Impact of normal and shear stresses due to wheel slip on hydrological properties of an agricultural clay loam: Experimental and new computerized approach

The main purpose of this study was to evaluate the effect that mechanical stresses acting under the slipping driving wheels of agricultural equipment have on the soil’s pore system and water flow process (surface runoff generation during extreme event). The field experiment simulated low slip (1%) and high slip (27%) on a clay loam. The stress on the soil surface and changes in the amounts of water flowing from macropores were simulated using the Tires/tracks And Soil Compaction (TASC) tool and the MACRO model, respectively. Taking a 65 kW tractor on a clay loam as a reference, results showed that an increase in slip of the rear wheels from 1% to 27% caused normal stress to increase from 90.6 kPa to 104.4 kPa at the topsoil level, and the maximum shear contact stress to rise drastically from 6.0 kPa to 61.6 kPa. At 27% slip, topsoil was sheared and displaced over a distance of 0.35 m. Excessive normal and shear stress values with high slip caused severe reductions of the soil’s macroporosity, saturated hydraulic conductivity, and water quantities flowing from topsoil macropores. Assuming that, under conditions of intense rainfall on sloping land, a loss in vertical water flow would mean an increase in surface runoff, we calculated that a rainfall intensity of 100 mm h-1 and a rainfall duration of 1 h would increase the runoff coefficient to 0.79 at low slip and to 1.00 at high slip, indicating that 100% of rainwater would be transformed into surface runoff at high slip. We expect that these effects have a significant impact on soil erosion and floods in steeper terrain (slope > 15°) and across larger surface areas (> 16 m2) than those included in our study.

The impact of medical errors on Swiss anaesthesiologists: a cross-sectional survey.

BACKGROUND Clinicians involved in medical errors can experience significant distress. This study aims to examine (1) how medical errors impact anaesthesiologists in key work and life domains; (2) anaesthesiologists' attitudes regarding support after errors; (3) and which anaesthesiologists are most affected by errors. METHODS This study is a mailed cross-sectional survey completed by 281 of the 542 clinically active anaesthesiologists (52% response rate) working at Switzerland's five university hospitals between July 2012 and April 2013. RESULTS Respondents reported that errors had negatively affected anxiety about future errors (51%), confidence in their ability as a doctor (45%), ability to sleep (36%), job satisfaction (32%), and professional reputation (9%). Respondents' lives were more likely to be affected as error severity increased. Ninety per cent of respondents disagreed that hospitals adequately support them in coping with the stress associated with medical errors. Nearly all of the respondents (92%) reported being interested in psychological counselling after a serious error, but many identified barriers to seeking counselling. However, there were significant differences between departments regarding error-related stress levels and attitudes about error-related support. Respondents were more likely to experience certain distress if they were female, older, had previously been involved in a serious error, and were dissatisfied with their last error disclosure. CONCLUSION Medical errors, even minor errors and near misses, can have a serious effect on clinicians. Health-care organisations need to do more to support clinicians in coping with the stress associated with medical errors.

Climatic and anthropogenic changes in Western Switzerland: Impacts on water stress

Recent observed hydro-climatic changes in mountainous areas are of concern as they may directly affect capacity to fulfill water needs. The canton of Vaud in Western Switzerland is an example of such a region as it has experienced water shortage episodes during the past decade. Based on an integrated modeling framework, this study explores how hydro-climatic conditions and water needs could evolve in mountain environments and assesses their potential impacts on water stress by the 2060 horizon. Flows were simulated based on a daily semi-distributed hydrological model. Future changes were derived from Swiss climate scenarios based on two regional climate models. Regarding water needs, the authorities of the canton of Vaud provided a population growth scenario while irrigation and livestock trends followed a business-as-usual scenario. Currently, the canton of Vaud experiences moderate water stress from June to August, except in its Alpine area where no stress is noted. In the 2060 horizon, water needs could exceed 80% of the rivers' available resources in low- to mid-altitude environments in mid-summer. This arises from the combination of drier and warmer climate that leads to longer and more severe low flows, and increasing urban (+ 40%) and irrigation (+ 25%) water needs. Highlighting regional differences supports the development of sustainable development pathways to reduce water tensions. Based on a quantitative assessment, this study also calls for broader impact studies including water quality issues.

