Measurement Of Physiological Responses Research Articles

Ecological correlates of fecal corticosterone metabolites in female Greater Sage-Grouse (Centrocercus urophasianus)

Measurement of physiological responses can reveal effects of ecological conditions on an animal and correlate with demographic parameters. Ecological conditions for many animal species have deteriorated as a function of invasive plants and habitat fragmentation. Expansion of juniper (genus Juniperus L.) trees and invasion of annual grasses into sagebrush (genus Artemisia L.) ecosystems have contributed to habitat degradation for Greater Sage-Grouse (Centrocercus urophasianus (Bonaparte, 1827); hereinafter Sage-Grouse), a species of conservation concern throughout its range. We evaluated relationships between habitat use in a landscape modified by juniper expansion and annual grasses and corticosterone metabolite levels (stress responses) in feces (FCORTm) of female Sage-Grouse. We used remotely sensed data to estimate vegetation cover within the home ranges of hens and accounted for factors that influence FCORTm in other vertebrates, such as age and weather. We collected 35 fecal samples from 22 radio-collared hens during the 2017–2018 brood-rearing season (24 May–26 July) in southwestern Idaho (USA). Concentrations of corticosterone increased with home range size but decreased with reproductive effort and temperature. The importance of home range size suggests that maintaining or improving habitats that promote smaller home ranges would likely facilitate a lower stress response by hens, which should benefit Sage-Grouse survival and reproduction.

PSI-11 Evaluation of Electronically Controlled Cooling Pad Flush Rates on Heat Stressed Gilts

Abstract This study was designed to evaluate the effects of electronically controlled cooling pads on measures of physiological responses in HS gilts. The study utilized 12 gilts randomly assigned into one of three treatment groups [Control(CN), flush 2.0 L cool water over 30 s every 4 min(F4), or flush 2.0 L over 30 s every 8 min(F8)] in a Latin Square design and replicated 12 times(2 repetitions/d over 6 d). Gilts were housed in farrowing crates and fed 1.2 kg at 0700 and 1300 h daily. On d 1 to 3(6 repetitions) the room was gradually heated from 18ºC to 32ºC, while on d 4 to 6 the room was gradually heated from 18ºC to 35ºC starting at 0730 or 1330 h. Once the temperature was achieved, cooling pads were turned on and the temperature was maintained for 2.5 h. Two baseline measurements were taken of respiration rates(RR), skin temperature through thermal imaging(IRTemp), and vaginal temperature(VTemp) before room heating began and then recorded every 20 minutes after pads were turned on. Measurements at the end of HS(PostH) and the change in values during the HS period(DIFF) were evaluated using PROC mixed of SAS. Gilts in F4 and F8 had lower RR than CN for PostH for both 32ºC and 35ºC (P< .05). DIFF in RR was less in F4 and F8 than in CN[(32ºC, P=.097) and (35ºC, P=.005)]. There was a tendency for DIFF in Vtemp at 32ºC between treatments (P=.064) but had no effect by treatment for PostH (P=.534). There was no effect in PostH and DIFF for IRTemp between treatments for 32ºC and 35ºC. PostH and DIFF for VTemp were significant at 35ºC (P=.009 and P=.001). PostH for RR was different at 35 ºC and 32 ºC (P=.0074; P=.0472) with F4 and F8 lesser and CN. In conclusion, cooling pads, regardless of flush rate, had positive impacts on physiological indicators of HS.

Bicyclists’ behavioral and physiological responses to varying roadway conditions and bicycle infrastructure

Population growth increase of vehicle ownership, and development patterns have resulted in greater levels of congestion, pollution, and crash frequency. A proposed solution to lessen current transportation system demands is to increase the share of bicycle trips. Furthermore, as cycling is perceived by some as both a dangerous and stressful mode of transportation, understanding the factors that lead to less comfortable and stressful riding, can help drive bicycle infrastructure development. To establish a more robust understanding of the behaviors of bicyclists and how infrastructure design and operations influence them, a bicycle simulator was used to evaluate bicyclist performance measures of velocity, horizontal displacement, and physiological responses (i.e., galvanic skin response) while riding in varying roadway conditions. Results showed that bicyclists in the bike lane condition, had a GSR reading 1.77 peaks per min less than when cycling in the no bike lane condition. When bicyclists were in no bike lane condition, the GSR reading was not affected by vehicle speed but it was affected by the vehicular volume. Additionally, females felt less comfortable when riding in either bike condition, even though they reported that they were “Strong and Fearless” riders. The methodology used for this study sets forth the foundation for future research that could evaluate varying facility designs and a wider range of individuals.

