WorldWideScience

Sample records for stress remained high

  1. Remaining life case history studies for high energy piping systems using equivalent stress

    International Nuclear Information System (INIS)

    Cohn, M.J.

    1987-01-01

    As the development of plant life extension for high energy piping systems is progressing, conventional piping system design methodologies are also being reevaluated. Traditional guidelines such as American National Standard Institute/American Society of Mechanical Engineers B31.1 (ANSI/ASME) were developed for plants having design lives in the 25- to 30-year regime based upon relatively short-term base metal creep data. These guidelines use a simplified approach for the piping analysis. Two types of stress criteria must be satisfied. The first type is longitudinal plus torsion stress checks for several types of loading conditions versus the material allowable stresses. The second type is an independent minimum wall thickness check which considers the hoop stress versus the material allowable stress. Seven case histories have been evaluated to estimate the minimum piping system creep life based on the current ANSI/ASME B31.1 finite element type of analysis, which is a traditional approach, versus a multiaxial stress state type of analysis. In nearly every case, the equivalent stress methodology predicted significantly higher stresses. Consequently, the equivalent stress methodology resulted in 11 to 96% lower time to rupture values as compared to the values predicted using ANSI/ASME B31.1 stresses

  2. Remaining life assessment of a high pressure turbine rotor

    International Nuclear Information System (INIS)

    Nguyen, Ninh; Little, Alfie

    2012-01-01

    This paper describes finite element and fracture mechanics based modelling work that provides a useful tool for evaluation of the remaining life of a high pressure (HP) steam turbine rotor that had experienced thermal fatigue cracking. An axis-symmetrical model of a HP rotor was constructed. Steam temperature, pressure and rotor speed data from start ups and shut downs were used for the thermal and stress analysis. Operating history and inspection records were used to benchmark the damage experienced by the rotor. Fracture mechanics crack growth analysis was carried out to evaluate the remaining life of the rotor under themal cyclic loading conditions. The work confirmed that the fracture mechanics approach in conjunction with finite element modelling provides a useful tool for assessing the remaining life of high temperature components in power plants.

  3. Highly efficient DNA extraction method from skeletal remains

    Directory of Open Access Journals (Sweden)

    Irena Zupanič Pajnič

    2011-03-01

    Full Text Available Background: This paper precisely describes the method of DNA extraction developed to acquire high quality DNA from the Second World War skeletal remains. The same method is also used for molecular genetic identification of unknown decomposed bodies in routine forensic casework where only bones and teeth are suitable for DNA typing. We analysed 109 bones and two teeth from WWII mass graves in Slovenia. Methods: We cleaned the bones and teeth, removed surface contaminants and ground the bones into powder, using liquid nitrogen . Prior to isolating the DNA in parallel using the BioRobot EZ1 (Qiagen, the powder was decalcified for three days. The nuclear DNA of the samples were quantified by real-time PCR method. We acquired autosomal genetic profiles and Y-chromosome haplotypes of the bones and teeth with PCR amplification of microsatellites, and mtDNA haplotypes 99. For the purpose of traceability in the event of contamination, we prepared elimination data bases including genetic profiles of the nuclear and mtDNA of all persons who have been in touch with the skeletal remains in any way. Results: We extracted up to 55 ng DNA/g of the teeth, up to 100 ng DNA/g of the femurs, up to 30 ng DNA/g of the tibias and up to 0.5 ng DNA/g of the humerus. The typing of autosomal and YSTR loci was successful in all of the teeth, in 98 % dekalof the femurs, and in 75 % to 81 % of the tibias and humerus. The typing of mtDNA was successful in all of the teeth, and in 96 % to 98 % of the bones. Conclusions: We managed to obtain nuclear DNA for successful STR typing from skeletal remains that were over 60 years old . The method of DNA extraction described here has proved to be highly efficient. We obtained 0.8 to 100 ng DNA/g of teeth or bones and complete genetic profiles of autosomal DNA, Y-STR haplotypes, and mtDNA haplotypes from only 0.5g bone and teeth samples.

  4. The aluminium content of infant formulas remains too high.

    Science.gov (United States)

    Chuchu, Nancy; Patel, Bhavini; Sebastian, Blaise; Exley, Christopher

    2013-10-08

    Recent research published in this journal highlighted the issue of the high content of aluminium in infant formulas. The expectation was that the findings would serve as a catalyst for manufacturers to address a significant problem of these, often necessary, components of infant nutrition. It is critically important that parents and other users have confidence in the safety of infant formulas and that they have reliable information to use in choosing a product with a lower content of aluminium. Herein, we have significantly extended the scope of the previous research and the aluminium content of 30 of the most widely available and often used infant formulas has been measured. Both ready-to-drink milks and milk powders were subjected to microwave digestion in the presence of 15.8 M HNO3 and 30% w/v H2O2 and the aluminium content of the digests was measured by TH GFAAS. Both ready-to-drink milks and milk powders were contaminated with aluminium. The concentration of aluminium across all milk products ranged from ca 100 to 430 μg/L. The concentration of aluminium in two soya-based milk products was 656 and 756 μg/L. The intake of aluminium from non-soya-based infant formulas varied from ca 100 to 300 μg per day. For soya-based milks it could be as high as 700 μg per day. All 30 infant formulas were contaminated with aluminium. There was no clear evidence that subsequent to the problem of aluminium being highlighted in a previous publication in this journal that contamination had been addressed and reduced. It is the opinion of the authors that regulatory and other non-voluntary methods are now required to reduce the aluminium content of infant formulas and thereby protect infants from chronic exposure to dietary aluminium.

  5. Prediction of the remaining lifetime of stainless steels under conditions of stress corrosion cracking

    International Nuclear Information System (INIS)

    Tandler, M.; Vehovar, L.; Dolecek, V.; Rotnik, U.

    2003-01-01

    The prediction of the lifetime of metal structures and equipment under conditions of stress corrosion is very complicated because of the complexity of this process of degradation. Recently a new method, based on the so-called corrosion elongation curves, has been found, which can be used to predict the time to failure under these conditions. By upgrading of these curves (and thus obtaining Upgraded Corrosion Elongation Curves - UCEC's) it has been possible to obtain a precise definition of the time needed for the initiation of the corrosion crack, and for its stable growth. It is upon this basis that diagrams for the prediction of remaining lifetime (DPRL's) have been developed. DPRL's can also be used to predict the values of various critical parameters which have to be achieved if a stress corrosion crack is to occur. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [de

  6. Epidural analgesia in early labour blocks the stress response but uterine contractions remain unchanged.

    Science.gov (United States)

    Scull, T J; Hemmings, G T; Carli, F; Weeks, S K; Mazza, L; Zingg, H H

    1998-07-01

    To determine the effect of epidural analgesia on biochemical markers of stress, plasma oxytocin concentrations and frequency of uterine contractions during the first stage of labour. Nine nulliparous women, in spontaneous labour, with a singleton fetus and cervical dilatation < or = 5 cm were enrolled. Epidural bupivacaine 0.25% (range 10-14 ml) was administered and bilateral sensory blockade to ice (T8-L4) achieved. Blood samples were collected before the epidermal block and every 10 min for one hour after the block was achieved for the measurement of plasma beta-endorphin, cortical, glucose, lactate and oxytocin concentrations. No exogenous oxytocin was given. Intensity of pain was assessed at the time of the blood sampling using a 10 cm visual analogue scale (VAS). The frequency of uterine contractions was recorded for 60 min before and after the epidural block. There was a decrease in plasma beta-endorphin and cortisol concentrations after epidural block (P < 0.01). There were no changes in plasma glucose and lactate concentrations. The mean VAS for pain decreased 10 min after epidural block was achieved and remained < 2 throughout the study period (P < 0.001). Mean plasma oxytocin concentrations did not change. The frequency of uterine contractions before and after the epidural block was similar. The metabolic stress response to the pain of labour was attenuated by epidural analgesia. In contrast, plasma oxytocin concentration and frequency of uterine contractions were unaffected by the attenuation of metabolic stress response.

  7. Remaining stress-state and strain-energy in tempered glass fragments

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik

    2016-01-01

    to the fragmentation process and some authors e.g. Barsom (J Am Ceram Soc 51(2):75, 1968), Gulati (Glass processing days, Tamglass Engineering Oy, Tampere, 1997), Warren (Fractography of glasses and ceramics IV, Alfred University, Alfred, 2001) and Tandon and Glass (Fracture mechanics of ceramics—active materials......When tempered glass breaks, it shatters into relatively small pieces depending on the residual stress state in the glass. This has been known for centuries and is currently used in standards for classifying whether a piece of glass is tempered or not. However, the process of fragmentation...... is complex and only a few, relatively simple, models have been suggested for predicting the fragment size. The full theoretical explanation is still to be found and this work aims at providing another brick to the puzzle. The strain-energy present in tempered glass is obviously contributing...

  8. Many Mobile Health Apps Target High-Need, High-Cost Populations, But Gaps Remain.

    Science.gov (United States)

    Singh, Karandeep; Drouin, Kaitlin; Newmark, Lisa P; Lee, JaeHo; Faxvaag, Arild; Rozenblum, Ronen; Pabo, Erika A; Landman, Adam; Klinger, Elissa; Bates, David W

    2016-12-01

    With rising smartphone ownership, mobile health applications (mHealth apps) have the potential to support high-need, high-cost populations in managing their health. While the number of available mHealth apps has grown substantially, no clear strategy has emerged on how providers should evaluate and recommend such apps to patients. Key stakeholders, including medical professional societies, insurers, and policy makers, have largely avoided formally recommending apps, which forces patients to obtain recommendations from other sources. To help stakeholders overcome barriers to reviewing and recommending apps, we evaluated 137 patient-facing mHealth apps-those intended for use by patients to manage their health-that were highly rated by consumers and recommended by experts and that targeted high-need, high-cost populations. We found that there is a wide variety of apps in the marketplace but that few apps address the needs of the patients who could benefit the most. We also found that consumers' ratings were poor indications of apps' clinical utility or usability and that most apps did not respond appropriately when a user entered potentially dangerous health information. Going forward, data privacy and security will continue to be major concerns in the dissemination of mHealth apps. Project HOPE—The People-to-People Health Foundation, Inc.

  9. Why does the need of HEU for high flux research reactors remain?

    International Nuclear Information System (INIS)

    Glaeser, W.

    1991-01-01

    It has shown that high performance high flux reactors need an ongoing supply of highly enriched uranium. The new fuel materials in their highly enriched version offer prospective for advanced and better neutron sources vital for the future of neutron research. This is another very attractive result of the RERTR programme. One-sided restriction would only provide marginal or no values for research. If we adopt the sometimes expressed views that high enriched RERTR developed fuel should only be made available when unique benefits to mankind could be obtained, then certainly basic research at the forefront belongs to this category. HEU would only pose theoretical difficulties, if it would remain under proper safeguards and obviously this is the way to be pursued. (orig.)

  10. Sleep in High Stress Occupations

    Science.gov (United States)

    Flynn-Evans, Erin

    2014-01-01

    High stress occupations are associated with sleep restriction, circadian misalignment and demanding workload. This presentation will provide an overview of sleep duration, circadian misalignment and fatigue countermeasures and performance outcomes during spaceflight and commercial aviation.

  11. SEDflume - High Shear Stress Flume

    Data.gov (United States)

    Federal Laboratory Consortium — The U.S. Army Corps of Engineers High Shear Stress flume (SEDflume) is designed for estimating erosion rates of fine-grained and mixed fine/coarse grained sediments...

  12. Prevalence of remaining horizontal instability in high-grade acromioclavicular joint injuries surgically managed.

    Science.gov (United States)

    Cisneros, Luis Natera; Reiriz, Juan Sarasquete

    2017-04-01

    To determine the prevalence of remaining horizontal instability in high-grade acromioclavicular joint (ACJ) injuries surgically managed by means of four different surgical strategies and to assess its relation to the clinical outcomes and the quality of life. In this multicentric non-randomized retrospective study, 53 patients with high-grade ACJ injuries surgically managed (by means of open or arthroscopic surgery) were clinically and radiographically assessed at 24 months or more after shoulder surgery. The presence of post-surgical remaining horizontal instability was evaluated by means of Alexander or axillary X-ray views. The study population was divided into two groups: patients with evidence of post-surgical remaining horizontal instability and patients without evidence of post-surgical remaining horizontal instability at the last follow-up visit. The relationship between remaining horizontal instability and the quality-of-life questionnaires was analyzed. 18.87% (10/53) of the Alexander or axillary X-rays views showed post-surgical remaining horizontal instability at the last follow-up visit (INSTAB-group). Results of the questionnaires were: (1) physical SF36 score (INSTAB-group 57.02 ± 3.17  and NO-INSTAB-group 57.66 ± 3.30, p = 0.583); (2) mental SF36 score (INSTAB-group 53.95 ± 3.98  and NO-INSTAB-group 55.71 ± 3.30, p = 0.150); (3) NRS for pain (INSTAB-group 1.30 ± 1.49 and NO-INSTAB-group 0.83  ± 1.08, p = 0.260); (4) DASH questionnaire (INSTAB-group 5.27 ± 5.42 and NO-INSTAB-group 3.06 ± 2.30, p = 0.049); (5) Constant score (INSTAB-group 93.4 ± 3.5 and NO-INSTAB-group 94.83  ± 4.3, p = 0.333); and Global satisfaction (INSTAB-group 8.7  ± 0.95 and NO-INSTAB-group 8.64 ± 1.03, p = 0.874). Independently of the type of procedure, post-surgical remaining horizontal instability was present in almost one-fifth of the patients, and this group of patients showed a significantly worse DASH score. The

  13. Why does fertility remain high among certain UK-born ethnic minority women?

    Directory of Open Access Journals (Sweden)

    Hill Kulu

    2016-12-01

    Full Text Available Background: Previous research has shown high total fertility among certain UK-born ethnic minorities, but the reasons behind their high fertility have remained far from clear. Some researchers attribute their elevated fertility levels to cultural factors, whereas others argue that high fertility is the consequence of their poor education and labour market prospects. Objective: This study investigates fertility among the descendants of immigrants in the UK and examines the determinants of high fertility among certain ethnic minority groups. Methods: We use data from the Understanding Society study and apply multivariate event history analysis. Results: The analysis shows, first, that relatively high second-, third-, and fourth-birth rates are responsible for the elevated total fertility among certain UK-born minorities, especially women of Pakistani and Bangladeshi origin. There is little variation in the first-birth rates among natives and immigrant descendants. Second, although fertility differences between ethnic minorities and native British women slightly decrease once religiosity and number of siblings are controlled for, significant differences persist. We conclude that cultural factors account for some elevated fertility among ethnic groups in the UK, whereas the role of education and employment seem to be only minor. Contribution: Cultural factors account for some elevated fertility among ethnic minorities in the UK, whereas the role of education and employment seem to be negligible.

  14. No novel, high penetrant gene might remain to be found in Japanese patients with unknown MODY.

    Science.gov (United States)

    Horikawa, Yukio; Hosomichi, Kazuyoshi; Enya, Mayumi; Ishiura, Hiroyuki; Suzuki, Yutaka; Tsuji, Shoji; Sugano, Sumio; Inoue, Ituro; Takeda, Jun

    2018-07-01

    MODY 5 and 6 have been shown to be low-penetrant MODYs. As the genetic background of unknown MODY is assumed to be similar, a new analytical strategy is applied here to elucidate genetic predispositions to unknown MODY. We examined to find whether there are major MODY gene loci remaining to be identified using SNP linkage analysis in Japanese. Whole-exome sequencing was performed with seven families with typical MODY. Candidates for novel MODY genes were examined combined with in silico network analysis. Some peaks were found only in either parametric or non-parametric analysis; however, none of these peaks showed a LOD score greater than 3.7, which is approved to be the significance threshold of evidence for linkage. Exome sequencing revealed that three mutated genes were common among 3 families and 42 mutated genes were common in two families. Only one of these genes, MYO5A, having rare amino acid mutations p.R849Q and p.V1601G, was involved in the biological network of known MODY genes through the intermediary of the INS. Although only one promising candidate gene, MYO5A, was identified, no novel, high penetrant MODY genes might remain to be found in Japanese MODY.

  15. Hypertensive emergencies remain a clinical problem and are associated with high mortality.

    Science.gov (United States)

    Roubsanthisuk, Weranuj; Wongsurin, Unticha; Buranakitjaroen, Peera

    2010-01-01

    We suspect that hypertensive emergencies remain a clinical problem and data on their long-term prognosis are lacking. This study was conducted in order to determine the frequency, management, and outcome of hypertensive emergencies in this era, in which hypertension treatment is more effective than in the past. We reviewed the medical records of patients with hypertensive emergencies admitted to the medical wards of Siriraj Hospital in 2003 and collected data on their characteristic, management, investigations, and follow-ups through 31 December 2007. There were 184 patients included. Hypertension has been previously diagnosed in 89% of cases. Nearly half also had diabetes mellitus and around a quarter had chronic kidney failure. Mean +/- SD of blood pressure at presentation was 205.96 +/- 21.36/114.60 +/- 20.59 mmHg. Cardiac complications and stroke accounted for 71% and 23% of all target organ damage, respectively. Intravenous nitroglycerine and furosemide were most frequently prescribed. Additional investigations to search for the causes of hypertension were performed in only 55 cases. The average hospital stay was 9.8 days. The in-hospital mortality rate was 15%. Some 26% of patients were lost to follow-up and another 20% died later. Only 19% of patients had regular follow-ups until the end of 2007 and remained on an average of 2.4 antihypertensive drugs. Hypertensive emergencies are usually found in patients with a history of hypertension and diabetes mellitus or kidney failure. Recommended investigations usually failed to identify the cause of hypertension. The mortality rate of these patients was extremely high while their adherence to treatment was extremely poor.

  16. Reliability of BOD POD Measurements Remains High After a Short-Duration Low-Carbohydrate Diet.

    Science.gov (United States)

    Greer, Beau Kjerulf; Edsall, Kathleen M; Greer, Anna E

    2016-04-01

    The purpose of the current study was to determine whether expected changes in body weight via a 3-day low-carbohydrate (LC) diet will disrupt the reliability of air displacement plethysmography measurements via BOD POD. Twenty-four subjects recorded their typical diets for 3 days before BOD POD and 7-site skinfold analyses. Subjects were matched for lean body mass and divided into low-CHO (LC) and control (CON) groups. The LC group was given instruction intended to prevent more than 50 grams/day of carbohydrate consumption for 3 consecutive days, and the CON group replicated their previously recorded diet. Body composition measurements were repeated after dietary intervention. Test-retest reliability measures were significant (p fat percentage in both the LC and the CON groups (rs = .993 and .965, respectively). Likewise, skinfold analysis for body fat percentage reliability was high in both groups (rs = .996 and .997, respectively). There were significant differences between 1st and 2nd BOD POD measurements for body mass (72.9 ± 13.3 vs. 72.1 ± 13.0 kg [M ± SD]) and body volume (69.0 ± 12.7-68.1 ± 12.2 L) in the LC group (p .05) in BOD POD-determined body fat percentage, lean body mass, or fat mass between the 1st and 2nd trial in either group. Body composition measures via BOD POD and 7-site skinfolds remain reliable after 3 days of an LC diet despite significant decreases in body mass.

  17. Remaining life assessment and plant life extension in high temperature components of power and petrochemical plant

    International Nuclear Information System (INIS)

    Fleming, A.

    2003-01-01

    This paper explains the reasons why plant life can so easily be extended beyond the original design life. It details the means by which plant life extension is normally achieved, a structured plan for achieving such plant life extension at reasonable cost and some of the key techniques used in assessing the remaining life and discusses the simple repair options available. (author)

  18. The Remaining Service Time Upon Reaching a High Level in M/G/1 Queues

    NARCIS (Netherlands)

    de Boer, Pieter-Tjerk; Nicola, V.F.; van Ommeren, Jan C.W.

    The distribution of the remaining service time upon reaching some target level in an M/G/1 queue is of theoretical as well as practical interest. In general, this distribution depends on the initial level as well as on the target level, say, B. Two initial levels are of particular interest, namely,

  19. Casting of organic glass by radiation-induced polymerization of glass-forming monomers at low temperature. II. Optical strain of remaining stress type

    International Nuclear Information System (INIS)

    Okubo, H.; Yoshii, F.; Kaetsu, I.; Honda, S.

    1978-01-01

    Previously it was found that casting could be carried out efficiently without strain formation by radiation-induced polymerization of glass-forming monomers. Two types of strain were observed in casting: thermal stream type, which was studied previously, and remained stress type. In this report, the effect of various factors on the formation of remaining stress-type strain in radiation-induced casting polymerization was studied. It was found that the molecular weight of prepolymer did not affect strain formation, while prepolymer concentration and viscosity of the system had a serious influence on strain formation. It could be deduced that this type of strain formed as a result of remaining inner stress due to poor relaxation of the shrinking stress. It was realized that less volume shrinkage of glass-forming monomers accompanying casting polymerization reduced the strain formation of this type in radiation-induced casting polymerization at low temperatures

  20. Grain Flow at High Stresses

    Science.gov (United States)

    McSaveney, M. J.

    2015-12-01

    The transport mechanism of rapid long-runout rock avalanches was a hotly debated topic when I came on the scene in 1967. So how come it is still debated today? My explanation is that it is the expected outcome of peer review, poor comprehension, and technological advances outpacing intellectual advances. Why think about the problem when we can model it! So let us think about the problem. Shreve thought that rock avalanches fell upon and trapped a layer of air. What physics was he thinking about? It is how feathers and tissue papers fall. When my rock avalanches fly, they fly like unlubricated bricks using the physics of projectiles and ballistics. But the main transport mechanism is not flight. The dominant impression from watching a rock avalanche in motion is of fluid flow, as Heim described it in 1882. A rock avalanche is a very large grain flow. Bagnold studied dispersive grain flows, but why should one assume that rock avalanches are dispersive grain flows as many do. The more common grain flow type is a dense grain flow and rock avalanches are dense grain flows in which the weight can and does generate very high stresses at grain contacts. Brittle rock deforms elastically up to its compressive strength, whereupon it breaks, releasing elastic strain as transient elastic strain (seismic energy to a seismologist, acoustic energy to a physicist). Melosh and others have shown that acoustic energy can fluidize a grain mass. There is no exotic physics behind grain flow at high stress. When grains break, the released elastic strain has to go somewhere, and it goes somewhere principally by transmission though grain contacts. Depending on the state of stress at the grain contact, the contact will pass the stress or will slip at conventional values of Coulomb friction. Enough thinking! A physical model of the entire process is too big for any laboratory. So whose numerical model will do it?

  1. High Altitude Remains Associated with Elevated Suicide Rates after Adjusting for Socioeconomic Status: A Study from South Korea

    OpenAIRE

    Kim, Jaelim; Choi, Nari; Lee, Yu-Jin; An, Hyonggin; Kim, Namkug; Yoon, Ho-Kyoung; Lee, Heon-Jeong

    2014-01-01

    There have been several studies supporting a possible relationship between high suicide rate and high altitude. However socioeconomic status may confound this association because low socioeconomic status, which is known to be related to a high suicide rate, is also associated with living at high altitude. This study aims to explore whether the relationship between high altitude and high suicide rate remains after adjusting for socioeconomic status in South Korea. We collected demographic data...

  2. The efficacy of high-throughput sequencing and target enrichment on charred archaeobotanical remains

    DEFF Research Database (Denmark)

    Nistelberger, H. M.; Smith, O.; Wales, Nathan

    2016-01-01

    . It has been suggested that high-throughput sequencing (HTS) technologies coupled with DNA enrichment techniques may overcome some of these limitations. Here we report the findings of HTS and target enrichment on four important archaeological crops (barley, grape, maize and rice) performed in three...... lightly-charred maize cob. Even with target enrichment, this sample failed to yield adequate data required to address fundamental questions in archaeology and biology. We further reanalysed part of an existing dataset on charred plant material, and found all purported endogenous DNA sequences were likely...

  3. The main challenges that remain in applying high-throughput sequencing to clinical diagnostics.

    Science.gov (United States)

    Loeffelholz, Michael; Fofanov, Yuriy

    2015-01-01

    Over the last 10 years, the quality, price and availability of high-throughput sequencing instruments have improved to the point that this technology may be close to becoming a routine tool in the diagnostic microbiology laboratory. Two groups of challenges, however, have to be resolved in order to move this powerful research technology into routine use in the clinical microbiology laboratory. The computational/bioinformatics challenges include data storage cost and privacy concerns, requiring analysis to be performed without access to cloud storage or expensive computational infrastructure. The logistical challenges include interpretation of complex results and acceptance and understanding of the advantages and limitations of this technology by the medical community. This article focuses on the approaches to address these challenges, such as file formats, algorithms, data collection, reporting and good laboratory practices.

  4. A HIGH-RESOLUTION SPECTROSCOPIC SEARCH FOR THE REMAINING DONOR FOR TYCHO'S SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Kerzendorf, Wolfgang E.; Yong, David; Schmidt, Brian P.; Murphy, Simon J.; Bessell, Michael S. [Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Simon, Joshua D. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Jeffery, C. Simon [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom); Anderson, Jay [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Podsiadlowski, Philipp [Department of Astrophysics, University of Oxford, Oxford, OX1 3RH (United Kingdom); Gal-Yam, Avishay [Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Silverman, Jeffrey M.; Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Nomoto, Ken' ichi [Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Venn, Kim A. [Department of Physics and Astronomy, University of Victoria, Elliott Building, 3800 Finnerty Road, Victoria, BC V8P 5C2 (Canada); Foley, Ryan J., E-mail: wkerzend@mso.anu.edu.au [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-09-10

    In this paper, we report on our analysis using Hubble Space Telescope astrometry and Keck-I HIRES spectroscopy of the central six stars of Tycho's supernova remnant (SN 1572). With these data, we measured the proper motions, radial velocities, rotational velocities, and chemical abundances of these objects. Regarding the chemical abundances, we do not confirm the unusually high [Ni/Fe] ratio previously reported for Tycho-G. Rather, we find that for all metrics in all stars, none exhibit the characteristics expected from traditional Type Ia supernova single-degenerate-scenario calculations. The only possible exception is Tycho-B, a rare, metal-poor A-type star; however, we are unable to find a suitable scenario for it. Thus, we suggest that SN 1572 cannot be explained by the standard single-degenerate model.

  5. A HIGH-RESOLUTION SPECTROSCOPIC SEARCH FOR THE REMAINING DONOR FOR TYCHO'S SUPERNOVA

    International Nuclear Information System (INIS)

    Kerzendorf, Wolfgang E.; Yong, David; Schmidt, Brian P.; Murphy, Simon J.; Bessell, Michael S.; Simon, Joshua D.; Jeffery, C. Simon; Anderson, Jay; Podsiadlowski, Philipp; Gal-Yam, Avishay; Silverman, Jeffrey M.; Filippenko, Alexei V.; Nomoto, Ken'ichi; Venn, Kim A.; Foley, Ryan J.

    2013-01-01

    In this paper, we report on our analysis using Hubble Space Telescope astrometry and Keck-I HIRES spectroscopy of the central six stars of Tycho's supernova remnant (SN 1572). With these data, we measured the proper motions, radial velocities, rotational velocities, and chemical abundances of these objects. Regarding the chemical abundances, we do not confirm the unusually high [Ni/Fe] ratio previously reported for Tycho-G. Rather, we find that for all metrics in all stars, none exhibit the characteristics expected from traditional Type Ia supernova single-degenerate-scenario calculations. The only possible exception is Tycho-B, a rare, metal-poor A-type star; however, we are unable to find a suitable scenario for it. Thus, we suggest that SN 1572 cannot be explained by the standard single-degenerate model

  6. Not in wilderness: African vulture strongholds remain in areas with high human density

    Science.gov (United States)

    Granadeiro, José Pedro; Monteiro, Hamilton; Nuno, Ana; Lecoq, Miguel; Cardoso, Paulo; Regalla, Aissa; Catry, Paulo

    2018-01-01

    Vultures constitute an important functional group in many ecosystems, providing crucial ecosystem services both in natural and humanized environments. These scavengers are facing massive declines worldwide, but in several African countries virtually nothing is known on populations’ status and threats, hampering the development of adequate conservation strategies. In Guinea-Bissau, globally important populations of Hooded Necrosyrtes monachus and African white-backed vultures Gyps africanus were recently reported. Using the country as a study area, we aim to characterize human-vulture interactions in West Africa applying a multidisciplinary approach. We assessed the status and distribution of vulture populations using data from 1711 km of roadside transects, examined predictors of their distribution, and produced a nationwide population estimate for the Hooded Vulture, using an innovative method based on the relationship between the size of human population in settlements and vulture numbers. We conducted 47 stakeholder interviews to assess perceived roles played by vultures, and to investigate potential anthropogenic threats. Hooded vultures were strongly associated with high human population densities, whereas no relation was found between African white-backed and Rüppell’s vultures and any of the tested predictors, which included cattle density, precipitation and Normalized Difference Vegetation Index, among others. We estimate a national population of 43347 Hooded vultures, the largest population reported in the species range. Respondents were generally aware of the services provided by vultures, especially waste and carcass removal, including in urban areas. Hunting for witchcraft and traditional medicine was the most frequently recognised threat, while poisoning was ranked as having the highest impact. We hypothesise that poisoning-related mortality may be affecting African white-backed and Rüppell’s vultures’ distribution and explain their scarcity

  7. Land Cover Mapping in Northern High Latitude Permafrost Regions with Satellite Data: Achievements and Remaining Challenges

    Directory of Open Access Journals (Sweden)

    Annett Bartsch

    2016-11-01

    Full Text Available Most applications of land cover maps that have been derived from satellite data over the Arctic require higher thematic detail than available in current global maps. A range of application studies has been reviewed, including up-scaling of carbon fluxes and pools, permafrost feature mapping and transition monitoring. Early land cover mapping studies were driven by the demand to characterize wildlife habitats. Later, in the 1990s, up-scaling of in situ measurements became central to the discipline of land cover mapping on local to regional scales at several sites across the Arctic. This includes the Kuparuk basin in Alaska, the Usa basin and the Lena Delta in Russia. All of these multi-purpose land cover maps have been derived from Landsat data. High resolution maps (from optical satellite data serve frequently as input for the characterization of periglacial features and also flux tower footprints in recent studies. The most used map to address circumpolar issues is the CAVM (Circum Arctic Vegetation Map based on AVHRR (1 km and has been manually derived. It provides the required thematic detail for many applications, but is confined to areas north of the treeline, and it is limited in spatial detail. A higher spatial resolution circumpolar land cover map with sufficient thematic content would be beneficial for a range of applications. Such a land cover classification should be compatible with existing global maps and applicable for multiple purposes. The thematic content of existing global maps has been assessed by comparison to the CAVM and regional maps. None of the maps provides the required thematic detail. Spatial resolution has been compared to used classes for local to regional applications. The required thematic detail increases with spatial resolution since coarser datasets are usually applied over larger areas covering more relevant landscape units. This is especially of concern when the entire Arctic is addressed. A spatial

  8. Viable-but-Nonculturable Listeria monocytogenes and Salmonella enterica Serovar Thompson Induced by Chlorine Stress Remain Infectious

    Directory of Open Access Journals (Sweden)

    Callum J. Highmore

    2018-04-01

    Full Text Available The microbiological safety of fresh produce is monitored almost exclusively by culture-based detection methods. However, bacterial food-borne pathogens are known to enter a viable-but-nonculturable (VBNC state in response to environmental stresses such as chlorine, which is commonly used for fresh produce decontamination. Here, complete VBNC induction of green fluorescent protein-tagged Listeria monocytogenes and Salmonella enterica serovar Thompson was achieved by exposure to 12 and 3 ppm chlorine, respectively. The pathogens were subjected to chlorine washing following incubation on spinach leaves. Culture data revealed that total viable L. monocytogenes and Salmonella Thompson populations became VBNC by 50 and 100 ppm chlorine, respectively, while enumeration by direct viable counting found that chlorine caused a <1-log reduction in viability. The pathogenicity of chlorine-induced VBNC L. monocytogenes and Salmonella Thompson was assessed by using Caenorhabditis elegans. Ingestion of VBNC pathogens by C. elegans resulted in a significant life span reduction (P = 0.0064 and P < 0.0001, and no significant difference between the life span reductions caused by the VBNC and culturable L. monocytogenes treatments was observed. L. monocytogenes was visualized beyond the nematode intestinal lumen, indicating resuscitation and cell invasion. These data emphasize the risk that VBNC food-borne pathogens could pose to public health should they continue to go undetected.

  9. Friction & Wear Under Very High Electromagnetic Stress

    National Research Council Canada - National Science Library

    Cowan, Richard S; Danyluk, Steven; Moon, Francis; Ford, J. C; Brenner, Donald W

    2004-01-01

    This document summarizes initial progress toward advancing the fundamental understanding of the friction, wear and mechanics of interfaces subjected to extreme electromagnetic stress, high relative...

  10. Mining highly stressed areas, part 1.

    CSIR Research Space (South Africa)

    Johnson, R

    1995-12-01

    Full Text Available The aim of this long-term project has been to focus on the extreme high-stress end of the mining spectrum. Such high stress conditions will prevail in certain ultra-deep mining operation of the near future, and are already being experienced...

  11. Managing Stress to Control High Blood Pressure

    Science.gov (United States)

    ... Aortic Aneurysm More Managing Stress to Control High Blood Pressure Updated:Jan 29,2018 The importance of stress ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

  12. High temperature aqueous stress corrosion testing device

    International Nuclear Information System (INIS)

    Bornstein, A.N.; Indig, M.E.

    1975-01-01

    A description is given of a device for stressing tensile samples contained within a high temperature, high pressure aqueous environment, thereby permitting determination of stress corrosion susceptibility of materials in a simple way. The stressing device couples an external piston to an internal tensile sample via a pull rod, with stresses being applied to the sample by pressurizing the piston. The device contains a fitting/seal arrangement including Teflon and weld seals which allow sealing of the internal system pressure and the external piston pressure. The fitting/seal arrangement allows free movement of the pull rod and the piston

  13. Remote Methodology used at B Plant Hanford to Map High Radiation and Contamination Fields and Document Remaining Hazards

    Energy Technology Data Exchange (ETDEWEB)

    SIMMONS, F.M.

    2000-01-01

    A remote radiation mapping system using the Gammacam{trademark} (AIL Systems Inc. Trademark) with real-time response was used in deactivating the B Plant at Hanford to produce digitized images showing actual radiation fields and dose rates. Deployment of this technology has significantly reduced labor requirements, decreased personnel exposure, and increased the accuracy of the measurements. Personnel entries into the high radiation/contamination areas was minimized for a dose savings of 30 Rem (.3 Seivert) and a cost savings of $640K. In addition, the data gathered was utilized along with historical information to estimate the amount of remaining hazardous waste in the process cells. The B Plant facility is a canyon facility containing 40 process cells which were used to separate cesium and strontium from high level waste. The cells and vessels are contaminated with chemicals used in the separation and purification processes. Most of the contaminants have been removed but the residual contamination from spills in the cells and heels in the tanks contribute to the localized high radioactivity. The Gammacam{trademark} system consists of a high density terbium-activated scintillating glass detector coupled with a digitized video camera. Composite images generated by the system are presented in pseudo color over a black and white image. Exposure times can be set from 10 milliseconds to 1 hour depending on the field intensity. This information coupled with process knowledge is then used to document the hazardous waste remaining in each cell. Additional uses for this radiation mapping system would be in support of facilities stabilization and deactivation activities at Hanford or other DOE sites. The system is currently scheduled for installation and mapping of the U Plant in 1999. This system is unique due to its portability and its suitability for use in high dose rate areas.

  14. Remote Methodology used at B Plant Hanford to Map High Radiation and Contamination Fields and Document Remaining Hazards

    International Nuclear Information System (INIS)

    SIMMONS, F.M.

    2000-01-01

    A remote radiation mapping system using the Gammacam(trademark) (AIL Systems Inc. Trademark) with real-time response was used in deactivating the B Plant at Hanford to produce digitized images showing actual radiation fields and dose rates. Deployment of this technology has significantly reduced labor requirements, decreased personnel exposure, and increased the accuracy of the measurements. Personnel entries into the high radiation/contamination areas was minimized for a dose savings of 30 Rem (.3 Seivert) and a cost savings of $640K. In addition, the data gathered was utilized along with historical information to estimate the amount of remaining hazardous waste in the process cells. The B Plant facility is a canyon facility containing 40 process cells which were used to separate cesium and strontium from high level waste. The cells and vessels are contaminated with chemicals used in the separation and purification processes. Most of the contaminants have been removed but the residual contamination from spills in the cells and heels in the tanks contribute to the localized high radioactivity. The Gammacam(trademark) system consists of a high density terbium-activated scintillating glass detector coupled with a digitized video camera. Composite images generated by the system are presented in pseudo color over a black and white image. Exposure times can be set from 10 milliseconds to 1 hour depending on the field intensity. This information coupled with process knowledge is then used to document the hazardous waste remaining in each cell. Additional uses for this radiation mapping system would be in support of facilities stabilization and deactivation activities at Hanford or other DOE sites. The system is currently scheduled for installation and mapping of the U Plant in 1999. This system is unique due to its portability and its suitability for use in high dose rate areas

  15. Aerosol pH buffering in the southeastern US: Fine particles remain highly acidic despite large reductions in sulfate

    Science.gov (United States)

    Weber, R. J.; Guo, H.; Russell, A. G.; Nenes, A.

    2015-12-01

    pH is a critical aerosol property that impacts many atmospheric processes, including biogenic secondary organic aerosol formation, gas-particle phase partitioning, and mineral dust or redox metal mobilization. Particle pH has also been linked to adverse health effects. Using a comprehensive data set from the Southern Oxidant and Aerosol Study (SOAS) as the basis for thermodynamic modeling, we have shown that particles are currently highly acidic in the southeastern US, with pH between 0 and 2. Sulfate and ammonium are the main acid-base components that determine particle pH in this region, however they have different sources and their concentrations are changing. Over 15 years of network data show that sulfur dioxide emission reductions have resulted in a roughly 70 percent decrease in sulfate, whereas ammonia emissions, mainly link to agricultural activities, have been largely steady, as have gas phase ammonia concentrations. This has led to the view that particles are becoming more neutralized. However, sensitivity analysis, based on thermodynamic modeling, to changing sulfate concentrations indicates that particles have remained highly acidic over the past decade, despite the large reductions in sulfate. Furthermore, anticipated continued reductions of sulfate and relatively constant ammonia emissions into the future will not significantly change particle pH until sulfate drops to clean continental background levels. The result reshapes our expectation of future particle pH and implies that atmospheric processes and adverse health effects linked to particle acidity will remain unchanged for some time into the future.

  16. Adaptation and survival of plants in high stress habitats via fungal endophyte conferred stress tolerance

    Science.gov (United States)

    Rodriguez, Rusty J.; Woodward, Claire; Redman, Regina S.

    2010-01-01

    From the Arctic to the Antarctic, plants thrive in diverse habitats that impose different levels of adaptive pressures depending on the type and degree of biotic and abiotic stresses inherent to each habitat (Stevens, 1989). At any particular location, the abundance and distribution of individual plant species vary tremendously and is theorized to be based on the ability to tolerate a wide range of edaphic conditions and habitat-specific stresses (Pianka, 1966). The ability of individual plant species to thrive in diverse habitats is commonly referred to as phenotypic plasticity and is thought to involve adaptations based on changes in the plant genome (Givnish, 2002; Pan et al., 2006; Robe and Griffiths, 2000; Schurr et al., 2006). Habitats that impose high levels of abiotic stress are typically colonized with fewer plant species compared to habitats imposing low levels of stress. Moreover, high stress habitats have decreased levels of plant abundance compared to low stress habitats even though these habitats may occur in close proximity to one another (Perelman et al., 2007). This is particularly interesting because all plants are known to perceive, transmit signals, and respond to abiotic stresses such as drought, heat, and salinity (Bartels and Sunkar, 2005; Bohnert et al., 1995). Although there has been extensive research performed to determine the genetic, molecular, and physiological bases of how plants respond to and tolerate stress, the nature of plant adaptation to high stress habitats remains unresolved (Leone et al., 2003; Maggio et al., 2003; Tuberosa et al., 2003). However, recent evidence indicates that a ubiquitous aspect of plant biology (fungal symbiosis) is involved in the adaptation and survival of at least some plants in high stress habitats (Rodriguez et al., 2008).

  17. Machine remaining useful life prediction: An integrated adaptive neuro-fuzzy and high-order particle filtering approach

    Science.gov (United States)

    Chen, Chaochao; Vachtsevanos, George; Orchard, Marcos E.

    2012-04-01

    Machine prognosis can be considered as the generation of long-term predictions that describe the evolution in time of a fault indicator, with the purpose of estimating the remaining useful life (RUL) of a failing component/subsystem so that timely maintenance can be performed to avoid catastrophic failures. This paper proposes an integrated RUL prediction method using adaptive neuro-fuzzy inference systems (ANFIS) and high-order particle filtering, which forecasts the time evolution of the fault indicator and estimates the probability density function (pdf) of RUL. The ANFIS is trained and integrated in a high-order particle filter as a model describing the fault progression. The high-order particle filter is used to estimate the current state and carry out p-step-ahead predictions via a set of particles. These predictions are used to estimate the RUL pdf. The performance of the proposed method is evaluated via the real-world data from a seeded fault test for a UH-60 helicopter planetary gear plate. The results demonstrate that it outperforms both the conventional ANFIS predictor and the particle-filter-based predictor where the fault growth model is a first-order model that is trained via the ANFIS.

  18. Smoking prevalence among lesbian, bisexual and queer women in Sydney remains high: Analysis of trends and correlates.

    Science.gov (United States)

    Deacon, Rachel M; Mooney-Somers, Julie

    2017-07-01

    To investigate smoking prevalence trends and correlates among lesbian, bisexual and queer-identifying (LBQ) women in Sydney, Australia. Data from 5007 respondents to a repeated cross-sectional community survey were used to examine smoking trends between 2004 and 2014. Multinomial logistic regression was used to examine smoking correlates. Thirty percent of respondents were current smokers, including 48% of 16 to 24-year-olds. A slight decrease in all-ages smoking over time was not reflected in the youngest age group. LBQ women who smoke have fewer economic, social and psychological resources than both women who never smoke and ex-smokers. High levels of alcohol and illicit drug use are also correlated with current smoking. Population-wide interventions have failed to address the persistently high prevalence of smoking among this sample of LBQ women. Tailored interventions may find utility focusing on personal resilience to deal with general and sexuality-specific stressors, as well as attending to poly-substance use. Acknowledgment of LBQ women as a priority group for tobacco reduction is urgently needed. We call on tobacco control agencies to consider sexuality and gender orientation in policy and partner with lesbian, gay, bisexual and transgender community organisations to develop culturally appropriate interventions. [Deacon RM, Mooney-Somers J Smoking prevalence among lesbian, bisexual and queer women in Sydney remains high: Analysis of trends and correlates Drug Alcohol Rev 2017;36:546-554]. © 2017 Australasian Professional Society on Alcohol and other Drugs.

  19. Stress concentration effects in high pressure components

    International Nuclear Information System (INIS)

    Aller, J.E.

    1990-01-01

    This paper examines the stress concentration effects of sideholes in thick walled, high pressure cylinders. It has been shown that the theoretical stress concentration factor at the intersection of a small crossbore in a closed end, thick walled cylinder varies between 3.0 and 4.0. Tests have shown that this effect can be greatly reduced in practice by carefully radiusing the bore intersection and autofrettaging the cylinder. It has also been shown that the minimum stress concentration factor occurs when the main bore and sidehole or crossbore have the same diameter, and the radius of the intersection is approximately equal to the sidehole radius. When the bore and sidehole intersection angle decreases from 90 degrees, the stress concentration factor increases significantly. Knowledge of these fundamental relationships can be used in maintaining, as well ad designing, high pressure equipment

  20. Stress and High Blood Pressure: What's the Connection?

    Science.gov (United States)

    Stress and high blood pressure: What's the connection? Stress and long-term high blood pressure may not be linked, but taking steps to reduce your stress can improve your general health, including your blood ...

  1. Anesthesia Service Use During Outpatient Gastroenterology Procedures Continued to Increase From 2010 to 2013 and Potentially Discretionary Spending Remained High.

    Science.gov (United States)

    Predmore, Zachary; Nie, Xiaoyu; Main, Regan; Mattke, Soeren; Liu, Hangsheng

    2017-02-01

    Previous studies have identified an increasing number of gastroenterology (GI) procedures using anesthesia services to provide sedation, with a majority of these services delivered to low-risk patients. The aim of this study was to update these trends with the most recent years of data. We used Medicare and commercial claims data from 2010 to 2013 to identify GI procedures and anesthesia services based on CPT codes, which were linked together using patient identifiers and dates of service. We defined low-risk patients as those who were classified as ASA (American Society of Anesthesiologists) physical status class I or II. For those patients without an ASA class listed on the claim, we used a prediction algorithm to impute an ASA physical status. Over 6.6 million patients in our sample had a GI procedure between 2010 and 2013. GI procedures involving anesthesia service accounted for 33.7% in 2010 and 47.6% in 2013 in Medicare patients, and 38.3% in 2010 and 53.0% in 2013 in commercially insured patients. Overall, as more patients used anesthesia services, total anesthesia service use in low-risk patients increased 14%, from 27,191 to 33,181 per million Medicare enrollees. Similarly, we observed a nearly identical uptick in commercially insured patients from 15,871 to 22,247 per million, an increase of almost 15%. During 2010-2013, spending associated with anesthesia services in low-risk patients increased from US$3.14 million to US$3.45 million per million Medicare enrollees and from US$7.69 million to US$10.66 million per million commercially insured patients. During 2010 to 2013, anesthesia service use in GI procedures continued to increase and the proportion of these services rendered for low-risk patients remained high.

  2. Mining highly stressed areas, part 2.

    CSIR Research Space (South Africa)

    Johnson, R

    1995-12-01

    Full Text Available A questionnaire related to mining at great depth and in very high stress conditions has been completed with the assistance of mine rock mechanics personnel on over twenty mines in all mining districts, and covering all deep level mines...

  3. Adolescents' sleep in low-stress and high-stress (exam) times: a prospective quasi-experiment.

    Science.gov (United States)

    Dewald, Julia F; Meijer, Anne Marie; Oort, Frans J; Kerkhof, Gerard A; Bögels, Susan M

    2014-01-01

    This prospective quasi-experiment (N = 175; mean age = 15.14 years) investigates changes in adolescents' sleep from low-stress (regular school week) to high-stress times (exam week), and examines the (moderating) role of chronic sleep reduction, baseline stress, and gender. Sleep was monitored over three consecutive weeks using actigraphy. Adolescents' sleep was more fragmented during the high-stress time than during the low-stress time, meaning that individuals slept more restless during stressful times. However, sleep efficiency, total sleep time, and sleep onset latency remained stable throughout the three consecutive weeks. High chronic sleep reduction was related to later bedtimes, later sleep start times, later sleep end times, later getting up times, and more time spent in bed. Furthermore, low chronic sleep reduction and high baseline stress levels were related to more fragmented sleep during stressful times. This study shows that stressful times can have negative effects on adolescents' sleep fragmentation, especially for adolescents with low chronic sleep reduction or high baseline stress levels.

  4. Oxidative stress and the high altitude environment

    Directory of Open Access Journals (Sweden)

    Jakub Krzeszowiak

    2013-03-01

    Full Text Available In the recent years there has been considerable interest in mountain sports, including mountaineering, owing to the general availability of climbing clothing and equipment as well trainings and professional literature. This raised a new question for the environmental and mountain medicine: Is mountaineering harmful to health? Potential hazards include the conditions existing in the alpine environment, i.e. lower atmospheric pressure leading to the development of hypobaric hypoxia, extreme physical effort, increased UV radiation, lack of access to fresh food, and mental stress. A reasonable measure of harmfulness of these factors is to determine the increase in the level of oxidative stress. Alpine environment can stimulate the antioxidant enzyme system but under specific circumstances it may exceed its capabilities with simultaneous consumption of low-molecular antioxidants resulting in increased generation of reactive oxygen species (ROS. This situation is referred to as oxidative stress. Rapid and uncontrolled proliferation of reactive oxygen species leads to a number of adverse changes, resulting in the above-average damage to the lipid structures of cell membranes (peroxidation, proteins (denaturation, and nucleic acids. Such situation within the human body cannot take place without resultant systemic consequences. This explains the malaise of people returning from high altitude and a marked decrease in their physical fitness. In addition, a theory is put forward that the increase in the level of oxidative stress is one of the factors responsible for the onset of acute mountain sickness (AMS. However, such statement requires further investigation because the currently available literature is inconclusive. This article presents the causes and effects of development of oxidative stress in the high mountains.

  5. Evidence of a high-Andean, mid-Holocene plant community: An ancient DNA analysis of glacially preserved remains.

    Science.gov (United States)

    Gould, Billie A; León, Blanca; Buffen, Aron M; Thompson, Lonnie G

    2010-09-01

    Around the world, tropical glaciers and ice caps are retreating at unprecedented rates because of climate change. In at least one location, along the margin of the Quelccaya Ice Cap in southeastern Peru, ancient plant remains have been continually uncovered since 2002. We used genetic analysis to identify plants that existed at these sites during the mid-Holocene. • We examined remains between 4576 and 5222 yr old, using PCR amplification, cloning, and sequencing of a fragment of the chloroplast trnL intron. We then matched these sequences to sequences in GenBank. • We found evidence of at least five taxa characteristic of wetlands, which occur primarily at lower elevations in the region today. • A diverse community most likely existed at these locations the last time they were ice-free and thus has the potential to reestablish with time. This is the first genetic analysis of vegetation uncovered by receding glacial ice, and it may become one of many as ancient plant materials are newly uncovered in a changing climate.

  6. A highly accurate predictive-adaptive method for lithium-ion battery remaining discharge energy prediction in electric vehicle applications

    International Nuclear Information System (INIS)

    Liu, Guangming; Ouyang, Minggao; Lu, Languang; Li, Jianqiu; Hua, Jianfeng

    2015-01-01

    Highlights: • An energy prediction (EP) method is introduced for battery E RDE determination. • EP determines E RDE through coupled prediction of future states, parameters, and output. • The PAEP combines parameter adaptation and prediction to update model parameters. • The PAEP provides improved E RDE accuracy compared with DC and other EP methods. - Abstract: In order to estimate the remaining driving range (RDR) in electric vehicles, the remaining discharge energy (E RDE ) of the applied battery system needs to be precisely predicted. Strongly affected by the load profiles, the available E RDE varies largely in real-world applications and requires specific determination. However, the commonly-used direct calculation (DC) method might result in certain energy prediction errors by relating the E RDE directly to the current state of charge (SOC). To enhance the E RDE accuracy, this paper presents a battery energy prediction (EP) method based on the predictive control theory, in which a coupled prediction of future battery state variation, battery model parameter change, and voltage response, is implemented on the E RDE prediction horizon, and the E RDE is subsequently accumulated and real-timely optimized. Three EP approaches with different model parameter updating routes are introduced, and the predictive-adaptive energy prediction (PAEP) method combining the real-time parameter identification and the future parameter prediction offers the best potential. Based on a large-format lithium-ion battery, the performance of different E RDE calculation methods is compared under various dynamic profiles. Results imply that the EP methods provide much better accuracy than the traditional DC method, and the PAEP could reduce the E RDE error by more than 90% and guarantee the relative energy prediction error under 2%, proving as a proper choice in online E RDE prediction. The correlation of SOC estimation and E RDE calculation is then discussed to illustrate the

  7. Instantaneous strain measurements during high-temperature stress cycling of a dispersion-strengthened niobium alloy

    International Nuclear Information System (INIS)

    Farkas, D.M.; Mishra, R.S.; Mukherjee, A.K.

    1995-01-01

    Experimental results obtained from stress cycling tests performed during high-temperature creep of a dispersion strengthened niobium alloy indicate that the instantaneous strain following the stress change decreases with accumulated strain. The true work-hardening rate was shown to be a small fraction of the elastic modulus which remained fairly constant throughout the strain history. The instantaneous strain change from a stress addition was typically greater than the strain from the corresponding stress reduction. This effect is quite pronounced for small stress changes and diminishes as the magnitude of the stress change increases. This implies that the mobility of dislocations is impeded in the reverse direction unless the magnitude of stress reduction exceeds the value of the internal stress

  8. High-resolution axial MR imaging of tibial stress injuries

    Directory of Open Access Journals (Sweden)

    Mammoto Takeo

    2012-05-01

    Full Text Available Abstract Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries.

  9. High-resolution axial MR imaging of tibial stress injuries

    Science.gov (United States)

    2012-01-01

    Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries. PMID:22574840

  10. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, T. [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W. [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J. [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H. [Siemens Power Generation (Germany)

    1998-12-31

    In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

  11. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, T [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H [Siemens Power Generation (Germany)

    1999-12-31

    In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

  12. Separating heat stress from moisture stress: analyzing yield response to high temperature in irrigated maize

    Science.gov (United States)

    Carter, Elizabeth K.; Melkonian, Jeff; Riha, Susan J.; Shaw, Stephen B.

    2016-09-01

    Several recent studies have indicated that high air temperatures are limiting maize (Zea mays L.) yields in the US Corn Belt and project significant yield losses with expected increases in growing season temperatures. Further work has suggested that high air temperatures are indicative of high evaporative demand, and that decreases in maize yields which correlate to high temperatures and vapor pressure deficits (VPD) likely reflect underlying soil moisture limitations. It remains unclear whether direct high temperature impacts on yields, independent of moisture stress, can be observed under current temperature regimes. Given that projected high temperature and moisture may not co-vary the same way as they have historically, quantitative analyzes of direct temperature impacts are critical for accurate yield projections and targeted mitigation strategies under shifting temperature regimes. To evaluate yield response to above optimum temperatures independent of soil moisture stress, we analyzed climate impacts on irrigated maize yields obtained from the National Corn Growers Association (NCGA) corn yield contests for Nebraska, Kansas and Missouri. In irrigated maize, we found no evidence of a direct negative impact on yield by daytime air temperature, calculated canopy temperature, or VPD when analyzed seasonally. Solar radiation was the primary yield-limiting climate variable. Our analyses suggested that elevated night temperature impacted yield by increasing rates of phenological development. High temperatures during grain-fill significantly interacted with yields, but this effect was often beneficial and included evidence of acquired thermo-tolerance. Furthermore, genetics and management—information uniquely available in the NCGA contest data—explained more yield variability than climate, and significantly modified crop response to climate. Thermo-acclimation, improved genetics and changes to management practices have the potential to partially or completely

  13. High Glucose Inhibits Neural Stem Cell Differentiation Through Oxidative Stress and Endoplasmic Reticulum Stress.

    Science.gov (United States)

    Chen, Xi; Shen, Wei-Bin; Yang, Penghua; Dong, Daoyin; Sun, Winny; Yang, Peixin

    2018-06-01

    Maternal diabetes induces neural tube defects by suppressing neurogenesis in the developing neuroepithelium. Our recent study further revealed that high glucose inhibited embryonic stem cell differentiation into neural lineage cells. However, the mechanism whereby high glucose suppresses neural differentiation is unclear. To investigate whether high glucose-induced oxidative stress and endoplasmic reticulum (ER) stress lead to the inhibition of neural differentiation, the effect of high glucose on neural stem cell (the C17.2 cell line) differentiation was examined. Neural stem cells were cultured in normal glucose (5 mM) or high glucose (25 mM) differentiation medium for 3, 5, and 7 days. High glucose suppressed neural stem cell differentiation by significantly decreasing the expression of the neuron marker Tuj1 and the glial cell marker GFAP and the numbers of Tuj1 + and GFAP + cells. The antioxidant enzyme superoxide dismutase mimetic Tempol reversed high glucose-decreased Tuj1 and GFAP expression and restored the numbers of neurons and glial cells differentiated from neural stem cells. Hydrogen peroxide treatment imitated the inhibitory effect of high glucose on neural stem cell differentiation. Both high glucose and hydrogen peroxide triggered ER stress, whereas Tempol blocked high glucose-induced ER stress. The ER stress inhibitor, 4-phenylbutyrate, abolished the inhibition of high glucose or hydrogen peroxide on neural stem cell differentiation. Thus, oxidative stress and its resultant ER stress mediate the inhibitory effect of high glucose on neural stem cell differentiation.

  14. Elevated level of serum triglyceride among high risk stress bank ...

    African Journals Online (AJOL)

    The objective of this study was to estimate lipid profile among high risk stress bank employees' correlated with heart disorders in Riyadh, Saudi Arabia. A total of 129 patients with high risk stress employees were involved in this study, which were divided into 69 males and 60 females between the age of 25 to 55 years.

  15. Achieving high aspect ratio wrinkles by modifying material network stress.

    Science.gov (United States)

    Chen, Yu-Cheng; Wang, Yan; McCarthy, Thomas J; Crosby, Alfred J

    2017-06-07

    Wrinkle aspect ratio, or the amplitude divided by the wavelength, is hindered by strain localization transitions when an increasing global compressive stress is applied to synthetic material systems. However, many examples from living organisms show extremely high aspect ratios, such as gut villi and flower petals. We use three experimental approaches to demonstrate that these high aspect ratio structures can be achieved by modifying the network stress in the wrinkle substrate. We modify the wrinkle stress and effectively delay the strain localization transition, such as folding, to larger aspect ratios by using a zero-stress initial wavy substrate, creating a secondary network with post-curing, or using chemical stress relaxation materials. A wrinkle aspect ratio as high as 0.85, almost three times higher than common values of synthetic wrinkles, is achieved, and a quantitative framework is presented to provide understanding the different strategies and predictions for future investigations.

  16. Highly stressed carbon film coatings on silicon potential applications

    CERN Multimedia

    Sharda, T

    2002-01-01

    The fabrication of highly stressed and strongly adhered nanocrystalline diamond films on Si substrates is presented. A microwave plasma CVD method with controlled and continuous bias current density was used to grow the films. The stress/curvature of the films can be varied and controlled by altering the BCD. Potential applications for these films include particle physics and x-ray optics.

  17. [PALEOPATHOLOGY OF HUMAN REMAINS].

    Science.gov (United States)

    Minozzi, Simona; Fornaciari, Gino

    2015-01-01

    Many diseases induce alterations in the human skeleton, leaving traces of their presence in ancient remains. Paleopathological examination of human remains not only allows the study of the history and evolution of the disease, but also the reconstruction of health conditions in the past populations. This paper describes the most interesting diseases observed in skeletal samples from the Roman Imperial Age necropoles found in urban and suburban areas of Rome during archaeological excavations in the last decades. The diseases observed were grouped into the following categories: articular diseases, traumas, infections, metabolic or nutritional diseases, congenital diseases and tumours, and some examples are reported for each group. Although extensive epidemiological investigation in ancient skeletal records is impossible, the palaeopathological study allowed to highlight the spread of numerous illnesses, many of which can be related to the life and health conditions of the Roman population.

  18. A high-temperature silicon-on-insulator stress sensor

    International Nuclear Information System (INIS)

    Wang Zheyao; Tian Kuo; Zhou Youzheng; Pan Liyang; Liu Litian; Hu Chaohong

    2008-01-01

    A piezoresistive stress sensor is developed using silicon-on-insulator (SOI) wafers and calibrated for stress measurement for high-temperature applications. The stress sensor consists of 'silicon-island-like' piezoresistor rosettes that are etched on the SOI layer. This eliminates leakage current and enables excellent electrical insulation at high temperature. To compensate for the measurement errors caused by the misalignment of the piezoresistor rosettes with respect to the crystallographic axes, an anisotropic micromachining technique, tetramethylammonium hydroxide etching, is employed to alleviate the misalignment issue. To realize temperature-compensated stress measurement, a planar diode is fabricated as a temperature sensor to decouple the temperature information from the piezoresistors, which are sensitive to both stress and temperature. Design, fabrication and calibration of the piezoresistors are given. SOI-related characteristics such as piezoresistive coefficients and temperature coefficients as well as the influence of the buried oxide layer are discussed in detail

  19. Comfort food is comforting to those most stressed: evidence of the chronic stress response network in high stress women.

    Science.gov (United States)

    Tomiyama, A Janet; Dallman, Mary F; Epel, Elissa S

    2011-11-01

    Chronically stressed rodents who are allowed to eat calorie-dense "comfort" food develop greater mesenteric fat, which in turn dampens hypothalamic-pituitary-adrenocortical (HPA) axis activity. We tested whether similar relations exist in humans, at least cross-sectionally. Fifty-nine healthy premenopausal women were exposed to a standard laboratory stressor to examine HPA response to acute stress and underwent diurnal saliva sampling for basal cortisol and response to dexamethasone administration. Based on perceived stress scores, women were divided into extreme quartiles of low versus high stress categories. We found as hypothesized that the high stress group had significantly greater BMI and sagittal diameter, and reported greater emotional eating. In response to acute lab stressor, the high stress group showed a blunted cortisol response, lower diurnal cortisol levels, and greater suppression in response to dexamethasone. These cross-sectional findings support the animal model, which suggests that long-term adaptation to chronic stress in the face of dense calories result in greater visceral fat accumulation (via ingestion of calorie-dense food), which in turn modulates HPA axis response, resulting in lower cortisol levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. High-Risk Stress Fractures: Diagnosis and Management.

    Science.gov (United States)

    McInnis, Kelly C; Ramey, Lindsay N

    2016-03-01

    Stress fractures are common overuse injuries in athletes. They occur during periods of increased training without adequate rest, disrupting normal bone reparative mechanisms. There are a host of intrinsic and extrinsic factors, including biochemical and biomechanical, that put athletes at risk. In most stress fractures, the diagnosis is primarily clinical, with imaging indicated at times, and management focused on symptom-free relative rest with advancement of activity as tolerated. Overall, stress fractures in athletes have an excellent prognosis for return to sport, with little risk of complication. There is a subset of injuries that have a greater risk of fracture progression, delayed healing, and nonunion and are generally more challenging to treat with nonoperative care. Specific locations of high-risk stress fracture include the femoral neck (tension side), patella, anterior tibia, medial malleolus, talus, tarsal navicular, proximal fifth metatarsal, and great toe sesamoids. These sites share a characteristic region of high tensile load and low blood flow. High-risk stress fractures require a more aggressive approach to evaluation, with imaging often necessary, to confirm early and accurate diagnosis and initiate immediate treatment. Treatment consists of nonweight-bearing immobilization, often with a prolonged period away from sport, and a more methodic and careful reintroduction to athletic activity. These stress fractures may require surgical intervention. A high index of suspicion is essential to avoid delayed diagnosis and optimize outcomes in this subset of stress fractures. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  1. High occupational stress and low career satisfaction of Korean surgeons.

    Science.gov (United States)

    Kang, Sang Hee; Boo, Yoon Jung; Lee, Ji Sung; Han, Hyung Joon; Jung, Cheol Woong; Kim, Chong Suk

    2015-02-01

    Surgery is a demanding and stressful field in Korea. Occupational stress can adversely affect the quality of care, decrease job satisfaction, and potentially increase medical errors. The aim of this study was to investigate the occupational stress and career satisfaction of Korean surgeons. We have conducted an electronic survey of 621 Korean surgeons for the occupational stress. Sixty-five questions were used to assess practical and personal characteristics and occupational stress using the Korean occupational stress scale (KOSS). The mean KOSS score was 49.31, which was higher than the average of Korean occupational stress (45.86) or that of other specialized professions (46.03). Young age, female gender, long working hours, and frequent night duties were significantly related to the higher KOSS score. Having spouse, having hobby and regular exercise decreased the KOSS score. Multiple linear regression analysis showed that long working hours and regular exercise were the independent factors associated with the KOSS score. Less than 50% of surgeons answered that they would become a surgeon again. Most surgeons (82.5%) did not want to recommend their child follow their career. Korean Surgeons have high occupational stress and low level of career satisfaction.

  2. The Chasm Remains.

    Science.gov (United States)

    Hill, Paul T.; Guin, Kacey; Celio, Mary Beth

    2003-01-01

    Argues that "A Nation at Risk" failed to address adequately problems of urban education, and thus the achievement gap between minority and white students still exists. Describes several problems that still plague low-performing urban schools, such as bureaucratic aversion to change, high levels of poverty, and low teacher quality and…

  3. Novel oral amphotericin B formulation (iCo-010) remains highly effective against murine systemic candidiasis following exposure to tropical temperature.

    Science.gov (United States)

    Wasan, Kishor M; Sivak, Olena; Bartlett, Karen; Wasan, Ellen K; Gershkovich, Pavel

    2015-01-01

    To evaluate the antifungal activity of amphotericin B (AmB) in a mouse model of systemic candidiasis following administration of a novel oral AmB formulation (iCo-010) that has been pre-exposed to tropical temperatures. Amphotericin B (AmB) was prepared as a 5 mg/mL dispersion in a mixture of Peceol, Gelucire 44/14 and VitE-TPGS 2,3 (iCo-010). The formulation was protected from light and incubated in a sealed container at 43 °C for 60 days. Mice infected with Candida albicans were treated with either iCo-010 formulation pre-incubated at 43 °C for 60 days or freshly prepared iCo-010 formulation at doses of 5, 10 and 20 mg/kg once daily for five consecutive days. Single intravenous 5 mg/kg dose of AmBisome® was used as a positive control group. Seven days following the last dose, the kidney, liver, spleen, lung, heart and brain were removed and the number of colony forming units (CFUs) was determined as a measure of tissue fungal load. In addition, the concentration of AmB within each tissue was determined using high performance liquid chromatography (HPLC). There were no significant differences in the reduction of CFUs and the concentration of AmB recovered in all organs at all iCo-010 doses tested between the freshly prepared iCo-010 formulation compared to the formulation that was incubated at 43 °C for 60 days. A novel oral AmB formulation, iCo-010, incubated at 43 °C for 60 days to simulate the exposure of the formulation to tropical temperatures remained highly effective against murine systemic candidiasis.

  4. Oxygen consumption remains stable while ammonia excretion is reduced upon short time exposure to high salinity in Macrobrachium acanthurus (Caridae: Palaemonidae, a recent freshwater colonizer

    Directory of Open Access Journals (Sweden)

    Carolina A. Freire

    2017-10-01

    Full Text Available ABSTRACT Palaemonid shrimps occur in the tropical and temperate regions of South America and the Indo-Pacific, in brackish/freshwater habitats, and marine coastal areas. They form a clade that recently (i.e., ~30 mya invaded freshwater, and one included genus, Macrobrachium Bate, 1868, is especially successful in limnic habitats. Adult Macrobrachium acanthurus (Wiegmann, 1836 dwell in coastal freshwaters, have diadromous habit, and need brackish water to develop. Thus, they are widely recognized as euryhaline. Here we test how this species responds to a short-term exposure to increased salinity. We hypothesized that abrupt exposure to high salinity would result in reduced gill ventilation/perfusion and decreased oxygen consumption. Shrimps were subjected to control (0 psu and experimental salinities (10, 20, 30 psu, for four and eight hours (n = 8 in each group. The water in the experimental containers was saturated with oxygen before the beginning of the experiment; aeration was interrupted before placing the shrimp in the experimental container. Dissolved oxygen (DO, ammonia concentration, and pH were measured from the aquaria water, at the start and end of each experiment. After exposure, the shrimp’s hemolymph was sampled for lactate and osmolality assays. Muscle tissue was sampled for hydration content (Muscle Water Content, MWC. Oxygen consumption was not reduced and hemolymph lactate did not increase with increased salinity. The pH of the water decreased with time, under all conditions. Ammonia excretion decreased with increased salinity. Hemolymph osmolality and MWC remained stable at 10 and 20 psu, but osmolality increased (~50% and MWC decreased (~4% at 30 psu. The expected reduction in oxygen consumption was not observed. This shrimp is able to tolerate significant changes in water salt concentrations for a few hours by keeping its metabolism in aerobic mode, and putatively shutting down branchial salt uptake to avoid massive salt

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

    Energy Technology Data Exchange (ETDEWEB)

    Uhlig, Benjamin

    2009-07-01

    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.)

  6. Stress and sleep quality in high school brazilian adolescents

    Directory of Open Access Journals (Sweden)

    Gema Mesquita

    2010-06-01

    Full Text Available OBJECTIVE: The objective of the present study is to analyze the effect of stress on sleep quality in a group of adolescents. METHOD: Two high schools in Alfenas, southern Minas Gerais State, Brazil, were chosen to participate in the study. The sample consisted of both genders (n=160 with 65.63% females. The age range of participants was 15 to18 years. The Pittsburgh Sleep Quality Index (PSQI was applied for collection of data to quantify sleep quality. The Lipp Inventory of Stress Symptoms that objectively identifies symptoms of stress was applied. RESULTS: It was observed that 23.53% of stressed students and 45.33% of unstressed ones sleep well; 76.47% of stressed pupils and 54.67% of those unstressed do not sleep well. With regard to school performance, a mean of 0.65 was found for stressed students and 0.60 for those without stress, Mann-Whitney (p=0.0596. CONCLUSION: Stress contributed to raising the percentage of poor sleepers, as ell as increasing ean school performance.OBJETIVO: O objetivo do presente estudo foi analisar a influência do stress sobre a qualidade do sono em um grupo de adolescentes. MÉTODO: Foram escolhidas duas instituições educacionais do ensino médio, na cidade de Alfenas, sul de Minas Gerais, Brasil. A amostra foi composta por ambos os sexos (n=160, com 65,63% do sexo feminino. A faixa etária dos participantes foi de 15 a 18 anos. Para a coleta de dados aplicou-se: Índice de Qualidade de Sono de Pittsburgh (IQSP utilizado para quantificar a qualidade do sono; o Inventário de Sintomas de Stress para Adultos de Lipp (ISSL que identifica de modo objetivo a sintomatologia de stress foi aplicado. RESULTADOS: Observou-se que 23,53% dos estressados dormem bem e 45,33% dos não estressados dormem bem; 76,47% dos estressados não dormem bem e 54,67% dos não estressados não dormem bem. Quanto ao rendimento escolar têm-se as médias 0,65 para os alunos estressados e 0,60 para aqueles que não sofrem de stress, Mann

  7. Effects of high mean stress on the high-cycle fatigue behavior of PWA 1480

    International Nuclear Information System (INIS)

    Majumdar, S.; Antolovich, S.; Milligan, W.

    1985-03-01

    PWA 1480 is a potential candidate material for use in the high-pressure fuel turbine blade of the Space Shuttle Main Engine. As an engine material it will be subjected to high-cycle fatigue loading superimposed on a high mean stress due to combined centrifugal and thermal loadings. This paper describes results obtained in an ongoing program to determine the effects of a high mean stress on the high-cycle fatigue behavior of this material

  8. Internal Stresses in Wires for High Field Magnets

    International Nuclear Information System (INIS)

    Han, K.; Embury, J.D.; Lawson, A.C.; Von Dreele, R.B.; Wood, J.T.; Richardson, J.W. Jr.

