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Sample records for adaptive coping mechanisms

  1. Combat health care providers and resiliency: adaptive coping mechanisms during and after deployment.

    PubMed

    Gibbons, Susanne W; Shafer, Michaela; Aramanda, Larry; Hickling, Edward J; Benedek, David M

    2014-05-01

    The purpose of this investigation was to understand the varied health care provider responses to traumas by identifying perceptions of control and self-efficacy, appraisal styles, and postevent coping strategies in active duty military nurses and physicians deployed to combat/terrorist regions. Twenty purposively sampled military health care providers completed a descriptive questionnaire, the Posttraumatic Stress Disorder Checklist, the General Self-Efficacy Scale, and a recorded semistructured interview that was later transcribed and content analyzed. Cognitive-behavioral determinants of healthy response to trauma were used to frame this descriptive interpretive study and to assist with developing a model for healthy adaptation in trauma-exposed health care providers. Participants felt they had the greatest control over their health care provider role in theater, and most expressed a belief that a sense of control and a sense of purpose were important to their coping. All used some form of social support to cope and many found calming activities that allowed for self-reflection to be helpful. Results from this analysis can be used to inform interventions and promote postevent coping behaviors that increase social support, strengthen important bonds, and enhance involvement in activities that elicit positive emotions. Health care providers experienced positive outcomes despite considerable traumatic exposure by using coping strategies that map closely to several principles of psychological first aid. This suggests a need to train all medical personnel in these concepts as they appear helpful in mitigating responses to the stress of combat-related exposures. PMID:23855421

  2. Coping with the Forced Swim Stressor: Towards Understanding an Adaptive Mechanism

    PubMed Central

    de Kloet, E. R.; Molendijk, M. L.

    2016-01-01

    In the forced swim test (FST) rodents progressively show increased episodes of immobility if immersed in a beaker with water from where escape is not possible. In this test, a compound qualifies as a potential antidepressant if it prevents or delays the transition to this passive (energy conserving) behavioural style. In the past decade however the switch from active to passive “coping” was used increasingly to describe the phenotype of an animal that has been exposed to a stressful history and/or genetic modification. A PubMed analysis revealed that in a rapidly increasing number of papers (currently more than 2,000) stress-related immobility in the FST is labeled as a depression-like phenotype. In this contribution we will examine the different phases of information processing during coping with the forced swim stressor. For this purpose we focus on the action of corticosterone that is mediated by the closely related mineralocorticoid receptors (MR) and glucocorticoid receptors (GR) in the limbic brain. The evidence available suggests a model in which we propose that the limbic MR-mediated response selection operates in complementary fashion with dopaminergic accumbens/prefrontal executive functions to regulate the transition between active and passive coping styles. Upon rescue from the beaker the preferred, mostly passive, coping style is stored in the memory via a GR-dependent action in the hippocampal dentate gyrus. It is concluded that the rodent's behavioural response to a forced swim stressor does not reflect depression. Rather the forced swim experience provides a unique paradigm to investigate the mechanistic underpinning of stress coping and adaptation. PMID:27034848

  3. Prochlorococcus and Synechococcus have Evolved Different Adaptive Mechanisms to Cope with Light and UV Stress

    PubMed Central

    Mella-Flores, Daniella; Six, Christophe; Ratin, Morgane; Partensky, Frédéric; Boutte, Christophe; Le Corguillé, Gildas; Marie, Dominique; Blot, Nicolas; Gourvil, Priscillia; Kolowrat, Christian; Garczarek, Laurence

    2012-01-01

    Prochlorococcus and Synechococcus, which numerically dominate vast oceanic areas, are the two most abundant oxygenic phototrophs on Earth. Although they require solar energy for photosynthesis, excess light and associated high UV radiations can induce high levels of oxidative stress that may have deleterious effects on their growth and productivity. Here, we compared the photophysiologies of the model strains Prochlorococcus marinus PCC 9511 and Synechococcus sp. WH7803 grown under a bell-shaped light/dark cycle of high visible light supplemented or not with UV. Prochlorococcus exhibited a higher sensitivity to photoinactivation than Synechococcus under both conditions, as shown by a larger drop of photosystem II (PSII) quantum yield at noon and different diel patterns of the D1 protein pool. In the presence of UV, the PSII repair rate was significantly depressed at noon in Prochlorococcus compared to Synechococcus. Additionally, Prochlorococcus was more sensitive than Synechococcus to oxidative stress, as shown by the different degrees of PSII photoinactivation after addition of hydrogen peroxide. A transcriptional analysis also revealed dramatic discrepancies between the two organisms in the diel expression patterns of several genes involved notably in the biosynthesis and/or repair of photosystems, light-harvesting complexes, CO2 fixation as well as protection mechanisms against light, UV, and oxidative stress, which likely translate profound differences in their light-controlled regulation. Altogether our results suggest that while Synechococcus has developed efficient ways to cope with light and UV stress, Prochlorococcus cells seemingly survive stressful hours of the day by launching a minimal set of protection mechanisms and by temporarily bringing down several key metabolic processes. This study provides unprecedented insights into understanding the distinct depth distributions and dynamics of these two picocyanobacteria in the field. PMID:23024637

  4. Surviving the crisis: Adaptive wisdom, coping mechanisms and local responses to avian influenza threats in Haining, China.

    PubMed

    Zhang, Letian; Pan, Tianshu

    2008-04-01

    Based on ethnographic research conducted in the summer of 2006, this paper examines local responses to the imminent threat of avian flu in Haining County of Zhejiang Province. During our field investigation, we conducted interviews with officials from local medical institutions (including the hospitals, the animal husbandry and veterinary station, and health clinics), to bureaus of public health and agro-economy. We also visited chicken farms, restaurants and farming households. We address the following factors that commonly structured the perceptions and actions of different social actors in the area of study: The changing mode of information-sharing and communication practices in the local communities; the official drive to professionalize the emergency response management system in the county; and the coping mechanisms that helped the villagers and town residents to weather the storm of avian flu. Our field research suggests that collective survival consciousness was translated into a spirit of voluntarism during the crisis. One important practical lesson we have learned from this study is that the adaptive wisdom embedded in local memories demonstrated its operational worth as a resourceful knowledge base for ordinary farmers to deal with food shortage, famine, plague and future pandemics. PMID:27268990

  5. Coping and adaptation process during puerperium

    PubMed Central

    Muñoz de Rodríguez, Lucy; Ruiz de Cárdenas, Carmen Helena

    2012-01-01

    Introduction: The puerperium is a stage that produces changes and adaptations in women, couples and family. Effective coping, during this stage, depends on the relationship between the demands of stressful or difficult situations and the recourses that the puerperal individual has. Roy (2004), in her Middle Range Theory about the Coping and Adaptation Processing, defines Coping as the ''behavioral and cognitive efforts that a person makes to meet the environment demands''. For the puerperal individual, the correct coping is necessary to maintain her physical and mental well being, especially against situations that can be stressful like breastfeeding and return to work. According to Lazarus and Folkman (1986), a resource for coping is to have someone who receives emotional support, informative and / or tangible. Objective: To review the issue of women coping and adaptation during the puerperium stage and the strategies that enhance this adaptation. Methods: search and selection of database articles: Cochrane, Medline, Ovid, ProQuest, Scielo, and Blackwell Synergy. Other sources: unpublished documents by Roy, published books on Roy´s Model, Websites from of international health organizations. Results: the need to recognize the puerperium as a stage that requires comprehensive care is evident, where nurses must be protagonist with the care offered to women and their families, considering the specific demands of this situation and recourses that promote effective coping and the family, education and health services. PMID:24893059

  6. Adaptive Behavior vs Adaptive Skills: Dimensions in Coping Development.

    ERIC Educational Resources Information Center

    Leland, Henry

    This paper views the adaptive behavior of individuals with mental retardation as a coping response to the biological and social demands of the environment. Adaptive skills are contrasted with adaptive behaviors, with skills being based primarily on developing new learning and habituating specific responses. Adaptive behavior represents a more…

  7. Coping with School Adaptation Problems

    ERIC Educational Resources Information Center

    Cowen, Emory L.

    1971-01-01

    Strategems to cope with maladaptation have been limited in effectiveness. Presented are some key problems they present as well as guidelines for a conceptually preferable set of strategems emphasizing principles which should serve to cut down materially on school maladjustment and restore children to effective school function. (Author/BY)

  8. Eating Disorders as Coping Mechanisms

    ERIC Educational Resources Information Center

    Wagener, Amy M.; Much, Kari

    2010-01-01

    This article focuses on the complex nature of eating disorders, specifically highlighting their use as coping mechanisms for underlying emotional and psychological concerns. Case examples of college counseling center clients are discussed in order to illustrate common ways in which eating disorders are utilized by clients with varying…

  9. Involuntary coping mechanisms: a psychodynamic perspective

    PubMed Central

    Vaillant, George E.

    2011-01-01

    Coping responses to stress can be divided into three broad categories. The first coping category involves voluntarily mobilizing social supports. The second category involves voluntary coping strategies like rehearsing responses to danger. The third coping category, like fever and leukocytosis, is involuntary. It entails deploying unconscious homeostatic mechanisms that reduce the disorganizing effects of sudden stress, DSM-5 offers a tentative hierarchy of defenses, from psychotic to immature to mature. The 70-year prospective Study of Development at Harvard provides a clinical validation of this hierarchy Maturity of coping predicted psychosocial adjustment to aging 25 years later, and was associated with not developing symptoms of post-traumatic stress disorder after very severe WWII combat. PMID:22034454

  10. Coping and adaptation in adults living with spinal cord injury.

    PubMed

    Barone, Stacey Hoffman; Waters, Katherine

    2012-10-01

    Biopsychosocial adaptation remains a multifaceted challenge for individuals with spinal cord injury, their families, and healthcare providers alike. The development of frequent medical complications necessitating healthcare interventions is an ongoing, debilitating, and costly problem for those living with spinal cord injuries. Although several demographic variables have been correlated with positive adaptation in individuals with spinal cord injury, the research outcome data present limitations in understanding and facilitating which coping techniques work best to augment biopsychosocial adaptation in this population. Coping facilitates adaptation and adjustment to stress and can help to increase quality of life in people living with spinal cord injury and reduce common complications. The purpose of this study was to determine the extent to which sociodemographic characteristics and hardiness explain coping in 243 adults living with a spinal cord injury. In addition, this study examined which predictors of coping explain biopsychosocial adaptation. A descriptive explanatory design was utilized. Standardized instruments were administered nationally to assess hardiness, coping, and physiological and psychosocial adaptation. Canonical correlation and multiple regression analyses indicated that less educated, less hardy, and recently injured participants were more likely to use escape-avoidance coping and less likely to use social support, problem solving, and positive reappraisal coping behaviors (p < .05). Individuals with paraplegia had a higher level of functional ability, spent less time in rehabilitation, had a greater sense of control, and experienced less frequent complications. The control dimension of hardiness was the only dimension that significantly related to biopsychosocial adaptation within this sample.

