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BACKGROUND: Manganese (Mn) plays a significant role in both human health and global industries. Epidemiological studies of exposed populations demonstrate a dose-dependent association between Mn and neuromotor effects ranging from subclinical effects to a clinically defined syndrome. However, little is known about the relationship between early life Mn biomarkers and adolescent postural balance OBJECTIVES: This study investigated the associations between childhood and adolescent Mn biomarkers and adolescent postural balance in participants from the longitudinal Marietta Communities Actively Researching Exposures Study (CARES) cohort. METHODS: Participants were recruited into CARES when they were 7–9 y old, and reenrolled at 13–18 years of age. At both time points, participants provided samples of blood, hair, and toenails that were analyzed for blood Mn and lead (Pb), serum cotinine, hair Mn, and toenail Mn. In adolescence, participants completed a postural balance assessment. Greater sway indicates postural instability (harmful effect), whereas lesser sway indicates postural stability (beneficial effect). Multivariable linear regression models were conducted to investigate the associations between childhood and adolescent Mn biomarkers and adolescent postural balance adjusted for age, sex, height–weight ratio, parent/caregiver intelligence quotient, socioeconomic status, blood Pb, and serum cotinine. RESULTS: CARES participants who completed the adolescent postural balance assessment (푛 = 123) were 98% White and 54% female and had a mean age of 16 y (range: 13–18 y). In both childhood and adolescence, higher Mn biomarker concentrations were significantly associated with greater adolescent sway measures. Supplemental analyses revealed sex-specific associations; higher childhood Mn biomarker concentrations were significantly associated with greater sway in females compared with males DISCUSSION: This study found childhood and adolescent Mn biomarkers were associated with subclinical neuromotor effects in adolescence. This study demonstrates postural balance as a sensitive measure to assess the association between Mn biomarkers and neuromotor function. [ABSTRACT FROM AUTHOR]

Objectives. Postural imbalance can result from hyperthermia-mediated muscular fatigue and is a major factor contributing to injuries from falling. The objective of this study was to investigate the effect of exercise-induced hyperthermia and the impact of cooling on postural balance while wearing fire-fighters' protective clothing (FPC) in a hot environment. Methods. A portable force platform measured postural balance characterized by postural sway patterns using center of pressure metrics. Twelve healthy, physically fit males were recruited to stand on the force platform once with eyes open and once with eyes closed before and after treadmill exercise (40% ...O2max) inside an environmental chamber under hot and humid conditions (30 °C and 70% relative humidity) while wearing FPC. Subjects participated in two randomly assigned experimental phases: control and cooling intervention. Results. A significant increase in physiological responses and postural balance metrics was observed after exercising in the heat chamber while wearing FPC. Cooling resulted in a significant effect only on postural sway speed after exercise-induced hyperthermia. Conclusions. Hyperthermia can negatively alter postural balance metrics, which may lead to an increased likelihood of falling. The utilization of body cooling reduced the thermal strain but had limited impact on postural balance stability. [ABSTRACT FROM AUTHOR]

Firefighters' protective clothing (FPC) can limit human thermoregulation due to limited water vapor permeability and insulation. This study investigated the effect of cooling on the physiological responses and probability of hyperthermia in subjects wearing FPC during exercise in a hot environment. Twelve males participated in this study. A maximal graded treadmill exercise test was performed to measure maximal oxygen uptake ( V ̇ O2max) and to assess subjects' capacity to perform the assigned exercise. Exercise included treadmill walking at 40% V ̇ O2max in warm (30 °C) and humid (70% RH) conditions for 40 min while wearing FPC. Subjects participated in two randomly counterbalanced assigned experimental protocols: control (no cooling) and intervention (cooling). The experimental intervention consisted of a cooling garment infused with cooled water (18 °C) through silastic tubing sewn into the fabric and worn underneath FPC. Each subject served as their own control and, therefore, completed both the control and intervention of the protocol. A logistic regression model was used to analyze the interaction effect of cooling on the probability of progression to hyperthermia (Tc ≥ 38 °C). Subjects' physiological responses increased during exercise in a warm and humid environment. Active cooling decreased (p < 0.05) the thermal stress thereby reducing the probability of hyperthermia while exercising in hot and humid conditions. The results indicate that when cooling was used each subject, on average, was 91% less likely to reach the lower threshold limit of hyperthermia. Exercise in hot environments while wearing FPC results in significant physiological strain, which may lead to hyperthermia. Utilization of a cooling garment reduced physiological strain and the probability of hyperthermia. [ABSTRACT FROM AUTHOR]