    1998-01-01

    The codeformation of Cu-Ag or Cu-Nb composite wires used for high field magnets has a number of important microstructural consequences, including the production of very fine scale structures, the development of very high internal surface area to volume ratios during the drawing and the storage of defects at interphase interfaces. In addition, the fabrication and codeformation of phases which differ in crystal structure, thermal expansion, elastic modulus and lattice parameter lead to the development of short wavelength internal stresses. These internal stresses are measured by neutron diffraction and transmission electron microscopy as a function of the imposed drawing strain. The internal stresses lead to important changes in elastic plastic response which can be related to both magnet design and service life and these aspects will be described in detail

  9. Machine Learning for High-Throughput Stress Phenotyping in Plants.

    Science.gov (United States)

    Singh, Arti; Ganapathysubramanian, Baskar; Singh, Asheesh Kumar; Sarkar, Soumik

    2016-02-01

    Advances in automated and high-throughput imaging technologies have resulted in a deluge of high-resolution images and sensor data of plants. However, extracting patterns and features from this large corpus of data requires the use of machine learning (ML) tools to enable data assimilation and feature identification for stress phenotyping. Four stages of the decision cycle in plant stress phenotyping and plant breeding activities where different ML approaches can be deployed are (i) identification, (ii) classification, (iii) quantification, and (iv) prediction (ICQP). We provide here a comprehensive overview and user-friendly taxonomy of ML tools to enable the plant community to correctly and easily apply the appropriate ML tools and best-practice guidelines for various biotic and abiotic stress traits. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Effects of high concentration of chromium stress on physiological ...

    African Journals Online (AJOL)

    We studied the effects of high concentration of chromium (Cr) stress on physiological and biochemical characters and accumulation of Cr in Pingyang Tezao tea [Camellia sinensis (L) O. Kutze 'Pingyangtezao'] through a pot experiment. The results show that the indicators of photosynthesis were all suppressed with ...

  11. High salt intake enhances swim stress-induced PVN vasopressin cell activation and active stress coping.

    Science.gov (United States)

    Mitchell, N C; Gilman, T L; Daws, L C; Toney, G M

    2018-07-01

    Stress contributes to many psychiatric disorders; however, responsivity to stressors can vary depending on previous or current stress exposure. Relatively innocuous heterotypic (differing in type) stressors can summate to result in exaggerated neuronal and behavioral responses. Here we investigated the ability of prior high dietary sodium chloride (salt) intake, a dehydrating osmotic stressor, to enhance neuronal and behavioral responses of mice to an acute psychogenic swim stress (SS). Further, we evaluated the contribution of the osmo-regulatory stress-related neuropeptide arginine vasopressin (VP) in the hypothalamic paraventricular nucleus (PVN), one of only a few brain regions that synthesize VP. The purpose of this study was to determine the impact of high dietary salt intake on responsivity to heterotypic stress and the potential contribution of VPergic-mediated neuronal activity on high salt-induced stress modulation, thereby providing insight into how dietary (homeostatic) and environmental (psychogenic) stressors might interact to facilitate psychiatric disorder vulnerability. Salt loading (SL) with 4% saline for 7 days was used to dehydrate and osmotically stress mice prior to exposure to an acute SS. Fluid intake and hematological measurements were taken to quantify osmotic dehydration, and serum corticosterone levels were measured to index stress axis activation. Immunohistochemistry (IHC) was used to stain for the immediate early gene product c-Fos to quantify effects of SL on SS-induced activation of neurons in the PVN and extended amygdala - brain regions that are synaptically connected and implicated in responding to osmotic stress and in modulation of SS behavior, respectively. Lastly, the role of VPergic PVN neurons and VP type 1 receptor (V1R) activity in the amygdala in mediating effects of SL on SS behavior was evaluated by quantifying c-Fos activation of VPergic PVN neurons and, in functional experiments, by nano-injecting the V1R selective

  12. Fatigue crack closure behavior at high stress ratios

    Science.gov (United States)

    Turner, C. Christopher; Carman, C. Davis; Hillberry, Ben M.

    1988-01-01

    Fatigue crack delay behavior at high stress ratio caused by single peak overloads was investigated in two thicknesses of 7475-T731 aluminum alloy. Closure measurements indicated no closure occurred before or throughout the overload plastic zones following the overload. This was further substantiated by comparing the specimen compliance following the overload with the compliance of a low R ratio test when the crack was fully open. Scanning electron microscope studies revealed that crack tunneling and possibly reinitiation of the crack occurred, most likely a result of crack-tip blunting. The number of delay cycles was greater for the thinner mixed mode stress state specimen than for the thicker plane strain stress state specimen, which is similar to low R ratio test results and may be due to a larger plastic zone for the mixed mode cased.

  13. Integrative Medicine Patients Have High Stress, Pain, and Psychological Symptoms.

    Science.gov (United States)

    Wolever, Ruth Q; Goel, Nikita S; Roberts, Rhonda S; Caldwell, Karen; Kligler, Benjamin; Dusek, Jeffery A; Perlman, Adam; Dolor, Rowena; Abrams, Donald I

    2015-01-01

    Integrative medicine (IM) is a rapidly growing field whose providers report clinical success in treating significant stress, chronic pain, and depressive and anxiety symptoms. While IM therapies have demonstrated efficacy for numerous medical conditions, IM for psychological symptoms has been slower to gain recognition in the medical community. This large, cross-sectional study is the first of its kind to document the psychosocial profiles of 4182 patients at 9 IM clinics that form the BraveNet Practice-Based Research Network (PBRN). IM patients reported higher levels of perceived stress, pain, and depressive symptoms, and lower levels of quality of life compared with national norms. Per provider reports, 60% of patients had at least one of the following: stress (9.3%), fatigue (10.2%), anxiety (7.7%), depression (7.2%), and/or sleep disorders (4.8%). Pain, having both physiological and psychological components, was also included and is the most common condition treated at IM clinics. Those with high stress, psychological conditions, and pain were most frequently treated with acupuncture, IM physician consultation, exercise, chiropractic services, diet/nutrition counseling, and massage. With baseline information on clinical presentation and service utilization, future PBRN studies can examine promising interventions delivered at the clinic to treat stress and psychological conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Psychological stress in high level sailors during competition

    Directory of Open Access Journals (Sweden)

    Luciana Segato

    2010-09-01

    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.

  15. Psychological stress in high level sailors during competition

    Directory of Open Access Journals (Sweden)

    L. Segato

    2010-01-01

    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.

  16. Identification of Variants of Hepatitis C Virus (HCV Entry Factors in Patients Highly Exposed to HCV but Remaining Uninfected: An ANRS Case-Control Study.

    Directory of Open Access Journals (Sweden)

    Baptiste Fouquet

    Full Text Available Hepatitis C virus (HCV causes persistent infection in 75% of cases and is a major public health problem worldwide. More than 92% of intravenous drug users (IDU infected by human immunodeficiency virus type 1 (HIV-1 are seropositive for HCV, and it is conceivable that some HIV-1-infected IDU who remain uninfected by HCV may be genetically resistant.Here we conducted a case-control study to identify mutations in HCV entry coreceptors in HIV-infected IDU who remained uninfected by HCV. We recruited 138 patients, comprising 22 HIV+ HCV- case IDU and 116 HIV+ HCV+ control IDU. We focused on coreceptors in which point mutations are known to abolish HCV infectivity in vitro. Our previous study of the Claudin-1 gene revealed no specific variants in the same case population. Here we performed direct genomic sequencing of the Claudin-6, Claudin-9, Occludin and Scavenger receptor-B1 (SCARB1 gene coding regions. Most HIV+ HCV- IDU had no mutations in HCV coreceptors. However, two HIV+ HCV- patients harbored a total of four specific mutations/variants of HCV entry factors that were not found in the HIV+ HCV+ controls. One case patient harbored heterozygous variants of both Claudin-6 and Occludin, and the other case patient harbored two heterozygous variants of SCARB1. This suggests that HCV resistance might involve complex genetic events and factors other than coreceptors, a situation similar to that reported for HIV-1 resistance.

  17. Creep, fatigue and creep-fatigue damage evaluation and estimation of remaining life of SUS 304 austenitic stainless steel at high temperature

    International Nuclear Information System (INIS)

    Nishino, Seiichi; Sakane, Masao; Ohnami, Masateru

    1986-01-01

    Experimental study was made on the damage evaluation and estimation of remaining life of SUS 304 stainless steel in creep, low-cycle fatigue and creep-fatigue at 873 K in air. Creep, fatigue and creep-fatigue damage curves were drawn by the method proposed by D.A. Woodford and the relations between these damages and non-destructive parameters, i.e., microvickers hardness and quantities obtained from X-ray diffraction, were discussed. From these tests, the following conclusions were obtained. (1) Constant damage lines in the diagram of remaining lives in creep and fatigue could be drawn by changing load levels during the tests. Constant damage lines in creep-fatigue were also made by a linear damage rule using both static creep and fatigue damage curves, which agree well with the experimental data in creep-fatigue. (2) Microvickers hardness and half-value breadth in X-ray diffraction are appropriate parameters to evaluate creep damage but are not proper to evaluate fatigue damage. Particle size and microstrain obtained by X-ray profile analysis are good parameters to evaluate both creep and fatigue damages. (author)

  18. Modelling Of Residual Stresses Induced By High Speed Milling Process

    International Nuclear Information System (INIS)

    Desmaison, Olivier; Mocellin, Katia; Jardin, Nicolas

    2011-01-01

    Maintenance processes used in heavy industries often include high speed milling operations. The reliability of the post-process material state has to be studied. Numerical simulation appears to be a very interesting way to supply an efficient residual stresses (RS) distribution prediction.Because the adiabatic shear band and the serrated chip shaping are features of the austenitic stainless steel high speed machining, a 2D high speed orthogonal cutting model is briefly presented. This finite element model, developed on Forge registered software, is based on data taken from Outeiro and al.'s paper [1]. A new behaviour law fully coupling Johnson-Cook's constitutive law and Latham and Cockcroft's damage model is detailed in this paper. It ensures results that fit those found in literature.Then, the numerical tools used on the 2D model are integrated to a 3D high speed milling model. Residual stresses distribution is analysed, on the surface and into the depth of the material. Various revolutions and passes of the two teeth hemispheric mill on the workpiece are simulated. Thus the sensitivity of the residual stresses generation to the cutting conditions can be discussed. In order to validate the 3D model, a comparison of the cutting forces measured by EDF R and D to those given by numerical simulations is achieved.

  19. Adolescents' sleep in low-stress and high-stress (exam) times: a prospective quasi-experiment

    NARCIS (Netherlands)

    Dewald, J.F.; Meijer, A.M.; Oort, F.J.; Kerkhof, G.A.; Bögels, S.M.

    2014-01-01

    This prospective quasi-experiment (N=175; mean age: 15.14 years) investigates changes in adolescents' sleep from low-stress (regular school week) to high-stress times (exam week) and examines the (moderating) role of chronic sleep reduction, baseline stress, and gender. Sleep was monitored over

  20. Adolescents' Sleep in Low-Stress and High-Stress (Exam) Times: A Prospective Quasi-Experiment

    NARCIS (Netherlands)

    Dewald, Julia F.; Meijer, Anne Marie; Oort, Frans J.; Kerkhof, Gerard A.; Bögels, Susan M.

    2014-01-01

    This prospective quasi-experiment (N = 175; mean age = 15.14 years) investigates changes in adolescents' sleep from low-stress (regular school week) to high-stress times (exam week), and examines the (moderating) role of chronic sleep reduction, baseline stress, and gender. Sleep was monitored over

  1. High intake of heterocyclic amines from meat is associated with oxidative stress.

    Science.gov (United States)

    Carvalho, A M; Miranda, A M; Santos, F A; Loureiro, A P M; Fisberg, R M; Marchioni, D M

    2015-04-28

    High meat intake has been related to chronic diseases such as cancer and CVD. One hypothesis is that heterocyclic amines (HCA), which are formed during the cooking process of meat, can generate reactive species. These compounds can cause oxidation of lipids, proteins and DNA, resulting in oxidative stress, cell damage and loss of biological function. This association has been seen in vitro; however, it remains unclear in vivo. The aim of the present study was to investigate the association between oxidative stress and HCA intake, and oxidative stress and meat intake. Data were from the Health Survey for Sao Paulo--ISA-Capital (561 adult and elderly). Food intake was estimated by one 24-h dietary recall (24HR) complemented by a detailed FFQ with preferences of cooking methods and level of doneness for meat. HCA intake was estimated linking the meat from the 24HR to a database of HCA. Oxidative stress was estimated by malondialdehyde (MDA) concentration in the plasma, after derivatisation with thiobarbituric acid and quantification by HPLC/diode array. Analyses were performed using multivariate logistic regressions adjusted for smoking, sex, age, BMI, skin colour, energy intake, fruit and vegetable intake, and physical activity. A positive association between HCA intake and MDA concentration (OR 1·17; 95% CI 1·01, 1·38) was observed, showing that HCA from meat may contribute to increase oxidative stress, and may consequently increase the risk of chronic diseases.

  2. Transversal incision of the vagina favors the remaining of the tape in the middle-third urethra compared to longitudinal incision during transobturator sling procedures for stress urinary incontinence.

    Science.gov (United States)

    Pirtea, L; Sas, I; Ilina, Razvan; Grigoraș, D; Mazilu, O

    2015-07-17

    To describe a new type of incision of the vagina during transobturator sling procedure and to evaluate by ultrasound the tape position at 3, 6 and 12 months after surgery. We conducted a prospective study including 51 patients with urinary stress incontinence who underwent sling procedure using the transversal vaginal incision. Tape position was evaluated by ultrasound at 3, 6 and 12 months after surgery and expressed as a percentage of the urethral length (the proximal third of the urethral length 0-39 %, the middle third 40-60 %, and the distal third 60-100 %). Informed consent was obtained from all patients prior to their inclusion in the study. All procedures have been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments and were approved by the Institutional Review Board and Ethical Committee of "Victor Babeş" University of Medicine and Pharmacy Timisoara before the beginning of the study (no 7/17.04.2012). At 3 months after surgery, 3.92 % of the slings were located in the proximal third of the urethra, 88.23 % in the middle third of the urethra and 7.84 % in the distal third. At 6 and 12 months after surgery we obtained similar results: 9.81 % of the slings were located in the proximal third of the urethra, 82.35 % in the middle third and 7.84 % in the distal third of the urethra. The transversal incision of the vagina offers a minimal dissection along the long axis of the urethra favoring the remaining of the tape in the middle third of the urethra.

  3. Multiple High Voltage Pulse Stressing of Polymer Thick Film Resistors

    Directory of Open Access Journals (Sweden)

    Busi Rambabu

    2014-01-01

    Full Text Available The purpose of this paper is to study high voltage interactions in polymer thick film resistors, namely, polyvinyl chloride- (PVC- graphite thick film resistors, and their applications in universal trimming of these resistors. High voltages in the form of impulses for various pulse durations and with different amplitudes have been applied to polymer thick film resistors and we observed the variation of resistance of these resistors with high voltages. It has been found that the resistance of polymer thick film resistors decreases in the case of higher resistivity materials and the resistance of polymer thick film resistor increases in the case of lower resistivity materials when high voltage impulses are applied to them. It has been also found that multiple high voltage pulse (MHVP stressing can be used to trim the polymer thick film resistors either upwards or downwards.

  4. Modeling the distribution of white spruce (Picea glauca) for Alaska with high accuracy: an open access role-model for predicting tree species in last remaining wilderness areas

    Science.gov (United States)

    Bettina Ohse; Falk Huettmann; Stefanie M. Ickert-Bond; Glenn P. Juday

    2009-01-01

    Most wilderness areas still lack accurate distribution information on tree species. We met this need with a predictive GIS modeling approach, using freely available digital data and computer programs to efficiently obtain high-quality species distribution maps. Here we present a digital map with the predicted distribution of white spruce (Picea glauca...

  5. Role of high-fat diet in stress response of Drosophila.

    Directory of Open Access Journals (Sweden)

    Erilynn T Heinrichsen

    Full Text Available Obesity is associated with many diseases, one of the most common being obstructive sleep apnea (OSA, which in turn leads to blood gas disturbances, including intermittent hypoxia (IH. Obesity, OSA and IH are associated with metabolic changes, and while much mammalian work has been done, mechanisms underlying the response to IH, the role of obesity and the interaction of obesity and hypoxia remain unknown. As a model organism, Drosophila offers tremendous power to study a specific phenotype and, at a subsequent stage, to uncover and study fundamental mechanisms, given the conservation of molecular pathways. Herein, we characterize the phenotype of Drosophila on a high-fat diet in normoxia, IH and constant hypoxia (CH using triglyceride and glucose levels, response to stress and lifespan. We found that female flies on a high-fat diet show increased triglyceride levels (p<0.001 and a shortened lifespan in normoxia, IH and CH. Furthermore, flies on a high-fat diet in normoxia and CH show diminished tolerance to stress, with decreased survival after exposure to extreme cold or anoxia (p<0.001. Of interest, IH seems to rescue this decreased cold tolerance, as flies on a high-fat diet almost completely recovered from cold stress following IH. We conclude that the cross talk between hypoxia and a high-fat diet can be either deleterious or compensatory, depending on the nature of the hypoxic treatment.

  6. Notwithstanding High Prevalence of Overweight and Obesity, Smoking Remains the Most Important Factor in Poor Self-rated Health and Hospital Use in an Australian Regional Community

    Directory of Open Access Journals (Sweden)

    Helen Mary Haines

    2017-08-01

    Full Text Available Objective: To classify a rural community sample by their modifiable health behaviours and identify the prevalence of chronic conditions, poor self-rated health, obesity and hospital use. Method: Secondary analysis of a cross- sectional self-report questionnaire in the Hume region of Victoria, Australia. Cluster analysis using the two-step method was applied to responses to health behaviour items. Results: 1,259 questionnaires were completed. Overall 63% were overweight or obese. Three groups were identified: ‘Healthy Lifestyle’ (63%, ‘Non Smoking, Unhealthy Lifestyle’ (25% and ‘Smokers’ (12%. ‘Healthy lifestyle’ were older and more highly educated than the other two groups while ‘Non Smoking, Unhealthy Lifestyle’ were more likely to be obese. ‘Smokers’ had the highest rate of poor self-rated health. Prevalence of chronic conditions was similar in each group (>20%. ‘Smokers’ were twice as likely to have had two or more visits to hospital in the preceding year even after adjustment for age, gender and education. Conclusion: High rates of overweight and obesity were identified but ‘Smokers’ were at the greatest risk for poor self-rated health and hospitalisation. Implications for Public Health: Within an environment of high rates of chronic ill health and obesity, primary care clinicians and public health policy makers must maintain their vigilance in encouraging people to quit smoking.

  7. Average effect estimates remain similar as evidence evolves from single trials to high-quality bodies of evidence: a meta-epidemiologic study.

    Science.gov (United States)

    Gartlehner, Gerald; Dobrescu, Andreea; Evans, Tammeka Swinson; Thaler, Kylie; Nussbaumer, Barbara; Sommer, Isolde; Lohr, Kathleen N

    2016-01-01

    The objective of our study was to use a diverse sample of medical interventions to assess empirically whether first trials rendered substantially different treatment effect estimates than reliable, high-quality bodies of evidence. We used a meta-epidemiologic study design using 100 randomly selected bodies of evidence from Cochrane reports that had been graded as high quality of evidence. To determine the concordance of effect estimates between first and subsequent trials, we applied both quantitative and qualitative approaches. For quantitative assessment, we used Lin's concordance correlation and calculated z-scores; to determine the magnitude of differences of treatment effects, we calculated standardized mean differences (SMDs) and ratios of relative risks. We determined qualitative concordance based on a two-tiered approach incorporating changes in statistical significance and magnitude of effect. First trials both overestimated and underestimated the true treatment effects in no discernible pattern. Nevertheless, depending on the definition of concordance, effect estimates of first trials were concordant with pooled subsequent studies in at least 33% but up to 50% of comparisons. The pooled magnitude of change as bodies of evidence advanced from single trials to high-quality bodies of evidence was 0.16 SMD [95% confidence interval (CI): 0.12, 0.21]. In 80% of comparisons, the difference in effect estimates was smaller than 0.5 SMDs. In first trials with large treatment effects (>0.5 SMD), however, estimates of effect substantially changed as new evidence accrued (mean change 0.68 SMD; 95% CI: 0.50, 0.86). Results of first trials often change, but the magnitude of change, on average, is small. Exceptions are first trials that present large treatment effects, which often dissipate as new evidence accrues. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Omethoate treatment mitigates high salt stress inhibited maize seed germination.

    Science.gov (United States)

    Yang, Kejun; Zhang, Yifei; Zhu, Lianhua; Li, Zuotong; Deng, Benliang

    2018-01-01

    Omethoate (OM) is a highly toxic organophophate insecticide, which is resistant to biodegradation in the environment and is widely used for pest control in agriculture. The effect of OM on maize seed germination was evaluated under salt stress. Salt (800mM) greatly reduced germination of maize seed and this could be reversed by OM. Additionally, H 2 O 2 treatment further improved the effect of OM on seed germination. Higher H 2 O 2 content was measured in OM treated seed compared to those with salt stress alone. Dimethylthiourea (DTMU), a specific scavenger of reactive oxygen species (ROS), inhibited the effect of OM on seed germination, as did IMZ (imidazole), an inhibitor of NADPH oxidase. Abscisic acid (ABA) inhibited the effect of OM on seed germination, whereas fluridone, a specific inhibitor of ABA biosynthesis, enhanced the effect of OM. Taken together, these findings suggest a role of ROS and ABA in the promotion of maize seed germination by OM under salt stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. An Investigation of the Correlation among Sources of Stress, Perceived Stress, and Coping styles in High School Students

    Directory of Open Access Journals (Sweden)

    Farhadh Asghari

    2016-07-01

    Full Text Available Background and Objectives: Coping with stress is an important issue, especially in regard to source of stress and perceived stress in adolescence period. In this research, the correlation among stress sources, perceived stress, and coping styles was investigated in high school students. Methods: The present research was a descriptive correlational study. The research sample consisted of 575 high school students from the families of personnel of Bushehr University of Medical Sciences in education year 2014-15 who were selected by multistage cluster sampling method. Stress source scale, perceived stress scale and Tehran coping styles scale, were used for data collection. The data were analyzed using statistical methods, including Pearson correlation coefficient and multivariate regression analysis. Results: In this study, 50% of students had perceived stress higher than cut-off point. Stress sources of students were related to school and maturity. There was a positive correlation between problem-oriented coping style and perceived stress, and there was a negative and inverse correlation between problem-oriented coping style and stress related to school and maturity. There was a positive correlation between positive emotion-oriented coping style and perceived stress, but there was a negative and inverse correlation between problem-oriented coping style and stress related to school and maturity. There was no significant correlation between emotion-oriented coping style and stress related to school, maturity, family, and peers. There was a positive correlation between negative emotion-oriented coping style and stress related to school, maturity, and peers. Conclusion: According to the findings of this study, the level of correlation was not significant and no significant relationship could be found between the variables with this level of correlation. Therefore, it is suggested that more extensive researches be conducted on the relationship between

  10. Treatment of posttraumatic stress disorder in postwar Kosovo high school students using mind-body skills groups: a pilot study.

    Science.gov (United States)

    Gordon, James S; Staples, Julie K; Blyta, Afrim; Bytyqi, Murat

    2004-04-01

    This preliminary study examined whether the practice of mind-body techniques decreases symptoms of posttraumatic stress in adolescents. Posttraumatic Stress Reaction Index questionnaires were collected from 139 high school students in Kosovo who participated in a 6-week program that included meditation, biofeedback, drawings, autogenic training, guided imagery, genograms, movement, and breathing techniques. Three separate programs were held approximately 2 months apart. There was no control group. Posttraumatic stress scores significantly decreased after participation in the programs. These scores remained decreased in the 2 groups that participated in the follow-up study when compared to pretest measures. These data indicate that mind-body skills groups were effective in reducing posttraumatic stress symptoms in war-traumatized high school students.

  11. Stress

    Science.gov (United States)

    ... can be life-saving. But chronic stress can cause both physical and mental harm. There are at least three different types of stress: Routine stress related to the pressures of work, family, and other daily responsibilities Stress brought about ...

  12. Oxidative stress at high altitude: genotype–phenotype correlations

    Directory of Open Access Journals (Sweden)

    Pandey P

    2014-05-01

    Full Text Available Priyanka Pandey,1,2 MA Qadar Pasha1,2 1CSIR-Institute of Genomics and Integrative Biology, Delhi, India; 2Department of Biotechnology, University of Pune, Ganeshkhind, Pune, India Abstract: It has been well-documented that the hypobaric hypoxic environment at high altitude (HA causes stress to both the permanent residents of HA and the sojourners. This oxidative stress primarily disturbs the oxygen-sensing and vascular homeostasis pathways, thereby upsetting normal human physiology, especially in sojourners. These environmental challenges have caused dynamic evolutionary changes within natives of HA, allowing them to develop adaptive plasticity. This review focuses on the genomic and biochemical features of the molecules involved in the oxygen-sensing and vascular homeostasis pathways with respect to HA pulmonary edema (HAPE and adaptation. We review the role of genetic markers such as HIF-prolyl hydroxylase 2, endothelial PAS domain-containing protein 1, endothelial nitric oxide synthase, endothelin 1, cytochrome b-245 alpha polypeptide, and glutathione S-transferase pi 1, as well as three circulatory biomarkers (nitric oxide, endothelin 1, and 8-iso-prostaglandin F2α, by highlighting approaches such as candidate gene and genome-wide, adopted in deciphering the pathways. A disagreement between the two approaches has also been highlighted. In addition, we discuss that an overrepresentation of wild-type alleles in HA natives and mutant alleles of same polymorphisms in HAPE patients implies that the allelic variants at the same locus are involved in adaptation and HAPE, respectively. Moreover, healthy sojourners present a number of genomic features similar to HA natives, further strengthening the concept of genetic predisposition. A trend in correlation between protective and risk alleles and altered levels of circulatory markers clearly documents the phenomenon of genotype–phenotype correlations. We conclude that the genetic and biochemical

  13. Stress corrosion cracking of highly irradiated 316 stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Morihito; Fukuya, Koji; Fujii, Katsuhiko; Nakajima, Nobuo; Furutani, Gen [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2001-09-01

    Mechanical property tests, grain boundary (GB) composition analysis and slow strain rate test (SSRT) in simulated PWR primary water changing dissolved hydrogen (DH) and dissolved oxygen (DO) content were carried out on cold-worked (CW) 316 stainless steels which were irradiated to 1-8x10{sup 26} n/m{sup 2} (E>0.1 MeV) in a Japanese PWR in order to evaluate irradiation-assisted stress corrosion cracking (IASCC) susceptibility. Highly irradiated stainless steels were susceptible to intergranular stress corrosion cracking (IGSCC) in both hydrogenated water and oxygenated water and to intergranular cracking in inert gas atmosphere. IASCC susceptibility increased with increasing DH content (0-45 ccH{sub 2}/kgH{sub 2}O). Hydrogen content of the section containing fracture surface was higher than that of the section far from fracture surface. These results suggest that hydrogen would have an important role for IASCC. While mechanical property was saturated, GB segregation and IASCC susceptibility increased with an increase in fluence, suggesting that GB segregation would have a dominant role for an increase in IASCC susceptibility at this high fluence region. (author)

  14. High lung volume increases stress failure in pulmonary capillaries

    Science.gov (United States)

    Fu, Z.; Costello, M. L.; Tsukimoto, K.; Prediletto, R.; Elliott, A. R.; Mathieu-Costello, O.; West, J. B.

    1992-01-01

    We previously showed that when pulmonary capillaries in anesthetized rabbits are exposed to a transmural pressure (Ptm) of approximately 40 mmHg, stress failure of the walls occurs with disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers. The present study was designed to test whether stress failure occurred more frequently at high than at low lung volumes for the same Ptm. Lungs of anesthetized rabbits were inflated to a transpulmonary pressure of 20 cmH2O, perfused with autologous blood at 32.5 or 2.5 cmH2O Ptm, and fixed by intravascular perfusion. Samples were examined by both transmission and scanning electron microscopy. The results were compared with those of a previous study in which the lung was inflated to a transpulmonary pressure of 5 cmH2O. There was a large increase in the frequency of stress failure of the capillary walls at the higher lung volume. For example, at 32.5 cmH2O Ptm, the number of endothelial breaks per millimeter cell lining was 7.1 +/- 2.2 at the high lung volume compared with 0.7 +/- 0.4 at the low lung volume. The corresponding values for epithelium were 8.5 +/- 1.6 and 0.9 +/- 0.6. Both differences were significant (P less than 0.05). At 52.5 cmH2O Ptm, the results for endothelium were 20.7 +/- 7.6 (high volume) and 7.1 +/- 2.1 (low volume), and the corresponding results for epithelium were 32.8 +/- 11.9 and 11.4 +/- 3.7. At 32.5 cmH2O Ptm, the thickness of the blood-gas barrier was greater at the higher lung volume, consistent with the development of more interstitial edema. Ballooning of the epithelium caused by accumulation of edema fluid between the epithelial cell and its basement membrane was seen at 32.5 and 52.5 cmH2O Ptm. At high lung volume, the breaks tended to be narrower and fewer were oriented perpendicular to the axis of the pulmonary capillaries than at low lung volumes. Transmission and scanning electron microscopy measurements agreed well. Our findings provide a physiological

  15. High glucose alters retinal astrocytes phenotype through increased production of inflammatory cytokines and oxidative stress.

    Directory of Open Access Journals (Sweden)

    Eui Seok Shin

    Full Text Available Astrocytes are macroglial cells that have a crucial role in development of the retinal vasculature and maintenance of the blood-retina-barrier (BRB. Diabetes affects the physiology and function of retinal vascular cells including astrocytes (AC leading to breakdown of BRB. However, the detailed cellular mechanisms leading to retinal AC dysfunction under high glucose conditions remain unclear. Here we show that high glucose conditions did not induce the apoptosis of retinal AC, but instead increased their rate of DNA synthesis and adhesion to extracellular matrix proteins. These alterations were associated with changes in intracellular signaling pathways involved in cell survival, migration and proliferation. High glucose conditions also affected the expression of inflammatory cytokines in retinal AC, activated NF-κB, and prevented their network formation on Matrigel. In addition, we showed that the attenuation of retinal AC migration under high glucose conditions, and capillary morphogenesis of retinal endothelial cells on Matrigel, was mediated through increased oxidative stress. Antioxidant proteins including heme oxygenase-1 and peroxiredoxin-2 levels were also increased in retinal AC under high glucose conditions through nuclear localization of transcription factor nuclear factor-erythroid 2-related factor-2. Together our results demonstrated that high glucose conditions alter the function of retinal AC by increased production of inflammatory cytokines and oxidative stress with significant impact on their proliferation, adhesion, and migration.

  16. Stress/strain/time properties of highly compacted bentonite

    International Nuclear Information System (INIS)

    Pusch, R.

    1983-05-01

    In this paper, a recently developed creep theory based on statistical mechanics has been used to analyze a number of experimental creep curves, the conclusion being that the creep behavior of dense MX-80 bentonite is in agreement with the physical model, and that the average bond strength is within the hydrogen bond region. The latter conclusion thus indicates that interparticle displacements leading to macroscopic creep takes place in interparticle and intraparticle water lattices. These findings were taken as a justification to apply the creep theory to a prediction of the settlement over a one million year period. It gave an estimated settlement of 1 cm at maximum, which is of no practical significance. The thixotropic and viscous properties of highly compacted bentonite present certain difficulties in the determination and evaluation of the stress/strain/time parameters that are required for ordinary elastic and elasto-plastic analyses. Still, these parameters could be sufficiently well identified to allow for a preliminary estimation of the stresses induced in the metal canisters by slight rock displacements. The analysis, suggests that a 1 cm rapid shear perpendicular to the axes of the canisters can take place without harming them. (author)

  17. Biochemical basis of the high resistance to oxidative stress in ...

    Indian Academy of Sciences (India)

    Unknown

    581. Keywords. Apoptosis; D. discoideum; oxidative stress; antioxidant enzymes; lipid peroxidation ..... multiple toxic effects of oxidative stress that is related to several pathological conditions ... culture. This work was supported by a grant to RB.

  18. Stresses evolution at high temperature (200°C on the interface of thin films in magnetic components

    Directory of Open Access Journals (Sweden)

    Doumit Nicole

    2014-07-01

    Full Text Available In the field of electronics, the increase of operating temperatures is a major industrial and scientific challenge because it allows reducing mass and volume of components especially in the aeronautic domain. So minimizing our components reduce masses and the use of cooling systems. For that, the behaviours and interface stresses of our components (in particular magnetic inductors and transformers that are constituted of one magnetic layer (YIG or an alumina substrate (Al2O3 representing the substrate and a thin copper film are studied at high temperature (200°C. COMSOL Multiphysics is used to simulate our work and to validate our measurements results. In this paper, we will present stresses results according to the geometrical copper parameters necessary for the component fabrication. Results show that stresses increase with temperature and copper’s thickness while remaining always lower than 200MPa which is the rupture stress value.

  19. Biochemical basis of the high resistance to oxidative stress

    Indian Academy of Sciences (India)

    Aerobic organisms experience oxidative stress due to generation of reactive oxygen species during normal aerobic metabolism. In addition, several chemicals also generate reactive oxygen species which induce oxidative stress. Thus oxidative stress constitutes a major threat to organisms living in aerobic environments.

  20. Primitive Path Analysis and Stress Distribution in Highly Strained Macromolecules.

    Science.gov (United States)

    Hsu, Hsiao-Ping; Kremer, Kurt

    2018-01-16

    Polymer material properties are strongly affected by entanglement effects. For long polymer chains and composite materials, they are expected to be at the origin of many technically important phenomena, such as shear thinning or the Mullins effect, which microscopically can be related to topological constraints between chains. Starting from fully equilibrated highly entangled polymer melts, we investigate the effect of isochoric elongation on the entanglement structure and force distribution of such systems. Theoretically, the related viscoelastic response usually is discussed in terms of the tube model. We relate stress relaxation in the linear and nonlinear viscoelastic regimes to a primitive path analysis (PPA) and show that tension forces both along the original paths and along primitive paths, that is, the backbone of the tube, in the stretching direction correspond to each other. Unlike homogeneous relaxation along the chain contour, the PPA reveals a so far not observed long-lived clustering of topological constraints along the chains in the deformed state.

  1. High stresses stored in fault zones: example of the Nojima fault (Japan

    Directory of Open Access Journals (Sweden)

    A.-M. Boullier

    2018-04-01

    Full Text Available During the last decade pulverized rocks have been described on outcrops along large active faults and attributed to damage related to a propagating seismic rupture front. Questions remain concerning the maximal lateral distance from the fault plane and maximal depth for dynamic damage to be imprinted in rocks. In order to document these questions, a representative core sample of granodiorite located 51.3 m from the Nojima fault (Japan that was drilled after the Hyogo-ken Nanbu (Kobe earthquake is studied by using electron backscattered diffraction (EBSD and high-resolution X-ray Laue microdiffraction. Although located outside of the Nojima damage fault zone and macroscopically undeformed, the sample shows pervasive microfractures and local fragmentation. These features are attributed to the first stage of seismic activity along the Nojima fault characterized by laumontite as the main sealing mineral. EBSD mapping was used in order to characterize the crystallographic orientation and deformation microstructures in the sample, and X-ray microdiffraction was used to measure elastic strain and residual stresses on each point of the mapped quartz grain. Both methods give consistent results on the crystallographic orientation and show small and short wavelength misorientations associated with laumontite-sealed microfractures and alignments of tiny fluid inclusions. Deformation microstructures in quartz are symptomatic of the semi-brittle faulting regime, in which low-temperature brittle plastic deformation and stress-driven dissolution-deposition processes occur conjointly. This deformation occurred at a 3.7–11.1 km depth interval as indicated by the laumontite stability domain. Residual stresses are calculated from deviatoric elastic strain tensor measured using X-ray Laue microdiffraction using the Hooke's law. The modal value of the von Mises stress distribution is at 100 MPa and the mean at 141 MPa. Such stress values are comparable to

  2. High stresses stored in fault zones: example of the Nojima fault (Japan)

    Science.gov (United States)

    Boullier, Anne-Marie; Robach, Odile; Ildefonse, Benoît; Barou, Fabrice; Mainprice, David; Ohtani, Tomoyuki; Fujimoto, Koichiro

    2018-04-01

    During the last decade pulverized rocks have been described on outcrops along large active faults and attributed to damage related to a propagating seismic rupture front. Questions remain concerning the maximal lateral distance from the fault plane and maximal depth for dynamic damage to be imprinted in rocks. In order to document these questions, a representative core sample of granodiorite located 51.3 m from the Nojima fault (Japan) that was drilled after the Hyogo-ken Nanbu (Kobe) earthquake is studied by using electron backscattered diffraction (EBSD) and high-resolution X-ray Laue microdiffraction. Although located outside of the Nojima damage fault zone and macroscopically undeformed, the sample shows pervasive microfractures and local fragmentation. These features are attributed to the first stage of seismic activity along the Nojima fault characterized by laumontite as the main sealing mineral. EBSD mapping was used in order to characterize the crystallographic orientation and deformation microstructures in the sample, and X-ray microdiffraction was used to measure elastic strain and residual stresses on each point of the mapped quartz grain. Both methods give consistent results on the crystallographic orientation and show small and short wavelength misorientations associated with laumontite-sealed microfractures and alignments of tiny fluid inclusions. Deformation microstructures in quartz are symptomatic of the semi-brittle faulting regime, in which low-temperature brittle plastic deformation and stress-driven dissolution-deposition processes occur conjointly. This deformation occurred at a 3.7-11.1 km depth interval as indicated by the laumontite stability domain. Residual stresses are calculated from deviatoric elastic strain tensor measured using X-ray Laue microdiffraction using the Hooke's law. The modal value of the von Mises stress distribution is at 100 MPa and the mean at 141 MPa. Such stress values are comparable to the peak strength of a

  3. Residual stress in a thick section high strength T-butt weld

    International Nuclear Information System (INIS)

    Pearce, S.V.; Linton, V.M.; Oliver, E.C.

    2008-01-01

    Residual stresses in a structure are generated as a result of the various fabrication and welding processes used to make the component. Being able to quantify these residual stresses is a key step in determining the continuing integrity of a structure in service. In this work, the residual stresses around a high strength, quenched and tempered steel T-butt web to curved plate weld have been measured using neutron strain scanning. The results show that the residual stresses near the weld were dominated by the welding residual stresses, while the stresses further from the weld were dominated by the bending residual stresses. The results suggest that the combination of welding-induced residual stress and significant pre-welding residual stress, as in the case of a thick bent section of plate can significantly alter the residual stress profile from that in a flat plate

  4. High carotenoids content can enhance resistance of selected Pinctada fucata families to high temperature stress.

    Science.gov (United States)

    Meng, Zihao; Zhang, Bo; Liu, Baosuo; Li, Haimei; Fan, Sigang; Yu, Dahui

    2017-02-01

    Carotenoids are a class of natural antioxidants widely found in aquatic, and they have significant effects on the growth, survival, and immunity of these organisms. To investigate the mechanisms of carotenoids in high temperature resistance, we observed the immune response of selected pearl oyster Pinctada fucata (Akoya pearl oyster) families with different carotenoids contents to high temperature stress. The results indicated that the survival rate (SR) of P. fucata decreased significantly with increase in temperature from 26 °C to 34 °C and with the decrease of total carotenoids content (TCC); when the TCC was higher, the SR tended to be higher. TCC and total antioxidant capacity (TAC) decreased significantly at 30 °C with increasing stress time. Correlation analysis indicated that TAC was positively and linearly correlated with TCC, and SR was S-type correlated with TCC and TAC. Immune analysis indicated that levels of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) in selected families (with higher TCC) under temperature stress (at 30 °C) were generally significantly lower than in the control group (with lowest TCC) and from 0 to 96 h, the levels of each of these substances varied significantly. Levels of SOD, CAT, and MDA within each family first rose from 0 to 3 h, then decreased to their lowest point after 24 h, and then rose again to their highest levels at 96 h. When TCC was higher, the levels of SOD, CAT, and MDA tended to be lower. These findings indicated that carotenoids play an important role in improving survival rates of P. fucata under high temperature stress by enhancing animals' antioxidant system, and could serve as an index for breeding stress-resistant lines in selective breeding practices. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Static and kinetic friction of granite at high normal stress

    Science.gov (United States)

    Byerlee, J.D.

    1970-01-01

    Frictional sliding on ground surfaces of granite, angle of sliding planes 30?? and 45??, was investigated as a function of confining pressure. Over the normal stress range of 2-12 kb, the static frictional shear stress ??s follows the relationship ??s = 0??5 + 0?? ??n and the kinetic frictional shear stress ??k was calculated to be ??k = 0??25 + 0??47 ??n. ?? 1970.

  6. High glucose-mediated oxidative stress impairs cell migration.

    Directory of Open Access Journals (Sweden)

    Marcelo L Lamers

    Full Text Available Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we evaluate the hypothesis that high glucose concentrations inhibit cell migration. Using CHO.K1 cells, NIH-3T3 fibroblasts, mouse embryonic fibroblasts and primary skin fibroblasts from control and diabetic rats cultured in 5 mM D-glucose (low glucose, LG, 25 mM D-glucose (high glucose, HG or 25 mM L-glucose medium (osmotic control--OC, we analyzed the migration speed, protrusion stability, cell polarity, adhesion maturation and the activity of the small Rho GTPase Rac1. We also analyzed the effects of reactive oxygen species by incubating cells with the antioxidant N-Acetyl-Cysteine (NAC. We observed that HG conditions inhibited cell migration when compared to LG or OC. This inhibition resulted from impaired cell polarity, protrusion destabilization and inhibition of adhesion maturation. Conversely, Rac1 activity, which promotes protrusion and blocks adhesion maturation, was increased in HG conditions, thus providing a mechanistic basis for the HG phenotype. Most of the HG effects were partially or completely rescued by treatment with NAC. These findings demonstrate that HG impairs cell migration due to an increase in oxidative stress that causes polarity loss, deficient adhesion and protrusion. These alterations arise, in large part, from increased Rac1 activity and may contribute to the poor wound healing observed in diabetic patients.

  7. High-resolution stress measurements for microsystem and semiconductor applications

    Science.gov (United States)

    Vogel, Dietmar; Keller, Juergen; Michel, Bernd

    2006-04-01

    Research results obtained for local stress determination on micro and nanotechnology components are summarized. It meets the concern of controlling stresses introduced to sensors, MEMS and electronics devices during different micromachining processes. The method bases on deformation measurement options made available inside focused ion beam equipment. Removing locally material by ion beam milling existing stresses / residual stresses lead to deformation fields around the milled feature. Digital image correlation techniques are used to extract deformation values from micrographs captured before and after milling. In the paper, two main milling features have been analyzed - through hole and through slit milling. Analytical solutions for stress release fields of in-plane stresses have been derived and compared to respective experimental findings. Their good agreement allows to settle a method for determination of residual stress values, which is demonstrated for thin membranes manufactured by silicon micro technology. Some emphasis is made on the elimination of main error sources for stress determination, like rigid body object displacements and rotations due to drifts of experimental conditions under FIB imaging. In order to illustrate potential application areas of the method residual stress suppression by ion implantation is evaluated by the method and reported here.

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

    Science.gov (United States)

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

    2008-06-01

    Stress is a growing public health problem, but there are only a few studies with national representative samples on the occurrence of stress. The aim of this study was to assess the level of stress, measured by the Perceived Stress Scale, in Denmark, and to identify and characterize the group with high levels of stress by factors measured at both the individual and neighbourhood levels in a national representative sample of the Danish population. The 10,022 participants in the National Health Interview Survey 2005 were asked about perceived stress and individual factors in a cross-sectional design. Information on neighbourhood factors was derived from a national registry. Data were analysed by means of logistic regression models. Low education, heavy smoking, physical inactivity, lack of social network and poor working conditions were associated with perceived stress. For women, living in a neighbourhood with low average education, and for men, living in a neighbourhood with a high rate of crime and a low degree of ethnic diversity, were associated with higher perceived stress. Perceived stress was also related to indicators of morbidity. The group with high 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.

  9. Academic stress levels were positively associated with sweet food consumption among Korean high-school students.

    Science.gov (United States)

    Kim, Yeonsoo; Yang, Hye Young; Kim, Ae-Jung; Lim, Yunsook

    2013-01-01

    The objectives of the present study were to identify the association among levels of persistent academic stress, appetite, and dietary habits and to determine the specific types of sweet foods consumed by Korean high-school students according to their academic stress levels. The study participants included 333 high-school students in the 10th to 12th grades in Kyunggi Province, Korea. The level of academic stress was scored with a 75-item academic stress scale and was categorized as high, medium, or low. A food-frequency questionnaire was used to measure the sugar intake from sweet foods. Korean high-school students with a high academic stress level had larger meals than the other students. Compared with students with low academic stress, the students with high academic stress had a higher frequency of sugar intake from the following food types: confectionaries, candies and chocolates, breads, and flavored milk. Moreover, compared with students with low academic stress, the students with high academic stress had a higher total intake of sugar from the following food types: confectionaries, candies, chocolates, flavored milk, traditional Korean beverages, and spicy, sweet, and fried rice cakes. Unhealthy stress-related food choices may compromise high-school students' health and contribute to their morbidity. The findings of the present study could be used to help nutritionists develop effective strategies for nutritional education and counseling to improve adolescent health. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Effects of High Mean Stress on High-cycle Fatigue Behavior of PWA 1480

    Science.gov (United States)

    Majumdar, S.; Antolovich, S. D.; Milligan, W. W.

    1985-01-01

    PWA 1480 is a potential candidate material for use in the high-pressure fuel turbine blade of the space shuttle main engine. As an engine material it will be subjected to high-cycle fatigue loading superimposed on a high mean stress due to combined centrifugal and thermal loadings. The present paper describes the results obtained in an ongoing program at the Argonne National Laboratory, sponsored by NASA Lewis, to determine the effects of a high mean stress on the high-cycle fatigue behavior of this material. Straight-gauge high-cycle fatigue specimens, 0.2 inch in diameter and with the specimen axis in the 001 direction, were supplied by NASA Lewis. The nominal room temperature yield and ultimate strength of the material were 146 and 154 ksi, respectively. Each specimen was polished with 1-micron diamond paste prior to testing. However, the surface of each specimen contained many pores, some of which were as large as 50 micron. In the initial tests, specimens were subjected to axial-strain-controlled cycles. However, very little cyclic plasticity was observed.

  11. Adverse effect of high migration stress on mental health during pregnancy: a case report.

    Science.gov (United States)

    Lecompte, Vanessa; Richard-Fortier, Zoé; Rousseau, Cécile

    2017-02-01

    Despite empirical evidence on the numerous consequences associated with high migration stress and mental health problems during pregnancy, a psychosocial stress assessment is rarely done, leaving it largely unaddressed. This case illustration sheds light on the common multiple risk factors related to migration stress that have to be taken into consideration when addressing perinatal mental health, and highlights the importance of obstetric appointments as a unique opportunity to assess psychosocial stress and mobilize interdisciplinary interventions.

  12. Crowd behaviour during high-stress evacuations in an immersive virtual environment

    Science.gov (United States)

    Kapadia, Mubbasir; Thrash, Tyler; Sumner, Robert W.; Gross, Markus; Helbing, Dirk; Hölscher, Christoph

    2016-01-01

    Understanding the collective dynamics of crowd movements during stressful emergency situations is central to reducing the risk of deadly crowd disasters. Yet, their systematic experimental study remains a challenging open problem due to ethical and methodological constraints. In this paper, we demonstrate the viability of shared three-dimensional virtual environments as an experimental platform for conducting crowd experiments with real people. In particular, we show that crowds of real human subjects moving and interacting in an immersive three-dimensional virtual environment exhibit typical patterns of real crowds as observed in real-life crowded situations. These include the manifestation of social conventions and the emergence of self-organized patterns during egress scenarios. High-stress evacuation experiments conducted in this virtual environment reveal movements characterized by mass herding and dangerous overcrowding as they occur in crowd disasters. We describe the behavioural mechanisms at play under such extreme conditions and identify critical zones where overcrowding may occur. Furthermore, we show that herding spontaneously emerges from a density effect without the need to assume an increase of the individual tendency to imitate peers. Our experiments reveal the promise of immersive virtual environments as an ethical, cost-efficient, yet accurate platform for exploring crowd behaviour in high-risk situations with real human subjects. PMID:27605166

  13. Crowd behaviour during high-stress evacuations in an immersive virtual environment.

    Science.gov (United States)

    Moussaïd, Mehdi; Kapadia, Mubbasir; Thrash, Tyler; Sumner, Robert W; Gross, Markus; Helbing, Dirk; Hölscher, Christoph

    2016-09-01

    Understanding the collective dynamics of crowd movements during stressful emergency situations is central to reducing the risk of deadly crowd disasters. Yet, their systematic experimental study remains a challenging open problem due to ethical and methodological constraints. In this paper, we demonstrate the viability of shared three-dimensional virtual environments as an experimental platform for conducting crowd experiments with real people. In particular, we show that crowds of real human subjects moving and interacting in an immersive three-dimensional virtual environment exhibit typical patterns of real crowds as observed in real-life crowded situations. These include the manifestation of social conventions and the emergence of self-organized patterns during egress scenarios. High-stress evacuation experiments conducted in this virtual environment reveal movements characterized by mass herding and dangerous overcrowding as they occur in crowd disasters. We describe the behavioural mechanisms at play under such extreme conditions and identify critical zones where overcrowding may occur. Furthermore, we show that herding spontaneously emerges from a density effect without the need to assume an increase of the individual tendency to imitate peers. Our experiments reveal the promise of immersive virtual environments as an ethical, cost-efficient, yet accurate platform for exploring crowd behaviour in high-risk situations with real human subjects. © 2016 The Authors.

  14. Systemic Oxidative Stress Is Increased to a Greater Degree in Young, Obese Women Following Consumption of a High Fat Meal

    Directory of Open Access Journals (Sweden)

    Richard J. Bloomer

    2009-01-01

    Full Text Available High fat meals induce oxidative stress, which is associated with the pathogenesis of disease. Obese individuals have elevated resting biomarkers of oxidative stress compared to non-obese. We compared blood oxidative stress biomarkers in obese (n = 14; 30 ± 2 years; BMI 35 ± 1 kg•m−2 and non-obese (n = 16; 24 ± 2 years; BMI 23 ± 1 kg•m−2 women, in response to a high fat meal. Blood samples were collected pre-meal (fasted, and at 1, 2, 4 and 6 hours post meal, and assayed for trolox equivalent antioxidant capacity (TEAC, xanthine oxidase activity (XO, hydrogen peroxide (H2O2, malondialdehyde (MDA, triglycerides (TAG, and glucose. An obesity status effect was noted for all variables (p 0.05, contrasts revealed greater values in obese compared to non-obese women for XO, H2O2, MDA, TAG and glucose, and lower values for TEAC at times from 1–6 hours post feeding (p ≤ 0.03. We conclude that young, obese women experience a similar pattern of increase in blood oxidative stress biomarkers in response to a high fat meal, as compared to non-obese women. However, the overall oxidative stress is greater in obese women, and values appear to remain elevated for longer periods of time post feeding. These data provide insight into another potential mechanism related to obesity-mediated morbidity.

  15. Stress

    Science.gov (United States)

    ... taking care of an aging parent. With mental stress, the body pumps out hormones to no avail. Neither fighting ... with type 1 diabetes. This difference makes sense. Stress blocks the body from releasing insulin in people with type 2 ...

  16. Phenome data - High-sugar stress - DGBY | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data ...s.zip File size: 90KB File name: Original file: High-sugar_stress.xls File URL: ftp://ftp.biosciencedbc.jp/archive/dgby/LATEST/Hi... Center for Protein Sequences) About This Database Database Description Download License Update History of Thi...s Database Site Policy | Contact Us Phenome data - High-sugar stress - DGBY | LSDB Archive ... ...List Contact us DGBY Phenome data - High-sugar stress Data detail Data name Phenome data - High-sugar stress

  17. Surrounding rock stress analysis of underground high level waste repository

    International Nuclear Information System (INIS)

    Liu Wengang; Wang Ju; Wang Guangdi

    2006-01-01

    During decay of nuclear waste, enormous energy was released, which results in temperature change of surrounding rock of depository. Thermal stress was produced because thermal expansion of rock was controlled. Internal structure of surrounding rock was damaged and strength of rock was weakened. So, variation of stress was a dynamic process with the variation of temperature. BeiShan region of Gansu province was determined to be the depository field in the future, it is essential to make research on granite in this region. In the process of experiment, basic physical parameters of granite were analyzed preliminary with MTS. Long range temperature and stress filed was simulated considering the damage effect of surrounding rock, and rules of temperature and stress was achieved. (authors)

  18. Notch size effects on high cycle fatigue limit stress of Udimet 720

    International Nuclear Information System (INIS)

    Ren Weiju; Nicholas, Theodore

    2003-01-01

    Notch size effects on the high cycle fatigue (HCF) limit stress of Ni-base superalloy Udimet 720 were investigated on cylindrical specimens with three notch sizes of the same stress concentration factor K t =2.74. The HCF limit stress corresponding to a life of 10 6 cycles was experimentally determined at a stress ratio of 0.1 and a frequency of 25 Hz at room temperature. The stresses were calculated using finite element analysis (FEA) and the specimens analyzed using scanning electron microscopy (SEM). Test results show that at the same K t value, notch size can slightly affect the HCF limit stress of U720 when notch root plasticity occurs. FEA and SEM results reveal that the notch size effects are influenced by a complicated combination of the stress and plastic strain fields at the notch tip, the nominal stress, and the effects of prior plastic deformation on fatigue crack initiation

  19. And the Dead Remain Behind

    Directory of Open Access Journals (Sweden)

    Peter Read

    2013-08-01

    Full Text Available In most cultures the dead and their living relatives are held in a dialogic relationship. The dead have made it clear, while living, what they expect from their descendants. The living, for their part, wish to honour the tombs of their ancestors; at the least, to keep the graves of the recent dead from disrepair. Despite the strictures, the living can fail their responsibilities, for example, by migration to foreign countries. The peripatetic Chinese are one of the few cultures able to overcome the dilemma of the wanderer or the exile. With the help of a priest, an Australian Chinese migrant may summon the soul of an ancestor from an Asian grave to a Melbourne temple, where the spirit, though removed from its earthly vessel, will rest and remain at peace. Amongst cultures in which such practices are not culturally appropriate, to fail to honour the family dead can be exquisitely painful. Violence is the cause of most failure.

  20. High-resolution endovaginal MR imaging in stress urinary incontinence

    Energy Technology Data Exchange (ETDEWEB)

    Stoker, Jaap; Lameris, Johan S. [Department of Radiology, Academic Medical Center, University of Amsterdam, P.O. Box 22700, 1100 DE, Amsterdam (Netherlands); Rociu, Elena [Department of Radiology, Academic Medical Center, University of Amsterdam, P.O. Box 22700, 1100 DE, Amsterdam (Netherlands); Department of Radiology, Erasmus Medical Center, 3015 GD, Rotterdam (Netherlands); Bosch, J.L.H. Ruud [Department of Urology, Erasmus Medical Center, 3015 GD, Rotterdam (Netherlands); Messelink, Embert J. [Department of Urology, Academic Medical Center, University of Amsterdam, P.O. Box 22700, 1100 DE, Amsterdam (Netherlands); Department of Urology, Onze Lieve Vrouwe Gasthuis, 1091 HA, Amsterdam (Netherlands); Hulst, Victor P.M. van der [Department of Radiology, Onze Lieve Vrouwe Gasthuis, 1091 HA, Amsterdam (Netherlands); Groenendijk, Annette G. [Department of Gynecology, Onze Lieve Vrouwe Gasthuis, 1091 HA, Amsterdam (Netherlands); Eijkemans, Marinus J.C. [Department of Public Health, Erasmus Medical Center, 3015 GD, Rotterdam (Netherlands)

    2003-08-01

    The causes of stress urinary incontinence are not completely known. Recent papers have stressed the importance of more anatomical information, which may help to elucidate the mechanism of stress urinary incontinence. The purpose of this study was to evaluate the prevalence of lesions of the urethral support mechanism and lesions (defects and scars, thinning) of levator ani muscle with endovaginal MRI in a case-control study. Forty women (median age 52 years, age range 40-65 years) - 20 patients with stress urinary incontinence (cases) and 20 age-matched healthy volunteers (controls) - underwent endovaginal MRI: axial, coronal, and sagittal T2-weighted turbo spin echo. The examinations were evaluated for the presence of lesions of urethral supporting structures and levator ani and scar tissue of the levator ani. The thickness of the levator ani muscle was measured. Lesions of the urethral support system and levator ani were significantly more prevalent in cases than in controls (p<0.01). Median levator ani thickness in patients was significantly lower than in healthy controls [2.5 mm (range 0.9-4.1 mm) vs 3.9 mm (range 1.4-7 mm)] (p<0.01). This study indicates a relationship between stress urine incontinence and the presence of lesions of the urethral support and levator ani and levator ani thinning. (orig.)

  1. The stress-strain relationship for multilayers of the high Tc superconducting oxides

    International Nuclear Information System (INIS)

    Hidaka, H.; Yamamura, H.

    1988-01-01

    This paper reports the calculation of the stress-strain relationship for multilayers of the high Tc superconducting oxides. The elucidation of this relationship is expected quite helpful for the preparation of high-quality multilayers of these materials. This calculation is possible to do in the same way of Timoshenko's bi-metal treatment. The authors did computation of the residual stress and strain, and the state of stress and strain for these multilayers has been acquired in detail by this calculation

  2. Parenting stress and parent support among mothers with high and low education

    OpenAIRE

    Parkes, Alison; Sweeting, Helen; Wight, Daniel

    2015-01-01

    Current theorizing and evidence suggest that parenting stress might be greater among parents from both low and high socioeconomic positions (SEP) compared with those from intermediate levels because of material hardship among parents of low SEP and employment demands among parents of high SEP. However, little is known about how this socioeconomic variation in stress relates to the support that parents receive. This study explored whether variation in maternal parenting stress in a population ...

  3. Stress corrosion cracking of several high strength ferrous and nickel alloys

    Science.gov (United States)

    Nelson, E. E.

    1971-01-01

    The stress corrosion cracking resistance of several high strength ferrous and nickel base alloys has been determined in a sodium chloride solution. Results indicate that under these test conditions Multiphase MP35N, Unitemp L605, Inconel 718, Carpenter 20Cb and 20Cb-3 are highly resistant to stress corrosion cracking. AISI 410 and 431 stainless steels, 18 Ni maraging steel (250 grade) and AISI 4130 steel are susceptible to stress corrosion cracking under some conditions.

  4. Red Assembly: the work remains

    Directory of Open Access Journals (Sweden)

    Leslie Witz

    installed. What to do at this limit, at the transgressive encounter between saying yes and no to history, remains the challenge. It is the very challenge of what insistently remains.

  5. Stress corrosion in high-strength aluminum alloys

    Science.gov (United States)

    Dorward, R. C.; Hasse, K. R.

    1980-01-01

    Report describes results of stress-corrosion tests on aluminum alloys 7075, 7475, 7050, and 7049. Tests compare performance of original stress-corrosion-resistant (SCR) aluminum, 7075, with newer, higher-strength SCR alloys. Alloys 7050 and 7049 are found superior in short-transverse cross-corrosion resistance to older 7075 alloy; all alloys are subject to self-loading effect caused by wedging of corrosion products in cracks. Effect causes cracks to continue to grow, even at very-low externally applied loads.

  6. Green business will remain green

    International Nuclear Information System (INIS)

    Marcan, P.

    2008-01-01

    It all started with two words. Climate change. The carbon dioxide trading scheme, which was the politicians' idea on solving the number one global problem, followed. Four years ago, when the project was begun, there was no data for project initiation. Quotas for polluters mainly from energy production and other energy demanding industries were distributed based on spreadsheets, maximum output and expected future development of economies. Slovak companies have had a chance to profit from these arrangements since 2005. Many of them took advantage of the situation and turned the excessive quotas into an extraordinary profit which often reached hundreds of million Sk. The fact that the price of free quotas offered for sale dropped basically to 0 in 2006 only proved that the initial distribution was too generous. And the market reacted to the first official measurements of emissions. Slovak companies also contributed to this development. However, when planning the maximum emission volumes for 2008-2012 period, in spite of the fact that actual data were available, their expectations were not realistic. A glance at the figures in the proposal of the Ministry of Environment is sufficient to realize that there will be no major change in the future. And so for many Slovak companies business with a green future will remain green for the next five years. The state decided to give to selected companies even more free space as far as emissions are concerned. The most privileged companies can expect quotas increased by tens of percent. (author)

  7. Job Satisfaction, Stress and Coping Strategies among Moroccan High School Teachers.

    Science.gov (United States)

    Benmansour, Naima

    1998-01-01

    Studied job stress, job satisfaction, and coping strategies through self-report measures from 153 Moroccan high school teachers. Results show that 45% of the teachers were satisfied with their jobs, but over half reported high levels of stress, negatively correlated with job satisfaction. Factor analysis of 16 coping strategies produced four…

  8. Wind-Induced Fatigue Analysis of High-Rise Steel Structures Using Equivalent Structural Stress Method

    Directory of Open Access Journals (Sweden)

    Zhao Fang

    2017-01-01

    Full Text Available Welded beam-to-column connections of high-rise steel structures are susceptive to fatigue damage under wind loading. However, most fatigue assessments in the field of civil engineering are mainly based on nominal stress or hot spot stress theories, which has the disadvantage of dependence on the meshing styles and massive curves selected. To address this problem, in this paper, the equivalent structural stress method with advantages of mesh-insensitive quality and capability of unifying different stress-life curves (S-N curves into one is introduced to the wind-induced fatigue assessment of a large-scale complicated high-rise steel structure. The multi-scale finite element model is established and the corresponding wind loading is simulated. Fatigue life assessments using equivalent structural stress method, hot spot stress method and nominal stress method are performed, and the results are verified and comparisons are made. The mesh-insensitive quality is also verified. The results show that the lateral weld toe of the butt weld connecting the beam flange plate and the column is the location where fatigue damage most likely happens. Nominal stress method considers fatigue assessment of welds in a more global way by averaging all the stress on the weld section while in equivalent structural stress method and hot spot method local stress concentration can be taken into account more precisely.

  9. Silicon photonics: some remaining challenges

    Science.gov (United States)

    Reed, G. T.; Topley, R.; Khokhar, A. Z.; Thompson, D. J.; Stanković, S.; Reynolds, S.; Chen, X.; Soper, N.; Mitchell, C. J.; Hu, Y.; Shen, L.; Martinez-Jimenez, G.; Healy, N.; Mailis, S.; Peacock, A. C.; Nedeljkovic, M.; Gardes, F. Y.; Soler Penades, J.; Alonso-Ramos, C.; Ortega-Monux, A.; Wanguemert-Perez, G.; Molina-Fernandez, I.; Cheben, P.; Mashanovich, G. Z.

    2016-03-01

    This paper discusses some of the remaining challenges for silicon photonics, and how we at Southampton University have approached some of them. Despite phenomenal advances in the field of Silicon Photonics, there are a number of areas that still require development. For short to medium reach applications, there is a need to improve the power consumption of photonic circuits such that inter-chip, and perhaps intra-chip applications are viable. This means that yet smaller devices are required as well as thermally stable devices, and multiple wavelength channels. In turn this demands smaller, more efficient modulators, athermal circuits, and improved wavelength division multiplexers. The debate continues as to whether on-chip lasers are necessary for all applications, but an efficient low cost laser would benefit many applications. Multi-layer photonics offers the possibility of increasing the complexity and effectiveness of a given area of chip real estate, but it is a demanding challenge. Low cost packaging (in particular, passive alignment of fibre to waveguide), and effective wafer scale testing strategies, are also essential for mass market applications. Whilst solutions to these challenges would enhance most applications, a derivative technology is emerging, that of Mid Infra-Red (MIR) silicon photonics. This field will build on existing developments, but will require key enhancements to facilitate functionality at longer wavelengths. In common with mainstream silicon photonics, significant developments have been made, but there is still much left to do. Here we summarise some of our recent work towards wafer scale testing, passive alignment, multiplexing, and MIR silicon photonics technology.

  10. High CO2 Primes Plant Biotic Stress Defences through Redox-Linked Pathways.

    Science.gov (United States)

    Mhamdi, Amna; Noctor, Graham

    2016-10-01

    Industrial activities have caused tropospheric CO 2 concentrations to increase over the last two centuries, a trend that is predicted to continue for at least the next several decades. Here, we report that growth of plants in a CO 2 -enriched environment activates responses that are central to defense against pathogenic attack. Salicylic acid accumulation was triggered by high-growth CO 2 in Arabidopsis (Arabidopsis thaliana) and other plants such as bean (Phaseolus vulgaris). A detailed analysis in Arabidopsis revealed that elevated CO 2 primes multiple defense pathways, leading to increased resistance to bacterial and fungal challenge. Analysis of gene-specific mutants provided no evidence that activation of plant defense pathways by high CO 2 was caused by stomatal closure. Rather, the activation is partly linked to metabolic effects involving redox signaling. In support of this, genetic modification of redox components (glutathione contents and NADPH-generating enzymes) prevents full priming of the salicylic acid pathway and associated resistance by high CO 2 The data point to a particularly influential role for the nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase, a cytosolic enzyme whose role in plants remains unclear. Our observations add new information on relationships between high CO 2 and oxidative signaling and provide novel insight into plant stress responses in conditions of increased CO 2 . © 2016 American Society of Plant Biologists. All Rights Reserved.

  11. High CO2 Primes Plant Biotic Stress Defences through Redox-Linked Pathways1[OPEN

    Science.gov (United States)

    2016-01-01

    Industrial activities have caused tropospheric CO2 concentrations to increase over the last two centuries, a trend that is predicted to continue for at least the next several decades. Here, we report that growth of plants in a CO2-enriched environment activates responses that are central to defense against pathogenic attack. Salicylic acid accumulation was triggered by high-growth CO2 in Arabidopsis (Arabidopsis thaliana) and other plants such as bean (Phaseolus vulgaris). A detailed analysis in Arabidopsis revealed that elevated CO2 primes multiple defense pathways, leading to increased resistance to bacterial and fungal challenge. Analysis of gene-specific mutants provided no evidence that activation of plant defense pathways by high CO2 was caused by stomatal closure. Rather, the activation is partly linked to metabolic effects involving redox signaling. In support of this, genetic modification of redox components (glutathione contents and NADPH-generating enzymes) prevents full priming of the salicylic acid pathway and associated resistance by high CO2. The data point to a particularly influential role for the nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase, a cytosolic enzyme whose role in plants remains unclear. Our observations add new information on relationships between high CO2 and oxidative signaling and provide novel insight into plant stress responses in conditions of increased CO2. PMID:27578552

  12. Social stress induces high intensity sleep in rats

    NARCIS (Netherlands)

    Meerlo, P; Pragt, Bertrand J.; Daan, S

    1997-01-01

    We studied the effect of social stress on sleep electroencephalogram (EEG) in rats. Animals were subjected to a single social defeat by introducing them in the cage of an aggressive male conspecific for 1 h. The animals responded to the social conflict by a sharp increase in EEG slow-wave activity

  13. Families OverComing under Stress (FOCUS) for Early Childhood: Building Resilience for Young Children in High Stress Families

    Science.gov (United States)

    Mogil, Catherine; Paley, Blair; Doud, Tricia; Havens, Linda; Moore-Tyson, Jessica; Beardslee, William R.; Lester, Patricia

    2010-01-01

    Parental distress and trauma affects the entire family, including the youngest children. Families OverComing Under Stress (FOCUS) is a targeted prevention program for high-risk families that aims to enhance family cohesion, support the parent-child relationship, and build emotional regulation, communication, and problem-solving skills across the…

  14. Soil mechanical stresses in high wheel load agricultural field traffic: a case study

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Schjønning, Per

    2017-01-01

    highly skewed. Across tyres, the maximum stress in the contact area correlated linearly with, but was much higher than, the mean ground pressure. For each of the three soil depths, the maximum stresses under the tyres were significantly correlated with the wheel load, but not with other loading......Subsoil compaction is a serious long-term threat to soil functions. Only a few studies have quantified the mechanical stresses reaching deep subsoil layers for modern high wheel load machinery. In the present study we measured the vertical stresses in the tyre–soil contact area and at 0.3, 0...

  15. Residual stress evaluation by Barkhausen signals with a magnetic field sensor for high efficiency electrical motors

    Science.gov (United States)

    Tsuchida, Yuji; Enokizono, Masato

    2018-04-01

    The iron loss of industrial motors increases by residual stress during manufacturing processes. It is very important to make clear the distribution of the residual stress in the motor cores to reduce the iron loss in the motors. Barkhausen signals which occur on electrical steel sheets can be used for the evaluation of the residual stress because they are very sensitive to the material properties. Generally, a B-sensor is used to measure Barkhausen signals, however, we developed a new H-sensor to measure them and applied it into the stress evaluation. It is supposed that the Barkhausen signals by using a H-sensor can be much effective to the residual stress on the electrical steel sheets by referring our results regarding to the stress evaluations. We evaluated the tensile stress of the electrical steel sheets by measuring Barkhausen signals by using our developed H-sensor for high efficiency electrical motors.

  16. Metabolic and oxidative stress markers in Wistar rats after 2 months on a high-fat diet.

    Science.gov (United States)

    Auberval, Nathalie; Dal, Stéphanie; Bietiger, William; Pinget, Michel; Jeandidier, Nathalie; Maillard-Pedracini, Elisa; Schini-Kerth, Valérie; Sigrist, Séverine

    2014-01-01

    Metabolic syndrome is associated with an increased risk of cardiovascular and hepatic complications. Oxidative stress in metabolic tissues has emerged as a universal feature of metabolic syndrome and its co-morbidities. We aimed to develop a rapidly and easily induced model of metabolic syndrome in rats to evaluate its impact on plasma and tissue oxidative stress. Metabolic syndrome was induced in rats using a high-fat diet (HFD), and these rats were compared to rats fed a normal diet (ND) for 2 months. Metabolic control was determined by measuring body weight, blood glucose, triglycerides, lipid peroxidation and protein carbonylation in plasma. Insulinemia was evaluated through the measure of C-peptide. Histological analysis was performed on the pancreas, liver and blood vessels. After 2 months, the HFD induced an increase in body weight, insulin and triglycerides. Liver steatosis was also observed in the HFD group, which was associated with an increase in glycogen storage. In the pancreas, the HFD induced islet hyperplasia. Tissue oxidative stress was also increased in the liver, pancreas and blood vessels, but plasma oxidative stress remained unchanged. This paper reports the development of a fast and easy model of rat metabolic syndrome associated with tissue oxidative stress. This model may be a good tool for the biological validation of drugs or antioxidants to limit or prevent the complications of metabolic syndrome.

