaches for fatigue management are critical. PMID:22877676

NACA Computer at the Lewis Flight Propulsion Laboratory

NASA Image and Video Library

1951-02-21

A female computer at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory with a slide rule and Friden adding machine to make computations. The computer staff was introduced during World War II to relieve short-handed research engineers of some of the tedious computational work. The Computing Section was staffed by “computers,” young female employees, who often worked overnight when most of the tests were run. The computers obtained test data from the manometers and other instruments, made the initial computations, and plotted the data graphically. Researchers then analyzed the data and summarized the findings in a report or made modifications and ran the test again. There were over 400 female employees at the laboratory in 1944, including 100 computers. The use of computers was originally planned only for the duration of the war. The system was so successful that it was extended into the 1960s. The computers and analysts were located in the Altitude Wind Tunnel Shop and Office Building office wing during the 1940s and transferred to the new 8- by 6-Foot Supersonic Wind Tunnel in 1948.

78 FR 38555 - Importer Permit Requirements for Tobacco Products and Processed Tobacco, and Other Requirements...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-27

...This temporary rule amends the regulations of the Alcohol and Tobacco Tax and Trade Bureau (TTB) pertaining to permits for importers of tobacco products and processed tobacco by extending the duration of new permits from three years to five years. Based on its experience in the administration and enforcement of importer permits over the past decade, TTB believes that it can gain administrative efficiencies and reduce the burden on industry members, while still meeting the purposes of the limited-duration permit, by extending the permit duration to five years. This temporary rule also makes several technical corrections by amending the definition of ``Manufacturer of tobacco products'' to reflect a recent statutory change, and by amending a reference to the sale price of large cigars to incorporate a clarification published in a prior TTB temporary rule. Finally, this temporary rule incorporates and reissues TTB regulations pertaining to importer permit requirements for tobacco products, and minimum manufacturing and marking requirements for tobacco products and cigarette papers and tubes, and, as a result, these temporary regulations replace temporary regulations originally published in 1999. TTB is soliciting comments from all interested parties on these regulatory provisions through a notice of proposed rulemaking published elsewhere in this issue of the Federal Register.

Effectiveness of an Extended Yoga Treatment for Women with Chronic Posttraumatic Stress Disorder

PubMed Central

Price, Maggi; Musicaro, Regina; Turner, Jennifer; Suvak, Michael; Emerson, David; van der Kolk, Bessel

2017-01-01

Abstract Background: Yoga has been found to be an effective posttraumatic stress disorder (PTSD) treatment for a variety of trauma survivors, including females with chronic PTSD. Aim/Purpose: The current study builds on extant research by examining an extended trauma-sensitive yoga treatment for women with chronic PTSD. The study sought to optimize the results of a treatment protocol examined in a recent randomized controlled trial with a shorter duration and without assignment or monitoring of home practice. Materials and Methods: The authors examined a 20-week trauma-sensitive yoga treatment in a non-randomized single-group treatment feasibility study for women with chronic treatment-resistant PTSD (N = 9). The authors examined PTSD and dissociation symptom reduction over several assessment periods. Results: The results indicate that participants experienced significant reductions in PTSD and dissociative symptomatology above and beyond similar treatments of a shorter duration. Conclusions: The findings suggest that more intensive trauma-sensitive yoga treatment characterized by longer duration and intentional assignment and monitoring of home practice may be more advantageous for individuals with severe and chronic PTSD. The implications of the findings for the potentially more substantial role of yoga as an intervention for a subset of adults with chronic treatment-resistant PTSD are discussed. PMID:28121466

Is there competition between breast-feeding and maternal employment?

PubMed

Roe, B; Whittington, L A; Fein, S B; Teisl, M F

1999-05-01

Theory suggests that the decision to return to employment after childbirth and the decision to breast-feed may be jointly determined. We estimate models of simultaneous equations for two different aspects of the relationship between maternal employment and breast-feeding using 1993-1994 data from the U.S. Food and Drug Administration's Infant Feeding Practices Study. We first explore the simultaneous duration of breast-feeding and work leave following childbirth. We find that the duration of leave from work significantly affects the duration of breast-feeding, but the effect of breast-feeding on work leave is insignificant. We also estimate models of the daily hours of work and breast-feedings at infant ages 3 months and 6 months postpartum. At both times, the intensity of work effort significantly affects the intensity of breast-feeding, but the reverse is generally not found. Competition clearly exists between work and breast-feeding for many women in our sample.

7 CFR 631.11 - Conservation practice maintenance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... resource management systems or conservation practices applied under the contract for the duration of the... contract. (b) If the life span of the practices or resource management systems extends beyond the period of....11 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES...

Effectiveness and Safety of an Extended ICU Visitation Model for Delirium Prevention: A Before and After Study.

PubMed

Rosa, Regis Goulart; Tonietto, Tulio Frederico; da Silva, Daiana Barbosa; Gutierres, Franciele Aparecida; Ascoli, Aline Maria; Madeira, Laura Cordeiro; Rutzen, William; Falavigna, Maicon; Robinson, Caroline Cabral; Salluh, Jorge Ibrain; Cavalcanti, Alexandre Biasi; Azevedo, Luciano Cesar; Cremonese, Rafael Viegas; Haack, Tarissa Ribeiro; Eugênio, Cláudia Severgnini; Dornelles, Aline; Bessel, Marina; Teles, José Mario Meira; Skrobik, Yoanna; Teixeira, Cassiano

2017-10-01

To evaluate the effect of an extended visitation model compared with a restricted visitation model on the occurrence of delirium among ICU patients. Prospective single-center before and after study. Thirty-one-bed medical-surgical ICU. All patients greater than or equal to 18 years old with expected length of stay greater than or equal to 24 hours consecutively admitted to the ICU from May 2015 to November 2015. Change of visitation policy from a restricted visitation model (4.5 hr/d) to an extended visitation model (12 hr/d). Two hundred eighty-six patients were enrolled (141 restricted visitation model, 145 extended visitation model). The primary outcome was the cumulative incidence of delirium, assessed bid using the confusion assessment method for the ICU. Predefined secondary outcomes included duration of delirium/coma; any ICU-acquired infection; ICU-acquired bloodstream infection, pneumonia, and urinary tract infection; all-cause ICU mortality; and length of ICU stay. The median duration of visits increased from 133 minutes (interquartile range, 97.7-162.0) in restricted visitation model to 245 minutes (interquartile range, 175.0-272.0) in extended visitation model (p < 0.001). Fourteen patients (9.6%) developed delirium in extended visitation model compared with 29 (20.5%) in restricted visitation model (adjusted relative risk, 0.50; 95% CI, 0.26-0.95). In comparison with restricted visitation model patients, extended visitation model patients had shorter length of delirium/coma (1.5 d [interquartile range, 1.0-3.0] vs 3.0 d [interquartile range, 2.5-5.0]; p = 0.03) and ICU stay (3.0 d [interquartile range, 2.0-4.0] vs 4.0 d [interquartile range, 2.0-6.0]; p = 0.04). The rate of ICU-acquired infections and all-cause ICU mortality did not differ significantly between the two study groups. In this medical-surgical ICU, an extended visitation model was associated with reduced occurrence of delirium and shorter length of delirium/coma and ICU stay.

Time to unsafe sexual practice among cross-border female sex workers in Metemma Yohannes, North West Ethiopia.

PubMed

Gezie, Lemma Derseh; Taye, Belaynew Wassie; Ayele, Tadesse Awoke

2015-07-28

Because of the nature of their work, female sex workers are at risk of sexually transmitted diseases. Cross-border areas are places where this situation becomes worse. In Ethiopia, there has been a serious scarcity of studies on the time at which unsafe sexual practice starts and on factors which determine the practice among female sex workers there. Therefore, this study aimed to fill this identified gap. A total of 467 women who had been sex workers at least for three months prior to the resumption of the study were included. A structured and pre-tested questionnaire was used to collect data from July-August, 2010. Descriptive statistics was used to explore the data, and the Extended Cox-Regression model was employed to identify the predictors of time-to-unsafe sexual practice. The study participants were followed for 6, 643 person-months. The overall incidence density of unsafe sexual practice was 44.71 persons per 1000 persons-months. The hazard of unsafe sexual practice increased by 3.0 % every month (p-value =0.040) due to problem-drinking. Those female sex workers with familiarized clients had a two-fold hazard of practicing unsafe sex compared to their counterparts (AHR = 1.94 95 % CI 1.49, 2.53). The predominant sexual client type and the work place of sex workers were the other significant predictors of unsafe sexual practice. The incidence of unsafe sexual practice was found to be high among sex workers in the cross-border area. Time-to-unsafe sexual practice was significantly associated with female sex workers' status of familiarity with their clients, predominant sexual client type, their work place, and the interaction term of time and problem-drinking. Interventions need to be made on these controllable social and behavioral characteristics to help sex workers extend the duration of their safe sexual practice beyond the time they will quit sex work.

Extending Rest between Unloading Cycles Does Not Enhance Bone's Long-Term Recovery.

PubMed

Manske, Sarah L; Vijayaraghavan, Surabhi; Tuthill, Alyssa; Brutus, Olivier; Yang, Jie; Gupta, Shikha; Judex, Stefan

2015-10-01

Multiple exposures to unloading are overall more deleterious to the skeleton than is single exposure, although the rate of bone loss may diminish during multiple exposures. Here, we determined whether extending the reambulation (RA) period from 3 wk to 9 wk will mitigate bone loss during three distinct 3-wk hindlimb unloading (HLU) periods and enhance long-term recovery in skeletally mature, genetically heterogeneous mice. Female adult mice (4 months old) were subjected to three cycles of 3-wk unloading with 3-wk or 9-wk RA periods in between. Mice were terminated 46 wk after initiation of the study. Outcome measures for the distal femur were determined from multiple in vivo micro-computed tomography scans and finite-element modeling. Tripling RA duration enhanced trabecular bone recovery in between HLU periods but also increased the rate of loss of bone volume fraction (bone volume/tissue volume) and metaphyseal stiffness during subsequent HLU periods. With shorter RA periods, the magnitude of bone loss decreased by the second HLU period, whereas this decrease was delayed with longer RA periods. RA duration did not affect long-term recovery 46 wk after the start of the experimental protocol, as both HLU groups had similar levels of bone volume/tissue volume, cortical area, and stiffness. Individual cage activity levels were unrelated to the magnitude of bone loss during HLU or bone recovery during RA. These data suggest that extending recovery duration between periods of unloading may provide temporary benefits but is an ineffective long-term strategy for combating the devastation of trabecular morphology and mechanics, as temporarily enhanced recovery is largely cancelled out by greater susceptibility to unloading. They also emphasize that cortical bone is more amenable to long-term recovery than is trabecular bone.

Functional Recovery From Extended Warm Ischemia Associated With Partial Nephrectomy.

PubMed

Zhang, Zhiling; Zhao, Juping; Velet, Lily; Ercole, Cesar E; Remer, Erick M; Mir, Carme M; Li, Jianbo; Takagi, Toshio; Demirjian, Sevag; Campbell, Steven C

2016-01-01

To evaluate the impact of extended warm ischemia on incidence of acute kidney injury (AKI) and ultimate functional recovery after partial nephrectomy (PN), incorporating rigorous control for loss of parenchymal mass, and embedded within comparison to cohorts of patients managed with hypothermia or limited warm ischemia. From 2007 to 2014, 277 patients managed with PN had appropriate studies to evaluate changes in function/mass specifically within the operated kidney. Recovery from ischemia was defined as %function saved/%parenchymal mass saved. AKI was based on global renal function and defined as a ≥1.5-fold increase in serum creatinine above the preoperative level. Hypothermia was utilized in 112 patients (median = 27 minutes) and warm ischemia in 165 (median = 21 minutes). AKI strongly correlated with solitary kidney (P < .001) and duration (P < .001) but not type (P = .49) of ischemia. Median recovery from ischemia in the operated kidney was 100% (interquartile range [IQR] = 88%-109%) for cold ischemia, with 6 (5%) noted to have <80% recovery from ischemia. For the warm ischemia group, median recovery from ischemia was 91% (IQR = 82%-101%, P < .001 compared with hypothermia), and 34 (21%) had recovery from ischemia <80% (P < .001). For warm ischemia subgrouped by duration <25 minutes (n = 114), 25-35 minutes (n = 35), and >35 minutes (n = 16), median recovery from ischemia was 92% (IQR = 86%-100%), 90% (IQR = 78%-104%), and 91% (IQR = 80%-96%), respectively (P = .77). Our results suggest that AKI after PN correlates with duration but not with type of ischemia. However, subsequent recovery, which ultimately defines the new baseline glomerular filtration rate, is most reliable with hypothermia. However, most patients undergoing PN with warm ischemia still recover relatively strongly from ischemia, even if extended to 35-45 minutes. Copyright © 2015 Elsevier Inc. All rights reserved.

Changes in Sleep Duration During Transition to Statutory Retirement: A Longitudinal Cohort Study.

PubMed

Myllyntausta, Saana; Salo, Paula; Kronholm, Erkki; Aalto, Ville; Kivimäki, Mika; Vahtera, Jussi; Stenholm, Sari

2017-07-01

This study examined whether sleep duration changes during the transition from full-time work to statutory retirement and, if this were the case, which preretirement factors, including sociodemographic, work, lifestyle, and health factors, predict these changes. Data from repeated surveys of the Finnish Public Sector study, linked to records of retirement, were used. The study population consisted of 5785 participants who retired on a statutory basis in 2000-2011 and who had responded to surveys on sleep duration at least once immediately before and after their retirement (mean number of repeat study waves 3.6). Linear regression analyses with generalized estimating equations were used to examine changes in sleep duration around retirement. Before retirement there was a slight decrease in sleep duration. During the 4-year retirement transition, sleep duration increased from 7 hours 0 minutes (95% confidence interval [CI] 6 hours 54 minutes to 7 hours 6 minutes) to 7 hours and 22 minutes (95% CI 7 hours 16 minutes to 7 hours 27 minutes); thus, mean increase being 22 minutes. Increase in sleep duration was greatest in those who were short sleepers, heavy drinkers, or had sleep difficulties. After the retirement transition, sleep duration remained at approximately the same level, as no significant changes were observed. This longitudinal study suggests that transition from full-time work to statutory retirement is associated with an increase in sleep duration. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Sleep duration and sleep-related problems in different occupations in the Hordaland Health Study.

PubMed

Ursin, Reidun; Baste, Valborg; Moen, Bente E

2009-05-01

The aim of this study was to examine the relationship between occupation and sleep duration, sleepiness, insufficient sleep, and insomnia in day and shift workers (including night work and watches). The study was population-based and cross-sectional, and relied on self-administered questionnaires. It was conducted as part of the 1997-1999 Hordaland Health Study in collaboration with the Norwegian National Health Screening Service. Aged 40-45 years, 7782 participants answered a sleep questionnaire, reporting their occupation and whether or not they were employed in shift work. Our study found differences in sleep duration during the working week between occupational groups; in both shift and day workers. Craft workers, plant operators, and drivers slept less than leaders, and non-personal and personal service workers. Within some occupations (leaders, personal service workers, and plant operators), shift workers slept less than day workers. The mean sleep duration of shift workers was 15 minutes shorter than that of day workers. Rise times, but not bedtimes, were earlier in craft-and construction workers, plant operators, and drivers than in leaders and non-personal and personal service workers, particularly day workers. When adjusted for shift work and working hours - compared to leaders - craft workers, plant operators, and drivers had an increased risk of daytime sleepiness (odds ratio 1.5, 1.8, and 1.8 respectively) and of falling asleep at work (odds ratio 1.6, 2.1 and 2.0 respectively). Shift workers had an increased risk of falling asleep at work and insomnia. Occupation has separate effects on sleep duration and sleep-related problems, independent of the effects of shift work.

Benefits of napping and an extended duration of recovery sleep on alertness and immune cells after acute sleep restriction.

PubMed

Faraut, Brice; Boudjeltia, Karim Zouaoui; Dyzma, Michal; Rousseau, Alexandre; David, Elodie; Stenuit, Patricia; Franck, Thierry; Van Antwerpen, Pierre; Vanhaeverbeek, Michel; Kerkhofs, Myriam

2011-01-01

Understanding the interactions between sleep and the immune system may offer insight into why short sleep duration has been linked to negative health outcomes. We, therefore, investigated the effects of napping and extended recovery sleep after sleep restriction on the immune and inflammatory systems and sleepiness. After a baseline night, healthy young men slept for a 2-h night followed by either a standard 8-h recovery night (n=12), a 30-min nap (at 1 p.m.) in addition to an 8-h recovery night (n=10), or a 10-h extended recovery night (n=9). A control group slept 3 consecutive 8-h nights (n=9). Subjects underwent continuous electroencephalogram polysomnography and blood was sampled every day at 7 a.m. Leukocytes, inflammatory and atherogenesis biomarkers (high-sensitivity C-reactive protein, interleukin-8, myeloperoxidase, fibrinogen and apolipoproteins ApoB/ApoA), sleep patterns and sleepiness were investigated. All parameters remained unchanged in the control group. After sleep restriction, leukocyte and - among leukocyte subsets - neutrophil counts were increased, an effect that persisted after the 8-h recovery sleep, but, in subjects who had a nap or a 10-h recovery sleep, these values returned nearly to baseline. Inflammatory and atherogenesis biomarkers were unchanged except for higher myeloperoxidase levels after sleep restriction. The increased sleepiness after sleep restriction was reversed better in the nap and extended sleep recovery conditions. Saliva cortisol decreased immediately after the nap. Our results indicate that additional recovery sleep after sleep restriction provided by a midday nap prior to recovery sleep or a sleep extended night can improve alertness and return leukocyte counts to baseline values. Copyright © 2010 Elsevier Inc. All rights reserved.

Breastfeeding duration and offspring conduct problems: The moderating role of genetic risk.

PubMed

Jackson, Dylan B

2016-10-01

A sizable body of research has examined associations between breastfeeding and various facets of offspring development, including childhood behavioral problems. Notwithstanding the number of studies on the topic, breastfeeding has not consistently been linked to child misbehaviors. Moreover, empirical examinations of whether breastfeeding is differentially predictive of conduct problems among individuals with varying degrees of genetic risk are lacking. The present study examines whether a short duration of breastfeeding and genetic risk interact to predict conduct problems during childhood. A genetically informative design is employed to examine a subsample of twins from the Early Childhood Longitudinal Study: Birth Cohort (ECLS-B), a nationally representative sample of American children. The findings suggest that a shorter duration of breastfeeding only enhances the risk of offspring conduct problems among children who possess high levels of genetic risk. Conversely, longer breastfeeding durations were found to protect against childhood behavioral problems when genetic risk was high. Indicators of genetic risk may help to distinguish individuals whose behavioral development is most sensitive to the duration of breastfeeding. Future research should seek to replicate and extend these findings by considering genetic factors as potential markers of differential susceptibility to breastfeeding duration. Copyright © 2016 Elsevier Ltd. All rights reserved.

CS-duration and partial-reinforcement effects counteract overshadowing in select situations

PubMed Central

Urushihara, Kouji; Miller, Ralph R.

2008-01-01

Two experiments used rats in a conditioned lick suppression preparation to investigate how the conditioned stimulus (CS)-duration and partial-reinforcement effects (i.e., weakened responding due to conditioning with a CS of longer duration and presenting nonreinforced CSs intermingled with CS-unconditioned stimulus [US] pairings, respectively) interact with overshadowing. Experiment 1 found that when overshadowing treatment was combined with either extended CS duration or partial reinforcement, the response deficit was weaker than when either of these three treatments was administered alone. In Experiment 2, the generality of the findings in Experiment 1 was investigated by replicating it with various US-US intervals. This time counteraction was observed only when both the absolute duration of total CS exposure and the US-US interval were short. The results support neither the view that the ratio between the total CS exposure and total time in the context determines the CS-duration and the partial-reinforcement effects nor the view that these two effects arise from a loss of effectiveness of the excitatory CS-US association during CS-alone exposures in partial reinforcement or early periods of CS exposure with long CSs. PMID:18047218

[Non work-related sickness absence in 2013 in a Spanish banking sector company].

PubMed

Reinoso-Barbero, Luis; Díaz-Garrido, Ramón; González-Gómez, María Fernanda; Jaureguizar-Cervera, Enrique; Piñaga-Solé, Montserrat; Reyes-García, Rocío

2015-01-01

To describe the incidence and duration of episodes of non work-related temporary sickness absence (SA) between January and December of 2013, by diagnostic groups, in a banking sector company. Cross-sectional study of 3.193 episodes of SA (≥ day), excluding work-related injuries and illnesses. The distribution of the duration of SA episodes by medical diagnosis was analyzed by calculating the median duration, 25th and 75th percentiles, mean and standard deviation. The median duration of SA was 9 days for cases where there was a medical diagnosis (n=2.931, 91.8%); the 25th and 75th percentiles were 4 and 32 days, respectively. The most frequent pathologies were respiratory (19.9%), followed by musculoskeletal (19.1%) and pregnancy-related disorders (17.3%). Neoplasms had the longest median duration (49 days), followed by pregnancy-related disorders (39 days) and psychiatric disorders (23 days). Overall sickness absence incidence in our study population was lower, but had a longer duration, as compared to similar studies. The incidence and duration by diagnostic groups were very similar to that reported in the literature, except for pregnancy-related disorders, where both were clearly higher (incidence 4 to 11 times and duration 0.4 times larger) in our company (<0.001). This analysis is useful from a prevention perspective, and suggests the need to prioritize the study to the control of potential workplace exposures that might be affecting pregnant workers' health. Copyright belongs to the Societat Catalana de Salut Laboral.

Prerequisites and driving forces behind an extended working life among older workers.

PubMed

Hovbrandt, Pia; Håkansson, Carita; Albin, Maria; Carlsson, Gunilla; Nilsson, Kerstin

2017-11-28

Reforms are changing pension systems in many European countries, in order to both restrict early retirement and force people to extend their working life. From occupational therapy and occupational science perspectives, studies focusing on aspects of working life that motivate the older worker is urgent. The aim was to describe incentives behind an extended working life among people over age 65. Focus group methodology was used, with participants ages 66-71, from varying work fields: construction and technical companies and the municipal elderly care sector. Work was considered important and valuable to the degree of how challenging work was, the possibilities for inclusion in a team of colleagues and the chances for better personal finances. Amongst all, the participants expressed a feeling of a strengthened identity by being challenged and having the opportunity to manage working tasks. The finding showed the actual reasons behind an extended working life among older workers. However, a risk of rising social inequity may appear with increased working life if older people are forced to extend their working life due to a difficult financial situation as a pensioner. A variety of retirement options and initiatives in order to support older workers are justified.

Effects of cell culture conditions on antibody N-linked glycosylation--what affects high mannose 5 glycoform.

PubMed

Pacis, Efren; Yu, Marcella; Autsen, Jennifer; Bayer, Robert; Li, Feng

2011-10-01

The glycosylation profile of therapeutic antibodies is routinely analyzed throughout development to monitor the impact of process parameters and to ensure consistency, efficacy, and safety for clinical and commercial batches of therapeutic products. In this study, unusually high levels of the mannose-5 (Man5) glycoform were observed during the early development of a therapeutic antibody produced from a Chinese hamster ovary (CHO) cell line, model cell line A. Follow up studies indicated that the antibody Man5 level was increased throughout the course of cell culture production as a result of increasing cell culture medium osmolality levels and extending culture duration. With model cell line A, Man5 glycosylation increased more than twofold from 12% to 28% in the fed-batch process through a combination of high basal and feed media osmolality and increased run duration. The osmolality and culture duration effects were also observed for four other CHO antibody producing cell lines by adding NaCl in both basal and feed media and extending the culture duration of the cell culture process. Moreover, reduction of Man5 level from model cell line A was achieved by supplementing MnCl2 at appropriate concentrations. To further understand the role of glycosyltransferases in Man5 level, N-acetylglucosaminyltransferase I GnT-I mRNA levels at different osmolality conditions were measured. It has been hypothesized that specific enzyme activity in the glycosylation pathway could have been altered in this fed-batch process. Copyright © 2011 Wiley Periodicals, Inc.

Management of refractory trigeminal neuralgia using extended duration pulsed radiofrequency application.

PubMed

Thapa, Deepak; Ahuja, Vanita; Dass, Christopher; Verma, Parul

2015-01-01

Trigeminal neuralgia (TN) produces incapacitating facial pain that reduces quality of life in patients. Thermal radiofrequency (RF) ablation of gasserian ganglion (GG) is associated with masseter weakness and unpleasant sensations along the distribution of the ablated nerve. Pulsed radiofrequency (PRF) of GG has minimal side effects but literature is inconclusive regarding its benefit in refractory TN. Increasing the duration of PRF application to 6 minutes in TN produced encouraging results. PRF application to the saphenous nerve for 8 minutes reported improved pain relief and patient satisfaction. We report successful management of two patients of classic TN, which were refractory to medical management and interventional nerve blocks. The lesion site were confirmed with motor and sensory stimulation through a 22 G, 10 cm RF needle with 5 mm active tip. Both the patients received four cycles of PRF at 42 °C with each cycle of 120 seconds (8 minutes). The visual analogue scale (VAS) in case 1 reduced from pre-block score of 80 to score 10 post-block, while in case 2 the VAS reduced from pre-block score of 85 to score 15 post-block. During follow up both the patients are now pain free with minimal dose of carbamazepine at 12 and 6 months respectively. We used PRF for longer duration (8 minutes) in these patients, which resulted in improved VAS and WHOQOL-BREF score in these patients. PRF of mandibular division of GG for extended duration provided long-term effective pain relief and quality of life in patients of refractory classic TN.

