Sample records for stress levels measured

  1. Measuring Stress and Ability to Recover from Stress with Salivary Alpha-Amylase Levels


    to be resilient. So what is salivary alpha amylase ? To start, an amylase is enzyme in the body that hydrolyzes starch (breaks it down) into...Ability to Recover from Stress with Salivary α- Amylase Levels Authors Brandon L. Mulrine Michael F. Sheehan Lolita M. Burrell Michael...TITLE AND SUBTITLE Measuring Stress and Ability to Recover from Stress with Salivary Alpha Amylase Levels 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  2. Perceived and measured physical activity and mental stress levels in obstetricians.

    Martinez de Tejada, Begoña; Jastrow, Nicole; Poncet, Antoine; Le Scouezec, Iona; Irion, Olivier; Kayser, Bengt


    Obstetric work generates important subjective and objective mental stress and is perceived as a physically demanding activity by obstetricians. The aim of this study was to quantify physical and mental stress levels in obstetricians at work and during leisure activities to investigate their association with overall physical activity levels and professional experience. 18 obstetricians at the maternity unit of the University of Geneva Hospitals were enrolled in a prospective observational study. Physical activity and stress levels were measured in two different activity sectors (delivery room and outpatient clinic) and outside work. Physical activity was assessed by questionnaire, visual analogue scale (VAS), and accelerometer. Mental stress levels were assessed by validated questionnaires, VAS, measurement of urine catecholamines and salivary cortisol, and night-time heart rate variability indices. Daily stress levels were higher at work compared to outside work (all, P = 0.002). Adrenalin (P = 0.002) and dopamine (P = 0.09) levels were elevated after a labour suite shift and a trend was observed for reduced heart rate variability during the night after this shift. The median average daily number of steps was 7132 (range, 5283-8649). Subjects reached a median of 32 min (range, 19-49 min) of moderate or higher intensity (≥ 1952 counts/min) daily physical activity. Contrary to perception, obstetrics work is not physically demanding. It is, however, accompanied by important subjective and objective mental stress that may have a negative impact on health when combined with a lack of regular daily physical activity. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  3. A biological measure of stress levels in patients with functional movement disorders.

    Maurer, Carine W; LaFaver, Kathrin; Ameli, Rezvan; Toledo, Ryan; Hallett, Mark


    While the presence of co-existing psychological stressors has historically been used as a supportive factor in the diagnosis of functional neurological disorders, many patients with functional neurological disorders deny the presence of these stressors. The stress response circuitry in these patients remains largely unexplored. We performed an observational study examining biological stress levels in patients with functional movement disorders as compared with matched healthy controls. Specifically, we compared levels of circulating cortisol, the end-product of the hypothalamic-pituitary-adrenal axis. Salivary cortisol samples were collected from patients with "clinically definite" functional movement disorders (n = 33) and their age- and sex-matched controls (n = 33). Collections were performed at five standardized time points, reflecting participants' diurnal cortisol cycles. To rule out confounders, participants also underwent extensive psychological assessment including Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Hamilton Anxiety Rating Scale, and Hamilton Rating Scale for Depression. Patients with functional movement disorders did not differ from matched controls with respect to levels of circulating cortisol. We demonstrate that current stress levels are not altered in patients with functional movement disorders. Our results warrant careful review of current management of patients with functional neurological symptoms, and suggest that the insistence on heightened stress levels in these patients is unjustified. Published by Elsevier Ltd.

  4. Stress Levels of Agricultural Science Cooperating Teachers and Student Teachers: A Repeated Measures Comparative Assessment

    McKim, Billy R.; Rayfield, John; Harlin, Julie; Adams, Andy


    This study compared job stress levels of Texas agricultural science cooperating teachers and Texas agricultural science student teachers across a semester. The research objectives included describing secondary agricultural science cooperating teachers and student teachers perceptions of stressors, by time of semester (beginning, middle, and end),…

  5. Leveraging Stress Level

    Mitali PATHAK


    Full Text Available Stress is a costly business expense that affects both employee health and company profits. At the backdrop of this, the present research study is an attempt to explore and analysis the findings of the research studies which have been concluded in resolving and managing conflict arising through variances in stress level at the organizational hierarchy.

  6. Measuring stress level of dairy cows during milking using by geometric indices of heart rate variability

    Levente Kovács


    Full Text Available AbstractHeart rate (HR and heart rate variability (HRV were investigated in cows (n=32, age: 3.86 years, milk production: 35±2.5 kg, DIM: 150±15 milked in a parallel milking parlour. Geometric parameters of HRV (SD1 and SD2 were calculated using Poincare graphs. HRV indices of resting 1 h after midday milking (reference period were compared to those measured during the different phases of the evening milking (driving; in the holding pen; udder preparation; milking; after milking in the milking stall. There was no difference between the reference period and the different phases of milking in animal welfare terms. During the reference period SD2 (198.5 ms was significantly higher (p<0.05 than every other measured period suggesting an increasing parasympathetic tone after milking. This parasympathetic predominance decreased with time of the day (1.5 h after milking. SD2 was significantly affected by parity, by the breeding bull (p<0.01 and by milk production (p<0.05. SD2 was notably higher (102.8 ms in multiparous cows than in primiparous cows (p<0.017; α=0.005 during resting and milking. Results suggested that a conventional milking process is not really stressful for cows. Primiparous cows were more susceptible of milking process than multiparous ones. SD2 is a good marker of vagus activity and affected by several independent factors.

  7. Measurement of heat stress conditions at cow level and comparison to climate conditions at stationary locations inside a dairy barn.

    Schüller, Laura K; Heuwieser, Wolfgang


    The objectives of this study were to examine heat stress conditions at cow level and to investigate the relationship to the climate conditions at 5 different stationary locations inside a dairy barn. In addition, we compared the climate conditions at cow level between primiparous and multiparous cows for a period of 1 week after regrouping. The temperature-humidity index (THI) differed significantly between all stationary loggers. The lowest THI was measured at the window logger in the experimental stall and the highest THI was measured at the central logger in the experimental stall. The THI at the mobile cow loggers was 2·33 THI points higher than at the stationary loggers. Furthermore, the mean daily THI was higher at the mobile cow loggers than at the stationary loggers on all experimental days. The THI in the experimental pen was 0·44 THI points lower when the experimental cow group was located inside the milking parlour. The THI measured at the mobile cow loggers was 1·63 THI points higher when the experimental cow group was located inside the milking parlour. However, there was no significant difference for all climate variables between primiparous and multiparous cows. These results indicate, there is a wide range of climate conditions inside a dairy barn and especially areas with a great distance to a fresh air supply have an increased risk for the occurrence of heat stress conditions. Furthermore, the heat stress conditions are even higher at cow level and cows not only influence their climatic environment, but also generate microclimates within different locations inside the barn. Therefore climate conditions should be obtained at cow level to evaluate the heat stress conditions that dairy cows are actually exposed to.

  8. The Emotional Stress Reaction Questionnaire (ESRQ): Measurement of Stress Reaction Level in Field Conditions in 60 Seconds


    Woods & Hampson, 2005) designed to measure the five dimensions/factors in the Big Five model of personality ( Costa & McCrae , 1992): Extraversion...National Defense University Press. Costa , P. T. Jr, & McCrae , R. R. (1992). NEO PI-R: Professional manual. Odessa, FL: Psychological Assessment

  9. Evaluating the Risk of a Fifth Metatarsal Stress Fracture by Measuring the Serum 25-Hydroxyvitamin D Levels.

    Shimasaki, Yu; Nagao, Masashi; Miyamori, Takayuki; Aoba, Yukihiro; Fukushi, Norifumi; Saita, Yoshitomo; Ikeda, Hiroshi; Kim, Sung-Gon; Nozawa, Masahiko; Kaneko, Kazuo; Yoshimura, Masafumi


    The fifth metatarsal bone is a common site of stress fractures in soccer athletes. Although several endocrine risk factors for stress fractures have been proposed, the endocrine risks for fifth metatarsal (5-MT) stress fractures have not been evaluated. To evaluate the endocrine risks of fifth metatarsal stress fractures, we conducted a cumulative case-control study. The present study included 37 athletes, of which 18 had a history of a zone 2 or zone 3 fifth metatarsal stress fracture and 19 controls. We analyzed serum 25-hydroxyvitamin D (25-OHD), serum parathyroid hormone (PTH), as well as biochemical markers of bone turnover by univariate or multivariate analyses. Logistic regression analyses adjusted for multiple confounders revealed that insufficient serum 25-OHD levels less than 30 ng/mL (odds ratio [OR], 23.3), higher serum PTH levels (OR, 1.01), or higher serum bone-specific isoform of alkaline phosphatase levels (OR, 1.10) rather than serum tartrate-resistant acid phosphatase 5b were associated with statistically significantly increased odds of 5-MT stress fractures. A postestimation calculation demonstrated that 25-OHD levels of 10 and 20 ng/mL were associated with 5.1 and 2.9 times greater odds for 5-MT stress fractures, respectively. 25-OHD insufficiency was associated with an increased incidence of 5-MT stress fractures. This insight may be useful for intervening to prevent 5-MT stress fractures. Level III, case-control study. © The Author(s) 2015.

  10. Residual-stress measurements

    Ezeilo, A.N.; Webster, G.A. [Imperial College, London (United Kingdom); Webster, P.J. [Salford Univ. (United Kingdom)


    Because neutrons can penetrate distances of up to 50 mm in most engineering materials, this makes them unique for establishing residual-stress distributions non-destructively. D1A is particularly suited for through-surface measurements as it does not suffer from instrumental surface aberrations commonly found on multidetector instruments, while D20 is best for fast internal-strain scanning. Two examples for residual-stress measurements in a shot-peened material, and in a weld are presented to demonstrate the attractive features of both instruments. (author).

  11. Investigating First Year Education Students' Stress Level

    Geng, Gretchen; Midford, Richard


    This paper investigated the stress levels of first-year education students who undertake teaching practicum and theory units during their first year of teacher education program. First, 139 first-year and 143 other years' education students completed the PSS-10 scale, which measures perceived level of stress. Then, 147 first-year education…

  12. Effect of Posttraumatic Stress on Study Time in a Task Measuring Four Component Processes Underlying Text-Level Reading

    Sullivan, Michael P.; Griffiths, Gina G.; Sohlberg, Mckay Moore


    Purpose: To investigate the effect of combat-related posttraumatic stress disorder (PTSD) on 4 components underlying text-level reading comprehension. Method: A group of 17 veterans with PTSD and 17 matched control participants took part. An experimental task required participants to read and study 3-sentence paragraphs describing semantic…

  13. Stress level in wild harbour porpoises (Phocoena phocoena) during satellite tagging measured by respiration, heart rate and cortisol

    Eskesen, Ida Grønborg; Teilmann, J.; Geertsen, B. M.


    analysed from blood samples. Differences in heart rates, respiration rates and cortisol levels before and during the tagging events were investigated. An overall significant decrease Of 31.5% in respiration rate was found during the tagging event period, while mature porpoises respired significantly more...... and lowering it into the water seem to stabilize a stressed animal. Therefore, general precaution and individual judgement based on experience is essential when handling wild harbour porpoises....

  14. Changing stress levels through gaining information on stress

    S.N. Madu


    Full Text Available Objective: The aim of this research was to find out the effect of the Information Phase of a Stress Management Program (SMP on the perceptions of participants about their stress levels. Method: A total sample of 100 workers (nursing staff, private business men and women, laboratory assistants, the protective services [foreman and security staff], as well as people in human resources departments took part in this study. All the participants were from the Northern and Gauteng Provinces in South Africa. The Combined Hassles and Uplifts Scale (Folkman & Lazarus, 1989 was used as an instrument to measure the perceived stress level of participants in a SMP. Result: A significant reduction in stress levels was achieved among those who received the Information Phase of the SMP only, as well as those who received the whole stress management techniques. There was no significant difference between the amount of reduction in perceived stress-levels achieved among those that received the Information Phase of the SMP only, compared to that of those who received the whole techniques. Conclusion: The authors conclude that where the resources are limited, only the information phase of a SMP may be given to desiring clients. That should help to save time and money spent on participating in SMPs. This should however not discourage the use of the whole SPM, where affordable. Keywords: Stress Management Programs, Information Phase, Perception, Stress Level.

  15. Situation criticality and basketball officials' stress levels.

    Ritchie, Jason; Basevitch, Itay; Rodenberg, Ryan; Tenenbaum, Gershon


    Officials are expected to perform impeccably despite the wide range of stressors they experience. A stressor that officials frequently report is situation criticality. Situation criticality is comprised of score differential (i.e., more pressure in close games) and time remaining in a game (i.e., more pressure as time expires), which affects athletes' stress levels. The present study explored the effect of situation criticality on officials' stress levels. High school basketball officials (n = 108) with an average of 18.1 (SD = 11.2) years of officiating experience were given a survey packet containing game situations that varied in criticality. For each game situation (n = 9) officials completed the overall stress and appraisal portions of the Stress Appraisal Measure (SAM). Results revealed that situation criticality has an effect on officials' perceived stress levels. Both threat and challenge appraisals were positively correlated with perceived stress. Overall, these findings indicate that officials' stress levels fluctuate within games depending on score differential and time of game. The findings encourage officials to recognise and manage their stress, possibly through their appraisals. Additionally, the findings can affect the training of officials in the management of stress, as well as prompt the consideration of potential rule changes that reflect the increased situational demands on officials in critical situations (e.g., expanded instant replay).

  16. Interferometric Measurement Of Residual Stress

    Danyluk, Steven; Andonian, A. T.


    Stress averaged through thickness of plate measured nondestructively. Theory of elasticity combined with laser interferometric technique into technique for measurement of residual stresses in solid objects - usually in thin, nominally-flat plates. Measurements particularly useful in inspection of wafers of single-crystal silicon for making solar cells or integrated circuits, because stresses remaining after crystal-growing process cause buckling or fracture. Used to predict deflections of plates caused by known applied loads under specified boundary condition, or to infer applied loads that cause known deflections. Also used to relate known deflections to residual stresses equivalent to stresses produced by fictitious applied loads.

  17. Electromechanical Apparatus Measures Residual Stress

    Chern, Engmin J.; Flom, Yury


    Nondestructive test exploits relationship between stress and eddy-current-probe resistance. Yields data on residual stress or strain in metal tension/compression specimen (stress or strain remaining in specimen when no stress applied from without). Apparatus is assembly of commercial equipment: tension-or-compression testing machine, eddy-current probe, impedance gain-and-phase analyzer measuring impedance of probe coil, and desktop computer, which controls other equipment and processes data received from impedance gain-and-phase analyzer.

  18. Measuring Levels of Stress and Depression in Mothers of Children Using Hearing Aids and Cochlear Implants: A Comparative Study

    Prakash, Santhi S; Prakash, S. G. R.; Ravichandran, Aparna; Susan, K. Y.; Alex, Winnie


    Hearing impairment is an exceptional circumstance that restricts the child's ability to communicate verbally. Depression is a common stress-related response for hearing parents of children with hearing loss. Evidence suggests that mothers are more inclined than fathers to experience depression in response to their child's hearing loss (Mavrolas,…

  19. Response of Listeria monocytogenes to disinfection stress at the single-cell and population levels as monitored by intracellular pH measurements and viable-cell counts

    Kastbjerg, Vicky Gaedt; Nielsen, Dennis S.; Arneborg, Nils;


    of the bacterium. In situ analyses of Listeria monocytogenes single cells were performed during exposure to different concentrations of the disinfectant Incimaxx DES to study a possible population subdivision. Bacterial survival was quantified with plate counting and disinfection stress at the single-cell level...... by measuring intracellular pH (pHi) over time by fluorescence ratio imaging microscopy. pHi values were initially 7 to 7.5 and decreased in both attached and planktonic L. monocytogenes cells during exposure to sublethal and lethal concentrations of Incimaxx DES. The response of the bacterial population...... that a population of L. monocytogenes cells, whether planktonic or attached, is homogenous with respect to sensitivity to an acidic disinfectant studied on the single-cell level. Hence a major subpopulation more tolerant to disinfectants, and hence more persistent, does not appear to be present....

  20. Heat Stress Level among Construction Workers.

    Aliasghar Farshad


    Full Text Available The purpose of this study was to determine the level of heat stress to construction workers using Thermal Work Limit (TWL and Wet Bulb Globe Temperature (WBGT indices and by measuring Urine Specific Gravity (USG among construction workers in Iran and comparing the appropriateness of these indices for measuring heat stress in Iran climate.This comparative and experimental study was conducted during September 2012 in Baghe Ketabe Tehran, one of the large size construction sites in Tehran City, Iran. Sixty participants were randomly selected in two groups (exposed to sun and non-exposed among the construction workers in a construction campus with similar work type, climate and diet. TWL and WBGT and USG were measured in two consequent days and at the beginning, mid and end of the work shift, for both groups.The mean WBGT index was 22.6 ± 0.9 °C for control group and 27.5 ± 1.2 °C for exposure group, the mean TWL index measure was 215.8 ± 5.2 W/m(2 for control group and 144 ± 9.8 W/m(2 for exposure group and the mean USG was 1.0213 ± 0.0054 in control group and 1.026 ± 0.005 in exposure group. There was a significant difference in TWL, WBGT and USG between exposed and non-exposed group (P<0.01.workers were at an allowed level of heat stress. TWL, WBGT and USG measures were significantly correlated; however as TWL level enabled classification based on required intervention, it had some merit over WBGT index.

  1. Interindividual differences in stress sensitivity: basal and stress-induced cortisol levels differentially predict neural vigilance processing under stress.

    Henckens, Marloes J A G; Klumpers, Floris; Everaerd, Daphne; Kooijman, Sabine C; van Wingen, Guido A; Fernández, Guillén


    Stress exposure is known to precipitate psychological disorders. However, large differences exist in how individuals respond to stressful situations. A major marker for stress sensitivity is hypothalamus-pituitary-adrenal (HPA)-axis function. Here, we studied how interindividual variance in both basal cortisol levels and stress-induced cortisol responses predicts differences in neural vigilance processing during stress exposure. Implementing a randomized, counterbalanced, crossover design, 120 healthy male participants were exposed to a stress-induction and control procedure, followed by an emotional perception task (viewing fearful and happy faces) during fMRI scanning. Stress sensitivity was assessed using physiological (salivary cortisol levels) and psychological measures (trait questionnaires). High stress-induced cortisol responses were associated with increased stress sensitivity as assessed by psychological questionnaires, a stronger stress-induced increase in medial temporal activity and greater differential amygdala responses to fearful as opposed to happy faces under control conditions. In contrast, high basal cortisol levels were related to relative stress resilience as reflected by higher extraversion scores, a lower stress-induced increase in amygdala activity and enhanced differential processing of fearful compared with happy faces under stress. These findings seem to reflect a critical role for HPA-axis signaling in stress coping; higher basal levels indicate stress resilience, whereas higher cortisol responsivity to stress might facilitate recovery in those individuals prone to react sensitively to stress. © The Author (2015). Published by Oxford University Press. For Permissions, please email:

  2. Stress Level and Adversity Quotient among Single Working Mothers

    Dianne Bautista Solis


    may conduct further studies using other measures for stress level and adversity quotient or they may focus on the children of single working mothers.

  3. Accelerated Wafer-Level Integrated Circuit Reliability Testing for Electromigration in Metal Interconnects with Enhanced Thermal Modeling, Structure Design, Control of Stress, and Experimental Measurements.

    Shih, Chih-Ching

    Wafer-level electromigration tests have been developed recently to fulfill the need for rapid testing in integrated circuit production facilities. We have developed an improved thermal model-TEARS (Thermal Energy Accounts for the Resistance of the System) that supports these tests. Our model is enhanced by treatments for determination of the thermal conductivity of metal, K_{m}, heat sinking effects of the voltage probes and current lead terminations, and thermoelectric power. Our TEARS analysis of multi-element SWEAT (Standard Wafer-level Electromigration Acceleration Test) structures yields design criteria for the length of current injection leads and choice of voltage probe locations to isolate test units from the heat sinking effect of current lead terminations. This also provides greater insight into the current for thermal runaway. From our TEARS model and Black's equation for lifetime prediction, we have developed an algorithm for a fast and accurate control of stress in SWEAT tests. We have developed a lookup table approach for precise electromigration characterizations without complicated calculations. It decides the peak temperature in the metal, T_ {max}, and the thermal conductivity of the insulator, K_{i}, from an experimental resistance measurement at a given current. We introduce a characteristic temperature, T _{EO}, which is much simpler to use than conventional temperature coefficient of the electrical resistivity of metal for calibration and transfer of calibration data of metallic films as their own temperature sensors. The use of T_{EO} also allows us to establish system specifications for a desirable accuracy in temperature measurement. Our experimental results are the first to show the effects of series elemental SWEAT units on the system failure distribution, spatial failure distribution in SWEAT structures, and bimodal distributions for straight-line structures. The adaptive approach of our TEARS based SWEAT test decides the value of Black

  4. Neutron residual stress measurements in linepipe

    Law, Michael [ANTSO, PMB1 Menai, NSW, 2234 (Australia)]. E-mail:; Gnaepel-Herold, Thomas [Department of Materials Science and Engineering, NCNR and University of Maryland (United States); Luzin, Vladimir [Department of Materials Science and Engineering, NCNR and University of Maryland (United States); Bowie, Graham [cNCNR and State University of New York at Stoneybrook (United States): Blue Scope Steel (Australia)


    Residual stresses in gas pipelines are generated by manufacturing and construction processes and may affect the subsequent pipe integrity. In the present work, the residual stresses in eight samples of linepipe were measured by neutron diffraction. Residual stresses changed with some coating processes. This has special implications in understanding and mitigating stress corrosion cracking, a major safety and economic problem in some gas pipelines.

  5. Decreased Stress Levels in Nurses: A Benefit of Quiet Time.

    Riemer, Heather C; Mates, Joanna; Ryan, Linda; Schleder, Bonnie J


    The benefits of quiet time, a therapeutic method of improving the health care environment, have been evaluated in patients, but only a few studies have examined the effects of quiet time on intensive care nurses. To evaluate the effects of implementing quiet time in a medical-surgical intensive care unit on levels of light, noise, and nurses' stress. Quiet time consisted of turning down the unit lights for a designated time. Levels of light, noise, and nurses' stress were measured. Nurses' stress levels were measured by using a 100-point visual analog scale; unit noise, by using a digital sound level meter (model 407736, Extech Instruments); and unit light, by using an illumination light meter (model 615, Huygen Corporation). Measurements were obtained 30 minutes before and 30 minutes, 1 hour, and 2 hours after implementation of quiet time. Analysis of variance and comparisons of means indicated that both light levels and nurses' stress levels were significantly decreased after quiet time (both P levels were also decreased after quiet time, but the decrease was not significant (P = .08). Use of quiet time resulted in decreased light levels and decreased stress levels among nurses. Quiet time is an easily performed energy-saving intervention to promote a healthy work environment. ©2015 American Association of Critical-Care Nurses.

  6. Helium II level measurement techniques

    Celik, D.; Hilton, D. K.; Zhang, T.; Van Sciver, S. W.


    In this paper, a survey of cryogenic liquid level measurement techniques applicable to superfluid helium (He II) is given. The survey includes both continuous and discrete measurement techniques. A number of different probes and controlling circuits for this purpose have been described in the literature. They fall into one of the following categories: capacitive liquid level gauges, superconducting wire liquid level gauges, thermodynamic (heat transfer-based) liquid level gauges, resistive gauges, ultrasound and transmission line-based level detectors. The present paper reviews these techniques and their suitability for He II service. In addition to these methods, techniques for measuring the total liquid volume and mass gauging are also discussed.

  7. Measurements of residual stress in fracture mechanics coupons

    Prime, Michael B [Los Alamos National Laboratory; Hill, Michael R [U.C. DAVIS; Nav Dalen, John E [HILL ENGINEERING


    This paper describes measurements of residual stress in coupons used for fracture mechanics testing. The primary objective of the measurements is to quantify the distribution of residual stress acting to open (and/or close) the crack across the crack plane. The slitting method and the contour method are two destructive residual stress measurement methods particularly capable of addressing that objective, and these were applied to measure residual stress in a set of identically prepared compact tension (C(T)) coupons. Comparison of the results of the two measurement methods provides some useful observations. Results from fracture mechanics tests of residual stress bearing coupons and fracture analysis, based on linear superposition of applied and residual stresses, show consistent behavior of coupons having various levels of residual stress.

  8. Levels of meaning in family stress theory.

    Patterson, J M; Garwick, A W


    Major stressful life events, particularly those that have chronic hardships, create a crisis for families that often leads to reorganization in the family's style of functioning. A major factor in this reorganization is the meaning the family gives to the stressful event. Often the meaning extends beyond the event itself and leads to a changed view of the family system and even to a changed view of the world. Building on other family stress models, we elaborate the family's definition of the stressor into three levels of family meanings: (1) situational meanings, (2) family identity, and (3) family world view. Examples from clinical work and studies of families adapting to chronic illness are used to illustrate the relationship between these three levels of meaning, particularly as they change in response to crisis. Implications for clinical and empirical work are discussed.

  9. Response of Listeria monocytogenes to disinfection stress at the single-cell and population levels as monitored by intracellular pH measurements and viable-cell counts

    Kastbjerg, Vicky Gaedt; Nielsen, Dennis S.; Arneborg, Nils


    Listeria monocytogenes has a remarkable ability to survive and persist in food production environments. The purpose of the present study was to determine if cells in a population of L. monocytogenes differ in sensitivity to disinfection agents as this could be a factor explaining persistence...... of the bacterium. In situ analyses of Listeria monocytogenes single cells were performed during exposure to different concentrations of the disinfectant Incimaxx DES to study a possible population subdivision. Bacterial survival was quantified with plate counting and disinfection stress at the single-cell level...... was homogenous; hence, subpopulations were not detected. However, pregrowth with NaCl protected the planktonic bacterial cells during disinfection with Incimaxx (0.0015%) since pHi was higher (6 to 6.5) for the bacterial population pregrown with NaCl than for cells grown without NaCl (pHi 5 to 5.5) (P

  10. Low-level Radioactivity Measurements

    Hurtgen, C


    The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advice the nuclear and non-nuclear industry in matters concerning radioactive contamination and/or low-level radioactivity measurements; (4) to maintain the quality assurance system according to the EN45001/ISO17025 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 2000 are reported.

  11. Low-level Radioactivity Measurements

    Hurtgen, C


    The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advise the nuclear and non-nuclear industry on problems of radioactive contamination and low-level radioactivity measurements; (4) to maintain and improve the quality assurance system according to the ISO17025 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 2001 are reported.

  12. Assessing Stress in Arctic Lemmings: Fecal Metabolite Levels Reflect Plasma Free Corticosterone Levels.

    Fauteux, Dominique; Gauthier, Gilles; Berteaux, Dominique; Bosson, Curtis; Palme, Rupert; Boonstra, Rudy

    Interest in the ecology of stress in wild populations has triggered the development of noninvasive methods for quantifying stress hormones. Measurement of fecal corticosteroid metabolites (FCMs) is one such method, but it is still unclear whether FCMs can be a reliable proxy of free plasma glucocorticoids. To assess the validity of this assumption, we carried out a robust assessment on brown lemmings (Lemmus trimucronatus) from Bylot Island, Nunavut, Canada, that were hand captured and anesthetized and related plasma glucocorticoid levels to fecal metabolite glucocorticoid levels. We examined endogenous factors that could explain interindividual variability. Blood corticosterone was measured from samples obtained on capture and 30 min later, and FCM levels were measured from animals kept in captivity for 72 h. Plasma free corticosterone increased 135-fold over baseline values 30 min after capture, which confirmed that initial handling was perceived as a stressor. We found that FCM levels were highly related with free (marginal [Formula: see text] = 0.53) but not with total ([Formula: see text] = 0.02) corticosterone levels, regardless of age, sex, and reproductive condition. FCM levels started increasing 2 h after capture and reached maximum levels 4 h after capture. No circadian rhythm in FCMs was found. Plasma total corticosterone levels were much higher in adult females compared with adult males, but this difference was much smaller when measuring free corticosterone levels and FCM levels. Our results suggest that FCM levels are good measures of stress by being closely related to plasma free corticosterone levels in brown lemmings.

  13. Residual stress measurements in carbon steel

    Heyman, J. S.; Min, N.


    External dc magnetic field-induced changes in natural velocity of Rayleigh surface waves were measured in steel specimens under various stress conditions. The low field slopes of curves representing the fractional changes of natural velocity were proved to provide correct stress information in steels with different metallurgical properties. The slopes of curves under uniaxial compression, exceeding about one third of the yield stress, fell below zero in all the specimens when magnetized along the stress axis. The slopes under tension varied among different steels but remained positive in any circumstances. The stress effect was observed for both applied and residual stress. A physical interpretation of these results is given based on the stress-induced domain structure changes and the delta epsilon effect. Most importantly, it is found that the influence of detailed metallurgical properties cause only secondary effects on the obtained stress information.

  14. Experimental Measurement of In Situ Stress

    Tibbo, Maria; Milkereit, Bernd; Nasseri, Farzine; Schmitt, Douglas; Young, Paul


    The World Stress Map data is determined by stress indicators including earthquake focal mechanisms, in situ measurement in mining, oil and gas boreholes as well as the borehole cores, and geologic data. Unfortunately, these measurements are not only infrequent but sometimes infeasible, and do not provide nearly enough data points with high accuracy to correctly infer stress fields in deep mines around the world. Improvements in stress measurements of Earth's crust is fundamental to several industries such as oil and gas, mining, nuclear waste management, and enhanced geothermal systems. Quantifying the state of stress and the geophysical properties of different rock types is a major complication in geophysical monitoring of deep mines. Most stress measurement techniques involve either the boreholes or their cores, however these measurements usually only give stress along one axis, not the complete stress tensor. The goal of this project is to investigate a new method of acquiring a complete stress tensor of the in situ stress in the Earth's crust. This project is part of a comprehensive, exploration geophysical study in a deep, highly stressed mine located in Sudbury, Ontario, Canada, and focuses on two boreholes located in this mine. These boreholes are approximately 400 m long with NQ diameters and are located at depths of about 1300 - 1600 m and 1700 - 2000 m. Two borehole logging surveys were performed on both boreholes, October 2013 and July 2015, in order to perform a time-lapse analysis of the geophysical changes in the mine. These multi-parameter surveys include caliper, full waveform sonic, televiewer, chargeability (IP), and resistivity. Laboratory experiments have been performed on borehole core samples of varying geologies from each borehole. These experiments have measured the geophysical properties including elastic modulus, bulk modulus, P- and S-wave velocities, and density. The apparatus' used for this project are geophysical imaging cells capable

  15. Periodontal treatment decreases plasma oxidized LDL level and oxidative stress.

    Tamaki, Naofumi; Tomofuji, Takaaki; Ekuni, Daisuke; Yamanaka, Reiko; Morita, Manabu


    Periodontitis induces excessive production of reactive oxygen species in periodontal lesions. This may impair circulating pro-oxidant/anti-oxidant balance and induce the oxidation of low-density lipoprotein (LDL) in blood. The purpose of this study was to monitor circulating oxidized LDL and oxidative stress in subjects with chronic periodontitis following non-surgical periodontal treatment. Plasma levels of oxidized LDL and oxidative stress in 22 otherwise healthy non-smokers with chronic periodontitis (mean age 44.0 years) were measured at baseline and at 1 and 2 months after non-surgical periodontal treatment. At baseline, chronic periodontitis patients had higher plasma levels of oxidized LDL and oxidative stress than healthy subjects (p surgical periodontal treatment were effective in decreasing oxLDL, which was positively associated with a reduction in circulating oxidative stress.

  16. Work related stress and blood glucose levels.

    Sancini, A; Ricci, S; Tomei, F; Sacco, C; Pacchiarotti, A; Nardone, N; Ricci, P; Suppi, A; De Cesare, D P; Anzelmo, V; Giubilati, R; Pimpinella, B; Rosati, M V; Tomei, G


    The aim of the study is to evaluate work-related subjective stress in a group of workers on a major Italian company in the field of healthcare through the administration of a valid "questionnaire-tool indicator" (HSE Indicator Tool), and to analyze any correlation between stress levels taken from questionnaire scores and blood glucose values. We studied a final sample consisting of 241 subjects with different tasks. The HSE questionnaire - made up of 35 items (divided into 7 organizational dimensions) with 5 possible answers - has been distributed to all the subjects in occasion of the health surveillance examinations provided by law. The questionnaire was then analyzed using its specific software to process the results related to the 7 dimensions. These results were compared using the Pearson correlation and multiple linear regression with the blood glucose values obtained from each subject. From the analysis of the data the following areas resulted critical, in other words linked to an intermediate (yellow area) or high (red area) condition of stress: sustain from managers, sustain from colleagues, quality of relationships and professional changes. A significant positive correlation (p <0.05) between the mean values of all critical areas and the concentrations of glucose values have been highlighted with the correlation index of Pearson. Multiple linear regression confirmed these findings, showing that the critical dimensions resulting from the questionnaire were the significant variables that can increase the levels of blood glucose. The preliminary results indicate that perceived work stress can be statistically associated with increased levels of blood glucose.

  17. Yoga practice improves executive function by attenuating stress levels.

    Gothe, Neha P; Keswani, Rahul K; McAuley, Edward


    Prolonged activation of the hypothalamus-pituitary-adrenal system is thought to have deleterious effects on brain function. Neuroendocrine studies suggest that brain exposure to higher cortisol concentrations contribute to cognitive deficits as we age. Mind-body techniques such as yoga have shown to improve stress levels by restoring the body's sympathetic-parasympathetic balance. The objective of this study was to determine whether yoga practice moderated the stress response resulting in improved executive function. Sedentary community dwelling older adults (N=118, Mean age=62.02) were randomized to an 8-week yoga intervention or a stretching control group. At baseline and following 8 weeks, all participants completed measures of executive function, self-reported stress and anxiety and provided saliva samples before and after cognitive testing to assess cortisol. Yoga participants showed improved accuracy on executive function measures and an attenuated cortisol response compared to their stretching counterparts who showed increased cortisol levels and poor cognitive performance at follow up. The change in cortisol levels as well as self-reported stress and anxiety levels predicted performance on the running span task, n-back working memory and task switching paradigm (β's=0.27-0.38, p's≤0.05 for yoga and β's=-0.37-0.47, p's≤0.01 for stretching control). Eight weeks of regular yoga practice resulted in improved working memory performance that was mediated by an attenuated response to stress as measured by self-report stress and objective salivary cortisol measurements. This trial offers evidence for non-traditional physical activity interventions such as yoga that may be helpful in restoring HPA balance in older adults, thereby preventing cognitive decline. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Measurements for stresses in machine components

    Yakovlev, V F


    Measurements for Stresses in Machine Components focuses on the state of stress and strain of components and members, which determines the service life and strength of machines and structures. This book is divided into four chapters. Chapter I describes the physical basis of several methods of measuring strains, which includes strain gauges, photoelasticity, X-ray diffraction, brittle coatings, and dividing grids. The basic concepts of the electric strain gauge method for measuring stresses inside machine components are covered in Chapter II. Chapter III elaborates on the results of experim

  19. Acute stress induces increases in salivary IL-10 levels.

    Szabo, Yvette Z; Newton, Tamara L; Miller, James J; Lyle, Keith B; Fernandez-Botran, Rafael


    The purpose of this study was to investigate the stress-reactivity of the anti-inflammatory cytokine, IL-10, in saliva and to determine how salivary IL-10 levels change in relation to those of IL-1β, a pro-inflammatory cytokine, following stress. Healthy young adults were randomly assigned to retrieve a negative emotional memory (n = 46) or complete a modified version of the Trier Social Stress Test (n = 45). Saliva samples were taken 10 min before (baseline) and 50 min after (post-stressor) onset of a 10-min stressor, and were assayed using a high sensitivity multiplex assay for cytokines. Measurable IL-10 levels (above the minimum detectable concentration) were found in 96% of the baseline samples, and 98% of the post-stressor samples. Flow rate-adjusted salivary IL-10 levels as well as IL-1β/IL-10 ratios showed moderate but statistically significant increases in response to stress. Measurement of salivary IL-10 and pro-/anti-inflammatory cytokine ratios may be useful, noninvasive tools, in stress research.

  20. Economic Stress and Suicide: Multilevel Analyses. Part 2: Cross-Level Analyses of Economic Stress and Suicidal Ideation.

    Dooley, David; And Others


    Conducted two studies on economic stress and suicide on same population. Second study combined aggregate economic indicators with individual-level measures of stressful events, symptoms, and suicidal ideation obtained in survey of Los Angeles, California (1978-82). Findings revealed small associations between economic stress and suicide or…

  1. Bottom stress measurements on the inner shelf

    Sherwood, Christopher R.; Scully, Malcolm; Trowbridge, John


    Bottom stress shapes the mean circulation patterns, controls sediment transport, and influences benthic habitat in the coastal ocean. Accurate and precise measurements of bottom stress have proved elusive, in part because of the difficulty in separating the turbulent eddies that transport momentum from inviscid wave-induced motions. Direct covariance measurements from a pair of acoustic Doppler velocimeters has proved capable of providing robust estimates, so we designed a mobile platform coined the NIMBBLE for these measurements, and deployed two of them and two more conventional quadpods at seven sites on the inner shelf over a period of seven months. The resulting covariance estimates of stress and bottom roughness were lower than log-fit estimates, especially during calmer periods. Analyses of these data suggest the NIMBBLEs may provide an accurate and practical method for measuring bottom stress.

  2. Stress level and stress management skills of admitted baccalaureate nursing students.

    Murdock, Calla; Naber, Jessica; Perlow, Michael


    The purpose of this study was to review the stress levels and the stress management skills of admitted baccalaureate nursing students at a rural public university. Subjects completed a questionnaire to estimate stress levels, causes of stress, stress management skills, and the use of stress management skills. Stress levels by gender and group were compared using analysis of variance (ANOVA). No significant differences in stress levels by semester were discovered. A significant difference was discovered when stress levels were compared by gender. Subjects also responded that students should be taught stress management skills upon admission into the program. Additionally, stress management skills should be reinforced each semester to help students identify causes and better manage their stress. Research in the area of stress and nursing students has been sporadically attempted through the years. However, focus on stress, gender, and program placement is far less evident. The purpose of this study was to answer the following research question: What are the stress levels and the stress management skills of baccalaureate nursing students? To that end, a questionnaire was developed to identify the stress and stress management skills of the baccalaureate nursing students with the results analyzed for frequency and percentages. This study looked not only at the stress levels and stress management skills of the baccalaureate nursing student, but also took into account the subject's gender and program placement.

  3. Symmetry and Asymmetry Level Measures

    Angel Garrido


    Full Text Available Usually, Symmetry and Asymmetry are considered as two opposite sides of a coin: an object is either totally symmetric, or totally asymmetric, relative to pattern objects. Intermediate situations of partial symmetry or partial asymmetry are not considered. But this dichotomy on the classification lacks of a necessary and realistic gradation. For this reason, it is convenient to introduce "shade regions", modulating the degree of Symmetry (a fuzzy concept. Here, we will analyze the Asymmetry problem by successive attempts of description and by the introduction of the Asymmetry Level Function, as a new Normal Fuzzy Measure. Our results (both Theorems and Corollaries suppose to be some new and original contributions to such very active and interesting field of research. Previously, we proceed to the analysis of the state of art.

  4. Oxidative Stress in Autism: Elevated Cerebellar 3-nitrotyrosine Levels

    Elizabeth M. Sajdel-Sulkowska


    Full Text Available It has been suggested that oxidative stress and/or mercury compounds play an important role in the pathophysiology of autism. This study compared for the first time the cerebellar levels of the oxidative stress marker 3-nitrotyrosine (3-NT, mercury (Hg and the antioxidant selenium (Se levels between control and autistic subjects. Tissue homogenates were prepared in the presence of protease inhibitors from the frozen cerebellar tissue of control (n=10; mean age, 15.5 years; mean PMI, 15.5 hours and autistic (n=9; mean age 12.1 years; mean PMI, 19.3 hours subjects. The concentration of cerebellar 3-NT, determined by ELISA, in controls ranged from 13.69 to 49.04 pmol g-1 of tissue; the concentration of 3-NT in autistic cases ranged from 3.91 to 333.03 pmol g-1 of tissue. Mean cerebellar 3-NT was elevated in autism by 68.9% and the increase was statistically significant (p=0.045. Cerebellar Hg, measured by atomic absorption spectrometry ranged from 0.9 to 35 pmol g-1 tissue in controls (n=10 and from 3.2 to 80.7 pmol g-1 tissue in autistic cases (n=9; the 68.2% increase in cerebellar Hg was not statistically significant. However, there was a positive correlation between cerebellar 3-NT and Hg levels (r=0.7961, p=0.0001. A small decrease in cerebellar Se levels in autism, measured by atomic absorption spectroscopy, was not statistically significant but was accompanied by a 42.9% reduction in the molar ratio of Se to Hg in the autistic cerebellum. While preliminary, the results of the present study add elevated oxidative stress markers in brain to the growing body of data reflecting greater oxidative stress in autism.

  5. Level of Work Related Stress among Teachers in Elementary Schools

    Teuta Agai–Demjaha


    CONCLUSION: Our findings confirm that the majority of interviewed teachers perceived their work-related stress as high or very high. In terms of the relationship between the level of teachers’ stress and certain demographic and job characteristics, according to our results, the level of work-related stress has shown significantly high relation to gender, age, levels of grades taught as well as working experience, and significant relation to the level of education.

  6. Quantifying Stress in Marine Mammals: Measuring Biologically Active Cortisol in Cetaceans and Pinnipeds


    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Quantifying Stress in Marine Mammals : Measuring...boonstra/ LONG-TERM GOALS This research will improve our ability to measure stress in marine mammals . Stress hormones (glucocorticoids... mammal researchers to measure free glucocorticoid levels. OBJECTIVES This project has two main objectives, both related to improving our

  7. Stress levels, gender and personality factors in teachers.

    Fontana, D; Abouserie, R


    The study reports an investigation of stress levels, gender and personality dimensions in a sample of school teachers. The Professional Life Stress Scale (PLSS) was used to assess teachers' stress levels and the Eysenck Personality Questionnaire (EPQ) was used to define their personality dimensions (Extroversion-Introversion, Neuroticism-High Psychoticism-Low Psychoticism). The study sample consisted of 95 teachers, 51 females and 44 males. Results revealed that the majority of teachers sampled, 72.6 per cent, were experiencing moderate levels of stress, and 23.2 per cent serious levels. T-test results showed no significant difference between male and female teachers in stress levels. Correlation analysis between stress level and personality dimensions revealed significant positive correlation between stress and psychoticism. A significant negative correlation emerged between stress and extroversion, and a significant positive correlation between stress and neuroticism. A multiple regression analysis revealed that extroversion and neuroticism were the best predictors of stress levels. Overall, the results therefore indicated that personality dimensions appear to contribute more to stress levels than do the variables of either age or gender.

  8. Sweet craving and ghrelin and leptin levels in women during stress.

    Macedo, Danielle Marques; Diez-Garcia, Rosa Wanda


    Ingesting sweet substances in excess may attenuate the effects of stress in women and impact leptin levels, which are also affected by alcohol dependence and overeating. Excess intake of sweet substances also influences ghrelin levels, involved in the onset of food intake and stress. This paper aimed to identify sweet craving (SC) in women with stress to assess how it impacts basal leptin and active ghrelin levels, anthropometric measurements, and body composition. This observational, transversal study included 57 women and used the Stress Symptoms Inventory Lipp in Adults (ISSL); it verified that 31 of the participants were stressed, whereas 26 were symptom-free. The Questionnaire for Assessment of Sweet Substance Dependence and Abuse helped to characterize SC. ELISA furnished leptin and active ghrelin serum levels. HOMA was also evaluated. Electrical bioimpedance provided body composition values. Among the women with stress, 77.42% had SC, and they behaved differently from women without SC. Women with SC exhibited significantly higher basal leptin levels (P stress did not differ statistically in terms of leptin levels. Active ghrelin levels in stressed and non-stressed women and in women with and without SC were similar. A larger number of women with SC presented body fat percentage higher than 30% (P Stressed women had significantly higher waist circumference than non-stressed women (P Stressed women are more prone to SC, and this condition is associated with increased basal leptin levels, larger hip circumference, and altered body composition. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. RAGE polymorphisms and oxidative stress levels in Hashimoto's thyroiditis.

    Giannakou, Maria; Saltiki, Katerina; Mantzou, Emily; Loukari, Eleni; Philippou, Georgios; Terzidis, Konstantinos; Lili, Kiriaki; Stavrianos, Charalampos; Kyprianou, Miltiades; Alevizaki, Maria


    Polymorphisms of the receptor for advanced glycation end products (RAGE) gene have been studied in various autoimmune disorders, but not in Hashimoto's thyroiditis. Also, increased oxidative stress has been described in patients with Hashimoto's thyroiditis. The aim of this study was to investigate the possible role of two common RAGE polymorphisms (-429T>C, -374T>A) in Hashimoto's thyroiditis; in parallel, we studied oxidative stress levels. A total of 300 consecutive euthyroid women were examined and classified into three groups: Hashimoto's thyroiditis with treatment (n = 96), Hashimoto's thyroiditis without treatment (n = 109) and controls (n = 95). For a rough evaluation of oxidative stress, total lipid peroxide levels in serum were measured. The -429T>C AluI and -374T>A MfeI polymorphisms of RAGE were studied in genomic DNA. Significant association of the RAGE system with Hashimoto's thyroiditis was found only with regard to the prevalence of the -429T>C, but not with -374T>A polymorphism. The levels of oxidative stress were significantly elevated in Hashimoto's thyroiditis patients under treatment. Further analysis demonstrated that an oxidative stress cut-off value of 590 μmol/L is associated with an increased risk of progression of Hashimoto's thyroiditis from euthyroidism to hypothyroidism; this risk is further increased in carriers of the RAGE -429T>C polymorphism. Our findings indicate that both examined risk factors may be implicated in the occurrence of Hashimoto's thyroiditis, but this covers only a fraction of the pathophysiology of the disease. © 2017 Stichting European Society for Clinical Investigation Journal Foundation.

  10. Plasma vanillylmandelic acid level as an index of psychological stress response in normal subjects.

    Fukuda, M; Hata, A; Niwa, S; Hiramatsu, K; Honda, H; Nakagome, K; Iwanami, A


    The relationships between psychological stress responses and plasma levels of vanillylmandelic acid (VMA), 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxyindolacetic acid (5-HIAA) were investigated in normal volunteers. Two questionnaires were used to measure stress: the Psychological Stress Response Scale (PSRS) and the State-Trait Anxiety Inventory (STAI). Plasma levels of VMA--but not MHPG, HVA, and 5-HIAA--showed significant positive correlations with PSRS emotional and cognitive-behavioral stress and STAI state anxiety. Significant positive correlations were also found between plasma levels of VMA and MHPG and psychological stress responses measured repeatedly in a longitudinal study of an Olympic swimmer. Plasma VMA measurements, which reflect the level of activity of the peripheral sympathetic nervous system, may provide a useful biochemical index of psychological stress responses in normal subjects.

  11. Reliable practical technique for in-situ rock stress measurements in deep gold mines.

    Stacey, TR


    Full Text Available The proposed primary output of this research project is the development of a set of equipment and method of in situ stress measurements in a high stress environment typical of the deep level gold mines....

  12. An ultrasonic technique for measuring stress in fasteners

    Stevens, K. J.; Day, P.; Byron, D.


    High temperature bolting alloys are extensively used in the thermal power generation industry as for example, reheat ESV and Governor valve studs. Remnant life assessment methodologies and plant maintenance procedures require the monitoring of the operational stress levels in these fasteners. Some conventional ultrasonic techniques require longitudinal wave measurements to be undertaken when the nut on the bolt is loosened and then re-tightened. Other techniques use a combination of shear waves and longitudinal waves. In this paper, the problems and pitfalls associated with various ultrasonic techniques for measuring stress in bolts, is discussed. An ultrasonic technique developed for measuring the stress in Durehete 1055 bolts is presented. Material from a textured rolled bar has been used as a test bed in the development work. The technique uses shear wave birefringence and compression waves at several frequencies to measure texture, fastener length and the average stress. The technique was developed by making ultrasonic measurements on bolts tensioned in universal testing machines and a hydraulic nut. The ultrasonic measurements of residual stress have been checked against strain gauge measurements. The Durehete bolts have a hollow cylinder geometry of restricted dimensions, which significantly alters compression and shear wave velocities from bulk values and introduces hoop stresses which can be measured by rotating the polarization of the shear wave probe. Modelling of the experimental results has been undertaken using theories for the elastic wave propagation through waveguides. The dispersion equations allow the velocity and length of the fastener to be measured ultrasonically in some situations where the length of the fastener can not be measured directly with a vernier caliper or micrometer and/or where it is undesirable to loosen nuts to take calibration readings of the shear and compression wave velocities.

  13. Relationship between stress levels and the status of serum ...



    Jul 26, 2014 ... exposure and serum antioxidant vitamins' levels would certainly provide a clue towards stress ... vitamins. Key Words: Stress, oxidative stress, antioxidant, vitamin A, Vitamin C ... lipid peroxidation or by oxidizing DNA or protein.[9] Damages to DNA cause mutations ... paired comparison analysis[17].

  14. Perceived stress at work is associated with lower levels of DHEA-S.

    Lennartsson, Anna-Karin; Theorell, Töres; Rockwood, Alan L; Kushnir, Mark M; Jonsdottir, Ingibjörg H


    It is known that long-term psychosocial stress may cause or contribute to different diseases and symptoms and accelerate aging. One of the consequences of prolonged psychosocial stress may be a negative effect on the levels of dehydroepiandrosterone (DHEA) and its sulphated metabolite dehydroepiandrosterone sulphate (DHEA-S). The aim of this study is to investigate whether levels of DHEA and DHEA-S differ in individuals who report perceived stress at work compared to individuals who report no perceived stress at work. Morning fasting DHEA-S and DHEA levels were measured in serum in a non-stressed group (n = 40) and a stressed group (n = 41). DHEA and DHEA-S levels were compared between the groups using ANCOVA, controlling for age. The mean DHEA-S levels were 23% lower in the subjects who reported stress at work compared to the non-stressed group. Statistical analysis (ANCOVA) showed a significant difference in DHEA-S levels between the groups (p = 0.010). There was no difference in DHEA level between the groups. This study indicates that stressed individual have markedly lower levels of DHEA-S. Given the important and beneficial functions of DHEA and DHEA-S, lower levels of DHEA-S may constitute one link between psychosocial stress, ill health and accelerated ageing.

  15. Perceived stress at work is associated with lower levels of DHEA-S.

    Anna-Karin Lennartsson

    Full Text Available BACKGROUND: It is known that long-term psychosocial stress may cause or contribute to different diseases and symptoms and accelerate aging. One of the consequences of prolonged psychosocial stress may be a negative effect on the levels of dehydroepiandrosterone (DHEA and its sulphated metabolite dehydroepiandrosterone sulphate (DHEA-S. The aim of this study is to investigate whether levels of DHEA and DHEA-S differ in individuals who report perceived stress at work compared to individuals who report no perceived stress at work. METHODS: Morning fasting DHEA-S and DHEA levels were measured in serum in a non-stressed group (n = 40 and a stressed group (n = 41. DHEA and DHEA-S levels were compared between the groups using ANCOVA, controlling for age. RESULTS: The mean DHEA-S levels were 23% lower in the subjects who reported stress at work compared to the non-stressed group. Statistical analysis (ANCOVA showed a significant difference in DHEA-S levels between the groups (p = 0.010. There was no difference in DHEA level between the groups. CONCLUSIONS: This study indicates that stressed individual have markedly lower levels of DHEA-S. Given the important and beneficial functions of DHEA and DHEA-S, lower levels of DHEA-S may constitute one link between psychosocial stress, ill health and accelerated ageing.

  16. Prevalence of stress and stress tolerance levels among adolescent boys - a district level cross sectional study in South India.

    Roy, Kallol; Kamath, Veena G; Kamath, Asha; Alex, Johnson; Hegde, Asha


    Adolescence is a tumultuous period of hormonal and psychological transitions ranging from 10 to 19 years (WHO). This growth phase is usually accompanied by stressors. Very few studies have reported the prevalence of stress levels among adolescent boys. Our aim was to assess the prevalence and determinants of stress and its tolerance levels among high school boys. A cross sectional study design was selected for this purpose. A standardized self reported questionnaire was administered to 1153 high school boys. A score of 130 and more was used to classify the participants as stressed. The prevalence of stress and its tolerance levels was found to be 55% and 33.7%, respectively. Also correlations suggest that parental education and occupational status play a significant role in adolescent stress. Together, these findings suggest necessitating an intervention to counter the same. The proportion of stressed adolescent boys (55.5%) reported to have poor stress tolerance (41%). Studies addressing stress among high school adolescents remain unexplored. The basic determinants of stress are not researched upon these age groups. Our study reports the prevalence of stress to be 55% among high school boys. This could be the fundamental basis of designing suitable stress management programs for adolescents that could reduce their stress levels.

  17. Measurement of probability distributions for internal stresses in dislocated crystals

    Wilkinson, Angus J.; Tarleton, Edmund; Vilalta-Clemente, Arantxa; Collins, David M. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Jiang, Jun; Britton, T. Benjamin [Department of Materials, Imperial College London, Royal School of Mines, Exhibition Road, London SW7 2AZ (United Kingdom)


    Here, we analyse residual stress distributions obtained from various crystal systems using high resolution electron backscatter diffraction (EBSD) measurements. Histograms showing stress probability distributions exhibit tails extending to very high stress levels. We demonstrate that these extreme stress values are consistent with the functional form that should be expected for dislocated crystals. Analysis initially developed by Groma and co-workers for X-ray line profile analysis and based on the so-called “restricted second moment of the probability distribution” can be used to estimate the total dislocation density. The generality of the results are illustrated by application to three quite different systems, namely, face centred cubic Cu deformed in uniaxial tension, a body centred cubic steel deformed to larger strain by cold rolling, and hexagonal InAlN layers grown on misfitting sapphire and silicon carbide substrates.

  18. Flexible Micropost Arrays for Shear Stress Measurement

    Wohl, Christopher J.; Palmieri, Frank L.; Hopkins, John W.; Jackson, Allen M.; Connell, John W.; Lin, Yi; Cisotto, Alexxandra A.


    Increased fuel costs, heightened environmental protection requirements, and noise abatement continue to place drag reduction at the forefront of aerospace research priorities. Unfortunately, shortfalls still exist in the fundamental understanding of boundary-layer airflow over aerodynamic surfaces, especially regarding drag arising from skin friction. For example, there is insufficient availability of instrumentation to adequately characterize complex flows with strong pressure gradients, heat transfer, wall mass flux, three-dimensionality, separation, shock waves, and transient phenomena. One example is the acoustic liner efficacy on aircraft engine nacelle walls. Active measurement of shear stress in boundary layer airflow would enable a better understanding of how aircraft structure and flight dynamics affect skin friction. Current shear stress measurement techniques suffer from reliability, complexity, and airflow disruption, thereby compromising resultant shear stress data. The state-of-the-art for shear stress sensing uses indirect or direct measurement techniques. Indirect measurements (e.g., hot-wire, heat flux gages, oil interferometry, laser Doppler anemometry, small scale pressure drag surfaces, i.e., fences) require intricate knowledge of the studied flow, restrictive instrument arrangements, large surface areas, flow disruption, or seeding material; with smaller, higher bandwidth probes under development. Direct measurements involve strain displacement of a sensor element and require no prior knowledge of the flow. Unfortunately, conventional "floating" recessed components for direct measurements are mm to cm in size. Whispering gallery mode devices and Fiber Bragg Gratings are examples of recent additions to this type of sensor with much smaller (?m) sensor components. Direct detection techniques are often single point measurements and difficult to calibrate and implement in wind tunnel experiments. In addition, the wiring, packaging, and installation

  19. Psychological Needs as the Predictor of Teachers' Perceived Stress Levels

    Avci, Ahmet; Bozgeyikli, Hasan; Kesici, Sahin


    The purpose of this study is to examine the relationship between teachers' psychological needs and perceived stress levels. First of all, the differentiation status of teachers' psychological needs and perceived stress levels in terms of gender, type of institution and type of the school variables was examined. Then, the psychological need's level…

  20. An Exploratory Study of Factors Affecting Stress Levels Among ...

    Current research shows that stress levels among the teaching personnel has ... to determine: (1) factors that affect stress levels of teachers in primary school as a ... and gender of teachers; (2) coping strategies that are used by these teachers ...

  1. On the Wind Stress - Sea Level Power Law.


    The response of coastal sea level to local forcing by synpotic scale winds is usually assumed to be linear in wind stress . However, the response of...response to wind stress may allow significant improvement in the analysis of some sea-level problems. (Author)

  2. Measurements of emission rates of hydrocarbons from sunflower as a function of temperature, light intensity and stress (ozone levels); Bestimmung von Emissionsraten pflanzlicher Kohlenwasserstoffe bei Sonnenblumen in Abhaengigkeit von Temperatur, Lichtintensitaet und Stress, insbesondere von der Belastung mit Ozon

    Schuh, G.; Wildt, J.; Kley, D.


    The emission rates of isoprene, mono- and sesquiterpenes from sunflower (Helianthus annuus L. cv. giganteus) were determined in an environmental chamber, a continuously stirred tank reactor. {alpha}-pinene, {beta}-caryophyllene and two oxygenated compounds were emitted. The emission rates of all terpenes increased exponentially with temperature. Substance specific differences of the rate of increase of the emission rates were observed. For all substances the dependence of their emission rates on temperature increased with increasing light intensity. Increasing lightflux resulted in an increase of the emission rates for all substances. The raise of emission rates with lightflux was dependent on temperature and increased with increasing temperature. During periods without plant stress the emission rates exhibited a good correlation with the rate of transpiration as well as with the rate of net photosynthesis. Sunflowers emitted higher amounts of terpenes when they were stressed by mechanical, wounding and ozone treatment as well as nutrient- or water deficiency. The emission rates increased by a factor of 5-300. Exposure with ozone had an effect on hydrocarbon emission rates with a delay-time. 3-4 h after exposure with 25-120 ppb ozone the emission rates increased by factor of 5-100. This increase was only observed on the first day of exposure. Nutrient deficiency resulted in an increase of emission rates by a factor of 10-300. In situations of mechanical, wounding and ozone stress, substance specific changes in the emission spectrum were observed. A model was developed to explain the observed phenomena. The main pathway of ozone loss in the chamber is caused by the uptake through the stomata of the plants. However, up to 50% of the ozone loss must be explained by other processes indirectly caused by the plants. (orig./MG) [Deutsch] In Laborversuchen wurden Emissionsraten biogener Kohlenwasserstoffe von Sonnenblumen gemessen. Die groessten Emissionsraten wiesen die

  3. Stress level of people with psoriasis at a public hospital*

    Leovigildo, Érida Silva; David, Rose Ana Rios; Mendes, Andreia Santos


    Background Psoriasis is a chronic dermatosis of unknown etiology with a tendency to relapse after treatment. The disease is frequently linked to psychological stress due to the embarrassment caused by the lesions. Objective To analyze the stress level presented by psoriasis patients followed at the Dermatology Service of a public hospital in Salvador, Bahia state, Brazil. Methods A cross-sectional study of a consecutive convenience sample composed of 60 participants. We used Lipp's Stress Symptoms Inventory for Adults to assess stress levels. The questionnaire identifies and classifies physical and psychological symptoms according to three stages of stress: alarming, resistance, and exhaustion. We also collected socio-demographic and clinical data that could be associated with psoriasis. Results 85% of the participants presented stress. Lipp's questionnaire results revealed that 48% were in the resistance stage and 37% in the exhaustion stage. Women presented higher levels of stress. Of the total 28 women, 64% were in exhaustion stage, 29% in the resistance stage, and only 7% presented no stress symptoms. Of the total 32 men, 44% were in resistance stage, 34% in exhaustion stage, and 22% presented no stress symptoms. Regarding physical and psychological symptoms, psychological symptomatology was prevalent (55%). Conclusions Based on the number of patients in exhaustion stage, we can conclude that stress levels of the participants were high regardless the type of psoriasis and treatment duration. PMID:27579739

  4. Levels of occupational stress and stressful activities for nurses working in emergency

    José Ricardo Ferreira da Fonseca


    Full Text Available The study aimed to identify stress levels, areas and their activities identified as stressful by nurses working in the emergence in Manaus, AM, Brazil. It is an epidemiological, cross-sectional design, with 36 emergency nurses from December 2010 to January 2011. The Bianchi Stress Scale with 57 questions was used. The nurses were at risk for high levels of stress. The most stressful areas were the operation of the unit, conditions of work and personnel administration, and the most stressful activity was the request for equipment review and repair. The difference by Friedman test between the areas was significant (p <0.05, Dunn post-test significant (p <0.05 when compared by peers. The accumulation of management activities with the assistance activities can generate higher levels of stress, it is necessary to invest in improving the work environment and management support to minimize the stress experienced at work.

  5. The interplay of stress and sleep impacts BDNF level.

    Maria Giese

    Full Text Available BACKGROUND: Sleep plays a pivotal role in normal biological functions. Sleep loss results in higher stress vulnerability and is often found in mental disorders. There is evidence that brain-derived neurotrophic factor (BDNF could be a central player in this relationship. Recently, we could demonstrate that subjects suffering from current symptoms of insomnia exhibited significantly decreased serum BDNF levels compared with sleep-healthy controls. In accordance with the paradigm indicating a link between sleep and BDNF, we aimed to investigate if the stress system influences the association between sleep and BDNF. METHODOLOGY/PRINCIPAL FINDINGS: Participants with current symptoms of insomnia plus a former diagnosis of Restless Legs Syndrome (RLS and/or Periodic Limb Movement (PLM and sleep healthy controls were included in the study. They completed questionnaires on sleep (ISI, Insomnia Severity Index and stress (PSS, Perceived Stress Scale and provided a blood sample for determination of serum BDNF. We found a significant interaction between stress and insomnia with an impact on serum BDNF levels. Moreover, insomnia severity groups and score on the PSS each revealed a significant main effect on serum BDNF levels. Insomnia severity was associated with increased stress experience affecting serum BDNF levels. Of note, the association between stress and BDNF was only observed in subjects without insomnia. Using a mediation model, sleep was revealed as a mediator of the association between stress experience and serum BDNF levels. CONCLUSIONS: This is the first study to show that the interplay between stress and sleep impacts BDNF levels, suggesting an important role of this relationship in the pathogenesis of stress-associated mental disorders. Hence, we suggest sleep as a key mediator at the connection between stress and BDNF. Whether sleep is maintained or disturbed might explain why some individuals are able to handle a certain stress load while

  6. Stress Levels of Nurses in Oncology Outpatient Units.

    Ko, Woonhwa; Kiser-Larson, Norma


    Oncology nursing is often a source of substantial stress for nurses. Many nurses, particularly novice nurses, have inadequate preparation to care for patients at the end of life and their families. Unless nurses prevent or manage work-related stress by using effective coping strategies, oncology nursing staff will continue to suffer from burnout and compassion fatigue. The purpose of this article is to identify stress levels and stressful factors of nurses working in oncology outpatient units and to explore coping behaviors for work-related stress of oncology staff nurses in outpatient units. A descriptive, cross-sectional design was used to identify stress levels and stressful factors for outpatient oncology nurses, investigate differences in stress levels among nurses' demographic characteristics, and explore coping behaviors of the nurses. Study participants (N = 40) included RNs and licensed practical nurses who completed the Nursing Stress Scale, three open-ended questions, and a demographic questionnaire. The highest sources of stress were workload and patient death and dying. Demographic variables of age and work experience in nursing showed a significant positive relationship to work-related stress scores. The three most frequently used coping behaviors were verbalizing, exercising or relaxing, and taking time for self. Continuing education programs on stress management are highly recommended. Outpatient oncology nurses should be nurtured and supported through tailored interventions at multiple levels to help them find effective coping strategies and develop self-care competencies. Although younger and less experienced nurses had lower mean stress scores than older and more experienced nurses, the continuing education programs and tailored interventions would be helpful for all oncology nursing staff.

  7. Measuring Interlayer Shear Stress in Bilayer Graphene

    Wang, Guorui; Dai, Zhaohe; Wang, Yanlei; Tan, PingHeng; Liu, Luqi; Xu, Zhiping; Wei, Yueguang; Huang, Rui; Zhang, Zhong


    Monolayer two-dimensional (2D) crystals exhibit a host of intriguing properties, but the most exciting applications may come from stacking them into multilayer structures. Interlayer and interfacial shear interactions could play a crucial role in the performance and reliability of these applications, but little is known about the key parameters controlling shear deformation across the layers and interfaces between 2D materials. Herein, we report the first measurement of the interlayer shear stress of bilayer graphene based on pressurized microscale bubble loading devices. We demonstrate continuous growth of an interlayer shear zone outside the bubble edge and extract an interlayer shear stress of 40 kPa based on a membrane analysis for bilayer graphene bubbles. Meanwhile, a much higher interfacial shear stress of 1.64 MPa was determined for monolayer graphene on a silicon oxide substrate. Our results not only provide insights into the interfacial shear responses of the thinnest structures possible, but also establish an experimental method for characterizing the fundamental interlayer shear properties of the emerging 2D materials for potential applications in multilayer systems.

