Low Stress Situations Research Articles

Effects of Expressive Writing on "Choking under Pressure" in High Test-Anxious Individuals.

(1) Background: High test-anxious students often fail to perform at their actual level and are prone to choking under pressure (CUP). The aim of the present study was to investigate whether expressive writing (EW) can help high test-anxious individuals reduce the degree of the CUP effect, and whether the intervention effects were different in people with different working memory capacities. (2) Methods: High test-anxious participants wrote expressively (EW group) or neutrally (control group) according to guidance, and then completed a modular arithmetic (MA) task under a high-stress condition. (3) Results: The state anxiety score of the control group was significantly higher than that of the EW group in the high-pressure situation, indicating that the EW intervention was helpful to alleviate the state anxiety. Subjects with high working memory capacity in the control group performed the complex MA task significantly less accurately in the high-stress situation than in the low-stress situation, showing the CUP effect. There was no significant difference in complex MA task scores between high- and low-stress situations for subjects with high working memory capacity in the EW group, indicating that the EW intervention can reduce the degree of the CUP effect. (4) Conclusions: EW intervention was effective in reducing state anxiety levels and attenuating the detrimental effects of test stress on cognitive processing in test-anxious individuals with high working memory capacity.

Boot Camp in a Box: Initial Experience with Pretraining Skills Preparation for New Interns

In order to increase selected skills at onset of training, we provided newly matched PGY-1 trainees with materials and instructions to practice these skills, as well as the opportunity to share video-recorded performance and receive feedback based on these videos. Knot tying and suturing kits, instruments and supplies, and video instructions for task performance were sent to newly matched trainees to our program (n = 10), with instructions to practice 4 tasks (1- and 2-handed knot tying, interrupted and running suturing) until self-assessed comfort with each task was achieved or the 8-week time point before start of training was reached. Each trainee returned a video of each task, which was graded by blinded reviewers for time and errors using an itemized evaluation instrument (12 items for suturing and five items for knot-tying). Feedback (annotations of submitted videos) was provided after grading was completed. Task performance was repeated and reassessed at the time of new intern "Boot Camp" and again 8 weeks after start of training. Performance scores were compared for the 3 time points and with scores of PGY 2-4 residents using ANOVA with posthoc tests. Compliance with instruction for practice and return of video recorded tasks in the months before start of PGY-1 training was high, with only 1 of 10 failing to return knot-tying videos. A significant pattern of performance change (p < 0.05) was observed for all tasks with an initial decrease between the pre-employment practice period and the Boot Camp test followed by an increase to the highest level of performance 2 months after start of training. At that point, scores were not significantly different than those of more senior residents. A high level of compliance was achieved with requested skills practice and video documentation of performance. We attribute the consistently lower scores on the tasks during Boot Camp tests to higher stress test environment which was apt to be less favorable than having the trainee choose to submit their best possible preresidency video recording of performance in a low-stress situation. Subsequent achievement of significantly higher performance even compared to more senior residents may have been helped by incentivized pretraining practice.

Emotion regulation in the context of daily stress: Impact on daily affect

A daily diary study was used to examine how person-level emotion regulation (i.e., reappraisal and suppression) impacts daily affect following stressful daily life events. Research has highlighted the positive and negative impacts of reappraisal and suppression on daily affect, respectively, but has yet to investigate emotion regulation in light of daily stress. After completing a measure of emotion regulation, participants completed measures of daily stress and daily affect at the end of each day for one week. As hypothesized, multilevel modeling results indicated that as daily stress increased, individuals were more likely to report lower positive and higher negative affect. Consistent with prior research, reappraisal was associated with better affect. Suppression was associated with lower positive affect. The main finding of this study was a significant cross-level interaction of daily stress and suppression on daily positive affect where individuals high in suppression experienced lower positive affect on days of high stress than days of low stress. This suggests that suppression may not be detrimental in low stress situations when emotion regulation is less important, but negatively impacts positive affect during high stress. These results point to the importance of considering emotion regulation in the context of stressful life events.

