Group-level Mean Research Articles

A spectrum of altered non-rapid eye movement sleep in schizophrenia.

Multiple facets of sleep neurophysiology, including electroencephalography (EEG) metrics such as non-rapid eye movement (NREM) spindles and slow oscillations, are altered in individuals with schizophrenia (SCZ). However, beyond group-level analyses, the extent to which NREM deficits vary among patients is unclear, as are their relationships to other sources of heterogeneity including clinical factors, ageing, cognitive profiles and medication regimens. Using newly collected high-density sleep EEG data on 103 individuals with SCZ and 68 controls, we first sought to replicate our previously reported group-level differences between patients and controls (original N=130) during N2 stage. Then in the combined sample (N=301 including 175 patients), we characterized patient-to-patient variability. We replicated all group-level mean differences and confirmed the high accuracy of our predictive model (AUC=0.93 for diagnosis). Compared to controls, patients showed significantly increased between-individual variability across many (26%) sleep metrics. Although multiple clinical and cognitive factors were associated with NREM metrics, collectively they did not account for much of the general increase in patient-to-patient variability. Medication regimen was a greater contributor to variability. Some sleep metrics including fast spindle density showed exaggerated age-related effects in SCZ, and patients exhibited older predicted biological ages based on the sleep EEG; further, among patients, certain medications exacerbated these effects, in particular olanzapine. Collectively, our results point to a spectrum of N2 sleep deficits among SCZ patients that can be measured objectively and at scale, with relevance to both the etiological heterogeneity of SCZ as well as potential iatrogenic effects of antipsychotic medication.

Development of a new equation and validation of earlier resting energy expenditure predicting equations in adults living in Tehran.

Predictive equations have been considered as a practical approach for estimating resting energy expenditure (REE) across multiple populations, but their accuracy for each community remains to be determined. Thus, the purposes of this study were to determine the validity of REE predictive equations and to develop a new REE predictive equation in adults living in Tehran. The study included 284 subjects (158 females) aged 18-60 years old from two cross-sectional studies conducted in Tehrani populations. Anthropometric measurements were assessed using standard protocols. REE was measured using indirect calorimetry (IC) and was estimated using preexisting equations. A new equation was also developed based on the REE from IC and variables such as age, sex, height, and weight. Measured REE was compared to new equation and preexisting predictive equations via correlation, linear regression, and Bland-Altman tests. The new equation and the equations by Mifflin-St. Jeor, Livingston, Frankenfield, Nichols, Müller, and Ganpule demonstrated the best predictive value at a group level (mean percentage error=-2.2 to 2.4 %). At an individual level, the new equation and the equations by Mara, Frankenfield, Roza, Nikooyeh, and Harris & Benedict showed the greatest accuracies compared to measured REE (accuracy prediction=50-53%). This study highlights the importance of considering race when predicting REE. It also demonstrates that the newly developed equation is more appropriate in a clinical setting at group but not individual level. Thus, further research is needed to examine the new equation in an independent sample.