  11. [Coping strategies in adaptation of higher education students].

    PubMed

    das Neves Mira Freitas, Helena Cristina

    2007-01-01

    The adjustment to higher education can be understood as a multidimensional process, which requires by the student a development of adaptive skills to a new and dynamic context in itself. To meet these challenges students have to develop effective coping strategies, enabling them to be adapted to the context. The school has a key role in the help it can give to these young people, in order to adapt effectively.

  12. [Coping strategies in adaptation of higher education students].

    PubMed

    das Neves Mira Freitas, Helena Cristina

    2007-01-01

    The adjustment to higher education can be understood as a multidimensional process, which requires by the student a development of adaptive skills to a new and dynamic context in itself. To meet these challenges students have to develop effective coping strategies, enabling them to be adapted to the context. The school has a key role in the help it can give to these young people, in order to adapt effectively. PMID:18372532

  13. Coping Strategies and Adaptation of Mothers of Children with Handicapping Conditions.

    ERIC Educational Resources Information Center

    Hooshyar, Nahid T.

    Mothers' coping mechanisms and adaptations to having a handicapped child were analyzed through extensive structured interviews with mothers of eight preschool-aged Down syndrome children and a language impaired child. Three illustrative case studies are presented, and general conclusions are drawn. Mothers of Down syndrome children go through the…

  14. [Spanish adaptation of Hobfoll's Strategic Approach to Coping Scale (SACS)].

    PubMed

    Pedrero Pérez, Eduardo J; Santed Germán, Miguel A; Pérez García, Ana M

    2012-01-01

    The present research adapted the Strategic Approach to Coping Scale (SACS), developed by Hobfoll and colleagues, to the Spanish population. SACS is an instrument derived from Hobfoll's Conservation of Resources Theory, which emphasises the contribution of social factors to coping processes. This instrument assesses coping strategies in 9-subscales, organised in three dimensions: orientation to the problem (active/passive), use of social resources (prosocial/antisocial), and orientation to others involved (direct/indirect). The Spanish version, administered to a non-clinical sample (N= 767), found 7-subscales structured in prosocial/antisocial, active/passive and reflexive/intuitive dimensions, with adequate reliability and construct validity. To conclude, the Spanish SACS is a potentially useful and reliable instrument for research and clinical purposes, mainly in areas in which social components need to be explicitly considered.

  15. Personality and illness adaptation in adults with type 1 diabetes: the intervening role of illness coping and perceptions.

    PubMed

    Rassart, Jessica; Luyckx, Koen; Klimstra, Theo A; Moons, Philip; Groven, Chris; Weets, Ilse

    2014-03-01

    Inspired by the common sense model, the present cross-sectional study examined illness perceptions and coping as intervening mechanisms in the relationship between Big Five personality traits and illness adaptation in adults with Type 1 diabetes. A total of 368 individuals with Type 1 diabetes (18-35 years old) completed questionnaires on personality, diabetes-related problems, illness perceptions, and illness coping. First, Neuroticism, Agreeableness, and Conscientiousness predicted patients' illness adaptation, above and beyond the effects of sex, age, and illness duration. Second, illness coping was found to be an important mediating mechanism in the relationship between the Big Five and illness adaptation. Finally, perceived consequences and perceived personal control partially mediated the relationship between the Big Five and illness coping. These findings underscore the importance of examining patients' personality to shed light on their daily functioning and, hence, call for tailored intervention programs which take into account the personality of the individual patient.

  16. Coping Mechanisms of Unemployed African Men with Dependents.

    ERIC Educational Resources Information Center

    van der Merwe, Pauline; Greeff, Abraham P.

    2003-01-01

    Evaluates the efficiency of the coping mechanisms of 82 unemployed African men with dependents. Results revealed significant relationships between perceived stress and stressful life events, as well as between perceived stress and four groups of coping mechanisms, the strongest relationships being reported for stressful life events, psychological…

  17. Internet Addiction and Psychosocial Maladjustment: Avoidant Coping and Coping Inflexibility as Psychological Mechanisms.

    PubMed

    Cheng, Cecilia; Sun, Peizhen; Mak, Kwok-Kei

    2015-09-01

    This 6 month prospective study systematically tested some multivariate models that advanced the understanding of the psychological mechanisms underlying Internet addiction and psychosocial maladjustment. On the basis of previous theories, avoidant coping and coping inflexibility were proposed as underlying mechanisms. Participants were 271 Chinese undergraduates (75% women, Mage=20.49) who took part in both phases of this study. Structural equation modeling was performed to obtain the best fit models for both the cross-sectional and the prospective data. The cross-sectional model testing revealed statistically significant mediating effects for both avoidant coping (β=0.149 [95% CI 0.071-0.226], p=0.002) and coping flexibility (β=0.048 [95% CI 0.013-0.081], p=0.032). The prospective model testing further showed that avoidant coping mediated the relationship between Internet addiction and Time 2 psychosocial maladjustment (β=0.141 [95% CI 0.065-0.216], p=0.005), as well as that between coping flexibility and Time 2 psychosocial maladjustment (β=-0.096 [95% CI -0.161 to -0.031], p=0.015). This study was the first to establish theory-driven models, which unveiled an inflexible, avoidant coping style as psychological mechanisms that explained the link between Internet addiction and psychosocial maladjustment.

  18. Coping and Defense Mechanisms of Mothers of Learning Disabled Children.

    ERIC Educational Resources Information Center

    Faerstein, Leslie Morrison

    1986-01-01

    Mothers (N=24) generally evidenced coping mechanisms when involved with medical, social, and educational agencies, and were able to obtain services. However, coping functions broke down in direct confrontation with the child. Mothers, contrary to traditional attitudes, experienced relief at receiving a diagnosis, confirming their suspicions rather…

  19. Adaptive Capacity in Tanzanian Maasailand: Changing strategies to cope with drought in fragmented landscapes

    PubMed Central

    Riosmena, Fernando

    2014-01-01

    This study examines the ways in which the adaptive capacity of households to climatic events varies within communities and is mediated by institutional and landscape changes. We present qualitative and quantitative data from two Maasai communities differentially exposed to the devastating drought of 2009 in Northern Tanzania. We show how rangeland fragmentation combined with the decoupling of institutions and landscapes are affecting pastoralists ability to cope with drought. Our data highlight that mobility remains a key coping mechanism for pastoralists to avoid cattle loss during a drought. However, mobility is now happening in new ways that require not only large amounts of money but new forms of knowledge and connections outside of customary reciprocity networks. Those least affected by the drought, in terms of cattle lost, were those with large herds who were able to sell some of their cattle and to pay for private access to pastures outside of Maasai areas. Drawing on an entitlements framework, we argue that the new coping mechanisms are not available to all, could be making some households more vulnerable to climate change, and reduce the adaptive capacity of the overall system as reciprocity networks and customary institutions are weakened. As such, we posit that adaptive capacity to climate change is uneven within and across communities, is scale-dependent, and is intimately tied to institutional and landscape changes. PMID:25400331

  20. Perceived Control and Adaptive Coping: Programs for Adolescent Students Who Have Learning Disabilities

    ERIC Educational Resources Information Center

    Firth, Nola; Frydenberg, Erica; Greaves, Daryl

    2008-01-01

    This study explored the effect of a coping program and a teacher feedback intervention on perceived control and adaptive coping for 98 adolescent students who had specific learning disabilities. The coping program was modified to build personal control and to address the needs of students who have specific learning disabilities. The teacher…

  1. Student Teacher Stress and Coping Mechanisms.

    ERIC Educational Resources Information Center

    Hemmings, Brian; Hockley, Tania

    2002-01-01

    Surveys of 43 student teachers taking a 9 week practicum in rural Australian primary schools and case studies of four of them found that student teacher stress diminished over time. Five coping strategies were identified: communicating with others, self help, relaxation/recreation, teaching and managing, and organization. (Contains 32 references.)…

  2. Vulnerability, Sensitivity, and Coping/Adaptive Capacity Worldwide

    SciTech Connect

    Malone, Elizabeth L.; Brenkert, Antoinette L.

    2009-10-01

    Research and analyses have repeatedly shown that impacts of climate change will be unevenly distributed and will affect various societies in various ways. The severity of impacts will depend in part on ability to cope in the short term and adapt in the longer term. However, it has been difficult to find a comparative basis on which to assess differential impacts of climate change. This chapter describes the Vulnerability-Resilience Indicator Model that uses 18 proxy indicators, grouped into 8 elements, to assess on a quantitative basis the comparative potential vulnerability and resilience of countries to climate change. The model integrates socioeconomic and environmental information such as land use, crop production, water availability, per capita GDP, inequality, and health status. Comparative results for 160 countries are presented and analyzed.

  3. [Phenylketonuria: illness experience and coping mechanisms].

    PubMed

    Weglage, J; Fünders, B; von Teeffelen-Heithoff, A; Ullrich, K

    1993-09-01

    If patients with PKU follow a strict diet low in phenylalanine from soon after birth their intellectual and psychomotor development will be within the normal range. Recent studies have shown that it is necessary to continue the burdensome diet throughout one's life. This is in contrast to past practice and puts additional emphasis on psychosocial aspects of PKU. In the present retrospective study we investigated how adolescent patients and their relatives' experience and cope with this chronic disease. PMID:8237123

  4. Development of Maladaptive Coping: A Functional Adaptation to Chronic, Uncontrollable Stress

    PubMed Central

    Wadsworth, Martha E.