Highly Maneuverable Low-Cost Underwater Glider: Design and Development

This letter presents the design and potential impact of the developed Research Oriented Underwater Glider for Hands-on Investigative Engineering (ROUGHIE). The ROUGHIE is an open-source, highly maneuverable, and low-cost vehicle that enables rapid development and testing of new hardware and software. ROUGHIE is an internally actuated glider capable of performing steady sawtooth glides in shallow water down to 3 m, tight turns with a minimum radius of 3 m, and a minimum endurance of 60 h. The novelty of this study is twofold: 1) a rail-based design to facilitate modularity and ease of assembly and 2) an effective internal rotary mass mechanism to increase maneuverability and perform tight turns. The ROUGHIE design strategically uses 3D printed plastic parts in low stress situations, which allows extreme design flexibility and enables tightly packed modules that can be easily customized.

Effects of early life adversity on cortisol/salivary alpha-amylase symmetry in free-ranging juvenile rhesus macaques

Early life adversity (ELA) affects physiological and behavioral development. One key component is the relationship between the developing Hypothalamic-Pituitary-Adrenal (HPA) axis and the Sympathetic Nervous System (SNS). Recent studies suggest a relationship between early life adversity and asymmetry in cortisol (a measure of HPA activation) and salivary alpha-amylase (sAA: a correlate of SNS activation) responses to stress among human children, but to our knowledge there have been no comparable studies in nonhumans. Here, we investigate the responses of these two analytes in “low stress” and “high stress” situations in free-ranging juvenile rhesus macaques (Macaca mulatta) on Cayo Santiago, Puerto Rico. Behavioral data on maternal maltreatment were collected during the first 3months of life to determine individual rates of ELA, and saliva samples were collected from subjects noninvasively during juvenility. Irrespective of ELA, salivary alpha-amylase levels were lower in low stress situations and higher in high stress situations. For cortisol however, high ELA subjects exhibited higher low stress concentrations and blunted acute responses during high stress situations compared to moderate and low ELA subjects. Cortisol and sAA values were positively correlated among low ELA subjects, suggesting symmetry, but were uncorrelated or negatively correlated among moderate and high ELA subjects, suggesting asymmetry in these individuals. These findings indicate dysregulation of the stress response among juveniles maltreated during infancy: specifically, attenuated cortisol reactivity coupled with typical sAA reactivity characterize the stress response profiles of juveniles exposed to higher rates of ELA during the first 3months of life.

Experimental study on the performance of compensation grouting in structured soil

Most laboratory test research has focused on grouting efficiency in homogeneous reconstituted soft clay. However, the natural sedimentary soils generally behave differently from reconstituted soils due to the effect of soil structure. A series of laboratory grouting tests were conducted to research the effect of soil structure on the performance of compensation grouting. The effects of grouting volume, overlying load and grouting location on the performance of compensation grouting under different soil structures were also studied. Reconstituted soil was altered with added cement to simulate artificial structured soil. The results showed that the final grouting efficiency was positive and significantly increased with the increase of stress ratio within a certain range when grouting in normally consolidated structured clay. However, in the same low yield stress situation, the artificial structured soil had a lower final grouting efficiency than the overconsolidated reconstituted soil. The larger of normalized grouting volume could increase the final grouting efficiency for both reconstituted and artificial structured soils. Whereas, the effect of the overlying load on final grouting efficiencies was unfavourable, and was independent of the stress ratio. As for the layered soil specimens, grouting in the artificial structured soil layer was the most efficient. In addition, the peak grouting pressure was affected by the stress ratio and the overlying load, and it could be predicted with an empirical equation when the overlying load was less than the yield stress. The end time of primary consolidation and the proportion of secondary consolidation settlement varied with the different soil structures, grouting volumes, overlying loads and grouting locations.