0978 A Spectrum of Altered Non-rapid Eye Movement Sleep in Schizophrenia

Abstract Introduction Multiple facets of sleep neurophysiology, including electroencephalography (EEG) metrics such as non-rapid eye movement (NREM) spindles and slow oscillations (SO), are altered in individuals with schizophrenia (SCZ). However, beyond group-level analyses which treat all patients as a unitary set, the extent to which NREM deficits vary among patients is unclear, as are their relationships to other sources of heterogeneity including clinical factors, illness duration and ageing, cognitive profiles and medication regimens. Methods Using newly collected high-density sleep EEG data on 103 individuals with SCZ and 68 controls, we first sought to replicate our previously reported (Kozhemiako et. al, eLife, 2022) group-level mean differences between patients and controls (original N=130). Then in the combined sample (N=301 including 175 patients), we characterized patient-to-patient variability in NREM neurophysiology. Sleep EEG preprocessing was conducted using an open-source package called Luna (http://zzz.bwh.harvard.edu/luna/). Results We replicated all group-level mean differences and confirmed the high accuracy of our predictive model (Area Under the ROC Curve, AUC = 0.93 for diagnosis). Compared to controls, patients showed significantly increased between-individual variability across many (26%) sleep metrics, with patterns only partially recapitulating those for group-level mean differences. Although multiple clinical and cognitive factors were associated with NREM metrics including spindle density, collectively they did not account for much of the general increase in patient-to-patient variability. Medication regime was a greater (albeit still partial) generator of variability, although original group mean differences persisted after controlling for medications. Some sleep metrics including fast spindle density showed exaggerated and accelerated age-related effects in SCZ, and patients exhibited older predicted biological ages based on an independent model of ageing and the sleep EEG. Conclusion We demonstrated robust and replicable alterations in sleep neurophysiology in individuals with SCZ and highlighted distinct patterns of effects contrasting between-group means versus within-group variances. That increased NREM heterogeneity was not explained by traditional clinical or cognitive patient assessments suggests the sleep EEG provides novel, nonredundant information to support the goals of personalized medicine. Collectively, our results point to a spectrum of NREM sleep deficits among SCZ Support (if any)

Real-World Effectiveness, Safety, and Health-Related Quality of Life in Patients Receiving Adjuvant Nivolumab for Melanoma in Belgium and Luxembourg: Results of PRESERV MEL.

Nivolumab, an anti-programmed cell death 1 immuno-oncology therapy, is approved as an adjuvant treatment for patients with completely resected stage III or stage IV melanoma. PRESERV MEL (Prospective and REtrospective Study of nivolumab thERapy in adjuVant MELanoma) is a real-world observational study evaluating the effectiveness and safety of adjuvant nivolumab in patients with completely resected stage III or stage IV melanoma in clinical practice in Belgium and Luxembourg. Patients were enrolled prospectively and retrospectively during a 2-year period (January 2019-January 2021), and will be followed for 5 years. The results reported here are for the second interim analysis (cutoff date 31 December 2021). The index date was the date of first administration of adjuvant nivolumab. Patients received nivolumab for up to 12 months per label. Outcomes included relapse-free survival (RFS), adverse events (AEs)/treatment-related AEs (TRAEs), and health-related quality of life (HRQoL; assessed in prospectively enrolled patients using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30), Functional Assessment of Cancer Therapy-Melanoma (FACT-M), and EQ-5D-3L instruments). HRQoL was evaluated at group level (mean change in scores from baseline based on minimally important differences) and individual patient level (percentage of patients with clinically important scores based on threshold of clinical importance). Outcomes were analyzed descriptively. The study enrolled 152 patients (125 prospective, 27 retrospective) at 15 hospitals in Belgium and Luxembourg. Minimum potential follow-up at time of analysis was 11.4 months. Median age was 60 years (range 29-85), and 53% of patients were male. At 12 and 18 months, the RFS rates were 74.7% (95% confidence interval (CI): 66.9-80.9) and 68.4% (95% CI: 60.0-75.5), respectively. Median RFS was not reached. Grade 3 or 4 TRAEs were reported in 14% of patients. AEs led to treatment discontinuation in 23% of patients. Deaths occurred in 3% of patients and were not related to treatment. Questionnaire completion rates for HRQoL were high at baseline (90-94%) and at 24 months (78-81%). In the group-level analysis for HRQoL, mean changes in scores from baseline remained stable and did not exceed prespecified thresholds for minimally important differences during and after treatment, except for a clinically meaningful improvement in FACT-M surgery subscale scores. In the individual patient-level analysis for EORTC QLQ-C30 subscales, the percentages of patients who reported clinically relevant scores for fatigue and cognitive impairment increased during treatment (at 9 months) compared with baseline. After treatment cessation (at 18 months), the percentage of patients who reported clinically relevant scores for fatigue decreased. However, the percentages of patients who reported clinically relevant scores for emotional, cognitive, and social impairment increased at 18 months compared with during treatment. Most patients with emotional impairment at 9 and 18 months did not experience disease recurrence (91% and 89%, respectively). These results confirm the real-world effectiveness and safety of nivolumab as an adjuvant treatment for patients with completely resected stage III or stage IV melanoma. Cancer-specific, disease-specific, and generic HRQoL were maintained during and after treatment. The percentage of patients reporting emotional and cognitive impairment increased after treatment cessation, emphasizing the need for further investigation and tailored supportive care in these patients.

