Important Stressors Research Articles

Sedimentation and overfishing drive changes in early succession and coral recruitment.

Sedimentation and overfishing are important local stressors on coral reefs that can independently result in declines in coral recruitment and shifts to algal-dominated states. However, the role of herbivory in driving recovery across environmental gradients is often unclear. Here we investigate early successional benthic communities and coral recruitment across a sediment gradient in Palau, Micronesia over a 12-month period. Total sedimentation rates measured by 'TurfPods' varied from 0.03 ± 0.1 SE mg cm-2 d-1 at offshore sites to 1.32 ± 0.2 mg cm-2 d-1 at inshore sites. To assess benthic succession, three-dimensional settlement tiles were deployed at sites with experimental cages used to exclude tile access to larger herbivorous fish. Benthic assemblages exhibited rapid transitions across the sediment gradient within three months of deployment. At low levels of sedimentation (less than 0.6 mg cm-2 d-1), herbivory resulted in communities dominated by coral recruitment inducers (short turf algae and crustose coralline algae), whereas exclusion of herbivores resulted in the overgrowth of coral inhibitors (encrusting and upright foliose macroalgae). An 'inducer threshold' was found under increasing levels of sedimentation (greater than 0.6 mg cm-2 d-1), with coral inducers having limited to no presence in communities, and herbivore access to tiles resulted in sediment-laden turf algal assemblages, while exclusion of herbivores resulted in invertebrates (sponges, ascidians) and terrestrial sediment accumulation. A 'coral recruitment threshold' was found at 0.8 mg cm-2 d-1, below which net coral recruitment was reduced by 50% in the absence of herbivores, while recruitment was minimal above the threshold. Our results highlight nonlinear trajectories of benthic succession across sediment gradients and identify strong interactions between sediment and herbivory that have cascading effects on coral recruitment. Local management strategies that aim to reduce sedimentation and turbidity and manage herbivore fisheries can have measurable effects on benthic community succession and coral recruitment, enhancing reef resilience and driving coral recovery.

PHOTOTOXICITY OF α-TERTHIENYL AND PSORALENE INROSE AND MUSTARD APHIDS (MACROSIPHUM ROSAE & LIPAPHIS ERYSIMI) IN DOON VALLEY

Climate change has an impact on agriculture and insect pests that affect the crop production. Aphid pests occur throughout the temperate region of the world andcause direct damage by sucking plants sap which affects growth and yield of the crops. Species of aphids are diverse and ubiquitous but their importance among crop differs.Ultraviolet radiation (UVR) is an electromagnetic radiation and constitutes about 10% of the total light output of sunlight. Ultraviolet-B coming due to ozone depletion is the most photo chemically reactive wavelength of solar radiation and important stressor to organisms particularly in their early stages of life and affect ecosystem. Psoralene and alpha- terthienyl are naturally occurring plant metabolites found in many crops and become photo reactive in presence of solar ultraviolet- B radiation. Measurement of solar ultraviolet radiation (UV-B and UV-E) was performed in Garhwalregion of Uttarakhand. Morphological, behavioural changes, mortality rate and glutathione contents were observed in mustard and roseaphids after ultraviolet-B irradiation with psoralene and α-terthienyl photo sensitizers. UV-B and UV-E radiation showed seasonal, diurnal and altitudinal variations. α- terthienyland psoralenewith ultraviolet-B radiation showed stunted growth, morphological changes, low reproduction and high mortality up to 26% in aphids. Reduction in glutathione (GSH) level in aphids was also observed after UV- B and photosensitizersexposure.Enhanced UV-B was found more toxic with photosensitizers andthus, can be used as natural insecticide. Dose, intensity and species dependent changes in toxicity of psoralene and α- terthienyl were observed in aphids. Resultsindicate that UV-B radiation with photosensitizers has toxic effect on aphids population, dispersal and diversity. Psoralene was found more toxic than α- terthienyl in aphids. Mustard aphid (Lipaphis erysimi) was found more sensitive than rose aphid (Macrosiphum rosae).