The acceptability, usability and short-term outcomes of Get Real: A web-based program for psychotic-like experiences (PLEs)

ABSTRACT Background Psychotic-like experiences (PLEs) are subclinical delusional ideas and perceptual disturbances that have been associated with a range of adverse mental health outcomes. This study reports a qualitative and quantitative analysis of the acceptability, usability and short term outcomes of Get Real, a web program for PLEs in young people. Methods Participants were twelve respondents to an online survey, who reported at least one PLE in the previous 3 months, and were currently distressed. Ratings of the program were collected after participants trialled it for a month. Individual semi-structured interviews then elicited qualitative feedback, which was analyzed using Consensual Qualitative Research (CQR) methodology. PLEs and distress were reassessed at 3 months post-baseline. Results User ratings supported the program's acceptability, usability and perceived utility. Significant reductions in the number, frequency and severity of PLE-related distress were found at 3 months follow-up. The CQR analysis identified four qualitative domains: initial and current understandings of PLEs, responses to the program, and context of its use. Initial understanding involved emotional reactions, avoidance or minimization, limited coping skills and non-psychotic attributions. After using the program, participants saw PLEs as normal and common, had greater self-awareness and understanding of stress, and reported increased capacity to cope and accept experiences. Positive responses to the program focused on its normalization of PLEs, usefulness of its strategies, self-monitoring of mood, and information putting PLEs into perspective. Some respondents wanted more specific and individualized information, thought the program would be more useful for other audiences, or doubted its effectiveness. The program was mostly used in low-stress situations. Conclusions The current study provided initial support for the acceptability, utility and positive short-term outcomes of Get Real. The program now requires efficacy testing in randomized controlled trials.

Knowing loved ones' end-of-life health care wishes: Attachment security predicts caregivers' accuracy.

At times, caregivers make life-and-death decisions for loved ones. Yet very little is known about the factors that make caregivers more or less accurate as surrogate decision makers for their loved ones. Previous research suggests that in low stress situations, individuals with high attachment-related anxiety are attentive to their relationship partners' wishes and concerns, but get overwhelmed by stressful situations. Individuals with high attachment-related avoidance are likely to avoid intimacy and stressful situations altogether. We hypothesized that both of these insecure attachment patterns limit surrogates' ability to process distressing information and should therefore be associated with lower accuracy in the stressful task of predicting their loved ones' end-of-life health care wishes. Older patients visiting a medical clinic stated their preferences toward end-of-life health care in different health contexts, and surrogate decision makers independently predicted those preferences. For comparison purposes, surrogates also predicted patients' perceptions of everyday living conditions so that surrogates' accuracy of their loved ones' perceptions in nonstressful situations could be assessed. Surrogates high on either type of insecure attachment dimension were less accurate in predicting their loved ones' end-of-life health care wishes. It is interesting to note that even though surrogates' attachment-related anxiety was associated with lower accuracy of end-of-life health care wishes of their loved ones, it was associated with higher accuracy in the nonstressful task of predicting their loved ones' everyday living conditions. Attachment orientation plays an important role in accuracy about loved ones' end-of-life health care wishes. Interventions may target emotion regulation strategies associated with insecure attachment orientations.

Competition increases with abiotic stress and regulates the diversity of biological soil crusts

Summary 1. The stress‐gradient hypothesis (SGH) predicts that the frequency of facilitative and competitive interactions will vary inversely across abiotic stress gradients, with facilitation being more common when abiotic stress is high. The effect of competition intensity on species richness is generally thought to be negative, but tests along true stress gradients are lacking. This body of research has primarily focused on vascular plants and could be well informed by broadening to other communities. 2. We report the first regional‐scale test of the SGH using biological soil crusts dominated by mosses and lichens, a key multi‐functional community of arid and semi‐arid ecosystems worldwide. We examined the intensity of facilitative or competitive interactions at the level of the community and among species pairs along an aridity gradient. Along this gradient we also examined the relationship between competition intensity and species richness. 3. All evidence strongly suggested that negative species interactions are prevalent in this study system and much more common than expected by chance. At the community scale, we found that abiotic stress associated with aridity was positively related to and explained 6–56% of the variance in indicators of facilitation or competition, dependent on the index and algorithm used. Despite this intriguing contradiction of the SGH at the whole community scale, we found scant dependency of species‐level interactions upon abiotic stress. However, the sign and intensity of these interactions proved to be species‐specific. We also found that the relationship between competition and species richness, usually negatively affected by competition, was positively related to richness at low abiotic stress, and negatively related to richness at high abiotic stress. 4. Synthesis. We propose that the response of species interactions to stress gradients may partially depend upon the particular modes of facilitation and competition, in addition to type of stressor and life‐history strategies of species involved. We also hypothesize that because stress can act as a filter, a greater number of species interactions are possible under low stress conditions. We believe that this may render intransitivity dominant over niche segregation and expansion, potentially resulting in positive effects of competition on species richness in low stress situations.