Effect of Footwear Versus Barefoot on Double-Leg Jump-Landing and Jump Height Measures: A Randomized Cross-Over Study.

Assessing individuals in their own athletic footwear in clinics is common, but can affect movement, performance, and clinical measures. The aim was to compare overall Landing Error Scoring System (LESS) scores, injury risk categorization, specific LESS errors, and jump heights between habitual athletic footwear and barefoot conditions. Randomized cross-over laboratory study. Eighty healthy individuals (55% male) completed the LESS following standard procedures (i.e., land from a 30-cm box to a distance of 50% of body height and then jump upwards maximally). Participants performed the LESS three times in two randomized conditions: footwear and barefoot. LESS data were extracted from 2D videos to compare group-level mean LESS scores, group-level and individual-level injury risk categorization (5-error threshold), specific landing errors, and jump heights between conditions. LESS scores were significantly greater (0.3 errors, p=0.022) and jump heights were significantly lower (0.6 cm, p=0.029) in footwear than barefoot, but differences were trivial (d = 0.18 and -0.07, respectively) and not clinically meaningful. Although the number of high injury-risk participants was not statistically different at a group level (p=1.000); 27 individuals (33.8%) exhibited a clinically meaningful difference between conditions of one error or more in LESS score, categorization was inconsistent for 16.3% of individuals, and four of the 17 landing errors significantly differed between conditions. At a group level, habitual athletic footwear does not meaningfully influence LESS scores, risk categorization, or jump height. At an individual level, footwear can meaningfully affect LESS scores, risk categorization, and alter landing strategies. Use of consistent protocol and footwear is advised for assessing movement patterns and injury risk from the LESS given the unknown predictive value of this test barefoot. Level 3.©The Author(s).

Effect of an overhead goal on landing error scoring system and jump height measures

ObjectivesCompare overall Landing Error Scoring System (LESS) scores, risk categorisation, specific LESS errors, and double-leg jump-landing jump heights between overhead goal and no goal conditions. DesignRandomised cross-over. SettingLaboratory. Participants76 (51% male). Main outcome measuresParticipants landed from a 30-cm box to 50% of their body height and immediately jumped vertically for maximum height. Participants completed three trials under two random-ordered conditions: with and without overhead goal. Group-level mean LESS scores, risk categorisation (5-error threshold), specific landing errors, and jump heights were compared between conditions. ResultsMean LESS scores were greater (0.3 errors, p < 0.001) with the overhead goal, but this small difference was not clinically meaningful. Similarly, although the number of high-risk participants was greater with the overhead goal (p = 0.039), the 9.2% difference was trivial. Participants jumped 2.7 cm higher with the overhead goal (p < 0.001) without affecting the occurrence of any specific LESS errors. DiscussionPerforming the LESS with an overhead goal enhances sport specificity and elicits greater vertical jump performances with minimal change in landing errors and injury-risk categorisation. Adding an overhead goal to LESS might enhance its suitability for injury risk screening, although the predictive value of LESS with an overhead goal needs confirmation.