  17. Study of stress corrosion cracking initiation of high alloy materials

    Energy Technology Data Exchange (ETDEWEB)

    Blahetova, Marie; Cihal, Vladimir; Lasek, Stanislav [Department of Materials Engineering, VSB - Technical University of Ostrava, tr. 17. listopadu 15, 708 33 Ostrava - Poruba (Czech Republic)

    2004-07-01

    The stainless steels and related alloys with sufficient resistance to a general corrosion can be susceptible to a localized corrosion (pitting, cracking, intergranular corrosion) in certain environment under specific conditions. The Drop Evaporation Test (DET) was developed for study of stainless materials resistance to stress corrosion cracking (SCC) at elevated temperatures 100 - 300 deg. C under constant external load using a chloride containing water solution. In the contribution the initiation and propagation of short cracks as well as pits were observed during the test. The crack initiation and/or propagation can be influenced by the cyclic thermal stresses, when the diluted water solution drops cool down the hot sample. The coordinates measurement of microscopic pits and sharp corrosion crack tips by the travelling microscope method allowed to derive the crack growth lengths and rates of short cracks. (authors)

  18. Study of stress corrosion cracking initiation of high alloy materials

    International Nuclear Information System (INIS)

    Blahetova, Marie; Cihal, Vladimir; Lasek, Stanislav

    2004-01-01

    The stainless steels and related alloys with sufficient resistance to a general corrosion can be susceptible to a localized corrosion (pitting, cracking, intergranular corrosion) in certain environment under specific conditions. The Drop Evaporation Test (DET) was developed for study of stainless materials resistance to stress corrosion cracking (SCC) at elevated temperatures 100 - 300 deg. C under constant external load using a chloride containing water solution. In the contribution the initiation and propagation of short cracks as well as pits were observed during the test. The crack initiation and/or propagation can be influenced by the cyclic thermal stresses, when the diluted water solution drops cool down the hot sample. The coordinates measurement of microscopic pits and sharp corrosion crack tips by the travelling microscope method allowed to derive the crack growth lengths and rates of short cracks. (authors)

  19. Deciphering Stress State of Seismogenic Faults in Oklahoma and Kansas Based on High-resolution Stress Maps

    Science.gov (United States)

    Qin, Y.; Chen, X.; Haffener, J.; Trugman, D. T.; Carpenter, B.; Reches, Z.

    2017-12-01

    Induced seismicity in Oklahoma and Kansas delineates clear fault trends. It is assumed that fluid injection reactivates faults which are optimally oriented relative to the regional tectonic stress field. We utilized recently improved earthquake locations and more complete focal mechanism catalogs to quantitatively analyze the stress state of seismogenic faults with high-resolution stress maps. The steps of analysis are: (1) Mapping the faults by clustering seismicity using a nearest-neighbor approach, manually picking the fault in each cluster and calculating the fault geometry using principal component analysis. (2) Running a stress inversion with 0.2° grid spacing to produce an in-situ stress map. (3) The fault stress state is determined from fault geometry and a 3D Mohr circle. The parameter `understress' is calculated to quantify the criticalness of these faults. If it approaches 0, the fault is critically stressed; while understress=1 means there is no shear stress on the fault. Our results indicate that most of the active faults have a planar shape (planarity>0.8), and dip steeply (dip>70°). The fault trends are distributed mainly in conjugate set ranges of [50°,70°] and [100°,120°]. More importantly, these conjugate trends are consistent with mapped basement fractures in southern Oklahoma, suggesting similar basement features from regional tectonics. The fault length data shows a loglinear relationship with the maximum earthquake magnitude with an expected maximum magnitude range from 3.2 to 4.4 for most seismogenic faults. Based on 3D local Mohr circle, we find that 61% of the faults have low understress (0.5) are located within highest-rate injection zones and therefore are likely to be influenced by high pore pressure. The faults that hosted the largest earthquakes, M5.7 Prague and M5.8 Pawnee are critically stressed (understress 0.2). These differences may help in understanding earthquake sequences, for example, the predominantly aftershock

  20. Remain stable.; Schoen stabil bleiben.

    Energy Technology Data Exchange (ETDEWEB)

    Teroerde, Michael; Schulz, Detlef [Helmut-Schmidt-Univ., Hamburg (Germany). Professur fuer Elektrische Energiesysteme; Eckoldt, Hans-Joerg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Fachgebiet Magnetstromversorgung

    2013-11-15

    In the German power grid the increasing photovoltaic power plants and wind turbines provide due to their volatile energy supply high demands on the control of the power grid. In the case of malfunctions in the network short-term energy storage could participate in the grid control. Superconducting magnetic energy storage (SMES) belongs to the efficient short-term energy storage. A SMES system was investigated at DESY in Hamburg. [German] Im deutschen Stromnetz stellen die zunehmenden Photovoltaik- und Windkraftanlagen aufgrund ihrer stark schwankenden Energieeinspeisung hohe Anforderungen an die Regelung des Stromnetzes. Bei eventuell auftretenden Stoerungen im Netz koennten Kurzzeitenergiespeicher an der Netzregelung teilnehmen. Zu den effizienten Kurzzeitspeichern gehoeren supraleitende magnetische Energiespeicher (SMES). Ein SMES-System wurde bei DESY in Hamburg untersucht.

  1. High hydrostatic pressure leads to free radicals accumulation in yeast cells triggering oxidative stress.

    Science.gov (United States)

    Bravim, Fernanda; Mota, Mainã M; Fernandes, A Alberto R; Fernandes, Patricia M B

    2016-08-01

    Saccharomyces cerevisiae is a unicellular organism that during the fermentative process is exposed to a variable environment; hence, resistance to multiple stress conditions is a desirable trait. The stress caused by high hydrostatic pressure (HHP) in S. cerevisiae resembles the injuries generated by other industrial stresses. In this study, it was confirmed that gene expression pattern in response to HHP displays an oxidative stress response profile which is expanded upon hydrostatic pressure release. Actually, reactive oxygen species (ROS) concentration level increased in yeast cells exposed to HHP treatment and an incubation period at room pressure led to a decrease in intracellular ROS concentration. On the other hand, ethylic, thermic and osmotic stresses did not result in any ROS accumulation in yeast cells. Microarray analysis revealed an upregulation of genes related to methionine metabolism, appearing to be a specific cellular response to HHP, and not related to other stresses, such as heat and osmotic stresses. Next, we investigated whether enhanced oxidative stress tolerance leads to enhanced tolerance to HHP stress. Overexpression of STF2 is known to enhance tolerance to oxidative stress and we show that it also leads to enhanced tolerance to HHP stress. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Melatonin induction and its role in high light stress tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Lee, Hyoung Yool; Back, Kyoungwhan

    2018-05-16

    In plants, melatonin is a potent bioactive molecule involved in the response against various biotic and abiotic stresses. However, little is known of its defensive role against high light (HL) stress. In this study, we found that melatonin was transiently induced in response to HL stress in Arabidopsis thaliana with a simultaneous increase in the expression of melatonin biosynthetic genes, including serotonin N-acetyltransferase1 (SNAT1). Transient induction of melatonin was also observed in the flu mutant, a singlet oxygen ( 1 O 2 )-producing mutant, upon light exposure, suggestive of melatonin induction by chloroplastidic 1 O 2 against HL stress. An Arabidopsis snat1 mutant was devoid of melatonin induction upon HL stress, resulting in high susceptibility to HL stress. Exogenous melatonin treatment mitigated damage caused by HL stress in the snat1 mutant by reducing O 2 - production and increasing the expression of various ROS-responsive genes. In analogy, an Arabidopsis SNAT1-overexpressing line showed increased tolerance of HL stress concomitant with a reduction in malondialdehyde and ion leakage. A complementation line expressing an Arabidopsis SNAT1 genomic fragment in the snat1 mutant completely restored HL stress susceptibility in the snat1 mutant to levels comparable to that of wild-type Col-0 plants. The results of the analysis of several Arabidopsis genetic lines reveal for the first time at the genetic level that melatonin is involved in conferring HL stress tolerance in plants. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. High novelty-seeking rats are resilient to negative physiological effects of the early life stress.

    Science.gov (United States)

    Clinton, Sarah M; Watson, Stanley J; Akil, Huda

    2014-01-01

    Exposure to early life stress dramatically impacts adult behavior, physiology, and neuroendocrine function. Using rats bred for novelty-seeking differences and known to display divergent anxiety, depression, and stress vulnerability, we examined the interaction between early life adversity and genetic predisposition for high- versus low-emotional reactivity. Thus, bred Low Novelty Responder (bLR) rats, which naturally exhibit high anxiety- and depression-like behavior, and bred High Novelty Responder (bHR) rats, which show low anxiety/depression together with elevated aggression, impulsivity, and addictive behavior, were subjected to daily 3 h maternal separation (MS) stress postnatal days 1-14. We hypothesized that MS stress would differentially impact adult bHR/bLR behavior, physiology (stress-induced defecation), and neuroendocrine reactivity. While MS stress did not impact bHR and bLR anxiety-like behavior in the open field test and elevated plus maze, it exacerbated bLRs' already high physiological response to stress - stress-induced defecation. In both tests, MS bLR adult offspring showed exaggerated stress-induced defecation compared to bLR controls while bHR offspring were unaffected. MS also selectively impacted bLRs' (but not bHRs') neuroendocrine stress reactivity, producing an exaggerated corticosterone acute stress response in MS bLR versus control bLR rats. These findings highlight how genetic predisposition shapes individuals' response to early life stress. Future work will explore neural mechanisms underlying the distinct behavioral and neuroendocrine consequences of MS in bHR/bLR animals.

  4. Microstructural investigation of vintage pipeline steels highly susceptible to stress corrosion cracking

    Science.gov (United States)

    Torres, Monica

    The use of pipelines for the transmission of gas offers not only efficiency, but a number of economic advantages. Nevertheless, pipelines are subject to aggressive operating conditions and environments which can lead to in-service degradation [1] and thus to failures. These failures can have catastrophic consequences, such as environmental damage and loss of life [2]. One of the most dangerous threats to pipeline integrity is stress corrosion cracking (SCC). Despite the substantial progress that has been achieved in the field, due to the complex nature of this phenomenon there is still not a complete understanding of this form of external corrosion. This makes its detection and prevention a challenge and therefore a risk to pipeline integrity, and most importantly, to the safety of the population. SCC cracks are the result of the interaction between a corrosive environment, applied stresses, and a susceptible microstructure. To date, what defines a susceptible microstructure remains ambiguous, as SCC has been observed in a range of steel grades, microstructures, chemical composition, and grain sizes. Therefore, in order to be able to accurately predict and prevent this hazardous form of corrosion, it is imperative to advance our knowledge on the subject and gain a better understanding on the microstructural features of highly susceptible pipeline materials, especially in the subsurface zone where crack nucleation must take place. Therefore, a microstructural characterization of the region near the surface layer was carried-out utilizing TEM. TEM analysis revealed the dislocation character, ferrite morphology, and apparent carbide precipitation in some grain boundaries. Furthermore, light microscopy, SEM, and hardness testing were performed to expand our knowledge on the microscopical features of highly SCC susceptible service components. This investigation presents a new approach to SCC characterization, which exposed the sub-surface region microscopical

  5. Overexpression of monoubiquitin improves photosynthesis in transgenic tobacco plants following high temperature stress.

    Science.gov (United States)

    Tian, Fengxia; Gong, Jiangfeng; Zhang, Jin; Feng, Yanan; Wang, Guokun; Guo, Qifang; Wang, Wei

    2014-09-01

    The ubiquitin/26S proteasome system (Ub/26S) is implicated in abiotic stress responses in plants. In this paper, transgenic tobacco plants overexpressing Ta-Ub2 from wheat were used to study the functions of Ub in the improvement of photosynthesis under high temperature (45°C) stress. We observed higher levels of Ub conjugates in transgenic plants under high temperature stress conditions compared to wild type (WT) as a result of the constitutive overexpression of Ta-Ub2, suggesting increased protein degradation by the 26S proteasome system under high temperature stress. Overexpressing Ub increased the photosynthetic rate (Pn) of transgenic tobacco plants, consistent with the improved ATPase activity in the thylakoid membrane and enhanced efficiency of PSII photochemistry. The higher D1 protein levels following high temperature stress in transgenic plants than WT were also observed. These findings imply that Ub may be involved in tolerance of photosynthesis to high temperature stress in plants. Compared with WT, the transgenic plants showed lower protein carbonylation and malondialdehyde (MDA) levels, less reactive oxygen species (ROS) accumulation, but higher antioxidant enzyme activity under high temperature stress. These findings suggest that the improved antioxidant capacity of transgenic plants may be one of the most important mechanisms underlying Ub-regulated high temperature tolerance. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  7. Stress !!!

    OpenAIRE

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten. Opvallend is dat mannelijke studenten uit Twente zich veel minder druk lijken te maken over hun studie. Onder vrouwen ligt de stress juist erg hoog ten opzichte van het landelijk gemiddelde.

  8. The probability distribution of intergranular stress corrosion cracking life for sensitized 304 stainless steels in high temperature, high purity water

    International Nuclear Information System (INIS)

    Akashi, Masatsune; Kenjyo, Takao; Matsukura, Shinji; Kawamoto, Teruaki

    1984-01-01

    In order to discuss the probability distribution of intergranular stress corrsion carcking life for sensitized 304 stainless steels, a series of the creviced bent beem (CBB) and the uni-axial constant load tests were carried out in oxygenated high temperature, high purity water. The following concludions were resulted; (1) The initiation process of intergranular stress corrosion cracking has been assumed to be approximated by the Poisson stochastic process, based on the CBB test results. (2) The probability distribution of intergranular stress corrosion cracking life may consequently be approximated by the exponential probability distribution. (3) The experimental data could be fitted to the exponential probability distribution. (author)

  9. Idea on patent ; It is high time to stress quality

    International Nuclear Information System (INIS)

    2012-03-01

    This book deals with patent stressing on the quality, which includes from idea to technical business, It's simple to register the computer program, why do patent lawyer appoint the patent attorney's office? construction of patent right range, a good patent and a bad patent, strong patent and weak patent. It doesn't allow for Dus to use as we like, each patent has different value, Let's write technical specifications, advice on talking for invention with a patent attorney's office and what kind of task do intellectual property division do?

  10. A tensile stage for high-stress low-strain fibre studies

    DEFF Research Database (Denmark)

    Pauw, Brian Richard; Vigild, Martin Etchells; Mortensen, Kell

    2011-01-01

    Determining the effects of stress on the internal structure of high-performance fibres may provide insight into their structure-property relationships. The deformation of voids inside a poly(p-phenylene terephthalamide) (PPTA) fibre upon application of stress is one such effect which may be obser...

  11. STRESS FRACTURE OF THE FIRST RIB IN A HIGH SCHOOL WEIGHT LIFTER

    Directory of Open Access Journals (Sweden)

    Hiroyuki Fujioka

    2009-06-01

    Full Text Available A 17-year-old boy, who played a weight lifting in high school, sustained stress fracture of the first rib without any causes. We successfully treated first rib stress fracture with limitation of using the upper extremity and with using low-intensity pulsed ultrasound

  12. Obesity promotes oxidative stress and exacerbates blood-brain barrier disruption after high-intensity exercise

    Directory of Open Access Journals (Sweden)

    Hee-Tae Roh

    2017-06-01

    Conclusion: Our study suggests that episodic vigorous exercise can increase oxidative stress and blood neurotrophic factor levels and induce disruption of the BBB. Moreover, high levels of neurotrophic factor in the blood after exercise in the obese group may be due to BBB disruption, and it is assumed that oxidative stress was the main cause of this BBB disruption.

  13. Tolerance of spermatogonia to oxidative stress is due to high levels of Zn and Cu/Zn superoxide dismutase.

    Directory of Open Access Journals (Sweden)

    Fritzie T Celino

    Full Text Available BACKGROUND: Spermatogonia are highly tolerant to reactive oxygen species (ROS attack while advanced-stage germ cells such as spermatozoa are much more susceptible, but the precise reason for this variation in ROS tolerance remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using the Japanese eel testicular culture system that enables a complete spermatogenesis in vitro, we report that advanced-stage germ cells undergo intense apoptosis and exhibit strong signal for 8-hydroxy-2'-deoxyguanosine, an oxidative DNA damage marker, upon exposure to hypoxanthine-generated ROS while spermatogonia remain unaltered. Activity assay of antioxidant enzyme, superoxide dismutase (SOD and Western blot analysis using an anti-Copper/Zinc (Cu/Zn SOD antibody showed a high SOD activity and Cu/Zn SOD protein concentration during early spermatogenesis. Immunohistochemistry showed a strong expression for Cu/Zn SOD in spermatogonia but weak expression in advanced-stage germ cells. Zn deficiency reduced activity of the recombinant eel Cu/Zn SOD protein. Cu/Zn SOD siRNA decreased Cu/Zn SOD expression in spermatogonia and led to increased oxidative damage. CONCLUSIONS/SIGNIFICANCE: These data indicate that the presence of high levels of Cu/Zn SOD and Zn render spermatogonia resistant to ROS, and consequently protected from oxidative stress. These findings provide the biochemical basis for the high tolerance of spermatogonia to oxidative stress.

  14. Persistent high job demands and reactivity to mental stress predict future ambulatory blood pressure.

    Science.gov (United States)

    Steptoe, A; Cropley, M

    2000-05-01

    To test the hypothesis that work stress (persistent high job demands over 1 year) in combination with high reactivity to mental stress predict ambulatory blood pressure. Assessment of cardiovascular responses to standardized behavioural tasks, job demands, and ambulatory blood pressure over a working day and evening after 12 months. We studied 81 school teachers (26 men, 55 women), 36 of whom experienced persistent high job demands over 1 year, while 45 reported lower job demands. Participants were divided on the basis of high and low job demands, and high and low systolic pressure reactions to an uncontrollable stress task. Blood pressure and concurrent physical activity were monitored using ambulatory apparatus from 0900 to 2230 h on a working day. Cardiovascular stress reactivity was associated with waist/hip ratio. Systolic and diastolic pressure during the working day were greater in high job demand participants who were stress reactive than in other groups, after adjustment for age, baseline blood pressure, body mass index and negative affectivity. The difference was not accounted for by variations in physical activity. Cardiovascular stress reactivity and sustained psychosocial stress may act in concert to increase cardiovascular risk in susceptible individuals.

  15. High intensity and reduced volume training attenuates stress and recovery levels in elite swimmers

    DEFF Research Database (Denmark)

    Elbe, Anne-Marie; Rasmussen, Camilla P; Nielsen, Glen

    2016-01-01

    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....... The Recovery Stress Questionnaire - Sport was used to measure the swimmers' stress and recovery levels. After the 12 week intervention, the general stress level was 16.6% (2.6-30.7%; mean and 95% CI) lower and the general recovery level was 6.5% (0.7-12.4%) higher in HIT compared to the CON, after adjusting...... 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....

  16. Mean stress effects on high-cycle fatigue of Alloy 718

    International Nuclear Information System (INIS)

    Korth, G.E.

    1980-07-01

    This report covers an investigation of the effects of tensile mean stress on the high-cycle fatigue properties of Alloy 718. Three test temperatures (24, 427, and 649 degree C) were employed, and there were tests in both strain and load control. Results were compared with three different models: linear Modified-Goodman, Peterson cubic, and stress-strain parameter. The linear Modified-Goodman model gave good correlation with actual test data for low and moderate mean stress values, but the stress-strain parameter showed excellent correlation over the entire range of possible mean stresses and therefore is recommended for predicting mean stress effects of Alloy 718. 13 refs., 12 figs

  17. Is the effect of alcohol on risk of stroke confined to highly stressed persons?

    DEFF Research Database (Denmark)

    Nielsen, N R; Truelsen, T; Barefoot, J C

    2005-01-01

    BACKGROUND: Psychological stress and alcohol are both suggested as risk factors for stroke. Further, there appears to be a close relation between stress and alcohol consumption. Several experimental studies have found alcohol consumption to reduce the immediate effects of stress in a laboratory...... setting. We aimed to examine whether the association between alcohol and stroke depends on level of self-reported stress in a large prospective cohort. METHODS: The 5,373 men and 6,723 women participating in the second examination of the Copenhagen City Heart Study in 1981-1983 were asked at baseline...... about their self-reported level of stress and their weekly alcohol consumption. The participants were followed-up until 31st of December 1997 during which 880 first ever stroke events occurred. Data were analysed by means of Cox regression modelling. RESULTS: At a high stress level, weekly total...

  18. Can high social capital at the workplace buffer against stress and musculoskeletal pain?

    DEFF Research Database (Denmark)

    Jay, Kenneth; Andersen, Lars L.

    2018-01-01

    Work-related musculoskeletal pain and stress are both highly prevalent in the working environment and relate well to the biopsychosocial model. While the onset of musculoskeletal pain is often dependent on the biological element of the biopsychosocial model, chronic pain is often influenced...... by psychological and social factors. Similarly, stress is also influenced by biological, psychological, and social factors. This study investigates the possibility of social capital being a buffer for stress and musculoskeletal pain in a group of female laboratory technicians.Female laboratory technicians (n = 500......) replied to questions about stress (Cohens Perceived Stress Scale-10), musculoskeletal pain (0-10 visual analog scale), and social capital at the workplace (bonding [in teams], bridging [between teams], and linking [between teams and leaders]). Outcome variables were stress and musculoskeletal pain...

  19. High-risk diagnosis, social stress, and parent-child relationships: A moderation model.

    Science.gov (United States)

    Bentley, Eryn; Millman, Zachary B; Thompson, Elizabeth; Demro, Caroline; Kline, Emily; Pitts, Steven C; DeVylder, Jordan E; Smith, Melissa Edmondson; Reeves, Gloria; Schiffman, Jason

    2016-07-01

    Stress is related to symptom severity among youth at clinical high-risk (CHR) for psychosis, although this relation may be influenced by protective factors. We explored whether the association of CHR diagnosis with social stress is moderated by the quality of parent-child relationships in a sample of 96 (36 CHR; 60 help-seeking controls) adolescents and young adults receiving mental health services. We examined self-reported social stress and parent-child relationships as measured by the Behavior Assessment System for Children, Second Edition (BASC-2), and determined CHR status from the clinician-administered Structured Interview for Psychosis-Risk Syndrome (SIPS). The social stress subscale, part of the clinical domain of the BASC-2, assesses feelings of stress and tension in personal relationships and the relations with parents subscale, part of the adaptive domain of the BASC-2, assesses perceptions of importance in family and quality of parent-child relationship. There was a modest direct relation between risk diagnosis and social stress. Among those at CHR, however, there was a significant relation between parent-child relationships and social stress (b=-0.73, t[92]=-3.77, psocial stress for those at risk for psychosis. Findings provide additional evidence to suggest that interventions that simultaneously target both social stress and parent-child relationships might be relevant for adolescents and young adults at clinical high-risk for psychosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Stress corrosion cracking of austenitic stainless steel in high temperature and high pressure water

    International Nuclear Information System (INIS)

    Uragami, Ken

    1977-01-01

    Austenitic stainless steels used in for equipment in chemical plants have failed owing to stress corrosion cracking (SCC). These failures brought about great problems in some cases. The failures were caused by chloride, sulfide and alkali solution environment, in particular, by chloride solution environment. It was known that SCC was caused not only by high content chloride solution such as 42% MgCl 2 solution but also by high temperature water containing Cl - ions as NaCl. In order to estimate quantitatively the effects of some factors on SCC in high temperature water environment, the effects of Cl - ion contents, oxygen partial pressure (increasing in proportion to dissolved oxygen), pH and temperature were investigated. Moreover SCC sensitivity owing to the difference of materials and heat treatments was also investigated. The experimental results obtained are summarized as follows: (1) Regarding the effect of contaminant Cl - ions in proportion as Cl - ion contents increased, the material life extremely decreased owing to SCC. The tendency of decreasing was affected by the level of oxygen partial pressure. (2) Three regions of SCC sensitivity existed and they depended upon oxygen partial pressure. These were a region that did not show SCC sensitivity, a region of the highest SCC sensitivity and a region of somewhat lower SCC sensitivity. (3) In the case of SUS304 steel and 500 ppm Cl - ion contents SCC did not occur at 150 0 C, but it occurred and caused failures at 200 0 C and 250 0 C. (auth.)

  1. Genotypic response of detached leaves versus intact plants for chlorophyll fluorescence parameters under high temperature stress in wheat

    DEFF Research Database (Denmark)

    Sharma, Dew Kumari; Fernández, Juan Olivares; Rosenqvist, Eva

    2014-01-01

    The genotypic response of wheat cultivars as affected by two methods of heat stress treatment (treatment of intact plants in growth chambers versus treatment of detached leaves in test tubes) in a temperature controlled water bath were compared to investigate how such different methods of heat...... to high temperatures. Further, the results suggest that genetic factors associated with cultivar differences are different for the two methods of heat treatment........ The responses of the same cultivars to heat stress were compared between the two methods of heat treatment. The results showed that in detached leaves, all of the fluorescence parameters remained almost unaffected in control (20°C at all durations tested), indicating that the detachment itself did not affect...

  2. Combat high or traumatic stress: violent offending is associated with appetitive aggression but not with symptoms of traumatic stress

    Directory of Open Access Journals (Sweden)

    Anke eKöbach

    2015-01-01

    Full Text Available Former members of armed groups in eastern DRCongo had typically witnessed, experienced and perpetrated extreme forms of violence. Enhanced trauma-related symptoms had been shown in prior research. But also lashing out in self-defense is a familiar response to threat defined as reactive aggression. Another potential response is appetitive aggression, in which the perpetration of excessive violence is perceived as pleasurable (combat high. What roles do these forms of aggressive behavior play in modern warfare and how are they related to posttraumatic stress symptoms? To answer the question, we sought to determine predictors for appetitive aggressive and trauma-related mental illness, and investigated the frequency of psychopathological symptoms for high- and low-intensity conflict demobilization settings. To this end, we interviewed 213 former members of (paramilitary groups in the eastern Democratic Republic of Congo in regard to their combat exposure, posttraumatic stress, appetitive aggression, depression, suicidality, and drug dependence. Random forest regression embedded in a conditional inference framework revealed that perpetrated violent acts are not necessarily stressful. In fact, the experience of violent acts that typically implicated salient cues of hunting (e.g., blood, suffering of the victim, etc. had the strongest association with an appetite for aggression. Furthermore, the number of lifetime perpetrated violent acts was the most important predictor of appetitive aggression. However, the number of perpetrated violent acts did not significantly affect the posttraumatic stress. Greater intensity of conflict was associated with more severe posttraumatic stress symptoms and depression. Psychotherapeutic interventions that address appetitive aggression in addition to trauma-related mental illness, including drug dependence, therefore seem indispensible for a successful reintegration of those who fought in the current civil wars.

  3. Effects of water stress and high temperature on photosynthetic rates of two species of Prosopis.

    Science.gov (United States)

    Delatorre, Jose; Pinto, Manuel; Cardemil, Liliana

    2008-08-21

    The main aim of this research was to compare the photosynthetic responses of two species of Prosopis, Prosopis chilensis (algarrobo) and Prosopis tamarugo (tamarugo) subjected to heat and water stress, to determine how heat shock or water deficit, either individually or combined, affect the photosynthesis of these two species. The photosynthetic rates expressed as a function of photon flow density (PFD) were determined by the O(2) liberated, in seedlings of tamarugo and algarrobo subjected to two water potentials: -0.3 MPa and -2.5 MPa and to three temperatures: 25 degrees C, 35 degrees C and 40 degrees C. Light response curves were constructed to obtain light compensation and light saturation points, maximum photosynthetic rates, quantum yields and dark respiration rates. The photochemical efficiency as the F(v)/F(m) ratio and the amount of RUBISCO were also determined under heat shock, water deficit, and under the combined action of both stress. Photosynthetic rates at a light intensity higher than 500 micromole photons m(-2)s(-1) were not significantly different (P>0.05) between species when measured at 25 degrees C under the same water potential. The maximum photosynthetic rates decreased with temperature in both species and with water deficit in algarrobo. At 40 degrees C and -2.5 MPa, the photosynthetic rate of algarrobo fell to 72% of that of tamarugo. The quantum yield decreased in algarrobo with temperature and water deficit and it was reduced by 50% when the conditions were 40 degrees C and -2.5 MPa. Dark respiration increased by 62% respect to the control at 40 degrees C in tamarugo while remained unchanged in algarrobo. The photochemical efficiency decreased with both, high temperature and water deficit, without differences between species. RUBISCO content increased in algarrobo 35 degrees C. Water deficit reduced the amount of RUBISCO in both species. The results of this work support the conclusion that in both Prosopis species, the interaction between

  4. Association between Sleep Duration and Perceived Stress: Salaried Worker in Circumstances of High Workload

    Directory of Open Access Journals (Sweden)

    Dong-Woo Choi

    2018-04-01

    Full Text Available The aim of this study was to find the association between sleep duration and perceived stress in salaried workers according to occupational categories and which lifestyle factors affected those correlations in South Korea. This study used data from the 2015 Community Health Survey (CHS. The self-reported sleep duration was used as the dependent variable in this study. We explored sleep duration and stress awareness among salaried workers, as well as household income and educational level with multiple logistic regression analysis. Salaried workers who slept for five or less hours had a higher odds ratio for high-stress awareness (OR: 1.86, 95% CI: 1.74–1.98. Stress awareness is associated with short sleep duration; specialized workers, office workers, those with above mid-high household income and graduate, university, or college level workers especially need to sleep adequately to manage stress.

  5. Occupational stress and cardiovascular risk factors in high-ranking government officials and office workers.

    Science.gov (United States)

    Mirmohammadi, Seyyed Jalil; Taheri, Mahmoud; Mehrparvar, Amir Houshang; Heydari, Mohammad; Saadati Kanafi, Ali; Mostaghaci, Mehrdad

    2014-08-01

    Cardiovascular diseases are among the most important sources of mortality and morbidity, and have a high disease burden. There are some major well-known risk factors, which contribute to the development of these diseases. Occupational stress is caused due to imbalance between job demands and individual's ability, and it has been implicated as an etiology for cardiovascular diseases. This study was conducted to evaluate the cardiovascular risk factors and different dimensions of occupational stress in high-ranking government officials, comparing an age and sex-matched group of office workers with them. We invited 90 high-ranking officials who managed the main governmental offices in a city, and 90 age and sex-matched office workers. The subjects were required to fill the occupational role questionnaire (Osipow) which evaluated their personal and medical history as well as occupational stress. Then, we performed physical examination and laboratory tests to check for cardiovascular risk factors. Finally, the frequency of cardiovascular risk factors and occupational stress of two groups were compared. High-ranking officials in our study had less work experience in their current jobs and smoked fewer pack-years of cigarette, but they had higher waist and hip circumference, higher triglyceride level, more stress from role overload and responsibility, and higher total stress score. Our group of office workers had more occupational stress because of role ambiguity and insufficiency, but their overall job stress was less than officials. The officials have higher scores in some dimensions of occupational stress and higher overall stress score. Some cardiovascular risk factors were also more frequent in managers.

  6. Analysis of the Residual Stresses in Helical Cylindrical Springs at High Temperature

    Directory of Open Access Journals (Sweden)

    H. Sun

    2015-01-01

    Full Text Available Creep is one of the basic properties of materials, its speed significantly depends on the temperature. Helical cylindrical springs are widely used in the elements of heating systems. This results in necessity of taking into account the effect of temperature on the stress-strain state of the spring. The object of research is a helical cylindrical spring used at high temperatures. Under this condition the spring state stability should be ensured.The paper studies relaxation of stress state and generation of residual stresses. Calculations are carried out in ABAQUS environment. The purpose of this work is to discuss the law of relaxation and residual stress in the spring.This paper describes the basic creep theories of helical cylindrical spring material. The calculation formulas of shear stress relaxation for a fixed compression ratio are obtained. Distribution and character of stress contour lines in the cross section of spring are presented. The stress relaxation – time relationships are discussed. The approximate formula for calculating relaxation shear stresses in the cross section of helical springs is obtained.The paper investigates creep ratio and law of residual stress variation in the cross-section of spring at 650℃. Computer simulation in ABAQUS environment was used. Research presents a finite element model of the spring creep in the cross-section.The paper conducts analysis of the stress changes for the creep under constant load. Under constant load stresses are quickly decreased in the around area of cross-section and are increased in the centre, i.e. the maximum and minimum stresses come close with time. Research work shows the possibility for using the approximate formula to calculate the relaxation shear stress in the cross section of spring and can provide a theoretical basis for predicting the service life of spring at high temperatures.In research relaxation processes of stress state are studied. Finite element model is cre

  7. Into the pressure cooker: Student stress in college preparatory high schools.

    Science.gov (United States)

    Feld, Lauren D; Shusterman, Anna

    2015-06-01

    The goals of this study were to (1) measure psychological, physiological, and behavioral indicators of stress, (2) assess the relationship between stress and student attitudes, and (3) explore coping behaviors in response to stress, among a sample of students in two academically high-achieving environments. Three hundred thirty-three students in grades 9 through 12 from two college-preparatory high schools completed a cross-sectional online survey that included the Students' Life Satisfaction Scale, School Attitude Assessment Questionnaire-Revised, and assessments for stress-related indicators, including eating, sleeping and exercise, and strategies they utilized for coping with stress. Students reported a high prevalence of physical and psychological correlates of stress, and related unhealthy behaviors such as widespread and chronic sleep deprivation and rushed meals. The results suggest areas to focus attention for identifying and addressing maladaptive responses to stress among high-achieving student populations. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  8. Parenting stress and parent support among mothers with high and low education.

    Science.gov (United States)

    Parkes, Alison; Sweeting, Helen; Wight, Daniel

    2015-12-01

    Current theorizing and evidence suggest that parenting stress might be greater among parents from both low and high socioeconomic positions (SEP) compared with those from intermediate levels because of material hardship among parents of low SEP and employment demands among parents of high SEP. However, little is known about how this socioeconomic variation in stress relates to the support that parents receive. This study explored whether variation in maternal parenting stress in a population sample was associated with support deficits. To obtain a clearer understanding of support deficits among mothers of high and low education, we distinguished subgroups according to mothers' migrant and single-parent status. Participants were 5,865 mothers from the Growing Up in Scotland Study, who were interviewed when their children were 10 months old. Parenting stress was greater among mothers with either high or low education than among mothers with intermediate education, although it was highest for those with low education. Support deficits accounted for around 50% of higher stress among high- and low-educated groups. Less frequent grandparent contact mediated parenting stress among both high- and low-educated mothers, particularly migrants. Aside from this common feature, different aspects of support were relevant for high- compared with low-educated mothers. For high-educated mothers, reliance on formal childcare and less frequent support from friends mediated higher stress. Among low-educated mothers, smaller grandparent and friend networks and barriers to professional parent support mediated higher stress. Implications of differing support deficits are discussed. (c) 2015 APA, all rights reserved).

  9. Caffeine prevents cognitive impairment induced by chronic psychosocial stress and/or high fat-high carbohydrate diet.

    Science.gov (United States)

    Alzoubi, K H; Abdul-Razzak, K K; Khabour, O F; Al-Tuweiq, G M; Alzubi, M A; Alkadhi, K A

    2013-01-15

    Caffeine alleviates cognitive impairment associated with a variety of health conditions. In this study, we examined the effect of caffeine treatment on chronic stress- and/or high fat-high carbohydrate Western diet (WD)-induced impairment of learning and memory in rats. Chronic psychosocial stress, WD and caffeine (0.3 g/L in drinking water) were simultaneously administered for 3 months to adult male Wistar rats. At the conclusion of the 3 months, and while the previous treatments continued, rats were tested in the radial arm water maze (RAWM) for learning, short-term and long-term memory. This procedure was applied on a daily basis to all animals for 5 consecutive days or until the animal reaches days to criterion (DTC) in the 12th learning trial and memory tests. DTC is the number of days that the animal takes to make zero error in two consecutive days. Chronic stress and/or WD groups caused impaired learning, which was prevented by chronic caffeine administration. In the memory tests, chronic caffeine administration also prevented memory impairment during chronic stress conditions and/or WD. Furthermore, DTC value for caffeine treated stress, WD, and stress/WD groups indicated that caffeine normalizes memory impairment in these groups. These results showed that chronic caffeine administration prevented stress and/or WD-induced impairment of spatial learning and memory. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Metal stress consequences on frost hardiness of plants at northern high latitudes: a review and hypothesis

    International Nuclear Information System (INIS)

    Taulavuori, Kari; Prasad, M.N.V.; Taulavuori, Erja; Laine, Kari

    2005-01-01

    This paper reviews the potential of trace/heavy metal-induced stress to reduce plant frost hardiness at northern high latitudes. The scientific questions are first outlined prior to a brief summary of heavy metal tolerance. The concepts of plant capacity and survival adaptation were used to formulate a hypothesis, according to which heavy metal stress may reduce plant frost hardiness for the following reasons: (1) Heavy metals change membrane properties through impaired resource acquisition and subsequent diminution of the cryoprotectant pool. (2) Heavy metals change membrane properties directly through oxidative stress, i.e. an increase of active oxygen species. (3) The involved co-stress may further increase oxidative stress. (4) The risk of frost injury increases due to membrane alterations. An opposite perspective was also discussed: could metal stress result in enhanced plant frost hardiness? This phenomenon could be based on the metabolism (i.e. glutathione, polyamines, proline, heat shock proteins) underlying a possible general adaptation syndrome of stress (GAS). As a result of the review it was suggested that metal-induced stress seems to reduce rather than increase plant frost hardiness. - Metal stress may reduce plant frost hardiness

  11. Metal stress consequences on frost hardiness of plants at northern high latitudes: a review and hypothesis

    Energy Technology Data Exchange (ETDEWEB)

    Taulavuori, Kari [Department of Biology, University of Oulu, PO Box 3000, FIN-90014, Oulu (Finland)]. E-mail: kari.taulavuori@oulu.fi; Prasad, M.N.V. [Department of Plant Sciences, University of Hyderabad, Hyderabad 500 046, Andhra Pradesh (India); Taulavuori, Erja [Department of Biology, University of Oulu, PO Box 3000, FIN-90014, Oulu (Finland); Laine, Kari [Department of Biology, University of Oulu, PO Box 3000, FIN-90014, Oulu (Finland)

    2005-05-01

    This paper reviews the potential of trace/heavy metal-induced stress to reduce plant frost hardiness at northern high latitudes. The scientific questions are first outlined prior to a brief summary of heavy metal tolerance. The concepts of plant capacity and survival adaptation were used to formulate a hypothesis, according to which heavy metal stress may reduce plant frost hardiness for the following reasons: (1) Heavy metals change membrane properties through impaired resource acquisition and subsequent diminution of the cryoprotectant pool. (2) Heavy metals change membrane properties directly through oxidative stress, i.e. an increase of active oxygen species. (3) The involved co-stress may further increase oxidative stress. (4) The risk of frost injury increases due to membrane alterations. An opposite perspective was also discussed: could metal stress result in enhanced plant frost hardiness? This phenomenon could be based on the metabolism (i.e. glutathione, polyamines, proline, heat shock proteins) underlying a possible general adaptation syndrome of stress (GAS). As a result of the review it was suggested that metal-induced stress seems to reduce rather than increase plant frost hardiness. - Metal stress may reduce plant frost hardiness.

  12. Stress !!!

    NARCIS (Netherlands)

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten.

  13. A family history of Type 1 alcoholism differentiates alcohol consumption in high cortisol responders to stress.

    Science.gov (United States)

    Brkic, Sejla; Söderpalm, Bo; Söderpalm Gordh, Anna

    2015-03-01

    The differentiation between high and low cortisol responders to stress is of interest in determining the risk factors which may, along with genetic vulnerability, influence alcohol intake. Thirty-two healthy volunteers, family history positive to alcoholism (FHP, n = 16) and family history negative (FHN, n = 16) attended two laboratory sessions during which alcohol or placebo was offered. There were no differences in consumption of alcohol or placebo between FHP and FHN subjects. STUDY 2: Fifty-eight healthy social drinkers, FHP (n = 27) and FHN (n = 31) attended two laboratory sessions. They were administered either alcohol or placebo in both sessions they attended. All subjects underwent either a stress task (the Trier Social Stress Test, TSST) or a stress-free period, at two separate occasions, before being offered beverage. After the salivary cortisol analysis, subjects in each group were divided into high (HCR) or low (LCR) cortisol responders. After stress, subjects who were FHP-HCR consumed more alcohol than FHN-HCR. There were no differences in the placebo intake between FHP and FHN subjects regardless of their cortisol response. This result indicates that stress promotes alcohol consumption only in subjects with a family history of Type 1 alcoholism who show an increase in cortisol response to stress. This behaviour is similar to that previously observed in alcohol dependent individuals after stress and thus could represent an endophenotype posing a risk for future development of alcohol use disorders. Copyright © 2015. Published by Elsevier Inc.

  14. Maternal high-fat diet intensifies the metabolic response to stress in male rat offspring.

    Science.gov (United States)

    Karbaschi, Roxana; Zardooz, Homeira; Khodagholi, Fariba; Dargahi, Leila; Salimi, Mina; Rashidi, FatemehSadat

    2017-01-01

    The mother's consumption of high-fat food can affect glucose metabolism and the hypothalamic-pituitary-adrenal axis responsiveness in the offspring and potentially affect the metabolic responses to stress as well. This study examines the effect of maternal high-fat diet on the expression of pancreatic glucose transporter 2 and the secretion of insulin in response to stress in offspring. Female rats were randomly divided into normal and high-fat diet groups and were fed in accordance with their given diets from pre-pregnancy to the end of lactation. The offspring were divided into control (NC and HFC) and stress (NS and HFS) groups based on their mothers' diet and exposure to stress in adulthood. After the two-week stress induction period was over, an intraperitoneal glucose tolerance test (IPGTT) was performed and plasma glucose and insulin levels were assessed. The pancreas was then removed for measuring insulin secretion from the isolated islets as well as glucose transporter 2 mRNA expression and protein levels. According to the results obtained, plasma corticosterone concentrations increased significantly on days 1 and 14 of the stress induction period and were lower on the last day compared to on the first day. In both the NS and HFS groups, stress reduced plasma insulin concentration in the IPGTT without changing the plasma glucose concentration, suggesting an increased insulin sensitivity in the NS and HFS groups, although more markedly in the latter. Stress reduced insulin secretion (at high glucose concentrations) and increased glucose transporter 2 mRNA and protein expression, especially in the HFS group. Mothers' high-fat diet appears to intensify the stress response by changing the programming of the neuroendocrine system in the offspring.

  15. Dealing Collectively with Critical Incident Stress Reactions in High Risk Work Environments

    DEFF Research Database (Denmark)

    Müller-Leonhardt, Alice; Strøbæk, Pernille Solveig; Vogt, joachim

    2015-01-01

    organisations. Indeed, we found that the CISM programme once integrated within the socio-cultural patterns of this specific working environment enhanced not only individual feelings of being supported but also organisational safety culture. Keywords: coping; safety culture; critical incident stress management......aim of this paper is to shift the representation of coping patterns within high risk occupations to an existential part of cultural pattern and social structure, which characterises high reliability organisations. Drawing upon the specific peer model of critical incident stress management (CISM......), in which qualified operational peers support colleagues who experienced critical incident stress, the paper discusses critical incident stress management in air traffic control. Our study revealed coping patterns that co-vary with the culture that the CISM programme fostered within this specific high...

  16. The study on stress-strain state of the spring at high temperature using ABAQUS

    Directory of Open Access Journals (Sweden)

    H Sun

    2014-01-01

    Full Text Available Cylindrical helical springs are widely used in the elements of thermal energy devices. It is necessary to guarantee the stability of the stress state of spring in high temperature. Relaxation phenomenon of stress is studied in this paper. Calculations are carried out in the environment of ABAQUS. The verification is taken out using analytical calculations.This paper describes the distribution and character of stress contour lines on the cross section of spring under the condition of instantaneous load, explicates the relaxation law with time. Research object is cylindrical helical spring, that working at high temperature. The purpose of this work is to get the stress relaxation law of spring, and to guarantee the long-term strength.This article presents the basic theory of helical spring. Establishes spring mathematical model of creep under the loads of compression and torsion. The stress formulas of each component in the cross section of spring are given. The calculation process of relaxation is analyzed in the program ABAQUS.In this paper compare the analytical formulas of spring stress with the simulation results, which are created by program ABAQUS.Finite element model for stress creep analysis in the cross section is created, material of spring – stainless steel 10X18N9T, springs are used at the temperature 650℃.At the beginning, stress-stain of spring is in the elastic state. Analyzes the change law of creep stress under the condition of constant load and a fixed compression.When analyzing under the condition of a fixed compression, the stresses are quickly decreased in most area in the cross section of spring, and the point of minimum shear stress gradually moves to the direction of outer diameter, because of this, stresses in a small area near the center increase slowly at first then decrease gradually with time. When analyzing under the condition of constant load, the stresses are quickly decreased in the around area and in creased

  17. High performance thermal stress analysis on the earth simulator

    International Nuclear Information System (INIS)

    Noriyuki, Kushida; Hiroshi, Okuda; Genki, Yagawa

    2003-01-01

    In this study, the thermal stress finite element analysis code optimized for the earth simulator was developed. A processor node of which of the earth simulator is the 8-way vector processor, and each processor can communicate using the message passing interface. Thus, there are two ways to parallelize the finite element method on the earth simulator. The first method is to assign one processor for one sub-domain, and the second method is to assign one node (=8 processors) for one sub-domain considering the shared memory type parallelization. Considering that the preconditioned conjugate gradient (PCG) method, which is one of the suitable linear equation solvers for the large-scale parallel finite element methods, shows the better convergence behavior if the number of domains is the smaller, we have determined to employ PCG and the hybrid parallelization, which is based on the shared and distributed memory type parallelization. It has been said that it is hard to obtain the good parallel or vector performance, since the finite element method is based on unstructured grids. In such situation, the reordering is inevitable to improve the computational performance [2]. In this study, we used three reordering methods, i.e. Reverse Cuthil-McKee (RCM), cyclic multicolor (CM) and diagonal jagged descending storage (DJDS)[3]. RCM provides the good convergence of the incomplete lower-upper (ILU) PCG, but causes the load imbalance. On the other hand, CM provides the good load balance, but worsens the convergence of ILU PCG if the vector length is so long. Therefore, we used the combined-method of RCM and CM. DJDS is the method to store the sparse matrices such that longer vector length can be obtained. For attaining the efficient inter-node parallelization, such partitioning methods as the recursive coordinate bisection (RCM) or MeTIS have been used. Computational performance of the practical large-scale engineering problems will be shown at the meeting. (author)

  18. Investigation of smooth specimen scc test procedures; variations in environment, specimen size, stressing frame, and stress state. [for high strength aluminum alloys

    Science.gov (United States)

    Lifka, B. W.; Sprowls, D. O.; Kelsey, R. A.

    1975-01-01

    The variables studied in the stress-corrosion cracking performance of high strength aluminum alloys were: (1) corrosiveness of the environment, (2) specimen size and stiffness of the stressing system, (3) interpretation of transgranular cracking, and (4) interaction of the state of stress and specimen orientation in a product with an anisotropic grain structure. It was shown that the probability of failure and time to fracture for a specimen loaded in direct tension are influenced by corrosion pattern, the stressing assembly stiffness, and the notch tensile strength of the alloy. Results demonstrate that the combination of a normal tension stress and a shear stress acting on the plane of maximum susceptibility in a product with a highly directional grain cause the greatest tendency for stress-corrosion cracking.

  19. Biaxial stress driven tetragonal symmetry breaking and high-temperature ferromagnetic semiconductor from half-metallic CrO2

    Science.gov (United States)

    Xiao, Xiang-Bo; Liu, Bang-Gui

    2018-03-01

    It is highly desirable to combine the full spin polarization of carriers with modern semiconductor technology for spintronic applications. For this purpose, one needs good crystalline ferromagnetic (or ferrimagnetic) semiconductors with high Curie temperatures. Rutile CrO2 is a half-metallic spintronic material with Curie temperature 394 K and can have nearly full spin polarization at room temperature. Here, we find through first-principles investigation that when a biaxial compressive stress is applied on rutile CrO2, the density of states at the Fermi level decreases with the in-plane compressive strain, there is a structural phase transition to an orthorhombic phase at the strain of -5.6 % , and then appears an electronic phase transition to a semiconductor phase at -6.1 % . Further analysis shows that this structural transition, accompanying the tetragonal symmetry breaking, is induced by the stress-driven distortion and rotation of the oxygen octahedron of Cr, and the half-metal-semiconductor transition originates from the enhancement of the crystal field splitting due to the structural change. Importantly, our systematic total-energy comparison indicates the ferromagnetic Curie temperature remains almost independent of the strain, near 400 K. This biaxial stress can be realized by applying biaxial pressure or growing the CrO2 epitaxially on appropriate substrates. These results should be useful for realizing full (100%) spin polarization of controllable carriers as one uses in modern semiconductor technology.

  20. Stress-Dilatancy of Cambria Sand for Triaxial Tests at High Pressures

    Science.gov (United States)

    Szypcio, Zenon

    2017-12-01

    In this paper, the stress-dilatancy relationship of Cambria sand for drained triaxial compression and extension tests at high stress level is investigated. The stress dilatancy relationship is obtained by use of frictional state theory and experimental tests data published in literature. It is shown that stress-dilatancy relationship is bilinear, described by three parameters of frictional state theory: critical frictional angle and two other parameters. It is accepted that critical friction angle is independent of confining pressure. The two additional parameters are strongly dependent on confining pressure and different for initial and advanced stages. The point at which the values of these parameters change is termed as Transformation Shear Point. This point is not simply visible either in stress ratio-strain or the volume strain-shear strain relationship which are traditionally shown in soil mechanics papers. Transformation Shear Point is very characteristic in stress ratio-plastic dilatancy plane. Thus, stress ratio- plastic dilatancy is very important for describing stress-strain behaviour of soils. The relationship shown in the paper can be used in soil modelling in the future.

  1. Role of high-temperature creep stress in thermally grown oxide growth of thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, K.; Nakao, Y.; Seo, D.; Miura, H.; Shoji, T. [Tohoku Univ., Sendai (Japan)

    2008-07-01

    Thermally grown oxide (TGO) grows at the top / bond coating interface of the thermal barrier coating (TBC) in service. It is supposed that the failures of the TBC occur due to thermal stress and the decrease of adhesive strength caused by the TGO growth. Recently, large local stress has been found to change both the diffusion constant of oxygen through an existing oxide and the rate of chemical reaction at the oxide / oxidized material interface. Since high thermal stress occurs in the TBC, the volume expansion of the newly grown oxide, and centrifugal force, the growth rate of the TGO may change depending on not only temperature but also the stress. The aim of this study is to make clear the influence of stress on the growth rate of the TGO quantitatively. As a result, the thickness of the TGO clearly increases with increase of the amplitude of the applied stress and temperature. The increase rate of the TGO thickness is approximately 23% when the applied stress is increased from 0 to 205 MPa at 900 C, and approximately 29% when the stress is increased from 0 to 150 MPa at 950 C. (orig.)

  2. Metal stress consequences on frost hardiness of plants at northern high latitudes: a review and hypothesis.

    Science.gov (United States)

    Taulavuori, Kari; Prasad, M N V; Taulavuori, Erja; Laine, Kari

    2005-05-01

    This paper reviews the potential of trace/heavy metal-induced stress to reduce plant frost hardiness at northern high latitudes. The scientific questions are first outlined prior to a brief summary of heavy metal tolerance. The concepts of plant capacity and survival adaptation were used to formulate a hypothesis, according to which heavy metal stress may reduce plant frost hardiness for the following reasons: (1) Heavy metals change membrane properties through impaired resource acquisition and subsequent diminution of the cryoprotectant pool. (2) Heavy metals change membrane properties directly through oxidative stress, i.e. an increase of active oxygen species. (3) The involved co-stress may further increase oxidative stress. (4) The risk of frost injury increases due to membrane alterations. An opposite perspective was also discussed: could metal stress result in enhanced plant frost hardiness? This phenomenon could be based on the metabolism (i.e. glutathione, polyamines, proline, heat shock proteins) underlying a possible general adaptation syndrome of stress (GAS). As a result of the review it was suggested that metal-induced stress seems to reduce rather than increase plant frost hardiness.

  3. High Dose Ascorbate Causes Both Genotoxic and Metabolic Stress in Glioma Cells

    Science.gov (United States)

    Castro, Maria Leticia; Carson, Georgia M.; McConnell, Melanie J.; Herst, Patries M.

    2017-01-01

    We have previously shown that exposure to high dose ascorbate causes double stranded breaks (DSBs) and a build-up in S-phase in glioblastoma (GBM) cell lines. Here we investigated whether or not this was due to genotoxic stress as well as metabolic stress generated by exposure to high dose ascorbate, radiation, ascorbate plus radiation and H2O2 in established and primary GBM cell lines. Genotoxic stress was measured as phosphorylation of the variant histone protein, H2AX, 8-oxo-7,8-dihydroguanine (8OH-dG) positive cells and cells with comet tails. Metabolic stress was measured as a decrease in NADH flux, mitochondrial membrane potential (by CMXRos), ATP levels (by ATP luminescence) and mitochondrial superoxide production (by mitoSOX). High dose ascorbate, ascorbate plus radiation, and H2O2 treatments induced both genotoxic and metabolic stress. Exposure to high dose ascorbate blocked DNA synthesis in both DNA damaged and undamaged cell of ascorbate sensitive GBM cell lines. H2O2 treatment blocked DNA synthesis in all cell lines with and without DNA damage. DNA synthesis arrest in cells with damaged DNA is likely due to both genotoxic and metabolic stress. However, arrest in DNA synthesis in cells with undamaged DNA is likely due to oxidative damage to components of the mitochondrial energy metabolism pathway. PMID:28737676

  4. High stress monitoring of prestressing tendons in nuclear concrete vessels using fibre-optic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Perry, M., E-mail: marcus.perry@strath.ac.uk [Institute for Energy and Environment, University of Strathclyde, 204 George Street, Glasgow G1 1XW (United Kingdom); Yan, Z.; Sun, Z.; Zhang, L. [Aston Institute of Photonic Technologies, Aston University, Birmingham B4 7ET (United Kingdom); Niewczas, P. [Institute for Energy and Environment, University of Strathclyde, 204 George Street, Glasgow G1 1XW (United Kingdom); Johnston, M. [Civil Design Group, EDF Energy, Nuclear Generation, East Kilbride G74 5PG (United Kingdom)

    2014-03-15

    Highlights: • We weld radiation-resistant optical fibre strain sensors to steel prestressing tendons. • We prove the sensors can survive 1300 MPa stress (80% of steel's tensile strength). • Mechanical relaxation of sensors is characterised under 1300 MPa stress over 10 h. • Strain transfer between tendon and sensor remains at 69% after relaxation. • Sensors can withstand and measure deflection of tendon around a 4.5 m bend radius. - Abstract: Maintaining the structural health of prestressed concrete nuclear containments is a key element in ensuring nuclear reactors are capable of meeting their safety requirements. This paper discusses the attachment, fabrication and characterisation of optical fibre strain sensors suitable for the prestress monitoring of irradiated steel prestressing tendons. The all-metal fabrication and welding process allowed the instrumented strand to simultaneously monitor and apply stresses up to 1300 MPa (80% of steel's ultimate tensile strength). There were no adverse effects to the strand's mechanical properties or integrity. After sensor relaxation through cyclic stress treatment, strain transfer between the optical fibre sensors and the strand remained at 69%. The fibre strain sensors could also withstand the non-axial forces induced as the strand was deflected around a 4.5 m bend radius. Further development of this technology has the potential to augment current prestress monitoring practices, allowing distributed measurements of short- and long-term prestress losses in nuclear prestressed-concrete vessels.

  5. Transformation of localized necking of strain space into stress space for advanced high strength steel sheet

    Science.gov (United States)

    Nakwattanaset, Aeksuwat; Suranuntchai, Surasak

    2018-03-01

    Normally, Forming Limit Curves (FLCs) can’t explain for shear fracture better than Damage Curve, this article aims to show the experimental of Forming Limit Curve (FLC) for Advanced High Strength Steel (AHSS) sheets grade JAC780Y with the Nakazima forming test and tensile tests of different sample geometries. From these results, the Forming Limit Curve (strain space) was transformed to damage curve (stress space) between plastic strain and stress triaxiality. Therefore, Stress space transformed using by Hill-48 and von-Mises yield function. This article shows that two of these yield criterions can use in the transformation.

  6. Heat transfer and structure stress analysis of micro packaging component of high power light emitting diode

    Directory of Open Access Journals (Sweden)

    Hsu Chih-Neng

    2013-01-01

    Full Text Available This paper focuses on the heat transfer and structural stress analysis of the micro- scale packaging structure of a high-power light emitting diode. The thermal-effect and thermal-stress of light emitting diode are determined numerically. Light emitting diode is attached to the silicon substrate through the wire bonding process by using epoxy as die bond material. The silicon substrate is etched with holes at the bottom and filled with high conductivity copper material. The chip temperature and structure stress increase with input power consumption. The micro light emitting diode is mounted on the heat sink to increase the heat dissipation performance, to decrease chip temperature, to enhance the material structure reliability and safety, and to avoid structure failure as well. This paper has successfully used the finite element method to the micro-scale light emitting diode heat transfer and stress concentration at the edges through etched holes.

  7. Stress Recovery Effects of High- and Low-Frequency Amplified Music on Heart Rate Variability.

    Science.gov (United States)

    Nakajima, Yoshie; Tanaka, Naofumi; Mima, Tatsuya; Izumi, Shin-Ichi

    Sounds can induce autonomic responses in listeners. However, the modulatory effect of specific frequency components of music is not fully understood. Here, we examined the role of the frequency component of music on autonomic responses. Specifically, we presented music that had been amplified in the high- or low-frequency domains. Twelve healthy women listened to white noise, a stress-inducing noise, and then one of three versions of a piece of music: original, low-, or high-frequency amplified. To measure autonomic response, we calculated the high-frequency normalized unit (HFnu), low-frequency normalized unit, and the LF/HF ratio from the heart rate using electrocardiography. We defined the stress recovery ratio as the value obtained after participants listened to music following scratching noise, normalized by the value obtained after participants listened to white noise after the stress noise, in terms of the HFnu, low-frequency normalized unit, LF/HF ratio, and heart rate. Results indicated that high-frequency amplified music had the highest HFnu of the three versions. The stress recovery ratio of HFnu under the high-frequency amplified stimulus was significantly larger than that under the low-frequency stimulus. Our results suggest that the high-frequency component of music plays a greater role in stress relief than low-frequency components.

  8. A high-order boundary integral method for surface diffusions on elastically stressed axisymmetric rods

    OpenAIRE

    Li, Xiaofan; Nie, Qing

    2009-01-01

    Many applications in materials involve surface diffusion of elastically stressed solids. Study of singularity formation and long-time behavior of such solid surfaces requires accurate simulations in both space and time. Here we present a high-order boundary integral method for an elastically stressed solid with axi-symmetry due to surface diffusions. In this method, the boundary integrals for isotropic elasticity in axi-symmetric geometry are approximated through modified alternating quadratu...

  9. Academic stress and personality interact to increase the neural response to high-calorie food cues.

    Science.gov (United States)

    Neseliler, Selin; Tannenbaum, Beth; Zacchia, Maria; Larcher, Kevin; Coulter, Kirsty; Lamarche, Marie; Marliss, Errol B; Pruessner, Jens; Dagher, Alain

    2017-09-01

    Psychosocial stress is associated with an increased intake of palatable foods and weight gain in stress-reactive individuals. Personality traits have been shown to predict stress-reactivity. However, it is not known if personality traits influence brain activity in regions implicated in appetite control during psychosocial stress. The current study assessed whether Gray's Behavioural Inhibition System (BIS) scale, a measure of stress-reactivity, was related to the activity of brain regions implicated in appetite control during a stressful period. Twenty-two undergraduate students participated in a functional magnetic resonance imaging (fMRI) experiment once during a non-exam period and once during final exams in a counter-balanced order. In the scanner, they viewed food and scenery pictures. In the exam compared with the non-exam condition, BIS scores related to increased perceived stress and correlated with increased blood-oxygen-level dependent (BOLD) response to high-calorie food images in regions implicated in food reward and subjective value, such as the ventromedial prefrontal cortex, (vmPFC) and the amygdala. BIS scores negatively related to the functional connectivity between the vmPFC and the dorsolateral prefrontal cortex. The results demonstrate that the BIS trait influences stress reactivity. This is observed both as an increased activity in brain regions implicated in computing the value of food cues and decreased connectivity of these regions to prefrontal regions implicated in self-control. This suggests that the effects of real life stress on appetitive brain function and self-control is modulated by a personality trait. This may help to explain why stressful periods can lead to overeating in vulnerable individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. High Hydrostatic Pressure Extract of Ginger Exerts Antistress Effects in Immobilization-Stressed Rats.

    Science.gov (United States)

    Moon, Sohee; Lee, Mak-Soon; Jung, Sunyoon; Kang, Bori; Kim, Seog-Young; Park, Seonyoung; Son, Hye-Yeon; Kim, Chong-Tai; Jo, Young-Hee; Kim, In-Hwan; Kim, Young Soon; Kim, Yangha

    2017-09-01

    Stress contributes to physiological changes such as weight loss and hormonal imbalances. The aim of the present study was to investigate antistress effects of high hydrostatic pressure extract of ginger (HPG) in immobilization-stressed rats. Male Sprague-Dawley rats (n = 24) were divided into three groups as follows: control (C), immobilization stress (2 h daily, for 2 weeks) (S), and immobilization stress (2 h daily, for 2 weeks) plus oral administration of HPG (150 mg/kg body weight/day) (S+G). Immobilization stress reduced the body weight gain and thymus weight by 50.2% and 31.3%, respectively, compared to the control group. The levels of serum aspartate transaminase, alanine transaminase, and corticosterone were significantly higher in the stress group, compared to the control group. Moreover, immobilization stress elevated the mRNA levels of tyrosine hydroxylase (Th), dopamine beta-hydroxylase (Dbh), and cytochrome P450 side-chain cleavage (P450scc), which are related to catecholamine and corticosterone synthesis in the adrenal gland. HPG administration also increased the body weight gain and thymus weight by 12.7% and 16.6%, respectively, compared to the stress group. Furthermore, the mRNA levels of Th, Dbh, phenylethanolamine-N-methyltransferase, and P450scc were elevated by the HPG treatment when compared to the stress group. These results suggest that HPG would have antistress effects partially via the reversal of stress-induced physiological changes and suppression of mRNA expression of genes related to corticosterone and catecholamine synthetic enzymes.

  11. Vildagliptin Can Alleviate Endoplasmic Reticulum Stress in the Liver Induced by a High Fat Diet.

    Science.gov (United States)

    Ma, Xiaoqing; Du, Wenhua; Shao, Shanshan; Yu, Chunxiao; Zhou, Lingyan; Jing, Fei

    2018-01-01

    Purpose. We investigated whether a DDP-4 inhibitor, vildagliptin, alleviated ER stress induced by a high fat diet and improved hepatic lipid deposition. Methods. C57BL/6 mice received standard chow diet (CD), high fat diet (HFD), and HFD administered with vildagliptin (50 mg/Kg) (V-HFD). After administration for 12 weeks, serum alanine aminotransferase, glucose, cholesterol, triglyceride, and insulin levels were analyzed. Samples of liver underwent histological examination and transmission electron microscopy, real-time PCR for gene expression levels, and western blots for protein expression levels. ER stress was induced in HepG2 cells with palmitic acid and the effects of vildagliptin were investigated. Results. HFD mice showed increased liver weight/body weight (20.27%) and liver triglycerides (314.75%) compared to CD mice, but these decreased by 9.27% and 21.83%, respectively, in V-HFD mice. In the liver, HFD induced the expression of ER stress indicators significantly, which were obviously decreased by vildagliptin. In vitro, the expressions of molecular indicators of ER stress were reduced in HepG2 when vildagliptin was administered. Conclusions. Vildagliptin alleviates hepatic ER stress in a mouse high fat diet model. In HepG2 cells, vildagliptin directly reduced ER stress. Therefore, vildagliptin may be a potential agent for nonalcoholic fatty liver disease.

  12. Vildagliptin Can Alleviate Endoplasmic Reticulum Stress in the Liver Induced by a High Fat Diet

    Directory of Open Access Journals (Sweden)

    Xiaoqing Ma

    2018-01-01

    Full Text Available Purpose. We investigated whether a DDP-4 inhibitor, vildagliptin, alleviated ER stress induced by a high fat diet and improved hepatic lipid deposition. Methods. C57BL/6 mice received standard chow diet (CD, high fat diet (HFD, and HFD administered with vildagliptin (50 mg/Kg (V-HFD. After administration for 12 weeks, serum alanine aminotransferase, glucose, cholesterol, triglyceride, and insulin levels were analyzed. Samples of liver underwent histological examination and transmission electron microscopy, real-time PCR for gene expression levels, and western blots for protein expression levels. ER stress was induced in HepG2 cells with palmitic acid and the effects of vildagliptin were investigated. Results. HFD mice showed increased liver weight/body weight (20.27% and liver triglycerides (314.75% compared to CD mice, but these decreased by 9.27% and 21.83%, respectively, in V-HFD mice. In the liver, HFD induced the expression of ER stress indicators significantly, which were obviously decreased by vildagliptin. In vitro, the expressions of molecular indicators of ER stress were reduced in HepG2 when vildagliptin was administered. Conclusions. Vildagliptin alleviates hepatic ER stress in a mouse high fat diet model. In HepG2 cells, vildagliptin directly reduced ER stress. Therefore, vildagliptin may be a potential agent for nonalcoholic fatty liver disease.

  13. Endoplasmic reticulum stress involved in high-fat diet and palmitic acid-induced vascular damages and fenofibrate intervention

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yunxia, E-mail: wwwdluyx@sina.com [Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, Anhui 230032 (China); The Comprehensive Laboratory, Anhui Medical University, Hefei, Anhui 230032 (China); Cheng, Jingjing [Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, Anhui 230032 (China); Chen, Li [Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, Anhui 230032 (China); Department of Medical Laboratory, Anhui Provincial Hospital, Hefei, Anhui 230001 (China); Li, Chaofei; Chen, Guanjun [Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, Anhui 230032 (China); Gui, Li [The Comprehensive Laboratory, Anhui Medical University, Hefei, Anhui 230032 (China); Shen, Bing [Department of Physiology, Anhui Medical University, Hefei, Anhui 230032 (China); Zhang, Qiu [Department of Endocrinology, First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022 (China)

    2015-02-27

    Fenofibrate (FF) is widely used to lower blood lipids in clinical practice, but whether its protective effect on endothelium-dependent vasodilatation (EDV) in thoracic aorta is related with endoplasmic reticulum (ER) stress remains unknown. In this study, female Sprauge Dawley rats were divided into standard chow diets (SCD), high-fat diets (HFD) and HFD plus FF treatment group (HFD + FF) randomly. The rats of latter two groups were given HFD feeding for 5 months, then HFD + FF rats were treated with FF (30 mg/kg, once daily) via gavage for another 2 months. The pathological and tensional changes, protein expression of eNOS, and ER stress related genes in thoracic aorta were measured. Then impacts of palmitic acid (PA) and FF on EDV of thoracic aorta from normal female SD rats were observed. Ultimately the expression of ER stress related genes were assessed in primary mouse aortic endothelial cells (MAEC) treated by fenofibric acid (FA) and PA. We found that FF treatment improved serum lipid levels and pathological changes in thoracic aorta, accompanied with decreased ER stress and increased phosphorylation of eNOS. FF pretreatment also improved EDV impaired by different concentrations of PA treatment. The dose- and time-dependent inhibition of cell proliferation by PA were inverted by FA pretreatment. Phosphorylation of eNOS and expression of ER stress related genes were all inverted by FA pretreatment in PA-treated MAEC. Our findings show that fenofibrate recovers damaged EDV by chronic HFD feeding and acute stimulation of PA, this effect is related with decreased ER stress and increased phosphorylation of eNOS. - Highlights: • Fenofibrate treatment improved pathological changes in thoracic aorta by chronic high-fat-diet feeding. • Fenofibrate pretreatment improved endothelium-dependent vasodilation impaired by different concentrations of palmitic acid. • The inhibition of proliferation in endothelial cells by palmitic acid were inverted by fenofibric

  14. Blockage of High-Affinity Choline Transporter Increases Visceral Hypersensitivity in Rats with Chronic Stress

    Directory of Open Access Journals (Sweden)

    Chen Zhao

    2018-01-01

    Full Text Available Background. Visceral hypersensitivity is a common feature of irritable bowel syndrome. Cholinergic system involves in the development of visceral hypersensitivity, and high-affinity choline transporter (CHT1 is of crucial importance in choline uptake system. However, involvement of CHT1 in visceral hypersensitivity remains unknown. The research aimed to study the CHT1 expression in dorsal root ganglions (DRGs and the role of CHT1 in visceral hypersensitivity. Methods. Repetitive water avoidance stress (WAS was used to induce visceral hypersensitivity in rats. Colorectal distension (CRD was determined, and the abdominal withdrawal reflex (AWR and threshold intensity data were recorded to measure the visceral sensitivity. After intraperitoneal injection of hemicholinium-3 (HC-3, the specific inhibitor of CHT1, CRD data were also recorded. The CHT1 expression of DRGs was investigated by Western blotting, immunohistochemistry, and quantitative RT-PCR. Acetylcholine levels in the DRGs were detected by the assay kit. Results. Repetitive WAS increased the AWR score of CRD at high distension pressure and decreased the mean threshold of rats. The CHT1 expression and acetylcholine concentration of DRG were significantly increased in WAS rats. After the administration of HC-3, the AWR score in WAS group was significantly increased at higher distension pressure while the threshold intensity was significantly reduced compared to the normal saline group. Acetylcholine concentration was significantly lower than the normal saline rats. Conclusion. Our research firstly reports that CHT1 is overexpressed in noninflammatory visceral hypersensitivity, and blockage of CHT1 can enhance the visceral hypersensitivity. CHT1 may play an inhibitory role in visceral hypersensitivity.

