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1.
Virtual Reality (VR) has emerged as a promising tool in many domains of therapy and rehabilitation, and has recently attracted the attention of researchers and clinicians working with elderly people with MCI, Alzheimer’s disease and related disorders. Here we present a study testing the feasibility of using highly realistic image-based rendered VR with patients with MCI and dementia. We designed an attentional task to train selective and sustained attention, and we tested a VR and a paper version of this task in a single-session within-subjects design. Results showed that participants with MCI and dementia reported to be highly satisfied and interested in the task, and they reported high feelings of security, low discomfort, anxiety and fatigue. In addition, participants reported a preference for the VR condition compared to the paper condition, even if the task was more difficult. Interestingly, apathetic participants showed a preference for the VR condition stronger than that of non-apathetic participants. These findings suggest that VR-based training can be considered as an interesting tool to improve adherence to cognitive training in elderly people with cognitive impairment.  相似文献   

2.
Glucocorticoid steroids modulate immunocompetence in complex ways with both immunoenhancing and immunosuppressive effects in vertebrates exposed to different stressors. Such bimodal effects have been associated with variation in duration and intensity of the stress response. Given that natural populations have been exposed to a multitude of stressors, a better understanding of the functional association between duration and intensity of the stress response, the resulting changes in glucocorticoid plasma levels and their impact on different aspects of immunocompetence emerges as a cornerstone for vertebrate conservation strategies. We investigated the effects of a restraint challenge (with and without movement restriction), long-term captivity, and transdermal corticosterone application on plasma levels of corticosterone (hereinafter referred to as CORT) and different parameters of innate immunocompetence in the male cururu toads (Rhinella icterica). We show that for R. icterica restraint for 24h proved to be a stressful condition, increasing CORT by 3-fold without consistent immunological changes. However, the application of a more intense stressor (restraint with movement restriction), for the same period, potentiated this response resulting in a 9-fold increase in CORT, associated with increase Neutrophil/Lymphocyte ratio (N:L) and a lower bacterial killing ability (BKA). Transdermal application of corticosterone efficiently mimics repeated acute stress response events, without changing the immune parameters even after 13 days of treatment. Interestingly, long-term captivity did not mitigate the stress response, since the toads maintained 3-fold increased CORT even after 3 months under these conditions. Moreover, long-term captivity in the same condition increased total leukocyte count (TLC) and generated an even greater decrease in BKA, suggesting that consequences of the stress response can be aggravated by time in captivity.  相似文献   

3.
4.
The hormone corticosterone (CORT) is an important component of a bird’s response to environmental stress, but it can also have negative effects. Therefore, birds on migration are hypothesized to have repressed stress responses (migration-modulation hypothesis). In contrast to earlier studies on long-distance migrants, we evaluate this hypothesis in a population containing both migratory and resident individuals. We use a population of partially migratory blue tits (Cyanistes caeruleus) in southern Sweden as a model species. Migrants had higher CORT levels at the time of capture than residents, indicating migratory preparations, adaptation to stressors, higher allostatic load or possibly low social status. Migrants and residents had the same stress response, thus contradicting the migration-modulation hypothesis. We suggest that migrants travelling short distances are more benefited than harmed by retaining the ability to respond to stress.  相似文献   

5.
Variation in response styles in the hypothalamic-pituitary-adrenal (HPA) axis are known to be predictors of short- and long-term health outcomes. The nature of HPA responses to stressors changes with developmental stage, and some components of the stress response exhibit long-term individual consistency (i.e., are trait-like) while others are transient or variable (i.e., state-like). Here we evaluated the response of marmoset monkeys (Callithrix geoffroyi) to a standardized social stressor (social separation and exposure to a novel environment) at three different stages of development: juvenile, subadult, and young adult. We monitored levels of urinary cortisol (CORT), and derived multiple measures of HPA activity: Baseline CORT, CORT reactivity, CORT Area Under the Curve (AUC), and CORT regulation. Juvenile marmosets exhibited the most dramatic stress response, had higher AUCs, and tended to show poorer regulation. While baseline CORT and CORT regulation were not consistent within an individual across age, CORT reactivity and measures of AUC were highly correlated across time; i.e., individuals with high stress reactivity and AUC as juveniles also had high measures as subadults and adults, and vice-versa. Marmoset co-twins did not exhibit similar patterns of stress reactivity. These data suggest that regardless of the source of variation in stress response styles in marmosets, individually-distinctive patterns are established by six months of age, and persist for at least a year throughout different phases of marmoset life history.  相似文献   