  8. Stress levels of psychiatric nursing staff

    Looff, P.C. de; Kuijpers, E.; Nijman, H.L.I.


    During a total of 30 shifts, the arousal levels of 10 psychiatric nurses were assessed while working on a (forensic) psychiatric admissions ward. Arousal was assessed by means of a small device (wristband) by which the Skin Conductance Level (SCL) of the participating nurses was monitored. Each nurs

  9. Stress levels of psychiatric nursing staff

    Looff, P.C. de; Kuijpers, E.; Nijman, H.L.I.


    During a total of 30 shifts, the arousal levels of 10 psychiatric nurses were assessed while working on a (forensic) psychiatric admissions ward. Arousal was assessed by means of a small device (wristband) by which the Skin Conductance Level (SCL) of the participating nurses was monitored. Each

  10. Neutron stress measurement of W-fiber reinforced Cu composite

    Nishida, M; Ikeuchi, Y; Minakawa, N


    Stress measurement methods using neutron and X-ray diffraction were examined by comparing the surface stresses with internal stresses in the continuous tungsten-fiber reinforced copper-matrix composite. Surface stresses were measured by X-ray stress measurement with the sin sup 2 psi method. Furthermore, the sin sup 2 psi method and the most common triaxal measurement method using Hooke's equation were employed for internal stress measurement by neutron diffraction. On the other hand, microstress distributions developed by the difference in the thermal expansion coefficients between these two phases were calculated by FEM. The weighted average strains and stresses were compared with the experimental results. The FEM results agreed with the experimental results qualitatively and confirmed the importance of the triaxial stress analysis in the neutron stress measurement. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  11. Towards ambulatory mental stress measurement from physiological parameters

    Wijsman, J.L.P; Vullers, Ruud; Polito, Salvatore; Agell, Carlos; Penders, Julien; Hermens, Hermanus J.

    Ambulatory mental stress monitoring requires longterm physiological measurements. This paper presents a data collection protocol for ambulatory recording of physiological parameters for stress measurement purposes. We present a wearable sensor system for ambulatory recording of ECG, EMG, respiration

  12. Towards ambulatory mental stress measurement from physiological parameters

    Wijsman, Jacqueline; Vullers, Ruud; Polito, Salvatore; Agell, Carlos; Penders, Julien; Hermens, Hermie


    Ambulatory mental stress monitoring requires longterm physiological measurements. This paper presents a data collection protocol for ambulatory recording of physiological parameters for stress measurement purposes. We present a wearable sensor system for ambulatory recording of ECG, EMG, respiration

  13. Evapotranspiration Modeling and Measurements at Ecosystem Level

    Sirca, C.; Snyder, R. L.; Mereu, S.; Kovács-Láng, E.; Ónodi, G.; Spano, D.


    In recent years, the availability of reference evapotranspiration (ETo) data is greatly increased. ETo, in conjunction with coefficients accounting for the difference between the vegetation and the reference surface, provides estimation of the actual evapotranspiration (ETa). The coefficients approach was applied in the past mainly for crops, due the lack of experimental data and difficulties to account for terrain and vegetation variability in natural ecosystems. Moreover, the assessment of ETa over large spatial scale by measurements is often time consuming, and requires several measurement points with relatively expensive and sophisticated instrumentation and techniques (e.g. eddy covariance). The Ecosystem Water Program (ECOWAT) was recently developed to help estimates of ETa of ecosystems by accounting for microclimate, vegetation type, plant density, and water stress. ETa on natural and semi-natural ecosystems has several applications, e.g. water status assessment, fire danger estimation, and ecosystem management practices. In this work, results obtained using ECOWAT to assess ETa of a forest ecosystem located in Hungary are reported. The site is a part of the EU-FP7 INCREASE project, which aims to study the effects of climate change on European shrubland ecosystems. In the site, a climate manipulation experiment was setted up to have a warming and a drought treatment (besides the control). Each treatment was replicated three times We show how the ECOWAT model performed when the predicted actual evapotranspiration is compared with actual evapotranspiration obtained from Surface Renewal method and with soil moisture measurements. ECOWAT was able to capture the differences in the water balance at treatment level, confirming its potential as a tool for water status assessment. For the Surface Renewal method, high frequency temperature data were collected to estimate the sensible heat flux (H'). The net radiation (Rn) and soil heat flux density (G) were also

  14. European adolescents' level of perceived stress and its relationship with body adiposity--the HELENA Study.

    De Vriendt, Tineke; Clays, Els; Maes, Lea; De Bourdeaudhuij, Ilse; Vicente-Rodriguez, Germàn; Moreno, Luis A; Nagy, Eniko; Molnár, Dénes; Ortega, Francisco B; Dietrich, Sabine; Manios, Yannis; De Henauw, Stefaan


    Since stress is hypothesized to be involved in the aetiology of obesity, the present study examined the current perception of stress in European adolescents and the association between adolescent perceived stress and their adiposity. Observational data from 1121 adolescents aged 12.5-17.5 years from six European cities involved in the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional study, was investigated. The adolescents completed the adolescent stress questionnaire, comprising 10 different stress dimensions. Anthropometric measurements (weight, height, skinfold thicknesses and circumferences) and bioelectrical impedance analysis were performed, and personal characteristics (age, pubertal stage and parental education) were collected. The measures of perceived stress were described for boys and girls separately and gender differences were investigated. Associations between the adolescents' perceived stress and indicators of general (body mass index z-score, sum of skinfold thicknesses and body fat%) and abdominal (waist and hip circumference, and waist/height ratio) adiposity were examined using hierarchical linear models. While girls reported systematically higher levels of stress compared with boys, their stress profiles were similar, with highest levels for school-related stress followed by future uncertainty. Only in girls, perceived stress was significantly associated with increased measures of general and abdominal adiposity. In boys, no relationship between perceived stress and adiposity measures was observed. School is reported to be an important source of adolescent stress and should be the focus of stress management campaigns. Only in girls, the hypothesis that stress might be involved in the aetiology of obesity during adolescence was supported.

  15. Anxiety and Stress Levels on Liver Transplantation Candidates.

    Teixeira, H R S; Marques, D M; Lopes, A R F; Ziviani, L C; Magro, J T J; Mente, Ênio D; Castro-E-Silva, O; Galvão, C M; Mendes, K D S


    The objective of the present study was to determine the anxiety and stress levels of liver transplant candidates during the preoperative period. A cross-sectional, prospective study was conducted on 52 liver transplantation candidates seen at a specialized public hospital outpatient clinic in the interior of the state of São Paulo, Brazil. Data were collected from November 2014 to April 2015 using a self-applicable questionnaire for the assessment of anxiety (State-Trait Anxiety Inventory, short version) and stress (Perceived Stress Scale), in addition to sociodemographic and clinic characterization. The mean (±SD) anxiety level detected was 23.06 ± 5.51 points, with 1.92% of the subjects showing minimum levels (0 to 12 points), 59.62% a medium level (12 to 24 points), 36.54% a moderate level (24 to 36 points), and 1.92% a severe level (36 to 48 points) of anxiety. The mean level on the stress scale was 12.10 ± 5.62 points, with 7.69% of the subjects showing high stress levels. When individuals with good and poor stress levels were compared, a significant difference was observed between them (P = .0004). The Spearman correlation test showed that the higher the stress, the higher the levels of anxiety (r = 0.4258), P stress levels since the waiting period for the organ generates emotional changes that can affect the quality of life of the patient and the success of this complex therapeutic modality. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Study on determination of stress level by seismic stress drops and the stress axis deflections before and after large earthquakes

    WAN Yong-ge


    To obtain the stress level at the earthquake source, this paper sets forth the solution of the stress magnitude at the earthquake source by seismic stress drop and the stress axis deflections before and after large earthquakes. The pre-seismic and post-seismic stress direction can be statistically determined by a large collection of foreshock and aftershock focal mechanism data while the stress drop can be determined through the source fracture inversion from seismic wave data or crust deformation data. The paper attempts to make a fundamental contribution to seismic dynamics.

  17. The Level of Stress in Male and Female School Students

    Khan, Zamirullah; Lanin, Abul Barkat; Ahmad, Naseem


    This study aimed at the level of stress in male and female school students. For the purpose of the study the researcher randomly selected 64 school students aged between 14-18 years. To collect the data researcher used students stress scale (SSS) developed by Dr. Zaki Akhtar (2011). During collection of data researcher used means and method fit…

  18. Stress level and academic performance of university students in ...

    Stress level and academic performance of university students in Kwara State, Nigeria. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES ... organize stress management seminars and workshops in collaboration with the Counselling and Human Development department.

  19. Plasma cortisol levels in malnourished children with and without superimposed acute stress

    Paisey, R. B.; Angers, Marielena; Frenk, S.


    Plasma cortisol levels were measured in 13 children with marasmus, in 7 with kwashiorkor, and in 24 normal children. Cortisol levels in the malnourished children did not differ from those of the normal group, either before or after 15 or 30 days of treatment, unless there was superimposed acute stress. Stress caused by complications such as hypoglycaemia, infection, hypothermia, or acidosis led to raised plasma cortisol levels. PMID:4733640

  20. Elevated stress hormone levels relate to Epstein-Barr virus reactivation in astronauts

    Stowe, R. P.; Pierson, D. L.; Barrett, A. D.


    OBJECTIVE: The objective of this study was to determine the effects of stress and spaceflight on levels of neuroendocrine hormones and Epstein-Barr virus (EBV)-specific antibodies in astronauts. METHODS: Antiviral antibody titers and stress hormones were measured in plasma samples collected from 28 astronauts at their annual medical exam (baseline), 10 days before launch (L-10), landing day (R+0), and 3 days after landing (R+3). Urinary stress hormones were also measured at L-10 and R+0. RESULTS: Significant increases (p stresses associated with spaceflight resulted in decreased virus-specific T-cell immunity and reactivation of EBV.

  1. Association among stress, salivary cortisol levels, and chronic periodontitis.

    Refulio, Zoila; Rocafuerte, Marco; de la Rosa, Manuel; Mendoza, Gerardo; Chambrone, Leandro


    Chronic periodontitis (CP) seems to be associated with stress and depression, but little information on this possible association is available in the literature. Thus, the objective of this study was to evaluate the association among stress, the salivary cortisol level (SCL), and CP. Seventy systemically healthy subjects were included in the study from January to September 2011. Full medical and dental histories were obtained, and the following measurements were recorded: 1) probing depth; 2) clinical attachment level; 3) bleeding on probing; and 4) tooth mobility. Saliva samples were collected for the evaluation of SCL (via a highly sensitive electrochemiluminescence immunoassay), and all subjects also answered a questionnaire (i.e., the Zung Self-rating Depression Scale). The odds ratio (OR) with a 95% confidence interval (CI) was calculated, and one way analysis of variance and the Tukey-Kramer method were performed. A total of 36 subjects with CP (51.4%) and 34 without CP were evaluated. Of them, all of the subjects with CP and one periodontally healthy subject were diagnosed with depression. Subjects with moderate CP had statistically significantly higher levels of SCL than subjects with a diagnosis of slight CP (P=0.006). Also, subjects with severe CP showed the same outcome when compared to those with slight CP (P=0.012). In addition, 46 subjects presented high SCL whereas 24 had a normal level. CP was found to be correlated with the SCL, with an OR of 4.14 (95% CI, 1.43 to 12.01). Subjects with a high SCL and depression may show an increased risk for CP.

  2. Residual Stress Determination from a Laser-Based Curvature Measurement

    Swank, William David; Gavalya, Rick Allen; Wright, Julie Knibloe; Wright, Richard Neil


    Thermally sprayed coating characteristics and mechanical properties are in part a result of the residual stress developed during the fabrication process. The total stress state in a coating/substrate is comprised of the quench stress and the coefficient of thermal expansion (CTE) mismatch stress. The quench stress is developed when molten particles impact the substrate and rapidly cool and solidify. The CTE mismatch stress results from a large difference in the thermal expansion coefficients of the coating and substrate material. It comes into effect when the substrate/coating combination cools from the equilibrated deposit temperature to room temperature. This paper describes a laser-based technique for measuring the curvature of a coated substrate and the analysis required to determine residual stress from curvature measurements. Quench stresses were determined by heating the specimen back to the deposit temperature thus removing the CTE mismatch stress. By subtracting the quench stress from the total residual stress at room temperature, the CTE mismatch stress was estimated. Residual stress measurements for thick (>1mm) spinel coatings with a Ni-Al bond coat on 304 stainless steel substrates were made. It was determined that a significant portion of the residual stress results from the quenching stress of the bond coat and that the spinel coating produces a larger CTE mismatch stress than quench stress.

  3. Drinking behaviors by stress level in Korean university students.

    Chung, Hye-Kyung; Lee, Hae-Young


    The purposes of this study are to estimate the stress level of university students, and to verify the relationships between stress level and drinking behavior. A questionnaire survey was administered to 430 university students in the Gangwon area in Korea from November 5 to November 28, 2008, and data from 391 students were used for the final statistical analysis. The most stressful factor was "Worry about academic achievements" (2.86 by Likert-type 4 point scale). The subjects were divided into two groups, a low stress group (≤ 65.0) and a high stress group (≥ 66.0), by the mean value (65.1) and median value (66.0) of the stress levels. The drinking frequency was not different between the two stress groups, but the amount of alcohol consumption was significantly different (P negatively correlated with drinking frequency and the amount of alcohol consumption (P negatively correlated with the amount of drinking (P effect of drinking was "Drinking enables me to get together with people and shape my sociability" (2.73). The higher stress group showed significantly higher scores on several items in the categories of motives (P negative experience (P effects (P alcohol consumption.

  4. Measurement of residual stresses using fracture mechanics weight functions

    Fan, Y. [Bettis Atomic Power Laboratory, West Mifflin, PA (United States)


    A residual stress measurement method has been developed to quantify through-the-thickness residual stresses. Accurate measurement of residual stresses is crucial for many engineering structures. Fabrication processes such as welding and machining generate residual stresses that are difficult to predict. Residual stresses affect the integrity of structures through promoting failures due to brittle fracture, fatigue, stress corrosion cracking, and wear. In this work, the weight function theory of fracture mechanics is used to measure residual stresses. The weight function theory is an important development in computational fracture mechanics. Stress intensity factors for arbitrary stress distribution on the crack faces can be accurately and efficiently computed for predicting crack growth. This paper demonstrates that the weight functions are equally useful in measuring residual stresses. In this method, an artificial crack is created by a thin cut in a structure containing residual stresses. The cut relieves the residual stresses normal to the crack-face and allows the relieved residual stresses to deform the structure. Strain gages placed adjacent to the cut measure the relieved strains corresponding to incrementally increasing depths of the cut. The weight functions of the cracked body relate the measured strains to the residual stresses normal to the cut within the structure. The procedure details, such as numerical integration of the singular functions in applying the weight function method, will be discussed. (author)

  5. Characterization of cardiac oxidative stress levels in patients with atrial fibrillation.

    Okada, Ayako; Kashima, Yuichiro; Tomita, Takeshi; Takeuchi, Takahiro; Aizawa, Kazunori; Takahashi, Masafumi; Ikeda, Uichi


    Atrial fibrillation (AF) is associated with oxidative stress and elevated brain natriuretic peptide (BNP) levels. However, the exact cardiac origin of oxidative stress and its association with BNP levels in AF patients remain unclear. Therefore, we investigated the chamber-specific plasma oxidative stress levels in patients with paroxysmal AF (PAF) and persistent AF (PSAF). Diacron-reactive oxygen metabolite (dROM) levels were measured in patients with PAF (n = 50) and PSAF (n = 35) at different cardiac sites before ablation and in peripheral vein 3 months after ablation. For all sites, dROM levels were higher in PSAF patients than in PAF patients; the levels were the highest in the coronary sinus at 429.0 (interquartile range: 392.0-449.0) vs. 374.0 (357.0-397.8) Carratelli units (P levels in the coronary sinus were related to the BNP levels (r = 0.436, P levels was related to that in the peripheral BNP levels in patients with symptomatic improvement (r = 0.473, P stress may either be a cause or consequence of prolonged AF, and cardiac oxidative stress levels correlated with BNP levels, though a possible source of oxidative stress in AF patients may be systemic circulation.

  6. Hardiness Mediates Stress and Impact Level in ED Nurses Who Experienced a Violent Event.

    Park, Jin Hee; Lee, Eun Nam; Kong, Kyung Ran; Jang, Moon Jung


    This secondary analysis examined the mediating effect of hardiness between stress and impact level in ED nurses who experienced a violent event. This correlational study was conducted from June to August 2014. We used the visual analog scale to measure stress level, the Impact of Event Scale-Revised to measure impact level after the violent event, and the Dispositional Resilience Scale to measure hardiness. We then analyzed mediating effects with the Sobel test. Data were collected in 31 emergency medical centers located in B city in Korea. Data from 321 ED nurses who experienced a violent event were analyzed. Most nurses (91.9%) were women, with a mean age of 28.73 years. The main outcome measure was the mediating effect of hardiness between stress and impact level after ED nurses experienced violence. We found that both violence-related stress (B = 0.22, P event. Based on results of a Sobel test, hardiness partially mediated the relationship between violence-related stress and impact level from a violent event (Z = 2.03, P = .044). Hardiness had an effect on reducing the impact level of ED nurses who had experienced a violent event and had a mediating role in mitigating their stress. Therefore, we recommend the development of an intervention program that emphasizes the improvement of hardiness in ED nurses. Copyright © 2017 Emergency Nurses Association. Published by Elsevier Inc. All rights reserved.

  7. Analytical Investigation for In Situ Stress Measurement with Rheological Stress Recovery Method and Its Application

    Quansheng Liu


    Full Text Available In situ stress is one of the most important parameters in underground engineering. Due to the difficulty and weakness of current stress measurement methods in deep soft rock, a new one, rheological stress recovery (RSR method, to determine three-dimensional stress tensor is developed. It is supposed that rock stresses will recover gradually with time and can be measured by embedding transducers into the borehole. In order to explore the relationship between the measured recovery stress and the initial stress, analytical solutions are developed for the stress measurement process with RSR method in a viscoelastic surrounding rock. The results showed that the measured recovery stress would be more close to the initial stress if the rock mass has a better rheological property, and the property of grouting material should be close to that of rock mass. Then, the RSR method, as well as overcoring technique, was carried out to measure the in situ stresses in Pingdingshan Number 1 coal mines in Henan Province, China. The stress measurement results are basically in the same order, and the major principal stresses are approximately in the direction of NW-SE, which correlates well with the stress regime of Pingdingshan zone known from the tectonic movement history.

  8. A Wireless Fluid-Level Measurement Technique

    Woodard, Stanley E.; Taylor, Bryant D.


    This paper presents the application of a recently developed wireless measurement acquisition system to fluid-level measurement. This type of fluid-level measurement system alleviates many shortcomings of fluid-level measurement methods currently being used, including limited applicability of any one fluid-level sensor design. Measurement acquisition shortcomings include the necessity for power to be supplied to each sensor and for the measurement to be extracted from each sensor via a physical connection to the sensor. Another shortcoming is existing measurement systems require that a data channel and signal conditioning electronics be dedicated to each sensor. Use of wires results in other shortcomings such as logistics needed to add or replace sensors, weight, potential for electrical arcing and wire degradations. The fluid level sensor design is a simple passive inductor-capacitor circuit that is not subject to mechanical failure that is possible when float and lever-arm systems are used. Methods are presented for using the sensor in caustic, acidic or cryogenic fluids. Oscillating magnetic fields are used to power the sensor. Once electrically excited, the sensor produces a magnetic field response. The response frequency corresponds to the amount to fluid within the capacitor s electric field. The sensor design can be modified for measuring the level of any fluid or fluent substance that can be stored in a non-conductive reservoir. The interrogation method for discerning changes in the sensor response frequency is also presented.

  9. Realtime 3D stress measurement in curing epoxy packaging

    Richter, Jacob; Hyldgård, A.; Birkelund, Karen;


    This paper presents a novel method to characterize stress in microsystem packaging. A circular p-type piezoresistor is implemented on a (001) silicon chip. We use the circular stress sensor to determine the packaging induced stress in a polystyrene tube filled with epoxy. The epoxy curing process...... is monitored by stress measurements. From the stress measurements we conclude that the epoxy cures in 8 hours at room temperature. We find the difference in in-plane normal stresses to be sigmaxx-sigmayy=6.7 MPa and (sigmaxx+sigmayy-0.4sigmazz)=232 MPa....

  10. Assessing maize foliar water stress levels under field conditions ...

    Assessing maize foliar water stress levels under field conditions using in-situ ... is non-destructive to the crops as opposed to other traditional ground-based methods. ... water indices that could monitor the water status at leaf level on maize (Zea ... about AJOL · AJOL's Partners · Contact AJOL · Terms and Conditions of Use.

  11. Estimation of the Level of Residual Stress in Wires with a Magnetic Method

    Suliga M.


    Full Text Available Residual stress present in wires after drawing process affects their magnetic properties. The paper presents a concept to estimate the level of residual stress on the basis of measurements of hysteresis loops. In order to describe the effect qualitatively the Jiles-Atherton-Sablik description is adapted. On the basis of variations in hysteresis loop shapes the average values of residual stress in wires for different single draft values are determined. It was found that the estimated average values by magnetic stresses are comparable with the results of numerical modeling and experimental studies.

  12. Measuring nonlinear stresses generated by defects in 3D colloidal crystals

    Lin, Neil Y C; Schall, Peter; Sethna, James P; Cohen, Itai


    The mechanical, structural and functional properties of crystals are determined by their defects and the distribution of stresses surrounding these defects has broad implications for the understanding of transport phenomena. When the defect density rises to levels routinely found in real-world materials, transport is governed by local stresses that are predominantly nonlinear. Such stress fields however, cannot be measured using conventional bulk and local measurement techniques. Here, we report direct and spatially resolved experimental measurements of the nonlinear stresses surrounding colloidal crystalline defect cores, and show that the stresses at vacancy cores generate attractive interactions between them. We also directly visualize the softening of crystalline regions surrounding dislocation cores, and find that stress fluctuations in quiescent polycrystals are uniformly distributed rather than localized at grain boundaries, as is the case in strained atomic polycrystals. Nonlinear stress measurements ...

  13. Estradiol levels modulate brain activity and negative responses to psychosocial stress across the menstrual cycle.

    Albert, Kimberly; Pruessner, Jens; Newhouse, Paul


    Although ovarian hormones are thought to have a potential role in the well-known sex difference in mood and anxiety disorders, the mechanisms through which ovarian hormone changes contribute to stress regulation are not well understood. One mechanism by which ovarian hormones might impact mood regulation is by mediating the effect of psychosocial stress, which often precedes depressive episodes and may have mood consequences that are particularly relevant in women. In the current study, brain activity and mood response to psychosocial stress was examined in healthy, normally cycling women at either the high or low estradiol phase of the menstrual cycle. Twenty eight women were exposed to the Montreal Imaging Stress Task (MIST), with brain activity determined through functional magnetic resonance imaging, and behavioral response assessed with subjective mood and stress measures. Brain activity responses to psychosocial stress differed between women in the low versus high estrogen phase of the menstrual cycle: women with high estradiol levels showed significantly less deactivation in limbic regions during psychosocial stress compared to women with low estradiol levels. Additionally, women with higher estradiol levels also had less subjective distress in response to the MIST than women with lower estradiol levels. The results of this study suggest that, in normally cycling premenopausal women, high estradiol levels attenuate the brain activation changes and negative mood response to psychosocial stress. Normal ovarian hormone fluctuations may alter the impact of psychosocially stressful events by presenting periods of increased vulnerability to psychosocial stress during low estradiol phases of the menstrual cycle. This menstrual cycle-related fluctuation in stress vulnerability may be relevant to the greater risk for affective disorder or post-traumatic stress disorder in women. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Factors Associated With High Levels of Perceived Prenatal Stress Among Inner-City Women.

    Rieger, Kendra L; Heaman, Maureen I


    To explore the factors associated with high rates of perceived prenatal stress among inner-city women. Observational cross-sectional study. We conducted a secondary analysis of data from 603 inner-city women. In our study, 330 participants (54.7%) self-identified as First Nations, Metis, or First Nations/Metis. Prenatal stress was measured with Cohen's Perceived Stress Scale. A social ecological model provided the theoretical framework for the study, and variables representing all levels of the model were selected for study. Data analyses included t tests to compare women with high stress and low/moderate stress, univariable logistic regression analysis to determine the association of selected factors with maternal stress, and multivariable logistic regression analysis to provide adjusted odds ratios and 95% confidence intervals for the factors. Of the 603 participants, 17.2% (104) reported high levels of perceived stress, and 82.8% (499) reported low/moderate levels. The high-stress group included a significantly greater proportion of First Nations, Metis, or First Nations/Metis women (76.0%) than the low/moderate-stress group (50.3%). Low rates of self-esteem and social support, residential mobility, abuse before/during pregnancy, and experiencing discrimination were significantly associated with high levels of perceived prenatal stress. Our findings demonstrated that factors that influence prenatal stress occur at all levels of the social ecological model. The identified factors are amenable to change, and implications for practice include the need for psychosocial risk assessment, alternative forms of prenatal care, relational care, and advocacy initiatives. A greater understanding of the complex factors associated with high rates of perceived prenatal stress can inform the development of effective interventions for inner-city women. Copyright © 2016 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses. Published by Elsevier Inc. All rights

  15. Plasma levels of oxidative stress-responsive apoptosis inducing protein (ORAIP) in rats subjected to physicochemical oxidative stresses.

    Yao, Takako; Fujimura, Tsutomu; Murayama, Kimie; Seko, Yoshinori


    Oxidative stress is known to play a pivotal role in the pathogenesis of various disorders including atherosclerosis, aging and especially ischaemia/reperfusion injury. It causes cell damage that leads to apoptosis. However, the precise mechanism has been uncertain. Recently, we identified an apoptosis-inducing humoral factor in a hypoxia/reoxygenated medium of cardiac myocytes. We named this novel post-translationally modified secreted form of eukaryotic translation initiation factor 5A (eIF5A) as oxidative stress-responsive apoptosis inducing protein (ORAIP). We developed a sandwich ELISA and confirmed that myocardial ischaemia/reperfusion markedly increased plasma levels of ORAIP. To investigate whether the role of ORAIP is common to various types of oxidative stress, we measured plasma ORAIP levels in rats subjected to three physicochemical models of oxidative stress including N2/O2 inhalation, cold/warm-stress (heat shock) and blood acidification. In all three models, plasma ORAIP levels significantly increased and reached a peak level at 10-30 min after stimulation, then decreased within 60 min. The (mean±S.E.M.) plasma ORAIP levels before and after (peak) stimulation were (16.4±9.6) and (55.2±34.2) ng/ml in N2/O2 inhalation, (14.1±12.4) and (34.3±14.6) ng/ml in cold/warm-stress, and (18.9±14.3) and (134.0±67.2) ng/ml in blood acidification study. These data strongly suggest that secretion of ORAIP in response to oxidative stress is universal mechanism and plays an essential role. ORAIP will be an important novel biomarker as well as a specific therapeutic target of these oxidative stress-induced cell injuries. © 2016 The Author(s).

  16. Evaluation and correlation of stress scores with blood pressure, endogenous cortisol levels, and homocysteine levels in patients with central serous chorioretinopathy and comparison with age-matched controls.

    Agarwal, Abhishek; Garg, Monika; Dixit, Nikhil; Godara, Rohini


    Stress had been associated with the development of central serous chorioretinopathy (CSC). The study was designed to evaluate the effect of stress on other risk factors of CSC such as serum cortisol levels, serum homocysteine levels, and blood pressure (BP) in CSC patients. To compare stress scores, serum cortisol and serum homocysteine levels, and BP of CSC patients with that of control population and to correlate stress scores of CSC patients with BP, serum cortisol levels, and serum homocysteine levels. Stress scores, serum morning and evening cortisol levels, serum homocysteine levels, systolic and diastolic BP of 54 CSC patients were measured and compared with that of 54 age- and sex-related controls using Student's t-test. Stress scores of CSC patients were correlated with systolic and diastolic BP, serum morning and evening cortisol levels and serum homocysteine levels and Pearson correlation coefficient (r) were calculated. Stress scores, serum homocysteine levels, serum morning and evening cortisol levels, and systolic and diastolic BP were all elevated in CSC patients as compared with age- and sex-related controls (P Stress scores of CSC patients were found to correlate strongly with serum homocysteine levels, serum morning and evening cortisol levels, and systolic and diastolic BP, with r values 0.82, 0.8, 0.8, 0.8, and 0.81, respectively (P Stress scores were elevated in CSC patients and were strongly correlated with serum homocysteine and cortisol levels and BP.

  17. Prevalence of stress level among Bank employees in urban Puducherry, India

    S Ganesh Kumar


    Full Text Available Background and Objective: Stress is an important health area of concern among bank employees. The study aims to assess the stress level and its associated factors among bank employees. Materials and Methods: A cross-sectional study was conducted among 192 bank employees in urban Puducherry, India. Stress level was assessed by Cohen′s Perceived Stress scale and classified into low (0-11, average (12-15, high (16-20, and very high (21 and above based on the stress scores. Collected data were analyzed by using univariate analysis. Results: Majority of them had high and very high level of stress (75.5%, confidence interval: 69.4-81.6%. The variables that include age group, sex, category of work, smoking and alcohol use were not found to be significantly associated with the stress level (P > 0.05. With respect to question items, handling personal problems and things were going their way were answered as fairly often and very often by the majority of the subjects. Conclusion: Stress level among bank employees is high, which necessitates intervention measures for this vulnerable group.

  18. StressPhone: smartphone based platform for measurement of cortisol for stress detection (Conference Presentation)

    Jain, Aadhar; Rey, Elizabeth; Lee, Seoho; O'Dell, Dakota; Erickson, David


    Anxiety disorders are estimated to be the most common mental illness in US affecting around 40 million people and related job stress is estimated to cost US industry up to $300 billion due to lower productivity and absenteeism. A personal diagnostic device which could help identify stressed individuals would therefore be a huge boost for workforce productivity. We are therefore developing a point of care diagnostic device that can be integrated with smartphones or tablets for the measurement of cortisol - a stress related salivary biomarker, which is known to be strongly involved in body's fight-or-flight response to a stressor (physical or mental). The device is based around a competitive lateral flow assay whose results can then be read and quantified through an accessory compatible with the smartphone. In this presentation, we report the development and results of such an assay and the integrated device. We then present the results of a study relating the diurnal patterns of cortisol levels and the alertness of an individual based on the circadian rhythm and sleep patterns of the individual. We hope to use the insight provided by combining the information provided by levels of stress related to chemical biomarkers of the individual with the physical biomarkers to lead to a better informed and optimized activity schedule for maximized work output.

  19. Measuring type II stresses using 3DXRD

    Oddershede, Jette; Schmidt, Søren; Poulsen, Henning Friis;


    An algorithm is presented for characterization of the grain resolved (type II) stress states in a polycrystalline sample based on monochromatic X-ray diffraction data. The algorithm is a robust 12-parameter-per-grain fit of the centre-of-mass grain positions, orientations and stress tensors...

  20. Measuring Bus Drivers' Occupational Stress Under Changing Working Conditions

    Hlotova, Y.; Cats, O.; Meijer, S.A.


    Stress is an immense problem in modern society; approximately half of all occupational illnesses are directly or indirectly related to stress. The work of a bus driver is typically associated with high stress levels that negatively influence individual well-being as well as workforce management. The

  1. Measuring Bus Drivers' Occupational Stress Under Changing Working Conditions

    Hlotova, Y.; Cats, O.; Meijer, S.A.


    Stress is an immense problem in modern society; approximately half of all occupational illnesses are directly or indirectly related to stress. The work of a bus driver is typically associated with high stress levels that negatively influence individual well-being as well as workforce management. The

  2. Acute Physical Stress Increases Serum Levels of Specific microRNAs.

    Hosoya, Tadashi; Hashiyada, Masaki; Funayama, Masato


    MicroRNA (miR) is non-coding small RNA that regulate mRNA at the post-transcriptional level by degradation or inhibition. To find physical stress markers, we developed a rat model involving a simple and complicated stress and measured serum miR levels. To demonstrate changes in serum miR levels when physical stress is applied, we constructed three stress modalities using rats: alcohol intake, treadmill running and restraint. After alcohol administration, the rats were made to run on a treadmill and some of the rats were further stressed by restraining with a 2 kg water bag immediately after the treadmill run. The rats were grouped as follows: control, run for 20 min, run for 90 min, run and restrained for 20 min, run and restrained for 90 min. Using total RNA extracted from sera, expression levels of eight miRs were measured by real-time PCR. The level of miR-199a was increased by 20 min stress procedures and the levels of miR-1, miR-24a and miR-133a/b were increased by 90 min stress procedures. No change in the levels of miR-208, miR-212 or miR-296-5p was seen under any stress conditions. There was no significant difference between a treadmill run only and a combination of treadmill run and being restrained by a 2 kg water bag. We demonstrated that a combination of these serum miRs might indicate the intensity of stress experienced.

  3. Using Conjugate Gradient Network to Classify Stress Level of Patients.

    Er. S. Pawar


    Full Text Available Diagnosis of stress is important because it can cause many diseases e.g., heart disease, headache, migraine, sleep problems, irritability etc. Diagnosis of stress in patients often involves acquisition of biological signals for example heart rate, electrocardiogram (ECG, electromyography signals (EMG etc. Stress diagnosis using biomedical signals is difficult and since the biomedical signals are too complex to generate any rule an experienced person or expert is needed to determine stress levels. Also, it is not feasible to use all the features that are available or possible to extract from the signal. So, relevant features should be chosen from the extracted features that are capable to diagnose stress. Electronics devices are increasingly being seen in the field of medicine for diagnosis, therapy, checking of stress levels etc. The research and development work of medical electronics engineers leads to the manufacturing of sophisticated diagnostic medical equipment needed to ensure good health care. Biomedical engineering combines the design and problem solving skills of engineering with medical and biological sciences to improve health care diagnosis and treatment.

  4. Galvanic Skin Response as a Measure of Soldier Stress


    in the body have been used as an effective measure of stress, including social stress such as performance in front of an audience (Nater, La Marca ...Lake, CA, 1992. Nater, U. M.; La Marca , R.; Florin, L.; Moses, A.; Langhans, W.; Koller, M. M.; Ehlert, U. Stress-Induced Changes in Human

  5. Reduction in plasma vasopressin levels of dehydrated rats following acute stress

    Keil, L. C.; Severs, W. B.


    Results are presented for an investigation directed to substantiate and extend preliminary findings of stress-induced reduction in plasma arginine vasopressin (pAVP). Since normally hydrated rats have very low levels of pAVP, it is difficult to measure reliably any decrease in pAVP that may result from stress. To overcome this problem, the pAVP levels of the tested rats were raised by dehydration prior to application of stress. A radioimmunoassay for pAVP is described and used to determine the levels of vasopressin in the plasma of nondehydrated and dehydrated rats after exposure to ether or acceleration stress. Plasma pAVP is also determined in rats following nicotine administration. It is shown that exposure of nondehydrated rats to ether or acceleration stress does not elicit any significant alterations in circulating pAVP levels while nicotine injections stimulate a marked increase. In particular, ether and acceleration stress produce a rapid reduction in the pAVP level of dehydrated rats, the decrease being observed in both large and small animals. The mechanism for this reduction in pAVP level following stress is yet unknown.

  6. Effects of a Humor Therapy Program on Stress Levels in Pediatric Inpatients.

    Sánchez, Julio C; Echeverri, Luis F; Londoño, Manuel J; Ochoa, Sergio A; Quiroz, Andrés F; Romero, César R; Ruiz, Joaquín O


    Disease and hospitalization generate stress, which can affect the response to treatment. Humor has been used in many hospitals to decrease stress. The aim of this study was to evaluate the impact of a humor therapy program on stress levels in pediatric inpatients. In the first phase, an intervention and a control group were studied over 2 consecutive 3-month periods; the interventions were performed by a team of artists trained in humor therapy. Salivary cortisol levels were measured by enzyme-linked immunosorbent assay, and the Weisz test, a pictorial chart that determines subjective stress perception, and the Parker test, which assesses objective stress, were applied. In the second phase, salivary cortisol levels were measured and the Weisz test was administered before and after the interventions. A total of 306 patients were recruited into this study: 198 in the first phase (94 in the intervention group and 104 in the nonintervention group) and 108 in the second phase. There were no differences between groups regarding age, sex, or medical diagnosis. The children in the intervention group presented lower cortisol levels, lower scores on the Parker test, and higher scores on the Weisz test than children in the nonintervention group. In the second phase, the children showed lower salivary cortisol levels and higher scores on the Weisz test after the intervention. Humor therapy has beneficial effects on stress and cortisol levels in pediatric inpatients. This supports the implementation and reinforcement of these therapies in pediatric hospitals. Copyright © 2017 by the American Academy of Pediatrics.

  7. The effect of upper gastrointestinal system endoscopy process on serum oxidative stress levels.

    Turan, Mehmet Nuri; Aslan, Mehmet; Bolukbas, Filiz Fusun; Bolukbas, Cengiz; Selek, Sahbettin; Sabuncu, Tevfik


    Some authors have investigated the effects of oxidative stress in some process such as undergoing laparoscopic. However, the effect of upper gastrointestinal system endoscopy process on oxidative stress is unclear. We evaluated the short-term effect of upper gastrointestinal system endoscopy process on oxidative stress. Thirty patients who underwent endoscopy process and 20 healthy controls were enrolled in the prospective study. Serum total antioxidant capacity and total oxidant status measurements were measured before and after endoscopy process. The ratio percentage of total oxidant status to total antioxidant capacity was regarded as oxidative stress index. Before endoscopy process, serum total antioxidant capacity levels were higher, while serum total oxidant status levels and oxidative stress index values were lower in patients than controls, but this difference was not statistically significant (all, p > 0.05). After endoscopy process, serum total antioxidant capacity and total oxidant status levels were significantly higher in patients than before endoscopy process (both, p oxidative stress index values were slight higher in patients but this difference was not statistically significant (p > 0.05). We observed that serum TAC and TOS levels were increased in patients who underwent endoscopy process after endoscopy process. However, short-time upper gastrointestinal system endoscopy process did not cause an important change in the oxidative stress index. Further studies enrolling a larger number of patients are required to clarify the results obtained here.

  8. Stress Measurement with an Improved Hollow Inclusion Technique In Jinchuan Nickel Mine


    Borehole overcoring stress measurement with an improved hollow inclusion technique was carried out at 10 points on 3 levels in Jinchuan nickel mine which is situated in north-west of China. Through the measurement, 3-D in situ stress state at the measuring points and distribution characteristics of the stress field in the mine were obtained. The stress state in Jinchuan mine is dominated by the horizontal tectonic stress field. The maximum principal stress is horizontal which is about twice the weight of the overburden and its orientation is approximately vertical to the regional tectonic line. The difference between two horizontal principal stresses is quite large which is an important reason to cause failure of underground excavations.

  9. Level of Perceived Stress Among Lectures in Nigerian Universities

    Ofoegbu, Felicia; Nwadiani, Mon


    The purpose of the study was to provide empirical evidence on the level of stress among lecturers in Nigerian universities. On the whole eight universities were used for the study. A sample of 228 (123 male and 105 female) lecturers was selected according to the variables of age, sex, marital status, experience, domicile, areas of specialization,…

  10. Level of Perceived Stress Among Lectures in Nigerian Universities

    Ofoegbu, Felicia; Nwadiani, Mon


    The purpose of the study was to provide empirical evidence on the level of stress among lecturers in Nigerian universities. On the whole eight universities were used for the study. A sample of 228 (123 male and 105 female) lecturers was selected according to the variables of age, sex, marital status, experience, domicile, areas of specialization,…

  11. Oxidative stress level and tyrosinase activity in vitiligo patients

    Eskandani M


    Full Text Available Background: Vitiligo is an acquired pigmentary disorder of the skin. Genetic factors, oxidative stress, autoimmunity, and neurochemical agents might be contributing factors for the development of the disease. Aims: To evaluate the oxidative stress level and tyrosinase activity in vitiligo patients and to compare them with healthy volunteers. Materials and Methods: We used Comet assay to evaluate DNA strand breaks in peripheral blood cells of active vitiligo patients. We then extracted total protein from lesional and nonlesional skin of ten selected patients. Tyrosinase activity was found to play a crucial role in melanogenesis. Results: The basal level of systemic oxidative DNA strand breaks in leukocytes increased in vitiligo patients compared to healthy participants. We observed that tyrosinase activity in lesional skin was lower than in nonlesional skin. Conclusion: Our finding suggests that increased levels of oxidative stress might impact tyrosinase activity and eumelanin synthesis via anabolism pathway of melanin synthesis. In sum, we observed a negative correlation between levels of systemic oxidative stress and of tyrosinase activity.

  12. Decreased total antioxidant levels and increased oxidative stress in ...

    aDepartment of Human Biology, Walter Sisulu University, Mthatha, South Africa ... (TAO) levels and oxidative stress in type 2 diabetes mellitus (T2DM) patients with that of .... –70 °C if not analysed on the day of collection and used within a.

  13. Axillary temperature measurement: a less stressful alternative for hospitalised cats?

    Girod, M; Vandenheede, M; Farnir, F; Gommeren, K


    Rectal temperature measurement (RTM) can promote stress and defensive behaviour in hospitalised cats. The aim of this study was to assess if axillary temperature measurement (ATM) could be a reliable and less stressful alternative for these animals. In this prospective study, paired rectal and axillary temperatures were measured in 42 cats, either by a veterinarian or a student. To assess the impact of these procedures on the cat's stress state, their heart rate was checked and a cat stress score (CSS) was defined and graded from 1 (relaxed) to 5 (terrified). A moderate correlation was found between RTM and ATM (r=0.52; Pcats.

  14. Level of occupational stress of court probation officers and style of coping with stress

    Łukasz Wirkus


    Full Text Available Background The relationship between a court probation officer and their ward is a specific one and is frequently connected with enormous individuals costs. This fact is connected with the character of the job, and with the conditions determining its character. Psychosocial threats may influence both mental and somatic health, directly or indirectly, by means of the influence exerted by stress. Participants and procedure The main study was conducted at the offices of the teams of the Court Probation Service. The teams of the Court Probation Service are part of the structure of the following 9, randomly selected, district courts (DCs: DC Wrocław, DC Bydgoszcz, DC Szczecin, DC Poznań, DC Łódź, DC Lublin, DC Kraków, DC Katowice and DC Białystok. Participation in the research was voluntary and anonymous; the tools were arranged in sets, and the sequence of those sets was random. The sets of research tools were received by 1,000 individuals altogether. Results The conducted research confirmed the need to verify the significance of the feeling of occupational stress of court probation officers at the workplace and the correlations between it and a number of variables. Below, I present statistical analyses concerning various aspects of occupational stress experienced in the studied group, including correlations between the general level of occupational stress and the dimensions of it, and organizational predictors. The objective of the research was to indicate the styles of coping with stress and the correlations of them with the stress felt by court probation officers. Conclusions The research confirms a significant influence exerted by organizational determinants upon the general level of felt occupational stress. Professional court probation officers experience a higher level of felt occupational stress; what is conducive to that is high encumbrance with occupational responsibilities, and also functioning directly in structures of the court of

  15. Effects of Different Genres of Music on Stress Levels.

    Marshall, O. W.; Tomcala, Maryjane

    The response of patients with stress problems to one of five music genres during biofeedback training is measured. Fifty male and female patients between the ages of 15 and 25 who were receiving psychotherapy, self-help counseling, and physical fitness training as well as biofeedback training comprised the sample. Using a Biofeedback Systems…

  16. Elevated social stress levels and depressive symptoms in primary hyperhidrosis.

    Gross, Katharina M; Schote, Andrea B; Schneider, Katja Kerstin; Schulz, André; Meyer, Jobst


    Primary hyperhidrosis is defined as excessive sweating of certain body areas without physiological reasons. Hyperhidrotic individuals report a high psychological strain and an impairment of their quality of life. Thus, the aim of the study is to investigate the relation between hyperhidrosis and different psychological as well as physiological aspects of chronic stress as a co-factor for the etiology of depression. In this study, forty hyperhidrotic subjects were compared to forty age- and sex-matched healthy control subjects. The Trier Inventory of Chronic Stress ('Trierer Inventar zum chronischen Stress': TICS), the Beck Depression Inventory (BDI-II) and the Screening for Somatoform Disorders (SOMS-2) were used to examine the correlation between primary hyperhidrosis and stress as well as accompanying depressive and somatic symptoms. The cortisol awakening response of each subject was analyzed as a physiological stress correlate. In hyperhidrotics, we found a significant lack of social recognition as well as significantly more depressive symptoms compared to the control subjects. A subgroup of patients with axillary hyperhidrosis had the highest impact on these increased issues of chronic stress, pointing to a higher embarrassment in these subjects. Especially in social situations, hyperhidrotics showed higher stress levels, whereby a vicious circle of stress and sweating is triggered. However, the cortisol awakening response did not significantly differ between hyperhidrotics and controls. Moreover, affected persons suffer from more depressive symptoms, which may be caused by feelings of shame and a lack of self-confidence. This initial study provides an impetus for further investigation to reveal a causative relationship between hyperhidrosis and its psychological concomitants.

  17. Elevated social stress levels and depressive symptoms in primary hyperhidrosis.

    Katharina M Gross

    Full Text Available Primary hyperhidrosis is defined as excessive sweating of certain body areas without physiological reasons. Hyperhidrotic individuals report a high psychological strain and an impairment of their quality of life. Thus, the aim of the study is to investigate the relation between hyperhidrosis and different psychological as well as physiological aspects of chronic stress as a co-factor for the etiology of depression. In this study, forty hyperhidrotic subjects were compared to forty age- and sex-matched healthy control subjects. The Trier Inventory of Chronic Stress ('Trierer Inventar zum chronischen Stress': TICS, the Beck Depression Inventory (BDI-II and the Screening for Somatoform Disorders (SOMS-2 were used to examine the correlation between primary hyperhidrosis and stress as well as accompanying depressive and somatic symptoms. The cortisol awakening response of each subject was analyzed as a physiological stress correlate. In hyperhidrotics, we found a significant lack of social recognition as well as significantly more depressive symptoms compared to the control subjects. A subgroup of patients with axillary hyperhidrosis had the highest impact on these increased issues of chronic stress, pointing to a higher embarrassment in these subjects. Especially in social situations, hyperhidrotics showed higher stress levels, whereby a vicious circle of stress and sweating is triggered. However, the cortisol awakening response did not significantly differ between hyperhidrotics and controls. Moreover, affected persons suffer from more depressive symptoms, which may be caused by feelings of shame and a lack of self-confidence. This initial study provides an impetus for further investigation to reveal a causative relationship between hyperhidrosis and its psychological concomitants.

  18. Effects of stress on exacerbation of diabetes mellitus, serum glucose and cortisol levels and body weight in rats.

    Radahmadi, Maryam; Shadan, Farrokh; Karimian, Seied Morteza; Sadr, Seied Shahab-e-din; Nasimi, Ali


    The effects of stress on the serum glucose, serum cortisol levels and body weight were investigated to clarify the possible link between the stress and diabetes. The experiments were performed on nondiabetic and streptozotocin diabetic rats divided to control, sham and stressed groups. Water immersion was used as stressor. After the experiment, blood samples were collected. The serum glucose level (SGL) was measured by the glucose oxidase method and serum cortisol level (SCL) was determined by radioimmunoassay. Stress caused a significant increase in glucose level in both nondiabetic and diabetic rats. In diabetes rats, a significant increase in SCL was observed. Stress did not cause, however, significant increases in SCL. A significant weight loss took place in rats exposed to stress and that was much greater in diabetic animals. The stress with mainly psychic component exacerbated the diabetes in streptozotocin treated rats and the glucose levels increased significantly also in nondiabetic controls, but no glucose was detected in their urine.

  19. Environmental stress level evaluation approach based on physical model and interval grey association degree

    Deng Guanqian; Qiu Jing; Liu Guanjun; Lv Kehong


    Associating environmental stresses (ESs) with built-in test (BIT) output is an important means to help diagnose intermittent faults (IFs).Aiming at low efficiency in association of traditional time stress measurement device (TSMD),an association model is built.Thereafter,a novel approach is given to evaluate the integrated environmental stress (IES) level.Firstly,the selection principle and approach of main environmental stresses (MESs) and key characteristic parameters (KCPs) are presented based on fault mode,mechanism,and ESs analysis (FMMEA).Secondly,reference stress events (RSEs) are constructed by dividing IES into three stress levels according to its impact on faults; and then the association model between integrated environmental stress event (IESE) and BIT output is built.Thirdly,an interval grey association approach to evaluate IES level is proposed due to the interval number of IES value.Consequently,the association output can be obtained as well.Finally,a case study is presented to demonstrate the proposed approach.Results show the proposed model and approach are effective and feasible.This approach can be used to guide ESs measure,record,and association.It is well suited for on-line assistant diagnosis of faults,especially IFs.

  20. Experimental Development of a Novel Stress Sensor for in situ Stress Measurement

    Polsky, Yarom [ORNL; Lance, Michael J [ORNL; Mattus, Catherine H [ORNL; Daniels, Ryan J [ORNL


    This paper will describe ongoing work to adapt a previously demonstrated method for measuring stress in ceramics to develop a borehole deployed in situ stress sensor. The method involves the use of a cementitious material which exhibits a strong piezo-spectroscopic stress response as a downhole stress gage. A description of the conceptual approach will be provided along with preliminary analysis and proof-of-concept laboratory results.

  1. How to Identify and Prioritize Psychosocial Factors Impacting Stress Level.

    Mounia N Hocine

    Full Text Available We develop a methodological approach to identify and prioritize psychosocial factors (stressors requiring priority action to reduce stress levels. Data analysis was carried out on a random sample of 10 000 French employees who completed, during a routine interview with the occupational physician, a 25-item questionnaire about stress levels, as well as a questionnaire about 58 stressors grouped into 5 latent variables: job control, job context, relationships at work, tasks performed and recognition. Our method combines Importance-Performance Analysis, a valuable approach for prioritizing improvements in the quality of services, with Partial Least Squares-Path modeling, a Structural Equation Modeling approach widely applied in psychosocial research. Findings on our data suggest two areas worthy of attention: one with five stressors on which decision makers should concentrate, and another with five stressors that managers should leave alone when acting to reduce stress levels. We show that IPA is robust when answers to questions are dichotomized, as opposed to the initial 6-point Likert scale. We believe that our approach will be a useful tool for experts and decision-makers in the field of stress management and prevention.

  2. Torsional ultrasonic wave based level measurement system

    Holcomb, David E. (Oak Ridge, TN); Kisner, Roger A. (Knoxville, TN)


    A level measurement system suitable for use in a high temperature and pressure environment to measure the level of coolant fluid within the environment, the system including a volume of coolant fluid located in a coolant region of the high temperature and pressure environment and having a level therein; an ultrasonic waveguide blade that is positioned within the desired coolant region of the high temperature and pressure environment; a magnetostrictive electrical assembly located within the high temperature and pressure environment and configured to operate in the environment and cooperate with the waveguide blade to launch and receive ultrasonic waves; and an external signal processing system located outside of the high temperature and pressure environment and configured for communicating with the electrical assembly located within the high temperature and pressure environment.

  3. Are PTH levels related to oxidative stress and inflammation in chronic kidney disease patients on hemodialysis?

    Marcel Jaqueto

    Full Text Available Abstract Introduction: Patients at end stage renal disease have higher levels of inflammation and oxidative stress than the general population. Many factors contribute to these issues, and the parathyroid hormone (PTH is also implicated. Objective: The study was conducted in order to assess the relationship between PTH levels and inflammation and oxidative stress in hemodialysis patients. Methods: Cross-sectional study with patients of two hemodialysis facilities in Londrina, Brazil. Patients with other conditions known to generate oxidative stress and inflammation were excluded. Blood levels of PTH and biochemical parameters of inflammation (interleukins 1 and 6, tumor necrosis factor-alpha and oxidative stress (total plasma antioxidant capacity, malonic dialdehyde, lipid hydroperoxidation, advanced oxidation protein products, quantification of nitric oxide metabolites, and 8-isoprostane were measured before a dialysis session. Then, we made correlation analyses between PTH levels - either as the continuous variable or categorized into tertiles-, and inflammatory and oxidative stress biomarkers. Results: PTH did not show any correlation with the tested inflammation and oxidative stress parameters, nor as continuous variable neither as categorical variable. Conclusion: In this descriptive study, the results suggest that the inflammation and oxidative stress of hemodialysis patients probably arise from mechanisms other than secondary hyperparathyroidism.

  4. The measurement of in situ stress using NQR/NMR

    Schempp, E.; Murdoch, J. B.; Klainer, S. M.


    The measurement of stress in rocks underground is a difficult but very important problem in mining engineering and in the design of underground waste repositories. The structural stability of any excavation is critically dependent on the stress distribution in the surrounding rock and its capability to bear the stress, which can build up to hundreds of atmospheres in deep mines. Because existing methods for the determination of stress have limitations, Lawrence Berkeley Laboratory (LBL) has been investigating the use of spectroscopic techniques - nuclear quadrupole resonance (NQR) and nuclear magnetic resonance (NMR) - for rapid in situ measurements of three-dimensional stress in both salt and hard rock. Efforts in the past year have been directed toward computer simulation of boreholes stress patterns and NQR lineshapes, laboratory measurements on salt and aluminosilicates, and construction of a state-of-the-art pulsed NQR spectrometer.

  5. Measurment Of Residual Stress In Ferromagnetic Materials

    Namkung, Min; Yost, William T.; Kushnick, Peter W.; Grainger, John L.


    Magnetoacoustic (MAC) and magnetoacoustic emission (MAE) techniques combined to provide complete characterization of residual stresses in ferromagnetic structural materials. Combination of MAC and MAE techniques makes it possible to characterize residual tension and compression without being limited by surface conditions and unavailability of calibration standards. Significant in field of characterization of materials as well as detection of fatigue failure.

  6. Local residual stress measurements on nitride layers

    Mansilla, C.; Ocelik, V.; De Hosson, J. Th. M.


    In this work, local stresses in different nitrided maraging steel samples of high practical interest for industrial applications were studied through the so-called micro-slit milling method using a focused ion beam. The nitrogen concentration profiles were acquired by glow discharge optical emission

  7. Measurment Of Residual Stress In Ferromagnetic Materials

    Namkung, Min; Yost, William T.; Kushnick, Peter W.; Grainger, John L.


    Magnetoacoustic (MAC) and magnetoacoustic emission (MAE) techniques combined to provide complete characterization of residual stresses in ferromagnetic structural materials. Combination of MAC and MAE techniques makes it possible to characterize residual tension and compression without being limited by surface conditions and unavailability of calibration standards. Significant in field of characterization of materials as well as detection of fatigue failure.

  8. Assessment of stress level of forestry experts with academic education.

    Landekić, Matija; Martinić, Ivan; Lovrić, Marko; Sporcić, Mario


    This paper provides the results of an applied research of forests engineers connected to their risk of mental stress occurrence in everyday work. This paper also has a component of a basic research, in which the adequacy and reliability of applied methodology in this kind of researches is examined. The mental stress induced risk is tested by usage of an e-mail survey which consists out of 23-part ERI (Effort-Reward Imbalance) questionnaire. For the assessment of mental stress exposure level following indicators have been used: 1) ERI--ratio of devoted effort and achieved reward, and 2) overcommitment. These indicators have been analyzed in comparison to the demographic parameters (gender, age) and the complexity of assigned jobs of the interviewees. The interview was applied on a randomly sampled forestry experts employed in public and private sector. The analysis of reliability of the three components of ERI questionnaire has showed satisfactory internal consistency. Descriptive statistics has been done regarding gender and the complexity of assigned jobs. The testing of the "devoted effort/achieved reward" variable (E/R index) has shown a statistically significant difference of the index value between male interviewees on managerial and standard expert positions. The value of E/R index was x > or = 1 at 18.97% of the sampled interviewees, which indicates a divergence between devoted effort and achieved reward, and also points to a possibility of mental stress occurrence risk. Multiple response tables have shown that female interviewees with less than 20 years of professional experience manifest stress related symptoms earlier than their male colleagues with similar professional experience do. Regression analysis has shown a significant correlation of E/R index to gender, internship and overcommitment. This research also assesses the viability of the applied method as an instrument of forestry experts' mental stress level determination.

  9. Investigations of some rock stress measuring techniques and the stress field in Norway

    Hanssen, Tor Harald


    Rock stresses are important to the safe construction and operation of all man-made structures in rock, whether In mining, civil or petroleum engineering. The crucial issue is their relative magnitude and orientation. This thesis develops equipment and methods for further rock stress assessment and reevaluates existing overcoring rock stress measurements, and relates this information to the present geological setting. Both laboratory work and field work are involved. In the field, rock stresses are measured by the overcoring and the hydraulic fracturing technique. An observation technique for assessing likely high stresses is developed. The field data refer to several hydropower projects and to some offshore hydrocarbon fields. The principal sections are: (1) Tectonic setting in the western Fennoscandia, (2) Triaxial rock stress measurements by overcoring using the NTH cell (a strain gauge cell developed at the Norwegian technical university in Trondheim and based on the CSIR cell of the South African Council for Scientific and Industrial Research), (3) Laboratory testing of the NTH cell, (4) Quality ranking of stresses measured by the NTH cell, (4) Recalculated rock stresses and implications to the regional stress field, (5) Hydraulic fracturing stress measurements. 113 refs., 98 figs., 62 tabs.

  10. Psychological stress in high level sailors during competition

    Luciana Segato


    Full Text Available The purpose of this work was to investigate the psychological stress present in elite sailors in a competition. Based on a descriptive field research, 31 elite sailors volunteered to participate. They answered the Perceived Stress Scale (Cohen & Williamson, 1988 and also specific questions on self-control, sources and strategies of coping. Data were analyzed by using descriptive and inferential (Student t test and Pearson's correlation statistics. These athletes revealed low and moderate scores (M = 20.00, DP = 6.83 of stress originated from both intrinsic (ship troubles, team disorders and extrinsic (study, working and training, family and financial problems sources. The group reported good stress control during competition through the use of cognitive (avoidance and somatic (listening music, resting/sleeping, talk to friends strategies. It is important that sailors are able to control and cope with high levels of psychological stress and to understand how to proceed when under unstable and unexpected situations that arise during competition.

  11. Psychological stress in high level sailors during competition

    L. Segato


    Full Text Available The purpose of this work was to investigate the psychological stress present in elite sailors in a competition. Based on a descriptive field research, 31 elite sailors volunteered to participate. They answered the Perceived Stress Scale (Cohen & Williamson, 1988 and also specific questions on self-control, sources and strategies of coping. Data were analyzed by using descriptive and inferential (Student t test and Pearson's correlation statistics. These athletes revealed low and moderate scores (M = 20.00, DP = 6.83 of stress originated from both intrinsic (ship troubles, team disorders and extrinsic (study, working and training, family and financial problems sources. The group reported good stress control during competition through the use of cognitive (avoidance and somatic (listening music, resting/sleeping, talk to friends strategies. It is important that sailors are able to control and cope with high levels of psychological stress and to understand how to proceed when under unstable and unexpected situations that arise during competition.

  12. Seasonal changes in stress indicators in high level football.

    Faude, O; Kellmann, M; Ammann, T; Schnittker, R; Meyer, T


    This study aimed at describing changes in stress and performance indicators throughout a competitive season in high level football. 15 players (19.5±3.0 years, 181±5 cm, 75.7±9.0 kg) competing under professional circumstances were tested at baseline and 3 times during the season 2008/09 (in-season 1, 2, 3). Testing consisted of the Recovery-Stress Questionnaire for Athletes (Total Stress and Recovery score), vertical jump tests (counter movement and drop jump (DJ)), and a maximal ramp-like running test. Average match exposure was higher during a 3-weeks period prior to in-season 3 compared to in-season 1 and 2 (1.5 vs. 1 h/week, p=0.05). Total Stress score was elevated at in-season 1 and 2 compared to baseline (pcorrelated with the corresponding changes in Total Stress score (r=-0.55 and r=-0.61, pstress and a lack of recovery towards the end of a season might be indicated by psychometric deteriorations. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Plasma selenium levels and oxidative stress biomarkers: a gene-environment interaction population-based study.

    Galan-Chilet, Inmaculada; Tellez-Plaza, Maria; Guallar, Eliseo; De Marco, Griselda; Lopez-Izquierdo, Raul; Gonzalez-Manzano, Isabel; Carmen Tormos, M; Martin-Nuñez, Gracia M; Rojo-Martinez, Gemma; Saez, Guillermo T; Martín-Escudero, Juan C; Redon, Josep; Javier Chaves, F


    The role of selenium exposure in preventing chronic disease is controversial, especially in selenium-repleted populations. At high concentrations, selenium exposure may increase oxidative stress. Studies evaluating the interaction of genetic variation in genes involved in oxidative stress pathways and selenium are scarce. We evaluated the cross-sectional association of plasma selenium concentrations with oxidative stress levels, measured as oxidized to reduced glutathione ratio (GSSG/GSH), malondialdehyde (MDA), and 8-oxo-7,8-dihydroguanine (8-oxo-dG) in urine, and the interacting role of genetic variation in oxidative stress candidate genes, in a representative sample of 1445 men and women aged 18-85 years from Spain. The geometric mean of plasma selenium levels in the study sample was 84.76 µg/L. In fully adjusted models the geometric mean ratios for oxidative stress biomarker levels comparing the highest to the lowest quintiles of plasma selenium levels were 0.61 (0.50-0.76) for GSSG/GSH, 0.89 (0.79-1.00) for MDA, and 1.06 (0.96-1.18) for 8-oxo-dG. We observed nonlinear dose-responses of selenium exposure and oxidative stress biomarkers, with plasma selenium concentrations above ~110 μg/L being positively associated with 8-oxo-dG, but inversely associated with GSSG/GSH and MDA. In addition, we identified potential risk genotypes associated with increased levels of oxidative stress markers with high selenium levels. Our findings support that high selenium levels increase oxidative stress in some biological processes. More studies are needed to disentangle the complexity of selenium biology and the relevance of potential gene-selenium interactions in relation to health outcomes in human populations. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Stress in childhood, adolescence and early adulthood, and cortisol levels in older age.

    Harris, Mathew A; Cox, Simon R; Brett, Caroline E; Deary, Ian J; MacLullich, Alasdair M J


    The glucocorticoid hypothesis suggests that overexposure to stress may cause permanent upregulation of cortisol. Stress in youth may therefore influence cortisol levels even in older age. Using data from the 6-Day Sample, we investigated the effects of high stress in childhood, adolescence and early adulthood - as well as individual variables contributing to these measures; parental loss, social deprivation, school and home moves, illness, divorce and job instability - upon cortisol levels at age 77 years. Waking, waking +45 min (peak) and evening salivary cortisol samples were collected from 159 participants, and the 150 who were not using steroid medications were included in this study. After correcting for multiple comparisons, the only significant association was between early-adulthood job instability and later-life peak cortisol levels. After excluding participants with dementia or possible mild cognitive impairment, early-adulthood high stress showed significant associations with lower evening and mean cortisol levels, suggesting downregulation by stress, but these results did not survive correction for multiple comparisons. Overall, our results do not provide strong evidence of a relationship between stress in youth and later-life cortisol levels, but do suggest that some more long-term stressors, such as job instability, may indeed produce lasting upregulation of cortisol, persisting into the mid-to-late seventies.

  15. Eleveted Stress Regime within Birimian Metallurgenic Province of Ghana-Implications to Deep Level Mining

    M. Affam


    Full Text Available This study aims at evaluating the likely effect of high stress regime within the rocks of the Birimian Supergroup of Ghana, dated middle Precambrian and offer remediation strategies. The stress levels were therefore assessed between 26-level to 50-levels (i.e., 755 to 1500 m deep within the deepest mine in the formation. Results indicated that pre-and-post mining stresses levels were 75 and 200 MPa, respectively. These levels are quite high and could induce stress related instabilities. Fundamental studies of failure behaviour of the rockmass show that elevated stress regime of this kind poses great potential for eminent rock bursting within the Birimian. Such situations demand concerted efforts of strategic mine design measures, including modified excavation geometry and destressing or preconditioning. These methods could be exploited to extend the normal zone of stress induced fractured rock to a greater depth ahead of the excavation face. Support could be improved further by adopting higher rockbolting density or tougher mesh together with shortcrete. If the excavation becomes prone to moderate rockbursting, provision of appropriate support structure can also be made either to limit the bulking process or reduce excessive rock deformation.