Impact of differential item functioning on group score reporting in the context of large-scale assessments

We investigated the potential impact of differential item functioning (DIF) on group-level mean and standard deviation estimates using empirical and simulated data in the context of large-scale assessment. For the empirical investigation, PISA 2018 cognitive domains (Reading, Mathematics, and Science) data were analyzed using Jackknife sampling to explore the impact of DIF on the country scores and their standard errors. We found that the countries that have a large number of DIF items tend to increase the difference of the country scores computed with and without the DIF adjustment. In addition, standard errors of the country score differences also increased with the number of DIF items. For the simulation study, we evaluated bias and root mean squared error (RMSE) of the group mean and standard deviation estimates using the multigroup item response theory (IRT) model to explore the extent to which DIF items create a bias of the group mean scores and how effectively the DIF adjustment corrects the bias under various conditions. We found that the DIF adjustment reduced the bias by 50% on average. The implications and limitations of the study are further discussed.

Inclusion of image-based in vivo experimental data into the Hill-type muscle model affects the estimation of individual force-sharing strategies during walking

The study of muscle coordination requires knowledge of the force produced by individual muscles, which can be estimated using Hill-type models. Predicted forces from Hill-type models are sensitive to the muscle’s maximal force-generating capacity (Fmax), however, to our knowledge, no study has investigated the effect of different Fmax personalization methods on predicted muscle forces. The aim of this study was to determine the influence of two personalization methods on predicted force-sharing strategies between the human gastrocnemii during walking. Twelve participants performed a walking protocol where we estimated muscle activation using surface electromyography and fascicle length, velocity, and pennation angle using B-mode ultrasound to inform the Hill-type model. Fmax was determined using either a scaling method or experimental method. The scaling method used anthropometric scaling to determine both muscle volume and fiber length, which were used to estimate the Fmax of the gastrocnemius medialis and lateralis. The experimental method used muscle volume and fascicle length obtained from magnetic resonance imaging and diffusion tensor imaging, respectively. We found that the scaling and the experimental method predicted similar gastrocnemii force-sharing strategies at the group level (mean over the participants). However, substantial differences between methods in predicted force-sharing strategies was apparent for some participants revealing the limited ability of the scaling method to predict force-sharing strategies at the level of individual participants. Further personalization of muscle models using in vivo experimental data from imaging techniques is therefore likely important when using force predictions to inform the diagnosis and management of neurological and orthopedic conditions.

Intra- and interspecific variation in self-control capacities of parrots in a delay of gratification task

Forgoing immediate satisfaction for higher pay-offs in the future (delayed gratification) could be adaptive in situations that wild animals may encounter. To explain species-differences in self-control, hypotheses based on social complexity, feeding ecology, brain size and metabolic rate have been proposed. To explore these hypotheses in a comparative setting, we tested three macaw species (neotropical parrots)—great green macaws (N = 8), blue-throated macaws (N = 6), blue-headed macaws (N = 6)—and the distantly related African grey parrots (afrotropical parrots; N = 8) in a modified rotating tray task, in which subjects are required to inhibit consuming a constantly available low-quality reward in favour of a high-quality reward that becomes available only after an increasing delay (min. 5 s, max. 60 s). All four species successfully waited for a minimum of 8.3 s ± 11.7 s (group level mean ± SD) with African greys reaching a delay of 29.4 ± 15.2 s, and great green macaws—as best performing macaw species—tolerating delays of 20 s ± 8 s. The best performing African grey individual reached a maximum delay of 50 s, whereas, a great green and a blue-throated macaw tolerated a delay of 30 s max. Females tolerated higher maximum delays than males. Engaging in distraction behaviours enhanced waiting performance across species and all birds were able to anticipate the waiting duration. Our results suggest that both feeding and socio-ecological complexity may be a factor in self-control, but further systematically collected comparative data on self-control of different (parrot) species are required to test the evolutionary hypotheses rigorously.