Coping with inclement weather conditions due to high temperature and water deficit in rice: An insight from genetic and biochemical perspectives.

Climatic fluctuations, temperature extremes, and water scarcity are becoming increasingly unpredictable with the passage of time. Such environmental atrocities have been the scourge of agriculture over the ages, bringing with them poor harvests and threat of famine. Rice production, owing to its high-water requirement for cultivation, is highly vulnerable to the threat of changing climate, particularly prolonged drought and high temperature, individually or in combination. Amidst all the abiotic stresses, heat and drought are considered as the most important concurrent stressors, largely affecting rice yield and productivity under the current scenario. Such threats heighten the need for new breeding and cultivation strategies in generating abiotic stress-resilient rice varieties with better yield potential. Responses of rice to these stresses can be categorized at the morphological, physiological and biochemical levels. This review examines the physiological and molecular mechanism, in the form of up regulation of several defense machineries of rice varieties to cope with drought stress (DS), high temperature stress (HTS), and their combination (DS-HTS). Genotypic differences among rice varieties in their tolerance ability have also been addressed. The review also appraises research studies conducted in rice regarding various phenotypic traits, genetic loci and response mechanisms to stress conditions to help craft new breeding strategies for improved tolerance to DS and HTS, singly or in combination. The review also encompasses the gene regulatory networks and transcription factors, and their cross-talks in mediating tolerance to such stresses. Understanding the epigenetic regulation, involving DNA methylation and histone modification during such hostile situations, will also play a crucial role in our comprehensive understanding of combinatorial stress responses. Taken together, this review consolidates current research and available information on promising rice cultivars with desirable traits as well as advocates synergistic and complementary approaches in molecular and systems biology to develop new rice breeds that favorably respond to DS-HTS-induced abiotic stress.

Multiple stressors interact to impair the performance of bumblebee Bombus terrestris colonies

Bumblebees are constantly exposed to a wide range of biotic and abiotic stresses which they must defend themselves against to survive. Pathogens and pesticides represent important stressors that influence bumblebee health, both when acting alone or in combination. To better understand bumblebee health, we need to investigate how these factors interact, yet experimental studies to date generally focus on only one or two stressors. The aim of this study is to evaluate how combined effects of four important stressors (the gut parasite Nosema ceranae, the neonicotinoid insecticide thiamethoxam, the pyrethroid insecticide cypermethrin and the EBI fungicide tebuconazole) interact to affect bumblebees at the individual and colony levels. We established seven treatment groups of colonies that we pulse exposed to different combinations of these stressors for 2weeks under laboratory conditions. Colonies were subsequently placed in the field for 7weeks to evaluate the effect of treatments on the prevalence of N. ceranae in inoculated bumblebees, expression levels of immunity and detoxification-related genes, food collection, weight gain, worker and male numbers, and production of worker brood and reproductives. Exposure to pesticide mixtures reduced food collection by bumblebees. All immunity-related genes were upregulated in the bumblebees inoculated with N. ceranae when they had not been exposed to pesticide mixtures, and bumblebees exposed to the fungicide and the pyrethroid were less likely to have N. ceranae. Combined exposure to the three-pesticide mixture and N. ceranae reduced bumblebee colony growth, and all treatments had detrimental effects on brood production. The groups exposed to the neonicotinoid insecticide produced 40%-76% fewer queens than control colonies. Our findings show that exposure to combinations of stressors that bumblebees frequently come into contact with have detrimental effects on colony health and performance and could therefore have an impact at the population level. These results also have significant implications for current practices and policies for pesticide risk assessment and use as the combinations tested here are frequently applied simultaneously in the field. Understanding the interactions between different stressors will be crucial for improving our ability to manage bee populations and for ensuring pollination services into the future.

