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Perception-action coupling, the ability to 'read and react' to the environment, is essential for military personnel to operate within complex and unpredictable environments. Exposure to military operational stressors (e.g., caloric restriction, sleep loss, physical exertion), including around-the-clock operations, may compromise perception-action coupling, thereby impacting performance and safety. We examined the combined effects of simulated military operational stress (SMOS) and time-of-day on perception-action coupling. Fifty-seven active duty and reservist military personnel (45 M; 26.4 ± 5.6 years) completed a 5-day SMOS protocol that included two consecutive days of caloric restriction, and sleep restriction, and disruption. Participants completed a tablet-based perception-action coupling task (PACT) that involves perceiving whether virtual balls fit through virtual apertures. Familiarization occurred on day 0. Eight trials across day 1 (18:00, 22:00), 2 (04:00, 18:00, 22:00) and 3 (04:00, 18:00, 22:00) were analyzed. Mixed models were run to examine the interactive and main effects of day, and time-of-day on PACT response speed and accuracy outcomes. PACT response speed and accuracy outcomes improved at 18:00 and 22:00, whereas performance at 04:00 deteriorated across days. Perception-action coupling performance was resilient to SMOS, except in the early morning when the circadian drive for sleep is high, and the effects of sleep loss are more prominent.

Simulated military operational stress (SMOS) provides a useful model to better understand resilience in humans as the stress associated with caloric restriction, sleep deficits, and fatiguing exertion degrades physical and cognitive performance. Habitual physical activity may confer resilience against these stressors by promoting favorable use-dependent neuroplasticity, but it is unclear how physical activity, resilience, and corticospinal excitability (CSE) relate during SMOS. To examine associations between corticospinal excitability, physical activity, and physical performance during SMOS. Fifty-three service members (age: 26 ± 5 yr, 13 women) completed a 5-day and -night intervention composed of familiarization, baseline, SMOS (2 nights/days), and recovery days. During SMOS, participants performed rigorous physical and cognitive activities while receiving half of normal sleep (two 2-h blocks) and caloric requirements. Lower and upper limb CSE were determined with transcranial magnetic stimulation (TMS) stimulus-response curves. Self-reported resilience, physical activity, military-specific physical performance (TMT), and endocrine factors were compared in individuals with high (HIGH) and low CSE based on a median split of lower limb CSE at baseline. HIGH had greater physical activity and better TMT performance throughout SMOS. Both groups maintained physical performance despite substantial psychophysiological stress. Physical activity, resilience, and TMT performance were directly associated with lower limb CSE. Individual differences in physical activity coincide with lower (but not upper) limb CSE. Such use-dependent corticospinal excitability directly relates to resilience and physical performance during SMOS. Future studies may use noninvasive neuromodulation to clarify the interplay among CSE, physical activity, and resilience and improve physical and cognitive performance. NEW & NOTEWORTHY We demonstrate that individual differences in physical activity levels coincide with lower limb corticospinal excitability. Such use-dependent corticospinal excitability directly relates to resilience and physical performance during a 5-day simulation of military operational stress with caloric restriction, sleep restriction and disruption, and heavy physical and cognitive exertion.

Background Preliminary evidence indicates that non–rapid eye movement (NREM) sleep is implicated in enhancing working memory (WM) performance across days in healthy individuals. While REM sleep has been implicated in other forms of memory, its role in WM remains unclear. Further, the relationship between sleep changes and WM improvement is largely unknown in posttraumatic stress disorder (PTSD). Examining the relationship between changes in sleep and WM improvement in healthy participants and participants with PTSD may inform cognitive enhancement strategies and intervention targets. Methods Repeated assessments of WM and overnight measurement of NREM and REM sleep parameters were performed in 79 participants (participants with PTSD: n = 33) during a 48-hour laboratory stay. Relationships between sleep parameter changes, WM performance changes, and clinical characteristics were analyzed in PTSD and healthy groups. Results A between-night enhancement in both NREM and REM sleep parameters in frontoparietal areas predicted across-day better WM performance in healthy participants, particularly in those with improved performance. In contrast, in participants with PTSD, an enhancement of these sleep parameters predicted a worse WM performance and was also associated with more PTSD-related sleep disturbances. Conclusions This study shows that higher sleep activity in frontoparietal areas leads to enhanced WM performance in healthy individuals, whereas in individuals with PTSD, it likely reflects the presence of sleep disturbances that interfere with WM improvement. Interventions focused on addressing sleep disturbances could therefore ameliorate cognitive impairments in individuals with PTSD.