6.
Adhesion of bacteria to epithelial tissue is an essential step in the progression of the urinary tract infections. Reduction of virulence factors responsible for microbial attachment may help to decrease or inhibit colonization of the host organism by pathogens. In the age of increasing bacterial antibiotic resistance, more and more attention is being paid to the use of plants and/or their bioactive components in the prevention and treatment of human infections. Asiatic acid (AA) and ursolic acid (UA), two plant secondary metabolites, were used as potential antibacterial agents. The current study aimed to determine the possible impact of AA and UA on morphology, hydrophobicity, and adhesion of clinical uropathogenic Escherichia coli strains (UPEC) to the uroepithelial cells. Our work describes for the first time the effects exerted by AA and UA on virulence factors of UPECs. The impact of both acids on the cell surface hydrophobicity of the investigated strains was very weak. The results clearly show the influence of AA and UA on the presence of P fimbriae and curli fibers, morphology of the UPECs cells and their adhesion to epithelium; however, some differences between activities of AA and UA were found.  相似文献   

7.
1. The aim of this study was to compare the effects of acute amphetamine (AMPH) treatment and restraint stress on plasma level of prolactin (PRL) and PRL mRNA expression in the adenohypophysis in Sprague–Dawley and Lewis male rats, the latter known to have a deficient hypothalamo–pituitary-adrenal (HPA) axis.2. Both restraint stress and AMPH treatment (i.p. in a dose of 8 mg/kg of b.w.) were applied 15 or 30 min before termination of the experiment. Plasma PRL and corticosterone (CORT) were determined by radioimmunoassay. PRL mRNA expression was estimated by a dot-blot hybridization.3. Restraint stress and AMPH treatment induced a significant increase in theCORT plasma level, as an indicator of stress response. Compared to Sprague–Dawley rats, the magnitude of CORT increase after both stimuli was significantly lower in Lewis rats.4. Although restraint stress significantly increased the PRL plasma levels in both rat strains, AMPH treatment reduced the PRL levels in both rat strains. However, the changes of PRL plasma levels had another pattern in Lewis rats than in Sprague–Dawley rats. Control plasma PRL levels were significantly higher in Lewis rats, and in this rat strain AMPH treatment for 30 min increased the PRL levels as compared to the values obtained after AMPH treatment for 15 min.5. Expression of PRL mRNA in adenohypophysis by restraint stress and AMPH treatment had a similar pattern. After a 15-min lasting restraint stress, the expression of PRL mRNA was decreased insignificantly in both rat strains. AMPH treatment induced in Sprague–Dawley rats a significant decrease of PRL mRNA after a 15-min interval while after 30 min there was a significant increase. However, in Lewis rats AMPH failed to significantly change PRL mRNA.6. The results from the present study indicate that the mechanisms mediatingthe effects of acute restraint stress and acute AMPH treatment differ in PRL response in Sprague–Dawley and Lewis male rat strains. Differences in the observed responses in Lewis rats could be related to the deficient activity of HPA axis in this rat strain.  相似文献   

8.
Because glucocorticoid (stress) hormones fundamentally affect various aspects of the behaviour, life history and fitness of free-living vertebrates, there is a need to understand the environmental factors shaping their variation in natural populations. Here, we examined whether spatial heterogeneity in breeding territory quality affected the stress of colonial king penguin (Aptenodytes patagonicus). We assessed the effects of local climate (wind, sun and ambient temperature) and social conditions (number of neighbours, distance to neighbours) on the baseline levels of plasma total corticosterone (CORT) in 77 incubating and 42 chick-brooding birds, breeding on territories of central or peripheral colony location. We also assessed the oxidative stress status of a sub-sample of central vs. peripheral chick-brooders to determine whether chronic stress arose from breeding on specific territories. On average, we found that brooders had 55 % higher CORT levels than incubators. Regardless of breeding status, central birds experienced greater social density (higher number of neighbours, shorter distance between territories) and had higher CORT levels than peripheral birds. Increasing social density positively explained 40 % of the variation in CORT levels of both incubators and brooders, but the effect was more pronounced in brooders. In contrast, climate was similar among breeding territories and did not significantly affect the CORT levels of breeding birds. In brooders, oxidative stress status was not affected by local density or weather conditions. These results highlight that local heterogeneity in breeding (including social) conditions may strongly affect the stress levels of breeding seabirds. The fitness consequences of such variation remain to be investigated.  相似文献   