Carbon-11 Reveals Opposing Roles of Auxin and Salicylic Acid in Regulating Leaf Physiology, Leaf Metabolism, and Resource Allocation Patterns that Impact Root Growth in Zea mays

Auxin (IAA) is an important regulator of plant development and root differentiation. Although recent studies indicate that salicylic acid (SA) may also be important in this context by interfering with IAA signaling, comparatively little is known about its impact on the plant’s physiology, metabolism, and growth characteristics. Using carbon-11, a short-lived radioisotope (t 1/2 = 20.4 min) administered as 11CO2 to maize plants (B73), we measured changes in these functions using SA and IAA treatments. IAA application decreased total root biomass, though it increased lateral root growth at the expense of primary root elongation. IAA-mediated inhibition of root growth was correlated with decreased 11CO2 fixation, photosystem II (PSII) efficiency, and total leaf carbon export of 11C-photoassimilates and their allocation belowground. Furthermore, IAA application increased leaf starch content. On the other hand, SA application increased total root biomass, 11CO2 fixation, PSII efficiency, and leaf carbon export of 11C-photoassimilates, but it decreased leaf starch content. IAA and SA induction patterns were also examined after root-herbivore attack by Diabrotica virgifera to place possible hormone crosstalk into a realistic environmental context. We found that 4 days after infestation, IAA was induced in the midzone and root tip, whereas SA was induced only in the upper proximal zone of damaged roots. We conclude that antagonistic crosstalk exists between IAA and SA which can affect the development of maize plants, particularly through alteration of the root system’s architecture, and we propose that the integration of both signals may shape the plant’s response to environmental stress.

Enhanced emotional empathy after psychosocial stress in young healthy men

Empathy is a core prerequisite for human social behavior. Relatively, little is known about how empathy is influenced by social stress and its associated neuroendocrine alterations. The current study was designed to test the impact of acute stress on emotional and cognitive empathy. Healthy male participants were exposed to a psychosocial laboratory stressor (trier social stress test, (TSST)) or a well-matched control condition (Placebo-TSST). Afterwards they participated in an empathy test measuring emotional and cognitive empathy (multifaceted empathy test, (MET)). Stress exposure caused an increase in negative affect, a rise in salivary alpha amylase and a rise in cortisol. Participants exposed to stress reported more emotional empathy in response to pictures displaying both positive and negative emotional social scenes. Cognitive empathy (emotion recognition) in contrast did not differ between the stress and the control group. The current findings provide initial evidence for enhanced emotional empathy after acute psychosocial stress.

Growth at moderately elevated temperature alters the physiological response of the photosynthetic apparatus to heat stress in pea (Pisum sativum L.) leaves

The impact of heat stress on the functioning of the photosynthetic apparatus was examined in pea (Pisum sativum L.) plants grown at control (25 °C; 25 °C-plants) or moderately elevated temperature (35 °C; 35 °C-plants). In both types of plants net photosynthesis (Pn) decreased with increasing leaf temperature (LT) and was more than 80% reduced at 45 °C as compared to 25 °C. In the 25 °C-plants, LTs higher than 40 °C could result in a complete suppression of Pn. Short-term acclimation to heat stress did not alter the temperature response of Pn. Chlorophyll a fluorescence measurements revealed that photosynthetic electron transport (PET) started to decrease when LT increased above 35 °C and that growth at 35 °C improved the thermal stability of the thylakoid membranes. In the 25 °C-plants, but not in the 35 °C-plants, the maximum quantum yield of the photosystem II primary photochemistry, as judged by measuring the Fv/Fm ratio, decreased significantly at LTs higher than 38 °C. A post-illumination heat-induced reduction of the plastoquinone pool was observed in the 25 °C-plants, but not in the 35 °C-plants. Inhibition of Pn by heat stress correlated with a reduction of the activation state of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Western-blot analysis of Rubisco activase showed that heat stress resulted in a redistribution of activase polypeptides from the soluble to the insoluble fraction of extracts. Heat-dependent inhibition of Pn and PET could be reduced by increasing the intercellular CO2 concentration, but much more effectively so in the 35 °C-plants than in the 25 °C-plants. The 35 °C-plants recovered more efficiently from heat-dependent inhibition of Pn than the 25 °C-plants. The results show that growth at moderately high temperature hardly diminished inhibition of Pn by heat stress that originated from a reversible heat-dependent reduction of the Rubisco activation state. However, by improving the thermal stability of the thylakoid membranes it allowed the photosynthetic apparatus to preserve its functional potential at high LTs, thus minimizing the after-effects of heat stress.