Posttraumatic stress disorder-related sleep disturbances may increase daytime sleepiness and compromise performance in individuals with posttraumatic stress disorder. We investigated nighttime sleep predictors of sleepiness in Veterans with and without posttraumatic stress disorder. Thirty-seven post-9/11 Veterans with posttraumatic stress disorder and 47 without posttraumatic stress disorder (Control) completed a 48-h lab stay. Nighttime quantitative EEG and sleep architecture parameters were collected with polysomnography. Data from daytime sleepiness batteries assessing subjective sleepiness (global vigor questionnaire), objective sleepiness (Multiple Sleep Latency Tests) and alertness (psychomotor vigilance task) were included in analyses. Independent samples t-tests and linear regressions were performed to identify group differences in sleepiness and nighttime sleep predictors of sleepiness in the overall sample and within each group. Participants with posttraumatic stress disorder had higher subjective sleepiness (t = 4.20; p .001) and lower alertness (psychomotor vigilance task reaction time (t = -3.70; p .001) and lapses: t = -2.13; p = .04) than the control group. Objective daytime sleepiness did not differ between groups (t = -0.79, p = .43). In the whole sample, higher rapid eye movement delta power predicted lower alertness quantified by psychomotor vigilance task reaction time (β = 0.372, p = .013) and lapses (β = 0.388, p = .013). More fragmented sleep predicted higher objective sleepiness in the posttraumatic stress disorder group (β = -.467, p = .005) but no other nighttime sleep measures influenced the relationship between group and sleepiness. Objective measures of sleep and sleepiness were not associated with the increased subjective sleepiness and reduced alertness of the posttraumatic stress disorder group.

Study Objectives Sleep spindles are waxing and waning EEG waves exemplifying the main fast oscillatory activity occurring during NREM sleep. Several recent studies have established that sleep spindle abnormalities are present in schizophrenia spectrum disorders, including in early-course and first-episode patients, and those spindle deficits are associated with some of the cognitive impairments commonly observed in these patients. Cognitive deficits are often observed before the onset of psychosis and seem to predict poor functional outcomes in individuals at clinical high-risk for psychosis (CHR). Yet, the presence of spindle abnormalities and their relationship with cognitive dysfunction has not been investigated in CHR. Methods In this study, overnight high-density (hd)-EEG recordings were collected in 24 CHR and 24 healthy control (HC) subjects. Spindle density, duration, amplitude, and frequency were computed and compared between CHR and HC. Furthermore, WM was assessed for both HC and CHR, and its relationship with spindle parameters was examined. Results CHR had reduced spindle duration in centro-parietal and prefrontal regions, with the largest decrease in the right prefrontal area. Moderation analysis showed that the relation between spindle duration and spindle frequency was altered in CHR relative to HC. Furthermore, CHR had reduced WM performance compared to HC, which was predicted by spindle frequency, whereas in HC spindle frequency, duration, and density all predicted working memory performance. Conclusion Altogether, these findings indicate that sleep spindles are altered in CHR individuals, and spindle alterations are associated with their cognitive deficits, thus representing a sleep-specific putative neurophysiological biomarker of cognitive dysfunction in psychosis risk.

Conkright, WR, Beckner, ME, Sinnott, AM, Eagle, SR, Martin, BJ, Lagoy, AD, Proessl, F, Lovalekar, M, Doyle, TLA, Agostinelli, P, Sekel, NM, Flanagan, SD, Germain, A, Connaboy, C, and Nindl, BC. Neuromuscular performance and hormonal responses to military operational stress in men and women. J Strength Cond Res XX(X): 000-000, 2021-Women have recently been integrated into ground close combat positions; however, there are limited data in women in these roles. We aimed to test the hypothesis that there would be no sex-specific neuromuscular responses, but hormonal signaling would be differentially impacted when exposed to simulated military operational stress (SMOS). Neuromuscular performance was assessed daily using a tactical mobility test (TMT) in 54 male and 15 female military members. Blood was drawn before/after TMT. Mood states were assessed each morning. Unloaded 300-m shuttle time increased 6% in both sexes and remained 7% higher after 1 day of recovery compared with baseline (p 0.05). Growth hormone increased in men, but not women, before to after TMT (p < 0.001 vs. p = 0.086). Women experienced a greater decline in insulin-like growth factor-I across days compared with men (ηp2 = 0.778 vs. 0.209, respectively, p < 0.001). Brain-derived neurotrophic factor increased significantly in men only from before to after TMT on day 1 (men: +107% vs. women: +10%) but no difference on days 3 or 4. Cortisol increased 69% from before to after TMT when averaged by sex and day. Negative mood states (depression, tension, and anger) and altered hormonal concentrations were associated with poorer TMT performance. Acute SMOS differentially impacted circulating hormonal milieu in men and women, but no differences in physical performance responses. Unloaded 300-m shuttle was negatively impacted while other fitness domains were maintained. Relationships between performance and mood/endocrine signaling highlight the potential for self-report measures and biomarkers to serve as indicators of performance change.