How Do Nocebo Phenomena Provide a Theoretical Framework for the COVID-19 Pandemic?

The COVID-19 pandemic is a major health issue, which leads to psychological and behavioural changes. In particular, among various negative feelings, fear seems to be one of the main emotional reactions that can be as contagious as the virus itself. The actual pandemic is likely to function as an important stressor, especially in terms of chronic anxiety and lack of control over the succession of unforeseeable environmental events. In this direction, the psychological impact of previous quarantine measures showed important negative psychological effects, including post-traumatic stress symptoms (PTTS) with long-lasting effects. The presence of psychological discomfort and disturbances due to negative contextual factors can be studied using the nocebo phenomenon as a possible theoretical explanatory framework. Although in the absence of studies linking nocebo to Covid-19 and data-driven evidence, the context of the actual pandemic may be seen as a fertile ground for amplified discomfort and anxiety. The media provide dramatic and negative descriptions and often present conflicting sources of information, which can lead to physical and mental health problems, diminishing response to treatment. This can be worse when supported by conspiracy theories or misinformation. The aim of this perspective review is to propose a new theoretical framework for the COVID-19 pandemic, which should be supported by future empirical studies. In particular, the negative contextual factors, which can predispose individuals to psychological distress and the onset of the nocebo phenomena will be presented here, in order to suggest possible guidelines to mitigate the devastating effects of COVID-19.

IDENTIFIKACIJA STRESORJEV NA PODROČJU DELA RADIOLOŠKIH INŽENIRJEV

Purpose: The aim of this research is to defi ne stress and correlated factors and identify which stressors are present among radiographers in relation to their workplace. Methods: A total of 450 radiographers received a questionnaire that covers a variety of workplace stressors, which conditions aff ect stress, how frequently radiographers notice stress and to what extent they use coping mechanisms. The online survey was available on the website 1ka and the results were analysed using the IBM SPSS program. Results: A total of 236 radiographers completed the survey (52.4% response rate). Interpersonal relations and management staff cause the highest level of stress, while the most important stressor is a conflict with a supervisor (3.38). Radiographers who work in a field of radiotherapy perceive the most stress. There is no difference between a healthcare activity in relation to levels of perceived stress. We could not identify any statistically significant differences in perceived stress in relation to gender or age (p?0.05). Radiographers who asses their relationship with co-workers and supervisors as good perceive lower levels of stress. Additionally, the same results are present with radiographers who are satisfied because they work in a multidisciplinary team (p?0.05). Teaching new staff has a positive correlation with occupational stress development. Unnecessary radiological procedures, along with unclear roles, have no effect on the development of stress behaviour (p>0.05). However, a conflict between roles has a major association (p?0.05) with stress occurrence. The most frequent methods for reducing symptoms of stress are caring for one’s health and physical appearance (3.77). It proved that communication with patients and duty work (p<0.05) represent significant elements of the workload. Most radiographers think that physical conditions in the workplace could be improved. Discussion and conclusion: The results show that radiographers notice a variety of stressors in their workplace. The most important are related to interpersonal relations. Further research should include analysis of stress within particular fields of radiography that would help to explain occupational stress.

Life cycle bioenergetics of the gray seal (Halichoerus grypus) in the Baltic Sea: Population response to environmental stress