  15. Blockage of High-Affinity Choline Transporter Increases Visceral Hypersensitivity in Rats with Chronic Stress

    Science.gov (United States)

    2018-01-01

    Background Visceral hypersensitivity is a common feature of irritable bowel syndrome. Cholinergic system involves in the development of visceral hypersensitivity, and high-affinity choline transporter (CHT1) is of crucial importance in choline uptake system. However, involvement of CHT1 in visceral hypersensitivity remains unknown. The research aimed to study the CHT1 expression in dorsal root ganglions (DRGs) and the role of CHT1 in visceral hypersensitivity. Methods Repetitive water avoidance stress (WAS) was used to induce visceral hypersensitivity in rats. Colorectal distension (CRD) was determined, and the abdominal withdrawal reflex (AWR) and threshold intensity data were recorded to measure the visceral sensitivity. After intraperitoneal injection of hemicholinium-3 (HC-3), the specific inhibitor of CHT1, CRD data were also recorded. The CHT1 expression of DRGs was investigated by Western blotting, immunohistochemistry, and quantitative RT-PCR. Acetylcholine levels in the DRGs were detected by the assay kit. Results Repetitive WAS increased the AWR score of CRD at high distension pressure and decreased the mean threshold of rats. The CHT1 expression and acetylcholine concentration of DRG were significantly increased in WAS rats. After the administration of HC-3, the AWR score in WAS group was significantly increased at higher distension pressure while the threshold intensity was significantly reduced compared to the normal saline group. Acetylcholine concentration was significantly lower than the normal saline rats. Conclusion Our research firstly reports that CHT1 is overexpressed in noninflammatory visceral hypersensitivity, and blockage of CHT1 can enhance the visceral hypersensitivity. CHT1 may play an inhibitory role in visceral hypersensitivity. PMID:29849603

  16. Boron application improves yield of rice cultivars under high temperature stress during vegetative and reproductive stages.

    Science.gov (United States)

    Shahid, Mohammad; Nayak, Amaresh Kumar; Tripathi, Rahul; Katara, Jawahar Lal; Bihari, Priyanka; Lal, Banwari; Gautam, Priyanka

    2018-04-12

    It is reported that high temperatures (HT) would cause a marked decrease in world rice production. In tropical regions, high temperatures are a constraint to rice production and the most damaging effect is on spikelet sterility. Boron (B) plays a very important role in the cell wall formation, sugar translocation, and reproduction of the rice crop and could play an important role in alleviating high temperature stress. A pot culture experiment was conducted to study the effect of B application on high temperature tolerance of rice cultivars in B-deficient soil. The treatments comprised of four boron application treatments viz. control (B0), soil application of 1 kg B ha -1 (B1), soil application of 2 kg B ha -1 (B2), and foliar spray of 0.2% B (Bfs); three rice cultivars viz. Annapurna (HT stress tolerant), Naveen, and Shatabdi (both HT stress susceptible); and three temperature regimes viz. ambient (AT), HT at vegetative stage (HTV), and HT at reproductive stage (HTR). The results revealed that high temperature stress during vegetative or flowering stage reduced grain yield of rice cultivars mainly because of low pollen viability and spikelet fertility. The effects of high temperature on the spikelet fertility and grain filling varied among cultivars and the growth stages of plant when exposed to the high temperature stress. Under high temperature stress, the tolerant cultivar displays higher cell membrane stability, less accumulation of osmolytes, more antioxidant enzyme activities, and higher pollen viability and spikelet fertility than the susceptible cultivars. In the present work, soil application of boron was effective in reducing the negative effects of high temperature both at vegetative and reproductive stages. Application of B results into higher grain yield under both ambient and high temperature condition over control for all the three cultivars; however, more increase was observed for the susceptible cultivar over the tolerant one. The results

  17. Boron application improves yield of rice cultivars under high temperature stress during vegetative and reproductive stages

    Science.gov (United States)

    Shahid, Mohammad; Nayak, Amaresh Kumar; Tripathi, Rahul; Katara, Jawahar Lal; Bihari, Priyanka; Lal, Banwari; Gautam, Priyanka

    2018-04-01

    It is reported that high temperatures (HT) would cause a marked decrease in world rice production. In tropical regions, high temperatures are a constraint to rice production and the most damaging effect is on spikelet sterility. Boron (B) plays a very important role in the cell wall formation, sugar translocation, and reproduction of the rice crop and could play an important role in alleviating high temperature stress. A pot culture experiment was conducted to study the effect of B application on high temperature tolerance of rice cultivars in B-deficient soil. The treatments comprised of four boron application treatments viz. control (B0), soil application of 1 kg B ha-1 (B1), soil application of 2 kg B ha-1 (B2), and foliar spray of 0.2% B (Bfs); three rice cultivars viz. Annapurna (HT stress tolerant), Naveen, and Shatabdi (both HT stress susceptible); and three temperature regimes viz. ambient (AT), HT at vegetative stage (HTV), and HT at reproductive stage (HTR). The results revealed that high temperature stress during vegetative or flowering stage reduced grain yield of rice cultivars mainly because of low pollen viability and spikelet fertility. The effects of high temperature on the spikelet fertility and grain filling varied among cultivars and the growth stages of plant when exposed to the high temperature stress. Under high temperature stress, the tolerant cultivar displays higher cell membrane stability, less accumulation of osmolytes, more antioxidant enzyme activities, and higher pollen viability and spikelet fertility than the susceptible cultivars. In the present work, soil application of boron was effective in reducing the negative effects of high temperature both at vegetative and reproductive stages. Application of B results into higher grain yield under both ambient and high temperature condition over control for all the three cultivars; however, more increase was observed for the susceptible cultivar over the tolerant one. The results suggest

  18. Maternal high-fat diet intensifies the metabolic response to stress in male rat offspring

    OpenAIRE

    Karbaschi, Roxana; Zardooz, Homeira; Khodagholi, Fariba; Dargahi, Leila; Salimi, Mina; Rashidi, FatemehSadat

    2017-01-01

    Background The mother?s consumption of high-fat food can affect glucose metabolism and the hypothalamic?pituitary?adrenal axis responsiveness in the offspring and potentially affect the metabolic responses to stress as well. This study examines the effect of maternal high-fat diet on the expression of pancreatic glucose transporter 2 and the secretion of insulin in response to stress in offspring. Methods Female rats were randomly divided into normal and high-fat diet groups and were fed in a...

  19. Stress.

    Science.gov (United States)

    Chambers, David W

    2008-01-01

    We all experience stress as a regular, and sometimes damaging and sometimes useful, part of our daily lives. In our normal ups and downs, we have our share of exhaustion, despondency, and outrage--matched with their corresponding positive moods. But burnout and workaholism are different. They are chronic, dysfunctional, self-reinforcing, life-shortening habits. Dentists, nurses, teachers, ministers, social workers, and entertainers are especially susceptible to burnout; not because they are hard-working professionals (they tend to be), but because they are caring perfectionists who share control for the success of what they do with others and perform under the scrutiny of their colleagues (they tend to). Workaholics are also trapped in self-sealing cycles, but the elements are ever-receding visions of control and using constant activity as a barrier against facing reality. This essay explores the symptoms, mechanisms, causes, and successful coping strategies for burnout and workaholism. It also takes a look at the general stress response on the physiological level and at some of the damage American society inflicts on itself.

  20. Heat priming induces trans-generational tolerance to high temperature stress in wheat

    Directory of Open Access Journals (Sweden)

    Xiao eWang

    2016-04-01

    Full Text Available Wheat plants are very sensitive to high temperature stress during grain filling. Effects of heat priming applied to the first generation on tolerance of the successive generation to post-anthesis high temperature stress were investigated. Compared with the progeny of non-heat primed plants (NH, the progeny of heat-primed plants (PH possessed higher grain yield, leaf photosynthesis and activities of antioxidant enzymes and lower cell membrane damage under high temperature stress. In the transcriptome profile, 1430 probes showed obvious difference in expression between PH and NH. These genes were related to signal transduction, transcription, energy, defense, and protein destination and storage, respectively. The gene encoding the lysine-specific histone demethylase 1 (LSD1 which was involved in histone demethylation related to epigenetic modification was up-regulated in the PH compared with NH. The proteome analysis indicated that the proteins involved in photosynthesis, energy production and protein destination and storage were up-regulated in the PH compared with NH. In short, thermos-tolerance was induced through heritable epigenetic alternation and signaling transduction, both processes further triggered prompt modifications of defense related responses in anti-oxidation, transcription, energy production, and protein destination and storage in the progeny of the primed plants under high temperature stress. It was concluded that trans-generation thermo-tolerance was induced by heat priming in the first generation, and this might be an effective measure to cope with severe high-temperature stresses during key growth stages in wheat production.

  1. ¿Por qué siguen siendo tan altas las tasas de mortalidad por malnutrición grave? Why have mortality rates for severe malnutrition remained so high?

    Directory of Open Access Journals (Sweden)

    C. Schofield

    1997-04-01

    Full Text Available La revisión de las publicaciones que han aparecido en los últimos cinco decenios revela que la mediana de la tasa de letalidad de la malnutrición grave no se ha modificado en ese período y que suele oscilar de 20 a 30%, con los mayores porcentajes (50 a 60% atribuibles a los casos de malnutrición edematosa. Una causa probable de la persistencia de la mortalidad elevada es el tratamiento inapropiado de los casos. Según una encuesta de centros de tratamiento en distintas partes del mundo (n = 79, es común que a los niños con enfermedad aguda se les prescriban dietas inadecuadas con un alto contenido de proteínas, energía y sodio y un bajo contenido de micronutrientes. Se encontró que ciertas prácticas que podrían acarrear consecuencias funestas, como la prescripción de diuréticos para el edema, estaban ampliamente difundidas. También se comprobó que muchos de los manuales de instrucción eran anticuados y encerraban contradicciones. Ya que se pueden lograr tasas bajas de mortalidad por malnutrición con los tratamientos apropiados, es preciso formular y aplicar pautas terapéuticas actualizadas, de carácter práctico y prescriptivo más que descriptivo, como parte de un programa integral de capacitación.A review of the literature that has appeared over the past five decades indicates that the median case fatality from severe malnutrition has remained unchanged over this period and is typically 20-30%, with the highest levels (50-60% being among those with edematous malnutrition. A likely cause of this continuing high mortality is faulty case-management. A survey of treatment centres worldwide (n = 79 showed that for acutely ill children, inappropriate diets that are high in protein, energy and sodium and low in micronutrients are commonplace. Practices that could have fatal consequences, such as prescribing diuretics for edema, were found to be widespread. Evidence of outmoded and conflicting teaching manuals also emerged. Since

  2. Can high social capital at the workplace buffer against stress and musculoskeletal pain?

    Science.gov (United States)

    Jay, Kenneth; Andersen, Lars L.

    2018-01-01

    Abstract Work-related musculoskeletal pain and stress are both highly prevalent in the working environment and relate well to the biopsychosocial model. While the onset of musculoskeletal pain is often dependent on the biological element of the biopsychosocial model, chronic pain is often influenced by psychological and social factors. Similarly, stress is also influenced by biological, psychological, and social factors. This study investigates the possibility of social capital being a buffer for stress and musculoskeletal pain in a group of female laboratory technicians. Female laboratory technicians (n = 500) replied to questions about stress (Cohens Perceived Stress Scale-10), musculoskeletal pain (0–10 visual analog scale), and social capital at the workplace (bonding [in teams], bridging [between teams], and linking [between teams and leaders]). Outcome variables were stress and musculoskeletal pain and the predictor variable was social capital. General linear models tested the association of the 3 types of social capital (predictor variables) with stress and pain (mutually adjusted outcome variables). Analyses were controlled for age, lifestyle (body mass index, smoking), seniority, and working hours per week. For stress as outcome, moderate and high bonding social capital were different from low social capital with −2.04 (95% confidence interval [CI] −3.33 to −0.76) and −4.56 (95% CI −5.84 to −3.28) points on the Perceived Stress Scale of 0 to 42, respectively. Similarly, moderate and high bridging social capital were different from low social capital with −1.50 (95% CI −2.76 to −0.24) and −4.39 (95% CI −5.75 to −3.03), respectively. For linking, only high social was significantly different from low with −2.94 (95% CI −4.28 to −1.60). None of the 3 types of social capital was associated with musculoskeletal pain. Higher levels of social capital at the workplace appear to buffer against stress, but not against

  3. Some remaining problems in HCDA analysis

    International Nuclear Information System (INIS)

    Chang, Y.W.

    1981-01-01

    The safety assessment and licensing of liquid-metal fast breeder reactors (LMFBRs) requires an analysis on the capability of the reactor primary system to sustain the consequences of a hypothetical core-disruptive accident (HCDA). Although computational methods and computer programs developed for HCDA analyses can predict reasonably well the response of the primary containment system, and follow up the phenomena of HCDA from the start of excursion to the time of dynamic equilibrium in the system, there remain areas in the HCDA analysis that merit further analytical and experimental studies. These are the analysis of fluid impact on reactor cover, three-dimensional analysis, the treatment of the perforated plates, material properties under high strain rates and under high temperatures, the treatment of multifield flows, and the treatment of prestressed concrete reactor vessels. The purpose of this paper is to discuss the structural mechanics of HCDA analysis in these areas where improvements are needed

  4. High Temperature Uniaxial Compression and Stress-Relaxation Behavior of India-Specific RAFM Steel

    Science.gov (United States)

    Shah, Naimish S.; Sunil, Saurav; Sarkar, Apu

    2018-05-01

    India-specific reduced activity ferritic martensitic steel (INRAFM), a modified 9Cr-1Mo grade, has been developed by India as its own structural material for fabrication of the Indian Test Blanket Module (TBM) to be installed in the International Thermonuclear Energy Reactor (ITER). The extensive study on mechanical and physical properties of this material has been currently going on for appraisal of this material before being put to use in the ITER. High temperature compression, stress-relaxation, and strain-rate change behavior of the INRAFM steel have been investigated. The optical microscopic and scanning electron microscopic characterizations were carried out to observe the microstructural changes that occur during uniaxial compressive deformation test. Comparable true plastic stress values at 300 °C and 500 °C and a high drop in true plastic stress at 600 °C were observed during the compression test. Stress-relaxation behaviors were investigated at 500 °C, 550 °C, and 600 °C at a strain rate of 10-3 s-1. The creep properties of the steel at different temperatures were predicted from the stress-relaxation test. The Norton's stress exponent (n) was found to decrease with the increasing temperature. Using Bird-Mukherjee-Dorn relationship, the temperature-compensated normalized strain rate vs stress was plotted. The stress exponent (n) value of 10.05 was obtained from the normalized plot. The increasing nature of the strain rate sensitivity (m) with the test temperature was found from strain-rate change test. The low plastic stability with m 0.06 was observed at 600 °C. The activation volume (V *) values were obtained in the range of 100 to 300 b3. By comparing the experimental values with the literature, the rate-controlling mechanisms at the thermally activated region of high temperature were found to be the nonconservative movement of jogged screw dislocations and thermal breaking of attractive junctions.

  5. Acute stress induces hyperacusis in women with high levels of emotional exhaustion.

    Science.gov (United States)

    Hasson, Dan; Theorell, Töres; Bergquist, Jonas; Canlon, Barbara

    2013-01-01

    Hearing problems is one of the top ten public health disorders in the general population and there is a well-established relationship between stress and hearing problems. The aim of the present study was to explore if an acute stress will increase auditory sensitivity (hyperacusis) in individuals with high levels of emotional exhaustion (EE). Hyperacusis was assessed using uncomfortable loudness levels (ULL) in 348 individuals (140 men; 208 women; age 23-71 years). Multivariate analyses (ordered logistic regression), were used to calculate odds ratios, including interacting or confounding effects of age, gender, ear wax and hearing loss (PTA). Two-way ANCOVAs were used to assess possible differences in mean ULLs between EE groups pre- and post-acute stress task (a combination of cold pressor, emotional Stroop and Social stress/video recording). There were no baseline differences in mean ULLs between the three EE groups (one-way ANOVA). However, after the acute stress exposure there were significant differences in ULL means between the EE-groups in women. Post-hoc analyses showed that the differences in mean ULLs were between those with high vs. low EE (range 5.5-6.5 dB). Similar results were found for frequencies 0.5 and 1 kHz. The results demonstrate that women with high EE-levels display hyperacusis after an acute stress task. The odds of having hyperacusis were 2.5 (2 kHz, right ear; left ns) and 2.2 (4 kHz, right ear; left ns) times higher among those with high EE compared to those with low levels. All these results are adjusted for age, hearing loss and ear wax. Women with high levels of emotional exhaustion become more sensitive to sound after an acute stress task. This novel finding highlights the importance of including emotional exhaustion in the diagnosis and treatment of hearing problems.

  6. Acute stress induces hyperacusis in women with high levels of emotional exhaustion.

    Directory of Open Access Journals (Sweden)

    Dan Hasson

    Full Text Available BACKGROUND: Hearing problems is one of the top ten public health disorders in the general population and there is a well-established relationship between stress and hearing problems. The aim of the present study was to explore if an acute stress will increase auditory sensitivity (hyperacusis in individuals with high levels of emotional exhaustion (EE. METHODS: Hyperacusis was assessed using uncomfortable loudness levels (ULL in 348 individuals (140 men; 208 women; age 23-71 years. Multivariate analyses (ordered logistic regression, were used to calculate odds ratios, including interacting or confounding effects of age, gender, ear wax and hearing loss (PTA. Two-way ANCOVAs were used to assess possible differences in mean ULLs between EE groups pre- and post-acute stress task (a combination of cold pressor, emotional Stroop and Social stress/video recording. RESULTS: There were no baseline differences in mean ULLs between the three EE groups (one-way ANOVA. However, after the acute stress exposure there were significant differences in ULL means between the EE-groups in women. Post-hoc analyses showed that the differences in mean ULLs were between those with high vs. low EE (range 5.5-6.5 dB. Similar results were found for frequencies 0.5 and 1 kHz. The results demonstrate that women with high EE-levels display hyperacusis after an acute stress task. The odds of having hyperacusis were 2.5 (2 kHz, right ear; left ns and 2.2 (4 kHz, right ear; left ns times higher among those with high EE compared to those with low levels. All these results are adjusted for age, hearing loss and ear wax. CONCLUSION: Women with high levels of emotional exhaustion become more sensitive to sound after an acute stress task. This novel finding highlights the importance of including emotional exhaustion in the diagnosis and treatment of hearing problems.

  7. A Window into South Korean Culture: Stress and Coping in Female High School Students

    Science.gov (United States)

    VanderGast, Tim S.; Foxx, Sejal Parikh; Flowers, Claudia; Rouse, Andrew Thomas; Decker, Karen M.

    2015-01-01

    In an effort to increase multicultural competence, professional counselors in the United States analyzed archival data from high school students from Seoul, South Korea. A sample of all female (N = 577) high school students responded to survey questions related to stress and coping. Results demonstrated statistical significance in levels of stress…

  8. High frequency modeling of power transformers. Stresses and diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Bjerkan, Eilert

    2005-05-15

    In this thesis a reliable, versatile and rigorous method for high frequency power transformer modeling is searched and established. The purpose is to apply this model to sensitivity analysis of FRA (Frequency Response Analysis) which is a quite new diagnostic method for assessing the mechanical integrity of power transformer windings on-site. The method should be versatile in terms of being able to estimate internal and external over voltages and resonances. Another important aspect is that the method chosen is suitable for real transformer geometries. In order to verify the suitability of the model for real transformers, a specific test-object is used. This is a 20MVA transformer, and details are given in chapter 1.4. The high frequency power transformer model is established from geometrical and constructional information from the manufacturer, together with available material characteristics. All circuit parameters in the lumped circuit representation are calculated based on these data. No empirical modifications need to be performed. Comparison shows capability of reasonable accuracy in the range from 10 khz to 1 MHz utilizing a disc-to-disc representation. A compromise between accuracy of model due to discretization and complexity of the model in a turn-to-turn representation is inevitable. The importance of the iron core is emphasized through a comparison of representations with/without the core included. Frequency-dependent phenomena are accurately represented using an isotropic equivalent for windings and core, even with a coarse mesh for the FEM-model. This is achieved through a frequency-dependent complex permeability representation of the materials. This permeability is deduced from an analytical solution of the frequency-dependent magnetic field inside the conductors and the core. The importance of dielectric losses in a transformer model is also assessed. Since published data on the high frequency properties of press board are limited, some initial

  9. High Compressive Stresses Near the Surface of the Sierra Nevada, California

    Science.gov (United States)

    Martel, S. J.; Logan, J. M.; Stock, G. M.

    2012-12-01

    Observations and stress measurements in granitic rocks of the Sierra Nevada, California reveal strong compressive stresses parallel to the surface of the range at shallow depths. New overcoring measurements show high compressive stresses at three locations along an east-west transect through Yosemite National Park. At the westernmost site (west end of Tenaya Lake), the mean compressive stress is 1.9. At the middle site (north shore of Tenaya Lake) the mean compressive stress is 6.8 MPa. At the easternmost site (south side of Lembert Dome) the mean compressive stress is 3.0 MPa. The trend of the most compressive stress at these sites is within ~30° of the strike of the local topographic surface. Previously published hydraulic fracturing measurements by others elsewhere in the Sierra Nevada indicate surface-parallel compressive stresses of several MPa within several tens of meters of the surface, with the stress magnitudes generally diminishing to the west. Both the new and the previously published compressive stress magnitudes are consistent with the presence of sheeting joints (i.e., "exfoliation joints") in the Sierra Nevada, which require lateral compressive stresses of several MPa to form. These fractures are widespread: they are distributed in granitic rocks from the north end of the range to its southern tip and across the width of the range. Uplift along the normal faults of the eastern escarpment, recently measured by others at ~1-2 mm/yr, probably contributes to these stresses substantially. Geodetic surveys reveal that normal faulting flexes a range concave upwards in response to fault slip, and this flexure is predicted by elastic dislocation models. The topographic relief of the eastern escarpment of the Sierra Nevada is 2-4 km, and since alluvial fill generally buries the bedrock east of the faults, the offset of granitic rocks is at least that much. Compressive stresses of several MPa are predicted by elastic dislocation models of the range front

  10. High stress, lack of sleep, low school performance, and suicide attempts are associated with high energy drink intake in adolescents.

    Directory of Open Access Journals (Sweden)

    So Young Kim

    Full Text Available Although an association between energy drinks and suicide has been suggested, few prior studies have considered the role of emotional factors including stress, sleep, and school performance in adolescents. This study aimed to evaluate the association of energy drinks with suicide, independent of possible confounders including stress, sleep, and school performance.In total, 121,106 adolescents with 13-18 years olds from the 2014 and 2015 Korea Youth Risk Behavior Web-based Survey were surveyed for age, sex, region of residence, economic level, paternal and maternal education level, sleep time, stress level, school performance, frequency of energy drink intake, and suicide attempts. Subjective stress levels were classified into severe, moderate, mild, a little, and no stress. Sleep time was divided into 6 groups: < 6 h; 6 ≤ h < 7; 7 ≤ h < 8; 8 ≤ h < 9; and ≥ 9 h. School performance was classified into 5 levels: A (highest, B (middle, high, C (middle, D (middle, low, and E (lowest. Frequency of energy drink consumption was divided into 3 groups: ≥ 3, 1-2, and 0 times a week. The associations of sleep time, stress level, and school performance with suicide attempts and the frequency of energy drink intake were analyzed using multiple and ordinal logistic regression analysis, respectively, with complex sampling. The relationship between frequency of energy drink intake and suicide attempts was analyzed using multiple logistic regression analysis with complex sampling.Higher stress levels, lack of sleep, and low school performance were significantly associated with suicide attempts (each P < 0.001. These variables of high stress level, abnormal sleep time, and low school performance were also proportionally related with higher energy drink intake (P < 0.001. Frequent energy drink intake was significantly associated with suicide attempts in multiple logistic regression analyses (AOR for frequency of energy intake ≥ 3 times a week = 3.03, 95

  11. Elite sport is not an additional source of distress for adolescents with high stress levels.

    Science.gov (United States)

    Gerber, Markus; Holsboer-Trachsler, Edith; Pühse, Uwe; Brand, Serge

    2011-04-01

    This study examined whether participation in elite sport interacts with stress in decreasing or increasing symptoms of depression and anxiety among adolescents, and further, whether the interplay between participation in high-performance sport and stress is related to the perceived quality of sleep. 434 adolescents (278 girls, 156 boys; age: M = 17.2 yr.) from 15 "Swiss Olympic Sport Classes" and 9 conventional classes answered a questionnaire and completed a 7-day sleep log. Analyses of covariance showed that heightened stress was related to more depressive symptoms and higher scores for trait-anxiety. Moreover, those classified as having poor sleep by a median split cutoff reported higher levels of depressive symptoms. No significant (multivariate) main effects were found for high-performance sport athletes. Similarly, no significant two- or three-way interaction effects were found. These results caution against exaggerated expectations concerning sport participation as a stress buffer. Nevertheless, participation in high-performance sport was not found to be an additional source of distress for adolescents who reported high stress levels despite prior research that has pointed toward such a relationship.

  12. Compressive pre-stress effects on magnetostrictive behaviors of highly textured Galfenol and Alfenol thin sheets

    Directory of Open Access Journals (Sweden)

    Julia R. Downing

    2017-05-01

    Full Text Available Fe-Ga (Galfenol and Fe-Al (Alfenol are rare-earth-free magnetostrictive alloys with mechanical robustness and strong magnetoelastic coupling. Since highly textured Galfenol and Alfenol thin sheets along orientations have been developed with magnetostrictive performances of ∼270 ppm and ∼160 ppm, respectively, they have been of great interest in sensor and energy harvesting applications. In this work, we investigate stress-dependent magnetostrictive behaviors in highly textured rolled sheets of NbC-added Fe80Al20 and Fe81Ga19 alloys with a single (011 grain coverage of ∼90%. A compact fixture was designed and used to introduce a uniform compressive pre-stress to those thin sheet samples along a [100] direction. As compressive pre-stress was increased to above 100 MPa, the maximum observed magnetostriction increased 42% in parallel magnetostriction along the stress direction, λ//, in highly textured (011 Fe81Ga19 thin sheets for a compressive pre-stress of 60 MPa. The same phenomena were observed for (011 Fe80Al20 (maximum increase of 88% with a 49 MPa compressive stress. This trend is shown to be consistent with published results on the effect of pre-stress on magnetostriction in rods of single crystal and textured polycrystalline Fe-Ga alloy of similar compositions, and single crystal data gathered using our experimental set up. Interestingly, the saturating field (Hs does not vary with pre-stresses, while the saturating field in rod-shaped samples of Fe-Ga increases with an increase of pre-stress. This suggests that for a range of compressive pre-stresses, thin sheet samples have larger values of d33 transduction coefficients and susceptibility than rod-shaped samples of similar alloy compositions, and hence they should provide performance benefits when used in sensor and actuator device applications. Thus, we discuss potential reasons for the unexpected trends in Hs with pre-stress, and present preliminary results from tests conducted

  13. Rock Strength Anisotropy in High Stress Conditions: A Case Study for Application to Shaft Stability Assessments

    Directory of Open Access Journals (Sweden)

    Watson Julian Matthew

    2015-03-01

    Full Text Available Although rock strength anisotropy is a well-known phenomenon in rock mechanics, its impact on geotechnical design is often ignored or underestimated. This paper explores the concept of anisotropy in a high stress environment using an improved unified constitutive model (IUCM, which can account for more complex failure mechanisms. The IUCM is used to better understand the typical responses of anisotropic rocks to underground mining. This study applies the IUCM to a proposed rock shaft located in high stress/anisotropic conditions. Results suggest that the effect of rock strength anisotropy must be taken into consideration when assessing the rock mass response to mining in high stress and anisotropic rock conditions.

  14. High fat diet aggravates arsenic induced oxidative stress in rat heart and liver.

    Science.gov (United States)

    Dutta, Mousumi; Ghosh, Debosree; Ghosh, Arnab Kumar; Bose, Gargi; Chattopadhyay, Aindrila; Rudra, Smita; Dey, Monalisa; Bandyopadhyay, Arkita; Pattari, Sanjib K; Mallick, Sanjaya; Bandyopadhyay, Debasish

    2014-04-01

    Arsenic is a well known global groundwater contaminant. Exposure of human body to arsenic causes various hazardous effects via oxidative stress. Nutrition is an important susceptible factor which can affect arsenic toxicity by several plausible mechanisms. Development of modern civilization led to alteration in the lifestyle as well as food habits of the people both in urban and rural areas which led to increased use of junk food containing high level of fat. The present study was aimed at investigating the effect of high fat diet on heart and liver tissues of rats when they were co-treated with arsenic. This study was established by elucidating heart weight to body weight ratio as well as analysis of the various functional markers, oxidative stress biomarkers and also the activity of the antioxidant enzymes. Histological analysis confirmed the biochemical investigations. From this study it can be concluded that high fat diet increased arsenic induced oxidative stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Testing the accelerating moment release (AMR) hypothesis in areas of high stress

    Science.gov (United States)

    Guilhem, Aurélie; Bürgmann, Roland; Freed, Andrew M.; Ali, Syed Tabrez

    2013-11-01

    Several retrospective analyses have proposed that significant increases in moment release occurred prior to many large earthquakes of recent times. However, the finding of accelerating moment release (AMR) strongly depends on the choice of three parameters: (1) magnitude range, (2) area being considered surrounding the events and (3) the time period prior to the large earthquakes. Consequently, the AMR analysis has been criticized as being a posteriori data-fitting exercise with no new predictive power. As AMR has been hypothesized to relate to changes in the state of stress around the eventual epicentre, we compare here AMR results to models of stress accumulation in California. Instead of assuming a complete stress drop on all surrounding fault segments implied by a back-slip stress lobe method, we consider that stress evolves dynamically, punctuated by the occurrence of earthquakes, and governed by the elastic and viscous properties of the lithosphere. We study the seismicity of southern California and extract events for AMR calculations following the systematic approach employed in previous studies. We present several sensitivity tests of the method, as well as grid-search analyses over the region between 1955 and 2005 using fixed magnitude range, radius of the search area and period of time. The results are compared to the occurrence of large events and to maps of Coulomb stress changes. The Coulomb stress maps are compiled using the coseismic stress from all M > 7.0 earthquakes since 1812, their subsequent post-seismic relaxation, and the interseismic strain accumulation. We find no convincing correlation of seismicity rate changes in recent decades with areas of high stress that would support the AMR hypothesis. Furthermore, this indicates limited utility for practical earthquake hazard analysis in southern California, and possibly other regions.

  16. Financial stress, parent functioning and adolescent problem behavior: an actor-partner interdependence approach to family stress processes in low-, middle-, and high-income families.

    Science.gov (United States)

    Ponnet, Koen

    2014-10-01

    The family stress model proposes that financial stress experienced by parents is associated with problem behavior in adolescents. The present study applied an actor-partner interdependence approach to the family stress model and focused on low-, middle-, and high-income families to broaden our understanding of the pathways by which the financial stress of mothers and fathers are related to adolescent outcomes. The study uses dyadic data (N = 798 heterosexual couples) from the Relationship between Mothers, Fathers and Children study in which two-parent families with an adolescent between 11 and 17 years of age participated. Path-analytic results indicated that in each of the families the association between parents' financial stress and problem behavior in adolescents is mediated through parents' depressive symptoms, interparental conflict, and positive parenting. Family stress processes also appear to operate in different ways for low-, middle-, and high-income families. In addition to a higher absolute level of financial stress in low-income families, financial stress experienced by mothers and fathers in these families had significant direct and indirect effects on problem behavior in adolescents, while in middle- and high-income families only significant indirect effects were found. The financial stress of a low-income mother also had a more detrimental impact on her level of depressive feelings than it had on mothers in middle-income families. Furthermore, the study revealed gender differences in the pathways of mothers and fathers. Implications for research, clinical practice, and policy are also discussed.

  17. Stress relief of ceramic components in high voltage assemblies. Final report

    International Nuclear Information System (INIS)

    Heinen, R.J.

    1979-02-01

    Two types of ceramic packages were evaluated to determine the effectiveness of encapsulating the ceramic components in beta eucryptite filled epoxy. The requirements (no high voltage breakdown, no ceramic cracking, and no encapsulant cracking) were met by the spark gap assembly, but the sprytron assembly had cracking in the encapsulant after thermal cycling. The encapsulation of the ceramic component in beta eucryptite filled epoxy with a stress decoupling material selectively applied in the stress concentrated areas were used to prevent cracking in the sprytron encapsulant. This method is proposed as the standard encapsulation process for high voltage ceramic components

  18. Application of a Full Reynolds Stress Model to High Lift Flows

    Science.gov (United States)

    Lee-Rausch, E. M.; Rumsey, C. L.; Eisfeld, B.

    2016-01-01

    A recently developed second-moment Reynolds stress model was applied to two challenging high-lift flows: (1) transonic flow over the ONERA M6 wing, and (2) subsonic flow over the DLR-F11 wing-body configuration from the second AIAA High Lift Prediction Workshop. In this study, the Reynolds stress model results were contrasted with those obtained from one- and two{equation turbulence models, and were found to be competitive in terms of the prediction of shock location and separation. For an ONERA M6 case, results from multiple codes, grids, and models were compared, with the Reynolds stress model tending to yield a slightly smaller shock-induced separation bubble near the wing tip than the simpler models, but all models were fairly close to the limited experimental surface pressure data. For a series of high-lift DLR{F11 cases, the range of results was more limited, but there was indication that the Reynolds stress model yielded less-separated results than the one-equation model near maximum lift. These less-separated results were similar to results from the one-equation model with a quadratic constitutive relation. Additional computations need to be performed before a more definitive assessment of the Reynolds stress model can be made.

  19. Population cycles: generalities, exceptions and remaining mysteries

    Science.gov (United States)

    2018-01-01

    Population cycles are one of nature's great mysteries. For almost a hundred years, innumerable studies have probed the causes of cyclic dynamics in snowshoe hares, voles and lemmings, forest Lepidoptera and grouse. Even though cyclic species have very different life histories, similarities in mechanisms related to their dynamics are apparent. In addition to high reproductive rates and density-related mortality from predators, pathogens or parasitoids, other characteristics include transgenerational reduced reproduction and dispersal with increasing-peak densities, and genetic similarity among populations. Experiments to stop cyclic dynamics and comparisons of cyclic and noncyclic populations provide some understanding but both reproduction and mortality must be considered. What determines variation in amplitude and periodicity of population outbreaks remains a mystery. PMID:29563267

  20. Does hypertension remain after kidney transplantation?

    Directory of Open Access Journals (Sweden)

    Gholamreza Pourmand

    2015-05-01

    Full Text Available Hypertension is a common complication of kidney transplantation with the prevalence of 80%. Studies in adults have shown a high prevalence of hypertension (HTN in the first three months of transplantation while this rate is reduced to 50- 60% at the end of the first year. HTN remains as a major risk factor for cardiovascular diseases, lower graft survival rates and poor function of transplanted kidney in adults and children. In this retrospective study, medical records of 400 kidney transplantation patients of Sina Hospital were evaluated. Patients were followed monthly for the 1st year, every two months in the 2nd year and every three months after that. In this study 244 (61% patients were male. Mean ± SD age of recipients was 39.3 ± 13.8 years. In most patients (40.8% the cause of end-stage renal disease (ESRD was unknown followed by HTN (26.3%. A total of 166 (41.5% patients had been hypertensive before transplantation and 234 (58.5% had normal blood pressure. Among these 234 individuals, 94 (40.2% developed post-transplantation HTN. On the other hand, among 166 pre-transplant hypertensive patients, 86 patients (56.8% remained hypertensive after transplantation. Totally 180 (45% patients had post-transplantation HTN and 220 patients (55% didn't develop HTN. Based on the findings, the incidence of post-transplantation hypertension is high, and kidney transplantation does not lead to remission of hypertension. On the other hand, hypertension is one of the main causes of ESRD. Thus, early screening of hypertension can prevent kidney damage and reduce further problems in renal transplant recipients.

  1. Optimization of Residual Stress of High Temperature Treatment Using Genetic Algorithm and Neural Network

    Directory of Open Access Journals (Sweden)

    M. Susmikanti

    2015-12-01

    Full Text Available In a nuclear industry area, high temperature treatment of materials is a factor which requires special attention. Assessment needs to be conducted on the properties of the materials used, including the strength of the materials. The measurement of material properties under thermal processes may reflect residual stresses. The use of Genetic Algorithm (GA to determine the optimal residual stress is one way to determine the strength of a material. In residual stress modeling with several parameters, it is sometimes difficult to solve for the optimal value through analytical or numerical calculations. Here, GA is an efficient algorithm which can generate the optimal values, both minima and maxima. The purposes of this research are to obtain the optimization of variable in residual stress models using GA and to predict the center of residual stress distribution, using fuzzy neural network (FNN while the artificial neural network (ANN used for modeling. In this work a single-material 316/316L stainless steel bar is modeled. The minimal residual stresses of the material at high temperatures were obtained with GA and analytical calculations. At a temperature of 6500C, the GA optimal residual stress estimation converged at –711.3689 MPa at adistance of 0.002934 mm from center point, whereas the analytical calculation result at that temperature and position is -975.556 MPa . At a temperature of 8500C, the GA result was -969.868 MPa at 0.002757 mm from the center point, while with analytical result was -1061.13 MPa. The difference in residual stress between GA and analytical results at a temperatureof6500C is about 27 %, while at 8500C it is 8.67 %. The distribution of residual stress showed a grouping concentrated around a coordinate of (-76; 76 MPa. The residuals stress model is a degree-two polynomial with coefficients of 50.33, -76.54, and -55.2, respectively, with a standard deviation of 7.874.

  2. Close-range hyperspectral image analysis for the early detection of stress responses in individual plants in a high-throughput phenotyping platform

    Science.gov (United States)

    Mohd Asaari, Mohd Shahrimie; Mishra, Puneet; Mertens, Stien; Dhondt, Stijn; Inzé, Dirk; Wuyts, Nathalie; Scheunders, Paul

    2018-04-01

    The potential of close-range hyperspectral imaging (HSI) as a tool for detecting early drought stress responses in plants grown in a high-throughput plant phenotyping platform (HTPPP) was explored. Reflectance spectra from leaves in close-range imaging are highly influenced by plant geometry and its specific alignment towards the imaging system. This induces high uninformative variability in the recorded signals, whereas the spectral signature informing on plant biological traits remains undisclosed. A linear reflectance model that describes the effect of the distance and orientation of each pixel of a plant with respect to the imaging system was applied. By solving this model for the linear coefficients, the spectra were corrected for the uninformative illumination effects. This approach, however, was constrained by the requirement of a reference spectrum, which was difficult to obtain. As an alternative, the standard normal variate (SNV) normalisation method was applied to reduce this uninformative variability. Once the envisioned illumination effects were eliminated, the remaining differences in plant spectra were assumed to be related to changes in plant traits. To distinguish the stress-related phenomena from regular growth dynamics, a spectral analysis procedure was developed based on clustering, a supervised band selection, and a direct calculation of a spectral similarity measure against a reference. To test the significance of the discrimination between healthy and stressed plants, a statistical test was conducted using a one-way analysis of variance (ANOVA) technique. The proposed analysis techniques was validated with HSI data of maize plants (Zea mays L.) acquired in a HTPPP for early detection of drought stress in maize plant. Results showed that the pre-processing of reflectance spectra with the SNV effectively reduces the variability due to the expected illumination effects. The proposed spectral analysis method on the normalized spectra successfully

  3. Social Stress and Substance Use Disparities by Sexual Orientation Among High School Students.

    Science.gov (United States)

    Lowry, Richard; Johns, Michelle M; Robin, Leah E; Kann, Laura K

    2017-10-01

    Sexual minority youth often experience increased social stress due to prejudice, discrimination, harassment, and victimization. Increased stress may help explain the disproportionate use of substances like tobacco, alcohol, marijuana, and other illicit drug use by sexual minority youth. This study examined the effect of social stress on substance use disparities by sexual orientation among U.S. high school students. In 2016, data from the national 2015 Youth Risk Behavior Survey, conducted among a nationally representative sample of 15,624 U.S. high school students, were analyzed to examine the effect of school-related (threatened/injured at school, bullied at school, bullied electronically, felt unsafe at school) and non-school-related (forced sexual intercourse, early sexual debut) social stress on substance use disparities by sexual orientation, by comparing unadjusted prevalence ratios (PRs) and adjusted (for social stressors, age, sex, and race/ethnicity) prevalence ratios (APRs). Unadjusted PRs reflected significantly (pprevention programs might appropriately include strategies to reduce social stress, including policies and practices designed to provide a safe school environment and improved access to social and mental health services. Published by Elsevier Inc.

  4. Stress analysis in high-temperature superconductors under pulsed field magnetization

    Science.gov (United States)

    Wu, Haowei; Yong, Huadong; Zhou, Youhe

    2018-04-01

    Bulk high-temperature superconductors (HTSs) have a high critical current density and can trap a large magnetic field. When bulk superconductors are magnetized by the pulsed field magnetization (PFM) technique, they are also subjected to a large electromagnetic stress, and the resulting thermal stress may cause cracking of the superconductor due to the brittle nature of the sample. In this paper, based on the H-formulation and the law of heat transfer, we can obtain the distributions of electromagnetic field and temperature, which are in qualitative agreement with experiment. After that, based on the dynamic equilibrium equations, the mechanical response of the bulk superconductor is determined. During the PFM process, the change in temperature has a dramatic effect on the radial and hoop stresses, and the maximum radial and hoop stress are 24.2 {{MPa}} and 22.6 {{MPa}}, respectively. The mechanical responses of a superconductor for different cases are also studied, such as the peak value of the applied field and the size of bulk superconductors. Finally, the stresses are also presented for different magnetization methods.

  5. Corrosion Behavior of the Stressed Sensitized Austenitic Stainless Steels of High Nitrogen Content in Seawater

    Directory of Open Access Journals (Sweden)

    A. Almubarak

    2013-01-01

    Full Text Available The purpose of this paper is to study the effect of high nitrogen content on corrosion behavior of austenitic stainless steels in seawater under severe conditions such as tensile stresses and existence of sensitization in the structure. A constant tensile stress has been applied to sensitized specimens types 304, 316L, 304LN, 304NH, and 316NH stainless steels. Microstructure investigation revealed various degrees of stress corrosion cracking. SCC was severe in type 304, moderate in types 316L and 304LN, and very slight in types 304NH and 316NH. The electrochemical polarization curves showed an obvious second current peak for the sensitized alloys which indicated the existence of second phase in the structure and the presence of intergranular stress corrosion cracking. EPR test provided a rapid and efficient nondestructive testing method for showing passivity, degree of sensitization and determining IGSCC for stainless steels in seawater. A significant conclusion was obtained that austenitic stainless steels of high nitrogen content corrode at a much slower rate increase pitting resistance and offer an excellent resistance to stress corrosion cracking in seawater.

  6. Proteomic analysis of broccoli (Brassica oleracea) under high temperature and waterlogging stresses.

    Science.gov (United States)

    Lin, Hsin-Hung; Lin, Kuan-Hung; Chen, Su-Ching; Shen, Yu-Hsing; Lo, Hsiao-Feng

    2015-12-01

    The production of broccoli (Brassica oleracea) is largely reduced by waterlogging and high temperature stresses. Heat-tolerant and heat-susceptible broccoli cultivars TSS-AVRDC-2 and B-75, respectively, were used for physiological and proteomic analyses. The objective of this study was to identify TSS-AVRDC-2 and B-75 proteins differentially regulated at different time periods in response to waterlogging at 40 °C for three days. TSS-AVRDC-2 exhibited significantly higher chlorophyll content, lower stomatal conductance, and better H 2 O 2 scavenging under stress in comparison to B-75. Two-dimensional liquid phase fractionation analyses revealed that Rubisco proteins in both varieties were regulated under stressing treatments, and that TSS-AVRDC-2 had higher levels of both Rubisco large and small subunit transcripts than B-75 when subjected to high temperature and/or waterlogging. This report utilizes physiological and proteomic approaches to discover changes in the protein expression profiles of broccoli in response to heat and waterlogging stresses. Higher levels of Rubisco proteins in TSS-AVRDC-2 could lead to increased carbon fixation efficiency to provide sufficient energy to enable stress tolerance under waterlogging at 40 °C.

  7. Intergranular stress corrosion cracking of low alloy and carbon steels in high temperature pure water

    International Nuclear Information System (INIS)

    Tsubota, M.; Sakamoto, H.; Tsuzuki, R.

    1993-01-01

    Stress corrosion cracking (SCC) behavior of low alloy steels (A508 and SNCM630) and a carbon steel (SGV480) in high temperature water has been examined with relation to the heat treatment condition, including a long time aging, and the mechanical properties. Intergranular stress corrosion cracking (IGSCC) as observed in the highly hardened specimens, and there was observed in the highly hardened specimens, and there was observed in the highly hardened specimens, and there was observed a close relationship between hardness and SCC susceptibility. From the engineering point of view, it was concluded that adequate SR (stress relief) or tempering heat treatment is necessary to avoid the IGSCC of the welded structures made of low alloy and carbon steels. A508 heat treated with specified quench and temper did not show the SCC susceptibility, even after aging 10000 hours at 350, 400 and 450 degrees C. Tensile properties corresponding to the critical hardness for SSC susceptibility coincided with the values at the 'necking point' in the true stress-strain curve. Ductile-brittle transition observed in the fracture toughness test also occurred at around the critical hardness for SCC susceptibility. Therefore, it was conjectured that the limitation of plasticity was an absolute cause for the SCC susceptibility of the steels

  8. Rapid chilling cannot prevent inferior pork quality caused by high preslaughter stress

    NARCIS (Netherlands)

    Hambrecht, E.; Eissen, J.J.; Klein, W.J.H.; Ducro, B.J.; Smits, C.H.M.; Verstegen, M.W.A.; Hartog, den L.A.

    2004-01-01

    The present experiment investigated whether increasing chilling rate could improve meat quality in pigs exposed to either minimal or high stress immediately preslaughter. Pigs (n = 192) were offspring of halothane-free lines. On various days, four groups of 48 pigs were processed at a commercial

  9. The response of high and low polyamine producing cell lines to aluminum and calcium stress

    Science.gov (United States)

    Sridev Mohapatra; Smita Cherry; Rakesh Minocha; Rajtilak Majumdar; Palaniswamy Thangavel; Stephanie Long; Subhash C. Minocha

    2010-01-01

    The diamine putrescine (Put) has been shown to accumulate in tree leaves in response to high Al and low Ca in the soil, leading to the suggestion that this response may provide a physiological advantage to leaf cells under conditions of Al stress. The increase in Put is reversed by Ca supplementation in the soil. Using two cell lines of poplar (Populus nigra...

  10. Psychological Properties and Stress Tolerance of High-Qualified Athletes Specializing in Athletic Walking

    Directory of Open Access Journals (Sweden)

    Vasyl Vasylyuk

    2018-04-01

    Full Text Available In the field of sports, there is a strong interest in the behavioral strategies of professional athletes, thus the study of the psychological characteristics of highly skilled athletes is a very topical issue. The article raises the question of the characteristics of the sports environment and the manifestations of stress among athletes. In the paper the psychological features of the personalities of highly qualified athletes who specialize in athletic walking on a scale of neuroticism and extraversion are investigated and the level of neuro-psychological stability of highly skilled athletes specializing in athletic walking is revealed. The main factors of stress in sports activities are: intense competition during a sporting contestation aimed at establishing a record or achieving victory over the rival; maximum physical and psychological stress during the contestation; systematic, long and intense training, which significantly affect the daily regime and everyday life. Two types of stress among athletes are singled out: social-emotional and training. A study of 12 highly qualified athletes who specialize in athletic walking showed that most of them (50 % have ambivert abilities. They are concordants and normostenics that are characterized by significant emotional stability, good adaptability, resistance to external influences. However, among the respondents there were some with low and below average neuropsychic stability.

  11. Creep and rupture of an ODS alloy with high stress rupture ductility. [Oxide Dispersion Strengthened

    Science.gov (United States)

    Mcalarney, M. E.; Arsons, R. M.; Howson, T. E.; Tien, J. K.; Baranow, S.

    1982-01-01

    The creep and stress rupture properties of an oxide (Y2O3) dispersion strengthened nickel-base alloy, which also is strengthened by gamma-prime precipitates, was studied at 760 and 1093 C. At both temperatures, the alloy YDNiCrAl exhibits unusually high stress rupture ductility as measured by both elongation and reduction in area. Failure was transgranular, and different modes of failure were observed including crystallographic fracture at intermediate temperatures and tearing or necking almost to a chisel point at higher temperatures. While the rupture ductility was high, the creep strength of the alloy was low relative to conventional gamma prime strengthened superalloys in the intermediate temperature range and to ODS alloys in the higher temperature range. These findings are discussed with respect to the alloy composition; the strengthening oxide phases, which are inhomogeneously dispersed; the grain morphology, which is coarse and elongated and exhibits many included grains; and the second phase inclusion particles occurring at grain boundaries and in the matrix. The creep properties, in particular the high stress dependencies and high creep activation energies measured, are discussed with respect to the resisting stress model of creep in particle strengthened alloys.

  12. Interpersonal stress, performance level, and parental support : A Longitudinal study among highly skilled young soccer players

    NARCIS (Netherlands)

    Van Yperen, N.W.

    1995-01-01

    This study of 65 highly skilled young male soccer players (mean age = 16.6 years) employed a 7-month longitudinal design to examine the causal relationship between performance level and interpersonal stress within the team. Particular attention was paid to the moderating effect of parental support.

  13. A high-order boundary integral method for surface diffusions on elastically stressed axisymmetric rods.

    Science.gov (United States)

    Li, Xiaofan; Nie, Qing

    2009-07-01

    Many applications in materials involve surface diffusion of elastically stressed solids. Study of singularity formation and long-time behavior of such solid surfaces requires accurate simulations in both space and time. Here we present a high-order boundary integral method for an elastically stressed solid with axi-symmetry due to surface diffusions. In this method, the boundary integrals for isotropic elasticity in axi-symmetric geometry are approximated through modified alternating quadratures along with an extrapolation technique, leading to an arbitrarily high-order quadrature; in addition, a high-order (temporal) integration factor method, based on explicit representation of the mean curvature, is used to reduce the stability constraint on time-step. To apply this method to a periodic (in axial direction) and axi-symmetric elastically stressed cylinder, we also present a fast and accurate summation method for the periodic Green's functions of isotropic elasticity. Using the high-order boundary integral method, we demonstrate that in absence of elasticity the cylinder surface pinches in finite time at the axis of the symmetry and the universal cone angle of the pinching is found to be consistent with the previous studies based on a self-similar assumption. In the presence of elastic stress, we show that a finite time, geometrical singularity occurs well before the cylindrical solid collapses onto the axis of symmetry, and the angle of the corner singularity on the cylinder surface is also estimated.

  14. Quantitative analysis of localized stresses in irradiated stainless steels using high resolution electron backscatter diffraction and molecular dynamics modeling

    International Nuclear Information System (INIS)

    Johnson, D.C.; Kuhr, B.; Farkas, D.; Was, G.S.

    2016-01-01

    Quantitative measurements of stress near dislocation channel–grain boundary (DC–GB) interaction sites were made using high resolution electron backscatter diffraction (HREBSD) and have been compared with molecular dynamics (MD) simulations. Tensile stress normal to the grain boundary was significantly elevated at discontinuous DC–GB intersections with peak magnitudes roughly an order of magnitude greater than at sites where slip transfer occurred. These results constitute the first measurement of stress amplification at DC–GB intersections and provide support to the theory that high normal stress at the grain boundary may be a key driver for the initiation of irradiation assisted stress corrosion cracks.

  15. Mortality and morbidity remain high despite captopril and/or valsartan therapy in elderly patients with left ventricular systolic dysfunction, heart failure, or both after acute myocardial infarction - Results from the Valsartan in Acute Myocardial Infarction Trial (VALIANT)

    NARCIS (Netherlands)

    White, HD; Aylward, PEG; Huang, Z; Dalby, AJ; Weaver, WD; Barvik, S; Marin-Neto, JA; Murin, J; Nordlander, RO; van Gilst, WH; Zannad, F; McMurray, JJV; Califf, RM; Pfeffer, MA

    2005-01-01

    Background - The elderly constitute an increasing proportion of acute myocardial infarction patients and have disproportionately high mortality and morbidity. Those with heart failure or impaired left ventricular left ventricular function after acute myocardial infarction have high complication and

  16. X-Ray Diffraction Techniques and Finite Element Modeling to Control Residual Stress in High-Temperature Pressure Vessels

    National Research Council Canada - National Science Library

    Lee, S

    1999-01-01

    Manufacturing operations, such as swage autofrettage, shot peening, and overload processes, have been used to impart advantageous residual stresses to improve fatigue life in components used in high...

  17. Very high cycle fatigue crack initiation in electroplated Ni films under extreme stress gradients

    International Nuclear Information System (INIS)

    Baumert, E.K.; Pierron, O.N.

    2012-01-01

    A characterization technique based on kilohertz micro-resonators is presented to investigate the very high cycle fatigue behavior of 20 μm thick electroplated Ni films with a columnar microstructure (grain diameter less than 2 μm). The films exhibit superior fatigue resistance due to the extreme stress gradients at the surface. The effects of stress amplitude and environment on the formation of fatigue extrusions and micro-cracks are discussed based on scanning electron microscopy and the tracking of the specimens’ resonant frequency.

  18. Prognostic value of stress echocardiography in women with high (⩾80%) probability of coronary artery disease

    OpenAIRE

    Davar, J; Roberts, E; Coghlan, J; Evans, T; Lipkin, D

    2001-01-01

    OBJECTIVE—To assess the prognostic significance of stress echocardiography in women with a high probability of coronary artery disease (CAD).
SETTING—Secondary and tertiary cardiology unit at a university teaching hospital.
PARTICIPANTS—A total of 135 women (mean (SD) age 63 (9) years) with pre-test probability of CAD ⩾80% were selected from a database of patients investigated by treadmill or dobutamine stress echocardiography between 1995 and 1998.
MAIN OUTCOME MEASURES—Patients were followe...

  19. 3D numerical thermal stress analysis of the high power target for the SLC Positron Source

    International Nuclear Information System (INIS)

    Reuter, E.M.; Hodgson, J.A.

    1991-05-01

    The volumetrically nonuniform power deposition of the incident 33 GeV electron beam in the SLC Positron Source Target is hypothesized to be the most likely cause target failure. The resultant pulsed temperature distributions are known to generate complicated stress fields with no known closed-form analytical solution. 3D finite element analyses of these temperature distributions and associated thermal stress fields in the new High Power Target are described here. Operational guidelines based on the results of these analyses combined with assumptions made about the fatigue characteristics of the exotic target material are proposed. 6 refs., 4 figs

  20. Oxidative stress plays a role in high glucose-induced activation of pancreatic stellate cells

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Gyeong Ryul; Lee, Esder; Chun, Hyun-Ji; Yoon, Kun-Ho; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho, E-mail: kihos@catholic.ac.kr

    2013-09-20

    Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated and cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation.

  1. Oxidative stress plays a role in high glucose-induced activation of pancreatic stellate cells

    International Nuclear Information System (INIS)

    Ryu, Gyeong Ryul; Lee, Esder; Chun, Hyun-Ji; Yoon, Kun-Ho; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho

    2013-01-01

    Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated and cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation

  2. Behaviour of a pre-stressed concrete pressure-vessel subjected to a high temperature gradient

    International Nuclear Information System (INIS)

    Dubois, F.

    1965-01-01

    After a review of the problems presented by pressure-vessels for atomic reactors (shape of the vessel, pressures, openings, foundations, etc.) the advantages of pre-stressed concrete vessels with respect to steel ones are given. The use of pre-stressed concrete vessels however presents many difficulties connected with the properties of concrete. Thus, because of the absence of an exact knowledge of the material, it is necessary to place a sealed layer of steel against the concrete, to have a thermal insulator or a cooling circuit for limiting the deformations and stresses, etc. It follows that the study of the behaviour of pre-stressed concrete and of the vessel subjected- to a high temperature gradient can yield useful information. A one-tenth scale model of a pre-stressed concrete cylindrical vessel without any side openings and without a base has been built. Before giving a description of the tests the authors consider some theoretical aspects concerning 'scale model-actual structure' similitude conditions and the calculation of the thermal and mechanical effects. The pre-stressed concrete model was heated internally by a 'pyrotenax' element and cooled externally by a very strong air current. The concrete was pre-stressed using horizontal and vertical cables held at 80 kg/cm 2 ; the thermal gradient was 160 deg. C. During the various tests, measurements were made of the overall and local deformations, the changes in water content, the elasticity modulus, the stress and creep of the cables and the depths of the cracks. The overall deformations observed are in line with thermal deformation theories and the creep of the cables attained 20 to 30 per cent according to their position relative to the internal surface. The dynamic elasticity modulus decreased by half but the concrete keeps its good mechanical properties. Finally, cracks 8 to 12 cm deep and 2 to 3 mms wide appeared in that part of the concrete which was not pre-stressed. The results obtained make it

  3. A STUDY OF THE PRESSURE SOLUTION AND DEFORMATION OF QUARTZ CRYSTALS AT HIGH pH AND UNDER HIGH STRESS

    Directory of Open Access Journals (Sweden)

    JUNG-HAE CHOI

    2013-02-01

    Full Text Available Bentonite is generally used as a buffer material in high-level radioactive waste disposal facilities and consists of 50% quartz by weight. Quartz strongly affects the behavior of bentonite over very long periods. For this reason, quartz dissolution experiment was performed under high-pressure and high-alkalinity conditions based on the conditions found in a high-level radioactive waste disposal facility located deep underground. In this study, two quartz dissolution experiments were conducted on 1 quartz beads under low-pressure and high-alkalinity conditions and 2 a single quartz crystal under high-pressure and high-alkalinity conditions. Following the experiments, a confocal laser scanning microscope (CLSM was used to observe the surfaces of experimental samples. Numerical analyses using the finite element method (FEM were also performed to quantify the deformation of contact area. Quartz dissolution was observed in both experiments. This deformation was due to a concentrated compressive stress field, as indicated by the quartz deformation of the contact area through the FEM analysis. According to the numerical results, a high compressive stress field acted upon the neighboring contact area, which showed a rapid dissolution rate compared to other areas of the sample.

  4. Vildagliptin Can Alleviate Endoplasmic Reticulum Stress in the Liver Induced by a High Fat Diet

    OpenAIRE

    Ma, Xiaoqing; Du, Wenhua; Shao, Shanshan; Yu, Chunxiao; Zhou, Lingyan; Jing, Fei

    2018-01-01

    Purpose. We investigated whether a DDP-4 inhibitor, vildagliptin, alleviated ER stress induced by a high fat diet and improved hepatic lipid deposition. Methods. C57BL/6 mice received standard chow diet (CD), high fat diet (HFD), and HFD administered with vildagliptin (50 mg/Kg) (V-HFD). After administration for 12 weeks, serum alanine aminotransferase, glucose, cholesterol, triglyceride, and insulin levels were analyzed. Samples of liver underwent histological examination and transmission el...

  5. A Comparative Study of the Academic Stress and Depression among High School Girl and Boy Students

    Science.gov (United States)

    Khanehkeshi, Ali; Basavarajappa

    2012-01-01

    This paper compares the difference between boy and girl high school students of 1st grade to 3rd grade in academic stress and depression. Using a random stratified sampling 120 girl and boy students (60 girls and 60 boys) were selected from 1st grade (n = 40), 2nd grade (n = 40) and 3rd grade (n = 40) high school students. In this study gender and…

  6. A switch from high-fidelity to error-prone DNA double-strand break repair underlies stress-induced mutation.

    Science.gov (United States)

    Ponder, Rebecca G; Fonville, Natalie C; Rosenberg, Susan M

    2005-09-16

    Special mechanisms of mutation are induced in microbes under growth-limiting stress causing genetic instability, including occasional adaptive mutations that may speed evolution. Both the mutation mechanisms and their control by stress have remained elusive. We provide evidence that the molecular basis for stress-induced mutagenesis in an E. coli model is error-prone DNA double-strand break repair (DSBR). I-SceI-endonuclease-induced DSBs strongly activate stress-induced mutations near the DSB, but not globally. The same proteins are required as for cells without induced DSBs: DSBR proteins, DinB-error-prone polymerase, and the RpoS starvation-stress-response regulator. Mutation is promoted by homology between cut and uncut DNA molecules, supporting a homology-mediated DSBR mechanism. DSBs also promote gene amplification. Finally, DSBs activate mutation only during stationary phase/starvation but will during exponential growth if RpoS is expressed. Our findings reveal an RpoS-controlled switch from high-fidelity to mutagenic DSBR under stress. This limits genetic instability both in time and to localized genome regions, potentially important evolutionary strategies.

  7. Isotopically Enriched C-13 Diamond Anvil as a Stress Sensor in High Pressure Experiments

    Science.gov (United States)

    Vohra, Yogesh; Qiu, Wei; Kondratyev, Andreiy; Velisavljevic, Nenad; Baker, Paul

    2004-03-01

    The conventional high pressure diamond anvils were modified by growing an isotopically pure C-13 diamond layer by microwave plasma chemical vapor deposition using methane/hydrogen/oxygen chemistry. The isotopically pure C-13 nature of the culet of the diamond anvil was confirmed by the Raman spectroscopy measurements. This isotopically engineered diamond anvil was used against a natural abundance diamond anvil for high pressure experiments in a diamond anvil cell. Spatial resolved Raman spectroscopy was used to measure the stress induced shift in the C-13 layer as well as the undelying C-12 layer to ultra high pressures. The observed shift and splitiing of the diamond first order Raman spectrum was correlated with the stress distribution in the diamond anvil cell. The experimental results will be compared with the finite element modeling results using NIKE-2D software in order to create a mathematical relationship between sets of the following parameters: vertical (z axis) distance; horizontal (r axis) distance; max shear stress, and pressure. The isotopically enriched diamond anvils offer unique opportunities to measure stress distribution in the diamond anvil cell devices.

  8. Analysis of occupational stress in a high fashion clothing factory with upper limb biomechanical overload.

    Science.gov (United States)

    Forcella, Laura; Bonfiglioli, Roberta; Cutilli, Piero; Siciliano, Eugenio; Di Donato, Angela; Di Nicola, Marta; Antonucci, Andrea; Di Giampaolo, Luca; Boscolo, Paolo; Violante, Francesco Saverio

    2012-07-01

    To study job stress and upper limb biomechanical overload due to repetitive and forceful manual activities in a factory producing high fashion clothing. A total of 518 workers (433 women and 85 men) were investigated to determine anxiety, occupational stress (using the Italian version of the Karasek Job Content Questionnaire) and perception of symptoms (using the Italian version of the Somatization scale of Symptom Checklist SCL-90). Biomechanical overload was analyzed using the OCRA Check list. Biomechanical assessment did not reveal high-risk jobs, except for cutting. Although the perception of anxiety and job insecurity was within the normal range, all the workers showed a high level of job strain (correlated with the perception of symptoms) due to very low decision latitude. Occupational stress resulted partially in line with biomechanical risk factors; however, the perception of low decision latitude seems to play a major role in determining job strain. Interactions between physical and psychological factors cannot be demonstrated. Anyway, simultaneous long-term monitoring of occupational stress features and biomechanical overload could guide workplace interventions aimed at reducing the risk of adverse health effects.

  9. Physiological and biochemical response to high temperature stress in Okra (Abelmoschus esculentus L. Moench)

    Science.gov (United States)

    Hayamanesh, Shahnoosh; Keitel, Claudia; Ahmad, Nabil; Trethowan, Richard

    2016-04-01

    High temperature has been shown to lower the growth and yield of Okra, an important summer vegetable crop grown in Asia, Africa, the Middle East and Australia. We aimed to characterise the physiological and biochemical response of Okra to heat stress. 150 genotypes from Pakistan and the AVRDC (The World Vegetable Centre) were screened for their physiological response (fluorescence, electrolyte leakage and yield) to heat in a greenhouse. Four genotypes (including heat tolerant and sensitive) were selected and subsequently grown in control and hot greenhouses. Daytime temperatures were on average 10°C warmer in the hot greenhouse, whereas nighttime temperatures were similar between the two temperature treatments. During a 12 week period, the physiological (assimilation rate, transpiration rate, stomatal conductance, fluorescence, electrolyte leakage, water potential) and biochemical (carbohydrates, sugar alcohols, C content) response of the four genotypes to heat stress was assessed. The effect of heat stress on the C allocation patterns and yield in Okra will be discussed.

  10. A study on fatigue crack growth model considering high mean loading effects based on structural stress

    International Nuclear Information System (INIS)

    Kim, Jong Sung; Kim, Cheol; Jin, Tae Eun; Dong, P.

    2004-01-01

    The mesh-insensitive structural stress procedure by Dong is modified to apply to the welded joints with local thickness variation and inarguable shear/normal stresses along local discontinuity surface. In order to make use of the structural stress based K solution for fatigue correlation of welded joints, a proper crack growth model needs to be developed. There exist some significant discrepancies in inferring the slope or crack growth exponent in the conventional Paris law regime. Two-stage crack growth model was not considered since its applications are focused upon the fatigue behavior in welded joints in which the load ratio effects are considered negligible. In this paper, a two-stage crack growth law considering high mean loading is proposed and proven to be effective in unifying the so-called anomalous short crack growth data

  11. Temporal and voltage stress stability of high performance indium-zinc-oxide thin film transistors

    Science.gov (United States)

    Song, Yang; Katsman, Alexander; Butcher, Amy L.; Paine, David C.; Zaslavsky, Alexander

    2017-10-01

    Thin film transistors (TFTs) based on transparent oxide semiconductors, such as indium zinc oxide (IZO), are of interest due to their improved characteristics compared to traditional a-Si TFTs. Previously, we reported on top-gated IZO TFTs with an in-situ formed HfO2 gate insulator and IZO active channel, showing high performance: on/off ratio of ∼107, threshold voltage VT near zero, extracted low-field mobility μ0 = 95 cm2/V·s, and near-perfect subthreshold slope at 62 mV/decade. Since device stability is essential for technological applications, in this paper we report on the temporal and voltage stress stability of IZO TFTs. Our devices exhibit a small negative VT shift as they age, consistent with an increasing carrier density resulting from an increasing oxygen vacancy concentration in the channel. Under gate bias stress, freshly annealed TFTs show a negative VT shift during negative VG gate bias stress, while aged (>1 week) TFTs show a positive VT shift during negative VG stress. This indicates two competing mechanisms, which we identify as the field-enhanced generation of oxygen vacancies and the field-assisted migration of oxygen vacancies, respectively. A simplified kinetic model of the vacancy concentration evolution in the IZO channel under electrical stress is provided.

  12. Effects of metallurgical factors on stress corrosion cracking of Ni-base alloys in high temperature water

    International Nuclear Information System (INIS)

    Yonezawa, T.; Sasaguri, N.; Onimura, K.

    1988-01-01

    Nickel-base Alloy 600 is the principal material used for the steam generator tubes of PWRs. Generally, this alloy has been proven to be satisfactory for this application, however when it is subjected to extremely high stress level in PWR primary water, it may suffer from stress corrosion cracking. The authors have systematically studied the effects of test temperature and such metallurgical factors as cold working, chemical composition and heat treatment on the stress corrosion cracking of Alloy 600 in high temperature water, and also on that of Alloy 690 which is a promising material for the tubes and may provide improved crrosion resistance for steam generators. The test materials, the stress corrosion cracking test and the test results are reported. When the test temperature was raise, the stress corrosion cracking of the nickel-base alloys was accelerated. The time of stress corrosion cracking occurrence decreased with increasing applied stress, and it occurred at the stress level higher than the 0.2 % offset proof stress of Alloy 600. In Alloy 690, stress corrosion cracking was not observed at such stress level. Cold worked Alloy 600 showed higher resistance to stress corrosion cracking than the annealed alloy. (Kako, I.)

  13. Modulation of hepatic inflammation and energy-sensing pathways in the rat liver by high-fructose diet and chronic stress.

    Science.gov (United States)

    Veličković, Nataša; Teofilović, Ana; Ilić, Dragana; Djordjevic, Ana; Vojnović Milutinović, Danijela; Petrović, Snježana; Preitner, Frederic; Tappy, Luc; Matić, Gordana

    2018-05-29

    High-fructose consumption and chronic stress are both associated with metabolic inflammation and insulin resistance. Recently, disturbed activity of energy sensor AMP-activated protein kinase (AMPK) was recognized as mediator between nutrient-induced stress and inflammation. Thus, we analyzed the effects of high-fructose diet, alone or in combination with chronic stress, on glucose homeostasis, inflammation and expression of energy sensing proteins in the rat liver. In male Wistar rats exposed to 9-week 20% fructose diet and/or 4-week chronic unpredictable stress we measured plasma and hepatic corticosterone level, indicators of glucose homeostasis and lipid metabolism, hepatic inflammation (pro- and anti-inflammatory cytokine levels, Toll-like receptor 4, NLRP3, activation of NFκB, JNK and ERK pathways) and levels of energy-sensing proteins AMPK, SIRT1 and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). High-fructose diet led to glucose intolerance, activation of NFκB and JNK pathways and increased intrahepatic IL-1β, TNFα and inhibitory phosphorylation of insulin receptor substrate 1 on Ser 307 . It also decreased phospho-AMPK/AMPK ratio and increased SIRT1 expression. Stress alone increased plasma and hepatic corticosterone but did not influence glucose tolerance, nor hepatic inflammatory or energy-sensing proteins. After the combined treatment, hepatic corticosterone was increased, glucose tolerance remained preserved, while hepatic inflammation was partially prevented despite decreased AMPK activity. High-fructose diet resulted in glucose intolerance, hepatic inflammation, decreased AMPK activity and reduced insulin sensitivity. Chronic stress alone did not exert such effects, but when applied together with high-fructose diet it could partially prevent fructose-induced inflammation, presumably due to increased hepatic glucocorticoids.

