SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Exposure

384

Case reports describe persistent erectile dysfunction (PED) associated with exposure to 5α-reductase inhibitors (5α-RIs). Clinical trial reports and the manufacturers' full prescribing information (FPI) for finasteride and dutasteride state that risk of sexual adverse effects is not increased by longer duration of 5α-RI exposure and that sexual adverse effects of 5α-RIs resolve in men who discontinue exposure.

Concepts: Clinical trial, Effectiveness, ClinicalTrials.gov, Pharmaceutical industry, Adverse drug reaction, Erectile dysfunction, Exposure

170

PTSD symptoms were pervasive among children and adolescents after experiencing or exposure to traumatic events. Screening and diagnosis of PTSD symptoms is crucial in trauma-related research and practice. The 13-item Children’s Revised Impact of Event Scale (CRIES) has been demonstrated to be a valid and reliable tool to achieve this goal. This study was designed to examine the psychometric properties of the 13-item CRIES in a sample of Chinese debris flood victims.

Concepts: Psychological trauma, Exposure, Exposé, PTSD

166

BACKGROUND: Static posture, repetitive movements and lack of physical variation are known risk factors for work-related musculoskeletal disorders, and thus needs to be properly assessed in occupational studies. The aims of this study were (i) to investigate the effectiveness of a conventional exposure variation analysis (EVA) in discriminating exposure time lines and (ii) to compare it with a new cluster-based method for analysis of exposure variation. METHODS: For this purpose, we simulated a repeated cyclic exposure varying within each cycle between “low” and “high” exposure levels in a “near” or “far” range, and with “low” or “high” velocities (exposure change rates). The duration of each cycle was also manipulated by selecting a “small” or “large” standard deviation of the cycle time. Theses parameters reflected three dimensions of exposure variation, i.e. range, frequency and temporal similarity.Each simulation trace included two realizations of 100 concatenated cycles with either low (rho = 0.1), medium (rho = 0.5) or high (rho = 0.9) correlation between the realizations. These traces were analyzed by conventional EVA, and a novel cluster-based EVA (C-EVA). Principal component analysis (PCA) was applied on the marginal distributions of 1) the EVA of each of the realizations (univariate approach), 2) a combination of the EVA of both realizations (multivariate approach) and 3) C-EVA. The least number of principal components describing more than 90% of variability in each case was selected and the projection of marginal distributions along the selected principal component was calculated. A linear classifier was then applied to these projections to discriminate between the simulated exposure patterns, and the accuracy of classified realizations was determined. RESULTS: C-EVA classified exposures more correctly than univariate and multivariate EVA approaches; classification accuracy was 49%, 47% and 52% for EVA (univariate and multivariate), and C-EVA, respectively (p < 0.001). All three methods performed poorly in discriminating exposure patterns differing with respect to the variability in cycle time duration. CONCLUSION: While C-EVA had a higher accuracy than conventional EVA, both failed to detect differences in temporal similarity. The data-driven optimality of data reduction and the capability of handling multiple exposure time lines in a single analysis are the advantages of the C-EVA.

Concepts: Multivariate statistics, Factor analysis, Principal component analysis, Exposure, Singular value decomposition, Photography, Linear discriminant analysis, The Unscrambler

37

The animal world is full of brilliant colours and striking patterns that serve to hide individuals or attract the attention of others. False eyespots are pervasive across a variety of animal taxa and are among nature’s most conspicuous markings. Understanding the adaptive significance of eyespots has long fascinated evolutionary ecologists. Here we show for the first time that the size of eyespots is plastic and increases upon exposure to predators. Associated with the growth of eyespots there is a corresponding reduction in growth of eyes in juvenile Ambon damselfish, Pomacentrus amboinensis. These morphological changes likely direct attacks away from the head region. Exposure to predators also induced changes in prey behaviour and morphology. Such changes could prevent or deter attacks and increase burst speed, aiding in escape. Damselfish exposed to predators had drastically higher survival suffering only 10% mortality while controls suffered 60% mortality 72 h after release.

Concepts: Fungus, Predation, Ecology, Exposure, Exposé, Suffering, Pomacentridae, Pomacentrus

28

Background:  Research on resilience in the aftermath of potentially traumatic life events (PTE) is still evolving. For decades, researchers have documented resilience in children exposed to corrosive early environments, such as poverty or chronic maltreatment. Relatively more recently, the study of resilience has migrated to the investigation of isolated PTE in adults. Methods:  In this article, we first consider some of the key differences in the conceptualization of resilience following chronic adversity versus resilience following single-incident traumas, and then describe some of the misunderstandings that have developed about these constructs. To organize our discussion, we introduce the terms emergent resilience and minimal-impact resilience to represent trajectories of positive adjustment in these two domains, respectively. Results:  We focused in particular on minimal-impact resilience, and reviewed recent advances in statistical modeling of latent trajectories that have informed the most recent research on minimal-impact resilience in both children and adults and the variables that predict it, including demographic variables, exposure, past and current stressors, resources, personality, positive emotion, coping and appraisal, and flexibility in coping and emotion regulation. Conclusions:  The research on minimal-impact resilience is nascent. Further research is warranted with implications for a multiple levels of analysis approach to elucidate the processes that may mitigate or modify the impact of a PTE at different developmental stages.