Does Breast-feeding Relate to Development of Atopic Dermatitis in Young Korean Children?: Based on the Fourth and Fifth Korea National Health and Nutrition Examination Survey 2007-2012.

PubMed

Lee, Kyung Suk; Rha, Yeong Ho; Oh, In Hwan; Choi, Yong Sung; Kim, Young Eun; Choi, Sun Hee

2017-07-01

There have been conflicting reports concerning the relationship between breast-feeding and the development of atopic dermatitis (AD) in early childhood. The objective of this study was to investigate the associations between breast-feeding and the risk of AD in early childhood in Korea. We combined the fourth and fifth Korea National Health and Nutrition Examination Survey data collected from 2007 to 2012 and analyzed 2,015 children at 1 to 3 years old. Regression analysis was used to determine the association of the following variables: AD, feeding types, duration of breast-feeding, and others. The annual prevalence of exclusive breast-feeding and AD decreased. Parents with allergic diseases preferred breast-feeding and extended duration of feeding compared with those without. In multiple logistic regression analyses, exclusive breast-feeding in feeding type I (P=0.070; adjusted odds ratio [OR]=1.990), exclusive breast-feeding in feeding type II (P=0.095; adjusted OR=1.495) and breast-feeding duration (P=0.430; adjusted OR=1.013) were not significantly related to AD. Breast-feeding was not found to be associated with an occurrence of AD in young children. Rather, parents with histories of allergic diseases tended to prefer breast-feeding and extend its duration. To clarify the role of breast-feeding in the development of AD, a nation-wide prospective study is needed. Copyright © 2017 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease

Early Prevention of Childhood Disability in Developing Countries.

ERIC Educational Resources Information Center

Simeonsson, Rune J.

1991-01-01

This paper presents a disability prevention framework for community-based rehabilitation services, by conceptualizing early intervention in terms of primary, secondary, and tertiary levels of prevention. The framework views prevention as the effort to reduce a disability's expression, duration, or extended impact. (Author/JDD)

Thermodynamic considerations in the support of life for long space voyages

NASA Technical Reports Server (NTRS)

Iberall, A. S.; Cardon, S. Z.

1979-01-01

The essential requirements for the maintenance of life, particularly human life, on isolated space missions of long duration were investigated through the study of extended irreversible thermodynamics. The characterization of a four trophic level system was developed. Questions of stability are discussed.

Maternal sleep duration and complaints of vital exhaustion during pregnancy is associated with placental abruption.

PubMed

Qiu, Chunfang; Sanchez, Sixto E; Gelaye, Bizu; Enquobahrie, Daniel A; Ananth, Cande V; Williams, Michelle A

2015-02-01

Sleep disorders are associated with cardiovascular complications and preterm delivery (PTD). Insufficient sleep results in metabolic alterations and increased inflammation, both known to contribute to placental abruption (abruption), a determinant of PTD. We examined associations of abruption with sleep duration and complaints of vital exhaustion. The study included 164 abruption cases and 160 controls in a multicenter study in Peru. Data on habitual sleep duration and vital exhaustion during the first 6 months of pregnancy were elicited during interviews conducted following delivery. Women were categorized according to short, normal and long sleep duration (≤6, 7-8 and ≥9 h); and frequency of feeling exhausted. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. Short and long sleep durations were associated with increased odds of abruption. The ORs of abruption in relation to short (≤6 h) and long (≥9 h) sleep duration were 2.0 (95% CI 1.1-3.7) and 2.1 (95% CI 1.1-4.1), compared with normal sleep duration (7-8 h). Complaints of vital exhaustion were also associated with abruption (OR = 2.37; 95% CI 1.46-3.85), and were independent of sleep duration. We extend the existing literature and support the thesis that maternal sleep habits and disorders should be assessed among pregnant women.

Two-Phase Thermal Switching System for a Small, Extended Duration Lunar Science Platform

NASA Technical Reports Server (NTRS)

Bugby, D.; Farmer, J.; OConnor, B.; Wirzburger, M.; Abel, E.; Stouffer, C.

2010-01-01

Issue: extended duration lunar science platforms, using solar/battery or radioisotope power, require thermal switching systems that: a) Provide efficient cooling during the 15-earth-day 390 K lunar day; b) Consume minimal power during the 15-earth-day 100 K lunar night. Objective: carry out an analytical study of thermal switching systems that can meet the thermal requirements of: a) International Lunar Network (ILN) anchor node mission - primary focus; b) Other missions such as polar crater landers. ILN Anchor Nodes: network of geophysical science platforms to better understand the interior structure/composition of the moon: a) Rationale: no data since Apollo seismic stations ceased operation in 1977; b) Anchor Nodes: small, low-power, long-life (6-yr) landers with seismographic and a few other science instruments (see next chart); c) WEB: warm electronics box houses ILN anchor node electronics/batteries. Technology Need: thermal switching system that will keep the WEB cool during the lunar day and warm during the lunar night.

Tunable picosecond infrared pulses generated by stimulated electronic Raman scattering of a mode-locked Ti:Sapphire laser in potassium vapor

NASA Astrophysics Data System (ADS)

Ohde, H.; Lin, S.; Minoh, A.; Shimizu, F. O.; Aono, M.; Suzuki, T.

1996-01-01

A down-conversion to the mid-infrared region by using Stimulated Electronic Raman Scattering (SERS) in potassium vapor is described. The pump radiation is a frequency-doubled regeneratively amplified Ti:Sapphire laser with a pulse duration of 2 ps, pulse energy of 0.2 mJ, and repetition rate of 10 Hz. With the pumping frequency tuned around the potassium 4 s-5 p transition, nearly transform-limited infrared radiation tunable between 2.2 and 3.4 μm has been generated with a peak infrared energy of 12 µJ, corresponding to a quantum efficiency of 17%, and with a pulse duration of 2 ps. The present tuning range could be extended by extending the tuning range of the pump laser. In comparison, intense infrared radiation of 90 µJ energy but with a very narrow tunability around 2.9 μm has also been generated by SERS in barium vapor.

Extended Duration Orbiter Medical Project

NASA Technical Reports Server (NTRS)

Sawin, Charles F. (Editor); Taylor, Gerald R. (Editor); Smith, Wanda L. (Editor); Brown, J. Travis (Technical Monitor)

1999-01-01

Biomedical issues have presented a challenge to flight physicians, scientists, and engineers ever since the advent of high-speed, high-altitude airplane flight in the 1940s. In 1958, preparations began for the first manned space flights of Project Mercury. The medical data and flight experience gained through Mercury's six flights and the Gemini, Apollo, and Skylab projects, as well as subsequent space flights, comprised the knowledge base that was used to develop and implement the Extended Duration Orbiter Medical Project (EDOMP). The EDOMP yielded substantial amounts of data in six areas of space biomedical research. In addition, a significant amount of hardware was developed and tested under the EDOMP. This hardware was designed to improve data gathering capabilities and maintain crew physical fitness, while minimizing the overall impact to the microgravity environment. The biomedical findings as well as the hardware development results realized from the EDOMP have been important to the continuing success of extended Space Shuttle flights and have formed the basis for medical studies of crew members living for three to five months aboard the Russian space station, Mir. EDOMP data and hardware are also being used in preparation for the construction and habitation of International Space Station. All data sets were grouped to be non-attributable to individuals, and submitted to NASA s Life Sciences Data Archive.

Object size determines the spatial spread of visual time

PubMed Central

McGraw, Paul V.; Roach, Neil W.; Whitaker, David

2016-01-01

A key question for temporal processing research is how the nervous system extracts event duration, despite a notable lack of neural structures dedicated to duration encoding. This is in stark contrast with the orderly arrangement of neurons tasked with spatial processing. In this study, we examine the linkage between the spatial and temporal domains. We use sensory adaptation techniques to generate after-effects where perceived duration is either compressed or expanded in the opposite direction to the adapting stimulus' duration. Our results indicate that these after-effects are broadly tuned, extending over an area approximately five times the size of the stimulus. This region is directly related to the size of the adapting stimulus—the larger the adapting stimulus the greater the spatial spread of the after-effect. We construct a simple model to test predictions based on overlapping adapted versus non-adapted neuronal populations and show that our effects cannot be explained by any single, fixed-scale neural filtering. Rather, our effects are best explained by a self-scaled mechanism underpinned by duration selective neurons that also pool spatial information across earlier stages of visual processing. PMID:27466452

Eye movements and serial memory for visual-spatial information: does time spent fixating contribute to recall?

PubMed

Saint-Aubin, Jean; Tremblay, Sébastien; Jalbert, Annie

2007-01-01

This research investigated the nature of encoding and its contribution to serial recall for visual-spatial information. In order to do so, we examined the relationship between fixation duration and recall performance. Using the dot task--a series of seven dots spatially distributed on a monitor screen is presented sequentially for immediate recall--performance and eye-tracking data were recorded during the presentation of the to-be-remembered items. When participants were free to move their eyes at their will, both fixation durations and probability of correct recall decreased as a function of serial position. Furthermore, imposing constant durations of fixation across all serial positions had a beneficial impact (though relatively small) on item but not order recall. Great care was taken to isolate the effect of fixation duration from that of presentation duration. Although eye movement at encoding contributes to immediate memory, it is not decisive in shaping serial recall performance. Our results also provide further evidence that the distinction between item and order information, well-established in the verbal domain, extends to visual-spatial information.

[Breastfeeding (part one): Frequency, benefits and drawbacks, optimal duration and factors influencing its initiation and prolongation. Clinical guidelines for practice].

PubMed

Chantry, A A; Monier, I; Marcellin, L

2015-12-01

The objectives were to on assess the frequency and the duration of breastfeeding in France. On the other hand, the objectives were to identify its benefits and drawbacks, and to study the factors influencing its initiation and its extension. Bibliographic research in Medline, Google Scholar and in the Cochrane Library. Breastfeeding concerns in France about 70% of children at birth (EL2). Its median duration is about 15 weeks and 3 weeks ½ for exclusive breastfeeding. At three months, only one third of children breastfed at birth are still being breastfed (EL2). Whether this is due to the composition of breast milk or the behavior of mothers with their children or their socio-cultural level, or even by all these components at once, breastfeeding is associated with better cognitive development children (EL2). This effect is even more reinforced that mothers breastfeed exclusively and prolonged (EL2). As part of the prevention of many diseases (ear infections, gastrointestinal infections, atopic diseases, obesity and cardiovascular diseases…), exclusive and prolonged breastfeeding (grade B) between 4 to 6 months is recommended (professional consensus). Breastfeeding is not a means of preventing postpartum depression (professional consensus). To reduce the incidence of breast cancer, prolonged breastfeeding is recommended (grade B). In order to increase the rate of initiation of breastfeeding as well as its duration, it is recommended that health professionals work closely with mothers in their project (grade A), the breastfeeding promotion messages include message to husbands (grade B), and to promote breastfeeding on demand without fixed interval between feedings (grade B). However, there is not enough data to recommend the use of a specific position during breastfeeding, or the use of one or two breast or to early start breastfeeding or not (professional consensus). Exclusive and extended breastfeeding is recommended (grade B) between 4 to 6 months (professional consensus). Copyright © 2015. Published by Elsevier Masson SAS.

Operational plans for life science payloads - From experiment selection through postflight reporting

NASA Technical Reports Server (NTRS)

Mccollum, G. W.; Nelson, W. G.; Wells, G. W.

1976-01-01

Key features of operational plans developed in a study of the Space Shuttle era life science payloads program are presented. The data describes the overall acquisition, staging, and integration of payload elements, as well as program implementation methods and mission support requirements. Five configurations were selected as representative payloads: (a) carry-on laboratories - medical emphasis experiments, (b) mini-laboratories - medical/biology experiments, (c) seven-day dedicated laboratories - medical/biology experiments, (d) 30-day dedicated laboratories - Regenerative Life Support Evaluation (RLSE) with selected life science experiments, and (e) Biomedical Experiments Scientific Satellite (BESS) - extended duration primate (Type I) and small vertebrate (Type II) missions. The recommended operational methods described in the paper are compared to the fundamental data which has been developed in the life science Spacelab Mission Simulation (SMS) test series. Areas assessed include crew training, experiment development and integration, testing, data-dissemination, organization interfaces, and principal investigator working relationships.

Growth behavior of carbon nanotubes on multilayered metal catalyst film (Al/Fe/Mo) in chemical vapor deposition

NASA Astrophysics Data System (ADS)

Cui, H.; Eres, G.; Howe, J. Y.; Puretzky, A.; Varela, M.; Geohegan, D. B.; Lowndes, D. H.

2003-03-01

The temperature- and time- dependences of carbon nanotube (CNT) growth by chemical vapor deposition are studied using a multilayered Al/Fe/Mo catalyst on silicon substrates. Within the 600 - 1100 ^oC temperature range in these studies, narrower temperature ranges were determined for the growth of aligned multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs). Aligned MWCNT growth is favored at lower temperatures ( ˜700 ^oC). At 900 ^oC, in contrast to earlier work, double-walled carbon nanotubes (DWCNTs) are found more abundant than SWCNTs. At further elevated temperature, highly defective carbon structures are produced. Defects also are found to accumulate faster than the ordered graphitic structure if the growth of CNTs is extended to long growth durations. Atomic force microscopy, field emission scanning electron microscopy, high resolution transmission electron microscopy, and Raman spectroscopy are used to characterize the catalyst and various types of CNTs.

FY 2017 Center Innovation Fund Annual Report - Highlights/Abstract section

NASA Technical Reports Server (NTRS)

Hintze, Paul; Youngquist, Robert C.; Massa, Gioia D.; Meier, Anne J.

2017-01-01

This project evaluated the feasibility of low pressure cold plasma (CP) for two applications: disinfection of produce grown in space and sterilization of medical equipment in space. Currently there is no ISS capability for disinfecting pick and eat crops, food utensils, food production areas, or medical devices. This deficit is extended to projected long duration missions. Small, portable, cold plasma devices would provide an enhanced benefit to crew health and address issues concerning microbial cross contamination. The technology would contribute to the reduction of solid waste since currently crews utilize benzalkonium chloride wet wipes for cleaning surfaces and might use PRO-SAN wipes for cleaning vegetables. CP cleaning/disinfection/sterilization can work on many surfaces, including all metals, most polymers, and this project evaluated produce. Therefore CP provides a simple system that has many different cleaning application in space: produce, medical equipment, cutlery, miscellaneous tools.

Long-Term Lunar Radiation Degradation Effects on Materials

NASA Technical Reports Server (NTRS)

Rojdev, Kristina; ORourke, Mary Jane; Koontz, Steve; Alred, John; Hill, Charles; Devivar, Rodrigo; Morera-Felix, Shakira; Atwell, William; Nutt, Steve; Sabbann, Leslie

2010-01-01

The National Aeronautics and Space Administration (NASA) is focused on developing technologies for extending human presence beyond low Earth orbit. These technologies are to advance the state-of-the-art and provide for longer duration missions outside the protection of Earth's magnetosphere. One technology of great interest for large structures is advanced composite materials, due to their weight and cost savings, enhanced radiation protection for the crew, and potential for performance improvements when compared with existing metals. However, these materials have not been characterized for the interplanetary space environment, and particularly the effects of high energy radiation, which is known to cause damage to polymeric materials. Therefore, a study focusing on a lunar habitation element was undertaken to investigate the integrity of potential structural composite materials after exposure to a long-term lunar radiation environment. An overview of the study results are presented, along with a discussion of recommended future work.

A Mission Concept Based on the ISECG Human Lunar Surface Architecture

NASA Technical Reports Server (NTRS)

Gruener, J. E.; Lawrence, S. J.

2017-01-01

The National Aeronautics and Space Administration (NASA) is participating in the International Space Exploration Coordination Group (ISECG), working together with 13 other space agencies to advance a long-range human space exploration strategy. The ISECG has developed a Global Exploration Roadmap (GER) that reflects the coordinated international dialog and continued preparation for exploration beyond low-Earth orbit - beginning with the International Space Station (ISS) and continuing to the Moon, near-Earth asteroids, and Mars [1]. The roadmap demonstrates how initial capabilities can enable a variety of missions in the lunar vicinity, responding to individual and common goals and objectives, while contributing to building partnerships required for sustainable human space exploration that delivers value to the public. The current GER includes three different near-term themes: exploration of a near-Earth asteroid, extended duration crew missions in cis-lunar space, and humans to the lunar surface.

Space Shuttle Projects

NASA Image and Video Library

1984-04-07

This is an onboard photo of the deployment of the Long Duration Exposure Facility (LDEF) from the cargo bay of the Space Shuttle Orbiter Challenger STS-41C mission, April 7, 1984. After a five year stay in space, the LDEF was retrieved during the STS-32 mission by the Space Shuttle Orbiter Columbia in January 1990 and was returned to Earth for close examination and analysis. The LDEF was designed by the Marshall Space Flight Center (MSFC) to test the performance of spacecraft materials, components, and systems that have been exposed to the environment of micrometeoroids, space debris, radiation particles, atomic oxygen, and solar radiation for an extended period of time. Proving invaluable to the development of both future spacecraft and the International Space Station (ISS), the LDEF carried 57 science and technology experiments, the work of more than 200 investigators, 33 private companies, 21 universities, 7 NASA centers, 9 Department of Defense laboratories, and 8 forein countries.

Individualized Behavioral Health Monitoring Tool

NASA Technical Reports Server (NTRS)

Mollicone, Daniel

2015-01-01

Behavioral health risks during long-duration space exploration missions are among the most difficult to predict, detect, and mitigate. Given the anticipated extended duration of future missions and their isolated, extreme, and confined environments, there is the possibility that behavior conditions and mental disorders will develop among astronaut crew. Pulsar Informatics, Inc., has developed a health monitoring tool that provides a means to detect and address behavioral disorders and mental conditions at an early stage. The tool integrates all available behavioral measures collected during a mission to identify possible health indicator warning signs within the context of quantitatively tracked mission stressors. It is unobtrusive and requires minimal crew time and effort to train and utilize. The monitoring tool can be deployed in space analog environments for validation testing and ultimate deployment in long-duration space exploration missions.

Contrasts in the Behavior of Tremor Episodes in Cascadia and Japan

NASA Astrophysics Data System (ADS)

Armbruster, J. G.

2016-12-01

Tectonic tremor is observed in episodes with varying duration, intensity and spatial extent. In Cascadia the POLARIS broadband deployment, 2003-2006, provides good coverage of the southern Vancouver Island region with strong, widely distributed tremor sources extending 100 km along the plate interface. There the tremor can be classified into major episodes occurring at 14 month intervals with duration 20-30 days and minor episodes lasting hours to 10 days. Within that shorter duration minor episodes can produce strong signals. There is a clear pattern that minor episodes are located at the deeper part of the plate interface, 43-50 km deep. Major episodes are mostly generated from the shallower, 33-43 km deep, portion of the plate interface with some activation of the deeper sources. This suggests a simple mechanism of stress loading from below, transmitted upward by the tremor/slow-slip episodes. We compare this to the northern Kii Peninsula region of southwest Japan which has strong tremor sources extending 100 km along strike covered by HINET stations and find differences. The spectrum of episode durations in Japan, from less than an hour to 13 days, are not easily classified into major and minor. The range in depth observed in Japan is narrower than in Cascadia, 34-45 km for 98% of the clustered events. Here we divide the episodes into three groups based on their spatial extent. Large episodes occur at intervals of 6 months and occupy the southern 2/3, northern 2/3 or whole of the 100 km long zone. The small episodes are predominately seen from paired sources at the top and bottom of the active zone located where large episodes terminate. Intermediate episodes are the fewest in number and extend from the bottom to the top, often encompassing pairs of small sources. The observations in Japan will require a more complex model of stress loading. These results were achieved with the cross-station location method. The envelope location method might not have sufficient resolution to resolve these patterns in Japan.

Rurality/Urbanism and Extended Familism Among Working- and Lower-Class Blacks.

ERIC Educational Resources Information Center

Dietrich, Katheryn Thomas

A comprehensive look is taken at the rural-urban variation in extended familism among a segment of the population for which extended familism purportedly is especially salient: lower and working class black Americans. The study is guided by the general hypothesis that rurality/urbanism affects extended familism when nonecological variables are…

[Beneficial effect of maternity leave on delivery].

PubMed

Xu, Qian; Séguin, Louise; Goulet, Lise

2002-01-01

To identify the contribution of the duration of the prenatal maternity leave on term delivery. Characteristics of the prenatal maternity leave and delivery among 363 working women who had delivered a full-term infant at 1 of 4 hospitals in Montreal during 1996 were studied. The presence of an intervention or complication during delivery was observed in 68.9% of the participants. The average duration of the prenatal maternity leave was about 8 weeks (SD = 7). The adjusted risk of a difficult delivery decreased significantly with the duration of the prenatal maternity leave (OR = 0.96; 95% CI: 0.93-0.99). The duration of the maternity leave before delivery is associated with an easier term delivery for working women.

HARBO, a simple computer-aided observation method for recording work postures.

PubMed

Wiktorin, C; Mortimer, M; Ekenvall, L; Kilbom, A; Hjelm, E W

1995-12-01

The aim of the study was to present an observation method focusing on the positions of the hands relative to the body and to evaluate whether this simple observation technique gives a reliable estimate of the total time spent in each of five work postures during one workday. In the first part of the study the interobserver reliability of the observation method was tested with eight blue-collar workers. In the second part the observed time spent with work above the shoulder level was tested in relation to an upper-arm position analyzer, and observed time spent in work below knuckle level was tested in relation to a trunk flexion analyzer, both with 72 blue-collar workers. The interobserver reliability for full-day registrations was high. The intraclass correlation coefficients ranged from 0.99 to 1.00. The observed duration of work with hands above shoulder level correlated well with the measured duration of pronounced arm elevation (> 75 degrees). The product moment correlation coefficient was 0.97. The observed duration of work with hands below knuckle level correlated well with the measured duration of pronounced trunk flexion angles (> 40 degrees). The product moment correlation coefficient was 0.98. The present observation method, designed to make postural observations continuously for several hours, is easy to learn and seems reliable.

Senescence sweetening of chip and fry processing potatoes

USDA-ARS?s Scientific Manuscript database

Potato storage makes the crop available over an extended time period, but increases financial risk to growers and end users. Senescence sweetening limits storage duration for chip and fry processing potatoes because it results in an unacceptable accumulation of reducing sugars that result in dark-co...

PA Discussion Topics

DTIC Science & Technology

2011-02-04

Solid Oxide fuel cell and Lithium Ion battery (~150 watts) • Enables extended mission durations • 12 hours of full power; 30 hours of silent watch...Hybrid fuel cell system is designed to replace the existing lead-acid batteries with an upgraded Solid Oxide fuel cell and Lithium Ion battery (~250

The Effects of Changing the Phase and Duration of Sleep

ERIC Educational Resources Information Center

Taub, John M.; Berger, Ralph J.

1976-01-01

The purpose of the present experiment was to compare the effects on performance and mood of reduced and extended sleep with those following temporal shifts of sleep in a single group of subjects who characteristically sleep 9.5-10.5 hours per night. (Author)

Impacts of extended working hours in logging

Treesearch

Dana Mitchell; Tom Gallagher

2008-01-01

Last year at the 2007 AIM in Minneapolis, MN, the authors presented the human factors impacts to consider when implementing extended working hours in the logging industry. In a continuation of this project, we have researched existing literature to identify possible actions that logging business owners can take to reduce the impact of extended working hours on their...

Gender differences in the duration of non-work-related sickness absence episodes due to musculoskeletal disorders.

PubMed

Arcas, M Marta; Delclos, George L; Torá-Rocamora, Isabel; Martínez, José Miguel; Benavides, Fernando G

2016-11-01

There is wide evidence that women present longer duration of sickness absence (SA) than men. Musculoskeletal disorders are influenced by gender due to the sexual division of work. 354 432 episodes of non-work-related SA due to musculoskeletal disorders, which were registered in Catalonia between 2005 and 2008, were selected. The outcome variable was the duration of SA. Frailty survival models, stratified by sex and adjusted for explanatory variables (age, employment status, case management, economic activity and repeated episode), were fitted to study the association between each variable and the duration of SA, obtaining HRs. Women presented longer SA episodes than men in all variable categories. A trend from shorter to longer duration of SA with increasing age was observed in men, whereas in women, it had a fluctuating pattern. Analysing most frequent diagnostic subgroups from the sample, only 'non-specific lumbago' and 'sciatic lumbago' showed these age patterns. Frailty survival models applied to these 2 subgroups confirmed the described age patterns in SA duration. Women have longer non-work-related SA due to musculoskeletal disorders than men. However, while men have longer absences as their age increases, in women some older groups have shorter absences than younger ones. These findings could be explained by gender differences in the interaction between paid work and family demands. Our results highlight the need for continued research on SA from a gender perspective, in order to improve management of SA in terms of clinical practice and public policies. 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/.