Estimating the Audibility of Industrial Noise to Denning Polar Bears

ABSTRACTOil and gas activities on Alaska's North Slope overlap spatially with polar bear (Ursus maritimus) maternal denning habitat and temporally with the peri‐partum and emergence periods. Noise associated with these activities can be substantial and concerns regarding the effects on polar bears have been acknowledged. But the secluded and ephemeral nature of subnivean maternal dens renders the measurement of behavioral and physiological responses of bears to noise exposure challenging, except for rare cases when disturbance‐prompted den abandonment has been documented. These limitations, coupled with the uncertainty associated with the synergistic effects of anthropogenic activities on bears in a rapidly changing Arctic, prompt the need to develop predictive models of disturbance to ensure management guidelines effectively mitigate disturbance. Towards this end, we characterized noise propagation from 9 sources (2 aircraft, 2 over‐tundra tracked vehicles, 4 wheeled on‐road vehicles, and humans walking) used to support industrial activities around artificial snow dens near Milne Point, Alaska, USA, in March–April 2010. We built dens in 4 configurations to mimic variability in den roof thickness and to evaluate differences in noise propagation from when the den was closed compared to being open, similar to den emergence. We integrated these data with an existing polar bear audiogram and developed models to predict auditory‐detection probabilities as a function of distance from the den. Within a closed den, aircraft had high probabilities (detection probability ≥75%) of being detected by polar bears at distances ≤1.6 km and ground‐based sources had high probabilities of detection at distances ≤0.8 km. On average, closed dens reduced noise levels by 15 decibels (dB) relative to open dens. Our findings indicate that although polar bear snow dens effectively attenuate acoustic sound pressure levels, noise from some industrial support vehicles was likely to be detected farther from dens than previously documented. These results reinforce the importance of maintaining buffer zones around polar bear dens to minimize the potential for den disturbance. © 2020 The Wildlife Society.

Assessing Cognitive Performance Using Physiological and Facial Features

Sensing and machine learning advances have enabled the unobtrusive measurement of physiological responses and facial expressions so as to estimate one's cognitive performance. This often boils down to mapping the states of the cognitive processes underpinning human cognition: physiological responses (e.g., heart rate) and facial expressions (e.g., frowning) often reflect the states of our cognitive processes. However, it remains unclear whether physiological responses and facial expressions used in one particular task (e.g., gaming) can reliably assess cognitive performance in another task (e.g., coding), because complex and diverse tasks often require varying levels and combinations of cognitive processes. In this paper, we measure the cross-task reliability of physiological and facial responses. Specifically, we assess cognitive performance based on physiological responses and facial expressions for 123 participants in 4 independent studies (3 studies for out-of-sampling training and testing, and 1 study for evaluation only): (1) a Pac-Man game, (2) an adaptive-assessment task, (3) a code-debugging task, and (4) a gaze-based game. We follow an ensemble learning approach after cross-training and cross-testing with all possible combinations of the 3 first datasets. We save the 4th dataset only for testing purposes, and we showcase how to engineer generalizable features that predict cognitive performance. Our results show that the extracted features do generalize, and can reliably predict cognitive performance across a diverse set of cognitive tasks that require different combinations of problem-solving, decision-making, and learning processes for their completion.

Interpersonal Distance During Real-Time Social Interaction: Insights From Subjective Experience, Behavior, and Physiology.