  14. Fear of failure, psychological stress, and burnout among adolescent athletes competing in high level sport.

    Science.gov (United States)

    Gustafsson, H; Sagar, S S; Stenling, A

    2017-12-01

    The purpose of this study was to investigate fear of failure in highly competitive junior athletes and the association with psychological stress and burnout. In total 258 athletes (152 males and 108 females) ranged in age from 15 to 19 years (M = 17.4 years, SD = 1.08) participated. Athletes competed in variety of sports including both team and individual sports. Results showed in a variable-oriented approach using regression analyses that one dimension, fear of experiencing shame and embarrassment had a statistically significant effect on perceived psychological stress and one dimension of burnout, reduced sense of accomplishment. However, adopting a person-oriented approach using latent class analysis, we found that athletes with high levels of fear failure on all dimensions scored high on burnout. We also found another class with high scores on burnout. These athletes had high scores on the individual-oriented dimensions of fear of failure and low scores on the other oriented fear of failure dimensions. The findings indicate that fear of failure is related to burnout and psychological stress in athletes and that this association is mainly associated with the individual-oriented dimensions of fear of failure. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. The flavoprotein Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Akira; Kawahara, Nobuhiro [Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan); Takagi, Hiroshi, E-mail: hiro@bs.naist.jp [Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer NO is produced from L-arginine in response to elevated temperature in yeast. Black-Right-Pointing-Pointer Tah18 was first identified as the yeast protein involved in NO synthesis. Black-Right-Pointing-Pointer Tah18-dependent NO synthesis confers tolerance to high-temperature on yeast cells. -- Abstract: Nitric oxide (NO) is a ubiquitous signaling molecule involved in the regulation of a large number of cellular functions. In the unicellular eukaryote yeast, NO may be involved in stress response pathways, but its role is poorly understood due to the lack of mammalian NO synthase (NOS) orthologues. Previously, we have proposed the oxidative stress-induced L-arginine synthesis and its physiological role under stress conditions in yeast Saccharomyces cerevisiae. Here, our experimental results indicated that increased conversion of L-proline into L-arginine led to NO production in response to elevated temperature. We also showed that the flavoprotein Tah18, which was previously reported to transfer electrons to the Fe-S cluster protein Dre2, was involved in NO synthesis in yeast. Gene knockdown analysis demonstrated that Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells. As it appears that such a unique cell protection mechanism is specific to yeasts and fungi, it represents a promising target for antifungal activity.

  16. The flavoprotein Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells

    International Nuclear Information System (INIS)

    Nishimura, Akira; Kawahara, Nobuhiro; Takagi, Hiroshi

    2013-01-01

    Highlights: ► NO is produced from L-arginine in response to elevated temperature in yeast. ► Tah18 was first identified as the yeast protein involved in NO synthesis. ► Tah18-dependent NO synthesis confers tolerance to high-temperature on yeast cells. -- Abstract: Nitric oxide (NO) is a ubiquitous signaling molecule involved in the regulation of a large number of cellular functions. In the unicellular eukaryote yeast, NO may be involved in stress response pathways, but its role is poorly understood due to the lack of mammalian NO synthase (NOS) orthologues. Previously, we have proposed the oxidative stress-induced L-arginine synthesis and its physiological role under stress conditions in yeast Saccharomyces cerevisiae. Here, our experimental results indicated that increased conversion of L-proline into L-arginine led to NO production in response to elevated temperature. We also showed that the flavoprotein Tah18, which was previously reported to transfer electrons to the Fe–S cluster protein Dre2, was involved in NO synthesis in yeast. Gene knockdown analysis demonstrated that Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells. As it appears that such a unique cell protection mechanism is specific to yeasts and fungi, it represents a promising target for antifungal activity.

  17. Measurement and interpretation of threshold stress intensity factors for steels in high-pressure hydrogen gas.

    Energy Technology Data Exchange (ETDEWEB)

    Dadfarnia, Mohsen (University of Illinois at Urbana-Champaign, Urbana, IL); Nibur, Kevin A.; San Marchi, Christopher W.; Sofronis, Petros (University of Illinois at Urbana-Champaign, Urbana, IL); Somerday, Brian P.; Foulk, James W., III; Hayden, Gary A. (CP Industries, McKeesport, PA)

    2010-07-01

    Threshold stress intensity factors were measured in high-pressure hydrogen gas for a variety of low alloy ferritic steels using both constant crack opening displacement and rising crack opening displacement procedures. The sustained load cracking procedures are generally consistent with those in ASME Article KD-10 of Section VIII Division 3 of the Boiler and Pressure Vessel Code, which was recently published to guide design of high-pressure hydrogen vessels. Three definitions of threshold were established for the two test methods: K{sub THi}* is the maximum applied stress intensity factor for which no crack extension was observed under constant displacement; K{sub THa} is the stress intensity factor at the arrest position for a crack that extended under constant displacement; and K{sub JH} is the stress intensity factor at the onset of crack extension under rising displacement. The apparent crack initiation threshold under constant displacement, K{sub THi}*, and the crack arrest threshold, K{sub THa}, were both found to be non-conservative due to the hydrogen exposure and crack-tip deformation histories associated with typical procedures for sustained-load cracking tests under constant displacement. In contrast, K{sub JH}, which is measured under concurrent rising displacement and hydrogen gas exposure, provides a more conservative hydrogen-assisted fracture threshold that is relevant to structural components in which sub-critical crack extension is driven by internal hydrogen gas pressure.

  18. Impact of high cholesterol and endoplasmic reticulum stress on metabolic diseases: An updated mini-review

    Directory of Open Access Journals (Sweden)

    Erdi Sozen

    2017-08-01

    Full Text Available Endoplasmic reticulum (ER is the major site of protein folding and calcium storage. Beside the role of ER in protein homeostasis, it controls the cholesterol production and lipid-membrane biosynthesis as well as surviving and cell death signaling mechanisms in the cell. It is well-documented that elevated plasma cholesterol induces adverse effects in cardiovascular diseases (CVDs, liver disorders, such as non-alcoholic fatty liver disease (NAFLD, non-alcoholic steatosis hepatitis (NASH, and metabolic diseases which are associated with oxidative and ER stress. Recent animal model and human studies have showed high cholesterol and ER stress as an emerging factors involved in the development of many metabolic diseases. In this review, we will summarize the crucial effects of hypercholesterolemia and ER stress response in the pathogenesis of CVDs, NAFLD/NASH, diabetes and obesity which are major health problems in western countries. Keywords: Endoplasmic reticulum stress, High cholesterol, Cardiovascular diseases, Non-alcoholic fatty liver disease, Non-alcoholic steatosis hepatitis

  19. Suppression of endothelial t-PA expression by prolonged high laminar shear stress

    International Nuclear Information System (INIS)

    Ulfhammer, Erik; Carlstroem, Maria; Bergh, Niklas; Larsson, Pia; Karlsson, Lena; Jern, Sverker

    2009-01-01

    Primary hypertension is associated with an impaired capacity for acute release of endothelial tissue-type plasminogen activator (t-PA), which is an important local protective response to prevent thrombus extension. As hypertensive vascular remodeling potentially results in increased vascular wall shear stress, we investigated the impact of shear on regulation of t-PA. Cultured human endothelial cells were exposed to low (≤1.5 dyn/cm 2 ) or high (25 dyn/cm 2 ) laminar shear stress for up to 48 h in two different experimental models. Using real-time RT-PCR and ELISA, shear stress was observed to time and magnitude-dependently suppress t-PA transcript and protein secretion to approximately 30% of basal levels. Mechanistic experiments revealed reduced nuclear protein binding to the t-PA specific CRE element (EMSA) and an almost completely abrogated shear response with pharmacologic JNK inhibition. We conclude that prolonged high laminar shear stress suppresses endothelial t-PA expression and may therefore contribute to the enhanced risk of arterial thrombosis in hypertensive disease.

  20. Growth and Development Temperature Influences Level of Tolerance to High Light Stress 1

    Science.gov (United States)

    Steffen, Kenneth L.; Palta, Jiwan P.

    1989-01-01

    The influence of growth and development temperature on the relative tolerance of photosynthetic tissue to high light stress at chilling temperatures was investigated. Two tuber-bearing potato species, Solanum tuberosum L. cv Red Pontiac and Solanum commersonii were grown for 4 weeks, at either 12 or 24°C with 12 hours of about 375 micromoles per second per square meter of photosynthetically active radiation. Paired leaf discs were cut from directly across the midvein of leaflets of comparable developmental stage and light environment from each species at each growth temperature treatment. One disc of each pair was exposed to 1°C and about 1000 micromoles per second per square meter photosynthetically active radiation for 4 hours, and the other disc was held at 1°C in total darkness for the same duration. Photosynthetic tissue of S. tuberosum, developed at 12°C, was much more tolerant to high light and low temperature stress than tissue developed under 24°C conditions. Following the high light treatment, 24°C-grown S. tuberosum tissue demonstrated light-limited and light-saturated rates that were approximately 50% of their paired dark controls. In contrast, the 12°C-grown tissue from S. tuberosum that was subjected to the light stress showed only a 18 and 6% reduction in light-limited and light-saturated rates of photosynthetic oxygen evolution, respectively. Tissue from 24°C-grown S. commersonii was much less sensitive to the light stress than was tissue from S. tuberosum grown under the same conditions. The results presented here demonstrate that: (a) acclimation of S. tuberosum to lower temperature growth conditions with a constant light environment, results in the increased capacity of photosynthetic tissue to tolerate high light stress at chilling temperature and (b) following growth and development at relatively high temperatures S. commersonii, a frost- and heat-tolerant wild species, has a much greater tolerance to the high light stress at chilling

  1. Effect of chronic mild stress on hippocampal transcriptome in mice selected for high and low stress-induced analgesia and displaying different emotional behaviors.

    Science.gov (United States)

    Lisowski, Pawel; Juszczak, Grzegorz R; Goscik, Joanna; Wieczorek, Marek; Zwierzchowski, Lech; Swiergiel, Artur H

    2011-01-01

    There is increasing evidence that mood disorders may derive from the impact of environmental pressure on genetically susceptible individuals. Stress-induced hippocampal plasticity has been implicated in depression. We studied hippocampal transcriptomes in strains of mice that display high (HA) and low (LA) swim stress-induced analgesia and that differ in emotional behaviors and responses to different classes of antidepressants. Chronic mild stress (CMS) affected expression of a number of genes common for both strains. CMS also produced strain specific changes in expression suggesting that hippocampal responses to stress depend on genotype. Considerably larger number of genes, biological processes, molecular functions, biochemical pathways, and gene networks were affected by CMS in LA than in HA mice. The results suggest that potential drug targets against detrimental effects of stress include glutamate transporters, and cholinergic, cholecystokinin (CCK), glucocorticoids, and thyroid hormones receptors. Furthermore, some biological processes evoked by stress and different between the strains, such as apoptosis, neurogenesis and chromatin modifications, may be responsible for the long-term, irreversible effects of stress and suggest a role for epigenetic regulation of mood related stress responses. Copyright © 2010 Elsevier B.V. and ECNP. All rights reserved.

  2. Investigation of thermoelastic stresses induced at high altitudes on aircraft external fuel tanks

    Science.gov (United States)

    Mousseau, Stephanie Lynn Steber

    As composite technology has grown over the past several decades, the use of composite materials in military applications has become more feasible and widely accepted. Although composite materials provide many benefits, including strength optimization and reduced weight, damage and repair of these materials creates an additional challenge, especially when operating in a marine environment, such as on a carrier deck. This is evident within the Navy, as excessive damage often leads to the scrapping of F/A-18 External Fuel Tanks. This damage comes in many forms, the most elusive of which is delamination. Often the delamination found on the tanks is beyond repairable limits and the cause unknown, making it difficult to predict and prevent. The purpose of this investigation was to study the structure of the Navy's 330 gallon External Fuel Tanks and investigate one potential cause of delamination, stresses induced at high altitudes by cold temperatures. A stress analysis was completed using finite element software, and validation of the model was accomplished through testing of a scale model specimen. Due to the difficulties in modeling and predicting delamination, such as unknown presence of voids and understanding failure criteria, delamination was not modeled in Abaqus, rather stresses were observed and characteristics were studied to understand the potential for delamination within the layup. In addition, studies were performed to understand the effect of material properties and layup sequence on the stress distribution within the tank. Alternative design solutions are presented which could reduce the radial stresses within the tank, and recommendations are made for further study to understand the trade-offs between stress, cost, and manufacturability.

  3. Transgenic banana plants overexpressing a native plasma membrane aquaporin MusaPIP1;2 display high tolerance levels to different abiotic stresses.

    Science.gov (United States)

    Sreedharan, Shareena; Shekhawat, Upendra K S; Ganapathi, Thumballi R

    2013-10-01

    Water transport across cellular membranes is regulated by a family of water channel proteins known as aquaporins (AQPs). As most abiotic stresses like suboptimal temperatures, drought or salinity result in cellular dehydration, it is imperative to study the cause-effect relationship between AQPs and the cellular consequences of abiotic stress stimuli. Although plant cells have a high isoform diversity of AQPs, the individual and integrated roles of individual AQPs in optimal and suboptimal physiological conditions remain unclear. Herein, we have identified a plasma membrane intrinsic protein gene (MusaPIP1;2) from banana and characterized it by overexpression in transgenic banana plants. Cellular localization assay performed using MusaPIP1;2::GFP fusion protein indicated that MusaPIP1;2 translocated to plasma membrane in transformed banana cells. Transgenic banana plants overexpressing MusaPIP1;2 constitutively displayed better abiotic stress survival characteristics. The transgenic lines had lower malondialdehyde levels, elevated proline and relative water content and higher photosynthetic efficiency as compared to equivalent controls under different abiotic stress conditions. Greenhouse-maintained hardened transgenic plants showed faster recovery towards normal growth and development after cessation of abiotic stress stimuli, thereby underlining the importance of these plants in actual environmental conditions wherein the stress stimuli is often transient but severe. Further, transgenic plants where the overexpression of MusaPIP1;2 was made conditional by tagging it with a stress-inducible native dehydrin promoter also showed similar stress tolerance characteristics in in vitro and in vivo assays. Plants developed in this study could potentially enable banana cultivation in areas where adverse environmental conditions hitherto preclude commercial banana cultivation. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons

  4. The Role of Trauma and Stressful Life Events among Individuals at Clinical High Risk for Psychosis: A Review

    Directory of Open Access Journals (Sweden)

    Danessa Mayo

    2017-04-01

    Full Text Available The experience of childhood trauma (CT and stressful life events (SLEs is associated with subsequent development of a variety of mental health conditions, including psychotic illness. Recent research identifying adolescents and young adults at clinical high risk (CHR for psychosis allows for prospective evaluation of the impact of trauma and adverse life events on psychosis onset and other outcomes, addressing etiological questions that cannot be answered in studies of fully psychotic or non-clinical populations. This article provides a comprehensive review of the current emerging literature on trauma and adverse life events in the CHR population. Up to 80% of CHR youth endorse a lifetime history of childhood traumatic events and victimization (e.g., bullying. Several studies have shown that the experience of CT predicts psychosis onset among CHR individuals, while the literature on the influence of recent SLEs (e.g., death of a loved one remains inconclusive. Multiple models have been proposed to explain the link between trauma and psychosis, including the stress-vulnerability and stress-sensitivity hypotheses, with emphases on both cognitive processes and neurobiological mechanisms (e.g., the hypothalamic–pituitary–adrenal axis. Despite the preponderance of CHR individuals who endorse either CT or SLEs, no clinical trials have been conducted evaluating interventions for trauma in CHR youth to date. Furthermore, the current process of formal identification and assessment of trauma, SLEs, and their impact on CHR youth is inconsistent in research and clinical practice. Recommendations for improving trauma assessment, treatment, and future research directions in the CHR field are provided.

  5. Content analysis to detect high stress in oral interviews and text documents

    Science.gov (United States)

    Thirumalainambi, Rajkumar (Inventor); Jorgensen, Charles C. (Inventor)

    2012-01-01

    A system of interrogation to estimate whether a subject of interrogation is likely experiencing high stress, emotional volatility and/or internal conflict in the subject's responses to an interviewer's questions. The system applies one or more of four procedures, a first statistical analysis, a second statistical analysis, a third analysis and a heat map analysis, to identify one or more documents containing the subject's responses for which further examination is recommended. Words in the documents are characterized in terms of dimensions representing different classes of emotions and states of mind, in which the subject's responses that manifest high stress, emotional volatility and/or internal conflict are identified. A heat map visually displays the dimensions manifested by the subject's responses in different colors, textures, geometric shapes or other visually distinguishable indicia.

  6. Mosaic-shaped cathode for highly durable solid oxide fuel cell under thermal stress

    Science.gov (United States)

    Joo, Jong Hoon; Jeong, Jaewon; Kim, Se Young; Yoo, Chung-Yul; Jung, Doh Won; Park, Hee Jung; Kwak, Chan; Yu, Ji Haeng

    2014-02-01

    In this study, we propose a novel "mosaic structure" for a SOFC (solid oxide fuel cell) cathode with high thermal expansion to improve the stability against thermal stress. Self-organizing mosaic-shaped cathode has been successfully achieved by controlling the amount of binder in the dip-coating solution. The anode-supported cell with mosaic-shaped cathode shows itself to be highly durable performance for rapid thermal cycles, however, the performance of the cell with a non-mosaic cathode exhibits severe deterioration originated from the delamination at the cathode/electrolyte interface after 7 thermal cycles. The thermal stability of an SOFC cathode can be evidently improved by controlling the surface morphology. In view of the importance of the thermal expansion properties of the cathode, the effects of cathode morphology on the thermal stress stability are discussed.

  7. Transcriptomic analysis of Petunia hybrida in response to salt stress using high throughput RNA sequencing.

    Directory of Open Access Journals (Sweden)

    Gonzalo H Villarino

    Full Text Available Salinity and drought stress are the primary cause of crop losses worldwide. In sodic saline soils sodium chloride (NaCl disrupts normal plant growth and development. The complex interactions of plant systems with abiotic stress have made RNA sequencing a more holistic and appealing approach to study transcriptome level responses in a single cell and/or tissue. In this work, we determined the Petunia transcriptome response to NaCl stress by sequencing leaf samples and assembling 196 million Illumina reads with Trinity software. Using our reference transcriptome we identified more than 7,000 genes that were differentially expressed within 24 h of acute NaCl stress. The proposed transcriptome can also be used as an excellent tool for biological and bioinformatics in the absence of an available Petunia genome and it is available at the SOL Genomics Network (SGN http://solgenomics.net. Genes related to regulation of reactive oxygen species, transport, and signal transductions as well as novel and undescribed transcripts were among those differentially expressed in response to salt stress. The candidate genes identified in this study can be applied as markers for breeding or to genetically engineer plants to enhance salt tolerance. Gene Ontology analyses indicated that most of the NaCl damage happened at 24 h inducing genotoxicity, affecting transport and organelles due to the high concentration of Na+ ions. Finally, we report a modification to the library preparation protocol whereby cDNA samples were bar-coded with non-HPLC purified primers, without affecting the quality and quantity of the RNA-seq data. The methodological improvement presented here could substantially reduce the cost of sample preparation for future high-throughput RNA sequencing experiments.

  8. Transcriptomic analysis of Petunia hybrida in response to salt stress using high throughput RNA sequencing.

    Science.gov (United States)

    Villarino, Gonzalo H; Bombarely, Aureliano; Giovannoni, James J; Scanlon, Michael J; Mattson, Neil S

    2014-01-01

    Salinity and drought stress are the primary cause of crop losses worldwide. In sodic saline soils sodium chloride (NaCl) disrupts normal plant growth and development. The complex interactions of plant systems with abiotic stress have made RNA sequencing a more holistic and appealing approach to study transcriptome level responses in a single cell and/or tissue. In this work, we determined the Petunia transcriptome response to NaCl stress by sequencing leaf samples and assembling 196 million Illumina reads with Trinity software. Using our reference transcriptome we identified more than 7,000 genes that were differentially expressed within 24 h of acute NaCl stress. The proposed transcriptome can also be used as an excellent tool for biological and bioinformatics in the absence of an available Petunia genome and it is available at the SOL Genomics Network (SGN) http://solgenomics.net. Genes related to regulation of reactive oxygen species, transport, and signal transductions as well as novel and undescribed transcripts were among those differentially expressed in response to salt stress. The candidate genes identified in this study can be applied as markers for breeding or to genetically engineer plants to enhance salt tolerance. Gene Ontology analyses indicated that most of the NaCl damage happened at 24 h inducing genotoxicity, affecting transport and organelles due to the high concentration of Na+ ions. Finally, we report a modification to the library preparation protocol whereby cDNA samples were bar-coded with non-HPLC purified primers, without affecting the quality and quantity of the RNA-seq data. The methodological improvement presented here could substantially reduce the cost of sample preparation for future high-throughput RNA sequencing experiments.

  9. Severe Trauma Stress Inoculation Training for Combat Medics using High Fidelity Simulation

    Science.gov (United States)

    2013-12-01

    expressions; and improved sensors and communication systems for current medical training simulators. He has prior experience in software development for DoD...the "look and feel" of such injuries by providing the highly realistic visual, auditory, and haptic (touch) stimuli necessary to elicit stress...addressed during development included the following: • Microcontroller-based control system for monitoring sensors and automating the actions of the

  10. Modeling the effects of high-G stress on pilots in a tracking task

    Science.gov (United States)

    Korn, J.; Kleinman, D. L.

    1978-01-01

    Air-to-air tracking experiments were conducted at the Aerospace Medical Research Laboratories using both fixed and moving base dynamic environment simulators. The obtained data, which includes longitudinal error of a simulated air-to-air tracking task as well as other auxiliary variables, was analyzed using an ensemble averaging method. In conjunction with these experiments, the optimal control model is applied to model a human operator under high-G stress.

  11. Thermal stress estimation in relation to spalling of HSC restrained with steel rings at high temperatures

    Directory of Open Access Journals (Sweden)

    Tanibe T.

    2013-09-01

    Full Text Available This paper reports on an experimental study regarding the behavior of steel ring-restrained concrete in response to fire exposure. The study was conducted to enable estimation of thermal stress based on steel ring strain in such concrete under the conditions of a RABT 30 heating curve. The specimens used were made from high-strength concrete (Fc: 80 MPa restrained using steel rings with thicknesses of 0.5, 8 and 18 mm.

  12. Muscle-like high-stress dielectric elastomer actuators with oil capsules

    International Nuclear Information System (INIS)

    La, Thanh-Giang; Lau, Gih-Keong; Shiau, Li-Lynn; Wei-Yee Tan, Adrian

    2014-01-01

    Despite being capable of generating large strains, dielectric elastomer actuators (DEAs) are short of strength. Often, they cannot produce enough stress or as much work as that achievable by human elbow muscles. Their maximum actuation capacity is limited by the electrical breakdown of dielectric elastomers. Often, failures of these soft actuators are pre-mature and localized at the weakest spot under high field and high stress. Localized breakdowns, such as electrical arcing, thermal runaway and punctures, could spread to ultimately cause rupture if they were not stopped. This work shows that dielectric oil immersion and self-clearable electrodes nibbed the buds of localized breakdowns from DEAs. Dielectric oil encapsulation in soft-membrane capsules was found to help the DEA sustain an ultra-high electrical breakdown field of 835 MVm −1 , which is 46% higher than the electrical breakdown strength of the dry DEA in air at 570 MV m −1 . Because of the increased apparent dielectric strength, this oil-capsuled DEA realizes a higher maximum isotonic work density of up to 31.51Jkg −1 , which is 43.8% higher than that realized by the DEA in air. Meanwhile, it produces higher maximum isometric stress of up to 1.05 MPa, which is 75% higher than that produced by the DEA in air. Such improved actuator performances are comparable to those achieved by human flexor muscles, which can exert up to 1.2 MPa during elbow flexion. This muscle-like, high-stress dielectric elastomeric actuation is very promising to drive future human-like robots. (paper)

  13. Effect of heat treatment conditions on stress corrosion cracking resistance of alloy X-750 in high temperature water

    International Nuclear Information System (INIS)

    Yonezawa, Toshio; Onimura, Kichiro; Sakamoto, Naruo; Sasaguri, Nobuya; Susukida, Hiroshi; Nakata, Hidenori.

    1984-01-01

    In order to improve the resistance of the Alloy X-750 in high temperature and high purity water, the authors investigated the influence of heat treatment condition on the stress corrosion cracking resistance of the alloy. This paper describes results of the stress corrosion cracking test and some discussion on the mechanism of the stress corrosion cracking of Alloy X-750 in deaerated high temperature water. The following results were obtained. (1) The stress corrosion cracking resistance of Alloy X-750 in deaerated high temperature water remarkably depended upon the heat treatment condition. The materials solution heat treated and aged within temperature ranges from 1065 to 1100 0 C and from 704 to 732 0 C, respectively, have a good resistance to the stress corrosion cracking in deaerated high temperature water. Especially, water cooling after the solution heat treatment gives an excellent resistance to the stress corrosion cracking in deaerated high temperature water. (2) Any correlations were not observed between the stress corrosion cracking susceptibility of Alloy X-750 in deaerated high temperature water and grain boundary chromium depleted zones, precipitate free zones and the grain boundary segregation of impurity elements and so on. It appears that there are good correlations between the stress corrosion cracking resistance of the alloy in the environment and the kinds, morphology and coherency of precipitates along the grain boundaries. (author)

  14. High hydrostatic pressure resistance of Campylobacter jejuni after different sublethal stresses.

    Science.gov (United States)

    Sagarzazu, N; Cebrián, G; Condón, S; Mackey, B; Mañas, P

    2010-07-01

    To study the development of resistance responses in Campylobacter jejuni to high hydrostatic pressure (HHP) treatments after the exposure to different stressful conditions that may be encountered in food-processing environments, such as acid pH, elevated temperatures and cold storage. Campylobacter jejuni cells in exponential and stationary growth phase were exposed to different sublethal stresses (acid, heat and cold shocks) prior to evaluate the development of resistance responses to HHP. For exponential-phase cells, neither of the conditions tested increased nor decreased HHP resistance of C. jejuni. For stationary-phase cells, acid and heat adaptation-sensitized C. jejuni cells to the subsequent pressure treatment. On the contrary, cold-adapted stationary-phase cells developed resistance to HHP. Whereas C. jejuni can be classified as a stress sensitive micro-organism, our findings have demonstrated that it can develop resistance responses under different stressing conditions. The resistance of stationary phase C. jejuni to HHP was increased after cells were exposed to cold temperatures. The results of this study contribute to a better knowledge of the physiology of C. jejuni and its survival to food preservation agents. Results here presented may help in the design of combined processes for food preservation based on HHP technology. © 2009 The Authors. Journal compilation © 2009 The Society for Applied Microbiology.

  15. Anterior tibial stress fractures treated with anterior tension band plating in high-performance athletes.

    Science.gov (United States)

    Cruz, Alexandre Santa; de Hollanda, João Paris Buarque; Duarte, Aires; Hungria Neto, José Soares

    2013-06-01

    The non-surgical treatment of anterior tibial cortex stress fractures requires long periods of abstention from sports activities and often results in non-union. Many different surgical techniques have already been previously described to treat these fractures, but there is no consensus on the best treatment. We describe the outcome of treatment using anterior tibial tension band plating in three high-performance athletes (4 legs) with anterior tibial cortex stress fractures. Tibial osteosynthesis with a 3.5-mm locking compression plate in the anterolateral aspect of the tibia was performed in all patients diagnosed with anterior tibial stress fracture after September 2010 at Santa Casa Hospital. All of the fractures were consolidated within a period of 3 months after surgery, allowing for an early return to pre-injury levels of competitive sports activity. There were no infection, non-union, malunion or anterior knee pain complications. Anterior tibial tension band plating leads to prompt fracture consolidation and is a good alternative for the treatment of anterior tibial cortex stress fractures. Bone grafts were shown to be unnecessary.

  16. Stress corrosion of very high purity stainless steels in alkaline media

    International Nuclear Information System (INIS)

    Hechmat-Dehcordi, Ebrahim

    1981-01-01

    This research thesis reports the study of stress corrosion resistance of stainless steels in caustic environments. It notably concerns the electronuclear industrial sector, the production of soda by electrolysis, and the preparation of hydrogen as energy vector. After a presentation of the experimental conditions, the author highlights the influence of purity on stress corrosion cracking of 20Cr-25Ni-type austenitic alloys. The specific action of a high number of addition metallic and non-metallic elements has been studied. Stress corrosion tests have been also performed in autoclave on austeno-ferritic (21 to 25 pc Cr - 6 to 10 pc Ni) as well as ferritic (26 pc Cr) grades. The author reports the study of electrochemical properties of stainless steel in soda by means of potentiostatic techniques with an application of Pourbaix thermodynamic equilibrium diagrams, and the study of the chemical composition of passivation thin layers by Auger spectroscopy. He more particularly studies the influence of electrode potential and of some addition elements on the chemical characteristics of oxides developed at the surface of austenite. Then, the author tries to establish correlations between strain hardening microstructure of the various steels and their sensitivity to stress corrosion [fr

  17. Humic Acid Confers HIGH-AFFINITY K+ TRANSPORTER 1-Mediated Salinity Stress Tolerance in Arabidopsis.

    Science.gov (United States)

    Khaleda, Laila; Park, Hee Jin; Yun, Dae-Jin; Jeon, Jong-Rok; Kim, Min Gab; Cha, Joon-Yung; Kim, Woe-Yeon

    2017-12-31

    Excessive salt disrupts intracellular ion homeostasis and inhibits plant growth, which poses a serious threat to global food security. Plants have adapted various strategies to survive in unfavorable saline soil conditions. Here, we show that humic acid (HA) is a good soil amendment that can be used to help overcome salinity stress because it markedly reduces the adverse effects of salinity on Arabidopsis thaliana seedlings. To identify the molecular mechanisms of HA-induced salt stress tolerance in Arabidopsis, we examined possible roles of a sodium influx transporter HIGH-AFFINITY K+ TRANSPORTER 1 (HKT1). Salt-induced root growth inhibition in HKT1 overexpressor transgenic plants (HKT1-OX) was rescued by application of HA, but not in wild-type and other plants. Moreover, salt-induced degradation of HKT1 protein was blocked by HA treatment. In addition, the application of HA to HKT1-OX seedlings led to increased distribution of Na+ in roots up to the elongation zone and caused the reabsorption of Na+ by xylem and parenchyma cells. Both the influx of the secondary messenger calcium and its cytosolic release appear to function in the destabilization of HKT1 protein under salt stress. Taken together, these results suggest that HA could be applied to the field to enhance plant growth and salt stress tolerance via post-transcriptional control of the HKT1 transporter gene under saline conditions.

  18. Study of high density polyethylene under UV irradiation or mechanical stress by fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Douminge, L.

    2010-05-01

    Due to their diversity and their wide range of applications, polymers have emerged in our environment. For technical applications, these materials can be exposed to aggressive environment leading to an alteration of their properties. The effects of this degradation are linked to the concept of life duration, corresponding to the time required for a property to reach a threshold below which the material becomes unusable. Monitoring the ageing of polymer materials constitute a major challenge. Fluorescence spectroscopy is a technique able to provide accurate information concerning this issue. In this study, emphasis was placed on the use of fluorescence spectroscopy to study the phenomena involved in either the UV radiation or mechanical stresses of a polymer. In the case of high density polyethylene, the lack of intrinsic fluorescent signal leads to the use of a dye. This dye gives a fluorescent response depending on its microenvironment. All modifications in the macromolecular chain generate a shift of the fluorescent peak. This work can be dissociated in two major parts, on one hand the influence of UV aging on the fluorescent response and in another hand the influence of mechanical stresses. In the first part, complementary analyses like FTIR or DSC are used to correlate fluorescent results with known photo degradation mechanisms. The results show the great sensibility of the technique to the microstructural rearrangement in the polymer. In the second part, the dependence between the stress and the fluorescence emission gives opportunity to evaluate internal stresses in the material during cyclic solicitations. (author)

  19. Calculation of Debye-Scherrer diffraction patterns from highly stressed polycrystalline materials

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, M. J., E-mail: macdonm@umich.edu [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States); SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Vorberger, J. [Helmholtz Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Gamboa, E. J.; Glenzer, S. H.; Fletcher, L. B. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Drake, R. P. [Climate and Space Sciences and Engineering, Applied Physics, and Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2016-06-07

    Calculations of Debye-Scherrer diffraction patterns from polycrystalline materials have typically been done in the limit of small deviatoric stresses. Although these methods are well suited for experiments conducted near hydrostatic conditions, more robust models are required to diagnose the large strain anisotropies present in dynamic compression experiments. A method to predict Debye-Scherrer diffraction patterns for arbitrary strains has been presented in the Voigt (iso-strain) limit [Higginbotham, J. Appl. Phys. 115, 174906 (2014)]. Here, we present a method to calculate Debye-Scherrer diffraction patterns from highly stressed polycrystalline samples in the Reuss (iso-stress) limit. This analysis uses elastic constants to calculate lattice strains for all initial crystallite orientations, enabling elastic anisotropy and sample texture effects to be modeled directly. The effects of probing geometry, deviatoric stresses, and sample texture are demonstrated and compared to Voigt limit predictions. An example of shock-compressed polycrystalline diamond is presented to illustrate how this model can be applied and demonstrates the importance of including material strength when interpreting diffraction in dynamic compression experiments.

  20. Does the low hole transport mass in and Si nanowires lead to mobility enhancements at high field and stress: A self-consistent tight-binding study

    Science.gov (United States)

    Kotlyar, R.; Linton, T. D.; Rios, R.; Giles, M. D.; Cea, S. M.; Kuhn, K. J.; Povolotskyi, Michael; Kubis, Tillmann; Klimeck, Gerhard

    2012-06-01

    The hole surface roughness and phonon limited mobility in the silicon , , and square nanowires under the technologically important conditions of applied gate bias and stress are studied with the self-consistent Poisson-sp3d5s*-SO tight-binding bandstructure method. Under an applied gate field, the hole carriers in a wire undergo a volume to surface inversion transition diminishing the positive effects of the high and valence band nonparabolicities, which are known to lead to the large gains of the phonon limited mobility at a zero field in narrow wires. Nonetheless, the hole mobility in the unstressed wires down to the 5 nm size remains competitive or shows an enhancement at high gate field over the large wire limit. Down to the studied 3 nm sizes, the hole mobility is degraded by strong surface roughness scattering in and wires. The channels are shown to experience less surface scattering degradation. The physics of the surface roughness scattering dependence on wafer and channel orientations in a wire is discussed. The calculated uniaxial compressive channel stress gains of the hole mobility are found to reduce in the narrow wires and at the high field. This exacerbates the stressed mobility degradation with size. Nonetheless, stress gains of a factor of 2 are obtained for wires down to 3 nm size at a 5×1012 cm-2 hole inversion density per gate area.

  1. Effects of job-related stress and burnout on asthenopia among high-tech workers.

    Science.gov (United States)

    Ostrovsky, Anat; Ribak, Joseph; Pereg, Avihu; Gaton, Dan

    2012-01-01

    Eye- and vision-related symptoms are the most frequent health problems among computer users. The findings of eye strain, tired eyes, eye irritation, burning sensation, redness, blurred vision and double vision, when appearing together, have recently been termed 'computer vision syndrome', or asthenopia. To examine the frequency and intensity of asthenopia among individuals employed in research and development departments of high-tech firms and the effects of job stress and burnout on ocular complaints, this study included 106 subjects, 42 high-tech workers (study group) and 64 bank employees (control group). All participants completed self-report questionnaires covering demographics, asthenopia, satisfaction with work environmental conditions, job-related stress and burnout. There was a significant between-group difference in the intensity of asthenopia, but not in its frequency. Burnout appeared to be a significant contributing factor to the intensity and frequency of asthenopia. This study shows that burnout is a significant factor in asthenopic complaints in high-tech workers. This manuscript analyses the effects of psychological environmental factors, such as job stress and burnout, on ocular complaints at the workplace of computer users. The findings may have an ergonomic impact on how to improve health, safety and comfort of the working environment among computer users, for better perception of the job environment, efficacy and production.

  2. Subcellular proteomic characterization of the high-temperature stress response of the cyanobacterium Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Cheevadhanarak Supapon

    2009-09-01

    Full Text Available Abstract The present study examined the changes in protein expression in Spirulina platensis upon exposure to high temperature, with the changes in expression analyzed at the subcellular level. In addition, the transcriptional expression level of some differentially expressed proteins, the expression pattern clustering, and the protein-protein interaction network were analyzed. The results obtained from differential expression analysis revealed up-regulation of proteins involved in two-component response systems, DNA damage and repair systems, molecular chaperones, known stress-related proteins, and proteins involved in other biological processes, such as capsule formation and unsaturated fatty acid biosynthesis. The clustering of all differentially expressed proteins in the three cellular compartments showed: (i the majority of the proteins in all fractions were sustained tolerance proteins, suggesting the roles of these proteins in the tolerance to high temperature stress, (ii the level of resistance proteins in the photosynthetic membrane was 2-fold higher than the level in two other fractions, correlating with the rapid inactivation of the photosynthetic system in response to high temperature. Subcellular communication among the three cellular compartments via protein-protein interactions was clearly shown by the PPI network analysis. Furthermore, this analysis also showed a connection between temperature stress and nitrogen and ammonia assimilation.

  3. Oxidative stress does not influence local sweat rate during high-intensity exercise.

    Science.gov (United States)

    Meade, Robert D; Fujii, Naoto; Poirier, Martin P; Boulay, Pierre; Sigal, Ronald J; Kenny, Glen P

    2018-02-01

    What is the central question of this study? We evaluated whether oxidative stress attenuates the contribution of nitric oxide to sweating during high-intensity exercise. What is the main finding and its importance? In contrast to our previous report of an oxidative stress-mediated reduction in nitric oxide-dependent cutaneous vasodilatation in this cohort during intense exercise, we demonstrated no influence of local ascorbate administration on the sweating response during moderate- (∼51% peak oxygen uptake) or high-intensity exercise (∼72% peak oxygen uptake). These new findings provide important mechanistic insight into how exercise-induced oxidative stress impacts sudomotor activity. Nitric oxide (NO)-dependent sweating is diminished during high- but not moderate-intensity exercise. We evaluated whether this impairment stems from increased oxidative stress during high-intensity exercise. On two separate days, 11 young (24 ± 4 years) men cycled in the heat (35°C) at a moderate [500 W; 52 ± 6% peak oxygen uptake (V̇O2 peak )] or high (700 W; 71 ± 5% V̇O2 peak ) rate of metabolic heat production. Each session included two 30 min exercise bouts separated by a 20 min recovery period. Local sweat rate was monitored at four forearm skin sites continuously perfused via intradermal microdialysis with the following: (i) lactated Ringer solution (Control); (ii) 10 mm ascorbate (Ascorbate; non-selective antioxidant); (iii) 10 mm N G -nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor); or (iv) 10 mm ascorbate plus 10 mm l-NAME (Ascorbate + l-NAME). During moderate exercise, sweat rate was attenuated at the l-NAME and Ascorbate + l-NAME sites (both ∼1.0 mg min -1  cm -2 ; all P < 0.05) but not at the Ascorbate site (∼1.1 mg min -1  cm -2 ; both P ≥ 0.28) in comparison to the Control site (∼1.1 mg min -1  cm -2 ). However, no differences were observed between treatment sites (∼1.4 mg min -1  cm -2 ; P = 0

  4. Ghost Remains After Black Hole Eruption

    Science.gov (United States)

    2009-05-01

    NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence of a huge eruption produced by the black hole. This discovery presents astronomers with a valuable opportunity to observe phenomena that occurred when the Universe was very young. The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source, a.k.a. HDF 130, is over 10 billion light years away and existed at a time 3 billion years after the Big Bang, when galaxies and black holes were forming at a high rate. "We'd seen this fuzzy object a few years ago, but didn't realize until now that we were seeing a ghost", said Andy Fabian of the Cambridge University in the United Kingdom. "It's not out there to haunt us, rather it's telling us something - in this case what was happening in this galaxy billions of year ago." Fabian and colleagues think the X-ray glow from HDF 130 is evidence for a powerful outburst from its central black hole in the form of jets of energetic particles traveling at almost the speed of light. When the eruption was ongoing, it produced prodigious amounts of radio and X-radiation, but after several million years, the radio signal faded from view as the electrons radiated away their energy. HDF 130 Chandra X-ray Image of HDF 130 However, less energetic electrons can still produce X-rays by interacting with the pervasive sea of photons remaining from the Big Bang - the cosmic background radiation. Collisions between these electrons and the background photons can impart enough energy to the photons to boost them into the X-ray energy band. This process produces an extended X-ray source that lasts for another 30 million years or so. "This ghost tells us about the black hole's eruption long after

  5. Brown rice and its component, γ-oryzanol, attenuate the preference for high-fat diet by decreasing hypothalamic endoplasmic reticulum stress in mice.

    Science.gov (United States)

    Kozuka, Chisayo; Yabiku, Kouichi; Sunagawa, Sumito; Ueda, Rei; Taira, Shin-Ichiro; Ohshiro, Hiroyuki; Ikema, Tomomi; Yamakawa, Ken; Higa, Moritake; Tanaka, Hideaki; Takayama, Chitoshi; Matsushita, Masayuki; Oyadomari, Seiichi; Shimabukuro, Michio; Masuzaki, Hiroaki

    2012-12-01

    Brown rice is known to improve glucose intolerance and prevent the onset of diabetes. However, the underlying mechanisms remain obscure. In the current study, we investigated the effect of brown rice and its major component, γ-oryzanol (Orz), on feeding behavior and fuel homeostasis in mice. When mice were allowed free access to a brown rice-containing chow diet (CD) and a high-fat diet (HFD), they significantly preferred CD to HFD. To reduce hypothalamic endoplasmic reticulum (ER) stress on an HFD, mice were administered with 4-phenylbutyric acid, a chemical chaperone, which caused them to prefer the CD. Notably, oral administration of Orz, a mixture of major bioactive components in brown rice, also improved glucose intolerance and attenuated hypothalamic ER stress in mice fed the HFD. In murine primary neuronal cells, Orz attenuated the tunicamycin-induced ER stress. In luciferase reporter assays in human embryonic kidney 293 cells, Orz suppressed the activation of ER stress-responsive cis-acting elements and unfolded protein response element, suggesting that Orz acts as a chemical chaperone in viable cells. Collectively, the current study is the first demonstration that brown rice and Orz improve glucose metabolism, reduce hypothalamic ER stress, and, consequently, attenuate the preference for dietary fat in mice fed an HFD.

  6. Influence of cadmium stress on root exudates of high cadmium accumulating rice line (Oryza sativa L.).

    Science.gov (United States)

    Fu, Huijie; Yu, Haiying; Li, Tingxuan; Zhang, Xizhou

    2018-04-15

    A hydroponic experiment with two different cadmium (Cd) accumulating rice lines of Lu527-8 (the high Cd accumulating rice line) and Lu527-4 (the normal rice line) was carried out to explore the links among Cd stress, root exudates and Cd accumulation. The results showed that (1) Cd stress increased quantities of organic acids, but had no effect on composition in root exudates of the two rice lines. In Cd treatments, the contents of every detected organic acid in root exudates of Lu527-8 were 1.76-2.43 times higher than those of Lu527-4. Significant positive correlations between organic acids contents and Cd contents in plants were observed in both rice lines, except that malic acid was only highly relevant to Lu527-8, but not to Lu527-4. (2) Both composition and quantities of amino acids in root exudates changed a lot under Cd stress and this change differed in two rice lines. In control, four amino acids (glutamic acid, glycine, tyrosine and histidine) were detected in two rice lines. Under Cd stress, eight amino acids in Lu527-8 and seven amino acids in Lu527-4 could be detected, among which phenylalanine was only secreted by Lu527-8 and alanine, methionine and lysine were secreted by both rice lines. The contents of those four newly secreted amino acids from Lu527-8 increased significantly with the increase of Cd dose and each had a high-positive correlation with Cd contents, but the same change did not appear in Lu527-4. The difference between two rice lines in secretion of organic acids and amino acids may be related to their different Cd uptake properties. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Interactive effects of chronic stress and a high-sucrose diet on nonalcoholic fatty liver in young adult male rats.

    Science.gov (United States)

    Corona-Pérez, Adriana; Díaz-Muñoz, Mauricio; Cuevas-Romero, Estela; Luna-Moreno, Dalia; Valente-Godínez, Héctor; Vázquez-Martínez, Olivia; Martínez-Gómez, Margarita; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

    2017-11-01

    Glucocorticoids have been implicated in nonalcoholic fatty liver diseases (NAFLD). The influence of a palatable diet on the response to stress is controversial. This study explored whether a high-sucrose diet could protect from hepatic steatosis induced by chronic restraint stress in young adult rats. Male Wistar rats aged 21 days were allocated into four groups (n = 6-8 per group): control, chronic restraint stress, 30% sucrose diet, and 30% sucrose diet plus chronic restraint stress. After being exposed to either tap water or sucrose solution during eight weeks, half of the rats belonging to each group were subject or not to repeated restraint stress (1 h per day, 5 days per week) during four weeks. Triacylglycerol (TAG), oxidative stress, activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1), infiltration of immune cells, and glycogen amount in the liver were quantified. Serum concentrations of corticosterone and testosterone were also measured. The stressed group showed normal serum concentrations of corticosterone and did not have hepatic steatosis. However, this group showed increased glycogen, inflammation, mild fibrosis, oxidative stress, and a high activity of 11β-HSD-1 in the liver. The group exposed to the high-sucrose diet had lower concentrations of corticosterone, hepatic steatosis and moderate fibrosis. The group subject to high-sucrose diet plus chronic restraint stress showed low concentrations of corticosterone, hepatic steatosis, oxidative stress, and high concentrations of testosterone. Thus, restraint stress and a high-sucrose diet each generate different components of nonalcoholic fatty liver in young adult rats. The combination of both the factors could promote a faster development of NAFLD.

  8. Integrated approach for stress analysis of high performance diesel engine cylinder head

    Science.gov (United States)

    Chainov, N. D.; Myagkov, L. L.; Malastowski, N. S.; Blinov, A. S.

    2018-03-01

    Growing thermal and mechanical loads due to development of engines with high level of a mean effective pressure determine requirements to cylinder head durability. In this paper, computational schemes for thermal and mechanical stress analysis of a high performance diesel engine cylinder head were described. The most important aspects in this approach are the account of temperature fields of conjugated details (valves and saddles), heat transfer modeling in a cooling jacket of a cylinder head and topology optimization of the detail force scheme. Simulation results are shown and analyzed.

  9. Study Of The Effect Of Stress Management Skills On Anxiety Status Among Teachers In Meybod District High Schools On 2012

    Directory of Open Access Journals (Sweden)

    F Servat

    2015-05-01

    Conclusion: regarding the high level of anxiety among teachers and necessity of doing interventional program, planned stress management educations are successful in reducing anxiety. That programs which are presented to persons step by step, provide a cognition of the environment and it's stressful factors to individuals and finally reduces the stress and then the anxiety level. Determining the efficacy of the programs on personality anxiety requires studies with longer follow up.

  10. Fish remains and humankind: part two

    Directory of Open Access Journals (Sweden)

    Andrew K G Jones

    1998-07-01

    Full Text Available The significance of aquatic resources to past human groups is not adequately reflected in the published literature - a deficiency which is gradually being acknowledged by the archaeological community world-wide. The publication of the following three papers goes some way to redress this problem. Originally presented at an International Council of Archaeozoology (ICAZ Fish Remains Working Group meeting in York, U.K. in 1987, these papers offer clear evidence of the range of interest in ancient fish remains across the world. Further papers from the York meeting were published in Internet Archaeology 3 in 1997.

  11. Tensile stress corrosion cracking of type 304 stainless steel irradiated to very high dose

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H. M.; Ruther, W. E.; Strain, R. V.; Shack, W. J.

    2001-09-01

    Certain safety-related core internal structural components of light water reactors, usually fabricated from Type 304 or 316 austenitic stainless steels (SSs), accumulate very high levels of irradiation damage (20--100 displacement per atom or dpa) by the end of life. The data bases and mechanistic understanding of, the degradation of such highly irradiated components, however, are not well established. A key question is the nature of irradiation-assisted intergranular cracking at very high dose, i.e., is it purely mechanical failure or is it stress-commotion cracking? In this work, hot-cell tests and microstructural characterization were performed on Type 304 SS from the hexagonal fuel can of the decommissioned EBR-11 reactor after irradiation to {approximately}50 dpa at {approximately}370 C. Slow-strain-rate tensile tests were conducted at 289 C in air and in water at several levels of electrochemical potential (ECP), and microstructural characteristics were analyzed by scanning and transmission electron microcopies. The material deformed significantly by twinning and exhibited surprisingly high ductility in air, but was susceptible to severe intergranular stress corrosion cracking (IGSCC) at high ECP. Low levels of dissolved O and ECP were effective in suppressing the susceptibility of the heavily irradiated material to IGSCC, indicating that the stress corrosion process associated with irradiation-induced grain-boundary Cr depletion, rather than purely mechanical separation of grain boundaries, plays the dominant role. However, although IGSCC was suppressed, the material was susceptible to dislocation channeling at low ECP, and this susceptibility led to poor work-hardening capability and low ductility.

  12. Normally closed microgrippers using a highly stressed diamond-like carbon and Ni bimorph structure

    Science.gov (United States)

    Luo, J. K.; Flewitt, A. J.; Spearing, S. M.; Fleck, N. A.; Milne, W. I.

    2004-12-01

    A normally closed microgripper with a radius of curvature of 18-50 μm using a diamond-like carbon (DLC) and stress free electroplated Ni bimorph structure has been demonstrated. The large curvature in the fingers of the microgrippers is due to the high compressive stress of the DLC layer. The radius of curvature of the figures can be adjusted by the thickness ratio, and the closure of the devices can also be adjusted by varying the finger length. This device works much more efficiently than other bimorph structures due to the large difference in thermal expansion coefficients between the DLC and the Ni layers. Preliminary electrical tests have shown these microgrippers can be opened by 60°-90° at an applied power of <20mW.

  13. Stress and Damage in Polymer Matrix Composite Materials Due to Material Degradation at High Temperatures

    Science.gov (United States)

    McManus, Hugh L.; Chamis, Christos C.

    1996-01-01

    This report describes analytical methods for calculating stresses and damage caused by degradation of the matrix constituent in polymer matrix composite materials. Laminate geometry, material properties, and matrix degradation states are specified as functions of position and time. Matrix shrinkage and property changes are modeled as functions of the degradation states. The model is incorporated into an existing composite mechanics computer code. Stresses, strains, and deformations at the laminate, ply, and micro levels are calculated, and from these calculations it is determined if there is failure of any kind. The rationale for the model (based on published experimental work) is presented, its integration into the laminate analysis code is outlined, and example results are given, with comparisons to existing material and structural data. The mechanisms behind the changes in properties and in surface cracking during long-term aging of polyimide matrix composites are clarified. High-temperature-material test methods are also evaluated.

  14. Fatty acids from high rate algal pond's microalgal biomass and osmotic stress effects.

    Science.gov (United States)

    Drira, Neila; Dhouibi, Nedra; Hammami, Saoussen; Piras, Alessandra; Rosa, Antonella; Porcedda, Silvia; Dhaouadi, Hatem

    2017-11-01

    The extraction of oil from a wild microalgae biomass collected from a domestic wastewater treatment facility's high rate algal pond (HRAP) was investigated. An experiment plan was used to determine the most efficient extraction method, the optimal temperature, time and solvent system based on total lipids yield. Microwave-assisted extraction was the most efficient method whether in n-hexane or in a mixture of chloroform/methanol compared to Soxhlet, homogenization, and ultrasounds assisted extractions. This same wild biomass was cultivated in a photobioreactor (PBR) and the effect of osmotic stress was studied. The lipids extraction yield after 3days of stress increased by more than four folds without any significant loss of biomass, however, the quality of extracted total lipids in terms of saturated, monounsaturated and polyunsaturated fatty acids was not affected by salinity change in the culture medium. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Preventing overtraining in athletes in high-intensity sports and stress/recovery monitoring.

    Science.gov (United States)

    Kellmann, M

    2010-10-01

    In sports, the importance of optimizing the recovery-stress state is critical. Effective recovery from intense training loads often faced by elite athletes can often determine sporting success or failure. In recent decades, athletes, coaches, and sport scientists have been keen to find creative, new methods for improving the quality and quantity of training for athletes. These efforts have consistently faced barriers, including overtraining, fatigue, injury, illness, and burnout. Physiological and psychological limits dictate a need for research that addresses the avoidance of overtraining, maximizes recovery, and successfully negotiates the fine line between high and excessive training loads. Monitoring instruments like the Recovery-Stress Questionnaire for Athletes can assist with this research by providing a tool to assess their perceived state of recovery. This article will highlight the importance of recovery for elite athletes and provide an overview of monitoring instruments. © 2010 John Wiley & Sons A/S.

  16. Stress corrosion cracking tests on high-level-waste container materials in simulated tuff repository environments

    International Nuclear Information System (INIS)

    Abraham, T.; Jain, H.; Soo, P.

    1986-06-01

    Types 304L, 316L, and 321 austenitic stainless steel and Incoloy 825 are being considered as candidate container materials for emplacing high-level waste in a tuff repository. The stress corrosion cracking susceptibility of these materials under simulated tuff repository conditions was evaluated by using the notched C-ring method. The tests were conducted in boiling synthetic groundwater as well as in the steam/air phase above the boiling solutions. All specimens were in contact with crushed Topopah Spring tuff. The investigation showed that microcracks are frequently observed after testing as a result of stress corrosion cracking or intergranular attack. Results showing changes in water chemistry during test are also presented

  17. Stress Response to High Magnetic Fields in Transgenic Arabidopsis thaliana Plants.

    Science.gov (United States)

    Morgan, A. N.; Watson, B. C.; Maloney, J. R.; Meisel, M. W.; Brooks, J. S.; Paul, A.-L.; Ferl, R. J.

    2000-03-01

    With increasingly greater strength magnetic fields becoming available in research and medicine, the response of living tissue exposed to high magnetic fields has come under investigation. In this experiment, genetically engineered arabidopsis plants were exposed to homogeneous magnetic fields of varying strengths using a superconducting NMR magnet (0 to 9 T) at UF and a resistive magnet (0 to 25 T) at the NHMFL. The engineered plants produce the enzyme β-glucaronidase (GUS) when under stressful environmental conditions. The level of GUS activity is determined through qualitative histochemical assays and quantitative fluorometric assays. The control group of plants experienced baseline levels of GUS activity, but some of the plants that were exposed to magnetic fields in excess of 9 T show increased stress response. Additional information is available at http://www.phys.ufl.edu/ ~meisel/maglev.htm.

  18. Fatigue Behavior of Steel Fiber Reinforced High-Strength Concrete under Different Stress Levels

    Science.gov (United States)

    Zhang, Chong; Gao, Danying; Gu, Zhiqiang

    2017-12-01

    The investigation was conducted to study the fatigue behavior of steel fiber reinforced high-strength concrete (SFRHSC) beams. A series of 5 SFRHSC beams was conducted flexural fatigue tests at different stress level S of 0.5, 0.55, 0.6, 0.7 and 0.8 respectively. Static test was conducted to determine the ultimate static capacity prior to fatigue tests. Fatigue modes and S-N curves were analyzed. Besides, two fatige life prediction model were analyzed and compared. It was found that stress level S significantly influenced the fatigue life of SFRHSC beams and the fatigue behavior of SFRHSC beams was mainly determined by the tensile reinforcement.

  19. Observations of hydrotectonic stress/strain events at a basement high at the Nicoya outer rise

    Science.gov (United States)

    Tryon, M. D.; Brown, K. M.

    2005-12-01

    There is substantial and growing evidence from heat flow and coring investigations that the oceanic plate off Costa Rica is highly hydrologically active and that this activity is responsible for one of the most anomalously cold thermal environments encountered in the oceanic environment. Recent work by Fisher, et al. has identified limited regions above certain topographic highs with extremely high heat flows. Pore water profiles from cores above these thinly sedimented basement highs suggest upward flow on the order of ~1 cm/yr. These highs may be the principal regions of out-flow from the basement in this region and, thus, can potentially be used to constrain the general level of hydrologic activity. The nine Chemical and Aqueous Transport (CAT) meters we deployed at one of the highest heatflow sites provide a temporal record of both in-flow and out-flow of aqueous fluids at rates as low as 0.1 mm/yr. Our objective was to provide a direct measurement of long term flow rates to address the following questions: (1) What are the characteristic fluid fluxes at basement highs of the low heat flow region of the northern Costa Rican incoming plate, and (2) is this flow temporally variable? The results of the instrument deployments agree quite closely in general with the coring results in that the background rates are on the order of 1 cm/yr or less. There is, however, considerable detail in the temporal records which suggest small scale tectonic stress transients causing temporary increases in flow rate. While this is certainly not an area of major tectonic activity, the site is located at the top of the outer rise where one would expect bending-related stress and fault reactivation to occur. The CAT meters are capable of detecting minute strain events in the underlying sediments and therefore may be detecting small localized strain events. Two periods of increased flow lasting a few weeks each occur during the 5 month deployment and are indicated on all of the

  20. Endoplasmic reticulum stress does not contribute to steatohepatitis in obese and insulin-resistant high-fat-diet-fed foz/foz mice.

    Science.gov (United States)

    Legry, Vanessa; Van Rooyen, Derrick M; Lambert, Barbara; Sempoux, Christine; Poekes, Laurence; Español-Suñer, Regina; Molendi-Coste, Olivier; Horsmans, Yves; Farrell, Geoffrey C; Leclercq, Isabelle A

    2014-10-01

    Non-alcoholic fatty liver (steatosis) and steatohepatitis [non-alcoholic steatohepatitis (NASH)] are hepatic complications of the metabolic syndrome. Endoplasmic reticulum (ER) stress is proposed as a crucial disease mechanism in obese and insulin-resistant animals (such as ob/ob mice) with simple steatosis, but its role in NASH remains controversial. We therefore evaluated the role of ER stress as a disease mechanism in foz/foz mice, which develop both the metabolic and histological features that mimic human NASH. We explored ER stress markers in the liver of foz/foz mice in response to a high-fat diet (HFD) at several time points. We then evaluated the effect of treatment with an ER stress inducer tunicamycin, or conversely with the ER protectant tauroursodeoxycholic acid (TUDCA), on the metabolic and hepatic features. foz/foz mice are obese, glucose intolerant and develop NASH characterized by steatosis, inflammation, ballooned hepatocytes and apoptosis from 6 weeks of HFD feeding. This was not associated with activation of the upstream unfolded protein response [phospho-eukaryotic initiation factor 2α (eIF2α), inositol-requiring enzyme 1α (IRE1α) activity and spliced X-box-binding protein 1 (Xbp1)]. Activation of c-Jun N-terminal kinase (JNK) and up-regulation of activating transcription factor-4 (Atf4) and CCAAT/enhancer-binding protein-homologous protein (Chop) transcripts were however compatible with a 'pathological' response to ER stress. We tested this by using intervention experiments. Induction of chronic ER stress failed to worsen obesity, glucose intolerance and NASH pathology in HFD-fed foz/foz mice. In addition, the ER protectant TUDCA, although reducing steatosis, failed to improve glucose intolerance, hepatic inflammation and apoptosis in HFD-fed foz/foz mice. These results show that signals driving hepatic inflammation, apoptosis and insulin resistance are independent of ER stress in obese diabetic mice with steatohepatitis.

  1. Anelasticity of olivine single crystals investigated by stress-reduction tests and high-angular resolution electron backscatter diffraction

    Science.gov (United States)

    Wallis, D.; Hansen, L. N.; Kempton, I.; Wilkinson, A. J.

    2017-12-01

    Geodynamic phenomena, including glacial isostatic adjustment and postseismic deformation, can involve transient deformation in response to changes in differential stress acting on mantle rocks. As such, rheological models of transient deformation are incorporated in predictions of associated processes, including sea-level rise and stress redistribution after earthquakes. However, experimental constraints on rheological models for transient deformation of mantle materials are sparse. In particular, experiments involving stress reductions have been lacking. Moreover, a material's response to a reduction in stress can provide clues to the microphysical processes controlling deformation. To constrain models of transient deformation of mantle rocks we performed stress-reduction tests on single crystals of olivine at 1250-1300°C. Mechanical and piezoelectric actuators controlled constant initial stress during creep. At various strain intervals stress was reduced near-instantaneously using the piezoelectric actuator, inducing both elastic and anelastic (time-dependent) lengthening of the samples. A range of magnitudes of stress reduction were applied, typically unloading 10-90% of the initial stress. High-angular resolution electron backscatter diffraction (HR-EBSD), based on cross-correlation of diffraction patterns, was used to map dislocation density and elastic strain distributions in the recovered samples. Magnitudes of anelastic back-strain increase with increasing magnitudes of stress reduction and show a marked increase when stress reductions exceed 50% of the initial stress, consistent with previous observations in metals and alloys. This observation is inconsistent with the Burgers rheological model commonly used to describe transient behaviour and suggests that the style of rheological behaviour depends on the magnitude of stress change. HR-EBSD maps reveal that the crystal lattices are smoothly curved and generally lack subgrain boundaries and elastic strain

  2. Why Agricultural Educators Remain in the Classroom

    Science.gov (United States)

    Crutchfield, Nina; Ritz, Rudy; Burris, Scott

    2013-01-01

    The purpose of this study was to identify and describe factors that are related to agricultural educator career retention and to explore the relationships between work engagement, work-life balance, occupational commitment, and personal and career factors as related to the decision to remain in the teaching profession. The target population for…

  3. Juveniles' Motivations for Remaining in Prostitution

    Science.gov (United States)

    Hwang, Shu-Ling; Bedford, Olwen

    2004-01-01

    Qualitative data from in-depth interviews were collected in 1990-1991, 1992, and 2000 with 49 prostituted juveniles remanded to two rehabilitation centers in Taiwan. These data are analyzed to explore Taiwanese prostituted juveniles' feelings about themselves and their work, their motivations for remaining in prostitution, and their difficulties…

  4. Kadav Moun PSA (:60) (Human Remains)

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

    This is an important public health announcement about safety precautions for those handling human remains. Language: Haitian Creole.  Created: 2/18/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 2/18/2010.

  5. The Annuity Puzzle Remains a Puzzle

    NARCIS (Netherlands)

    Peijnenburg, J.M.J.; Werker, Bas; Nijman, Theo

    We examine incomplete annuity menus and background risk as possible drivers of divergence from full annuitization. Contrary to what is often suggested in the literature, we find that full annuitization remains optimal if saving is possible after retirement. This holds irrespective of whether real or

  6. Stress reaction in crayfish: chlorides help to withstand stress in high nitrite concentration conditions – preliminary study

    Directory of Open Access Journals (Sweden)

    Kozák P.

    2011-06-01

    Full Text Available A non-invasive method of recording cardiac activity (heart rate – HR and stress reaction (stress index – SI was used to understand the immediate and ongoing stress reaction of crayfish to the chemical stimuli. This method detects changes in the shape and amplitude parameters of the response to the stress factors, which characterized the crayfish functional state. Experimental animals (Astacus leptodactylus were divided to the two groups with (400 mg·L-1 Cl− and without added chlorides and then exposed to a stepwise increased level of nitrite to the final (sublethal-lethal concentration of 60 mg·L-1 N-NO\\hbox{$_{2}^{-}$}−2 within 24 hours. The course of crayfish reaction was evident and provided information about their reaction to the sublethal-lethal concentration over time. As expected, a less prominent stress reaction was detected in the group with chlorides. The non-invasive method successfully evaluated the sensing of chemical stimuli in water through HR and SI changes.

  7. The Effect of Parenting Stress on Child Behavior Problems in High-Risk Children with Prenatal Drug Exposure

    Science.gov (United States)

    Bagner, Daniel M.; Sheinkopf, Stephen J.; Miller-Loncar, Cynthia; LaGasse, Linda L.; Lester, Barry M.; Liu, Jing; Bauer, Charles R.; Shankaran, Seetha; Bada, Henrietta; Das, Abhik

    2009-01-01

    Objective: To examine the relationship between early parenting stress and later child behavior in a high-risk sample and measure the effect of drug exposure on the relationship between parenting stress and child behavior. Methods: A subset of child-caregiver dyads (n = 607) were selected from the Maternal Lifestyle Study (MLS), which is a large…

  8. Linear and nonlinear characterization of low-stress high-confinement silicon-rich nitride waveguides.

    Science.gov (United States)

    Krückel, Clemens J; Fülöp, Attila; Klintberg, Thomas; Bengtsson, Jörgen; Andrekson, Peter A; Torres-Company, Víctor

    2015-10-05

    In this paper we introduce a low-stress silicon enriched nitride platform that has potential for nonlinear and highly integrated optics. The manufacturing process of this platform is CMOS compatible and the increased silicon content allows tensile stress reduction and crack free layer growth of 700 nm. Additional benefits of the silicon enriched nitride is a measured nonlinear Kerr coefficient n(2) of 1.4·10(-18) m(2)/W (5 times higher than stoichiometric silicon nitride) and a refractive index of 2.1 at 1550 nm that enables high optical field confinement allowing high intensity nonlinear optics and light guidance even with small bending radii. We analyze the waveguide loss (∼1 dB/cm) in a spectrally resolved fashion and include scattering loss simulations based on waveguide surface roughness measurements. Detailed simulations show the possibility for fine dispersion and nonlinear engineering. In nonlinear experiments we present continuous-wave wavelength conversion and demonstrate that the material does not show nonlinear absorption effects. Finally, we demonstrate microfabrication of resonators with high Q-factors (∼10(5)).

  9. Sex-dependent effects of high-fat-diet feeding on rat pancreas oxidative stress.

    Science.gov (United States)

    Gómez-Pérez, Yolanda; Gianotti, Magdalena; Lladó, Isabel; Proenza, Ana M

    2011-07-01

    The objective of the study was to investigate whether sex differences in oxidative stress-associated insulin resistance previously reported in rats could be attributed to a possible sex dimorphism in pancreas redox status. Fifteen-month-old male and female Wistar rats were fed a control diet or a high-fat diet for 14 weeks. Serum glucose, lipids, and hormone levels were measured. Insulin immunohistochemistry and morphometric analysis of islets were performed. Pancreas triglyceride content, oxidative damage, and antioxidant enzymatic activities were determined. Lipoprotein lipase, hormone-sensitive lipase, and uncoupling protein 2 (UCP2) levels were also measured. Male rats showed a more marked insulin resistance profile than females. In control female rats, pancreas Mn-superoxide dismutase activity and UCP2 levels were higher, and oxidative damage was lower compared with males. High-fat-diet feeding decreased pancreas triglyceride content in female rats and UCP2 levels in male rats. High-fat-diet female rats showed larger islets than both their control and sex counterparts. These results confirm the existence of a sex dimorphism in pancreas oxidative status in both control and high-fat-diet feeding situations, with female rats showing higher protection against oxidative stress, thus maintaining pancreatic function and contributing to a lower risk of insulin resistance.

  10. Calculation of stress intensity factors for circumferential semi-elliptical cracks with high aspect ratio in pipes

    International Nuclear Information System (INIS)

    Zareei, A.; Nabavi, S.M.

    2016-01-01

    In this paper, stress intensity factors are calculated at the deepest point of an internal circumferential semi-elliptical crack in a pipe subjected to any arbitrary load. Based on the three dimensional finite element analysis, a weight function is proposed for high aspect ratio semi-elliptical cracks in pipes. An effective expression is developed analytically to evaluate the stress intensity factor using the weight function method. For several crack face stress fields and welding residual stress distributions, the weight function is validated against finite element data and those in the literature. Based on the comparison results, it can be concluded that the solution proposed in this paper is effective in engineering applications. - Highlights: • Analysis of internal circumferential semi-elliptical cracks with high aspect ratio in pipes. • A weight function is proposed for the calculation of the stress intensity factors for the deepest point of the crack. • An effective closed form expression is proposed to evaluate the stress intensity factors. • Prediction of stress intensity factors for any applied stress gradients through the wall thickness without any limitations. • A three-dimensional finite element modeling employs to calculate the stress intensity factors for different geometries.

  11. The Arabidopsis Transcription Factor MYB112 Promotes Anthocyanin Formation during Salinity and under High Light Stress.

    Science.gov (United States)

    Lotkowska, Magda E; Tohge, Takayuki; Fernie, Alisdair R; Xue, Gang-Ping; Balazadeh, Salma; Mueller-Roeber, Bernd

    2015-11-01

    MYB transcription factors (TFs) are important regulators of flavonoid biosynthesis in plants. Here, we report MYB112 as a formerly unknown regulator of anthocyanin accumulation in Arabidopsis (Arabidopsis thaliana). Expression profiling after chemically induced overexpression of MYB112 identified 28 up- and 28 down-regulated genes 5 h after inducer treatment, including MYB7 and MYB32, which are both induced. In addition, upon extended induction, MYB112 also positively affects the expression of PRODUCTION OF ANTHOCYANIN PIGMENT1, a key TF of anthocyanin biosynthesis, but acts negatively toward MYB12 and MYB111, which both control flavonol biosynthesis. MYB112 binds to an 8-bp DNA fragment containing the core sequence (A/T/G)(A/C)CC(A/T)(A/G/T)(A/C)(T/C). By electrophoretic mobility shift assay and chromatin immunoprecipitation coupled to quantitative polymerase chain reaction, we show that MYB112 binds in vitro and in vivo to MYB7 and MYB32 promoters, revealing them as direct downstream target genes. We further show that MYB112 expression is up-regulated by salinity and high light stress, environmental parameters that both require the MYB112 TF for anthocyanin accumulation under these stresses. In contrast to several other MYB TFs affecting anthocyanin biosynthesis, MYB112 expression is not controlled by nitrogen limitation or an excess of carbon. Thus, MYB112 constitutes a regulator that promotes anthocyanin accumulation under abiotic stress conditions. © 2015 American Society of Plant Biologists. All Rights Reserved.

  12. Stress-strain relationship of high-strength steel (HSS) reinforcing bars

    Science.gov (United States)

    Anggraini, Retno; Tavio, Raka, I. Gede Putu; Agustiar

    2018-05-01

    The introduction of High-Strength Steel (HSS) reinforcing bars in reinforced concrete members has gained much attention in recent years and led to many advantages such as construction timesaving. It is also more economical since it can reduce the amount of reinforcing steel bars used in concrete members which in turn alleviates the congestion of reinforcement. Up to present, the building codes, e.g. American Concrete Institute (ACI) 318M-14 and Standard National Indonesia (SNI) 2847:2013, still restrict the use of higher-strength steel reinforcing bars for concrete design up to Grade 420 MPa due to the possible suspected brittle behavior of concrete members. This paper evaluates the characteristics of stress-strain relationships of HSS bars if they are comparable to the characteristics of those of Grade 420 MPa. To achieve the objective of the study, a series of steel bars from various grades (420, 550, 650, and 700 MPa) was selected. Tensile tests of these steel samples were conducted under displacement-controlled mode to capture the complete stress-strain curves and particularly the post-yield response of the steel bars. The results indicate that all the steel bars tested had the actual yield strengths greater than the corresponding specified values. The stress-strain curves of HSS reinforcing bars (Grade 550, 650, and 700 MPa) performed slightly different characteristics with those of Grade 420 MPa.