  16. Physical fitness level affects perception of chronic stress in military trainees.

    Tuch, Carolin; Teubel, Thomas; La Marca, Roberto; Roos, Lilian; Annen, Hubert; Wyss, Thomas


    This study investigated whether physical fitness affects the perception of chronic stress in military trainees while controlling for established factors influencing stress perception. The sample consisted of 273 men (20.23 ± 1.12 years, 73.56 ± 10.52 kg, 1.78 ± 0.06 m). Physical fitness was measured by progressive endurance run (maximum oxygen uptake; VO2 max), standing long jump, seated shot put, trunk muscle strength, and one leg standing test. Perceived stress was measured using the Perceived Stress Questionnaire in Weeks 1 and 11 of basic military training (BMT). VO2 max and four influencing variables (perceived stress in Week 1, neuroticism, transformational leadership style, and education level) explained 44.44% of the variance of the increase in perceived stress during 10 weeks of BMT (R(2)  = 0.444, F = 23.334, p stress. We conclude that it is advisable to provide conscripts with a specific endurance training program prior to BMT for stress prevention reasons. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Phase stress measurements in composite materials

    Akiniwa, Yoshiaki; Tanaka, Keisuke [Nagoya Univ. (Japan). School of Engineering


    Using an aluminum alloy composite containing 20 wt.% of SiC powder and an aluminum alloy itself, a phase stress under monoaxial tensile load was tested using x-ray and neutron methods, to compare both of them. For specimens, a 20 vol.% SiC powder reinforced aluminum alloy and an aluminum alloy itself were used. As a result, the following results could be obtained. Young`s modulus and Poisson ratio of the aluminum alloy itself using x-ray method were E=74.5 GPa and {nu}=0.312, respectively, and those using neutron method were E=75.3 GPa and {nu}=0.384, respectively. A relationship between loading stress and lattice strain of the aluminum alloy itself using neutron method was possible to approximate linearly by containing macroscopic plastic deformation region. The lattice strain of each phase in the composite increased proportionally with loading stress in its elastic region, but when remarkably increasing plastic deformation, the lattice strain decreased proportionally in aluminum phase and increased in SiC phase. (G.K.)

  18. Green space and stress: evidence from cortisol measures in deprived urban communities.

    Roe, Jenny J; Thompson, Catharine Ward; Aspinall, Peter A; Brewer, Mark J; Duff, Elizabeth I; Miller, David; Mitchell, Richard; Clow, Angela


    Contact with green space in the environment has been associated with mental health benefits, but the mechanism underpinning this association is not clear. This study extends an earlier exploratory study showing that more green space in deprived urban neighbourhoods in Scotland is linked to lower levels of perceived stress and improved physiological stress as measured by diurnal patterns of cortisol secretion. Salivary cortisol concentrations were measured at 3, 6 and 9 h post awakening over two consecutive weekdays, together with measures of perceived stress. Participants (n = 106) were men and women not in work aged between 35-55 years, resident in socially disadvantaged districts from the same Scottish, UK, urban context as the earlier study. Results from linear regression analyses showed a significant and negative relationship between higher green space levels and stress levels, indicating living in areas with a higher percentage of green space is associated with lower stress, confirming the earlier study findings. This study further extends the findings by showing significant gender differences in stress patterns by levels of green space, with women in lower green space areas showing higher levels of stress. A significant interaction effect between gender and percentage green space on mean cortisol concentrations showed a positive effect of higher green space in relation to cortisol measures in women, but not in men. Higher levels of neighbourhood green space were associated with healthier mean cortisol levels in women whilst also attenuating higher cortisol levels in men. We conclude that higher levels of green space in residential neighbourhoods, for this deprived urban population of middle-aged men and women not in work, are linked with lower perceived stress and a steeper (healthier) diurnal cortisol decline. However, overall patterns and levels of cortisol secretion in men and women were differentially related to neighbourhood green space and warrant

  19. Field measurement and analysis of harmonic levels

    Karunakara, K.; Muthu Kumar, E.; Rajesh Kumar, O.; Nambudiri, P.V.V.; Srinivasan, K.N. [Central Power Research Institute, Bangalore (India)


    The level of harmonics on the transmission and distribution network is rising over the years, due to the rapid development and usage of electronic and semiconductor devices in the industries, as these devices produce harmonic currents. As the harmonic currents produced by these devices are unproductive and affect the ideal sinusoidal waveshapes, these have to be limited to a tolerable limit at the Point of Common Coupling (PCC). Before setting a tolerable limit on harmonics it is necessary to know the level of harmonics already present in the system, so that the limits suggested are comprehensive and practicable. To have a fair idea about the current and voltage harmonics on the Indian system, Central Power Research Institute (CPRI) has carried out a lot of measurements both on the distribution network and transmission network over the past 13 years. This paper discusses the harmonic measurements carried out by CPRI on different loads and voltage levels on the Indian network. The methodology adopted for measurement and results are also discussed in this paper. (author)

  20. Acute effects of traditional Thai massage on cortisol levels, arterial blood pressure and stress perception in academic stress condition: A single blind randomised controlled trial.

    Bennett, Surussawadi; Bennett, Michael John; Chatchawan, Uraiwon; Jenjaiwit, Patcharaporn; Pantumethakul, Rungthip; Kunhasura, Soontorn; Eungpinichpong, Wichai


    Traditional Thai massage (TTM) has been applied widely to promote relaxation. However, there is little evidence to support its efficacy on academic stress. A randomised controlled trial was performed to examine the acute effects of TTM on cortisol level, blood pressure, heart rate and stress perception in academic stress. This prospective trial included 36 physiotherapy students with a self perceived stress score of between 3 and 5. They were randomly allocated into the TTM (18 people) group or the control group (18 people). Saliva cortisol level, blood pressure, heart rate and stress perception rating were measured before and after the intervention. Both groups showed a significant reduction in cortisol level and heart rate when compared with baseline (p stress of TTM.

  1. Measuring depth profiles of residual stress with Raman spectroscopy

    Enloe, W.S.; Sparks, R.G.; Paesler, M.A.


    Knowledge of the variation of residual stress is a very important factor in understanding the properties of machined surfaces. The nature of the residual stress can determine a part`s susceptibility to wear deformation, and cracking. Raman spectroscopy is known to be a very useful technique for measuring residual stress in many materials. These measurements are routinely made with a lateral resolution of 1{mu}m and an accuracy of 0.1 kbar. The variation of stress with depth; however, has not received much attention in the past. A novel technique has been developed that allows quantitative measurement of the variation of the residual stress with depth with an accuracy of 10nm in the z direction. Qualitative techniques for determining whether the stress is varying with depth are presented. It is also demonstrated that when the stress is changing over the volume sampled, errors can be introduced if the variation of the stress with depth is ignored. Computer aided data analysis is used to determine the depth dependence of the residual stress.

  2. Stress measurement in thick plates using nonlinear ultrasonics

    Abbasi, Zeynab, E-mail:, E-mail:; Ozevin, Didem, E-mail:, E-mail: [University of Illinois at Chicago, Civil and Materials Engineering, 842 W Taylor Street ERF 2095, Chicago, IL 60607 (United States)


    In this paper the interaction between nonlinear ultrasonic characteristics and stress state of complex loaded thick steel plates using fundamental theory of nonlinear ultrasonics is investigated in order to measure the stress state at a given cross section. The measurement concept is based on phased array placement of ultrasonic transmitter-receiver to scan three angles of a given cross section using Rayleigh waves. The change in the ultrasonic data in thick steel plates is influenced by normal and shear stresses; therefore, three measurements are needed to solve the equations simultaneously. Different thickness plates are studied in order to understand the interaction of Rayleigh wave penetration depth and shear stress. The purpose is that as the thickness becomes smaller, the shear stress becomes negligible at the angled measurement. For thicker cross section, shear stress becomes influential if the depth of penetration of Rayleigh wave is greater than the half of the thickness. The influences of plate thickness and ultrasonic frequency on the identification of stress tensor are numerically studied in 3D structural geometry and Murnaghan material model. The experimental component of this study includes uniaxial loading of the plate while measuring ultrasonic wave at three directions (perpendicular, parallel and angled to the loading direction). Instead of rotating transmitter-receiver pair for each test, a device capable of measuring the three angles is designed.

  3. Stress measurement in thick plates using nonlinear ultrasonics

    Abbasi, Zeynab; Ozevin, Didem


    In this paper the interaction between nonlinear ultrasonic characteristics and stress state of complex loaded thick steel plates using fundamental theory of nonlinear ultrasonics is investigated in order to measure the stress state at a given cross section. The measurement concept is based on phased array placement of ultrasonic transmitter-receiver to scan three angles of a given cross section using Rayleigh waves. The change in the ultrasonic data in thick steel plates is influenced by normal and shear stresses; therefore, three measurements are needed to solve the equations simultaneously. Different thickness plates are studied in order to understand the interaction of Rayleigh wave penetration depth and shear stress. The purpose is that as the thickness becomes smaller, the shear stress becomes negligible at the angled measurement. For thicker cross section, shear stress becomes influential if the depth of penetration of Rayleigh wave is greater than the half of the thickness. The influences of plate thickness and ultrasonic frequency on the identification of stress tensor are numerically studied in 3D structural geometry and Murnaghan material model. The experimental component of this study includes uniaxial loading of the plate while measuring ultrasonic wave at three directions (perpendicular, parallel and angled to the loading direction). Instead of rotating transmitter-receiver pair for each test, a device capable of measuring the three angles is designed.

  4. Comparing measured with simulated vertical soil stress under vehicle load

    Keller, Thomas; Lamandé, Mathieu; Arvidsson, Johan;

    in the soil profile at 0.3, 0.5 and 0.7 m depth was measured during wheeling at field capacity on five soils (13-66% clay). Stress propagation was then simulated with the semi-analytical model, using vertical stress at 0.1 m depth estimated from tyre characteristics as upper boundary condition, and v...

  5. Comparing measured with simulated vertical soil stress under vehicle load

    Keller, Thomas; Lamandé, Mathieu; Arvidsson, Johan

    in the soil profile at 0.3, 0.5 and 0.7 m depth was measured during wheeling at field capacity on five soils (13-66% clay). Stress propagation was then simulated with the semi-analytical model, using vertical stress at 0.1 m depth estimated from tyre characteristics as upper boundary condition, and v...

  6. Transient water stress in a vegetation canopy - Simulations and measurements

    Carlson, Toby N.; Belles, James E.; Gillies, Robert R.


    Consideration is given to observational and modeling evidence of transient water stress, the effects of the transpiration plateau on the canopy radiometric temperature, and the factors responsible for the onset of the transpiration plateau, such as soil moisture. Attention is also given to the point at which the transient stress can be detected by remote measurement of surface temperature.

  7. Measurement of spatial stress gradients near grain boundaries

    Basu, Indranil; Ocelík, Vaclav; De Hosson, Jeff Th M.


    A correlative method based on electron back scattered diffraction and focused ion-beam–digital image correlation slit milling technique was used to quantitatively determine spatially resolved stress profiles in the vicinity of grain boundaries in pure titanium. Measured local stress gradients were

  8. 3D Tyre/Road pavement contact stress measurements

    De Beer, Morris


    Full Text Available The CSIR’s proprietary Stress-in-Motion (SIM) measurements provide rational descriptions of 1D, 2D and 3D tyre/road pavement stresses for: Road pavement design testing and evaluation, as well as tyre design, testing and evaluation....

  9. Serum Levels of Stress Hormones and Oxidative Stress Biomarkers Differ according to Sasang Constitutional Type

    Hyeong Geug Kim


    Full Text Available Objectives. This study investigated whether Sasang constitutional type is associated with differences in the serum levels of stress hormones and oxidative stress. Methods. A total of 236 participants (77 males and 159 females were enrolled. The serum levels of cortisol, adrenaline, reactive oxygen species (ROS, and malondialdehyde (MDA were analyzed. Results. The distribution of Sasang constitutional types was as follows: Taeumin, 35.6%; Soumin, 33.0%; and Soyangin, 31.4%. The serum cortisol levels of Taeumin were significantly lower than Soumin (p<0.1 in both sexes and Soyangin (p<0.05 in males and p<0.1 in females. The adrenaline levels were also significantly lower in Taeumin than in Soumin (p<0.05 in males and p<0.1 in females and Soyangin (p<0.1 in males. Serum ROS levels were significantly higher in Soyangin than in Taeumin and Soumin (p<0.05 in males, whereas MDA levels were significantly lower in Taeumin compared with Soumin and Soyangin (p<0.05 in males and p<0.1 in females. Conclusion. Taeumin type may tolerate psychological or oxidative stress better than other types, which suggests a biological mechanism to explain the different pathophysiological features of Sasang constitutional types.

  10. Measurements of thermal residual stresses in SiC/Ti-15-3 composites

    Bobet, J.-L.; Masuda, C. [National Research Inst. for Metals, Tsukuba, Ibaraki (Japan)


    Residual stresses present in an as received and thermally cycled SCS-6/Ti-15-3 metal matrix composite (MMC) have been approached via X-ray diffraction (sin{sup 2}{psi}) experiments. Determination of stress profiles have been achieved by successive removal of the matrix from the composite surface by electropolishing. Axial and hoop stresses in the matrix were tensile (higher on the surface) and those measured in the fiber were compressive (about -500 to -600 MPa). A stress gradient normal to the surface of the composite was found. Measurement of residual stress levels in the composite subjected to thermal cycling from 400degC to 800degC in an inert atmosphere or in vacuum revealed a huge stress relaxation after only 200 cycles. (author)

  11. Measuring Thermal Stress of Dairy Cattle Based on Temperature Humidity Index (THI) in Tropical Climate

    Sugiono; Dewi Hardiningtyas; Rudy Soenoko


    Thermal comfort for workers is very important factor to increase their performance, as well as the comfort level of dairy cattle will influence in milk productivity. The purposes of the paper is to measure the level of heat stress and then use the information to design the dairy cattle house for increasing thermal comfort. The research is started with literature review of heat stress and early survey of environment condition e.g. temperature, wind speed and relative humidity. The next step is...

  12. Randomized, controlled trial of three levels of critical incident stress intervention.

    Macnab, Andrew; Sun, Charles; Lowe, John


    Stress debriefing following exposure to a critical incident is becoming more prevalent. Its aim is to prevent or minimize the development of excessive stress response symptoms that lead to loss of productivity or effectiveness in the workplace or at home. There is little evidence that any form of psychological debriefing is effective. This study evaluated the effectiveness of three intervention strategies, and attempted to correlate the symptoms with the severity of the incident and level of intervention. A randomized, controlled trial of three levels of critical stress intervention was conducted in the British Columbia Ambulance Service (BCAS), in British Columbia, Canada, among paramedics and emergency medical technicians (EMTs), reporting critical incident stress. Outcomes were measured at one week (Stanford Acute Stress Reaction Questionnaire (SASRQ), the Life Impact Score (LIS), and Schedule of Recent Events (SRE)), and at three months and six months following the intervention (Impact of Events (IE), Coping Mechanisms, LIS, and SRE). Fifty calls were received during the 26-month study period (incident and scores on the SASRQ, IE, or LIS, or between any of these scores. There was no consistent pattern in the stress scores over time. Requests for critical incident stress intervention were uncommon. The need for intervention may not be as great as generally is assumed. Further randomized trials, ideally multicenter studies, are indicated.

  13. Aerobic Fitness Level Affects Cardiovascular and Salivary Alpha Amylase Responses to Acute Psychosocial Stress.

    Wyss, Thomas; Boesch, Maria; Roos, Lilian; Tschopp, Céline; Frei, Klaus M; Annen, Hubert; La Marca, Roberto


    Good physical fitness seems to help the individual to buffer the potential harmful impact of psychosocial stress on somatic and mental health. The aim of the present study is to investigate the role of physical fitness levels on the autonomic nervous system (ANS; i.e. heart rate and salivary alpha amylase) responses to acute psychosocial stress, while controlling for established factors influencing individual stress reactions. The Trier Social Stress Test for Groups (TSST-G) was executed with 302 male recruits during their first week of Swiss Army basic training. Heart rate was measured continuously, and salivary alpha amylase was measured twice, before and after the stress intervention. In the same week, all volunteers participated in a physical fitness test and they responded to questionnaires on lifestyle factors and personal traits. A multiple linear regression analysis was conducted to determine ANS responses to acute psychosocial stress from physical fitness test performances, controlling for personal traits, behavioural factors, and socioeconomic data. Multiple linear regression revealed three variables predicting 15 % of the variance in heart rate response (area under the individual heart rate response curve during TSST-G) and four variables predicting 12 % of the variance in salivary alpha amylase response (salivary alpha amylase level immediately after the TSST-G) to acute psychosocial stress. A strong performance at the progressive endurance run (high maximal oxygen consumption) was a significant predictor of ANS response in both models: low area under the heart rate response curve during TSST-G as well as low salivary alpha amylase level after TSST-G. Further, high muscle power, non-smoking, high extraversion, and low agreeableness were predictors of a favourable ANS response in either one of the two dependent variables. Good physical fitness, especially good aerobic endurance capacity, is an important protective factor against health


    Retno Lestari


    Full Text Available Introduction: A nurse who experience burnout feelings will influence their motivation, and quality performance. This situation is probably affecting a decline in work quality towards the caring behaviour demonstrated by nurses to their patiens, particularly for a nurse who are working in the long-stay installation room facing directly to patient's problems. The purpose of this research is to identify the work stress level of nurse towards the nurse's caring behaviour in the long-stay installation room (IRNA in general hospital in Malang. Method: This research used descriptive – correlational, the sampling was Non Probability Purposive Sampling with 93 nurses as the corresponds. The data was analyzed by operating Correlation Pearson, with a significance of p < 0.05. Result: The result found that there was a substantial correlation between the work stress level and the nurse's caring behaviour with p = 0.008 and r = -0.274, and it was a negative correlation. Discussion: It means that when the stress level of nurses will declined, the nurse's caring behavior automatically will beamplified. Conversely, if the stess level of nurses intensively increased, the nurse's caring behaviour become decreased. Thus, this research is needed to be analyzed further in order to asses the quality of caring behaviour by expanding the connected indicator and variable. It is aimed to improve the professionalism and quality of nurses in giving the best service to patients this research need to be continued further in order to asses the quality of nurse's caring behavior by expanding the variable, which is related to internal factors, such as knowledge, perception, emotion, ect and also connected to external factors, such as environment, both physically and non physically like: climate, human being, social economic, culture and ect.

  15. Measurement invariance of the perceived stress scale and latent mean differences across gender and time.

    Barbosa-Leiker, Celestina; Kostick, Marylynne; Lei, Ming; McPherson, Sterling; Roper, Virginia; Hoekstra, Trynke; Wright, Bruce


    Measurement invariance of the 2-factor model of the Perceived Stress Scale--10-item version (Cohen & Williamson, 1988) was tested across men and women at two time points and in the combined total sample over a 2-year time frame (n = 871). Measurement invariance results indicated that the scale measured the latent factors, stress and counter-stress, equivalently in men and women and over time. With measurement invariance demonstrated, differences in latent means were tested. Results indicated that men had lower levels of frequencies of stressors, and at one time point, higher levels of counter-stress, when compared with women. When examining change in frequencies of stressors and counter-stress over 2 years with the combined male and female sample, stressors remained stable, yet counter-stress increased over time. These findings may aid in the interpretation of results when examining stressors and counter-stress in clinical samples where one would expect stress to increase, whereas positive psychological states decrease.

  16. [Stress hormones liberated by fangotherapy. ACTH and beta-endorphin levels under heat stress].

    Giusti, P; Cima, L; Tinello, A; Cozzi, F; Targa, L; Lazzarin, P; Todesco, S


    In 6 healthy subjects submitted to fango therapy in the Euganean thermal baths (Italy), the plasma concentrations of beta-endorphin and ACTH increased transitorily but significantly. These results correlate with the release of these peptides by the pituitary in response to thermal stressing. The analgesic and hypothermic action responsible for good toleration of thermal stress induced by fango therapy, can be explained by this increase in plasma beta-endorphin. The repeated brief increases in plasma beta-endorphin during thermal treatment result in progressive improvement in articular and muscular symptomatology. The results of our study on plasma levels of ACTH confirm that the thermal stress associated with fango therapy activates the pituitary gland. Immunomodulatory effects are discussed.

  17. High precision stress measurements in semiconductor structures by Raman microscopy

    Uhlig, Benjamin


    Stress in silicon structures plays an essential role in modern semiconductor technology. This stress has to be measured and due to the ongoing miniaturization in today's semiconductor industry, the measuring method has to meet certain requirements. The present thesis deals with the question how Raman spectroscopy can be used to measure the state of stress in semiconductor structures. In the first chapter the relation between Raman peakshift and stress in the material is explained. It is shown that detailed stress maps with a spatial resolution close to the diffraction limit can be obtained in structured semiconductor samples. Furthermore a novel procedure, the so called Stokes-AntiStokes-Difference method is introduced. With this method, topography, tool or drift effects can be distinguished from stress related influences in the sample. In the next chapter Tip-enhanced Raman Scattering (TERS) and its application for an improvement in lateral resolution is discussed. For this, a study is presented, which shows the influence of metal particles on the intensity and localization of the Raman signal. A method to attach metal particles to scannable tips is successfully applied. First TERS scans are shown and their impact on and challenges for high resolution stress measurements on semiconductor structures is explained. (orig.)

  18. Ultrasonic measurement of residual stress in shot peened aluminum alloy

    Lavrentyev, Anton I.; Veronesi, William A.


    Shot peening is a well-known method for extending the fatigue life of metal components by introducing compressive residual stresses near their surfaces. The capability to non-destructively evaluate the near surface residual stress would greatly aid the assurance of proper fatigue life in shot-peened components. This paper addresses issues encountered in near-surface residual stress measurement by an ultrasonic surface wave method. In this method, a variation of ultrasonic surface wave speed with shot peening intensity is measured. Since the effective wave penetration depth inversely related to the excitation frequency, by making measurements at different frequencies, the method has the potential to provide the stress-depth profile. Experiments were conducted on aluminum specimens (alloy 7075-T7351) peened within the Almen peening intensity from 4A-16A. Several factors were found to contribute to the measured responses: surface roughness, near surface texture change, dislocation density increase and residual stress. In this paper, the contributions of residual stress, dislocation density and surface roughness to the overall effect are separately estimated. It is shown that the experimentally observed velocity change in shot peened samples is dominated by the effect of surface roughness while the role of residual stress is much smaller.

  19. Evaluation of Oxidative Stress Parameters and Urinary Deoxypyridinoline Levels in Geriatric Patients with Osteoporosis

    Demir, Mehmet; Ulas, Turgay; Tutoglu, Ahmet; Boyaci, Ahmet; Karakas, Emel Yigit; Sezen, Hatice; Ustunel, Murat; Bilinc, Hasan; Gencer, Mehmet; Buyukhatipoglu, Hakan


    [Purpose] To evaluate the oxidative stress parameters and urinary deoxypyridinoline levels in geriatric patients with osteoporosis. [Subjects and Methods] Eighty geriatric patients aged over 65 years were recruited. Patients were divided into two groups: Group 1 (n=40) consisted of patients with osteoporosis, and Group 2 (n=40) consisted of patients without osteoporosis. Bone mineral density measurements were performed for all patients using DEXA. Oxidative stress parameters were analyzed in blood samples, and deoxypyridinoline levels were analyzed in 24-hour urinary samples. [Results] Compared to Group 2, the total antioxidant status and oxidative stress index levels of Group 1 were not significantly different; however, total oxidant status and 24-hour urinary deoxypyridinoline levels were significantly higher. Pearson correlation coefficients indicated that OSI and urinary deoxypyridinoline levels were not correlated with any biochemical parameters. ROC-curve analysis revealed that urinary deoxypyridinoline levels over 30.80 mg/ml predicted osteoporosis with 67% sensitivity and 68% specificity (area under the curve = 0.734; %95 CI: 0.624–0.844). [Conclusion] Our results indicate that oxidative stress would play a role in the pathogenesis of osteoporosis, and that urinary deoxypyridinoline levels may be a useful screening test for osteoporosis. PMID:25276024

  20. Eo-1 Hyperion Measures Canopy Drought Stress In Amazonia

    Asner, Gregory P.; Nepstad, Daniel; Cardinot, Gina; Moutinho, Paulo; Harris, Thomas; Ray, David


    The central, south and southeast portions of the Amazon Basin experience a period of decreased cloud cover and precipitation from June through November. There are likely important effects of seasonal and interannual rainfall variation on forest leaf area index, canopy water stress, productivity and regional carbon cycling in the Amazon. While both ground and spaceborne studies of precipitation continue to improve, there has been almost no progress made in observing forest canopy responses to rainfall variability in the humid tropics. This shortfall stems from the large stature of the vegetation and great spatial extent of tropical forests, both of which strongly impede field studies of forest responses to water availability. Those few studies employing satellite measures of canopy responses to seasonal and interannual drought (e.g., Bohlman et al. 1998, Asner et al. 2000) have been limited by the spectral resolution and sampling available from Landsat and AVHRR sensors. We report on a study combining the first landscape-level, managed drought experiment in Amazon tropical forest with the first spaceborne imaging spectrometer observations of this experimental area. Using extensive field data on rainfall inputs, soil water content, and both leaf and canopy responses, we test the hypothesis that spectroscopic signatures unique to hyperspectral observations can be used to quantify relative differences in canopy stress resulting from water availability.

  1. Measuring receptive collocational competence across proficiency levels

    Déogratias Nizonkiza


    Full Text Available The present study investigates, (i English as Foreign Language (EFL learners’ receptive collocational knowledge growth in relation to their linguistic proficiency level; (ii how much receptive collocational knowledge is acquired as proficiency develops; and (iii the extent to which receptive knowledge of collocations of EFL learners varies across word frequency bands. A proficiency measure and a collocation test were administered to English majors at the University of Burundi. Results of the study suggest that receptive collocational competence develops alongside EFL learners’ linguistic proficiency; which lends empirical support to Gyllstad (2007, 2009 and Author (2011 among others, who reported similar findings. Furthermore, EFL learners’ collocations growth seems to be quantifiable wherein both linguistic proficiency level and word frequency occupy a crucial role. While more gains in terms of collocations that EFL learners could potentially add as a result of change in proficiency are found at lower levels of proficiency; collocations of words from more frequent word bands seem to be mastered first, and more gains are found at more frequent word bands. These results confirm earlier findings on the non-linearity nature of vocabulary growth (cf. Meara 1996 and the fundamental role played by frequency in word knowledge for vocabulary in general (Nation 1983, 1990, Nation and Beglar 2007, which are extended here to collocations knowledge.

  2. Teacher Stress Inventory: validation of the Greek version and perceived stress levels among 3,447 educators

    Kourmousi N


    Full Text Available Ntina Kourmousi, Christina Darviri, Liza Varvogli, Evangelos C Alexopoulos School of Medicine, University of Athens, Athens, Greece Background: The Teacher Stress Inventory (TSI is an instrument for measuring occupational stress in teachers. This study aimed to translate and adapt it for use in Greece, and then assess its reliability and validity. Methods: The Greek versions of the TSI and the 14-item Perceived Stress Scale (PSS-14 were posted on all Greek educators' official sites during May 2012. A nationwide sample of 3,447 teachers of all levels and specialties completed the questionnaires via the Internet. Reliability was determined by the calculation of Cronbach's alpha coefficient. Confirmatory factor analysis was conducted and validity was further examined by investigating the correlation of the TSI with the PSS-14 and their association with demographics and work-related factors. Results: Satisfactory Cronbach's alpha values (above 0.70 were found for all TSI dimensions. Confirmatory factor analysis confirmed the two-factor construct of TSI (root mean square error of approximation, comparative fit index, and goodness-of-fit index values were 0.079, 0.956, and 0.951, respectively, confirming the pre-established theory for the two latent variables, Stress Sources and Stress Manifestations. Significant correlations were found between TSI subscales, PSS-14 sex, age, lack of support, and students' difficulties. Conclusion: The Greek version of the TSI was found to have satisfactory psychometric properties, and its use for assessing stress in Greek teachers is warranted. Keywords: TSI, reliability, validity, Greek educators, occupational stress, psychosocial factors

  3. Respirometry increases cortisol levels in rainbow trout Oncorhynchus mykiss: implications for measurements of metabolic rate

    Murray, L.; Rennie, M. D.; Svendsen, Jon Christian


    This study aimed to assess the extent to which chasing, handling and confining Oncorhynchus mykiss to a small respirometer chamber during respirometric experiments is stressful and affects metabolic measurements. The study observed increased cortisol levels in animals tested using a chase protocol...... and subsequent intermittent-flow respirometry, suggesting that this procedural treatment may stress animals...

  4. Effect of music on anxiety, stress, and depression levels in patients undergoing coronary angiography.

    Moradipanah, F; Mohammadi, E; Mohammadil, A Z


    Control of stress and anxiety and the promotion of comfort are challenges facing health practitioners involved in catheterization. The aim of this case-control study was to examine the effect of music on the levels of anxiety, stress, and depression experienced by patients undergoing coronary angiography, as measured by the 21-item Depression Anxiety Stress Scales. Differences in pre- and post-intervention scores demonstrated that there were significant decreases in mean scores of state anxiety (P = 0.006), stress (P = 0.001) and depression P = 0.02) in the intervention group, who listened to 20 minutes of relaxing music, as compared with the control group who had 20 minutes of bed rest.

  5. Measuring stress variation with depth using Barkhausen signals

    Kypris, O.; Nlebedim, I. C.; Jiles, D. C.


    Magnetic Barkhausen noise analysis (BNA) is an established technique for the characterization of stress in ferromagnetic materials. An important application is the evaluation of residual stress in aerospace components, where shot-peening is used to strengthen the part by inducing compressive residual stresses on its surface. However, the evaluation of the resulting stress-depth gradients cannot be achieved by conventional BNA methods, where signals are interpreted in the time domain. The immediate alternative of using x-ray diffraction stress analysis is less than ideal, as the use of electropolishing to remove surface layers renders the part useless after inspection. Thus, a need for advancing the current BNA techniques prevails. In this work, it is shown how a parametric model for the frequency spectrum of Barkhausen emissions can be used to detect variations of stress along depth in ferromagnetic materials. Proof of concept is demonstrated by inducing linear stress-depth gradients using four-point bending, and fitting the model to the frequency spectra of measured Barkhausen signals, using a simulated annealing algorithm to extract the model parameters. Validation of our model suggests that in bulk samples the Barkhausen frequency spectrum can be expressed by a multi-exponential function with a dependence on stress and depth. One practical application of this spectroscopy method is the non-destructive evaluation of residual stress-depth profiles in aerospace components, thus helping to prevent catastrophic failures.

  6. A new sensor for stress measurement based on blood flow fluctuations

    Fine, I.; Kaminsky, A. V.; Shenkman, L.


    It is widely recognized that effective stress management could have a dramatic impact on health care and preventive medicine. In order to meet this need, efficient and seamless sensing and analytic tools for the non-invasive stress monitoring during daily life are required. The existing sensors still do not meet the needs in terms of specificity and robustness. We utilized a miniaturized dynamic light scattering sensor (mDLS) which is specially adjusted to measure skin blood flow fluctuations and provides multi- parametric capabilities. Based on the measured dynamic light scattering signal from the red blood cells flowing in skin, a new concept of hemodynamic indexes (HI) and oscillatory hemodynamic indexes (OHI) have been developed. This approach was utilized for stress level assessment for a few usecase scenario. The new stress index was generated through the HI and OHI parameters. In order to validate this new non-invasive stress index, a group of 19 healthy volunteers was studied by measuring the mDLS sensor located on the wrist. Mental stress was induced by using the cognitive dissonance test of Stroop. We found that OHIs indexes have high sensitivity to the mental stress response for most of the tested subjects. In addition, we examined the capability of using this new stress index for the individual monitoring of the diurnal stress level. We found that the new stress index exhibits similar trends as reported for to the well-known diurnal behavior of cortisol levels. Finally, we demonstrated that this new marker provides good sensitivity and specificity to the stress response to sound and musical emotional arousal.

  7. Evaluation of response to restraint stress by salivary corticosterone levels in adult male mice.

    Nohara, Masakatsu; Tohei, Atsushi; Sato, Takumi; Amao, Hiromi


    Saliva as a sampling method is a low invasive technique for the detection of physiologically active substances, as opposed to sampling the plasma or serum. In this study, we obtained glucocorticoids transferred from the blood to the saliva from mice treated with 2.0 mg/kg via an intraperitoneal injection of cortisol. Next, to evaluate the effect of restraint stress using mouse saliva-collected under anesthesia by mixed anesthetic agents-we measured plasma and salivary corticosterone levels at 60 min after restraint stress. Moreover, to evaluate salivary corticosterone response to stress in the same individual mouse, an adequate recovery period (1, 3 and 7 days) after anesthesia was examined. The results demonstrate that exogenous cortisol was detected in the saliva and the plasma, in mice treated with cortisol. Restraint stress significantly increased corticosterone levels in both the plasma and saliva (Pstress significantly increased salivary corticosterone levels in all three groups (1-, 3- and 7-day recovery). However, the statistical evidence of corticosterone increase is stronger in the 7-day recovery group (Plevels in saliva reflect its levels in the plasma, and salivary corticosterone is a useful, less-invasive biomarker of physical stress in mice. The present study may contribute to concepts of Reduction and Refinement of the three Rs in small animal experiments.

  8. Salt stress alters DNA methylation levels in alfalfa (Medicago spp).

    Al-Lawati, A; Al-Bahry, S; Victor, R; Al-Lawati, A H; Yaish, M W


    Modification of DNA methylation status is one of the mechanisms used by plants to adjust gene expression at both the transcriptional and posttranscriptional levels when plants are exposed to suboptimal conditions. Under abiotic stress, different cultivars often show heritable phenotypic variation accompanied by epigenetic polymorphisms at the DNA methylation level. This variation may provide the raw materials for plant breeding programs that aim to enhance abiotic stress tolerance, including salt tolerance. In this study, methylation-sensitive amplified polymorphism (MSAP) analysis was used to assess cytosine methylation levels in alfalfa (Medicago spp) roots exposed to increasing NaCl concentrations (0.0, 8.0, 12.0, and 20.0 dS/m). Eleven indigenous landraces were analyzed, in addition to a salt-tolerant cultivar that was used as a control. There was a slight increase in DNA methylation upon exposure to high levels of soil salinity. Phylogenetic analysis using MSAP showed epigenetic variation within and between the alfalfa landraces when exposed to saline conditions. Based on MSAP and enzyme-linked immunosorbent assay results, we found that salinity increased global DNA methylation status, particularly in plants exposed to the highest level of salinity (20 dS/m). Quantitative reverse transcription-polymerase chain reaction indicated that this might be mediated by the overexpression of methyltransferase homolog genes after exposure to saline conditions. DNA demethylation using 5-azacytidine reduced seedling lengths and dry and fresh weights, indicating a possible decrease in salinity tolerance. These results suggest that salinity affects DNA methylation flexibility.

  9. Effects of carbamazepine on cortisol levels and behavioral responses to stress in the fish Jenynsia multidentata.

    Calcagno, Emilia; Durando, Patricia; Valdés, M Eugenia; Franchioni, Liliana; Bistoni, María de los Ángeles


    Carbamazepine (CBZ) is an anticonvulsant drug, prescribed worldwide for the treatment of epilepsy, bipolar disorder and trigeminal neuralgia, which has been frequently detected in aquatic environments. The objective of this study was to analyze if CBZ modifies scototaxis and shoaling behaviors and/or whole-body cortisol levels of the one-sided livebearing fish Jenynsia multidentata under stress condition. Female adults of J. multidentata were exposed to 0, 10, 50 and 200μgCBZ/L during 14days. After CBZ exposure, fish were subjected to restraint stress during 15min. Control animals were not exposed to CBZ or stress. In the light/dark preference test (scototaxis), the individuals under acute restraint stress (without CBZ) exhibited a significant increase in the mean speed and in the time spent both in the light compartment and in the bottom of the tank with respect to controls. They also showed a tendency to stay longer frozen in the light compartment. Fish exposed to 10 and 50μgCBZ/L showed a significant reduction in mean speed compared to stressed fish without CBZ. A reduction in the time spent in the bottom of the tank was also observed in fish exposed to 10μgCBZ/L. Fish exposed to 200μgCBZ/L showed a decreasing tendency in all behavioral endpoints (time spent in the light compartment, mean speed, time spent at the bottom and freezing) in comparison to stressed fish not exposed to CBZ. Considering whole-body cortisol results, fish under acute restraint stress (without CBZ) significantly increased their hormone levels with respect to the control group, while fish exposed to CBZ and acute restraint stress, significantly decreased their whole-body cortisol levels. There were no significant changes in shoaling behavior due to either stress or CBZ exposure and no significant differences in whole-body cortisol levels between experimental groups. Considering that the light/dark and shoaling tests measure different stress response behaviors regulated by different

  10. Professional stress in general practitioners and psychiatrists: The level of psycologic distress and burnout risk

    Vićentić Sreten


    Full Text Available Background/Aim. So far, studies of stress have shown that physicians are at a high risk of sickness from psychic and somatic disorders related to professional stress, that can lead to important disturbance of personal, familiar and professional functionating. The aim of this study was to investigate the doctors exposition level to professional stress, to compare stress level in general practitioners (GP group with that in the group of psychiatrists and risk level for the apperance of burnout syndrome. Methods. This cross-section study included subjects recruited by a random sample method. Thirty General Practice doctors and 30 psychiatrists (totally 60 doctors filled the set of 3 questionnaires: Sociodemographics features, General Health Questionnaire (GHQ; Goldberg D, 1991, and Maslach Burnout Inventory (MBI; Maslach C, 1996. Appropriate statistical procedures (Pearson test, t-test, variance analysis in interpretation of the results were used. Results. A total level of psychic distress measured with the GHQ test in both groups of physicians was very low implying their good mental health. A difference in Burnout risk based on MBI test between the groups was statistically significant (χ2 = 4,286; p < 0.05 only at subscale Personal Accomplishment (MBI-PA; it was a consequence of a higher number of GPs with medium burnout risk (13.3 : 0.0%. However, even 35 physicians from the sample were affected with a high burnout risk measured with subscales Emotional Ehausation (MBI-EE and MBI-DP, showing that both groups of physicians had risk for the appearance of burnout syndrome. Conclusion. The obtained results showed a high burnout risk level in both, GPs and psychiatrists, groups. In both groups there was no presence of psychic disorders (anxiety, depression, insomnia, while there was a high level of emotional ehausation and overtension by job, and also a lower total personal accomplishment. Level of exposition to professional stress is higher in GPs

  11. Measuring short-term stress in birds: Comparing different endpoints of the endocrine-immune interface.

    Huber, Nikolaus; Fusani, Leonida; Ferretti, Andrea; Mahr, Katharina; Canoine, Virginie


    Stress is a collective term for certain conditions and sequences of physiological events enabling living organisms to overcome unpredictable and uncontrollable situations. The context-dependent nature, multidimensional course and large individual variability make stress responses difficult to measure. In avian species, a plethora of studies on short-term stress responses have been conducted by measuring the corticosteroid response to a standardized stress protocol. Here we aimed to test the viability of the Leukocyte Coping Capacity (LCC), measuring oxygen radical production by leukocytes, to assess short-term stress in birds. We collected blood samples from captive house sparrows (Passer domesticus) in the two seasons of winter and spring, right after capture and 30min thereafter. In order to assess the overall physiological stress response to a standardized stressor, i.e. handling and temporary constraint, we measured LCC and additionally combined it with measures of total circulating glucocorticoids (GCs) and oxidative stress. All three methodologies detected significant changes due to the stressor albeit they were not correlated with each other and revealed different information. There was no significant change in oxidative stress levels between the two time points although the amount of relative oxidative damage as well as the anti-oxidative capacity changed significantly. We observed a significant seasonal difference in GC stress response with no difference between sexes. On the contrary, LCC measures revealed with a high individual consistency, that individuals experienced a similar magnitude of stress in both seasons with a significant difference between sexes. Total GC-levels have to be interpreted with caution regarding the assessment of short-term stress reactions. We therefore suggest to supplementary combine classical approaches for measuring stress with the immunological tool of LCC. Our results reveal LCC as a strong and reliable tool to assess short

  12. Role of serum levels of irisin and oxidative stress markers in pregnant women with and without gestational diabetes.

    Usluoğullari, Betül; Usluogullari, Celil Alper; Balkan, Fevzi; Orkmez, Mustafa


    Irisin regulates glucose levels, lipid levels, insulin sensitivity, and low-grade inflammation. Gestational diabetes mellitus (GDM) is a common metabolic complication of pregnancy, and is associated with increased rates of perinatal problems. Oxidative stress biomarkers have a role in the pathogenesis of patients with GDM. In total, 94 patients were included in our study including 46 control patients and 48 patients with GDM. Fasting blood glucose, HOMA-IR, total oxidative stress (TOS), irisin, and oxidative stress index (OSI) levels of the patients were measured. Serum OGTT, OSI, irisin HOMA, TOS, and insulin levels were statistically significantly higher in the patient group than in the control group. This was the first study to investigate the relation between serum irisin levels and oxidative stress markers in patients with GDM. The results revealed that irisin is an oxidative stress marker and a metabolic protective hormone.

  13. The Influence of Time Management Practices on Job Stress Level among Beginning Secondary Agriculture Teachers

    Lambert, Misty D.; Torres, Robert M.; Tummons, John D.


    Monitoring the stress of teachers continues to be important--particularly stress levels of beginning agriculture teachers. The study sought to describe the relationship between beginning teachers' perceived ability to manage their time and their level of stress. The Time Management Practices Inventory and the Job Stress Survey were used to measure…

  14. Measurement techniques for in situ stresses around underground constructions in a deep clay formation

    Li X.L.


    Full Text Available Disposal in deep underground geological formations is internationally recognized as the most viable option for the long-term management of high-level radioactive waste. In Belgium, the Boom clay formation is extensively studied in this context, in particular at the 225 m deep HADES Underground Research Facility in Mol. A cost-effective design of deep underground structures requires an accurate assessment of the in situ stresses; a good estimation of these stresses is also essential when interpreting in situ experiments regarding the hydro-mechanical behaviour of the host formation. Different measurement techniques are available to provide data on the stress evolution and other mechanical properties of the geological formation. The measurement can be direct (measurement of total pressure, or it can be an indirect technique, deriving the stress from related quantities such as strain (changes in structural members. Most total stress measurements are performed through permanently installed sensors; also once-only measurements are performed through specific methods (e.g. pressuremeter. Direct measurement of the stress state is challenging due to the complex mechanical behaviour of the clay, and the fact that the sensor installation inevitably disturbs the original stress field. This paper describes ways to deal with these problems and presents the results obtained using different techniques at HADES.

  15. Research on a system and method of automated whole-field measurement of optical glass stress

    Zhang, Li-jun; Tang, Yi; Bai, Ting-zhu


    On the basis of the principle of single quarter wave plate method, a model of automatic whole-field measuring optical glass stress is presented, which is called "4+1steps phase shifting method" including the model for the isoclinic parameter and the stress birefringence. According to this model, an automatic whole-field measuring system is established. The correctness of the model was testified by numeric emulation experiments under the preset conditions of isoclinic angle and stress birefringence. Practical measurement obtained a result coincident with the actual distribution of the isoclinic angle and the birefringence. The automatic whole-field measuring model and system can achieve the whole process intelligently and automatically, and dispose the disadvantages of tradition method about interpreting the stress level by subjective judging birefringence of some selected spots.

  16. Buried wire gage for wall shear stress measurements

    Murthy, V. S.; Rose, W. C.


    A buried wire gage for measuring wall shear stress in fluid flow was studied and further developed. Several methods of making this relatively new type of gage were examined to arrive at a successful technique that is well-suited for wind-tunnel testing. A series of measurements was made to demonstrate the adequacy of a two-point calibration procedure for these gages. The buried wire gage is also demonstrated to be ideally suited for quantitative measurement of wall shear stress in wind-tunnel testing.

  17. Measuring occupational stress: development of the pressure management indicator.

    Williams, S; Cooper, C L


    The study of occupational stress is hindered by the lack of compact and comprehensive standardized measurement tools. The Pressure Management Indicator (PMI) is a 120-item self-report questionnaire developed from the Occupational Stress Indicator (OSI). The PMI is more reliable, more comprehensive, and shorter than the OSI. It provides an integrated measure of the major dimensions of occupational stress. The outcome scales measure job satisfaction, organizational satisfaction, organizational security, organizational commitment, anxiety--depression, resilience, worry, physical symptoms, and exhaustion. The stressor scales cover pressure from workload, relationships, career development, managerial responsibility, personal responsibility, home demands, and daily hassles. The moderator variables measure drive, impatience, control, decision latitude, and the coping strategies of problem focus, life work balance, and social support.

  18. Measuring wind and stress under tropical cyclones with scatterometer

    Liu, W. Timothy


    Ocean surface stress, the turbulent transport of momentum, is largely derived from wind through a drag coefficient. In tropical cyclones (TC), scatterometers have difficulty in measuring strong wind and there is large uncertainty in the drag coefficient. We postulate that the microwave backscatter from ocean surface roughness, which is in equilibrium with local stress, does not distinguish weather systems. The reduced sensitivity of scatterometer wind retrieval algorithm under the strong wind is an air-sea interaction problem that is caused by a change in the behavior of the drag coefficient and not a sensor problem. Under this assumption, we applied a stress retrieval algorithm developed over a moderate wind range to retrieve stress under the strong winds of TCs. Over a moderate wind range, the abundant wind measurements and more established drag coefficient value allow sufficient stress data to be computed from wind to develop a stress retrieval algorithm for the scatterometer. Using unprecedented large amount of stress retrieved from the scatterometer coincident with strong winds in TC, we showed that the drag coefficient decreases with wind speed at a much steeper rate than previously revealed, for wind speeds over 25 m/s. The result implies that the ocean applies less drag to inhibit TC intensification and the TC causes less ocean mixing and surface cooling than previous studies indicated. With continuous and extensive coverage from constellations of scatterometers for several decades, the impact of tropical cyclones on the ocean and the feedback from the ocean are examined.

  19. Residual stress measurement in silicon sheet by shadow moire interferometry

    Kwon, Y.; Danyluk, S.; Bucciarelli, L.; Kalejs, J. P.


    A shadow moire interferometry technique has been developed to measure residual strain in thin silicon sheet. The curvature of a segment of sheet undergoing four-point bending is analyzed to include the applied bending moments, the in-plane residual stresses, and the 'end effect' of the sheet since it is of finite length. The technique is applied to obtain residual stress distributions for silicon sheet grown by the edge-defined film-fed growth technique.

  20. Measuring Propellant Stress Relaxation Modulus Using Dynamic Mechanical Analyzer


    P. N., Singh, P. P., and Bhattacharya, B., “Determination of Activation Energy of Relaxation Events in Composite Solid Propellants by Dynamic...Article 3. DATES COVERED (From - To) 04 August 2016 – 29 March 2017 4. TITLE AND SUBTITLE Measuring Propellant Stress Relaxation Modulus Using Dynamic...ERC 14. ABSTRACT A method for determining the stress relaxation master curve of solid rocket propellants was developed. The propellant was tested in

  1. Correlations between stress hormone levels in umbilical cord blood and duration of delivery.

    Sano, Yoko; Doi, Takayuki; Kikuchi, Suguru; Kawai, Kennta; Tanaka, Minoru


    Correlations between umbilical cord blood concentration of stress response hormone cortisol and prolactin, and delivery duration were examined. Thirty-three cases were selected in which both mothers and neonates were healthy, and the neonates were delivered at full term. The umbilical cord blood was collected at the time of delivery and concentrations of cortisol and prolactin were measured. The cortisol level was significantly higher after vacuum-assisted delivery than after spontaneous delivery (p=0.044). Significant positive correlations (p=0.0289) were observed between cortisol level and delivery duration. In particular, the duration of the second stage of delivery showed stronger positive correlation (p=0.0304) with the cortisol level. The prolactin level showed weak correlation with the duration of full delivery and the second stage of delivery. The findings suggest that foetuses may respond to stress by uterine contraction during delivery.

  2. Stress among nurses: an examination of salivary cortisol levels on work and day off

    Maria Cecilia Pires da Rocha


    Full Text Available The present study evaluates the use of salivary cortisol concentration as a physiological index of the stress level among nurses on their work day and day off and correlates it with the questionnaire used to measure occupational stress in nurses (Inventário de Estresse em Enfermeiros - IEE. This is a comparative, cross-sectional descriptive study in which sociodemographic data, IEE results and salivary cortisol levels were used. Fifty-seven nurses participated in the study (80.7% females and a mean age of 37.1 years old. The IEE average score was 124.5. The average cortisol level was 564.1 ng/m on work day and 354.1 ng/mL on day off. Nurses who had double workdays presented high values of salivary cortisol during the work day (638.1 ng/mL. In conclusion, salivary cortisol identified the nurses’ stress level, and differences were found between a work day and day off. On the nurses’ day off, their salivary cortisol levels and stress scores were lower.

  3. Medical Students’ Stress Levels and Sense of Well Being after Six Weeks of Yoga and Meditation

    Lona Prasad


    Full Text Available Objective. To determine the effect of six weeks of yoga and meditation on medical students’ levels of perceived stress and sense of wellbeing prior to taking their exams. Methods. We conducted a prospective case-control study of first-through-third-year medical students at our academic institution, measuring levels of perceived stress and sense of wellbeing before and after a six-week yoga and meditation intervention. Questionnaires used for evaluation included the perceived stress scale (PSS and self-assessment surveys (SAS. The postintervention surveys were completed on the day of the students’ written exams. Results. A total of thirteen women and fourteen men participated. Median age was 28 (24 yrs–32 yrs. 48.1% were Caucasian, 7.4% Black, 11.1% Hispanic, 11.1% Asian, and 22.2% other. Paired t-tests showed a statistically significant reduction in perceived stress (18.44 versus 14.52; p=0.004 after the six-week yoga and meditation program. After the yoga intervention, self-assessment survey results showed a significant improvement in feelings of peace, focus, and endurance. Improvements in happiness, positivity, personal satisfaction, and self-confidence were also seen. An improvement in unsubstantiated parameters such as patience and fatigue was observed. Conclusion. Yoga and meditation may be effective in reducing stress levels and improving aspects of personal wellbeing in medical students.

  4. Medical Students' Stress Levels and Sense of Well Being after Six Weeks of Yoga and Meditation

    Varrey, Aneesha; Sisti, Giovanni


    Objective. To determine the effect of six weeks of yoga and meditation on medical students' levels of perceived stress and sense of wellbeing prior to taking their exams. Methods. We conducted a prospective case-control study of first-through-third-year medical students at our academic institution, measuring levels of perceived stress and sense of wellbeing before and after a six-week yoga and meditation intervention. Questionnaires used for evaluation included the perceived stress scale (PSS) and self-assessment surveys (SAS). The postintervention surveys were completed on the day of the students' written exams. Results. A total of thirteen women and fourteen men participated. Median age was 28 (24 yrs–32 yrs). 48.1% were Caucasian, 7.4% Black, 11.1% Hispanic, 11.1% Asian, and 22.2% other. Paired t-tests showed a statistically significant reduction in perceived stress (18.44 versus 14.52; p = 0.004) after the six-week yoga and meditation program. After the yoga intervention, self-assessment survey results showed a significant improvement in feelings of peace, focus, and endurance. Improvements in happiness, positivity, personal satisfaction, and self-confidence were also seen. An improvement in unsubstantiated parameters such as patience and fatigue was observed. Conclusion. Yoga and meditation may be effective in reducing stress levels and improving aspects of personal wellbeing in medical students. PMID:28053644

  5. Stress induced lipid production in Chlorella vulgaris: relationship with specific intracellular reactive species levels.

    Menon, Kavya R; Balan, Ranjini; Suraishkumar, G K


    Microalgae have significant potential to be an important alternative energy source, but the challenges to the commercialization of bio-oil from microalgae need to be overcome for the potential to be realized. The application of stress can be used to improve bio-oil yields from algae. Nevertheless, the understanding of stress effects is fragmented due to the lack of a suitable, direct quantitative marker for stress. The lack of understanding seems to have limited the development of stress based strategies to improve bio-oil yields, and hence the commercialization of microalgae-based bio-oil. In this study, we have proposed and used the specific intracellular reactive species levels (siROS) particularly hydroxyl and superoxide radical levels, separately, as direct, quantitative, markers for stress, irrespective of the type of stress induced. Although ROS reactions are extremely rapid, the siROS level can be assumed to be at pseudo-steady state compared to the time scales of metabolism, growth and production, and hence they can be effective stress markers at particular time points. Also, the specific intracellular (si-) hydroxyl and superoxide radical levels are easy to measure through fluorimetry. Interestingly, irrespective of the conditions employed in this study, that is, nutrient excess/limitation or different light wavelengths, the cell concentrations are correlated to the siROS levels in an inverse power law fashion. The composite plots of cell concentration (y) and siROS (x) yielded the correlations of y = k1  · x(-0.7) and y = k2  · x(-0.79) , for si-hydroxyl and si-superoxide radical levels, respectively. The specific intracellular (si-) neutral lipid levels, which determine the bio-oil productivity, are related in a direct power law fashion to the specific hydroxyl radical levels. The composite plot of si-neutral lipid levels (z) and si-hydroxyl radical level (x) yielded a correlation of z = k3  · x(0.65) . More interestingly, a

  6. Measurement Challenges at Low Blood Lead Levels.

    Caldwell, Kathleen L; Cheng, Po-Yung; Jarrett, Jeffery M; Makhmudov, Amir; Vance, Kathryn; Ward, Cynthia D; Jones, Robert L; Mortensen, Mary E


    In 2012, the Centers for Disease Control and Prevention (CDC) adopted its Advisory Committee on Childhood Lead Poisoning Prevention recommendation to use a population-based reference value to identify children and environments associated with lead hazards. The current reference value of 5 μg/dL is calculated as the 97.5th percentile of the distribution of blood lead levels (BLLs) in children 1 to 5 years old from 2007 to 2010 NHANES data. We calculated and updated selected percentiles, including the 97.5th percentile, by using NHANES 2011 to 2014 blood lead data and examined demographic characteristics of children whose blood lead was ≥90th percentile value. The 97.5th percentile BLL of 3.48 µg/dL highlighted analytical laboratory and clinical interpretation challenges of blood lead measurements ≤5 μg/dL. Review of 5 years of results for target blood lead values Lead and Multi-Element Proficiency quality assurance program showed 40% unable to quantify and reported a nondetectable result at a target blood lead value of 1.48 µg/dL, compared with 5.5% at a target BLL of 4.60 µg/dL. We describe actions taken at the CDC's Environmental Health Laboratory in the National Center for Environmental Health, which measures blood lead for NHANES, to improve analytical accuracy and precision and to reduce external lead contamination during blood collection and analysis. Copyright © 2017 by the American Academy of Pediatrics.

  7. Yoga reduces perceived stress and exhaustion levels in healthy elderly individuals.

    Lindahl, Eric; Tilton, Katherine; Eickholt, Nicole; Ferguson-Stegall, Lisa


    This study investigated whether a 7-week yoga intervention could improve physical function, perceived stress, and mental/emotional wellness in elderly participants. 8 participants (66.5 ± 0.3 years) attended 2 60-min Hatha yoga sessions/week for 7 weeks, and performed pre- and post-intervention assessments. Balance was assessed using a 5-test battery. Flexibility was measured by sit-and-reach and shoulder flexibility tests. Functional mobility tests included 8-ft up-and-go, 5 chair stands, and 4-m walk. Participants completed SF-12, exhaustion level, and Perceived Stress Scale (PSS) questionnaires. SF-12 Mental Component Summary scores, exhaustion levels, and PSS scores improved post-intervention. No differences were found for physical function measures. Yoga participation can improve mental/emotional wellness, exhaustion levels, and stress levels in elderly individuals, even without measurable improvements in physical function. Clinicians and health practitioners who work with the elderly should consider yoga as a potential therapeutic modality for improving important aspects of quality of life in this population. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Increased oxidative stress and plasma Hsp70 levels among gasoline filling station attendants.

    Xia, Bing; Chen, Kangcheng; Lv, Yingnan; Huang, Damin; Liu, Jing; Liang, Guiqiang; Zhang, Li'e; Wang, Fenfen; Su, Cheng; Zou, Yunfeng; Yang, Xiaobo


    Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn) and is used as an antiknock agent and octane enhancer in gasoline. In this article, we tested the oxidative stress and heat stress protein (Hsp) 70 levels of gasoline station attendants to explore potential plasma biomarkers. Furthermore, the dose-response relationship was also identified. A total of 144 workers, including 96 petrol fillers and 48 cashiers, participated in the study. Ambient concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) and Mn were monitored at nine filling stations. During the measuring process, the individual cumulative exposure index was calculated. Plasma oxidative stress and Hsp70 levels were also analysed using enzyme-linked immunosorbent assay. The BTEX time-weighted average in office areas was significantly lower than in refuelling areas ( p stress indicators compared with the control group, respectively: superoxide dismutase (SOD), 39.18 ± 6.05 U/mL versus 52.84 ± 3.87 U/mL; glutathione peroxidase (GSH-Px), 186.07 ± 15.63 U versus 194.38 ± 10.42 U; and malondialdehyde (MDA), 1.68 ± 0.52 nmol/L versus 1.43 ± 0.64 nmol/L (in all comparisons, p level in the exposed group (2.77 ± 0.64 ng/mL) was significantly higher than in the control group (2.32 ± 0.87 ng/mL; p levels were inversely correlated with the activities of SOD ( r = -0.305) and GSH-Px ( r = -0.302) in the exposed group ( p levels and plasma MDA levels ( p stress among filling station attendants. Plasma Hsp70 levels could be used as a sensitive responsive biomarker for exposed workers.

  9. Molecular force sensors to measure stress in cells

    Prabhune, Meenakshi; Rehfeldt, Florian; Schmidt, Christoph F.


    Molecularly generated forces are essential for most activities of biological cells, but also for the maintenance of steady state or homeostasis. To quantitatively understand cellular dynamics in migration, division, or mechanically guided differentiation, it will be important to exactly measure stress fields within the cell and the extracellular matrix. Traction force microscopy and related techniques have been established to determine the stress transmitted from adherent cells to their substrates. However, different approaches are needed to directly assess the stress generated inside the cell. This has recently led to the development of novel molecular force sensors. In this topical review, we briefly mention methods used to measure cell-external forces, and then summarize and explain different designs for the measurement of cell-internal forces with their respective advantages and disadvantages.

  10. The role of stress and level of burnout in job performance among nurses.

    Gandi, Joshua C; Wai, Paul S; Karick, Haruna; Dagona, Zubairu K


    Nurses' empathy for and connection with patients demonstrates core professional values which are essential but, consequently, attract certain factors capable of inducing stress. Studies of the roles and responsibilities associated with nursing have implicated multiple and conflicting demands which might not be without some resultant effects. However, little research has been conducted on these work characteristics in developing economies to determine how these might impact the nurse employees' performance. There is need for evidence-based empirical findings to facilitate improvement in healthcare services. This study examined stress and level of burnout among Nigerian nurses (n = 2245) who were selected using stratified random sampling. The participants were measured using an 'abridged measures booklet' adopted from the Maslach Burnout Inventory-General Survey (MBI-GS), Job Autonomy Questionnaire (JAQ), Questionnaire on Organisational Stress-Doetinchem (VOS-D) and Job Diagnostic Survey (JDS). The roles of work-home interference (WHI) and home-work interference (HWI), with respect to work characteristics and burnout (paying special attention to gender), were examined. Analyses using t-tests and linear regression showed no gender differences in burnout levels among Nigerian nurses, who experience medium to high levels of emotional exhaustion, medium levels of depersonalisation and high levels of personal accomplishment. WHI and HWI were found to mediate the relationship between work characteristics and burnout. The meditational relationship differs between genders. This study calls for further research into gender and burnout among the caring professions, especially in under-developed and developing economies of the world.

  11. Normal stress measurement via image analysis of interfacial deformation

    Lowry, Brian; Höpfl, Wolfgang


    The first coefficient of normal stress in polymer solutions is determined via image analysis. The method measures pointwise normal stresses along a sheared liquid-liquid interface. In the case of a steady rotating liquid bridge, the deformation of the interface is strictly due to normal stress swelling effects. In our experiments, a cylindrical liquid bridge of polystyrene solution rotates in a cylindrical bath filled with a glycerol-water solution of similar density. The shape of the interface and the jump in normal stress across the interface are determined using pressure-stress image analysis (P-SIA) from high resolution digital images. The stress resolution is better than 0.1 Pa at the free interface. The polystyrene solution exhibits a normal stress at the interface which grows with the square of the rotation rate. This effect is absent for Newtonian liquids, and is in excellent agreement with the ideal low shear behaviour of polymer solutions. Small density differences between the liquids are taken into consideration, showing that centrifugal effects are negligible. This method is potentially an excellent alternative to classical rheometry at low shear rates.

  12. Predicting levels of Latino depression: acculturation, acculturative stress, and coping.

    Torres, Lucas


    Past research has noted that aspects of living in the United States place Latinos at risk for experiencing psychological problems. However, the specific features of the adaptation process that contribute to depression remain unclear. The purpose of the present study was to investigate the ability of acculturation, acculturative stress, and coping to predict membership into low, medium, and high groups of depression among Latinos. Within a group of 148 Latino adults from the community, a multinomial logistic regression revealed that an Anglo orientation, English competency pressures, and active coping differentiated high from low depression and that a Latino orientation and, to some extent, the pressure to acculturate distinguished medium from low depression. These results highlight a pattern of characteristics that function as risk and protective factors in relation to level of symptom severity. The findings are discussed in terms of implications for Latino mental health, including considerations for intervention and prevention.

  13. [Impact of a music therapy program on the stress level of health professionals].

    Taets, Gunnar Glauco de Cunto; Borba-Pinheiro, Claudio Joaquim; de Figueiredo, Nébia Maria Almeida; Dantas, Estélio Henrique Martin


    The study aimed to assess the effects of a music therapy program on the level of stress for female professionals working in a private hospital in Rio de Janeiro-RJ, Brazil. Thirty four female volunteers with 33.3 ± 8.5 years of age from different levels of professional participated in the study. We used the Lipp's inventory of symptoms of stress for adults (ISSL) to evaluate the level of stress of participants before and after music therapy. The program consisted of twelve sessions using the techniques of music therapy Improvisation and Musical Re-creation held once a week with 50 minutes / session in a period of three months. The Wilcoxon test for repeated measures was used for statistical analysis. The study showed a statistically significant decrease (Δ = - 60%, p music therapy program. In conclusion, the present study that the music therapy program was effective in decrease the level of stress of women health professionals working in a private hospital in Rio de Janeiro-RJ, Brazil.

  14. Stress levels of student population in Costa Rica. Differences according to socioeconomic, academic achievement, educational level, and geographic location variables

    Sebastien Belhumeur


    Full Text Available : In this paper are described the stress levels of the student population about the variables: socioeconomic status, academic performance, academic level, geographical area and gender. For this purpose, a survey was administered to a randomized sample of 112 students of different careers from the main campus of the University of Costa Rica. Results showed that the major sources of stress in students are academic and financial pressures. Also, results showed that students whose place of origin is far from the main campus of the university have higher levels of stress and finally, women tend to handle higher levels of stress than men.

  15. Brain and hepatic Hsp70 protein levels in heat-acclimated broiler chickens during heat stress

    EN Guerreiro


    Full Text Available In the present study we have investigated the effects of heat acclimation on brain and hepatic Hsp70 protein levels and body temperature of broiler chickens in response to gradual heat stress. Two groups of broilers were raised up to 47 days of age under distinct temperature conditions: thermoneutral (TN, according to bird age or hot environmental (HS, 31-33°C. At 46 days of age, the birds reared at high ambient temperature were transferred to thermoneutrality conditions. After 18 h, these birds and the birds reared at thermoneutral temperature were submitted to gradual heat stress in a climatic chamber so that environment temperature was increased from 28 to 40ºC at a rate of 2ºC/h. Colonic temperature was measured using a thermometer sensor probe at each two hours, and hepatic and brain tissues were collected immediately after slaughter in order to assess Hsp70 protein level by Western blotting analysis. The colonic temperatures of birds reared at high temperature increased steeply during the first 2 h of heat stress (1.06ºC/h and more slowly thereafter (0.59ºC/h. Broilers reared at thermoneutral temperature showed a small increase in the first 4 h of heat stress (0.18ºC/h and then colonic temperature increased sharply (0.72ºC/h. Nevertheless, both groups presented similar final colonic temperature by the end of the stress period. Hsp70 levels (ng Hsp70 µg total protein-1 did not change in the liver or brain of the birds reared at high temperature. On the other hand, both liver and brain Hsp70 levels increased significantly during heat stress in the animals reared at thermoneutrality, with a higher expression of this peptide in brain tissue.

  16. Neutron diffraction facility for internal stress measurements at JAERI

    Tsuchiya, Yoshinori; Minakawa, Nobuaki; Morii, Yukio [Japan Atomic Energy Research Inst., Tokyo (Japan)


    The Neutron Diffractometer for Residual Stress Analysis (RESA) is a two axis type neutron diffractometer with a goniometer controllable to specimen position in high precision for spatial distribution measurement of residual stress and with one- and zero-dimensional detectors, and has a characteristics of providing a pin-hole type neutron ray diaphragm to obtain local informations of the specimen. It is elucidated from the reported examples that the RESA in JAERI has a capacity of sufficient detection to a local strain with 10{sup -3} to 10{sup -4}. The residual stress measurement in JAERI is just in beginning state, and has many necessities to do a lot of trial measurements on various materials in future. And, when finishing the construction of pulsed neutron source under planning in JAERI, it can be expected to realize a neutron intensity of more than one hundred for the residual stress measurement and to construct a powerful measurement instrument in combination with introduction of testing method for TOF. (G.K.)