    2015-01-01

    Health disparities are rooted in childhood and stem from adverse early environments that damage physiologic stress-response systems. Developmental psychobiological models of the effects of chronic stress account for both the negative effects of a stress-response system calibrated to a dangerous and unpredictable environment from a health perspective, and the positive effects of such an adaptively calibrated stress response from a functional perspective. Our research suggests that contexts that produce functionally adapted physiologic responses to stress also encourage a functionally adapted coping response—coping that can result in maladjustment in physical and mental health, but enables children to grow and develop within those contexts. In this article, I highlight the value of reframing maladaptive coping as functional adaptation to understand more completely the development of children’s coping in different contexts, and the value of such a conceptual shift for coping-based theory, research, and intervention. PMID:26019717

  5. Change in coping and defense mechanisms across adulthood: longitudinal findings in a European American sample.

    PubMed

    Diehl, Manfred; Chui, Helena; Hay, Elizabeth L; Lumley, Mark A; Grühn, Daniel; Labouvie-Vief, Gisela

    2014-02-01

    This study examined longitudinal changes in coping and defense mechanisms in an age- and gender-stratified sample of 392 European American adults. Nonlinear age-related changes were found for the coping mechanisms of sublimation and suppression and the defense mechanisms of intellectualization, doubt, displacement, and regression. The change trajectories for sublimation and suppression showed that their use increased from adolescence to late middle age and early old age and remained mostly stable into late old age. The change trajectory for intellectualization showed that the use of this defense mechanism increased from adolescence to middle age, remained stable until late midlife, and started to decline thereafter. The defense mechanisms of doubt, displacement, and regression showed decreases from adolescence until early old age, with increases occurring again after the age of 65. Linear age-related decreases were found for the coping mechanism of ego regression and the defense mechanisms of isolation and rationalization. Gender and socioeconomic status were associated with the mean levels of several coping and defense mechanisms but did not moderate age-related changes. Increases in ego level were associated with increased use of the defense mechanism intellectualization and decreased use of the defense mechanisms of doubt and displacement. Overall, these findings in a European American sample suggest that most individuals showed development in the direction of more adaptive and less maladaptive coping and defense strategies from adolescence until late middle age or early old age. However, in late old age this development was reversed, presenting potential challenges to the adaptive capacity of older adults.

  6. Coping with thermal challenges: physiological adaptations to environmental temperatures.

    PubMed

    Tattersall, Glenn J; Sinclair, Brent J; Withers, Philip C; Fields, Peter A; Seebacher, Frank; Cooper, Christine E; Maloney, Shane K

    2012-07-01

    Temperature profoundly influences physiological responses in animals, primarily due to the effects on biochemical reaction rates. Since physiological responses are often exemplified by their rate dependency (e.g., rate of blood flow, rate of metabolism, rate of heat production, and rate of ion pumping), the study of temperature adaptations has a long history in comparative and evolutionary physiology. Animals may either defend a fairly constant temperature by recruiting biochemical mechanisms of heat production and utilizing physiological responses geared toward modifying heat loss and heat gain from the environment, or utilize biochemical modifications to allow for physiological adjustments to temperature. Biochemical adaptations to temperature involve alterations in protein structure that compromise the effects of increased temperatures on improving catalytic enzyme function with the detrimental influences of higher temperature on protein stability. Temperature has acted to shape the responses of animal proteins in manners that generally preserve turnover rates at animals' normal, or optimal, body temperatures. Physiological responses to cold and warmth differ depending on whether animals maintain elevated body temperatures (endothermic) or exhibit minimal internal heat production (ectothermic). In both cases, however, these mechanisms involve regulated neural and hormonal over heat flow to the body or heat flow within the body. Examples of biochemical responses to temperature in endotherms involve metabolic uncoupling mechanisms that decrease metabolic efficiency with the outcome of producing heat, whereas ectothermic adaptations to temperature are best exemplified by the numerous mechanisms that allow for the tolerance or avoidance of ice crystal formation at temperatures below 0°C.

  7. Coping with Work Stressors in Nursing. Effects of Adaptive versus Maladaptive Strategies.

    ERIC Educational Resources Information Center

    Parasuraman, Saroj; Hansen, Donna

    1987-01-01

    The effect of coping behaviors on nurses' affective reactions to work-generated stressors was assessed, using data gathered from 215 nurses in a medical center hospital in the Midwest. Adaptive coping, reflecting problem-solving behaviors, was found to moderate the relationships of work overload and resource inadequacy with felt stress. (Author/CH)

  8. EFL Foreign Teacher Stress in Korea: Causes and Coping Mechanisms

    ERIC Educational Resources Information Center

    Brundage, Gregory C.

    2007-01-01

    Survey study of 53 foreign EFL teachers in Jeonju City, South Korea looks at causes of teacher stress and coping mechanisms between the years of 2004 and 2006. Results show foreign EFL teachers report moderate levels of stress and attribute stresses in roughly equal measures to student misbehavior and school director/administrative sources. Survey…

  9. Physiological mechanisms in coping with climate change.

    PubMed

    Fuller, Andrea; Dawson, Terence; Helmuth, Brian; Hetem, Robyn S; Mitchell, Duncan; Maloney, Shane K

    2010-01-01

    Although many studies have modeled the effects of climate change on future species distributions and extinctions, the theoretical approach most commonly used-climate envelope modeling-typically ignores the potential physiological capacity of animals to respond to climate change. We explore the consequences of the phenotypic plasticity available to animals, by examining physiological responses of free-living animals in their natural habitats and by applying integrative, mechanistic models of heat exchange in invertebrates and humans. Specifically, we explore how behavioral, autonomic, and morphological modifications such as nocturnal activity, selective brain cooling, and body color may potentially serve as buffers to the consequences of climate change. Although some species may adapt to climate change through phenotypic plasticity, there are significant limits to this strategy. Furthermore, predictions of the response of organisms to changes in climate can be erroneous when modeled at large scales using coarse spatial or temporal data. Environmental heterogeneity can provide habitats suitable for species even though large-scale changes in the climate might predict a species' extinction. A detailed understanding of physiology, combined with integrative biophysical modeling and ecological manipulation, provides a powerful tool for predicting future ecological patterns and managing their consequences.

  10. Stress Coping Mechanisms in Elderly Adults: An Initial Study of Recreational and Other Coping Behaviors in Nursing Home Patients

    ERIC Educational Resources Information Center

    Hunter, I. Roy; Gillen, Mark C.

    2009-01-01

    Residents (N = 32) of 3 skilled nursing homes participated in a study designed to document the nature of the stressors they experienced and the coping mechanisms they used. Medical issues were the most common stressors. The most common coping responses were prayer, reading, watching television, listening to music, and talking to friends and…

  11. Family Adaptation and Coping among Siblings of Cancer Patients, Their Brothers and Sisters, and Nonclinical Controls.

    ERIC Educational Resources Information Center

    Madan-Swain, Avi; And Others

    1993-01-01

    Examined coping and family adaptation in siblings (n=32) of cancer patients, their ill brothers and sisters (n=19), and control group of nonclinical children (n=10) with healthy siblings. Gender and age of sibling, birth order, and number of siblings were examined. Found better adaptation in larger families and decreased family involvement among…

  12. Compulsive Eating: The Emotional Link of Its Use as a Coping Mechanism for Resident Freshman Female College Students.

    ERIC Educational Resources Information Center

    Beylerian, Nvair Kadian

    An 18-year old's freshman year in college is not only a test of his or her intellect, but also a test in social skills, adaptability to new living situations, and other conditions. This study examined the link of emotions to compulsive eating and its use as a coping mechanism for female college students. It explores the stresses of the transition…

  13. The Sense of Self-Continuity as a Resource in Adaptive Coping with Job Loss

    ERIC Educational Resources Information Center

    Sadeh, Noa; Karniol, Rachel

    2012-01-01

    This study examined the relation between the sense of self-continuity, defined as the ability to perceive oneself as extending temporally backwards into the past and forwards into the future, and the adaptiveness of strategies of coping with job loss. We created a web site that was linked to several Israeli web sites dealing with unemployment in…

  14. Bibliography of Selected Literature in the 1970s Related to Crises, Family Stress, Coping and Adaptation.

    ERIC Educational Resources Information Center

    Chesser, Barbara

    This bibliography of literature from the 1970s related to crises, family stress, coping, and adaptation contains references of particular interest to professionals in the areas of counseling, education, and family social, psychological and health services. The bibliography is divided into 26 categories; references are classified according to major…

  15. At a Foreign University: An International Study of Adaptation and Coping.

    ERIC Educational Resources Information Center

    Klineberg, Otto; Hull, Frank W., IV

    An international study of adaptation and coping of students, faculty, and administrators involved with foreign student exchange is examined using data obtained in 11 countries--Brazil, Canada, the Federal Republic of Germany, France, Hong Kong, India, Iran, Japan, Kenya, the United Kingdom, and the United States. The following are included:…

  16. The Mechanism by Which Interpersonal Coping Flexibility Influences Self-Esteem

    ERIC Educational Resources Information Center

    Gan, Yiqun; Liu, Jun

    2012-01-01

    The objectives of the present study were to conceptualize interpersonal coping flexibility and to explore how it influences personal adaptation. Two hundred sixty two university students were classified based on their responses to prompts about their degree of prioritizing harmony and the number of coping strategies they employed when dealing with…

  17. Change in Coping and Defense Mechanisms across Adulthood: Longitudinal Findings in a European American Sample

    ERIC Educational Resources Information Center

    Diehl, Manfred; Chui, Helena; Hay, Elizabeth L.; Lumley, Mark A.; Grühn, Daniel; Labouvie-Vief, Gisela

    2014-01-01

    This study examined longitudinal changes in coping and defense mechanisms in an age- and gender-stratified sample of 392 European American adults. Nonlinear age-related changes were found for the coping mechanisms of sublimation and suppression and the defense mechanisms of intellectualization, doubt, displacement, and regression. The change…

  18. Cultural adaptation of the Brief COPE for Persons Living with HIV/AIDS in Southern India

    PubMed Central

    Mohanraj, Rani; Jeyaseelan, Visalakshi; Kumar, Shuba; Mani, Thenmozhi; Rao, Deepa; Murray, Katherine R.; Manhart, Lisa E.