  13. Simulation of distortion and residual stress in high pressure die casting – modelling and experiments

    International Nuclear Information System (INIS)

    Hofer, P; Kaschnitz, E; Schumacher, P

    2012-01-01

    Two individual high-pressure die-casting geometries were developed in order to study the influence of process parameters and different alloys on the distortion behaviour of castings. These geometries were a stress lattice and a V-shaped sample tending to form residual stress due to different wall thickness respectively by a deliberate massive gating system. In the experimental castings the influence of the most important process parameters such as die temperature and die opening time and the cooling regime was examined. The time evolution of process temperatures was measured using thermal imaging. The heat transfer coefficients were adapted to the observed temperature distributions. Castings were produced from the two alloys AlSi12 and AlSi10MnMg. The distortion of the castings was measured by means of a tactile measuring device. For the alloy AlSi10MnMg thermo-physical and thermo-mechanical data were obtained using differential scanning calorimetry, laser flash technique, dilatometry and tensile testing at elevated temperatures. These data were used for modelling the material behaviour of the AlSi10MnMg alloy in the numerical model while for the alloy AlSi12(Fe) literature data were used. Process and stress simulation were conducted using the commercial FEM software ANSYS Workbench. A survey on the results of the comparison between simulation and experiment is given for both alloys.

  14. Explosives remain preferred methods for platform abandonment

    International Nuclear Information System (INIS)

    Pulsipher, A.; Daniel, W. IV; Kiesler, J.E.; Mackey, V. III

    1996-01-01

    Economics and safety concerns indicate that methods involving explosives remain the most practical and cost-effective means for abandoning oil and gas structures in the Gulf of Mexico. A decade has passed since 51 dead sea turtles, many endangered Kemp's Ridleys, washed ashore on the Texas coast shortly after explosives helped remove several offshore platforms. Although no relationship between the explosions and the dead turtles was ever established, in response to widespread public concern, the US Minerals Management Service (MMS) and National Marine Fisheries Service (NMFS) implemented regulations limiting the size and timing of explosive charges. Also, more importantly, they required that operators pay for observers to survey waters surrounding platforms scheduled for removal for 48 hr before any detonations. If observers spot sea turtles or marine mammals within the danger zone, the platform abandonment is delayed until the turtles leave or are removed. However, concern about the effects of explosives on marine life remains

  15. Speaking under pressure: low linguistic complexity is linked to high physiological and emotional stress reactivity.

    Science.gov (United States)

    Saslow, Laura R; McCoy, Shannon; van der Löwe, Ilmo; Cosley, Brandon; Vartan, Arbi; Oveis, Christopher; Keltner, Dacher; Moskowitz, Judith T; Epel, Elissa S

    2014-03-01

    What can a speech reveal about someone's state? We tested the idea that greater stress reactivity would relate to lower linguistic cognitive complexity while speaking. In Study 1, we tested whether heart rate and emotional stress reactivity to a stressful discussion would relate to lower linguistic complexity. In Studies 2 and 3, we tested whether a greater cortisol response to a standardized stressful task including a speech (Trier Social Stress Test) would be linked to speaking with less linguistic complexity during the task. We found evidence that measures of stress responsivity (emotional and physiological) and chronic stress are tied to variability in the cognitive complexity of speech. Taken together, these results provide evidence that our individual experiences of stress or "stress signatures"-how our body and mind react to stress both in the moment and over the longer term-are linked to how complex our speech under stress. Copyright © 2013 Society for Psychophysiological Research.

  16. Perceived social stress and symptom severity among help-seeking adolescents with versus without clinical high-risk for psychosis.

    Science.gov (United States)

    Millman, Zachary B; Pitts, Steven C; Thompson, Elizabeth; Kline, Emily R; Demro, Caroline; Weintraub, Marc J; DeVylder, Jordan E; Mittal, Vijay A; Reeves, Gloria M; Schiffman, Jason

    2018-02-01

    Research suggests that social stress exposure influences illness presentation and course among youth at clinical high-risk (CHR) for psychosis, though less is known about the extent to which self-reported perceptions of social stress relate to the severity of positive symptoms. Importantly, despite the notion that youth at CHR are especially susceptible to elevations in positive symptoms under conditions of stress, no study has examined this presumption relative to other psychiatric groups. Extending previous work demonstrating that perceived social stress was higher in a CHR group than in a clinical group of non-CHR, help-seeking controls, the current study aimed to: (1) examine whether perceived social stress is related to the severity of attenuated positive symptoms in the full sample (N=110); and (2) determine whether CHR status moderates the stress-symptom relation. Exploratory analyses examined relations of perceived social stress to negative, disorganized, and general symptoms. Greater perceptions of social stress were associated with more severe positive symptoms in the entire sample; however, although positive symptoms and perceived social stress were higher in the CHR group, the strength of this relation was statistically indistinguishable across groups. No differential effect of perceived social stress was observed for any symptom domain. Results provide some support for the diathesis-stress model of psychosis, while also suggesting that social stress and symptomatology are related independent of clinical vulnerability to psychosis. Future research would benefit from longitudinal studies of stress-symptom relations across CHR and help-seeking control groups. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Ameliorative effect of vitamin E on hepatic oxidative stress and hypoimmunity induced by high-fat diet in turbot (Scophthalmus maximus).

    Science.gov (United States)

    Jia, Yudong; Jing, Qiqi; Niu, Huaxin; Huang, Bin

    2017-08-01

    This study was conducted to examine the effects of vitamin E on growth performance, oxidative stress and non-specific immunity of turbot (Scophthalmus maximus) fed with high-fat diet. Results showed that high-fat diet significantly increased hepatosomatic index, viscerosomatic index, hepatic malondialdehyde level and decreased catalase and superoxide dismutase activities, whereas final weight, specific growth rate and survival rate remained unchanged. Meanwhile, nitro blue tetrazolium positive leucocytes of head kidney, respiratory burst activity in head-kidney macrophage, phagocytic index and serum lysozyme activity were significantly reduced after feeding with high-fat diet. Furthermore, fish fed with high-fat diet promoted higher expression of heat shock protein (hsp70, hsp90), and inhibited expression of complement component 3 (c3) in the liver and tumor necrosis factor-α (tnf-α), interleukine 1β (il-1β), toll like receptor 22 (tlr-22) in the spleen and head-kidney, respectively. However, simultaneous supplementation with 480 mg kg -1 vitamin E protected turbot against high-fat diet-induced hepatic oxidative stress, hypoimmunity through attenuating lipid peroxidation, renewing antioxidant enzymes activities and nonspecific immune responses, and modulating the expression of stress protein (hsp70, hsp90) and immune-related genes (c3, tnf-α, il-1β, tlr-22). In conclusion, the obtained results indicate the vitamin E as a wildly used functional feed additive contributes potentially to alleviate high-fat diet-induced hepatic oxidative stress and hypoimmunity, maintain the health, and improve the broodstock management for turbot. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Microstructuring of thermo-mechanically highly stressed surfaces final report of the DFG research group 576

    CERN Document Server

    Rienäcker, Adrian; Knoll, Gunter; Bach, Friedrich-Wilhelm; Maier, Hans; Reithmeier, Eduard; Dinkelacker, Friedrich

    2015-01-01

    This contributed volume presents the final research results of the DFG Research Group 576, which is a joint initiative of five different institutes of the Leibniz Universität Hannover and the Universität Kassel, Germany. The research of the DFG Research Group 576 focuses on improving the tribological behavior of thermomechanically highly stressed surfaces, particularly on cylinder liner for combustion engines. The target audience primarily comprises researchers and experts in the field but the book may also be beneficial for graduate students who want to specialize in the field.

  19. Sulphide stress corrosion behaviour of a nickel coated high-strength low-alloyed steel

    Energy Technology Data Exchange (ETDEWEB)

    Salvago, G; Fumagalli, G; Cigada, A; Scolari, P

    1987-01-01

    The sulphide stress corrosion cracking (SSCC) of the quenched and tempered AISI 4137 H steel either bare or coated with nickel alloys was examined. Both traditional electrochemical and linear elastic fracture mechanics methods were used to examine cracking in the NACE environment and in environments simulating the geothermal fluids found in the area of Larderello in Italy. Some tests were carried out on a geothermal well in Ferrara. High nickel content coatings seem to increase the SSCC resistance of the AISI 4137-H steel. Galvanic couplings effects are possible factors responsible for the behaviour in SSCC.

  20. Fractographic investigation of stress corrosion cracking of steels for high-strength bolts

    International Nuclear Information System (INIS)

    Gladshtejn, L.I.; Goritskij, V.M.; Evtushenko, N.A.; Sokolov, S.P.; Panfilova, L.M.

    1980-01-01

    By the methods of quantitative fractography studied is the effect of chemical composition on stress corrosion cracking resistance in the mean agressive medium (pH=2.2) and the fracture structure of cylindrical delta samples with the notch (K=2.75) of high-strength chromium steel. It is shown that the alloying of the 40 steel with Cr, Si, V increases its strength under short-time loading but leads to forming of brittle areas in fracture under long time effect of corrosion medium

  1. Device for detecting imminent failure of high-dielectric stress capacitors. [Patent application

    Science.gov (United States)

    McDuff, G.G.

    1980-11-05

    A device is described for detecting imminent failure of a high-dielectric stress capacitor utilizing circuitry for detecting pulse width variations and pulse magnitude variations. Inexpensive microprocessor circuitry is utilized to make numerical calculations of digital data supplied by detection circuitry for comparison of pulse width data and magnitude data to determine if preselected ranges have been exceeded, thereby indicating imminent failure of a capacitor. Detection circuitry may be incorporated in transmission lines, pulse power circuitry, including laser pulse circuitry or any circuitry where capacitors or capacitor banks are utilized.

  2. Microfabrication of large-area circular high-stress silicon nitride membranes for optomechanical applications

    Directory of Open Access Journals (Sweden)

    E. Serra

    2016-06-01

    Full Text Available In view of the integration of membrane resonators with more complex MEMS structures, we developed a general fabrication procedure for circular shape SiNx membranes using Deep Reactive Ion Etching (DRIE. Large area and high-stress SiNx membranes were fabricated and used as optomechanical resonators in a Michelson interferometer, where Q values up to 1.3 × 106 were measured at cryogenic temperatures, and in a Fabry-Pérot cavity, where an optical finesse up to 50000 has been observed.

  3. Scaphoid Stress Fracture in High-Level Gymnast: A Case Report

    Directory of Open Access Journals (Sweden)

    J. C. Nakamoto

    2011-01-01

    Full Text Available We present the case of an 18-year-old high-level gymnast who sustained a stress fracture of the scaphoid associated with a distal radial epiphysiolysis. Clinical evaluation demonstrated decreased range of motion of the affected wrist and insidious pain on the snuffbox and tenderness on the distal radial physis. He was submitted to surgical treatment with scaphoid percutaneous fixation and radial styloid process in situ fixation. Clinical features improved, and he got back to competition 6 months after surgery without symptoms and with complete range of motion.

  4. Green Leaf Volatile Emissions during High Temperature and Drought Stress in a Central Amazon Rainforest.

    Science.gov (United States)

    Jardine, Kolby J; Chambers, Jeffrey Q; Holm, Jennifer; Jardine, Angela B; Fontes, Clarissa G; Zorzanelli, Raquel F; Meyers, Kimberly T; de Souza, Vinicius Fernadez; Garcia, Sabrina; Gimenez, Bruno O; Piva, Luani R de O; Higuchi, Niro; Artaxo, Paulo; Martin, Scot; Manzi, Antônio O

    2015-09-15

    Prolonged drought stress combined with high leaf temperatures can induce programmed leaf senescence involving lipid peroxidation, and the loss of net carbon assimilation during early stages of tree mortality. Periodic droughts are known to induce widespread tree mortality in the Amazon rainforest, but little is known about the role of lipid peroxidation during drought-induced leaf senescence. In this study, we present observations of green leaf volatile (GLV) emissions during membrane peroxidation processes associated with the combined effects of high leaf temperatures and drought-induced leaf senescence from individual detached leaves and a rainforest ecosystem in the central Amazon. Temperature-dependent leaf emissions of volatile terpenoids were observed during the morning, and together with transpiration and net photosynthesis, showed a post-midday depression. This post-midday depression was associated with a stimulation of C₅ and C₆ GLV emissions, which continued to increase throughout the late afternoon in a temperature-independent fashion. During the 2010 drought in the Amazon Basin, which resulted in widespread tree mortality, green leaf volatile emissions (C₆ GLVs) were observed to build up within the forest canopy atmosphere, likely associated with high leaf temperatures and enhanced drought-induced leaf senescence processes. The results suggest that observations of GLVs in the tropical boundary layer could be used as a chemical sensor of reduced ecosystem productivity associated with drought stress.

  5. ALDH2 Inhibition Potentiates High Glucose Stress-Induced Injury in Cultured Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Guodong Pan

    2016-01-01

    Full Text Available Aldehyde dehydrogenase (ALDH gene superfamily consists of 19 isozymes. They are present in various organs and involved in metabolizing aldehydes that are biologically generated. For instance, ALDH2, a cardiac mitochondrial ALDH isozyme, is known to detoxify 4-hydroxy-2-nonenal, a reactive aldehyde produced upon lipid peroxidation in diabetic conditions. We hypothesized that inhibition of ALDH leads to the accumulation of unmetabolized 4HNE and consequently exacerbates injury in cells subjected to high glucose stress. H9C2 cardiomyocyte cell lines were pretreated with 10 μM disulfiram (DSF, an inhibitor of ALDH2 or vehicle (DMSO for 2 hours, and then subjected to high glucose stress {33 mM D-glucose (HG or 33 mM D-mannitol as an osmotic control (Ctrl} for 24 hrs. The decrease in ALDH2 activity with DSF pretreatment was higher in HG group when compared to Ctrl group. Increased 4HNE adduct formation with DSF pretreatment was higher in HG group compared to Ctrl group. Pretreatment with DSF leads to potentiated HG-induced cell death in cultured H9C2 cardiomyocytes by lowering mitochondrial membrane potential. Our results indicate that ALDH2 activity is important in preventing high glucose induced cellular dysfunction.

  6. Occupational stress and biomechanical risk in a high fashion clothing company.

    Science.gov (United States)

    Forcella, Laura; Bonfiglioli, Roberta; Cutilli, Piero; Antonucci, Andrea; Di Donato, Angela; Siciliano, Eugenio; Cortini, Michela; Violante, Francesco Saverio; Boscolo, Paolo

    2012-01-01

    Psychosocial discomfort may amplify job-related risk factors. The aim of this study is to evaluate job stress in a high fashion clothing company with upper limb biomechanical overload due to repetitive and forceful manual activities. Biomechanical risk was analyzed and in part reduced using the OCRA Check list. A total of 518 workers (433 females and 85 males) were investigated to determine anxiety (by STAI 1 and 2), occupational stress (using the Italian version of the Karasek Job Content Questionnaire) and perception of symptoms. Final biomechanical assessment did not reveal high risk jobs, except for cutting. Although the perception of anxiety and job insecurity was within the normal range, all the workers showed a high level of job strain (correlated with the perception of symptoms) due, probably, to very low decision latitude. It was suggested that job strain may increase the perception of symptoms. Moreover, the result of this study indicates that musculoskeletal overload has to be further analyzed since its low level is not in agreement with the level of discomfort due to the repetitive tasks.

  7. Cytokine production as a putative biological mechanism underlying stress sensitization in high combat exposed soldiers

    NARCIS (Netherlands)

    Smid, Geert E.; van Zuiden, Mirjam; Geuze, Elbert; Kavelaars, Annemieke; Heijnen, Cobi J.; Vermetten, Eric

    2015-01-01

    Objective: Combat stress exposed soldiers may respond to post-deployment stressful life events (SLE) with increases in symptoms of posttraumatic stress disorder (PTSD), consistent with a model of stress sensitization. Several lines of research point to sensitization as a model to describe the

  8. Cytokine production as a putative biological mechanism underlying stress sensitization in high combat exposed soldiers

    NARCIS (Netherlands)

    Smid, Geert E.; van Zuiden, Mirjam; Geuze, Elbert; Kavelaars, Annemieke; Heijnen, Cobi J.; Vermetten, Eric

    2015-01-01

    Combat stress exposed soldiers may respond to post-deployment stressful life events (SLE) with increases in symptoms of posttraumatic stress disorder (PTSD), consistent with a model of stress sensitization. Several lines of research point to sensitization as a model to describe the relations between

  9. Mechanical stresses and strains in superconducting dipole magnets for high energy accelerators

    International Nuclear Information System (INIS)

    Greben, L.I.; Mironov, E.S.; Moustafin, H.H.

    1979-01-01

    Stress and strain distributions in superconducting dipole magnets were investigated numerically. A finite element computer program was developed to calculate stresses and displacements due to thermal stress, electromagnetic forces and prestressing of structural elements. Real mechanical and thermal properties of superconducting dipole elements are taken into account. Numerical results of stress and strain patterns in dipole magnets are presented

  10. Tolerance of wheat and lettuce plants grown on human mineralized waste to high temperature stress

    Science.gov (United States)

    Ushakova, Sofya A.; Tikhomirov, Alexander A.; Shikhov, Valentin N.; Gros, Jean-Bernard; Golovko, Tamara K.; Dal'ke, Igor V.; Zakhozhii, Ilya G.

    2013-06-01

    The main objective of a life support system for space missions is to supply a crew with food, water and oxygen, and to eliminate their wastes. The ultimate goal is to achieve the highest degree of closure of the system using controlled processes offering a high level of reliability and flexibility. Enhancement of closure of a biological life support system (BLSS) that includes plants relies on increased regeneration of plant waste, and utilization of solid and liquid human wastes. Clearly, the robustness of a BLSS subjected to stress will be substantially determined by the robustness of the plant components of the phototrophic unit. The aim of the present work was to estimate the heat resistance of two plants (wheat and lettuce) grown on human wastes. Human exometabolites mineralized by hydrogen peroxide in an electromagnetic field were used to make a nutrient solution for the plants. We looked for a possible increase in the heat tolerance of the wheat plants using changes in photosynthetically active radiation (PAR) intensity during heat stress. At age 15 days, plants were subjected to a rise in air temperature (from 23 ± 1 °C to 44 ± 1 °С) under different PAR intensities for 4 h. The status of the photosynthetic apparatus of the plants was assessed by external СО2 gas exchange and fluorescence measurements. The increased irradiance of the plants during the high temperature period demonstrated its protective action for both the photosynthetic apparatus of the leaves and subsequent plant growth and development. The productivity of the plants subjected to temperature changes at 250 W m-2 of PAR did not differ from that of controls, whereas the productivity of the plants subjected to the same heat stress but in darkness was halved.

  11. Water stress from high-volume hydraulic fracturing potentially threatens aquatic biodiversity and ecosystem services in Arkansas, United States

    Science.gov (United States)

    Entrekin, Sally; Trainor, Anne; Saiers, James; Patterson, Lauren; Maloney, Kelly O.; Fargione, Joseph; Kiesecker, Joseph M.; Baruch-Mordo, Sharon; Konschnik, Katherine E.; Wiseman, Hannah; Nicot, Jean-Philippe; Ryan, Joseph N.

    2018-01-01

    Demand for high-volume, short duration water withdrawals could create water stress to aquatic organisms in Fayetteville Shale streams sourced for hydraulic fracturing fluids. We estimated potential water stress using permitted water withdrawal volumes and actual water withdrawals compared to monthly median, low, and high streamflows. Risk for biological stress was considered at 20% of long-term median and 10% of high- and low-flow thresholds. Future well build-out projections estimated potential for continued stress. Most water was permitted from small, free-flowing streams and “frack” ponds (dammed streams). Permitted 12-h pumping volumes exceeded median streamflow at 50% of withdrawal sites in June, when flows were low. Daily water usage, from operator disclosures, compared to median streamflow showed possible water stress in 7–51% of catchments from June–November, respectively. If 100% of produced water was recycled, per-well water use declined by 25%, reducing threshold exceedance by 10%. Future water stress was predicted to occur in fewer catchments important for drinking water and species of conservation concern due to the decline in new well installations and increased use of recycled water. Accessible and precise withdrawal and streamflow data are critical moving forward to assess and mitigate water stress in streams that experience high-volume withdrawals.

  12. Water Stress from High-Volume Hydraulic Fracturing Potentially Threatens Aquatic Biodiversity and Ecosystem Services in Arkansas, United States.

    Science.gov (United States)

    Entrekin, Sally; Trainor, Anne; Saiers, James; Patterson, Lauren; Maloney, Kelly; Fargione, Joseph; Kiesecker, Joseph; Baruch-Mordo, Sharon; Konschnik, Katherine; Wiseman, Hannah; Nicot, Jean-Philippe; Ryan, Joseph N

    2018-02-20

    Demand for high-volume, short duration water withdrawals could create water stress to aquatic organisms in Fayetteville Shale streams sourced for hydraulic fracturing fluids. We estimated potential water stress using permitted water withdrawal volumes and actual water withdrawals compared to monthly median, low, and high streamflows. Risk for biological stress was considered at 20% of long-term median and 10% of high- and low-flow thresholds. Future well build-out projections estimated potential for continued stress. Most water was permitted from small, free-flowing streams and "frack" ponds (dammed streams). Permitted 12-h pumping volumes exceeded median streamflow at 50% of withdrawal sites in June, when flows were low. Daily water usage, from operator disclosures, compared to median streamflow showed possible water stress in 7-51% of catchments from June-November, respectively. If 100% of produced water was recycled, per-well water use declined by 25%, reducing threshold exceedance by 10%. Future water stress was predicted to occur in fewer catchments important for drinking water and species of conservation concern due to the decline in new well installations and increased use of recycled water. Accessible and precise withdrawal and streamflow data are critical moving forward to assess and mitigate water stress in streams that experience high-volume withdrawals.

  13. Long-term high-fat diet induces pancreatic injuries via pancreatic microcirculatory disturbances and oxidative stress in rats with hyperlipidemia

    International Nuclear Information System (INIS)

    Yan Mingxian; Li Yanqing; Meng Min; Ren Hongbo; Kou Yi

    2006-01-01

    Relations between hyperlipidemia and chronic pancreatitis remain unclear. Microcirculatory disturbances and oxidative stress are involved in pathogeneses of a high numbers of diseases. The objective of this study was to induce hyperlipidemia in rats by long-term high-fat diet intake, then investigate the biochemical, microcirculatory, and histological alterations in blood and pancreatic tissues of these animals, and discuss their potential significances. Pancreatic blood flow was detected by intravital microscope; malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were measured in pancreatic tissues for assessment of oxidative stress and α-smooth muscle actin (α-SMA) expression was determined by immunohistochemical staining and RT-PCR. The results showed that the velocity of pancreatic microvascular blood flow of rats with hyperlipidemia decreased significantly as compared to control value (p = 0.008). Pancreatic MDA content increased whereas SOD activity decreased in these rats (p = 0.022; p = 0.039, respectively). Histologically, microvesicles in acinar and islet cells, dilated rough endoplasmic reticulum, swollen mitochondrion and modified vascular endothelial cells were observed under light microscope and transmission electron microscope. In addition, α-SMA expression was up-regulated significantly (p < 0.05). These results suggest that long-term high-fat diet can induce chronic pancreatic injuries which could be considered as 'nonalcoholic fatty pancreatic disease', and pancreatic microcirculatory disturbances and oxidative stress may play an important part in the underlying pathogenesis

  14. Red Yeast Rice Protects Circulating Bone Marrow-Derived Proangiogenic Cells against High-Glucose-Induced Senescence and Oxidative Stress: The Role of Heme Oxygenase-1

    Directory of Open Access Journals (Sweden)

    Jung-Tung Liu

    2017-01-01

    Full Text Available The inflammation and oxidative stress of bone marrow-derived proangiogenic cells (PACs, also named endothelial progenitor cells, triggered by hyperglycemia contributes significantly to vascular dysfunction. There is supporting evidence that the consumption of red yeast rice (RYR; Monascus purpureus-fermented rice reduces the vascular complications of diabetes; however, the underlying mechanism remains unclear. This study aimed to elucidate the effects of RYR extract in PACs, focusing particularly on the role of a potent antioxidative enzyme, heme oxygenase-1 (HO-1. We found that treatment with RYR extract induced nuclear factor erythroid-2-related factor nuclear translocation and HO-1 mRNA and protein levels in PACs. RYR extract inhibited high-glucose-induced (30 mM PAC senescence and the development of reactive oxygen species (ROS in a dose-dependent manner. The HO-1 inducer cobalt protoporphyrin IX also decreased high-glucose-induced cell senescence and oxidative stress, whereas the HO-1 enzyme inhibitor zinc protoporphyrin IX and HO-1 small interfering RNA significantly reversed RYR extract-caused inhibition of senescence and reduction of oxidative stress in high-glucose-treated PACs. These results suggest that RYR extract serves as alternative and complementary medicine in the treatment of these diseases, by inducing HO-1, thereby decreasing the vascular complications of diabetes.

  15. High energy X-ray diffraction analysis of strain and residual stress in silicon nitride ceramic diffusion bonds

    International Nuclear Information System (INIS)

    Vila, M.; Prieto, C.; Miranzo, P.; Osendi, M.I.; Terry, A.E.; Vaughan, G.B.M.

    2005-01-01

    High resolution X-ray scanning diffractometry is used to study the residual stress in binary metal/ceramic (Ni/Si 3 N 4 ) diffusion bonds fabricated by simultaneous high temperature heating and uniaxial pressing. In order to diminish the experimental error on the stress determination, the method consists of three steps: (i) to measure the axial and radial strains following some selected lines at the inner volume of the ceramic; (ii) to fit the strain data using finite element method (FEM) analysis and (iii) to determinate stresses by using the results obtained from the FEM method in the strain calculation

  16. Recovery and deformation substructures of zircaloy-4 in high temperature plasticity under stationary or non-stationary stress

    International Nuclear Information System (INIS)

    Bocek, M.; Armas, I.

    1982-01-01

    It was the aim of the present investigation to examine how the recovery rate in creep is influenced by a non-stationary stress. For purposes of phenomenological analysis it is postulated that, irrespective of whether the applied stress is stationary or not, for large strains the mean internal stress sigmasub(i) approaches a stationary value sigmasub(i,s). The stationary recovery rate Rsub(s) for constant load creep turns out be governed by the applied stress indicating that the recovery mechanism is dynamic in nature. For sigma-ramp loading, Rsub(s) is dependent on the stress rate sigma. In tensional stress cycling, Rsub(s) is governed by the maximum stress sigmasub(M) and is also dependent on the ratio of sigmasub(M) to the minimum stress sigma 0 . TEM examination of Zircaloy-4 specimens crept at 800 0 C at constant and cycling load respectively could not reveal any differences in the deformation substructure for the two loading types. Subgrain formation did not appear, individual dislocations were observed only rarely. However, typical networks were formed as well as pileups which perhaps are responsible for the back stress in high temperature plasticity (HTP). (orig.)

  17. Tension Band Plating for Chronic Anterior Tibial Stress Fractures in High-Performance Athletes.

    Science.gov (United States)

    Zbeda, Robert M; Sculco, Peter K; Urch, Ekaterina Y; Lazaro, Lionel E; Borens, Olivier; Williams, Riley J; Lorich, Dean G; Wellman, David S; Helfet, David L

    2015-07-01

    Anterior tibial stress fractures are associated with high rates of delayed union and nonunion, which can be particularly devastating to a professional athlete who requires rapid return to competition. Current surgical treatment strategies include intramedullary nailing, which has satisfactory rates of fracture union but an associated risk of anterior knee pain. Anterior tension band plating is a biomechanically sound alternative treatment for these fractures. Tension band plating of chronic anterior tibial stress fractures leads to rapid healing and return to physical activity and avoids the anterior knee pain associated with intramedullary nailing. Case series; Level of evidence, 4. Between 2001 and 2013, there were 13 chronic anterior tibial stress fractures in 12 professional or collegiate athletes who underwent tension band plating after failing nonoperative management. Patient charts were retrospectively reviewed for demographics, injury history, and surgical details. Radiographs were used to assess time to osseous union. Follow-up notes and phone interviews were used to determine follow-up time, return to training time, and whether the patient was able to return to competition. Cases included 13 stress fractures in 12 patients (9 females, 3 males). Five patients were track-and-field athletes, 4 patients played basketball, 2 patients played volleyball, and 1 was a ballet dancer. Five patients were Division I collegiate athletes and 7 were professional or Olympic athletes. Average age at time of surgery was 23.6 years (range, 20-32 years). Osseous union occurred on average at 9.6 weeks (range, 5.3-16.9 weeks) after surgery. Patients returned to training on average at 11.1 weeks (range, 5.7-20 weeks). Ninety-two percent (12/13) eventually returned to preinjury competition levels. Thirty-eight percent (5/13) underwent removal of hardware for plate prominence. There was no incidence of infection or nonunion. Anterior tension band plating for chronic tibial stress

  18. High-intensity training reduces intermittent hypoxia-induced ER stress and myocardial infarct size.

    Science.gov (United States)

    Bourdier, Guillaume; Flore, Patrice; Sanchez, Hervé; Pepin, Jean-Louis; Belaidi, Elise; Arnaud, Claire

    2016-01-15

    Chronic intermittent hypoxia (IH) is described as the major detrimental factor leading to cardiovascular morbimortality in obstructive sleep apnea (OSA) patients. OSA patients exhibit increased infarct size after a myocardial event, and previous animal studies have shown that chronic IH could be the main mechanism. Endoplasmic reticulum (ER) stress plays a major role in the pathophysiology of cardiovascular disease. High-intensity training (HIT) exerts beneficial effects on the cardiovascular system. Thus, we hypothesized that HIT could prevent IH-induced ER stress and the increase in infarct size. Male Wistar rats were exposed to 21 days of IH (21-5% fraction of inspired O2, 60-s cycle, 8 h/day) or normoxia. After 1 wk of IH alone, rats were submitted daily to both IH and HIT (2 × 24 min, 15-30m/min). Rat hearts were either rapidly frozen to evaluate ER stress by Western blot analysis or submitted to an ischemia-reperfusion protocol ex vivo (30 min of global ischemia/120 min of reperfusion). IH induced cardiac proapoptotic ER stress, characterized by increased expression of glucose-regulated protein kinase 78, phosphorylated protein kinase-like ER kinase, activating transcription factor 4, and C/EBP homologous protein. IH-induced myocardial apoptosis was confirmed by increased expression of cleaved caspase-3. These IH-associated proapoptotic alterations were associated with a significant increase in infarct size (35.4 ± 3.2% vs. 22.7 ± 1.7% of ventricles in IH + sedenary and normoxia + sedentary groups, respectively, P < 0.05). HIT prevented both the IH-induced proapoptotic ER stress and increased myocardial infarct size (28.8 ± 3.9% and 21.0 ± 5.1% in IH + HIT and normoxia + HIT groups, respectively, P = 0.28). In conclusion, these findings suggest that HIT could represent a preventive strategy to limit IH-induced myocardial ischemia-reperfusion damages in OSA patients. Copyright © 2016 the American Physiological Society.

  19. Effect of Schisandrae on stress system of soldiers undergone high-intensity military training

    Directory of Open Access Journals (Sweden)

    Nan XIA

    2014-03-01

    Full Text Available Objective To explore the changes in basic serum levels of hypothalamus-pituitrin-adrenal (HPA axis, hypothalamus-pituitrin-gonad (HPG axis and proinflammatory cytokines IL-1, IL-2 and IL-6 in repeated acute stress caused by one-week intensive training, and study the effects of oral administration of Schisandrae, salidroside and Schisandrae compound on the contents of those stress hormones and cytokines mentioned above. Methods One hundred and twenty healthy soldiers chosen from junior infantry combat troops who had never received long-term amphibious training were randomly divided into four groups (30 each: group A (Schisandrae compound group, group B (Schisandrae group, group C (salidroside group and group D (control group. Each and every soldier of all the groups underwent high-intensity composite military training, 8 hours per day, for a week. Venous blood sampling was collected at 7:00-8:00 a.m. before and after the training, respectively. Levels of cortisol (CORT, adrenocorticotropic hormone (ACTH, testosterone (T, IL-1, IL-2 and IL-6 in different groups were measured by radioimmunoassay (RIA. The changes in the levels of all the above mentioned hormones and cytokines in every group were observed and compared. Results In group D, as compared with the pre-stress levels, no marked difference was found in the levels of serum CORT and ACTH (P>0.05, but the levels of T and IL-6 significantly decreased (P0.05. In group C, the levels of T and IL-6 significantly decreased (P0.05. In group A, the serum levels of CORT, ACTH, T, IL-1 and IL-6 significantly decreased, while that of IL-2 significantly increased (P<0.01. As compared with group D, the level of ACTH in group A and group B, the level of IL-2 in group C significantly decreased (P<0.05. Conclusions  Schisandrae and Schisandrae compound have a marked and lasting inhibitory effect on the activation of HPA axis and the elevation of serum CORT levels induced by stress, while the similar

  20. Momordica charantia (bitter melon attenuates high-fat diet-associated oxidative stress and neuroinflammation

    Directory of Open Access Journals (Sweden)

    Feher Domonkos

    2011-06-01

    Full Text Available Abstract Background The rising epidemic of obesity is associated with cognitive decline and is considered as one of the major risk factors for neurodegenerative diseases. Neuroinflammation is a critical component in the progression of several neurological and neurodegenerative diseases. Increased metabolic flux to the brain during overnutrition and obesity can orchestrate stress response, blood-brain barrier (BBB disruption, recruitment of inflammatory immune cells from peripheral blood and microglial cells activation leading to neuroinflammation. The lack of an effective treatment for obesity-associated brain dysfunction may have far-reaching public health ramifications, urgently necessitating the identification of appropriate preventive and therapeutic strategies. The objective of our study was to investigate the neuroprotective effects of Momordica charantia (bitter melon on high-fat diet (HFD-associated BBB disruption, stress and neuroinflammatory cytokines. Methods C57BL/6 female mice were fed HFD with and without bitter melon (BM for 16 weeks. BBB disruption was analyzed using Evans blue dye. Phosphate-buffered saline (PBS perfused brains were analyzed for neuroinflammatory markers such as interleukin-22 (IL-22, IL-17R, IL-16, NF-κB1, and glial cells activation markers such as Iba1, CD11b, GFAP and S100β. Additionally, antioxidant enzymes, ER-stress proteins, and stress-resistant transcription factors, sirtuin 1 (Sirt1 and forkhead box class O transcription factor (FoxO were analyzed using microarray, quantitative real-time RT-PCR, western immunoblotting and enzymatic assays. Systemic inflammation was analyzed using cytokine antibody array. Results BM ameliorated HFD-associated changes in BBB permeability as evident by reduced leakage of Evans blue dye. HFD-induced glial cells activation and expression of neuroinflammatory markers such as NF-κB1, IL-16, IL-22 as well as IL-17R were normalized in the brains of mice supplemented with BM

  1. Jinlida reduces insulin resistance and ameliorates liver oxidative stress in high-fat fed rats.

    Science.gov (United States)

    Liu, Yixuan; Song, An; Zang, Shasha; Wang, Chao; Song, Guangyao; Li, Xiaoling; Zhu, Yajun; Yu, Xian; Li, Ling; Wang, Yun; Duan, Liyuan

    2015-03-13

    Jinlida (JLD) is a compound preparation formulated on the basis of traditional Chinese medicine and is officially approved for the treatment of type 2 diabetes (T2DM) in China. We aimed to elucidate the mechanism of JLD treatment, in comparison to metformin treatment, on ameliorating insulin sensitivity in insulin resistant rats and to reveal its anti-oxidant properties. Rats were fed with standard or high-fat diet for 6 weeks. After 6 weeks, the high-fat fed rats were subdivided into five groups and orally fed with JLD or metformin for 8 weeks. Fasting blood glucose (FBG), fasting blood insulin, blood lipid and antioxidant enzymes were measured. Intraperitoneal glucose tolerance test (IPGTT) and hyperinsulinemic euglycemic clamp technique were carried out to measure insulin sensitivity. Gene expression of the major signaling pathway molecules that regulate glucose uptake, including insulin receptor (INSR), insulin receptor substrate-1 (IRS-1), phosphoinositide-3-kinase (PI3K), protein kinase beta (AKT), and glucose transporter type 2 (GLUT2), were assessed by quantitative RT-PCR. The totle and phosphorylation expression of IRS-1, AKT, JNK and p38MAPK were determined by Western blot. Treatment with JLD effectively ameliorated the high-fat induced hyperglycemia, hyperinsulinemia and hyperlipidemia. Similar to metformin, the high insulin resistance in high-fat fed rats was significantly decreased by JLD treatment. JLD displayed anti-oxidant effects, coupled with up-regulation of the insulin signaling pathway. The attenuation of hepatic oxidative stress by JLD treatment was associated with reduced phosphorylation protein levels of JNK and p38MAPK. Treatment with JLD could moderate glucose and lipid metabolism as well as reduce hepatic oxidative stress, most likely through the JNK and p38MAPK pathways. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Decomposition Technique for Remaining Useful Life Prediction

    Science.gov (United States)

    Saha, Bhaskar (Inventor); Goebel, Kai F. (Inventor); Saxena, Abhinav (Inventor); Celaya, Jose R. (Inventor)

    2014-01-01

    The prognostic tool disclosed here decomposes the problem of estimating the remaining useful life (RUL) of a component or sub-system into two separate regression problems: the feature-to-damage mapping and the operational conditions-to-damage-rate mapping. These maps are initially generated in off-line mode. One or more regression algorithms are used to generate each of these maps from measurements (and features derived from these), operational conditions, and ground truth information. This decomposition technique allows for the explicit quantification and management of different sources of uncertainty present in the process. Next, the maps are used in an on-line mode where run-time data (sensor measurements and operational conditions) are used in conjunction with the maps generated in off-line mode to estimate both current damage state as well as future damage accumulation. Remaining life is computed by subtracting the instance when the extrapolated damage reaches the failure threshold from the instance when the prediction is made.

  3. Industry remains stuck in a transitional mode

    International Nuclear Information System (INIS)

    Garb, F.A.

    1991-01-01

    The near future for industry remains foggy for several obvious reasons. The shake-up of the Soviet Union and how the pieces will reform remains unclear. How successful efforts are to privatize government oil company operations around the world has yet to be determined. A long sought peace in the Middle East seems to be inching closer, but will this continue? If it does continue, what impact will it have on world energy policy? Will American companies, which are now transferring their attention to foreign E and P, also maintain an interest in domestic activities? Is the U.S. economy really on the upswing? We are told that the worst of the recession is over, but try telling this to thousands of workers in the oil patch who are being released monthly by the big players in domestic operations. This paper reports that 1992 should be a better year than 1991, if measured in opportunity. There are more exploration and acquisition options available, both domestically and internationally, than there have been in years. Probably more opportunities exist than there are players-certainly more than can be funded with current financial resources

  4. A survey of diet self-efficacy and food intake in students with high and low perceived stress.

    Science.gov (United States)

    Nastaskin, Robyn S; Fiocco, Alexandra J

    2015-04-23

    Given the rise in obesity and obesity-related disorders, understanding the relationship between stress, self-efficacy and food choice in young adulthood may have implications for preventing negative health outcomes later in life that stem from poor eating habits. The current study examined whether stress levels and diet self-efficacy may be associated with unhealthy eating habits in young adults. Male and female undergraduate students (N = 136) completed questionnaires that tap into diet self-efficacy (DSE), perceived stress (PS), sodium, and fat intake. Sex differences in choice of food were predicted, and low levels of perceived stress and high diet self-efficacy were expected to be associated with lower fat and sodium intake. Findings indicate an interaction between perceived stress and diet self-efficacy on fat intake and a main effect for diet self-efficacy on sodium intake in this population. As expected, low levels of perceived stress and high diet self-efficacy were associated with the lowest levels of fat and sodium intake in students. Findings were driven by females. This study provides preliminary evidence that diet self-efficacy and perceived stress levels relate to nutrient intake in young adult females, and that increasing diet self-efficacy and reducing perceived stress in young adult females may lead to reductions in fat and sodium intake, leading to healthier eating habits.

  5. The physiological stress response to high-intensity sprint exercise following the ingestion of sodium bicarbonate.

    Science.gov (United States)

    Peart, Daniel J; Kirk, Richard J; Hillman, Angela R; Madden, Leigh A; Siegler, Jason C; Vince, Rebecca V

    2013-01-01

    The purpose of this study was to investigate the effects of pre-exercise alkalosis on the physiological stress response to high-intensity exercise. Seven physically active males (age 22 ± 3 years, height 1.82 ± 0.06 m, mass 81.3 ± 8.4 kg and peak power output 300 ± 22 W) performed a repeated sprint cycle exercise following a dose of 0.3 g kg(-1) body mass of sodium bicarbonate (NaHCO(3)) (BICARB), or a placebo of 0.045 g kg(-1) body mass of sodium chloride (PLAC). Monocyte-expressed heat shock protein 72 (HSP72) and plasma thiobarbituric acid reactive substances (TBARS) were significantly attenuated in BICARB compared to PLAC (p = 0.04 and p = 0.039, respectively), however total anti-oxidant capacity, the ratio of oxidised to total glutathione, cortisol, interleukin 6 and interleukin 8 were not significantly induced by the exercise. In conclusion, monocyte-expressed HSP72 is significantly increased following high-intensity anaerobic exercise, and its attenuation following such exercise with the ingestion of NaHCO(3) is unlikely to be due to a decreased oxidative stress.

  6. Literature Survey on the Stress Corrosion Cracking of Low-Alloy Steels in High Temperature Water

    Energy Technology Data Exchange (ETDEWEB)

    Seifert, H.P

    2002-02-01

    The present report is a summary of a literature survey on the stress corrosion cracking (SCC) behaviour/ mechanisms in low-alloy steels (LAS) in high-temperature water with special emphasis to primary-pressure-boundary components of boiling water reactors (BWR). A brief overview on the current state of knowledge concerning SCC of low-alloy reactor pressure vessel and piping steels under BWR conditions is given. After a short introduction on general aspects of SCC, the main influence parameter and available quantitative literature data concerning SCC of LAS in high-temperature water are discussed on a phenomenological basis followed by a summary of the most popular SCC models for this corrosion system. The BWR operating experience and service cracking incidents are discussed with respect to the existing laboratory data and background knowledge. Finally, the most important open questions and topics for further experimental investigations are outlined. (author)

  7. The influence of peak shock stress on the high pressure phase transformation in Zr

    International Nuclear Information System (INIS)

    Cerreta, E K; Addessio, F L; Bronkhorst, C A; Brown, D W; Escobedo, J P; Fensin, S J; Gray, G T III; Lookman, T; Rigg, P A; Trujillo, C P

    2014-01-01

    At high pressures zirconium is known to undergo a phase transformation from the hexagonal close packed (HCP) alpha phase to the simple hexagonal omega phase. Under conditions of shock loading, a significant volume fraction of high-pressure omega phase is retained upon release. However, the hysteresis in this transformation is not well represented by equilibrium phase diagrams and the multi-phase plasticity under shock conditions is not well understood. For these reasons, the influence of peak shock stress and temperature on the retention of omega phase in Zr has been explored. VISAR and PDV measurements along with post-mortem metallographic and neutron diffraction characterization of soft recovered specimens have been utilized to quantify the volume fraction of retained omega phase and qualitatively understand the kinetics of this transformation. In turn, soft recovered specimens with varying volume fractions of retained omega phase have been utilized to understand the contribution of omega and alpha phases to strength in shock loaded Zr.

  8. Nickel--chromium strain gages for cryogenic stress analysis of superconducting structures in high magnetic fields

    International Nuclear Information System (INIS)

    Freynik, H.S. Jr.; Roach, D.R.; Deis, D.W.; Hirzel, D.G.

    1977-01-01

    Evaluation and calibration measurements were performed on commercial nickel-chromium metal-foil strain gages in a high-magnetic-field (12 T), liquid-helium (4.2 K) environment. The purpose was to fully characterize strain gages for use at cryogenic temperatures in high magnetic fields. In this study, the magnetoresistance of a number of strain gages was measured in three orthogonal directions at mechanical strain levels to 8900 μm/m. As a result, a unique calibration curve was defined for magnetoresistance strain errors that is independent of strain level and field direction to 12 T at 4.2 K. A current strain-gage application is the measurement of superconductor mechanical properties. These gages will soon be used in the stress analysis of superconducting fusion magnets during cooldown from ambient temperatures and during operation at 4.2 K with magnetic fields to 12 T

  9. High wall shear stress and spatial gradients in vascular pathology: a review.

    Science.gov (United States)

    Dolan, Jennifer M; Kolega, John; Meng, Hui

    2013-07-01

    Cardiovascular pathologies such as intracranial aneurysms (IAs) and atherosclerosis preferentially localize to bifurcations and curvatures where hemodynamics are complex. While extensive knowledge about low wall shear stress (WSS) has been generated in the past, due to its strong relevance to atherogenesis, high WSS (typically >3 Pa) has emerged as a key regulator of vascular biology and pathology as well, receiving renewed interests. As reviewed here, chronic high WSS not only stimulates adaptive outward remodeling, but also contributes to saccular IA formation (at bifurcation apices or outer curves) and atherosclerotic plaque destabilization (in stenosed vessels). Recent advances in understanding IA pathogenesis have shed new light on the role of high WSS in pathological vascular remodeling. In complex geometries, high WSS can couple with significant spatial WSS gradient (WSSG). A combination of high WSS and positive WSSG has been shown to trigger aneurysm initiation. Since endothelial cells (ECs) are sensors of WSS, we have begun to elucidate EC responses to high WSS alone and in combination with WSSG. Understanding such responses will provide insight into not only aneurysm formation, but also plaque destabilization and other vascular pathologies and potentially lead to improved strategies for disease management and novel targets for pharmacological intervention.

  10. Shotgun microbial profiling of fossil remains

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Ermini, Luca; Jónsson, Hákon

    2014-01-01

    the specimen of interest, but instead reflect environmental organisms that colonized the specimen after death. Here, we characterize the microbial diversity recovered from seven c. 200- to 13 000-year-old horse bones collected from northern Siberia. We use a robust, taxonomy-based assignment approach...... to identify the microorganisms present in ancient DNA extracts and quantify their relative abundance. Our results suggest that molecular preservation niches exist within ancient samples that can potentially be used to characterize the environments from which the remains are recovered. In addition, microbial...... community profiling of the seven specimens revealed site-specific environmental signatures. These microbial communities appear to comprise mainly organisms that colonized the fossils recently. Our approach significantly extends the amount of useful data that can be recovered from ancient specimens using...

  11. Political, energy events will remain interwoven

    International Nuclear Information System (INIS)

    Jones, D.P.

    1991-01-01

    This paper reports that it is possible to discuss the significance of political and energy events separately, but, in truth, they are intricately interwoven. Furthermore, there are those who will argue that since the two are inseparable, the future is not predictable; so why bother in the endeavor. It is possible that the central point of the exercise may have been missed-yes, the future is unpredictable exclamation point However, the objective of prediction is secondary. The objective of understanding the dynamic forces of change is primary exclamation point With this view of recent history, it is perhaps appropriate to pause and think about the future of the petroleum industry. The future as shaped by political, energy, economic, environmental and technological forces will direct our lives and markets during this decade. Most importantly, what will be the direction that successful businesses take to remain competitive in a global environment? These are interesting issues worthy of provocative thoughts and innovative ideas

  12. Nuclear remains an economic and ecologic asset

    International Nuclear Information System (INIS)

    Le Ngoc, Boris

    2015-01-01

    The author herein outlines the several benefits of nuclear energy and nuclear industry for France. He first outlines that France possesses 97 per cent of de-carbonated electricity thanks to nuclear energy (77 pc) and renewable energies (20 pc, mainly hydraulic), and that renewable energies must be developed in the building and transport sectors to be able to get rid of the environmentally and financially costly fossil energies. He outlines that reactor maintenance and the nuclear fuel cycle industry are fields of technological leadership for the French nuclear industry which is, after motor industry and aircraft industry, the third industrial sector in France. He indicates that nuclear electricity is to remain the most competitive one, and that nuclear energy and renewable energies must not be opposed to it but considered as complementary in the struggle against climate change, i.e. to reduce greenhouse gas emissions and to get rid of the prevalence of fossil energies

  13. Neglecting rice milling yield and quality underestimates economic losses from high-temperature stress.

    Directory of Open Access Journals (Sweden)

    Nathaniel B Lyman

    Full Text Available Future increases in global surface temperature threaten those worldwide who depend on rice production for their livelihoods and food security. Past analyses of high-temperature stress on rice production have focused on paddy yield and have failed to account for the detrimental impact of high temperatures on milling quality outcomes, which ultimately determine edible (marketable rice yield and market value. Using genotype specific rice yield and milling quality data on six common rice varieties from Arkansas, USA, combined with on-site, half-hourly and daily temperature observations, we show a nonlinear effect of high-temperature stress exposure on yield and milling quality. A 1 °C increase in average growing season temperature reduces paddy yield by 6.2%, total milled rice yield by 7.1% to 8.0%, head rice yield by 9.0% to 13.8%, and total milling revenue by 8.1% to 11.0%, across genotypes. Our results indicate that failure to account for changes in milling quality leads to understatement of the impacts of high temperatures on rice production outcomes. These dramatic losses result from reduced paddy yield and increased percentages of chalky and broken kernels, which together decrease the quantity and market value of milled rice. Recently published estimates show paddy yield reductions of up to 10% across the major rice-producing regions of South and Southeast Asia due to rising temperatures. The results of our study suggest that the often-cited 10% figure underestimates the economic implications of climate change for rice producers, thus potentially threatening future food security for global rice producers and consumers.

  14. Epidemiology of stress fracture injuries among US high school athletes, 2005-2006 through 2012-2013.

    Science.gov (United States)

    Changstrom, Bradley G; Brou, Lina; Khodaee, Morteza; Braund, Cortney; Comstock, R Dawn

    2015-01-01

    High school athletes in the United States sustain millions of injuries annually, approximately 10% of which are fractures. However, there is no clear estimate of the number of stress fractures sustained by high school athletes annually despite reports that stress fractures account for 0.7% to 20% of injuries seen in sports medicine clinics. This suggests a high utilization of resources for a potentially preventable injury. In addition, stress fractures have been associated with low energy availability and disordered eating in young athletes, highlighting the importance of early recognition and intervention. To investigate stress fracture rates and patterns in a large national sample of US high school athletes. Descriptive epidemiologic study. Data from High School RIO (Reporting Information Online), a national sports injury surveillance study, were analyzed to describe rates and patterns of stress fracture injury sustained from 2005-2006 through 2012-2013, across sports and by sex. From 2005-2006 through 2012-2013, a total of 51,773 injuries were sustained during 25,268,873 athlete-exposures, of which 389 (0.8%) were stress fractures, resulting in an overall stress fracture rate of 1.54 per 100,000 athlete-exposures. Rates per 100,000 athlete-exposures were highest in girls' cross country (10.62), girls' gymnastics (7.43), and boys' cross country (5.42). In sex-comparable sports, girls sustained more stress fractures (63.3%) than did boys (36.7%) and had higher rates of stress fracture (2.22 vs 1.27; rate ratio, 1.75; 95% CI, 1.38-2.23). The most commonly injured sites were the lower leg (40.3% of all stress fractures), foot (34.9%), and lower back/lumbar spine/pelvis (15.2%). Management was nonsurgical in 98.7% of the cases, and 65.3% of injuries resulted in ≥3 weeks of time loss, medical disqualification, or an end to the season before athletes could return to play. Although a rare injury, stress fractures cause considerable morbidity for high school athletes

  15. Polyamine stress at high pH in Escherichia coli K-12

    Directory of Open Access Journals (Sweden)

    Tate Daniel P

    2005-10-01

    Full Text Available Abstract Background Polyamines such as spermine and spermidine are required for growth of Escherichia coli; they interact with nucleic acids, and they bind to ribosomes. Polyamines block porins and decrease membrane permeability, activities that may protect cells in acid. At high concentrations, however, polyamines impair growth. They impair growth more severely at high pH, probably due to their increased uptake as membrane-permeant weak bases. The role of pH is critical in understanding polyamine stress. Results The effect of polyamines was tested on survival of Escherichia coli K-12 W3110 in extreme acid or base (pH conditions outside the growth range. At pH 2, 10 mM spermine increased survival by 2-fold, and putrescine increased survival by 30%. At pH 9.8, however, E. coli survival was decreased 100-fold by 10 mM spermine, putrescine, cadaverine, or spermidine. At pH 8.5, spermine decreased the growth rate substantially, whereas little effect was seen at pH 5.5. Spermidine required ten-fold higher concentrations to impair growth. On proteomic 2-D gels, spermine and spermidine caused differential expression of 31 different proteins. During log-phase growth at pH 7.0, 1 mM spermine induced eight proteins, including PykF, GlpK, SerS, DeaD, OmpC and OmpF. Proteins repressed included acetate-inducible enzymes (YfiD, Pta, Lpd as well as RapA (HepA, and FabB. At pH 8.5, spermine induced additional proteins: TnaA, OmpA, YrdA and NanA (YhcJ and also repressed 17 proteins. Four of the proteins that spermine induced (GlpK, OmpA, OmpF, TnaA and five that were repressed (Lpd, Pta, SucB, TpiA, YfiD show similar induction or repression, respectively, in base compared to acid. Most of these base stress proteins were also regulated by spermidine, but only at ten-fold higher concentration (10 mM at high pH (pH 8.5. Conclusion Polyamines increase survival in extreme acid, but decrease E. coli survival in extreme base. Growth inhibition by spermine and

  16. Fatigue Moderates the Relationship Between Perceived Stress and Suicidal Ideation: Evidence From Two High-Resolution Studies.

    Science.gov (United States)

    Kleiman, Evan M; Turner, Brianna J; Chapman, Alexander L; Nock, Matthew K

    2018-01-01

    Theoretical models of self-harm suggest that high perceived stress and high fatigue (which might affect the ability to cope with stress) may interact to predict the short-term occurrence of suicidal ideation and nonsuicidal self-injury (NSSI). We tested 3 approaches to examining this interaction, each of which provided a different understanding of the specific nature of these associations: comparing each individual's daily stress/fatigue to the entire sample's overall average (i.e., grand-mean centering), comparing each individual's daily perceived stress/fatigue to his or her overall average (i.e., group- or participant-mean centering), and comparing each individual's average perceived stress/fatigue to the sample's overall average (i.e., centering participant means on overall grand mean). In 2 studies, adolescents (n = 30; 574 daily reports, M age = 17.3 years, range = 12-19; 87.6% female) and young adults (n = 60; 698 daily reports; M age = 23.25 years, range = 18-35; 85% female) completed daily measures of perceived stress, fatigue, suicidal ideation, and NSSI. In both samples, the interaction between high daily perceived stress and high daily fatigue predicted greater odds of daily suicidal ideation (but not NSSI). Only the model comparing each individual's daily stress/fatigue to the entire sample's overall average was consistently significant across the two studies. Participants were most likely to experience suicidal ideation on days when both perceived stress and fatigue were elevated relative to the average level experienced across people and time points. Studies should build upon these findings with more in-depth examination of the temporal nature of stability and change in these factors as they relate to sustained suicidal ideation.

  17. Response of plants to high concentrations of uranium stress and the screening of remediation plants

    International Nuclear Information System (INIS)

    Tang Yongjin; Luo Xuegang; Zeng Feng; Jiang Shijie

    2013-01-01

    Studies of the resistance and accumulation ability of different plant species to uranium (U) has important influence on the bioremediation of U contaminated soil. The resistance and enrichment ability of high concentrations of U (500 mg · kg"-"1 soil) in fourteen plant species were investigated and evaluated in this study in order to screen remediation plants for governance soil U contamination. The results showed that: (1) high concentrations of U stress had different effects on the emergence and survival of the different plants. The seed emergence of Hibiscus esculentus was reduced by 2/3, but the seed emergence of Gynura cusimbua (D. Don) S. Moore, Chenopodium album L. and Phaseolus vulgaris var. humilis Alef were not reduced. Under the contaminated soil, all the sesamum indicum died within a month after the emergence and the survival number of Amaranth and Iresine herbstii 'Aureo-reticulata' reduced by about 80%. But the survival number of Alternanthera philoxeroides (Mart.) Griseb., Chenopodium album L. and Phaseolus vulgaris var. humilis Alef were not influenced. (2) The biomass of the plants would be reduced by 8-99% in the uranium-contaminated soil. The anti-stress ability of Phaseolus vulgaris var. humilis Alef was the strongest in the fourteen plants, and Cucurbita pepo L., Sorghumbicolor (L.) Moench, Ipomoea aquatica Forsk, Helianthus annuus, Chenopodium album L. and Alternanthera philoxeroides (Mart.) Griseb. showed some the anti-stress ability. (3) Significant differences were found in the capacity of plants to absorb uranium between under high-uranium contaminated soil and under the non-uranium contaminated soil were. The plants with higher uranium content in thenon-contaminated soil were Gomphrena globosa, and Cucurbita pepo L., which were 2.249 mg · kg"-"1 DW and 1.620 mg · kg"-"1 DW, respectively. But the plants with higher uranium content in the high uranium contaminated soil were Cichorium intybus L., Amaranth and Ipomoea aquatica Forsk, which

  18. Determination of Remaining Useful Life of Gas Turbine Blade

    Directory of Open Access Journals (Sweden)

    Meor Said Mior Azman

    2016-01-01

    Full Text Available The aim of this research is to determine the remaining useful life of gas turbine blade, using service-exposed turbine blades. This task is performed using Stress Rupture Test (SRT under accelerated test conditions where the applied stresses to the specimen is between 400 MPa to 600 MPa and the test temperature is 850°C. The study will focus on the creep behaviour of the 52000 hours service-exposed blades, complemented with creep-rupture modelling using JMatPro software and microstructure examination using optical microscope. The test specimens, made up of Ni-based superalloy of the first stage turbine blades, are machined based on International Standard (ISO 24. The results from the SRT will be analyzed using these two main equations – Larson-Miller Parameter and Life Fraction Rule. Based on the results of the remaining useful life analysis, the 52000h service-exposed blade has the condition to operate in the range of another 4751 hr to 18362 hr. The microstructure examinations shows traces of carbide precipitation that deteriorate the grain boundaries that occurs during creep process. Creep-rupture life modelling using JMatPro software has shown good agreement with the accelerated creep rupture test with minimal error.

  19. Consideration of microstructure evolution and residual stress measurement near severe worked surface using high energy x-ray

    International Nuclear Information System (INIS)

    Hashimoto, Tadafumi; Mochizuki, Masahito; Shobu, Takahisa

    2012-01-01

    It is necessary to establish a measurement method that can evaluate accurate stress on the surface. However, the microstructure evolution takes place near the surface due to severe plastic deformation, since structural members have been superpositioned a lot of working processes to complete. As well known, a plane stress can't be assumed on the severe worked surface. Therefore we have been proposed the measurement method that can be measured the in-depth distribution of residual stress components by using high energy X-ray from a synchrotron radiation source. There is the combination of the constant penetration depth method and tri-axial stress analysis. Measurements were performed by diffraction planes for the orientation parameter Γ=0.25 of which elastic constants are nearly equal to the mechanical one. The stress components obtained must be converted to the stress components in real space by using optimization technique, since it corresponds to the weighted average stress components associated with the attenuation of X-ray in materials. The predicted stress components distribution agrees very well with the corrected one which was measured by the conventional removal method. To verify the availability of the proposed method, thermal aging variation of residual stress components on the severe worked surface under elevated temperature was investigated using specimen superpositioned working processes (i.e., welding, machining, peening). It is clarified that the residual stress components increase with thermal aging, using the diffraction planes in hard elastic constants to the bulk. This result suggests that the thermal stability of residual stress has the dependence of the diffraction plane. (author)

  20. Adverse effect of combination of chronic psychosocial stress and high fat diet on hippocampus-dependent memory in rats.

    Science.gov (United States)

    Alzoubi, K H; Abdul-Razzak, K K; Khabour, O F; Al-Tuweiq, G M; Alzubi, M A; Alkadhi, K A

    2009-12-01

    The combined effects of high fat diet (HFD) and chronic stress on the hippocampus-dependent spatial learning and memory were studied in rats using the radial arm water maze (RAWM). Chronic psychosocial stress and/or HFD were simultaneously administered for 3 months to young adult male Wister rats. In the RAWM, rats were subjected to 12 learning trials as well as short-term and long-term memory tests. This procedure was applied on a daily basis until the animal reaches days to criterion (DTC) in the 12th learning trial and in memory tests. DTC is the number of days that the animal takes to make zero error in two consecutive days. Groups were compared based on the number of errors per trial or test as well as on the DTC. Chronic stress, HFD and chronic stress/HFD animal groups showed impaired learning as indicated by committing significantly (Pchronic stress, HFD and chronic stress/HFD groups showed significantly impaired performance compared to control group. Additionally, the stress/HFD was the only group that showed significantly impaired performance in memory tests on the 5th training day, suggesting more severe memory impairment in that group. Furthermore, DTC value for above groups indicated that chronic stress or HFD, alone, resulted in a mild impairment of spatial memory, but the combination of chronic stress and HFD resulted in a more severe and long-lasting memory impairment. The data indicated that the combination of stress and HFD produced more deleterious effects on hippocampal cognitive function than either chronic stress or HFD alone.

  1. Geraniol improves endothelial function by inhibiting NOX-2 derived oxidative stress in high fat diet fed mice

    International Nuclear Information System (INIS)

    Wang, Xiaoyu; Zhao, Shiqi; Su, Mengqi; Sun, Li; Zhang, Song; Wang, Dingyu; Liu, Zhaorui; Yuan, Yue; Liu, Yang; Li, Yue

    2016-01-01

    Endothelial dysfunction occurs in obese patients and high-fat diet (HFD) fed experimental animals. While geraniol has been reported to ameliorate inflammation and oxidative stress, inhibit tumor cell proliferation, and improve atherosclerosis, its direct effect on endothelial function remains uncharacterized. The present study therefore investigated the effect of geraniol on endothelial function in HFD mice and its underlying mechanisms. C57 BL/6 mice were fed an HFD (n = 40) or a normal diet (n = 20) for 8 weeks. HFD fed mice then were randomized to intraperitoneal treatment with geraniol (n = 20) or vehicle (n = 20) for another 6 weeks. Acetylcholine (Ach)-induced endothelial dependent vasorelaxation was measured on wire myography; reactive oxygen species (ROS) generation was assessed by fluorescence imaging, and NADPH oxidases (NOXs) and adhesive molecules VCAM-1 and ICAM-1 protein expression by western blotting. Geraniol improved endothelial function in HFD fed mice, as evidenced by its: 1. restoring endothelial dependent vasorelaxation induced by Ach, and reversing increased VCAM-1 and ICAM-1 expression; 2. attenuating HFD induced increased serum TBARS and aortic ROS generation; and 3. downregulating aortic NOX-2 expression in both HFD fed mice and in palmitic acid treated endothelial cells. Geraniol therefore protects against endothelial dysfunction induced by HFD through reducing NOX-2 associated ROS generation. -- Highlights: •Geraniol improved endothelial dependent relaxation in high fat diet fed mice. •Geraniol alleviated vascular injury in high fat diet fed mice. •Geraniol inhibited ROS generation through downregulating NOX-2 expression.

  2. Geraniol improves endothelial function by inhibiting NOX-2 derived oxidative stress in high fat diet fed mice

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoyu; Zhao, Shiqi; Su, Mengqi; Sun, Li; Zhang, Song; Wang, Dingyu; Liu, Zhaorui; Yuan, Yue; Liu, Yang [Department of Cardiology, the First Affiliated Hospital, Harbin Medical University, Harbin 150001, Heilongjiang Province (China); Li, Yue, E-mail: ly99ly@vip.163.com [Department of Cardiology, the First Affiliated Hospital, Harbin Medical University, Harbin 150001, Heilongjiang Province (China); Key Laboratory of Cardiac Diseases and Heart Failure, Harbin Medical University, Harbin, 150001, Heilongjiang Province (China)

    2016-05-20

    Endothelial dysfunction occurs in obese patients and high-fat diet (HFD) fed experimental animals. While geraniol has been reported to ameliorate inflammation and oxidative stress, inhibit tumor cell proliferation, and improve atherosclerosis, its direct effect on endothelial function remains uncharacterized. The present study therefore investigated the effect of geraniol on endothelial function in HFD mice and its underlying mechanisms. C57 BL/6 mice were fed an HFD (n = 40) or a normal diet (n = 20) for 8 weeks. HFD fed mice then were randomized to intraperitoneal treatment with geraniol (n = 20) or vehicle (n = 20) for another 6 weeks. Acetylcholine (Ach)-induced endothelial dependent vasorelaxation was measured on wire myography; reactive oxygen species (ROS) generation was assessed by fluorescence imaging, and NADPH oxidases (NOXs) and adhesive molecules VCAM-1 and ICAM-1 protein expression by western blotting. Geraniol improved endothelial function in HFD fed mice, as evidenced by its: 1. restoring endothelial dependent vasorelaxation induced by Ach, and reversing increased VCAM-1 and ICAM-1 expression; 2. attenuating HFD induced increased serum TBARS and aortic ROS generation; and 3. downregulating aortic NOX-2 expression in both HFD fed mice and in palmitic acid treated endothelial cells. Geraniol therefore protects against endothelial dysfunction induced by HFD through reducing NOX-2 associated ROS generation. -- Highlights: •Geraniol improved endothelial dependent relaxation in high fat diet fed mice. •Geraniol alleviated vascular injury in high fat diet fed mice. •Geraniol inhibited ROS generation through downregulating NOX-2 expression.

  3. Encoding negative events under stress: high subjective arousal is related to accurate emotional memory despite misinformation exposure.

    Science.gov (United States)

    Hoscheidt, Siobhan M; LaBar, Kevin S; Ryan, Lee; Jacobs, W Jake; Nadel, Lynn

    2014-07-01

    Stress at encoding affects memory processes, typically enhancing, or preserving, memory for emotional information. These effects have interesting implications for eyewitness accounts, which in real-world contexts typically involve encoding an aversive event under stressful conditions followed by potential exposure to misinformation. The present study investigated memory for a negative event encoded under stress and subsequent misinformation endorsement. Healthy young adults participated in a between-groups design with three experimental sessions conducted 48 h apart. Session one consisted of a psychosocial stress induction (or control task) followed by incidental encoding of a negative slideshow. During session two, participants were asked questions about the slideshow, during which a random subgroup was exposed to misinformation. Memory for the slideshow was tested during the third session. Assessment of memory accuracy across stress and no-stress groups revealed that stress induced just prior to encoding led to significantly better memory for the slideshow overall. The classic misinformation effect was also observed - participants exposed to misinformation were significantly more likely to endorse false information during memory testing. In the stress group, however, memory accuracy and misinformation effects were moderated by arousal experienced during encoding of the negative event. Misinformed-stress group participants who reported that the negative slideshow elicited high arousal during encoding were less likely to endorse misinformation for the most aversive phase of the story. Furthermore, these individuals showed better memory for components of the aversive slideshow phase that had been directly misinformed. Results from the current study provide evidence that stress and high subjective arousal elicited by a negative event act concomitantly during encoding to enhance emotional memory such that the most aversive aspects of the event are well remembered and

  4. High Dietary Fat Intake during Lactation Promotes the Development of Social Stress-Induced Obesity in the Offspring of Mice.

    Science.gov (United States)

    Tsuduki, Tsuyoshi; Yamamoto, Kazushi; E, Shuang; Hatakeyama, Yu; Sakamoto, Yu

    2015-07-17

    This study examined how a maternal high-fat diet (HD) during lactation and exposure of offspring to isolation stress influence the susceptibility of offspring to the development of obesity. C57BL/6J mice were fed a commercial diet (CD) during pregnancy and a CD or HD during lactation. Male offspring were weaned at three weeks of age, fed a CD until seven weeks of age, and fed a CD or HD until 11 weeks of age. Offspring were housed alone (isolation stress) or at six per cage (ordinary circumstances). Thus, offspring were assigned to one of eight groups: dams fed a CD or HD during lactation and offspring fed a CD or HD and housed under ordinary circumstances or isolation stress. Serum corticosterone level was significantly elevated by isolation stress. High-fat feeding of offspring reduced their serum corticosterone level, which was significantly elevated by a maternal HD. A maternal HD and isolation stress had combined effects in elevating the serum corticosterone level. These findings suggest that a maternal HD during lactation enhances the stress sensitivity of offspring. White adipose tissue weights were significantly increased by a maternal HD and isolation stress and by their combination. In addition, significant adipocyte hypertrophy was induced by a maternal HD and isolation stress and exacerbated by their combination. Thus, a maternal HD and isolation stress promote visceral fat accumulation and adipocyte hypertrophy, accelerating the progression of obesity through their combined effects. The mechanism may involve enhanced fatty acid synthesis and lipid influx from blood into adipose tissue. These findings demonstrate that a maternal HD during lactation may increase the susceptibility of offspring to the development of stress-induced obesity.

  5. Blunted hypothalamo-pituitary adrenal axis response to predator odor predicts high stress reactivity.

    Science.gov (United States)

    Whitaker, Annie M; Gilpin, Nicholas W

    2015-08-01

    Individuals with trauma- and stress-related disorders exhibit increases in avoidance of trauma-related stimuli, heightened anxiety and altered neuroendocrine stress responses. Our laboratory uses a rodent model of stress that mimics the avoidance symptom cluster associated with stress-related disorders. Animals are classified as 'Avoiders' or 'Non-Avoiders' post-stress based on avoidance of predator-odor paired context. Utilizing this model, we are able to examine subpopulation differences in stress reactivity. Here, we used this predator odor model of stress to examine differences in anxiety-like behavior and hypothalamo-pituitary adrenal (HPA) axis function in animals that avoid a predator-paired context relative to those that do not. Rats were exposed to predator odor stress paired with a context and tested for avoidance (24h and 11days), anxiety-like behavior (48h and 5days) and HPA activation following stress. Control animals were exposed to room air. Predator odor stress produced avoidance in approximately 65% of the animals at 24h that persisted 11days post-stress. Both Avoiders and Non-Avoiders exhibited a heightened anxiety-like behavior at 48h and 5days post-stress when compared to unstressed Controls. Non-Avoiders exhibited significant increases in circulating adrenocorticotropin hormone (ACTH) and corticosterone (CORT) concentrations immediately following predator odor stress compared to Controls and this response was significantly attenuated in Avoiders. There was an inverse correlation between circulating ACTH/CORT concentrations and avoidance, indicating that lower levels of ACTH/CORT predicted higher levels of avoidance. These results suggest that stress effects on HPA stress axis activation predict long-term avoidance of stress-paired stimuli, and build on previous data showing the utility of this model for exploring the neurobiological mechanisms of trauma- and stress-related disorders. Copyright © 2015. Published by Elsevier Inc.