Sleep-wake disturbances in individuals at clinical high risk (CHR) of psychosis may relate to increased symptom severity and contribute to disease progression. Here, we examined differences in rest-activity rhythms (RAR) measures, derived from actigraphy, and objective sleep outcomes, derived from electroencephalography (EEG), between 12 CHR and 16 healthy comparison (HC) individuals. Further, we examined the relationships between RAR disturbances, objective sleep outcomes and clinical psychosis symptoms (i.e., negative, positive, disorganized, general symptoms). Sleep-wake behaviors were monitored via actigraphy for 3-7 days (CHR: 5.7 ± 1.7 days; HC: 6.3 ± 1.2 days) prior to participants spending a night in the sleep laboratory, which was monitored with EEG. Separate regressions were used to examine the effect of clinical group on RAR measures and objective sleep outcomes after controlling for age and gender. CHR participants were found to be less active, specifically during the evening (17:00-20:00; β = 1.145, SE = 0.362, p = .004) and nighttime (21:00-24:00; β = 1.152, SE = 0.326, p = .002) relative to HC. Further, CHR participants had more fragmented sleep (wake after sleep onset: β = 0.888, SE = 0.395, p = .034) and more hyperarousal during sleep (NREM gamma activity: β = 1.087, SE = 0.348, p = .005), but these sleep disturbances were not related to reduced activity or clinical symptoms, whereas lower nighttime activity was related to more disorganized symptoms (ρ = -.640, p = .025). Thus, increasing activity through behavioral interventions may have additional beneficial effects on CHR clinical symptoms.

Visible abnormalities on the thyroid cartilage may be indicative of perimortem trauma including fractures or sharp force trauma. During autopsy, the thyroid cartilage must be freed of surrounding soft tissue before these abnormalities can be clearly observed. Several processing methods were first experimentally tested on pig ears to narrow down which might work best to process human thyroid cartilage. Several methods in the categories of hot water maceration, chemical/enzyme maceration, and dermestid beetles were then tested on a sample of 37 human thyroid cartilages. An adapted 22-point scoring system was used to score the efficacy of each processing method. Chemical maceration using bleach was found to be the best method for removing surrounding tissue from thyroid cartilage, with Arm & HammerTM powdered laundry detergent as a close second. These methods are inexpensive, quick, and easy to implement, making them a simple addition to busy medical examiner's offices or forensic anthropology laboratories.

In recent years, catastrophic hurricanes have devastated numerous areas, prompting a need to build resilience particularly in at-risk populations that rely on health care and social services. The Maternal and Child Health (MCH) workforce covers a wide breadth of services to pregnant women, families, and children with special health care needs. Research has noted the need to strengthen this workforce with training and skills to help their patients and clients prepare, respond, and recover from disasters.Focus groups and interviews with 35 Florida parents and professionals impacted by Hurricanes Irma, Maria, and Michael were conducted to evaluate the stressors placed on systems of care serving mothers and infants in Florida. Journey mapping was used to explore opportunities for improving MCH training and services.Results highlight the importance of increased communication and collaboration between families and providers, coordination among health care and social services providers, effective public messaging, tailored preparedness materials and processes, and the need for post-disaster mental health services and employment resources.Ultimately, hurricane preparation and mitigation are key for improving community resilience and these efforts should be tailored to MCH populations as well as delivered by the providers who know their needs best.

Ultra-short-term (UST;5 min) heart rate variability (HRV) is increasingly used to indirectly assess autonomic nervous system modulation and physical health. However, UST HRV estimates may vary with measurement technique, physiological state, and data preprocessing. The purpose of this investigation was to assess the information content of UST HRV and its sensitivity to different physiological states and preprocessing techniques. 26 time, frequency, and non-linear HRV measures were determined in 80 healthy men (age: 22.1 ± 3.7 yr) and 25 women (age: 19.4 ± 2.8 yr) from 2-min ECG recordings during seated and standing rest, low-intensity exercise, and seated recovery after maximal exercise. For men, HRV measures obtained during each condition were further analyzed with principal component analysis, k-means clustering, and one-way ANCOVAs. Backward stepwise regression was used to determine the ability of UST HRV to predict aerobic fitness. The sensitivity of UST HRV estimates to different artifact correction procedures was determined with intraclass correlation coefficients. Compared with men, women displayed HRV characteristics suggestive of greater vagal modulation. Nearly 80% of HRV information content was distilled into three principal components comprised of similar measures across conditions. K-means clusters varied in composition and HRV characteristics but not aerobic fitness, which was best predicted by HRV during standing rest. HRV estimates differed depending on artifact correction procedures but were generally similar after individualized correction. Our results indicate that UST HRV measures display redundancy but convey state-specific information and do not strongly predict aerobic fitness in healthy men. Most UST HRV measures are robust to slight differences in artifact correction procedures.