    2014-01-01

    Physical and psychological stressors of HIV infection demand adequate coping responses from persons living with HIV/AIDS (PLHA) and coping strategies may vary by cultural context. The Brief COPE is a well validated scale that has been used extensively to assess coping with cancer, depression, and HIV infection in other settings, but never in India. In this study we translated and validated the 28 item Brief COPE among 299 PLHA in South India, assessing reliability, validity, and cultural appropriateness. Although the original scale demonstrated acceptable internal consistency (alpha=0.70) and good convergent validity with depression, the test-retest reliability was marginal (test-retest=0.6) and the original factor structure demonstrated poor fit in a confirmatory factor analysis (CFA). An exploratory factor analysis (EFA) yielded a 16 item scale with 5 factors (active planning, social support, avoidant emotions, substance use, religion). A second CFA demonstrated good model fit and acceptable reliability (alpha=0.61) of the adapted scale. PMID:25096895

  19. Learning to cope with stress: psychobiological mechanisms of stress resilience.

    PubMed

    Cabib, Simona; Campus, Paolo; Colelli, Valentina

    2012-01-01

    Stress is the main non-genetic source of psychopathology. Therefore, the identification of neurobiological bases of resilience, the resistance to pathological outcomes of stress, is a most relevant topic of research. It is an accepted view that resilient individuals are those who do not develop helplessness, or other depression-like phenotypes, following a history of stress. In the present review, we discuss the phenotypic differences between mice of the inbred C57BL/6J and DBA/2J strains that could be associated with the strain-specific resistance to helplessness observable in DBA/2J mice. The reviewed results support the hypothesis that resilience to stress-promoted helplessness develops through interactions between a specific genetic makeup and a history of stress, and is associated with an active coping style, a bias toward the use of stimulus-response learning, and specific adaptive changes of mesoaccumbens dopamine transmission under stress. Finally, evidence that compulsivity represents a side effect of the neuroadaptive processes fostering resistance to develop depressive-like phenotypes under stress is discussed.

  20. Pre-adaptations and the evolution of pollination by sexual deception: Cope's rule of specialization revisited.

    PubMed

    Vereecken, Nicolas J; Wilson, Carol A; Hötling, Susann; Schulz, Stefan; Banketov, Sergey A; Mardulyn, Patrick

    2012-12-01

    Pollination by sexual deception is arguably one of the most unusual liaisons linking plants and insects, and perhaps the most illustrative example of extreme floral specialization in angiosperms. While considerable progress has been made in understanding the floral traits involved in sexual deception, less is known about how this remarkable mimicry system might have arisen, the role of pre-adaptations in promoting its evolution and its extent as a pollination mechanism outside the few groups of plants (primarily orchids) where it has been described to date. In the Euro-Mediterranean region, pollination by sexual deception is traditionally considered to be the hallmark of the orchid genus Ophrys. Here, we introduce two new cases outside of Ophrys, in plant groups dominated by generalized, shelter-mimicking species. On the basis of phylogenetic reconstructions of ancestral pollination strategies, we provide evidence for independent and bidirectional evolutionary transitions between generalized (shelter mimicry) and specialized (sexual deception) pollination strategies in three groups of flowering plants, and suggest that pseudocopulation has evolved from pre-adaptations (floral colours, shapes and odour bouquets) that selectively attract male pollinators through shelter mimicry. These findings, along with comparative analyses of floral traits (colours and scents), shed light on particular phenotypic changes that might have fuelled the parallel evolution of these extraordinary pollination strategies. Collectively, our results provide the first substantive insights into how pollination sexual deception might have evolved in the Euro-Mediterranean region, and demonstrate that even the most extreme cases of pollinator specialization can reverse to more generalized interactions, breaking 'Cope's rule of specialization'.

  1. Coping, acculturation, and psychological adaptation among migrants: a theoretical and empirical review and synthesis of the literature

    PubMed Central

    Kuo, Ben C.H.

    2014-01-01

    Given the continuous, dynamic demographic changes internationally due to intensive worldwide migration and globalization, the need to more fully understand how migrants adapt and cope with acculturation experiences in their new host cultural environment is imperative and timely. However, a comprehensive review of what we currently know about the relationship between coping behavior and acculturation experience for individuals undergoing cultural changes has not yet been undertaken. Hence, the current article aims to compile, review, and examine cumulative cross-cultural psychological research that sheds light on the relationships among coping, acculturation, and psychological and mental health outcomes for migrants. To this end, this present article reviews prevailing literature pertaining to: (a) the stress and coping conceptual perspective of acculturation; (b) four theoretical models of coping, acculturation and cultural adaptation; (c) differential coping pattern among diverse acculturating migrant groups; and (d) the relationship between coping variabilities and acculturation levels among migrants. In terms of theoretical understanding, this review points to the relative strengths and limitations associated with each of the four theoretical models on coping-acculturation-adaptation. These theories and the empirical studies reviewed in this article further highlight the central role of coping behaviors/strategies in the acculturation process and outcome for migrants and ethnic populations, both conceptually and functionally. Moreover, the review shows that across studies culturally preferred coping patterns exist among acculturating migrants and migrant groups and vary with migrants' acculturation levels. Implications and limitations of the existing literature for coping, acculturation, and psychological adaptation research are discussed and recommendations for future research are put forth. PMID:25750766

  2. Coping Mechanisms for Crop Plants in Drought-prone Environments

    PubMed Central

    Neumann, Peter M.

    2008-01-01

    Background Drought is a major limitation to plant productivity. Various options are available for increasing water availability and sustaining growth of crop plants in drought-prone environments. Scope After a general introduction to the problems of water availability, this review focuses on a critical evaluation of recent progress in unravelling mechanisms for modifying plant growth responses to drought. Conclusions Investigations of key regulatory mechanisms integrating plant growth responses to water deficits at the whole-organism, cellular and genomic levels continue to provide novel and exiting research findings. For example, recent reports contradict the widespread conception that root-derived abscisic acid is necessarily involved in signalling for stomatal and shoot-growth responses to soil water deficits. The findings bring into question the theoretical basis for alternate-side root-irrigation techniques. Similarly, recent reports indicate that increased ABA production or increased aquaporin expression did not lead to improved drought resistance. Other reports have concerned key genes and proteins involved in regulation of flowering (FT), vegetative growth (DELLA), leaf senescence (IPT) and desiccation tolerance (LEA). Introgression of such genes, with suitable promoters, can greatly impact on whole-plant responses to drought. Further developments could facilitate the introduction by breeders of new crop varieties with growth physiologies tailored to improved field performance under drought. Parallel efforts to encourage the introduction of supplementary irrigation with water made available by improved conservation measures and by sea- or brackish-water desalination, will probably provide comprehensive solutions to coping with drought-prone environments. PMID:18252764

  3. Evolution of adaptation mechanisms: Adaptation energy, stress, and oscillating death.

    PubMed

    Gorban, Alexander N; Tyukina, Tatiana A; Smirnova, Elena V; Pokidysheva, Lyudmila I

    2016-09-21

    In 1938, Selye proposed the notion of adaptation energy and published 'Experimental evidence supporting the conception of adaptation energy.' Adaptation of an animal to different factors appears as the spending of one resource. Adaptation energy is a hypothetical extensive quantity spent for adaptation. This term causes much debate when one takes it literally, as a physical quantity, i.e. a sort of energy. The controversial points of view impede the systematic use of the notion of adaptation energy despite experimental evidence. Nevertheless, the response to many harmful factors often has general non-specific form and we suggest that the mechanisms of physiological adaptation admit a very general and nonspecific description. We aim to demonstrate that Selye׳s adaptation energy is the cornerstone of the top-down approach to modelling of non-specific adaptation processes. We analyze Selye׳s axioms of adaptation energy together with Goldstone׳s modifications and propose a series of models for interpretation of these axioms. Adaptation energy is considered as an internal coordinate on the 'dominant path' in the model of adaptation. The phenomena of 'oscillating death' and 'oscillating remission' are predicted on the base of the dynamical models of adaptation. Natural selection plays a key role in the evolution of mechanisms of physiological adaptation. We use the fitness optimization approach to study of the distribution of resources for neutralization of harmful factors, during adaptation to a multifactor environment, and analyze the optimal strategies for different systems of factors.

  4. The adaptive problems of female teenage refugees and their behavioral adjustment methods for coping

    PubMed Central

    Mhaidat, Fatin

    2016-01-01

    This study aimed at identifying the levels of adaptive problems among teenage female refugees in the government schools and explored the behavioral methods that were used to cope with the problems. The sample was composed of 220 Syrian female students (seventh to first secondary grades) enrolled at government schools within the Zarqa Directorate and who came to Jordan due to the war conditions in their home country. The study used the scale of adaptive problems that consists of four dimensions (depression, anger and hostility, low self-esteem, and feeling insecure) and a questionnaire of the behavioral adjustment methods for dealing with the problem of asylum. The results indicated that the Syrian teenage female refugees suffer a moderate degree of adaptation problems, and the positive adjustment methods they have used are more than the negatives. PMID:27175098

  5. Molecular mechanisms of temperature adaptation.

    PubMed

    Bagriantsev, Sviatoslav N; Gracheva, Elena O

    2015-08-15

    Thermal perception is a fundamental physiological process pertaining to the vast majority of organisms. In vertebrates, environmental temperature is detected by the primary afferents of the somatosensory neurons in the skin, which express a 'choir' of ion channels tuned to detect particular temperatures. Nearly two decades of research have revealed a number of receptor ion channels that mediate the perception of several temperature ranges, but most still remain molecularly orphaned. Yet even within this well-researched realm, most of our knowledge largely pertains to two closely related species of rodents, mice and rats. While these are standard biomedical research models, mice and rats provide a limited perspective to elucidate the general principles that drive somatosensory evolution. In recent years, significant advances have been made in understanding the molecular mechanism of temperature adaptation in evolutionarily distant vertebrates and in organisms with acute thermal sensitivity. These studies have revealed the remarkable versatility of the somatosensory system and highlighted adaptations at the molecular level, which often include changes in biophysical properties of ion channels from the transient receptor potential family. Exploiting non-standard animal models has the potential to provide unexpected insights into general principles of thermosensation and thermoregulation, unachievable using the rodent model alone.