  6. Lack of effect of high-protein vs. high-carbohydrate meal intake on stress-related mood and eating behavior

    Directory of Open Access Journals (Sweden)

    Lemmens Sofie G

    2011-12-01

    Full Text Available Abstract Background Consumption of meals with different macronutrients, especially high in carbohydrates, may influence stress-related eating behavior. We aimed to investigate whether consumption of high-protein vs. high-carbohydrate meals influences stress-related mood, food reward, i.e. 'liking' and 'wanting', and post-meal energy intake. Methods Participants (n = 38, 19m/19f, age = 25 ± 9 y, BMI = 25.0 ± 3.3 kg/m2 came to the university four times, fasted, once for a stress session receiving a high-protein meal, once for a rest session receiving a high-protein meal, once for a stress session receiving a high-carbohydrate meal and once for a rest session receiving a high-carbohydrate meal (randomized cross-over design. The high-protein and high-carbohydrate test meals (energy percentage protein/carbohydrate/fat 65/5/30 vs. 6/64/30 matched for energy density (4 kJ/g and daily energy requirements (30%. Stress was induced using an ego-threatening test. Pre- and post-meal 'liking' and 'wanting' (for bread, filling, drinks, dessert, snacks, stationery (non-food alternative as control was measured by means of a computer test. Following the post-meal 'wanting' measurement, participants received and consumed their wanted food items (post-meal energy intake. Appetite profile (visual analogue scales, mood state (Profile Of Mood State and State Trait Anxiety Inventory questionnaires, and post-meal energy intake were measured. Results Participants showed increased feelings of depression and anxiety during stress (P Conclusions Consumption of a high-protein vs. high-carbohydrate meal appears to have limited impact on stress-related eating behavior. Only participants with high disinhibition showed decreased subsequent 'wanting' and energy intake during rest; this effect disappeared under stress. Acute stress overruled effects of consumption of high-protein foods. Trial registration The study was registered in the Dutch Trial Register (NTR1904. The

  7. High stress, lack of sleep, low school performance, and suicide attempts are associated with high energy drink intake in adolescents.

    Science.gov (United States)

    Kim, So Young; Sim, Songyong; Choi, Hyo Geun

    2017-01-01

    Although an association between energy drinks and suicide has been suggested, few prior studies have considered the role of emotional factors including stress, sleep, and school performance in adolescents. This study aimed to evaluate the association of energy drinks with suicide, independent of possible confounders including stress, sleep, and school performance. In total, 121,106 adolescents with 13-18 years olds from the 2014 and 2015 Korea Youth Risk Behavior Web-based Survey were surveyed for age, sex, region of residence, economic level, paternal and maternal education level, sleep time, stress level, school performance, frequency of energy drink intake, and suicide attempts. Subjective stress levels were classified into severe, moderate, mild, a little, and no stress. Sleep time was divided into 6 groups: sleep time, stress level, and school performance with suicide attempts and the frequency of energy drink intake were analyzed using multiple and ordinal logistic regression analysis, respectively, with complex sampling. The relationship between frequency of energy drink intake and suicide attempts was analyzed using multiple logistic regression analysis with complex sampling. Higher stress levels, lack of sleep, and low school performance were significantly associated with suicide attempts (each P stress level, abnormal sleep time, and low school performance were also proportionally related with higher energy drink intake (P stress, inadequate sleep, and low school performance were related with more energy drink intake and suicide attempts in Korean adolescents. Frequent energy drink intake was positively related with suicide attempts, even after adjusting for stress, sleep time, and school performance.

  8. Incorporation of the stress concentration slots into the flexures for a high-performance microaccelerometer

    International Nuclear Information System (INIS)

    Zhao Yulong; Sun Lu; Liu Yan; Wang Weizhong; Tian Bian

    2012-01-01

    Presented in this paper is a development of a high-performance piezoresistive microaccelerometer based on the slot etching in the quad flexures for the vibration detection of high speed spindle. The proposed structure consists of a proof mass supported by four thin flexures with slots etched in the middle. Boron diffused piezoresistors located near the stress concentration regions are used for sensing the localized stress resulting from the incorporation of the slots into the flexures. Theoretical analysis and finite element analysis show satisfactory results of an improved sensitivity and favorable natural frequency higher than 10 kHz, conforming to the initial design requirements. The microfabrication techniques are described to prototype the two accelerometer chips, one with slots and the other one without slots. The tested microaccelerometers with 3 V DC power supply show an average sensitivity of 0.424 mV/g normal to the proof mass plane, increased by 60.6% than the ones without slots. An average transverse sensitivity is found to be 9.2 μV/g along X axis and 14.2 μV/g along Y axis, either of which is less than 3.5% of prime-axis sensitivity. Concerning the resonant frequency, dynamic experiment shows about 12.46 kHz and is available for the proposed design with a tiny loss of 3.5% compared with the quad-beam design. When taking the product of sensitivity and natural frequency as judgment criteria, an inspiring increase by 28.6% of the figure of merit is accomplished for the proposed accelerometer. Overall, the findings of this study confirm the feasibility of incorporating slots into the conventional configurations to improve the sensor sensitivity while maintaining a comparatively high natural frequency.

  9. High-electric-field-stress-induced degradation of SiN passivated AlGaN/GaN high electron mobility transistors

    International Nuclear Information System (INIS)

    Wen-Ping, Gu; Huan-Tao, Duan; Jin-Yu, Ni; Yue, Hao; Jin-Cheng, Zhang; Qian, Feng; Xiao-Hua, Ma

    2009-01-01

    AlGaN/GaN high electron mobility transistors (HEMTs) are fabricated by employing SiN passivation, this paper investigates the degradation due to the high-electric-field stress. After the stress, a recoverable degradation has been found, consisting of the decrease of saturation drain current I Dsat , maximal transconductance g m , and the positive shift of threshold voltage V TH at high drain-source voltage V DS . The high-electric-field stress degrades the electric characteristics of AlGaN/GaN HEMTs because the high field increases the electron trapping at the surface and in AlGaN barrier layer. The SiN passivation of AlGaN/GaN HEMTs decreases the surface trapping and 2DEG depletion a little during the high-electric-field stress. After the hot carrier stress with V DS = 20 V and V GS = 0 V applied to the device for 10 4 sec, the SiN passivation decreases the stress-induced degradation of I Dsat from 36% to 30%. Both on-state and pulse-state stresses produce comparative decrease of I Dsat , which shows that although the passivation is effective in suppressing electron trapping in surface states, it does not protect the device from high-electric-field degradation in nature. So passivation in conjunction with other technological solutions like cap layer, prepassivation surface treatments, or field-plate gate to weaken high-electric-field degradation should be adopted. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  10. Demountable low stress high field toroidal field magnet system for tokamak fusion reactors

    International Nuclear Information System (INIS)

    Powell, J.; Hsieh, D.; Lehner, J.; Suenaga, M.

    1978-01-01

    A new type of superconducting magnet system for large fusion reactors is described. Instead of winding large planar or multi-axis coils, as has been proposed in previous fusion reactor designs, the superconducting coils are made by joining together several prefabricated conductor sections. The joints can be unmade and sections removed if they fail. Conductor sections can be made at a factory and shipped to the reactor site for assembly. The conductor stress level in the assembled coil can be kept small by external support of the coil at a number of points along its perimeter, so that the magnetic forces are transmitted to an external warm reinforcement structure. This warm reinforcement structure can also be the primary containment for the fusion reactor, constructed similar to a PCRV (Prestressed Concrete Reactor Vessel) used in fission reactors. Low thermal conductivity, high strength supports are used to transfer the magnetic forces to the external reinforcement through a hydraulic system. The hydraulic supports are movable and can be programmed to accommodate thermal contraction and to minimize stress in the superconducting coil. (author)

  11. Demountable low stress high field toroidal field magnet system for tokamak fusion reactors

    International Nuclear Information System (INIS)

    Powell, J.; Hsieh, D.; Lehner, J.; Suenaga, M.

    1977-01-01

    A new type of superconducting magnet system for large fusion reactors is described in this report. Instead of winding large planar or multi-axis coils, as has been proposed in previous fusion reactor designs, the superconducting coils are made by joining together several prefabricated conductor sections. The joints can be unmade and sections removed if they fail. Conductor sections can be made at a factory and shipped to the reactor site for assembly. The conductor stress level in the assembled coil can be kept small by external support of the coil at a number of points along its perimeter, so that the magnetic forces are transmitted to an external warm reinforcement structure. This warm reinforcement structure can also be the primary containment for the fusion reactor, constructed similar to a PCRV (Prestressed Concrete Reactor Vessel) used in fission reactors. Low thermal conductivity, high strength supports are used to transfer the magnetic forces to the external reinforcement through a hydraulic system. The hydraulic supports are movable and can be programmed to accommodate thermal contraction and to minimize stress in the superconducting coil

  12. Zeolites relieves inhibitory stress from high concentrations of long chain fatty acids.

    Science.gov (United States)

    Nordell, Erik; Hansson, Anna B; Karlsson, Martin

    2013-12-01

    Protein and fat rich slaughterhouse waste is a very attractive waste stream for the production of biogas because of the high biochemical methane potential of the substrate. The material has however some drawbacks as the sole material for biogas production due to the production of several process disturbing metabolites such as ammonia, sulfides and long chain fatty acids. We can in this work present results that show that zeolites have the potential to relieve inhibitory stress from the presence of long chain fatty acids. Moreover, the results strongly indicate that it is mainly acetic acid consumers that are most negatively affected by long chain fatty acids and that the mechanism of stress relief is an adsorption of long chain fatty acids to the zeolites. In addition to this, it is shown that the effect is immediate and that only a small amount of zeolites is necessary to cancel the inhibitory effect of long chain fatty acids. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Stress Corrosion Cracking of alloy 600 in high temperature water: a study of mechanisms

    International Nuclear Information System (INIS)

    Boursier, J.M.; Bouvier, O. de; Gras, J.M.; Noel, D.; Vaillant, F.; Rios, R.

    1992-12-01

    Investigations of the stress corrosion cracking behaviour of Alloy 600 tubing in high temperature water were performed in order to get a precise knowledge of the different stages of the cracking and their dependence on various parameters. The compatibility of the results with the main mechanisms to be considered was examined. Results showed three stages in the cracking: a true incubation time, a slow-rate propagation period followed by a rapid-propagation stage. Tests separating stress and strain rate contributions show that the strain rate is the main parameter which controls the crack propagation. The hydrogen overpressure was found to increase the crack growth rate up to 1-4 bar, but a strong decrease is observed from 4 to 20 bar. Analysis of the hydrogen ingress in the metal showed that it is neither correlated to the hydrogen overpressure nor to the severity of cracking; so cracking resulting from an hydrogen-model is unlikely. No detrimental effect of oxygen (4 bar) was noticed both in the mill-annealed and the sensitized conditions. Finally, none of the classical mechanisms, neither hydrogen-assisted cracking nor slip-step dissolution, can correctly describe the observed behaviour. Some fractographic examinations, and an influence of primary water on the creep rate of Alloy 600, lead to consider that other recent mechanisms, involving an interaction between dissolution and plasticity, have to be considered

  14. Photobiomodulation Leads to Reduced Oxidative Stress in Rats Submitted to High-Intensity Resistive Exercise

    Directory of Open Access Journals (Sweden)

    Helenita Antonia de Oliveira

    2018-01-01

    Full Text Available The aim of this study was to determine whether oxidative stress markers are influenced by low-intensity laser therapy (LLLT in rats subjected to a high-intensity resistive exercise session (RE. Female Wistar rats divided into three experimental groups (Ctr: control, 4J: LLLT, and RE and subdivided based on the sampling times (instantly or 24 h postexercise underwent irradiation with LLLT using three-point transcutaneous method on the hind legs, which was applied to the gastrocnemius muscle at the distal, medial, and proximal points. Laser (4J or placebo (device off were carried out 60 sec prior to RE that consisted of four climbs bearing the maximum load with a 2 min time interval between each climb. Lipoperoxidation levels and antioxidant capacity were obtained in muscle. Lipoperoxidation levels were increased (4-HNE and CL markers instantly post-RE. LLLT prior to RE avoided the increase of the lipid peroxidation levels. Similar results were also notified for oxidation protein assays. The GPx and FRAP activities did not reduce instantly or 24 h after RE. SOD increased 24 h after RE, while CAT activity did not change with RE or LLLT. In conclusion, LLLT prior to RE reduced the oxidative stress markers, as well as, avoided reduction, and still increased the antioxidant capacity.

  15. Saccharomyces cerevisiae KNU5377 stress response during high-temperature ethanol fermentation.

    Science.gov (United States)

    Kim, Il-Sup; Kim, Young-Saeng; Kim, Hyun; Jin, Ingnyol; Yoon, Ho-Sung

    2013-03-01

    Fuel ethanol production is far more costly to produce than fossil fuels. There are a number of approaches to cost-effective fuel ethanol production from biomass. We characterized stress response of thermotolerant Saccharomyces cerevisiae KNU5377 during glucose-based batch fermentation at high temperature (40°C). S. cerevisiae KNU5377 (KNU5377) transcription factors (Hsf1, Msn2/4, and Yap1), metabolic enzymes (hexokinase, glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, and alcohol dehydrogenase), antioxidant enzymes (thioredoxin 3, thioredoxin reductase, and porin), and molecular chaperones and its cofactors (Hsp104, Hsp82, Hsp60, Hsp42, Hsp30, Hsp26, Cpr1, Sti1, and Zpr1) are upregulated during fermentation, in comparison to S. cerevisiae S288C (S288C). Expression of glyceraldehyde-3-phosphate dehydrogenase increased significantly in KNU5377 cells. In addition, cellular hydroperoxide and protein oxidation, particularly lipid peroxidation of triosephosphate isomerase, was lower in KNU5377 than in S288C. Thus, KNU5377 activates various cell rescue proteins through transcription activators, improving tolerance and increasing alcohol yield by rapidly responding to fermentation stress through redox homeostasis and proteostasis.

  16. Fatigue Life Prediction of High Modulus Asphalt Concrete Based on the Local Stress-Strain Method

    Directory of Open Access Journals (Sweden)

    Mulian Zheng

    2017-03-01

    Full Text Available Previously published studies have proposed fatigue life prediction models for dense graded asphalt pavement based on flexural fatigue test. This study focused on the fatigue life prediction of High Modulus Asphalt Concrete (HMAC pavement using the local strain-stress method and direct tension fatigue test. First, the direct tension fatigue test at various strain levels was conducted on HMAC prism samples cut from plate specimens. Afterwards, their true stress-strain loop curves were obtained and modified to develop the strain-fatigue life equation. Then the nominal strain of HMAC course determined using finite element method was converted into local strain using the Neuber method. Finally, based on the established fatigue equation and converted local strain, a method to predict the pavement fatigue crack initiation life was proposed and the fatigue life of a typical HMAC overlay pavement which runs a risk of bottom-up cracking was predicted and validated. Results show that the proposed method was able to produce satisfactory crack initiation life.

  17. High level compressive residual stresses produced in aluminum alloys by laser shock processing

    International Nuclear Information System (INIS)

    Gomez-Rosas, G.; Rubio-Gonzalez, C.; Ocana, J.L; Molpeceres, C.; Porro, J.A.; Chi-Moreno, W.; Morales, M.

    2005-01-01

    Laser shock processing (LSP) has been proposed as a competitive alternative technology to classical treatments for improving fatigue and wear resistance of metals. We present a configuration and results for metal surface treatments in underwater laser irradiation at 1064 nm. A convergent lens is used to deliver 1.2 J/cm 2 in a 8 ns laser FWHM pulse produced by 10 Hz Q-switched Nd:YAG, two laser spot diameters were used: 0.8 and 1.5 mm. Results using pulse densities of 2500 pulses/cm 2 in 6061-T6 aluminum samples and 5000 pulses/cm 2 in 2024 aluminum samples are presented. High level of compressive residual stresses are produced -1600 MPa for 6061-T6 Al alloy, and -1400 MPa for 2024 Al alloy. It has been shown that surface residual stress level is higher than that achieved by conventional shot peening and with greater depths. This method can be applied to surface treatment of final metal products

  18. Evaluation of barley (hordeum vulgare l.) germplasm for high forage production under salt stress

    International Nuclear Information System (INIS)

    Saleem, A.; Qurainy, F.A.; Akram, N.A.

    2014-01-01

    To explore high biomass producing salt tolerant cultivars of a potential forage crop barley (Hordeum vulgare L.), 30-day old plants of 105 different accessions from different origin were subjected to saline and non-saline (control) conditions for 45 days. Salinity stress (150 mM NaCl) markedly suppressed plant growth (shoot and/or root fresh and dry weights), chlorophyll pigments (a and b), internal CO/sub 2/ concentration, stomatal conductance, rate of transpiration and photosynthesis, while a considerable salt-induced increase was observed in all fluorescence related attributes including efficiency of photosystem-II (Fv/Fm), co-efficient of non-photochemical quenching (QN), photochemical quenching (QP), and non-photochemical quenching (NPQ) in all 105 accessions of barley. The response of all 105 barley accessions to salt stress varied significantly for all the morpho-physiological attributes determined in the present study. Overall, on the basis of shoot and root dry weights, accessions, 4050, 4053, 4056, 4163, 4228, 4229, 4244, 4245, 4290, 4414, 4415, 4427, 4452, Mahali, Jesto, 4165, 4229, 4249, 4405, 4409, 4426, 4456, and Giza 123 were found superior while accessions, 4245, 4158, 4166, 4246, 4406, 4423, 4441, 4442 4447, 4453 and 4458 inferior under saline conditions. (author)

  19. Characterizing the intra-urban spatiotemporal dynamics of High Heat Stress Zones (Hotspots)

    Science.gov (United States)

    Shreevastava, A.; Rao, P. S.; McGrath, G. S.

    2017-12-01

    In this study, we present an innovative framework to characterize the spatio-temporal dynamics of High Heat Stress Zones (Hot spots) created within an Urban area in the event of a Heat Wave. Heat waves are one of the leading causes of weather-related human mortality in many countries, and cities receive its worst brunt. The extreme heat stress within urban areas is often a synergistic combination of large-scale meteorological events, and the locally exacerbated impacts due to Urban Heat Islands (UHI). UHI is typically characterized as the difference between mean temperature of the urban and rural area. As a result, it fails to capture the significant variability that exists within the city itself. This variability arises from the diverse and complex spatial geometries of cities. Previous studies that have attempted to quantify the heat stress at an intra-urban scale are labor intensive, expensive, and difficult to emulate globally as they rely on availability of extensive data and their assimilation. The proposed study takes advantage of the well-established notion of fractal properties of cities to make the methods scalable to other cities where in-situ observational data might not be available. As an input, land surface temperatures are estimated using Landsat data. Using clustering analysis, we probe the emergence of thermal hotspots. The probability distributions (PD) of these hotspots are found to follow a power-law distribution in agreement with fractal characteristics of the city. PDs of several archetypical cities are then investigated to compare the effect of different spatial structures (e.g. monocentric v/s polycentric, sprawl v/s compact). Further, the temporal variability of the distributions on a diurnal as well as a seasonal scale is discussed. Finally, the spatiotemporal dynamics of the urban hotspots under a heat-wave (E.g. Delhi Heat wave, 2015) are compared against the non-heat wave scenarios. In summary, a technique that is globally adaptive and

  20. High self-perceived stress and poor coping in intellectually able adults with autism spectrum disorder.

    Science.gov (United States)

    Hirvikoski, Tatja; Blomqvist, My

    2015-08-01

    Despite average intellectual capacity, autistic traits may complicate performance in many everyday situations, thus leading to stress. This study focuses on stress in everyday life in intellectually able adults with autism spectrum disorders. In total, 53 adults (25 with autism spectrum disorder and 28 typical adults from the general population) completed the Perceived Stress Scale. Autistic traits were assessed using the Autism Spectrum Quotient. Adults with autism spectrum disorder reported significantly higher subjective stress and poorer ability to cope with stress in everyday life, as compared to typical adults. Autistic traits were associated with both subjective stress/distress and coping in this cross-sectional series. The long-term consequences of chronic stress in everyday life, as well as treatment intervention focusing on stress and coping, should be addressed in future research as well as in the clinical management of intellectually able adults with autism spectrum disorder. © The Author(s) 2014.

  1. The Human Remains from HMS Pandora

    Directory of Open Access Journals (Sweden)

    D.P. Steptoe

    2002-04-01

    Full Text Available In 1977 the wreck of HMS Pandora (the ship that was sent to re-capture the Bounty mutineers was discovered off the north coast of Queensland. Since 1983, the Queensland Museum Maritime Archaeology section has carried out systematic excavation of the wreck. During the years 1986 and 1995-1998, more than 200 human bone and bone fragments were recovered. Osteological investigation revealed that this material represented three males. Their ages were estimated at approximately 17 +/-2 years, 22 +/-3 years and 28 +/-4 years, with statures of 168 +/-4cm, 167 +/-4cm, and 166cm +/-3cm respectively. All three individuals were probably Caucasian, although precise determination of ethnicity was not possible. In addition to poor dental hygiene, signs of chronic diseases suggestive of rickets and syphilis were observed. Evidence of spina bifida was seen on one of the skeletons, as were other skeletal anomalies. Various taphonomic processes affecting the remains were also observed and described. Compact bone was observed under the scanning electron microscope and found to be structurally coherent. Profiles of the three skeletons were compared with historical information about the 35 men lost with the ship, but no precise identification could be made. The investigation did not reveal the cause of death. Further research, such as DNA analysis, is being carried out at the time of publication.

  2. SMART POINT CLOUD: DEFINITION AND REMAINING CHALLENGES

    Directory of Open Access Journals (Sweden)

    F. Poux

    2016-10-01

    Full Text Available Dealing with coloured point cloud acquired from terrestrial laser scanner, this paper identifies remaining challenges for a new data structure: the smart point cloud. This concept arises with the statement that massive and discretized spatial information from active remote sensing technology is often underused due to data mining limitations. The generalisation of point cloud data associated with the heterogeneity and temporality of such datasets is the main issue regarding structure, segmentation, classification, and interaction for an immediate understanding. We propose to use both point cloud properties and human knowledge through machine learning to rapidly extract pertinent information, using user-centered information (smart data rather than raw data. A review of feature detection, machine learning frameworks and database systems indexed both for mining queries and data visualisation is studied. Based on existing approaches, we propose a new 3-block flexible framework around device expertise, analytic expertise and domain base reflexion. This contribution serves as the first step for the realisation of a comprehensive smart point cloud data structure.

  3. Stress memory induced rearrangements of HSP transcription, photosystem II photochemistry and metabolism of tall fescue (Festuca arundinacea Schreb. in response to high-temperature stress

    Directory of Open Access Journals (Sweden)

    Tao eHu

    2015-06-01

    Full Text Available When plants are pre-exposed to stress, they can produce some stable signals and physiological reactions that may be carried forward as ‘stress memory’. However, there is insufficient information about is known about plants’ stress memory responses mechanisms. Here, two tall fescue genotypes, heat-tolerant PI 574522 and heat-sensitive PI 512315, were subjected to recurring high-temperature pre-acclimation treatment. Two heat shock protein (HSP genes, LMW-HSP and HMW-HSP, exhibited transcriptional memory for their higher transcript abundance during one or more subsequent stresses (S2, S3, S4 relative to the first stress (S1, and basal transcript levels during the recovery states (R1, R2 and R3. Activated transcriptional memory from two trainable genes could persist up to 4 days, and induce higher thermotolerance in tall fescue. This was confirmed by greater turf quality and lower electrolyte leakage. Pre-acclimation treatment inhibited the decline at steps of O-J-I-P and energy transport fluxes in active Photosystem II reaction center (PSII RC for both tall fescue genotypes. The heat stress memory was associated with major shifts in leaf metabolite profiles. Furthermore, there was an exclusive increase in leaf organic acids (citric acid, malic acid, tris phosphoric acid, threonic acid, sugars (sucrose, glucose, idose, allose, talose, glucoheptose, tagatose, psicose, amino acids (serine, proline, pyroglutamic acid, glycine, alanine and one fatty acid (butanoic acid in pre-acclimated plants. These discoveries involved in transcriptional memory, PSII RC energy transport and metabolite profiles could provide new insights into the plant high–temperature response process.

  4. Effects of mean tensile stresses on high-cycle fatigue life and strain accumulation in some reactor materials

    International Nuclear Information System (INIS)

    Soo, P.; Chow, J.G.Y.

    1977-05-01

    An assessment has been made of the effects of mean tensile stresses on the high-cycle fatigue behavior of solution-treated Type 304 stainless steel, normalized and tempered 2 1 / 4 Cr-1Mo steel, Incoloy-800H, and low-carbon Incoloy-800. Mean stresses are usually detrimental to fatigue strength, especially at high temperatures and stress levels, where significant creep can occur during fatigue cycling. Depending on the magnitudes of the alternating and mean stresses, failure may be creep or fatigue controlled. Strain accumulation is also affected by these stress levels and possibly, also, by the cyclic work-hardening characteristics of the material. It is shown that the Goodman Law for estimating mean stress effects is inadequate, since it does not account for time-dependent deformation. An alternative expression not having such a limitation was, therefore, derived and this relates the alternating and mean stresses to the time to failure. Based on limited metallographic observations of fatigue striations in the 2 1 / 4 Cr-1Mo steel an estimate was made of the crack propagation rate. It was found that a crack of critical size could, under certain conditions, propagate through most of the specimen diameter in a matter of seconds. This presents a more significant safety problem than the case for a crack extending under low-cycle conditions since preventative measures probably could not be implemented before the crack had grown to a large size

  5. Chemical chaperones reduce ER stress and adipose tissue inflammation in high fat diet-induced mouse model of obesity.

    Science.gov (United States)

    Chen, Yaqin; Wu, Zhihong; Zhao, Shuiping; Xiang, Rong

    2016-06-08

    Obesity, which is characteristic by chronic inflammation, is defined as abnormal or excessive fat accumulation in adipose tissues. Endoplasmic reticulum (ER) stress is increased in adipose tissue of obese state and is known to be strongly associated with chronic inflammation. The aim of this study was to investigate the effect of ER stress on adipokine secretion in obese mice and explore the potential mechanisms. In this study, we found high-fat diet induced-obesity contributed to strengthened ER stress and triggered chronic inflammation in adipose tissue. Chemical chaperones, 4-PBA and TUDCA, modified metabolic disorders and decreased the levels of inflammatory cytokines in obese mice fed a high-fat diet. The alleviation of ER stress is in accordance with the decrease of free cholesterol in adipose tissue. Furthermore chemical chaperones suppress NF-κB activity in adipose tissue of obese mice in vivo. In vitro studies showed IKK/NF-κB may be involved in the signal transduction of adipokine secretion dysfunction induced by ER stress. The present study revealed the possibility that inhibition of ER stress may be a novel drug target for metabolic abnormalities associated with obesity. Further studies are now needed to characterize the initial incentive of sustained ER stress in obese.

  6. The association between high levels of cumulative life stress and aberrant resting state EEG dynamics in old age.

    Science.gov (United States)

    Marshall, Amanda C; Cooper, Nicholas R

    2017-07-01

    Cumulative experienced stress produces shortcomings in old adults' cognitive performance. These are reflected in electrophysiological changes tied to task execution. This study explored whether stress-related aberrations in older adults' electroencephalographic (EEG) activity were also apparent in the system at rest. To this effect, the amount of stressful life events experienced by 60 young and 60 elderly participants were assessed in conjunction with resting state power changes in the delta, theta, alpha, and beta frequencies during a resting EEG recording. Findings revealed elevated levels of delta power among elderly individuals reporting high levels of cumulative life stress. These differed significantly from young high and low stress individuals and old adults with low levels of stress. Increases of delta activity have been linked to the emergence of conditions such as Alzheimer's Disease and Mild Cognitive Impairment. Thus, a potential interpretation of our findings associates large amounts of cumulative stress with an increased risk of developing age-related cognitive pathologies in later life. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    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...

  8. Physical Symptoms of Stress, Depression, and Suicidal Ideation in High School Students.

    Science.gov (United States)

    Herman, Sandra L.; Lester, David

    1994-01-01

    Examined depression among 97 adolescents with and without psychosomatic stress symptoms and explored relationship between psychosomatic stress symptoms and preoccupation with suicide. Found that occurrence of minor physical symptoms of stress, but not major psychosomatic disorders, was associated with depression. Physical symptoms were not…

  9. Copepod swimming behavior, respiration, and expression of stress-related genes in response to high stocking densities

    DEFF Research Database (Denmark)

    Nilsson, Birgitte; Jakobsen, Hans Henrik; Stief, Peter

    2017-01-01

    is problematic for calanoid copepod species like Acartia tonsa. In the present study, we evaluated the response of copepods experiencing stress under high-density conditions by assessing the acute stress level of A. tonsa. Control density was at 100 ind. L−1 while the treatments were increased stepwise up to 10......,000 ind. L−1. Three biological/physiological end-points were studied: swimming behavior, respiration rate and expression level of stress-related genes. None of the elevated densities caused any significant change in swimming behavior, respiration rate or gene expression level. This study suggests...... that adults of A. tonsa do not exhibit any measurable acute stress response when exposed to high culture densities for 12 h....

  10. Deposition of low stress, high transmittance SiC as an x-ray mask membrane using ECR plasma CVD

    CERN Document Server

    Lee, S Y; Lim, S T; Ahn, J H

    1998-01-01

    SiC for x-ray mask membrane is deposited by Electron Cyclotron Resonance plasma Chemical Vapor Deposition from SiH sub 4 /CH sub 4 Ar mixtures. Stoichiometric SiC is deposited at SiH sub 4 /CH sub 4 ratio of 0.4, deposition temperature of 600.deg.C and microwave power of 500 W with +- 5% thickness uniformity, As-deposited film has compressive residual stress, very smooth surface (31 A rms) and high optical transmittance of 90% at 633 nm wavelength. The microstructure of this film consists of the nanocrystalline particle (100 A approx 200A) embedded in amorphous matrix. Residual stress can be turned to tensile stress via Rapid Thermal Annealing in N sub 2 atmosphere, while suppressing structural change during annealing, As a result, smooth (37 A rms) SiC film with moderate tensile stress and high optical transmittance (85% at 633 nm wavelength) is obtained.

  11. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Nosratola D Vaziri

    Full Text Available Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammonia leading to endotoxemia and bacterial translocation; and restriction of potassium-rich fruits and vegetables which are common sources of fermentable fiber. Restriction of these foods leads to depletion of bacteria that convert indigestible carbohydrates to short chain fatty acids which are important nutrients for colonocytes and regulatory T lymphocytes. We hypothesized that a high resistant starch diet attenuates CKD progression. Male Sprague Dawley rats were fed a chow containing 0.7% adenine for 2 weeks to induce CKD. Rats were then fed diets supplemented with amylopectin (low-fiber control or high fermentable fiber (amylose maize resistant starch, HAM-RS2 for 3 weeks. CKD rats consuming low fiber diet exhibited reduced creatinine clearance, interstitial fibrosis, inflammation, tubular damage, activation of NFkB, upregulation of pro-inflammatory, pro-oxidant, and pro-fibrotic molecules; impaired Nrf2 activity, down-regulation of antioxidant enzymes, and disruption of colonic epithelial tight junction. The high resistant starch diet significantly attenuated these abnormalities. Thus high resistant starch diet retards CKD progression and attenuates oxidative stress and inflammation in rats. Future studies are needed to explore the impact of HAM-RS2 in CKD patients.

  12. What remains of the Arrow oil?

    International Nuclear Information System (INIS)

    Sergy, G.; Owens, E.

    1993-01-01

    In February 1970, the tanker Arrow became grounded 6.5 km off the north shore of Chedabucto Bay, Nova Scotia, and nearly 72,000 bbl of Bunker C fuel oil were released from the vessel during its subsequent breakup and sinking. The oil was washed ashore in various degrees over an estimated 305 km of the bay's 604-km shoreline, of which only 48 km were cleaned. In addition, the tanker Kurdistan broke in two in pack ice in March 1979 in the Cabot Strait area, spilling ca 54,000 bbl of Bunker C, some of which was later found at 16 locations along the northeast and east shorelines of Chedabucto Bay. In summer 1992, a systematic ground survey of the bay's shorelines was conducted using Environment Canada Shoreline Cleanup Assessment Team (SCAT) procedures. Standard observations were made of oil distribution and width, thickness, and character of the oil residues in 419 coastal segments. Results from the survey are summarized. Oil was found to be present on 13.3 km of the shoreline, with heavy oiling restricted to 1.3 km primarily in the areas of Black Duck Cove and Lennox Passage. Some of this residual oil was identified as coming from the Arrow. Natural weathering processes account for removal of most of the spilled oil from the bay. Oil remaining on the shore was found in areas outside of the zone of physical wave action, in areas of nearshore mixing where fine sediments are not present to weather the oil through biophysical processes, or in crusts formed by oil weathered on the surface. The systematic description of oiled shorelines using the SCAT methodology proved very successful, even for such an old spill. 6 refs

  13. Mice selected for high versus low stress reactivity: a new animal model for affective disorders.

    Science.gov (United States)

    Touma, Chadi; Bunck, Mirjam; Glasl, Lisa; Nussbaumer, Markus; Palme, Rupert; Stein, Hendrik; Wolferstätter, Michael; Zeh, Ramona; Zimbelmann, Marina; Holsboer, Florian; Landgraf, Rainer

    2008-07-01

    Affective disorders such as major depression are among the most prevalent and costly diseases of the central nervous system, but the underlying mechanisms are still poorly understood. In recent years, it has become evident that alterations of the stress hormone system, in particular dysfunctions (hyper- or hypo-activity) of the hypothalamic-pituitary-adrenal (HPA) axis, play a prominent role in the development of major depressive disorders. Therefore, we aimed to generate a new animal model comprising these neuroendocrine core symptoms in order to unravel parameters underlying increased or decreased stress reactivity. Starting from a population of outbred mice (parental generation: 100 males and 100 females of the CD-1 strain), two breeding lines were established according to the outcome of a 'stress reactivity test' (SRT), consisting of a 15-min restraint period and tail blood samplings immediately before and after exposure to the stressor. Mice showing a very high or a very low secretion of corticosterone in the SRT, i.e. animals expressing a hyper- or a hypo-reactivity of the HPA axis, were selected for the 'high reactivity' (HR) and the 'low reactivity' (LR) breeding line, respectively. Additionally, a third breeding line was established consisting of animals with an 'intermediate reactivity' (IR) in the SRT. Already in the first generation, i.e. animals derived from breeding pairs selected from the parental generation, significant differences in the reactivity of the HPA axis between HR, IR, and LR mice were observed. Moreover, these differences were found across all subsequent generations and could be increased by selective breeding, which indicates a genetic basis of the respective phenotype. Repeated testing of individuals in the SRT furthermore proved that the observed differences in stress responsiveness are present already early in life and can be regarded as a robust genetic predisposition. Tests investigating the animal's emotionality including anxiety

  14. Fractures in high-strength bolts due to hydrogen induced stress corrosion. Causes and corrective actions

    International Nuclear Information System (INIS)

    Hoche, Holger; Oechsner, Matthias

    2017-01-01

    Delayed brittle fractures of high-strength bolts of the strength class 10.9 are presented, taking the example of three damage cases. The respective damage mechanisms could be attributed to hydrogen induced stress corrosion which was caused, in turn, by hydrogen absorption during operation. The examples were chosen with a particular focus on the material condition's susceptibility which explains the cause for the occurrence of the damage mechanism. However, in only one of the three cases the susceptibility was evident and could be explained by violations of normative specifications and an unfavorable material choice. Whereas in the two other examples, only slight or no deviations from the standards and/or regulations could be found. The influencing parameters that caused the damage, those that further promoted the damage, as well as possible corrective actions are discussed taking into account the three exemplary damage cases.

  15. Progressive current degradation and breakdown behavior in GaN LEDs under high reverse bias stress

    International Nuclear Information System (INIS)

    Zhao Linna; Yu Peihong; Yan Dawei; Zhou Hao; Wu Jinbo; Cui Zhiqiang; Gu Xiaofeng; Guo Zixiang; Sun Huarui

    2017-01-01

    The progressive current degradation and breakdown behaviors of GaN-based light emitting diodes under high reverse-bias stress are studied by combining the electrical, optical, and surface morphology characterizations. The current features a typical “soft breakdown” behavior, which is linearly correlated to an increase of the accumulative number of electroluminescence spots. The time-to-failure for each failure site approximately obeys a Weibull distribution with slopes of about 0.67 and 4.09 at the infant and wear-out periods, respectively. After breakdown, visible craters can be observed at the device surface as a result of transient electrostatic discharge. By performing focused ion beam cuts coupled with scan electron microscope, we observed a local current shunt path in the surface layer, caused by the rapid microstructure deterioration due to significant current heating effect, consistent well with the optical beam induced resistance change observations. (paper)

  16. Heritable transmission of stress resistance by high dietary glucose in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Arnaud Tauffenberger

    2014-05-01

    Full Text Available Glucose is a major energy source and is a key regulator of metabolism but excessive dietary glucose is linked to several disorders including type 2 diabetes, obesity and cardiac dysfunction. Dietary intake greatly influences organismal survival but whether the effects of nutritional status are transmitted to the offspring is an unresolved question. Here we show that exposing Caenorhabditis elegans to high glucose concentrations in the parental generation leads to opposing negative effects on fecundity, while having protective effects against cellular stress in the descendent progeny. The transgenerational inheritance of glucose-mediated phenotypes is dependent on the insulin/IGF-like signalling pathway and components of the histone H3 lysine 4 trimethylase complex are essential for transmission of inherited phenotypes. Thus dietary over-consumption phenotypes are heritable with profound effects on the health and survival of descendants.

  17. Effect of microstructure on the sulphide stress cracking susceptibility of a high strength pipeline steel

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, E. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, 62209-Cuernavaca, Mor. (Mexico); Gonzalez-Rodriguez, J.G. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, 62209-Cuernavaca, Mor. (Mexico)], E-mail: ggonzalez@uaem.mx; Torres-Islas, A.; Serna, S. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, 62209-Cuernavaca, Mor. (Mexico); Campillo, B. [Intituto de Ciencias Fisicas-Facultad de Quimicas-Universidad Nacional Autonoma de Mexico Cuernavaca, Mor. (Mexico); Dominguez-Patino, G. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, 62209-Cuernavaca, Mor. (Mexico); Juarez-Islas, J.A. [Instituto de Investigaciones en Materiales-Universidad Nacional Autonoma de Mexico, Circuito Exterior S/N, Cd. Universitaria, C.P. 04510, Mexico, D.F. (Mexico)

    2008-12-15

    The sulphide stress cracking (SSC) susceptibility of a newly developed high strength microalloyed steel with three different microstructures has been evaluated using the slow strain rate testing (SSRT) technique. Studies were complemented with potentiodynamic polarization curves and hydrogen permeation measurements. Material included a C-Mn steel having Ni, Cu, and Mo as main microalloying elements with three microstructures: martensitic, ferritic and ferritic + bainitic. Testing temperatures included 25, 50, 70 and 90 deg. C. Detailed SEM observations of the microstructure and fracture surfaces were done to identify possible degradation mechanisms. The results showed that in all cases, the corrosion rate, number of hydrogen atoms at the surface and the percentage reduction in area increased with temperature. The steel with a martensitic microstructure had the highest SSC susceptibility at all temperatures, whereas the ferritic steels were susceptible only at 25 deg. C, and the most likely mechanism is hydrogen embrittlement assisted by anodic dissolution.

  18. Involvement of Potassium Transport Systems in the Response of Synechocystis PCC 6803 Cyanobacteria to External pH Change, High-Intensity Light Stress and Heavy Metal Stress.

    Science.gov (United States)

    Checchetto, Vanessa; Segalla, Anna; Sato, Yuki; Bergantino, Elisabetta; Szabo, Ildiko; Uozumi, Nobuyuki

    2016-04-01

    The unicellular photosynthetic cyanobacterium, able to survive in varying environments, is the only prokaryote that directly converts solar energy and CO2 into organic material and is thus relevant for primary production in many ecosystems. To maintain the intracellular and intrathylakoid ion homeostasis upon different environmental challenges, the concentration of potassium as a major intracellular cation has to be optimized by various K(+)uptake-mediated transport systems. We reveal here the specific and concerted physiological function of three K(+)transporters of the plasma and thylakoid membranes, namely of SynK (K(+)channel), KtrB (Ktr/Trk/HKT) and KdpA (Kdp) in Synechocystis sp. strain PCC 6803, under specific stress conditions. The behavior of the wild type, single, double and triple mutants was compared, revealing that only Synk contributes to heavy metal-induced stress, while only Ktr/Kdp is involved in osmotic and salt stress adaptation. With regards to pH shifts in the external medium, the Kdp/Ktr uptake systems play an important role in the adaptation to acidic pH. Ktr, by affecting the CO2 concentration mechanism via its action on the bicarbonate transporter SbtA, might also be responsible for the observed effects concerning high-light stress and calcification. In the case of illumination with high-intensity light, a synergistic action of Kdr/Ktp and SynK is required in order to avoid oxidative stress and ensure cell viability. In summary, this study dissects, using growth tests, measurement of photosynthetic activity and analysis of ultrastructure, the physiological role of three K(+)transporters in adaptation of the cyanobacteria to various environmental changes. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  19. Sense of coherence as a mediator of stress among high school students in Tromsø, Norway.

    OpenAIRE

    Mellem, Lise Sand

    2008-01-01

    School adaptation seems to have an impact on social, psychological, and behavioural outcomes. Empirical evidence on the stress moderating role of the sense of coherence (SOC), which implies to which degree one find life meaningful, comprehensible and manageable, may offer a scope for development of prevention policies. The aim of this study was to examine the relationship and interactions between high school students perceived stress (PSQ), sense of coherence (SOC-13), perceived health co...

  20. Detection of Free Polyamines in Plants Subjected to Abiotic Stresses by High-Performance Liquid Chromatography (HPLC).

    Science.gov (United States)

    Gong, Xiaoqing; Liu, Ji-Hong

    2017-01-01

    High-performance liquid chromatography (HPLC) is a sensitive, rapid, and accurate technique to detect and characterize various metabolites from plants. The metabolites are extracted with different solvents and eluted with appropriate mobile phases in a designed HPLC program. Polyamines are known to accumulate under abiotic stress conditions in various plant species and thought to provide protection against oxidative stress by scavenging reactive oxygen species. Here, we describe a common method to detect the free polyamines in plant tissues both qualitatively and quantitatively.

  1. Metabolic and oxidative stress markers in Wistar rats after 2?months on a high-fat diet

    OpenAIRE

    Auberval, Nathalie; Dal, St?phanie; Bietiger, William; Pinget, Michel; Jeandidier, Nathalie; Maillard-Pedracini, Elisa; Schini-Kerth, Val?rie; Sigrist, S?verine

    2014-01-01

    Background Metabolic syndrome is associated with an increased risk of cardiovascular and hepatic complications. Oxidative stress in metabolic tissues has emerged as a universal feature of metabolic syndrome and its co-morbidities. We aimed to develop a rapidly and easily induced model of metabolic syndrome in rats to evaluate its impact on plasma and tissue oxidative stress. Materials and methods Metabolic syndrome was induced in rats using a high-fat diet (HFD), and these rats were compared ...

  2. High-Fat Diet Induces Oxidative Stress and MPK2 and HSP83 Gene Expression in Drosophila melanogaster

    OpenAIRE

    Trindade de Paula, Mariane; Poetini Silva, M?rcia R?sula; Machado Araujo, St?fani; Cardoso Bortolotto, Vandreza; Barreto Meichtry, Luana; Zemolin, Ana Paula Pegoraro; Wallau, Gabriel L.; Jesse, Cristiano Ricardo; Franco, Jeferson Lu?s; Posser, Tha?s; Prigol, Marina

    2016-01-01

    The consumption of a high-fat diet (HFD) causes alteration in normal metabolism affecting lifespan of flies; however molecular mechanism associated with this damage in flies is not well known. This study evaluates the effects of ingestion of a diet supplemented with 10% and 20% of coconut oil, which is rich in saturated fatty acids, on oxidative stress and cells stress signaling pathways. After exposure to the diet for seven days, cellular and mitochondrial viability, lipid peroxidation and a...

  3. High doses of the histone deacetylase inhibitor sodium butyrate trigger a stress-like response.

    Science.gov (United States)

    Gagliano, Humberto; Delgado-Morales, Raul; Sanz-Garcia, Ancor; Armario, Antonio

    2014-04-01

    The hypothalamic-pituitary-adrenal (HPA) axis is activated by a wide range of stimuli, including drugs. Here we report that in male rats, a dose of sodium butyrate (NaBu) that is typically used to inhibit histone deacetylation (1200 mg/kg) increased the peripheral levels of HPA hormones and glucose. In a further experiment, we compared the effects of two different doses of NaBu (200 and 1200 mg/kg) and equimolar saline solutions on peripheral neuroendocrine markers and brain c-Fos expression to demonstrate a specific stress-like effect of NaBu that is not related to hypertonicity and to localise putatively involved brain areas. Only the high dose of NaBu increased the plasma levels of stress markers. The equimolar (hypertonic) saline solution also activated the HPA axis and the c-Fos expression in the paraventricular nucleus of the hypothalamus (PVN), a key area for the control of the HPA axis, but the effects were of a lower magnitude than those of NaBu. Regarding other brain areas, group differences in c-Fos expression were not observed in the medial prefrontal cortex or the medial amygdala, but they were observed in the central amygdala and the lateral ventral septum. However, only the latter area of the NaBu group showed enhanced c-Fos expression that was significantly higher than that after hypertonic saline. The present data indicate that high doses of NaBu appear to act as a pharmacological stressor, and this fact should be taken into account when using this drug to study the role of epigenetic processes in learning and emotional behaviour. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Remaining life diagnosis method and device for nuclear reactor

    International Nuclear Information System (INIS)

    Yamamoto, Michiyoshi.

    1996-01-01

    A neutron flux measuring means is inserted from the outside of a reactor pressure vessel during reactor operation to forecast neutron-degradation of materials of incore structural components in the vicinity of portions to be measured based on the measured values, and the remaining life of the reactor is diagnosed by the forecast degraded state. In this case, the neutron fluxes to be measured are desirably fast and/or medium neutron fluxes. As the positions where the measuring means is to be inserted, for example, the vicinity of the structural components at the periphery of the fuel assembly is selected. Aging degradation characteristics of the structural components are determined by using the aging degradation data for the structural materials. The remaining life is analyzed based on obtained aging degradation characteristics and stress evaluation data of the incore structural components at portions to be measured. Neutron irradiation amount of structural components at predetermined positions can be recognized accurately, and appropriate countermeasures can be taken depending on the forecast remaining life thereby enabling to improve the reliability of the reactor. (N.H.)

  5. Prenatal stress increases the obesogenic effects of a high-fat-sucrose diet in adult rats in a sex-specific manner.

    Science.gov (United States)

    Paternain, L; de la Garza, A L; Batlle, M A; Milagro, F I; Martínez, J A; Campión, J

    2013-03-01

    Stress during pregnancy can induce metabolic disorders in adult offspring. To analyze the possible differential response to a high-fat-sucrose (HFS) diet in offspring affected by prenatal stress (PNS) or not, pregnant Wistar rats (n = 11) were exposed to a chronic mild stress during the third week of gestation. The aim of this study was to model a chronic depressive-like state that develops over time in response to exposure of rats to a series of mild and unpredictable stressors. Control dams (n = 11) remained undisturbed. Adult offspring were fed chow or HFS diet (20% protein, 35% carbohydrate, 45% fat) for 10 weeks. Changes in adiposity, biochemical profile, and retroperitoneal adipose tissue gene expression by real-time polymerase chain reaction were analyzed. An interaction was observed between HFS and PNS concerning visceral adiposity, with higher fat mass in HFS-fed stressed rats, statistically significant only in females. HFS modified lipid profile and increased insulin resistance biomarkers, while PNS reduced insulin concentrations and the homeostasis model assessment index. HFS diet increased gene (mRNA) expression for leptin and apelin and decreased cyclin-dependent kinase inhibitor 1A and fatty acid synthase (Fasn), whereas PNS increased Fasn and stearoyl-CoA desaturase1. An interaction between diet and PNS was observed for adiponutrin (Adpn) and peroxisome proliferator-activated receptor-γ coactivator1-α (Ppargc1a) gene expression: Adpn was increased by the PNS only in HFS-fed rats, whereas Ppargc1a was increased by the PNS only in chow-fed rats. From these results, it can be concluded that experience of maternal stress during intrauterine development can enhance predisposition to obesity induced by a HFS diet intake.

  6. High School Dropout in Proximal Context: The Triggering Role of Stressful Life Events.

    Science.gov (United States)

    Dupéré, Véronique; Dion, Eric; Leventhal, Tama; Archambault, Isabelle; Crosnoe, Robert; Janosz, Michel

    2018-03-01

    Adolescents who drop out of high school experience enduring negative consequences across many domains. Yet, the circumstances triggering their departure are poorly understood. This study examined the precipitating role of recent psychosocial stressors by comparing three groups of Canadian high school students (52% boys; M age  = 16.3 years; N = 545): recent dropouts, matched at-risk students who remain in school, and average students. Results indicate that in comparison with the two other groups, dropouts were over three times more likely to have experienced recent acute stressors rated as severe by independent coders. These stressors occurred across a variety of domains. Considering the circumstances in which youth decide to drop out has implications for future research and for policy and practice. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

  7. High-throughput characterization of stresses in thin film materials libraries using Si cantilever array wafers and digital holographic microscopy.

    Science.gov (United States)

    Lai, Y W; Hamann, S; Ehmann, M; Ludwig, A

    2011-06-01

    We report the development of an advanced high-throughput stress characterization method for thin film materials libraries sputter-deposited on micro-machined cantilever arrays consisting of around 1500 cantilevers on 4-inch silicon-on-insulator wafers. A low-cost custom-designed digital holographic microscope (DHM) is employed to simultaneously monitor the thin film thickness, the surface topography and the curvature of each of the cantilevers before and after deposition. The variation in stress state across the thin film materials library is then calculated by Stoney's equation based on the obtained radii of curvature of the cantilevers and film thicknesses. DHM with nanometer-scale out-of-plane resolution allows stress measurements in a wide range, at least from several MPa to several GPa. By using an automatic x-y translation stage, the local stresses within a 4-inch materials library are mapped with high accuracy within 10 min. The speed of measurement is greatly improved compared with the prior laser scanning approach that needs more than an hour of measuring time. A high-throughput stress measurement of an as-deposited Fe-Pd-W materials library was evaluated for demonstration. The fast characterization method is expected to accelerate the development of (functional) thin films, e.g., (magnetic) shape memory materials, whose functionality is greatly stress dependent. © 2011 American Institute of Physics

  8. Behavior of surface residual stress in explosion hardened high manganese austenitic cast steel due to repeated impact loads

    International Nuclear Information System (INIS)

    Oda, Akira; Miyagawa, Hideaki

    1985-01-01

    Explosion hardened high manganese austenitic cast steel is being tried for rail crossing recently. From the previous studies, it became clear that high tensile residual stress was generated in the hardened surface layer by explosion and microcracks were observed. In this study, therefore, the behavior of surface residual stress in explosion hardened steel due to repeated impact loads was examined and compared with those of the original and shot peened steels. The results obtained are summarized as follows: (1) In the initial stage of the repetition of impact, high tensile surface residual stress in explosion hardened steel decreased rapidly with the repetition of impact, while those of the original and shot peened steels increased rapidly. This difference was attributed to the difference in depth of the work hardened layer in three testing materials. (2) Beyond 20 impacts the residual stress of three test specimens decreased gradually, and at more than 2000 impacts the compressive stress of about 500 MPa was produced regardless of the histories of working of testing materials. (3) The linear law in the second stage of residual stress fading was applicable to this case, and the range of the linear relationship was related to the depth of the work hardened layer of testing material. (4) From the changes in half-value breadth and peak intensity of diffraction X-ray, it was supposed that a peculiar microscopic strain exists in explosion hardened steel. (author)

  9. High-throughput characterization of stresses in thin film materials libraries using Si cantilever array wafers and digital holographic microscopy

    International Nuclear Information System (INIS)

    Lai, Y. W.; Ludwig, A.; Hamann, S.; Ehmann, M.

    2011-01-01

    We report the development of an advanced high-throughput stress characterization method for thin film materials libraries sputter-deposited on micro-machined cantilever arrays consisting of around 1500 cantilevers on 4-inch silicon-on-insulator wafers. A low-cost custom-designed digital holographic microscope (DHM) is employed to simultaneously monitor the thin film thickness, the surface topography and the curvature of each of the cantilevers before and after deposition. The variation in stress state across the thin film materials library is then calculated by Stoney's equation based on the obtained radii of curvature of the cantilevers and film thicknesses. DHM with nanometer-scale out-of-plane resolution allows stress measurements in a wide range, at least from several MPa to several GPa. By using an automatic x-y translation stage, the local stresses within a 4-inch materials library are mapped with high accuracy within 10 min. The speed of measurement is greatly improved compared with the prior laser scanning approach that needs more than an hour of measuring time. A high-throughput stress measurement of an as-deposited Fe-Pd-W materials library was evaluated for demonstration. The fast characterization method is expected to accelerate the development of (functional) thin films, e.g., (magnetic) shape memory materials, whose functionality is greatly stress dependent.

  10. Cortical surface area reduction in identification of subjects at high risk for post-traumatic stress disorder: A pilot study.

    Science.gov (United States)

    Hu, Hao; Sun, Yawen; Su, Shanshan; Wang, Yao; Qiu, Yongming; Yang, Xi; Zhou, Yan; Xiao, Zeping; Wang, Zhen

    2018-01-01

    Victims of motor vehicle accidents often develop post-traumatic stress disorder, which causes significant social function loss. For the difficulty in treating post-traumatic stress disorder, identification of subjects at high risk for post-traumatic stress disorder is essential for providing possible intervention. This paper aims to examine the cortical structural traits related to susceptibility to post-traumatic stress disorder. To address this issue, we performed structural magnetic resonance imaging study in motor vehicle accident victims within 48 hours from the accidents. A total of 70 victims, available for both clinical and magnetic resonance imaging data, enrolled in our study. Upon completion of 6-month follow-up, 29 of them developed post-traumatic stress disorder, while 41 of them didn't. At baseline, voxelwise comparisons of cortical thickness, cortical area and cortical volume were conducted between post-traumatic stress disorder group and trauma control group. As expected, several reduced cortical volume within frontal-temporal loop were observed in post-traumatic stress disorder. For cortical thickness, no between-group differences were observed. There were three clusters in left hemisphere and one cluster in right hemisphere showing decreased cortical area in post-traumatic stress disorder patients, compared with trauma controls. Peak voxels of the three clusters in left hemisphere were separately located in superior parietal cortex, insula and rostral anterior cingulate cortex. The finding of reduced surface area of left insula and left rostral anterior cingulate cortex suggests that shrinked surface area in motor vehicle accident victims could act as potential biomarker of subjects at high risk for post-traumatic stress disorder.

  11. Peeling stress analysis for an inhomogeneous high-Tc superconductor with a discontinuous interface at the substrate

    International Nuclear Information System (INIS)

    Gao Zhiwen; Lee, Kang Yong; Zhou Youhe

    2011-01-01

    Research highlights: → The thermal stress generated in the inhomogeneous HTS is larger on a SiTiO 3 substrate than on a MgO substrate. → The maximum thermal stresses, i.e., the peeling stresses, occur near the bottom corner of the inhomogeneous HTS and may induce fracture behavior at the bi-material interface. → The inhomogeneous HTS cools at a slower pace than the homogeneous HTS from the room temperature to the operating temperature. → The magnitude of the peeling stress for a homogeneous HTS is larger than that for an inhomogeneous HTS. - Abstract: This paper presents an analysis of a superconductor-substrate system to calculate the peeling stress of a high temperature superconductor (HTS) when the temperature decreases from ambient to operating conditions (cryogenic temperatures). Firstly, the values for the material properties of the inhomogeneous high temperature superconductor (HTS) were obtained by fitting a second order polynomial to the experimental data. It is assumed that the material properties of the inhomogeneous HTS vary with varying height coordinate and temperature. Then, through the proposed graded finite element method, the coupled thermo-mechanical equations were solved numerically. The numerical results show that the thermal stress generated in the inhomogeneous HTS is larger on a SiTiO 3 substrate than on a MgO substrate. The maximum thermal stresses, i.e., the peeling stresses, occur near the bottom corner of the inhomogeneous HTS and may induce fracture behavior at the bi-material interface. The inhomogeneous HTS cools at a slower pace than the homogeneous HTS from the room temperature to the operating temperature. It is also shown that the magnitude of the peeling stress for a homogeneous HTS is larger than that for an inhomogeneous HTS. It is intended that the model presented here be useful to researchers who are interested in the mechanical properties of an inhomogeneous HTS.

  12. Sequestration of highly expressed mRNAs in cytoplasmic granules, P-bodies, and stress granules enhances cell viability.

    Directory of Open Access Journals (Sweden)

    Anna Lavut

    Full Text Available Transcriptome analyses indicate that a core 10%-15% of the yeast genome is modulated by a variety of different stresses. However, not all the induced genes undergo translation, and null mutants of many induced genes do not show elevated sensitivity to the particular stress. Elucidation of the RNA lifecycle reveals accumulation of non-translating mRNAs in cytoplasmic granules, P-bodies, and stress granules for future regulation. P-bodies contain enzymes for mRNA degradation; under stress conditions mRNAs may be transferred to stress granules for storage and return to translation. Protein degradation by the ubiquitin-proteasome system is elevated by stress; and here we analyzed the steady state levels, decay, and subcellular localization of the mRNA of the gene encoding the F-box protein, UFO1, that is induced by stress. Using the MS2L mRNA reporter system UFO1 mRNA was observed in granules that colocalized with P-bodies and stress granules. These P-bodies stored diverse mRNAs. Granules of two mRNAs transported prior to translation, ASH1-MS2L and OXA1-MS2L, docked with P-bodies. HSP12 mRNA that gave rise to highly elevated protein levels was not observed in granules under these stress conditions. ecd3, pat1 double mutants that are defective in P-body formation were sensitive to mRNAs expressed ectopically from strong promoters. These highly expressed mRNAs showed elevated translation compared with wild-type cells, and the viability of the mutants was strongly reduced. ecd3, pat1 mutants also exhibited increased sensitivity to different stresses. Our interpretation is that sequestration of highly expressed mRNAs in P-bodies is essential for viability. Storage of mRNAs for future regulation may contribute to the discrepancy between the steady state levels of many stress-induced mRNAs and their proteins. Sorting of mRNAs for future translation or decay by individual cells could generate potentially different phenotypes in a genetically identical

  13. High glucose, glucose fluctuation and carbonyl stress enhance brain microvascular endothelial barrier dysfunction: Implications for diabetic cerebral microvasculature.

    Science.gov (United States)

    Li, Wei; Maloney, Ronald E; Aw, Tak Yee

    2015-08-01

    We previously demonstrated that in normal glucose (5mM), methylglyoxal (MG, a model of carbonyl stress) induced brain microvascular endothelial cell (IHEC) dysfunction that was associated with occludin glycation and prevented by N-acetylcysteine (NAC). Herein, we investigated the impact of high glucose and low GSH, conditions that mimicked the diabetic state, on MG-induced IHEC dysfunction. MG-induced loss of transendothelial electrical resistance (TEER) was potentiated in IHECs cultured for 7 or 12 days in 25 mM glucose (hyperglycemia); moreover, barrier function remained disrupted 6h after cell transfer to normal glucose media (acute glycemic fluctuation). Notably, basal occludin glycation was elevated under these glycemic states. TEER loss was exaggerated by inhibition of glutathione (GSH) synthesis and abrogated by NAC, which corresponded to GSH decreases and increases, respectively. Significantly, glyoxalase II activity was attenuated in hyperglycemic cells. Moreover, hyperglycemia and GSH inhibition increased MG accumulation, consistent with a compromised capacity for MG elimination. α-Oxoaldehydes (MG plus glyoxal) levels were elevated in streptozotocin-induced diabetic rat plasma. Immunohistochemistry revealed a prevalence of MG-positive, but fewer occludin-positive microvessels in the diabetic brain in vivo, and Western analysis confirmed an increase in MG-occludin adducts. These results provide the first evidence that hyperglycemia and acute glucose fluctuation promote MG-occludin formation and exacerbate brain microvascular endothelial dysfunction. Low occludin expression and high glycated-occludin contents in diabetic brain in vivo are factors that would contribute to the dysfunction of the cerebral microvasculature during diabetes. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  14. High glucose, glucose fluctuation and carbonyl stress enhance brain microvascular endothelial barrier dysfunction: Implications for diabetic cerebral microvasculature

    Directory of Open Access Journals (Sweden)

    Wei Li

    2015-08-01

    Full Text Available We previously demonstrated that in normal glucose (5 mM, methylglyoxal (MG, a model of carbonyl stress induced brain microvascular endothelial cell (IHEC dysfunction that was associated with occludin glycation and prevented by N-acetylcysteine (NAC. Herein, we investigated the impact of high glucose and low GSH, conditions that mimicked the diabetic state, on MG-induced IHEC dysfunction. MG-induced loss of transendothelial electrical resistance (TEER was potentiated in IHECs cultured for 7 or 12 days in 25 mM glucose (hyperglycemia; moreover, barrier function remained disrupted 6 h after cell transfer to normal glucose media (acute glycemic fluctuation. Notably, basal occludin glycation was elevated under these glycemic states. TEER loss was exaggerated by inhibition of glutathione (GSH synthesis and abrogated by NAC, which corresponded to GSH decreases and increases, respectively. Significantly, glyoxalase II activity was attenuated in hyperglycemic cells. Moreover, hyperglycemia and GSH inhibition increased MG accumulation, consistent with a compromised capacity for MG elimination. α-Oxoaldehydes (MG plus glyoxal levels were elevated in streptozotocin-induced diabetic rat plasma. Immunohistochemistry revealed a prevalence of MG-positive, but fewer occludin-positive microvessels in the diabetic brain in vivo, and Western analysis confirmed an increase in MG–occludin adducts. These results provide the first evidence that hyperglycemia and acute glucose fluctuation promote MG–occludin formation and exacerbate brain microvascular endothelial dysfunction. Low occludin expression and high glycated-occludin contents in diabetic brain in vivo are factors that would contribute to the dysfunction of the cerebral microvasculature during diabetes.

  15. Melatonin treatment at dry-off improves reproductive performance postpartum in high-producing dairy cows under heat stress conditions.

    Science.gov (United States)

    Garcia-Ispierto, I; Abdelfatah, A; López-Gatius, F

    2013-08-01

    The aim of this study was to determine the effect of melatonin treatment during the early dry-off period on subsequent reproductive performance and milk production in high-producing dairy cows under heat stress conditions. In experiment I, addressing the pharmacokinetics of melatonin treatment in lactating dairy cows, doses of untreated, 3, 6, 9 or 12 implants/animal (18-mg melatonin each implant) were given as subcutaneous implants on gestation day 120-20 multiparous lactating dairy cows (four cows/dose group). Experiment II was performed during the warm season on 25 heifers and 114 high milk-producing Holstein-Friesian cows. Animals were randomly assigned to a control (C) or melatonin group (M). Animals in the M group received nine implants (heifers) or 12 (cows) of melatonin on day 220 of gestation. In experiment I, cows in the 12 implants group showed a higher maximum melatonin concentration (Cmax ) and area under the concentration curve from treatment day 0 to day 49 (AUC0-49d ) than those in the remaining groups, among which there were no significant differences in this variable. In experiment II, the likelihood of repeat breeding syndrome (pregnancy loss (first trimester) were 0.36 and 0.19 times lower in treated than control animals, respectively. Plasma prolactin levels decreased significantly (p = 0.01) after melatonin treatment and recovered during the postpartum compared to control cows. No significant effects on milk production were observed in the subsequent lactation. Significant differences in days open between groups (means 123 ± 71.9 and 103 ± 43, respectively, for C and M; p = 0.02) were registered. In conclusion, melatonin treatment in the early dry-off period improves the reproductive performance of dairy cattle, reducing the number of days open, repeat breeding syndrome and pregnancy loss. © 2012 Blackwell Verlag GmbH.

  16. Exercise training alters effect of high-fat feeding on the ACTH stress response in pigs.

    Science.gov (United States)

    Jankord, Ryan; Ganjam, Venkataseshu K; Turk, James R; Hamilton, Marc T; Laughlin, M Harold

    2008-06-01

    Eating and physical activity behaviors influence neuroendocrine output. The purpose of this study was to test, in an animal model of diet-induced cardiovascular disease, the effects of high-fat feeding and exercise training on hypothalamo-pituitary-adrenocortical (HPA) axis activity. We hypothesized that a high-fat diet would increase circulating free fatty acids (FFAs) and decrease the adrenocorticotropic hormone (ACTH) and cortisol response to an acute stressor. We also hypothesized that exercise training would reverse the high-fat diet-induced changes in FFAs and thereby restore the ACTH and cortisol response. Pigs were placed in 1 of 4 groups (normal diet, sedentary; normal diet, exercise training; high-fat diet, sedentary; high-fat diet, exercise training; n = 8/group). Animals were placed on their respective dietary and activity treatments for 16-20 weeks. After completion of the treatments animals were anesthetized and underwent surgical intubation. Blood samples were collected after surgery and the ACTH and cortisol response to surgery was determined and the circulating concentrations of FFAs, glucose, cholesterol, insulin, and IGF-1 were measured. Consistent with our hypothesis, high-fat feeding increased FFAs by 200% and decreased the ACTH stress response by 40%. In exercise-trained animals, the high-fat diet also increased FFA; however, the increase in FFA in exercise-trained pigs was accompanied by a 60% increase in the ACTH response. The divergent effect of high-fat feeding on ACTH response was not expected, as exercise training alone had no effect on the ACTH response. Results demonstrate a significant interaction between diet and exercise and their effect on the ACTH response. The divergent effects of high-fat diet could not be explained by changes in weight gain, blood glucose, insulin, or IGF-1, as these were altered by high-fat feeding, but unaffected by exercise training. Thus, the increase in FFA with high-fat feeding may explain the blunted

  17. Effects of a high mean stress on the high cycle fatigue life of PWA 1480 and correlation of data by linear elastic fracture mechanics

    Science.gov (United States)

    Majumdar, S.; Kwasny, R.

    1985-01-01

    High-cycle fatigue tests using 5-mm-diameter smooth specimens were performed on the single crystal alloy PWA 1480 (001 axis) at 70F (room temperature) in air and at 100F (538C) in vacuum (10 to the -6 power torr). Tests were conducted at zero mean stress as well as at high tensile mean stress. The results indicate that, although a tensile mean stress, in general, reduces life, the reduction in fatigue strength, for a given mean stress at a life of one million cycles, is much less than what is predicted by the usual linear Goodman plot. Further, the material appears to be significantly more resistant to mean stress effects at 1000F than at 70F. Metallographic examinations of failed specimens indicate that failures in all cases are initiated from micropores of sizes of the order of 30 to 40 microns. Since the macroscopic stress-strain response in all cases was observed to be linear elastic, linear elastic fracture mechanics (LEFM) analyses were carried out to determine the crack growth curves of the material assuming that crack initiation from a micropore (a sub o = 40 microns) occurs very early in life. The results indicate that the calculated crack growth rates at an R (defined as the ratio between minimum stress to maximum stress) value of zero are approximately the same at 70F as at 1000F. However, the calculated crack growth rates at other R ratios, both positive and negative, tend to be higher at 70F than at 1000F. Calculated threshold effects at large R values tend to be independent of temperature in the temperature regime studied. They are relatively constant with increasing R ratio up to a value of about 0.6, beyond which the calculated threshold stress intensity factor range decreases rapidly with increasing R ratios.

  18. Chronic stress exposure may affect the brain's response to high calorie food cues and predispose to obesogenic eating habits.

    Science.gov (United States)

    Tryon, Matthew S; Carter, Cameron S; Decant, Rashel; Laugero, Kevin D

    2013-08-15

    Exaggerated reactivity to food cues involving calorically-dense foods may significantly contribute to food consumption beyond caloric need. Chronic stress, which can induce palatable "comfort" food consumption, may trigger or reinforce neural pathways leading to stronger reactions to highly rewarding foods. We implemented functional magnetic resonance imaging (fMRI) to assess whether chronic stress influences activation in reward, motivation and executive brain regions in response to pictures of high calorie and low calorie foods in thirty women. On separate lab visits, we also assessed food intake from a snack food buffet and circulating cortisol. In women reporting higher chronic stress (HCS), pictures of high calorie foods elicited exaggerated activity in regions of the brain involving reward, motivation, and habitual decision-making. In response to pictures of high calorie food, higher chronic stress was also associated with significant deactivation in frontal regions (BA10; BA46) linked to strategic planning and emotional control. In functional connectivity analysis, HCS strengthened connectivity between amygdala and the putamen, while LCS enhanced connectivity between amygdala and the anterior cingulate and anterior prefrontal cortex (BA10). A hypocortisolemic signature and more consumption of high calorie foods from the snack buffet were observed in the HCS group. These results suggest that persistent stress exposure may alter the brain's response to food in ways that predispose individuals to poor eating habits which, if sustained, may increase risk for obesity. © 2013.

  19. Effect of Short-Term High Fat Diet Inducing Obesity on Hematological, Some Biochemical Parameters and Testicular Oxidative Stress in Male Rats

    Directory of Open Access Journals (Sweden)

    Sherif M. Shawky

    2015-10-01

    Full Text Available Obesity constitutes a health problem due to its increasing worldwide prevalence. Among the health detriments caused by obesity, reproduction is disrupted. Some studies have shown a relationship between obesity and infertility, but until now it remains controversial. The objective of the current work was to examine the effect of diet-induced obesity on blood parameters, liver and kidney function tests, lipid profile and testicular oxidative stress. For that purpose, Male rats were fed ad libitum with a standard diet (control group; n.= 15 and high fat diet (HFD group; n.= 15 for 6 weeks. Hematological parameters, urea, creatinine, albumin were similar between the two groups. Intergroup testosterone levels were also comparable. The high fat diet induced significant increase in serum triglycerides, cholesterol, low density lipoprotein and very low density lipoprotein cholesterol concentrations. This diet also increases significantly alanine aminotransferase and aspartate aminotransferase activities and decreased total protein level and high-density lipoprotein cholesterol concentration. Furthermore, HFD showed a significant increasing in malondialdehyde contents in testes and decreasing in superoxide dismutase activity, the results of this study concluded that short-term high fat diet affect on liver enzymes and causing oxidative stress in testes.