Wildlife population dynamics are shaped by multiple natural and anthropogenic factors, including predation, competition, stressful life history events, and external environmental stressors such as diseases and pollution. Marine mammals such as gray seals rely on extensive blubber layers for insulation and energy storage, making this tissue critical for survival and reproduction. This lipid rich blubber layer also accumulates hazardous fat soluble pollutants, such as polychlorinated biphenyls (PCBs), that can directly impact adipose function or be mobilized during periods of negative energy balance or transferred to offspring to exert further impacts on target tissues or vulnerable life stages. To predict how marine mammals will respond to ecological and anthropogenic stressors, it is necessary to use process-based modelling approaches that integrate environmental inputs, full species life history, and stressor impacts with individual dynamics of energy intake, storage, and utilization. The purpose of this study was to develop a full lifecycle dynamic energy budget and individual based model (DEB-IBM) that captured Baltic gray seal physiology and life history, and showcase potential applications of the model to predict population responses to select stressors known to threaten gray seals and other marine mammals around the world. We explore variations of three ecologically important stressors using phenomenological simulations: food limitation, endocrine disrupting chemicals that reduce fertility, and infectious disease. Using our calibrated DEB-IBM for Baltic gray seals, we found that continuous incremental food limitation can be more detrimental to population size than short random events of starvation, and further, that the effect of endocrine disruptors on population growth and structure is delayed due to bioaccumulation, and that communicable diseases significantly decrease population growth even when spillover events are relatively less frequent. One important finding is the delayed effect on population growth rate from some stressors, several years after the exposure period, resulting from a decline in somatic growth, increased age at maturation and decreased fecundity. Such delayed responses are ignored in current models of population viability and can be important in the correct assessment of population extinction risks. The model presented here provides a test bed on which effects of new hazardous substances and different scenarios of future environmental change affecting food availability and/or seal energetic demands can be investigated. Thus, the framework provides a tool for better understanding how diverse environmental stressors affect marine mammal populations and can be used to guide scientifically based management.

Land-Cover Patterns and Hydrogeomorphology of Tributaries: Are These Important Stressors for the Water Quality of Reservoirs in the Mediterranean Region?

Four streams in the Guadiana watershed were followed up to assess hydrogeomorphological and physicochemical characteristics, and to analyze its correlation with land use/land cover (LULC), analyzing their possible influence in reservoir water quality and possible influence in the reservoir water quality. The highest amounts of organic descriptors and nutrients were quantified in streams with the major percentage of olive groves and vineyards and urban land cover classes. Streams more influenced by agro-silvo-pastoral class presented better water quality, as this type of LULC acts as a buffer of the contamination runoff. The results highlighted that the hydrogeomorphology of the streams may influence the transfer of pollutants loads to reservoirs. Hence, in intermittent streams characterized by coarse particles in the sediment, high amounts of pollutants are accumulated when the flow ceases, and are further transported to the reservoirs when the flow retakes. On the contrary, streams with sediments characterized by a great percentage of fine particles and organic matter do not induce so much stress in reservoirs, since these allow the adsorption of nutrients and trace elements, without their transfer to reservoirs.

Effect of sulfide and the role of root mass on metabolic fluxes in the seagrass Zostera marina

While seagrass communities serve important ecological and economic purposes, their health has been declining worldwide. Sediment sulfide toxicity might be an important stressor of seagrasses, but isolating single variables is difficult in the field and few studies have investigated direct physiological effects. We used flow-through respirometry to investigate whether sulfide affects fluxes of metabolic gases (O2, CO2, NH3, H2S) by the shoots and roots of the North American native seagrass Zostera marina. O2 transport from the shoots to the roots occurs in Z. marina and might also be involved in sulfide detoxification. We therefore hypothesized that such O2 transport would occur to a greater extent in plants with higher shoot-to-root mass ratios, improving sulfide detoxification, thereby maintaining nitrogen uptake by the roots. We found that the roots primarily consumed O2, which increased with increasing shoot-to-root mass ratio, but this relationship was dominated by root mass and was disrupted by sulfide. In response to sulfide, root O2 consumption decreased by more than 50 %, whereas shoot photosynthesis (O2 production; light) and aerobic respiration (O2 uptake; dark) were not significantly affected. H2S concentrations decreased in root chambers, indicating either oxidation from shoot-supplied O2 or uptake of sulfide by roots. Besides O2 and H2S, no other gas flux was affected by sulfide exposure. Our data suggest that root mass controls the physiological space of Z. marina between sulfide-free and sulfide-rich conditions and this space increases with decreasing seagrass size.