9.
Stress coping styles have been characterized as a proactive/reactive dichotomy in laboratory and domesticated animals. In this study, we examined the prevalence of proactive/reactive stress coping styles in wild-caught short-tailed singing mice (Scotinomys teguina). We compared stress responses to spontaneous singing, a social and reproductive behavior that characterizes this species. To establish proactive/reactive profiles for singing mice, we measured exploratory and anxiety behavior using an open-field behavioral test. We examined correlations between open-field behaviors and fecal corticosterone (CORT) metabolites, baseline plasma CORT, and stress-induced CORT. Mice with proactive behavioral responses in the open-field had higher fecal CORT titers than reactive males, but did not differ in baseline or stress-induced plasma CORT. We suggest that individual differences in CORT metabolism may contribute to this surprising pattern. Males that sang in the open-field were behaviorally proactive and had lower stress-induced CORT, indicating a link between stress responses and singing in this species. Overall, the data demonstrate that singing mice offer an interesting model for exploring how stress reactivity can shape social behaviors.  相似文献   

10.
Extreme environmental temperature could impact the physiology and ecology of animals. The stress endocrine axis provides necessary physiological stress response to acute (day–day) stressors. Presently, there are no empirical evidences showing that exposure to extreme thermal stressor could cause chronic stress in amphibians. This could also modulate the physiological endocrine sensitivity to acute stressors and have serious implications for stress coping in amphibians, particularly those living in fragmented and disease prone environments. We addressed this important question using the cane toad (Rhinella marina) model from its introduced range in Queensland, Australia. We quantified their physiological endocrine sensitivity to a standard acute (capture and handling) stressor after exposing the cane toads to thermal shock at 35 °C for 30 min daily for 34 days. Corticosterone (CORT) responses to the capture and handling protocol were measured on three sampling intervals (days 14, 24, and 34) to determine whether the physiological endocrine sensitivity was maintained or modulated over-time. Two control groups (C1 for baseline CORT measurement only and C2 acute handled only) and two temperature treatment groups (T1 received daily thermal shock up to day 14 only and a recovery phase of 20 days and T2 received thermal shock daily for 34 days). Results showed that baseline CORT levels remained high on day 14 (combined effect of capture, captivity and thermal stress) for both T1 and T2. Furthermore, baseline CORT levels decreased for T1 once the thermal shock was removed after day 14 and returned to baseline by day 29. On the contrary, baseline CORT levels kept on increasing for T2 over the 34 days of daily thermal shocks. Furthermore, the magnitudes of the acute CORT responses or physiological endocrine sensitivity were consistently high for both C1 and T1. However, acute CORT responses for T2 toads were dramatically reduced between days 24 and 34. These novel findings suggest that repeated exposure to extreme thermal stressor could cause chronic stress and consequently suppress the physiological endocrine sensitivity to acute stressors (e.g. pathogenic diseases) in amphibians.  相似文献   