  17. Improving Earthquake Stress Drop Measurements - What can we Really Resolve?

    Abercrombie, R. E.; Bannister, S. C.; Fry, B.; Ruhl, C. J.; Kozlowska, M.


    Earthquake stress drop is fundamental to understanding the physics of the rupture process. Although it is superficially simple to calculate an estimate of stress drop from the corner frequency of the radiated spectrum, it is much harder to be certain that measurements are reliable and accurate. The same is true of other measurements of stress drop and radiated energy. The large number of studies of earthquake stress drop, the high variability in results (~0.1-100 MPa), the large uncertainties, and the ongoing scaling controversy are evidence for this. We investigate the resolution and uncertainties of stress drops calculated using an empirical Green's function (EGF) approach. Earthquakes in 3 sequences at Parkfield, California are recorded by multiple borehole stations and have abundant smaller earthquakes to use as EGFs (Abercrombie, 2014). The earthquakes in the largest magnitude cluster (M~2.1) exhibit clear temporal variation of stress drop. Independent studies obtained a similar pattern implying that it is resolvable for these well-recorded, simple sources. The borehole data reveal a similar temporal pattern for another sequence, not resolvable in an earlier study using surface recordings. The earthquakes in the third sequence have complex sources; corner frequency measurements for this sequence are highly variable and poorly resolved. We use the earthquakes in the first cluster to quantify the uncertainties likely to arise in less optimal settings. The limited signal bandwidth and the quality of the EGF assumption are major sources of error. Averaging across multiple stations improves the resolution, as does using multiple good EGFs (Abercrombie, 2015). We adapt the approach to apply to larger data sets. We focus on New Zealand, with the aim of resolving stress drop variability in a variety of tectonic settings. We investigate stacking over stations and multiple EGFs, and compare earthquakes (M~3-6) from both the overlying and the subducting plates.

  18. A Quantitative Examination Whether Education Mitigates Stress Levels among Law Enforcement Officers

    Metts, Gary A.


    Stress is damaging if it is continual, overwhelming. and prolonged. Law enforcement officers face stressful events daily. A relationship exists between stress levels and the physical and psychological effects to the human body. Although there is a general understanding of the damage stress can do physically and psychologically, many elements that…

  19. Water stress, CO2 and photoperiod influence hormone levels in wheat

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)


    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  20. Water stress, CO2 and photoperiod influence hormone levels in wheat

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)


    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  1. The Acute Effect of Aerobic Exercise on Measures of Stress.

    Fort, Inza L.; And Others

    The immediate response of stress to aerobic exercise was measured by utilizing the Palmar Sweat Index (PSI) and the State-Trait Anxiety Inventory (STAI). Forty subjects (20 male and 20 female) from the ages of 18-30 sustained a single bout of aerobic activity for 30 minutes at 60 percent of their maximum heart rate. Pre-treatment procedures…

  2. Stressed snakes strike first: Hormone levels and defensive behavior in free ranging cottonmouths (Agkistrodon piscivorus).

    Herr, Mark W; Graham, Sean P; Langkilde, Tracy


    Stress is believed to be an important factor mediating animal behavior. Here we explore the relationship between concentrations of a stress hormone and defensive behavior of a snake. The cottonmouth (Agkistrodon piscivorus) is an abundant, large-bodied pitviper that is well known for its intense defensive behaviors. The defensive behaviors and hormonal ecology of cottonmouths have been studied extensively, but the interaction between these is not well understood. We conducted field trials, recording the snake's behavior and obtaining blood samples to quantify plasma CORT concentrations, both upon first encountering a snake and after a 30min standardized confinement stressor. We found that snakes with elevated levels of baseline CORT at first encounter were more likely to strike than exhibit a threat display when approached in the field. However, this behavior was not related to the magnitude of the snake's CORT increase following confinement, suggesting that more stress-prone snakes are not more defensive. Post-stressor antipredator behavior was also not related to any of our CORT measures. This study suggests that baseline CORT levels can be important correlates of defensive behavior. If this is a causative relationship, environmental challenges that increase baseline stress levels of populations may elevate cottonmouth defensive behavior. This would increase costs associated with defensive behavior (energetic, lost opportunity, etc.) and have important consequences for animal-human interactions.

  3. Children's stress during a restorative dental treatment: assessment using salivary cortisol measurements.

    Akyuz, S; Pince, S; Hekin, N


    Dental environment may be a source of stress for the young patient. Such stressful conditions may provoke fear in anxious children. It is well known that stress produces an activation adrenal steroid secretion. Among the methods for assessing child dental fear, measurement of salivary cortisol level is a simple method, because especially in children, sampling of saliva is easy, and cortisol levels in saliva closely mirror serum free cortisol levels, independent of salivary flow rate. For this study, the salivary cortisol levels of 8 children (mean age 5.6 yr) were measured receiving initial dental treatment. Saliva samples were collected via cotton rolls placed to the floor of the mouth at four stages; prior to treatment, during cavitation, placement of the liner and the restoration. Statistical comparison of the results were done by Student-t test. The increase in salivary cortisol levels during cavitation at the first and secondary appointments were significant (p0.05). The results of this study suggest that in restorative procedures, mostly it is the cavitation step that creates stress and anxiety in children. Knowledge of the most stressful condition may be helpful for the dentist to prepare the child to treatment steps.

  4. Feasibility of using a biowatch to monitor GSR as a measure of radiologists' stress and fatigue

    Krupinski, Elizabeth A.; MacKinnon, Lea; Reiner, Bruce I.


    We have been investigating the impact of fatigue on diagnostic performance of radiologists interpreting medical images. In previous studies we found evidence that eye strain could be objectively measured and that it correlates highly with degradations in diagnostic accuracy as radiologists work long hours. Eye strain however can be difficult to measure in a non-invasive and continuous manner over the work day so we have been investigating other ways to measure physiological stress and fatigue. In this study we evaluated the feasibility of using a commercially available biowatch to measure galvanic skin response (GSR), a well known indicator of stress. 10 radiology residents wore the biowatch for about 8 hours during their normal work day and data were automatically collected at 10 Hz. They completed the Swedish Occupational Fatigue Inventory (SOFI) at the start and finish of the day. GSR values (microsiemens) ranged from 0.14 to 38.27 with an average of 0.50 (0.28 median). Overall GSR tended to be fairly constant as the day progressed, but there were definite spikes indicating higher levels of stress. SOFI scores indicated greater levels of fatigue and stress at the end of the work day. Although further work is needed, GSR measurements obtained via an easy to wear watch may provide a means to monitor stress/fatigue and alert radiologists when to take a break from interpreting images to avoid making errors.

  5. Relationship between serum DHEAS and oxidative stress levels of body mass index in healthy postmenopausal women.

    Goy, Burhan; Atmaca, Murat; Aslan, Mehmet; Ucler, Rıfkı; Alay, Murat; Seven, Ismet; Demir, Halit; Ozturk, Mustafa


    Menopause is a natural step in the process of aging. Postmenopausal women have decreased levels of antioxidants and increased oxidative stress, the latter of which plays an important role in atherogenesis. The aim of the present study was to evaluate the relationship of the body mass index (BMI) with serum catalase activity, malondialdehyde (MDA), and dehydroepiandrosterone sulfate (DHEAS) levels in healthy postmenopausal women and estimate whether the MDA/DHEAS ratio is a possible marker of oxidative stress for determining cardiovascular risk in these women. We investigated serum catalase activity, MDA, and DHEAS levels, parity history, age, and BMI in 96 healthy postmenopausal women aged 50-82 years. The serum MDA levels and catalase activity were measured spectrophotometrically. The serum DHEAS levels were measured using an enzyme-linked immunosorbent assay. The ratio percentage of the serum DHEAS levels to serum MDA levels was designated as a biomarker for oxidative stress. The mean BMI of the patients was 31.72 ± 6.16 kg/m(2) (range = 20.5-47.94). The MDA/DHEAS ratio was significantly decreased in patients with a BMI over 30 compared to that of patients with a BMI between 25 and 30 (P = 0.025). Moreover, BMI was positively correlated with serum DHEAS levels (r = 0.285, P < 0.01) and negatively correlated with the MDA/DHEAS ratio (r = -0.241, P < 0.05) in postmenopausal women. Furthermore, BMI was observed to be a potential predictor of the MDA/DHEAS ratio based on covariance analysis (P = 0.039). Our results indicate that healthy, obese, postmenopausal women have a decreased MDA/DHEAS ratio. Additionally, BMI was observed to be a potential predictor of the MDA/DHEAS ratio.

  6. Live music reduces stress levels in very low-birthweight infants.

    Schwilling, Diana; Vogeser, Michael; Kirchhoff, Fabian; Schwaiblmair, Frauke; Boulesteix, Anne-Laure; Schulze, Andreas; Flemmer, Andreas W


    Music might benefit preterm infants in stressful, intensive care environments. However, data on stress level indicators, determined by salivary cortisol levels, are scarce. We evaluated the effect of live harp music on the stress level indicators of preterm infants in a neonatal intensive care unit (NICU). We exposed 20 stable preterm infants to music for 15 min on three consecutive days. Saliva was collected before the music was played and 25 min and 4 h after it ended. Salivary cortisol levels were measured by liquid chromatography-tandem mass spectrometry and vital signs, oxygen saturation, bradycardia, apnoeas and oxygen desaturations were recorded. Pain levels were assessed by the Bernese Pain Scale for Neonates. Salivary cortisol was significantly lower 25 min (18.9 nmol/L [3.9-35.6] p = 0.001) and 4 h after music (17.4 nmol/L [3.9-35.3] p = 0.003) than at baseline 4 h before exposure (19.5 nmol/L [7.2-51.1]). After music, the number of apnoeas and oxygen desaturations was significantly reduced on all three, days and the number of bradycardia episodes on day one. Pain scores significantly improved after music on all 3 days. Exposure to live music reduced salivary cortisol and had beneficial effects on the physiologic parameters of stable preterm infants in a NICU. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  7. Reiki brief report: using Reiki to reduce stress levels in a nine-year-old child.

    Bukowski, Elaine L; Berardi, Diana


    A nine-year-old female with a history of perinatal stroke, seizures, and type-I diabetes was seen for six weeks of Reiki to determine the effects of Reiki on relaxation, and in turn, the prevention of future seizures. The secondary and tertiary aims were to determine the effects of Reiki on sleep patterns and the stress levels of the mother. There was a decrease in stress in both the child and the mother, as measured by a modified Perceived Stress Scale and a Perceived Stress Scale, respectively. There was no change in the child's overall sense of well-being, as measured by a global questionnaire. There was a positive change in sleep patterns on 33.3% of the nights during which the study occurred, as reported on a sleep log kept by the mother. The child and the Reiki Master (a Reiki practitioner who has completed all three levels of Reiki certification training and trains and certifies individuals in the practice of Reiki as well as provides Reiki to individuals) experienced warmth and tingling sensations on the same area of the child during the Reiki sessions. The child relaxed within the first five to seven minutes of each session as reported by the Reiki Master. There were no reports of seizures during this study. Reiki may be a useful adjunct for children with increased stress levels and sleep disturbances secondary to their medical condition. Further research is warranted to evaluate the use of Reiki in children, particularly with a large sample size, and to evaluate the long-term use of Reiki and its effects on adequate sleep.

  8. Stress levels of critical care doctors in India: A national survey

    Rahul Amte


    Full Text Available Background: Doctors working in critical care units are prone to higher stress due to various factors such as higher mortality and morbidity, demanding service conditions and need for higher knowledge and technical skill. Aim: The aim was to evaluate the stress level and the causative stressors in doctors working in critical care units in India. Materials and Methods: A two modality questionnaire-based cross-sectional survey was conducted. In manual mode, randomly selected delegates attending the annual congress of Indian Society of Critical Care Medicine filled the questionnaire. In the electronic mode, the questionnaires were E-mailed to critical care doctors. These questionnaires were based on General Health Questionnaire-12 (GHQ-12. Completely filled 242 responses were utilized for comparative and correlation analysis. Results: Prevalence of moderate to severe stress level was 40% with a mean score of 2 on GHQ-12 scale. Too much responsibility at times and managing VIP patients ranked as the top two stressors studied, while the difficult relationship with colleagues and sexual harassment were the least. Intensivists were spending longest hours in the Intensive Care Unit (ICU followed by pulmonologists and anesthetists. The mean number of ICU bed critical care doctors entrusted with was 13.2 ± 6.3. Substance abuse to relieve stress was reported as alcohol (21%, anxiolytic or antidepressants (18% and smoking (14%. Conclusion: Despite the higher workload, stress levels measured in our survey in Indian critical care doctors were lower compared to International data. Substantiation of this data through a wider study and broad-based measures to improve the quality of critical care units and quality of the lives of these doctors is the need of the hour.


    Groundwater flow models are usually calibrated with respect to water level measurements collected at intervals of several months or even years. Measurements of these kinds are not sensitive to sudden or short stress conditions, such as impact from stormwater drainage flow or flas...

  10. Principles of the measurement of residual stress by neutron diffraction

    Webster, G.A.; Ezeilo, A.N. [Imperial Coll. of Science and Technology, London (United Kingdom). Dept. of Mechanical Engineering


    The presence of residual stresses in engineering components can significantly affect their load carrying capacity and resistance to fracture. In order to quantify their effect it is necessary to know their magnitude and distribution. Neutron diffraction is the most suitable method of obtaining these stresses non-destructively in the interior of components. In this paper the principles of the technique are described. A monochromatic beam of neutrons, or time of flight measurements, can be employed. In each case, components of strain are determined directly from changes in the lattice spacings between crystals. Residual stresses can then be calculated from these strains. The experimental procedures for making the measurements are described and precautions for achieving reliable results discussed. These include choice of crystal planes on which to make measurements, extent of masking needed to identify a suitable sampling volume, type of detector and alignment procedure. Methods of achieving a stress free reference are also considered. A selection of practical examples is included to demonstrate the success of the technique. (author) 14 figs., 1 tab., 18 refs.

  11. Evaluation of Pressure Pain Threshold as a Measure of Perceived Stress and High Job Strain.

    Hven, Lisbeth; Frost, Poul; Bonde, Jens Peter Ellekilde


    To investigate whether pressure pain threshold (PPT), determined by pressure algometry, can be used as an objective measure of perceived stress and job strain. We used cross-sectional base line data collected during 1994 to 1995 within the Project on Research and Intervention in Monotonous work (PRIM), which included 3123 employees from a variety of Danish companies. Questionnaire data included 18 items on stress symptoms, 23 items from the Karasek scale on job strain, and information on discomfort in specified anatomical regions was also collected. Clinical examinations included pressure pain algometry measurements of PPT on the trapezius and supraspinatus muscles and the tibia. Associations of stress symptoms and job strain with PPT of each site was analyzed for men and women separately with adjustment for age body mass index, and discomfort in the anatomical region closest to the point of pressure algometry using multivariable linear regression. We found significant inverse associations between perceived stress and PPT in both genders in models adjusting for age and body mass index: the higher level of perceived stress, the lower the threshold. For job strain, associations were weaker and only present in men. In men all associations were attenuated when adjusting for reported discomfort in regions close to the site of pressure algometry. The distributions of PPT among stressed and non-stressed persons were strongly overlapping. Despite significant associations between perceived stress and PPT, the discriminative capability of PPT to distinguish individuals with and without stress is low. PPT measured by pressure algometry seems not applicable as a diagnostic tool of a state of mental stress.

  12. Perinatal Oxidative Stress May Affect Fetal Ghrelin Levels in Humans

    Zhong-Cheng Luo; Jean-François Bilodeau; Anne Monique Nuyt; Fraser, William D; Pierre Julien; Francois Audibert; Lin Xiao; Carole Garofalo; Emile Levy


    In vitro cell model studies have shown that oxidative stress may affect beta-cell function. It is unknown whether oxidative stress may affect metabolic health in human fetuses/newborns. In a singleton pregnancy cohort (n = 248), we studied maternal (24–28 weeks gestation) and cord plasma biomarkers of oxidative stress [malondialdehyde (MDA), F2-isoprostanes] in relation to fetal metabolic health biomarkers including cord plasma glucose-to-insulin ratio (an indicator of insulin sensitivity), p...

  13. Changes in eosinophil and corticosterone levels and catecholamine metabolism during emotionalpainful stress

    Malyshev, V.V.; Manukhin, B.N.; Petrova, V.A.


    The aim of this investigation was to study blood levels of eosinophils, corticosterone (CS), adrenalin, noradrenalin (NA), and dopamine (DA) during the development of the stress reaction, and also to study neuronal uptake and synthesis of catecholamines in the adrenals and heart. In some animal groups, the neuronal uptake of /sup 3/H-NA and the intensity of /sup 3/H-Na and /sup 3/H-DA synthesis from /sup 3/H-tyrosine were investigated by a method described previously, 2 h after the end of induction of emotional-painful stress (EPS). Radioactivity was measured on an SL-30 liquid scintillation counter. A regular relationship was found between changes in blood eosinophil level, the CH concentration, and catecholamine metabolism in the course of EPS.

  14. A Hydraulic Stress Measurement System for Deep Borehole Investigations

    Ask, Maria; Ask, Daniel; Cornet, Francois; Nilsson, Tommy


    Luleå University of Technology (LTU) is developing and building a wire-line system for hydraulic rock stress measurements, with funding from the Swedish Research Council and Luleå University of Technology. In this project, LTU is collaborating with University of Strasbourg and Geosigma AB. The stress state influences drilling and drillability, as well as rock mass stability and permeability. Therefore, knowledge about the state of in-situ stress (stress magnitudes, and orientations) and its spatial variation with depth is essential for many underground rock engineering projects, for example for underground storage of hazardous material (e.g. nuclear waste, carbon dioxide), deep geothermal exploration, and underground infrastructure (e.g. tunneling, hydropower dams). The system is designed to conduct hydraulic stress testing in slim boreholes. There are three types of test methods: (1) hydraulic fracturing, (2) sleeve fracturing and (3) hydraulic testing of pre-existing fractures. These are robust methods for determining in situ stresses from boreholes. Integration of the three methods allows determination of the three-dimensional stress tensor and its spatial variation with depth in a scientific unambiguously way. The stress system is composed of a downhole and a surface unit. The downhole unit consists of hydraulic fracturing equipment (straddle packers and downhole imaging tool) and their associated data acquisition systems. The testing system is state of the art in several aspects including: (1) Large depth range (3 km), (2) Ability to test three borehole dimensions (N=76 mm, H=96 mm, and P=122 mm), (3) Resistivity imager maps the orientation of tested fracture; (4) Highly stiff and resistive to corrosion downhole testing equipment; and (5) Very detailed control on the injection flow rate and cumulative volume is obtained by a hydraulic injection pump with variable piston rate, and a highly sensitive flow-meter. At EGU General Assembly 2017, we would like to

  15. The Influence of Social Support on the Levels of Depression, Anxiety and Stress among Students in Ghana

    Kugbey, Nuworza; Osei-Boadi, Samuel; Atefoe, Ethel Akpene


    This study examined the impact of social support from family, friends and significant others on the levels depression, anxiety and stress among undergraduate students of University of Ghana. A total of one hundred and sixty-five (165) students were sampled from all the levels and were administered with standardized questionnaires measuring social…

  16. Linear and nonlinear modulus surfaces in stress space, from stress-strain measurements on Berea sandstone

    M. Boudjema


    Full Text Available The elastic response of many rocks to quasistatic stress changes is highly nonlinear and hysteretic, displaying discrete memory. Rocks also display unusual nonlinear response to dynamic stress changes. A model to describe the elastic behavior of rocks and other consolidated materials is called the Preisach-Mayergoyz (PM space model. In contrast to the traditional analytic approach to stress-strain, the PM space picture establishes a relationship between the quasistatic data and a number density of hysteretic mesoscopic elastic elements in the rock. The number density allows us to make quantitative predictions of dynamic elastic properties. Using the PM space model, we analyze a complex suite of quasistatic stress-strain data taken on Berea sandstone. We predict a dynamic bulk modulus and a dynamic shear modulus surface as a function of mean stress and shear stress. Our predictions for the dynamic moduli compare favorably to moduli derived from time of flight measurements. We derive a set of nonlinear elastic constants and a set of constants that describe the hysteretic behavior of the sandstone.

  17. Raman microprobe measurements of stress in ion implanted materials

    Nugent, K.W.; Prawer, S.; Weiser, P.S.; Dooley, S.P. [Melbourne Univ., Parkville, VIC (Australia). School of Physics


    Raman microprobe measurements of ion implanted diamond and silicon have shown significant shifts in the Raman line due to stresses in the materials. The Raman line shifts to higher energy if the stress is compressive and to lower energy for tensile stress{sup 1}. The silicon sample was implanted in a 60 {mu}m square with 2.56 x 10{sup 17} ions per square centimeter of 2 MeV Helium. This led to the formation of raised squares with the top 370mm above the original surface. In Raman studies of silicon using visible light, the depth of penetration of the laser beam into the sample is much less than one micron. It was found that the Raman line is due to the silicon overlying the damage region. The diamond sample was implanted with 2 x 10{sup 15} ions per square centimeter of 2.8 MeV carbon. It was concluded that the Raman spectrum could provide information concerning both the magnitude and the direction of stress in an ion implanted sample. It was possible in some cases to determine whether the stress direction is parallel or perpendicular to the sample surface. 1 refs., 2 figs.

  18. Stress Rupture Life Reliability Measures for Composite Overwrapped Pressure Vessels

    Murthy, Pappu L. N.; Thesken, John C.; Phoenix, S. Leigh; Grimes-Ledesma, Lorie


    Composite Overwrapped Pressure Vessels (COPVs) are often used for storing pressurant gases onboard spacecraft. Kevlar (DuPont), glass, carbon and other more recent fibers have all been used as overwraps. Due to the fact that overwraps are subjected to sustained loads for an extended period during a mission, stress rupture failure is a major concern. It is therefore important to ascertain the reliability of these vessels by analysis, since the testing of each flight design cannot be completed on a practical time scale. The present paper examines specifically a Weibull statistics based stress rupture model and considers the various uncertainties associated with the model parameters. The paper also examines several reliability estimate measures that would be of use for the purpose of recertification and for qualifying flight worthiness of these vessels. Specifically, deterministic values for a point estimate, mean estimate and 90/95 percent confidence estimates of the reliability are all examined for a typical flight quality vessel under constant stress. The mean and the 90/95 percent confidence estimates are computed using Monte-Carlo simulation techniques by assuming distribution statistics of model parameters based also on simulation and on the available data, especially the sample sizes represented in the data. The data for the stress rupture model are obtained from the Lawrence Livermore National Laboratories (LLNL) stress rupture testing program, carried out for the past 35 years. Deterministic as well as probabilistic sensitivities are examined.

  19. Endogenous auxin and jasmonic acid levels are differentially modulated by abiotic stresses in rice

    Hao eDu


    Full Text Available Abiotic stresses such as drought, salinity, and adverse temperatures are major limiting factors for plant growth and reproduction. Plant responses to these stresses are coordinated by arrays of regulatory networks including the induction of endogenous abscisic acid (ABA, a well documented phytohormone for stress responses. However, whether or how these abiotic stresses affect the endogenous biosynthesis or metabolism of other phytohormones remains largely unknown. Here, we report the changes of endogenous indole-3-acetic acid (IAA and jasmonic acid (JA levels and expression of genes related to the biosynthesis or signalling of these hormones in rice under various abiotic stress conditions. The IAA content was decreased after drought stress, but it was significantly increased under cold and heat stresses. And the auxin-regulated gravitropism of root tip was inhibited by cold stress. Many genes involved in the IAA biosynthesis and signalling were changed in transcript level under these stresses, and the changes were essentially in agreement with the change of endogenous IAA level. Interestingly, the endogenous JA content was increased markedly under drought and cold stresses, but it was reduced by heat stress. Accordingly, many genes involved in JA biosynthesis and signalling were induced by drought and cold treatment but these genes were significantly suppressed by heat stress. We concluded that endogenous levels of IAA and JA were differentially regulated by abiotic stresses in rice, implying diverse roles of these hormones in stress responses.

  20. Impact of stress and levels of corticosterone on the development of breast cancer in rats

    De la Roca-Chiapas JM


    Full Text Available José María De la Roca-Chiapas,1 Gloria Barbosa-Sabanero,2 Jorge Antonio Martínez-García,3 Joel Martínez-Soto,1 Víctor Manuel Ramos-Frausto,1 Leivy Patricia González-Ramírez,1 Ken Nowack4 1Department of Psychology, 2Department of Medical Sciences, Division of Health Sciences, Campus Leon-University of Guanajuato, Guanajuato, 3General Regional Hospital of Leon, Guanajuato, Mexico; 4Envisia Learning, Inc., Santa Monica, CA, USA Abstract: Stress is experienced during cancer, and impairs the immune system's ability to protect the body. Our aim was to investigate if isolation stress has an impact on the development of tumors in rats, and to measure the size and number of tumors and the levels of corticosterone. Breast cancer was induced in two groups of female rats (N=20 by administration of a single dose of N-methyl-N-nitrosourea 50 mg/kg. Rats in the control group (cancer induction condition were allowed to remain together in a large cage, whereas in the second group, rats were also exposed to a stressful condition, that is, isolation (cancer induction and isolation condition, CIIC. The CIIC group displayed anxious behavior after 10 weeks of isolation. In the CIIC group, 16 tumors developed, compared with only eleven tumors in the control cancer induction condition group. In addition, compared with the control group, the volume of tumors in the CIIC group was greater, and more rats had more than one tumor and cells showed greater morphological damage. Levels of corticosterone were also significantly different between the two groups. This study supports the hypothesis that stress can influence the development of cancer, but that stress itself is not a sufficient factor for the development of cancer in rats. The study also provides new information for development of experimental studies and controlled environments. Keywords: breast cancer, corticosterone, isolation condition, psychoneuroimmunology, stress

  1. Leptin Level and Oxidative Stress Contribute to Obesity-Induced Low Testosterone in Murine Testicular Tissue

    Jian Zhao


    Full Text Available Objective. This study evaluated the effects of obesity on the function of reproductive organs in male mice and the possible mechanism of male secondary hypogonadism (SH in obesity. Methods. Ninety-six mice were randomly assigned to three groups: the control group, diet-induced obesity group, and diet-induced obesity resistant group for 8 weeks and 19 weeks. The effects of short- and long-term high-fat diet on the reproductive organs were determined by measuring sperm count and motility, relative testis weight, testosterone level, pathological changes and apoptosis of Leydig cells. Oxidative stress was evaluated by determining malondialdehyde, H2O2, NO levels, and GSH in testis tissues. CAT, SOD, GSH-Px and Nrf2 mRNA were measured by real-time PCR. Results. Short- and long-term high-fat diet decreased sperm count and motility, relative testis weight, testosterone level; decreased CAT, SOD, GSH-Px and Nrf2 mRNA expression; increased MDA, H2O2, NO and leptin levels; inhibited the activity of CAT and GSH-Px enzymes. Pathological injury and apoptosis of Leydig cells were found in testis tissue. Conclusions. Pathological damage of Leydig cells, oxidative stress in testis tissue, and high level of leptin may provide some evidence to clarify the mechanisms of male SH in obesity.

  2. Design and analysis of a toroidal tester for the measurement of core losses under axial compressive stress

    Alatawneh, Natheer; Rahman, Tanvir; Lowther, David A.; Chromik, Richard


    Electric machine cores are subjected to mechanical stresses due to manufacturing processes. These stresses include radial, circumferential and axial components that may have significant influences on the magnetic properties of the electrical steel and hence, on the output and efficiencies of electrical machines. Previously, most studies of iron losses due to mechanical stress have considered only radial and circumferential components. In this work, an improved toroidal tester has been designed and developed to measure the core losses and the magnetic properties of electrical steel under a compressive axial stress. The shape of the toroidal ring has been verified using 3D stress analysis. Also, 3D electromagnetic simulations show a uniform flux density distribution in the specimen with a variation of 0.03 T and a maximum average induction level of 1.5 T. The developed design has been prototyped, and measurements were carried out using a steel sample of grade 35WW300. Measurements show that applying small mechanical stresses normal to the sample thickness rises the delivered core losses, then the losses decrease continuously as the stress increases. However, the drop in core losses at high stresses does not go lower than the free-stress condition. Physical explanations for the observed trend of core losses as a function of stress are provided based on core loss separation to the hysteresis and eddy current loss components. The experimental results show that the effect of axial compressive stress on magnetic properties of electrical steel at high level of inductions becomes less pronounced.

  3. Plasma, salivary and urinary cortisol levels following physiological and stress doses of hydrocortisone in normal volunteers.

    Jung, Caroline; Greco, Santo; Nguyen, Hanh H T; Ho, Jui T; Lewis, John G; Torpy, David J; Inder, Warrick J


    Glucocorticoid replacement is essential in patients with primary and secondary adrenal insufficiency, but many patients remain on higher than recommended dose regimens. There is no uniformly accepted method to monitor the dose in individual patients. We have compared cortisol concentrations in plasma, saliva and urine achieved following "physiological" and "stress" doses of hydrocortisone as potential methods for monitoring glucocorticoid replacement. Cortisol profiles were measured in plasma, saliva and urine following "physiological" (20 mg oral) or "stress" (50 mg intravenous) doses of hydrocortisone in dexamethasone-suppressed healthy subjects (8 in each group), compared to endogenous cortisol levels (12 subjects). Total plasma cortisol was measured half-hourly, and salivary cortisol and urinary cortisol:creatinine ratio were measured hourly from time 0 (between 0830 and 0900) to 5 h. Endogenous plasma corticosteroid-binding globulin (CBG) levels were measured at time 0 and 5 h, and hourly from time 0 to 5 h following administration of oral or intravenous hydrocortisone. Plasma free cortisol was calculated using Coolens' equation. Plasma, salivary and urine cortisol at 2 h after oral hydrocortisone gave a good indication of peak cortisol concentrations, which were uniformly supraphysiological. Intravenous hydrocortisone administration achieved very high 30 minute cortisol concentrations. Total plasma cortisol correlated significantly with both saliva and urine cortisol after oral and intravenous hydrocortisone (P cortisol and urinary cortisol:creatinine ratio may provide useful alternatives to plasma cortisol measurements to monitor replacement doses in hypoadrenal patients.

  4. Assessment of nursing students' stress levels and coping strategies in operating room practice.

    Yildiz Findik, Ummu; Ozbas, Ayfer; Cavdar, Ikbal; Yildizeli Topcu, Sacide; Onler, Ebru


    The aim of this study was to evaluate the stress levels and stress coping strategies of nursing students in their first operating room experience. This descriptive study was done with 126 nursing students who were having an experience in an operating room for the first time. Data were collected by using Personal Information Form, Clinical Stress Questionnaire, and Styles of Coping Inventory. The nursing students mostly had low clinical stress levels (M = 27.56, SD = 10.76) and adopted a self-confident approach in coping with stress (M = 14.3, SD = 3.58). The nursing students generally employed a helpless/self-accusatory approach among passive patterns as their clinical stress levels increased, used a self-confident and optimistic approach among active patterns as their average age increased, and those who had never been to an operating room previously used a submissive approach among passive patterns. The results showed that low levels of stress caused the nursing students to use active patterns in coping with stress, whereas increasing levels of stress resulted in employing passive patterns in stress coping. The nursing students should be ensured to maintain low levels of stress and use active patterns in stress coping.

  5. Assessment the effect of NO inhibition on hippocampal normetanephrine level in stress and non-stress conditions in adult male rats

    Hana Molahoveizeh


    Full Text Available Background: Nitric oxide (NO has a role in the regulation of neurotransmitters release such as norepinephrine, in the hippocampus.Normetanephrine (NMN is a metabolite of norepinephrine created by action of catechol-O-methyl transferase (COMT on norepinephrine. Several studies have shown that various stresses increased release of norepinephrine and its metabolites. Therefore in the present study, the role of Nitric oxide in regulation of norepinephrine release and its metabolism was investigated by administration of L-NAME (NO synthase inhibitor in stressed and non-stressed rats. Materials and Methods: For this purpose, 50 adult rats were divided into 10 groups, of which 5 groups were exposed to restraint stress while another 5 groups were without stress. These two set of groups included intact, saline and L-NAME (20, 40, 80 mg/kg. Thirty minutes after intraperituneal injection of L-NAME, brains removed, the hippocampus dissected, weighed, homogenized and centrifuged then amount of NMN measured by ELISA kit. Results: The results showed that in non-stressed condition amount of NMN were significantly increased in group that received L-NAME (80 mg/kg in comparison with other groups but in stress condition, amount of NMN was significantly decreased in groups that received L-NAME (20,40,80 mg/kg, in comparison with control and saline groups. Comparison between stress and non-stressed groups showed that stress alone cause an increase in amount of NMN in control and saline groups. Conclusion: In conclusion, NO synthesis inhibition produced opposite responses with respect to NMN amount in the presence or absence of stress, and probably L-NAME preventing the effect of stress on increasing NMN levels mediated by nitrergic pathway.

  6. Variations in Oxidative Stress Levels in 3 Days Follow-up in Ultramarathon Mountain Race Athletes.

    Spanidis, Ypatios; Stagos, Dimitrios; Orfanou, Marina; Goutzourelas, Nikolaos; Bar-Or, David; Spandidos, Demetrios; Kouretas, Demetrios


    Spanidis, Y, Stagos, D, Orfanou, M, Goutzourelas, N, Bar-or, D, Spandidos, D, and Kouretas, D. Variations in oxidative stress levels in 3 days follow-up in ultramarathon mountain race athletes. J Strength Cond Res 31(3): 582-594, 2017-The aim of the present study was the monitoring of the redox status of runners participating in a mountain ultramarathon race of 103 km. Blood samples from 12 runners were collected prerace and 24, 48, and 72 hours postrace. The samples were analyzed by using conventional oxidative stress markers, such as protein carbonyls (CARB), thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC) in plasma, as well as glutathione (GSH) levels and catalase (CAT) activity in erythrocytes. In addition, 2 novel markers, the static oxidation-reduction potential marker (sORP) and the capacity oxidation-reduction potential (cORP), were measured in plasma. The results showed significant increase in sORP levels and significant decrease in cORP and GSH levels postrace compared with prerace. The other markers did not exhibit significant changes postrace compared with prerace. Furthermore, an interindividual analysis showed that in all athletes but one sORP was increased, whereas cORP was decreased. Moreover, GSH levels were decreased in all athletes at least at 2 time points postrace compared with prerace. The other markers exhibited great variations between different athletes. In conclusion, ORP and GSH markers suggested that oxidative stress has existed even 3 days post ultramarathon race. The practical applications from these results would be that the most effective markers for short-term monitoring of ultramarathon mountain race-induced oxidative stress were sORP, cORP, and GSH. Also, administration of supplements enhancing especially GSH is recommended during ultramarathon mountain races to prevent manifestation of pathological conditions.

  7. Survey of career satisfaction, lifestyle, and stress levels among pharmacy school faculty.

    Lindfelt, Tristan A; Ip, Eric J; Barnett, Mitchell J


    U.S. pharmacy school faculty were surveyed to assess their career satisfaction, lifestyle, and stress levels. A 48-item survey, administered through Qualtrics (Provo, UT), was sent to current members of the American Association of Colleges of Pharmacy and included questions regarding respondents' academic institution and appointment status; lifestyle traits; career satisfaction; work-life balance; neurologic and psychiatric diagnoses; use of illicit drugs, alcohol, and tobacco; and stress levels. of the 4787 faculty invited to participate in the survey, 811 usable surveys were collected (16.9% response rate). Nearly all respondents (95.0%) reported working 40 or more hours per week. The majority had an average daily one-way commute of less than 30 minutes (64.2%), slept 5.5-7.5 hours per night (74.8%), and exercised for no more than 120 minutes per week (61.8%). A majority of respondents (63.7%) reported being very or extremely satisfied with their current position in academia. Only 36.9% reported being very or extremely satisfied with their work-life balance. Mean perceived stress scores were near those found in the general adult population. Although most respondents reported seeing a primary care provider and dentist annually, other findings regarding preventive health measures were not as encouraging. A survey of pharmacy faculty in the United States revealed high levels of job satisfaction among respondents, but lower levels of satisfaction with work-life balance and comparable levels of stress to the general population were found. Administrators and stakeholders should explore options to improve lifestyle factors to decrease potential burnout among faculty. Copyright © 2015 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  8. The effect of organisational restructuring on job satisfaction, career aspirations and stress levels of employees

    E. N. Marais


    Full Text Available The field study reported here examined the effects of organisational restructuring on employees' job satisfaction, career aspirations and stress levels. Immediately after restructuring took place in the organisation, the employees affected by this advent were tested to determine whether restructuring would impact on the three variables. Eight months after restructuring in the organisation took place their job satisfaction, career aspirations and stress levels were measured again. The results of the research indicated no changes in job satisfaction levels, career aspirations or stress levels. The results provided no support for the expectation that after a time lapse of eight months the effects or organisational restructuring would diminish and that workers would experience a greater degree of job satisfaction. In addition, it would appear that the time lapse did not improve perceived career prospects or that stress levels decreased. Opsomming Die navorsing wat hier gerapporteer word/ het die effek van organisatoriese herstrukturering op werknemers se werkstevredenheid, loopbaanaspirasies en spanningsvlakke ondersoek. Onmiddellik nadat herstrukturering in die organisasie plaasgcvind het, is die werknemers wat deur die herstrukturering geraak is, getoets om vas te stel of herstrukturering 'n impak op die drie veranderlikes sou hê. Agt maande later is hul werkstevredenheid, loopbaanaspirasies en spanningsvlakke weer gemeet. Daar is gevind dat die werknemers se reaksie op organisatoriese herstrukturering onveranderd gebly het. Die resultate het geen steun verleen aan die verwagting dat die tydsverloop van agt maande die effek van organisatoriese herstrukturering sal verminder nie en dat werknemers tot 'n groter mate werkstevredenheid sal ervaar nie. Dit blyk verder dat die tydsverloop ook nie verbeterde loopbaanvooruitsigte tot gevolg gehad het of dat die werknemers se spanningsvlakke verlaag het nie.

  9. Organizational politics, nurses' stress, burnout levels, turnover intention and job satisfaction.

    Labrague, L J; McEnroe-Petitte, D M; Gloe, D; Tsaras, K; Arteche, D L; Maldia, F


    This is a research report examining the influence of organizational politics perceptions on nurses' work outcomes (job satisfaction, work stress, job burnout and turnover intention). Organizational politics is a phenomenon common in almost all institutions and is linked with undesirable consequences in employees. Despite the plethora of research around the world on this topic, studies describing organizational politics in nursing remain underexplored. A cross-sectional research design was utilized in this study. One hundred sixty-six (166) nurses participated. Five standardized tools were used: the Job Satisfaction Index, the Job Stress Scale, the Burnout Measure Scale, the Turnover Intention Inventory Scale and the Perception of Organizational Politics Scale. Nurses employed both in private and government-owned hospitals perceived moderate levels of organizational politics. Positive correlations were identified between perceived organizational politics and job stress, turnover intention and job burnout. Negative correlations were found between perceived organizational politics and job satisfaction. Perceptions of workplace politics in Filipino nurses were lower when compared to findings in other international studies. A strong link was found between organizational politics perceptions and the four job outcomes (stress and burnout levels, turnover intention and job satisfaction). Use of a self-reporting questionnaire and exclusion of nurses from other provinces. Perceived organizational politics predicted nurses' stress and burnout levels, turnover intention and job satisfaction. The findings of this study may provide a valuable perspective of this organizational issue and could assist policymakers and nurse administrators in formulating interventions that could minimize the effect of workplace politics. © 2016 International Council of Nurses.

  10. Wall shear stress measurements using a new transducer

    Vakili, A. D.; Wu, J. M.; Lawing, P. L.


    A new instrument has been developed for direct measurement of wall shear stress. This instrument is simple and symmetric in design with small moving mass and no internal friction. Features employed in the design of this instrument eliminate most of the difficulties associated with the traditional floating element balances. Vibration problems associated with the floating element skin friction balances have been found to be minimized by the design features and optional damping provided. The unique design of this instrument eliminates or reduces the errors associated with conventional floating-element devices: such as errors due to gaps, pressure gradient, acceleration, heat transfer and temperature change. The instrument is equipped with various sensing systems and the output signal is a linear function of the wall shear stress. Measurement made in three different tunnels show good agreement with theory and data obtained by the floating element devices.

  11. Mechanical Stress Measurement During Thin-Film Fabrication

    Broadway, David M. (Inventor)


    A method and system are provided for determining mechanical stress experienced by a film during fabrication thereof on a substrate positioned in a vacuum deposition chamber. The substrate's first surface is disposed to have the film deposited thereon and the substrate's opposing second surface is a specular reflective surface. A portion of the substrate is supported. An optical displacement sensor is positioned in the vacuum deposition chamber in a spaced-apart relationship with respect to a portion of the substrate's second surface. During film deposition on the substrate's first surface, displacement of the portion of the substrate's second surface is measured using the optical displacement sensor. The measured displacement is indicative of a radius of curvature of the substrate, and the radius of curvature is indicative of mechanical stress being experienced by the film.

  12. Brief strategic therapy in first myocardial infarction patients with increased levels of stress: a randomized clinical trial.

    Rakowska, Jadwiga Małgorzata


    Little is known about the impact of interventions targeting chronic stress levels on clinical outcomes among myocardial infarction (MI) patients with increased levels of stress. To examine the impact of the addition of brief strategic therapy (BST) to usual care (UC) on clinical outcomes in first MI patients with increased levels of stress. Eighty-one patients were randomly assigned to BST in conjunction with UC (medical treatment, risk factor information, and guidance on unhealthy behavior change) or to UC. The outcome measures were scores on the Perceived Stress Scale, reinfarction and cardiac mortality rates, and scores on the Health Survey. Measures were taken before, post-treatment, and at two follow-ups. Patients subjected to BST showed reduced perceived stress at post-treatment and maintained decreased levels at follow-ups. At 1-year follow-up, they had a lower rate of non-fatal reinfarction, and at 2.5-year follow-up, they had a lower rate of fatal reinfarction. Their mental and physical health was improved at post-treatment and this was sustained at follow-ups. The addition of BST to UC favorably influences the disease course after MI in patients with increased levels of stress.

  13. Strain Measurement Using FBG on COPV in Stress Rupture Test

    Banks, Curtis; Grant, Joseph


    White Sands Test Facility (WSTF) was requested to perform ambient temperature hydrostatic pressurization testing of a Space Transportation System (STS) 40-in. Kevlar Composite Overwrapped Pressure Vessel (COPV). The 40-in. vessel was of the same design and approximate age as the STS Main Propulsion System (MPS) and Orbiter Maneuvering System (OMS) vessels. The NASA Engineering Safety Center (NESC) assembled a team of experts and conducted an assessment that involved a review of national Kevlar COPY data. During the review, the STS COPVs were found to be beyond their original certification of ten years. The team observed that the likelihood of STS COPV Stress rupture, a catastrophic burst before leak failure mode, was greater than previously believed. Consequently, a detailed assessment of remaining stress rupture life became necessary. Prior to STS-114, a certification deviation was written for two flights of OV-103 (Discovery) and OV-104 (Atlantis) per rationale that was based on an extensive review of the Lawrence Livermore National Laboratories, COPV data, and revisions to the STS COPV stress levels. In order to obtain flight rationale to extend the certification deviation through the end of the Program, the Orbiter Project Office has directed an interagency COPV team to conduct further testing and analysis to investigate conservatism in the stress rupture model and evaluate material age degradation. Additional analysis of stress rupture life requires understanding the fiber stresses including stress that occurs due to thru-wall composite compression in COPV components. Data must be obtained at both zero gauge pressure (pre-stress) and at the component operating pressure so that this phenomenon can be properly evaluated. The zero gauge pressure stresses are predominantly a result of the autofrettage process used during vessel manufacture. Determining these pre-stresses and the constitutive behavior of the overwrap at pressure will provide necessary information

  14. The Difficult Patient Stress Scale: a new instrument to measure interpersonal stress in nursing.

    Santamaria, N


    This study describes the development of the Difficult Patient Stress Scale, an instrument designed to investigate the stress that nurses experience when they are involved in interpersonal conflict with patients. The DPSS is based on the theoretical conceptualization of stress proposed by DeLongis, Lazarus and Folkman and on the personality theory of Individual Psychology. The DPSS utilises visual analog scales to measure nurses' responses to hypothetical scenarios that present typical, difficult nurse-patient situations. The DPSS has been tested over a period of two years with 228 nurses and the results to date indicate that it is valid, reliable and suitable for use in the clinical environment. It is proposed that it may provide a useful instrument for exploring the impact and frequency of interpersonal stressors in nursing and may assist in the development of educational programs to better equip nurses to deal with interpersonal nurse-patient conflict.


    A. Annunziato


    Full Text Available A new mareograph device has been designed at the Joint Research Centre (JRC of the European Commission (EC in order improve the sea level network in use for the Tsunami Hazard monitoring in the Mediterranean Sea and in the North Atlantic area (NEAMTWS area of UNESCO. The instrument has the characteristic to be cheap and very effective but its reliability, duration and quality need to be determined and qualified. For this reason a number of experimental campaigns are being conducted, whose first results are presented here. In collaboration with the UNESCO/IOC (Intergovernmental Oceanographic Commission, responsible of the definition of the Tsunami Warning System of this geographical area, a set of 20 devices has been offered by JRC for a period of 1 year of testing of the devices; the surveys for the installation of the devices is under way and the installation should be completed by the end of 2015.

  16. Oxidative Stress Level in the Testes of Mice and Rats during Nickel Intoxication

    Eugenia Murawska-Ciałowicz


    Full Text Available The genotioxic and carcinogenic effect of nickel probably results from its capacity to produce reactive oxygen species (ROS and disturb the redox balance. The aim of the study was to find out if rats lacking spermatic protamine 2 are less susceptible to Ni(II than mice. Consequently, the levels of malondialdehyde + 4 hydroxynonenal (MDA+4HDA − markers of lipid peroxidation, as well as the level of reduced glutathione (GSH were measured within the rat and mouse testes. Our results showed that the levels of lipid peroxidation markers were elevated in testicular homogenates of intoxicated mice without any changes in rats. GSH level was lower in the group of intoxicated mice comparing to the control without statistically significant changes in rats’ homogenates. Moreover, the level of GSH in the testes of intoxicated mice was lower than in rats. On the basis of our results, it appears that Ni(II can initiate oxidative stress in the testes of mice but not of rats and can reduce GSH level. Consequently, the antioxidative defense of the testes is reduced. Ni(II that causes oxidative stress in the testes may also contribute to infertility.

  17. Developments in wireline in-situ rock stress measurement

    Pedroso, Carlos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Canas, Jesus A.; Holzberg, Bruno; Gmach, Helmut [Schlumberger Servicos de Petroleo Ltda., Rio de Janeiro, RJ (Brazil)


    This paper presents recent developments of in-situ stress measurements with wireline tools. The stress measurements are based on the micro hydraulic techniques that can be initialized when an interval is pressurized by pumping fluid until a tensile fracture begins or by packers fracturing (sleeve fracturing). Ultrasonic and Micro-resistivity borehole image logs (before and after the testes) are used as a complement, in order to observe the fractures created by the tests, evaluating the mechanical behavior of the formation. An offshore case study is presented, where shales and tight sandstones at depths deeper than 4500 meters depth were successfully evaluated. A workflow to succeed on stress measurements on such environments is proposed, what includes a planning phase: where breakdown pressures ranges are estimated and compared with the capacity of the tools, a Real Time Monitoring phase, where a decision tree is proposed to help on quick decisions while testing, and an interpretation phase, where appropriate techniques are indicated to evaluate the results. Also, the paper presents the main operational needs to succeed on such environments. Basically, such tests require an entirely software controlled, motorized and modular design tool consisting of dual packer (DP), pump out and flow control modules (Figure 1). These modules were upgraded for the present environment: conditions such as temperatures above 300 deg F, formation pressures above 10,000 psia, very low formation permeability, high pressure differential need and oil based mud (OBM) environment. (author)

  18. Experiences on pollution level measurement in Mexico

    Montoya-Tena, Gerardo; Hernandez-Corona, Ramiro; Ramirez-Vazquez, Isaias [Instituto de Investigaciones Electricas, Reforma 113 Cuernavaca, Mor. (Mexico)


    The pollution on overhead insulators is influenced by the pollutant type as well as by the climate of the site. In Mexico, due to its orography and diversity of lands, there are several areas where the failures on the overhead insulation are mainly caused by the pollution. Since the decade of 1980s, various studies have been performed to solve or at least alleviate such transmission and distribution power line pollution-related problems. This paper presents a description of several studies conducted by the Mexican Electrical Research Institute 'Instituto de Investigaciones Electricas' (IIE) together with the Mexican electrical utility 'Comision Federal de Electricidad' (CFE), from the elaboration of a contamination map to the development of a system for measuring leakage current, which is used as a tool for the in-service diagnostic of insulators installed on lines of transmission. (author)

  19. Decreased total antioxidant levels and increased oxidative stress in ...

    Journal of Endocrinology, Metabolism and Diabetes of South Africa ... and oxidative stress in type 2 diabetes mellitus (T2DM) patients with that of healthy controls ... Conclusion: Early management through an antioxidant-rich diet and lifestyle ...

  20. Elevated social stress levels and depressive symptoms in primary hyperhidrosis

    Gross, Katharina M; Schote, Andrea B; Schneider, Katja Kerstin; Schulz, André; Meyer, Jobst


    .... Thus, the aim of the study is to investigate the relation between hyperhidrosis and different psychological as well as physiological aspects of chronic stress as a co-factor for the etiology of depression...

  1. Stress and physiological, behavioral and performance patterns of children under varied air ion levels

    Fornof, K. T.; Gilbert, G. O.


    The possibility that individual differences in reactivity to stressors are a major factor underlying discordant results reported for air ion studies prompted an investigation of response patterns in school children under both normal indoor air ion levels and moderately increased negative air ion levels (4000±500/cm3). It was hypothesized that the impact of stressors is reduced with high negative air ionization, and that resultant changes in stress effects would be differentially exhibited according to the children's normal degree of stimulus reactivity. A counter-balanced, replicative, withinssubject design was selected, and the subjects were 12 environmentally sensitive, 1st 4th grade school children. In addition to monitoring stress effects on activity level, attention span, concentration to task and conceptual performance, measures were also made of urinary 5-hydroxyindole acetic acid levels and skin resistance response (SRR) to determine if changes extended to the physiological state. The cold water test was used to add physical stress and enable calculations of Lacey's autonomic lability scores (ALS) as indicators of individual reactivity. The results show main effects for air ions on both physiological parameters, with 48% less change in %SRR ( Pstress tolerance. Strong interactive effects for ALS x air ion condition appeared, with high and low ALS children reacting oppositely to negative air ions in measures of skin resistance level ( P<0.01), wrist activity ( P<0.01) and digit span backwards ( P<0.004). Thus individual differences in autonomic reactivity and the presence or absence of stressors appear as critical elements for internal validity, and in preventing consequent skewed results from obscuring progress in air ion research.

  2. Long-term vegetarians have low oxidative stress, body fat, and cholesterol levels.

    Kim, Mi Kyung; Cho, Sang Woon; Park, Yoo Kyoung


    Excessive oxidative stress and abnormal blood lipids may cause chronic diseases. This risk can be reduced by consuming an antioxidant- and fiber-rich vegetarian diet. We compared biomarkers of oxidative stress, antioxidant capacity, and lipid profiles of sex- and age-matched long-term vegetarians and omnivores in Korea. Forty-five vegetarians (23 men and 22 women; mean age, 49.5 ± 5.3 years), who had maintained a vegetarian diet for a minimum of 15 years, and 30 omnivores (15 men and 15 women; mean age, 48.9 ± 3.6 years) participated in this study. Their 1-day, 24-h recall, and 2-day dietary records were analyzed. Oxidative stress was measured by the levels of diacron reactive oxygen metabolites (d-ROM). Antioxidant status was determined by the biological antioxidant potential (BAP) and levels of endogenous antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. We observed that vegetarians had a significantly lower body fat percentage (21.6 ± 6.4%) than that of omnivores (25.4 ± 4.6%; P vegetarians than those in omnivores (331.82 ± 77.96 and 375.80 ± 67.26 Carratelli units; P vegetarians and omnivores were 173.73 ± 31.42 mg/dL and 193.17 ± 37.89 mg/dL, respectively (P vegetarians and omnivores, respectively, indicating that vegetarians had significantly lower lipid levels. Thus, oxidative stress, body fat, and cholesterol levels were lower in long-term vegetarians than those in omnivores.

  3. Interindividual differences in stress sensitivity: basal and stress-induced cortisol levels differentially predict neural vigilance processing under stress

    Henckens, M.J.A.G.; Klumpers, F.; Everaerd, D.S.; Kooijman, S.C.; van Wingen, G.A.; Fernandez, G.S.E.


    Stress exposure is known to precipitate psychological disorders. However, large differences exist in how individuals respond to stressful situations. A major marker for stress sensitivity is hypothalamus-pituitary-adrenal (HPA)-axis function. Here, we studied how interindividual variance in both bas

  4. Interindividual differences in stress sensitivity: Basal and stress-induced cortisol levels differentially predict neural vigilance processing under stress

    Henckens, M.J.A.G.; Klumpers, F.; Everaerd, D.S.; Kooijman, S.C.; Wingen, G.A. van; Fernandez, G.S.E.


    Stress exposure is known to precipitate psychological disorders. However, large differences exist in how individuals respond to stressful situations. A major marker for stress sensitivity is hypothalamus-pituitary-adrenal (HPA)-axis function. Here, we studied how interindividual variance in both bas

  5. Interindividual differences in stress sensitivity: Basal and stress-induced cortisol levels differentially predict neural vigilance processing under stress

    Henckens, M.J.A.G.; Klumpers, F.; Everaerd, D.S.; Kooijman, S.C.; Wingen, G.A. van; Fernandez, G.S.E.


    Stress exposure is known to precipitate psychological disorders. However, large differences exist in how individuals respond to stressful situations. A major marker for stress sensitivity is hypothalamus-pituitary-adrenal (HPA)-axis function. Here, we studied how interindividual variance in both

  6. Interindividual differences in stress sensitivity: basal and stress-induced cortisol levels differentially predict neural vigilance processing under stress

    Henckens, M.J.A.G.; Klumpers, F.; Everaerd, D.S.; Kooijman, S.C.; van Wingen, G.A.; Fernandez, G.S.E.


    Stress exposure is known to precipitate psychological disorders. However, large differences exist in how individuals respond to stressful situations. A major marker for stress sensitivity is hypothalamus-pituitary-adrenal (HPA)-axis function. Here, we studied how interindividual variance in both

  7. Comet assay as an indirect measure of systemic oxidative stress.

    Fang, Lei; Neutzner, Albert; Turtschi, Stephanie; Flammer, Josef; Mozaffarieh, Maneli


    Higher eukaryotic organisms cannot live without oxygen; yet, paradoxically, oxygen can be harmful to them. The oxygen molecule is chemically relatively inert because it has two unpaired electrons located in different pi * anti-bonding orbitals. These two electrons have parallel spins, meaning they rotate in the same direction about their own axes. This is why the oxygen molecule is not very reactive. Activation of oxygen may occur by two different mechanisms; either through reduction via one electron at a time (monovalent reduction), or through the absorption of sufficient energy to reverse the spin of one of the unpaired electrons. This results in the production of reactive oxidative species (ROS). There are a number of ways in which the human body eliminates ROS in its physiological state. If ROS production exceeds the repair capacity, oxidative stress results and damages different molecules. There are many different methods by which oxidative stress can be measured. This manuscript focuses on one of the methods named cell gel electrophoresis, also known as "comet assay" which allows measurement of DNA breaks. If all factors known to cause DNA damage, other than oxidative stress are kept constant, the amount of DNA damage measured by comet assay is a good parameter of oxidative stress. The principle is simple and relies upon the fact that DNA molecules are negatively charged. An intact DNA molecule has such a large size that it does not migrate during electrophoresis. DNA breaks, however, if present result in smaller fragments which move in the electrical field towards the anode. Smaller fragments migrate faster. As the fragments have different sizes the final result of the electrophoresis is not a distinct line but rather a continuum with the shape of a comet. The system allows a quantification of the resulting "comet" and thus of the DNA breaks in the cell.

  8. An increase in salivary interleukin-6 level following acute psychosocial stress and its biological correlates in healthy young adults.

    Izawa, Shuhei; Sugaya, Nagisa; Kimura, Kenta; Ogawa, Namiko; Yamada, Kosuke C; Shirotsuki, Kentaro; Mikami, Ikuyo; Hirata, Kanako; Nagano, Yuichiro; Nomura, Shinobu


    Although interleukin-6 (IL-6) has been investigated frequently in stress research, knowledge regarding the biological processes of IL-6 in association with psychosocial stress remains incomplete. This study focused on salivary IL-6 and reports its temporal variation and biological correlates following acute psychosocial stress. Fifty healthy young adults (39 male and 11 female students) were subjected to the psychosocial stress test 'Trier Social Stress Test' (TSST), wherein the participants were asked to deliver a speech and perform a mental arithmetic task in front of 2 audiences. Collection of saliva samples, measurement of heart rate, and assessment of negative moods by visual analogue scales were conducted before, during, and after TSST. Salivary IL-6 levels increased by approximately 50% in response to the TSST and remained elevated for 20 min after the stress tasks were completed. Cluster analyses revealed that individuals with sustained elevation of IL-6 levels following the TSST exhibited a lower cortisol response compared to individuals with lower IL-6 levels. In the correlation analyses, a greater IL-6 response was associated with a higher heart rate during the mental arithmetic task (r=.351, ppsychosocial stress, and suggests that sympathetic activity and cortisol secretion are involved in elevation of salivary IL-6 levels.

  9. Depression, anxiety and stress levels in industrial workers: A pilot study in Bangalore, India

    Sheldon Rao


    Full Text Available Background: Mental health disorders affect around 500 million people worldwide. In India, around 10-12% of people are affected by a mental disorder either due to stress, depression, anxiety, or any other cause. Mental health of workers affects the productivity of the workplace, with estimates putting these losses to be over 100 million dollars annually. Aims: The study aims to measure depression, anxiety, and stress levels of workers in an industry and to investigate if it has any effect on productivity of the firm. Materials and Methods: The study utilized a cross-sectional design and was conducted among workmen of the firm. A sociodemographic based questionnaire and a mental health screening tool -Depression Anxiety Stress Scale (DASS-21 were used for the same. A total of 90 completed questionnaires were analyzed for the study. The data was analyzed for central tendencies as well as for any associations and correlations. Results: The study showed that none of the workers had a positive score for depression. It also showed that around 36% of the workers had a positive score for anxiety and 18% of the workers had a positive score for stress on DASS-21 scale. The odds ratio between stress and number of leaves taken by a worker in the last 3 months suggested a dose-response relationship, but was statistically insignificant. Conclusion: The study found a prevalence rate of around 18-36% for anxiety and stress amongst the workers at the factory. Large-scale studies will help understand the effect mental health status has on the Indian workplace.

  10. Time Course of Behavioral Alteration and mRNA Levels of Neurotrophic Factor Following Stress Exposure in Mouse.

    Hashikawa, Naoya; Ogawa, Takumi; Sakamoto, Yusuke; Ogawa, Mami; Matsuo, Yumi; Zamami, Yoshito; Hashikawa-Hobara, Narumi


    Stress is known to affect neurotrophic factor expression, which induces depression-like behavior. However, whether there are time-dependent changes in neurotrophic factor mRNA expression following stress remains unclear. In the present study, we tested whether chronic stress exposure induces long-term changes in depression-related behavior, serum corticosterone, and hippocampal proliferation as well as neurotrophic factor family mRNA levels, such as brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), neurotrophin-3 (NT-3), and ciliary neurotrophic factor (CNTF), in the mouse hippocampus. The mRNA level of neurotrophic factors (BDNF, NGF, NT-3, and CNTF) was measured using the real-time PCR. The serum corticosterone level was evaluated by enzyme-linked immunosorbent assay, and, for each subject, the hippocampal proliferation was examined by 5-bromo-2-deoxyuridine immunostaining. Mice exhibited depression-like behavior in the forced-swim test (FST) and decreased BDNF mRNA and hippocampal proliferation in the middle of the stress exposure. After 15 days of stress exposure, we observed increased immobility in the FST, serum corticosterone levels, and BDNF mRNA levels and degenerated hippocampal proliferation, maintained for at least 2 weeks. Anhedonia-like behavior in the sucrose preference test and NGF mRNA levels were decreased following 15 days of stress. NGF mRNA levels were significantly higher 1 week after stress exposure. The current data demonstrate that chronic stress exposure induces prolonged BDNF and NGF mRNA changes and increases corticosterone levels and depression-like behavior in the FST, but does not alter other neurotrophic factors or performance in the sucrose preference test.

  11. Stresses and residual stresses optical measurements systems evaluation; Avaliacao de sistemas opticos de medicao de tensoes e tensoes residuais em dutos

    Peixoto Filho, Flavio Tito; Goncalves Junior, Armando Albertazzi [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Lab. de Metrologia e Automatizacao (LABMETRO)


    There is always a constant concern about the pipelines' integrity. An important control parameter is the level of total mechanical stresses acting over the pipeline. However, the loading and residual stresses acting on a pipeline are not measured in the field as much as necessary. Technical difficulties and the high cost of the nowadays techniques and the hostile measurement conditions are the main reason for that. An alternative method has been developed at the Universidade Federal de Santa Catarina (UFSC) since 1992. A new optical measurement device is used to measure strains, mechanical stresses and residual stresses acting over the structure. A metrological and functional evaluation of this system is the main focus of this paper. (author)

  12. The Research of the Relationship between Perceived Stress Level and Times of Vibration of Vocal Folds

    Yin Zhigang


    Full Text Available Whether a syllable is perceived as stressed or not and whether the stress is strong or weak are hot issues in speech prosody research and speech recognition. A focus of the stress study is on the investigation of the acoustic factors which contribute to the perception of stress level. This study examined all possible acoustic/physiological cues to stress based on data from Annotated Chinese Speech Corpus and proposed that times of vibration of vocal folds (TVVF reflects stress level best. It is traditionally held that pitch and duration are the most important acoustic parameters to stress. But for Chinese which is a tone language and features special strong-weak pattern in prosody, these two parameters might not be the best ones to represent stress degree. This paper proposed that TVVF, reflected as the number of wave pulses of the vocalic part of a syllable, is the ideal parameter to stress level. Since number of pulses is the integral of pitch and duration (Pulse=?f(pitchdt, TVVF can embody the effect of stress on both pitch and duration. The analyses revealed that TVVF is most correlated with the grades of stress. Therefore, it can be a more effective parameter indicating stress level.

  13. Immunoreactive cortisone in droppings reflect stress levels, diet and growth rate of gull-billed tern chicks.

    Albano, Noelia; Santiago-Quesada, Francisco; Masero, José A; Sánchez-Guzmán, Juan M; Möstl, Erich


    Blood levels of corticosterone have been traditionally analyzed to assess stress levels in birds; however, measuring steroid hormone metabolites in feces and droppings has gained much interest as a noninvasive technique successfully used for such purposed in vertebrates. Diet may affect these fecal metabolite levels (e.g., due to nutritional stress), however, this variable has not been taken into account in studies with chicks despite the great dietary flexibility of many avian species. In this study, we addressed for the first time this key issue and validated the technique in wild gull-billed tern chicks (Gelochelidon nilotica). Several enzyme immunoassays were used to determine the most appropriate test to measure the stress response. Subsequently, we performed an experiment in captivity to assess adrenocortical activity in gull-billed tern chicks fed with two diets: piscivorous vs. insectivorous. Finally, the relation between the chicks' growth rate and excreted immunoreactive glucocorticoid metabolites (EGMs) was also evaluated. We found the immunoreactive cortisone metabolites to be a good index of stress (as being an index of adrenocortical reactivity) in chicks of this species. Fish-fed chicks had higher levels of cortisone metabolites when comparing both concentration and total daily excreted metabolites. Within each treatment diet, cortisone metabolite levels and growth rates were negatively correlated. These findings suggest that the diet should be considered when using this technique for comparative purposes and highlight the trade-off between stress levels and chicks growth rates. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. The effect of neonatal maternal stress on plasma levels of adrenocorticotropic hormone, corticosterone, leptin, and ghrelin in adult male rats exposed to acute heterotypic stressor.

    Holubová, A; Štofková, A; Jurčovičová, J; Šlamberová, R


    Activation of the hypothalamic-pituitary-adrenal (HPA) axis is important for maintenance of homeostasis during stress. Recent studies have shown a connection between the HPA axis and adipose tissue. The present study investigated the effect of acute heterotypic stress on plasma levels of adrenocorticotropic hormone (ACTH), corticosterone (CORT), leptin, and ghrelin in adult male rats with respect to neonatal maternal social and physical stressors. Thirty rat mothers and sixty of their male progeny were used. Pups were divided into three groups: unstressed control (C), stressed by maternal social stressor (S), stressed by maternal social and physical stressors (SW). Levels of hormones were measured in adult male progeny following an acute swimming stress (10 min) or no stress. ELISA immunoassay was used to measured hormones. The ACTH and CORT levels were significantly increased in all groups of adult progeny after acute stress; however, CORT levels were significantly lower in both neonatally stressed groups compared to controls. After acute stress, plasma leptin levels were decreased in the C and SW groups but increased in the S group. The data suggest that long-term neonatal stressors lead to lower sensitivity of ACTH receptors in the adrenal cortex, which could be a sign of stress adaptation in adulthood. Acute stress in adult male rats changes plasma levels of leptin differently relative to social or physical neonatal stressors.