Youth at Clinical High Risk (CHR) represent a unique population enriched for precursors of major psychiatric disorders. Sleep disturbances are consistently reported in CHR individuals. However, there is a dearth of studies investigating quantifiable objective measures of sleep dysfunction in CHR youth. In this study, sleep high density (hd)-EEG recordings were collected in twenty-two CHR and twenty healthy comparison (HC) subjects. Sleep architecture parameters, as well as sleep EEG power spectra in five frequency bands, were computed and compared between CHR and HC groups during non-rapid eye movement (NREM) sleep. Furthermore, correlation analyses between sleep EEG power spectra, sleep architecture parameters, and clinical symptoms, assessed with the Scale of Prodromal Symptoms (SOPS), were conducted in CHR participants. Our results show that CHR individuals had more Wakefulness After Sleep Onset (WASO) compared to HC participants. CHR also showed a higher NREM sleep gamma EEG power, which was observed in a large fronto-parieto-occipital area, relative to HC. Additionally, higher NREM gamma activity in lateral fronto-occipital regions was associated with more WASO, and increased NREM gamma power in medial fronto/parietal areas correlated with worse SOPS negative symptoms. Altogether, these findings suggest that topographically specific increases in EEG gamma activity during NREM sleep represent neurophysiological signatures underlying some of the objectively assessed sleep disturbances and clinical symptoms of CHR individuals.

The double-cone coil (D-CONE) is frequently used in transcranial magnetic stimulation (TMS) experiments that target the motor cortex (M1) lower-limb representation. Anecdotal evidence and modeling studies have shed light on the off-target effects of D-CONE TMS but the physiological extent remains undetermined.To characterize the off-target effects of D-CONE TMS based on bilateral corticospinal responses in the legs and hands.Thirty (N = 30) participants (9 women, age: 26 ± 5yrs) completed a stimulus-response curve procedure with D-CONE TMS applied to the dominant vastus lateralis (cVL) and motor-evoked potentials (MEPs) recorded in each active VL and resting first dorsal interosseous (FDI). As a positive control (CON), the dominant FDI was directly targeted with a figure-of-eight coil and MEPs were similarly recorded in each active FDI and resting VL. MEPOff-target responses were evident in all muscles, with similar MEPConcurrent MEP recordings in bilateral upper- and lower-extremity muscles confirm that lower-limb D-CONE TMS produces substantial distance-dependent off-target effects. In addition to monitoring corticospinal responses in off-target muscles to improve targeting accuracy in real-time, future studies may incorporate off-target information into statistical models post-hoc.

Background Pulmonary function tests (PFTs) are currently recommended for liver transplant candidates. We hypothesized that PFTs may not provide added clinical value to the evaluation of liver transplant patients. Methods We conducted a retrospective cohort study of adult cadaveric liver transplants from 2012 to 2018. Abnormal PFTs were defined as restrictive disease of diffusing capacity of the lungs for carbon monoxide (DLCO) Results We analyzed data on 415 liver transplant patients (358 abnormal PFT results and 57 normal results). The liver transplant patients with abnormal PFTs had no difference in number of intensive care unit (ICU) days ( P = .68), length of stay ( P = .24), or intubation days ( P = .33). There were no differences in pulmonary complications including pleural effusion ( P = .30), hemo/pneumothorax ( P = .74), pneumonia ( P = .66), acute respiratory distress syndrome ( P = .57), or pulmonary edema ( P = .73). The significant finding between groups was a higher rate of reintubation in liver transplant patients with normal PFTs ( P = .02). There was no difference in graft survival ( P = .53) or patient survival ( P = .42). Discussion Abnormal PFTs, found in 86% of liver transplant patients, did not correlate with complications, graft failure, or mortality. PFTs contribute to the high cost of liver transplants but do not help predict which patients are at risk of postoperative complications.