11.
Translocation and reintroduction have become major conservation actions in attempts to create self-sustaining wild populations of threatened species. However, avian translocations have a high failure rate and causes for failure are poorly understood. While ‘stress’ is often cited as an important factor in translocation failure, empirical evidence of physiological stress is lacking. Here we show that experimental translocation leads to changes in the physiological stress response in chukar partridge, Alectoris chukar. We found that capture alone significantly decreased the acute glucocorticoid (corticosterone, CORT) response, but adding exposure to captivity and transport further altered the stress response axis (the hypothalamic–pituitary–adrenal axis) as evident from a decreased sensitivity of the negative feedback system. Animals that were exposed to the entire translocation procedure, in addition to the reduced acute stress response and disrupted negative feedback, had significantly lower baseline CORT concentrations and significantly reduced body weight. These data indicate that translocation alters stress physiology and that chronic stress is potentially a major factor in translocation failure. Under current practices, the restoration of threatened species through translocation may unwittingly depend on the success of chronically stressed individuals. This conclusion emphasizes the need for understanding and alleviating translocation-induced chronic stress in order to use most effectively this important conservation tool.  相似文献   

12.
This study assessed the efficacy of using visual and auditory biofeedback while immersed in a tridimensional videogame to practice a stress management skill (tactical breathing). All 41 participants were soldiers who had previously received basic stress management training and first aid training in combat. On the first day, they received a 15-minute refresher briefing and were randomly assigned to either: (a) no additional stress management training (SMT) for three days, or (b) 30-minute sessions (one per day for three days) of biofeedback-assisted SMT while immersed in a horror/first-person shooter game. The training was performed in a dark and enclosed environment using a 50-inch television with active stereoscopic display and loudspeakers. On the last day, all participants underwent a live simulated ambush with an improvised explosive device, where they had to provide first aid to a wounded soldier. Stress levels were measured with salivary cortisol collected when waking-up, before and after the live simulation. Stress was also measured with heart rate at baseline, during an apprehension phase, and during the live simulation. Repeated-measure ANOVAs and ANCOVAs confirmed that practicing SMT was effective in reducing stress. Results are discussed in terms of the advantages of the proposed program for military personnel and the need to practice SMT.  相似文献   

13.
The purpose of this study was to examine the effects of a mental challenge on cardiovascular and endocrine [epinephrine (EPI), norepinephrine (NE), and cortisol (CORT)] responses to subsequent low-intensity physical exertion. Twelve males (23.25 ± 0.45 years) completed three sessions, including a graded exercise test on a cycle ergometer and two counter-balanced mental stress trials. In the mental challenge-control condition (MC), participants sat quietly for 20 min following a 20 min mental challenge whereas in the mental challenge-exercise condition (MEC) subjects cycled at 35% of maximal oxygen consumption (VO2max) following the mental challenge. Repeated-measures ANOVAs were used to assess state anxiety (SAI), cardiovascular variables, EPI, NE, and CORT levels across time between conditions. Participants reported significantly greater increases in SAI scores immediately after the mental challenge, which then decreased post-challenge in both conditions. Neither EPI or NE demonstrated an alteration in levels in either condition, but CORT significantly increased after the mental challenge in both conditions and then maintained a significantly greater level during the MEC compared to the MC condition from midexercise through 15 min of recovery. Area-under-the-curve calculations for CORT was significantly greater in the MEC compared to the MC. Results suggest that the initial mental challenge may have acted to enhance the overall adrenal response to the subsequent anticipation of and actual participation in the low-level physical challenge.  相似文献   

14.
Feather corticosterone (CORT) levels are increasingly employed as biomarkers of environmental stress. However, it is unclear if feather CORT levels reflect stress and/or workload in the wild. We investigated whether feather CORT represents a biomarker of environmental stress and reproductive effort in tree swallows (Tachycineta bicolor). Specifically, we examined whether individual state and investment during reproduction could predict feather CORT levels in subsequently moulted feathers and whether those levels could predict future survival and reproductive success. Through a manipulation of flight cost during breeding, we also investigated whether an increase in stress level would be reflected in subsequently grown feathers, and whether those levels could predict future success. We found that CORT levels of feathers grown during moult did not (1) reflect past breeding experience (n = 29), (2) predict reproductive output (n = 18), or (3) respond to a manipulation of flight effort during reproduction (10 experimental, 14 control females). While higher feather CORT levels predicted higher return rate (a proxy for survival), they did so only in the manipulated group (n = 36), and this relationship was opposite to expected. Overall, our results add to the mixed literature reporting that feather CORT levels can be positively, negatively, or not related to proxies of within-season and longer-term fitness (i.e., carryover effects). In addition, our results indicate that CORT levels or disturbances experienced during one time (e.g., breeding) may not carry over to subsequent stages (e.g., moult). We, therefore, petition for directed research investigating whether feather CORT represents exposure to chronic stress in feathers grown during moult.  相似文献   