  6. Molecular mechanisms of temperature adaptation

    PubMed Central

    Bagriantsev, Sviatoslav N; Gracheva, Elena O

    2015-01-01

    Thermal perception is a fundamental physiological process pertaining to the vast majority of organisms. In vertebrates, environmental temperature is detected by the primary afferents of the somatosensory neurons in the skin, which express a ‘choir’ of ion channels tuned to detect particular temperatures. Nearly two decades of research have revealed a number of receptor ion channels that mediate the perception of several temperature ranges, but most still remain molecularly orphaned. Yet even within this well-researched realm, most of our knowledge largely pertains to two closely related species of rodents, mice and rats. While these are standard biomedical research models, mice and rats provide a limited perspective to elucidate the general principles that drive somatosensory evolution. In recent years, significant advances have been made in understanding the molecular mechanism of temperature adaptation in evolutionarily distant vertebrates and in organisms with acute thermal sensitivity. These studies have revealed the remarkable versatility of the somatosensory system and highlighted adaptations at the molecular level, which often include changes in biophysical properties of ion channels from the transient receptor potential family. Exploiting non-standard animal models has the potential to provide unexpected insights into general principles of thermosensation and thermoregulation, unachievable using the rodent model alone. PMID:25433072

  7. Molecular mechanisms of temperature adaptation.

    PubMed

    Bagriantsev, Sviatoslav N; Gracheva, Elena O

    2015-08-15

    Thermal perception is a fundamental physiological process pertaining to the vast majority of organisms. In vertebrates, environmental temperature is detected by the primary afferents of the somatosensory neurons in the skin, which express a 'choir' of ion channels tuned to detect particular temperatures. Nearly two decades of research have revealed a number of receptor ion channels that mediate the perception of several temperature ranges, but most still remain molecularly orphaned. Yet even within this well-researched realm, most of our knowledge largely pertains to two closely related species of rodents, mice and rats. While these are standard biomedical research models, mice and rats provide a limited perspective to elucidate the general principles that drive somatosensory evolution. In recent years, significant advances have been made in understanding the molecular mechanism of temperature adaptation in evolutionarily distant vertebrates and in organisms with acute thermal sensitivity. These studies have revealed the remarkable versatility of the somatosensory system and highlighted adaptations at the molecular level, which often include changes in biophysical properties of ion channels from the transient receptor potential family. Exploiting non-standard animal models has the potential to provide unexpected insights into general principles of thermosensation and thermoregulation, unachievable using the rodent model alone. PMID:25433072

  8. Early change in defence mechanisms and coping in short-term dynamic psychotherapy: relations with symptoms and alliance.

    PubMed

    Kramer, Ueli; De Roten, Yves; Michel, Luc; Despland, Jean-Nicholas

    2009-01-01

    Several patient-related variables have already been investigated as predictors of change in psychodynamic psychotherapy. Defensive functioning is one of them. However, few studies have investigated adaptational processes, encompassing defence mechanisms and coping, from an integrative or comparative viewpoint. This study includes 32 patients, mainly diagnosed with adjustment disorder and undergoing time-limited psychodynamic psychotherapy lasting up to 40 sessions, and will focus on early change in defence and coping. Observer-rater methodology was applied to the transcripts of two sessions of the first part of the psychotherapeutic process. It is assumed that the contextual-relational variable of therapeutic alliance intervenes as moderator on change in adaptational processes. Results corroborated the hypothesis, but only for coping, whereas for defences, overall functioning remained stable over the first 20 sessions of psychotherapy. These results are discussed within the framework of disentangling processes underlying adaptation, i.e., related to issues on trait and state aspects, as well as the role of the therapeutic alliance.

  9. Adaptive Coping under Conditions of Extreme Stress: Multilevel Influences on the Determinants of Resilience in Maltreated Children

    ERIC Educational Resources Information Center

    Cicchetti, Dante; Rogosch, Fred A.

    2009-01-01

    The study of resilience in maltreated children reveals the possibility of coping processes and resources on multiple levels of analysis as children strive to adapt under conditions of severe stress. In a maltreating context, aspects of self-organization, including self-esteem, self-reliance, emotion regulation, and adaptable yet reserved…

  10. Physiological mechanisms used by fish to cope with salinity stress.

    PubMed

    Kültz, Dietmar

    2015-06-01

    Salinity represents a critical environmental factor for all aquatic organisms, including fishes. Environments of stable salinity are inhabited by stenohaline fishes having narrow salinity tolerance ranges. Environments of variable salinity are inhabited by euryhaline fishes having wide salinity tolerance ranges. Euryhaline fishes harbor mechanisms that control dynamic changes in osmoregulatory strategy from active salt absorption to salt secretion and from water excretion to water retention. These mechanisms of dynamic control of osmoregulatory strategy include the ability to perceive changes in environmental salinity that perturb body water and salt homeostasis (osmosensing), signaling networks that encode information about the direction and magnitude of salinity change, and epithelial transport and permeability effectors. These mechanisms of euryhalinity likely arose by mosaic evolution involving ancestral and derived protein functions. Most proteins necessary for euryhalinity are also critical for other biological functions and are preserved even in stenohaline fish. Only a few proteins have evolved functions specific to euryhaline fish and they may vary in different fish taxa because of multiple independent phylogenetic origins of euryhalinity in fish. Moreover, proteins involved in combinatorial osmosensing are likely interchangeable. Most euryhaline fishes have an upper salinity tolerance limit of approximately 2× seawater (60 g kg(-1)). However, some species tolerate up to 130 g kg(-1) salinity and they may be able to do so by switching their adaptive strategy when the salinity exceeds 60 g kg(-1). The superior salinity stress tolerance of euryhaline fishes represents an evolutionary advantage favoring their expansion and adaptive radiation in a climate of rapidly changing and pulsatory fluctuating salinity. Because such a climate scenario has been predicted, it is intriguing to mechanistically understand euryhalinity and how this complex

  11. Mixed-gender groups: coping strategies and factors of psychological adaptation in a polar environment.

    PubMed

    Rosnet, Elisabeth; Jurion, Sylvie; Cazes, Geneviève; Bachelard, Claude

    2004-07-01

    The polar environment is often seen as a good analog for long-term space missions in terms of isolation and confinement. This paper focuses on the psychological adaptation of both the men and women in mixed-gender groups in the French polar station Dumont d'Urville. The first 49 expeditions to this station were composed of men only in groups of 25-30. In 2000, two women were included in the first mixed-gender wintering group, followed by five women in 2001. This study on coping strategies and psychological adaptation was included in an end-of-mission debriefing performed by a psychologist. Data were collected using a few quantitative tools and a semi-structured interview, and focused on adaptation to wintering, coping strategies, and information on interpersonal relationships. Including women in a wintering group seems to have had positive effects on the general climate of the group by reducing men's rude behavior, but it also seems to be an important stressor for both men and women when the females' average age is close to the males' because seduction behaviors appear and rivalry, frustration, and sexual harassment frequently result. The use of problem-oriented strategies helps women to adapt. There are strong arguments indicating that living in an isolated and confined environment magnifies the usual difficulties that arise in mixed-gender relationships. Difficulties may be magnified in space since the group size is smaller and the confinement more extreme. This implies the need for rigorous select-in criteria for both men and women, especially for relational criteria, and for group training after selection.

  12. Mixed-gender groups: coping strategies and factors of psychological adaptation in a polar environment.

    PubMed

    Rosnet, Elisabeth; Jurion, Sylvie; Cazes, Geneviève; Bachelard, Claude

    2004-07-01

    The polar environment is often seen as a good analog for long-term space missions in terms of isolation and confinement. This paper focuses on the psychological adaptation of both the men and women in mixed-gender groups in the French polar station Dumont d'Urville. The first 49 expeditions to this station were composed of men only in groups of 25-30. In 2000, two women were included in the first mixed-gender wintering group, followed by five women in 2001. This study on coping strategies and psychological adaptation was included in an end-of-mission debriefing performed by a psychologist. Data were collected using a few quantitative tools and a semi-structured interview, and focused on adaptation to wintering, coping strategies, and information on interpersonal relationships. Including women in a wintering group seems to have had positive effects on the general climate of the group by reducing men's rude behavior, but it also seems to be an important stressor for both men and women when the females' average age is close to the males' because seduction behaviors appear and rivalry, frustration, and sexual harassment frequently result. The use of problem-oriented strategies helps women to adapt. There are strong arguments indicating that living in an isolated and confined environment magnifies the usual difficulties that arise in mixed-gender relationships. Difficulties may be magnified in space since the group size is smaller and the confinement more extreme. This implies the need for rigorous select-in criteria for both men and women, especially for relational criteria, and for group training after selection. PMID:15267070

  13. [Adaptation and psychometric proprieties study for the Portuguese version of the Adolescent Coping Scale - Escala de Coping para Adolescentes].

    PubMed

    Guerreiro, Diogo Frasquilho; Cruz, Diana; Figueira, Maria Luísa; Sampaio, Daniel

    2014-01-01

    Introdução: O coping é um processo psicológico que leva ao ajustamento individual perante situações de stress. A Adolescent Coping Scale é um instrumento de investigação e uma ferramenta clínica, amplamente utilizada. O presente estudo tem como objectivos desenvolver uma versão Portuguesa da Adolescent Coping Scale e analisar as estratégias e estilos de coping dos jovens da nossa amostra.Material e Métodos: Um questionário anónimo compreendendo a Adolescent Coping Scale obteve respostas de 1 713 alunos (56% do sexo feminino, com idades compreendidas entre os 12 e os 20 anos e uma média etária de 16). O estudo de validade da escala contemplou: análise em componentes principais e avaliação da consistência interna; análise confirmatória através de modelo de equações estruturais. Posteriormente, foram comparadas por género as estratégias e estilos de coping da amostra (testes t para amostras independentes).Resultados: A estrutura final da adaptação da Adolescent Coping Scale reteve 70 itens, que avaliam 16 estratégias de coping agrupadas em três estilos distintos. As escalas apresentaram bons valores de consistência interna (alfas de Cronbach compreendidos entre 0,63 e 0,86, com a exceção de uma dimensão que apresentou um valor de 0,55) e o modelo confirmatório demonstrou bom fit (goodness of fit index compreendidos entre 0,94 e 0,96). Foram eliminadas duas estratégias de coping por motivos estatísticos (ausência de saturação de itens suficientes nas dimensões correspondentes). Verificámos que o estilo de coping focado na resolução do problema é aquele maioritariamente utilizado pelos adolescentes da nossa amostra, em ambos os sexos. No sexo feminino observaram-se valores médios mais elevados nos estilos de coping não produtivo e de referência a outros.Discussão: A versão adaptada apresenta elevada semelhança com a escala original, com alterações minor espectáveis tendo em conta que o coping é influenciado por

  14. Drought Adaptation Mechanisms Should Guide Experimental Design.

    PubMed

    Gilbert, Matthew E; Medina, Viviana

    2016-08-01

    The mechanism, or hypothesis, of how a plant might be adapted to drought should strongly influence experimental design. For instance, an experiment testing for water conservation should be distinct from a damage-tolerance evaluation. We define here four new, general mechanisms for plant adaptation to drought such that experiments can be more easily designed based upon the definitions. A series of experimental methods are suggested together with appropriate physiological measurements related to the drought adaptation mechanisms. The suggestion is made that the experimental manipulation should match the rate, length, and severity of soil water deficit (SWD) necessary to test the hypothesized type of drought adaptation mechanism. PMID:27090148