INTRODUCTION: Designed as a more ecological measure of reaction times, the Perception-Action Coupling Task (PACT) has shown good reliability and within-subject stability. However, a lengthy testing period was required. Perceptual-motor judgments are known to be affected by proximity of the stimulus to the action boundary. The current study sought to determine the effects of action boundary proximity on PACT performance, and whether redundant levels of stimuli, eliciting similar responses, can be eliminated to shorten the PACT.METHODS: There were 9 men and 7 women who completed 4 testing sessions, consisting of 3 familiarization cycles and 6 testing cycles of the PACT. For the PACT, subjects made judgments on whether a series of balls presented on a tablet afford “posting” (can fit) through a series of apertures. There were 8 ratios of ball to aperture size (B-AR) presented, ranging from 0.2 to 1.8, with each ratio appearing 12 times (12 trials) per cycle. Reaction times and judgment accuracy were calculated, and averaged across all B-ARs. Ratios and individual trials within each B-AR were systematically eliminated. Variables were re-averaged, and intraclass correlation coefficients (ICC) and coefficients of variation (CVTE) were calculated in an iterative manner.RESULTS: With elimination of the 0.2 and 1.8 B-ARs, the PACT showed good reliability (ICC = 0.81–0.99) and consistent within-subject stability (CVTE = 2.2–14.7%). Reliability (ICC = 0.81–0.97) and stability (CVTE = 2.6–15.6%) were unaffected with elimination of up to 8 trials from each B-AR.DISCUSSION: The shortened PACT resulted in an almost 50% reduction in total familiarization/testing time required, significantly increasing usability.Johnson CD, LaGoy AD, Pepping G-J, Eagle SR, Beethe AZ, Bower JL, Alfano CA, Simpson RJ, Connaboy C. Action boundary proximity effects on perceptual-motor judgments. Aerosp Med Hum Perform. 2019; 90(12):1000–1008.

Purpose To study the impact of 48 h of simulated military operational stress (SMOS) on executive function, in addition to the role of trait resilience (RES) and aerobic fitness (FIT) on executive function performance. Associations between executive function and neuropeptide-Y (NPY), brain-derived neurotropic factor (BDNF), insulin-like growth factor-I (IGF-I), oxytocin, and α-klotho (klotho) were assessed to elucidate potential biomarkers that may contribute to cognitive performance during a multi-factorial stress scenario. Methods: Fifty-four service members (SM) (26.4 ± 5.4 years, 178.0 ± 6.5 cm, 85.2 ± 14.0 kg) completed the 5-day protocol, including daily physical exertion and 48 h of restricted sleep and caloric intake. Each morning subjects completed a fasted blood draw followed by Cognition, a 10-part cognitive test battery assessing executive function. SMs were grouped into tertiles [low (L-), moderate (M-), high (H-)] based on Connor Davidson Resilience Score (RES) and V ˙ O2peak (FIT). Repeated measures ANOVA were run to analyze the effect of day on cognitive performance and biomarker concentration. Separate two-way mixed ANOVAs were run to determine the interaction of group by day on cognitive function. Friedman test with Bonferroni-corrected pairwise comparisons were used if assumptions for ANOVA were not met. Associations between changes in biomarkers and cognitive performance were analyzed using parametric and non-parametric correlation coefficients. Results: SMOS reduced SM vigilance –11.3% (p 0.05). Vigilance was compromised during SMOS in L - and M-RES (p = 0.007 and p = 0.001, respectively) as well as L - and M-FIT (p = 0.001 and p = 0.031, respectively). SMOS reduced circulating concentrations of α-klotho -7.2% (p = 0.004), NPY -6.4% (p = 0.001), and IGF-I -8.1% (p 0.05). Several modest associations between neuroendocrine biomarkers and cognitive performance were identified. Conclusion: This study demonstrates H-FIT and H-RES may buffer the impact of SMOS on vigilance. SMOS negatively impacted circulating neuroendocrine biomarkers. While BDNF returned to baseline concentrations by the end of the 5 d protocol, NPY, IGF-I, and α-klotho may require a longer recovery period. These data suggest that the military may benefit by training and/or selection processes targeting at augmenting trait resilience and aerobic fitness for increased readiness.

Recent studies have concluded that athletes have increased risk of musculoskeletal injury following sport-related concussion. While an underlying explanation is still unknown, perceptual-motor control may be implicated in this increased risk. Some authors have purported that indirect perception (i.e., a “top-down” view of neuromuscular control) may be disrupted following sport-related concussion. Direct perception theory states that the athlete and environment are inextricably linked in a continuous perception–action coupling loop. That is, the athlete is able to directly perceive opportunities for action (e.g., “affordances”) in the environment. Based on these notions, the aim of the current paper was to introduce a theoretical model that argues that sport-related concussion may dysregulate the direct perception process, potentially increasing behavioral risk of musculoskeletal injury during sport. Our model is integrated with a sport-related concussion clinical treatment model, which highlights individualized profiles that characterize the heterogeneous response to sport-related concussion. These profiles have a typical constellation of symptoms (e.g., anxiety, fatigue, ocular dysfunction, etc.), which themselves have been associated with disrupted perception–action coupling, independent of sport-related concussion. Therefore, we argue that athletes who have not re-established perception–action coupling loops following sport-related concussion may be at increased risk of subsequent musculoskeletal injury.