Physical distance is a prominent feature in face-to-face social interactions and allows regulating social encounters. Close interpersonal distance (IPD) increases emotional responses during interaction and has been related to avoidance behavior in social anxiety. However, a systematic investigation of the effects of IPD on subjective experience combined with measures of physiological arousal and behavioral responses during real-time social interaction has been missing. Virtual Reality allows for a controlled manipulation of IPD while maintaining naturalistic social encounters. The present study investigates IPD in social interaction using a novel paradigm in Virtual Reality. Thirty-six participants approached virtual agents and engaged in short interactions. IPD was varied between 3.5 and 1 m by manipulating the distance at which agents reacted to the participant's approach. Closer distances were rated as more arousing, less pleasant, and less natural than longer distances and this effect was significantly modulated by social anxiety scores. Skin conductance responses were also increased at short distances compared to longer distances. Finally, an interaction of IPD and social anxiety was observed for avoidance behavior, measured as participants' backward motion during interaction, with stronger avoidance related to close distances and high values of social anxiety. These results highlight the influence of IPD on experience, physiological response, and behavior during social interaction. The interaction of social anxiety and IPD suggests including the manipulation of IPD in behavioral tests in Virtual Reality as a promising tool for the treatment of social anxiety disorder.

Measurements of Physiological Stress Responses in C. Elegans.

Organisms are often exposed to fluctuating environments and changes in intracellular homeostasis, which can have detrimental effects on their proteome and physiology. Thus, organisms have evolved targeted and specific stress responses dedicated to repair damage and maintain homeostasis. These mechanisms include the unfolded protein response of the endoplasmic reticulum (UPRER), the unfolded protein response of the mitochondria (UPRMT), the heat shock response (HSR), and the oxidative stress response (OxSR). The protocols presented here describe methods to detect and characterize the activation of these pathways and their physiological consequences in the nematode, C. elegans. First, the use of pathway-specific fluorescent transcriptional reporters is described for rapid cellular characterization, drug screening, or large-scale genetic screening (e.g., RNAi or mutant libraries). In addition, complementary, robust physiological assays are described, which can be used to directly assess sensitivity of animals to specific stressors, serving as functional validation of the transcriptional reporters. Together, these methods allow for rapid characterization of the cellular and physiological effects of internal and external proteotoxic perturbations.

Gene Transcript Profiling in Desert Bighorn Sheep

ABSTRACTRespiratory disease is a key factor affecting the conservation and recovery of bighorn sheep (Ovis canadensis) populations. Innovative, minimally invasive tools such as gene transcription–based diagnostics have the potential to improve our understanding of the broad range of factors that can affect the health of wild sheep. Evaluation of transcript levels for genes representative of multiple internal systems enables measurement of physiological responses of individuals as well as populations to environmental stressors such as pathogens, nutritional deficiency, or contaminants. We developed real‐time polymerase chain reaction assays for 14 genes of interest representing systems including inflammation, cell signaling, detoxification, antiviral, antibacterial, or general stress. Initial results from desert bighorn sheep (O. c. nelsoni) sampled from the River, Muddy, and Bare mountains as well as from the Pintwater Range, in southern Nevada, USA, indicated unique transcript profiles associated with each population. This initial study provides the framework from which controlled variable or longitudinal studies can be made, thus augmenting the potential to inform management actions in the future. © 2020 The Wildlife Society.

A new aerobic fitness score based on lactate sensing during submaximal exercise.

Given the known clinical utility of cardiorespiratory fitness, measurement of physiological responses to submaximal exercise may be a feasible approach well suited for diagnostic and prognostic purposes in non-athletes and the chronically ill. Lactate levels and watt output during a short submaximal exercise and a subsequent relaxation period yield an aerobic score that is consistent with cardiorespiratory fitness grades in non-athletes and that may be used as a marker in such approaches. In this study, 28 females (23 ± 3 years) were submitted to a 15 min submaximal recumbent bike session, and their capillary and saliva lactate concentrations were recorded and plotted against time. An individual aerobic score was calculated from this curve, using watt output during equal relative percentiles of maximum heart-rate benchmarks. The scores were compared with respective results in a V̇O2max test and with a similar scoring system in 14 older (51 ± 9 years) females; they correlated with the 6 categories of the V̇O2max test results and classified into 3 categories of V̇O2max grades (very poor/poor; fair/good; excellent/superior) with a combined accuracy of 80.95%. More studies are required to validate the potential utility of this submaximal test as an additional risk factor for diagnostic purposes in non-athletes. Novelty points: A novel method for estimating cardiorespiratory fitness during submaximal exercise consistent with V̇O2max performance. The method yields an aerobic score that may be used as a marker for diagnostic and prognostic purposes.