Are chronotype, social jetlag and sleep duration associated with health measured by Work Ability Index?

PubMed

Yong, Mei; Fischer, Dorothee; Germann, Christina; Lang, Stefan; Vetter, Céline; Oberlinner, Christoph

The present study investigates the impact of chronotype, social jetlag and sleep duration on self-perceived health, measured by Work Ability Index (WAI), within an industrial setting. Between 2011 and 2013, 2474 day and shift workers participated in a health check offered by an occupational health promotion program and filled out the Munich ChronoType Questionnaire (adapted to the rotational 12-h schedule for shift workers) and the WAI. We computed sleep duration on work and free days, chronotype, and social jetlag. We used linear regression models to examine chronotype, sleep duration and social jetlag for association with the WAI sum score, and proportional odds models to estimate the combined effect of social jetlag and sleep duration. Participants reported an average daily sleep duration of 7.35 h (SD: 1.2 h), had an average chronotype of 3:08 a.m. (SD: 1 h), and the average social jetlag corresponded to 1.96 h (SD: 2.05 h). Increasing social jetlag and shorter sleep duration were independently associated with a decreasing WAI, while chronotype per se was not associated with WAI. Short sleep duration combined with high social jetlag significantly increased the risk of poor WAI (OR = 1.36; 95% CI: 1.09-1.72), while long sleep duration and high social jetlag were not associated with poor WAI (OR = 1.09; 95% CI: 0.88-1.35). Our results add to a growing body of literature, suggesting that circadian misalignment, but not chronotype per se, may be critical for health. Our results indicate that longer sleep may override the adverse effects of social jetlag on WAI.

Functional disability and depression in the general population. Results from the Netherlands Mental Health Survey and Incidence Study (NEMESIS).

PubMed

Spijker, J; Graaf, R; Bijl, R V; Beekman, A T F; Ormel, J; Nolen, W A

2004-09-01

Data on the temporal relationships between duration of depression and recovery and functional disability are sparse. These relationships were examined in subjects from the general population (n = 250) with newly originated episodes of DSM-III-R major depression. The Netherlands Mental Health Survey and Incidence Study is a prospective epidemiological survey in the adult population (n = 7076), using the Composite International Diagnostic Interview (CIDI). Duration of depression and duration of recovery over 2 years were assessed with a life chart interview. Functional disabilities were assessed with the MOS-SF-36 and with absence days from work. Functional disabilities and absence days in depressed individuals were not found to be associated with duration of depression. Functioning in daily activities improved with longer duration of recovery but social functioning not. Functioning deteriorates by actual depressive symptomatology and comorbid anxiety but not by longer duration of depression. After symptomatic recovery, functioning improves to premorbid level, irrespective of the length of the depression. Improvements in daily activities and work can be expected with longer duration of recovery.

Flight controller alertness and performance during MOD shiftwork operations

NASA Technical Reports Server (NTRS)

Kelly, Sean M.; Rosekind, Mark R.; Dinges, David F.; Miller, Donna L.; Gillen, Kelly A.; Gregory, Kevin B.; Aguilar, Ronald D.; Smith, Roy M.

1994-01-01

Decreased alertness and performance associated with fatigue, sleep loss, and circadian disruption are issues faced by a diverse range of shiftwork operations. During STS operations, MOD personnel provide 24 hr. coverage of critical tasks. A joint JSC and ARC project was undertaken to examine these issues in flight controllers during MOD shiftwork operations. An initial operational test of procedures and measures was conducted during STS-53 in Dec. 1992. The study measures included a background questionnaire, a subjective daily logbook completed on a 24 hr. basis (to report sleep patterns, work periods, etc.), and an 8 minute performance and mood test battery administered at the beginning, middle, and end of each shift period. Seventeen Flight controllers representing the 3 Orbit shifts participated. The initial results clearly support further data collection during other STS missions to document baseline levels of alertness and performance during MOD shiftwork operations. These issues are especially pertinent for the night shift operations and the acute phase advance required for the transition of day shift personnel into the night for shuttle launch. Implementation and evaluation of the countermeasure strategies to maximize alertness and performance is planned. As STS missions extend to further extended duration orbiters, timelines and planning for 24 circadian disruption will remain highly relevant in the MOD environment.

When performance and risk taking are related: Working for rewards is related to risk taking when the value of rewards is presented briefly.

PubMed

Veling, Harm; Bijleveld, Erik

2015-12-01

Valuable monetary rewards can boost human performance on various effortful tasks even when the value of the rewards is presented too briefly to allow for strategic decision making. However, the mechanism by which briefly-presented reward information influences performance has remained unclear. One possibility is that performance after briefly-presented reward information is primarily boosted via activation of the dopamine reward system, whereas performance after very visible reward information is driven more by strategic processes. To examine this hypothesis, we first presented participants with a task in which they could earn rewards of relatively low (1 cent) or high (10 cents) value, and the value information was presented either briefly (17 ms) or for an extended duration (300 ms). Furthermore, responsiveness of the dopamine system was indirectly estimated with a measure of risk taking, the Balloon Analogue Risk Task (BART). Results showed that performance after high- compared to low-value rewards was indeed related to the BART scores only when reward information was presented briefly. These results are suggestive of the possibility that brief presentation of reward information boosts performance directly via activating the dopamine system, whereas extended presentation of reward information leads to more strategic reward-driven behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

Tough Composite Hydrogels with High Loading and Local Release of Biological Drugs.

PubMed

Li, Jianyu; Weber, Eckhard; Guth-Gundel, Sabine; Schuleit, Michael; Kuttler, Andreas; Halleux, Christine; Accart, Nathalie; Doelemeyer, Arno; Basler, Anne; Tigani, Bruno; Wuersch, Kuno; Fornaro, Mara; Kneissel, Michaela; Stafford, Alexander; Freedman, Benjamin R; Mooney, David J

2018-05-01

Hydrogels are under active development for controlled drug delivery, but their clinical translation is limited by low drug loading capacity, deficiencies in mechanical toughness and storage stability, and poor control over the drug release that often results in burst release and short release duration. This work reports a design of composite clay hydrogels, which simultaneously achieve a spectrum of mechanical, storage, and drug loading/releasing properties to address the critical needs from translational perspectives. The clay nanoparticles provide large surface areas to adsorb biological drugs, and assemble into microparticles that are physically trapped within and toughen hydrogel networks. The composite hydrogels demonstrate feasibility of storage, and extended release of large quantities of an insulin-like growth factor-1 mimetic protein (8 mg mL -1 ) over four weeks. The release rate is primarily governed by ionic exchange and can be upregulated by low pH, which is typical for injured tissues. A rodent model of Achilles tendon injury is used to demonstrate that the composite hydrogels allow for highly extended and localized release of biological drugs in vivo, while demonstrating biodegradation and biocompatibility. These attributes make the composite hydrogel a promising system for drug delivery and regenerative medicine. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prediction of scaling physics laws for proton acceleration with extended parameter space of the NIF ARC

NASA Astrophysics Data System (ADS)

Bhutwala, Krish; Beg, Farhat; Mariscal, Derek; Wilks, Scott; Ma, Tammy

2017-10-01

The Advanced Radiographic Capability (ARC) laser at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is the world's most energetic short-pulse laser. It comprises four beamlets, each of substantial energy ( 1.5 kJ), extended short-pulse duration (10-30 ps), and large focal spot (>=50% of energy in 150 µm spot). This allows ARC to achieve proton and light ion acceleration via the Target Normal Sheath Acceleration (TNSA) mechanism, but it is yet unknown how proton beam characteristics scale with ARC-regime laser parameters. As theory has also not yet been validated for laser-generated protons at ARC-regime laser parameters, we attempt to formulate the scaling physics of proton beam characteristics as a function of laser energy, intensity, focal spot size, pulse length, target geometry, etc. through a review of relevant proton acceleration experiments from laser facilities across the world. These predicted scaling laws should then guide target design and future diagnostics for desired proton beam experiments on the NIF ARC. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and funded by the LLNL LDRD program under tracking code 17-ERD-039.

Ti:sapphire-pumped diamond Raman laser with sub-100-fs pulse duration.

PubMed

Murtagh, Michelle; Lin, Jipeng; Mildren, Richard P; Spence, David J

2014-05-15

We report a synchronously pumped femtosecond diamond Raman laser operating at 895 nm with a 33% slope efficiency. Pumped using a mode-locked Ti:sapphire laser at 800 nm with a duration of 170 fs, the bandwidth of the Stokes output is broadened and chirped to enable subsequent pulse compression to 95 fs using a prism pair. Modeling results indicate that self-phase modulation drives the broadening of the Stokes spectrum in this highly transient laser. Our results demonstrate the potential for Raman conversion to extend the wavelength coverage and pulse shorten Ti:sapphire lasers.

Note: Attenuation motion of acoustically levitated spherical rotor

NASA Astrophysics Data System (ADS)

Lü, P.; Hong, Z. Y.; Yin, J. F.; Yan, N.; Zhai, W.; Wang, H. P.

2016-11-01

Here we observe the attenuation motion of spherical rotors levitated by near-field acoustic radiation force and analyze the factors that affect the duration time of free rotation. It is found that the rotating speed of freely rotating rotor decreases exponentially with respect to time. The time constant of exponential attenuation motion depends mainly on the levitation height, the mass of rotor, and the depth of concave ultrasound emitter. Large levitation height, large mass of rotor, and small depth of concave emitter are beneficial to increase the time constant and hence extend the duration time of free rotation.

Note: Attenuation motion of acoustically levitated spherical rotor.

PubMed

Lü, P; Hong, Z Y; Yin, J F; Yan, N; Zhai, W; Wang, H P

2016-11-01

Here we observe the attenuation motion of spherical rotors levitated by near-field acoustic radiation force and analyze the factors that affect the duration time of free rotation. It is found that the rotating speed of freely rotating rotor decreases exponentially with respect to time. The time constant of exponential attenuation motion depends mainly on the levitation height, the mass of rotor, and the depth of concave ultrasound emitter. Large levitation height, large mass of rotor, and small depth of concave emitter are beneficial to increase the time constant and hence extend the duration time of free rotation.

Flywheel induction motor-generator for magnet power supply in small fusion device.

PubMed

Hatakeyma, S; Yoshino, F; Tsutsui, H; Tsuji-Iio, S

2016-04-01

A flywheel motor-generator (MG) for the toroidal field (TF) coils of a small fusion device was developed which utilizes a commercially available squirrel-cage induction motor. Advantages of the MG are comparably-long duration, quick power response, and easy implementation of power control compared with conventional capacitor-type power supply. A 55-kW MG was fabricated, and TF coils of a small fusion device were energized. The duration of the current flat-top was extended to 1 s which is much longer than those of conventional small devices (around 10-100 ms).

Flywheel induction motor-generator for magnet power supply in small fusion device

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

Hatakeyma, S., E-mail: hatakeyama.shoichi@torus.nr.titech.ac.jp; Yoshino, F.; Tsutsui, H.

2016-04-15

A flywheel motor-generator (MG) for the toroidal field (TF) coils of a small fusion device was developed which utilizes a commercially available squirrel-cage induction motor. Advantages of the MG are comparably-long duration, quick power response, and easy implementation of power control compared with conventional capacitor-type power supply. A 55-kW MG was fabricated, and TF coils of a small fusion device were energized. The duration of the current flat-top was extended to 1 s which is much longer than those of conventional small devices (around 10–100 ms).

Development of Milestone Schedules for Selected Logistics Support Directorate Programs. Appendix A. Part 2. Task Summaries.

DTIC Science & Technology

1987-09-15

MAC; CODE NUMBER: NONE AND REPAIR PARTS AND SPECIAL TOOLS LIST (RPSTL). RESPONSIBILITY: ROY & ILS DURATION: 32.00 WORK DAYS PRE PPPL SCHEDULE...ILS DURATION: 22.00 WORK DAYS R/V PPPL SCHEDULE: DVPMARPS REVIEW AND VALIDATE PRELIMINARY PROVISIONING PARTS LIST. CODE NUMBER: NONE RESPONSIBILITY

The impact of unwaged domestic work on the duration and timing of sleep of female nurses working full-time on rotating 3-shift rosters.

PubMed

Clissold, G; Smith, P; Acutt, B

2001-12-01

The study examined the impact of family type on the timing and duration of sleep of 16 experienced female shiftworkers working a rotating 3-shift roster. The nurses lived in one of three domestic lifestyle arrangements: single with no child care responsibilities (N = 4), partnered with no child care responsibilities (N = 5) and partnered with child care responsibilities (N = 7). Self report sleep diaries were used to collect data over a period of 28 days, following which each nurse took part in a conversational interview. Comparisons of the roster mean sleep durations between groups show that nurses who do not have the added unwaged workload of child care, record significantly more sleep than nurses with such responsibilities. Analysis of the data by shift type shows a significant difference for afternoon shift: nurses with child care responsibilities record a significantly earlier rise time and a significantly shorter total sleep duration. The interview data further highlights how sleep patterns are related to the time constraints of both domestic and waged work.

[Inability to work: analysis of sickness benefits granted in the State of Rondônia].

PubMed

Jakobi, Heinz Roland; Barbosa-Branco, Anadergh; Bueno, Luis Fernando; Ferreira, Ricardo de Godoi Mattos; Camargo, Luís Marcelo Aranha

2013-11-01

This is a descriptive epidemiological study aiming to o estimate the prevalence and duration of sickness benefits granted by the Brazilian Social Security Institute, as well as the clinical causes of inability to work among employees in Rondonia in 2008. The prevalence was submitted by 10,000 workers and stratified by sex, age, diagnosis, economic activity, and type and duration of benefits. Men had a higher prevalence and duration of benefits. Social security benefits were found to be 2,5 times more prevalent than accident benefits and both increased with age. Labor accidents were more prevalent in the age group ranging between 50-59 years, and Forestry, construction and manpower leasing: had the highest prevalence. The main diagnostic groups were injuries, musculoskeletal system disorders and digestive diseases. The duration of the sickness benefits was higher among men, =40 years and in the social security category. The economic activity is an important risk factor for Inability to work, and it needs to be further explored in order to improve sickness prevention and reduce the impact on workers' health arising from environmental conditions and working processes.

Military Internal Medicine Resident Decision to Apply to Fellowship and Extend Military Commitment.

PubMed

Barsoumian, Alice E; Hartzell, Joshua D; Bonura, Erin M; Ressner, Roseanne A; Whitman, Timothy J; Yun, Heather C

2018-02-06

Nationally, the number of internal medicine physicians practicing in primary care has decreased amidst increasing interest in hospitalist medicine. Current priorities in the Military Health System include access to primary care and retention of trained personnel. Recently, we have conducted a study of military internal medicine residents' decision to enter infectious disease. As part of our larger effort, we saw an opportunity to characterize factors impacting decision making of internal medicine residents' desire to apply for subspecialty training and to extend active duty service obligations. Questions were developed after discussion with various military graduate medical education and internal medicine leaders, underwent external review, and were added to a larger question set. The survey link was distributed electronically to all U.S. military affiliated residencies' graduating internal medicine residents in December 2016-January 2017. Data were analyzed by decision to apply to fellowship and decision to extend military obligation using Fisher's exact test or Pearon's chi-square test. Sixty-eight residents from 10 of 11 military residency programs responded, for a response rate of 51%. The majority (62%) applied to fellowship to start after residency completion. Reasons cited for applying to fellowship included wanting to become a specialist as soon as possible (74%), wishing to avoid being a general internist (57%), and because they are unable to practice as a hospitalist in the military (52%). Fellowship applicants were more likely to plan to extend their military obligation than non-applicants, as did those with longer duration of military commitments. No other factors, including Uniformed Services University attendance or participation in undergraduate military experiences, were found to impact plan to extend active duty service commitment. The majority of graduating internal medicine residents apply for fellowship and report a desire to avoid being a general internist. Prospective fellows anticipate extending their active duty commitment, as do those with longer commitments. Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2018. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Short sleep duration, shift work, and actual days taken off work are predictive life-style risk factors for new-onset metabolic syndrome: a seven-year cohort study of 40,000 male workers.

PubMed

Itani, Osamu; Kaneita, Yoshitaka; Tokiya, Mikiko; Jike, Maki; Murata, Atsushi; Nakagome, Sachi; Otsuka, Yuichiro; Ohida, Takashi

2017-11-01

This longitudinal study investigated the effects of various lifestyle-related factors - including sleep duration, shift work, and actual days taken off work - on new-onset metabolic syndrome (MetS). A total of 39,182 male employees (mean age 42.4 ± 9.8 years) of a local government organization in Japan were followed up for a maximum of seven years, between 1999 and 2006. Multivariate analysis (Cox proportional hazard method) identified seven high-risk lifestyle factors that were significantly associated with new-onset MetS or a range of metabolic factors (obesity, hypertension, hyperglycemia, dyslipidemia): (1) short sleep duration (<5 h/day), (2) shift work, (3) insufficient number of days off work, (4) always eating until satiety, (5) not trying to take every opportunity to walk, (6) alcohol intake ≥60 g/day, and (7) smoking. In addition, a higher number of these high-risk lifestyle factors significantly promoted the onset of MetS. The hazard ratio for MetS associated with 0-1 high-risk lifestyle parameters per subject at the baseline was set at 1.00. Hazard ratios associated with the following numbers of high-risk lifestyle parameters were: 1.22 (95% CI 1.15-1.29) for 2-3 of these parameters; and 1.43 (1.33-1.54) for 4-7. An increase in the number of high-risk lifestyle factors - such as short sleep duration, shift work, and an insufficient number of days off work - increased the risk of MetS onset. Comprehensive strategies to improve a range of lifestyle factors for workers, such as sleep duration and days off work, could reduce the risk of MetS onset. Copyright © 2017 Elsevier B.V. All rights reserved.

Sleep and sleepiness among working and non-working high school evening students.

PubMed

Teixeira, Liliane Reis; Lowden, Arne; Turte, Samantha Lemos; Nagai, Roberta; Moreno, Claudia Roberta de Castro; Latorre, Maria do Rosário Dias de Oliveira; Fischer, Frida Marina

2007-01-01

The aim of this study was to evaluate patterns of sleepiness, comparing working and non-working students. The study was conducted on high school students attending evening classes (19:00-22:30 h) at a public school in São Paulo, Brazil. The study group consisted of working (n=51) and non-working (n=41) students, aged 14-21 yrs. The students answered a questionnaire about working and living conditions and reported health symptoms and diseases. For seven consecutive days, actigraphy measurements were recorded, and the students also filled in a sleep diary. Sleepiness ratings were given six times per day, including upon waking and at bedtime, using the Karolinska Sleepiness Scale. Statistical analyses included three-way ANOVA and t-test. The mean sleep duration during weekdays was shorter among workers (7.2 h) than non-workers (8.8 h) (t=4.34; p<.01). The mean duration of night awakenings was longer among workers on Tuesdays and Wednesdays (28.2 min) and shorter on Mondays (24.2 min) (t=2.57; p=.03). Among workers, mean napping duration was longer on Mondays and Tuesdays (89.9 min) (t=2.27; p=.03) but shorter on Fridays and Sundays (31.4 min) (t=3.13; p=.03). Sleep efficiency was lower on Fridays among non-workers. Working students were moderately sleepier than non-workers during the week and also during class on specific days: Mondays (13:00-15:00 h), Wednesdays (19:00-22:00 h), and Fridays (22:00-00:59 h). The study found that daytime sleepiness of workers is moderately higher in the evening. This might be due to a work effect, reducing the available time for sleep and shortening the sleep duration. Sleepiness and shorter sleep duration can have a negative impact on the quality of life and school development of high school students.

Short sleep duration among workers--United States, 2010.

PubMed

2012-04-27

Insufficient sleep can have serious and sometimes fatal consequences for fatigued workers and others around them. For example, an estimated 20% of vehicle crashes are linked to drowsy driving. The National Sleep Foundation recommends that healthy adults sleep 7-9 hours per day. To assess the prevalence of short sleep duration among workers, CDC analyzed data from the 2010 National Health Interview Survey (NHIS). The analysis compared sleep duration by age group, race/ethnicity, sex, marital status, education, and employment characteristics. Overall, 30.0% of civilian employed U.S. adults (approximately 40.6 million workers) reported an average sleep duration of ≤6 hours per day. The prevalence of short sleep duration (≤6 hours per day) varied by industry of employment (range: 24.1%-41.6%), with a significantly higher rate of short sleep duration among workers in manufacturing (34.1%) compared with all workers combined. Among all workers, those who usually worked the night shift had a much higher prevalence of short sleep duration (44.0%, representing approximately 2.2 million night shift workers) than those who worked the day shift (28.8%, representing approximately 28.3 million day shift workers). An especially high prevalence of short sleep duration was reported by night shift workers in the transportation and warehousing (69.7%) and health-care and social assistance (52.3%) industries. Targeted interventions, such as evidence-based shift system designs that improve sleep opportunities and evidence-based training programs on sleep and working hours tailored for managers and employees, should be implemented to protect the health and safety of workers, their coworkers, and the public.

The effect of part-time sick leave for employees with mental disorders.

PubMed

Høgelund, Jan; Holm, Anders; Eplov, Lene Falgaard

2012-12-01

Part-time sick leave (PTSL) allows employees on full-time sick leave (FTSL) to resume work at reduced hours. When the partly absent employee's health improves, working hours are increased until the employee is able to work regular hours. Studies have found that PTSL is an effective instrument for reducing sick leave durations for employees with musculoskeletal disorders and for employees on sick leave in general. This is the first published article to document how PTSL affects sick leave durations for employees with mental disorders. The aim is to estimate the effect of PTSL on the duration until returning to regular working hours for employees with mental disorders. We compare this effect to that of PTSL for employees with non-mental disorders ('other disorders'). We use combined survey and register data about 226 employees on long-term sick leave with mental disorders and 638 employees with other disorders. These data contain information about type of disorder, PTSL and FTSL (full-time sick leave) durations, and various background characteristics. We use a mixed proportional hazard regression model that allows us to control for unobserved differences between employees on PTSL and those on FTSL. Our analyses show that PTSL has no effect on the duration until returning to regular working hours for employees with mental disorders. Furthermore, looking at specific disorders such as depression and stress-related conditions, we find no significant effects of PTSL. In contrast, in line with previous research, we find that PTSL significantly reduces the duration until returning to regular working hours for employees with other disorders. The analyses also illustrate the importance of controlling for unobserved differences between employees on PTSL and those on FTSL. Without this control, PTSL significantly reduces the duration until returning to regular working hours. When we control for unobserved characteristics, this effect decreases, and for employees with mental disorders the effect vanishes entirely. The lack of an effect of PTSL for employees with mental disorders needs replication in other studies. If subsequent studies confirm our findings, one should not necessarily conclude that PTSL is an ineffective intervention: PTSL may play a role in combination with other workplace interventions and in combination with person-centred interventions. The study is limited by self-reported data about disorders and a relatively small number of employees with mental disorders. Our findings suggest that while PTSL reduces sick leave durations for employees with other disorders, it does not affect sick leave durations for employees with mental disorders. These results may indicate that PTSL by itself is insufficient for promoting the return to work of employees with mental disorders. Future studies could benefit from larger data sets with disorder information based on medical assessments. In addition to quantitative effect studies, future studies could focus on qualitative workplace mechanisms that may counteract the potential positive effects of PTSL for employees on sick leave with mental disorders.

Holding the baby: early mother-infant contact after childbirth and outcomes.

PubMed

Redshaw, Maggie; Hennegan, Julie; Kruske, Sue

2014-05-01

to describe the timing, type and duration of initial infant contact and associated demographic and clinical factors in addition to investigating the impact of early contact on breastfeeding and maternal health and well being after birth. data from a recent population survey of women birthing in Queensland, Australia were used to describe the nature of the first hold and associated demographic characteristics. Initial comparisons, with subsequent adjustment for type of birthing facility and mode of childbirth, were used to assess associations between timing, type and duration of initial contact and outcomes. Further analyses were conducted to investigate a dose-response relationship between duration of first contact and outcomes. women who had an unassisted vaginal birth held their infant sooner, and for longer than women who had an assisted vaginal birth or caesarean and were more satisfied with their early contact. Multivariate models showed a number of demographic and clinical interventions contributing to timing, duration and type of first contact with type of birthing facility (public/private), area of residence, and assisted birth as prominent factors. For women who had a vaginal birth; early, skin-to-skin, and longer duration of initial contact were associated with high rates of breastfeeding initiation and breastfeeding at discharge, but not breastfeeding at 13 weeks. Some aspects of early contact were associated with improved maternal well being. However, these associations were not found for women who had a caesarean birth. With longer durations of first contact, a dose-response effect was found for breastfeeding. results of the study provide a description of current practice in Queensland, Australia and factors impacting on early contact. For vaginal births, findings add to the evidence in support of early skin-to-skin contact for an extended period. It is suggested that all research in this area should consider the effects of early contact separately for women having vaginal and caesarean births. care providers should consider extending the period of early contact in routine care following vaginal birth and explore the way in which women having a caesarean birth might be better supported in benefitting from early contact with their infant. Copyright © 2014. Published by Elsevier Ltd.