Metamorphosis of human lumbar vertebrae induced by VEPTR growth modulation and stress shielding

INTRODUCTION Distraction-based spinal growth modulation by growing rods or vertical expandable prosthetic titanium ribs (VEPTRs) is the mainstay of instrumented operative strategies to correct early onset spinal deformities. In order to objectify the benefits, it has become common sense to measure the gain in spine height by assessing T1-S1 distance on anteroposterior (AP) radiographs. However, by ignoring growth changes on vertebral levels and by limiting measurement to one plane, valuable data is missed regarding the three-dimensional (3D) effects of growth modulation. This information might be interesting when it comes to final fusion or, even more so, when the protective growing implants are removed and the spine re-exposed to physiologic forces at the end of growth. METHODS The goal of this retrospective radiographic study was to assess the growth modulating impact of year-long, distraction-based VEPTR treatment on the morphology of single vertebral bodies. We digitally measured lumbar vertebral body height (VBH) and upper endplate depth (VBD) at the time of the index procedure and at follow-up in nine patients with rib-to-ileum constructs (G1) spanning an anatomically normal lumbar spine. Nine patients with congenital thoracic scoliosis and VEPTR rib-to-rib constructs, but uninstrumented lumbar spines, served as controls (G2). All had undergone more than eight half-yearly VEPTR expansions. A Wilcoxon signed-rank test was used for statistical comparison of initial and follow-up VBH, VBD and height/depth (H/D) ratio (significance level 0.05). RESULTS The average age was 7.1 years (G1) and 5.2 year (G2, p > 0.05) at initial surgery; the average overall follow-up time was 5.5 years (p = 1). In both groups, VBH increased significantly without a significant intergroup difference. Group 1 did not show significant growth in depth, whereas VBD increased significantly in the control group. As a consequence, the H/D ratio increased significantly in group 1 whereas it remained unchanged in group 2. The growth rate for height in mm/year was 1.4 (group 1) and 1.1 (group 2, p = 0.45), and for depth, it was -0.3 and 1.1 (p < 0.05), respectively. CONCLUSIONS VEPTR growth modulating treatment alters the geometry of vertebral bodies by increasing the H/D ratio. We hypothesize that the implant-related deprivation from axial loads (stress-shielding) impairs anteroposterior growth. The biomechanical consequence of such slender vertebrae when exposed to unprotected loads in case of definitive VEPTR removal at the end of growth is uncertain.

Resilience as a correlate of acute stress disorder symptoms in patients with acute myocardial infarction

OBJECTIVES Myocardial infarction (MI) may be experienced as a traumatic event causing acute stress disorder (ASD). This mental disorder has an impact on the daily life of patients and is associated with the development of post-traumatic stress disorder. Trait resilience has been shown to be a protective factor for post-traumatic stress disorder, but its association with ASD in patients with MI is elusive and was examined in this study. METHODS We investigated 71 consecutive patients with acute MI within 48 h of having stable haemodynamic conditions established and for 3 months thereafter. All patients completed the Acute Stress Disorder Scale and the Resilience Scale to self-rate the severity of ASD symptoms and trait resilience, respectively. RESULTS Hierarchical regression analysis showed that greater resilience was associated with lower symptoms of ASD independent of covariates (b=-0.22, p<0.05). Post hoc analysis revealed resilience level to be inversely associated with the ASD symptom clusters of re-experiencing (b=-0.05, p<0.05) and arousal (b=-0.09, p<0.05), but not with dissociation and avoidance. CONCLUSIONS The findings suggest that patients with acute MI with higher trait resilience experience relatively fewer symptoms of ASD during MI. Resilience was particularly associated with re-experiencing and arousal symptoms. Our findings contribute to a better understanding of resilience as a potentially important correlate of ASD in the context of traumatic situations such as acute MI. These results emphasise the importance of identifying patients with low resilience in medical settings and to offer them adequate support.