Stress is affected by a combination of work- and non-work-related stressors and social support

Abstract Background Work-related stress has received much attention. However, the relative importance of work- and non-work-related stressors on stress level has received less attention. The present study aims to determine the relative importance of work- and non-work-related stressors and social support on stress level at population level. Methods The study used data from the population-based health survey 'How are you?' in 2017 in Central Denmark Region (N = 32,417). Stress level was measured using the Perceived Stress Scale. Stressors were measured in nine domains including work situation and non-work related stressors. Furthermore, perceived social support was assessed. The study used dominance analyses based upon regression models with perceived stress as the dependent variable and stressors and social support as independent variables for describing the variance in stress level. Analyses were adjusted for gender, age, education and ethnic background. Results Work-related and non-work related stressors along with social support explained 43% of the variance in stress level. The three most important contributors to the explained variance in stress level were 'disease', 'social support' and 'work situation'. Stratified by labour marked status, stressors and social support explained 38% (in work) and 46% (outside the labour marked) of the variance in stress level. Most important independent variables were 'work situation', 'social support' and 'disease' (in work), and 'disease', 'work situation' and 'financial circumstances' (outside the labour marked). Conclusions Stress was affected by work- and non-work-related stressors and social support. At populations-level 'disease' was the most important stressor. However, among respondents in work 'work situation' was the most important stressor, whereas 'disease' was the most important stressor outside the labour marked. Key messages Stress level is affected by a combination of work- and non-work-related stressors and social support. As a consequence stress prevention should not focus solely on work-related stressors.

Daily temperature variation lowers the lethal and sublethal impact of a pesticide pulse due to a higher degradation rate

Daily temperature variation (DTV) is an important warming-related stressor that may magnify pesticide toxicity. Yet, it is unknown whether the pesticide impact under DTV is partly ameliorated by a faster pesticide degradation caused by cyclically higher temperatures under DTV. As synergisms may be more likely under energy-limiting conditions, the impact of the pesticide chlorpyrifos was tested under DTV on the mosquito Culex pipiens in the absence and presence of interspecific competition with the water flea Daphnia magna. Chlorpyrifos exposure at a constant temperature without interspecific competition caused considerable mortality, decreased development time, and increased pupal mass of C. pipiens. Competition with D. magna had negative sublethal effects, but it did not affect the toxicity of chlorpyrifos. In contrast, the presence of C. pipiens decreased the impact of chlorpyrifos on D. magna probably due to corporal absorption of chlorpyrifos by C. pipiens. A key finding was that chlorpyrifos no longer caused lethal effects on C. pipiens under DTV, despite DTV on its own being mildly lethal. Additionally, chlorpyrifos exposure under DTV decreased development time less and had no effect anymore on pupal mass compared to chlorpyrifos exposure at a constant temperature. Similarly, the negative chlorpyrifos impact on adult survival of D. magna was less under DTV than at the constant temperature. This could be explained by a faster chlorpyrifos degradation under DTV. This antagonism between pesticide exposure and DTV is likely widespread because organisms experience DTV, many pesticides are applied in pulses, and pesticide degradation is faster at higher temperatures.

Reduced quality of sterile Queensland fruit fly following post-production stress from hypoxia, irradiation and vibration

The sterile insect technique (SIT), a benign pest control strategy, is currently undergoing a substantial renewal for controlling the Queensland fruit fly (Q-fly), a major horticultural pest in Australia. Production and delivery of high-quality flies is fundamental to effective SIT. While efforts are commonly made to improve production at a factory level (both quantity and quality), the methods and conditions during post-production operations also need to be tuned to minimize reductions in fly quality. Hypoxia, irradiation and vibration are important stressors that are experienced by pupae during production, packing and transportation. However, little is known about the impacts of such stressors on Q-fly quality. We conducted two laboratory experiments to investigate the response of Q-fly to such post-production stressors, with the aim of then developing guidelines that minimize quality reductions for SIT programs. In Experiment 1, Q-fly pupae of different ages (3, 6 or 9-day old) were exposed to vibrations for 5, 30, 60 and 300 s. Flight ability tests revealed that 6- and 9-day-old pupae were the most sensitive to vibration, with significant reduction in emergence and percentage of fliers. In Experiment 2, the effect of hypoxia, irradiation and vibration, in isolation or in combination, was evaluated on 9-day-old pupae. Irradiation and vibration exhibited a multiplicative negative effect on flight ability parameters. It is recommended not to subject pupae to intense or extensive vibration during the late pupal stage and to avoid prolonged periods of hypoxia.