  15. Monocular and binocular mechanisms mediating flicker adaptation.

    PubMed

    Zhuang, Xiaohua; Shevell, Steven K

    2015-12-01

    Flicker adaptation reduces subsequent temporal contrast sensitivity. Recent studies show that this adaptation likely results from neural changes in the magnocellular visual pathway, but whether this adaptation occurs at a monocular or a binocular level, or both, is unclear. Here, two experiments address this question. The first experiment exploits the observation that flicker adaptation is stronger at higher than lower temporal frequencies. Observers' two eyes adapted to 3Hz flicker with an incremental pulse at 1/4 duty cycle, either in-phase or out-of-phase in the two eyes. At the binocular level, the flicker rate was 6Hz in the out-of-phase condition if the two eyes' pulse trains sum. Similar sensitivity reduction was found in both phase conditions, as expected for independent monocular adapting mechanisms. The second experiment tested for interocular transfer of adaptation between eyes. Results showed that (1) flicker adaptation was strongest with adapting and test fields in only the same eye, (2) adaptation can be partially transferred interocularly with adaptation in only the opposite eye, and (3) adaptation was weakened when both eyes were adapted simultaneously at different contrasts, compared to test-eye adaptation alone. Taken together, the findings are consistent with mechanisms of flicker adaptation at both the monocular and binocular level. PMID:26505684

  16. Coping and psychosocial adaptation to Type 2 diabetes in older Blacks born in the Southern US and the Caribbean.

    PubMed

    Degazon, Cynthia E; Parker, Veronica G

    2007-04-01

    Older Black men and women (n = 212) with Type 2 diabetes completed questionnaires. Spearman's rho correlation indicated that confrontive coping strategies supported effective psychosocial adaptation for persons originally from Haiti and Jamaica, while emotive coping strategies were related to ineffective psychosocial adaptation for persons originally from Barbados and to increased psychological distress for all participants. Women used more palliative coping; no gender differences were observed for psychosocial adaptation. Health care orientation, extended family relationships, and psychological distress domains distinguished Blacks born in Haiti from Blacks born in Barbados and Jamaica, the Southern US and Jamaica, and the Southern US, Barbados, and Jamaica. Findings from this study may aid in the development of interventions focused on improving diabetes self-management for older Blacks. PMID:17380516

  17. Positive coping styles and perigenual ACC volume: two related mechanisms for conferring resilience?

    PubMed

    Holz, Nathalie E; Boecker, Regina; Jennen-Steinmetz, Christine; Buchmann, Arlette F; Blomeyer, Dorothea; Baumeister, Sarah; Plichta, Michael M; Esser, Günter; Schmidt, Martin; Meyer-Lindenberg, Andreas; Banaschewski, Tobias; Brandeis, Daniel; Laucht, Manfred

    2016-05-01

    Stress exposure has been linked to increased rates of depression and anxiety in adults, particularly in females, and has been associated with maladaptive changes in the anterior cingulate cortex (ACC), which is an important brain structure involved in internalizing disorders. Coping styles are important mediators of the stress reaction by establishing homeostasis, and may thus confer resilience to stress-related psychopathology. Anatomical scans were acquired in 181 healthy participants at age 25 years. Positive coping styles were determined using a self-report questionnaire (German Stress Coping Questionnaire, SVF78) at age 22 years. Adult anxiety and depression symptoms were assessed at ages 22, 23 and 25 years with the Young Adult Self-Report. Information on previous internalizing diagnoses was obtained by diagnostic interview (2-19 years). Positive coping styles were associated with increased ACC volume. ACC volume and positive coping styles predicted anxiety and depression in a sex-dependent manner with increased positive coping and ACC volume being related to lower levels of psychopathology in females, but not in males. These results remained significant when controlled for previous internalizing diagnoses. These findings indicate that positive coping styles and ACC volume are two linked mechanisms, which may serve as protective factors against internalizing disorders. PMID:26743466

  18. Positive coping styles and perigenual ACC volume: two related mechanisms for conferring resilience?

    PubMed

    Holz, Nathalie E; Boecker, Regina; Jennen-Steinmetz, Christine; Buchmann, Arlette F; Blomeyer, Dorothea; Baumeister, Sarah; Plichta, Michael M; Esser, Günter; Schmidt, Martin; Meyer-Lindenberg, Andreas; Banaschewski, Tobias; Brandeis, Daniel; Laucht, Manfred

    2016-05-01

    Stress exposure has been linked to increased rates of depression and anxiety in adults, particularly in females, and has been associated with maladaptive changes in the anterior cingulate cortex (ACC), which is an important brain structure involved in internalizing disorders. Coping styles are important mediators of the stress reaction by establishing homeostasis, and may thus confer resilience to stress-related psychopathology. Anatomical scans were acquired in 181 healthy participants at age 25 years. Positive coping styles were determined using a self-report questionnaire (German Stress Coping Questionnaire, SVF78) at age 22 years. Adult anxiety and depression symptoms were assessed at ages 22, 23 and 25 years with the Young Adult Self-Report. Information on previous internalizing diagnoses was obtained by diagnostic interview (2-19 years). Positive coping styles were associated with increased ACC volume. ACC volume and positive coping styles predicted anxiety and depression in a sex-dependent manner with increased positive coping and ACC volume being related to lower levels of psychopathology in females, but not in males. These results remained significant when controlled for previous internalizing diagnoses. These findings indicate that positive coping styles and ACC volume are two linked mechanisms, which may serve as protective factors against internalizing disorders.

  19. Longitudinal Effects of Social Support and Adaptive Coping on the Emotional Well-Being of Survivors of Localized Prostate Cancer

    PubMed Central

    Zhou, Eric S.; Penedo, Frank J.; Bustillo, Natalie E.; Benedict, Catherine; Rasheed, Mikal; Lechner, Suzanne; Soloway, Mark; Kava, Bruce R.; Schneiderman, Neil; Antoni, Michael H.

    2010-01-01

    Survivors of prostate cancer experience treatment-related physical side effects that can compromise emotional well-being for years post treatment. There is limited research investigating how social support and the use of coping may affect the emotional well-being of this population following treatment. The aim of this study was to investigate how social support and coping impact emotional well-being 2 years after treatment in survivors of localized prostate cancer who have received either radical prostatectomy or radiotherapy. Psychosocial and disease-specific measures were administered to an ethnically and demographically diverse sample of 180 men treated for localized prostate cancer at baseline and at 2-year follow-up. Regression analyses demonstrated that higher levels of social support at baseline predicted better emotional well-being 2 years later. Furthermore, higher levels of adaptive coping at baseline partially mediated the relationship between social support and emotional well-being. Supportive relationships may contribute to improved emotional well-being following treatment by facilitating the use of adaptive coping strategies. Attention should be given to strengthening social support networks and educating survivors of prostate cancer on adaptive coping techniques. PMID:21086876

  20. Mental Health, Substance Use, and Adaptive Coping among Social Work Students in the Aftermath of Hurricanes Katrina and Rita

    ERIC Educational Resources Information Center

    Lemieux, Catherine M.; Plummer, Carol A.; Richardson, Roslyn; Simon, Cassandra E.; Ai, Amy L.

    2010-01-01

    The current study examined mental health symptomology, substance use, and adaptive coping among 416 social work students following Hurricanes Katrina and Rita. Among participants, 47% scored at or above the clinical level for depression, with 6% of students showing clinical PTSD-like symptoms, and 16.9% reporting substance use. Two thirds (66.9%)…

  1. Water management to cope with and adapt to climate variability and change.

    NASA Astrophysics Data System (ADS)

    Hamdy, A.; Trisorio-Liuzzi, G.

    2009-04-01

    In many parts of the world, variability in climatic conditions is already resulting in major impacts. These impacts are wide ranging and the link to water management problems is obvious and profound. The know-how and the available information undoubtedly indicate that climate change will lead to an intensification of the global hydrological cycle and can have major impacts on regional water resources, affecting both ground and surface water supply for sectorial water uses and, in particular, the irrigation field imposing notable negative effects on food security and poverty alleviation programs in most arid and semi-arid developing countries. At the United Nations Millennium Summit, in September 2000, world leaders adopted the Millennium Development Declaration. From this declaration, the IWRM was recognised as the key concept the water sector should be using for water related development and measures and, hence, for achieving the water related MDG's. However, the potential impacts of climate change and increasing climate variability are not sufficiently addressed in the IWRM plans. Indeed, only a very limited IWRM national plans have been prepared, coping with climate variability and changes. This is mainly due to the lack of operational instruments to deal with climate change and climate variability issues. This is particularly true in developing countries where the financial, human and ecological impacts are potentially greatest and where water resources may be already highly stressed, but the capacity to cope and adapt is weakest. Climate change has now brought realities including mainly rising temperatures and increasing frequency of floods and droughts that present new challenges to be addressed by the IWRM practice. There are already several regional and international initiatives underway that focus on various aspects of water resources management those to be linked with climate changes and vulnerability issues. This is the way where the water resources

  2. Building adaptive capacity to cope with increasing vulnerability due to climatic change in Africa A new approach

    NASA Astrophysics Data System (ADS)

    Twomlow, Steve; Mugabe, Francis T.; Mwale, Moses; Delve, Robert; Nanja, Durton; Carberry, Peter; Howden, Mark

    The world community faces many risks from climate change, with most scenarios indicating higher temperatures and more erratic rainfall in Africa. Predictions for southern Africa suggest a general decrease in total seasonal rainfall, accompanied by more frequent in-season dry spells that will significantly impact crop and livestock production, and hence economic growth in the region. The hardest hit will be the rural poor in the drier areas, where crop failure due to drought is already common and chronic food emergencies afflict the region in most years. Lessons can be learnt on how the rural poor currently cope with the vagaries of climate and these can be used to help them adapt their current production systems to the future threats of further climate change. But this assumes the institutions that work towards the economic empowerment of the rural poor have the requisite skills to understand their current coping strategies and how adaptation can be facilitated. A new initiative led by Midlands State University and the Zambian Meteorological Office proposes that improving the ability of institutions that train the ‘Future Change Agents’, who will subsequently support smallholder communities in adapting their agricultural practices to current climate variability, is the first step in building adaptive capacity to cope with future climate change. The capacity of African scientists, regional organizations and decision-makers in dealing with the issues of climate change and adaptation will be enhanced on a continuing basis, and the impacts of their agricultural development programs improved.

  3. Adaptive livelihood strategies for coping with water scarcity in the drylands of central Tanzania

    NASA Astrophysics Data System (ADS)

    Liwenga, Emma T.