Impaired empathy and increased anger following social exclusion in non-intoxicated opioid users

RationaleSocial functioning is modulated by the endogenous opioid system. In opioid use disorder, social functioning appears disrupted, but little research has delineated the nature of these deficits and their relationship to acute opioid use.ObjectivesThe current study aimed to assess both emotional and cognitive empathy, along with subjective and physiological responses to social exclusion in opioid users who were either acutely intoxicated or non-intoxicated from using opioids.MethodsIndividuals on an opioid substitution medication (OSM) were divided into ‘intoxicated users’ (had taken their OSM the same day as testing, n = 20) and ‘non-intoxicated users’ (had taken their OSM > 12 h ago, n = 20) and compared with opioid-naïve controls (n = 24). Empathy was assessed using the multifaceted empathy test and self-report questionnaire. Participants also underwent a period of social exclusion (Cyberball Game) and completed measures of mood and physiological responses (salivary cortisol and heart rate).ResultsNon-intoxicated users had significantly lower emotional empathy (the ability to experience others’ emotions), as well as greater anger after social exclusion when compared with the intoxicated users and controls. Anger did not change with social exclusion in the intoxicated user group and cortisol levels were lower overall.ConclusionsReduced ability to spontaneously share the emotions of others was reported in non-intoxicated users, particularly regarding positive emotions. There was some support for the idea of hyperalgesia to social pain, but this was restricted to an enhanced anger response in non-intoxicated users. Equivalent rates of empathy between the intoxicated users and controls could indicate some remediating effects of acute opioids.

The Application of Wearable Technology to Quantify Health and Wellbeing Co-benefits From Urban Wetlands.

Improved nature provision in urban environments offers great potential for achieving both biodiversity conservation and public health objectives. Yet there are few experimental studies that address links between specific natural environments and physiological and/or psychological changes that could contribute to the health and wellbeing co-benefits of urban nature. In addition, relative to green space, the salutogenic impact of aquatic environments are understudied. Here, we present a feasibility study examining the use of low-cost wearable technology to quantify the psychophysiological effects of short-term exposure to urban wetlands. The study took place at the WWT London Wetland Centre, which is characterized by its contrasting biodiverse wetland habitat and surrounding urban setting. Thirty-six healthy participants experienced counterbalanced exposures to an indoor space, a wetland, an urban site. We continuously recorded electroencephalographic (EEG) data and real-time physiological stress responses; with additional monitoring of post-exposure self-reported mood states. We found a significant effect of site on mean resting heart rate (HR), with increased HR in the urban setting, although this was only observed in participants with pre-existing high stress. We found no significant differences in other measures of physiological stress responses (heart rate variability and electrodermal activity). The EEG data showed modulation of high beta band activity only in the wetland setting, potentially related to changes in attention. However, the EEG findings were confounded by low quality signals and artifacts caused by movement and environmental interference. Assessments of self-reported mood states demonstrated an increase in positive feelings in the wetland setting. A pronounced decrease in negative feelings in the wetland setting was observed in stressed individuals only. Our results suggest that pre-existing stress levels may be an important modulator of the salutogenic effect of blue-green space. We provide partial support for the hypothesis that exposure to blue-green space promotes stress recovery and for the use of low-cost psychophysiological measurements to quantify the potential stress-reducing effects of blue–green space exposure in urban dwellers. Further technological refinement is required for this approach to become a viable tool to support evidence-based decision-making for public health and green/blue space provision.

Potential Impact of Construction Noise on Selected Zoo Animals.