The Effect of Qigong Meditation on Serum Cortisol, BDNF, and Cognitive Function: A Pilot Study

Background: Mind–body practices have a variety of health implications, including inflammatory modulation, cognitive improvement, and impact on neurofunction. Some of these effects have been demonstrated through rapidly developing technology and their impact on circulating blood levels of hormones and other molecules. As neurotrophic factors like brain-derived neurotrophic factor (BDNF) and hormones such as cortisol have been shown to play a role in cognitive function, this pilot study assessed the influence of a mind–body intervention, Qigong, on circulating levels in participants. Methods: Participants were prospectively enrolled to perform three separate cognitive assessments before and after a 30-minute, self-guided Qigong meditation developed from historical literature. Each participant was assigned to one of two groups according to their level of experience with meditation. Circulating levels of BDNF and cortisol were analyzed before and after the intervention. Group-level mean changes in BDNF and cortisol, as well as mean change in cognitive assessment score, were compared between groups using t-tests. Results: Fourteen participants were enrolled with equal allocation to the two groups. Though BDNF increased in inexperienced meditators and decreased in experienced meditators after Qigong, there were no differences in the mean change between groups. Similarly, no differences were noted in cortisol between groups; however, there was a significant reduction in all participants after Qigong (n=14, P=0.001). No significant difference in cognitive assessment was noted between groups after Qigong compared to baseline. Conclusion: This pilot study provides preliminary data to suggest circulating levels of cortisol may respond to Qigong meditation. While we were able to indirectly measure cognitive function and directly measure circulating levels of BDNF, the small sample size in this study did not allow us to determine the relationship with Qigong. Larger studies are needed to expand on these findings.

Validation of the factor structure of the Eating Pathology Symptoms Inventory in an international sample of sexual minority men

Sexual minority individuals are at greater risk for the development of eating-disorder (ED) psychopathology. Despite the importance of understanding ED symptoms in sexual minority men, most ED measures were developed and validated in heterosexual, young adult, white women. The psychometric properties of ED measures in diverse populations remain largely unknown. The purpose of this study was to test: 1) whether the eight-factor structure of the Eating Pathology Symptoms Inventory (EPSI) replicated in sexual minority men and 2) group-level mean differences between gay and bisexual men on the eight EPSI scales. International participants (N = 722 sexual minority men from 20 countries) were recruited via the Grindr smartphone application. Confirmatory factor analysis (CFA) was completed using a weighted least square mean and variance adjusted estimator. Group differences in eating pathology between gay and bisexual men were tested using independent samples t-tests. The CFA model fit was good on all fit indices (CFI/TLI > 0.90, RMSEA < 0.06). Gay and bisexual men only differed on the EPSI Binge Eating scale. The results of this investigation suggest that the EPSI may be a useful tool for understanding eating pathology in this population. Using psychometrically sound assessment tools for sexual minority men is a vital piece of treatment planning and clinical decision making. The current study fills an important gap in the clinical and research literature by testing the validity and psychometric properties of a commonly used ED measure in sexual minority men.

A Prototype Comparison of Human Trafficking Warning Signs: U.S. Midwest Frontline Workers’ Perceptions

ABSTRACT Guided by the cognitive prototype approach, this article examines the prototype structure of the frontline workers’ perceptions concerning warning sign indicators in human trafficking. Online survey responses across a range of workplace sectors were analyzed using multiple-group confirmatory factor analysis (MG-CFA) for three groups. These groups were based on respondents’ self-reported human trafficking experiences: no witness (no encounter of human trafficking), sex trafficking witness, and labor trafficking witness. The MG-CFA analysis revealed a three-factor structure – physical condition, reproductive health, and personal risk – representing the participants’ perceptions of the warning signs. Further analysis showed group-level mean (latent intercept) and variance differences between the prototype structures of the three witness groups. The final structural model results indicate that these group-level prototype differences can be explained by two organizational resource variables: identification protocol and training. The results are discussed in light of the current empirical literature on human trafficking identification, stereotypical frames of victimhood, and policy practices.