    In this paper, it is argued that local knowledge for adapting to water scarcity is important for integrated resource management by taking into consideration both the natural and social constraints in a particular setting based on accumulated experience. The paper examines the relevance of local knowledge in sustaining agricultural production in the semiarid areas of central Tanzania. The paper specifically focuses on how water scarcity, as the major limiting factor, is addressed in the study area using local knowledge to sustain livelihoods of its people. The study was conducted in four villages; Mzula, Ilolo, Chanhumba and Ngahelezi, situation in Mvumi Division in Dodoma Region. The study mainly employed qualitative data collection techniques. Participatory methods provided a means of exploring perceptions and gaining deeper insights regarding natural resource utilization in terms of problems and opportunities. The main data sources drawn upon in this study were documentation, group interviews and field observations. Group interviews involved discussions with a group of 6-12 people selected on the basis of gender, age and socio-economic groups. Data analysis entailed structural and content analysis within the adaptive livelihood framework in relation to management of water scarcity using local knowledge. The findings confirm that rainfall is the main limiting factor for agricultural activities in the drylands of Central Tanzania. As such, local communities have developed, through time, indigenous knowledge to cope with such environments utilizing seasonality and diversity of landscapes. Use of this local knowledge is therefore effective in managing water scarcity by ensuring a continuous production of crops throughout the year. This practice implies increased food availability and accessibility through sales of such agricultural products. Local innovations for water management, such as cultivation in sandy rivers, appear to be very important means of accessing

  4. Spirituality: A Coping Mechanism in the Lives of Adults with Congenital Disabilities

    ERIC Educational Resources Information Center

    Specht, Jacqueline A.; King, Gillian A.; Willoughby, Colleen; Brown, Elizabeth G.; Smith, Linda

    2005-01-01

    The purpose of this study was to gain insight into the perspective of individuals with congenital disabilities about spirituality as a coping mechanism during crucial times in their lives, Qualitative analysis of interviews assessing turning points in the lives of 15 adults (6 women and 9 men; M = 37 years) with spina bifida, cerebral palsy, or…

  5. Altruism--a coping mechanism for patients on clinical trials: a nursing perspective.

    PubMed

    Sanders, Judith Brown; Seda, Julie S; Kardinal, Carl G

    2013-10-01

    Altruism often is expressed by patients with advanced cancer as a coping mechanism and a motivational factor for participation in clinical trials. Those who participate develop a sense of hope that their life is a contribution, which may continue to live beyond their deaths.

  6. An examination of stress, coping, and adaptation in nurses in a recovery and monitoring program.

    PubMed

    Bowen, Marie Katherine; Taylor, Kathleen P; Marcus-Aiyeku, Ulanda; Krause-Parello, Cheryl A

    2012-10-01

    Addiction rates in nurses are higher than in the general population. The relationship between stress, coping, and adaptation in nurses (N = 82) enrolled in a recovery and monitoring program in the state of New Jersey was examined. Social support, a variable tested as a mediator of this relationship, was also examined. Participants completed the Perceived Stress Scale, Multidimensional Scale of Perceived Social Support, and Psychological General Well-Being Index. Negative relationships were found between stress and social support and stress and well-being, and a positive relationship was found between social support and well-being (all ps < .05). The direct relationship between stress and well-being was decreased in the presence of social support. The findings of this research suggest that, to assist nurses, an increased awareness of stress and its injurious effects on overall well-being must be identified so proactive measures can be implemented to prevent potential untoward consequences. Ultimately, methods to strengthen social support and social networks will enhance the probability of sustained recovery, relapse prevention, and safe reentry into nursing practice. Implications for behavioral health providers and health care practitioners are discussed.

  7. Financial Adaptation among College Students: Helping Students Cope with Financial Strain

    ERIC Educational Resources Information Center

    Serido, Joyce; Shim, Soyeon; Xiao, Jing Jian; Tang, Chuanyi; Card, Noel A.

    2014-01-01

    This study examines the impact of the recent financial crisis on co-occurring patterns of change in financial strain and financial coping behaviors of college students (N = 748) using two-timed, longitudinal data collected prior to the 2008 financial crisis and again one year later. Using a stress and coping framework, we found that different…

  8. Mechanisms to cope with arsenic or cadmium excess in plants.

    PubMed

    Verbruggen, Nathalie; Hermans, Christian; Schat, Henk

    2009-06-01

    The metalloid arsenic and the heavy metal cadmium have no demonstrated biological function in plants. Both elements are highly toxic and of major concern with respect to their accumulation in soils, in the food-chain or in drinking water. Arsenate is taken up by phosphate transporters and rapidly reduced to arsenite, As(III). In reducing environments, As(III) is taken up by aquaporin nodulin 26-like intrinsic proteins. Cd(2+) enters the root via essential metal uptake systems. As(III) and Cd(2+) share some similarity between their toxicology and sequestration machineries. Recent progress in understanding the mechanisms of As and Cd uptake and detoxification is presented, including the elucidation of why rice takes up so much arsenic from soil and of mechanisms of As and Cd hypertolerance.

  9. Families of Adolescents and Adults with Autism Spectrum Disorders in Taiwan: The Role of Social Support and Coping in Family Adaptation and Maternal Well-Being

    ERIC Educational Resources Information Center

    Lin, Ling-Yi; Orsmond, Gael I.; Coster, Wendy J.; Cohn, Ellen S.

    2011-01-01

    In this study we examined differences in social support and coping between mothers of adolescents and adults with an autism spectrum disorder (ASD) in Taiwan and the United States and to investigate the effects of social support and coping strategies on family adaptation and maternal well-being. Participants were 76 Taiwanese mothers who had at…

  10. Mechanisms for coping with submergence and waterlogging in rice

    PubMed Central

    2012-01-01

    Rice (Oryza sativa L.), unlike other cereals, can grow well in paddy fields and is highly tolerant of excess water stress, from either submergence (in which part or all of the plant is under water) or waterlogging (in which excess water in soil limits gas diffusion). Rice handles submergence stress by internal aeration and growth controls. A quiescence strategy based on Submergence-1A (SUB1A) or an escape strategy based on SNORKEL1 (SK1) and SNORKEL2 (SK2) is used for the growth controls. On the other hand, rice handles waterlogging stress by forming lysigenous aerenchyma and a barrier to radial O2 loss (ROL) in roots in order to supply O2 to the root tip. In this article, we summarize recent advances in understanding the mechanisms of responding to excess water stresses (i.e., submergence and waterlogging) in rice and other gramineous plants. PMID:24764502

  11. Gender differences in psychological adaptation and coping in parents of pediatric cancer patients.

    PubMed

    Hoekstra-Weebers, J E; Jaspers, J P; Kamps, W A; Klip, E C

    1998-01-01

    This study investigated differences in psychological distress and coping styles between fathers and mothers of pediatric cancer patients, over a 1-year time period. Also examined were (dis)similarities in couples in distress and coping, and the relationship between (dis)similarities in coping and psychological functioning of both members of a couple. Parents (n = 124, 62 couples) were assessed at diagnosis, at 6 and 12 months. Fathers and mothers experienced higher levels of psychiatric symptomatology and psychological distress at diagnosis than men and women of a normgroup. Distress declined significantly with time. Although parents did not report more symptoms than the normgroup 12 months post-diagnosis, they still were psychologically out of balance. Contrary to findings in the general population, no differences were found between fathers and mothers in psychiatric symptoms or psychological distress on any of the measurements. Only a few gender differences in coping were found. Fathers used more active-problem focusing at diagnosis and a less palliative reaction pattern at 12 months than did mothers. Mothers used more social-support seeking on all measurements. A tendency for similarity in the use of the coping styles within couples was found. Discrepancies in coping in couples were positively related to distress in fathers at diagnosis. However, 12 months later, the more discrepant the couples were in their coping preferences the more distress the mothers indicated.

  12. Evaluation of marginal fit and internal adaptation of zirconia copings fabricated by two CAD - CAM systems: An in vitro study

    PubMed Central

    Rajan, Balaji N; Jayaraman, Srinivasan; Kandhasamy, Baburajan; Rajakumaran, Ilangkumaran

    2015-01-01

    Statement of Problem: Three main factors which determine the success of an All-ceramic restoration are esthetic value, resistance to fracture and third being the marginal fit. Marginal fit and internal adaptation are crucial factors in increasing the longevity of the restoration. Newer and economical CAD CAM systems have been introduced claiming better marginal fit and adaptation of All ceramic crowns. CAD CAM systems involves scanning of the die or the tooth preparation and milling of the restoration, which may have variations among the systems available. Aim of the Study: Our study intended to check the marginal fit and internal adaptation of commonly used CAD CAM systems namely CERAMILL and CEREC -In Lab MC XL. Materials and Methods: Two groups of typodont teeth (n = 10) were prepared using a standardized protocol to receive All ceramic copings. 10 samples of Group A were used for fabrication of copings using CERAMILL system and 10 samples of Group B were used for fabrication of copings using CEREC -In Lab MC XL system. They were then luted with glass ionomer cement under mild finger pressure. Samples were embedded in resin and sliced longitudinally. They were then viewed under stereomicroscope and readings were measured along 15 points using ImageScope software. The P value was set at 0.05 at 95% confidence interval with 80% power. The data were checked for normality and unpaired t-test was used to evaluate the results of the two groups. Results: The overall internal adaptation was 61.5 ± 5.2 μm for CERAMILL and 56.9 ± 5.7 μm for CEREC -In Lab MC XL (P < 0.05). The marginal fit for CERAMILL was 83 μm and for CEREC -In Lab MC XL was 68 μm (P < 0.05). Conclusion: The marginal adaptation of CEREC -In Lab MC XL (68 μm) was found to be superior to CERAMILL (83 μm) (P < 0.05). Both the CEREC -In Lab MC XL and CERAMILL copings demonstrated internal adaptation and marginal fit within acceptable discrepancy range. When corroborating both the internal adaptation

  13. Ionizing Radiation: how fungi cope, adapt, and exploit with the help of melanin

    PubMed Central

    Dadachova, Ekaterina; Casadevall, Arturo

    2008-01-01

    SUMMARY OF RECENT ADVANCES Life on Earth has always existed in the flux of ionizing radiation. However, fungi seem to interact with the ionizing radiation differently from other Earth’s inhabitants. Recent data show that melanized fungal species like those from Chernobyl’s reactor respond to ionizing radiation with enhanced growth. Fungi colonize space stations and adapt morphologically to extreme conditions. Radiation exposure causes upregulation of many key genes, and an inducible microhomology-mediated recombination pathway could be a potential mechanism of adaptive evolution in eukaryotes. The discovery of melanized organisms in high radiation environments, the space stations, Antarctic mountains, and in the reactor cooling water combined with phenomenon of ‘radiotropism’ raises the tantalizing possibility that melanins have functions analogous to other energy harvesting pigments such as chlorophylls. PMID:18848901

  14. Lessons learned in developing a culturally adapted intervention for African-American families coping with parental cancer.