Simple SummaryAnimals in zoos can adapt to many noises they hear on a regular basis. However, construction noise that is intense or occurs unpredictably may negatively impact the welfare state of some animals and induce a chronic stress response. This study aimed to understand the behavioral response to construction noise of selected species in an urban zoo in order to guide mitigating actions in advance of, and during, a planned construction project. The behavior of elephants, giraffes, emus and alligators was recorded during 90-min exposures to different sound environments including ambient sound, and four construction sound treatments. A non-invasive measure of physiological stress response was also measured in emus. All species appeared to respond to the recorded noise, with giraffes, elephants and emu, demonstrating behavioral changes potentially indicative of agitation or stress. This study has implications for the trade-offs that occur when zoos seek to improve long-term animal welfare through enclosure refurbishment and short-term impacts on animals exposed to construction noise.In anticipation of a major construction project in an urban New Zealand zoo, a study was initiated to assess the response to construction noise of selected animal species (elephant, giraffe, emu and alligator) previously observed to be sensitive to this kind of noise. The overall aim was to detect any signs of aversive responses to this noise to enable keepers to recognize these and take any necessary mitigating actions during the construction period. The experimental approach involved the creation of acoustic maps of each focal animal enclosure, a series of 90-min video recordings of the animals’ behavior in response to ambient noise (control) and amplified broadcast of pre-recorded continuous and intermittent construction noise. Concentration of fecal corticosterone metabolites was also measured for the emus. Key findings were that giraffes, elephants and emus appeared to show an increase in behaviors that could indicate stress or agitation including vigilance and locomotion and may prefer quieter regions of their enclosure during sound exposure. Giraffes also increased close contact with conspecifics when exposed to construction noise. While alligators did not show clear evidence of noise-related stress, our findings indicated that all focal species showed some behavioral responses to recorded construction noise.

Remote physiological monitoring provides unique insights on the cardiovascular performance and stress responses of freely swimming rainbow trout in aquaculture

Investigating the mechanisms that fish employ to maintain homeostasis in their everyday life requires measurements of physiological and behavioural responses in the field. With multivariate bio-loggers, we continuously measured gastrointestinal blood flow (GBF), heart rate, activity and body temperature in rainbow trout (Oncorhynchus mykiss) swimming freely amongst ~5000 conspecifics in a sea cage. Our findings clearly demonstrate that while both acute aquaculture-related stress and spontaneous activity resulted in transient reductions in GBF (i.e. reductions of up to 65%), recovery from stressful handling practices subsequently involved a substantial and prolonged gastrointestinal hyperemia far beyond the level observed prior to the stressor. The gastrointestinal hyperemia may be necessary to repair the damage to the gastrointestinal tract caused by acute stress. Furthermore, heart rate responses to acute stress or voluntary activity differed depending on the individual’s physiological state. Stressed fish (i.e. mean heart rates >70 beats min−1) exhibited a bradycardic response to acute stress or activity, whereas fish with mean heart rates <60 beats min−1 instead demonstrated strong tachycardic responses. Remote monitoring of physiological and behavioural variables using bio-loggers can provide unique insights into ‘real-life’ responses of animals, which can largely differ from the responses observed in confined laboratory settings.

Silicon nutrition improves growth of salt-stressed wheat by modulating flows and partitioning of Na+, Cl− and mineral ions

Silicon (Si) is reported to improve salt stress tolerance of cereals, but little is known about the effects of Si on flows and partitioning of sodium (Na+), chloride (Cl−), and essential mineral ions at the tissue and cellular level. Wheat (Triticum aestivum L.) was exposed to 200 mM NaCl for 30 d in hydroponics, with or without 2 mM Si. X-ray microanalysis coupled with scanning electron microscopy (SEM) was used to quantify the cell-specific ion profiles across root and leaf cells, paralleled by measurements of wheat growth and physiological responses. Under salt stress, higher Na+ and Cl− concentrations were detected in root epidermal, cortical and stelar cells, eventually increasing their concentrations in different leaf cells, being highest in the epidermal cells and lowest in the vascular bundle cells. The potassium (K+) and magnesium (Mg2+) profiles were generally opposite to those of Na+ and Cl−. NaCl-dependent deregulation of essential nutrient homeostasis and excessive toxic ions accumulation in leaves was correlated with enhanced electrolyte leakage index (ELI), decreased chlorophyll contents, photosynthesis and other physiological parameters, and ultimately hampered plant growth. Conversely, Si addition improved the growth and physiological performance of salinized wheat by reducing Na+ and Cl− concentration in root epidermal and cortical cells, and it improved root uptake and storage of K+ and Mg2+ ions and their loading into xylem for distribution to shoots. These results suggest that Si-mediated inhibition of Na+ uptake, maintained nutrient homeostasis and improved physiological parameters to contribute to wheat growth improvement under salt stress.