15.
Reactive oxygen species may contribute to apoptosis in lymphoid tissues observed after exercise. Thymic and splenic tissues excised from control mice (C) or mice immediately after (t0) or 24 h after (t24) a run to exhaustion (RTE) were assayed for biochemical indexes of oxidative stress [thymic and splenic membrane lipid peroxides, superoxide dismutase, catalase, plasma uric acid (UA), and ascorbic acid (AA)]. There were significant increases in membrane lipid peroxides in thymus (P < 0.001) and spleen (P < 0.001) in acutely exercised mice relative to controls (thymus: C = 2.74 +/- 0.80 microM; t0 = 7.45 +/- 0.48 microM; t24 = 9.44 +/-1.41 microM; spleen: C = 0.48 +/- 0.22 microM; t0 = 1.78 +/- 0.28 microM; t24 = 2. 81 +/- 0.34 microM). The thymic and splenic tissue antioxidant enzymes concentrations of superoxide dismutase and catalase were significantly lower in samples collected at t0 relative to C and t24 mice (P < 0.001). Plasma UA and AA levels were used to assess the impact of the RTE on the peripheral antioxidant pool. There was no significant change in UA levels and a significant reduction in plasma AA concentrations (P < 0.001); the reduction in plasma AA occurred at t24 (6.53 +/- 1.64 microM) relative to t0 (13.11 +/- 0. 71 microM) and C (13.26 +/- 1.2 microM). These results suggest that oxidative damage occurs in lymphoid tissues after RTE exercise and that such damage may contribute to lymphocyte damage observed after acute exercise.  相似文献   

16.
The aim of this study was to investigate the cumulative effects of intensive resistance training on salivary immunoglobulin A (SIgA) and cortisol responses in elite male weightlifters. Eleven elite male Taiwanese weightlifters were trained through 3 training stages before a national weightlifting competition, and this was followed by a 2-week recovery stage. Resting saliva samples were collected once in each of the 4 stages. Salivary concentrations of total protein (TP), SIgA, lactoferrin, and cortisol were measured. The results showed that (a) salivary TP concentrations were not significantly affected; (b) resting levels of SIgA, the ratio of SIgA to TP (SIgA/TP), cortisol, and the ratio of cortisol to TP (cortisol/TP) were significantly higher in the training stages than in the recovery stage; (c) a positive correlation was revealed between the ratios of SIgA/TP and cortisol/TP; and (d) the resting salivary lactoferrin concentrations and the ratio of lactoferrin to TP (lactoferrin/TP) were significantly lower in stage 1 than in the recovery stage. The findings in this study suggest that prolonged, intensive resistance training exerts cumulative effects on SIgA and cortisol responses in elite weightlifters.  相似文献   

17.
Petroleum can disrupt endocrine function in humans and wildlife, and interacts in particularly complex ways with the hypothalamus-pituitary-adrenal (HPA) axis, responsible for the release of the stress hormones corticosterone and cortisol (hereafter CORT). Ingested petroleum can act in an additive fashion with other stressors to cause increased mortality, but it is not clear exactly why—does petroleum disrupt feedback mechanisms, stress hormone production, or both? This laboratory study aimed to quantify the effects of ingested Gulf of Mexico crude oil on the physiological stress response of house sparrows (Passer domesticus). We examined baseline and stress-induced CORT, negative feedback, and adrenal sensitivity in house sparrows given a 1% oil or control diet (n = 12 in each group). We found that four weeks on a 1% oil diet did not alter baseline CORT titers or efficacy of negative feedback, but significantly reduced sparrows'' ability to secrete CORT in response to a standardized stressor and adrenocorticotropin hormone injection, suggesting that oil damages the steroid-synthesizing cells of the adrenal. In another group of animals on the same 1% oil (n = 9) or control diets (n = 8), we examined concentrations of eight different blood chemistry parameters, and CORT in feathers grown before and during the feeding experiments as other potential biomarkers of oil exposure. None of the blood chemistry parameters differed between birds on the oil and control diets after two or four weeks of feeding, nor did feather CORT differ between the two groups. Overall, this study suggests that the response of CORT to stressors, but not baseline HPA function, may be a particularly sensitive bioindicator of sub-lethal chronic effects of crude oil exposure.  相似文献   