  20. Can high social capital at the workplace buffer against stress and musculoskeletal pain?: Cross-sectional study.

    Science.gov (United States)

    Jay, Kenneth; Andersen, Lars L

    2018-03-01

    Work-related musculoskeletal pain and stress are both highly prevalent in the working environment and relate well to the biopsychosocial model. While the onset of musculoskeletal pain is often dependent on the biological element of the biopsychosocial model, chronic pain is often influenced by psychological and social factors. Similarly, stress is also influenced by biological, psychological, and social factors. This study investigates the possibility of social capital being a buffer for stress and musculoskeletal pain in a group of female laboratory technicians.Female laboratory technicians (n = 500) replied to questions about stress (Cohens Perceived Stress Scale-10), musculoskeletal pain (0-10 visual analog scale), and social capital at the workplace (bonding [in teams], bridging [between teams], and linking [between teams and leaders]). Outcome variables were stress and musculoskeletal pain and the predictor variable was social capital. General linear models tested the association of the 3 types of social capital (predictor variables) with stress and pain (mutually adjusted outcome variables). Analyses were controlled for age, lifestyle (body mass index, smoking), seniority, and working hours per week.For stress as outcome, moderate and high bonding social capital were different from low social capital with -2.04 (95% confidence interval [CI] -3.33 to -0.76) and -4.56 (95% CI -5.84 to -3.28) points on the Perceived Stress Scale of 0 to 42, respectively. Similarly, moderate and high bridging social capital were different from low social capital with -1.50 (95% CI -2.76 to -0.24) and -4.39 (95% CI -5.75 to -3.03), respectively. For linking, only high social was significantly different from low with -2.94 (95% CI -4.28 to -1.60). None of the 3 types of social capital was associated with musculoskeletal pain.Higher levels of social capital at the workplace appear to buffer against stress, but not against musculoskeletal pain. Intervention studies should

  1. The Arabidopsis transcription factor ANAC032 represses anthocyanin biosynthesis in response to high sucrose and oxidative and abiotic stresses

    Directory of Open Access Journals (Sweden)

    Kashif Mahmood

    2016-10-01

    Full Text Available Production of anthocyanins is one of the adaptive responses employed by plants during stress conditions. During stress, anthocyanin biosynthesis is mainly regulated at the transcriptional level via a complex interplay between activators and repressors of anthocyanin biosynthesis genes. In this study, we investigated the role of a NAC transcription factor, ANAC032, in the regulation of anthocyanin biosynthesis during stress conditions. ANAC032 expression was found to be induced by exogenous sucrose as well as high light stress. Using biochemical, molecular and transgenic approaches, we show that ANAC032 represses anthocyanin biosynthesis in response to sucrose treatment, high light and oxidative stress. ANAC032 was found to negatively affect anthocyanin accumulation and the expression of anthocyanin biosynthesis (DFR, ANS/LDOX and positive regulatory (TT8 genes as demonstrated in overexpression line (35S:ANAC032 compared to wild-type under high light stress. The chimeric repressor line (35S:ANAC032-SRDX exhibited the opposite expression patterns for these genes. The negative impact of ANAC032 on the expression of DFR, ANS/LDOX and TT8 was found to be correlated with the altered expression of negative regulators of anthocyanin biosynthesis, AtMYBL2 and SPL9. In addition to this, ANAC032 also repressed the MeJA- and ABA-induced anthocyanin biosynthesis. As a result, transgenic lines overexpressing ANAC032 (35S:ANAC032 produced drastically reduced levels of anthocyanin pigment compared to wild-type when challenged with salinity stress. However, transgenic chimeric repressor lines (35S:ANAC032-SRDX exhibited the opposite phenotype. Our results suggest that ANAC032 functions as a negative regulator of anthocyanin biosynthesis in Arabidopsis thaliana during stress conditions.

  2. Proband Mental Health Difficulties and Parental Stress Predict Mental Health in Toddlers at High-Risk for Autism Spectrum Disorders

    Science.gov (United States)

    Crea, Katherine; Dissanayake, Cheryl; Hudry, Kristelle

    2016-01-01

    Family-related predictors of mental health problems were investigated among 30 toddlers at familial high-risk for autism spectrum disorders (ASD) and 28 controls followed from age 2- to 3-years. Parents completed the self-report Depression Anxiety Stress Scales and the parent-report Behavior Assessment System for Children. High-risk toddlers were…

  3. Failure mechanism of coated biomaterials under high impact-sliding contact stresses

    Science.gov (United States)

    Chen, Ying

    This study uses a newly developed testing method--- inclined cyclic impact-sliding test to investigate the failure behaviors of different types of biomaterials, (SS316L, Ti6Al4V and CoCr) coated by different coatings (TiN, DLC and PEO), under extremely high dynamic contact stress conditions. This test method can simulate the combined impact and sliding/rolling loading conditions, which is very practical in many aspects of commercial usages. During the tests, fatigue cracking, chipping, peeling and material transferring were observed in damaged area. This research is mainly focused on the failure behaviors of load-bearing materials which cyclic impacting and sliding are always involved. This purpose was accomplished in the three stages: First, impact-sliding test was carried out on TiN coated unhardened M2. It was found that soft substrate can cause early failure of coating due to the considerable plastic deformation in the substrate. In this case, stronger substrate is required to support coating better when tested under high contact stresses. Second, PEO coated Ti-6Al-4V was tested under pure sliding and impact-sliding wear conditions. PEO coating was found not strong enough to afford the high contact pressure under cyclic impact-sliding wear test due to its porous surface structure. However, the wear performance of PEO coating was enhanced due to the sub-stoichiometric oxide. To sum up, for load-bearing biomedical implants involved in high impacting movement, PEO coating may not be a promising surface protection. Third, the dense, smooth PVD/CVD bio-inert coatings were reconsidered. DLC and TiN coatings, combined by different substrates together with different interface materials were tested under the cyclic impact-sliding test using a set of proper loading. The results show that to choose a proper combination of coating, interface and substrate based on their mechanical properties is of great importance under the test condition. Hard substrates provide support

  4. 28-homobrassinolide Protects Photosynthetic Machinery in Indian mustard Under High Temperature Stress

    Directory of Open Access Journals (Sweden)

    Qazi Fariduddin

    2014-03-01

    Full Text Available High temperature is a serious threat to crop production. Brassinosteroids (BRs, a group of plant steroidal hormones, can reduce effects of abiotic stresses. The present study was aimed to study the potency of brassinosteroids on high temperature induced changes in Indian mustard (Brassica juncea L. for effects on growth, chlorophyll, photosynthesis, photosystem II, antioxidant system and proline. Surface sterilized seeds of Indian mustard were sown in pots, grown for 21 days and treated with double distilled water or 0.01 µM of 28-homobrassinolide. Treated plants, after 24 h, were exposed to 30°C or 40°C for 48 h. One set of plants were kept at ambient temperature, 25°C, as the control. Plants were harvested at 30 days stage of growth to assess the various parameters. Plants exposed to 40°C had a decline in growth, leaf water potential, chlorophyll, photosynthetic rate, and activities of carbonic anhydrase (E.C.4.2.1.1 and nitrate reductase (E.C.1.6.1.1. The 28-homobrassinolide alone improved growth and photosynthesis responses along with various enzymes activities. Treatment of plants with HBL prior to exposure to 40°C, partially reduced damage and completely controlled damage when exposure was to 30°C. Levels of the antioxidative enzymes catalase (E.C.1.11.1.6, peroxidase (E.C.1.11.1.7, and superoxide dismutase (E.C.1.15.1.1, and the level of proline increased in response to 30 or 40°C and were further enhanced in the presence of 28-homobrassinolide. Plants grown under high temperature had increased levels of H2O2; application of HBL before temperature treatment decreased H2O2 content compared to the control. Elevated levels of antioxidative enzymes and proline might be responsible for conferring tolerance to high temperature stress in Indian mustard and overcome the loss of productivity of the crop.

  5. Fate of nuclear waste site remains unclear

    International Nuclear Information System (INIS)

    Anderson, E.V.

    1980-01-01

    The only commercial nuclear fuel reprocessing plant in the U.S., located in West Valley, N.Y., has been shut down since 1972, and no efforts have yet been made to clean up the site. The site contains a spent-fuel pool, high level liquid waste storage tanks, and two radioactive waste burial grounds. Nuclear Fuel Services, Inc., has been leasing the site from the New York State Energy RandD Authority. Federal litigation may ensue, prompted by NRC and DOE, if the company refuses to decontaminate the area when its lease expires at the end of 1980. DOE has developed a plan to solidify the liquid wastes at the facility but needs additional legislation and funding to implement the scheme

  6. Human bovine tuberculosis - remains in the differential.

    LENUS (Irish Health Repository)

    Bilal, Shaukat

    2010-11-01

    Mycobacterium bovis is a pathogen of cattle. The unpasteurized milk of affected cattle is a source of infection in humans. Despite the screening of cattle and the pasteurization of milk, M bovis has not been eradicated. A high index of clinical suspicion is needed in symptomatic patients with a history of possible exposure. At risk groups include animal workers, farmers, meat packers, vets and zoo keepers. Humans are usually infected by the aerosol route. We present two cases of human bovine tuberculosis. One was a presumptive case and the second was a confirmed case. Both responded well to antituberculous therapy. In the confirmed case, there was evidence of transmission to the partner living in the same house. Rifampicin prophylaxis was given to the exposed case. The M. bovis from the confirmed case was isoniazid resistant, in addition to having the well known resistance to pyrazinamide. Isoniazid resistance has been described before in those who are immunocompromised. We describe it in an immunocompetent patient.

  7. Using the quantum yields of photosystem II and the rate of net photosynthesis to moniter high irradiance and temperature stress in chrysanthemum (Dendrantherma grandiflora)

    DEFF Research Database (Denmark)

    Janka, Eshetu; Körner, Oliver; Rosenqvist, Eva

    2015-01-01

    and quantum yield of PSII remaining low until the temperature reaches 28 °C and 2) the integration of online measurements to monitor photosynthesis and PSII operating efficiency may be used to optimise dynamic greenhouse control regimes by detecting plant stress caused by extreme microclimatic conditions.......Under a dynamic greenhouse climate control regime, temperature is adjusted to optimise plant physiological responses to prevailing irradiance levels; thus, both temperature and irradiance are used by the plant to maximise the rate of photosynthesis, assuming other factors are not limiting...... irradiance, the maximum Pn and ETR were reached at 24 °C. Increased irradiance decreased the PSII operating efficiency and increased NPQ, while both high irradiance and temperature had a significant effect on the PSII operating efficiency at temperatures >28 °C. Under high irradiance and temperature, changes...

  8. Maternal high-fat diet induces metabolic stress response disorders in offspring hypothalamus.

    Science.gov (United States)

    Nguyen, Long The; Saad, Sonia; Tan, Yi; Pollock, Carol; Chen, Hui

    2017-07-01

    Maternal obesity has been shown to increase the risk of obesity and related disorders in the offspring, which has been partially attributed to changes of appetite regulators in the offspring hypothalamus. On the other hand, endoplasmic reticulum (ER) stress and autophagy have been implicated in hypothalamic neuropeptide dysregulation, thus may also play important roles in such transgenerational effect. In this study, we show that offspring born to high-fat diet-fed dams showed significantly increased body weight and glucose intolerance, adiposity and plasma triglyceride level at weaning. Hypothalamic mRNA level of the orexigenic neuropeptide Y (NPY) was increased, while the levels of the anorexigenic pro-opiomelanocortin (POMC), NPY1 receptor (NPY1R) and melanocortin-4 receptor (MC4R) were significantly downregulated. In association, the expression of unfolded protein response (UPR) markers including glucose-regulated protein (GRP)94 and endoplasmic reticulum DNA J domain-containing protein (Erdj)4 was reduced. By contrast, protein levels of autophagy-related genes Atg5 and Atg7, as well as mitophagy marker Parkin, were slightly increased. The administration of 4-phenyl butyrate (PBA), a chemical chaperone of protein folding and UPR activator, in the offspring from postnatal day 4 significantly reduced their body weight, fat deposition, which were in association with increased activating transcription factor (ATF)4, immunoglobulin-binding protein (BiP) and Erdj4 mRNA as well as reduced Parkin, PTEN-induced putative kinase (PINK)1 and dynamin-related protein (Drp)1 protein expression levels. These results suggest that hypothalamic ER stress and mitophagy are among the regulatory factors of offspring metabolic changes due to maternal obesity. © 2017 Society for Endocrinology.

  9. High altitude induced anorexia: effect of changes in leptin and oxidative stress levels.

    Science.gov (United States)

    Vats, Praveen; Singh, Vijay Kumar; Singh, Som Nath; Singh, Shashi Bala

    2007-01-01

    High altitude (HA) exposure usually leads to a significant weight loss in non-acclimatized humans. Anorexia is believed to be the main cause of this body weight loss. Appetite regulatory peptides, i.e. leptin and neuropeptide Y play a key role in food intake and energy homeostasis. Recent studies suggests increased oxidative stress during HA exposure. In present study effect of HA exposure on levels of leptin and NPY was evaluated along with N-acetyl cysteine (NAC) and vitamin E supplementation in relation to food intake and body weight changes. The study was conducted on 30 healthy male volunteers (age 19-29 years). Subjects were divided randomly into three groups of 10 each. Group 1 (placebo) supplemented with 400 mg of calcium gluconate, group 2 and 3 were supplemented with 400 mg of NAC and 400 mg vitamin E, respectively per day. The study was conducted at low altitude (320 m, Phase I), at HA 3600 m (Phase II) and at an altitude of 4580 m (Phase III). On HA exposure significant reduction in plasma leptin levels was observed in all the groups on day 2 (Phase II) along with decrease in food intake and reduction in body weight. Statistically significant increase in blood malondialdehyde (MDA) levels was seen in all the groups on HA exposure (Phase II, Day 2), but the maximum increase was in case of placebo group (65.1%) on day 2 (Phase II) in comparison to low altitude values. The decrease in energy intake was almost same in all the groups indicating that antioxidant supplementation did not provide any protection against HA anorexia. From the study, it may be concluded that leptin and oxidative stress possibly are not the key players for HA anorexia.

  10. Population Structure, Genetic Diversity and Molecular Marker-Trait Association Analysis for High Temperature Stress Tolerance in Rice.

    Directory of Open Access Journals (Sweden)

    Sharat Kumar Pradhan

    Full Text Available Rice exhibits enormous genetic diversity, population structure and molecular marker-traits associated with abiotic stress tolerance to high temperature stress. A set of breeding lines and landraces representing 240 germplasm lines were studied. Based on spikelet fertility percent under high temperature, tolerant genotypes were broadly classified into four classes. Genetic diversity indicated a moderate level of genetic base of the population for the trait studied. Wright's F statistic estimates showed a deviation of Hardy-Weinberg expectation in the population. The analysis of molecular variance revealed 25 percent variation between population, 61 percent among individuals and 14 percent within individuals in the set. The STRUCTURE analysis categorized the entire population into three sub-populations and suggested that most of the landraces in each sub-population had a common primary ancestor with few admix individuals. The composition of materials in the panel showed the presence of many QTLs representing the entire genome for the expression of tolerance. The strongly associated marker RM547 tagged with spikelet fertility under stress and the markers like RM228, RM205, RM247, RM242, INDEL3 and RM314 indirectly controlling the high temperature stress tolerance were detected through both mixed linear model and general linear model TASSEL analysis. These markers can be deployed as a resource for marker-assisted breeding program of high temperature stress tolerance.

  11. Measurements of internal stresses in bond coating using high energy x-rays from synchrotron radiation source

    CERN Document Server

    Suzuki, K; Akiniwa, Y; Nishio, K; Kawamura, M; Okado, H

    2002-01-01

    Thermal barrier coating (TBC) techniques enable high temperature combustion of turbines made of Ni-base alloy. TBC is made of zirconia top coating on NiCoCrAlY bond coating. The internal stresses in the bond coating play essential role in the delamination or fracture of TBC in service. With the X-rays from laboratory equipments, it is impossible to measure nondestructively the internal stress in the bond coating under the top coating. synchrotron radiations with a high energy and high brightness have a large penetration depth as compared with laboratory X-rays. Using the high energy X-rays from the synchrotron radiation, it is possible to measure the internal stress in the bond coating through the top coating. In this study, the furnace, which can heat a specimen to 1473 K, was developed for the stress measurement of the thermal barrier coatings. The internal stresses in the bond coating were measured at the room temperature, 773 K, 1073 K and 1373 K by using the 311 diffraction from Ni sub 3 Al with about 73...

  12. Population Structure, Genetic Diversity and Molecular Marker-Trait Association Analysis for High Temperature Stress Tolerance in Rice.

    Science.gov (United States)

    Pradhan, Sharat Kumar; Barik, Saumya Ranjan; Sahoo, Ambika; Mohapatra, Sudipti; Nayak, Deepak Kumar; Mahender, Anumalla; Meher, Jitandriya; Anandan, Annamalai; Pandit, Elssa

    2016-01-01

    Rice exhibits enormous genetic diversity, population structure and molecular marker-traits associated with abiotic stress tolerance to high temperature stress. A set of breeding lines and landraces representing 240 germplasm lines were studied. Based on spikelet fertility percent under high temperature, tolerant genotypes were broadly classified into four classes. Genetic diversity indicated a moderate level of genetic base of the population for the trait studied. Wright's F statistic estimates showed a deviation of Hardy-Weinberg expectation in the population. The analysis of molecular variance revealed 25 percent variation between population, 61 percent among individuals and 14 percent within individuals in the set. The STRUCTURE analysis categorized the entire population into three sub-populations and suggested that most of the landraces in each sub-population had a common primary ancestor with few admix individuals. The composition of materials in the panel showed the presence of many QTLs representing the entire genome for the expression of tolerance. The strongly associated marker RM547 tagged with spikelet fertility under stress and the markers like RM228, RM205, RM247, RM242, INDEL3 and RM314 indirectly controlling the high temperature stress tolerance were detected through both mixed linear model and general linear model TASSEL analysis. These markers can be deployed as a resource for marker-assisted breeding program of high temperature stress tolerance.

  13. Psychotherapy for Borderline Personality Disorder: Progress and Remaining Challenges.

    Science.gov (United States)

    Links, Paul S; Shah, Ravi; Eynan, Rahel

    2017-03-01

    The main purpose of this review was to critically evaluate the literature on psychotherapies for borderline personality disorder (BPD) published over the past 5 years to identify the progress with remaining challenges and to determine priority areas for future research. A systematic review of the literature over the last 5 years was undertaken. The review yielded 184 relevant abstracts, and after applying inclusion criteria, 16 articles were fully reviewed based on the articles' implications for future research and/or clinical practice. Our review indicated that patients with various severities benefited from psychotherapy; more intensive therapies were not significantly superior to less intensive therapies; enhancing emotion regulation processes and fostering more coherent self-identity were important mechanisms of change; therapies had been extended to patients with BPD and posttraumatic stress disorder; and more research was needed to be directed at functional outcomes.

  14. Silicon Priming Created an Enhanced Tolerance in Alfalfa (Medicago sativa L.) Seedlings in Response to High Alkaline Stress.

    Science.gov (United States)

    Liu, Duo; Liu, Miao; Liu, Xiao-Long; Cheng, Xian-Guo; Liang, Zheng-Wei

    2018-01-01

    Alkaline stress as a result of higher pH usually triggers more severe physiological damage to plants than that of saline stress with a neutral pH. In the present study, we demonstrated that silicon (Si) priming of alfalfa ( Medicago sativa L.) seedlings increased their tolerance to high alkaline stress situations. Gongnong No. 1 seedlings were subjected to alkaline stress simulated by 25 mM Na 2 CO 3 (pH 11.2). Alkaline stress greatly decreased the biomass and caused severe lodging or wilting of alfalfa seedlings. In contrast, the application of Si to alfalfa seedlings 36 h prior to the alkaline treatment significantly alleviated the damage symptoms and greatly increased the biomass and chlorophyll content. Because of being concomitant with increasing photosynthesis and water use efficiency, decreasing membrane injury and malondialdehyde content, and increasing peroxidase and catalase ascorbate activities in alfalfa leaves, thereby alleviating the triggered oxidative damage by alkaline stress to the plant. Furthermore, Si priming significantly decreased the accumulation of protein and proline content in alfalfa, thus reducing photosynthetic feedback repression. Si priming significantly accumulated more Na in the roots, but led to a decrease of Na accumulation and an increase of K accumulation in the leaves under alkaline stress. Meanwhile, Si priming decreased the accumulation of metal ions such as Mg, Fe, Mn, and Zn in the roots of alfalfa seedlings under alkaline stress. Collectively, these results suggested that Si is involved in the metabolic or physiological changes and has a potent priming effect on the alkaline tolerance of alfalfa seedlings. The present study indicated that Si priming is a new approach to improve the alkaline tolerance in alfalfa and provides increasing information for further exploration of the alkaline stress response at the molecular level in alfalfa.

  15. Stress at work: Differential experiences of high versus low SES workers.

    Science.gov (United States)

    Damaske, Sarah; Zawadzki, Matthew J; Smyth, Joshua M

    2016-05-01

    This paper asks whether workers with higher socioeconomic status (SES) experience different levels of stress at work than workers with lower SES and, if so, what might explain these differences. We collected innovative assessments of immediate objective and subjective measures of stress at multiple time points across consecutive days from 122 employed men and women. We find that in comparison to higher SES individuals, those with lower SES reported greater happiness at work, less self-reported stress, and less perceived stress; cortisol, a biological marker of stress, was unrelated to SES. Worker's momentary perceptions of the workplace were predicted by SES, with higher SES individuals more commonly reporting feeling unable to meet work demands, fewer work resources, and less positive work appraisals. In turn, perceptions of the workplace had a generally consistent and robust effect on positive mood, subjective stress, and cortisol. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    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. RESULTS: 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 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....

  17. Residual stress development and relief in high strength aluminium alloys using standard and retrogression thermal treatments

    OpenAIRE

    Robinson, J.S; Tanner, D.A

    2003-01-01

    peer-reviewed Residual stresses develop in the aluminium alloy 7010 when the material is quenched from the solution heat treatment temperature. Residual stress measurements have been made using the X-ray diffraction technique and a longitudinal split sawcut method to determine the magnitude of residual stress that develops in specimens sectioned from large open die forgings as a result of (a) quenching these specimens into water at different temperatures, and (b) cold water quenching from ...

  18. Validation of a Residual Stress Measurement Method by Swept High-Frequency Eddy Currents

    International Nuclear Information System (INIS)

    Lee, C.; Shen, Y.; Lo, C. C. H.; Nakagawa, N.

    2007-01-01

    This paper reports on a swept high-frequency eddy current (SHFEC) measurement method developed for electromagnetic nondestructive characterization of residual stresses in shot peened aerospace materials. In this approach, we regard shot-peened surfaces as modified surface layers of varying conductivity, and determine the conductivity deviation profile by inversion of the SHFEC data. The SHFEC measurement system consists of a pair of closely matched printed-circuit-board coils driven by laboratory instrument under software control. This provides improved sensitivity and high frequency performance compared to conventional coils, so that swept frequency EC measurements up to 50 MHz can be made to achieve the smallest skin depth of 80 μm for nickel-based superalloys. We devised a conductivity profile inversion procedure based on the laterally uniform multi-layer theory of Cheng, Dodd and Deeds. The main contribution of this paper is the methodology validation. Namely, the forward and inverse models were validated against measurements on artificial layer specimens consisting of metal films with different conductivities placed on a metallic substrate. The inversion determined the film conductivities which were found to agree with those measured using the direct current potential drop (DCPD) method

  19. Validation of a Residual Stress Measurement Method by Swept High-Frequency Eddy Currents

    Science.gov (United States)

    Lee, C.; Shen, Y.; Lo, C. C. H.; Nakagawa, N.

    2007-03-01

    This paper reports on a swept high-frequency eddy current (SHFEC) measurement method developed for electromagnetic nondestructive characterization of residual stresses in shot peened aerospace materials. In this approach, we regard shot-peened surfaces as modified surface layers of varying conductivity, and determine the conductivity deviation profile by inversion of the SHFEC data. The SHFEC measurement system consists of a pair of closely matched printed-circuit-board coils driven by laboratory instrument under software control. This provides improved sensitivity and high frequency performance compared to conventional coils, so that swept frequency EC measurements up to 50 MHz can be made to achieve the smallest skin depth of 80 μm for nickel-based superalloys. We devised a conductivity profile inversion procedure based on the laterally uniform multi-layer theory of Cheng, Dodd and Deeds. The main contribution of this paper is the methodology validation. Namely, the forward and inverse models were validated against measurements on artificial layer specimens consisting of metal films with different conductivities placed on a metallic substrate. The inversion determined the film conductivities which were found to agree with those measured using the direct current potential drop (DCPD) method.

  20. Alterations in wheat pollen lipidome during high day and night temperature stress.

    Science.gov (United States)

    Narayanan, Sruthi; Prasad, P V Vara; Welti, Ruth

    2018-01-26

    Understanding the adaptive changes in wheat pollen lipidome under high temperature (HT) stress is critical to improving seed set and developing HT tolerant wheat varieties. We measured 89 pollen lipid species under optimum and high day and/or night temperatures using electrospray ionization-tandem mass spectrometry in wheat plants. The pollen lipidome had a distinct composition compared with that of leaves. Unlike in leaves, 34:3 and 36:6 species dominated the composition of extraplastidic phospholipids in pollen under optimum and HT conditions. The most HT-responsive lipids were extraplastidic phospholipids, phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol, phosphatidic acid, and phosphatidylserine. The unsaturation levels of the extraplastidic phospholipids decreased through the decreases in the levels of 18:3 and increases in the levels of 16:0, 18:0, 18:1, and 18:2 acyl chains. PC and PE were negatively correlated. Higher PC:PE at HT indicated possible PE-to-PC conversion, lower PE formation, or increased PE degradation, relative to PC. Correlation analysis revealed lipids experiencing coordinated metabolism under HT and confirmed the HT responsiveness of extraplastidic phospholipids. Comparison of the present results on wheat pollen with results of our previous research on wheat leaves suggests that similar lipid changes contribute to HT adaptation in both leaves and pollen, though the lipidomes have inherently distinct compositions. © 2018 John Wiley & Sons Ltd.

  1. High Pb concentration stress on Typha latifolia growth and Pb removal in microcosm wetlands.

    Science.gov (United States)

    Han, Jianqiu; Chen, Fengzhen; Zhou, Yumei; Wang, Chaohua

    2015-01-01

    When constructed wetlands are used to treat high-Pb wastewater, Pb may become a stress to wetland plants, which subsequently reduces treatment performance and the other ecosystem services. To facilitate the design and operation of constructed wetlands for treatment of Pb-rich wastewater, we investigated the irreversible inhibitory level of Pb for Typha latifolia through experiments in microcosm wetlands. Seven horizontal subsurface flow constructed wetlands were built with rectangular plastic tanks and packed with marble chips and sand. All wetlands were transplanted with nine stems of Typha latifolia each. The wetlands were batch operated in a greenhouse with artificial wastewater (10 L each) for 12 days. Influent to the seven wetlands had different concentrations of Pb: 0 mg/L, 10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 200 mg/L, and 500 mg/L, respectively. The results suggested that leaf chlorophyll relative content, relative growth rate, photosynthetic characteristics, activities of superoxide dismutase, peroxidase, and content of malondialdehyde were not affected when initial Pb concentration was at 100 mg/L and below. But when initial Pb concentration was above 100 mg/L, all of them were seriously affected. We conclude that high Pb concentrations wastewater could inhibit the growth of Typha latifolia and decrease the removal rate of wetlands.

  2. Occupational status moderates the association between current perceived stress and high blood pressure: evidence from the IPC cohort study

    Science.gov (United States)

    Wiernik, Emmanuel; Pannier, Bruno; Czernichow, Sébastien; Nabi, Hermann; Hanon, Olivier; Simon, Tabassome; Simon, Jean-Marc; Thomas, Frédérique; Bean, Kathy; Consoli, Silla; Danchin, Nicolas; Lemogne, Cédric

    2013-01-01

    Although lay beliefs commonly relate high blood pressure to psychological stress exposure, research findings are conflicting. This study examined the association between current perceived stress and high blood pressure and explored the potential impact of occupational status on this association. Resting blood pressure was measured in 122,816 adults (84,994 men), aged ≥30 years (mean age ± standard deviation: 46.8±9.9 years), without history of cardiovascular and renal disease and not on either psychotropic or antihypertensive drugs. High blood pressure was defined as systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg. Perceived stress in the past month was measured with the 4-item perceived stress scale. A total of 33,154 participants (27.0%) had high blood pressure (151±14/90±9 mmHg). After adjustment for all variables except occupational status, perceived stress was associated with high blood pressure (odds ratio for a 5-point increase: 1.06, 95% confidence interval: [1.03–1.09]). This association was no longer significant after additional adjustment for occupational status (odds ratio: 1.01 [0.99–1.04]). There was a significant interaction (phigh blood pressure among individuals of high occupational status (odds ratio: 0.91, [0.87–0.96]) but positively associated among those of low status (odds ratio: 1.10, [1.03–1.17]) or unemployed (odds ratio: 1.13, [1.03–1.24]). Sensitivity analyses yielded similar results. The association between current perceived stress and blood pressure depends upon occupational status. This interaction may account for previous conflicting results and warrants further studies to explore its underlying mechanisms. PMID:23319539

  3. Response of the diatom Phaeodactylum tricornutum to photooxidative stress resulting from high light exposure.

    Directory of Open Access Journals (Sweden)

    Nuno Domingues

    Full Text Available The response of microalgae to photooxidative stress resulting from high light exposure is a well-studied phenomenon. However, direct analyses of photosystem II (PSII D1 protein (the main target of photoinhibition in diatoms are scarce. In this study, the response of the diatom model species Phaeodactylum tricornutum to short-term exposure to high light was examined and the levels of D1 protein determined immunochemically. Low light (LL acclimated cells (40 µmol photons m(-2 s(-1 subjected to high light (HL, 1,250 µmol photons m(-2 s(-1 showed rapid induction of non-photochemical quenching (NPQ and ca. 20-fold increase in diatoxanthin (DT concentration. This resulted from the conversion of diadinoxanthin (DD to DT through the activation of the DD-cycle. D1 protein levels under LL decreased about 30% after 1 h of the addition of lincomycin (LINC, a chloroplast protein synthesis inhibitor, showing significant D1 degradation and repair under low irradiance. Exposure to HL lead to a 3.2-fold increase in D1 degradation rate, whereas average D1 repair rate was 1.3-x higher under HL than LL, leading to decreased levels of D1 protein under HL. There were significant effects of both HL and LINC on P. tricornutum maximum quantum yield of PSII (F(v/F(m, showing a reduction of active PSII reaction centres. Partial recovery of F(v/F(m in the dark demonstrates the photosynthetic resilience of this diatom to changes in the light regime. P. tricornutum showed high allocation of total protein to D1 and an active D1-repair cycle to limit photoinhibition.

  4. Effects of dietary organic chromium and vitamin C supplementation on performance, immune responses, blood metabolites, and stress status of laying hens subjected to high stocking density.

    Science.gov (United States)

    Mirfendereski, E; Jahanian, R

    2015-02-01

    The present study was carried out to investigate the effects of dietary supplementation of chromium-methionine (CrMet) and vitamin C (VC) on performance, immune response, and stress status of laying hens subjected to high stocking density. A total of 360 Hy-Line W-36 leghorn hens (at 26 wk old) were used in a 2×3×2 factorial arrangement that had 2 cage densities (5 and 7 hens per cage), 3 Cr levels (0, 500, and 1,000 ppb as CrMet), and 2 dietary VC levels (0 and 500 ppm as L-ascorbic acid). The trial lasted for 12 wk. The first 2 wk were for adaptation (26 to 28 wk of age), and the remaining 10 wk served as the main recording period. In addition to performance, immune response to Newcastle disease virus (NDV) was assessed at d 7 and 14 postvaccination. Also, the birds' stress status was evaluated by analyzing appropriate plasma metabolites. The results showed that hens in cages with higher stocking density had lower hen-day egg production, egg mass, and feed intake compared with those in normal density cages (Pfeed conversion efficiency (Pfeed conversion ratio in VC-unsupplemented diets. Although plasma concentrations of triglycerides and high-density lipoproteins were not influenced by dietary treatments, supplemental CrMet decreased plasma cholesterol levels (Phens kept at a density of 7 hens/cage were significantly higher than those of hens in normal cage density (Phens. While high stocking density caused a marked increase in plasma corticosterone (Phens. The high stocking density challenge suppressed NDV antibody response (Phens kept at a density of 7 hens/cage (P<0.01). From the present observations, it can be concluded that CrMet can improve laying performance largely because it alleviates harmful responses to stressful conditions. © 2015 Poultry Science Association Inc.

  5. Effects of cyclic tensile loading on stress corrosion cracking susceptibility for sensitized Type 304 stainless steel in 290 C high purity water

    International Nuclear Information System (INIS)

    Takaku, H.; Tokiwai, M.; Hirano, H.

    1979-01-01

    The effects of load waveform on intergranular stress corrosion cracking (IGSCC) susceptibility have been examined for sensitized Type 304 stainless steels in a 290 C high purity water loop. Concerning the strain rate in the trapezoidal stress waveform, it was found that IGSCC susceptibility was higher for smaller values of the strain rate. It was also shown that IGSCC susceptibility became higher when the holding time at the upper stress was prolonged, and when the upper stress was high. The occurrence of IGSCC for sensitized Type 304 stainless steel became easy due to the application of cyclic tensile stress in 290 C high purity water

  6. [Relationship between occupational stress and working ability of workers in a petroleum processing enterprise in high altitude area].

    Science.gov (United States)

    Ma, X M; Kang, H L; Shi, C B; Li, Y; Wu, Y F; Liu, Z H; Wang, G; Lei, H Y

    2017-12-20

    Objective: To investigate the relationship between occupational stress and working ability of workers in a petroleum processing enterprise in a high altitude area. Methods: A total of 728 workers in a petroleum processing enterprise at an altitude of 2850 m were subjected to a survey using Occupational Stress Inventory (OSI) , Work Ability Index (WAI) Scale, Occupational Role Questionnaire (ORQ) , Personal Strain Questionnaire (PSQ) , and Personal Resource Questionnaire (PRQ) from May 2014 to August 2016. Results: Of the 728 workers, 55 (7.6%) had a poor working ability, moderate in 262 (35.9%) , and good in 411 (56.5%). There were significant differences in WAI between the workers with different types of work, sexes, ages, and working years ( P occupational stress groups ( P Occupational stress is an influencing factor for the working ability of workers in the petroleum processing enterprise in the high altitude area. Hypoxia in high altitude area may further reduce the working ability. In order to reduce occupational stress and improve work ability, it should be considered to strengthen skills training, improve the working environment, and pay attention to mental health.

  7. Maternal stress and high-fat diet effect on maternal behavior, milk composition, and pup ingestive behavior.

    Science.gov (United States)

    Purcell, Ryan H; Sun, Bo; Pass, Lauren L; Power, Michael L; Moran, Timothy H; Tamashiro, Kellie L K

    2011-09-01

    Chronic variable prenatal stress or maternal high-fat diet results in offspring that are significantly heavier by the end of the first postnatal week with increased adiposity by weaning. It is unclear, however, what role maternal care and diet play in the ontogenesis of this phenotype and what contributions come from differences already established in the rat pups. In the present studies, we examined maternal behavior and milk composition as well as offspring ingestive behavior. Our aim was to better understand the development of the obese phenotype in offspring from dams subjected to prenatal stress and/or fed a high-fat (HF) diet during gestation and lactation. We found that dams maintained on a HF diet through gestation and lactation spent significantly more time nursing their pups during the first postnatal week. In addition, offspring of prenatal stress dams consumed more milk at postnatal day (PND) 3 and offspring of HF dams consume more milk on PND 7 in an independent ingestion test. Milk from HF dams showed a significant increase in fat content from PND 10-21. Together these results suggest that gestational dietary or stress manipulations can alter the rat offspring's developmental environment, evidence of which is apparent by PND 3. Alterations in maternal care, milk composition, and pup consumption during the early postnatal period may contribute to long-term changes in body weight and adiposity induced by maternal prenatal stress or high-fat diet. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Bioarchaeological Analysis of the Human Skeletal Remains from the Late Mediaeval Cemetery of Koprivno, Southern Croatia

    Directory of Open Access Journals (Sweden)

    Mario Novak

    2011-06-01

    Full Text Available The paper presents the results of bioarchaeological analysis of the late mediaeval (13th-14th century skeletal sample from Koprivno, southern Croatia. Skeletal remains of 21 individuals (eight males, nine females, and four subadults were examined for the possible presence of dental pathologies (caries and alveolar bone diseases, subadult stress indicators (cribra orbitalia and dental enamel hypoplasia, degenerative osteoarthritis of the vertebrae and major joints, Schmorl’s nodes on vertebrae, periostitis, and bone trauma. The analysed sample is characterised by high frequency of alveolar bone disease, most probably as a result of somewhat longer average life span (around 41 years and very poor oral hygiene, while the data concerning dental caries indicate mixed diet evenly based on meat and cereals. High frequencies of cribra orbitalia, dental enamel hypoplasia and periostitis suggest frequent episodes of physiological stress (hunger, epidemics of infectious diseases which is in accordance with historical data. Distribution and prevalence of cranial traumas strongly suggest a relatively high degree of interpersonal violence in the analysed community.

  9. Relationships of alcohol use, stress, avoidance coping, and other factors with mental health in a highly educated workforce.

    Science.gov (United States)

    Koopman, Cheryl; Wanat, Stanley F; Whitsell, Shelly; Westrup, Darrah; Matano, Robert A

    2003-01-01

    The relationships of drinking, stress, life satisfaction, coping style, and antidepressant use to mental health were examined in a highly educated workforce. This study used a one-time mail-out, mail-back cross-sectional survey design to examine the relationships of mental health with three kinds of stress (life events, work stress, home stress); two kinds of life satisfaction (work and home); use of avoidance coping; and antidepressant use. This study was conducted at a large worksite in northern California in which the workforce was comprised of predominantly highly educated employees. Questionnaires were mailed to a random sample of 10% of 8567 employees, and 504 were completed and returned by participants (59%). Complete data were provided by 460 participants (53%). Respondents completed the Mental Health Index, the Alcohol Use Disorders Identification Test (AUDIT), and measures of coping style, work and home stress and satisfaction, stressful life events, and antidepressant use. Mean Mental Health Index scores were at the 32nd percentile of the U.S. population-based norms, with low percentile values associated with worse mental health. Using multiple regression analysis, the factors examined in this study were significantly related to Mental Health Index scores as the dependent variable [F(16, 443) = 27.41, p stress at work (p home (p work (p home life (p = .01); engaging in avoidance coping (p stress, home satisfaction and work stress, home satisfaction and avoidance coping, and home satisfaction and use of antidepressants. Mental health status was poorer on average in a highly educated workforce compared with general U.S. norms. Most of the factors that were found to be associated with poorer mental health were ones that are potentially modifiable, such as experiencing more stress and less satisfaction in work and home life and engaging in current hazardous or harmful drinking. The findings that mental health is worse among individual employees who exhibit

  10. Threading dislocation movement in AlGaN/GaN-on-Si high electron mobility transistors under high temperature reverse bias stressing

    Directory of Open Access Journals (Sweden)

    W. A. Sasangka

    2016-09-01

    Full Text Available Dislocations are known to be associated with both physical and electrical degradation mechanisms of AlGaN/GaN-on-Si high electron mobility transistors (HEMTs. We have observed threading dislocation movement toward the gate-edges in AlGaN/GaN-on-Si HEMT under high reverse bias stressing. Stressed devices have higher threading dislocation densities (i.e. ∼5 × 109/cm2 at the gate-edges, as compared to unstressed devices (i.e. ∼2.5 × 109/cm2. Dislocation movement correlates well with high tensile stress (∼1.6 GPa at the gate-edges, as seen from inverse piezoelectric calculations and x-ray synchrotron diffraction residual stress measurements. Based on Peierls stress calculation, we believe that threading dislocations move via glide in 〈 11 2 ¯ 0 〉 / { 1 1 ¯ 00 } and 〈 11 2 ¯ 0 〉 / { 1 1 ¯ 01 } slip systems. This result illustrates the importance of threading dislocation mobility in controlling the reliability of AlGaN/GaN-on-Si HEMTs.

  11. Anatomical traits related to stress in high density populations of Typha angustifolia L. (Typhaceae

    Directory of Open Access Journals (Sweden)

    F. F. Corrêa

    Full Text Available Abstract Some macrophytes species show a high growth potential, colonizing large areas on aquatic environments. Cattail (Typha angustifolia L. uncontrolled growth causes several problems to human activities and local biodiversity, but this also may lead to competition and further problems for this species itself. Thus, the objective of this study was to investigate anatomical modifications on T. angustifolia plants from different population densities, once it can help to understand its biology. Roots and leaves were collected from natural populations growing under high and low densities. These plant materials were fixed and submitted to usual plant microtechnique procedures. Slides were observed and photographed under light microscopy and images were analyzed in the UTHSCSA-Imagetool software. The experimental design was completely randomized with two treatments and ten replicates, data were submitted to one-way ANOVA and Scott-Knott test at p<0.05. Leaves from low density populations showed higher stomatal density and index. These modifications on stomatal characteristics were more evident on the leaf abaxial surface. Plants from low density populations showed thicker mesophyll and higher proportion of aerenchymal area. Roots from low density populations showed a higher proportion of the vascular cylinder. Whereas, plants from higher density populations showed greater thickness of the endodermis, exodermis, phloem and root cortex. Higher density populations showed a higher proportion of aerenchymal gaps in the root cortex. Therefore, cattail plants from populations growing under high density population show anatomical traits typical of plants under stress, which promotes the development of less functional anatomical modifications to aquatic environments.

  12. Stress corrosion cracking behaviour of Alloy 600 in high temperature water

    International Nuclear Information System (INIS)

    Webb, G.L.; Burke, M.G.

    1995-01-01

    The stress corrosion cracking (SCC) susceptibility of Alloy 600 in deaerated water at 360 deg. C, as measured with statistically-loaded U-bend specimens, is dependent upon microstructure and whether the material was cold-worked and annealed (CWA) or hot-worked and annealed (HWA). All cracking was intergranular, and materials lacking grain boundary carbides were most susceptible to SCC initiation. CWA tubing materials are more susceptible to SCC initiation than HWA ring-rolled forging materials with similar microstructures, as determined by light optical metallography (LOM). In CWA tubing materials one crack dominated and grew to a large size that was observable by visual inspection. HWA materials with a low hot-working finishing temperature (below 925 deg. C) and final anneals at temperatures ranging from 1010 deg. C to 1065 deg. C developed both large cracks, similar to those found in CWA materials, and also small intergranular microcracks, which are detectable only by destructive metallographic examination. HWA materials with a high hot-working finishing temperature (above 980 deg. C) and high-temperature final anneal (above 1040 deg. C), with grain boundaries that are fully decorated, developed only microcracks, which were observed in all specimens examined. These materials developed no large, visually detectable cracks, even after more than 300 weeks exposure. A low-temperature thermal treatment (610 deg. C for 7h), which reduced or eliminates SCC in Alloy 600, did not eliminate microcrack formation in the high temperature processed HWA materials. Detailed microstructural characterization using conventional metallographic and analytical electron microscopy (AEM) techniques was performed on selected materials to identify the factors responsible for the observed differences in cracking behaviour. 11 refs, 12 figs, 3 tabs

  13. Efficacy and Tolerability of High-Dose Escitalopram in Posttraumatic Stress Disorder.

    Science.gov (United States)

    Qi, Wei; Gevonden, Martin; Shalev, Arieh

    2017-02-01

    Open-label trials suggest that escitalopram (up to 20 mg/d) is an effective treatment for some, but not all posttraumatic stress disorder (PTSD) patients. Higher doses of escitalopram effectively reduced major depression symptoms in patients who had not responded to regular doses. The current study examines the efficacy, tolerability, and adherence to high-dose escitalopram in PTSD. Forty-five PTSD patients received 12 weeks of gradually increasing doses of escitalopram reaching 40 mg daily at 4 weeks. Among those, 12 participants received regular doses of antidepressants at study onset including escitalopram (n = 7). The Clinician-Administered PTSD Scale (CAPS) evaluated PTSD symptoms severity before treatment, at 3 months (upon treatment termination), and at 6 months (maintenance effect). A 20% reduction in CAPS scores was deemed clinically significant. Adverse events and medication adherence were monitored at each clinical session. Linear mixed-models analysis showed a significant reduction of mean CAPS scores (11.5 ± 18.1 points) at 3 months and maintenance of gains by 6 months (F2,34.56 = 8.15, P = 0.001). Eleven participants (34.3%) showed clinically significant improvement at 3 months. Only 9 participants (20%) left the study. There were no serious adverse events and few mild ones with only 2 adverse events (diarrhea, 11.1%; drowsiness, 11.1%) reported by more than 10% of participants. High doses of escitalopram are tolerable and well adhered to in PTSD. Their beneficial effect at a group level is due to a particularly good response in a subset of patients.Variability in prior pharmacological treatment precludes a definite attribution of the results to high doses of escitalopram.

  14. High Self-Perceived Stress and Poor Coping in Intellectually Able Adults with Autism Spectrum Disorder

    Science.gov (United States)

    Hirvikoski, Tatja; Blomqvist, My

    2015-01-01

    Despite average intellectual capacity, autistic traits may complicate performance in many everyday situations, thus leading to stress. This study focuses on stress in everyday life in intellectually able adults with autism spectrum disorders. In total, 53 adults (25 with autism spectrum disorder and 28 typical adults from the general population)…

  15. Psychosocial stress impairs working memory at high loads: An association with cortisol levels and memory retrieval

    NARCIS (Netherlands)

    Oei, N.Y.L.; Everaerd, W.T.A.M.; Elzinga, B.M.; van Well, S.; Bermond, B.

    2006-01-01

    Stress and cortisol are known to impair memory retrieval of well-consolidated declarative material. The effects of cortisol on memory retrieval may in particular be due to glucocorticoid (GC) receptors in the hippocampus and prefrontal cortex (PFC). Therefore, effects of stress and cortisol should

  16. Recovery stress and shape memory stability in Ni-Ti-Cu thin wires at high temperatures

    Czech Academy of Sciences Publication Activity Database

    Molnár, Peter; Van Humbeeck, J.

    2011-01-01

    Roč. 102, č. 11 (2011), s. 1362-1368 ISSN 1862-5282 Institutional research plan: CEZ:AV0Z10100520 Keywords : shape memory alloys * recovery stress * Ni-Ti-Cu * stress relaxation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.830, year: 2011 http://www.ijmr.de/directlink.asp?MK110596

  17. Methodology for Extraction of Remaining Sodium of Used Sodium Containers

    International Nuclear Information System (INIS)

    Jung, Minhwan; Kim, Jongman; Cho, Youngil; Jeong, Jiyoung

    2014-01-01

    Sodium used as a coolant in the SFR (Sodium-cooled Fast Reactor) reacts easily with most elements due to its high reactivity. If sodium at high temperature leaks outside of a system boundary and makes contact with oxygen, it starts to burn and toxic aerosols are produced. In addition, it generates flammable hydrogen gas through a reaction with water. Hydrogen gas can be explosive within the range of 4.75 vol%. Therefore, the sodium should be handled carefully in accordance with standard procedures even though there is a small amount of target sodium remainings inside the containers and drums used for experiment. After the experiment, all sodium experimental apparatuses should be dismantled carefully through a series of draining, residual sodium extraction, and cleaning if they are no longer reused. In this work, a system for the extraction of the remaining sodium of used sodium drums has been developed and an operation procedure for the system has been established. In this work, a methodology for the extraction of remaining sodium out of the used sodium container has been developed as one of the sodium facility maintenance works. The sodium extraction system for remaining sodium of the used drums was designed and tested successfully. This work will contribute to an establishment of sodium handling technology for PGSFR. (Prototype Gen-IV Sodium-cooled Fast Reactor)

  18. Couple stress theory of curved rods. 2-D, high order, Timoshenko’s and Euler-Bernoulli models

    Directory of Open Access Journals (Sweden)

    Zozulya V.V.

    2017-01-01

    Full Text Available New models for plane curved rods based on linear couple stress theory of elasticity have been developed.2-D theory is developed from general 2-D equations of linear couple stress elasticity using a special curvilinear system of coordinates related to the middle line of the rod as well as special hypothesis based on assumptions that take into account the fact that the rod is thin. High order theory is based on the expansion of the equations of the theory of elasticity into Fourier series in terms of Legendre polynomials. First, stress and strain tensors, vectors of displacements and rotation along with body forces have been expanded into Fourier series in terms of Legendre polynomials with respect to a thickness coordinate.Thereby, all equations of elasticity including Hooke’s law have been transformed to the corresponding equations for Fourier coefficients. Then, in the same way as in the theory of elasticity, a system of differential equations in terms of displacements and boundary conditions for Fourier coefficients have been obtained. Timoshenko’s and Euler-Bernoulli theories are based on the classical hypothesis and the 2-D equations of linear couple stress theory of elasticity in a special curvilinear system. The obtained equations can be used to calculate stress-strain and to model thin walled structures in macro, micro and nano scales when taking into account couple stress and rotation effects.

  19. The relationship between stressful working conditions and high alcohol consumption and severe alcohol problems in an urban general population

    DEFF Research Database (Denmark)

    Romelsjö, A; Hasin, D; Hilton, M

    1992-01-01

    The relationship between 15 measures of stressful working conditions and high alcohol consumption (35 g 100% ethanol per day or more for men and 25 g or more for women) was studied, using cross-sectional data from a general population survey of 1344 males and 1494 females; the ages 25-64 years......-adjusted odds ratios, were positive and some were negative when high alcohol consumption was the endpoint, but there was a clear variation by sex and social class. Generally the positive associations were stronger among male non-manual employees. Among males, there was a clear association between stressful...... increased odds ratios were lower when subjects with an alcohol diagnosis at inpatient care during 1980-84 were excluded in the analyses. On the whole, our findings are not conclusive. The strong, but imprecise associations between stressful working conditions and severe alcohol problems, are however...

  20. Numerical method for analysis of temperature rises and thermal stresses around high level radioactive waste repository in granite

    International Nuclear Information System (INIS)

    Shimooka, Hiroshi

    1982-01-01

    The disposal of high-level radioactive waste should result in temperature rises and thermal stresses which change the hydraulic conductivity of the rock around the repository. For safety analysis on disposal of high-level radioactive waste into hard rock, it is necessary to find the temperature rises and thermal stresses distributions around the repository. In this paper, these distribution changes are analyzed by the use of the finite difference method. In advance of numerical analysis, it is required to simplify the shapes and properties of the repository and the rock. Several kinds of numerical models are prepared, and the results of this analysis are examined. And, the waste disposal methods are discussed from the stand-points of the temperature rise and thermal stress analysis. (author)

  1. Stressful Life Events and Predictors of Post-traumatic Growth among High-Risk Early Emerging Adults.

    Science.gov (United States)

    Arpawong, Thalida E; Rohrbach, Louise A; Milam, Joel E; Unger, Jennifer B; Land, Helen; Sun, Ping; Spruijt-Metz, Donna; Sussman, Steve

    2016-01-01

    Stressful life events (SLEs) may elicit positive psychosocial change among youth, referred to as Post-traumatic Growth (PTG). We assessed types of SLEs experienced, degree to which participants reported PTG, and variables predicting PTG across 24 months among a sample of high risk, ethnically diverse early emerging adults. Participants were recruited from alternative high schools ( n = 564; mean age=16.8; 65% Hispanic). Multi-level regression models were constructed to examine the impact of environmental (SLE quantity, severity) and personal factors (hedonic ability, perceived stress, developmental stage, future time orientation) on a composite score of PTG. The majority of participants reported positive changes resulted from their most life-altering SLE of the past two years. Predictors of PTG included fewer SLEs, less general stress, having a future time perspective, and greater identification with the developmental stage of Emerging Adulthood. Findings suggest intervention targets to foster positive adaptation among early emerging adults who experience frequent SLEs.

  2. Stress corrosion cracking of stainless steel under deaerated high-temperature water. Influence of cold work and processing orientation

    International Nuclear Information System (INIS)

    Terachi, Takumi; Yamada, Takuyo; Chiba, Goro; Arioka, Koji

    2006-01-01

    The influence of cold work and processing orientation on the propagation of stress corrosion cracking (SCC) of stainless steel under hydrogenated high-temperature water was examined. It was shown that (1) the crack growth rates increased with heaviness of cold work, and (2) processing orientation affected crack growth rate with cracking direction. Crack growth rates showed anisotropy of T-L>>T-S>L-S, with T-S and L-S branches representing high shear stress direction. Geometric deformation of crystal grains due to cold work caused the anisotropy and shear stress also assisted the SCC propagation. (3) The step intervals of slip like patterns observed on intergranular facets increased cold work. (4) Nano-indentation hardness of the crack tip together with EBSD measurement indicated that the change of hardness due to crack propagation was less than 5% cold-work, even though the distance from the crack tip was 10μm. (author)

  3. The Arabidopsis Transcription Factor ANAC032 Represses Anthocyanin Biosynthesis in Response to High Sucrose and Oxidative and Abiotic Stresses.

    Science.gov (United States)

    Mahmood, Kashif; Xu, Zhenhua; El-Kereamy, Ashraf; Casaretto, José A; Rothstein, Steven J

    2016-01-01

    Production of anthocyanins is one of the adaptive responses employed by plants during stress conditions. During stress, anthocyanin biosynthesis is mainly regulated at the transcriptional level via a complex interplay between activators and repressors of anthocyanin biosynthesis genes. In this study, we investigated the role of a NAC transcription factor, ANAC032, in the regulation of anthocyanin biosynthesis during stress conditions. ANAC032 expression was found to be induced by exogenous sucrose as well as high light (HL) stress. Using biochemical, molecular and transgenic approaches, we show that ANAC032 represses anthocyanin biosynthesis in response to sucrose treatment, HL and oxidative stress. ANAC032 was found to negatively affect anthocyanin accumulation and the expression of anthocyanin biosynthesis ( DFR, ANS/LDOX) and positive regulatory ( TT8) genes as demonstrated in overexpression line (35S:ANAC032) compared to wild-type under HL stress. The chimeric repressor line (35S:ANAC032-SRDX) exhibited the opposite expression patterns for these genes. The negative impact of ANAC032 on the expression of DFR, ANS/LDOX and TT8 was found to be correlated with the altered expression of negative regulators of anthocyanin biosynthesis, AtMYBL2 and SPL9 . In addition to this, ANAC032 also repressed the MeJA- and ABA-induced anthocyanin biosynthesis. As a result, transgenic lines overexpressing ANAC032 (35S:ANAC032) produced drastically reduced levels of anthocyanin pigment compared to wild-type when challenged with salinity stress. However, transgenic chimeric repressor lines (35S:ANAC032-SRDX) exhibited the opposite phenotype. Our results suggest that ANAC032 functions as a negative regulator of anthocyanin biosynthesis in Arabidopsis thaliana during stress conditions.

  4. microRNAs involved in auxin signalling modulate male sterility under high-temperature stress in cotton (Gossypium hirsutum).

    Science.gov (United States)

    Ding, Yuanhao; Ma, Yizan; Liu, Nian; Xu, Jiao; Hu, Qin; Li, Yaoyao; Wu, Yuanlong; Xie, Sai; Zhu, Longfu; Min, Ling; Zhang, Xianlong

    2017-09-01

    Male sterility caused by long-term high-temperature (HT) stress occurs widely in crops. MicroRNAs (miRNAs), a class of endogenous non-coding small RNAs, play an important role in the plant response to various abiotic stresses. To dissect the working principle of miRNAs in male sterility under HT stress in cotton, a total of 112 known miRNAs, 270 novel miRNAs and 347 target genes were identified from anthers of HT-insensitive (84021) and HT-sensitive (H05) cotton cultivars under normal-temperature and HT conditions through small RNA and degradome sequencing. Quantitative reverse transcriptase-polymerase chain reaction and 5'-RNA ligase-mediated rapid amplification of cDNA ends experiments were used to validate the sequencing data. The results show that miR156 was suppressed by HT stress in both 84021 and H05; miR160 was suppressed in 84021 but induced in H05. Correspondingly, SPLs (target genes of miR156) were induced both in 84021 and H05; ARF10 and ARF17 (target genes of miR160) were induced in 84021 but suppressed in H05. Overexpressing miR160 increased cotton sensitivity to HT stress seen as anther indehiscence, associated with the suppression of ARF10 and ARF17 expression, thereby activating the auxin response that leads to anther indehiscence. Supporting this role for auxin, exogenous Indole-3-acetic acid (IAA) leads to a stronger male sterility phenotype both in 84021 and H05 under HT stress. Cotton plants overexpressing miR157 suppressed the auxin signal, and also showed enhanced sensitivity to HT stress, with microspore abortion and anther indehiscence. Thus, we propose that the auxin signal, mediated by miRNAs, is essential for cotton anther fertility under HT stress. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  5. Quality of Life, Mental Health and Educational Stress of High School Students in the Northeast of Thailand.

    Science.gov (United States)

    Assana, Supat; Laohasiriwong, Wongsa; Rangseekajee, Poonsri

    2017-08-01

    Majority of high school students in Thailand aim to study at universities. Therefore, they spend a lot of time studying in both classrooms and tutorial classes, that could cause stress, health problems and deteriorate their Quality Of Life (QOL). However, there has been no study on these issues in Thai context. To describe the status of QOL, mental health, educational stress, well-being and determine factors associated with QOL among high school students in the Northeast of Thailand. This cross-sectional study was conducted in the Northeast of Thailand among 1,112 students of grade 10 th , 11 th and 12 th . Multistage random sampling was used to select high schools in 5 provinces. A self-administered questionnaire was used to assess QOL, educational stress, anxiety, depression and well-being. The association between the covariates was observed by using Generalized Linear Mixed (logistic regression) Model (GLMM). The prevalence of high level of QOL was 36% (95%CI: 32.30 to 41.69); whereas, 26.18% (95% CI: 16.72 to 35.63) had high level of educational stress and 16.41% (95% CI: 2.20 to 30.71) had severe anxiety. Prevalence of depression was 18.55% (95%CI: 9.86 to 27.23) and low level of well-being was 13.41% (95% CI: 0.18 to 27.14). The factors significantly associated with high QOL were; not having depression (Adj. OR= 3.07; 95%CI: (2.23 to 4.22); peducational stress and anxiety. Depression, anxiety and general well-being had influences on QOL of high school students.

  6. The effects of anticipating a high-stress task on sleep and performance during simulated on-call work.

    Science.gov (United States)

    Sprajcer, Madeline; Jay, Sarah M; Vincent, Grace E; Vakulin, Andrew; Lack, Leon; Ferguson, Sally A

    2018-04-22

    On-call work is used to manage around the clock working requirements in a variety of industries. Often, tasks that must be performed while on-call are highly important, difficult and/or stressful by nature and, as such, may impact the level of anxiety that is experienced by on-call workers. Heightened anxiety is associated with poor sleep, which affects next-day cognitive performance. Twenty-four male participants (20-35 years old) spent an adaptation, a control and two counterbalanced on-call nights in a time-isolated sleep laboratory. On one of the on-call nights they were told that they would be required to do a speech upon waking (high-stress condition), whereas on the other night they were instructed that they would be required to read to themselves (low-stress condition). Pre-bed anxiety was measured by the State Trait Anxiety Inventory form x-1, and polysomnography and quantitative electroencephalogram analyses were used to investigate sleep. Performance was assessed across each day using the 10-min psychomotor vigilance task (09:30 hours, 12:00 hours, 14:30 hours, 17:00 hours). The results indicated that participants experienced no significant changes in pre-bed anxiety or sleep between conditions. However, performance on the psychomotor vigilance task was best in the high-stress condition, possibly as a result of heightened physiological arousal caused by performing the stressful task that morning. This suggests that performing a high-stress task may be protective of cognitive performance to some degree when sleep is not disrupted. © 2018 European Sleep Research Society.

  7. High-Intensity Exercise Induced Oxidative Stress and Skeletal Muscle Damage in Postpubertal Boys and Girls: A Comparative Study.

    Science.gov (United States)

    Pal, Sangita; Chaki, Biswajit; Chattopadhyay, Sreya; Bandyopadhyay, Amit

    2018-04-01

    Pal, S, Chaki, B, Chattopadhyay, S, and Bandyopadhyay, A. High-intensity exercise induced oxidative stress and skeletal muscle damage in post-pubertal boys and girls: a comparative study. J Strength Cond Res 32(4): 1045-1052, 2018-The purpose of this study was to examine the sex variation in high-intensity exercise induced oxidative stress and muscle damage among 44 sedentary postpubertal boys and girls through estimation of postexercise release pattern of muscle damage markers like creatine kinase, lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and oxidative stress markers like extent of lipid peroxidation (thiobarbituric acid-reactive substances) and catalase activity. Muscle damage markers like creatine kinase, LDH, ALT, and AST were measured before, immediately after, and 24 and 48 hours after high-intensity incremental treadmill running. Oxidative stress markers like thiobarbituric acid-reactive substances and catalase activity were estimated before and immediately after the exercise. Lipid peroxidation and serum catalase activity increased significantly in both groups after exercise (p exercise level at 24 and 48 hours after exercise in both the sexes, (p exercise, the pattern of postexercise release of these markers were found to be similar in both the groups. Accordingly, it has been concluded from the present investigation that high-intensity exercise induces significant oxidative stress and increases indices of skeletal muscle damage in both postpubertal girls and boys. However, postpubertal girls are relatively better protected from oxidative stress and muscle damage as compared to the boys of similar age and physical activity level. It is further evident that sex difference may not be apparent for all the biomarkers of muscle damage in this age group.

  8. Fatigue as Presenting Symptom and a High Burden of Premature Ventricular Contractions Are Independently Associated With Increased Ventricular Wall Stress in Patients With Normal Left Ventricular Function.

    Science.gov (United States)

    van Huls van Taxis, Carine F B; Piers, Sebastiaan R D; de Riva Silva, Marta; Dekkers, Olaf M; Pijnappels, Daniël A; Schalij, Martin J; Wijnmaalen, Adrianus P; Zeppenfeld, Katja

    2015-12-01

    High idiopathic premature ventricular contractions (PVC) burden has been associated with PVC-induced cardiomyopathy. Patients may be symptomatic before left ventricular (LV) dysfunction develops. N-terminal pro-B-type natriuretic peptide (NT-proBNP) and circumferential end-systolic wall stress (cESS) on echocardiography are markers for increased ventricular wall stress. This study aimed to evaluate the relation between presenting symptoms, PVC burden, and increased ventricular wall stress in patients with frequent PVCs and preserved LV function. Eighty-three patients (41 men; 49±15 years) with idiopathic PVCs and normal LV function referred for PVC ablation were included. Type of symptoms (palpitations, fatigue, and [near-]syncope), PVC burden on 24-hour Holter, NT-proBNP levels, and cESS on echocardiography were assessed before and 3 months after ablation. Sustained successful ablation was defined as ≥80% PVC burden reduction during follow-up. Patients were symptomatic for 24 months (Q1-Q3, 16-60); 73% reported palpitations, 47% fatigue, and 30% (near-)syncope. Baseline PVC burden was 23±13%, median NT-proBNP 92 pg/mL (Q1-Q3 50-156), and cESS 143±35 kdyne/cm(2). Fatigue was associated with higher baseline NT-proBNP and cESS (PFatigue was independently associated with a significantly larger reduction in NT-proBNP. In patients with nonsuccessful ablation, NT-proBNP and cESS remained unchanged. In patients with frequent PVCs and preserved LV function, fatigue was associated with higher baseline NT-proBNP and cESS, and with a significantly larger reduction in NT-proBNP after sustained successful ablation. These findings support a link between fatigue and PVC-induced increased ventricular wall stress, despite preserved LV function. © 2015 American Heart Association, Inc.

  9. [Oxidative stress in Masters swimmers following high-intensity (interval) training (HI(I)T)].

    Science.gov (United States)

    Braun, Janina; Masoud, Magd; Brixius, Klara; Brinkmann, Christian

    2016-05-01

    Increased oxidative stress (OS) can promote diseases in the long term, but it can also trigger cellular adaptations in the short term. The present study aims to analyze whether a 3-month high-intensity (interval) training (HI(I)T) affects OS in 24 Masters swimmers (22-67 years) before (= basal) and after an all-out performance (swimming step-test). Data were analyzed for the entire group and differentiated according to sex and age (under 50 years (U50) and over 50 years (O50)). Prior to the HI(I)T intervention, a significant increase in OS from the basal to the all-out value was observed among the entire group and in the O50-subjects (subgroup analysis). Furthermore, significant increases in basal OS were evident for the entire group post-HI(I)T, but OS was only significantly increased in men in the subgroup analysis. No significant results were observed for women and U50-subjects. The response by Masters swimmers to HI(I)T depends on age and sex.

  10. The stress corrosion cracking of type 316 stainless steel in oxygenated and chlorinated high temperature water

    International Nuclear Information System (INIS)

    Congleton, J.; Shih, H.C.; Shoji, T.; Parkins, R.N.

    1985-01-01

    Slow strain rate stress corrosion tests have been performed on Type 316 stainless steel in 265 C water containing from 0 to 45 ppm oxygen and from < 0.1 to 1000 ppm chloride. The main difference between the present data and previously published results, the latter mainly for Type 304 stainless steel, is that as well as cracking occurring in water containing high oxygen and chloride, it is shown that a cracking regime exists at very low oxygen contents for a wide range of chloride contents. The type of cracking varies with the oxygen and chloride content of the water and the most severe cracking was of comparable extent in both the gauge length and the necked region of the specimen. The least severe cracking only caused cracks to occur in the necked region of the specimen and there was a range of oxygen and chloride contents in which no cracking occurred. The rest potential for annealed Type 316 stainless steel has been mapped for a wide range of oxygen and chloride content waters and it is shown that at 265 C the 'no-cracking' regime of the oxygen-chloride diagram corresponds to potentials in the range -200 to +150 mV(SHE). (author)

  11. Spirulina improves antioxidant status by reducing oxidative stress in rabbits fed a high-cholesterol diet.

    Science.gov (United States)

    Kim, Mi Yeon; Cheong, Sun Hee; Lee, Jeung Hee; Kim, Min Ji; Sok, Dai-Eun; Kim, Mee Ree

    2010-04-01

    The beneficial effect of Spirulina (Spirulina platensis) on tissue lipid peroxidation and oxidative DNA damage was tested in the hypercholesterolemic New Zealand White rabbit model. After hypercholesterolemia was induced by feeding a high cholesterol (0.5%) diet (HCD) for 4 weeks, then HCD supplemented with 1% or 5% Spirulina (SP1 or SP5, respectively) was provided for an additional 8 weeks. Spirulina supplementation significantly reduced the increased lipid peroxidation level in HCD-fed rabbits, and levels recovered to control values. Oxidative stress biomarkers such as glutathione, glutathione peroxidase, glutathione reductase, and glutathione S-transferase were significantly improved in the liver and red blood cells of rabbits fed SP1. Furthermore, SP5 induced antioxidant enzyme activity by 3.1-fold for glutathione, 2.5-fold for glutathione peroxidase, 2.7-fold for glutathione reductase, and 2.3-fold for glutathione S-transferase in liver, compared to the HCD group. DNA damage in lymphocytes was significantly reduced in both the SP1 and SP5 groups, based on the comet assay. Findings from the present study suggest that dietary supplementation with Spirulina may be useful to protect the cells from lipid peroxidation and oxidative DNA damage.

  12. Cellular Stress Response Gene Expression During Upper and Lower Body High Intensity Exercises.

    Science.gov (United States)

    Kochanowicz, Andrzej; Sawczyn, Stanisław; Niespodziński, Bartłomiej; Mieszkowski, Jan; Kochanowicz, Kazimierz; Żychowska, Małgorzata

    2017-01-01

    The aim was to compare the effect of upper and lower body high-intensity exercise on chosen genes expression in athletes and non-athletes. Fourteen elite male artistic gymnasts (EAG) aged 20.6 ± 3.3 years and 14 physically active men (PAM) aged 19.9 ± 1.0 years performed lower and upper body 30 s Wingate Tests. Blood samples were collected before, 5 and 30 minutes after each effort to assess gene expression via PCR. Significantly higher mechanical parameters after lower body exercise was observed in both groups, for relative power (8.7 ± 1.2 W/kg in gymnasts, 7.2 ± 1.2 W/kg in controls, p = 0.01) and mean power (6.7 ± 0.7 W/kg in gymnasts, 5.4 ± 0.8 W/kg in controls, p = 0.01). No differences in lower versus upper body gene expression were detected for all tested genes as well as between gymnasts and physical active man. For IL-6 m-RNA time-dependent effect was observed. Because of no significant differences in expression of genes associated with cellular stress response the similar adaptive effect to exercise may be obtained so by lower and upper body exercise.

  13. The draft genome of Tibetan hulless barley reveals adaptive patterns to the high stressful Tibetan Plateau.

    Science.gov (United States)

    Zeng, Xingquan; Long, Hai; Wang, Zhuo; Zhao, Shancen; Tang, Yawei; Huang, Zhiyong; Wang, Yulin; Xu, Qijun; Mao, Likai; Deng, Guangbing; Yao, Xiaoming; Li, Xiangfeng; Bai, Lijun; Yuan, Hongjun; Pan, Zhifen; Liu, Renjian; Chen, Xin; WangMu, QiMei; Chen, Ming; Yu, Lili; Liang, Junjun; DunZhu, DaWa; Zheng, Yuan; Yu, Shuiyang; LuoBu, ZhaXi; Guang, Xuanmin; Li, Jiang; Deng, Cao; Hu, Wushu; Chen, Chunhai; TaBa, XiongNu; Gao, Liyun; Lv, Xiaodan; Abu, Yuval Ben; Fang, Xiaodong; Nevo, Eviatar; Yu, Maoqun; Wang, Jun; Tashi, Nyima

    2015-01-27