Functional imaging of visual cortical layers and subplate in awake mice with optimized three-photon microscopy

Two-photon microscopy is used to image neuronal activity, but has severe limitations for studying deeper cortical layers. Here, we developed a custom three-photon microscope optimized to image a vertical column of the cerebral cortex > 1 mm in depth in awake mice with low (<20 mW) average laser power. Our measurements of physiological responses and tissue-damage thresholds define pulse parameters and safety limits for damage-free three-photon imaging. We image functional visual responses of neurons expressing GCaMP6s across all layers of the primary visual cortex (V1) and in the subplate. These recordings reveal diverse visual selectivity in deep layers: layer 5 neurons are more broadly tuned to visual stimuli, whereas mean orientation selectivity of layer 6 neurons is slightly sharper, compared to neurons in other layers. Subplate neurons, located in the white matter below cortical layer 6 and characterized here for the first time, show low visual responsivity and broad orientation selectivity.

Hypoglycemia Unawareness in T1DM Is Associated with Altered Brain Default Mode Network Connectivity

The impact of hypoglycemia awareness (HA) on brain resting state connectivity remains unclear. To examine the impact of HA on the default mode network (DMN), a functional network in the brain that is active during wakeful rest and associated with introspection, 12 T1DM individuals with hypo unawareness (T1DM-UW) (by Clarke score) (7F/5M, age 44±12 years, BMI 26.4±4.2 kg/m2, HbA1c 7.1±0.7) and 15 T1DM-Aware (AW) (10F/5M, age 30±7, BMI 24.5±3.1, HbA1C 7.1±0.9) individuals underwent resting state BOLD fMRI scanning to assess the DMN during a two-step euglycemic (Eu)-hypoglycemic (Hypo) clamp (90-60 mg/dl). T1DM-AW individuals exhibited a hypoglycemia-induced decrease in DMN connectivity (P&amp;lt;0.001). In contrast, T1DM-UW individuals showed no difference in connectivity between conditions. Moreover, the degree of DMN inhibition correlated inversely with plasma cortisol (r=-0.432, p=0.031), norepinephrine (r=-0.40, p=0.038) and positively with hypoglycemia symptom scores (r=0.40, p=0.037). These findings suggest that, unlike T1DM-AW individuals, hypoglycemia fails to elicit changes in the DMN amongst T1DM-UA individuals. Furthermore, the change in DMN connectivity is associated with measures of physiological and interoceptive responses to stress. These findings highlight the need for future studies to investigate whether avoidance of hypoglycemia can restore brain connectivity patterns. Disclosure D. Groskreutz: None. J. Hwang: None. D. Seo: None. C. Lacadie: None. L. Parikh: None. R. Belfort-DeAguiar: Research Support; Self; GlaxoSmithKline plc.. D. Scheinost: None. R. Sinha: None. T. Constable: None. R. Sherwin: Other Relationship; Self; QuintilesIMS, MannKind Corporation. Research Support; Self; Regeneron Pharmaceuticals, Inc.. Other Relationship; Self; ICON plc..

The costs of living at the edge: Seasonal stress in wild savanna-dwelling chimpanzees

Adaptations associated with shifting from a predominately forested habitat to a more open environment are considered a crucial step in hominin evolution. Understanding how chimpanzees, one of our closest-living relatives, are exposed to the selection pressures associated with living in a relatively sparse, hot, and dry environment can inform us about the relative importance of potential environmental stressors involved in adaptations to drier environments. We investigated the extent to which chimpanzees living in an extreme savanna habitat experience seasonal variability in either energy balance or thermoregulation (dehydration and heat exposure), as well as whether these potential environmental constraints are taxing to chimpanzee individuals. Specifically, we tested the hypothesis that savanna environments impose seasonally-relevant costs to chimpanzees. To this end, we collected 368 urine samples from one community of chimpanzees at Fongoli, Senegal, and measured c-peptide, creatinine, and cortisol as measures of physiological responses to environmental food, water, and heat constraints, respectively. We then evaluated the influence of climatic and phenological factors on these indicators. Results illustrated significant seasonal variation in all biomarkers, which corresponded to relevant ecological correlates. Furthermore, creatinine but not c-peptide correlated with cortisol levels, suggesting that chimpanzees in this environment endure periods of heat and dehydration stress, but are able to avoid stressful levels of negative energy balance. Using savanna chimpanzees as a referential model, our research lends support to the notion that thermoregulatory challenges were a significant factor in hominin evolution, and suggests these challenges may have overshadowed the challenges of maintaining adequate energetic balance during the expansion of the hominin range from wetter to drier environments.