Influence of Boiling Duration of GCSB-5 on Index Compound Content and Antioxidative and Anti-inflammatory Activity.

PubMed

Lee, In-Hee; Chung, Hwa-Jin; Shin, Joon-Shik; Ha, In-Hyuk; Kim, Me-Riong; Koh, Wonil; Lee, Jinho

2017-01-01

GCSB-5, an herbal drug composition with an anti-inflammatory effect, is prepared by boiling, which is the most common herbal extraction method in traditional Korean medicine. Several parameters are involved in the process, i.e., extractant type, herb-to-extractant ratio, extraction temperature and pressure, and total boiling time. The aim of this study was to examine the influence of boiling time on index compound amount and the antioxidative and anti-inflammatory activities of GCSB-5. Different samples of GCSB-5 were obtained by decocting for 30, 60, 90, 120, 150, and 240 min. Each sample was tested for hydrogen ion concentration (pH), total soluble solid content (TSSC), marker compound profiles, and antioxidative and anti-inflammatory activity. pH was found to decrease while TSSC increased with extended decoction. Marker compound contents for GCSB-5 (acanthoside D for Acanthopanax sessiliflorus Seem, 20-hydroxyecdysone for Achyranthes japonica Nakai, and pinoresinol diglucoside for Eucommia ulmoides Oliver) remained relatively constant regardless of the length of boiling. Total D-glucose amount increased with longer boiling. The antioxidative and anti-inflammatory potentials of GCSB-5 were not substantially affected by decoction duration. Biological characteristics and marker compound content of GCSB-5 were not altered significantly in prolonged boiling. Longer boiling duration of GCSB-5 did not increase yield in a time-dependent manner, but yields of 210 and 240 min samples were significantly higherHydrogen ion concentration of GCSB-5 samples decreased while total soluble solid content and D-glucose concentration levels increased with boiling durationAlthough concentrations of some index compounds increased with extended boiling duration of GCSB-5, increase was small and not in a direct proportional relationshipAntioxidative and anti-inflammatory properties of GCSB-5 were not substantially affected by decoction duration. Abbreviations used: CAM: Complementary and alternative medicine; KIOM: Korea Institute of Oriental Medicine; KMD: Korean medicine doctor; TSSC: Total soluble solid content; pH: Hydrogen ion concentration; HPLC: High-performance liquid chromatography; NO: Nitric oxide; NO 2 : Nitric dioxide; LPS: Lipopolysaccharide; DMSO: Dimethyl sulfoxide.

Effect of block weight on work demands and physical workload during masonry work.

PubMed

Van Der Molen, H F; Kuijer, P P F M; Hopmans, P P W; Houweling, A G; Faber, G S; Hoozemans, M J M; Frings-Dresen, M H W

2008-03-01

The effect of block weight on work demands and physical workload was determined for masons who laid sandstone building blocks over the course of a full work day. Three groups of five sandstone block masons participated. Each group worked with a different block weight: 11 kg, 14 kg or 16 kg. Productivity and durations of tasks and activities were assessed through real time observations at the work site. Energetic workload was also assessed through monitoring the heart rate and oxygen consumption at the work site. Spinal load of the low back was estimated by calculating the cumulated elastic energy stored in the lumbar spine using durations of activities and previous data on corresponding compression forces. Block weight had no effect on productivity, duration or frequency of tasks and activities, energetic workload or cumulative spinal load. Working with any of the block weights exceeded exposure guidelines for work demands and physical workload. This implies that, regardless of block weight in the range of 11 to 16 kg, mechanical lifting equipment or devices to adjust work height should be implemented to substantially lower the risk of low back injuries.

Computer work and self-reported variables on anthropometrics, computer usage, work ability, productivity, pain, and physical activity.

PubMed

Madeleine, Pascal; Vangsgaard, Steffen; Hviid Andersen, Johan; Ge, Hong-You; Arendt-Nielsen, Lars

2013-08-01

Computer users often report musculoskeletal complaints and pain in the upper extremities and the neck-shoulder region. However, recent epidemiological studies do not report a relationship between the extent of computer use and work-related musculoskeletal disorders (WMSD).The aim of this study was to conduct an explorative analysis on short and long-term pain complaints and work-related variables in a cohort of Danish computer users. A structured web-based questionnaire including questions related to musculoskeletal pain, anthropometrics, work-related variables, work ability, productivity, health-related parameters, lifestyle variables as well as physical activity during leisure time was designed. Six hundred and ninety office workers completed the questionnaire responding to an announcement posted in a union magazine. The questionnaire outcomes, i.e., pain intensity, duration and locations as well as anthropometrics, work-related variables, work ability, productivity, and level of physical activity, were stratified by gender and correlations were obtained. Women reported higher pain intensity, longer pain duration as well as more locations with pain than men (P < 0.05). In parallel, women scored poorer work ability and ability to fulfil the requirements on productivity than men (P < 0.05). Strong positive correlations were found between pain intensity and pain duration for the forearm, elbow, neck and shoulder (P < 0.001). Moderate negative correlations were seen between pain intensity and work ability/productivity (P < 0.001). The present results provide new key information on pain characteristics in office workers. The differences in pain characteristics, i.e., higher intensity, longer duration and more pain locations as well as poorer work ability reported by women workers relate to their higher risk of contracting WMSD. Overall, this investigation confirmed the complex interplay between anthropometrics, work ability, productivity, and pain perception among computer users.

Military milk: breastfeeding rates among Australian Defence Force women who return to military service following maternity leave.

PubMed

Stewart, Kelley

2015-02-01

The breastfeeding behaviors among Australian Defence Force women have not previously been examined. Studies have shown that breastfeeding prevalence and duration are affected by maternity leave entitlements and returning to work. This study aimed to benchmark breastfeeding initiation, prevalence, and duration among a cohort of Australian Defence Force women and to compare these findings against Australian population norms. A cross-sectional survey was conducted via email in 2008 for Australian Defence Force women who had taken maternity leave in the Australian financial year of 2006/2007. Analysis of breastfeeding indicators was undertaken. Ninety-eight percent of Australian Defence Force women in this cohort initiated breastfeeding and breastfed for a median duration of 8 months, returning to work when the mean age of the child was 8.4 months. Breastfeeding prevalence did not meet 2003 Australian National Health and Medical Research Council targets by 6 months postpartum but compared favorably to the Australian population norms. Sixty-six percent of the respondents returned to work full-time, with a median breastfeeding duration of 7 months. Women who returned to work part-time had a longer median duration of 10 months. Breastfeeding rates among this cohort of Australian Defence Force women compare favorably with the general Australian population until 9 months, coinciding with returning to work after a period of maternity leave. The results support recent Australian population studies on breastfeeding and employment. © The Author(s) 2014.

Linear Array Ultrasonic Testing Of A Thick Concrete Specimens For Non-Destructive Evaluation

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

Clayton, Dwight A.; Khazanovich, Lev; Zammerachi, Mattia

The University of Minnesota and Oak Ridge National Laboratory are collaborating on the design and construction of a concrete specimen with sufficient reinforcement density and cross-sectional size to represent a light water reactor (LWR) containment wall with various defects. The preliminary analysis of the collected data using extended synthetic aperture focussin technique (SAFT) reconstruction indicated a great potential of the ultrasound array technology for locating relatively shallow distresses. However, the resolution and reliability of the analysis is inversely proportional to the defect depth and the amount of reinforcement between the measurement point and the defect location. The objective of thismore » round of testing is to evaluate repeatability of the obtained reconstructions from measurements with different frequencies as well as to examine the effect of the duration of the sending ultrasound signal on the resulting reconstructions. Two series of testing are performed in this study. The objective of the first series is to evaluate repeatability of the measurements and resulting reconstructed images. The measurements use three center frequencies. Five measurements are performed at each location with and without lifting the device. The analysis of the collected data suggested that a linear array ultrasound system can produce reliably repeatable reconstructions using 50 kHz signals for relatively shallow depths (less than 0.5 m). However, for reconstructions at the greater depths the use of lower frequency and/or signal filtering to reduce the effect of signal noise may be required. The objective of the second series of testing is to obtain measurements with various impulse signal durations. The entire grid on the smooth surface is tested with four different various impulse signal durations. An analysis of the resulting extended SAFT reconstructions suggested that Kirchhoff-based migration leads to easier interpreting reconstructions when shorter duration impulse is used. Longer duration impulses may provide useful information for model-based reconstructions.« less

Dose to organs at risk in the upper abdomen in patients treated with extended fields by helical tomotherapy: a dosimetric and clinical preliminary study

PubMed Central

2013-01-01

Background The aim of this work was to determine the technical feasibility and safety of extended-field radiotherapy (EF), performed by Helical TomoTherapy, in patients with positive pelvic and/or para-aortic nodes. Dosimetric data were collected and acute and sub-acute toxicities of the upper abdominal organs at risk (OAR) were evaluated. Methods Twenty-nine patients suitable for EF irradiation for local disease and/or nodal disease in the pelvic or para-aortic area were treated. The prescription dose was 50.4/54 Gy (1.7-1.8 Gy/fraction) for prophylactic lymph nodes (N-) and 60–70.5 Gy (2–2.35 Gy/fraction) for clinically evident gross disease (N+). Modulation factor (MF), pitch and field width (FW) were chosen to optimize dose distribution and treatment duration. Dose values of PTVs and OAR were analysed. The length of the treatment field, the N + and N- volumes, and treatment duration were reported. To evaluate the safety of treatment, haematological, hepatic, renal and pancreatic functions were assessed before, during and after treatment. The median follow-up time was 17.6 months (range: 6–22 months). Results The treatment was well tolerated and all patients but one completed treatment without interruption. Four of the 29 patients experienced G3 haematological acute toxicity (13.8%), but no patient experienced sub-acute grade G3 toxicity. Ten patients experienced G1 and three G2 acute gastrointestinal toxicity (nausea). No sub-acute gastrointestinal or renal toxicity was observed. Only one (3.7%) patient had a persistent slight increase of pancreatic enzymes and two (7.4%) patients a slight increase of hepatic enzymes six months after radiotherapy (G1 toxicity). Conclusions With our treatment design and dose regimen, we found that EF treatment by TomoTherapy could be safely and effectively delivered with minimal acute and sub-acute toxicities in the upper abdomen area. PMID:24160769

Dose to organs at risk in the upper abdomen in patients treated with extended fields by helical tomotherapy: a dosimetric and clinical preliminary study.

PubMed

Bresciani, Sara; Garibaldi, Elisabetta; Cattari, Gabriella; Maggio, Angelo; Di Dia, Amalia; Delmastro, Elena; Gabriele, Domenico; Stasi, Michele; Gabriele, Pietro

2013-10-25

The aim of this work was to determine the technical feasibility and safety of extended-field radiotherapy (EF), performed by Helical TomoTherapy, in patients with positive pelvic and/or para-aortic nodes. Dosimetric data were collected and acute and sub-acute toxicities of the upper abdominal organs at risk (OAR) were evaluated. Twenty-nine patients suitable for EF irradiation for local disease and/or nodal disease in the pelvic or para-aortic area were treated. The prescription dose was 50.4/54 Gy (1.7-1.8 Gy/fraction) for prophylactic lymph nodes (N-) and 60-70.5 Gy (2-2.35 Gy/fraction) for clinically evident gross disease (N+). Modulation factor (MF), pitch and field width (FW) were chosen to optimize dose distribution and treatment duration. Dose values of PTVs and OAR were analysed. The length of the treatment field, the N + and N- volumes, and treatment duration were reported. To evaluate the safety of treatment, haematological, hepatic, renal and pancreatic functions were assessed before, during and after treatment. The median follow-up time was 17.6 months (range: 6-22 months). The treatment was well tolerated and all patients but one completed treatment without interruption. Four of the 29 patients experienced G3 haematological acute toxicity (13.8%), but no patient experienced sub-acute grade G3 toxicity. Ten patients experienced G1 and three G2 acute gastrointestinal toxicity (nausea). No sub-acute gastrointestinal or renal toxicity was observed. Only one (3.7%) patient had a persistent slight increase of pancreatic enzymes and two (7.4%) patients a slight increase of hepatic enzymes six months after radiotherapy (G1 toxicity). With our treatment design and dose regimen, we found that EF treatment by TomoTherapy could be safely and effectively delivered with minimal acute and sub-acute toxicities in the upper abdomen area.

12 CFR 403.5 - Declassification and downgrading.

Code of Federal Regulations, 2012 CFR

2012-01-01

... classification markings shall be lined through a statement placed on the cover or first page to indicate the... markings on each page shall be cancelled; otherwise, the statement on the cover or first page shall... taken earlier than originally scheduled, or the duration of classification is extended, the authority...

12 CFR 403.5 - Declassification and downgrading.

Code of Federal Regulations, 2011 CFR

2011-01-01

... classification markings shall be lined through a statement placed on the cover or first page to indicate the... markings on each page shall be cancelled; otherwise, the statement on the cover or first page shall... taken earlier than originally scheduled, or the duration of classification is extended, the authority...

43 CFR 17.204 - Assurances required.

Code of Federal Regulations, 2010 CFR

2010-10-01

... subsequent applications to the Department. (b) Duration of obligation. (1) In the case of Federal financial assistance extended in the form of real property or to provide real property or structures on the property..., for the period during which the real property or structures are used for the purpose for which Federal...

43 CFR 17.204 - Assurances required.

Code of Federal Regulations, 2011 CFR

2011-10-01

... subsequent applications to the Department. (b) Duration of obligation. (1) In the case of Federal financial assistance extended in the form of real property or to provide real property or structures on the property..., for the period during which the real property or structures are used for the purpose for which Federal...

46 CFR 25.26-1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... preparation and extended storage of food. This does not include small alcohol or propane stoves with limited cooking capability, or ice chests or similar devices that are intended for keeping small quantities of food for short durations. High seas means the waters beyond a line three nautical miles seaward of the...

20 CFR 336.4 - Base year compensation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Base year compensation. 336.4 Section 336.4... DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.4 Base year compensation. (a) Formula. For the purposes of this part, an employee's base year compensation includes any compensation in excess of...

20 CFR 336.4 - Base year compensation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Base year compensation. 336.4 Section 336.4... DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.4 Base year compensation. (a) Formula. For the purposes of this part, an employee's base year compensation includes any compensation in excess of...

20 CFR 336.4 - Base year compensation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Base year compensation. 336.4 Section 336.4... DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.4 Base year compensation. (a) Formula. For the purposes of this part, an employee's base year compensation includes any compensation in excess of...

Maximizing adhesion of auxin solutions to stem cuttings using sodium cellulose glycolate

USDA-ARS?s Scientific Manuscript database

Auxin solutions prepared with sodium cellulose glycolate (SCG; a thickening agent, also known as sodium carboxymethylcellulose) and applied to stem cuttings using a basal quick-dip extend the duration of exposure of cuttings to the auxin and have previously been shown to increase root number and/or ...

20 CFR 336.4 - Base year compensation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Base year compensation. 336.4 Section 336.4... DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.4 Base year compensation. (a) Formula. For the purposes of this part, an employee's base year compensation includes any compensation in excess of...

76 FR 77260 - Proposed Information Collection Request (ICR) for the Evaluation of the Unemployment Compensation...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-12

... Unemployment Compensation Provisions of the American Recovery and Reinvestment Act of 2009; Comment Request... major challenges for the U.S. system of unemployment compensation (UC). For example, sharply increasing lengths of unemployment spells prompted Federal legislation that extended the potential duration of UC...

Neural substrates of smoking cue reactivity: A meta-analysis of fMRI studies

PubMed Central

Engelmann, Jeffrey M.; Versace, Francesco; Robinson, Jason D.; Minnix, Jennifer A.; Lam, Cho Y.; Cui, Yong; Brown, Victoria L.; Cinciripini, Paul M.

2012-01-01

Reactivity to smoking-related cues may be an important factor that precipitates relapse in smokers who are trying to quit. The neurobiology of smoking cue reactivity has been investigated in several fMRI studies. We combined the results of these studies using activation likelihood estimation, a meta-analytic technique for fMRI data. Results of the meta-analysis indicated that smoking cues reliably evoke larger fMRI responses than neutral cues in the extended visual system, precuneus, posterior cingulate gyrus, anterior cingulate gyrus, dorsal and medial prefrontal cortex, insula, and dorsal striatum. Subtraction meta-analyses revealed that parts of the extended visual system and dorsal prefrontal cortex are more reliably responsive to smoking cues in deprived smokers than in non-deprived smokers, and that short-duration cues presented in event-related designs produce larger responses in the extended visual system than long-duration cues presented in blocked designs. The areas that were found to be responsive to smoking cues agree with theories of the neurobiology of cue reactivity, with two exceptions. First, there was a reliable cue reactivity effect in the precuneus, which is not typically considered a brain region important to addiction. Second, we found no significant effect in the nucleus accumbens, an area that plays a critical role in addiction, but this effect may have been due to technical difficulties associated with measuring fMRI data in that region. The results of this meta-analysis suggest that the extended visual system should receive more attention in future studies of smoking cue reactivity. PMID:22206965

Impact of Common Diabetes Risk Variant in MTNR1B on Sleep, Circadian, and Melatonin Physiology.

PubMed

Lane, Jacqueline M; Chang, Anne-Marie; Bjonnes, Andrew C; Aeschbach, Daniel; Anderson, Clare; Cade, Brian E; Cain, Sean W; Czeisler, Charles A; Gharib, Sina A; Gooley, Joshua J; Gottlieb, Daniel J; Grant, Struan F A; Klerman, Elizabeth B; Lauderdale, Diane S; Lockley, Steven W; Munch, Miriam; Patel, Sanjay; Punjabi, Naresh M; Rajaratnam, Shanthakumar M W; Rueger, Melanie; St Hilaire, Melissa A; Santhi, Nayantara; Scheuermaier, Karin; Van Reen, Eliza; Zee, Phyllis C; Shea, Steven A; Duffy, Jeanne F; Buxton, Orfeu M; Redline, Susan; Scheer, Frank A J L; Saxena, Richa

2016-06-01

The risk of type 2 diabetes (T2D) is increased by abnormalities in sleep quantity and quality, circadian alignment, and melatonin regulation. A common genetic variant in a receptor for the circadian-regulated hormone melatonin (MTNR1B) is associated with increased fasting blood glucose and risk of T2D, but whether sleep or circadian disruption mediates this risk is unknown. We aimed to test if MTNR1B diabetes risk variant rs10830963 associates with measures of sleep or circadian physiology in intensive in-laboratory protocols (n = 58-96) or cross-sectional studies with sleep quantity and quality and timing measures from self-report (n = 4,307-10,332), actigraphy (n = 1,513), or polysomnography (n = 3,021). In the in-laboratory studies, we found a significant association with a substantially longer duration of elevated melatonin levels (41 min) and delayed circadian phase of dim-light melatonin offset (1.37 h), partially mediated through delayed offset of melatonin synthesis. Furthermore, increased T2D risk in MTNR1B risk allele carriers was more pronounced in early risers versus late risers as determined by 7 days of actigraphy. Our results provide the surprising insight that the MTNR1B risk allele influences dynamics of melatonin secretion, generating a novel hypothesis that the MTNR1B risk allele may extend the duration of endogenous melatonin production later into the morning and that early waking may magnify the diabetes risk conferred by the risk allele. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Fatigue-Related Countermeasures for Long-Duration Exploration Missions

NASA Technical Reports Server (NTRS)

Whitmire, A.; Johnston, S.; Sipes, W.

2014-01-01

The NASA Human Research Program's (HRP) Behavioral Health and Performance Element (BHP) supports and conducts research to mitigate deleterious outcomes related to fatigue, sleep loss, circadian desynchronization, and work overload. Objective evidence indicates that within the context of the International Space Station (ISS), sleep is reduced and there is circadian misalignment. Despite chronic sleep loss and high workloads; however, astronauts successfully complete their missions. Contributing to their success is not only the tremendous skills and capabilities of each astronaut, but also the collaborative team efforts amongst the crew, between flight and ground crews, and through real-time care provided by medical personnel. It is anticipated that risks to human health and performance will increase in the context of exploration missions, where crewmembers will venture to deep space for extended durations and in small vehicles with limited communication with home. Hence, fatigue-related countermeasures are being developed and/or validated that include unobtrusive monitoring technologies to detect fatigue-related performance decrements, environmental countermeasures, and sleep education and training for flight and ground crews. Given that fatigue is an issue in current ISS missions, the BHP works collaboratively with Space Medicine operations to collect data in the operational environment, to validate fatigue-related countermeasures, and provide evidence-based mitigations. Our presentation will summarize fatigue-related operational research that is underway through NASA's BHP in partnership with its operational counterparts. Efforts include studies evaluating the effects of hypnotics, lighting protocols as countermeasures for circadian entrainment, and investigations involving education and training. This presentation will further identify, based on flight and terrestrial evidence, additional sleep and circadian countermeasures that may still be needed to support exploration missions. Lessons learned from transitioning research deliverables into ISS operations will also be discussed.

Cyclo-, magneto-, and bio-stratigraphic constraints on the duration of the CAMP event and its relationship to the Triassic-Jurassic boundary

NASA Astrophysics Data System (ADS)

Olsen, Paul E.; Kent, Dennis V.; Et-Touhami, Mohammed; Puffer, John

Early Mesozoic tholeiitic flood basalts of the Central Atlantic Magmatic Province (CAMP) are interbedded throughout much of their extent with cyclical lacustrine strata, allowing Milankovitch calibration of the duration of the extrusive episode. This cyclostratigraphy extends from the Newark basin of the northeastern US, where it was first worked out, to Nova Scotia and Morocco and constrains the outcropping extrusive event to less than 600 ky in duration, beginning roughly 20 ky after the Triassic-Jurassic boundary, and to within one pollen and spore zone and one vertebrate biochron. Based principally on the well-known Newark astronomically calibrated magnetic polarity time scale with new additions from the Hartford basin, the rather large scatter in recent radiometric dates from across CAMP (>10 m.y. ), centering on about ˜200 m.y., is not likely to be real. Rather, the existing paleomagnetic data from both intrusive and extrusive rocks suggest emplacement of nearly all the CAMP within less than 3 m.y. of nearly entirely normal polarity. The very few examples of reversed magnetizations suggest that some CAMP activity probably occurred just prior to the Triassic-Jurassic boundary. Published paleomagnetic and 40Ar/39Ar data from the Clubhouse Crossroads Basalt are reviewed and with new paleomagnetic data suggest that alteration and possible core misorientation could be responsible for the apparent differences with the CAMP. The Clubhouse Crossroads Basalt at the base of the Coastal Plain of South Carolina and Georgia provides a link to the volumetrically massive volcanic wedge of seaward dipping reflectors present in the subsurface off the southeastern US that may be part of the same igneous event, suggesting that the CAMP marks the formation of the oldest Atlantic oceanic crust.

Spatio-temporal correlations in the Manna model in one, three and five dimensions

NASA Astrophysics Data System (ADS)

Willis, Gary; Pruessner, Gunnar

2018-02-01

Although the paradigm of criticality is centered around spatial correlations and their anomalous scaling, not many studies of self-organized criticality (SOC) focus on spatial correlations. Often, integrated observables, such as avalanche size and duration, are used, not least as to avoid complications due to the unavoidable lack of translational invariance. The present work is a survey of spatio-temporal correlation functions in the Manna Model of SOC, measured numerically in detail in d = 1,3 and 5 dimensions and compared to theoretical results, in particular relating them to “integrated” observables such as avalanche size and duration scaling, that measure them indirectly. Contrary to the notion held by some of SOC models organizing into a critical state by re-arranging their spatial structure avalanche by avalanche, which may be expected to result in large, nontrivial, system-spanning spatial correlations in the quiescent state (between avalanches), correlations of inactive particles in the quiescent state have a small amplitude that does not and cannot increase with the system size, although they display (noisy) power law scaling over a range linear in the system size. Self-organization, however, does take place as the (one-point) density of inactive particles organizes into a particular profile that is asymptotically independent of the driving location, also demonstrated analytically in one dimension. Activity and its correlations, on the other hand, display nontrivial long-ranged spatio-temporal scaling with exponents that can be related to established results, in particular avalanche size and duration exponents. The correlation length and amplitude are set by the system size (confirmed analytically for some observables), as expected in systems displaying finite size scaling. In one dimension, we find some surprising inconsistencies of the dynamical exponent. A (spatially extended) mean field theory (MFT) is recovered, with some corrections, in five dimensions.