  15. Uncertainty Quantification and Comparison of Weld Residual Stress Measurements and Predictions.

    Lewis, John R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brooks, Dusty Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    In pressurized water reactors, the prevention, detection, and repair of cracks within dissimilar metal welds is essential to ensure proper plant functionality and safety. Weld residual stresses, which are difficult to model and cannot be directly measured, contribute to the formation and growth of cracks due to primary water stress corrosion cracking. Additionally, the uncertainty in weld residual stress measurements and modeling predictions is not well understood, further complicating the prediction of crack evolution. The purpose of this document is to develop methodology to quantify the uncertainty associated with weld residual stress that can be applied to modeling predictions and experimental measurements. Ultimately, the results can be used to assess the current state of uncertainty and to build confidence in both modeling and experimental procedures. The methodology consists of statistically modeling the variation in the weld residual stress profiles using functional data analysis techniques. Uncertainty is quantified using statistical bounds (e.g. confidence and tolerance bounds) constructed with a semi-parametric bootstrap procedure. Such bounds describe the range in which quantities of interest, such as means, are expected to lie as evidenced by the data. The methodology is extended to provide direct comparisons between experimental measurements and modeling predictions by constructing statistical confidence bounds for the average difference between the two quantities. The statistical bounds on the average difference can be used to assess the level of agreement between measurements and predictions. The methodology is applied to experimental measurements of residual stress obtained using two strain relief measurement methods and predictions from seven finite element models developed by different organizations during a round robin study.

  16. Serum prolidase activity, oxidative stress, and antioxidant enzyme levels in patients with renal cell carcinoma.

    Pirinççi, Necip; Kaba, Mehmet; Geçit, İlhan; Güneş, Mustafa; Yüksel, Mehmet Bilgehan; Tanık, Serhat; Arslan, Ayşe; Demir, Halit


    Prolidase is a member of the matrix metalloproteinase family. It plays a vital role in collagen turnover, matrix remodeling, and cell growth. Reactive oxygen species (ROS) have been implicated in the pathogenesis of various diseases, including cancers. Oxidative stress can cause tumor angiogenesis and may be carcinogenic. However, the relationship between antioxidant capacity and various cancers has been researched in several clinical trials. In our study, we aimed to identify serum prolidase activity, oxidative stress, and antioxidant enzyme levels in patients with renal tumors and to evaluate their relationships with each other. A total of 37 male patients with renal cell cancer and with a mean age of 56.28 ± 3.1 were included in the study. The control group comprising 36 male patients (mean age 56.31 ± 2.9) was randomly selected among the volunteers. Serum samples for measurement of superoxide dismutase (SOD), glutathione peroxidase (GSHPx), glutathione-S-transferase (GST), malondialdehyde (MDA), glutathione (GSH), and prolidase levels were kept at -20°C until they were used. Serum prolidase activity and MDA levels were significantly higher in renal cancer patients than in controls (all, p levels were significantly lower (p antioxidant levels in renal cancer. © The Author(s) 2013.

  17. Residual Stress Measurements After Proof and Flight: ETP-0403

    Webster, Ronald L..


    The intent of this testing was to evaluate the residual stresses that occur in and around the attachment details of a case stiffener segment that has been subjected to flight/recovery followed by proof loading. Not measured in this test were stresses relieved at joint disassembly due to out-of-round and interference effects, and those released by cutting the specimens out of the case segment. The test article was lightweight case stiffener segment 1U50715, S/N L023 which was flown in the forward stiffener position on flight SRM 14A and in the aft position on flight SRM24A. Both of these flights were flown with the 3 stiffener ring configuration. Stiffener L023 had a stiffener ring installed only on the aft stub in its first flight, and it had both rings installed on its second flight. No significant post flight damage was found on either flight. Finally, the segment was used on the DM-8 static test motor in the forward position. No stiffener rings were installed. It had only one proof pressurization prior to assignment to its first use, and it was cleaned and proof tested after each flight. Thus, the segment had seen 3 proof tests, two flight pressurizations, and two low intensity water impacts prior to manufacturing for use on DM-8. On DM-8 it received one static firing pressurization in the horizontal configuration. Residual stresses at the surface and in depth were evaluated by both the x-ray diffraction and neutron beam diffraction methods. The x-ray diffraction evaluations were conducted by Technology for Energy Corporation (TEC) at their facilities in Knoxville, TN. The neutron beam evaluations were done by Atomic Energy of Canada Limited (AECL) at the Chalk River Nuclear Laboratories in Ontario. The results showed general agreement with relatively high compressive residual stresses on the surface and moderate to low subsurface tensile residual stresses.

  18. Association Between High-Sensitivity Cardiac Troponin Levels and Myocardial Ischemia During Mental Stress and Conventional Stress.

    Hammadah, Muhammad; Al Mheid, Ibhar; Wilmot, Kobina; Ramadan, Ronnie; Alkhoder, Ayman; Obideen, Malik; Abdelhadi, Naser; Fang, Shuyang; Ibeanu, Ijeoma; Pimple, Pratik; Mohamed Kelli, Heval; Shah, Amit J; Pearce, Brad; Sun, Yan; Garcia, Ernest V; Kutner, Michael; Long, Qi; Ward, Laura; Bremner, J Douglas; Esteves, Fabio; Raggi, Paolo; Sheps, David; Vaccarino, Viola; Quyyumi, Arshed A


    This study sought to investigate whether patients with mental stress-induced myocardial ischemia will have high resting and post-mental stress high-sensitivity cardiac troponin I (hs-cTnI). Hs-cTnI is a marker of myocardial necrosis, and its elevated levels are associated with adverse outcomes. Hs-cTnI levels may increase with exercise in patients with coronary artery disease. Mental stress-induced myocardial ischemia is also linked to adverse outcomes. In this study, 587 patients with stable coronary artery disease underwent technetium Tc 99m sestamibi-single-photon emission tomography myocardial perfusion imaging during mental stress testing using a public speaking task and during conventional (pharmacologic/exercise) stress testing as a control condition. Ischemia was defined as new/worsening impairment in myocardial perfusion using a 17-segment model. The median hs-cTnI resting level was 4.3 (interquartile range [IQR]: 2.9 to 7.3) pg/ml. Overall, 16% and 34.8% of patients developed myocardial ischemia during mental and conventional stress, respectively. Compared with those without ischemia, median resting hs-cTnI levels were higher in patients who developed ischemia either during mental stress (5.9 [IQR: 3.9 to 8.3] vs. 4.1 [IQR: 2.7 to 7.0] pg/ml; p stress (5.4 [IQR: 3.9 to 9.3] vs. 3.9 [IQR: 2.5 to 6.5] pg/ml; p stress-induced ischemia. Although there was a significant increase in 45-min post-treadmill exercise hs-cTnI levels in those who developed ischemia, there was no significant increase after mental or pharmacological stress test. In patients with coronary artery disease, myocardial ischemia during either mental stress or conventional stress is associated with higher resting levels of hs-cTnI. This suggests that hs-cTnI elevation is an indicator of chronic ischemic burden experienced during everyday life. Whether elevated hs-cTnI levels are an indicator of adverse prognosis beyond inducible ischemia or whether it is amenable to intervention requires

  19. A Study on Reynolds Shear Stress Measurement by LDV

    Mizue Munekata; Hideki Ohba; Kazuyoshi Matsuzaki


    The measurement results by Laser Doppler Velocimetry (LDV) are compared with the direct numerical simulation result by Eggels et al.[1] for a cylindrical pipe flow. In the case of a pipe flow, the bias error for mean velocity is very small, because the local turbulent intensity is very small all over the pipe cross section. However the difference of the combination of u' and v' have considerable effects on Reynolds shear stress. From our investigation, it is found that the selection of coincidence time that is a necessary parameter for combination of u' and v' is more important in obtaining the accurate Reynolds shear stress. The suitable coincidence time is selected for a jet flow and the effectiveness of coincident time method or equal time interval method with coincidence data is shown.

  20. The effects of doxepin on stress-induced learning, memory impairments, and TNF-α level in the rat hippocampus.

    Azadbakht, Ali Ahmad; Radahmadi, Maryam; Javanmard, Shaghayegh Haghjooye; Reisi, Parham


    Stress has a profound impact on the nervous system and causes cognitive problems that are partly related to the inflammatory effects. Besides influencing the content of neurotransmitters, antidepressants such as doxepin are likely to have anti-inflammatory, anti-oxidative, and anti-apoptotic effects. Therefore, the present study investigated the effects of doxepin on passive avoidance learning and the levels of tumor necrosis factor-alpha (TNF-α) in the rat hippocampus following repeated restraint stress. Male Wistar rats were divided into five groups. Chronic stress was induced by keeping animals within an adjustable restraint chamber for 6 h every day for 21 successive days. In stress-doxepin group, stressed rats were given 1, 5 and 10 mg/kg of doxepin intraperitoneally (i.p) for 21 days and before placing them in restraint chamber. Healthy animals who served as control group and stressed rats received normal saline i.p. For evaluation of learning and memory, initial latency and step-through latency were determined using passive avoidance learning test. TNF-α levels were measured in hippocampus by enzyme-linked immunosorbant assay (ELISA) at the end of experiment. Induced stress considerably decreased the step through latencies in the rats (PStress-doxepin groups did not reveal any differences compared to control group at any given doses. TNF-α level was increased significantly (Pstress group. Only the low dose of doxepin (1 mg/kg) decreased TNF-α level. The present findings indicated that learning and memory are impaired in stressful conditions and doxepin prevented memory deficit. It seems that inflammation may involve in induced stress memory deficits, and that doxepin is helpful in alleviating the neural complications due to stress.

  1. [Changes in Kinetics of Chemiluminescence of Plasma as a Measure of Systemic Oxidative Stress in Humans].

    Sozarukova, M M; Polimova, A M; Proskurnina, E V; Vladimirov, Yu A


    Oxidative stress is a pathogenetic factor of many diseases. The control of its level is important for early diagnosis and therapy adjustment. In this work, antioxidant status was estimated in blood plasma. In the system of 2,2'-azo-bis(2-amidinopropane)dihydrochloride-luminol a set of chemiluminescence kinetic curve parameters is proposed for oxidative stress level estimation (the latent period τ(lat) and the increasing of analytical signal ΔI(CL)). Uric acid and albumin were shown as the main components that responsible for changes in chemiluminescence kinetic curve of plasma. Serum albumin undergoes oxidative modification in dose-depend manner under the action of UV irradiation, it causes the enhancement of antioxidant properties. Changes in plasma chemiluminescence kinetics are proposed as a measure of oxidative stress in human body.

  2. Evaluation of the levels of stress in the elderly living at home

    Juliana Ladeira Garbaccio


    Full Text Available This study aimed at evaluating the stress level of the elderly assisted by the Primary Health Care of Piumhi, in the Midwest of Minas Gerais, Brazil, in 2010. This was a cross-sectional research with of 64 elderly residents in households. There was a predominance of older women. Regarding chronic diseases 81.3% were bearers of chronic diseases, 75% were cardiac and 29.7% had depression. In the Inventory of Symptoms of Stress for Adults, seniors kept the average 7 (low stress, being more frequent cognitive stress. Female gender was associated with stress level (p<0.05. The elderly showed a good physical and mental status, and we identified low levels of stress, predominantly the cognitive stress type.

  3. Effect of cigarette smoking on levels of seminal oxidative stress in infertile men: a prospective study.

    Saleh, Ramadan A; Agarwal, Ashok; Sharma, Rakesh K; Nelson, David R; Thomas, Anthony J


    To investigate levels of seminal oxidative stress (OS) and sperm quality in a group of infertile men with a history of cigarette smoking. A prospective clinical study. Male infertility clinic, Urological Institute, the Cleveland Clinic Foundation, Cleveland, Ohio. Infertile men who smoked cigarettes (n = 20), infertile men who were nonsmokers (n = 32), and healthy nonsmoking donors (n = 13). Genital examination, standard semen analysis, sperm DNA damage. Levels of seminal reactive oxygen species (ROS) and total antioxidant capacity (TAC) measured by a chemiluminescence assay and seminal OS assessed by calculating a ROS-TAC score. Sperm DNA damage was measured by sperm chromatin structure assay. Smoking was associated with a 48% increase in seminal leukocyte concentrations (Peffects of seminal OS on fertility, physicians should advise infertile men who smoke cigarettes to quit.

  4. Effects of cutting and specimen size on neutron measurement of residual stresses

    Law, M.; Luzin, V.; Kirstein, O.


    To perform neutron residual stress measurements it is often necessary to cut samples to a manageable size. The effects of cutting a girth welded pipe were investigated with analytical methods and finite element analysis. The effect of cutting on measured stresses was calculated. A simplified method of modelling residual stresses in welds, "chill modelling", is introduced. In ring slitting a cut is made in the axial direction and the deformation is maeesured. The change in elastic stress can be calculated and added to neutron diffraction measurements made on a cut ring to calculate the original stresses. Residual stress measurements were performed to validate the ring slitting correction using ANSTO's residual stress diffractometer Kowari.

  5. Effects of perch access and age on physiological measures of stress in caged White Leghorn pullets.

    Yan, F F; Hester, P Y; Enneking, S A; Cheng, H W


    The neuroendocrine system controls animals' adaptability to their environments by releasing psychotropic compounds such as catecholamines [epinephrine (EP), norepinephrine (NE), and dopamine (DA)], corticosterone (CORT), and serotonin (5-hydroxytryptamine or 5-HT). Changes of these neuroendocrine compounds have been used as biomarkers of animals' stress responses associated with their well-being. Assuming that pullets, like laying hens, are highly motivated to perch, we hypothesize that pullets with access to perches will experience less stress than pullets that never have access to perches. The objective of this study was to examine the effects of perch access and age on physiological measurements of stress in White Leghorn pullets housed in conventional cages. Hatchlings (n = 1,064) were randomly assigned to 28 cages. Two parallel metal round perches were installed in each of 14 cages assigned the perch treatment, whereas control cages were without perches. Two birds per cage were bled at wk 4, 6, and 12 wk of age. Plasma levels of CORT, DA, EP, and NE, blood concentrations of 5-HT and Trp, and heterophil to lymphocyte ratios were measured. Data were analyzed using a 2-way ANOVA. The perch treatment or its interaction with age did not affect any parameter measured in the study. The increase in the concentrations of circulating EP, NE, 5-HT (numerical increase at 4 wk), and Trp in 4- and 6-wk-old pullets compared with 12-wk-old pullets is unclear, but may have been due to acute handling stress at younger ages. In contrast, concentrations of DA were less at 4 wk compared with levels at 6 and 12 wk of age. Plasma CORT levels and the heterophil to lymphocyte ratio, indicators of long-term stress, were unaffected by age (P = 0.07 and 0.49, respectively). These results indicated that age, but not perch access, affects neuroendocrine homeostasis in White Leghorn pullets. Pullets that were never exposed to perches showed no evidence of eliciting a stress response.

  6. Canopy-Level Photochemical Reflectance Index from Hyperspectral Remote Sensing and Leaf-Level Non-Photochemical Quenching as Early Indicators of Water Stress in Maize

    Shuren Chou


    Full Text Available In this study, we evaluated the effectiveness of photochemical reflectance index (PRI and non-photochemical quenching (NPQ for assessing water stress in maize for the purpose of developing remote sensing techniques for monitoring water deficits in crops. Leaf-level chlorophyll fluorescence and canopy-level PRI were measured concurrently over a maize field with five different irrigation treatments, ranging from 20% to 90% of the field capacity (FC. Significant correlations were found between leaf-level NPQ (NPQleaf and the ratio of chlorophyll to carotenoid content (Chl/Car (R2 = 0.71, p < 0.01 and between NPQleaf and the actual photochemical efficiency of photosystem II (ΔF/Fm′ (R2 = 0.81, p < 0.005. At the early growing stage, both canopy-level PRI and NPQleaf are good indicators of water stress (R2 = 0.65 and p < 0.05; R2 = 0.63 and p < 0.05, respectively. For assessment of extreme water stress on plant growth, a relationship is also established between the quantum yield of photochemistry in PSII (ΦP and the quantum yield of fluorescence (ΦF as determined from photochemical quenching (PQ and non-photochemical quenching (NPQleaf of excitation energy at different water stress levels. These results would be helpful in monitoring soil water stress on crops at large scales using remote sensing techniques.

  7. Word-Level Stress Patterns in the Academic Word List

    Murphy, John; Kandil, Magdi


    This paper addresses teachers and researchers of English as a second or foreign language who are interested in speech intelligibility training and/or vocabulary acquisition. The study reports a stress-pattern analysis of the Academic Word List (AWL) as made available by Coxhead [TESOL Quarterly 34 (2000) 213]. To examine the AWL in a new way, we…

  8. Measuring Thermal Stress of Dairy Cattle Based on Temperature Humidity Index (THI in Tropical Climate



    Full Text Available Thermal comfort for workers is very important factor to increase their performance, as well as the comfort level of dairy cattle will influence in milk productivity. The purposes of the paper is to measure the level of heat stress and then use the information to design the dairy cattle house for increasing thermal comfort. The research is started with literature review of heat stress and early survey of environment condition e.g. temperature, wind speed and relative humidity. The next step is using the information to determine the temperature humidity index (THI level for dairy cattle with maximum THI = 86 and 84 (moderate stress. The 3D CAD model and Computational Fluid Dynamic (CFD simulation are employed to looking for solution for reducing the discomfort thermal of dairy cattle. A scenario (fan air conditioning to get better condition of thermal comfort have been successfully presented with final THI index = 76 and 78 (mild stress. Finally, the paper shows how to reduce heat stress of cattle house by installation 3 exhaust fans in tropical climate.

  9. Acute stress effects on GABA and glutamate levels in the prefrontal cortex: A 7T (1)H magnetic resonance spectroscopy study.

    Houtepen, L C; Schür, R R; Wijnen, J P; Boer, V O; Boks, M P M; Kahn, R S; Joëls, M; Klomp, D W; Vinkers, C H


    There is ample evidence that the inhibitory GABA and the excitatory glutamate system are essential for an adequate response to stress. Both GABAergic and glutamatergic brain circuits modulate hypothalamus-pituitary-adrenal (HPA)-axis activity, and stress in turn affects glutamate and GABA levels in the rodent brain. However, studies examining stress-induced GABA and glutamate levels in the human brain are scarce. Therefore, we investigated the influence of acute psychosocial stress (using the Trier Social Stress Test) on glutamate and GABA levels in the medial prefrontal cortex of 29 healthy male individuals using 7 Tesla proton magnetic resonance spectroscopy. In vivo GABA and glutamate levels were measured before and 30 min after exposure to either the stress or the control condition. We found no associations between psychosocial stress or cortisol stress reactivity and changes over time in medial prefrontal glutamate and GABA levels. GABA and glutamate levels over time were significantly correlated in the control condition but not in the stress condition, suggesting that very subtle differential effects of stress on GABA and glutamate across individuals may occur. However, overall, acute psychosocial stress does not appear to affect in vivo medial prefrontal GABA and glutamate levels, at least this is not detectable with current practice (1)H-MRS.

  10. Stress-induced increases in brainstem amino acid levels are prevented by chronic sodium hydrosulfide treatment.

    Warenycia, M W; Kombian, S B; Reiffenstein, R J


    Neurotransmitter amino acid levels were measured in select brain regions of rats and mice after chronic treatment with sublethal doses of sodium hydrosulfide (NaHS). Brainstem aspartate, glutamate, glutamine, taurine and GABA levels increased in chronically but not acutely saline-treated rats. These increases may have been due to stress from frequent handling, and were prevented by chronic NaHS treatment (7.5 mg/kg ip every 8 hr for 3 consecutive days). In contrast, aspartate, glutamate and glutamine increased in female but not in male ICR mouse brainstems after once daily treatment with 7.0 mg/kg NaHS for 5 consecutive days. These effects of NaHS may indicate chronic low level H2S neurotoxicity. Differences between chronic and acute treatments, female and male responses, and treatment paradigms may complicate interpretations of such toxicity studies.


    王莹; 杨东伟; 谢雯; 庞炜; 蒋马莉; 韩太真


    Objective To observe the effects of chronic emotional stress on the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and malonialdehyde (MDA) level in female rats' brain. Methods The rats were randomly divided into 4 groups: normal control group (group N), emotional stress group (group E), emotional stress + pregnancy group (group E+P) and regularly drinking group (group R). Emotional stress in rats was induced by training rats with empty drinking bottles. Having been finished the stress procedure, the brain was taken out and homogenized. Then the activities of SOD, GSH-Px and MDA level were measured. Results Compared to group N, both the activities of SOD in brain tissues of group E and group E+P were significantly decreased (P<0.05 and P<0.01, respectively) while the MDA level increased (P<0.05). However, the extent of changes in group E+P was more obvious than that in E. GSH-Px activities in E+P and E were significantly changed. However, the GSH-Px activity in E+P was decreased (P<0.05) while the activity in E increased (P<0.05).Conclusion The chronic emotional stress can reduce the antioxidative system by decreasing the antioxidative enzyme activity and potentiating the lipid peroxidation in the brain. It is also suggested that the combination of emotional stress and pregnancy can augment the oxidative damage in rats' brain.

  12. The advising alliance for international and domestic graduate students: Measurement invariance and implications for academic stress.

    Rice, Kenneth G; Suh, Hanna; Yang, Xiaohui; Choe, Elise; Davis, Don E


    We expanded the focus of a prior study of international graduate student advising relationships (Rice et al., 2009) to examine advising experiences of both international and domestic students. International (n = 434) and domestic (n = 387) students completed the Advisory Working Alliance Inventory (AWAI-S; Schlosser & Gelso, 2001) and measures of advising experiences, perceived academic stress, and desire to change advisor. Measurement invariance analyses suggested that a 23-item AWAI-S showed support for scalar invariance. A bifactor structure showed superior fit to the 3-factor model or a second-order factor model for the AWAI-S. International and domestic graduate students did not differ in ratings of general alliance, academic stress, or desire to change advisors. General alliance was strongly related to less academic stress and less desire to change advisors. International students who felt disrespected by their advisors were more likely to be academically stressed than domestic students. Structured mentoring experiences were associated with lower stress and less desire to change, and this effect was similar in both international and domestic students. Overall, results suggested that the current level of measurement, and possibly theory development, regarding the advisory alliance is good at identifying generic satisfaction but weaker at differentiating components of the alliance. (c) 2016 APA, all rights reserved).

  13. Stress effects in prism coupling measurements of thin polymer films

    Agan, S.; Ay, F.; Kocabas, A.; Aydinli, A.


    Due to the increasingly important role of some polymers in optical waveguide technologies, precise measurement of their optical properties has become important. Typically, prism coupling to slab waveguides made of materials of interest is used to measure the relevant optical parameters. However, such measurements are often complicated by the softness of the polymer films when stress is applied to the prism to couple light into the waveguides. In this work, we have investigated the optical properties of three different polymers, polystyrene (PS), polymethyl-methacrylate (PMMA), and benzocyclobutane (BCB). For the first time, the dependence of the refractive index, film thickness, and birefringence on applied stress in these thin polymer films was determined by means of the prism coupling technique. Both symmetric trapezoid shaped and right-angle prisms were used to couple the light into the waveguides. It was found that trapezoid shaped prism coupling gives better results in these thin polymer films. The refractive index of PMMA was found to be in the range of 1.4869 up to 1.4876 for both TE and TM polarizations under the applied force, which causes a small decrease in the film thickness of up to 0.06 μm. PMMA waveguide films were found not to be birefringent. In contrast, both BCB and PS films exhibit birefringence albeit of opposing signs.

  14. Levels of oxidative stress biomarkers in seminal plasma and their relationship with seminal parameters

    Zarghami Nosratollah


    Decreasing seminal plasma antioxidants levels, especially catalase and TAC, could have significant role in etiology of impaired sperm function. Measurement of 8-Isoprostane may be used as a specific biomarker for assessing oxidative stress on sperm.

  15. Transactional stress and coping theory in accounting for psychological states measures

    V. Buško


    Full Text Available The paper examines a relative predictive value of some stable individual attributes and the processes of cognitive appraisals and coping with stress in accounting for specific components of anxiety state measures. Self-report instruments for the measurement of selected psychological constructs, i.e. perceived incompetence, externality, stress intensity and duration, situation-specific coping strategies, and the two anxiety state components, were taken in a sample of 449 male military basics trainees, ranging in age from 18-27. Hierarchical multiple regression analyses showed that the set of predictors employed could account for statistically, as well as theoretically and practically a significant part of variance in cognitive anxiety component (45,5%, and in visceral-emotional component (32,2% of the anxiety state. The extent of anxiety reactions assessed by both scales could primarily be explained by general perception of personal incompetence, as a relatively stable dimension of general self-concept. Of the ways of coping examined, reinterpretation of stressful events was the only strategy contributing to low level, whereas passivization, wishful thinking, and seeking social support contributed to higher levels of anxiety measured by both scales. The results give partial support to the basic hypotheses on the mediating role of coping in the relationships among particular components of the stress and coping models.

  16. Effects of Swimming Training on Stress Levels of the Students Aged 11-13

    Köroglu, Mihraç; Yigiter, Korkmaz


    The purpose of this research was to determine the effects of the swimming training program on stress levels of the students ages 11-13. To this end, 60 students from Private Sahin School in the Sakarya city participated in the study voluntarily. 60 students were divided into two groups and each group was included 30 students. Stress Level Scale II…

  17. 49 CFR Appendix C to Part 192 - Qualification of Welders for Low Stress Level Pipe


    ... 49 Transportation 3 2010-10-01 2010-10-01 false Qualification of Welders for Low Stress Level Pipe.... C Appendix C to Part 192—Qualification of Welders for Low Stress Level Pipe I. Basic test. The test... position welding. The beveling, root opening, and other details must conform to the specifications of...

  18. Characterization at the individual cell level and in whole blood samples of shear stress preventing red blood cells aggregation.

    Lee, K; Kinnunen, M; Danilina, A V; Ustinov, V D; Shin, S; Meglinski, I; Priezzhev, A V


    The aggregation of red blood cells (RBC) is an intrinsic feature of blood that has a strong impact on its microcirculation. For a number of years it has been attracting a great attention in basic research and clinical studies. Here, we study a relationship between the RBC aggregation parameters measured at the individual cell level and in a whole blood sample. The home made optical tweezers were used to measure the aggregating and disaggregating forces for a pair of interacting RBCs, at the individual cell level, in order to evaluate the corresponding shear stresses. The RheoScan aggregometer was used for the measurements of critical shear stress (CSS) in whole blood samples. The correlation between CSS and the shear stress required to stop an RBC pair from aggregating was found. The shear stress required to disaggregate a pair of RBCs using the double channel optical tweezers appeared to be about 10 times higher than CSS. The correlation between shear stresses required to prevent RBCs from aggregation at the individual cell level and in whole blood samples was estimated and assessed quantitatively. The experimental approach developed has a high potential for advancing hemorheological studies.

  19. Comparative stress levels among residents in three Chinese provincial capitals, 2001 and 2008.

    Tingzhong Yang

    Full Text Available OBJECTIVES: To compare stress levels among residents in large Chinese cities between 2001 and 2008. METHODS: Survey data were collected in three mainland Chinese capital cities in two waves, in 2001 and 2008, respectively. Participants were recruited through a multi-stage stratified sampling process. Stress was assessed using the Perceived Stress Scale, Chinese version (CPSS. Descriptive methods were used to estimate mean stress levels and associated 95% confidence intervals. Estimates were adjusted by post-stratification weights. RESULTS: Indicating stable stress levels, respective adjusted mean stress scores for the combined samples of study participants were 23.90 (95%CI: 23.68-24.12 in 2001 and 23.69 (95%CI: 23.38-24.01 in 2008. A lower stress level in 2008 than in 2001 manifested among residents who were under 25 years of age; female; with a college or higher level education; divorced, widowed, or separated; members of the managerial and clerical group; students or army personnel; or with an annual income of at least 30,000 RMB. CONCLUSION: The overall stress level did not change among the combined sample of residents in the three Chinese study cities between 2001 and 2008. However, levels remained high and varied across social strata, and may have reflected a national trend among urban residents. Findings indicate a need for a new health policy, and call for the design and implementation of evidence-based interventions that target the highest-risk groups.

  20. The constant threat of terrorism: stress levels and coping strategies amongst university students of Karachi.

    Ahmed, Ayesha Ejaz; Masood, Komal; Dean, Sohni Vicky; Shakir, Tanzila; Kardar, Ahmed Abdul Hafeez; Barlass, Usman; Imam, Syed Haider; Mohmand, Mohammad Ghawar Khan; Ibrahim, Hussain; Khan, Imad Saeed; Akram, Usman; Hasnain, Farid


    To assess the levels of stress in the face of terrorism and the adopted coping strategies, amongst the student population of universities in Karachi. A descriptive, cross sectional study was conducted on undergraduate students from four universities of Karachi. Self-administered questionnaires were filled out by 291 students. Pearson Chi-Square test was used to assess associations between stress levels and different variables at a level of significance of 0.05%. A total of 65.8% of the students had mild stress levels, 91.5% of university students were exposed to terrorism through television, while only 26.5% students reported personal exposure to terrorism. 67.4% students were forbidden by their parents to go out (p = 0.002). Most of those who had self exposure to an attack were the ones whose parents forbade them from going out (p = 0.00). Most commonly used coping strategy was increased faith in religion. Irritability was the most common stress symptom. A majority of students studying in universities of Karachi had mild stress levels due to the constant threat of terrorism whereas a minority had severe stress levels. Possible reasons for resilience and only mild stress levels could be the history of Karachi's internal conflicts and its prolonged duration of being exposed to terrorism. These students who are positive for stress need to be targeted for counseling either through the media or through their universities. More extensive research is needed in this area.

  1. Phobic anxiety and plasma levels of global oxidative stress in women

    Kaitlin A. Hagan


    Full Text Available Background and Objectives: Psychological distress has been hypothesized to be associated with adverse biologic states such as higher oxidative stress and inflammation. Yet, little is known about associations between a common form of distress -phobic anxiety- and global oxidative stress. Thus, we related phobic anxiety to plasma fluorescent oxidation products (FlOPs, a global oxidative stress marker. Methods: We conducted a cross-sectional analysis among 1,325 women (aged 43-70 years from the Nurses' Health Study. Phobic anxiety was measured using the Crown-Crisp Index (CCI. Adjusted least-squares mean log-transformed FlOPs were calculated across phobic categories. Logistic regression models were used to calculate odds ratios (OR comparing the highest CCI category (≥ 6 points vs. lower scores, across FlOPs quartiles. Results: No association was found between phobic anxiety categories and mean FlOP levels in multivariable adjusted linear models. Similarly, in multivariable logistic regression models there were no associations between FlOPs quartiles and likelihood of being in the highest phobic category. Comparing women in the highest vs. lowest FlOPs quartiles: FlOP_360: OR = 0.68 (95% CI: 0.40 - 1.15; FlOP_320: OR = 0.99 (95% CI: 0.61 - 1.61; FlOP_400: OR = 0.92 (95% CI: 0.52, 1.63. Conclusions: No cross-sectional association was found between phobic anxiety and a plasma measure of global oxidative stress in this sample of middle-aged and older women.

  2. Soybean aphid (Hemiptera: Aphididae) response to soybean plant defense: stress levels, tradeoffs, and cross-virulence.

    Enders, Laramy; Bickel, Ryan; Brisson, Jennifer; Heng-Moss, Tiffany; Siegfried, Blair; Zera, Anthony; Miller, Nick


    A variety of management methods to control the soybean aphid (Aphis glycines Matsumura) have been investigated since its invasion into North America in 2000, among them plant resistance has emerged as a viable option for reducing aphid damage to soybeans and preventing outbreaks. Plant resistance methods often use natural soybean plant defenses that impose stress on aphids by reducing fitness and altering behavior. Research efforts have heavily focused on identification and development of aphid resistant soybean varieties, leaving much unknown about soybean aphid response to stressful host plant defenses. In this study, we aimed to 1) evaluate lifetime fitness consequences and phenotypic variation in response to host plant-induced stress and 2) investigate whether trade-offs involving fitness costs and/or cross-virulence to multiple antibiotic soybean varieties exists. We compared aphid survival and reproduction during and after a short period of exposure to soybeans with the Rag2 resistance gene and measured aphid clonal variation in response to Rag2 soybeans. In addition, we measured the performance of Rag2 virulent and avirulent aphids on five soybean varieties with various forms of antibiotic resistance. Our results indicate that plant defenses impose high levels of stress and have long-term fitness consequences, even after aphids are removed from resistant plants. We identified one aphid clone that was able to colonize Rag2 among the seven clones tested, suggesting that virulent genotypes may be prevalent in natural populations. Finally, although we did not find evidence of cross-virulence to multiple antibiotic soybean varieties, our results suggest independent mechanisms of aphid virulence to Rag1 and Rag2 that may involve fitness costs.

  3. Sound level measurements using smartphone "apps": Useful or inaccurate?

    Daniel R Nast


    Full Text Available Many recreational activities are accompanied by loud concurrent sounds and decisions regarding the hearing hazards associated with these activities depend on accurate sound measurements. Sound level meters (SLMs are designed for this purpose, but these are technical instruments that are not typically available in recreational settings and require training to use properly. Mobile technology has made such sound level measurements more feasible for even inexperienced users. Here, we assessed the accuracy of sound level measurements made using five mobile phone applications or "apps" on an Apple iPhone 4S, one of the most widely used mobile phones. Accuracy was assessed by comparing application-based measurements to measurements made using a calibrated SLM. Whereas most apps erred by reporting higher sound levels, one application measured levels within 5 dB of a calibrated SLM across all frequencies tested.

  4. Effect of high fluoride and high fat on serum lipid levels and oxidative stress in rabbits.

    Sun, Liyan; Gao, Yanhui; Zhang, Wei; Liu, Hui; Sun, Dianjun


    The purpose of this study was to explore the effects of high fluoride and high fat on triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), total antioxidant capacity (T-AOC), lipid peroxide (LPO) and malondialdehyde (MDA) in rabbits. A factorial experimental design was used, with two factors (fluoride and fat) and three levels. Seventy-two male rabbits were randomly assigned into nine groups according to initial weight and serum lipid levels. The rabbits were fed with basic feed, moderate fat feed or high fat feed and drank tap water, fluoridated water at levels of 50 and 100mgfluorion/L freely. Biological materials were collected after 5 months, and serum lipid, T-AOC, LPO, and MDA levels were then measured. Using these data, the separate and interactive effects of high fluoride and high fat were analyzed. High fluoride and high fat both increased serum levels of TC, HDL-C and LDL-C significantly (Pfluoride and high fat (Pfluoride and high fat had different effects on TG levels: high fat significantly increased TG levels (Pfluoride had nothing to do with TG levels (P>0.05). High fat significantly elevated LPO and MDA levels and lowered T-AOC levels in serum (Pfluoride significantly increased LPO and MDA levels in serum (Pfluoride on these indexes. In summary, high fluoride and high fat increased serum TC and LDL-C levels individually and synergistically, and this would cause and aggravate hypercholesterolemia in rabbits. At the same time, high fluoride and high fat both made the accumulation of product of oxidative stress in experimental animals. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Serum Fetuin-A levels, insulin resistance and oxidative stress in women with polycystic ovary syndrome.

    Enli, Yasar; Fenkci, Semin Melahat; Fenkci, Veysel; Oztekin, Ozer


    This study was designed to determine serum Fetuin-A levels and establish whether serum Fetuin-A level is related with insulin resistance, oxidative stress, ovarian hyperandrogenism and dyslipidemia in women with polycystic ovary syndrome (PCOS). Twenty-two patients with PCOS and twenty-one healthy control women were evaluated in this controlled clinical study. Serum Fetuin-A, lipid fractions, glucose, insulin, malondialdehyde (MDA), myeloperoxidase (MPO), glutathione (GSH), superoxide dismutase (SOD) and other hormone (gonadotropins, androgens) levels were measured. The estimate of insulin resistance was calculated by homeostasis model assessment (HOMA-R). The women with PCOS had significantly higher serum fasting glucose, insulin, luteinizing hormone (LH), MDA, Fetuin-A levels, and LH/follicle-stimulating hormone (FSH) ratio, free androgen index (FAI), HOMA-IR than healthy women. However, sex hormone-binding globulin (SHBG) and GSH levels were significantly lower in patients with PCOS compared with controls. Fetuin-A was positively correlated with insulin, HOMA-IR and FAI. Multiple regression analysis revealed that FAI was strong predictor of serum Fetuin-A level. Serum Fetuin-A level was related with insulin resistance and ovarian hyperandrogenism in women with PCOS. These results suggest that Fetuin-A may have a role in triggering the processes leading to insulin resistance and androgen excess in PCOS.

  6. General job stress: a unidimensional measure and its non-linear relations with outcome variables.

    Yankelevich, Maya; Broadfoot, Alison; Gillespie, Jennifer Z; Gillespie, Michael A; Guidroz, Ashley


    This article aims to examine the non-linear relations between a general measure of job stress [Stress in General (SIG)] and two outcome variables: intentions to quit and job satisfaction. In so doing, we also re-examine the factor structure of the SIG and determine that, as a two-factor scale, it obscures non-linear relations with outcomes. Thus, in this research, we not only test for non-linear relations between stress and outcome variables but also present an updated version of the SIG scale. Using two distinct samples of working adults (sample 1, N = 589; sample 2, N = 4322), results indicate that a more parsimonious eight-item SIG has better model-data fit than the 15-item two-factor SIG and that the eight-item SIG has non-linear relations with job satisfaction and intentions to quit. Specifically, the revised SIG has an inverted curvilinear J-shaped relation with job satisfaction such that job satisfaction drops precipitously after a certain level of stress; the SIG has a J-shaped curvilinear relation with intentions to quit such that turnover intentions increase exponentially after a certain level of stress.

  7. What characterizes persons with high levels of perceived stress in Denmark? A national representative study

    Nielsen, Line; Curtis, Tine; Kristensen, Tage S


    -sectional design. Information on neighbourhood factors was derived from a national registry. Data were analysed by means of logistic regression models. RESULTS: Low education, heavy smoking, physical inactivity, lack of social network and poor working conditions were associated with perceived stress. For women...... perceived stress is characterized by individual and neighbourhood factors with negative impacts on quality of life and risk of illness. This knowledge can guide future stress prevention efforts. Additionally, the results suggest a negative social component where perceived stress, unhealthy lifestyle and low...... social status are accumulated, and perceived stress might be used as a measure to identify groups characterized by accumulation of risk factors....

  8. Higher perceived stress but lower cortisol levels found among young Greek adults living in a stressful social environment in comparison with Swedish young adults.

    Faresjö, Åshild; Theodorsson, Elvar; Chatziarzenis, Marios; Sapouna, Vasiliki; Claesson, Hans-Peter; Koppner, Jenny; Faresjö, Tomas


    The worldwide financial crisis during recent years has raised concerns of negative public health effects. This is notably evident in southern Europe. In Greece, where the financial austerity has been especially pronounced, the prevalence of mental health problems including depression and suicide has increased, and outbreaks of infectious diseases have risen. The main objective in this study was to investigate whether different indicators of health and stress levels measured by a new biomarker based on cortisol in human hair were different amongst comparable Greek and Swedish young adults, considering that Sweden has been much less affected by the recent economic crises. In this cross-sectional comparative study, young adults from the city of Athens in Greece (n = 124) and from the city of Linkoping in Sweden (n = 112) participated. The data collection comprised answering a questionnaire with different health indicators and hair samples being analyzed for the stress hormone cortisol, a biomarker with the ability to retrospectively measure long-term cortisol exposure. The Greek young adults reported significantly higher perceived stress (pstress exposure could lead to a lowering of the cortisol levels. This study points out a possible hypothesis that the cortisol levels of the Greek young adults might have been suppressed and their HPA-axis down-regulated after living in a stressful environment with economic and social pressure.

  9. Designing automation for complex work environments under different levels of stress.

    Sauer, Juergen; Nickel, Peter; Wastell, David


    This article examines the effectiveness of different forms of static and adaptable automation under low- and high-stress conditions. Forty participants were randomly assigned to one of four experimental conditions, comparing three levels of static automation (low, medium and high) and one level of adaptable automation, with the environmental stressor (noise) being varied as a within-subjects variable. Participants were trained for 4 h on a simulation of a process control environment, called AutoCAMS, followed by a 2.5-h testing session. Measures of performance, psychophysiology and subjective reactions were taken. The results showed that operators preferred higher levels of automation under noise than under quiet conditions. A number of parameters indicated negative effects of noise exposure, such as performance impairments, physiological stress reactions and higher mental workload. It also emerged that adaptable automation provided advantages over low and intermediate static automation, with regard to mental workload, effort expenditure and diagnostic performance. The article concludes that for the design of automation a wider range of operational scenarios reflecting adverse as well as ideal working conditions needs to be considered.

  10. Measuring Stress Distributions of Orthotropic Composite Material in Plane Stress State by the Lock-in Infrared Thermography Technique

    LI Xu-Dong; WANG Wei-Bo; LI Yong-Sheng; WU Dong-Liu


    Feasibility of measuring stress distributions of orthotropic composite materials and structures in plane stress state by the lock-in infrared thermography technique is analyzed and stress distributions of a lap joint structure made of a kind of glass reinforced plastic composite lamination plates under tensile loadings are obtained by the lock-in infrared thermography technique. Feasibility and credibility of using this technique to measure stress distributions of orthotropic composite materials and structures in plane stress state are proved by comparing the results with the data given by the digital speckle correlation method.%@@ Feasibility of measuring stress distributions of orthotropic composite materials and structures in plane stress state by the lock-in infrared thermography technique is analyzed and stress distributions of a lap joint structure made of a kind of glass reinforced plastic composite lamination plates under tensile loadings axe obtained by the lock-in infrared thermography technique.Feasibility and credibility of using this technique to measure stress distributions of orthotropic composite materials and structures in plane stress state axe proved by comparing the results with the data given by the digital speckle correlation method.

  11. Experimental investigation of the influence on static and cyclic deformation of structural soft clay of stress level

    CHEN Yunmin; CHEN Yingping; HUANG Bo


    This paper presents the experimental results performed to study the static and cyclic deformation behavior of undisturbed and remolded soft clays sampling from Xiaoshan.The consolidation tests indicated that the vertical strains of undisturbed soft clay could be divided into three stages with load increasing,however,the remolded clays were almost independent of stress level.The two cut-off points of these three stages are the preconsolidation stress and the structural yielding stress of the original clay,which could be determined by shear wave velocity measurement.The strains developed during cyclic tests of undisturbed and remolded soft clay,both having one turning point under different amplitude of cyclic stress.The strain developed slowly and stayed at a low level at the early stage,but developed quickly in a different way when the turning points were achieved and finally became great.The turning strains changed with different cyclic stress amplitudes,but they almost fell on a linear line whether undisturbed or remolded.Furthermore,the turning points of the remolded clay all fell on the same line of different confining stresses,including which of the undisturbed soft clay under confining pressure was larger than structural yielding stress.It was also found that the deformation characteristic of undisturbed and remolded Xiaoshan clay tend to be consistent when the structure of undisturbed soft clay is damaged.

  12. A cross-cultural comparison of the stress experienced by high-level career women

    Henriette S. van den Berg


    Full Text Available This study examines differences in the experience of work-related stress and of exposure to work-related stressors among South African career women of different ethnic groups. A sample of 732 women working in administrative, semi-professional, professional and managerial positions was involved. Analyses of covariance found signifcant differences in the level of stress reported by the different groups, with black women reporting the highest level of stress. Stressors pertaining to a lack of infrastructure and resources in the environment signifcantly contributed to the stress experienced by black women. All four groups reported discontent with their remuneration and fringe benefts.

  13. Salivary Testosterone Levels Under Psychological Stress and Its Relationship with Rumination and Five Personality Traits in Medical Students

    Afrisham, Reza; Sadegh-Nejadi, Sahar; SoliemaniFar, Omid; Kooti, Wesam; Ashtary-Larky, Damoon; Alamiri, Fatima; Najjar-Asl, Sedigheh; Khaneh-Keshi, Ali


    Objective The purpose of this study was to evaluate the salivary testosterone levels under psychological stress and its relationship with rumination and five personality traits in medical students. Methods A total of 58 medical students, who wanted to participate in the final exam, were selected by simple random sampling. Two months before the exam, in the basal conditions, the NEO Inventory short form, and the Emotional Control Questionnaire (ECQ) were completed. Saliva samples were taken from students in both the basal conditions and under exam stress. Salivary testosterone was measured by ELISA. Data was analyzed using multivariate analysis of variance with repeated measures, paired samples t-test, Pearson correlation and stepwise regression analysis. Results Salivary testosterone level of men showed a significant increase under exam stress (p<0.05). However, a non-significant although substantial reduction observed in women. A significant correlation was found between extroversion (r=-0.33) and openness to experience (r=0.30) with salivary testosterone (p<0.05). Extraversion, aggression control and emotional inhibition predicted 28% of variance of salivary testosterone under stress. Conclusion Salivary testosterone reactivity to stress can be determined by sexual differences, personality traits, and emotional control variables which may decrease or increase stress effects on biological responses, especially the salivary testosterone. PMID:27909455

  14. Effect of amputation level on the stress transferred to the femur by an artificial limb directly attached to the bone.

    Newcombe, L; Dewar, M; Blunn, G W; Fromme, P


    Attachment of an artificial limb directly to the skeleton has a number of potential benefits and the technique has been implemented for several amputation sites. In this paper the transfer of stress from an external, transfemoral prosthesis to the femur during normal walking activity is investigated. The stress distribution in the femur and at the implant-bone interface is calculated using finite element analysis for the 3D geometry and inhomogeneous, anisotropic material properties obtained from a CT scan of a healthy femur. Attachment of the prosthetic leg at three different levels of amputation is considered. Stress concentrations are found at the distal end of the bone and adjacent to the implant tip and stress shielding is observed adjacent to the implant. It is found that the stress distribution in the femur distal to the epiphysis, where the femur geometry is close to cylindrical, can be predicted from a cylindrical finite element model, using the correct choice of bone diameter as measured from a radiograph. Proximal to the lesser trochanter the stress decreases as the femur geometry diverges significantly from a cylinder. The stress concentration at the distal, resected end of the bone is removed when a collared implant is employed. These findings form the basis for appropriate settings of an external fail-safe device to protect the bone from excessive stress in the event of an undue load.

  15. Glucocorticoid levels after exposure to predator odor and chronic psychosocial stress with dexamethasone application in rats.

    Starcevic, Ana; Petricevic, Sasa; Radojicic, Zoran; Djulejic, Vuk; Ilankovic, Andrej; Starcevic, Branislav; Filipovic, Branislav


    This study was conducted to explore the effects of specific psychosocial paradigm on predator animal posttraumatic stress model and to test the hypothesis that psychosocially stressed rats would exibit abnormal levels of cortisol and a larger suppression of cortisol levels after the application of dexamethasone. Animals were divided in two groups: experimental and control groups. The experimental group was exposed to two types of stressors: acute immobilization stress, and combined predator stress and daily social stress with application of dexamethasone. Blood sampling was performed at three different times. We found statistically significant results after analyzing the differences between cortisol levels in different times of blood sampling in the group of animals exposed to stress with dexamethasone application. Statistical significance was found when we compared the experimental group with the control group in terms of elevated cortisol levels during blood sampling after stress paradigm exposition. Many significant disruptions in the functioning of the hypothalamic-pituitary-adrenal axis were observed, such as decrease in basal cortisol levels and enhanced dexamethasone-induced inhibition of cortisol levels. These findings are important because their impact can translate to human individuals with posttraumatic stress disorder, which is the most important role of every animal model in research. Copyright © 2016. Published by Elsevier Taiwan.

  16. Measuring Mechanical Properties by Staring: Using Stress Assessment from Local Structural Anisotropy (SALSA) to Probe Viscosity and Visualize Stress Networks in Colloidal Suspensions

    Cohen, Itai; Bierbaum, Matthew; Sethna, James; Lin, Neil


    Measurement of stress induced thermal fluctuations in materials can be used to determine macroscopic mechanical properties including viscosity in fluids, as well as bulk and shear moduli in solids. When extended to the single particle scale, such measurements also reveal underlying spatially inhomogeneous response mechanisms in systems such as glasses, gels, and polycrystals. Unfortunately, it is not possible to experimentally measure these temporal and spatial stress fluctuations in a colloidal suspension using conventional rheometers. Here however, we show that using fast confocal microscopy it is possible conduct a Stress Assessment from Local Structural Anisotropy (SALSA) to measure such spatio-temporal stress fluctuations. We directly image the microstructure of a nearly hard-sphere suspension using a high-speed confocal microscope and determine particle positions. We compute the structure anisotropy of the suspension and building on the Brady formalism, calculate particle-level stresses. In conjunction with the fluctuation-dissipation theorem, we then determine the bulk viscosity of a colloidal liquid. Furthermore, we show our local measurements allow direct visualization of the complex stress networks in a 3D supercooled liquid under compression. Our method provides an experimental approach that applies to a broad range of processes arising in sheared glasses, compressed gels, and even indented crystals.

  17. Neutron diffraction measurements for the determination of residual stresses in MMC tensile and fatigue specimens

    Fiori, F.; Girardin, E.; Giuliani, A.;


    , residual stresses are present in both the matrix and the particles microstructure, prior to any macroscopic loading. They vary with the temperature and with the type and level of loading imposed to the material, having a strong influence on the mechanical behaviour of MMCs. Neutron diffraction measurements...... have been performed at RISO (Roskilde, DK) and HMI-BENSC (Berlin, D), for the determination of residual stress in AA2124 + 17% SiCp and AA359 + 20% SiCp specimens, submitted to tensile and fatigue tests. For each of the investigated samples, the macrostress has been separated from the elastic...... and thermal mismatch microstresses. The results show that, in general, the main contribution to the stress state of both matrix and reinforcement is given by the thermal microstresses, already existing due to heat treatment prior to mechanical tests. (C) 2000 Elsevier Science B.V. All rights reserved....

  18. Selecting Level-Specific Specialized Vocabulary Using Statistical Measures

    Chujo, Kiyomi; Utiyama, Masao


    To find an easy-to-use, automated tool to identify technical vocabulary applicable to learners at various levels, nine statistical measures were applied to the 7.3-million-word "commerce and finance" component of the British National Corpus. The resulting word lists showed that each statistical measure extracted a different level of specialized…

  19. Serum 25-Hydroxyvitamin D Levels and Stress Fractures in Military Personnel: A Systematic Review and Meta-analysis.

    Dao, Dyda; Sodhi, Sukhmani; Tabasinejad, Rasam; Peterson, Devin; Ayeni, Olufemi R; Bhandari, Mohit; Farrokhyar, Forough


    Low serum 25-hydroxyvitamin D (25(OH)D) levels have been associated with stress fractures in various physically active populations such as the military. To examine the association between serum 25(OH)D levels and stress fractures in the military. Systematic review and meta-analysis. Relevant studies were identified through searching multiple databases and manually screening reference lists. Two reviewers independently selected the included studies by applying the eligibility criteria to the title, abstract, and/or full text of the articles yielded in the search. Two reviewers also independently conducted the methodological quality assessment and data extraction. A random-effects model was used to calculate the mean difference (MD) with 95% CI in serum 25(OH)D levels between stress fracture cases and controls. Nine observational studies on lower extremity stress fractures were eligible, and 1 was excluded due to inadequate data. A total of 2634 military personnel (age, 18-30 years; 44% male) with 761 cases (16% male) and 1873 controls (61% male) from 8 studies were included in the analysis. Three of the 8 studies measured serum 25(OH)D levels at the time of stress fracture diagnosis, and the 5 remaining studies measured serum 25(OH)D levels at the time of entry into basic training. The mean serum 25(OH)D level was lower in stress fracture cases than in controls at the time of entry into basic training (MD, -2.63 ng/mL; 95% CI, -5.80 to 0.54; P = .10; I(2) = 65%) and at the time of stress fracture diagnosis (MD, -2.26 ng/mL; 95% CI, -3.89 to -0.63; P = .007; I(2) = 42%). Despite the inherent limitations of the included studies, the study results suggest some association between low serum 25(OH)D levels and lower extremity stress fractures in military personnel. Given the rigorous training of military personnel, implementing strategies to ensure sufficient 25(OH)D levels may be beneficial for reducing the risk of stress fractures. © 2014 The Author(s).

  20. Development of a Modified Korean East Asian Student Stress Inventory by Comparing Stress Levels in Medical Students with Those in Non-Medical Students

    Shin, Hee Kon; Kang, Seok Hoon; Lim, Sun-Hye; Yang, Jeong Hee; Chae, Sunguk


    Background Medical students are usually under more stress than that experienced by non-medical students. Stress testing tools for Korean medical students have not been sufficiently studied. Thus, we adapted and modified the East Asian Student Stress Inventory (EASSI), a stress testing tool for Korean students studying abroad, and verified its usefulness as a stress test in Korean university students. We also compared and analyzed stress levels between medical and non-medical students. Methods...

  1. Residual stress in hydroxyapatite coating: nonlinear analysis and high-energy synchrotron measurements.

    Fogarassy, Paul; Cofino, Bruno; Millet, Pierre; Lodini, Alain


    The thermal deposition of hydroxyapatite (HA) on titanium alloy substrate (Ti-6A1-4V) leads to a structure that has very good osseointegration properties. However, clinical failures have been occasionally reported at the interface between substrate and coating. Lifetime is the main parameter in such prostheses; therefore, in order to improve their quality, it is necessary to evaluate the level of stresses near the interface. The high-energy synchrotron radiation combines the advantages of a bulk analysis and reduced volume of the gauge. The objective of our study was to calculate the residual stress using a nonlinear finite-element model and to measure residual stress level near the interface, in the hydroxyapatite coating and in titanium alloy substrate with a nondestructive and high-resolution experiment. The high-energy synchrotron radiation of the BM16 beam-line at ESRF (Grenoble-France) was used with a resolution of down to 10 micrometers. The experimental measurements validate the results found by means of nonlinear finite-element analysis of the plasma spraying induced stress.

  2. Properties of Swedish posttraumatic stress measures after a disaster.

    Arnberg, Filip K; Michel, Per-Olof; Johannesson, Kerstin Bergh


    This study evaluated the properties of Swedish versions of self-report measures of posttraumatic stress disorder (PTSD), with emphasis on the Impact of Event Scale-Revised (IES-R). Survey data from adult survivors 1, 3, and 6 years after the 2004 Indian Ocean tsunami (n=1506) included the IES-R (from which the IES-6 was derived) and the 12-item General Health Questionnaire (GHQ-12). The PTSD Checklist (PCL) was included in one survey. A structured clinical interview was performed after 6 years (n=142). Factor analyses of the IES-R and PCL indicated that a dysphoric-arousal model provided good fit invariant across assessments. Both measures were accurate in excluding PTSD while all measures provided poorer positive predictive values. The IES-R, but not the IES-6 and GHQ-12, evidenced stability across assessments. In conclusion, the Swedish IES-R and PCL are sound measures of chronic PTSD, and the findings illustrate important temporal aspects of PTSD assessment.

  3. The comparison of methods for measuring oxidative stress in zebrafish brains.

    Moussavi Nik, Seyyed Hani; Croft, Kevin; Mori, Trevor A; Lardelli, Michael


    The zebrafish is a versatile model organism with the potential to contribute to our understanding of the molecular pathological mechanisms underlying Alzheimer's disease (AD). An early characteristic of AD brain pathology is lipid peroxidation resulting from oxidative stress. However, changes in lipid peroxidation have not yet been assessed in zebrafish brains, and an earlier attempt to observe changes in F₂-isoprostane levels in the brains of zebrafish exposed to hypoxia was unsuccessful. In this article, we examine the utility of various assays of lipid peroxidation and more general assays of intracellular oxidative stress to detect the changes in oxidative stress in the brains of adult zebrafish exposed to hypoxia or explanted into a sodium azide solution for chemical mimicry of hypoxia. Levels of F₂-isoprostanes and F₄-neuroprostanes were low and variable in zebrafish brains such that statistically significant changes due to hypoxia or chemical mimicry of hypoxia could not be observed. However, measurement of lipid hydroperoxides did reveal significant changes in lipid peroxidation under these conditions, while analyses of catalase gene expression and an assay based on 2',7'-dicholorofluorescein oxidation also revealed changes in oxidative stress levels.

  4. How integrated are behavioral and endocrine stress response traits? A repeated measures approach to testing the stress-coping style model.

    Boulton, Kay; Couto, Elsa; Grimmer, Andrew J; Earley, Ryan L; Canario, Adelino V M; Wilson, Alastair J; Walling, Craig A


    It is widely expected that physiological and behavioral stress responses will be integrated within divergent stress-coping styles (SCS) and that these may represent opposite ends of a continuously varying reactive-proactive axis. If such a model is valid, then stress response traits should be repeatable and physiological and behavioral responses should also change in an integrated manner along a major axis of among-individual variation. While there is some evidence of association between endocrine and behavioral stress response traits, few studies incorporate repeated observations of both. To test this model, we use a multivariate, repeated measures approach in a captive-bred population of Xiphophorus birchmanni. We quantify among-individual variation in behavioral stress response to an open field trial (OFT) with simulated predator attack (SPA) and measure waterborne steroid hormone levels (cortisol, 11-ketotestosterone) before and after exposure. Under the mild stress stimulus (OFT), (multivariate) behavioral variation among individuals was consistent with a strong axis of personality (shy-bold) or coping style (reactive-proactive) variation. However, behavioral responses to a moderate stressor (SPA) were less repeatable, and robust statistical support for repeatable endocrine state over the full sampling period was limited to 11-ketotestosterone. Although post hoc analysis suggested cortisol expression was repeatable over short time periods, qualitative relationships between behavior and glucocorticoid levels were counter to our a priori expectations. Thus, while our results clearly show among-individual differences in behavioral and endocrine traits associated with stress response, the correlation structure between these is not consistent with a simple proactive-reactive axis of integrated stress-coping style. Additionally, the low repeatability of cortisol suggests caution is warranted if single observations (or indeed repeat measures over short sampling

  5. Stress-Related Growth in Racial/Ethnic Minority Adolescents: Measurement Structure and Validity

    Vaughn, Allison A.; Roesch, Scott C.; Aldridge, Arianna A.


    Stress-related growth is defined as the perception or experience of deriving benefits from encountering stressful circumstances and, thus, has been identified as a protective factor against stress. The current study revised and subsequently validated scores on an existing measure of stress-related growth in a sample of racial/ethnic minority…

  6. Measurements of sea level off Tikkavanipalem - Coast India

    Joseph, A.; Desai, R.G.P.; Peshwe, V.B.; Desa, E.; VijayKumar, K.; Desa, E.S.; Mehra, P.; Nagvekar, S.

    that are induced by local and remote meteorological forcings. The sea level residue (i.e. measured sea level minus the astronomically induced sea level) in this region is particularly by the local wind pattern and air pressure variations. The observed response...

  7. Static and dynamic stress analyses of the prototype high head Francis runner based on site measurement

    Huang, X.; Oram, C.; Sick, M.


    More efforts are put on hydro-power to balance voltage and frequency within seconds for primary control in modern smart grids. This requires hydraulic turbines to run at off-design conditions. especially at low load or speed-no load. Besides. the tendency of increasing power output and decreasing weight of the turbine runners has also led to the high level vibration problem of the runners. especially high head Francis runners. Therefore. it is important to carry out the static and dynamic stress analyses of prototype high head Francis runners. This paper investigates the static and dynamic stresses on the prototype high head Francis runner based on site measurements and numerical simulations. The site measurements are performed with pressure transducers and strain gauges. Based on the measured results. computational fluid dynamics (CFD) simulations for the flow channel from stay vane to draft tube cone are performed. Static pressure distributions and dynamic pressure pulsations caused by rotor-stator interaction (RSI) are obtained under various operating conditions. With the CFD results. static and dynamic stresses on the runner at different operating points are calculated by means of the finite element method (FEM). The agreement between simulation and measurement is analysed with linear regression method. which indicates that the numerical result agrees well with that of measurement. Furthermore. the maximum static and dynamic stresses on the runner blade are obtained at various operating points. The relations of the maximum stresses and the power output are discussed in detail. The influences of the boundary conditions on the structural behaviour of the runner are also discussed.

  8. An Estimation Method of Stress in Soft Rock Based on In-situ Measured Stress in Hard Rock

    LI Wen-ping; LI Xiao-qin; SUN Ru-hua


    The law of variation of deep rock stress in gravitational and tectonic stress fields is analyzed based on the Hoek-Brown strength criterion. In the gravitational stress field, the rocks in the shallow area are in an elastic state and the deep, relatively soft rock may be in a plastic state. However, in the tectonic stress field, the relatively soft rock in the shallow area is in a plastic state and the deep rock in an elastic state. A method is proposed to estimate stress values in coal and soft rock based on in-situ measurements of hard rock. Our estimation method relates to the type of stress field and stress state. The equations of rock stress in various stress states are presented for the elastic, plastic and critical states. The critical state is a special stress state, which indicates the conversion of the elastic to the plastic state in the gravitational stress field and the conversion of the plastic to the elastic state in the tectonic stress field. Two cases studies show that the estimation method is feasible.

  9. Using of abrasive water jet for measurement of residual stress in railway wheels

    Hlaváček, P. (Petr); Brumek, J.; Horsák, L.


    The paper provides a general introduction to methods of measurement of residual stresses on railway wheels. Determination of residual stress distribution is necessary for the prediction of wheel service life and possible catastrophic failure. Therefore experimental section is devoted to residual stress measurement using strain gauges according to standard EN 13262 + A1. During measurement, several segments of tested wheel were cut by abrasive water jet to detect changes of residual stresses o...

  10. Improving Parental Stress Levels Among Mothers Living with HIV: A Randomized Control Group Intervention Study

    Johnson, Erica R.; Davies, Susan L.; Aban, Inmaculada; Mugavero, Michael J.; Shrestha, Sadeep; Kempf, Mirjam-Colette


    Limited knowledge exists regarding parenting efficacy interventions for mothers living with HIV (MLH). This study evaluated the impact of a supportive group intervention on lowering parenting stress among MLH. Eighty MLH were randomized to a parenting (N=34) or health focused (control) (N=46) group intervention. Pre- and post-intervention stress levels were assessed using the Parental Stress Index-Short Form (PSI/SF). Differences in PSI/SF scores were examined using ANOVA, and predictors of P...

  11. Central serotonin transporter levels are associated with stress hormone response and anxiety

    Reimold, Matthias; Knobel, Astrid; Rapp, Michael A.; Batra, Anil; Wiedemann, Klaus; Ströhle, Andreas; Zimmer, Anke; Schönknecht, Peter; Smolka, Michael N.; Weinberger, Daniel R.; Goldman, David; Machulla, Hans-Jürgen; Bares, Roland; Heinz, Andreas


    Rationale Negative mood states are characterized by both stress hormone dysregulation and serotonergic dysfunction, reflected by altered thalamic serotonin transporter (5-HTT) levels. However, so far, no study examined the individual association between cortisol response and cerebral in vivo 5-HTT levels in patients suffering from negative mood states. Objective The objective of this cross-sectional study was to assess the interrelation of cortisol response, thalamic 5-HTT levels, and anxiety in healthy subjects and two previously published samples of patients with unipolar major depression (UMD) and obsessive–compulsive disorder (OCD), controlling for age, gender, 5-HTT genotype, smoking, and seasonality. Methods Regional 5-HTT levels and cortisol response to dexamethasone-corticotropin (Dex-CRH) challenge were assessed in consecutive samples of medication-free patients suffering from UMD (N=10) and OCD (N=10), and 20 healthy volunteers. The intervention used was combined Dex-CRH test and [11C]DASB positron emission tomography. The main outcome measures were: 5-HTT binding potential (BPND) in a predefined thalamic ROI, cortisol response defined as the maximum cortisol increase in the combined Dex-CRH-test, and state of anxiety from the state-trait-anxiety inventory. Results Reduced thalamic 5-HTT BPND was associated with increased cortisol response (r=−0.35, p<0.05; in patients: r=−0.53, p<0.01) and with increased state anxiety (r=−0.46, p<0.01), surviving correction for age, gender, 5-HTT genotype, smoking, and seasonality (p<0.05). The 5-HTT genotype, on the contrary, was not significantly associated with cortisol response (p=0.19) or negative mood (p=0.23). Conclusion The association between stress hormone response, thalamic 5-HTT levels, and anxiety in patients suffering from negative mood states suggests an interaction between two major mechanisms implicated in negative mood states in humans. PMID:20585760

  12. Soil Stress-Strain Behavior: Measurement, Modeling and Analysis

    Ling, Hoe I; Leshchinsky, Dov; Koseki, Junichi; A Collection of Papers of the Geotechnical Symposium in Rome


    This book is an outgrowth of the proceedings for the Geotechnical Symposium in Roma, which was held on March 16 and 17, 2006 in Rome, Italy. The Symposium was organized to celebrate the 60th birthday of Prof. Tatsuoka as well as honoring his research achievement. The publications are focused on the recent developments in the stress-strain behavior of geomaterials, with an emphasis on laboratory measurements, soil constitutive modeling and behavior of soil structures (such as reinforced soils, piles and slopes). The latest advancement in the field, such as the rate effect and dynamic behavior of both clay and sand, behavior of modified soils and soil mixtures, and soil liquefaction are addressed. A special keynote paper by Prof. Tatsuoka is included with three other keynote papers (presented by Prof. Lo Presti, Prof. Di Benedetto, and Prof. Shibuya).