Effect of Stress on Autonomic and Cardiovascular Systems in Military Population: A Systematic Review.

Stress is regulated by the autonomous nervous system, increasing the sympathetic modulation when a threat is perceived. A multifactorial response usually leads to significant behavioural modifications and alterations on homeostasis and physical and psychological status. Moreover, stress is an emotional response that can lead to psychosocial and psychophysiological adversity. Regarding military population, military operations and combat exposure are important stressors that influence acute and chronic stress response in soldiers, affecting their performance and health. A bibliographic search was carried out between April and May 2019, focusing on recent studies (2013–2019) that analysed psychophysiological response, stress, stress regulation, heart rate, heart rate variability, and posttraumatic stress disorder in military population. Autonomic and cardiovascular chronic stress seems to be modulated by experience and previous specific training of each military unit. Physical exercise, music embedded with binaural beat technology, bidirectional sensory motor rhythm training, heart rate variability biofeedback, and transcutaneous vagal nerve stimulation are the main techniques applied to balance stress and to recover body homeostasis. Since military population are usually exposed to multiple stressors, knowing previous training and experience, together with developing techniques to balance stress, is the main practical application in this field of study to balance autonomic and cardiovascular systems.

Potential Consequences of Climate and Management Scenarios for the Northeast Atlantic Mackerel Fishery

Climate change and fishing represent two of the most important stressors facing fish stocks. Forecasting the consequences of fishing scenarios has long been a central part of fisheries management. More recently, the effects of changing climate have been simulated alongside the effects of fishing to project their combined consequences for fish stocks. Here, we use an ecological individual-based model (IBM) to make predictions about how the Northeast Atlantic mackerel (NEAM) stock may respond to various fishing and climate scenarios out to 2050. Inputs to the IBM include Sea Surface Temperature (SST), chlorophyll concentration (as a proxy for prey availability) and rates of fishing mortality F at age. The climate scenarios comprise projections of SST and chlorophyll from an earth system model GFDL-ESM-2M under assumptions of high (RCP 2.6) and low (RCP 8.5) climate change mitigation action. Management scenarios comprise different levels of F, ranging from no fishing to rate Flim which represents an undesirable situation for management. In addition to these simple management scenarios, we also implement a hypothetical area closure in the North Sea, with different assumptions about how much fishing mortality is relocated elsewhere when it is closed. Our results suggest that, over the range of scenarios considered, fishing mortality has a larger effect than climate out to 2050. This result is evident in terms of stock size and spatial distribution in the summer months. We then show that the effects of area closures are highly sensitive to assumptions about how fishing mortality is relocated elsewhere after area closures. Going forward it would be useful to incorporate: 1) fishing fleet dynamics so that the behavioural response of fishers to area closures, and to the stock’s spatial distribution, can be better accounted for; and 2) additional climate-related stressors such as ocean acidification, deoxygenation and changes in prey composition.