Surface modification of mixed-phase hydrogenated TiO2 and corresponding photocatalytic response

NASA Astrophysics Data System (ADS)

Samsudin, Emy Marlina; Hamid, Sharifah Bee Abd; Juan, Joon Ching; Basirun, Wan Jefrey; Kandjani, Ahmad Esmaielzadeh

2015-12-01

Preparation of highly photo-activated TiO2 is achievable by hydrogenation at constant temperature and pressure, with controlled hydrogenation duration. The formation of surface disorders and Ti3+ is responsible for the color change from white unhydrogenated TiO2 to bluish-gray hydrogenated TiO2. This color change, together with increased oxygen vacancies and Ti3+ enhanced the solar light absorption from UV to infra-red region. Interestingly, no band gap narrowing is observed. The photocatalytic activity in the UV and visible region is controlled by Ti3+ and oxygen vacancies respectively. Both Ti3+ and oxygen vacancies increases the electron density on the catalyst surface thus facilitates rad OH radicals formation. The lifespan of surface photo-excited electrons and holes are also sustained thus prevents charge carrier recombination. However, excessive amount of oxygen vacancies deteriorates the photocatalytic activity as it serves as charge traps. Hydrogenation of TiO2 also promotes the growth of active {0 0 1} facets and facilitates the photocatalytic activity by higher concentration of surface OH radicals. However, the growth of {0 0 1} facets is small and insignificant toward the overall photo-kinetics. This work also shows that larger role is played by Ti3+ and oxygen vacancies rather than the surface disorders created during the hydrogenation process. It also demonstrates the ability of hydrogenated TiO2 to absorb wider range of photons even though at a similar band gap as unhydrogenated TiO2. In addition, the photocatalytic activity is shown to be decreased for extended hydrogenation duration due to excessive catalyst growth and loss in the total surface area. Thus, a balance in the physico-chemical properties of hydrogenated TiO2 is crucial to enhance the photocatalytic activity by simply controlling the hydrogenation duration.

Loss of ability to work and ability to live independently in Parkinson's disease.

PubMed

Jasinska-Myga, Barbara; Heckman, Michael G; Wider, Christian; Putzke, John D; Wszolek, Zbigniew K; Uitti, Ryan J

2012-02-01

Ability to work and live independently is of particular concern for patients with Parkinson's disease (PD). We studied a series of PD patients able to work or live independently at baseline, and evaluated potential risk factors for two separate outcomes: loss of ability to work and loss of ability to live independently. The series comprised 495 PD patients followed prospectively. Ability to work and ability to live independently were based on clinical interview and examination. Cox regression models adjusted for age and disease duration were used to evaluate associations of baseline characteristics with loss of ability to work and loss of ability to live independently. Higher UPDRS dyskinesia score, UPDRS instability score, UPDRS total score, Hoehn and Yahr stage, and presence of intellectual impairment at baseline were all associated with increased risk of future loss of ability to work and loss of ability to live independently (P ≤ 0.0033). Five years after initial visit, for patients ≤70 years of age with a disease duration ≤4 years at initial visit, 88% were still able to work and 90% to live independently. These estimates worsened as age and disease duration at initial visit increased; for patients >70 years of age with a disease duration >4 years, estimates at 5 years were 43% able to work and 57% able to live independently. The information provided in this study can offer useful information for PD patients in preparing for future ability to perform activities of daily living. Copyright © 2011 Elsevier Ltd. All rights reserved.

On-the-job moms: work and breastfeeding initiation and duration for a sample of low-income women.

PubMed

Kimbro, Rachel Tolbert

2006-01-01

As both employed and breastfeeding mothers increase, more women are facing the decision of whether and how to combine the behaviors. This paper examines three hypotheses for a sample of low-income women: 1) Mothers who expect to return to work after the birth of their baby will be less likely to initiate breastfeeding; 2) The timing of the return to work and quitting breastfeeding will coincide; 3) Mothers in professional jobs and Stay-at-Home (SAH) Moms will breastfeed for longer durations than mothers with other types of jobs. The Fragile Families and Child Wellbeing Study, a sample of mostly low-income, unmarried U.S. mothers, offers a unique opportunity to study this issue, as there is reason to believe that employment may impact breastfeeding differently for low-income women. Logistic regression determines the relationship between the expectation of work and breastfeeding initiation, and discrete-time logit models examine breastfeeding duration, the timing of the return to work, and occupation type. Expecting to work in the year after the baby's birth does not impact breastfeeding initiation. The timing of quitting breastfeeding and the return to work are closely and powerfully linked, and mothers in administrative and manual positions quit earlier than other women. Interestingly, women in service occupations do not differ in breastfeeding duration from SAH mothers or professionals. This research demonstrates that low-income women are having difficulty combining work and breastfeeding, which has important health implications for their infants, and that women working in administrative and manual occupations may face special constraints.

Duration analysis using matching pursuit algorithm reveals longer bouts of gamma rhythm.

PubMed

Chandran Ks, Subhash; Seelamantula, Chandra Sekhar; Ray, Supratim

2018-03-01

The gamma rhythm (30-80 Hz), often associated with high-level cortical functions, is believed to provide a temporal reference frame for spiking activity, for which it should have a stable center frequency and linear phase for an extended duration. However, recent studies that have estimated the power and phase of gamma as a function of time suggest that gamma occurs in short bursts and lacks the temporal structure required to act as a reference frame. Here, we show that the bursty appearance of gamma arises from the variability in the spectral estimator used in these studies. To overcome this problem, we use another duration estimator based on a matching pursuit algorithm that robustly estimates the duration of gamma in simulated data. Applying this algorithm to gamma oscillations recorded from implanted microelectrodes in the primary visual cortex of awake monkeys, we show that the median gamma duration is greater than 300 ms, which is three times longer than previously reported values. NEW & NOTEWORTHY Gamma oscillations (30-80 Hz) have been hypothesized to provide a temporal reference frame for coordination of spiking activity, but recent studies have shown that gamma occurs in very short bursts. We show that existing techniques have severely underestimated the rhythm duration, use a technique based on the Matching Pursuit algorithm, which provides a robust estimate of the duration, and show that the median duration of gamma is greater than 300 ms, much longer than previous estimates.

Duration analysis using matching pursuit algorithm reveals longer bouts of gamma rhythm

PubMed Central

Chandran KS, Subhash; Seelamantula, Chandra Sekhar

2018-01-01

The gamma rhythm (30–80 Hz), often associated with high-level cortical functions, is believed to provide a temporal reference frame for spiking activity, for which it should have a stable center frequency and linear phase for an extended duration. However, recent studies that have estimated the power and phase of gamma as a function of time suggest that gamma occurs in short bursts and lacks the temporal structure required to act as a reference frame. Here, we show that the bursty appearance of gamma arises from the variability in the spectral estimator used in these studies. To overcome this problem, we use another duration estimator based on a matching pursuit algorithm that robustly estimates the duration of gamma in simulated data. Applying this algorithm to gamma oscillations recorded from implanted microelectrodes in the primary visual cortex of awake monkeys, we show that the median gamma duration is greater than 300 ms, which is three times longer than previously reported values. NEW & NOTEWORTHY Gamma oscillations (30–80 Hz) have been hypothesized to provide a temporal reference frame for coordination of spiking activity, but recent studies have shown that gamma occurs in very short bursts. We show that existing techniques have severely underestimated the rhythm duration, use a technique based on the Matching Pursuit algorithm, which provides a robust estimate of the duration, and show that the median duration of gamma is greater than 300 ms, much longer than previous estimates. PMID:29118193

Higher education delays and shortens cognitive impairment: a multistate life table analysis of the US Health and Retirement Study.

PubMed

Reuser, Mieke; Willekens, Frans J; Bonneux, Luc

2011-05-01

Improved health may extend or shorten the duration of cognitive impairment by postponing incidence or death. We assess the duration of cognitive impairment in the US Health and Retirement Study (1992-2004) by self reported BMI, smoking and levels of education in men and women and three ethnic groups. We define multistate life tables by the transition rates to cognitive impairment, recovery and death and estimate Cox proportional hazard ratios for the studied determinants. 95% confidence intervals are obtained by bootstrapping. 55 year old white men and women expect to live 25.4 and 30.0 years, of which 1.7 [95% confidence intervals 1.5; 1.9] years and 2.7 [2.4; 2.9] years with cognitive impairment. Both black men and women live 3.7 [2.9; 4.5] years longer with cognitive impairment than whites, Hispanic men and women 3.2 [1.9; 4.6] and 5.8 [4.2; 7.5] years. BMI makes no difference. Smoking decreases the duration of cognitive impairment with 0.8 [0.4; 1.3] years by high mortality. Highly educated men and women live longer, but 1.6 years [1.1; 2.2] and 1.9 years [1.6; 2.6] shorter with cognitive impairment than lowly educated men and women. The effect of education is more pronounced among ethnic minorities. Higher life expectancy goes together with a longer period of cognitive impairment, but not for higher levels of education: that extends life in good cognitive health but shortens the period of cognitive impairment. The increased duration of cognitive impairment in minority ethnic groups needs further study, also in Europe.

Frequency and characteristics of infections caused by extended-spectrum beta-lactamase-producing organisms in neonates: a prospective cohort study.

PubMed

Vijayakanthi, Nandini; Bahl, Dheeraj; Kaur, Nirmaljit; Maria, Arti; Dubey, Nand Kishore

2013-01-01

This prospective cohort study was conducted to determine the frequency of infections caused by extended-spectrum beta-lactamase- (ESBL-) producing organisms, various bacteria producing ESBL, antibiotic susceptibility of these organisms, and the risk factors associated with these infections in a neonatal intensive care unit in a tertiary care hospital in North India. Of the 150 neonates enrolled in the study, 47 culture-positive neonates were included in the study cohort and were divided into two groups: ESBL-positive (8 neonates) and ESBL-negative (39 neonates) cohorts. Various organisms were isolated from 72 culture samples in these 47 neonates. Of these, 10 culture samples grew ESBL-positive organisms and 62 samples grew ESBL-negative organisms. The frequency of ESBL-producing organisms was found to be 5.3%. ESBL infection incidence densities were found to be 3.4 per 1000 patient-days. Klebsiella (60%) was the most common organism producing ESBL followed by Escherichia coli (30%) and Pseudomonas (10%). Eighty percent of the ESBL-producing organisms were sensitive to piperacillin-tazobactam. Risk factors found significant by univariate analysis (P < 0.05) were preterm, low birthweight, perinatal asphyxia, respiratory distress syndrome, anaemia, metabolic acidosis, prolonged mechanical ventilation (>7 days), length of hospitalization, length of level 3 stay, prior antibiotic use, central venous catheter duration, peripherally inserted central venous catheter duration, and total parenteral nutrition duration. Factors that retained significance in the logistic regression model were duration of hospital stay (adjusted OR: 0.958, CI: 0.920-0.997, and P value = 0.037) and gestational age (adjusted OR: 1.39, CI: 1.037-1.865, and P value = 0.028). There was no significant difference in the mortality between the two groups.

Optimal future liver remnant in patients treated with extensive preoperative chemotherapy for colorectal liver metastases.

PubMed

Shindoh, Junichi; Tzeng, Ching-Wei D; Aloia, Thomas A; Curley, Steven A; Zimmitti, Giuseppe; Wei, Steven H; Huang, Steven Y; Mahvash, Armeen; Gupta, Sanjay; Wallace, Michael J; Vauthey, Jean-Nicolas

2013-08-01

Patients with colorectal liver metastases (CLM) are increasingly treated with preoperative chemotherapy. Chemotherapy associated liver injury is associated with postoperative hepatic insufficiency (PHI) and mortality. The adequate minimum future liver remnant (FLR) volume in patients treated with extensive chemotherapy remains unknown. All patients with standardized FLR > 20 %, who underwent extended right hepatectomy for CLM from 1993-2011, were divided into three cohorts by chemotherapy duration: no chemotherapy (NC, n = 30), short duration (SD, ≤12 weeks, n = 78), long duration (LD, >12 weeks, n = 86). PHI and mortality were compared by using uni-/multivariate analyses. Optimal FLR for LD chemotherapy was determined using a minimum p-value approach. A total of 194 patients met inclusion criteria. LD chemotherapy was significantly associated with PHI (NC + SD 3.7 vs. LD 16.3%, p = 0.006). Ninety-day mortality rates were 0 % in NC, 1.3 % in SD, and 2.3% in LD patients, respectively (p = 0.95). In patients with FLR > 30 %, PHI occurred in only two patients (both LD, 2/20, 10 %), but all patients with FLR > 30 % survived. The best cutoff of FLR for preventing PHI after chemotherapy >12 weeks was estimated as >30 %. Both LD chemotherapy (odds ratio [OR] 5.4, p = 0.004) and FLR ≤ 30 % (OR 6.3, p = 0.019) were independent predictors of PHI. Preoperative chemotherapy >12 weeks increases the risk of PHI after extended right hepatectomy. In patients treated with long-duration chemotherapy, FLR > 30 % reduces the rate of PHI and may provide enough functional reserve for clinical rescue if PHI develops.

The lowest-dose, extended-cycle combined oral contraceptive pill with continuous ethinyl estradiol in the United States: a review of the literature on ethinyl estradiol 20 μg/levonorgestrel 100 μg + ethinyl estradiol 10 μg.

PubMed

Krishnan, Sheila; Kiley, Jessica

2010-08-10

Extended-cycle oral contraceptives (OCs) are increasing in popularity in the United States. A new extended-cycle OC that contains the lowest doses of ethinyl estradiol (EE) and levonorgestrel (LNG) + continuous EE throughout the cycle is now available. It provides 84 days of a low-dose, combined active pill containing levonorgestrel 100 μg and ethinyl estradiol 20 μg. Instead of 7 days of placebo following the active pills, the regimen delivers 7 days of ethinyl estradiol 10 μg. Existing studies reveal a similar efficacy and adverse effect profile compared with other extended-regimen OCs. Specifically, the unscheduled bleeding profile is similar to other extended-cycle OCs and improves with the increase in the duration of use. Although lower daily doses of hormonal exposure have potential benefit, to our knowledge, there are no published studies indicating that this specific regimen offers a lower incidence of hormone-related side effects or adverse events. In summary, this new extended-cycle OC provides patients a low-dose, extended-regimen OC option without sacrificing efficacy or tolerability.

Effects of the Workplace Health Promotion Activities Soccer and Zumba on Muscle Pain, Work Ability and Perceived Physical Exertion among Female Hospital Employees.

PubMed

Barene, Svein; Krustrup, Peter; Holtermann, Andreas

2014-01-01

This 40-week workplace physical training RCT investigated the effect of soccer and Zumba, respectively, on muscle pain intensity and duration, work ability, and rating of perceived exertion (RPE) during work among female hospital employees. 107 hospital employees were cluster-randomized into two training groups, and a control group. The training was conducted outside working hours as two-three 1-h sessions per week for the first 12 weeks, and continued as one-two 1-h sessions per week for the last 28 weeks. Muscle pain intensity and duration, work ability, and RPE during work were measured at baseline and after 12 and 40 weeks. After 12 weeks, both the soccer (-1.9, 95% CI, -3.0, -0.8, P = 0.001) and the Zumba group (-1.3, 95% CI, -2.3, -0.3, P = 0.01) reduced the pain intensity (on a scale from 0 to 10) in the neck-shoulder region (eta squared = 0.109), whereas only the soccer group (-1.9, 95% CI, -3.2, -0.7, P = 0.002, eta squared = 0.092) showed a reduction after 40 weeks referencing the control group. After 40 weeks, both the soccer (-16.4 days, 95% CI, -29.6, -3.2, P<0.02) and the Zumba group (-16.6 days, 95% CI, -28.9, -4.2, P<0.01) reduced the pain duration during the past 3 months in the neck-shoulder region (eta squared = 0.077). No significant effects on intensity or duration of pain in the lower back, RPE during work or work ability were found. The present study indicates that workplace initiated soccer and Zumba training improve neck-shoulder pain intensity as well as duration among female hospital employees. International Standard Randomized Controlled Trial Number Register ISRCTN 61986892.

Effects of the Workplace Health Promotion Activities Soccer and Zumba on Muscle Pain, Work Ability and Perceived Physical Exertion among Female Hospital Employees

PubMed Central

Barene, Svein; Krustrup, Peter; Holtermann, Andreas

2014-01-01

Objectives This 40-week workplace physical training RCT investigated the effect of soccer and Zumba, respectively, on muscle pain intensity and duration, work ability, and rating of perceived exertion (RPE) during work among female hospital employees. Methods 107 hospital employees were cluster-randomized into two training groups, and a control group. The training was conducted outside working hours as two-three 1-h sessions per week for the first 12 weeks, and continued as one-two 1-h sessions per week for the last 28 weeks. Muscle pain intensity and duration, work ability, and RPE during work were measured at baseline and after 12 and 40 weeks. Results After 12 weeks, both the soccer (−1.9, 95% CI, −3.0, −0.8, P = 0.001) and the Zumba group (−1.3, 95% CI, −2.3, −0.3, P = 0.01) reduced the pain intensity (on a scale from 0 to 10) in the neck-shoulder region (eta squared = 0.109), whereas only the soccer group (−1.9, 95% CI, −3.2, −0.7, P = 0.002, eta squared = 0.092) showed a reduction after 40 weeks referencing the control group. After 40 weeks, both the soccer (-16.4 days, 95% CI, −29.6, −3.2, P<0.02) and the Zumba group (-16.6 days, 95% CI, −28.9, −4.2, P<0.01) reduced the pain duration during the past 3 months in the neck-shoulder region (eta squared = 0.077). No significant effects on intensity or duration of pain in the lower back, RPE during work or work ability were found. Conclusions The present study indicates that workplace initiated soccer and Zumba training improve neck-shoulder pain intensity as well as duration among female hospital employees. Trial Registration International Standard Randomized Controlled Trial Number Register ISRCTN 61986892. PMID:25494175

Disability and sleep duration: evidence from the American Time Use Survey.

PubMed

Shandra, Carrie L; Kruger, Allison; Hale, Lauren

2014-07-01

Regular short and long sleep durations are associated with increased mortality and morbidity. While previous research shows significant sleep disparities between people with and without disabilities, less is known about the association between different types of disability and high-risk sleep using nationally representative data. We examine the association between short and long sleep durations and having a work disability or an impairment in sensory, cognitive, or physical functioning among a nationally representative sample of working-age adults in the United States. We estimate multinomial logistic regression models using data from the 2003-2012 American Time Use Survey to identify how different types of disabling conditions--net of other sociodemographic factors--relate to the likelihood of reporting short (6 h or fewer) or long (9 h or more) sleep, versus mid-range (between 6 and 9 h) sleep. For respondents with work disabilities versus those without work disabilities, the relative risk of short and long sleep is 1.4 and 1.5 times (respectively) that of those with mid-range sleep. The risk of short and long sleep durations is also higher among respondents with cognitive, physical, or multiple impairments. Individuals with disabilities are less likely than those without disabilities to have optimal sleep durations. These results demonstrate the importance of health promotion services among this population, with specific attention to sleep hygiene interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

Enhancing the Meaningfulness of Work for Astronauts on Long Duration Space Exploration Missions.

PubMed

Britt, Thomas W; Sytine, Anton; Brady, Ashley; Wilkes, Russ; Pittman, Rebecca; Jennings, Kristen; Goguen, Kandice

2017-08-01

Numerous authors have identified the stressors likely to be encountered on long duration space exploration missions (e.g., to Mars), including the possibility of significant crises, separation from family, boredom/monotony, and interpersonal conflict. Although many authors have noted that meaningful work may be beneficial for astronauts on these missions, none have detailed the sources of meaningful work for astronauts and how these sources may differ between astronauts. The present article identifies how engagement in meaningful work during long duration missions may mitigate the adverse effects of demands and increase the potential for benefits resulting from the missions. Semistructured interviews were conducted with nine NASA personnel, including astronauts, flight directors, and flight surgeons. Questions addressed sources of meaning for astronauts, characteristics of tasks that enhance vs. detract from meaning, and recommendations for enhancing meaning. Personnel mentioned contributing to humanity and the next generation, contributing to the mission, and exploration as the most meaningful aspects of their work. Characteristics of tasks that enhanced meaning included using a variety of skills, feeling personal control over their schedule, autonomy in the execution of tasks, and understanding the importance of the experiments conducted on the mission. Top recommendations to sustain meaning were insuring social needs were met through such activities as the strategic use of social media, giving astronauts autonomy as well as structure, and conducting training during transit. Implications are addressed for tailoring meaning-based interventions for astronauts participating on long duration missions and assessing the effectiveness of these interventions.Britt TW, Sytine A, Brady A, Wilkes R, Pittman R, Jennings K, Goguen K. Enhancing the meaningfulness of work for astronauts on long duration space exploration missions. Aerosp Med Hum Perform. 2017; 88(8):779-783.

Walking to work in Canada: health benefits, socio-economic characteristics and urban-regional variations.

PubMed

Kitchen, Peter; Williams, Allison; Chowhan, James

2011-04-04

There is mounting concern over increasing rates of physical inactivity and overweight/obesity among children and adult in Canada. There is a clear link between the amount of walking a person does and his or her health. The purpose of this paper is to assess the health factors, socio-economic characteristics and urban-regional variations of walking to work among adults in Canada. Data is drawn from two cycles of the Canadian Community Health Survey: 2001 and 2005. The study population is divided into three groups: non-walkers, lower-duration walkers and high-duration walkers. Logistic regression modeling tests the association between levels of walking and health related outcomes (diabetes, high blood pressure, stress, BMI, physical activity), socio-economic characteristics (sex, age, income, education) and place of residence (selected Census Metropolitan Areas). In 2005, the presence of diabetes and high blood pressure was not associated with any form of walking. Adults within the normal weight range were more likely to be high-duration walkers. Females and younger people were more likely to be lower-duration walkers but less likely to be high-duration walkers. There was a strong association between SES (particularly relative disadvantage) and walking to work. In both 2001 and 2005, the conditions influencing walking to work were especially prevalent in Canada's largest city, Toronto, as well as in several small to medium sized urban areas including Halifax, Kingston, Hamilton, Regina, Calgary and Victoria. A number of strategies can be followed to increase levels of walking in Canada. It is clear that for many people walking to work is not possible. However, strategies can be developed to encourage adults to incorporate walking into their daily work and commuting routines. These include mass transit walking and workplace walking programs.

Effectiveness of glucose-methanol extender for cryopreservation of Huso huso spermatozoa.

PubMed

Aramli, Mohammad Sadegh; Golshahi, Karim; Nazari, Rajab Mohammad; Aramli, Salim; Banan, Ashkan

2015-11-01

The present approach was designed to evaluate the methanol-glucose extender effects on sperm cryopreservation in beluga sturgeon, Huso huso. Sperm quality was examined by measuring post-thaw sperm motility and fertilizing rate at hatching stage. We first tested the effect of glucose concentration (0, 0.10, 0.15, 0.20 and 0.30M) in a methanol extender on post-thaw sperm motility. The optimal cryopreservation conditions were found to be 0.2M glucose in the extender. Then, motility and fertilization rates of sperm cryopreserved with 0.2M glucose and 10% methanol (GM) were compared to Tris-sucrose-KCl in 10% methanol extender (TSKM). Additionally, sperm motility and fertilizing ability in relation to 15 and 30min equilibration in GM extender before and after cryopreservation were measured. Higher post-thaw sperm motility duration and percentage as well as fertilization rate were obtained with the GM extender when compared to TSKM extender. Equilibration of sperm in extender did not affect the motility quality of either fresh-diluted or frozen/thawed sperm, while fertilization rate showed a significant decline alone after 30min of post-thaw storage. Our results indicated that the use of a simple extender consisting of 0.2M glucose in 10% methanol can be an alternative cryopreservation method to those previously described for sturgeons. Copyright © 2015 Elsevier B.V. All rights reserved.

Clinical Significance of Mobile Health Assessed Sleep Duration and Variability in Bipolar Disorder

PubMed Central

Kaufmann, Christopher N.; Gershon, Anda; Eyler, Lisa T.; Depp, Colin A.