  13. Chronic stress alters the expression levels of longevity-related genes in the rat hippocampus.

    Sánchez-Hidalgo, Ana C; Muñoz, Mario F; Herrera, Antonio J; Espinosa-Oliva, Ana M; Stowell, Rianne; Ayala, Antonio; Machado, Alberto; Venero, José L; de Pablos, Rocío M


    The molecular mechanisms underlying the negative effects of psychological stress on cellular stress during aging and neurodegenerative diseases are poorly understood. The main objective of this study was to test the effect of chronic psychological stress, and the consequent increase of circulating glucocorticoids, on several hippocampal genes involved in longevity. Sirtuin-1, p53, thioredoxin-interacting protein, and heat shock protein 70 were studied at the mRNA and protein levels in stressed and non-stressed animals. Stress treatment for 10 days decreased sirtuin-1 and heat shock protein 70 levels, but increased levels of p53, thioredoxin-interacting protein and the NADPH oxidase enzyme. Examination of protein expression following two months of stress treatment indicated that sirtuin-1 remained depressed. In contrast, an increase was observed for thioredoxin-interacting protein, heat shock protein 70, p53 and the NADPH oxidase enzyme. The effect of stress was reversed by mifepristone, a glucocorticoid receptor antagonist. These data suggest that chronic stress could contribute to aging in the hippocampus. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Reduced angiotensin II levels cause generalized vascular dysfunction via oxidant stress in hamster cheek pouch arterioles.

    Priestley, Jessica R C; Buelow, Matthew W; McEwen, Scott T; Weinberg, Brian D; Delaney, Melanie; Balus, Sarah F; Hoeppner, Carlyn; Dondlinger, Lynn; Lombard, Julian H


    We investigated the effect of suppressing plasma angiotensin II (ANG II) levels on arteriolar relaxation in the hamster cheek pouch. Arteriolar diameters were measured via television microscopy during short-term (3-6days) high salt (HS; 4% NaCl) diet and angiotensin converting enzyme (ACE) inhibition with captopril (100mg/kg/day). ACE inhibition and/or HS diet eliminated endothelium-dependent arteriolar dilation to acetylcholine, endothelium-independent dilation to the NO donor sodium nitroprusside, the prostacyclin analogs carbacyclin and iloprost, and the KATP channel opener cromakalim; and eliminated arteriolar constriction during KATP channel blockade with glibenclamide. Scavenging of superoxide radicals and low dose ANG II infusion (25ng/kg/min, subcutaneous) reduced oxidant stress and restored arteriolar dilation in arterioles of HS-fed hamsters. Vasoconstriction to topically-applied ANG II was unaffected by HS diet while arteriolar responses to elevation of superfusion solution PO2 were unaffected (5% O2, 10% O2) or reduced (21% O2) by HS diet. These findings indicate that sustained exposure to low levels of circulating ANG II leads to widespread dysfunction in endothelium-dependent and independent vascular relaxation mechanisms in cheek pouch arterioles by increasing vascular oxidant stress, but does not potentiate O2- or ANG II-induced constriction of arterioles in the distal microcirculation of normotensive hamsters. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Stress Levels of Kuwaiti Mothers of Children with SLD: Does Work and Educational Status Matter?

    Alazemi, Saad S.; Hadadian, Azar; Merbler, John B.; Wang, Cen


    Existing research literature indicates that parents of children with disabilities have higher stress. The purpose of this study was to examine differences in stress levels between mothers in relation to their children with specific learning disabilities (SLD). A sub sample of 91 mothers participated in the study. The outcome of the research…

  16. Expression levels of urotensin II are associated with endoplasmic reticulum stress in patients with severe preeclampsia.

    He, W-Y; Chen, G-J; Lai, X; Wu, F; Tang, C-S; Zhang, A-H


    Hypertensive disorders in pregnancy remain a leading cause of maternal and perinatal mortality and morbidity. We aim to study urotensin II (UII) and its association with the markers of endoplasmic reticulum stress (ERS) in placentas of patients with severe preeclampsia (SPE). Thirty-three patients with hypertensive disorders in pregnancy and twenty-two healthy pregnant women designated as healthy controls were recruited. Expression levels of UII, UII receptor (GPR14) and the markers of ERS in placenta specimens of patients were performed. Plasma and urinary UII levels were measured by radioimmunoassay method. Our study showed that the plasma levels of UII in patients with hypertensive disorders during pregnancy were significantly higher than that of the healthy control group. However, the urinary levels of UII had no difference in two groups. The expression level of mRNA and protein of UII, CCAAT/enhancer-binding protein homologous protein (CHOP) and glucose regulation protein 78 in placentas of SPE was significantly increased. Immunohistochemical analyses show that the expression levels of UII and ERS markers were mainly located in the cytoplasm of placental trophoblastic cells. Moreover, expression level of UII mRNA and protein was positively correlated with that of the markers of ERS. The positive correlation between UII and ERS markers expression level also corresponded with the level of patient's systolic blood pressure and proteinuria. In conclusion, we first verify that expression of UII is associated with ERS in patients with SPE. Our results indicate that UII may trigger ERS in placental trophoblastic cells in patients with preeclampsia.

  17. System for water level measurement based on pressure transducer

    Paczesny, Daniel; Marzecki, Michał; Woyke, Michał; Tarapata, Grzegorz


    The paper reports system for water level measurement, which is designed to be used for measuring liquid levels in the tanks of an autonomous industrial cleaning robot. The selected method of measurement utilized by the designed system is based on pressure measurement. Such system is insensitive on vibrations, foams presence and liquid impurities. The influences of variable pressure on the measurements were eliminated by utilizing the differential method and as well as the system design. The system is capable of measuring water level in tanks up to 400 mm of height with accuracy of about 2,5%. The system was tested in a container during filling and emptying with various liquids. Performed tests exhibited the linearity of the sensor characteristic and the lack of hysteresis. Obtained sensitivity of the sensor prototype was approximately 6,2 mV/mm H2O.

  18. PIV Measurement of Wall Shear Stress and Flow Structures within an Intracranial Aneurysm Model

    Chow, Ricky; Sparrow, Eph; Campbell, Gary; Divani, Afshin; Sheng, Jian


    The formation and rupture of an intracranial aneurysm (IA) is a debilitating and often lethal event. Geometric features of the aneurysm bulb and upstream artery, such as bulb size, bulb shape, and curvature of the artery, are two groups of factors that define the flow and stresses within an IA. Abnormal flow stresses are related to rupture. This presentation discusses the development of a quasi-3D PIV technique and its application in various glass models at Re = 275 and 550 to experimentally assess at a preliminary level the impact of geometry and flow rate. Some conclusions are to be drawn linking geometry of the flow domain to rupture risk. The extracted results also serve as the baseline case and as a precursor to a companion presentation by the authors discussing the impact of flow diverters, a new class of medical devices. The PIV experiments were performed in a fully index-matched flow facility, allowing for unobstructed observations over complex geometry. A reconstruction and analysis method was devised to obtain 3D mean wall stress distributions and flow fields. The quasi 3D measurements were reconstructed from orthogonal planes encompassing the entire glass model, spaced 0.4mm apart. Wall shear stresses were evaluated from the near-wall flow viscous stresses.

  19. Levels of salivary immunoglobulin A under psychological stress and its relationship with rumination and five personality traits in medical students

    Reza Afrishama


    Full Text Available Background and Objectives: The measurement of salivary immunoglobulin A is a useful and non-invasive method for measuring stress. Personality traits and rumination act as possible mediators in the relationship between psychological stressors and the immune system. This study was aimed to evaluate the levels of salivary IgA under psychological stress and its relationship with rumination and five personality traits in medical students. Methods: In this cross- sectional study, 45 medical students who intended to participate in the final exam were selected by simple random sampling. Two months before the exam, in the basal conditions, the NEO Personality Inventory-Short Form and Emotional Control Questionnaire (ECQ were completed. Saliva samples were taken from students in both the basal conditions and exam stress conditions. Salivary IgA was measured by an ELISA test. Data was analyzed using paired samples T-test, Pearson correlation analysis, and stepwise regression. Results: A significant reduction of salivary IgA levels was found in exam stress conditions. Also, a significant negative correlation was found between traits of neuroticism and rumination with salivary IgA, as well as a significant positive correlation between of openness to experience and emotional inhibition with salivary IgA. Openness to experience and emotional inhibition may predict a substantial variance (34% of salivary IgA under exam stress. Conclusions: Salivary IgA is reduced in response to exam stress. In addition, the rumination and personality traits may reduce or increase stress effects on the immune system, particularly the salivary IgA.

  20. Measurements of Creep Internal Stress Based on Constant Strain Rate and Its Application to Engineering

    TAO Wen-liang; WEI Tao


    This research is carried out on the basis of Constant Strain Rate(CSR) to measure creep internal stress. Measurements of creep internal stress are conducted on the material test machine by using the CSR method. A mathematical model of creep internal stress is also proposed and its application is presented in this paper.

  1. Sympathetic nervous system contributes to enhanced corticosterone levels following chronic stress.

    Lowrance, Steven A; Ionadi, Amy; McKay, Erin; Douglas, Xavier; Johnson, John D


    Exposure to chronic stress often elevates basal circulating glucocorticoids during the circadian nadir and leads to exaggerated glucocorticoid production following exposure to subsequent stressors. While glucocorticoid production is primarily mediated by the hypothalamic-pituitary-adrenal (HPA) axis, there is evidence that the sympathetic nervous system can affect diurnal glucocorticoid production by direct actions at the adrenal gland. Experiments here were designed to examine the role of the HPA and sympathetic nervous system in enhancing corticosterone production following chronic stress. Rats were exposed to a four-day stress paradigm or control conditions then exposed to acute restraint stress on the fifth day to examine corticosterone and ACTH responses. Repeated stressor exposure resulted in a small increase in corticosterone, but not ACTH, during the circadian nadir, and also resulted in exaggerated corticosterone production 5, 10, and 20min following restraint stress. While circulating ACTH levels increased after 5min of restraint, levels were not greater in chronic stress animals compared to controls until following 20min. Administration of astressin (a CRH antagonist) prior to restraint stress significantly reduced ACTH responses but did not prevent the sensitized corticosterone response in chronic stress animals. In contrast, administration of chlorisondamine (a ganglionic blocker) returned basal corticosterone levels in chronic stress animals to normal levels and reduced early corticosterone production following restraint (up to 10min) but did not block the exaggerated corticosterone response in chronic stress animals at 20min. These data indicate that increased sympathetic nervous system tone contributes to elevated basal and rapid glucocorticoid production following chronic stress, but HPA responses likely mediate peak corticosterone responses to stressors of longer duration. Copyright © 2016. Published by Elsevier Ltd.

  2. Effect of year of study on stress levels in male undergraduate dental students

    Alzahem AM


    Full Text Available Abdullah M Alzahem,1 Henk T van der Molen,2 Benjamin J de Boer31Advanced Education in General Dentistry (AEGD Residency Program, King Abdullah International Medical Research Center/King Saud bin Abdulaziz University for Health Sciences/National Guard Health Affairs, Riyadh, Saudi Arabia; 2Institute of Psychology, Faculty of Social Sciences, Erasmus University, Rotterdam, The Netherlands; 3Clinical Psychology, Princess Nora University, Riyadh, Saudi ArabiaObjective: Stress among dental students can be a significant threat, resulting in physical and/or mental illness, and have a negative effect on students' performance and the professional practice of dentistry. Stress can occur from different sources. The purpose of this study is to test whether the year of study has an effect on the stress levels of dental students.Method: Our study consisted of a cross-sectional survey using a modified version of the Dental Environment Stress (DES questionnaire. The questionnaires were filled out by male undergraduate dental students at King Saud University in Riyadh City during the 2010–2011 academic year (n = 214.Results: The results show the most common sources of stress: examinations and completing clinical requirements. Moreover, in the five-year lecture-based traditional curriculum, the third year students reported the highest level of stress, whereas the first year reported the lowest level of stress.Conclusion: Third year undergraduate dental students reported the highest level of stress. This stress could be reduced by reviewing and modifying the dental curriculum by allowing students to have contact with patients more gradually, starting from the first year, in addition to adding stress prevention and intervention programs in dental curricula.Keywords: dental, education, students, stress, study year

  3. Evaluation of the effects of dexamethasone-induced stress on levels of natural antibodies in immunized laying hens.

    Cecchini, Stefano; Rossetti, Michele; Tomaso, Francesco Di; Caputo, Anna Rocchina


    Natural antibodies (NAb) are an important humoral component of innate immunity, playing a pivotal role as first line of defence against pathogens even without prior antigen-specific activation or antigen-driven selection. The levels of NAb in plasma of young laying hens were explored in more detail and identified 2,4,6-trinitrophenyl bovine serum albumin (TNP-BSA), as the non-self antigen showing the highest levels of IgΥ- and IgM-NAb. Subsequently, the relation between specific antibody (SpAb) levels and NAb levels, and the effect of dexamethasone (DEX)-induced stress on the acquired Ab response and on NAb levels were examined. According to obtained results, the affinity of NAb and SpAb, measured using the thiocyanate elution method, resulted higher in SpAb than in NAb. After stress induction, IgM-NAb and SpAb levels showed a transient decrease, whereas the levels of IgΥ-NAb were not changed. Moreover, statistical analysis showed positive correlations between IgΥ- and IgM-NAb levels and between IgM-NAb and SpAb levels that are lost as stress has been induced, whereas no correlation was observed between IgΥ-NAb and SpAb levels, neither before nor after the DEX-administration. This indicates that IgM-NAb assessment could be a valid tool to estimate the potential of the acquired Ab response and that the dexamethasone-induced stress condition causes depression of IgM-NAb levels and the acquired Ab response, but it has no evaluable effects on IgΥ-NAb levels. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. How to measure prenatal stress? A systematic review of psychometric instruments to assess psychosocial stress during pregnancy.

    Nast, Irina; Bolten, Margarete; Meinlschmidt, Gunther; Hellhammer, Dirk H


    A growing body of literature documents associations of maternal psychosocial stress during pregnancy with fetal, infant and child behaviour and development. However, findings across studies are often inconsistent, which may in part be due to differences in stress definitions and assessments. We systematically reviewed methods applied to assess maternal psychosocial stress during pregnancy in studies looking at associations with biobehavioural outcomes in the offspring. A systematic literature search was performed on Web of Science and PubMed for the time period between January 1999 and October 2009. Psychometric instruments assessing maternal psychosocial stress during pregnancy were identified and described if data on psychometric properties were available. We identified 115 publications that assessed psychosocial stress during pregnancy with validated methods. These publications applied overall 43 different instruments assessing constructs falling under seven categories, ordered according to their frequency of use: anxiety, depression, daily hassles, aspects of psychological symptomatology (not reduced to anxiety or depression), life events, specific socio-environmental stressors and stress related to pregnancy and parenting. If available, we provide information on validity and reliability of the instruments for samples of pregnant women. Within the 'prenatal stress' research, a broad range of instruments is applied to assess psychosocial stress during pregnancy. Prenatal stress research should take into consideration that the variety of methods in use might hamper the comparability of stress research results. In each category of stress constructs, one instrument with good psychometric properties in pregnant women is highlighted as the best currently available measure. © 2013 John Wiley & Sons Ltd.

  5. A new stress model, a scream sound, alters learning and monoamine levels in rat brain.

    Hu, Lili; Yang, Juan; Song, Tusheng; Hou, Ni; Liu, Yong; Zhao, Xiaoge; Zhang, Dianzeng; Wang, Lumin; Wang, Tao; Huang, Chen


    Most existing animal models for stress involve the simultaneous application of physical and psychological stress factors. In the current study, we described and used a novel psychological stress model (scream sound stress). To study the validity of it, we carried out acute and chronic scream sound stress. First, adult Sprague-Dawley (SD) rats were randomly divided into white noise, stress and background groups. The white noise group and stress group were treated with white noise and scream sound for 4h in the morning respectively. Compared with white noise and background groups, exposure to acute scream sound increased corticosterone (CORT) level and decreased latency in Morris water maze (MWM) test. The levels of noradrenaline (NE), dopamine (DA), 5-hydroxytryptamine (5-HT), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were altered in the striatum, hypothalamus and hippocampus of stress rats. Second, adult SD rats were randomly divided into background and stress groups, which were treated with scream sound for three weeks. Exposure to chronic scream sound suppressed body weight gain, increased corticosterone (CORT) level, influenced the morphology of adrenal gland, improved spleen and thymus indices, and decreased latency in MWM test. NE, DA, DOPAC, HVA and 5-HIAA levels were also altered in the brain of stress rats. Our results suggested that scream sound, as a novel stressor, facilitated learning ability, as well as altered monoamine levels in the rat brain. Moreover, scream sound is easy to apply and can be applied in more animals at the same time.

  6. Mercury levels assessment and its relationship with oxidative stress biomarkers in children from three localities in Yucatan, Mexico.

    Rangel-Méndez, Jorge A; Arcega-Cabrera, Flor E; Fargher, Lane F; Moo-Puc, Rosa E


    Mercury (Hg) is a global pollutant that is released into the environment from geologic and anthropogenic sources. Once it enters an organism, it generates several toxicity mechanisms and oxidative stress has been proposed as the main one. Metal susceptibility is greater in children, which is a result of their physiology and behavior. In Yucatan, Mexico, burning of unregulated garbage dumps and household trash, ingestion of top marine predators, and pottery manufacturing are among the conditions that could promote Hg exposure. However, for Yucatan, there are no published studies that report Hg levels and associated oxidative stress status in children. Therefore, this study aimed to assess Hg levels in blood and urine and oxidative stress biomarkers levels in a sample of 107 healthy children from three localities in Yucatan, Mexico, as well as investigate the relationship between these parameters. Hg was detected in 11 (10.28%) of blood samples and 38 (35.51%) of urine samples collected from the participating children. Fourteen subjects showed Hg above recommended levels. The oxidative stress biomarkers were slightly elevated in comparison with other studies and were statistically different between the sampling sites. No linear correlation between Hg levels and oxidative stress biomarkers was found. Nevertheless, exploratory univariate and multivariate analysis showed non-linear relations among the measured variables. Globally, the study provides, for the first time, information regarding Hg levels and their relationship with oxidative stress biomarkers in a juvenile population from Mexico's southeast (Yucatan) region. In agreement with worldwide concern about Hg, this study should stimulate studies on metal monitoring in humans (especially children) among scientists working in Mexico, the establishment of polices for its regulation, and the reduction of human health risks.

  7. Habitat degradation and seasonality affect physiological stress levels of Eulemur collaris in littoral forest fragments.

    Michela Balestri

    Full Text Available The littoral forest on sandy soil is among the most threatened habitats in Madagascar and, as such, it represents a hot-spot within a conservation hot-spot. Assessing the health of the resident lemur fauna is not only critical for the long-term viability of these populations, but also necessary for the future re-habilitation of this unique habitat. Since the Endangered collared brown lemur, Eulemur collaris, is the largest seed disperser of the Malagasy south-eastern littoral forest its survival in this habitat is crucial. In this study we compared fecal glucocorticoid metabolite (fGCM levels, a measure of physiological stress and potential early indicator of population health, between groups of collared brown lemurs living in a degraded forest fragment and groups occurring in a more preserved area. For this, we analysed 279 fecal samples collected year-round from 4 groups of collared brown lemurs using a validated 11-oxoetiocholanolone enzyme immunoassay and tested if fGCM levels were influenced by reproductive stages, phenological seasons, sex, and habitat degradation. The lemurs living in the degraded forest had significantly higher fGCM levels than those living in the more preserved area. In particular, the highest fGCM levels were found during the mating season in all animals and in females during gestation in the degraded forest. Since mating and gestation are both occurring during the lean season in the littoral forest, these results likely reflect a combination of ecological and reproductive pressures. Our findings provide a clear indication that habitat degradation has additive effects to the challenges found in the natural habitat. Since increased stress hormone output may have long-term negative effects on population health and reproduction, our data emphasize the need for and may add to the development of effective conservation plans for the species.

  8. Sensing of damage and substrate stress in concrete using electro-mechanical impedance measurements of bonded PZT patches

    Narayanan, Arun; Subramaniam, Kolluru V. L.


    The influence of stress and induced damage in concrete on the electro-mechanical (EM) impedance response of bonded PZT patches is evaluated for applied compressive loading. Full field displacements obtained from digital image correlation are used to evaluate the level of stress-induced damage in concrete. Stress in the substrate produces an imposed strain on the PZT. A change in the imposed strain produces a rightward frequency shift and an increase in the amplitude of the resonant peak in the EM conductance spectrum of the PZT. An increase in the substrate compliance produces a decrease in the resonant frequency and an increase in the amplitude of the resonant peak. Changes in the resonant peak in the conductance spectrum induced by increasing substrate stress are of a significant magnitude when compared with the changes induced by damage. In the early stages of damage associated with distributed microcracking, the counteracting influences of increasing level of damage and increasing stress on the resonant peak result in no shift in frequency for measurements under applied load. There is however an increase in the amplitude of the resonance peak. When the applied stress is removed, there is a net decrease in frequency resulting from damage in the form of distributed microcracks. Measures of changes in the resonant peak based on root mean square deviation (RMSD), do not show any observable change when measurements are performed under applied loading. There is a consistent increase in RMSD values and frequency shift with increasing damage when the applied stress is removed. The centroidal measure of the normalized frequency spectrum reflects changes in substrate stress. At higher applied stress levels, there is a nonlinear increase in damage, leading to localization and cracking. The influence of damage is dominant in this region and significant changes are obtained in the RMSD values in both loaded and unloaded conditions.

  9. Effects of prebiotic, protein level, and stocking density on performance, immunity, and stress indicators of broilers

    Houshmand, M; Azhar, K; Zulkifli, I; Bejo, M H; Kamyab, A


    An experiment was conducted to determine the effects of period on the performance, immunity, and some stress indicators of broilers fed 2 levels of protein and stocked at a normal or high stocking density...

  10. Effects of Interior Plantscapes on Indoor Environments and Stress Level of High School Students

    So-Young Park; Jin-Su Song; Hyoung-Deug Kim; Kenji Yamane; Ki-Cheol Son


      Case studies were performed in two high schools (designated K and J) in Seoul, Korea in order to examine how in-class plantscapes consisting of ornamental plants affected the indoor environment and the stress level of students...

  11. Higher levels of physical activity are associated with lower hypothalamic-pituitary-adrenocortical axis reactivity to psychosocial stress in children.

    Martikainen, Silja; Pesonen, Anu-Katriina; Lahti, Jari; Heinonen, Kati; Feldt, Kimmo; Pyhälä, Riikka; Tammelin, Tuija; Kajantie, Eero; Eriksson, Johan G; Strandberg, Timo E; Räikkönen, Katri


    Children who undertake more physical activity (PA) not only have more optimal physical health but also enjoy better mental health. However, the pathways by which PA affects well-being remain unclear. To address this question, we examined whether objectively measured daytime PA was associated with diurnal hypothalamic-pituitary-adrenocortical axis (HPAA) activity and HPAA responses to psychosocial stress. We conducted a cross-sectional study in a birth cohort in Helsinki, Finland. We studied 258 8-year-old children. PA was assessed with wrist-worn accelerometers. Overall PA and percentage of time spent in vigorous PA (VPA) were categorized by sex into thirds. Salivary cortisol was measured diurnally and in response to the Trier Social Stress Test for Children. The children in different PA groups did not show differences in diurnal salivary cortisol (P > .10 for overall PA and VPA). Children with the highest levels of overall PA or VPA showed no, or only small, increases over time in salivary cortisol after stress (P = .10 and P =.03 for time in analyses of PA and VPA, respectively), whereas children belonging to the lowest and intermediate thirds showed significant increases over time in salivary cortisol after stress (P ≤ .002 for time in the analyses of overall PA and VPA). These results suggest that children with lower levels of daytime PA have higher HPAA activity in response to stress. These findings may offer insight into the pathways of PA on physical and mental well-being.

  12. Measuring bed shear stress along vegetated river beds using FST-hemispheres.

    Bockelmann-Evans, B N; Davies, R; Falconer, R A


    The measurement of the bed shear stress along vegetated river beds is essential for accurately predicting the water level, velocity and solute and sediment transport fluxes in computational hydroenvironmental models. Details are given herein of an experimental and theoretical study to determine the bed boundary shear stress along vegetated river beds introducing a novel field measuring method, namely the FliessWasserStammtisch (FST)-hemispheres. Although investigations have been conducted previously for sedimentary channels using the FST-hemispheres, this preliminary study is thought to be the first time that such hemispheres have been used to investigate the bed shear stresses in vegetated channels. FST-hemispheres were first developed by Statzner and Müller [1989. Standard hemispheres as indicators of flow characteristics in lotic benthos research. Freshwater Biology 21, 445-459] to act as an integrated indicator of the gross hydrodynamic stresses present near the bed. Test and validation data were found to be at least of the same order of magnitude for the stresses predicted from literature for sedimentary channels, with this study establishing the commencement of a database of calibrated FST-hemisphere laboratory data for vegetated channel beds. In a series of experiments, depths ranging from 0.1 to 0.28 m were considered, equating directly to comparable conditions in small rivers or streams. The results of this study provide a basis for enabling the FST-hemispheres to be used to evaluate the boundary shear stress for a wider range of applications in the future, including vegetated river beds.

  13. In-situ stress measurements and stress change monitoring to monitor overburden caving behaviour and hydraulic fracture pre-conditioning

    Puller Jesse W.; Mills Ken W.; Jeffrey Rob G.; Walker Rick J.


    A coal mine in New South Wales is longwall mining 300 m wide panels at a depth of 160–180 m directly below a 16–20 m thick conglomerate strata. As part of a strategy to use hydraulic fracturing to manage potential windblast and periodic caving hazards associated with these conglomerate strata, the in-situ stresses in the conglomerate were measured using ANZI strain cells and the overcoring method of stress relief. Changes in stress associated with abutment loading and placement of hydraulic fractures were also measured using ANZI strain cells installed from the surface and from underground. Overcore stress mea-surements have indicated that the vertical stress is the lowest principal stress so that hydraulic fractures placed ahead of mining form horizontally and so provide effective pre-conditioning to promote caving of the conglomerate strata. Monitoring of stress changes in the overburden strata during longwall retreat was undertaken at two different locations at the mine. The monitoring indicated stress changes were evi-dent 150 m ahead of the longwall face and abutment loading reached a maximum increase of about 7.5 MPa. The stresses ahead of mining change gradually with distance to the approaching longwall and in a direction consistent with the horizontal in-situ stresses. There was no evidence in the stress change monitoring results to indicate significant cyclical forward abutment loading ahead of the face. The for-ward abutment load determined from the stress change monitoring is consistent with the weight of over-burden strata overhanging the goaf indicated by subsidence monitoring.

  14. Repeated measures of urinary oxidative stress biomarkers during pregnancy and preterm birth.

    Ferguson, Kelly K; McElrath, Thomas F; Chen, Yin-Hsiu; Loch-Caruso, Rita; Mukherjee, Bhramar; Meeker, John D


    The purpose of this study was to investigate oxidative stress as a mechanism of preterm birth in human subjects; we examined associations between urinary biomarkers of oxidative stress that were measured at multiple time points during pregnancy and preterm birth. This nested case-control study included 130 mothers who delivered preterm and 352 mothers who delivered term who were originally recruited as part of an ongoing prospective birth cohort at Brigham and Women's Hospital. Two biomarkers that included 8-hydroxydeoxyguanosine (8-OHdG) and 8-isoprostane were measured in urine samples that were collected at up to 4 time points (median 10, 18, 26, and 35 weeks) during gestation. Urinary concentrations of 8-isoprostane and 8-OHdG decreased and increased, respectively, as pregnancy progressed. Average levels of 8-isoprostane across pregnancy were associated with increased odds of spontaneous preterm birth (adjusted odds ratio, 6.25; 95% confidence interval, 2.86-13.7), and associations were strongest with levels measured later in pregnancy. Average levels of 8-OHdG were protective against overall preterm birth (adjusted odds ratio, 0.19; 95% confidence interval, 0.10-0.34), and there were no apparent differences in the protective effect in cases of spontaneous preterm birth compared with cases of placental origin. Odds ratios for overall preterm birth were more protective in association with urinary 8-OHdG concentrations that were measured early in pregnancy. Maternal oxidative stress may be an important contributor to preterm birth, regardless of subtype and timing of exposure during pregnancy. The 2 biomarkers that were measured in the present study had opposite associations with preterm birth; an improved understanding of what each represents may help to identify more precisely important mechanisms in the pathway to preterm birth. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Measurement of dynamic gas disengagement profile by using an analog output level gauge

    Mikkilineni, S.; Koelle, M.; Xu, H.

    The dynamic gas disengagement profile was measured in a 0.14 m diameter and 3.66 m high plexiglas column by using an analog output gauge, which was connected to a data acquisition system. This analog output gauge is a high accuracy continuous measurement level gauge. It is made up of a wave guide, a float, a motion or stress sensing device and a probe housing. The fluid level at any gas velocity is obtained by using the data acquisition system. The dynamic gas disengagement profile produced one slope in the bubble flow and two slopes in the churn turbulent flow representing unimodal and bimodal distributions of bubbles.

  16. Expression Profiling of Abiotic Stress-Inducible Genes in response to Multiple Stresses in Rice (Oryza sativa L. Varieties with Contrasting Level of Stress Tolerance

    Supratim Basu


    Full Text Available The present study considered transcriptional profiles and protein expression analyses from shoot and/or root tissues under three abiotic stress conditions, namely, salinity, dehydration, and cold, as well as following exogenous abscisic acid treatment, at different time points of stress exposure in three indica rice varieties, IR-29 (salt sensitive, Pokkali, and Nonabokra (both salt tolerant. The candidate genes chosen for expression studies were HKT-1, SOS-3, NHX-1, SAPK5, SAPK7, NAC-1, Rab16A, OSBZ8, DREBP2, CRT/DREBP, WRKY24, and WRKY71, along with the candidate proteins OSBZ8, SAMDC, and GST. Gene expression profile revealed considerable differences between the salt-sensitive and salt-tolerant rice varieties, as the expression in the latter was higher even at the constitutive level, whereas it was inducible only by corresponding stress signals in IR-29. Whether in roots or shoots, the transcriptional responses to different stressors peaked following 24 h of stress/ABA exposure, and the transcript levels enhanced gradually with the period of exposure. The generality of stress responses at the transcriptional level was therefore time dependent. Heat map data also showed differential transcript abundance in the three varieties, correlating the observation with transcript profiling. In silico analysis of the upstream regions of all the genes represented the existence of conserved sequence motifs in single or multiple copies that are indispensable to abiotic stress response. Overall, the transcriptome and proteome analysis undertaken in the present study indicated that genes/proteins conferring tolerance, belonging to different functional classes, were overrepresented, thus providing novel insight into the functional basis of multiple stress tolerance in indica rice varieties. The present work will pave the way in future to select gene(s for overexpression, so as to generate broad spectrum resistance to multiple stresses simultaneously.

  17. The examination of sport managers and coaches’ stress levels and depressed mood at work in Turkey

    Bilge Donuk


    Full Text Available This paper is an investigation of stress levels and depressed mood at work in sport managers and coaches. Three different questionnaires were applied to professional sport managers (n=60 and coaches (n=52 in Turkey to regard to potential sources of stress before, during and after competitions. This sample represented approximately 21% of the total professional football, basketball and volleyball clubs in Turkey. The questionnaires used are “Perceived Stress Questionnaire”, “Anxiety-Stress Questionnaire” and “Depressed Mood at Work Questionnaire”. Our findings indicated that: The aim of first questionnaire was to assess perceived stressful situations and results show that general stress levels of managers and coaches are under the average. When we examine the second questionnaire consisting of health, physical condition, tension caused by stress; it is seen that negative effects of these factors increase. At last; according to the depressed mood at work questionnaire which evaluates the physiological conditions related to stress; it’s found out that both managers and coaches aren’t satisfied with their working atmosphere and managers’ unhappiness levels are higher than coaches are.

  18. Comparison of the Effect of Noise Levels on Stress Response in Two Different Operation Groups in an Orthopedic Surgery Room

    Hasibe Baytan Yildiz


    Full Text Available Aim: The aim of this randomized, single-blinded study was to evaluate the effects of noise on hemodynamic and neuroendocrine stress response by measuring the level of noise in the surgery rooms of patients undergoing knee operations under neuroaxial anesthesia. Gerec ve Yontem: We compared patient responses from two groups of patients: those undergoing knee operations in a surgery room where the noise level (measured in decibels is high, and those undergoing meniscus operations in a surgery room with lower noise levels. The STAI, the State-Trait Anxiety Inventory (STAI-1, and the anxiety test (STAI-2wereperformed at preoperative and postoperative periods. 20 ml of blood sample was taken for basal, intraoperative 30th minute, and postoperative 1st hour measurements. Systolic, diastolic, and mean arterial blood pressures were found to be higher in the high noise level group. ACTH levels were increased during the early postoperative period and became normal during the late postoperative period in the high noise level group whereas ACTH levels were significantly decreased in the low-noise level group. Basal cortisol levels were significantly higher in the high noise level group. HCRP, an inflammatory response mediator was found to be decreased in both groups. Early and late blood glucose levels were significantly higher in the high noise group. There was a greater increase in early and late blood glucose levels in the high noise group. In the postoperative period, although the state-trait anxiety inventory (STAI-2 levels being higher in patients subject to noisier environment determines how people feel independent of the conditions and state they are in, this result made us consider that the noise the patients were subjected to in the intraoperative period may cause a stress response. Discussion: As a result we believe that standard noise levels should be achieved by reducing the factors causing high noise levels in the operating room. This will

  19. Measurement of Acceptable Noise Level with Background Music

    Ahn, Hyun-Jung; Bahng, Junghwa; Lee, Jae Hee


    Background and Objectives Acceptable noise level (ANL) is a measure of the maximum background noise level (BNL) that a person is willing to tolerate while following a target story. Although researchers have used various sources of target sound in ANL measures, a limited type of background noise has been used. Extending the previous study of Gordon-Hickey & Moore (2007), the current study determined the effect of music genre and tempo on ANLs as possible factors affecting ANLs. We also investi...

  20. Future Climate CO2 Levels Mitigate Stress Impact on Plants: Increased Defense or Decreased Challenge?

    AbdElgawad, Hamada; Zinta, Gaurav; Beemster, Gerrit T S; Janssens, Ivan A; Asard, Han


    Elevated atmospheric CO2 can stimulate plant growth by providing additional C (fertilization effect), and is observed to mitigate abiotic stress impact. Although, the mechanisms underlying the stress mitigating effect are not yet clear, increased antioxidant defenses, have been held primarily responsible (antioxidant hypothesis). A systematic literature analysis, including "all" papers [Web of Science (WoS)-cited], addressing elevated CO2 effects on abiotic stress responses and antioxidants (105 papers), confirms the frequent occurrence of the stress mitigation effect. However, it also demonstrates that, in stress conditions, elevated CO2 is reported to increase antioxidants, only in about 22% of the observations (e.g., for polyphenols, peroxidases, superoxide dismutase, monodehydroascorbate reductase). In most observations, under stress and elevated CO2 the levels of key antioxidants and antioxidant enzymes are reported to remain unchanged (50%, e.g., ascorbate peroxidase, catalase, ascorbate), or even decreased (28%, e.g., glutathione peroxidase). Moreover, increases in antioxidants are not specific for a species group, growth facility, or stress type. It seems therefore unlikely that increased antioxidant defense is the major mechanism underlying CO2-mediated stress impact mitigation. Alternative processes, probably decreasing the oxidative challenge by reducing ROS production (e.g., photorespiration), are therefore likely to play important roles in elevated CO2 (relaxation hypothesis). Such parameters are however rarely investigated in connection with abiotic stress relief. Understanding the effect of elevated CO2 on plant growth and stress responses is imperative to understand the impact of climate changes on plant productivity.

  1. Anxiety mediates the effect of acute stress on working memory performance when cortisol levels are high: a moderated mediation analysis.

    Hood, Anna; Pulvers, Kim; Spady, Thomas J; Kliebenstein, Alexa; Bachand, Jennifer


    Anxiety is an aversive emotional state characterized by perceived uncontrollability and hypervigilance to threat that can frequently cause disruptions in higher-order cognitive processes like working memory. The attentional control theory (ACT) predicts that anxiety negatively affects the working memory system. This study tested the association between anxiety and working memory after the addition of stress and measured the glucocorticoid, cortisol. To better understand this relationship, we utilized a moderated mediation model. Undergraduate students from a public university (N = 103) self-reported their anxiety levels. Participants first completed a short-term memory test. During and after a forehead cold pressor task (stress vs. control procedure) participants completed a working memory test. Salivary cortisol was taken at baseline and after the last working memory test. Overall, acute stress had no effect on working memory. However, we found that anxiety levels mediated the influence of condition (stressed vs. control) on working memory, but only among those individuals who had high cortisol levels after exposure to acute stress, supporting a moderated mediation model. These results imply that activation of the hypothalamic-pituitary-adrenal axis was necessary for working memory impairment in anxious individuals. These results provide support for the ACT.

  2. Lithium modulates the chronic stress-induced effect on blood glucose level of male rats

    Popović Nataša


    Full Text Available In the present study we examined gross changes in the mass of whole adrenal glands and that of the adrenal cortex, as well as the serum corticosterone and glucose level of mature male Wistar rats subjected to three different treatments: animals subjected to chronic restraint-stress, animals injected with lithium (Li and chronically stressed rats treated with Li. Under all three conditions we observed hypertrophy of whole adrenals, as well as the adrenal cortices. Chronic restraint stress, solely or in combination with Li treatment, significantly elevated the corticosterone level, but did not change the blood glucose level. Animals treated only with Li exhibited an elevated serum corticosterone level and blood glucose level. The aim of our study was to investigate the modulation of the chronic stress-induced effect on the blood glucose level by lithium, as a possible mechanism of avoiding the damage caused by chronic stress. Our results showed that lithium is an agent of choice which may help to reduce stress-elevated corticosterone and replenish exhausted glucose storages in an organism.

  3. Computational Visual Stress Level Analysis of Calcareous Algae Exposed to Sedimentation

    Nilssen, Ingunn; Eide, Ingvar; de Oliveira Figueiredo, Marcia Abreu; de Souza Tâmega, Frederico Tapajós; Nattkemper, Tim W.


    This paper presents a machine learning based approach for analyses of photos collected from laboratory experiments conducted to assess the potential impact of water-based drill cuttings on deep-water rhodolith-forming calcareous algae. This pilot study uses imaging technology to quantify and monitor the stress levels of the calcareous algae Mesophyllum engelhartii (Foslie) Adey caused by various degrees of light exposure, flow intensity and amount of sediment. A machine learning based algorithm was applied to assess the temporal variation of the calcareous algae size (∼ mass) and color automatically. Measured size and color were correlated to the photosynthetic efficiency (maximum quantum yield of charge separation in photosystem II, ΦPSIImax) and degree of sediment coverage using multivariate regression. The multivariate regression showed correlations between time and calcareous algae sizes, as well as correlations between fluorescence and calcareous algae colors. PMID:27285611

  4. A Comparison between Deep and Shallow Stress Fields in Korea Using Earthquake Focal Mechanism Inversions and Hydraulic Fracturing Stress Measurements

    Lee, Rayeon; Chang, Chandong; Hong, Tae-kyung; Lee, Junhyung; Bae, Seong-Ho; Park, Eui-Seob; Park, Chan


    We are characterizing stress fields in Korea using two types of stress data: earthquake focal mechanism inversions (FMF) and hydraulic fracturing stress measurements (HF). The earthquake focal mechanism inversion data represent stress conditions at 2-20 km depths, whereas the hydraulic fracturing stress measurements, mostly conducted for geotechnical purposes, have been carried out at depths shallower than 1 km. We classified individual stress data based on the World Stress Map quality ranking scheme. A total of 20 FMF data were classified into A-B quality, possibly representing tectonic stress fields. A total of 83 HF data out of compiled 226 data were classified into B-C quality, which we use for shallow stress field characterization. The tectonic stress, revealed from the FMF data, is characterized by a remarkable consistency in its maximum stress (σ1) directions in and around Korea (N79±2° E), indicating a quite uniform deep stress field throughout. On the other hand, the shallow stress field, represented by HF data, exhibits local variations in σ1 directions, possibly due to effects of topography and geologic structures such as faults. Nonetheless, there is a general similarity in σ1 directions between deep and shallow stress fields. To investigate the shallow stress field statistically, we follow 'the mean orientation and wavelength analysis' suggested by Reiter et al. (2014). After the stress pattern analysis, the resulting stress points distribute sporadically over the country, not covering the entire region evenly. In the western part of Korea, the shallow σ1directions are generally uniform with their search radius reaching 100 km, where the average stress direction agrees well with those of the deep tectonic stress. We note two noticeable differences between shallow and deep stresses in the eastern part of Korea. First, the shallow σ1 orientations are markedly non-uniform in the southeastern part of Korea with their search radius less than 25 km

  5. Stress, depression, quality of life and salivary cortisol levels in community health agents.

    Knuth, Berenice Scaletzky; Cocco, Rafaela Abreu; Radtke, Vinicius Augusto; Medeiros, João Ricardo Carvalho; Oses, Jean Pierre; Wiener, Carolina David; Jansen, Karen


    To determine the prevalence of and factors associated with depression and stress with perceived quality of life and the salivary cortisol levels in Community Health Agent (CHA). Materials and Methods Cross-sectional descriptive study of CHAs in Pelotas-RS, Brazil. Data collection, including sociodemographic information and factors related to work and health. Beck Depression Inventory (BDI) II was used to assess depressive symptoms, Inventory of Stress Symptoms Lipp (ISSL) was used for the analysis of stress and the WHOQOL-BREF was used to investigate quality of life. Salivary cortisol was quantified via ELISA test. The assessments showed that 71.0% are in a state of stress resistance, 30.5% were in the alert state of stress and 32.8% were in the stress state of exhaustion. Depressive episodes (BDI≥12) were observed in 28.2%. The environmental domain had the lowest score for quality of life. We observed significantly higher salivary cortisol levels in CHAs with less than 1 year of service and with the lowest quality of life scores in the environmental subsection. A high prevalence of stress and depression was observed in this sample of CHAs. In addition, the worst levels of quality of life were identified in the environmental subsection. Cortisol levels corroborate these findings regarding quality of life within the environmental domain and began working less than a year previously.

  6. Measuring Structural Gender Equality in Mexico: A State Level Analysis

    Frias, Sonia M.


    The main goal of this article is to assess the level of gender equality across the 32 Mexican states. After reviewing conceptual and methodological issues related to previous measures of structural inequality I detail the logic and methodology involved in the construction of a composite and multidimensional measure of gender equality, at the…

  7. Oxidative stress and antioxidant levels in patients with anorexia nervosa: A systematic review and exploratory meta-analysis.

    Solmi, Marco; Veronese, Nicola; Manzato, Enzo; Sergi, Giuseppe; Favaro, Angela; Santonastaso, Paolo; Correll, Christoph U


    To systematically review and meta-analyze oxidative stress and antioxidant markers in anorexia nervosa (AN). Electronic PubMed search from database inception until 12/31/2013. Out of 1062 hits, 29 studies comparing oxidative stress/antioxidant markers between patients with AN and healthy controls (HCs) with a total of 1,729 participants (AN = 895, HCs = 834) were eligible. Data about oxidative stress and antioxidant markers, independent of their source, were extracted. We calculated random effects standardized mean differences (SMDs) as effect size measures for outcomes reported in ≥5 studies; others were summarized descriptively. Compared to HCs, AN patients showed significantly higher apolipoprotein B (ApoB) levels (studies = 7; n = 551; SMD = 0.75; p = .0003, I(2)  = 74%), with higher age being associated with higher ApoB (Coefficient: 0.61 ± 0.15, p levels were similar between AN and HCs (studies = 13; n = 509; SMD =-0.19; 95%CI: -0.62 to 0.24; p = .38; I(2)  = 81%), with neither age (p = .84) nor BMI (p = .52) being significant moderators. Lower superoxide dismutase levels were reported in 2 studies, while findings for vitamin A and its metabolites were inconclusive. In single studies, patients with AN had significantly higher catalase and nitric oxide (NO) parameter levels (platelet NO, exhaled NO and nitrites), such as lower glutathione and free cysteine levels, compared to HCs. AN appears to be associated with some markers of increased oxidative stress. Additional research is needed to discern whether oxidative stress is a potential cause or effect of AN, and whether treatments improving oxidative stress could be useful in AN. © 2015 Wiley Periodicals, Inc.

  8. Cortisol level measurements in fingernails as a retrospective index of hormone production.

    Izawa, Shuhei; Miki, Keiichi; Tsuchiya, Masao; Mitani, Takeshi; Midorikawa, Toru; Fuchu, Tatsuya; Komatsu, Taiki; Togo, Fumiharu


    The cortisol level in fingernails may reflect the hormone's cumulative production over a long period, but the notions have not been fully established. In this study, we investigated the association of cortisol in fingernails with cortisol accumulation over a long period (hair cortisol) and over a relatively short period (salivary cortisol). In study 1, hair and fingernail samples were collected from 58 middle-aged and elderly men. The cortisol level in hair samples was moderately associated with the level in fingernail samples (r = 0.29, p cortisol level in saliva over the whole day (area under the curve for cortisol) was moderately associated with the cortisol level measured in fingernail samples that were collected 4 months (r = 0.43, p cortisol level in fingernail samples might retrospectively represent hormone production during a given period. The cortisol level in fingernail samples may be useful in the investigation of the link between psychosocial stress and health.

  9. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.


    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of (/sup 3/H)Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in (14C)iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress (an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures), although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results.

  10. Academic Stress Influences Periodontal Health Condition and Interleukin-1 beta Level

    Sandra O. Kuswandani


    Full Text Available Stress is a risk factor for periodontal disease, causing increase levels of interleukin-1 beta that involve in periodontal destruction. Objective: To analyze the relationship between academic stress in residency program students conditions and levels of interleukin-1 beta in gingival crevicular fluid. Methods: Thirty eight subjects filled the questionnaire of Graduate Dental Environtmental Stress (GDES, periodontal examination and samples of gingival crevicular fluid were tested for interleukin-1 beta with the Enzyme-linked Immunosorbent Assay (ELISA test. Results: There were significant differences between academic stress to periodontal tissue in oral hygiene (p=0.038, bleeding on probing index (p=0.02, but no significant differences in pocket depth and loss of attachment (p=0.972. There were significant differences between academic stress to levels of interleukin-1 beta (p=0.03, but no significant differences between levels of interleukin-1 beta to periodontal tissue in oral hygiene (p=0.465, bleeding on probing index (p=0.826, pocket depth (p=0.968, and loss of attachment (p=0.968. Conclusion: Academic stress influences the periodontal risk factor and level of interleukin-1 beta.

  11. Unconscious fearful priming followed by a psychosocial stress test results in higher cortisol levels.

    Hänsel, Alexander; von Känel, Roland


    Human perception of stress includes an automatic pathway that processes subliminal presented stimuli below the threshold of conscious awareness. Subliminal stimuli can therefore activate the physiologic stress system. Unconscious emotional signals were shown to significantly moderate reactions and responses to subsequent stimuli, an effect called 'priming'. We hypothesized that subliminal presentation of a fearful signal during the Stroop task compared with an emotionally neutral one will prime stress reactivity in a subsequently applied psychosocial stress task, thereby yielding a significant increase in salivary cortisol. Half of 36 participants were repeatedly presented either a fearful face or a neutral one. After this, all underwent a psychosocial stress task. The fearful group showed a significant increase in cortisol levels (p = 0.022). This change was not affected by sex, age and body mass index, and it also did not change when taking resting cortisol levels into account. Post-hoc analyses showed that the increase in cortisol in the fearful group started immediately after the psychosocial stress test. Hence, subliminal exposure to a fearful signal in combination with the Stroop and followed by a psychosocial stress test leads to an increase in stress reactivity.

  12. Levels of Stress among General Practitioners, Students and Specialists In Pediatric Dentistry during Dental Treatment.

    Davidovich, E; Pessov, Y; Baniel, A; Ram, D


    To assess self-reported stress during the performance of different procedures in pediatric dentistry, according to the professional experience of the dentists. During the years 2010 to 2011, an anonymous survey was administered by means of an internet link, and by distribution at professional meetings of dentists . No statistically significant differences in stress were reported for maxilla and mandibular procedures. Placement of a rubber dam was rated as the most stressful procedure among dental students. For general practitioners and specialists, injection of local anesthesia to an anxious child was the most stressful procedure, regardless of age, sex, or years of professional experience. A negative correlation was found between years of experience and level of stress for all the procedures surveyed, but not for the use of nitrous oxide. No differences were found between male and female dentists in stress scores for any of the procedures. Higher rates of stress during operative procedures were reported among dental students than among experienced dentists. Anxiety of the pediatric patients, but not the location of the procedure: maxillary or mandibular, affected the dentists' reported level of stress.

  13. Correlation between psychological stress levels and the severity of overactive bladder symptoms.

    Lai, Henry; Gardner, Vivien; Vetter, Joel; Andriole, Gerald L


    The relationship between psychological stress and interstitial cystitis/bladder pain syndrome (IC/BPS) has been well described. Even though there is some overlapping of symptoms between overactive bladder (OAB) and IC/BPS, there have been very few studies that specifically investigated the relationship between psychological stress and urinary symptoms in OAB patients who do not have pelvic pain. Here we examined the relationship between psychological stress levels and the severity of overactive bladder (OAB) symptoms. Patients diagnosed with OAB (n=51), IC/BPS (n=27), and age-matched healthy controls (n=30) participated in a case control study that inquired about their psychological stress levels using the perceived stress scale (PSS). PSS reported by the three patient groups were compared. Among OAB patients, their responses on the PSS was correlated to OAB symptoms using the following questionnaires: 1) international consultation on incontinence - urinary incontinence (ICIQ-UI), 2) international consultation on incontinence - overactive bladder (ICIQ-OAB), 3) OAB-q short form, 4) urogenital distress inventory (UDI-6), 5) incontinence impact questionnaire (IIQ-7), 6) urgency severity scale (USS), 7) numeric rating scales of urgency symptom, and 8) frequency symptom. Spearman's correlation tests were performed to examine the relationship between psychological stress levels and the severity of OAB symptoms. OAB patients reported psychological stress levels that were as high as IC/BPS patients (median 17.0 versus 18.0, p=0.818, Wilcoxon sum rank test), and significantly higher than healthy controls (17.0, versus 7.5, p=0.001). Among OAB patients, there was a positive correlation between perceived stress levels and urinary incontinence symptoms (ICIQ-UI, Spearman's correlation coefficient=0.39, p=0.007), and impacts on quality of life (UDI-6, IIQ-7, OAB-q quality of life subscale; Spearman's correlation coefficient=0.32, 0.31, 0.39, and p=0.028, 0.005, 0

  14. Stress-responsiveness influences baseline glucocorticoid levels: Revisiting the under 3min sampling rule.

    Small, Thomas W; Bebus, Sara E; Bridge, Eli S; Elderbrock, Emily K; Ferguson, Stephen M; Jones, Blake C; Schoech, Stephan J


    Plasma glucocorticoid (CORT) levels collected within 3min of capture are commonly believed to reflect pre-stressor, baseline CORT levels. Differences in these "baseline" values are often interpreted as reflecting differences in health, or the amount of social and environmental stress recently experienced by an individual. When interpreting "baseline" values it is generally assumed that any effect of capture-and-handling during the initial sampling period is small enough and consistent enough among individuals to not obscure pre-capture differences in CORT levels. However, plasma CORT increases in less than 3min post-capture in many free-living, endothermic species in which timing has been assessed. In addition, the rate of CORT secretion and the maximum level attained (i.e., the degree of stress-responsiveness) during a severe stressor often differs among individuals of the same species. In Florida scrub-jays (Aphelocoma coerulescens), an individual's stress-responsiveness during a 30min post-capture stressor is correlated with CORT levels in samples collected within 1.5min of capture, suggesting there is an intrinsic connection between stress-responsiveness and pre-capture CORT levels. Although differences in stress-responsiveness accounted for just 11% of the variance in these samples, on average, higher stress-responsive jays (top third of individuals) had baseline values twice that of lower stress-responsive jays (bottom third). Further, plasma CORT levels begin to increase around 2min post-capture in this species, but the rate of increase between 2 and 3min differs markedly with CORT increasing more rapidly in jays with higher stress-responsiveness. Together, these data indicate that baseline CORT values can be influenced by an individual's stress response phenotype and the differences due to stress-responsiveness can be exaggerated during sample collection. In some cases, the effects of differences in stress-responsiveness and the increase in CORT during

  15. Amphetamine withdrawal differentially affects hippocampal and peripheral corticosterone levels in response to stress.

    Bray, Brenna; Scholl, Jamie L; Tu, Wenyu; Watt, Michael J; Renner, Kenneth J; Forster, Gina L


    Amphetamine withdrawal is associated with heightened anxiety-like behavior, which is directly driven by blunted stress-induced glucocorticoid receptor-dependent serotonin release in the ventral hippocampus. This suggests that glucocorticoid availability in the ventral hippocampus during stress may be reduced during amphetamine withdrawal. Therefore, we tested whether amphetamine withdrawal alters either peripheral or hippocampal corticosterone stress responses. Adult male rats received amphetamine (2.5mg/kg, ip) or saline for 14 days followed by 2 weeks of withdrawal. Contrary to our prediction, microdialysis samples from freely-moving rats revealed that restraint stress-induced corticosterone levels in the ventral hippocampus are enhanced by amphetamine withdrawal relative to controls. In separate groups of rats, plasma corticosterone levels increased immediately after 20min of restraint and decreased to below stress-naïve levels after 1h, indicating negative feedback regulation of corticosterone following stress. However, plasma corticosterone responses were similar in amphetamine-withdrawn and control rats. Neither amphetamine nor stress exposure significantly altered protein expression or enzyme activity of the steroidogenic enzymes 11β-hydroxysteroid dehydrogenase (11β-HSD1) or hexose-6-phosphate dehydrogenase (H6PD) in the ventral hippocampus. Our findings demonstrate for the first time that amphetamine withdrawal potentiates stress-induced corticosterone in the ventral hippocampus, which may contribute to increased behavioral stress sensitivity previously observed during amphetamine withdrawal. However, this is not mediated by either changes in plasma corticosterone or hippocampal steroidogenic enzymes. Establishing enhanced ventral hippocampal corticosterone as a direct cause of greater stress sensitivity may identify the glucocorticoid system as a novel target for treating behavioral symptoms of amphetamine withdrawal. Copyright © 2016 Elsevier B

  16. Early life low-level cadmium exposure is positively associated with increased oxidative stress

    Kippler, Maria [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Bakhtiar Hossain, Mohammad [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh); Department of Laboratory Medicine, Section of Occupational and Environmental Medicine, Lund University, Lund (Sweden); Lindh, Christian [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh); Moore, Sophie E. [MRC Keneba, MRC Laboratories (Gambia); Kabir, Iqbal [Department of Laboratory Medicine, Section of Occupational and Environmental Medicine, Lund University, Lund (Sweden); Vahter, Marie [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Broberg, Karin, E-mail: [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh)


    Environmental exposure to cadmium (Cd) is known to induce oxidative stress, a state of imbalance between the production of reactive oxygen species (ROS) and the ability to detoxify them, in adults. However, data are lacking on potential effects in early-life. We evaluated urinary concentrations of 8-oxo-7,8-dihydro-2 Prime -deoxyguanosine (8-oxodG), a recognized marker of oxidative DNA damage, in relation to Cd exposure in 96 predominantly breast-fed infants (11-17 weeks of age) in rural Bangladesh. Urinary 8-oxodG was measured using liquid chromatography tandem mass spectrometry and Cd in urine and breast milk by inductively coupled plasma mass spectrometry. Median concentration of 8-oxodG was 3.9 nmol/L, urinary Cd 0.30 {mu}g/L, and breast-milk Cd 0.13 {mu}g/L. In linear regression analyses, urinary 8-oxodG was positively associated with Cd in both urine (p=0.00067) and breast milk (p=0.0021), and negatively associated with body weight (kg; p=0.0041). Adjustment for age, body weight, socio-economic status, urinary arsenic, as well as magnesium, calcium, and copper in breast milk did not change the association between Cd exposure and urinary 8-oxodG. These findings suggest that early-life low-level exposure to Cd via breast milk induces oxidative stress. Further studies are warranted to elucidate whether this oxidative stress is associated with impaired child health and development.

  17. Measurements of extremely low radioactivity levels in BOREXINO

    Arpesella, C


    The techniques researched, developed and applied towards the measurement of radioisotope concentrations at ultra-low levels in the real-time solar neutrino experiment BOREXINO at Gran Sasso are presented and illustrated with specific results of widespread interest. We report the use of low-level germanium gamma spectrometry, low-level miniaturized gas proportional counters and low background scintillation detectors developed in solar neutrino research. Each now sets records in its field. We additionally describe our techniques of radiochemical ultra-pure, few atom manipulations and extractions. Forefront measurements also result from the powerful combination of neutron activation and low-level counting. Finally, with our techniques and commercially available mass spectrometry and atomic absorption spectroscopy, new low-level detection limits for isotopes of interest are obtained.

  18. Measuring mechanical stresses on inserts during injection molding

    Martina Heinle


    Full Text Available Assembly molding presents an interesting approach to innovative product solutions. Here, individual components can be simultaneously positioned, affixed, and provided with a casing. However, while overmolding elements in the mold cavity with hot polymer melt, high mechanical loads occur on, in some cases, very sensitive components such as electronic devices. For the design of such systems, it is important to know these stresses, the influences on their quantities, and mathematical options for their prediction. In this article, a new measurement method for determining the forces acting on a small element in the cavity during the injection molding process in three dimensions is presented. Therefore, a new installation method for a force sensor was developed. The results in this article concentrate on force changes during one molding cycle. Our research shows that there are different mechanical load spectra in the different phases of the molding process. For example, the force component in flow direction on an element in the cavity is positive in the direction of the flow during filling. However, after the filling step, the force becomes negative due to the contraction of the injected material and results in a continuously increasing permanent force.

  19. Some constraints on levels of shear stress in the crust from observations and theory.

    McGarr, A.


    In situ stress determinations in North America, southern Africa, and Australia indicate that on the average the maximum shear stress increases linearly with depth to at least 5.1 km measured in soft rock, such as shale and sandstone, and to 3.7 km in hard rock, including granite and quartzite. Regression lines fitted to the data yield gradients of 3.8 MPa/km and 6.6 MPa/km for soft and hard rock, respectively. Generally, the maximum shear stress in compressional states of stress for which the least principal stress is oriented near vertically is substantially greater than in extensional stress regimes, with the greatest principal stress in a vertical direction. The equations of equilibrium and compatibility can be used to provide functional constrains on the state of stress. If the stress is assumed to vary only with depth z in a given region, then all nonzero components must have the form A + Bz, where A and B are constants which generally differ for the various components. - Author

  20. Measuring water-borne cortisol in Poecilia latipinna:is the process stressful, can stress be minimized and is cortisol correlated with sex steroid release rates?

    Gabor, C R; Contreras, A


    The stress of water-borne hormone collection process was examined in sailfin mollies Poecilia latipinna. Baseline release rates of the stress hormone cortisol were measured and minimum confinement time for water sampling was evaluated for a standard 60 min v. a 30 min protocol. A 30 min hormone collection period reflects release rates over 60 min. Potential stress response to confinement in the beaker for the water-borne collection process was tested over 4 days. There was no evidence of stress due to the collection methods, as cortisol release rates did not differ significantly across four sequential days of handling for P. latipinna. Males and females did not differ significantly in baseline cortisol release rates. Baseline cortisol release rates from fish immediately after being collected in the field were also not significantly different than those in the 4 day confinement experiment. After exposure to a novel environment, however, P. latipinna mounted a stress response. Stress may also affect sex steroids and behaviour but cortisol release rates were not significantly correlated with sex steroids [11-ketotestosterone (KT), testosterone, or oestradiol], or mating attempts. The correlation between water-borne release rates and plasma steroid levels was validated for both cortisol and KT. Finally, normalizing cortisol release rates using standard length in lieu of mass is viable and accurate. Water-borne hormone assays are a valuable tool for investigating questions concerning the role of hormones in mediating stress responses and reproductive behaviours in P. latipinna and other livebearing fishes.

  1. Association of CD4+ T cell subpopulations and psychological stress measures in women living with HIV.

    Rehm, Kristina E; Konkle-Parker, Deborah


    Psychological stress is a known immunomodulator. In individuals with HIV, depression, the most common manifestation of increased psychological stress, can affect immune function with lower CD4+ T cell counts correlating with higher levels of depression. It is unknown how other forms of psychological stress can impact immune markers in people living with HIV. We conducted a cross-sectional study to determine how CD4+ T cell subpopulations correlated with different forms of psychological stress. We recruited 50 HIV-positive women as part of the Women's Interagency HIV Study. We assessed perceived stress, worry, acute anxiety, trait anxiety, and depression through self-report questionnaires and CD4+ T cell subpopulations using flow cytometry. Our sample was 96% African-American with a mean ± SD age and body mass index of 42 ± 8.8 years and 36.6 ± 11.5 kg/m(2), respectively. The mean ± SD scores on the psychological measures were as follows: Perceived Stress Scale (PSS), 16.5 ± 6.4; Penn State Worry Questionnaire (PSWQ), 47.7 ± 13.8; State-Trait Anxiety Inventory - State (STAIS), 39.1 ± 12.3; State-Trait Anxiety Inventory - Trait (STAIT), 40.2 ± 11.4; Center for Epidemiological Studies Depression Scale (CES-D), 15.6 ± 11.4. The mean + SD values for the immune parameters were as follows: regulatory T cells (Treg), 1.25% ± 0.7; T helper 1 (Th1), 14.9% ± 6.1; T helper 2 (Th2), 3.8% ± 2; Th1/Th2 ratio, 4.6 ± 3; and CD4+ T cell count (cells/mm(3)), 493 ± 251. Treg levels positively correlated with PSS, STAIS, and STAIT. CD4+ T cell count negatively correlated with PSS, PSWQ, STAIS, STAIT, and CES-D. These data suggest that immune function may be impacted by various forms of psychological stress in HIV-positive women. Interventions that target stress reduction may be useful in improving immune parameters and quality of life.

  2. Pulsed eddy current and ultrasonic data fusion applied to stress measurement

    Habibalahi, A.; Safizadeh, M. S.


    Stress measurement and its variation are key problems in the operating performance of materials. Stress can affect the material properties and the life of components. There are several destructive and nondestructive techniques that are used to measure stress. However, no single nondestructive testing (NDT) technique or method is satisfactory to fully assess stress. This paper presents an NDT data fusion method to improve stress measurement. An aluminum alloy 2024 specimen subjected to stress simulation is nondestructively inspected using pulsed eddy current and ultrasonic techniques. Following these nondestructive examinations, the information gathered from these two NDT methods has been fused using a suitable fuzzy combination operator. The results obtained with these processes are presented in this paper and their efficiency is discussed. It is shown that the fusion of NDT data with a suitable fuzzy operator can be adequate to improve the reliability of stress measurements.


    Ni Ketut Alit Armini


    Full Text Available Introduction: Many changes in psychology and biology increase primigravida’s stress in the third trimester. The stress response makes blood pressure being unstable, it causes bad effect for pregnancy. Classical music can be used as one of relaxation facilities that can reduce stress. The aimed of this study were to analyze the effect of classical music on stress level and blood pressure. Method: This study was used a quasy experimental purposive sampling design. The sample in this study were 14 pregnancy women in the third trimester in RSIA Cempaka Putih Permata Surabaya. The independent variable in this study was classical music and the dependent variable were stress level and blood pressure. Data were analyzed by Wilcoxon Signed Rank Test, Mann Withney U Test, Paired t Test and Independent t Test with significance level α≤0.05. Result: The result showed that the stress level in controlled group with p=0.567 and intervention group with p=0.025. The result of blood pressure in controlled group with p=0.522 in systolic blood pressure, p=0.35 in diastolic blood pressure and intervention group showed p=0.103 in systolic blood pressure and p=1.00 in diastolic blood pressure. Discussion: It can be concluded that listening classical music can reduce stress level, stabilize blood pressure, although blood pressure hasn’t significant result but mean of blood pressure show that it was stable. Further studies should be considered to used cortisol to identify stress biology response spesifically.