Reliability of walking speed in basic and complex conditions in healthy, older community-dwelling individuals.

There is a paucity of reliability data for walking speed tests in complex conditions to assess functioning in healthy older individuals. To evaluate the absolute intra- and intertest reliability of walking speed performed in basic and complex conditions in healthy older individuals. Fifty-two men and women of mean age 69.7 ± 3.2years were tested for habitual and maximal walking speed. Maximal speed was also assessed under different conditions, including walking on a path of reduced width; picking up objects; stepping over hurdles; stepping over hurdles wearing sunglasses and finally, carrying a box. Two testing sessions (separated by 4weeks) of two trials each were administered. Reliability was analysed by intra-class correlation coefficient (ICC), minimal detectable change (MDC) and Bland-Altman plots with limits of agreement (LOA). Intrasession ICCs ranged from good to excellent (0.89-0.95) except for picking up objects (0.44). Intersession ICCs were moderate to good (0.60-0.78) and %MDCs were acceptable (14-24%). Bland-Altman plots suggested a good agreement between the two testing sessions at group level (mean differences from - 0.02 to - 0.11m/s), and limited agreement between testing sessions at individual level (upper LOA from 0.13 to 0.37m/s and lower LOA from - 0.29 to - 0.49m/s). Complex walking speed tests are generally reliable measures displaying good and moderate intra- and inter-session reliability. Suchtests seem a more suitable functional assessment tool for heathy older subjects compared with simple walking. Some learning effect may be present and further reliability studies are needed.

Modeling Longitudinal Outcomes: A Contrast of Two Methods

Background: Repeated measures analysis of variance (ANOVA) is frequently used to model longitudinal data but does not appropriately account for within-person correlations over time, does not explicitly model time, and cannot flexibly handle missing data. In contrast, mixed-effects regression addresses these limitations. In this commentary, we compare these two methods using openly available tools. Methods: We emulated a real developmental study of elite skiers, tracking national rankings from 2011 to 2018. We constructed unconditional models of time (establishing the “pattern” of change) and conditional models of time (identifying factors that affect change over time), and contrasted these models against comparable repeated measures ANOVAs. Results: Mixed-effects regression allowed for linear and non-linear modeling of the skiers’ longitudinal trajectories despite missing data. Missing data is still a concern in mixed-effects regression models, but in the present dataset missingness could be accounted for by skiers’ ages, satisfying the missing at random assumption. Discussion: Although ANOVA and mixed-effects regression are both suitable for time-series data, their applications differ. ANOVA will be most parsimonious when the research question focuses on group-level mean differences at arbitrary time points. However, mixed-effects regression is more suitable where time is inherently important to the outcome, and where individual differences are of interest.

Submaximal Exercise Testing in Cardiovascular Rehabilitation Settings (BEST Study).

BackgroundThis study compared changes in measured versus predicted peak aerobic power (V̇O2peak) following cardiovascular rehabilitation (CR). Peak cardiopulmonary exercise testing (CPET) results were compared to four V̇O2peak estimation methods: the submaximal modified Bruce treadmill, Astrand-Ryhming cycle ergometer, and Chester step tests, and the Duke Activity Status Index (DASI).MethodsAdults with cardiovascular disease (CVD) who completed a 12-week CR program were assessed at baseline and 12 weeks follow-up. CPET, the DASI and three subsequent submaximal exercise tests were performed in a random order.ResultsOf the 50 adults (age: 57 ± 11 years) who participated, 46 completed the 12-week CR program and exercise tests. At baseline 69, 68, and 38% of the treadmill, step and cycle tests were successfully completed, respectively. At follow-up 67, 80, and 46% of the treadmill, step and cycle tests were successfully completed, respectively. No severe adverse events occurred. Significant improvements in V̇O2peak were observed with CPET (3.6 ± 5.5 mL.kg–1.min–1, p < 0.001) and the DASI (2.3 ± 4.2 mL.kg–1.min–1, p < 0.001). Bland-Altman plots of the change in V̇O2peak between CPET and the four V̇O2peak estimation methods revealed the following: a proportional bias and heteroscedastic 95% limits of agreement (95% LoA) for the treadmill test, and for the cycle and step tests and DASI, mean bias’ and 95% LoA of 1.0 mL.kg–1.min–1 (21.3, −19.3), 1.4 mL.kg–1.min–1 (15.0, −12.3) and 1.0 mL.kg–1.min–1 (13.8, −11.8), respectively.ConclusionGiven the greater number of successful tests, no serious adverse events and acceptable mean bias, the step test appears to be a valid and safe method for assessing group-level mean changes in V̇O2peak among patients in CR. The DASI also appears to be a valid and practical questionnaire. Wide limits of agreement, however, limit their use to predict individual-level changes.