Background Intentional self-inflicted injuries present unique challenges in treatment and prevention. We hypothesized intentional self-inflicted injuries would have higher in-hospital and postdischarge mortality than nonintentional self-inflicted injuries trauma. Methods Adult patients evaluated 2008 to 2012 were identified in our trauma registry and matched with mortality data from the National Death Index. Intentional self-inflicted injuries were identified using E-Codes. Readmissions were identified and analyzed. Intentional self-inflicted injuries patients who died in-hospital were compared with those surviving to discharge. Univariate analysis was performed using nonparametric tests. Kaplan-Meier curves were plotted to compare mortality ≤5 years postdischarge between intentional self-inflicted injuries and non-intentional self-inflicted injuries patients. Results In the study, 8,716 patient records were evaluated with 245 (2.8%) classified as intentional self-inflicted injuries. Eighteen (7.8%) patients with intentional self-inflicted injuries had multiple admissions, compared with 352 (4.4%) patients with nonintentional self-inflicted injuries with readmissions ( P = . 0210). In-hospital mortality was higher for intentional self-inflicted injuries compared with patients with non-intentional self-inflicted injuries (18.7% vs 4.9%, P 0001). Survival analysis demonstrated that patients with intentional self-inflicted injuries had significantly lower postdischarge mortality at multiple time points. Conclusion Patients with intentional self-inflicted injuries trauma have high in-hospital mortality, but low postdischarge mortality. We attribute this to high lethality mechanisms but appropriate psychiatric treatment and rehabilitation. However, the high intentional self-inflicted injuries readmission rate indicates further study of intentional self-inflicted injuries follow-up is warranted. Better prevention strategies are needed to identify and intervene in patients at-risk for intentional self-inflicted injuries.

BACKGROUND: The perception-action coupling task (PACT) was designed as a more ecologically valid measure of alertness/reaction times compared to currently used measures by aerospace researchers. The purpose of this study was to assess the reliability, within-subject variability, and systematic bias associated with the PACT.METHODS: There were 16 subjects (men/women = 9 / 7; age = 27.8 ± 3.6 yr) who completed 4 identical testing sessions. The PACT requires subjects to make judgements on whether a virtual ball could fit into an aperture. For each session, subjects completed nine cycles of the PACT, with each cycle lasting 5 min. Judgement accuracy and reaction time parameters were calculated for each cycle. Systematic bias was assessed with repeated-measures ANOVA, reliability with intraclass correlation coefficients (ICC), and within-subject variability with coefficients of variation (CVTE).RESULTS: Initiation time (Mean = 0.1065 s) showed the largest systematic bias, requiring the elimination of three cycles to reduce bias, with all other variables requiring, at the most, one. All variables showed acceptable reliability (ICC > 0.70) and within-subject variability (CVTE < 20%) with only one cycle after elimination of the first three cycles.CONCLUSIONS: With a three-cycle familiarization period, the PACT was found to be reliable and stable.Connaboy C, Johnson CD, LaGoy AD, Pepping G-J, Simpson RJ, Deng Z, Ma L, Bower JL, Eagle SR, Flanagan SD, Alfano CA. Intersession reliability and within-session stability of a novel perception-action coupling task. Aerosp Med Hum Perform. 2019; 90(2):77-83.

Background Exertional lower body musculoskeletal injuries (ELBI) cost billions of dollars and compromise the readiness and job performance of military service and public safety workers (i.e., tactical populations). The prevalence and burden of such injuries underscores the importance of prevention efforts during activities necessary to sustain core occupational competencies. Attempts to synthesize prevention techniques specific to tactical populations have provided limited insight on the comparative efficacy of interventions that do not modify physical training practices. There is also a need to assess the influence of sex, exposure, injury classification scheme, and study design. Thus, the primary purpose of the systematic review and planned meta-analysis detailed in this protocol is to evaluate the comparative efficacy of ELBI prevention strategies in tactical populations. Methods A systematic search strategy will be implemented in MEDLINE, EMBASE, Cochrane, and CINAHL. A multi-tiered process will be used to capture randomized controlled trials and prospective cohort studies that directly assess the prevention of ELBI in tactical population(s). Extracted data will be used to compare prevention strategies and assess the influence of heterogeneity related to occupation, sex, exposure, injury characteristics, and study quality. In addition, individual risk of bias, meta-bias, and the quality of the body of evidence will be rigorously tested. Discussion This systematic review and planned meta-analysis will comprehensively evaluate ELBI mitigation strategies in tactical populations, elucidate factors that influence responses to treatment, and assess the overall quality of the body of research. Results of this work will guide the prioritization of ELBI prevention strategies and direct future research efforts, with direct relevance to tactical, health and rehabilitation science, and human performance optimization stakeholders. Systematic review registration The systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 3 Jan 2018 (registration number CRD42018081799). Electronic supplementary material The online version of this article (10.1186/s13643-018-0730-9) contains supplementary material, which is available to authorized users.