2016-01-01

OBJECTIVE Sleep disturbances are prevalent, persistent, and impairing features of bipolar disorder. However, the near-term and cumulative impact of the severity and variability of sleep disturbances on symptoms and functioning remains unclear. We examined self-reported daily sleep duration and variability in relation to mood symptoms, medication adherence, cognitive functioning, and concurrent daily affect. METHODS Forty-one outpatients diagnosed with bipolar disorder were asked to provide daily reports of sleep duration and affect collected via ecological momentary assessment with smartphones over eleven weeks. Measures of depressive and manic symptoms, medication adherence, and cognitive function were collected at baseline and concurrent assessment of affect were collected daily. Analyses examined whether sleep duration or variability were associated with baseline measures and changes in same-day or next-day affect. RESULTS Greater sleep duration variability (but not average sleep duration) was associated with greater depressive and manic symptom severity, and lower medication adherence at baseline, and with lower and more variable ratings of positive affect and higher ratings of negative affect. Sleep durations shorter than 7-8 hours were associated with lower same-day ratings of positive and higher same-day ratings of negative affect, however this did not extend to next-day affect. CONCLUSIONS Greater cumulative day-to-day sleep duration variability, but not average sleep duration, was related to more severe mood symptoms, lower self-reported medication adherence and higher levels of negative affect. Bouts of short- or long-duration sleep had transient impact on affect. Day-to-day sleep variability may be important to incorporate into clinical assessment of sleep disturbances in bipolar disorder. PMID:27451108

Risk Factors for Extended Duration and Timing of Peak Severity of Hot Flashes

PubMed Central

Gallicchio, Lisa; Miller, Susan R.; Zacur, Howard A.; Flaws, Jodi A.

2016-01-01

Objective To identify risk factors associated with the duration of hot flashes and the time of peak hot flash severity in mid-life women. Methods A cohort of 647 women reporting hot flashes were followed for 1–7 years, with survey data and hormone measurements. Survival analysis determined the association of risk factors with the duration of hot flashes. Linear regression determined the association of risk factors with the time of peak severity. Final models were determined through stepwise model selection. Results Average hot flash duration was 2.5 years (range: 1–33), with peak severity on average at 2.96 years (range: 1–20). Duration of hot flashes was associated with race, education, menopause status, smoking history, BMI, alcohol consumption, leisure activity levels, and levels of estradiol and progesterone. In the final model, only race, alcohol consumption, leisure activity, and menopause were retained. White women had significantly shorter hot flash durations than non-white women. Women consuming at least 12 alcoholic drinks in the previous year had a significantly shorter duration of hot flashes with a smaller effect of hot flash duration on increasing in time to peak severity compared to those who consumed less than 12 alcoholic drinks in that year. Higher serum progesterone levels were associated with later peak severity if the duration of the hot flashes was less than 2 years and an earlier peak severity otherwise. Conclusions These results suggest that some behaviors (such as moderate alcohol consumption) are associated with shorter durations of hot flashes, and that progesterone was associated with the dynamics of hot flash severity. PMID:27149066

Clinical significance of mobile health assessed sleep duration and variability in bipolar disorder.

PubMed

Kaufmann, Christopher N; Gershon, Anda; Eyler, Lisa T; Depp, Colin A

2016-10-01

Sleep disturbances are prevalent, persistent, and impairing features of bipolar disorder. However, the near-term and cumulative impact of the severity and variability of sleep disturbances on symptoms and functioning remains unclear. We examined self-reported daily sleep duration and variability in relation to mood symptoms, medication adherence, cognitive functioning, and concurrent daily affect. Forty-one outpatients diagnosed with bipolar disorder were asked to provide daily reports of sleep duration and affect collected via ecological momentary assessment with smartphones over eleven weeks. Measures of depressive and manic symptoms, medication adherence, and cognitive function were collected at baseline and concurrent assessment of affect were collected daily. Analyses examined whether sleep duration or variability were associated with baseline measures and changes in same-day or next-day affect. Greater sleep duration variability (but not average sleep duration) was associated with greater depressive and manic symptom severity, and lower medication adherence at baseline, and with lower and more variable ratings of positive affect and higher ratings of negative affect. Sleep durations shorter than 7-8 h were associated with lower same-day ratings of positive and higher same-day ratings of negative affect, however this did not extend to next-day affect. Greater cumulative day-to-day sleep duration variability, but not average sleep duration, was related to more severe mood symptoms, lower self-reported medication adherence and higher levels of negative affect. Bouts of short- or long-duration sleep had transient impact on affect. Day-to-day sleep variability may be important to incorporate into clinical assessment of sleep disturbances in bipolar disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sleep Duration Modifies the Association of Overtime Work With Risk of Developing Type 2 Diabetes: Japan Epidemiology Collaboration on Occupational Health Study.

PubMed

Kuwahara, Keisuke; Imai, Teppei; Miyamoto, Toshiaki; Kochi, Takeshi; Eguchi, Masafumi; Nishihara, Akiko; Nakagawa, Tohru; Yamamoto, Shuichiro; Honda, Toru; Kabe, Isamu; Mizoue, Tetsuya; Dohi, Seitaro

2018-02-03

Evidence linking working hours and the risk of type 2 diabetes mellitus (T2DM) is limited and inconsistent in Asian populations. No study has addressed the combined association of long working hours and sleep deprivation on T2DM risk. We investigated the association of baseline overtime work with T2DM risk and assessed whether sleep duration modified the effect among Japanese. Participants were Japanese employees (28,489 men and 4,561 women) aged 30-64 years who reported overtime hours and had no history of diabetes at baseline (mostly in 2008). They were followed up until March 2014. New-onset T2DM was identified using subsequent checkup data, including measurement of fasting/random plasma glucose, glycated hemoglobin, and self-report of medical treatment. Hazard ratios (HRs) of T2DM were estimated using Cox regression analysis. The combined association of sleep duration and working hours was examined in a subgroup of workers (n = 27,590). During a mean follow-up period of 4.5 years, 1,975 adults developed T2DM. Overtime work was not materially associated with T2DM risk. In subgroup analysis, however, long working hours combined with insufficient sleep were associated with a significantly higher risk of T2DM (HR 1.42; 95% CI, 1.11-1.83), whereas long working hours with sufficient sleep were not (HR 0.99; 95% CI, 0.88-1.11) compared with the reference (<45 hours of overtime with sufficient sleep). Sleep duration modified the association of overtime work with the risk of developing T2DM. Further investigations to elucidate the long-term effect of long working hours on glucose metabolism are warranted.

Analysis and stochastic modelling of Intensity-Duration-Frequency relationship from 88 years of 10 min rainfall data in North Spain

NASA Astrophysics Data System (ADS)

Delgado, Oihane; Campo-Bescós, Miguel A.; López, J. Javier

2017-04-01

Frequently, when we are trying to solve certain hydrological engineering problems, it is often necessary to know rain intensity values related to a specific probability or return period, T. Based on analyses of extreme rainfall events at different time scale aggregation, we can deduce the relationships among Intensity-Duration-Frequency (IDF), that are widely used in hydraulic infrastructure design. However, the lack of long time series of rainfall intensities for smaller time periods, minutes or hours, leads to use mathematical expressions to characterize and extend these curves. One way to deduce them is through the development of synthetic rainfall time series generated from stochastic models, which is evaluated in this work. From recorded accumulated rainfall time series every 10 min in the pluviograph of Igueldo (San Sebastian, Spain) for the time period between 1927-2005, their homogeneity has been checked and possible statistically significant increasing or decreasing trends have also been shown. Subsequently, two models have been calibrated: Bartlett-Lewis and Markov chains models, which are based on the successions of storms, composed for a series of rainfall events, separated by a short interval of time each. Finally, synthetic ten-minute rainfall time series are generated, which allow to estimate detailed IDF curves and compare them with the estimated IDF based on the recorded data.

Assessment of 30-day mortality and complication rates associated with extended deep vein thrombosis prophylaxis following hip fracture surgery.

PubMed

Durand, Wesley M; Goodman, Avi D; Johnson, Joey P; Daniels, Alan H

2018-06-01

DVT is a common complication following lower extremity surgery, occurring in up to 60% of patients undergoing hip fracture surgery without postoperative anticoagulation. The risk of fatal PE continues well-beyond two weeks postoperatively, thus extended DVT prophylaxis beyond 14 days may be warranted. This investigation sought to examine the association between prescription of extended DVT prophylaxis and 30-day postoperative complications following hip fracture surgery. This study utilized the ACS NSQIP Hip Fracture Procedure Targeted dataset, a newly available set of patient variables for 2016. The outcome measures were death, occurrence of any postoperative complication, complication subtype, readmission or reoperation within 30-days postoperatively, and length of stay. The primary independent variable was medical DVT prophylaxis continued 28-days postoperatively ("extended DVT prophylaxis"). The control group contains both patients receiving no prophylaxis and those receiving short-duration prophylaxis. Multivariate stepwise logistic regression was employed to control for potential demographic, comorbidity, and procedural/medical confounding factors. In total, 7533 surgically treated hip fracture patients treated in 2016 were analyzed. Overall, 57.8% of patients (n = 4354) were prescribed extended DVT prophylaxis. On bivariate analysis, prescription of extended DVT prophylaxis was associated with significantly lower incidence of death (7.7% without vs. 2.7% with, p < 0.0001) and stroke/CVA (1.4% vs. 0.6%, p = 0.0016). In multivariate analysis, prescription of extended DVT prophylaxis was significantly associated with lower odds of death (OR 0.33, p < 0.0001), stroke/CVA (OR 0.44, p = 0.0010), and acute kidney injury (AKI) (OR 0.31, p = 0.0010). This retrospective cohort study of the 2016 ACS NSQIP found that hip fracture surgery patients prescribed ≥28 days of postoperative DVT prophylaxis exhibited 67% lower odds of death and significantly lower rates of AKI and stroke/CVA as compared to those prescribed short-duration prophylaxis. Given the retrospective and uncontrolled nature of this analysis, these results should be interpreted with caution, and additional prospective randomized controlled trials examining the association between extended DVT prophylaxis and postoperative outcomes are warranted. If these observations accurately reflect real-world experience, these data suggest that ≥28 days of DVT prophylaxis following hip fracture surgery should be strongly considered for patients without explicit contraindications. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Method of studying the effects of pharmacological substances on work capacity of animals in hypobaric hypoxia].

PubMed

Spasov, A A; Kovalev, G V; Tsibanev, A V

1990-08-01

The method of the study of medical agent influence and biological active substances on duration of small laboratory animals swimming has been worked out excluding the air. For this purpose the animals were placed into altitude chamber, filled with water by 1/3 (one-third) of its volume being in antiorthostatic position on dipping into water. It has been established that at the altitude of 4000 (four thousand) meters high the rat swimming duration became shorter in comparison with their work under normal pressure in 2.5-4 times. Bemitil stimulating work in hypobaric hypoxia depresses it sharply. Bemitil stimulating influence on the rat efficiency did not appear with rising. Antioxidant substance ionol increased efficiency in normal conditions and in hypoxia AKS-85 adaptogenic compound increased swimming in the height duration to a greater degree, mildronat substance for efficiency restoration produced actoprotective influence.

Sleep patterns of offshore day-workers in relation to overtime work and age.

PubMed

Parkes, Katharine R

2015-05-01

In addition to long contractual hours during offshore weeks (14 × 12 h shifts), many personnel on North Sea oil/gas installations also work overtime, but little is known about the implications of overtime for sleep patterns offshore. In this study, the additive and interactive effects of overtime and age were analysed as predictors of sleep duration and sleep quality among offshore day-workers (N = 551), 54% of whom reported overtime. Sleep duration and quality were impaired among personnel who worked overtime, relative to those who worked only standard shifts; there was also an inverse dose-response relationship between overtime hours and sleep duration. Although the sleep measures were more favourable during shore leave than during offshore weeks, there was little evidence of compensatory sleep patterns. These findings are discussed with reference to known performance and health effects of short sleep hours; formal guidance on overtime work offshore is noted; and methodological issues are considered. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Examining the impact of worker and workplace factors on prolonged work absences among Canadian nurses.

PubMed

Franche, Renée-Louise; Murray, Eleanor; Ibrahim, Selahadin; Smith, Peter; Carnide, Nancy; Côté, Pierre; Gibson, Jane; Koehoorn, Mieke

2011-08-01

To evaluate the impact of worker and workplace factors and of their relationships on work absence duration. Structural equation modeling of 11,762 female, Canadian nurses from the 2005 National Survey of the Work and Health of Nurses. Worker and workplace factors were associated with prolonged work absence. Key proximal predictors were pain-related work interference, depression, pain severity, and respect and support at work. More distal predictors were multimorbidity, abuse at work, and organizational culture. Worker health and workplace factors are important in explaining work absence duration. Self-management for pain and mood, adapted to the work context, may be useful for nurses with chronic pain or depression. Policy makers and administrators should focus on creating respect and support at work, and improving organizational culture.

Beyond parenting practices: extended kinship support and the academic adjustment of African-American and European-American teens.

PubMed

Pallock, Linda L; Lamborn, Susie D

2006-10-01

This study examined adolescents' perceptions of parenting practices and extended kinship support in relation to academic adjustment for 104 African American and 60 European American 9th and 10th graders (14 and 15 year olds). For African-American teens, parental acceptance was associated with school values, teacher bonding, and work orientation. Higher levels of behavioral control and lower levels of psychological control were associated with a stronger work orientation. After accounting for the demographic variables and the three parenting practices, higher levels of extended kinship support related to stronger school values, higher teacher bonding, and a stronger work orientation. For European-American teens, parental acceptance related to academic adjustment, including stronger school values, higher teacher bonding, and a stronger work orientation. European-American adolescents with stronger extended kinship networks reported higher teacher bonding and a stronger work orientation. Results indicate the importance of extended kinship support for both African-American and European-American adolescents.

Development of modified-release tablets of zolpidem tartrate by biphasic quick/slow delivery system.

PubMed

Mahapatra, Anjan Kumar; Sameeraja, N H; Murthy, P N

2015-06-01

Zolpidem tartrate is a non-benzodiazepine analogue of imidazopyridine of sedative and hypnotic category. It has a short half-life with usual dosage regimen being 5 mg, two times a day, or 10 mg, once daily. The duration of action is considered too short in certain circumstances. Thus, it is desirable to lengthen the duration of action. The formulation design was implemented by preparing extended-release tablets of zolpidem tartrate using the biphasic delivery system technology, where sodium starch glycolate acts as a superdisintegrant in immediate-release part and hydroxypropyl methyl cellulose as a release retarding agent in extended-release core. Tablets were prepared by direct compression. Both the core and the coat contained the drug. The pre-compression blends were evaluated for angle of repose, bulk density, and compressibility index. The tablets were evaluated for thickness, hardness, weight variation test, friability, and in vitro release studies. No interaction was observed between zolpidem tartrate and excipients from the Fourier transform infrared spectroscopy and differential scanning calorimetry analysis. The results of all the formulations prepared were compared with reference product Stilnoct®. Optimized formulations showed release patterns that match the United States Pharmacopeia (USP) guidelines for zolpidem tartrate extended-release tablets. The mechanism of drug release was studied using different mathematical models, and the optimized formulation has shown Fickian diffusion. Accelerated stability studies were performed on the optimized formulation.

The Second SWIFT Burst Alert Telescope (BAT) Gamma-Ray Burst Catalog

NASA Technical Reports Server (NTRS)

Sakamoto, T.; Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J. R.; Fenimore, E. E.; Gehrels, N.; Krimm, H. A.; Markwardt, C. B.; Palmer, D. M.; Parsons, A. M.;

Actigraph measures of sleep among female hospital employees working day or alternating day and night shifts.

PubMed

Korsiak, Jill; Tranmer, Joan; Leung, Michael; Borghese, Michael M; Aronson, Kristan J

2017-07-14

Sleep disturbance is common among shift workers, and may be an important factor in the effect of shift work on chronic disease development. In this cross-sectional study, we described sleep patterns of 294 female hospital workers (142 alternating day-night shift workers, 152 day workers) and determined associations between shift work and sleep duration. Rest-activity cycles were recorded with the ActiGraph GT3X+ for 1 week. Analyses were stratified by chronotype of shift workers. Using all study days to calculate average sleep duration, shift workers slept approximately 13 min less than day workers during main sleep periods, while 24-h sleep duration did not differ between day workers and shift workers. Results from age-adjusted models demonstrated that all shift workers, regardless of chronotype, slept 20-30 min less than day workers on day shifts during main and total sleep. Early and intermediate chronotypes working night shifts slept between 114 and 125 min less than day workers, both with regard to the main sleep episode and 24-h sleep duration, while the difference was less pronounced among late chronotypes. When sleep duration on free days was compared between shift workers and day workers, only shift workers with late chronotypes slept less, by approximately 50 min, than day workers during main sleep. Results from this study demonstrate how an alternating day-night shift work schedule impacts sleep negatively among female hospital workers, and the importance of considering chronotype in sleep research among shift workers. © 2017 European Sleep Research Society.

Associations of objectively measured sitting and standing with low-back pain intensity: a 6-month follow-up of construction and healthcare workers.

PubMed

Lunde, Lars-Kristian; Koch, Markus; Knardahl, Stein; Veiersted, Kaj Bo

2017-05-01

Objectives This study aimed to determine the associations between objectively measured sitting and standing duration and intensity of low-back pain (LBP) among Norwegian construction and healthcare workers. Methods One-hundred and twenty-four workers wore two accelerometers for 3-4 consecutive days, during work and leisure. Minutes of sitting and standing was calculated from accelerometer data. We obtained self-reported LBP intensity (0-3) at the time of objective measurement and after six months. We examined associations with linear mixed models and presented results per 100 minutes. Results For healthcare workers, the duration of sitting during work [β= -0.33, 95% confidence interval (95% CI) -0.55- -0.10] and during full-day (work + leisure) (β= -0.21, 95% CI -0.38- -0.04) was associated with baseline LBP intensity. Furthermore, minutes of sitting at work (β=-0.35, 95% CI -0.57- -0.13) and during the full day (β=-0.20, 95% CI -0.37- -0.04) were significantly associated with LBP intensity at six months. Associations were attenuated when adjusting for work-related mechanical and psychosocial covariates and objectively measured exposure during leisure time. No significant associations between sitting and LBP intensity were found for construction workers. Standing at work was not consistently associated with LBP intensity at baseline or after six months for any work sector. Conclusions This study suggests that a long duration of sitting at work is associated with lower levels of LBP intensity among healthcare workers. Standing duration had no consistent associations with LBP intensity.

Sleep and Cardio-Metabolic Disease.

PubMed

Cappuccio, Francesco P; Miller, Michelle A

2017-09-19

This review summarises and discusses the epidemiological evidence suggesting a causal relationship between sleep duration and cardio-metabolic risk and outcomes in population. Sleep duration is affected by a variety of cultural, social, psychological, behavioural, pathophysiological and environmental influences. Changes in modern society-like longer working hours, more shift-work, 24/7 availability of commodities and 24-h global connectivity-have been associated with a gradual reduction in sleep duration and sleeping patterns across westernised populations. We review the evidence of an association between sleep disturbances and the development of cardio-metabolic risk and disease and discuss the implications for causality of these associations. Prolonged curtailment of sleep duration is a risk factor for the development of obesity, diabetes, hypertension, heart disease and stroke and may contribute, in the long-term, to premature death.

Reduced sleep duration and history of work-related injuries among Washington State adolescents with a history of working.

PubMed

Graves, Janessa M; Miller, Mary E

2015-04-01

The relationship between sleep and occupational injury risk has not been adequately explored for working adolescents. Data were analyzed from the 2010 Washington State Healthy Youth Survey of 8th, 10th, and 12th grade public school students. Teens reported average school and weekend night sleep hours and history of work-related injury that received medical treatment. Multivariable logistic regression evaluated the association between sleep duration and occupational injury. Of 4,144 working teens, 6.4% reported ever having an occupational injury. Teens who sleep ≤5 hr/school night had greater odds of a history of occupational injury than those sleeping 8 hr (OR:2.91, 95% CI:1.85-4.57). No significant association was observed for weekend night sleep duration. Reduced school night sleep was associated with increased odds of work-related injury in adolescents. Long hours and late night schedules may contribute to decreased sleep time and potentially have other health and developmental impacts for youth. © 2015 Wiley Periodicals, Inc.

Field Test: Results from the One Year Mission

NASA Technical Reports Server (NTRS)

Reschke, M. F.; Kozlovskaya, I. B.; Kofman, I. S.; Tomilovskaya, E. S.; Cerisano, J. M.; Rosenberg, M. J. F.; Bloomberg, J. J.; Stenger, M. B.; Lee, S. M. C.; Laurie, S. S.;

14 CFR 121.351 - Communication and navigation equipment for extended over-water operations and for certain other...

Code of Federal Regulations, 2013 CFR

2013-01-01

... route being flown, and (3) The duration of the very high frequency communications gap. [Doc. No. 6258... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Communication and navigation equipment for... Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND...

14 CFR 121.351 - Communication and navigation equipment for extended over-water operations and for certain other...

Code of Federal Regulations, 2014 CFR

2014-01-01

... route being flown, and (3) The duration of the very high frequency communications gap. [Doc. No. 6258... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Communication and navigation equipment for... Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND...

14 CFR 121.351 - Communication and navigation equipment for extended over-water operations and for certain other...

Code of Federal Regulations, 2011 CFR

2011-01-01

... route being flown, and (3) The duration of the very high frequency communications gap. [Doc. No. 6258... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Communication and navigation equipment for... Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND...

14 CFR 121.351 - Communication and navigation equipment for extended over-water operations and for certain other...

Code of Federal Regulations, 2010 CFR

2010-01-01

... route being flown, and (3) The duration of the very high frequency communications gap. [Doc. No. 6258... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Communication and navigation equipment for... Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND...

14 CFR 121.351 - Communication and navigation equipment for extended over-water operations and for certain other...

Code of Federal Regulations, 2012 CFR

2012-01-01

... route being flown, and (3) The duration of the very high frequency communications gap. [Doc. No. 6258... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Communication and navigation equipment for... Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND...

77 FR 30024 - Notice of Proposed Withdrawal Extension and Opportunity for Public Meeting; South Dakota

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-21

... DEPARTMENT OF THE INTERIOR Bureau of Land Management [SDM 79849] Notice of Proposed Withdrawal Extension and Opportunity for Public Meeting; South Dakota AGENCY: Bureau of Land Management, Interior... application with the Department of the Interior, Bureau of Land Management, to extend the duration of Public...

78 FR 64531 - Notice of Proposed Withdrawal Extension, Sacramento Pass Recreation Area; Nevada

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-29

... Interior for Policy, Management and Budget proposes to extend the duration of Public Land Order (PLO) No..., sale, location, or entry under the general land laws, including the United States mining laws, but not from leasing under the mineral leasing laws, to protect the Sacramento Pass Recreation Area (SPRA) in...

77 FR 25829 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-01

.... These behavioral reactions are often shown as: Changing durations of surfacing and dives, number of... show no overt reactions to airgun pulses at distances beyond a few kilometers, even though the airgun... migrating bowhead whales show reactions, including avoidance, that sometimes extend to greater distances...

Extended duration of parturition season in North American elk (Cervus elaphus)

Treesearch

Barbara J. Keller; Amy D. Bleisch; Joshua J. Millspaugh; Chad P. Lehman; Jackie J. Kragel; Lonnie P. Hansen; Jason Sumners; Mark A. Rumble; Gary C. Brundige

2015-01-01

The timing of births in ungulates has significant implications for juvenile survival and population growth. For North American elk (Cervus elaphus), typical parturition season ranges from late May to early Jun., and juveniles born outside of this peak characteristically exhibit lowered survival. We observed abnormally long parturition seasons in free-ranging elk...

Framework for Evaluating Efficacy in Health Promoting Schools

ERIC Educational Resources Information Center

Lee, Albert; Keung, Vera Mei-wan; Lo, Amelia Siu-chee; Kwong, Amy Chi-ming; Armstrong, Erin Sophie

2014-01-01

Purpose: Successful implementation of Health Promoting Schools (HPS) depends on putting the model in the schools' context for both health improvement and school improvement. HPS can only be effective if the change can be sustained over an extended duration. The purpose of this paper is to discuss development of the HPS process by University…

Management of Children Using Cochlear Implants and Hearing Aids.

ERIC Educational Resources Information Center

Ching, Teresa Y. C.; Psarros, Colleen; Incerti, Paula; Hill, Mandy

2001-01-01

Four case studies identify six factors affecting successful use of a hearing aid with a cochlear implant: duration of hearing aid use prior to implantation, amount of residual hearing in the non-implanted ear, educational and listening demands, cosmetic issues, hearing aid rejection, and extended period of non-use of hearing aid. (Contains…

Human health risk assessment: models for predicting the effective exposure duration of on-site receptors exposed to contaminated groundwater.

PubMed

Baciocchi, Renato; Berardi, Simona; Verginelli, Iason

2010-09-15

Clean-up of contaminated sites is usually based on a risk-based approach for the definition of the remediation goals, which relies on the well known ASTM-RBCA standard procedure. In this procedure, migration of contaminants is described through simple analytical models and the source contaminants' concentration is supposed to be constant throughout the entire exposure period, i.e. 25-30 years. The latter assumption may often result over-protective of human health, leading to unrealistically low remediation goals. The aim of this work is to propose an alternative model taking in account the source depletion, while keeping the original simplicity and analytical form of the ASTM-RBCA approach. The results obtained by the application of this model are compared with those provided by the traditional ASTM-RBCA approach, by a model based on the source depletion algorithm of the RBCA ToolKit software and by a numerical model, allowing to assess its feasibility for inclusion in risk analysis procedures. The results discussed in this work are limited to on-site exposure to contaminated water by ingestion, but the approach proposed can be extended to other exposure pathways. Copyright 2010 Elsevier B.V. All rights reserved.