AVALIAÇÃO DO CONFORTO TÉRMICO PARA OVINOS EM EXPOSIÇÃO DURANTE FEIRA AGROPECUÁRIA DE SANTARÉM

RESUMO: A exposição de ovinos em feira agropecuária vem aumentando consideravelmente nos últimos anos, principalmente devido ao avanço de técnicas de manejo, nutrição e melhoramento genético. O presente trabalho objetivou-se avaliar a zona de conforto térmico em ovinos da raça Santa Inês e Dorper por meio de medições da temperatura, umidade relativa e respostas fisiológicas. O trabalho durou dois dias com a utilização de sete fêmeas de ambas as raças com idade média de sete meses. O experimento foi em delineamento experimental inteiramente casualizado em esquema fatorial 12x2. Para coleta das variáveis bioclimáticas utilizou-se a temperatura de bulbo seco, umidade relativa do ar, índice de temperatura e umidade, e as respostas fisiológicos foram frequência respiratória, frequência superficial (cabeça, tronco e garupa). Sob as condições ambientais adversas no local do experimento, os ovinos foram sujeitos ao estresse moderado, apresentando seus parâmetros fisiológicos acima da normalidade, em média, principalmente no período da tarde, estando fora da sua zona de termoneutralidade. A raça Santa Inês foi a que apresentou menor elevação da temperatura superficial, consequentemente, apontou maior tolerância ao estresse ambiental.PALAVRAS-CHAVE: Ambiência, Bioclimatologia, Estresse.

Measurement of physiological responses to acute stress in multiple occupations: A systematic review and implications for front line healthcare providers.

Optimizing performance of individuals in acutely stressful work-related situations requires a deeper understanding of the interaction between the demands of the stimuli and an individual's associated physiological response. Identifying these responses is particularly germane for healthcare professionals, who experience episodes of acute stress on a regular basis. The purpose of this review was to examine and synthesize empirical literature to identify studies assessing physiological responses to acute stress, determine common methods for measuring acute stress in near real-time, and identify common research designs employed across industries. A modified PRISMA approach was followed. Systematic searches were conducted of four databases (PsycINFO, Medline, PubMed, and Turning Research into Practice [TRIP]) to access eligibility. Reference list searches and a hand search were also conducted to identify other articles suitable for inclusion. Studies selected examined an acute physiological response while participants were engaged in a stress-inducing task. Twenty-two articles were included. Fifteen (68.2%) were centered on the human service industry while only three (13.6%) focused on healthcare professionals. Half of the studies incorporated a simulation into the research design while only two (9.1%) articles looked at physiological responses in real-world settings. Heart rate and cortisol emerged as the most common physiological measures collected. This review demonstrates that acute stress is primarily assessed retrospectively, and that there is a pragmatic gap in methodological approach, with many data collection methods inappropriate for the healthcare environment. Future research should capitalize on advancements in sensor technology to passively examine acute stress in healthcare professionals.

Assessment of emotional responses in preschoolers to an age-adapted stress task: Picture-based stress test and facial coding.

Objective: Acute stress exposure leads to physiological, behavioral and emotional stress responses. While measurements of physiological stress responses in young children have improved, assessments of correlates of emotional responses to stress in children at preschool age are still limited to the coding of video-taped responses and their validity is questionable. Therefore, the aim of this study was to develop and investigate a method to assess correlates of emotional responses to stress by experienced emotional responses (Picture-Stress-Test, PST) and by facial expressed emotional responses. Method: A total of 295 children aged 2–6 years of the SPLASHY study were assessed during an age-adapted stress task by heart rate variability, by videotapes (coded for positive and negative facial expression) and by the assessment of experienced emotional states at baseline, during the stress task and after the stress task. For this purpose, children were asked to estimate their own emotional state and to choose one of five pictures of rabbits with different emotional states (positive (happy) or negative (angry, anxious, stressed and sad)) depending on the estimated subjective emotional state. Results: Both correlates of emotional responses and heart rate variability significantly changed under stress condition. Children showed lower levels of positive states in the PST and in the videotaped material during the stress task. Conclusion: Measures of experienced emotional responses and of facial expression responses might represent valuable methods that could be combined to catch the broad range of correlates of emotional responses to a stress task in preschool children.