ICD-11 posttraumatic stress disorder, complex PTSD and adjustment disorder: the importance of stressors and traumatic life events

ABSTRACT Background: Although ICD-11 adjustment (AjD), posttraumatic stress (PTSD) and complex posttraumatic stress (CPTSD) are commonly diagnosed disorders following exposure to stressful or traumatic life events, their dimensional structure and co-occurrence has never been tested in a single study. The present study explored the latent structure of AjD, PTSD, and CPTSD symptoms and their relationship to stressful and traumatic life events to determine the degree of distinctiveness between these constructs. Methods: Participants were clinical patients (N = 331) who completed self-report measures of stressful and traumatic life events, AjD (The Adjustment Disorder – New Module 8 (ADNM-8)) and PTSD / CPTSD (The International Trauma Questionnaire – ITQ). Results: Using confirmatory factor analysis, a second-order model comprised of correlated latent variables of AjD, PTSD, and CPTSD provided the best fit of the data. It was also found that stressors and traumatic life events were positively associated with all of these conditions although childhood trauma was only associated with CPTSD. Conclusions: The current findings support the ICD-11 model of related-but-distinct stress-related disorders. We discuss the existence of a stress-response continuum and how the current findings impact the development of clinical interventions that may be shared across, or unique to, each stress-related disorder.

Mercury (Hg2+) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus

Freezing temperatures is an important stressor in the arctic regions and has a significant influence on the population dynamics and geographic distribution of terrestrial invertebrates. Toxic metals in the environment can interfere with protective cold-acclimation responses of organisms. It is therefore important to evaluate the combined effects of cold stress and environmental contaminants. Here, we aimed to investigate the effects of Hg (HgCl2) on various physiological aspects of freeze-tolerance in the earthworm (Enchytraeus albidus). We measured the levels of the cryoprotectant glucose, the glycogen content (source of glucose molecules for cryoprotection and fuel for metabolism), and changes in the composition of membrane phospholipid fatty acids (PLFA) as an indicator of lipid peroxidation.Freezing at −6 °C had no effect on survival in uncontaminated soil, however, survival of freezing in Hg contaminated soil was clearly reduced, especially at extended exposure times. Thus, the LC50 value in frozen soil decreased from 8.3 mg Hg kg−1 (when exposed for 17 days) to only 4.2 mg Hg kg−1 after 36 days’ exposure indicating that combined effects of Hg and freezing became larger at prolonged exposure times. Hg caused a depletion of glycogen reserves (almost 50% at 12 mg kg−1 dry soil), but despite this effect worms were able to maintain a constant cryoprotectant level (about 0.12 mg glucose mg−1 dry weight) at all Hg concentrations. Hg had clear negative effects on the proportion of unsaturated PLFAs, which could be an indication of lipid peroxidation. Since a high proportion of unsaturated fatty acids in the membrane is important for invertebrate freeze-tolerance, our results suggest that the negative effect of Hg on freeze-tolerance in E. albidus is related to degraded membrane functionality at low temperature.

Managing stress during the coronavirus disease 2019 pandemic and beyond: Reappraisal and mindset approaches.

The novel coronavirus disease 2019 (COVID‐19) pandemic is a global public health crisis of a scale not previously experienced in modern times (Kickbusch et al., 2020). Governmental ‘lockdown’ measures aimed at minimizing virus transmission including ‘stay at home’ orders, closure of businesses and places of congregation, and travel restrictions have had a substantive societal impact that permeates almost every facet of daily life (Gostin & Wiley, 2020; Shanafelt, Ripp, & Trockel, 2020). These widespread changes represent considerable sources of stress in the population and will have deleterious effects on mental and physical health going forward. As nations begin to emerge from ‘lockdown’, the collateral damage to human health caused by these restrictions has taken centre stage, and mental health issues, particularly stress‐related conditions and outcomes, are prominent among them. The imperative for strategies to assist in managing stress and minimizing concomitant health problems has become a priority. In this commentary, we outline how stress reappraisal interventions, which have come to the fore in recent years, may be a potentially efficacious, cost‐effective way to manage stress during and post‐pandemic, and minimize the health consequences.

A Novel In Situ Toxicity Identification Evaluation (iTIE) System for Determining which Chemicals Drive Impairments at Contaminated Sites.