Maternal diet affects juvenile Carpetan rock lizard performance and personality.

Differences in both stable and labile state variables are known to affect the emergence and maintenance of consistent interindividual behavioral variation (animal personality or behavioral syndrome), especially when experienced early in life. Variation in environmental conditions experienced by gestating mothers (viz. nongenetic maternal effects) is known to have significant impact on offspring condition and behavior; yet, their effect on behavioral consistency is not clear. Here, by applying an orthogonal experimental design, we aimed to study whether increased vitamin D3 content in maternal diet during gestation (vitamin‐supplemented vs. vitamin control treatments) combined with corticosterone treatment (corticosterone‐treated vs. corticosterone control treatments) applied on freshly hatched juveniles had an effect on individual state and behavioral consistency of juvenile Carpetan rock lizards (Iberolacerta cyreni). We tested the effect of our treatments on (a) climbing speed and the following levels of behavioral variation, (b) strength of animal personality (behavioral repeatability), (c) behavioral type (individual mean behavior), and (d) behavioral predictability (within‐individual behavioral variation unrelated to environmental change). We found higher locomotor performance of juveniles from the vitamin‐supplemented group (42.4% increase), irrespective of corticosterone treatment. While activity personality was present in all treatments, shelter use personality was present only in the vitamin‐supplemented × corticosterone‐treated treatment and risk‐taking personality was present in corticosterone control treatments. Contrary to our expectations, behavioral type was not affected by our treatments, indicating that individual quality can affect behavioral strategies without affecting group‐level mean behavior. Behavioral predictability decreased in individuals with low climbing speed, which could be interpreted as a form of antipredator strategy. Our results clearly demonstrate that maternal diet and corticosterone treatment have the potential to induce or hamper between‐individual variation in different components of boldness, often in interactions.

A Bayesian hierarchical point process model for epidermal nerve fiber patterns

We introduce the Thomas process in a Bayesian hierarchical setting as a model for point pattern data with a nested structure. This model is applied to a nerve fiber data set which consists of several point patterns of nerve entry points from 47 subjects divided into 3 groups, where the grouping is based on the diagnosed severity of a certain nerve disorder. The modeling assumption is that each point pattern is a realization of a Thomas process, with parameter values specific to the subject. These parameter values are in turn assumed to come from distributions that depend on which group the subject belongs to. To fit the model, we construct an MCMC algorithm, which is evaluated in a simulation study. The results of the simulation study indicate that the group level mean of each parameter is well estimated, but that the estimation of the between subject variance is more challenging. When fitting the model to the nerve fiber data, we find that the structure within clusters appears to be the same in all groups, but that the number of clusters decreases with the progression of the nerve disorder.