  4. Neighborhood-Level Stress and Circadian Cortisol: A Systematic Review and Meta-Analysis.

    Fatemeh Hosseini


    Full Text Available The main objective was to find association between basal cortisol and neighborhood-level stress. Systematic searches, including electronic and hand searches, were conducted. The most recent date of the search was July 26, 2013. Primary observational studies included if they considered stress related outcomes in the neighborhood context. Using the EndNote X7 advanced search option; the authors examined the abstracts and titles of the 18,092 articles to exclude obviously irrelevant studies, gray literature, discussion papers, reviews and, studies with no complete data. Two authors independently extracted data from the original reports into pre-designed data extraction forms based on the Data Extraction Template of the Cochrane Consumer and Communication Review Group (CCCRG. Ten studies with a total of 2,134 participants were synthesized and analyzed. Two studies out of ten received expanded meta-analysis. The overall effect size (95% CI for cortisol level for residents in neighborhoods with lower stress compared to inhabitants from higher was 0.12 (0.01, 0.23. This review is demonstrating a link between psychosocial or physical stress and cortisol obtained from saliva. However, living in high disorder neighborhoods results in higher level of cortisol. This represents a biological indicator of psychosocial/physical stress exposure (i.e., neighborhood disorder that reflects variances in stress exposure levels.

  5. Neighborhood-Level Stress and Circadian Cortisol: A Systematic Review and Meta-Analysis.

    Hosseini, Fatemeh; Adha, Nikmatul; Zainol, Rosilawati; Isahak, Marzuki; Nemati, Nahid


    The main objective was to find association between basal cortisol and neighborhood-level stress. Systematic searches, including electronic and hand searches, were conducted. The most recent date of the search was July 26, 2013. Primary observational studies included if they considered stress related outcomes in the neighborhood context. Using the EndNote X7 advanced search option; the authors examined the abstracts and titles of the 18,092 articles to exclude obviously irrelevant studies, gray literature, discussion papers, reviews and, studies with no complete data. Two authors independently extracted data from the original reports into pre-designed data extraction forms based on the Data Extraction Template of the Cochrane Consumer and Communication Review Group (CCCRG). Ten studies with a total of 2,134 participants were synthesized and analyzed. Two studies out of ten received expanded meta-analysis. The overall effect size (95% CI) for cortisol level for residents in neighborhoods with lower stress compared to inhabitants from higher was 0.12 (0.01, 0.23). This review is demonstrating a link between psychosocial or physical stress and cortisol obtained from saliva. However, living in high disorder neighborhoods results in higher level of cortisol. This represents a biological indicator of psychosocial/physical stress exposure (i.e., neighborhood disorder) that reflects variances in stress exposure levels.

  6. Oxidative stress reduces levels of dysbindin-1A via its PEST domain.

    Yap, Mei-Yi Alicia; Lo, Yew-Long; Talbot, Konrad; Ong, Wei-Yi


    Oxidative stress resulting from the generation of reactive oxygen species has been proposed as an etiological factor in schizophrenia. The present study tests the hypothesis that oxidative stress can affect levels of dysbindin-1A, encoded by Dtnbp1, a genetic risk factor for schizophrenia, via its PEST domain. In vitro studies on SH-SY5Y cells indicate that oxidative stress triggers proteasomal degradation of dysbindin-1A, and that this requires interactions with its PEST domain, which may be a TRIM32 target. We specifically found (a) that oxidative stress induced in SH-SY5Y cells by 500 µM hydrogen peroxide reduced levels of full-length dysbindin-1, but did not reduce levels of that protein lacking its PEST domain and (b) that levels of full-length dysbindin-1, but not dysbindin-1 lacking its PEST domain, were higher in cells treated with the proteasome inhibitor MG132. Oxidative stress thus emerges as the first known cellular factor regulating dysbindin-1 isoforms with PEST domains. These findings are consistent with the previously noted fact that phosphorylation of PEST domains often marks proteins for proteasomal degradation, and raises the possibility that treatments reducing oxidative stress in the brain, especially during development, may lower schizophrenia risk.

  7. Effects of the Higashi-Nihon earthquake: posttraumatic stress, psychological changes, and cortisol levels of survivors.

    Yuka Kotozaki

    Full Text Available On March 11, 2011, the Pacific side of Japan's northeast was devastated by an earthquake and tsunami. For years, many researchers have been working on ways of examining the psychological effects of earthquakes on survivors in disaster areas who have experienced aftershocks, catastrophic fires, and other damage caused by the earthquake. The goal of this study is to examine scores on psychological measures and salivary cortisol level in these individuals both before and three months after the earthquake. The participants had been measured for these variables before the earthquake. After the earthquake, we carried out PTSD screening using CAPS for participants for another experiment, and then again conducted the aforementioned tests. We collected saliva samples from all survivors. Our results show that social relationship scores on the WHO-QOL26, negative mood scores of the WHO-SUBI, total GHQ score, POMS confusion scores, and CMI emotional status score after the earthquake showed scores indicating significantly decreased compared to before the earthquake. On the other hand, salivary cortisol levels after the earthquake was significantly increased compared to before the earthquake. Moreover, the result of a multiple regression analysis found that negative mood score on the WHO-SUBI and social relationship score on the WHO-QOL26 were significantly related to salivary cortisol levels. Our results thus demonstrate that several psychological stress induced by the earthquake was associated with an increase in salivary cortisol levels. These results show similar findings to previous study. We anticipate that this study will provide a better understanding of posttraumatic responses in the early stages of adaptation to the trauma and expand effective prevention strategies and countermeasures for PTSD.

  8. Effects of seed nourished by different levels of nitrogen, biofertilizers and drought stress on germination indices and seedling growth of wheat (Tritium aestivum cv. Sayonz

    R. Yazdani-Biuki


    Full Text Available In order to study the effects of different levels of drought stress and plant growth promoting rhizobacteria on the germination indices of seeds harvested from wheat (Tritium aestivum L. cv. Sayonz in the field treated with different levels of nitrogen, in controlled conditions, a factorial layout based on completely randomized design with three replications, was conducted. Treatments included the seeds that collected from field that received amount of 0, 120, 240 and 360 Kg.ha-1 nitrogen fertilizer, types of biofertilizer (nitragin, biophosphouros and control and different levels of drought stress (0, -4, -8 and -12 bar. The results showed that simple effects of levels of biofertilizers and levels of drought stress were significant on the all germination characteristics of wheat, except for mean germination time, radicle length to plumule ratio and dry weights of radicle to plumule ratio, while levels of nitrogen fertilizer only was significant on germination, germination rate and germination index. The interaction effects had showed that the seeds harvested from nitrogen fertilizer at 240 Kg/ha and drought stress 0 and -4 bar had the highest germination. Nitragin bifertilizer increased drought stress resistance compared with control, so that the stress level -4 bar reducing germination for seeds treated with biosphouros and non-inoculated, than plants treated with nitragin, were 40 and 79%, respectively. Effects of three nitrogen fertilizer, biofertilizer and levels of drought stress were not significant on the characteristics measured.

  9. Hair cortisol levels, perceived stress and body mass index in women and children living in socioeconomically disadvantaged neighborhoods: the READI study.

    Olstad, Dana Lee; Ball, Kylie; Wright, Craig; Abbott, Gavin; Brown, Erin; Turner, Anne Isabella


    Disadvantaged communities provide adverse psychosocial exposures that have been linked to high levels of stress, and this may provide one explanatory pathway linking socioeconomic disadvantage to obesity. This study used hair cortisol analysis to quantify associations between stress and body mass index (BMI), and between hair cortisol and perceived psychological stress levels, in women and children living in socioeconomically disadvantaged neighborhoods. Participants were a volunteer sample of 70 women from the Resilience for Eating and Activity Despite Inequality study, including 30 maternal-child pairs. Women self-reported body weight, height and perceived psychological stress using the Perceived Stress Scale (PSS), and provided hair samples for themselves and their child. Children's body weight and height were measured. Following extraction, hair cortisol levels were measured using enzyme-linked immunosorbent assay. Multiple linear regression models examined associations between stress and BMI, and between hair cortisol and perceived stress levels in women and children. Women's hair cortisol levels were not associated with their BMI or PSS scores. Women's PSS scores were positively associated with their BMI (p = 0.015). Within maternal-child pairs, mothers and children's hair cortisol levels were strongly positively associated (p = 0.006). Maternal hair cortisol levels and PSS scores were unrelated to their child's zBMI. Children's hair cortisol levels were not associated with their zBMI or with their mother's PSS score. Findings suggest that cortisol-based and perceived psychological measures of stress may be distinct among women and children living in disadvantaged neighborhoods. Perceived psychological measures may be more important predictors of weight-related risk.

  10. Measurement of absorbed dose and proposed radiation exposure level

    Hasegawa, Takayuki; Koizumi, Masayuki; Furukawa, Tomo [Tokai Univ., Isehara, Kanagawa (Japan). Hospital


    Absorbed dose was measured in clinical X-ray examinations using thermoluminescence dosimeter (TLD). Moreover, we distributed the levels of radiation exposure into 3 classes. The presumed dose of the internal organs, e.g., uterus dose, was computed to depth doses with a surface dose. This information provides a prediction of the influence of radiation, and the examination can be performed with the informed consent of the patient. Moreover, we examined the distribution of the level of absorbed dose. We proposed two kinds of radiation exposure level, one to the fetus in a pregnant woman and a general level of radiation exposure that is not applied to pregnant women. The levels were as follows: 0.5 mGy and 100 mGy were considered the boundaries for fetal radiation exposure in a pregnant woman, and 200 mGy and 3 Gy were considered the boundaries for the general level of radiation exposure (excluding pregnant women). (author)

  11. Assessing College Student-Athletes' Life Stress: Initial Measurement Development and Validation

    Lu, Frank Jing-Horng; Hsu, Ya-Wen; Chan, Yuan-Shuo; Cheen, Jang-Rong; Kao, Kuei-Tsu


    College student-athletes have unique life stress that warrants close attention. The purpose of this study was to develop a reliable and valid measurement assessing college student-athletes' life stress. In Study 1, a focus group discussion and Delphi method produced a questionnaire draft, termed the College Student-Athletes' Life Stress Scale. In…

  12. Assessing College Student-Athletes' Life Stress: Initial Measurement Development and Validation

    Lu, Frank Jing-Horng; Hsu, Ya-Wen; Chan, Yuan-Shuo; Cheen, Jang-Rong; Kao, Kuei-Tsu


    College student-athletes have unique life stress that warrants close attention. The purpose of this study was to develop a reliable and valid measurement assessing college student-athletes' life stress. In Study 1, a focus group discussion and Delphi method produced a questionnaire draft, termed the College Student-Athletes' Life Stress Scale. In…

  13. Time-dependent miR-16 serum fluctuations together with reciprocal changes in the expression level of miR-16 in mesocortical circuit contribute to stress resilient phenotype in chronic mild stress - An animal model of depression.

    Zurawek, Dariusz; Kusmider, Maciej; Faron-Gorecka, Agata; Gruca, Piotr; Pabian, Paulina; Kolasa, Magdalena; Solich, Joanna; Szafran-Pilch, Kinga; Papp, Mariusz; Dziedzicka-Wasylewska, Marta


    MicroRNAs (miRNAs) are involved in stress-related pathologies. However, the molecular mechanisms underlying stress resilience are elusive. Using chronic mild stress (CMS), an animal model of depression, we identified animals exhibiting a resilient phenotype. We investigated serum levels of corticosterone, melatonin and 376 mature miRNAs to find peripheral biomarkers associated with the resilient phenotype. miR-16, selected during screening step, was assayed in different brain regions in order to find potential relationship between brain and peripheral alterations in response to stress. Two CMS experiments that lasted for 2 and 7 consecutive weeks were performed. During both CMS procedures, sucrose consumption levels were significantly decreased in anhedonic-like animals (presilient rats did not change despite the rats being stressed. Serum corticosterone measurements indicated that anhedonic-like animals had blunted hypothalamic-pituitary-adrenal (HPA) axis activity, whereas resilient animals exhibited dynamic responses to stress. miRNA profiling revealed that resilient animals had elevated serum levels of miR-16 after 7 weeks of CMS (adjusted p-valueresilient animals exhibited reciprocal changes in miR-16 expression level in mesocortical pathway after 2 weeks of CMS (pResilient animals can actively cope with stress on a biochemical level and miR-16 may contribute to a "stress-resistant" behavioral phenotype by pleiotropic modulation of the expression of genes involved in the function of the nervous system. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

  14. Levels of selected oxidative stress markers in the vitreous and serum of diabetic retinopathy patients

    Brzović-Šarić, Vlatka; Landeka, Irena; Šarić, Borna; Barberić, Monika; Andrijašević, Lidija; Cerovski, Branimir; Oršolić, Nada


    Purpose In diabetes, an impaired antioxidant defense system contributes to the development of diabetic retinopathy. The main objective of this paper was to find correlations of oxidative stress parameters within and between the vitreous and serum in patients with type 2 diabetes who had developed proliferative diabetic retinopathy. Methods The study included and compared two groups of patients who underwent vitrectomy: 37 patients with type 2 diabetes and proliferative retinopathy (PDR), and 50 patients with non-diabetic eye disorders (NDED). Vascular endothelial growth factor (VEGF), advanced oxidized protein product (AOPP), and oxidative stress markers (direct lipid hydroperoxidation (LPO), malondialdehyde (MDA), total superoxide dismutase (SOD), and glutathione (GSH)) were measured in the vitreous and serum of both groups and correlated with one another, between humoral compartments and with gender, age, and serum glucose levels. Results In the vitreous of PDR patients, VEGF, LPO, and MDA (p<0.05) were increased and SOD values were slightly lowered (p<0.05) than in NDED patients. Vitreous AOPP and GSH showed no differences between the groups. In the serum, AOPP, MDA, and SOD were increased (p<0.05) and VEGF was slightly increased (p<0.05) in the PDR group compared to NDED. With regard to gender, similar changes were recorded for both groups, except for the lower serum MDA in males than females in the NDED group. Advanced age showed no significant effect on changes of measured parameters in the vitreous. In the serum, VEGF was positively correlated (p<0.05) and MDA and SOD negatively correlated (p<0.05) with increasing age. Among measured parameters within and between the vitreous and serum, several correlative links occurred in the PDR group that were not present in the NDED group. The most prominent correlation changes were between serum LPO and vitreal LPO, serum SOD and vitreal LPO, serum LPO and serum SOD, and vitreal VEGF and serum SOD. Conclusions Among

  15. Measurement of Residual Stress in a Welded Branch Connection and Effects on Fracture Behaviour

    Law, M.; Luzin, V.; Kirstein, O.


    The branch analysed in this paper was not post weld heat treated, resulting in significant residual stresses. Assessment codes assume these to be at, or close to, yield. An integrity assessment of a welded branch connection was carried out using these high assumed residual stresses. The weld then had residual stresses determined by neutron diffraction, performed using ANSTO's residual stress diffractometer, Kowari. The maximum measured residual stress (290 MPa or 60% of yield) was much lower than the yield value assumed by assessment codes. Reanalysing with the actual residual stresses almost doubled the critical crack size, increasing the safety of the connection.

  16. Survey of horizontal stresses in coal mines from available measurements and mapping.

    Frith, R


    Full Text Available OF HORIZONTAL STRESS IN THE WITBANK AND HIGHVELD COALFIELDS 21 4.1 Is Horizontal Stress at Work in Roadway Roof Behaviour? 21 4.2 Summary of Measured Horizontal Stresses 24 4.3 Proposed Model for the Origin of Horizontal Stress Within the Coalfields 27 4... effects of horizontal stress could be further mitigated within the practicalities of the mining methods in use. Based on the work undertaken, the following project findings have been arrived at: (a) Horizontal stresses are clearly evident within both...

  17. Effects of Chlorophytum arundinaceum, Asparagus adscendens and Asparagus racemosus on pro-inflammatory cytokine and corticosterone levels produced by stress.

    Kanwar, Anubha Singh; Bhutani, Kamlesh Kumar


    Chlorophytum arundinaceum, Asparagus adscendens and Asparagus racemosus are used in the Indian traditional system of medicine for improving the general state of health and for stress-related immune disorders. The effects of the methanol and aqueous extracts of the tuberous roots of these plants were examined in an experimental mouse model of stress, induced by swimming. The extracts were shown to exert an inhibitory effect on pro-inflammatory cytokines, namely interleukin 1β and tumour necrosis factor α, and on the production of nitric oxide in mouse macrophage cells RAW 264.7 stimulated by lipopolysaccharide in vitro. Similar inhibition was also observed in the production of interleukin 2 in EL 4 lymphoma cells stimulated by concanavalin A. Corticosterone levels in serum and adrenal glands were measured. The findings suggest that these plants may be beneficial in the management of stress and inflammatory conditions. Copyright © 2010 John Wiley & Sons, Ltd.

  18. B-type natriuretic peptide (BNP serum levels in rats after forced repeated swimming stress

    Almira Hadžovic-Džuvo


    Full Text Available Aim To estimate the effects of forced repeated swimming stress on BNP serum levels in rats. Methods Adult male Wistar rats weighting between 280-330 g were divided into two groups: control group (n =8 and stress group (n =8. Rats in the stress group were exposed to forced swimming stress daily, for 7 days. The rats were forced to swim in plastic tanks (90 cm wide, 120 cm deep containing tap water (temperature ca. 25°C. The depth of water was 40 cm. Duration of each swimming session progressively increased from 10 minutes on the irst day to 40 minutes on days 6 and 7. Rats were sacriiced and blood was drawn from abdominal aorta for BNP analysis immediately after the last swimming session. B-type natriuretic serum level was determined by ELISA method using RAT BNP-32 kit (Phoenix Pharmaceutical Inc.. Results There was no statistically signiicant difference between mean BNP serum level in the stress group after the swimming period (0.81±0.14 ng/ml as compared to the unstressed group of rats (0.8 ±0.08ng/ml. After the swimming period mean body weight slightly decreased in the stress group in comparison with values before stress period (296.3 g vs.272.8 g, but this difference was not statistically signiicant. The stress period had no inluence on food intake in the stress rat group. Conclusion The workload consisting of 40-minutes long swimming session is not suficient to provoke BNP release from myocardium in rats.

  19. High-Stakes Testing and Its Relationship to Stress Levels of Secondary Teachers

    Christian, Sonya Colman


    This study investigated the relationship between high-stakes testing and the stress levels of secondary teachers in Jackson's Jackson Public School District. The independent variables of age, gender, subject taught, teaching experience, degree and school level were used to determine the differences of the various groups. A survey was piloted and…

  20. Development of Technology Readiness Level (TRL) Metrics and Risk Measures

    Engel, David W.; Dalton, Angela C.; Anderson, K. K.; Sivaramakrishnan, Chandrika; Lansing, Carina


    This is an internal project milestone report to document the CCSI Element 7 team's progress on developing Technology Readiness Level (TRL) metrics and risk measures. In this report, we provide a brief overview of the current technology readiness assessment research, document the development of technology readiness levels (TRLs) specific to carbon capture technologies, describe the risk measures and uncertainty quantification approaches used in our research, and conclude by discussing the next steps that the CCSI Task 7 team aims to accomplish.

  1. Going the distance solids level measurement with radar

    Little, Tim


    From industry newcomers to experienced veterans in the field of process instrumentation, this book offers a comprehensive guide to radar level measurement for solids that is both detailed and approachable. Beginning with a brief history of solids level measurement, the book covers topics such as frequency and performance, installation of radar devices, and connection to communication networks. Also included is a helpful guide on process intelligence troubleshooting. Explanatory diagrams accompany the text, along with a collection of interesting - and often humorous - anecdotes gathered over au

  2. Measurement of Noise Level in Enumeration Station in Rubber Industry

    Rizkya, I.; Syahputri, K.; Sari, R. M.; Siregar, I.


    This research was conducted in companies engaged in the production of crumb rubber. In the rubber industry, the potential noise occurs in the enumeration station. Stations enumeration use machine and equipment that potentially generated noise. Noise can be defined as an unwanted sound because it does not fit the context of space and time so that may interfere with the comfort and human health. The noise level measured at random during the initial observation station enumeration is 101.8 dB. This value has exceeded the Threshold Limit Value (TLV) Kep-51 / MEN / 1999 and SNI No. 16-7063-2004 so research must be done to measure the level of noise in the enumeration station. Quantitative methods used in the study. Observations made with the calculation method of equivalent noise level. Observations were made on six measurement points for one shift for three days. The results showed the noise level over the Threshold Limit Value is equal to 85 dBA/8 hours. Based on the measurement results, the whole point of observation was far above the threshold Limit Value (TLV). The highest noise level equivalent is in the observation point 6 with a value of 102, 21 dB.

  3. Measurement of lattice rotations and internal stresses in over one hundred individual grains during a stress-induced martensitic transformation

    Hachi Younes El


    Full Text Available To better understand the properties of polycrystals at a microscopic scale during cyclic mechanical loading we have measured the relationship between grain orientations, their positions inside the sample and their internal stresses. In this work, in-situ 3DXRD technique was performed on over hundred grains during the stress-induced martensitic transformation in a Cu-Al-Be shape memory alloy. Information about the position, orientation, and stress field was obtained for each austenitic grain. These results have been used to develop a procedure that allows automatic processing for a large number of grains, matching them during loading and leads to a quantitative stress field. A strong heterogeneity of stress state between the grains at the surface and in the volume is evident.

  4. The association of personality traits and coping styles according to stress level


    Background: Some personality traits and coping styles could be as risk factors in stressful situations. This study aimed to investigate the association of personality traits and coping styles according to the stress level. Meterials and Methods: This cross-sectional study was performed in 2011. A total of 4628 individuals over 20 years were selected by random sampling from nonacademic employees that working in 50 different centers across Isfahan province. Data were collected using 12-item Gen...

  5. Influence of age and length of service on the level of stress and burnout syndrome.

    Stanetić, Kosana; Tesanović, Gordana


    The burnout syndrome is a response to chronic emotional and interpersonal stressors which are related to workplace. Medicine is one of the professions at the greatest risk of suffering from burnout syndrome. The aim of this study was to assess the presence of stress and burnout syndrome in relation with age and length of service in the family medicine physicians in the Republic of Srpska. The study was carried out on the basis of a questionnaire survey among family medicine physicians in seven Primary Health Care Centres in the Republic of Srpska from February 1st to April 30th 2010. The participants fulfilled the questionnaire for self-assessment of stress level and the Maslach Burnout Inventory, which were amended with data regarding age, sex, length of service and educational and vocational level. The study included 199 (83.3%) female and 40 (16.7%) male participants. The physicians aged over 46 years and with the length of service over 21 years had statistically significant higher level of stress and emotional exhaustion than younger participants and participants with shorter length of service. Age and length of service have important influence on the level of stress and burnout syndrome: the older the physicians and the higher the length of service the higher the level of stress and the higher the risk of burnout syndrome.

  6. Durian Consumption Effect on the Plasma Malondialdehyde Level as Biomarker of Stress Oxidative in Rats

    Anugrah Aulia Ulil Amri


    Full Text Available Background: Excessive consumption of durian (Durio zibethinus Murray in Indonesia is often connected with its effect on health. This study aims to understand the effect of durian consumption to malondialdehyde (MDA in plasma as oxidative stress biomarker. Methods: The study used an experimental research design on animal models, in the Biochemistry and Molecular Biology Department, Faculty of Medicine, Universitas Indonesia, July–August 2012. Thirty two Sprague-Dawley rats were used, divided into four groups: control, treatment week 1, 2, and 3. Each treatment group was given 20 gram durian fruit diluted with water until 20 ml volume per oral, divided into two doses (10 ml each with 4 hours interlude between doses for 1 week, 2 weeks, and 3 weeks. All groups got normal diet and water ad libitum. Plasma MDA level was measured by TBARS method, then analyzed using Kurskal-Wallis and Mann-Whitney tests. Results: Seventeen samples were successfully decapitated (5 for control; 6 for week 1; 3 for week 2; 3 for week 3. Average plasma MDA level for control treatment week 1, 2 and 3 groups were 0.707 nmol/ml, 0.432 nmol/ml, 0.312 nmol/ml, and 0.746 nmol/ml respectively. Data was significant (p<0.05 with p=0.02. Compared with control group, a significant increase occurred in week 1 and 2 groups with p=0.028 and p=0.025 respectively. Conclusions: Results of durian consumption show MDA level significantly decreases in week 1 and 2. However, MDA level dramatically increases exceeding control group level in week 3.

  7. Job stress and agentic-communal personality traits related to serum cortisol levels of male workers in a Japanese medium-sized company: a cross-sectional study.

    Hirokawa, Kumi; Taniguchi, Toshiyo; Fujii, Yasuhito


    Although serum cortisol is a widely accepted index of stress levels, associations between job stress and cortisol levels have been inconsistent. Individual differences in personality traits were discussed as one compelling explanation for this discrepancy. Agentic-communal personality traits have been examined as possible predictive factors for psychological stress. This study investigated correlations among agentic-communal personality traits and serum cortisol levels. It was also investigated whether job stress levels modified correlations between agentic-communal personality and cortisol levels. Participants were 198 male workers (mean age = 52.2 years) employed by a shipbuilding company in Japan. Questionnaire data and blood samples were collected during an annual health checkup. Participants completed a self-report questionnaire that included the Job Content Questionnaire (JCQ) that assesses job control as job stress levels the Communion-Agency scale (CAS) and questions regarding health behaviors. Communion positively correlated with serum cortisol levels and unmitigated agency negatively correlated with serum cortisol levels. Stratified by job control, communion positively correlated with serum cortisol levels and agency negatively correlated with serum cortisol levels in participants with low levels of job control. Unmitigated agency negatively correlated with serum cortisol levels in participants with high levels of job control. Levels of job control may modify correlations of gender-related personality with serum cortisol levels. Especially with exposure to high job stress, male workers with high femininity (i.e., high communion and low agency) were more likely to have a high stress response as measured by serum cortisol levels.

  8. Numerical and experimental demonstration of shear stress measurement at thick steel plates using acoustoelasticity

    Abbasi, Zeynab; Ozevin, Didem


    The purpose of this article is to numerically quantify the stress state of complex loaded thick steel plates using the fundamental theory of acoustoelasticity, which is the relationship with stress and ultrasonic velocity in the nonlinear regime. The normal and shear stresses of a thick plate can be measured using a phased array placement of ultrasonic sensors and Rayleigh ultrasonic waves. Three measurement angles (i.e., 0 45 and 90 degrees) are selected since three measurements are needed to solve the stress tensor in an isotropic plate. The ultrasonic data is influenced significantly by the frequency of the Rayleigh waves as well as the thickness of the plate being examined; consequently the overall experimental process is influenced by the measurement parameters. In this study, a numerical demonstration is implemented to extract the nonlinearity coefficients using a 3D structural geometry and Murnaghan material model capable of examining the effects of various plate thicknesses and ultrasonic frequencies on the shear stress measurement. The purpose is that as the thickness becomes smaller, the shear stress becomes negligible at the angled measurement. For thicker cross section, shear stress becomes influential if the depth of penetration of Rayleigh wave is greater than the half of the thickness. The correlation between the depth of penetration and shear stress is then obtained. The numerical results are compared with 1 MHz ultrasonic frequency and a 3/8 inch thick steel plate loaded uniaxially while the measurement direction is angled to have the presence of shear stress in the measurement direction.

  9. Measurement and modeling of bed shear stress under solitary waves

    Jayakumar, S.; Guard, P.A.; Baldock, T.E.

    convolution integration methods forced with the free stream velocity and incorporating a range of eddy viscosity models. Wave friction factors were estimated from skin shear stress at different instances over the wave (viz., time of maximum positive total...

  10. Measuring cortisol in the water as an indicator of stress caused by increased loading density in common carp (Cyprinus carpio)

    Ruane, N.M.; Komen, J.


    The influence of a high loading density for a period of 28 days on growth, water quality and stress parameters in common carp (Cyprinus carpio) was investigated. In addition, cortisol levels in the water were measured during the experiment to investigate if a relationship exists between loading

  11. Applied environmental stresses to enhance the levels of polyphenolics in leaves of hawthorn plants.

    Kirakosyan, Ara; Kaufman, Peter; Warber, Sara; Zick, Suzanna; Aaronson, Keith; Bolling, Steven; Chul Chang, Soo


    In this investigation, two species of Crataegus (hawthorn) were chosen because their polyphenolic constituents have recently received greater attention for the treatment of patients with severe heart disease. One-year-old plants of hawthorn (Crataegus laevigata and C. monogyna) were subjected to water-deficit (continuous water deprivation), cold (4 degrees C), flooding (immersion of roots of plants in water) or herbivory (leaf removal) stress treatments (each of 10 days duration) in order to assess their effects on levels of polyphenolics, namely (-)-epicatechin, catechin, chlorogenic acid, vitexin, vitexin-2"-O-rhamnoside, acetylvitexin-2"-O-rhamnoside, hyperoside, quercetin, and rutin in the leaves. The working hypothesis followed is that one or more of these stress treatment will elicit increases in the levels of these polyphenolics. Cold stress causes increases in levels of vitexin-2"-O-rhamnoside, acetylvitexin-2"-O-rhamnoside, hyperoside, and quercetin in both Crataegus species. Water-deficit stress increased the productivity of chlorogenic acid, catechin, and (-)-epicatechin in both hawthorn species. Flooding and herbivory caused no net increases, and in some cases, decreases in levels of polyphenolics. These studies indicate that either water-deficit stress or cold stress treatments, or a combination of the two, can be used to enhance the levels of desired polyphenolics in the leaves of these two hawthorn species in a photobioreactor system. These results may have significance for hawthorn in adapting to water-deficit or cold stress and are important considerations for the use of hawthorn in the treatment of heart disease in humans.

  12. Animal performance and stress: responses and tolerance limits at different levels of biological organisation.

    Kassahn, Karin S; Crozier, Ross H; Pörtner, Hans O; Caley, M Julian


    Recent advances in molecular biology and the use of DNA microarrays for gene expression profiling are providing new insights into the animal stress response, particularly the effects of stress on gene regulation. However, interpretation of the complex transcriptional changes that occur during stress still poses many challenges because the relationship between changes at the transcriptional level and other levels of biological organisation is not well understood. To confront these challenges, a conceptual model linking physiological and transcriptional responses to stress would be helpful. Here, we provide the basis for one such model by synthesising data from organismal, endocrine, cellular, molecular, and genomic studies. We show using available examples from ectothermic vertebrates that reduced oxygen levels and oxidative stress are common to many stress conditions and that the responses to different types of stress, such as environmental, handling and confinement stress, often converge at the challenge of dealing with oxygen imbalance and oxidative stress. As a result, a common set of stress responses exists that is largely independent of the type of stressor applied. These common responses include the repair of DNA and protein damage, cell cycle arrest or apoptosis, changes in cellular metabolism that reflect the transition from a state of cellular growth to one of cellular repair, the release of stress hormones, changes in mitochondrial densities and properties, changes in oxygen transport capacities and changes in cardio-respiratory function. Changes at the transcriptional level recapitulate these common responses, with many stress-responsive genes functioning in cell cycle control, regulation of transcription, protein turnover, metabolism, and cellular repair. These common transcriptional responses to stress appear coordinated by only a limited number of stress-inducible and redox-sensitive transcription factors and signal transduction pathways, such as the

  13. Performance Improvement of Membrane Stress Measurement Equipment through Evaluation of Added Mass of Membrane and Error Correction

    Sang-Wook Jin


    Full Text Available One of the most important issues in keeping membrane structures in stable condition is to maintain the proper stress distribution over the membrane. However, it is difficult to determine the quantitative real stress level in the membrane after the completion of the structure. The stress relaxation phenomenon of the membrane and the fluttering effect due to strong wind or ponding caused by precipitation may cause severe damage to the membrane structure itself. Therefore, it is very important to know the magnitude of the existing stress in membrane structures for their maintenance. The authors have proposed a new method for separately estimating the membrane stress in two different directions using sound waves instead of directly measuring the membrane stress. The new method utilizes the resonance phenomenon of the membrane, which is induced by sound excitations given through an audio speaker. During such experiment, the effect of the surrounding air on the vibrating membrane cannot be overlooked in order to assure high measurement precision. In this paper, an evaluation scheme for the added mass of membrane with the effect of air on the vibrating membrane and the correction of measurement error is discussed. In addition, three types of membrane materials are used in the experiment in order to verify the expandability and accuracy of the membrane measurement equipment.

  14. Community Gardens as Health Promoters: Effects on Mental and Physical Stress Levels in Adults with and without Mental Disabilities

    Nugrahaning Sani Dewi


    Full Text Available The study focuses on psychological and physical effects of stress while performing community garden activities of various intensity levels. The aim of this study was to determine the psychological and physical effects in adults with (case group and without (control group mental disabilities. Salivary α-amylase (sAA levels and the stress response scale (SRS-18 were used for the psychological analysis (n = 42. For physical assessment (n = 13, electrocardiogram (ECG, surface electromyogram (sEMG, and respiration rate were continuously measured while performing the activities using a multichannel telemetry system. The results showed that following the activities, the case group exhibited decreasing sAA levels while control group exhibited increasing sAA levels. However, both groups exhibited lower SRS-18 results following the activities. Compared with the control group, the case group had a significantly lower increase in the ratio of the heart rate (IRHR (5.5% during low-intensity work (filling pots with soil, but a significantly higher IRHR (16.7% during high-intensity work (turning over soil. The case group experienced significantly higher levels of fatigue during high-intensity work (digging than during the rest condition. These findings indicate that appropriate workload allocation, according to health, is necessary in the community garden setting because reducing the intensity of work assignments for people with mental disabilities will reduce their physical stress.

  15. Serum antioxidant enzymes activities and oxidative stress levels in patients with acute ischemic stroke: influence on neurological status and outcome.

    Milanlioglu, Aysel; Aslan, Mehmet; Ozkol, Halil; Çilingir, Vedat; Nuri Aydın, Mehmet; Karadas, Sevdegül


    Oxidative stress is well believed to play a role in the pathogenesis of acute ischemic stroke. Reports on antioxidant enzyme activities in patients with stroke are conflicting. Therefore, the aim of this study was to investigate serum antioxidant enzyme activities and oxidative stress levels in patients with acute ischemic stroke within 1st, 5th, and 21st day after stroke onset and also the relationship between these results and the clinical status of patients. The current study comprised 45 patients with acute ischemic stroke and 30 healthy controls. Serum malondialdehyde (MDA) levels, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase activities were measured spectrophotometrically. Serum MDA levels were significantly higher in acute ischemic stroke patients within 24 h after stroke onset than controls (p levels did not change (p > 0.05). Serum SOD activity was significantly lower in 21st day compared to SOD activity of controls (p levels, GSH-Px, and CAT activities did not change significantly. Our study demonstrated that acute ischemic stroke patients have increased oxidative stress and decreased antioxidant enzymes activities. These findings indicated that an imbalance of oxidant and antioxidant status might play a role in the pathogenesis of acute ischemic stroke.

  16. Advanced oxidation protein product levels as a marker of oxidative stress in paediatric patients with chronic tonsillitis.

    Ozbay, I; Kucur, C; Koçak, F E; Savran, B; Oghan, F


    We aimed to determine whether advanced oxidation protein product (AOPP) levels can serve as a marker of oxidative stress in paediatric patients with chronic tonsillitis. Thirty children with chronic tonsillitis and 30 healthy children (control group) were recruited from the Otorhinolaryngology (ORL) and Paediatric Surgery departments, respectively, of Dumlupinar University Hospital. In the patient group, blood samples were collected before tonsillectomy, and tonsil tissue was sampled during the operation. Blood samples were also obtained from the control subjects. AOPP levels in the serum and tonsil tissue were measured by the spectrophotometric method. Serum AOPP levels were significantly higher in the patient group (13.1 ± 3.3 ng/ml) than in the control group (11.6 ± 2.3 ng/ml; P tonsil tissue in the patient group was significantly higher than the mean serum AOPP levels in the control and patient groups (P tonsil tissue and serum of patients with chronic tonsillitis compared to the serum AOPP levels in healthy controls. AOPPs may represent a novel class of pro-inflammatory molecules that are involved in oxidative stress in chronic tonsillitis. AOPPs may be used as a marker of oxidative stress in paediatric patients with chronic tonsillitis. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

  17. Creating Classroom-Level Measures of Citizenship Education Climate

    Barber, Carolyn; Sweetwood, Sachiko Ogata; King, Makini


    Optimal classroom climates for civic education encourage the development of knowledge, skills and dispositions necessary for students to become involved citizens. One of the simplest and most common ways of measuring classroom climate in this field is to aggregate individual students' perceptions of classroom climate to the group level; however,…

  18. Measuring higher cognitive levels by multiple choice questions: a myth?

    Ferland, J J; Dorval, J; Levasseur, L


    Available evidence is inconclusive as to the ability of multiple choice items to measure different taxonomic levels of the cognitive domain. The present study analysed the tests of the Examen de Synthèse for the years 1982, 1983 and 1984. Items used in the study were those for which a consensus was reached between three judges and committees for a given taxonomic level. The initial part of the study showed that judges do not classify items at random but according to a mental representation which is individual, personal and relatively stable. In examining results obtained by students, the study failed to show any significant difference in item difficulty or discrimination for items classified as measuring memorization, interpretation of data and problem-solving. Correlations between results (scores and ranks) obtained for items involving memorization and those obtained for items involving higher cognitive levels fail to show that different traits are measured. If further studies corroborate these results, then future efforts should be directed at developing other instruments to measure higher cognitive levels.

  19. Measuring Resistance to Change at the Within-Session Level

    Tonneau, Francois; Rios, Americo; Cabrera, Felipe


    Resistance to change is often studied by measuring response rate in various components of a multiple schedule. Response rate in each component is normalized (that is, divided by its baseline level) and then log-transformed. Differential resistance to change is demonstrated if the normalized, log-transformed response rate in one component decreases…

  20. Integrating detector for measuring low levels of gamma rays

    Samson, D.M.; Bos, A.J.J.


    Abstract of NL 1001913 (C2) The integrating detector (1) for measuring low levels of ~c-rays, added (9) to the natural background radiation, is provided with a screen (4) placed between at least two thermo-luminescent dosimeters (5-7). It is covered with a housing. Also claimed is the measuremen

  1. Creating Classroom-Level Measures of Citizenship Education Climate

    Barber, Carolyn; Sweetwood, Sachiko Ogata; King, Makini


    Optimal classroom climates for civic education encourage the development of knowledge, skills and dispositions necessary for students to become involved citizens. One of the simplest and most common ways of measuring classroom climate in this field is to aggregate individual students' perceptions of classroom climate to the group level; however,…

  2. Process Analysis and Level Measurement of Textbooks Use by Teachers

    Kong, Fanzhe; Shi, Ningzhong


    Teachers and textbooks are two important elements in curriculum implementation. Based on Concerns-Based Adoption Model (CBAM), a curriculum implementation measurement model designed by G. Hall and S. M. Hord, this paper analyzes the general process of curriculum implementation in terms of textbook use, establishes a model that gauges the level of…

  3. Measuring free thyroxine levels in neonatal heel-prick samples

    Boelen, A.; Veen, M. van; Verkerk, P.H.; Diependaal, G.; Loeber, G.; Elvers, B.; Endert, E.


    The Dutch neonatal screening scheme for Congenital Hypothyroidism (CH) is primarily based on the determination of thyroxine (T4) in filter paper blood spots. In the lowest 5% of T4 values, thyroxine binding globulin (TBG) is measured in order to be able to correct for occasional low TBG levels. Howe

  4. Measuring Developmental Levels of Understanding of Ability and Effort.

    Miller, Arden T.; Nicholls, John G.

    Discussed are research methods used to measure developmental changes in children's reasoning about ability. While adults generally differentiate ability, effort, luck, and task difficulty as causes for success and failure, children progressively think that effort or outcome is ability (level 1), that effort is the cause of performance outcomes…

  5. Measurement of indoor radon levels in the Bologna metropolitan area

    Beozzo, M. (ENEA, Bologna (Italy)); Bottazzi, E.; Calligola, P. (Istituto Nazionale di Fisica Nucleare, Bologna (Italy)) (and others)


    Indoor radon concentrations in Bologna were monitored using two types of detectors with different characteristics. The detectors were the polymeric track detector, CR-39, and activated charcoal. The measurements gave consistent results. It has been verified that the radon concentration in Bologna is well below the 'attention' level given in the scientific literature. (author).

  6. Authentication Assurance Level Application to the Inventory Sampling Measurement System

    Devaney, Mike M.; Kouzes, Richard T.; Hansen, Randy R.; Geelhood, Bruce D.


    This document concentrates on the identification of a standardized assessment approach for the verification of security functionality in specific equipment, the Inspection Sampling Measurement System (ISMS) being developed for MAYAK. Specifically, an Authentication Assurance Level 3 is proposed to be reached in authenticating the ISMS.

  7. Measuring Resistance to Change at the Within-Session Level

    Tonneau, Francois; Rios, Americo; Cabrera, Felipe


    Resistance to change is often studied by measuring response rate in various components of a multiple schedule. Response rate in each component is normalized (that is, divided by its baseline level) and then log-transformed. Differential resistance to change is demonstrated if the normalized, log-transformed response rate in one component decreases…

  8. Mindfulness and levels of stress: a comparison of beginner and advanced Hatha Yoga practitioners.

    Brisbon, Nicholas M; Lowery, Glenn A


    The present study was designed to examine mindfulness and stress levels in beginner and advanced practitioners of Hatha Yoga. Participants (N = 52) were recruited through Hatha Yoga schools local to western Massachusetts. Beginner practitioners (n = 24) were designated as those with under 5 years (M = 3.33) experience and advanced practitioners (n = 28) as those with over 5 years (M = 14.53) experience in Hatha Yoga. The participants completed the Mindful Attention Awareness Scale (MAAS; Brown and Ryan 2003) and the Perceived Stress Scale (PSS; Cohen et al. 1983) directly preceding a regularly scheduled Hatha Yoga class. Based on two independent-samples t-tests, advanced participants scored significantly higher in mindfulness levels (P Hatha Yoga may be an effective technique for enhancing mindfulness and decreasing stress levels in practitioners.

  9. A photoelastic measurement system for residual stress analysis in scintillating crystals by conoscopic imaging.

    Montalto, L; Paone, N; Scalise, L; Rinaldi, D


    The assessment of the stress state of scintillating crystals is an important issue for producers as well as users of such materials, because residual stress may arise during growth process. In this paper, a measurement system, based on the use of a photoelastic, conoscopic optical setup, is proposed for the assessment of stress state in scintillating crystals. Local stress values can be measured on the crystal in order to observe their spatial distribution. With the proposed system, it is possible to vary the dimensions of the inspected measurement volume. It has been validated with reference to a known stress state induced in a birefringent crystal sample and it has been tested for the case of loaded and unloaded samples, showing sub-millimetric spatial resolution and stress uncertainty ≤0.25 MPa. The proposed measurement system is a valid method for the inspection of scintillating crystals required by producers and users of such materials.

  10. The Border Community & Immigration Stress Scale: A Preliminary Examination of a Community Responsive Measure in Two Southwest Samples

    Carvajal, Scott C.; Rosales, Cecilia; Rubio-Goldsmith, Raquel; Sabo, Samantha; Ingram, Maia; McClelland, Debra Jean; Redondo, Floribella; Torres, Emma; Romero, Andrea J.; Oleary, Anna Ochoa; Sanchez, Zoila; de Zapien, Jill Guernsey


    Background Understanding contemporary socio-cultural stressors may assist educational, clinical and policy-level health promotion efforts. This study presents descriptive findings on a new measure, the Border Community & Immigration Stress Scale (BCISS). Methods The data were from two community surveys as part of community based participatory projects conducted in the Southwestern US border region. This scale includes stressful experiences reflected in extant measures, with new items reflecting heightened local migration pressures and health care barriers. Results Stressors representing each main domain, including novel ones, were reported with frequency and at high intensity in the predominantly Mexican-descent samples. Total stress was also significantly associated with mental and physical health indicators. Discussion The study suggests particularly high health burdens tied to the experience of stressors in the US border region. Further, many of the stressors are also likely relevant for other communities within developed nations also experiencing high levels of migration. PMID:22430894

  11. Gender disparities among the association between cumulative family-level stress & adolescent weight status.

    Hernandez, Daphne C; Pressler, Emily


    To investigate precursors to gender-related obesity disparities by examining multiple family-level stress indices. Analyses was based on adolescents born between 1975 and 1991 to women from the 1979 National Longitudinal Study of Youth data set (N=4762). Three types of family-level stressors were captured from birth to age 15: family disruption and conflict, financial strain, and maternal risky health behaviors, along with a total cumulative risk index. Body mass index was constructed on reference criteria for children outlined by the Centers for Disease Control. Multivariate logistic regressions were conducted for the three types of family stressors and for the total cumulative index. The accumulation of family disruption and conflict and financial stress was positively related to female adolescents being overweight/obese. Childhood exposure to maternal risky health behaviors was positively associated with higher weight status for male adolescents. Total cumulative stress was related to overweight/obesity for females, but not males. Different family-level stress indices are associated with the weight status of female and male adolescents. Combining types of family-level stress into one cumulative index appears to mask these differences. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Future climate CO2 levels mitigate stress in plants: increased defense or decreased challenge?

    Hamada eAbdelgawad


    Full Text Available AbstractElevated atmospheric CO2 can stimulate plant growth by providing additional C (fertilization effect, and is observed to mitigate abiotic stress impact. Although the mechanisms underlying the stress mitigating effect are not yet clear, increased antioxidant defenses, have been held primarily responsible (antioxidant hypothesis. A systematic literature analysis, including ‘all’ papers (Web of Science (WoS-cited, addressing elevated CO2 effects on abiotic stress responses and antioxidants (105 papers, confirms the frequent occurrence of the stress mitigation effect. However, it also demonstrates that, in stress conditions, elevated CO2 is reported to increase antioxidants, only in about 22% of the observations (e.g. for polyphenols, peroxidases, superoxide dismutase, monodehydroascorbate reductase. In most observations, under stress and elevated CO2 the levels of key antioxidants and antioxidant enzymes are reported to remain unchanged (50%, e.g. ascorbate peroxidase, catalase, ascorbate, or even decreased (28%, e.g. glutathione peroxidase. Moreover, increases in antioxidants are not specific for a species group, growth facility, or stress type. It seems therefore unlikely that increased antioxidant defense is the major mechanism underlying CO2-mediated stress impact mitigation. Alternative processes, probably decreasing the oxidative challenge by reducing ROS production (e.g. photorespiration, are therefore likely to play important roles in elevated CO2 (relaxation hypothesis. Such parameters are however rarely investigated in connection with abiotic stress relief. Understanding the effect of elevated CO2 on plant growth and stress responses is imperative to understand the impact of climate changes on plant productivity.

  13. Explicit control of adaptive automation under different levels of environmental stress.

    Sauer, Jürgen; Kao, Chung-Shan; Wastell, David; Nickel, Peter


    This article examines the effectiveness of three different forms of explicit control of adaptive automation under low- and high-stress conditions, operationalised by different levels of noise. In total, 60 participants were assigned to one of three types of automation design (free, prompted and forced choice). They were trained for 4 h on a highly automated simulation of a process control environment, called AutoCAMS. This was followed by a 4-h testing session under noise exposure and quiet conditions. Measures of performance, psychophysiology and subjective reactions were taken. The results showed that all three modes of explicit control of adaptive automation modes were able to attenuate the negative effects of noise. This was partly due to the fact that operators opted for higher levels of automation under noise. It also emerged that forced choice showed marginal advantages over the two other automation modes. Statement of Relevance: This work is relevant to the design of adaptive automation since it emphasises the need to consider the impact of work-related stressors during task completion. During the presence of stressors, different forms of operator support through automation may be required than under more favourable working conditions.

  14. Sex and ovarian steroids modulate brain-derived neurotrophic factor (BDNF) protein levels in rat hippocampus under stressful and non-stressful conditions.

    Franklin, Tamara B; Perrot-Sinal, Tara S


    Abnormal levels of brain-derived neurotrophic factor (BDNF) are associated with major depression, a disorder with a higher incidence in women than men. Stress affects BDNF levels in various brain regions and thus, a heightened stress response in females could contribute to the development of depression. As well, ovarian hormones directly affect brain levels of BDNF mRNA and protein. Two experiments were performed to investigate the effects of stress and sex and gonadal hormones on BDNF protein levels in CA1, CA3, and dentate gyrus (DG) subregions of the hippocampus. In the first experiment, male and female Sprague-Dawley rats were subjected to one hour of restraint stress or control handling prior to sacrifice. In the second experiment, fifty-one female rats were ovariectomized and separated into stress and control conditions, as described for the first experiment. Stressed and handled groups received a single injection of estrogen (E; 53h prior to stress), estrogen and progesterone (EP; E given at 53h and P given 5h prior to stress), or vehicle (OVX). In both experiments BDNF protein was quantified using an enzyme-linked immunosorbent enzyme assay (ELISA) in micropunches of hippocampus. Gonadally intact females had significantly higher levels of BDNF in CA3, but significantly lower levels in DG, relative to males. In CA3, stress significantly decreased BDNF in both males and females. In DG of ovariectomized female rats, the effects of stress were significantly different following EP vs. vehicle treatment. Thus, stress increased BDNF levels in EP-treated rats but decreased BDNF levels in vehicle-treated rats. Reduced trophic support in DG in the presence of estrogen and progesterone could jeopardize neurogenesis and under certain conditions could be a contributing factor to the hippocampal atrophy associated with stress-induced affective disorders. These results emphasize the need to consider sex, gonadal steroids, and hippocampal subregion when examining the

  15. Diurnal and stress-reactive dehydroepiandrosterone levels and telomere length in youth

    Andrew R Dismukes


    Full Text Available The current investigation examined the association between the aging-related biomarkers dehydroepiandrosterone (DHEA and telomere length (TL in community-recruited African-American youth. The examination of DHEA included stress reactive, basal and diurnal sampling, in order to elucidate the underlying physiological process that may overlap with TL. One hundred and two participants completed the Trier Social Stressor Test for children (TSST-C. TL was obtained from all youth from buccal swabs on the same day as the TSST-C. Saliva samples from 83 participants were obtained over the course of two additional days to measure waking and diurnal levels of DHEA. DHEA diurnal slope was a robust predictor of TL (B=0.516, P<0.05, while other DHEA values were not significantly associated with TL. This study is one of the first studies to examine basal, diurnal and reactivity measurements of DHEA in youth. Furthermore, this is the first study, to our knowledge, to demonstrate a positive association between DHEA, a putative anti-aging hormone, and TL, an indicator of cellular aging.

  16. Effects of osmotic stress on the kinds, forms and levels of polyamines in wheat coleoptiles.

    Liu, Huai-Pan; Zhu, Zi-Xue; Liu, Tian-Xue; Li, Chao-Hai


    The changes in levels and forms of polyamine (Pa) in the coleoptiles of two wheat (triticum aestivum L.) cultivars differing in drought tolerance were investigated under osmotic stress. The drought-tolerant 'Yumai 18' showed marked increases in free spermidine (Spd) and spermine (Spm) levels in coleoptiles after being treated with polyethylene glycol (PEG)-6000 for 2 d in the dark, while drought-sensitive 'Yangmai 9' showed a significant increase in free putrescine (Put) content. Treatment of coleoptiles with methylglyoxal-bis (guanylhydrazone) (MGBG), an S-adenosylmethionine decarboxylase (S-AMDC) inhibitor, resulted in reduction of free Spd and free Spm levels in coleoptiles and aggravation of PEG-induced injury to 'Yumai 18' coleoptile, while exogenous Spd treatment resulted in an increase in free Spd + free Spm content of coleoptiles, and an alleviation of PEG-induced injury to 'Yangmai 9' coleoptile. Osmotic stress induced significant increases in perchloric acid-soluble conjugated PA (PS conjugated PA) and perchloric acid-insoluble conjugated PA (PIS conjugated PA) levels in coleoptiles of 'Yumai 18' whereas osmotic stress affected only slightly the PS-conjugated PA and PIS-conjugated PA levels in 'Yangmai 9' coleoptiles. Treatment of coleoptiles with phenanthroline (o-Phen), an inhibitor of transglutaminase (TGase), also aggravated the PEG-induced injury to 'Yumai 18' coleoptiles, accompanied by the decreases in the level of PIS-conjugated PA. These results suggest that free Spd, free Spm and conjugated PA enhance the osmotic stress tolerance of wheat coleoptiles.

  17. Measurement of indoor radon concentration levels in Islamabad, Pakistan

    Rahman, S.U.; Anwar, J. [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Matiullah [PD, PINSTECH Nilore, Islamabad (Pakistan)], E-mail:


    Indoor radon measurement survey has been carried out in properly selected houses of the city of Islamabad. In this regard, CR-39-based NRPB radon dosimeters were used. The dosimeters were installed at head heights in bedroom and living room of each house. For intercomparison purpose, houses having basements were also selected. In such houses, dosimeters were installed in basements, ground floor and first floor. All the dosimeters were exposed to radon for a period of three months. After exposure, CR-39 detectors were etched for 16 h in 6 M NaOH at 80{sup 0}C and were counted under an optical microscope. The observed track densities were then related to radon concentration levels using a calibration factor of 2.7trackscm{sup -2}h{sup -1}(kBqm{sup -3}){sup -1}. Measured indoor radon concentration levels were found to vary from 11 to 78Bqm{sup -3}. The average radon concentration levels in bedrooms and sitting/living rooms in basements were found to be 40 and 32Bqm{sup -3}, respectively. In bedrooms and living rooms, on ground floor, the average radon concentration levels were found to be 30 and 27Bqm{sup -3}, whereas on first floor the average values were 29 and 27Bqm{sup -3}, respectively. The radon concentration levels found in this study are below the action level recommended by the ICRP.

  18. Effect of Stress Caused by Academic Tests on Cortisol and ProlactineLevels in a Group of Medical Students

    Alba Lucía Salamanca


    Full Text Available Introduction: The relationship betweenimmunological system and stress has been debatedin the last years. Neurohormonal changes produceimmunologic response variations with majorchanges in the cytokines levels, causing depressionof the cytolytic responses due to a decrease in theNK (Natural Killer cells population (1.Academic stress is a useful stress model to studyhormonal changes in the Hypotalamic-Pituitary–Adrenocortical (HPA axis (2, 3.Materials and Methods: The present studyevaluates th0e behavior of cortisol and prolactinehormones and their effect on the adaptativeresponses of Herpes Simplex Virus type I in apopulation of 26 medical students with agesbetween 14 and 27 years. Male students represented80.8% of the evaluated population. This is a threestage longitudinal intervention study whereantibodies, cortisol and prolactin levels weremeasured against Herpes Simplex Virus type I.The first measure was done 15 days previous tothe stressful event, the second during the stressfulevent (mid-academic period exams and the lastone, 15 days posterior to the stressful event. Allsamples were taken from 8:00 am to 10:00 am.Results and Discussion: Prolactine averagevalues were found to be significantly different (p< 0.001 when comparing the three stages.Cortisol values changes were near showingsignificant differences (p = 0.098, with an increaseduring the stressful event and a decrease after theexposure. Antibodies levels of Herpes SimplexVirus type I showed a significant difference (p =0.043 increasing tendency in the three stages.Adaptative responses to Herpes Simplex Virustype I augmented as a result of prolactineconcentration increase due to a stressor eventexposure. This explains an increment in thecytotoxic cell activity (NK cells which incrementcytokine concentration, such as INF-α, whichamplify humoral IgG antibody mediated response,according with obtained results. Even thoughcortisol levels do not significantly increased duringthe stressful



    In this article, a shear plate was mounted on the bottom in a wave flume and direct measurements of the smooth and rough bed shear stress under regular and irregular waves were conducted with the horizontal force exerted on the shear plates by the bottom shear stress in the wave boundary layer. Under immobile bed condition, grains of sand were glued uniformly and tightly onto the shear plate, being prevented from motion with the fluid flow and generation of sand ripples. The distribution of the bottom mean shear stress varying with time was measured by examining the interaction between the shear plate and shear transducers. The relation between the force measured by the shear transducers and its voltage is a linear one. Simultaneous measurements of the bottom velocity were carried out by an Acoustic Doppler Velocimeter (ADV), while the whole process was completely controlled by computers, bottom shear stress and velocity were synchronously measured. Based on the experimental results, it can be concluded that (1) the friction coefficient groews considerably with the increase of the Reynolds number, (2) the shear stress is a function varying with time and linearly proportional to the velocity. Compared with theoretical results and previous experimental data, it is shown that the experimental method is feasible and effective, A further study on the bed shear stress under regular or irregular waves can be carried out. And applicability to the laboratory studies on the initiation of sediments and the measurement of the shear stress after sediment imigration.

  20. Residual stress measurement in a metal microdevice by micro Raman spectroscopy

    Song, Chang; Du, Liqun; Qi, Leijie; Li, Yu; Li, Xiaojun; Li, Yuanqi


    Large residual stress induced during the electroforming process cannot be ignored to fabricate reliable metal microdevices. Accurate measurement is the basis for studying the residual stress. Influenced by the topological feature size of micron scale in the metal microdevice, residual stress in it can hardly be measured by common methods. In this manuscript, a methodology is proposed to measure the residual stress in the metal microdevice using micro Raman spectroscopy (MRS). To estimate the residual stress in metal materials, micron sized β-SiC particles were mixed in the electroforming solution for codeposition. First, the calculated expression relating the Raman shifts to the induced biaxial stress for β-SiC was derived based on the theory of phonon deformation potentials and Hooke’s law. Corresponding micro electroforming experiments were performed and the residual stress in Ni–SiC composite layer was both measured by x-ray diffraction (XRD) and MRS methods. Then, the validity of the MRS measurements was verified by comparing with the residual stress measured by XRD method. The reliability of the MRS method was further validated by the statistical student’s t-test. The MRS measurements were found to have no systematic error in comparison with the XRD measurements, which confirm that the residual stresses measured by the MRS method are reliable. Besides that, the MRS method, by which the residual stress in a micro inertial switch was measured, has been confirmed to be a convincing experiment tool for estimating the residual stress in metal microdevice with micron order topological feature size.

  1. The association of personality traits and coping styles according to stress level

    Hamid Afshar


    Full Text Available Background: Some personality traits and coping styles could be as risk factors in stressful situations. This study aimed to investigate the association of personality traits and coping styles according to the stress level. Meterials and Methods: This cross-sectional study was performed in 2011. A total of 4628 individuals over 20 years were selected by random sampling from nonacademic employees that working in 50 different centers across Isfahan province. Data were collected using 12-item General Health Questionnaire (GHQ-12, Big Five Personality Inventory Short Form and coping strategies scale, and individuals were divided into high and low-stress groups in term of GHQ-12. To analyze the data, a binary logistic regression analysis was conducted. Results: Mean age of participants was 36.3 ± 7.91 years and 56.26% (2604 of them were female. Neuroticism with adjusting covariates of demographic characteristics and the rest of personality traits was a risk factor for stress level with odds ratios (OR OR:1.24; but other personality traits were protective. Also, active coping styles were protective factors for OR of stress level with adjusting covariates of demographic characteristics and the rest of coping styles, and positive reinterpretation and growth was the most effective of coping style with OR:0.84. Conclusion: Some personality traits are associated with passive copings and cause high-stress level. So, it could be concluded that improve and strengthen effective coping strategies in individual with maladaptive traits should be considered as a crucial component of prevention and control programs of stress.

  2. The association of personality traits and coping styles according to stress level

    Afshar, Hamid; Roohafza, Hamid Reza; Keshteli, Ammar Hassanzadeh; Mazaheri, Mina; Feizi, Awat; Adibi, Peyman


    Background: Some personality traits and coping styles could be as risk factors in stressful situations. This study aimed to investigate the association of personality traits and coping styles according to the stress level. Meterials and Methods: This cross-sectional study was performed in 2011. A total of 4628 individuals over 20 years were selected by random sampling from nonacademic employees that working in 50 different centers across Isfahan province. Data were collected using 12-item General Health Questionnaire (GHQ-12), Big Five Personality Inventory Short Form and coping strategies scale, and individuals were divided into high and low-stress groups in term of GHQ-12. To analyze the data, a binary logistic regression analysis was conducted. Results: Mean age of participants was 36.3 ± 7.91 years and 56.26% (2604) of them were female. Neuroticism with adjusting covariates of demographic characteristics and the rest of personality traits was a risk factor for stress level with odds ratios (OR) OR:1.24; but other personality traits were protective. Also, active coping styles were protective factors for OR of stress level with adjusting covariates of demographic characteristics and the rest of coping styles, and positive reinterpretation and growth was the most effective of coping style with OR:0.84. Conclusion: Some personality traits are associated with passive copings and cause high-stress level. So, it could be concluded that improve and strengthen effective coping strategies in individual with maladaptive traits should be considered as a crucial component of prevention and control programs of stress. PMID:26109990

  3. Residual stress measurements of 2-phase sprayed coating layer

    Nishida, Masayuki [Kagawa Polytechnic College, Kagawa (Japan); Hanabusa, Takao


    In a series of the already reported single phase metal and ceramic melt sprayed films, on two phase melt sprayed films, their stress and thermal stress changes due to their bending load are tried to test. In order to prepare two phase state, austenitic stainless steel wire is used by a laser melt spraying method. In this method, CO{sub 2} laser is used for a thermal source, and proceeding direction of its laser is selected to cross melt spraying direction. As a result, the following facts can be elucidated. The stress values at {alpha}- and {gamma}-phase in the stainless steel film are linearly responsive to the bending load, and the stress change in {alpha}-phase is smaller than that in {gamma}-phase. In a heat and cool cycle, {alpha}-phase shows a trend of extension with increasing temperature but {gamma}-phase shows a trend of compression inversely. And, stress behavior at {alpha}- and {gamma}-phases in the stainless steel film does not agree with a mixing rule in common two-phase materials. (G.K.)

  4. Higher perceived stress but lower cortisol levels found among young Greek adults living in a stressful social environment in comparison with Swedish young adults.

    Åshild Faresjö

    Full Text Available The worldwide financial crisis during recent years has raised concerns of negative public health effects. This is notably evident in southern Europe. In Greece, where the financial austerity has been especially pronounced, the prevalence of mental health problems including depression and suicide has increased, and outbreaks of infectious diseases have risen. The main objective in this study was to investigate whether different indicators of health and stress levels measured by a new biomarker based on cortisol in human hair were different amongst comparable Greek and Swedish young adults, considering that Sweden has been much less affected by the recent economic crises. In this cross-sectional comparative study, young adults from the city of Athens in Greece (n = 124 and from the city of Linkoping in Sweden (n = 112 participated. The data collection comprised answering a questionnaire with different health indicators and hair samples being analyzed for the stress hormone cortisol, a biomarker with the ability to retrospectively measure long-term cortisol exposure. The Greek young adults reported significantly higher perceived stress (p<0.0001, had experienced more serious life events (p = 0.002, had lower hope for the future (p<0.0001, and had significantly more widespread symptoms of depression (p<0.0001 and anxiety (p<0.0001 than the Swedes. But, the Greeks were found to have significantly lower cortisol levels (p<0.0001 than the Swedes, and this difference was still significant in a multivariate regression (p<0.0001, after adjustments for potential intervening variables. A variety of factors related to differences in the physical or socio-cultural environment between the two sites, might possibly explain this finding. However, a potential biological mechanism is that long-term stress exposure could lead to a lowering of the cortisol levels. This study points out a possible hypothesis that the cortisol levels of the Greek young adults might

  5. Measuring the level of social support using latent class analysis.

    Santos, Letícia Marques; Amorim, Leila Denise A F; Santos, Darci Neves; Barreto, Maurício L


    Different instruments have been used to measure social support in epidemiological studies of which the most widely used is the Medical Outcomes Study Social Support Scale (SSS-MOS). However, these studies lack measures of the level of social support on health risks. We used latent class analysis (LCA) to distinguish subgroups with different levels of perceived social support and tested the consistency of these subgroups by their associations with the prevalence of Common Mental Disorders (CMD). This is a cross-sectional study of 1013 mothers living in the city of Salvador, Brazil in which psychosocial data were collected through home visits using the SSS-MOS and the Self Reporting Questionnaire-20. For each dimension of social support analysed here, we selected models with two classes using LCA. Multivariate logistic regression models were used to estimate the association between participants' perceived social support and the prevalence of CMD to verify the consistency of the groups defined by LCA. There was a clear difference in the reporting of perceived social support between those classified as high or low using LCA. The probability of perceiving several types of social support was lower in the subgroup classified as low level of social support (13.7-59.8%), and it was much higher in the group classified as high level of social support (84.3-98%). A greater prevalence of CMD was found among mothers with lower levels of social support. LCA seems to be a useful tool to improve measurement of perceived social support by separation into two levels in which the lower level is associated with an increased prevalence of CMD. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Measuring differentiation among populations at different levels of genetic integration

    Gregorius Hans-Rolf


    Full Text Available Abstract Background Most genetic studies of population differentiation are based on gene-pool frequencies. Population differences for gene associations that show up as deviations from Hardy-Weinberg proportions (homologous association or gametic disequilibria (non-homologous association are disregarded. Thus little is known about patterns of population differentiation at higher levels of genetic integration nor the causal forces. Results To fill this gap, a conceptual approach to the description and analysis of patterns of genetic differentiation at arbitrary levels of genetic integration (single or multiple loci, varying degrees of ploidy is introduced. Measurement of differentiation is based on the measure Δ of genetic distance between populations, which is in turn based on an elementary genic difference between individuals at any given level of genetic integration. It is proven that Δ does not decrease when the level of genetic integration is increased, with equality if the gene associations at the higher level follow the same function in both populations (e.g. equal inbreeding coefficients, no association between loci. The pattern of differentiation is described using the matrix of pairwise genetic distances Δ and the differentiation snail based on the symmetric population differentiation ΔSD. A measure of covariation compares patterns between levels. To show the significance of the observed differentiation among possible gene associations, a special permutation analysis is proposed. Applying this approach to published genetic data on oak, the differentiation is found to increase considerably from lower to higher levels of integration, revealing variation in the forms of gene association among populations. Conclusion This new approach to the analysis of genetic differentiation among populations demonstrates that the consideration of gene associations within populations adds a new quality to studies on population differentiation that is

  7. Hall coefficient measurement for residual stress assessment in precipitation hardened IN718 nickel-base superalloy

    Velicheti, Dheeraj; Nagy, Peter B.; Hassan, Waled


    We investigated the feasibility of residual stress assessment based on Hall coefficient measurements in precipitation hardened IN718 nickel-base superalloy. As a first step, we studied the influence of microstructural variations on the galvanomagnetic properties of IN718 nickel-base superalloy. We found that the Hall coefficient of IN718 increases from ≈ 8.0×10-11 m3/C in its fully annealed state of 15 HRC Rockwell hardness to ≈ 9.4×10-11 m3/C in its fully hardened state of 45 HRC. We also studied the influence of cold work, i.e., plastic deformation, at room temperature and found that cold work had negligible effect on the Hall coefficient of fully annealed IN718, but significantly reduced it in hardened states of the material. For example, measurements conducted on fully hardened IN718 specimens showed that the Hall coefficient decreased more or less linearly with cold work from its peak value of ≈ 9.4×10-11 m3/C in its intact state to ≈ 9.0×10-11 m3/C in its most deformed state of 22% plastic strain. We also studied the influence of applied stress and found that elastic strain significantly increases the Hall coefficient of IN718 regardless of the state of hardening. The relative sensitivity of the Hall coefficient to elastic strain was measured as a unitless gauge factor K that is defined as the ratio of the relative change of the Hall coefficient ΔRH/RH divided by the axial strain ɛ = σ/E, where σ is the applied uniaxial stress and E is the Young's modulus of the material. We determined that the galvanomagnetic gauge factor of IN718 is κ ≈ 2.6 - 2.9 depending on the hardness level. Besides the fairly high value of the gauge factor, it is important that it is positive, which means that compressive stress in surface-treated components decreases the Hall coefficient in a similar way as plastic deformation does, therefore the unfortunate cancellation that occurs in fully hardened IN718 in the case of electric conductivity measurements will not

  8. Study to evaluate the effectiveness of stress management workshops on response to general and occupational measures of stress.