Anxiety and Ability to Recognize Clinical Information in Dentistry

Stress significantly affects a person's cognitive ability to process information. Therefore, we hypothesized that patients' ability to recognize information related to the procedure they are about to undergo will be affected by the stressfulness of the situation (less recognition under a high-stress situation as compared with a low-stress situation). Patients (n = 66) were evaluated for their ability to recognize clinical information supplied on two different occasions: immediately before oral surgery (high-stress condition) and before suture removal (low-stress condition). Dental and state of anxiety and expectation of pain were also assessed. On both occasions, the patients' ability to recognize information correctly was low (less than 50%). Patients recognized significantly less information pre-operatively than before suture removal. State of anxiety, dental anxiety, and expectation to experience pain had a profound effect on their ability to recognize provided information correctly. Apparently, before dental treatment (high or low on stress), patients' ability to process information may be severely impaired.

Strain localization in geomaterials

Abstract The main purpose of this paper is a broad review of developments in observation and interpretation of localization in geomaterials in the laboratory, with an emphasis on low mean stress situations. Laboratory investigation of strain localization in granular soils and rocks has been pursued extensively and very accurate strain field evolution measurement techniques have been developed, including false relief stereophotogrammetry (FRS) and computed tomography (CT). These permit full characterization of strain localization, from onset to complete shear band formation. This paper reviews studies of sand, clay, sandstone, stiff marl and concrete, and observations of incipient and developed localization in initially ‘homogeneous’ laboratory tests are presented. Development of localization and peak strength, critical stress and strain, shear band orientation and thickness, and complex localization patterns are discussed. Deformation during triaxial compression of sand is shown to develop complex strain localization patterns. Consequently, the critical void ratio concept in granular materials is reconsidered. Void ratio evolution, global and local, monitored by CT, shows a limiting void ratio being rapidly attained in the strain localization zones. In cohesive materials (clays, rocks and concrete), crack development is also commonly observed. Displacement discontinuity measurement techniques are presented and the results for different cohesive geomaterials are discussed.

Stress and Inflammation as a Detrimental Combination for Peri-implant Bone Loss

The causes of peri-implant bone loss continue to be controversial. To determine the impact of biomechanical stress and inflammation, we investigated a total of 80 interforaminal implants in situ for more than 10 years. Two stress groups, with 14 patients each, were established: a low-stress situation with single-standing implants, and an increased-stress situation with splinted implants. To categorize inflammation, we introduced a Composite Inflammation Score using 4 inflammatory parameters. Peri-implant bone loss was calculated from digital panoramic radiographs. To differentiate between the effects of stress and inflammation, we compared bone loss in both stress groups at equivalent levels of inflammation. With greater Composite Inflammation Score values, a clear discrepancy between single-standing and splinted implants was evident (p = 0.117/0.000, regression analysis; p = 0.135/0.000, analysis of variance; p = 0.002, t tests). While stress and inflammation alone may not necessarily be detrimental factors, the presence of stress heightens peri-implant bone loss significantly as inflammation increases.

A Contextual Approach to the Development of Self‐regulatory Competencies: The Role of Maternal Unresponsivity and Toddlers’ Negative Affect in Stressful Situations

Abstract A prospective study examined the effects of maternal unresponsivity and of toddlers’ own negative affect on the child's subsequent ability to use effective attentional control strategies in preschool. Maternal and child behaviors were measured in situations that varied in the level of stress to test the hypothesis that behaviors in high stress situations would be more diagnostic of children's subsequent self‐regulatory behavior. As predicted, both maternal unresponsivity and toddlers’ negative affect, particularly in a high stress as opposed to a low stress situation, predicted children's later use of ineffective attentional control strategies. Similarly, maternal disengagement that occurred contingent to toddlers’ distress predicted ineffective attentional control strategies whereas maternal disengagement in response to toddlers’ non‐distress behaviors did not. The findings supported the utility of a contextual approach to understanding the impact of maternal and child characteristics on the development of self‐regulatory skills.