Human-dominated waterways contain thousands of chemicals. Determining which chemical is the most important stressor is important, yet very challenging. The Toxicity Identification Evaluation (TIE) procedure from the US Environmental Protection Agency uses a series of chemical and physical manipulations to fractionate compounds within a matrix and systematically identify potential toxicants through laboratory bioassay testing. Although this may provide useful information, it lacks ecological realism because it is subject to laboratory-related artifacts and is resource intensive. The in situ Toxicity Identification Evaluation (iTIE) technology was developed to improve this approach and has undergone a number of modifications over the past several years. The novel prototype 3 consists of an array of iTIE ambient water fractionation units. Each unit is connected to a peristaltic pumping system with an organism exposure chamber that receives water from a resin chamber to chemically fractionate test site water. Test organisms included freshwater and marine standard toxicity test species. Postfractionation waters are collected for subsequent chemical analyses. Currently, the resins allow for separation of ammonia, metals, and nonpolar organics; the subsequent toxicity responses are compared between treatments and unfractionated, ambient exposures. The iTIE system was deployed to a depth of 3 m and evaluated in streams and marine harbors. Chemical analyses of water and iTIE chemical sorptive resins confirmed chemical groups causing lethal to sublethal responses. The system proved to be as sensitive or more so than the traditional phase 1 TIE test and required almost half of the resources to complete. This iTIE prototype provides a robust technology that improves stressor-causality linkages and thereby supports strong evidence for ecological risk weight-of-evidence assessments. Environ Toxicol Chem 2020;39:1746-1754. © 2020 SETAC.

Low seasonal variation in greater mouse-eared bat (Myotis myotis) blood parameters.

The greater mouse-eared bat (Myotis myotis) is a flagship species for the protection of hibernation and summer maternity roosts in the Western Palearctic region. A range of pathogenic agents is known to put pressure on populations, including the white-nose syndrome fungus, for which the species shows the highest prevalence and infection intensity of all European bat species. Here, we perform analysis of blood parameters characteristic for the species during its natural annual life cycle in order to establish reference values. Despite sexual dimorphism and some univariate differences, the overall multivariate pattern suggests low seasonal variation with homeostatic mechanisms effectively regulating haematology and blood biochemistry ranges. Overall, the species displayed a high haematocrit and haemoglobin content and high concentration of urea, while blood glucose levels in swarming and hibernating bats ranged from hypo- to normoglycaemic. Unlike blood pH, concentrations of electrolytes were wide ranging. To conclude, baseline data for blood physiology are a useful tool for providing suitable medical care in rescue centres, for studying population health in bats adapting to environmental change, and for understanding bat responses to stressors of conservation and/or zoonotic importance.

Thermal Burn Injury Generates Bioactive Microvesicles: Evidence for a Novel Transport Mechanism for the Lipid Mediator Platelet-Activating Factor (PAF) That Involves Subcellular Particles and the PAF Receptor.

Thermal burn injuries are an important environmental stressor that can result in considerable morbidity and mortality. The exact mechanism by which an environmental stimulus to skin results in local and systemic effects is an area of active research. One potential mechanism to allow skin keratinocytes to disperse bioactive substances is via microvesicle particles, which are subcellular bodies released directly from cellular membranes. Our previous studies have indicated that thermal burn injury of the skin keratinocyte in vitro results in the production of the lipid mediator platelet-activating factor (PAF). The present studies demonstrate that thermal burn injury to keratinocytes in vitro and human skin explants ex vivo, and mice in vivo generate microvesicle particles. Use of pharmacologic and genetic tools indicates that the optimal release of microvesicles is dependent upon the PAF receptor. Of note, burn injury-stimulated microvesicle particles do not carry appreciable protein cytokines yet contain high levels of PAF. These studies describe a novel mechanism involving microvesicle particles by which a metabolically labile bioactive lipid can travel from cells in response to environmental stimuli.