    Heron, R J; McKeown, S; Tomenson, J A; Teasdale, E L


    This study was designed to evaluate the effectiveness of stress management training workshops within Zeneca Pharmaceuticals. The study was of cross-sectional design, comparing groups of workshop attendees and non-attendees. In addition, self-rated well-being scores of attendees were compared with results obtained pre-workshop and 2-3 months after the workshop. Employees participating in the study were drawn from the Manufacturing, Research and Development, Sales and Marketing sites of Zeneca Pharmaceuticals located in Cheshire, United Kingdom. Three hundred and ninety persons who had participated in stress management workshops since 1988 were matched for age, gender and department with an equal number of employees who had not attended stress management workshops. Outcome measures included self-rated well-being (as measured by the 30-question General Health Questionnaire), knowledge of company guidance on the management of stress in staff, and an assessment of coping strategies. Subjects who had not attended a stress management workshop were much more likely to have a poor understanding of the principles of management of stress in staff [odds ratio (OR) = 8.3; 95% confidence interval (CI) = 3.3-21.3] and more likely to have poor coping skills (OR = 2.8; CI = 1.3-6.1). However, mean scores for the two measures were similar in attendees and non-attendees. Self-rating of current well-being was strongly associated with the life-events score, but not related to workshop attendance. The study indicates that stress management training workshops reduce the prevalence of employees with a poor understanding of the principles of the management of stress in staff and with poor coping strategies. An improvement in the self-rated well-being observed shortly after the workshop was not sustained.

  9. Physiologic Measures of Animal Stress during Transitional States of Consciousness

    Robert E. Meyer


    Full Text Available Determination of the humaneness of methods used to produce unconsciousness in animals, whether for anesthesia, euthanasia, humane slaughter, or depopulation, relies on our ability to assess stress, pain, and consciousness within the contexts of method and application. Determining the subjective experience of animals during transitional states of consciousness, however, can be quite difficult; further, loss of consciousness with different agents or methods may occur at substantially different rates. Stress and distress may manifest behaviorally (e.g., overt escape behaviors, approach-avoidance preferences [aversion] or physiologically (e.g., movement, vocalization, changes in electroencephalographic activity, heart rate, sympathetic nervous system [SNS] activity, hypothalamic-pituitary axis [HPA] activity, such that a one-size-fits-all approach cannot be easily applied to evaluate methods or determine specific species applications. The purpose of this review is to discuss methods of evaluating stress in animals using physiologic methods, with emphasis on the transition between the conscious and unconscious states.

  10. Final Report: Geothermal dual acoustic tool for measurement of rock stress

    Normann, Randy A. [Perma Works LLC, Pattonville, TX (United States)


    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  11. Final Report. Geothermal Dual Acoustic Tool for Measurement of Rock Stress

    Normann, Randy A [Perma Works LLC, Pattonville, TX (United States)


    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  12. Accuracy of soil stress measurements as affected by transducer dimensions and shape

    Lamandé, Mathieu; Keller, Thomas; Berisso, Feto Esimo


    Accurate measurements of soil stress are needed to evaluate the impact of traffic on soil properties and prevent soil compaction. Four types of transducer commonly used to measure vertical stress were calibrated in realistic traffic conditions in the field. The four transducer types differed in s...

  13. Instruction manual for the use of CSIR triaxial rock stress measuring equipment

    Coetzer, SJ


    Full Text Available This is an updated version of CSIR Report no ME 1763 entitled "Instruction manual for the use for the CSIR triaxial rock stress measuring equipment" by F A Vreede. The manual contains a detailed description of CSIR Triaxial rock stress measuring...

  14. Final Report: Geothermal Dual Acoustic Tool for Measurement of Rock Stress

    Normann, Randy A.


    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  15. Exploring Stress Levels, Job Satisfaction, and Quality of Life in a Sample of Police Officers in Greece

    Evangelos C. Alexopoulos


    Conclusion: Higher levels of stress are related to an increased risk of reporting suboptimal job satisfaction and QoL. The magnitude of these associations varied depending on age, gender, and rank, highlighting the need for stress-management training.

  16. Job satisfaction and Job stress among various employees of tertiary care level hospital in central Uttar Pradesh, India

    Ruchi Yadav; Dhiraj Kumar Srivastava; Sanjeev Yadav; Sandip Kumar; Pankaj Kumar Jain; Sachin Gupta


    ...: To study the relationship between job satisfaction and job stress among various employees of tertiary care level hospital and to find the co-relates of job stress and job satisfaction. Materials & Methods...

  17. Stress release model and proxy measures of earthquake size. Application to Italian seismogenic sources

    Varini, Elisa; Rotondi, Renata; Basili, Roberto; Barba, Salvatore


    This study presents a series of self-correcting models that are obtained by integrating information about seismicity and fault sources in Italy. Four versions of the stress release model are analyzed, in which the evolution of the system over time is represented by the level of strain, moment, seismic energy, or energy scaled by the moment. We carry out the analysis on a regional basis by subdividing the study area into eight tectonically coherent regions. In each region, we reconstruct the seismic history and statistically evaluate the completeness of the resulting seismic catalog. Following the Bayesian paradigm, we apply Markov chain Monte Carlo methods to obtain parameter estimates and a measure of their uncertainty expressed by the simulated posterior distribution. The comparison of the four models through the Bayes factor and an information criterion provides evidence (to different degrees depending on the region) in favor of the stress release model based on the energy and the scaled energy. Therefore, among the quantities considered, this turns out to be the measure of the size of an earthquake to use in stress release models. At any instant, the time to the next event turns out to follow a Gompertz distribution, with a shape parameter that depends on time through the value of the conditional intensity at that instant. In light of this result, the issue of forecasting is tackled through both retrospective and prospective approaches. Retrospectively, the forecasting procedure is carried out on the occurrence times of the events recorded in each region, to determine whether the stress release model reproduces the observations used in the estimation procedure. Prospectively, the estimates of the time to the next event are compared with the dates of the earthquakes that occurred after the end of the learning catalog, in the 2003-2012 decade.

  18. Nitrogen Metabolism in Adaptation of Photosynthesis to Water Stress in Rice Grown under Different Nitrogen Levels

    Chu Zhong


    Full Text Available To investigate the role of nitrogen (N metabolism in the adaptation of photosynthesis to water stress in rice, a hydroponic experiment supplying with low N (0.72 mM, moderate N (2.86 mM, and high N (7.15 mM followed by 150 g⋅L-1 PEG-6000 induced water stress was conducted in a rainout shelter. Water stress induced stomatal limitation to photosynthesis at low N, but no significant effect was observed at moderate and high N. Non-photochemical quenching was higher at moderate and high N. In contrast, relative excessive energy at PSII level (EXC was declined with increasing N level. Malondialdehyde and hydrogen peroxide (H2O2 contents were in parallel with EXC. Water stress decreased catalase and ascorbate peroxidase activities at low N, resulting in increased H2O2 content and severer membrane lipid peroxidation; whereas the activities of antioxidative enzymes were increased at high N. In accordance with photosynthetic rate and antioxidative enzymes, water stress decreased the activities of key enzymes involving in N metabolism such as glutamate synthase and glutamate dehydrogenase, and photorespiratory key enzyme glycolate oxidase at low N. Concurrently, water stress increased nitrate content significantly at low N, but decreased nitrate content at moderate and high N. Contrary to nitrate, water stress increased proline content at moderate and high N. Our results suggest that N metabolism appears to be associated with the tolerance of photosynthesis to water stress in rice via affecting CO2 diffusion, antioxidant capacity, and osmotic adjustment.

  19. Low-level laser effects on bacterial cultures submitted to heat stress

    Gonçalves, E. M.; Guimarães, O. R.; Geller, M.; Paoli, F.; Fonseca, A. S.


    Low-level lasers have been used worldwide to treat a number of diseases, pain relief, and wound healing. Some studies demonstrated that low-level laser radiations induce effects depending on the physiological state and DNA repair mechanisms of cells. In this work we evaluated the effects of low-level red and infrared lasers on Escherichia coli cells deficient in SOS responses submitted to heat stress. Exponential and stationary E. coli cultures of wild type (AB1157), RecA deficient (AB2463) and LexA deficient (AB2494), both SOS response deficient, were exposed to low-level red and infrared lasers at different fluences and submitted to heat stress (42 °C, 20 min). After that, cell survival and morphology were evaluated. Previous exposure to red, but not infrared lasers, increases survival fractions and decreases the area ratios of E. coli AB1157 cells submitted to heat stress. Our research suggests that a low-level red laser increases cell viability and protects cells from morphological alteration in E. coli cultures submitted to heat stress depending on laser wavelength and SOS response.



    Traditional methods of residual stress measurement are generally destructive or semi-destructive, as well as expensive, time-consuming and complex to implement. With the new development of welded structure, traditional methods can not satisfy the need of full life task management. So the acoustical theory is introduced, since the ultrasonic technique provides a useful nondestructive tool in the evaluation of stresses. In this study an ultrasonic stress measurement experimental installation is established, which consists of a special transducer, a signal emission unit and a signal recipient processing unit. Longitudinal critically refracted wave is selected as the measurement wave mode. The supporting software is programmed by Labview software. The longitudinal residual stress and transverse residual stress of twin wire welded plate are measured by this installment, in which the measuring process is real-time, quick and nondestructive. The experiment results indicate that the system can satisfy the need of life evaluation for welded structure. The system is light and portable.

  1. Assessment of stress level among dental school students: An Indian outlook

    Pradeep S Tangade


    Full Text Available Background: Evaluating the factors influence student perception, might allow programmatic changes designed to enhance students′ psychosocial well-being and academic performance. The purpose of this study was to investigate perceived sources of stress on dental students and the role of parents in their career choice decisions. Methods : In a cross-sectional design, a modified dental environmental stress questionnaire was administered to all dental students. The responses to the questionnaire were based on a four-point Lickert scale, not stressful to severely stressful. Means and standard deviations were determined for stress scores of individuals for each item and were used to compare the classes, genders, and choices. Student′s t, one way ANOVA, and Newman Keuls multiple comparison post hoc tests were used to analysed the data at the significant level of P ≤ 0.05. Results: A total of 304 undergraduate students constituted the study population. Of the respondent, 60% were men and 40% were women. The final year students presented with higher stress scores. In gender comparison, men suffered more stress (62.9% than women (60.1%. According to the career choice decision, students forced by parents had more perception of stress (69.0% and the students staying in the hostel (62.7% showed more perception of stress than day scholars (56.3%. Conclusion: The study indicates that the congenial environment needs to be created for dental education and the parents also need to be counselled against forcing their children to join an educational programme i.e. not of their choice.

  2. Assessment of Stress Level among Dental School Students: An Indian Outlook.

    Tangade, Pradeep S; Mathur, Anmol; Gupta, Rahul; Chaudhary, Shikha


    Evaluating the factors influence student perception, might allow programmatic changes designed to enhance students' psychosocial well-being and academic performance. The purpose of this study was to investigate perceived sources of stress on dental students and the role of parents in their career choice decisions. In a cross-sectional design, a modified dental environmental stress questionnaire was administered to all dental students. The responses to the questionnaire were based on a four-point Lickert scale, not stressful to severely stressful. Means and standard deviations were determined for stress scores of individuals for each item and were used to compare the classes, genders, and choices. Student's t, one way ANOVA, and Newman Keuls multiple comparison post hoc tests were used to analysed the data at the significant level of P ≤ 0.05. A total of 304 undergraduate students constituted the study population. Of the respondent, 60% were men and 40% were women. The final year students presented with higher stress scores. In gender comparison, men suffered more stress (62.9%) than women (60.1%). According to the career choice decision, students forced by parents had more perception of stress (69.0%) and the students staying in the hostel (62.7%) showed more perception of stress than day scholars (56.3%). The study indicates that the congenial environment needs to be created for dental education and the parents also need to be counselled against forcing their children to join an educational programme i.e. not of their choice.

  3. The relationship between levels of resilience and coping styles in chiropractic students and perceived levels of stress and well-being.

    Innes, Stanley I


    The aim of this study was to explore the relationship between chiropractic students' coping styles and levels of resilience with their physical injuries, perceived levels of stress, and well-being. A questionnaire was distributed to the entire student body of the chiropractic program at Murdoch University, and gathered demographic variables and responses to the Connor-Davidson Resilience Scale, Perceived Levels of Stress Scale, Everyday Feelings Questionnaire, and Coping Inventory for Stressful Situations. Linear regression analysis was used to calculate for significant relationships. Of 244 students, 194 (81%) completed the surveys. Being female and not having recovered from an injury within 12 months was significantly associated with lower levels of well-being and higher levels of stress. Being female, possessing an increased use of an emotional-based coping style, and having lower levels of well-being were associated with higher levels of stress (R(2) = 0.65, F(6,164) = 50.47, p levels of well-being were associated with being female, higher perceived levels of stress, lower levels of resilience, and an increased use emotional coping styles (R(2) = 0.64, F[6,164] = 49.5, p levels of well-being and high levels of stress. These students may benefit from interventions aimed at enhancing their coping style choices and increasing their resilience levels. Future studies are recommended to see if these findings are consistent across chiropractic programs nationally and internationally.

  4. Moderate Level Alcohol During Pregnancy, Prenatal Stress, or Both and Limbic-Hypothalamic-Pituitary-Adrenocortical Axis Response to Stress in Rhesus Monkeys

    Schneider, Mary L.; Moore, Colleen F.; Kraemer, Gary W.


    This study examined the relationship between moderate-level prenatal alcohol exposure, prenatal stress, and postnatal response to a challenging event in 6-month-old rhesus monkeys. Forty-one rhesus monkey (Macaca mulatta) infants were exposed prenatally to moderate level alcohol, maternal stress, or both. Offspring plasma cortisol and…

  5. Moderate Level Alcohol During Pregnancy, Prenatal Stress, or Both and Limbic-Hypothalamic-Pituitary-Adrenocortical Axis Response to Stress in Rhesus Monkeys

    Schneider, Mary L.; Moore, Colleen F.; Kraemer, Gary W.


    This study examined the relationship between moderate-level prenatal alcohol exposure, prenatal stress, and postnatal response to a challenging event in 6-month-old rhesus monkeys. Forty-one rhesus monkey (Macaca mulatta) infants were exposed prenatally to moderate level alcohol, maternal stress, or both. Offspring plasma cortisol and…

  6. High intensity and reduced volume training attenuates stress and recovery levels in elite swimmers

    Elbe, Anne-Marie; Rasmussen, Camilla P; Nielsen, Glen


    for baseline values. No significant effects could be observed in sports-specific stress or sports-specific recovery. The results indicate that increasing training intensity and reducing training volume for 12 weeks can reduce general stress and increase general recovery levels in competitive swimmers.......This study investigated the effect of increased high-intensity interval training (HIT) at the expense of total training volume on the stress and recovery levels of elite swimmers. Forty-one elite swimmers participated in the study and were randomly assigned to either a HIT or a control group (CON......). Eleven swimmers did not complete the questionnaires. For 12 weeks both groups trained ~12 h per week. The amount of HIT was ~5 h vs. 1 h, and total distance was ~17 km vs. ~35 km per week for HIT and CON, respectively. HIT was performed as 6-10 × 10-30 s maximal effort interspersed by 2-4 min of rest...

  7. Wearable Biomedical Measurement Systems for Assessment of Mental Stress of Combatants in Real Time

    Fernando Seoane


    Full Text Available The Spanish Ministry of Defense, through its Future Combatant program, has sought to develop technology aids with the aim of extending combatants’ operational capabilities. Within this framework the ATREC project funded by the “Coincidente” program aims at analyzing diverse biometrics to assess by real time monitoring the stress levels of combatants. This project combines multidisciplinary disciplines and fields, including wearable instrumentation, textile technology, signal processing, pattern recognition and psychological analysis of the obtained information. In this work the ATREC project is described, including the different execution phases, the wearable biomedical measurement systems, the experimental setup, the biomedical signal analysis and speech processing performed. The preliminary results obtained from the data analysis collected during the first phase of the project are presented, indicating the good classification performance exhibited when using features obtained from electrocardiographic recordings and electrical bioimpedance measurements from the thorax. These results suggest that cardiac and respiration activity offer better biomarkers for assessment of stress than speech, galvanic skin response or skin temperature when recorded with wearable biomedical measurement systems.

  8. Effects of logging, hunting, and forest fragment size on physiological stress levels of two sympatric ateline primates in Colombia

    Rimbach, Rebecca; Link, Andrés; Heistermann, Michael; Gómez-Posada, Carolina; Galvis, Nelson; Heymann, Eckhard W.


    Habitat fragmentation and anthropogenic disturbances are of major concern to the conservation of endangered species because of their potentially negative impact on animal populations. Both processes can impose physiological stress (i.e. increased glucocorticoid output) on animals, and chronically elevated stress levels can have detrimental effects on the long-term viability of animal populations. Here, we investigated the effect of fragment size and human impact (logging and hunting pressure) on glucocorticoid levels of two sympatric Neotropical primates, the red howler monkey (Alouatta seniculus) and the critically endangered brown spider monkey (Ateles hybridus). These two species have been reported to contrast strongly in their ability to cope with anthropogenic disturbances. We collected faecal samples from eight spider monkey groups and 31 howler monkey groups, living in seven and 10 different forest fragments in Colombia, respectively. We measured faecal glucocorticoid metabolite (FGCM) levels in both species using previously validated methods. Surprisingly, fragment size did not influence FGCM levels in either species. Spider monkeys showed elevated FGCMs in fragments with the highest level of human impact, whereas we did not find this effect in howler monkeys. This suggests that the two species differ in their physiological responsiveness to anthropogenic changes, further emphasizing why brown spider monkeys are at higher extinction risk than red howler monkeys. If these anthropogenic disturbances persist in the long term, elevated FGCM levels can potentially lead to a state of chronic stress, which might limit the future viability of populations. We propose that FGCM measurements should be used as a tool to monitor populations living in disturbed areas and to assess the success of conservation strategies, such as corridors connecting forest fragments. PMID:27293615

  9. Self-reported and measured stress related responses associated with exposure to wind turbine noise.

    Michaud, David S; Feder, Katya; Keith, Stephen E; Voicescu, Sonia A; Marro, Leonora; Than, John; Guay, Mireille; Denning, Allison; Bower, Tara; Villeneuve, Paul J; Russell, Evan; Koren, Gideon; van den Berg, Frits


    The current study was the first to assess stress reactions associated with wind turbine noise (WTN) exposure using self-reported and objective measures. Randomly selected participants, aged 18-79 yr (606 males; 632 females), living between 0.25 and 11.22 km from wind turbines, were exposed to outdoor calculated WTN levels up to 46 dBA (response rate 78.9%). Multiple regression modeling left the great majority (77%-89%) of the variance in perceived stress scale (PSS) scores, hair cortisol concentrations, resting blood pressure, and heart rate unaccounted for, and WTN exposure had no apparent influence on any of these endpoints. PSS scores were positively, but weakly, related to cortisol concentrations and resting heart rate (Pearson r = 0.13 and r = 0.08, respectively). Across WTN categories, modeled mean PSS scores ranged from 13.15 to 13.84 (p = 0.8614). Modeled geometric means for hair cortisol concentrations, resting mean systolic, diastolic blood pressure, and heart rate were 150.54-191.12 ng/g (p = 0.5416), 113.38-116.82 mmHg (p = 0.4990), 67.98-70.34 mmHg (p = 0.5006), and 68.24-70.71 bpm (p = 0.5223), respectively. Irrespective of WTN levels, diastolic blood pressure appeared to be slightly (2.90 mmHg 95% CI: 0.75,5.05) higher among participants highly annoyed by blinking lights on turbines (p = 0.0081). Collectively, the findings do not support an association between exposure to WTN up to 46 dBA and elevated self-reported and objectively defined measures of stress.

  10. Measuring Moisture Levels in Graphite Epoxy Composite Sandwich Structures

    Nurge, Mark; Youngquist, Robert; Starr, Stanley


    Graphite epoxy composite (GEC) materials are used in the construction of rocket fairings, nose cones, interstage adapters, and heat shields due to their high strength and light weight. However, they absorb moisture depending on the environmental conditions they are exposed to prior to launch. Too much moisture absorption can become a problem when temperature and pressure changes experienced during launch cause the water to vaporize. The rapid state change of the water can result in structural failure of the material. In addition, heat and moisture combine to weaken GEC structures. Diffusion models that predict the total accumulated moisture content based on the environmental conditions are one accepted method of determining if the material strength has been reduced to an unacceptable level. However, there currently doesn t exist any field measurement technique to estimate the actual moisture content of a composite structure. A multi-layer diffusion model was constructed with Mathematica to predict moisture absorption and desorption from the GEC sandwich structure. This model is used in conjunction with relative humidity/temperature sensors both on the inside and outside of the material to determine the moisture levels in the structure. Because the core materials have much higher diffusivity than the face sheets, a single relative humidity measurement will accurately reflect the moisture levels in the core. When combined with an external relative humidity measurement, the model can be used to determine the moisture levels in the face sheets. Since diffusion is temperaturedependent, the temperature measurements are used to determine the diffusivity of the face sheets for the model computations.

  11. DLTS measurement of energetic levels, generated in silicon detectors

    Bosetti, M. [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Croitoru, N. [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Furetta, C. [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Leroy, C. [Universite de Montreal, Montreal, PQ H3C 3J7 (Canada); Pensotti, S. [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Rancoita, P.G. [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Rattaggi, M. [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Redaelli, M. [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Rizzatti, M. [Istituto Nazionale di Fisica Nucleare, Milan (Italy); Seidman, A. [Istituto Nazionale di Fisica Nucleare, Milan (Italy)


    DLTS (deep level transient spectroscopy) measurements were performed on irradiated Si detectors to record data on the energetic levels traps generated by neutrons. For moderate fluences ({phi}) of neutrons ({phi}<10{sup 12} n cm{sup -2}) electron and hole trap levels have been detected. Four electron trap levels were found for both FZ (float zone) and MCZ (magnetic Czochralsky) types of Si detectors but only two hole trap levels in FZ and one in MCZ detectors. This indicates that the type of silicon has an influence on the traps generated by irradiation. From the values obtained for the relative concentration of E1 centers in MCZ and FZ detectors, it results that the E1 centers are oxygen and not vacancy limited. Since the concentration of the E2, E3, and E4 levels are larger in FZ than in MCZ detectors, it may be assumed that the ``gettering effect`` can control the formation of deeper traps. Filling pulses were applied for various voltages and at the flat band filling voltage, maximum ratio of N{sub t}/N of the E1 center was achieved. This may indicate that the concentration of E1 centers, near the p{sup +}-n interface, can be larger than in the rest of the junction. (orig.).

  12. A Pilot Study on Measuring Customer’s Satisfaction Level

    Vide Boltez


    Full Text Available RQ: Determine the level of customer satisfaction of a company’s products and services to obtain information on needed improvements.Purpose: The purpose of measuring customer’s satisfaction level is to obtain information directly from the final buyer that bought our product. The next step is to analyze the information obtained and to take the results into consideration to improve the working process in production and in other departments of the company.Method: The method used for the pilot study to measure customer satisfaction was a short questionnaire that was given to 10 customers of our product and 10 completed questionnaires were obtained.Results: The results showed the level of satisfaction of final buyers of roof tiles and roofs that the company has achieved through their products and services. The results facilitate the production, logistics, purchasing and sales department to obtain information on positive satisfaction levels and areas that need change. At the same time, the final buyer was identified (i.e., name, surname, address, and so forth, which up until now had not been.Organization: The organization will save time and money in the future, because it will continuously measure customer satisfaction to improve production and other departments in the organization towards creating satisfied customers.Society: Final buyers of roofs are, and will be, more satisfied with their decisions, because the organization carries out after-sales satisfaction levels.Originality: The research was original, because up to this date the organization has not conducted research in such a manner.Limitations: The pilot study used 10 completed questionnaires that represent a very small sample to make any generalizations.

  13. Physical Activity, Energy Expenditure, Nutritional Habits, Quality of Sleep and Stress Levels in Shift-Working Health Care Personnel

    Vogt, Lena Johanna; Gärtner, Simone; Hannich, Hans Joachim; Steveling, Antje; Lerch, Markus M.


    Background Among health care personnel working regular hours or rotating shifts can affect parameters of general health and nutrition. We have investigated physical activity, sleep quality, metabolic activity and stress levels in health care workers from both groups. Methods We prospectively recruited 46 volunteer participants from the workforce of a University Medical Department of which 23 worked in rotating shifts (all nursing) and 21 non-shift regular hours (10 nursing, 13 clerical staff). All were investigated over 7 days by multisensory accelerometer (SenseWear Bodymedia® armband) and kept a detailed food diary. Physical activity and resting energy expenditure (REE) were measured in metabolic equivalents of task (METs). Quality of sleep was assessed as Pittsburgh Sleeping Quality Index and stress load using the Trier Inventory for Chronic Stress questionnaire (TICS). Results No significant differences were found for overall physical activity, steps per minute, time of exceeding the 3 METs level or sleep quality. A significant difference for physical activity during working hours was found between shift-workers vs. non-shift-workers (ppersonnel (median = 1.5 METs SE = 0.07, p<0.05). Non-shift-working nurses had a significantly lower REE than the other groups (p<0.05). The proportion of fat in the diet was significantly higher (p<0.05) in the office worker group (median = 42% SE = 1.2) whereas shift-working nurses consumed significantly more carbohydrates (median = 46% SE = 1.4) than clerical staff (median = 41% SE = 1.7). Stress assessment by TICS confirmed a significantly higher level of social overload in the shift working group (p<0.05). Conclusion In this prospective cohort study shift-working had no influence on overall physical activity. Lower physical activity during working hours appears to be compensated for during off-hours. Differences in nutritional habits and stress load warrant larger scale trials to determine the effect on implicit health

  14. Reduced levels of SCD1 accentuate palmitate-induced stress in insulin-producing β-cells

    Hovsepyan Meri


    Full Text Available Abstract Background Stearoyl-CoA desaturase 1 (SCD1 is an ER resident enzyme introducing a double-bond in saturated fatty acids. Global knockout of SCD1 in mouse increases fatty acid oxidation and insulin sensitivity which makes the animal resistant to diet-induced obesity. Inhibition of SCD1 has therefore been proposed as a potential therapy of the metabolic syndrome. Much of the work has focused on insulin target tissue and very little is known about how reduced levels of SCD1 would affect the insulin-producing β-cell, however. The aim of the present study was therefore to investigate how reduced levels of SCD1 affect the β-cell. Results Insulin-secreting MIN6 cells with reduced levels of SCD1 were established by siRNA mediated knockdown. When fatty acid oxidation was measured, no difference between cells with reduced levels of SCD1 and mock-transfected cells were found. Also, reducing levels of SCD1 did not affect insulin secretion in response to glucose. To investigate how SCD1 knockdown affected cellular mechanisms, differentially regulated proteins were identified by a proteomic approach. Cells with reduced levels of SCD1 had higher levels of ER chaperones and components of the proteasome. The higher amounts did not protect the β-cell from palmitate-induced ER stress and apoptosis. Instead, rise in levels of p-eIF2α and CHOP after palmitate exposure was 2-fold higher in cells with reduced levels of SCD1 compared to mock-transfected cells. Accordingly, apoptosis rose to higher levels after exposure to palmitate in cells with reduced levels of SCD1 compared to mock-transfected cells. Conclusions In conclusion, reduced levels of SCD1 augment palmitate-induced ER stress and apoptosis in the β-cell, which is an important caveat when considering targeting this enzyme as a treatment of the metabolic syndrome.

  15. Hair Measurements of Cortisol, DHEA, and DHEA to Cortisol Ratio as Biomarkers of Chronic Stress among People Living with HIV in China: Known-Group Validation

    Li, Xiaoming; Zilioli, Samuele; Chen, Zheng; Deng, Huihua; Pan, Juxian


    Background Existing literature suggests that endocrine measures, including the steroid hormones of cortisol and Dehydroepiandrosterone (DHEA), as well as the DHEA to cortisol ratio in the human hair can be used as promising biomarkers of chronic stress among humans. However, data are limited regarding the validity of these measures as biomarkers of chronic stress among people living with HIV (PLWH), whose endocrine system or hypothalamic pituitary adrenal (HPA) axis may be affected by HIV infection and/or antiretroviral therapy (ART) medications. Method Using hair sample data and self-reported survey from 60 PLWH in China, we examined the validity of three endocrine measures among Chinese PLWH using a known-groups validation strategy. High-stress group (n = 30) and low-stress group (n = 30) of PLWH were recruited through individual assessment interviews by a local licensed psychologist. The endocrine measures in hair were extracted and assessed by LC-APCI-MS/MS method. Both bivariate and multivariate analyses were conducted to examine the associations between the endocrine measures and the stress level, and to investigate if the associations differ by ART status. Results The levels of endocrine measures among Chinese PLWH were consistent with existing studies among PLWH. Generally, this pilot study confirmed the association between endocrine measures and chronic stress. The high stress group showed higher level hair cortisol and lower DHEA to cortisol ratio. The higher stress group also reported higher scores of stressful life events, perceived stress, anxiety and depression. Hair cortisol level was positively related to anxiety; DHEA was negatively associated with stressful life events; and the DHEA to cortisol ratio was positively related to stressful life events and perceived stress. ART did not affect the associations between the endocrine measures and stress level. Conclusions Our findings suggest that hair cortisol and DHEA to cortisol ratio can be used as

  16. Assessment of plasma B7-H3 levels in pediatric patients with different degrees of surgical stress.

    Li, Yan; Yuan, Qing; Huang, Jie; Li, Yi Ping; Pan, Jian; Feng, Xing; Zhang, Xue Guang; Wang, Jiang Huai; Wang, Jian


    Surgical stress initiates a series of host hormone, metabolism and immune responses, which predominantly affect the homeostatic mechanism of patients with major surgery. B7-H3 is a co-stimulatory molecule and has been shown to participate in both adaptive and innate immune responses. In this study we evaluated the clinical significance of plasma B7-H3 levels in pediatric patients with different types of operation and degrees of surgical stress. A total of 48 children received pediatric general and cardiac surgery were recruited into this study. Based on the surgical stress scoring, children were divided into moderate stress (n = 14) and severe stress (n = 34) groups. Plasma B7-H3 levels were assessed at selected time points: before surgery, immediately after surgery, at day 1, day 3, and day 7 after surgery. Correlations between plasma B7-H3 levels and surgical stress scores were also examined. Plasma B7-H3 levels were significantly decreased in all 48 pediatric patients after surgery compared to the B7-H3 level before surgery (p stress group, but not in the moderate stress group, immediately after surgery and at day 3 after surgery (p stress group had significantly lower plasma B7-H3 levels than moderate stress group at day 1, day 3, and day 7 after surgery (p levels at day 1 (p = 0.01) and day 3 (p = 0.025) after surgery correlated negatively with surgical stress scores. Plasma B7-H3 levels were decreased significantly in children subjected to pediatric general and cardiac surgery, which is closely associated with the severity of surgical stress. The negative correlation of plasma B7-H3 levels at day 1 and day 3 after surgery with surgical stress scoring implicates that the plasma B7-H3 level might be a useful biomarker for monitoring stress intensity during pediatric surgery.




    Full Text Available Pricing models for social efficiency focuses on assessing the quality, namely the comparison of the desired product to the consumer and the product received, the level of consumer satisfaction on the products and / or services will be therefore a very important component in measuring the effectiveness social. Between the two concepts there is a relationship of mutual interdependence: the level of consumer satisfaction is the result of the quality performance of products and services and high quality products and services is reflected in consumer satisfaction. From the theoretical point of view, according to the marketing strategy, it is necessary to bring to a common level of perceived benefit to consumer expectations. Customer satisfaction is actually the result of a complex information processing.

  18. Early Childhood Inservice and Preservice Teachers' Perceived Levels of Preparedness to Handle Stress in Their Students

    Onchwari, Jacqueline


    This article reports a study that investigated preservice and inservice early childhood teachers' perceived levels of preparedness to handle stress in early childhood and elementary education students. A survey that included vignettes was used to collect data. Data were analyzed both qualitatively and statistically, using one-way ANOVA, "t"-test,…

  19. Genetic interactions for heat stress and production level: predicting foreign from domestic data

    Genetic by environmental interactions were estimated from U.S. national data by separately adding random regressions for heat stress (HS) and herd production level (HL) to the all-breed animal model to improve predictions of future records and rankings in other climate and production situations. Yie...

  20. Acceptance of Dog Guides and Daily Stress Levels of Dog Guide Users and Nonusers

    Matsunaka, Kumiko; Koda, Naoko


    The degree of acceptance of dog guides at public facilities, which is required by law in Japan, was investigated, and evidence of rejection was found. Japanese people with visual impairments who used dog guides reported higher daily stress levels than did those who did not use dog guides. (Contains 3 tables and 1 figure.)

  1. Levels of Stress among Secondary School Administrators and Its Implication in Education Management in Kenya

    Ngari, S. M.; Ndungu, A.; Mwonya, R.; Ngumi, O.; Mumiukha, C.; Chepchieng, M.; Kariuki, M.


    Stress significantly affects performance and service delivery of workers. Given the important role that education plays in the society, coupled with the dynamic nature of the education sector there has been an increased social pressure on the education system in general and school administrators in particular. This influences their levels of…

  2. Acceptance of Dog Guides and Daily Stress Levels of Dog Guide Users and Nonusers

    Matsunaka, Kumiko; Koda, Naoko


    The degree of acceptance of dog guides at public facilities, which is required by law in Japan, was investigated, and evidence of rejection was found. Japanese people with visual impairments who used dog guides reported higher daily stress levels than did those who did not use dog guides. (Contains 3 tables and 1 figure.)

  3. The hippocampal response to psychosocial stress varies with salivary uric acid level.

    Goodman, Adam M; Wheelock, Muriah D; Harnett, Nathaniel G; Mrug, Sylvie; Granger, Douglas A; Knight, David C


    Uric acid is a naturally occurring, endogenous compound that impacts mental health. In particular, uric acid levels are associated with emotion-related psychopathology (e.g., anxiety and depression). Therefore, understanding uric acid's impact on the brain would provide valuable new knowledge regarding neural mechanisms that mediate the relationship between uric acid and mental health. Brain regions including the prefrontal cortex, amygdala, and hippocampus underlie stress reactivity and emotion regulation. Thus, uric acid may impact emotion by modifying the function of these brain regions. The present study used functional magnetic resonance imaging (fMRI) during a psychosocial stress task to investigate the relationship between baseline uric acid levels (in saliva) and brain function. Results demonstrate that activity within the bilateral hippocampal complex varied with uric acid concentrations. Specifically, activity within the hippocampus and surrounding cortex increased as a function of uric acid level. The current findings suggest that uric acid levels modulate stress-related hippocampal activity. Given that the hippocampus has been implicated in emotion regulation during psychosocial stress, the present findings offer a potential mechanism by which uric acid impacts mental health. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Levels of Stress among Secondary School Administrators and Its Implication in Education Management in Kenya

    Ngari, S. M.; Ndungu, A.; Mwonya, R.; Ngumi, O.; Mumiukha, C.; Chepchieng, M.; Kariuki, M.


    Stress significantly affects performance and service delivery of workers. Given the important role that education plays in the society, coupled with the dynamic nature of the education sector there has been an increased social pressure on the education system in general and school administrators in particular. This influences their levels of…

  5. Changes in homocysteine levels during normal pregnancy and preeclampsia and its relation with oxidative stress

    Shilpa A. V.


    Conclusions: The increased homocysteine levels in preeclampsia results in endothelial dysfunction and vasospasm. Also oxidative stress plays an important role in the pathogenesis of preeclampsia. Thus identifying the risk factors and aggressive management may prove to be beneficial in these women.

  6. Wind and Wind Stress Measurements in HiRes


    Sonic anemometers for three-dimensional mean and turbulent winds 2. Cup and vane anemometers for mean winds 3. Candidate propeller-vane anemometer to...2 – Paroscientific Barameter, Campbell Sonic Anemometer ; Level 3- 2x Met One Cup , Met One Vane, RM Young Propeller; Level 4 – 2x Met One Cup ; Level...5 – 2x Paroscientific Barometer; Level 6 – Campbell Sonic Anemometer , Modified Krypton Hygrometer, Met One Cup , Met One Vane; Level 7 – 2x RM Young

  7. Perceived stress, recurrent pain, and aggregate salivary cortisol measures in mid-adolescent girls and boys.

    Lindfors, Petra; Folkesson Hellstadius, Lisa; Östberg, Viveca


    Measures of perceived stress have been criticized for theoretical inconsistency. However, the validated pressure activation stress scale has been suggested as a theoretically sound alternative. But it is unclear how pressure and activation stress relate to objective and subjective measures including commonly used aggregate cortisol measures and health complaints respectively. Specifically, this study aimed at investigating how pressure and activation stress were related to aggregate salivary cortisol measures and recurrent pain in mid-adolescent girls and boys. Mid-adolescents (119 girls and 56 boys) provided self-reports in questionnaires on activation and pressure stress and recurrent pain (headache, stomach ache, neck/shoulder and back pain). Additionally, adolescents sampled saliva during an ordinary school day: (1) immediately at awakening; (2) 30 minutes after waking up; (3) 60 minutes after waking up, and (4) at 8 p.m. These samples were analyzed for cortisol. Hierarchical regressions showed no statistically significant associations between activation and pressure stress and cortisol, neither for girls nor for boys. However, activation and pressure stress were significantly associated with recurrent pain but only for girls. The findings may relate to subjective and objective measures reflecting distinct aspects of stress-related functioning. However, the study participants included mid-adolescents whose bodily systems are flexible and still relatively unaffected by the strain of their daily stress perceptions. To conclude, the non-significant relationships between activation and pressure stress and commonly used aggregate measures of cortisol adds to the understanding of how perceived stress may relate to physiological functioning in the daily life of adolescents when using such aggregate measures.

  8. Laser triangulation measurement of the level in a coal silo

    Sun Jiping; Jiang Jing


    Laser triangulation theory was used to develop a novel contact-free method for measuring the coal level in a silo under harsh environmental conditions found in coal mines,such as the presence of dense dust,high humidity,and low illumination.A laser source and a camera were mounted at the top of the silo.The laser spot projected into the silo was imaged by the camera.The pinhole imaging principle allows the level to be found from the lateral shift of the spot image on the sensor.A pre-calibrated look-up table of the coal depth versus spot position was used to obtain the depth.The measurement accuracy depends on the step size used during pre-calibration.The actual application of a device designed according to these principles shows that it is easy to implement.The detection of the coal level in a silo at the low illumination level found in coal mines is demonstrated.

  9. Population-Level Quality Measures for Behavioral Screening and Intervention.

    Brown, Richard L; Smith, Mindy A


    Delivered routinely in general health care settings, smoking, alcohol, depression, and obesity screening and intervention (behavioral screening and intervention [BSI]) could substantially improve population health and reduce health care costs. Yet BSI is seldom delivered in an evidence-based manner. This article assesses the adequacy of quality measures for BSI. Online searches of the National Quality Forum's Quality Positioning System and the National Clearinghouse for Quality Measures databases were conducted using the keywords smoking, tobacco, alcohol, depression, and obesity The types and focuses of each measure were classified, and differences between the metrics and evidence-based practice were identified. Most measures indicate whether BSI components are delivered, not how well. Clinicians can perform well on most metrics without delivering evidence-based services. More rigorous quality measures are needed. A new kind of measure is proposed, whereby separate terms representing the reach and effectiveness of key BSI components are multiplied to produce a single indicator of population-level impact for each behavioral topic.

  10. Propagation of Nonlinear Waves in Waveguides and Application to Nondestructive Stress Measurement

    Nucera, Claudio

    Propagation of nonlinear waves in waveguides is a field that has received an ever increasing interest in the last few decades. Nonlinear guided waves are excellent candidates for interrogating long waveguide like structures because they combine high sensitivity to structural conditions, typical of nonlinear parameters, with large inspection ranges, characteristic of wave propagation in bounded media. The primary topic of this dissertation is the analysis of ultrasonic waves, including ultrasonic guided waves, propagating in their nonlinear regime and their application to structural health monitoring problems, particularly the measurement of thermal stress in Continuous Welded Rail (CWR). Following an overview of basic physical principles generating nonlinearities in ultrasonic wave propagation, the case of higher-harmonic generation in multi-mode and dispersive guided waves is examined in more detail. A numerical framework is developed in order to predict favorable higher-order generation conditions (i.e. specific guided modes and frequencies) for waveguides of arbitrary cross-sections. This model is applied to various benchmark cases of complex structures. The nonlinear wave propagation model is then applied to the case of a constrained railroad track (CWR) subjected to thermal variations. This study is a direct response to the key need within the railroad transportation community to develop a technique able to measure thermal stresses in CWR, or determine the rail temperature corresponding to a null thermal stress (Neutral Temperature -- NT). The numerical simulation phase concludes with a numerical study performed using ABAQUS commercial finite element package. These analyses were crucial in predicting the evolution of the nonlinear parameter beta with thermal stress level acting in the rail. A novel physical model, based on interatomic potential, was developed to explain the origin of nonlinear wave propagation under constrained thermal expansion. In fact

  11. Remarks on residual stress measurement by hole-drilling and electronic speckle pattern interferometry.

    Barile, Claudia; Casavola, Caterina; Pappalettera, Giovanni; Pappalettere, Carmine


    Hole drilling is the most widespread method for measuring residual stress. It is based on the principle that drilling a hole in the material causes a local stress relaxation; the initial residual stress can be calculated by measuring strain in correspondence with each drill depth. Recently optical techniques were introduced to measure strain; in this case, the accuracy of the final results depends, among other factors, on the proper choice of the area of analysis. Deformations are in fact analyzed within an annulus determined by two parameters: the internal and the external radius. In this paper, the influence of the choice of the area of analysis was analysed. A known stress field was introduced on a Ti grade 5 sample and then the stress was measured in correspondence with different values of the internal and the external radius of analysis; results were finally compared with the expected theoretical value.

  12. The Relationship of Disordered Eating Attitudes with Stress Level, Bone Turnover Markers, and Bone Mineral Density in Obese Adolescents.

    Okbay Güneş, Aslı; Alikaşifoğlu, Müjgan; Şen Demirdöğen, Ezgi; Erginöz, Ethem; Demir, Türkay; Kucur, Mine; Ercan, Oya


    To investigate the effect of stress caused by disordered eating attitudes on bone health in obese adolescents. A cross-sectional study comprising 80 obese adolescents was performed from November 2013 to September 2014. Twenty-four-hour urinary free cortisol levels were measured as a biological marker of stress. Bone turnover was evaluated using bone-specific alkaline phosphatase, serum osteocalcin, and urinary N-telopeptide concentrations. Bone mineral density was measured using dual-energy X-ray absorptiometry. The Eating Disorder Examination Questionnaire, Dutch Eating Behavior Questionnaire, Children's Depression Inventory, and the State-Trait Anxiety Inventory for Children were used to assess eating disorders, depression, and anxiety. Psychiatric examinations were performed for binge eating disorders. In the Pearson's correlation test, a positive correlation was found between the 24-hour urinary cortisol level and Dutch Eating Behavior Questionnaire total and restrained eating subscale scores (pturnover and bone mineral density in our obese adolescents at the time of the study, our results suggest that disordered eating attitudes, and especially restrained eating attitudes, might be a source of stress. Therefore, studies in this area should continue.

  13. Mechanical Behavior of Methane Infiltrated Coal: the Roles of Gas Desorption, Stress Level and Loading Rate

    Wang, Shugang; Elsworth, Derek; Liu, Jishan


    We report laboratory experiments to investigate the role of gas desorption, stress level and loading rate on the mechanical behavior of methane infiltrated coal. Two suites of experiments are carried out. The first suite of experiments is conducted on coal (Lower Kittanning seam, West Virginia) at a confining stress of 2 MPa and methane pore pressures in the fracture of 1 MPa to examine the role of gas desorption. These include three undrained (hydraulically closed) experiments with different pore pressure distributions in the coal, namely, overpressured, normally pressured and underpressured, and one specimen under drained condition. Based on the experimental results, we find quantitative evidence that gas desorption weakens coal through two mechanisms: (1) reducing effective stress controlled by the ratio of gas desorption rate over the drainage rate, and (2) crushing coal due to the internal gas energy release controlled by gas composition, pressure and content. The second suite of experiments is conducted on coal (Upper B seam, Colorado) at confining stresses of 2 and 4 MPa, with pore pressures of 1 and 3 MPa, under underpressured and drained condition with three different loading rates to study the role of stress level and loading rate. We find that the Biot coefficient of coal specimens is coal. This study has important implications for the stability of underground coal seams.

  14. Evaluation of Stress Intensity and Anxiety Level in Preoperative Period of Cardiac Patients.

    Rosiek, Anna; Kornatowski, Tomasz; Rosiek-Kryszewska, Aleksandra; Leksowski, Łukasz; Leksowski, Krzysztof


    The stress related to patient's stay in a hospital increases when it is necessary to perform a surgery. Therefore, the study of the phenomenon of stress intensity in hospitalized patients has become an important issue for public health. The study was conducted in University Hospital No. 1 in the cardiosurgery clinic. The study involved 58 patients who were admitted as planned to the hospital. The study used a standardized questionnaire measuring intensity of the stress and also deepened interviews with patients about stress and anxiety felt before the surgery. The greater the patient's anxiety resulting from his state of health, the greater the intensity of stress in the preoperative period. This relationship is linear. The results of the study also made it possible to see intrapersonal factors (pain, illness, and suffering) and extrapersonal factors (anesthesia, surgery, and complications after surgery), which are causes of anxiety before surgery. The research showed high (negative) results of anxiety and stress associated with the disease, surgery, and complications after cardiac surgery. Active involvement in hospitalization elements, such as patient education before surgery, psychological support, and medical care organization taking into account patient's preferences, reduces the impact of stressors.

  15. Caregivers' Cortisol Levels and Perceived Stress in Home-Based and Center-Based Childcare

    Groeneveld, Marleen G.; Vermeer, Harriet J.; van IJzendoorn, Marinus H.; Linting, Marielle


    The current study examined professional caregivers' perceived and physiological stress, and associations with the quality of care they provide. Participants were 55 female caregivers from childcare homes and 46 female caregivers from childcare centers in the Netherlands. In both types of settings, equivalent measures and procedures were used. On…

  16. Caregivers' Cortisol Levels and Perceived Stress in Home-Based and Center-Based Childcare

    Groeneveld, Marleen G.; Vermeer, Harriet J.; van IJzendoorn, Marinus H.; Linting, Marielle


    The current study examined professional caregivers' perceived and physiological stress, and associations with the quality of care they provide. Participants were 55 female caregivers from childcare homes and 46 female caregivers from childcare centers in the Netherlands. In both types of settings, equivalent measures and procedures were used. On…

  17. Methods of Measuring Stress Relaxation in Composite Tape Springs


    additional analysis done in SOLIDWORKS . For the first method of analysis, PolyWorks is used to cut out the unnecessary portions of the raw scan data. Then...each tape spring is exported as a ‘.stl’ file. This file is imported as a surface into a SOLIDWORKS part file. The SOLIDWORKS parts are combined into...analyzed using MATLAB, PolyWorks, and SOLIDWORKS . These data provide a greater insight into the stress relaxation of tape springs when deformed

  18. Stress in the wild: chronic predator pressure and acute restraint affect plasma DHEA and corticosterone levels in a songbird.

    Newman, A E M; Zanette, L Y; Clinchy, M; Goodenough, N; Soma, K K


    The effects of chronic stressors on glucocorticoid levels are well described in laboratory rodents, but far less is known about the effects of chronic stressors on wild animals or on dehydroepiandrosterone (DHEA) levels. DHEA can be produced by the adrenal cortex and has prominent antiglucocorticoid properties. Here, we examined wild songbirds to elucidate the relationship between chronic predator pressure and plasma DHEA and corticosterone levels. We measured circulating steroid levels at baseline and after acute restraint in the breeding and nonbreeding seasons. During the breeding season, males in low predator pressure (LPP) environments had higher baseline DHEA levels than males in high predator pressure (HPP) environments. Also, acute restraint decreased DHEA levels in LPP males only but increased corticosterone levels in HPP and LPP males similarly. During the nonbreeding season, DHEA and corticosterone levels were lower than during the breeding season, and acute restraint decreased DHEA levels in both HPP and LPP males. Unlike males, breeding females showed no effect of predator pressure on baseline DHEA or corticosterone levels. These data suggest that naturalistic chronic and acute stressors affect circulating DHEA and corticosterone levels in wild animals and highlight the importance of using multiple endpoints when studying the physiological effects of chronic stress.

  19. Acute melatonin and para-chloroamphetamine interactions on pineal, brain and serum serotonin levels as well as stress hormone levels.

    Manzana, E J; Chen, W J; Champney, T H


    para-Chloroamphetamine, an amphetamine analog, alters serotonergic neurochemistry. In previous reports, melatonin (MEL), when administered with other amphetamine analogs, altered the decline in serotonin content produced by these analogs. The present studies assessed the effects of various doses of melatonin and p-chloroamphetamine on serotonin levels in numerous brain regions in male rats. Melatonin (10, 25 or 50 mg/kg, s.c.) and p-chloroamphetamine (3 or 5 mg/kg, s.c.) were administered and, 3 h later, brain samples and serum were collected. Serotonin levels in the serum and various regions of the brain were assayed using high-performance liquid chromatography. Melatonin in combination with a high dose of p-chloroamphetamine (5 mg/kg) produced cumulative deficits in serotonin levels in the serum. However, serotonin levels in the pineal, cortex or brain stem in all combined melatonin and p-chloroamphetamine groups were not significantly different from groups that received p-chloroamphetamine alone. Serum adrenocorticotropin (ACTH) and corticosterone levels were significantly elevated in the melatonin and p-chloroamphetamine combined groups, suggesting that animals receiving both treatments were more stressed than control animals or animals receiving melatonin or p-chloroamphetamine alone. These results indicate that melatonin does not alter p-chloroamphetamine-induced deficits in central serotonin levels. The increased serum adrenocorticotropic hormone, corticosterone and serotonin levels observed following melatonin and p-chloroamphetamine treatment suggest that this combination may have adverse peripheral effects.

  20. Degree of conversion and contraction stress development of a resin composite irradiated using halogen and LED at two C-factor levels.

    Cunha, Leonardo Gonçalves; Alonso, Roberta Caroline Bruschi; Neves, Ana Christina Claro; de Goes, Mario Fernando; Ferracane, Jack Liborio; Sinhoreti, Mário Alexandre Coelho


    This study verified the influence of curing methods and light sources on contraction stress, stress rate and degree of conversion (DC) of a restorative composite at two C-factor (CF) levels. For the stress test, composite (0.84 mm thick) was applied between two glass rods 5-mm in diameter mounted in a servohydraulic testing machine. Stress rates were calculated as the change in stress vs time at each second. DC was measured by micro-FTIR. Five curing methods were tested at two C-factor levels (1.5 and 3.0): High Intensity LED (LED HI), Continuous Light (QTH CL), Medium Intensity LED (LED MI), Low Intensity LED (LED LI) and Pulse Delay (QTH PD). The results were analyzed by ANOVA and Tukey's test (alpha = 0.05). For the stress test at CF 1.5, QTH PD presented lower values than LED HI, QTH CL and LED LI. At CF 3.0, no difference was observed among the curing methods. For all curing methods, stress values at CF 3.0 were statistically higher than those at CF 1.5. LED HI presented the highest maximum stress rate, followed by QTH CL, LED MI, LED LI and QTH PD for both C-factors. In the DC test, no difference was observed among the methods and between the C-factor levels.

  1. Workshop on industrial application of neutron diffraction. Stress measurement by neutron diffraction

    Minakawa, N; Morii, Y; Oyama, Y


    This workshop was planned to make use of the neutron from the reactor and the pulse neutron source JSNS for the industrial world. Especially, this workshop focused on the stress measurement by the neutron diffraction and it was held on the Tokai JAERI from October 15 to 16, 2001. The participant total was 93 and 40 participated from the industrial world. The introduction of the residual stress development of measurement technique by the neutron diffraction method and a research of the measurement of the residual stress such as the nuclear reactor material, the ordinary structure material, the composite material, the quenching steel, the high strength material were presented and discussed in this workshop. Moreover, it was introduced for the industrial world that an internal stress measurement is important for development of new product or an improvement of a manufacturing process. The question from the industrial world about which can be measured the product form, the size, the measurement precision, the reso...

  2. Neonatal Intensive Care and Child Psychiatry Inpatient Care: Do Different Working Conditions Influence Stress Levels?

    Evalotte Mörelius


    Full Text Available Introduction. Nurses often experience work-related stress. High stress can negatively affect job satisfaction and lead to emotional exhaustion with risk of burnout. Aim. To analyse possible differences in biological stress markers, psychosocial working conditions, health, and well-being between nurses working in two different departments. Methods. Stress was evaluated in nurses working in a neonatal intensive care unit (NICU (n=33 and nurses working in a child and adolescent psychiatry inpatient ward (CAP (n=14 using salivary cortisol and HbA1c. Salivary cortisol was measured three times a day on two consecutive days during two one-week periods, seven weeks apart (= 12 samples/person. Psychosocial working conditions, health, and well-being were measured once. Results. NICU nurses had better social support and more self-determination. CAP nurses had a lower salivary cortisol quotient, poorer general health, and higher client-related burnout scores. Conclusion. When comparing these nurses with existing norm data for Sweden, as a group their scores reflect less work-related stress than Swedes overall. However, the comparison between NICU and CAP nurses indicates a less healthy work situation for CAP nurses. Relevance to Clinical Practice. Healthcare managers need to acknowledge the less healthy work situation CAP nurses experience in order to provide optimal support and promote good health.




    Groundwater contaminated with hexavalent chromium, strontium-90, and uranium discharges into the Columbia River along approximately 16 km (10 mi) of the shoreline. Various treatment systems have and will continue to be implemented to eliminate the impact of Hanford Site contamination to the river. To optimize the various remediation strategies, it is important to understand interactions between groundwater and the surface water of the Columbia River. An automated system to record water levels in aquifer sampling tubes installed in the hyporheic zone was designed and tested to (1) gain a more complete understanding of groundwater/river water interactions based on gaining and losing conditions ofthe Columbia River, (2) record and interpret data for consistent and defensible groundwater/surface water conceptual models that may be used to better predict subsurface contaminant fate and transport, and (3) evaluate the hydrodynamic influence of extraction wells in an expanded pump-and-treat system to optimize the treatment system. A system to measure water levels in small-diameter aquifer tubes was designed and tested in the laboratory and field. The system was configured to allow manual measurements to periodically calibrate the instrument and to permit aquifer tube sampling without removing the transducer tube. Manual measurements were collected with an e-tape designed and fabricated especially for this test. Results indicate that the transducer system accurately records groundwater levels in aquifer tubes. These data are being used to refine the conceptual and numeric models to better understand interactions in the hyporheic zone of the Columbia River and the adjacent river water and groundwater, and changes in hydrochemistry relative to groundwater flux as river water recharges the aquifer and then drains back out in response to changes in the river level.

  4. Image-based Water Level Measurement Method under Stained Ruler

    Jae-do KIM; Young-joon HAN; Hern-soo HAHN


    This paper proposes the water level measuring method based on the image,while the ruler used to indicate the water level is stained.The contamination of the ruler weakens or eliminates many features which are required for the image processing.However,the feature of the color difference between the ruler and the water surface are firmer on the environmental change compare to the other features.As the color differences are embossed,only the region of the ruler is limited to eliminate the noise,and the average image is produced by using several continuous frames.A histogram is then produced based on the height axis of the produced intensity average image.Local peaks and local valleys are detected,and the section between the peak and valley which have the greatest change is looked for.The valley point at this very moment is used to detect the water level.The detected water level is then converted to the actual water level by using the mapping table.The proposed method is compared to the ultrasonic based method to evaluate its accuracy and efficiency on the various contaminated environments.

  5. Relationship between coping ways with stress and levels of IL-1β and cortisol in coronary heart disease patients

    Alireza Agha Yousefi


    Full Text Available Background and Aim: Coping ways with stress in coronary heart disease patients can lead to significant changes in the levels of biomarkers IL- 1 β and cortisol. Thus, the aim of the present study was to examine the relationship between coping ways with stress and level of IL- 1 β and cortisol in coronary heart disease patients.   Materials and Methods: The statistical population covered all patients with CHD who referred to Tehran Shahid Rajaie Heart Hospital. 44 patients with CHD admitted to different wards of the hospital were selected as eligible cases.In the present, Lazarus and Folkman questionnaires and Human IL- 1 β kits manufactured by Austrian Bender Med System Manufacturing Co and cortisol kits ( made by IBL Manufacturing Co., Germany,employing ELISA method of measurement ,were used.   Results: It was found that there was a significant positive correlation between emotional focused coping ways with biomarkers IL - 1 β and cortisol .But, a significant negative correlation was observed between problem focused coping ways and biomarkers IL-1 β and cortisol .Moreover, between 8 ways of coping with stress only predictive positive re-evaluation had a significant relationship with IL-1 β and Cortisol.   Conclusion: An increase in the use of problem focused coping ways including positive re-evaluation way can reduce levels of IL- 1 β and cortisol.

  6. Measurement of Acceptable Noise Level with Background Music.

    Ahn, Hyun-Jung; Bahng, Junghwa; Lee, Jae Hee


    Acceptable noise level (ANL) is a measure of the maximum background noise level (BNL) that a person is willing to tolerate while following a target story. Although researchers have used various sources of target sound in ANL measures, a limited type of background noise has been used. Extending the previous study of Gordon-Hickey & Moore (2007), the current study determined the effect of music genre and tempo on ANLs as possible factors affecting ANLs. We also investigated the relationships between individual ANLs and the familiarity of music samples and between music ANLs and subjective preference. Forty-one participants were seperated into two groups according to their ANLs, 29 low-ANL listeners and 12 high-ANL listeners. Using Korean ANL material, the individual ANLs were measured based on the listeners' most comfortable listening level and BNL. The ANLs were measured in six conditions, with different music tempo (fast, slow) and genre (K-pop, pop, classical) in a counterbalanced order. Overall, ANLs did not differ by the tempo of background music, but music genre significantly affected individual ANLs. We observed relatively higher ANLs with K-pop music and relatively lower ANLs with classical music. This tendency was similar in both low-ANL and high-ANL groups. However, the subjective ratings of music familiarity and preference affected ANLs differently for low-ANL and high-ANL groups. In contrast to the low-ANL listeners, the ANLs of the high-ANL listeners were significantly affected by music familiarity and preference. The genre of background music affected ANLs obtained using background music. The degree of music familiarity and preference appears to be associated with individual susceptibility to background music only for listeners who are greatly annoyed by background noise (high-ANL listeners).

  7. Impact of Ramadan Intermittent Fasting on Oxidative Stress Measured by Urinary 15-F2t-Isoprostane

    Mo'ez Al-Islam Ezzat Faris


    fast Ramadan were recruited. Urine and serum sampling and anthropometric and dietary assessments were conducted one week before Ramadan (T0, at the end of the third week of Ramadan (T1, and one month after Ramadan (T2. Biochemical measurements included urinary 15FIP, creatinine, and hematological indices. Results revealed that the urinary level of 15FIP measured at T0 was normal, while they showed a significantly (P<0.05 higher level when measured at T1 concomitant with a significant (P<0.05 increase in the body weight and total body fat percent. In conclusion, results suggest that increased body weight is associated with increased lipid peroxidation and oxidative stress, and the impact of RIF on oxidative stress is mediated by the changes in body weight at the end of the month.

  8. Urinary oxidative stress biomarkers among local residents measured 6years after the Hebei Spirit oil spill.

    Kim, Jung-Ah; Noh, Su Ryeon; Cheong, Hae-Kwan; Ha, Mina; Eom, Sang-Yong; Kim, Heon; Park, Myung-Sook; Chu, Yeonhee; Lee, Seung-Hwa; Choi, Kyungho


    In December 2007, the Hebei Spirit oil spill occurred on the west coast of South Korea. Association between crude oil exposure and the levels of urinary oxidative stress biomarkers was reported among the local residents, 1.5years after the accident. The aim of this study was to follow-up possible longer-term effects of the oil spill among the residents near the oil spill. Six years after the accident, urinary oxidative stress biomarkers of the residents were associated with surrogates of oil exposure. The target subjects were divided into two groups based on the distance of their residence to the spill site, i.e., those near the spill site ('Near' group, n=476), and those far from the spill ('Far' group, n=152). A questionnaire was administered by trained interviewers or self-reporting, and demographic information and other parameters of the participants, such as socioeconomic status, smoking and drinking behaviors, disease history, and duration of clean-up activities after the spill, were collected. The participants' levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) in 12 h urine samples were measured as indicators of oxidative DNA damage and lipid peroxidation, respectively. A general linear model was used for statistical analysis. Urinary MDA and 8-OHdG levels measured from 'Near' group, i.e., geometric mean of 2.19μmol/g creatinine, and 5.41μg/g creatinine, respectively, were higher than those of 'Far' group. Especially, urinary 8-OHdG levels in the 'Near' group were significantly higher than those of 'Far' after adjusting relevant covariates. In addition, the duration of clean-up activities showed a significant association with both urinary 8-OHdG and MDA levels. Even 6years after the oil spill, positive associations between oxidative stress biomarkers and surrogates of oil exposure were evident. While the present study design lacks biomarkers of exposure, the results of this study suggest that the consequences of oil pollution may last

  9. Effects of Chronic Psychosocial Stress on Reduction of Basal Glucocorticoid Levels and Suppression of Glucocorticoid Levels Following Dexamethasone Administration in Animal Model of PTSD

    Ana Starcevic


    Conclusion: Significant changes in HPA activity, reductions in basal glucocorticoid levels and enhanced dexamethasone induced inhibition of glucocorticoid levels have been manifested. All of this is manifested in PTSD patients also as many other stress induces changes.

  10. Measuring stress before and during pregnancy: a review of population-based studies of obstetric outcomes.

    Witt, Whitney P; Litzelman, Kristin; Cheng, Erika R; Wakeel, Fathima; Barker, Emily S


    Mounting evidence from clinic and convenience samples suggests that stress is an important predictor of adverse obstetric outcomes. Using a proposed theoretical framework, this review identified and synthesized the population-based literature on the measurement of stress prior to and during pregnancy in relation to obstetric outcomes. Population-based, peer-reviewed empirical articles that examined stress prior to or during pregnancy in relation to obstetric outcomes were identified in the PubMed and PsycInfo databases. Articles were evaluated to determine the domain(s) of stress (environmental, psychological, and/or biological), period(s) of stress (preconception and/or pregnancy), and strength of the association between stress and obstetric outcomes. Thirteen studies were evaluated. The identified studies were all conducted in developed countries. The majority of studies examined stress only during pregnancy (n = 10); three examined stress during bo