Product potential of paulownia timber

Summary FPC Timber Technology assessed the properties of timber from three 10-y-old paulownia (Paulownia fortunei) logs from Queensland. The logs were regular in form with some taper. No end checking was evident prior to sawing. Growth stresses were minimal and the logs were sawn without difficulty using a horizontal bandsaw mill to produce straight backsawn and quartersawn timber. Mean green sawn recovery was 55% of log volume. Milling waste that was stored green for eight weeks developed sap stain. The sawn timber was dried in a heat-and-vent kiln over 45 d, showing good drying quality. Stability in service should be high, although unit shrinkage was not assessed. The timber was straight-grained with a moderately coarse even texture, a straw yellow to pale brown colour and lightly figured. Grading to the FIFWA (1992) Industry Standard for Seasoned, Sawn and Skip-Dressed WA Hardwoods gave 51.8% dry recovery (not dressed) of Prime Grade timber. Mean volumetric shrinkage was estimated as 6.0%. Dressing to the standard dimensions specified in the FIFWA Standard would give dry dressed graded recovery of 38.2%. Air-dry density was 260 kg m−3; hardness measured using a modified Janka method was only 0.5 kN. The timber was ripped, crosscut, planed, sanded and bored without undue difficulty, notwithstanding a need for sharp tools and high cutter speeds. Router cuts were characterised by feathery edges that were improved by sanding. The timber achieved 100% wood failure in PVA glue tests and should therefore glue well. The test panels were fine sanded and finished to a high standard using a clear finish, but staining was less successful. These results conform with those in previous literature, and indicate that paulownia timber is suitable for wall and ceiling linings, claddings (if treated), decorative mouldings, picture frames, timber blinds, doors and windows. The timber also seems well suited as a substrate in veneered products including doors and tabletops, and as a general carcass material in low-stress situations where weight savings may result from its use.

The grooming analysis algorithm discriminates between different levels of anxiety in rats: potential utility for neurobehavioural stress research

Stress has long been known to affect grooming in rodent species, altering both its activity measures and behavioural microstructure. Since stress disturbs a general pattern of self-grooming uninterrupted cephalocaudal progression, the grooming analysis algorithm (Kalueff and Tuohimaa, Brain Res. Protocols, 2004; 15: 151–8) was previously designed for mice to enable the detection of stress by measuring alterations in grooming microstructure in different test situations. Since mice and rats are known to differ in their behaviours, including grooming, the aim of the current study was to test our approach in rats and evaluate the utility of this method for differentiation between high- and low-stress situations. For this, we have developed the rat grooming analysis algorithm (based on ethological analysis of incorrect transitions contrary to the cephalocaudal rule, interrupted grooming activity and the assessment of the regional distribution of grooming) and applied this algorithm to the light-exposed (high stress) and dark-exposed (low stress) groups of rats. Here, we show that the percentage of ‘incorrect’ transitions between different grooming patterns, the percentage of interrupted grooming bouts and altered regional distribution of grooming (less caudal grooming, more rostral grooming) may be used as behavioural markers of stress in rats. Our results suggest that this method can be a useful tool in neurobehavioural stress research including modelling stress-evoked states, psychopharmacological or behavioural neurogenetics research in rats.

Neuronal nitric oxide synthase knock-out mice show impaired cognitive performance

Nitric oxide (NO) plays a role in a series of neurobiological functions, underlying behavior and memory. The functional role of nNOS derived NO in cognitive functions, however, is elusive. We decided to study cognitive functions in the Morris water maze (MWM) and the multiple T-maze (MTM) in 3-month-old male nNOS-knock-out mice (nNOS KO). To study the influence of neurology and behavior, we performed tests in an observational battery, the rota-rod, the elevated plus maze (EPM), the open field (OF), and a social interaction test. In the memory and relearning task of the MWM, most nNOS KO failed whereas performing better in the MTM. nNOS KO displayed significantly increased frequency of grooming, center crossings, and entries into the center in the OF. The observational battery revealed significantly increased scores for touch–escape reaction, body position, locomotion, and pelvic- and tail-elevation together with reduced vocalization. In the EPM, the time spent in the closed arm and the grooming frequency were significantly increased whereas urination was absent. We conclude that nNOS KO show impaired spatial performance in the MWM and herewith confirm the role of nNOS in cognitive functions such as processing, maintenance, and recall of memory. It must be taken into account that the major behavioral findings of increased grooming and anxiety-related behaviors may have led to impaired function in the MWM. The fact that nNOS KO performed well in the MTM, reflecting a low stress situation points to the interpretation that nNOS inhibition affects cognitive functions under stressful conditions (MWM) only.