Background Musculoskeletal injuries (MSI) represent more than half of all injuries in tactical populations (i.e., military service and public safety workers including police, firefighters, emergency medical services (EMS)). Most lower extremity MSIs result from physical exertion during training, occupational tasks, and recreation. Such exertional lower extremity injuries (ELEI) produce a significant human and financial cost. Accordingly, significant efforts have been made to identify sensitive, specific, and reliable predictors of ELEI. There is a need to synthesize and evaluate the predictive value of risk factors for ELEI while addressing the influence of occupation, sex, exposure, injury characteristics, and study quality. Therefore, the purpose of this systematic review and planned meta-analysis is to evaluate risk factors for ELEI in tactical populations. Methods After the development of a search strategy, comprehensive searches will be conducted in MEDLINE, EMBASE, Cochrane, and CINAHL databases. Articles will be screened with a multi-user process and delimited to prospective comparative cohort studies that directly measure injury occurrence in the target population(s). Extracted data will be synthesized and assessed for reporting bias, meta-bias, and overall quality, with subgroup analyses to determine the influence of participant, injury, and exposure characteristics in addition to study quality. Discussion This systematic review and planned meta-analysis will comprehensively evaluate ELEI risk factors. Information gained will inform injury prevention protocols, facilitate the use of improved measurements, and identify requirements for future research. Trial Registration The systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 3 Jan 2018 (registration number CRD42018056977). Electronic supplementary material The online version of this article (10.1186/s13643-018-0883-6) contains supplementary material, which is available to authorized users.

Retinal prostheses promise to be a viable therapy for many forms of blindness. Direct stimulation of neurons using an organic light-sensitive, self-assembled monolayer surface offers a simple alternative to conventional semiconductor technology. For this purpose we have derivatized an indium tin oxide (ITO) substrate with the photosensitive dye, NK5962, using 3-(aminopropyl)trimethoxysilane (APTMS) as cross-linker. The surface was characterized through contact angle goniometry, electrochemical impedance spectroscopy, grazing angle infrared and ultraviolet-visible spectrophotometry. NG108-15 neurons were grown on the ITO-APTMS-NK5962 surface and neural responses from electrical stimulation vs. photostimulation through the ITO-APTMS-NK5962 surface were measured using patch clamp electrophysiology. Under these conditions, photostimulation of depolarized cells caused an approximate 2-fold increase in voltage-gated sodium (Na(+)) current amplitude at a membrane potential of -30mV. Our results demonstrate the feasibility of stimulating neurons, grown on light-sensitive surfaces, with light impulses, which ultimately may facilitate the fabrication of a simple, passive retinal prosthetic.

A 27-year-old primigravida patient with diastrophic dysplasia (DTD) presented to our obstetrics clinic at 8 weeks' gestational age. Diastrophic dysplasia is a rare, autosomal-recessive abnormality that presents multiple challenges to perinatal anesthetic management, including difficult airway management and relative contraindications to neuraxial anesthesia. The patient underwent elective cesarean delivery at 35 weeks' gestational age under general anesthesia. In this report, we describe our preoperative evaluation and management strategy that involved a multidisciplinary care team.