Soviet space flight: the human element.

PubMed

Garshnek, V

1988-05-01

Building on past experience and knowledge, the Soviet manned space flight effort has become broad, comprehensive, and forward-looking. Their long-running space station program has provided the capabilities to investigate long-term effects of microgravity on human physiology and behavior and test various countermeasures against microgravity-induced physiological deconditioning. Since the beginning of Soviet manned space flight, the biomedical training and preparation of cosmonauts has evolved from a process that increased human tolerance to space flight factors, to a system of interrelated measures to prepare cosmonauts physically and psychologically to live and work in space. Currently, the Soviet Union is constructing a multimodular space station, the Mir. With the emergence of dedicated laboratory modules, the Soviets have begun the transition from small-scale experimental research to large-scale production activities and specialized scientific work in space. In the future, additional laboratory modules will be added, including one dedicated to biomedical research, called the "Medilab." The longest manned space flight to date (326 days) has been completed by the Soviets. The biomedical effects of previous long-duration flights, and perhaps those of still greater length, may contribute important insight ito the possibility of extended missions beyond Earth, such as a voyage to Mars.

Length of maternity leave and health of mother and child--a review.

PubMed

Staehelin, Katharina; Bertea, Paola Coda; Stutz, Elisabeth Zemp

2007-01-01

Assessment of the literature on the length of maternity leaves and health of mothers and children; evaluation of the Swiss situation in view of the maternity leave policy implemented in 2005. Review of thirteen original studies identified by PubMed using topic-related terms. A positive association was shown between the length of maternity leave and mother's mental health and duration of breastfeeding. Extended maternity leaves were also associated with lower perinatal, neonatal and post-neonatal mortality rates as well as lower child mortality; however, results are obtained in ecological studies. There is less evidence regarding other health outcomes. The new policy in Switzerland extends maternity leave for a considerable number of women to 14 weeks. With this prolongation, fewer depressive symptoms and longer breastfeeding duration can be expected, while benefits regarding other health outcomes would warrant longer leaves. Longer maternity leaves are likely to produce health benefits. The new policy in Switzerland will probably improve the situation of those women, who previously were granted only minimal leave and/or mothers with additional social risk factors.

Effects of streamflows on stream-channel morphology in the eastern Niobrara National Scenic River, Nebraska, 1988–2010

USGS Publications Warehouse

Schaepe, Nathaniel J.; Alexander, Jason S.; Folz-Donahue, Kiernan

2016-03-09

Changes in channel metrics generally corresponded to changes in streamflow conditions, but other than changes in incipient flood-plain area, these changes were small and were not measured in all three segments simultaneously. Increases in total channel width (except in segment 1) and incipient flood-plain area between 1993 and 1999 corresponded to increases in streamflow. Channel narrowing (except in segment 1) between 1999 and 2003 corresponded to lower summer streamflows and extended durations of very low summer streamflow. Although the pattern of low summer streamflow and extended durations of very low summer streamflow continued during the 2004–6 period and at the beginning of the 2007–10 period, no further narrowing was measured. Consistent tributary summer inflows help to explain the resistance of segments 2 and 3 to further narrowing. Because segment 1 is already much narrower than segments 2 and 3, its average current velocity is likely to be swifter and, therefore, competent to offset further effects of the processes that led to its narrowness.

Silk Electrogel Based Gastroretentive Drug Delivery System

NASA Astrophysics Data System (ADS)

Wang, Qianrui

Gastric cancer has become a global pandemic and there is imperative to develop efficient therapies. Oral dosing strategy is the preferred route to deliver drugs for treating the disease. Recent studies suggested silk electro hydrogel, which is pH sensitive and reversible, has potential as a vehicle to deliver the drug in the stomach environment. The aim of this study is to establish in vitro electrogelation e-gel based silk gel as a gastroretentive drug delivery system. We successfully extended the duration of silk e-gel in artificial gastric juice by mixing silk solution with glycerol at different ratios before the electrogelation. Structural analysis indicated the extended duration was due to the change of beta sheet content. The glycerol mixed silk e-gel had good doxorubicin loading capability and could release doxorubicin in a sustained-release profile. Doxorubicin loaded silk e-gels were applied to human gastric cancer cells. Significant cell viability decrease was observed. We believe that with further characterization as well as functional analysis, the silk e-gel system has the potential to become an effective vehicle for gastric drug delivery applications.

Extended duration orbiter medical project countermeasure to reduce post space flight orthostatic intolerance (LBNP) (STS-50/USML-1)

NASA Technical Reports Server (NTRS)

Charles, John B.; Boettcher, Sheila W.

1994-01-01

During the STS-50/USML-1 mission and five other Shuttle flights, decompression of the legs and lower abdomen ('lower body negative pressure,' LBNP) was used: (1) to apply a standardized stress to the cardiovascular system, to document the loss of orthostatic function during an extended period in weightlessness, and (2) to test its efficacy as a treatment which may be used to protect astronauts from gravitationally-induced fainting during and after reentry on Space Shuttle flights. The loss of orthostatic tolerance (as determined by LBNP) occured even earlier than indicated by similar testing on Skylab (1973-1974). The treatment was shown to be effective in reversing some of the effects of extended weightlessness on the cardiovascular system for at least one day after treatment.

Definition study for an extended manned test of a regenerative life support system

NASA Technical Reports Server (NTRS)

1971-01-01

A program was defined which consists of extended ground-based manned tests of regenerative life support systems. The tests are to evaluate prototypes of advanced life support systems under operational, integrated conditions, thus providing data for the design of efficient environmental control and life support systems for use in long-duration space missions. The requirements are defined for test operations to provide a simulation of an orbiting space laboratory. The features of Phase A and B programs are described. These tests use proven backup equipment to ensure successful evaluation of the advanced subsystems. A pre-tests all-systems checkout period is provided to minimize equipment problems during extended testing and to familiarize all crew and operating staff members with test equipment and procedures.

[Maternity leave and experience of working mothers in Lebanon].

PubMed

Saadé, N; Barbour, B; Salameh, P

2010-09-01

We conducted a cross-sectional study of 802 Lebanese mothers to evaluate effect of rapid return to work on their health and that of their child. Breastfeeding practices were also assessed. The duration of maternity leave was insufficient for 72.8% of the women. Rapid return to work could cause physical and psychological problems depending on the type of work. The average length of breastfeeding was 4.7 months and while the average desired length was 10.9 months. Breastfeeding depended on the duration of the maternity leave, the possibility of breaks for breastfeeding and the presence of nurseries at work. Urgent interventions are necessary to prolong maternity leave and promote breastfeeding among working women.

The Effects of the Mars Exploration Rovers (MER) Work Schedule Regime on Locomotor Activity Circadian Rhythms, Sleep and Fatigue

NASA Technical Reports Server (NTRS)

DeRoshia, Charles W.; Colletti, Laura C.; Mallis, Melissa M.

2008-01-01

This study assessed human adaptation to a Mars sol by evaluating sleep metrics obtained by actigraphy and subjective responses in 22 participants, and circadian rhythmicity in locomotor activity in 9 participants assigned to Mars Exploration Rover (MER) operational work schedules (24.65 hour days) at the Jet Propulsion Laboratory in 2004. During MER operations, increased work shift durations and reduced sleep durations and time in bed were associated with the appearance of pronounced 12-hr (circasemidian) rhythms with reduced activity levels. Sleep duration, workload, and circadian rhythm stability have important implications for adaptability and maintenance of operational performance not only of MER operations personnel but also in space crews exposed to a Mars sol of 24.65 hours during future Mars missions.

Brain MRI lesions and atrophy are associated with employment status in patients with multiple sclerosis.

PubMed

Tauhid, Shahamat; Chu, Renxin; Sasane, Rahul; Glanz, Bonnie I; Neema, Mohit; Miller, Jennifer R; Kim, Gloria; Signorovitch, James E; Healy, Brian C; Chitnis, Tanuja; Weiner, Howard L; Bakshi, Rohit

2015-11-01

Multiple sclerosis (MS) commonly affects occupational function. We investigated the link between brain MRI and employment status. Patients with MS (n = 100) completed a Work Productivity and Activity Impairment (WPAI) (general health version) survey measuring employment status, absenteeism, presenteeism, and overall work and daily activity impairment. Patients "working for pay" were considered employed; "temporarily not working but looking for work," "not working or looking for work due to age," and "not working or looking for work due to disability" were considered not employed. Brain MRI T1 hypointense (T1LV) and T2 hyperintense (T2LV) lesion volumes were quantified. To assess lesional destructive capability, we calculated each subject's ratio of T1LV to T2LV (T1/T2). Normalized brain parenchymal volume (BPV) assessed brain atrophy. The mean (SD) age was 45.5 (9.7) years; disease duration was 12.1 (8.1) years; 75 % were women, 76 % were relapsing-remitting, and 76 % were employed. T1LV, T1/T2, Expanded Disability Status Scale (EDSS) scores, and activity impairment were lower and BPV was higher in the employed vs. not employed group (Wilcoxon tests, p < 0.05). Age, disease duration, MS clinical subtype, and T2LV did not differ between groups (p > 0.05). In multivariable logistic regression modeling, adjusting for age, sex, and disease duration, higher T1LV predicted a lower chance of employment (p < 0.05). Pearson correlations showed that EDSS was associated with activity impairment (p < 0.05). Disease duration, age, and MRI measures were not correlated with activity impairment or other WPAI outcomes (p > 0.05). We report a link between brain atrophy and lesions, particularly lesions with destructive potential, to MS employment status.

Work-Family Conflict and Employee Sleep: Evidence from IT Workers in the Work, Family and Health Study.

PubMed

Buxton, Orfeu M; Lee, Soomi; Beverly, Chloe; Berkman, Lisa F; Moen, Phyllis; Kelly, Erin L; Hammer, Leslie B; Almeida, David M

2016-10-01

Work-family conflict is a threat to healthy sleep behaviors among employees. This study aimed to examine how Work-to-Family Conflict (demands from work that interfere with one's family/personal life; WTFC) and Family-to-Work Conflict (demands from family/personal life that interfere with work; FTWC) are associated with several dimensions of sleep among information technology workers. Employees at a U.S. IT firm (n = 799) provided self-reports of sleep sufficiency (feeling rested upon waking), sleep quality, and sleep maintenance insomnia symptoms (waking up in the middle of the night or early morning) in the last month. They also provided a week of actigraphy for nighttime sleep duration, napping, sleep timing, and a novel sleep inconsistency measure. Analyses adjusted for work conditions (job demands, decision authority, schedule control, and family-supportive supervisor behavior), and household and sociodemographic characteristics. Employees who experienced higher WTFC reported less sleep sufficiency, poorer sleep quality, and more insomnia symptoms. Higher WTFC also predicted shorter nighttime sleep duration, greater likelihood of napping, and longer nap duration. Furthermore, higher WTFC was linked to greater inconsistency of nighttime sleep duration and sleep clock times, whereas higher FTWC was associated with more rigidity of sleep timing mostly driven by wake time. Results highlight the unique associations of WTFC/FTWC with employee sleep independent of other work conditions and household and sociodemographic characteristics. Our novel methodological approach demonstrates differential associations of WTFC and FTWC with inconsistency of sleep timing. Given the strong associations between WTFC and poor sleep, future research should focus on reducing WTFC. © 2016 Associated Professional Sleep Societies, LLC.

Recovery of Work-Related Stress: Complaint Reduction and Work-Resumption are Relatively Independent Processes.

PubMed

de Vente, Wieke; Kamphuis, Jan Henk; Blonk, Roland W B; Emmelkamp, Paul M G

2015-09-01

The process of recovery from work-related stress, consisting of complaint reduction and work-resumption, is not yet fully understood. The aim of this study was to investigate predictors of complaint reduction and work-resumption, as well as testing complaint reduction as a mediator in the association between predictors and work-resumption. Seventy-one patients on sickness-leave because of work-related stress complaints were followed over a period of 13 months. Predictors comprised personal (demographics, coping, cognitions), work-related (job-characteristics, social support), and illness-related (complaint duration, absence duration) variables. Dependent variables were distress complaints, burnout complaints, and work-resumption. Complaints reduced considerably over time to borderline clinical levels and work-resumption increased to 68% at 13 months. Predictors of stronger reduction of distress complaints were male gender, less working hours, less decision authority, more co-worker support, and shorter absence duration. Predictors of stronger reduction of burnout complaints were male gender, lower age, high education, less avoidant coping, less decision authority, more job security, and more co-worker support. Predictors of work-resumption were lower age and stronger reduction of burnout complaints. No indication for a mediating role of burnout complaints between the predictor age and work-resumption was found. Complaint reduction and work-resumption are relatively independent processes. Symptom reduction is influenced by individual and work-related characteristics, which holds promise for a multidisciplinary treatment approach for work-related stress.

[Effects of phytoecdysteroids and bemithyl on functional, metabolic, and immunobiological parameters of working capacity in experimental animals].

PubMed

Syrov, V N; Shakhmurova, G A; Khushbaktova, Z A

2008-01-01

Influence of phytoecdysteroids (isolated from Ajuga turkestanica) and bemithyl on the duration of swimming of laboratory animals (mice, rats) under various experimental conditions was studied. Turkesteron and cyasteron increased duration of dynamic work carried out by animals, decreased fatigue, and accelerated recovery processes to a greater extent that did bemithyl. The positive influence of phytoecdysteroids on the working capacity is based on the activation of metabolic processes in skeletal muscles, directed to support the homeostasis of energy production. Phytoecdysteroids also accelerate recovery of immune reactions which are decreased due to the exhausting physical work.

Short communication: Microbial quality of raw milk following commercial long-distance hauling.

PubMed

Darchuk, Emily M; Meunier-Goddik, Lisbeth; Waite-Cusic, Joy

2015-12-01

Hauling is a critical part of the commercial milk supply chain, yet very few studies have aimed to understand its effect on raw milk quality. This study focused on the effect of extended-duration tanker use during hauling on raw milk quality at a commercial facility. Standard tanker use [cleaned-in-place (CIP) once per 24h] served as a control and an incremental between-load water rinse with sanitizer treatment (RS) was evaluated to mitigate any effect from extended duration hauling. During this study, 1 commercial truck with 2 trailers was monitored for 10d. The truck collected milk at a large dairy farm, transported the milk to a manufacturing facility, and then returned to the same farm for a second load. Each round-trip journey took between 10 and 12h, allowing for 2 loads per 24-h use period. Following the second delivery, the truck was cleaned by CIP treatment starting a new treatment day. Producer samples were collected from the raw milk bulk tank on the farm before loading milk into the tanker. The same milk was sampled directly out of the tanker truck before unloading at the manufacturer. Effect on individual bacteria count, thermophilic spore count, and preliminary incubation count was quantified through common industry tests. Surface sponge swabs were also used to monitor tanker sanitation and the efficacy of cleaning treatments. Results did not identify a negative effect on raw milk quality due to extended duration hauling. Whereas the addition of RS did not provide any measurable quality benefits for the microbial milk quality, swab results demonstrated that the RS treatment was able to reduce surface bacteria in the tanker, although not to the same level as the full CIP treatment. Based on this study, current CIP practices for long distance milk hauling appear to be effective in mitigating any measurable effect on raw milk quality. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Impact of age on the efficacy and safety of extended-duration thromboprophylaxis in medical patients. Subgroup analysis from the EXCLAIM randomised trial.

PubMed

Yusen, Roger D; Hull, Russell D; Schellong, Sebastian M; Tapson, Victor F; Monreal, Manuel; Samama, Meyer-Michel; Chen, Min; Deslandes, Bruno; Turpie, Alexander G G

2013-12-01

The EXCLAIM study enrolled hospitalised acutely ill medical patients with age >40 years and recently-reduced mobility into a trial of extended-duration anticoagulant thromboprophylaxis. This post-hocanalysis evaluated the impact of age on patient outcomes. After completion of open-label therapy with enoxaparin 40 mg once-daily (10 ± 4 days), eligible patients underwent randomisation to receive double-blind therapy of enoxaparin (n=2,975) or placebo (n=2,988) for 28 ± 4 days. During follow-up, the venous thromboembolism (VTE) risk increased with age in both treatment groups. In patients with age >75 years, those who received extended-duration enoxaparin had lower incidence of VTE (2.5% vs 6.7%; absolute difference [AD] [95% confidence interval]: -4.2% [-6.5, -2.0]), proximal deep-vein thrombosis (2.5% vs 6.6%; AD -4.1% [-6.2, -2.0]), and symptomatic VTE (0.3% vs 1.5%; AD -1.2% [-2.2, -0.3]), in comparison to those who received placebo. In patients with age ≤75 years, those who received enoxaparin had reduced VTE (2.4% vs 2.8%; AD -0.4% [-1.5, 0.7]) and symptomatic VTE (0.2% vs 0.7%; AD -0.6% [-1.0, -0.1]) in comparison to those who received placebo. In both age subgroups, patients who received enoxaparin had increased rates of major bleeding versus those who received placebo: age >75 years (0.6% vs 0.2%; AD +0.3% [-0.2, 0.9], respectively); age ≤75 years (0.7% vs 0.2%; AD +0.5% [0.1, 0.9]). Patients in both age subgroups that received enoxaparin had similar low bleeding rates (0.6% and 0.7%, respectively). VTE risk increased with age, though the bleeding risk did not. Patients with age >75 years had a more favourable benefit-to-harm profile than younger patients.

Nutritional Biochemistry of Space Flight

NASA Technical Reports Server (NTRS)

Smith, Scott M.

2000-01-01

Adequate nutrition is critical for maintenance of crew health during and after extended-duration space flight. The impact of weightlessness on human physiology is profound, with effects on many systems related to nutrition, including bone, muscle, hematology, fluid and electrolyte regulation. Additionally, we have much to learn regarding the impact of weightlessness on absorption, mtabolism , and excretion of nutrients, and this will ultimately determine the nutrient requirements for extended-duration space flight. Existing nutritional requirements for extended-duration space flight have been formulated based on limited flight research, and extrapolation from ground-based research. NASA's Nutritional Biochemistry Laboratory is charged with defining the nutritional requirements for space flight. This is accomplished through both operational and research projects. A nutritional status assessment program is included operationally for all International Space Station astronauts. This medical requirement includes biochemical and dietary assessments, and is completed before, during, and after the missions. This program will provide information about crew health and nutritional status, and will also provide assessments of countermeasure efficacy. Ongoing research projects include studies of calcium and bone metabolism, and iron absorption and metabolism. The calcium studies include measurements of endocrine regulation of calcium homeostasis, biochemical marker of bone metabolism, and tracer kinetic studies of calcium movement in the body. These calcium kinetic studies allow for estimation of intestinal absorption, urinary excretion, and perhaps most importantly - deposition and resorption of calcium from bone. The Calcium Kinetics experiment is currently being prepared for flight on the Space Shuttle in 2001, and potentially for subsequent Shuttle and International Space Station missions. The iron study is intended to assess whether iron absorption is down-regulated dUl1ng space flight. This is critical due to the red blood cell changes which occur, and the increase in iron storage that has been observed after space flight. The Iron Absorption and Metabolism experiment is currently planned for long-term flights on the International Space Station.

Thrombus Burden of Deep Vein Thrombosis and Its Association with Thromboprophylaxis and D-Dimer Measurement: Insights from the APEX Trial.

PubMed

Chi, Gerald; Goldhaber, Samuel Z; Hull, Russell D; Hernandez, Adrian F; Kerneis, Mathieu; Al Khalfan, Fahad; Cohen, Alexander T; Harrington, Robert A; Gibson, C Michael

2017-12-01

Background The aim of this study was to evaluate the effect of betrixaban on the occurrence of deep vein thrombosis (DVT) and also the extent of thrombus and to assess the association of baseline D-dimer with subsequent thrombus burden. Methods In the APEX trial (ClinicalTrials.gov: NCT01583218), 7,513 acutely ill hospitalized medical patients were randomly assigned to extended-duration betrixaban (35–42 days) or enoxaparin (10 ± 4 days). D-dimer concentration was measured at baseline, and mandatory lower-extremity compression ultrasonography (CUS) was performed at 35 to 42 days. The thrombus burden of DVT was assessed by the number of non-compressible vascular segments in six target proximal veins and compared between treatment groups and D-dimer categories (≥2 × upper limit of normal [ULN] versus <2 × ULN). Results Compared with enoxaparin, extended-duration betrixaban reduced the DVT risk at 35 to 42 days (any-dose: relative risk [RR] = 0.76 [95% confidence interval: 0.61–0.94]; p = 0.013; full-dose: RR = 0.70 [0.55–0.90]; p = 0.005). Patients who received betrixaban were more likely to have a lower thrombus burden (p = 0.012 for any-dose and p = 0.001 for full-dose). Elevated D-dimer at baseline was independently associated with a 2.12-fold increased risk of developing DVT (p < 0.001). A greater thrombus burden was also observed in those with D-dimer ≥ 2 × ULN compared with <2 × ULN (p < 0.0001). Conclusion Extended-duration betrixaban reduced the number of venous segments with thrombosis at 35 to 42 days compared with enoxaparin. A positive D-dimer was associated with a greater extent of thrombus burden among acutely ill medical patients who developed DVT despite receiving thromboprophylaxis.

Evaluating sickness absence duration by musculoskeletal and mental health issues: a retrospective cohort study of Scottish healthcare workers.

PubMed

Demou, Evangelia; Smith, Shanley; Bhaskar, Abita; Mackay, Daniel F; Brown, Judith; Hunt, Kate; Vargas-Prada, Sergio; Macdonald, Ewan B

2018-01-26

Sickness absence (SA) among healthcare workers is associated with occupational and non-occupational risk factors and impacts employee health, healthcare delivery and patient health. At the same time, healthcare is one of the employment sectors with the highest rates of work-related ill health in the UK. Musculoskeletal (MSK) and mental health (MH) issues are leading causes of SA, but there is a lack of research on how certain MSK/MH conditions impact on SA duration. The study aim is to determine differences in SA duration by MH and MSK disorders in healthcare employees. Survival analyses were used to estimate SA duration due to MSK and MH problems over 6 years, and Cox's proportional hazards models to determine the HRs of returning to work, using a bespoke Scottish health board database with over 53 000 SA events. SA duration and time to return-to-work (RTW) were estimated for employees by age, gender, job and health conditions. MSK and MH conditions accounted for 27% and 6% of all SA events and 23.7% and 19.5% of all days lost, respectively. Average SA duration was 43.5 days for MSK and 53.9 days for MH conditions. For MSK conditions, employees with low back or neck pain had the fastest RTW (median P 50 : 7 days), whereas employees absent due to depression took the longest (P 50 : 54 days). The most influential sociodemographic variables affecting RTW were age, gender and job category. Using a unique and rich database, we found significant differences in SA duration by presenting condition in healthcare workers. MH conditions, and depression specifically, accounted for the most working days' absence. Significant variations in duration were also observed for MSK conditions. Our findings can inform public health practitioners and healthcare managers of the most significant factors impacting MSK-related and MH-related SA to develop and implement tailored and targeted workplace interventions. © 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.

Interns' compliance with accreditation council for graduate medical education work-hour limits.

PubMed

Landrigan, Christopher P; Barger, Laura K; Cade, Brian E; Ayas, Najib T; Czeisler, Charles A

2006-09-06

Sleep deprivation is associated with increased risk of serious medical errors and motor vehicle crashes among interns. The Accreditation Council for Graduate Medical Education (ACGME) introduced duty-hour standards in 2003 to reduce work hours. To estimate compliance with the ACGME duty-hour standards among interns. National prospective cohort study with monthly Web-based survey assessment of intern work and sleep hours using a validated instrument, conducted preimplementation (July 2002 through May 2003) and postimplementation (July 2003 through May 2004) of ACGME standards. Participants were 4015 of the approximately 37 253 interns in US residency programs in all specialties during this time; they completed 29 477 reports of their work and sleep hours. Overall and monthly rates of compliance with the ACGME standards. Postimplementation, 1068 (83.6%; 95% confidence interval [CI], 81.4%-85.5%) of 1278 of interns reported work hours in violation of the standards during 1 or more months. Working shifts greater than 30 consecutive hours was reported by 67.4% (95% CI, 64.8%-70.0%). Averaged over 4 weeks, 43.0% (95% CI, 40.3%-45.7%) reported working more than 80 hours weekly, and 43.7% (95% CI, 41.0%-46.5%) reported not having 1 day in 7 off work duties. Violations were reported during 3765 (44.0%; 95% CI, 43.0%-45.1%) of the 8553 intern-months assessed postimplementation (including vacation and ambulatory rotations), and during 2660 (61.5%; 95% CI, 60.0%-62.9%) of 4327 intern-months during which interns worked exclusively in inpatient settings. Postimplementation, 29.0% (95% CI, 28.7%-29.7%) of reported work weeks were more than 80 hours per week, 12.1% (95% CI, 11.8%-12.6%) were 90 or more hours per week, and 3.9% (95% CI, 3.7%-4.2%) were 100 or more hours per week. Comparing preimplementation to postimplementation responses, reported mean work duration decreased 5.8% from 70.7 (95% CI, 70.5-70.9) hours to 66.6 (95% CI, 66.3-66.9) hours per week (P<.001), and reported mean sleep duration increased 6.1% (22 minutes) from 5.91 (95% CI, 5.88-5.94) hours to 6.27 (95% CI, 6.23-6.31) hours per night (P<.001). However, reported mean sleep during extended shifts decreased 4.5%, from 2.69 (95% CI, 2.66-2.73) hours to 2.57 (95% CI, 2.52-2.62) hours (P<.001). In the first year following implementation of the ACGME duty-hour standards, interns commonly reported noncompliance with these requirements.