Association of Trait Resilience With Peritraumatic and Posttraumatic Stress in Patients With Myocardial Infarction.

OBJECTIVE Acute myocardial infarction (MI) is a life-threatening condition, leading to immediate fear and distress in many patients. Approximately 18% of patients develop posttraumatic stress disorder in the aftermath of MI. Trait resilience has shown to be a protective factor for the development of posttraumatic stress disorder. However, whether this buffering effect has already an impact on peritraumatic distress and applies to patients with MI is elusive. METHODS We investigated 98 consecutive patients with acute MI within 48 hours after having reached stable circulatory conditions and 3 months thereafter. Peritraumatic distress was assessed retrospectively with three single-item questions about pain, fear, and helplessness during MI. All patients completed the Posttraumatic Diagnostic Scale (PDS) and the Resilience Scale to self-rate posttraumatic stress and trait resilience. RESULTS Multivariate models adjusting for sociodemographic and medical factors showed that trait resilience was not associated with peritraumatic distress, but significantly so with posttraumatic stress. Patients with greater trait resilience showed lower PDS scores (b = -0.06, p < .001). There was no significant relationship between peritraumatic distress scores and PDS scores; resilience did not emerge as a moderator of this relationship. CONCLUSIONS The findings suggest that trait resilience does not buffer the perception of acute MI as stressful per se but may enhance better coping with the traumatic experience in the longer term, thus preventing the development of MI-associated posttraumatic stress. Trait resilience may play an important role in posttraumatic stress symptoms triggered by medical diseases such as acute MI.

Perception of a hectic hospital environment at admission relates to acute stress disorder symptoms in myocardial infarction patients.

OBJECTIVE Hospital crowding is a public health problem that may impact on the quality of medical treatment and increase the risk of developing traumatic stress, e.g., after myocardial infarction (MI). This study examines whether subjective appraisal of crowding at hospital admission due to MI is associated with acute stress disorder (ASD) symptoms. METHOD We investigated 102 consecutive patients with acute MI within 48h after having reached stable circulatory conditions. The appraisal of crowding was measured by the retrospective assessment of the perception of a hectic hospital environment at admission. Furthermore, patients completed the Acute Stress Disorder Scale to rate the psychological stress reaction. RESULTS The perception of a hectic hospital environment was associated with the development of ASD symptoms (r=0.254, P=.013) independently of demographic, peritraumatic and medical factors. Post hoc analysis revealed associations with dissociative (r=0.211, P=.041), reexperiencing (r=0.184, P=.074) and arousal (r=0.179, P=.083) symptoms. CONCLUSION The findings suggest that, besides objective circumstances, the way hospital admission due to MI is perceived by the patient may influence the development of MI-triggered ASD symptoms. The psychological and physiological long-term outcomes of the perception of a hectic hospital environment and the role of preventive interventions need further examination.

Standardized pelvic floor exercises improve stress urinary incontinence in women with intrinsic sphincter deficiency.

OBJECTIVES Pelvic floor rehabilitation is the conservative therapy of choice for women with stress urinary incontinence (SUI). The success rate of surgical procedures in SUI patients with intrinsic sphincter deficiency (ISD) is low. The aim of this study was to analyse the effect of a standardized physiotherapy on patients with SUI and normotonic urethra and ISD. METHODS In this study, 64 patients with ISD and 69 patients with normotonic urethra were enrolled. Maximum urethral pressure (MUCP) >20 cm H2 O was considered as normotonic urethral pressure. Before and after physiotherapy MUCP was measured and cough testing was performed. Additionally, patient reported outcome was assessed using the King's Health Questionnaire (KHQ). For statistical analyses Excel 2010 (Microsoft Inc; Redmond, Washington) and SPSS 20 (SPSS Inc; Chicago, Illinois) for Windows were used. Power calculation was based on the primary endpoint incontinence impact and general health. For power calculation, GraphPad Statmate version 2.00 for Windows was used. RESULTS Sixty-four patients with ISD and 69 patients with normotonic urethra were included in the study. In SUI patients with normotonic and hypotonic urethra KHQ-scores regarding the primary endpoins "general health" and "incontinence impact" significantly improved following standardized physiotherapy. In both groups MUCP increased after physiotherapy. In SUI patients with ISD standardized physiotherapy resulted in a decreased incidence of a positive cough test. CONCLUSIONS Standardized physiotherapy should be offered to patients with SUI and ISD. Long-term results are subject to future studies. Neurourol. Urodynam. © 2015 Wiley Periodicals, Inc.