Obesity is a major health problem. Effective treatment requires understanding the homeostatic responses to caloric restriction.The aim was to study Roux-en-Y gastric bypass patients longitudinally for 6 months after surgery to identify major factors modulating fat loss.We studied 13 patients (11 females and two males) aged 41.2 ± 2 yr. Mean body mass index was 44.6 ± 1.2 kg/m(2), with 50 ± 1% body fat (58.3 kg). Selection excluded patients with confounding comorbidities or treatments.Caloric intake was reduced 742 ± 82 kcal/d by 1 month and 450 kcal/d between 2 and 4 months postoperatively. By 6 months, relative to baseline, body mass index decreased 24.8 ± 1.1%; percentage body fat, 37.3 ± 3.2% (21.7 kg); fat free mass (FFM), 9.7 ± 1.2%; and resting metabolic rate (RMR), 18.1 ± 4.3%. RMR correlated with FFM at all times (r = 0.71; P0.0001), but FFM explained no more than 50% of RMR variance. Exercise capacity (treadmill walking, 53 m/min with increasing grade) improved with time. Mean nonexercise physical activity level was low (1.2, or 20% of RMR), with considerable variance among individuals. Fat loss did not correlate with the aggregate energy deficit or its individual components. Resting or postexercise respiratory exchange ratio (RER) was lowest, whereas plasma β-OH-butyrate and glycerol were highest, between 1 and 2 months after surgery. RER increased linearly with mild exercise, and fat loss correlated positively with physical activity level and RER.Although the ultimate cause for weight loss is the energy deficit, the variance in fat loss correlated with glucose oxidation, suggesting that glucose partition between oxidation (muscle) and storage (adipose tissue) is an important factor affecting fat loss in individuals submitted to Roux-en-Y gastric bypass.

The polycyclic aromatic hydrocarbons (PAHs; also referred to as the polynuclear aromatic hydrocarbons or PNAs) are commonly encountered at hazardous waste sites and are often the focus of site remediation activities. However, toxicity criteria are not available for all the PAHs. In the past, EPA has assessed risks posed by mixtures of PAHs by assuming that all carcinogenic PAHs are as potent as benzo[a]pyrene (B[a]P), one of the most potent PAHs. The available information on the toxicity of the PAHs suggests that most are considerably less potent than B[a]P and therefore, the EPA approach is likely to overestimate risks. Several approaches have been developed to allow the relative potency of the different PAHs to be considered in a site-specific risk assessment. This paper evaluates these approaches and presents a modified version that we feel more accurately reflects the state of knowledge on the relative potency of these compounds.

Questions about medication use during pregnancy and lactation are a concern for women and healthcare providers. Unfortunately, there is little experience with the use of most medications in human pregnancy and lactation at the time they are marketed. Even when information is available, it may not be readily accessible to women and healthcare providers. Nevertheless, medication use by pregnant and breastfeeding women may be beneficial, and even essential, to ensure the health of both mother and child. In addition, almost half of pregnancies in the United States each year are unintended, and medication exposures may occur in the early weeks of gestation before a pregnancy is recognized. For these reasons, it is critical that up-to-date information about the effects of medication use during pregnancy and lactation and the management of maternal conditions be available to women and healthcare providers. A comprehensive, coordinated public health approach that builds on and expands existing activities is needed to generate information about medication use, make that information readily available, and translate it into safe and effective healthcare. Critical components of this system include a central source of up-to-date information, further development and coordination of monitoring and research activities, the availability of counseling services throughout the country, development of standard communication messages, and a panel of experts to provide oversight. This will require collaborative support from government agencies, nonprofit organizations, academic and public health professionals, and healthcare providers to ensure safe and beneficial use of medications during pregnancy and lactation.

Polycyclic aromatic hydrocarbons (PAHs) were one of the first classes of compounds identified as carcinogens and are often chemicals of concern at hazardous waste sites. Remediation goals established by regulatory agencies for carcinogenic PAHs in soil are generally either risk based or based on the method detection limits. PAHs are products of incomplete combustion, are components of petroleum, and as such, are prevalent in the environment from both natural and anthropogenic sources. Background concentrations are often above risk- or detection limit-based criteria, and therefore these remediation goals are of limited practical use as target criteria. In addition, the approaches used to establish target criteria do not account for several factors that may produce over- or underestimates of risk associated with the PAHs. Because of the frequency with which these compounds are detected, it is imperative that reasonably achievable and practical remediation goals be established. This paper examines the various factors that contribute to over- and underestimates of risks associated with PAHs and presents an approach for establishing cleanup criteria that takes into account health risks, background concentrations, and achievability.

Assessing the risks to human health posed by contaminants present in soil requires an estimate of likely soil ingestion rates. In the past, direct measurements of soil ingestion were not available and risk assessors were forced to estimate soil ingestion rates based on observations of mouthing behavior and measurements of soil on hands. Recently, empirical data on soil ingestion rates have become available from two sources (Binder et al., 1986 and van Wijnen et al., 1986). Although preliminary, these data can be used to derive better estimates of soil ingestion rates for use in risk assessments. Estimates of average soil ingestion rates derived in this paper range from 25 to 100 mg/day, depending on the age of the individual at risk. Maximum soil ingestion rates that are unlikely to underestimate exposure range from 100 to 500 mg. A value of 5,000 mg/day is considered a reasonable estimate of a maximum single-day exposure for a child with habitual pica.