Work hours, workload, sleep and fatigue in Australian Rail Industry employees.

PubMed

Dorrian, Jillian; Baulk, Stuart D; Dawson, Drew

2011-01-01

Research suggests that less than 5 h sleep in the 24 h prior to work and/or more than 16 h of wakefulness can significantly increase the likelihood of fatigue-related impairment and error at work. Studies have also shown exponential safety declines with time on shift, with roughly double the likelihood of accident or injury after 10 h relative to the first 8h. While it is acknowledged that reduced sleep, increased wakefulness and longer work hours produce work-related fatigue, few studies have examined the impact of workload on this relationship. Studies in the rail industry have focused on drivers. This study investigated fatigue in a large sample of Australian Rail Industry Employees. Participants were from four companies (n = 90: 85m, 5f; mean age 40.2 ± 8.6 y). Data was analysed for a total of 713 shifts. Subjects wore wrist actigraphs and completed sleep and work diaries for 14-days. They also completed the Samn-Perelli Fatigue Scale at the beginning and end of shifts, and the NASA-TLX workload scale at least twice during each shift. Average (±SD) sleep length (7.2 ± 2.6h), prior wake at shift end (12.0 ± 4.7h), shift duration (8.0 ± 1.3) and fatigue (4.1 ± 1.3, "a little tired, less than fresh") were within limits generally considered acceptable from a fatigue perspective. However, participants received 5 h or less sleep in the prior 24 h on 13%, were awake for at least 16 h at the end of 16% and worked at least 10 h on 7% of shifts. Subjects reported that they felt "extremely tired, very difficult to concentrate," or "completely exhausted, unable to function effectively" on 13% of shifts. Sleep length (OR = 0.88, p < 0.01), shift duration (OR = 1.18, p < 0.05), night shift (REF = morning shift, OR = 2.12, p < 0.05) and workload ratings (OR = 1.2, p < 0.05) were significant predictors of ratings of extreme tiredness/exhaustion (yes/no). While on average, sleep loss, extended wakefulness, longer work hours and work-related fatigue do not appear problematic in this sample, there is still a notable percentage of shifts that are likely to be associated with high levels of work-related fatigue. Given the size of the Australian Rail Industry, with thousands of shifts occurring each day, this is potentially of operational concern. Further, results indicate that, in addition to sleep length, wakefulness and work hours, workload significantly influences fatigue. This has possible implications for bio-mathematical predictions of fatigue and for fatigue management more generally. Copyright © 2010. Published by Elsevier Ltd.

Associations of Shift Work and Its Duration with Work-Related Injury among Electronics Factory Workers in South Korea.

PubMed

Ryu, Jia; Jung-Choi, Kyunghee; Choi, Kyung-Hwa; Kwon, Ho-Jang; Kang, Chungwon; Kim, Hyunjoo

2017-11-21

This study aimed to explore the association between shift work and work-related injuries. We collected data on workers from an electronics factory. This cross-sectional study included 13,610 subjects, who were assessed based on a self-reported questionnaire about their shift work experiences, work-related injuries, and other covariates. Multiple logistic regression models were used to evaluate the associations between shift work and work-related injuries and were estimated using the odds ratio. We found that the current and past shift workers, compared to non-shift workers, were associated with a 2.7- and 1.7-fold higher risk of work-related injury. There was a dose-response relationship between shift work duration and work-related injury among current female shift workers. Shift work increased the risk of work-related injuries, and the impact could be different depending on gender.

Associations of Shift Work and Its Duration with Work-Related Injury among Electronics Factory Workers in South Korea

PubMed Central

Ryu, Jia; Jung-Choi, Kyunghee; Choi, Kyung-Hwa; Kwon, Ho-Jang; Kang, Chungwon

2017-01-01

This study aimed to explore the association between shift work and work-related injuries. We collected data on workers from an electronics factory. This cross-sectional study included 13,610 subjects, who were assessed based on a self-reported questionnaire about their shift work experiences, work-related injuries, and other covariates. Multiple logistic regression models were used to evaluate the associations between shift work and work-related injuries and were estimated using the odds ratio. We found that the current and past shift workers, compared to non-shift workers, were associated with a 2.7- and 1.7-fold higher risk of work-related injury. There was a dose-response relationship between shift work duration and work-related injury among current female shift workers. Shift work increased the risk of work-related injuries, and the impact could be different depending on gender. PMID:29160849

Assessing the Impact of Peer Educator Outreach on the Likelihood and Acceleration of Clinic Utilization among Sex Workers.

PubMed

Krishnamurthy, Parthasarathy; Hui, Sam K; Shivkumar, Narayanan; Gowda, Chandrasekhar; Pushpalatha, R

2016-01-01

Peer-led outreach is a critical element of HIV and STI-reduction interventions aimed at sex workers. We study the association between peer-led outreach to sex workers and the time to utilize health facilities for timely STI syndromic-detection and treatment. Using data on the timing of peer-outreach interventions and clinic visits, we utilize an Extended Cox model to assess whether peer educator outreach intensity is associated with accelerated clinic utilization among sex workers. Our data comes from 2705 female sex workers registered into Pragati, a women-in-sex-work outreach program, and followed from 2008 through 2012. We analyze this data using an Extended Cox model with the density of peer educator visits in a 30-day rolling window as the key predictor, while controlling for the sex workers' age, client volume, location of sex work, and education level. The principal outcome of interest is the timing of the first voluntary clinic utilization. More frequent peer visit is associated with earlier first clinic visit (HR: 1.83, 95% CI, 1.75-1.91, p < .001). In addition, 18% of all syndrome-based STI detected come from clinic visits in which the sex worker reports no symptoms, underscoring the importance of inducing clinic visits in the detection of STI. Additional models to test the robustness of these findings indicate consistent beneficial effect of peer educator outreach. Peer outreach density is associated with increased likelihood of-and shortened duration to-clinic utilization among female sex workers, suggesting potential staff resourcing implications. Given the observational nature of our study, however, these findings should be interpreted as an association rather than as a causal relationship.

Computer work and self-reported variables on anthropometrics, computer usage, work ability, productivity, pain, and physical activity

PubMed Central

2013-01-01

Background Computer users often report musculoskeletal complaints and pain in the upper extremities and the neck-shoulder region. However, recent epidemiological studies do not report a relationship between the extent of computer use and work-related musculoskeletal disorders (WMSD). The aim of this study was to conduct an explorative analysis on short and long-term pain complaints and work-related variables in a cohort of Danish computer users. Methods A structured web-based questionnaire including questions related to musculoskeletal pain, anthropometrics, work-related variables, work ability, productivity, health-related parameters, lifestyle variables as well as physical activity during leisure time was designed. Six hundred and ninety office workers completed the questionnaire responding to an announcement posted in a union magazine. The questionnaire outcomes, i.e., pain intensity, duration and locations as well as anthropometrics, work-related variables, work ability, productivity, and level of physical activity, were stratified by gender and correlations were obtained. Results Women reported higher pain intensity, longer pain duration as well as more locations with pain than men (P < 0.05). In parallel, women scored poorer work ability and ability to fulfil the requirements on productivity than men (P < 0.05). Strong positive correlations were found between pain intensity and pain duration for the forearm, elbow, neck and shoulder (P < 0.001). Moderate negative correlations were seen between pain intensity and work ability/productivity (P < 0.001). Conclusions The present results provide new key information on pain characteristics in office workers. The differences in pain characteristics, i.e., higher intensity, longer duration and more pain locations as well as poorer work ability reported by women workers relate to their higher risk of contracting WMSD. Overall, this investigation confirmed the complex interplay between anthropometrics, work ability, productivity, and pain perception among computer users. PMID:23915209

Efficacy and Safety of Amphetamine Extended-Release Oral Suspension in Children with Attention-Deficit/Hyperactivity Disorder.

PubMed

Childress, Ann C; Wigal, Sharon B; Brams, Matthew N; Turnbow, John M; Pincus, Yulia; Belden, Heidi W; Berry, Sally A

2018-06-01

To determine the efficacy and safety of amphetamine extended-release oral suspension (AMPH EROS) in the treatment of attention-deficit/hyperactivity disorder (ADHD) in a dose-optimized, randomized, double-blind, parallel-group study. Boys and girls aged 6 to 12 years diagnosed with ADHD were enrolled. During a 5-week, open-label, dose-optimization phase, patients began treatment with 2.5 or 5 mg/day of AMPH EROS; doses were titrated until an optimal dose (maximum 20 mg/day) was reached. During the double-blind phase, patients were randomized to receive treatment with either their optimized dose (10-20 mg/day) of AMPH EROS or placebo for 1 week. Efficacy was assessed in a laboratory classroom setting on the final day of double-blind treatment using the Swanson, Kotkin, Agler, M-Flynn, and Pelham (SKAMP) Rating Scale and Permanent Product Measure of Performance (PERMP) test. Safety was assessed measuring adverse events (AEs) and vital signs. The study was completed by 99 patients. The primary efficacy endpoint (change from predose SKAMP-Combined score at 4 hours postdose) and secondary endpoints (change from predose SKAMP-Combined scores at 1, 2, 6, 8, 10, 12, and 13 hours postdose) were statistically significantly improved with AMPH EROS treatment versus placebo at all time points. Onset of treatment effect was present by 1 hour postdosing, the first time point measured, and duration of efficacy lasted 13 hours postdosing. PERMP data mirrored the SKAMP-Combined score data. AEs (>5%) reported during dose optimization were decreased appetite, insomnia, affect lability, upper abdominal pain, mood swings, and headache. AMPH EROS was effective in reducing symptoms of ADHD and had a rapid onset and extended duration of effect. Reported AEs were consistent with those of other extended-release amphetamine products.

The impact of female reproductive function on outcomes after traumatic brain injury.

PubMed

Ripley, David L; Harrison-Felix, Cindy; Sendroy-Terrill, Melissa; Cusick, Christopher P; Dannels-McClure, Amy; Morey, Clare

2008-06-01

To determine the impact of traumatic brain injury (TBI) on female menstrual and reproductive functioning and to examine the relationships between severity of injury, duration of amenorrhea, and TBI outcomes. Retrospective cohort survey. Telephone interview. Women (N=30; age range, 18-45y), between 1 and 3 years postinjury, who had completed inpatient rehabilitation for TBI. Not applicable. Data collected included menstrual and reproductive functioning pre- and postinjury, demographic, and injury characteristics. Outcome measures included the Glasgow Outcome Scale-Extended (GOS-E), the Mayo-Portland Adaptability Inventory-4 (MPAI-4), and the Medical Outcome Study 12-Item Short-Form Health Survey, Version 2 (SF-12v2). The median duration of amenorrhea was 61 days (range, 20-344d). Many subjects' menstrual function changed after TBI, reporting a significant increase in skipped menses postinjury (P<.001) and a trend toward more painful menses (P=.061). More severe TBI, as measured by the duration of posttraumatic amnesia, was significantly predictive of a longer duration of amenorrhea (P=.004). Subjects with a shorter duration of amenorrhea scored significantly better on the SF-12 physical component subscale (P=.004), the GOS-E (P=.05), and the MPAI-4 participation subscale (P=.05) after controlling for age, injury severity, and time postinjury. The severity of TBI was predictive of duration of amenorrhea and a shorter duration of amenorrhea was predictive of better ratings of global outcome, community participation, and health-related quality of life postinjury.

Work-family balance after childbirth: the association between employer-offered leave characteristics and maternity leave duration.

PubMed

Guendelman, Sylvia; Goodman, Julia; Kharrazi, Martin; Lahiff, Maureen

2014-01-01

Early return to work after childbirth has been increasing among working mothers in the US. We assessed the relationship between access to employer-offered maternity leave (EOML) (both paid and unpaid) and uptake and duration of maternity leave following childbirth in a socio-economically diverse sample of full-time working women. We focus on California, a state that has long provided more generous maternity leave benefits than those offered by federal maternity leave policies through the State Disability Insurance program. The sample included 691 mothers who gave birth in Southern California in 2002-2003. Using weighted logistic regression, we examined the EOML-maternity leave duration relationship, controlling for whether the leave was paid, as well as other occupational, personality and health-related covariates. Compared with mothers who were offered more than 12 weeks of maternity leave, mothers with <6 weeks of EOML and those offered 6-12 weeks had five times higher odds of returning to work within 12 weeks; those offered no leave had six times higher odds of an early return. These relationships were similar after controlling for whether the leave was paid and after controlling for other occupational and health characteristics. Access to and duration of employer-offered maternity leave significantly determine timing of return to work following childbirth, potentially affecting work-family balance. Policy makers should recognize the pivotal role of employers in offering job security during and after maternity leave and consider widening the eligibility criteria of the Family and Medical Leave Act.

Sleep variability and fatigue in adolescents: Associations with school-related features.

PubMed

Matos, M G; Gaspar, T; Tomé, G; Paiva, T

2016-10-01

This study aims to evaluate the influences of sleep duration and sleep variability (SleepV), upon adolescents' school-related situations. The Health Behaviour in School-Aged Children (HBSC) survey is based on a self-completed questionnaire. The participants were 3164 pupils (53.7% girls), attending the 8th and 10th grades, 14.9 years old, and were inquired about subjective sleep duration during the week and weekends, SleepV, fatigue, difficulties in sleep initiation, school achievement, feelings towards schools, pressure with school work and skipping classes. Multiple regression models used, as dependent variables: (a) school achievement, (b) disliking school, (c) pressure with school work and (d) skipping classes, using as independent variables, each of the remaining school-related variables, fatigue, total sleep duration and difficulties in sleep initiation. The average sleep duration in the week and during weekdays was lower than recommended for these age groups, and almost half of students had high SleepV between weekdays and weekends. A logistic model revealed that the absence of SleepV was associated with lower perception of school work pressure, less frequent skipping classes, more infrequent fatigue and more infrequent difficulties in sleep initiation. Poor sleep quality, SleepV and insufficient sleep duration affected negatively school-related variables. © 2015 International Union of Psychological Science.

Testing the associations between different aspects of seafarers' employment contract and on-board internet access and their job and life satisfaction and health.

PubMed

Slišković, Ana; Penezić, Zvjezdan

2016-12-01

The aim of this study was to test for associations between different aspects of contract and on-board internet access and seafarers' satisfaction and health. Altogether 298 Croatian seafarers, all officers, employed on cargo ships, with a minimum work experience of two years with their current shipping company, participated in an online survey. The questionnaire included sociodemographic items, questions relating to their employment contract and internet access, and measures of job satisfaction, life satisfaction, mental health, and gastrointestinal and cardiovascular symptoms. Their job- and lifesatisfaction levels were higher for shorter duration on board, favourable ratio of work to non-work days, and compliance with the employment contract regarding the changes to work and non-work days. Mental health differed likewise but only in relation to two aspects of the contract: on-board duration and compliance with the contract. The level of gastrointestinal symptoms was lower in cases of shorter on-board duration and compliance with the contract, and in seafarers who have free, unlimited internet access on board. Lower level of cardiovascular symptoms was found in seafarers with free, unlimited internet access on board. Our findings suggest that in promoting satisfaction and health in seafaring, attention should be given to reducing on-board duration, compliance with the contract, and internet accessibility on board.

Neuroscience discipline science plan

NASA Technical Reports Server (NTRS)

1991-01-01

Over the past two decades, NASA's efforts in the neurosciences have developed into a program of research directed at understanding the acute changes that occur in the neurovestibular and sensorimotor systems during short-duration space missions. However, the proposed extended-duration flights of up to 28 days on the Shuttle orbiter and 6 months on Space Station Freedom, a lunar outpost, and Mars missions of perhaps 1-3 years in space, make it imperative that NASA's Life Sciences Division begin to concentrate research in the neurosciences on the chronic effects of exposure to microgravity on the nervous system. Major areas of research will be directed at understanding (1) central processing, (2) motor systems, (3) cognitive/spatial orientation, and (4) sensory receptors. The purpose of the Discipline Science Plan is to provide a conceptual strategy for NASA's Life Sciences Division research and development activities in the comprehensive area of neurosciences. It covers the significant research areas critical to NASA's programmatic requirements for the Extended-Duration Orbiter, Space Station Freedom, and exploration mission science activities. These science activities include ground-based and flight; basic, applied, and operational; and animal and human research and development. This document summarizes the current status of the program, outlines available knowledge, establishes goals and objectives, identifies science priorities, and defines critical questions in the subdiscipline areas of nervous system function. It contains a general plan that will be used by NASA Headquarters Program Offices and the field centers to review and plan basic, applied, and operational intramural and extramural research and development activities in this area.

Duration of protective immunity conferred by maternal tetanus toxoid immunization: further evidence from Matlab, Bangladesh.

PubMed Central

Koenig, M A; Roy, N C; McElrath, T; Shahidullah, M; Wojtyniak, B

1998-01-01

OBJECTIVES: Although maternal tetanus immunization has been shown to be highly effective in the prevention of neonatal tetanus, unresolved questions remain concerning the required minimum number of doses and the resulting duration of effective immunity. This study examined the duration of effective immunity against neonatal tetanus provided by maternal tetanus immunization. METHODS: A randomized, double-blind cholera vaccine trial of 41,571 children and nonpregnant adult women carried out in 1974 in the Matlab comparison area of rural Bangladesh provided a unique opportunity to address dose and immunity issues. RESULTS: Children of women who received either 1 or 2 injections of tetanus toxoid experienced 4- to 14-day mortality levels consistently lower than those of children of unimmunized mothers. Analysis of neonatal-tetanus-related mortality showed that 2 injections of tetanus toxoid provided significant protection for subsequent durations of up to 12 or 13 years. CONCLUSIONS: The data demonstrate that a limited-dose regimen of maternal tetanus toxoid provides significant and extended protection against the risk of neonatal tetanus death. PMID:9618617

Physical and cognitive capability in mid-adulthood as determinants of retirement and extended working life in a British cohort study.

PubMed

Stafford, Mai; Cooper, Rachel; Cadar, Dorina; Carr, Ewan; Murray, Emily; Richards, Marcus; Stansfeld, Stephen; Zaninotto, Paola; Head, Jenny; Kuh, Diana

2017-01-01

Objective Policy in many industrialized countries increasingly emphasizes extended working life. We examined associations between physical and cognitive capability in mid-adulthood and work in late adulthood. Methods Using self-reported physical limitations and performance-based physical and cognitive capability at age 53, assessed by trained nurses from the Medical Research Council (MRC) National Survey of Health and Development, we examined prospective associations with extended working (captured by age at and reason for retirement from main occupation, bridge employment in paid work after retirement from the main occupation, and voluntary work participation) up to age 68 among >2000 men and women. Results Number of reported physical limitations at age 53 was associated with higher likelihood of retiring for negative reasons and lower likelihood of participating in bridge employment, adjusted for occupational class, education, partner's employment, work disability at age 53, and gender. Better performance on physical and cognitive tests was associated with greater likelihood of participating in bridge or voluntary work. Cognitive capability in the top 10% compared with the middle 80% of the distribution was associated with an odds ratio of bridge employment of 1.71 [95% confidence interval (95% CI) 1.21-2.42]. Conclusions The possibility for an extending working life is less likely to be realized by those with poorer midlife physical or cognitive capability, independently of education, and social class. Interventions to promote capability, starting in mid-adulthood or earlier, could have long-term consequences for extending working.

A novel hydrogel electrolyte extender for rapid application of EEG sensors and extended recordings.

PubMed

Kleffner-Canucci, Killian; Luu, Phan; Naleway, John; Tucker, Don M

2012-04-30

Dense-array EEG recordings are now commonplace in research and gaining acceptance in clinical settings. Application of many sensors with traditional electrolytes is time consuming. Saline electrolytes can be used to minimize application time but recording duration is limited due to evaporation. In the present study, we evaluate a NIPAm (N-isopropyl acrylamide:acrylic acid) base electrolyte extender for use with saline electrolytes. Sensor-scalp impedances and EEG data quality acquired with the electrolyte extender are compared with those obtained for saline and an EEG electrolyte commonly used in clinical exams (Elefix). The results show that when used in conjunction with saline, electrode-scalp impedances and data across the EEG spectrum are comparable with those obtained using Elefix EEG paste. When used in conjunction with saline, the electrolyte extender permits rapid application of dense-sensor arrays and stable, high-quality EEG data to be obtained for at least 4.5 h. This is an enabling technology that will make benefits of dense-array EEG recordings practical for clinical applications. Copyright © 2011 Elsevier B.V. All rights reserved.

The influence of daily sleep patterns of commercial truck drivers on driving performance

PubMed Central

Chen, Guang Xiang; Fang, Youjia; Guo, Feng; Hanowski, Richard J.

2016-01-01

Fatigued and drowsy driving has been found to be a major cause of truck crashes. Lack of sleep is the number one cause of fatigue and drowsiness. However, there are limited data on the sleep patterns (sleep duration, sleep percentage in the duration of non-work period, and the time when sleep occurred) of truck drivers in non-work periods and the impact on driving performance. This paper examined sleep patterns of 96 commercial truck drivers during non-work periods and evaluated the influence these sleep patterns had on truck driving performance. Data were from the Naturalistic Truck Driving Study. Each driver participated in the study for approximately four weeks. A shift was defined as a non-work period followed by a work period. A total of 1397 shifts were identified. Four distinct sleep patterns were identified based on sleep duration, sleep start/end point in a non-work period, and the percentage of sleep with reference to the duration of non-work period. Driving performance was measured by safety-critical events, which included crashes, near-crashes, crash-relevant conflicts, and unintentional lane deviations. Negative binomial regression was used to evaluate the association between the sleep patterns and driving performance, adjusted for driver demographic information. The results showed that the sleep pattern with the highest safety-critical event rate was associated with shorter sleep, sleep in the early stage of a non-work period, and less sleep between 1 a.m. and 5 a.m. This study also found that male drivers, with fewer years of commercial vehicle driving experience and higher body mass index, were associated with deteriorated driving performance and increased driving risk. The results of this study could inform hours-of-service policy-making and benefit safety management in the trucking industry. PMID:26954762

Night shift work and stomach cancer risk in the MCC-Spain study.

PubMed

Gyarmati, Georgina; Turner, Michelle C; Castaño-Vinyals, Gemma; Espinosa, Ana; Papantoniou, Kyriaki; Alguacil, Juan; Costas, Laura; Pérez-Gómez, Beatriz; Martin Sanchez, Vicente; Ardanaz, Eva; Moreno, Victor; Gómez-Acebo, Inés; Fernández-Tardon, Guillermo; Villanueva Ballester, Vicent; Capelo, Rocio; Chirlaque, Maria-Dolores; Santibáñez, Miguel; Pollán, Marina; Aragonés, Nuria; Kogevinas, Manolis

2016-08-01

Night shift work has been classified as a probable human carcinogen by the International Agency for Research on Cancer, based on experimental studies and limited evidence on human breast cancer risk. Evidence at other cancer sites is scarce. We evaluated the association between night shift work and stomach cancer risk in a population-based case-control study. A total of 374 incident stomach adenocarcinoma cases and 2481 population controls were included from the MCC-Spain study. Detailed data on lifetime night shift work were collected including permanent and rotating shifts, and their cumulative duration (years). Adjusted unconditional logistic regression models were used in analysis. A total of 25.7% of cases and 22.5% of controls reported ever being a night shift worker. There was a weak positive, non-significant association between ever having had worked for at least 1 year in permanent night shifts and stomach cancer risk compared to never having worked night shifts (OR=1.2, 95% CI 0.9 to 1.8). However, there was an inverse 'U' shaped relationship with cumulative duration of permanent night shifts, with the highest risk observed in the intermediate duration category (OR 10-20 years=2.0, 95% CI 1.1 to 3.6) (p for trend=0.19). There was no association with ever having had worked in rotating night shifts (OR=0.9, 95% CI 0.6 to 1.2) and no trend according to cumulative duration (p for trend=0.68). We found no clear evidence concerning an association between night shift work and stomach cancer risk. 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/