Can urethrolysis resolve outlet obstruction related symptoms after Burch colposuspension for stress urinary incontinence?

OBJECTIVE Bladder outlet obstruction may occur after any incontinence surgery and may present as OAB, hesitancy and or the feeling of incomplete emptying. Aim of this study was to analyze the clinical and urodynamical outcome after urethrolysis in patients presenting with various clinical symptoms after Burch colposuspension for stress urinary incontinence. STUDY DESIGN Between January 2005 and December 2014, all patients who presented with symptoms and with bladder outlet obstruction were included. All patients had undergone Burch or Cowan colposuspension for stress urinary incontinence previously. Primary endpoint was the visual analogue scale (VAS) as measurement of patient perceived disease impact. Secondary endpoints were the various domains of the King's Health Questionnaire, urodynamic parameters as detrusor pressure at maximum flow, residual urine and sonographic bladder wall thickness before and six months after intervention. RESULTS Seventy-two female patients were included in this study whereof 42 suffered from urgency and urge incontinence, 20 from hesitancy and/or slow stream, seven from residual urine of more than 100ml and three from a combination of urgency and residual urine. VAS improved significantly (p<0.0001). Quality of life as determined by the King's Health Questionnaire improved for the domains general health, role limitations, emotions, physical limitations, personal limitations and incontinence impact significantly. Micturition pressure dropped significantly from 43cmH2O (95% CI 19-59cmH2O) to 18cmH2O (95% CI 16-23.5 H2O). Residual urine changed from 110ml (range 20-380ml) to 32ml (20-115ml). Bladder wall thickness decreased from 7mm (95% CI 6.235-7.152) to 5mm (95% CI 5.037-5.607; p<0.01). CONCLUSION Urethrolysis may resolve patients' symptoms and lower micturition pressure but irritative symptoms may persist.

Exercise and Mood: Exploring the Role of Exercise in Regulating Stress Reactivity in Bipolar Disorder

Bipolar Disorder (BD) is a recurrent and debilitating psychological disorder characterized by a chronic dysregulation of mood with fluctuations between extremely low (e.g., depression) and extremely elevated mood states (e.g., mania), and ranks as the 6th leading cause of disability in the world. Although research has consistently shown that exercise may have antidepressant and stress-attenuating benefits in other psychiatric illnesses (e.g., depression, anxiety), these benefits have not been directly investigated for BD. The current study represents the first known investigation to examine this relationship. Single-participant designs, with crossover and interaction treatment components (i.e., A/B/A/B/A, A/C/A/C/A, A/B/A/C/A, or A/C/A/B/A) were utilized to investigate the impact of participation in a prescribed regimen of exercise (EP) versus standard behavioral activation (SBA; i.e., non-exercise activity) has on stress perception and reactivity, and mood stability in a sample of individuals with BD. Individuals completed four total weeks of treatment, and psychophysiological measures of reactivity were recorded during a laboratory stress task (i.e., backward counting task) prior to and following each two-week intervention phase. No appreciable differences were found between levels of exercise participation between treatment groups. Interestingly, symptoms of depressed mood (BDI-II scores) decreased at similar rates following 4 weeks of treatment for all participants. BDI-II decreases were found to be most correlated with elective exercise participation, although this relationship was not significant. Regarding stress reactivity, elective participation in mild to moderate intensity exercise was found to reduce an individual’s perception of stress reactivity to an acute stressor, while participation in a prescribed program of exercise was more effective in reducing physiological response to the same task. Utilizing multiple forms of behavioral activation simultaneously was found to be most effective in decreasing perception of stress reactivity, and may also result in a positive change in the use of adaptive versus maladaptive coping strategies. Participation in a 4-week program of exercise appeared to provide the most benefit, consistent with exercise habituation theories. Overall, current findings provide preliminary support for the prophylactic benefits of including a prescribed and monitored program of exercise as an adjunct treatment for individuals with BD. Larger scale research is needed to more clearly determine the impact of exercise on stress reactivity and mood episode relapse in individuals with BD.