BACKGROUND: Prescribing patient care providers regularly experience insufficient sleep, putting them at increased risk of committing occupational injuries, accidents, and errors and developing chronic health conditions. OBJECTIVE: Identify antecedents to short sleep (≤6-hours sleep in 24-hour period) in the understudied population of hospital-based Advanced Practice Providers (APPs). METHODS: Using an ethnographic research design, data included APP and key stakeholder interviews, hospital observations, and relevant documents. Interview data were analyzed using modified constant comparative method. RESULTS: Nine APPs were interviewed, revealing four themes: Social/Family Obligations and Value of Connectivity, Community Value of Sleep, Organizational Value of Sleep, and Individual Biology and How the Body Values Sleep. APP decisions to prioritize sleep are based on an interplay of societal, professional, organizational, and personal values. Triangulated data verified results, except regarding how APP sleep deficit can lead to mood disturbances and the lack sleep consideration in patient care error reporting. CONCLUSIONS: Findings demonstrate the importance of consistency in messaging, action, and policy when promoting occupational sleep health among healthcare workers. Implications include instituting worker sleep education, leadership modeling healthy sleep habits, and inclusion of sleep in root cause analyses. Additional consideration includes evaluating the influence of nursing culture on nurse practitioners' sleep habits. [ABSTRACT FROM AUTHOR]

Extreme chronotype and circadian disrupting work hours may increase nurse disease risks. This national, cross-sectional study of nurses (N = 527) had three hypotheses. When chronotype and shift times are incongruent, nurses will experience increased likelihood of (1) obesity, (2) cardiovascular disease/risk factors, and (3) obesity or cardiovascular disease/risk factors when theoretically linked variables exist. Chronotype mismatched nurses' (n = 206) average sleep (6.1 hours, SD = 1.2) fell below 7–9 hours/24-hours sleep recommendations. Proportion of male nurses was significantly higher chronotype mismatched (12.3%) than matched (6.3%). Analyses found no direct relationship between chronotype match/mismatch with outcome variables. Exploratory interaction analysis demonstrated nurses with mismatched chronotype and above average sleep quality had an estimated 3.51 times the adjusted odds (95% CI 1.52,8.17; p =.003) of being obese. Although mechanism is unclear, this suggests sleep quality may be intricately associated with obesity. Further research is needed to inform nurses on health risks from disrupted sleep, chronotypes, and shift work. [ABSTRACT FROM AUTHOR]

This study investigated the effects of visual cues, muscular fatigue, task performance and experience of working on inclined surfaces on activity of postural muscles in the lower limbs associated with maintaining balance on three inclined surfaces – 0°, 14° and 26°. Normalised electromyographic (NEMG) data were collected in 44 professional roofers bilaterally from the rectus femoris, biceps femoris, tibialii anterior and gastrocnemii medial muscle groups. The 50th and 95th percentile NEMG amplitudes were used as EMG variables. Results showed that inclination angle and task performance caused a significant increase in the NEMG amplitudes of all postural muscles. Visual cues were significantly associated with a decrease in the 95th percentile EMG amplitude for the right gastrocnemius medial and tibialis anterior. Fatigue was related to a significant decrease in the NEMG amplitude for the rectus femoris. Experience of working on inclined surfaces did not have a significant effect on the NEMG amplitude. Practitioner Summary:Increasing angle of the working surface and task performance are two main factors contributing to muscular loading in the lower limb muscles. Input of visual cues while working on inclined surfaces may provide beneficial effects on reducing muscular loading to prevent occupational falls. [ABSTRACT FROM AUTHOR]