Stress-related preeclampsia: an evolutionary maladaptation in exaggerated stress during pregnancy?

The authors hypothesize that preeclampsia is a stress-related disease and an evolutionary maladaptation of exaggerated stress during human pregnancy. Epidemiologic studies show that relative risk for preeclampsia is increased in many stressful situations. Many risk factors for preeclampsia are stress-related. Low-stress situations, on the contrary, are protective. Stress in pregnancy corroborates all physiopathologic theories for preeclampsia; it does not contradict them. Animals exposed to intense stress show many characteristics of preeclampsia, and some animal models for human preeclampsia have been proposed. The stress–alarm reaction is protective for survival in animals. But the evolutionary maladaptation of this intense stress could lead to preeclampsia in humans.

Provocation with stress and electricity of patients with "sensitivity to electricity".

Twenty-four patients with self-reported "sensitivity to electricity" were divided into two groups and tested in a double-blind provocation study. These patients, who reported increased skin symptoms when exposed to electromagnetic fields, were compared with 12 age- and sex-matched controls. Both groups were exposed to 30-minute periods of high or low stress situations, with and without simultaneous exposure to electromagnetic fields from a visual display unit. The matched controls were tested twice and given the same exposure as the patients but had the fields turned on every time. Stress was induced by requiring the participants to act in accordance with a random sequence of flashing lights while simultaneously solving complicated mathematical problems. Blood samples were analyzed for levels of the stress-related hormones melatonin, prolactin, adrenocorticotrophic hormone, neuropeptide Y, and growth hormone, and the expression of different peptides, cellular markers, and cytokines (somatostatin, CD1, factor XIIIa, and tumor necrosis factor-alpha). Skin biopsies were also analyzed for the occurrence of mast cells. Stress provocation resulted in feelings of more intense mental stress and elevated heart rate. The patients reported increased skin symptoms when they knew or believed that the electromagnetic field was turned on. With the blind conditions there were no differences between "on" or "off." Inflammatory mediators and mast cells in the skin were not affected by the stress exposure or by exposure to electromagnetic fields. The main conclusion was that the patients did not react to the fields.

The Effect of Lessons in the Alexander Technique on Music Performance in High and Low Stress Situations

Twenty-five music students taking classes in performance were randomly assigned either to an experimental group who received a course of 15 lessons in the Alexander technique, or to a control. A variety of measures were taken on four occasions: in both high and low stress situations before and after treatment. The experimental group showed improvement relative to the control on the following measures: overall music and technical quality as judged by independent experts blind to subjects' condition assignment, heart rate variance, self-rated anxiety and positive attitude to performance. However, with the exception of heart rate variance, these effects were restricted to performance in the low stress class situations. There were no significant effects on height, peak flow or misuse as judged on the basis of videorecordings of behaviour by independent experts in the Alexander technique.

The development of aggression in toddlers: a study of low-income families.

The effort by developmental psychopathologists to understand the etiology of antisocial behavior has resulted in several significant findings. First, aggressive behavior is highly stable from early childhood into adolescence and adulthood. Second, parental factors including rearing practices and parental psychopathology, are correlated with childhood behavior problems. It was the aim of the present study to examine the correlates and stability of aggressive behavior in a sample of toddlers from low income families. Eight-nine mother-child dyads (52 boys and 37 girls) were observed in laboratory assessments when the child was 18- and 24-months old. Frequency and pervasiveness of aggression were coded from videotapes. Familial criminality, maternal depressive symptomatology, child noncompliance, and difficult child temperament were examined as contributors to the prediction of aggression in toddlers. Stability of aggression was moderate, especially for aggression occurring in low-stress situations. While there were few sex differences in the frequency and stability of aggression, there were marked differences in the correlates and predictors of aggression. Gender-specific, interactional models of the development of aggression are proposed.