Posttraumatic stress disorder among veterans of the Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) wars: Psychological comorbidities, postdeployment social support and unit support

Much attention has been given to treating Operation Iraqi Freedom/Operation Enduring (OIF/OEF) Veterans with posttraumatic stress disorder (PTSD). However, little attention is given to those Veterans who do not meet diagnostic criteria for PTSD but who may still benefit from intervention. Research is needed to investigate the impact of how different racial/ethnic backgrounds, different levels of social support and comorbid mental health disorders impact OIF/OEF Veterans with varying levels of PTSD. The purpose of this dissertation is to examine the association of comorbid Axis I disorders, race/ethnicity, different levels of postdeployment social support and unit support on OIF/OEF Veterans with varying levels of PTSD. Data for this dissertation were from postdeployment screenings of OIF/OEF Veterans from a large Veterans Affairs hospital in southeast Texas. To examine the study hypotheses, we conducted multinomial logistic regressions of the clinician reported data. ^ The first article examined the prevalence of subthreshold and full levels of PTSD and compared Axis I and alcohol use comorbidity rates among 1,362 OIF/OEF Veterans with varying levels of PTSD. Results suggest that OIF/OEF Veterans with subthreshold PTSD experience similar levels of psychological distress as those with full PTSD and highlight the need to provide timely and appropriate mental health services to individuals who may not meet the diagnostic criteria for full PTSD. ^ These results suggest that OIF/OEF Veterans of all race/ethnicities can benefit from strong social support systems. Postdeployment social support was found to be a protective factor against the development of PTSD among White, Black and Hispanic veterans while deployment unit support was a protective factor only among Black Veterans. The second article investigated the association between postdeployment social support and unit support with varying levels of PTSD by race/ethnicity among 1,115 OIF/OEF Veterans. ^ The results of this study can help to formulate treatment and interventions for OIF/OEF Veterans with varying levels of PTSD and social support systems.^

Impact of traffic pollution on telomere length and chronic diseases: Results from the multi-ethnic study of atherosclerosis and the Mexican-American cohort study

Exposure to air pollutants in urban locales has been associated with increased risk for chronic diseases including cardiovascular disease (CVD) and pulmonary diseases in epidemiological studies. The exact mechanism explaining how air pollution affects chronic disease is still unknown. However, oxidative stress and inflammatory pathways have been posited as likely mechanisms. ^ Data from the Multi-Ethnic Study of Atherosclerosis (MESA) and the Mexican-American Cohort Study (2003-2009) were used to examine the following aims, respectively: 1) to evaluate the association between long-term exposure to ambient particulate matter (PM) (PM10 and PM2.5) and nitrogen oxides (NO x) and telomere length (TL) among approximately 1,000 participants within MESA; and 2) to evaluate the association between traffic-related air pollution with self-reported asthma, diabetes, and hypertension among Mexican-Americans in Houston, Texas. ^ Our results from MESA were inconsistent regarding associations between long-term exposure to air pollution and shorter telomere length based on whether the participants came from New York (NY) or Los Angeles (LA). Although not statistically significant, we observed a negative association between long-term air pollution exposure and mean telomere length for NY participants, which was consistent with our hypothesis. Positive (statistically insignificant) associations were observed for LA participants. It is possible that our findings were more influenced by both outcome and exposure misclassification than by the absence of a relationship between pollution and TL. Future studies are needed that include longitudinal measures of telomere length as well as focus on effects of specific constituents of PM and other pollutant exposures on changes in telomere length over time. ^ This research provides support that Mexican-American adults who live near a major roadway or in close proximity to a dense street network have a higher prevalence of asthma. There was a non-significant trend towards an increased prevalence of adult asthma with increasing residential traffic exposure especially for residents who lived three or more years at their baseline address. Even though the prevalence of asthma is low in the Mexican-origin population, it is the fastest growing minority group in the U.S. and we would expect a growing number of Mexican-Americans who suffer from asthma in the future. Future studies are needed to better characterize risks for asthma associated with air pollution in this population.^