Association Between Deviation of Fairness Perceptions from Group Average and Serious Psychological Distress in Japanese Worksites: a Cross-Sectional Study

BackgroundWorkers with deviating fairness perceptions are likely to be excluded and become isolated at worksites, leading to psychological distress. The study aimed to examine the cross-sectional association between deviation of fairness perception from the group average and serious psychological distress in Japanese worksites.MethodsSecondary data analysis of an existing Japanese occupational cohort data using a multilevel logistic regression model was conducted for 8701 workers from 12 companies in Japan who participated in the baseline survey (from April 2010 to March 2012). Individual perception of interactional and procedural fairness was measured with the Japanese version of the Organizational Justice Scale. Group averages were calculated within workers’ reference groups, categorized by company affiliation, age group, gender, and occupational class. Psychological distress was measured using the K6 scale, and serious psychological distress was defined as a total K6 score of 13 or more.ResultsBoth low deviation and high deviation of interactional fairness perception were significantly and positively associated with serious psychological distress (odds ratio (OR) = 1.24, 95% confidence intervals (CI); 1.03–1.49 and OR = 1.57, 95% CI; 1.12–2.19), independently of individual-level fairness perception, group-level mean fairness perception, demographic characteristics, and health-related behaviors. Only high deviation of procedural fairness perception was significantly and positively related to serious psychological distress (OR = 1.51, 95% CI; 1.11–2.06).ConclusionsThe results indicated that divergent perceptions of fairness at worksites may deserve further exploration for equal achievement of workers’ psychological well-being.

Measurement of Active and Sedentary Behavior in Context of Large Epidemiologic Studies.

To assess the utility of measurement methods that may be more accurate and precise than traditional questionnaire-based estimates of habitual physical activity and sedentary behavior we compared the measurement properties of a past year questionnaire (AARP) and more comprehensive measures: an internet-based 24-h recall (ACT24), and a variety of estimates from an accelerometer (ActiGraph). Participants were 932 adults (50-74 yr) in a 12-month study that included reference measures of energy expenditure from doubly labeled water (DLW) and active and sedentary time via activPAL. Accuracy at the group level (mean differences) was generally better for both ACT24 and ActiGraph than the AARP questionnaire. The AARP accuracy for energy expenditure ranged from -4% to -13% lower than DLW, but its accuracy was poorer for physical activity duration (-48%) and sedentary time (-18%) versus activPAL. In contrast, ACT24 accuracy was within 3% to 10% of DLW expenditure measures and within 1% to 3% of active and sedentary time from activPAL. For ActiGraph, accuracy for energy expenditure was best for the Crouter 2-regression method (-2% to -7%), and for active and sedentary time the 100 counts per minute cutpoint was most accurate (-1% to 2%) at the group level. One administration of the AARP questionnaire was significantly correlated with long-term average from the reference measures (ρTX = 0.16-0.34) overall, but four ACT24 recalls had higher correlations (ρTX = 0.48-0.60), as did 4 d of ActiGraph assessment (ρTX = 0.54-0.87). New exposure assessments suitable for use in large epidemiologic studies (ACT24, ActiGraph) were more accurate and had higher correlations than a traditional questionnaire. Use of better more comprehensive measures in future epidemiologic studies could yield new etiologic discoveries and possibly new opportunities for prevention.

The effect of hardiness on symptoms of insomnia during a naval mission.

Sleep is increasingly being recognised as important for the health and well-being of sailors. The aim of the current study is to investigate the relationship between hardiness and reported insomnia-symptoms in a maritime military setting during a 4-month counter piracy naval mission in the Gulf of Aden. A sample of 281 officers, sailors, and enlisted personnel were measured on levels of hardiness before the mission. The participants were split into low and high hardiness groups based on the group level mean. Insomnia-symptoms were measured before, midway and at the end of the mission. The results showed a significant main effect of time and a significant main effect of hardiness. The crew experienced the most insomnia symptoms in the middle of the mission and the high hardy group experienced less insomnia symptoms, in total, during the mission. There was also found a significant interaction effect of time and hardiness. The high hardiness group experienced less insomnia symptoms before and towards the end of the mission. The results indicate that high levels of hardiness may be a protective factor between the stressors of a naval mission and symptoms of insomnia.