Concepts: Scientific method, Research, Psychological trauma, Demographics, Emotion, Exposure, Richard Lazarus, Adjustment disorder

26

Allostatic load reflects cumulative exposure to stressors throughout lifetime and has been associated with several adverse health outcomes. It is hypothesized that people with low socioeconomic status (SES) are exposed to higher chronic stress and have therefore greater levels of allostatic load.

Concepts: Anxiety, Socioeconomic status, Sociology, Stress, Exposure, Exposé, Social status

25

Environmental exposure of tourniquets has been associated with component damage rates, but the specific type of environmental exposure, such as heat, is unknown. Emergency-tourniquet damage has been associated with malfunction and loss of hemorrhage control, which may risk loss of life during first aid. The purposes of the study are to determine the damage rate of tourniquets exposed to heat and to compare the rate to that of controls.

Concepts: Life, Rates, Decision theory, Acceleration, Exposure, The Damage, Reaction rate, Emergency

25

The effect of exposure time, temperature, food simulants, especially additives on the release of silver from nanosilver-polyethylene composite films to food simulants has been studied. Two different type of nanosliver-polyethylene composite films (with or without additives) were chosen to conduct the experiment with the aim of exploring the behavior of silver migration. It was shown that the migration of silver into 50% ethanol at 40℃ and 70℃ was much less than that into 3% acetic acid. With the increase of exposure time and the temperature, the release of silver increased. The migration even continued after a long exposure time (14 days at 20℃, 10 days at 40℃, and 6 days at 70℃ respectively). Only about 0.15‰ of silver migrated from composite films with the additives into 3% acetic acid after 6 days of exposure at 70℃, while about 1.3% of silver migrated from composite films that did not contain additives under the same conditions. This could be due to the fact that the addition of the antioxidants and light stabilisers prevent silver from being oxidised, which is an important way for the release of silver.

Concepts: Oxygen, Ethanol, Acetic acid, Exposure, Vinegar, Photography, Shutter speed, Exposure value

18

Preschoolers in the United States are heavily exposed to unhealthy food advertisements. Whether such exposure promotes cued eating has not been documented in this age group.

Concepts: Nutrition, United States, Poverty in the United States, U.S. state, Exposure, Photography, In the Absence of Truth, Kindergarten

14

The aim of this investigation was to elucidate the reductions in muscle, skin and core temperature following exposure to -110°C whole body cryotherapy (WBC), and compare these to 8°C cold water immersion (CWI). Twenty active male subjects were randomly assigned to a 4-min exposure of WBC or CWI. A minimum of 7 days later subjects were exposed to the other treatment. Muscle temperature in the right vastus lateralis (n = 10); thigh skin (average, maximum and minimum) and rectal temperature (n = 10) were recorded before and 60 min after treatment. The greatest reduction (P<0.05) in muscle (mean ± SD; 1 cm: WBC, 1.6±1.2°C; CWI, 2.0±1.0°C; 2 cm: WBC, 1.2±0.7°C; CWI, 1.7±0.9°C; 3 cm: WBC, 1.6±0.6°C; CWI, 1.7±0.5°C) and rectal temperature (WBC, 0.3±0.2°C; CWI, 0.4±0.2°C) were observed 60 min after treatment. The largest reductions in average (WBC, 12.1±1.0°C; CWI, 8.4±0.7°C), minimum (WBC, 13.2±1.4°C; CWI, 8.7±0.7°C) and maximum (WBC, 8.8±2.0°C; CWI, 7.2±1.9°C) skin temperature occurred immediately after both CWI and WBC (P<0.05). Skin temperature was significantly lower (P<0.05) immediately after WBC compared to CWI. The present study demonstrates that a single WBC exposure decreases muscle and core temperature to a similar level of those experienced after CWI. Although both treatments significantly reduced skin temperature, WBC elicited a greater decrease compared to CWI. These data may provide information to clinicians and researchers attempting to optimise WBC and CWI protocols in a clinical or sporting setting.

Concepts: Temperature, Exposure, Rectum, Vastus lateralis muscle, Maxima and minima, Cold, Indian Reductions