18.
We describe a stress management intervention intended to reduce the damage and stress impact on the heart physiology and function of a group of caregivers (professional and non-professional) who work with patients with dementia. The intervention consisted in applying heart coherence techniques in a population of 72 caregivers of patients with dementia (42 professional and 29 non-professional caregivers) who had high scores in heart stress and burden tests. Six months after the training they were able to generate appropriate patterns of heart coherence, with a statistically significant decrease in their heart overload. We conclude that training in techniques of heart coherence and positive psychology had effective results on the stress management of the participant caregivers. This was a simple, inexpensive technique with lasting results. To our knowledge this is the first research in Spain studying the application of heart coherence techniques to caregivers of people with dementia.  相似文献   

19.
Fish faced with stressful stimuli launch an endocrine stress response through activation of the hypothalamic-pituitary-interrenal (HPI-) axis to release cortisol into the blood. Scientifically validated biomarkers to capture systemic cortisol exposure over longer periods of time are of utmost importance to assess chronic stress in governmental, wildlife, aquaculture and scientific settings. Here we demonstrate that cortisol in scales of common carp (Cyprinus carpio L.) is the long-sought biomarker for chronic stress. Undisturbed (CTR) and daily stressed (STRESS) carp were compared. Dexamethasone (DEX) or cortisol (CORT) fed fish served as negative and positive controls, respectively. Scale cortisol was quantified with a validated ultra-performance liquid chromatography tandem mass spectrometry method. An increase in scale cortisol content was found in STRESS and CORT but not in CTR and DEX fish. Scale cortisol content reflects its accumulation in a stressor and time dependent manner and validates the scale cortisol content as biomarker for chronic stress. Plasma analyses confirmed that (i) CTR, DEX and CORT treatments were effective, (ii) plasma cortisol of STRESS fish showed no signs of chronic HPI-axis activation, and (iii) plasma cortisol is a poor predictor for chronic stress. The expression of HPI key genes crf, pomc, and star were up-regulated in STRESS fish in the absence of a plasma cortisol response, as was the target gene of cortisol encoding subunit α1 of the Na+/K+-ATPase in gills. When lost, scales of fish regenerate fast. Regenerated scales corroborate our findings, offering (i) unsurpassed time resolution for cortisol incorporation and as such for stressful events, and (ii) the possibility to investigate stress in a well defined and controlled environment and time frame creating novel opportunities for bone physiological research. We conclude that the cortisol content in ontogenetic and regenerated scales is an innovative biomarker for chronic stress offering ample applications in science and industry.  相似文献   

20.
Traditional robotic work cell design and programming are considered inefficient and outdated in current industrial and market demands. In this research, virtual reality (VR) technology is used to improve human-robot interface, whereby complicated commands or programming knowledge is not required. The proposed solution, known as VR-based Programming of a Robotic Work Cell (VR-Rocell), consists of two sub-programmes, which are VR-Robotic Work Cell Layout (VR-RoWL) and VR-based Robot Teaching System (VR-RoT). VR-RoWL is developed to assign the layout design for an industrial robotic work cell, whereby VR-RoT is developed to overcome safety issues and lack of trained personnel in robot programming. Simple and user-friendly interfaces are designed for inexperienced users to generate robot commands without damaging the robot or interrupting the production line. The user is able to attempt numerous times to attain an optimum solution. A case study is conducted in the Robotics Laboratory to assemble an electronics casing and it is found that the output models are compatible with commercial software without loss of information. Furthermore, the generated KUKA commands are workable when loaded into a commercial simulator. The operation of the actual robotic work cell shows that the errors may be due to the dynamics of the KUKA robot rather than the accuracy of the generated programme. Therefore, it is concluded that the virtual reality based solution approach can be implemented in an industrial robotic work cell.  相似文献   

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