    PubMed

    Davey, Maureen P; Kissil, Karni; Lynch, Laura; Harmon, La-Rhonda; Hodgson, Nancy

    2012-12-01

    Prior clinical research supports the effectiveness of cancer support groups for cancer patients and their families, yet African-American families continue to be underrepresented in cancer support groups and in cancer clinical research studies. In order to fill this gap, we developed and evaluated a culturally adapted family support group for African-American families coping with parental cancer. We encountered unexpected challenges in overcoming barriers to recruitment, partnering with oncology providers, and building trust with the African-American community and African-American families coping with parental cancer. We describe actions taken during the two phases of this study and lessons learned along the way about recruiting and engaging African-American families in cancer support group studies, partnering with oncology providers, networking with the African-American community, and the importance of demonstrating cultural sensitivity to overcome the understandable historical legacy of mistrust.

  15. Peer Victimization: The Role of Emotions in Adaptive and Maladaptive Coping

    ERIC Educational Resources Information Center

    Kochenderfer-Ladd, Becky

    2004-01-01

    Mediator models were examined in which children's emotional reactions to peer aggression were hypothesized to mediate their selection of coping strategies and subsequent peer victimization and internalizing problems. Self-report data were collected from 145 ethnically diverse kindergarten through fifth grade children (66 females and 79 males) who…

  16. Measuring Coping Behavior in Liver Transplant Candidates: A Psychometric Analysis of the Brief COPE.

    PubMed

    Amoyal, Nicole; Fernandez, Anne C; Ng, Reuben; Fehon, Dwain C

    2016-09-01

    Liver transplant candidates must cope with significant physiological and psychological challenges. The Brief COPE is a frequently used measure of coping behavior; however, knowledge of the scale's factor structure and construct validity is limited with regard to liver transplant candidates. This study assessed the validity of the Brief COPE in 120 liver transplant candidates using exploratory factor analysis. Results revealed a 6-factor solution, only 2 of which were consistent with the original scale assignments. Construct validity of the 6 Brief COPE scales yielded in this study was demonstrated. The results indicate that the Brief COPE is valid, reliable, and can be meaningfully interpreted in liver transplant patients. Future research should confirm this factor structure and examine its predictive validity prior to widespread use among liver transplant patients. Suggestions are presented for enhancing the care of transplant candidates by promoting the use of adaptive coping mechanisms to manage distress.

  17. [Translation, cross-cultural adaptation, and content validation of the Portuguese version of the Coping Behaviours Inventory (CBI) for the Brazilian population].

    PubMed

    Constant, Hilda Maria Rodrigues Moleda; Figueiró, Luciana Rizzieri; Signor, Luciana; Bisch, Nadia Krubskaya; Barros, Helena Maria Tanhauser; Ferigolo, Maristela

    2014-10-01

    Coping skills correlate directly with the success of alcohol abstinence. Brazil previously lacked an instrument to identify alcohol users' specific coping skills. The current study therefore aimed to perform the translation, cross-cultural adaptation, and content validation of the Coping Behaviours Inventory (CBI). Procedures included translation and back-translation, cross-cultural adaptation, content evaluation, and a pilot study. The final Portuguese version was administered by telephone to 40 alcohol users seeking help through a telephone hotline called VIVAVOZ. The retranslated version was close to the original. As for content validation, most of the items proved satisfactory and acceptable. The theoretical dimension showed a mean kappa index of 0.666 between evaluators, which was considered a substantial level of agreement. The results were satisfactory and acceptable, demonstrating that the inventory is appropriate for investigating coping skills in Brazilian alcohol users.

  18. Female caregivers of stroke survivors: coping and adapting to a life that once was.

    PubMed

    Saban, Karen L; Hogan, Nancy S

    2012-02-01

    Despite the prevalence of women caring for stroke survivors, relatively little research has focused specifically on the experience and needs of informal female caregivers of stroke survivors. Therefore, the purpose of this study was to describe the experience of female caregivers who care for an adult family member who has experienced a stroke within the previous year using a qualitative methodology. A sample of 46 female caregivers of stroke survivors completed a demographic form and responded to open-ended written questions exploring their experiences as caregivers and how they coped with changes in their lives during the first year after the stroke. Four concepts emerged from the data: losing the life that once was, coping with daily burdens, creating a new normal, and interacting with healthcare providers. Findings suggest that female caregivers of stroke survivors grieve the life that they once shared with the stroke survivor and struggle to cope with multiple family and work demands while trying their best to interact with healthcare providers to attain the best possible care for their loved ones. Recognizing the unique challenges of female caregivers of stroke survivors may help nurses provide better support and resources to meet their needs.

  19. Adaptive mechanically controlled lubrication mechanism found in articular joints.

    PubMed

    Greene, George W; Banquy, Xavier; Lee, Dong Woog; Lowrey, Daniel D; Yu, Jing; Israelachvili, Jacob N

    2011-03-29

    Articular cartilage is a highly efficacious water-based tribological system that is optimized to provide low friction and wear protection at both low and high loads (pressures) and sliding velocities that must last over a lifetime. Although many different lubrication mechanisms have been proposed, it is becoming increasingly apparent that the tribological performance of cartilage cannot be attributed to a single mechanism acting alone but on the synergistic action of multiple "modes" of lubrication that are adapted to provide optimum lubrication as the normal loads, shear stresses, and rates change. Hyaluronic acid (HA) is abundant in cartilage and synovial fluid and widely thought to play a principal role in joint lubrication although this role remains unclear. HA is also known to complex readily with the glycoprotein lubricin (LUB) to form a cross-linked network that has also been shown to be critical to the wear prevention mechanism of joints. Friction experiments on porcine cartilage using the surface forces apparatus, and enzymatic digestion, reveal an "adaptive" role for an HA-LUB complex whereby, under compression, nominally free HA diffusing out of the cartilage becomes mechanically, i.e., physically, trapped at the interface by the increasingly constricted collagen pore network. The mechanically trapped HA-LUB complex now acts as an effective (chemically bound) "boundary lubricant"--reducing the friction force slightly but, more importantly, eliminating wear damage to the rubbing/shearing surfaces. This paper focuses on the contribution of HA in cartilage lubrication; however, the system as a whole requires both HA and LUB to function optimally under all conditions.

  20. HIV stigma and physical health symptoms: do social support, adaptive coping, and/or identity centrality act as resilience resources?

    PubMed

    Earnshaw, Valerie A; Lang, Shawn M; Lippitt, Margaret; Jin, Harry; Chaudoir, Stephenie R

    2015-01-01

    Despite efforts to eliminate it at the societal level, HIV stigma persists and continues to threaten the health of people living with HIV (PLWH). We tested whether social support, adaptive coping, and/or HIV identity centrality act as resilience resources by buffering people from the negative impact of enacted and/or anticipated stigma on stress and ultimately HIV symptoms. Ninety-three PLWH completed a survey, and data analyses tested for evidence of mediation and moderation. Results demonstrated that instrumental social support, perceived community support, and HIV identity centrality buffered participants from the association between anticipated stigma and HIV symptoms. That is, anticipated stigma was associated with HIV symptoms via stress only at low levels of these resources. No resources buffered participants from the impact of enacted stigma. Identifying and enhancing resilience resources among PLWH is critical for protecting PLWH from the harmful effects of stigma.

  1. Reproducible increases in blood pressure during intermittent noise exposure: underlying haemodynamic mechanisms specific to passive coping.

    PubMed

    Sawada, Y

    1993-01-01

    The purpose of the present study was to investigate the reproducibility of the increases in blood pressure found in our recent study on exposure to intermittent noise, to confirm the haemodynamic mechanism raising blood pressure (via an increase in peripheral vascular resistance expected to be specific to passive coping), and to assess baroreceptor cardiac reflex sensitivity in connection with the blood pressure elevation. A group of 16 young normotensive men participated in the experiment and underwent a 10-min intermittent exposure to pink noise at 100 dB (sound pressure level). The subjects also underwent three other stresses: a 1-min cold pressor test, a 3-min isometric handgrip and 3-min of mental arithmetic. The results indicated that blood pressure was elevated reproducibly for most of the noise exposure periods and that peripheral vascular resistance increased simultaneously, as expected. Baroreflex sensitivity was not suppressed. The results, as a whole, were in agreement with our recent findings for exposure to a similar type of noise and thus the reproducibility was corroborated. The mechanism raising blood pressure was similar in the cold pressor test. Conversely, during the isometric handgrip and mental arithmetic, blood pressure elevations were attributable mainly to increases in cardiac output. The implications of the opposing haemodynamic mechanisms raising blood pressure among the four stressful tasks have been discussed in relation to active versus passive coping required for each task. Differences in the magnitude of suppression observed in baroreflex sensitivity among the tasks have also been discussed in the context of defence reactions. PMID:8299606

  2. Neurobiological mechanisms of adaptative plasticity. A possible contribution to cybernetic studies.

    PubMed

    Giaquinto, S

    1990-10-01

    Cybernetics can take advantages of future development in the field of Plasticity. The adaptative abilities of the nervous tissue, which is capable to modify its own functional organization and cope with pathological events, are triggered by communication within a network carrying memorized variations in the functional activity of the system induced by external inputs. Plasticity is served by anatomical modifications, as well as by neurophysiological processes. Regeneration, reactive synaptogenesis, functional reorganization, redundancy, equipotentiality are discussed. Some of these mechanisms are still unclear in the human and probably far-fetched. Personal EEG contribution argues against redundancy and equipotentiality. PMID:2082721

  3. Effect of Roy’s Adaptation Model-Guided Education on Coping Strategies of the Veterans with Lower Extremities Amputation: A Double-Blind Randomized Controlled Clinical Trial

    PubMed Central

    Farsi, Zahra; Azarmi, Somayeh

    2016-01-01

    Background: Any defect in the extremities of the body can affect different life aspects. The purpose of this study was to investigate the effect of Roy’s adaptation model-guided education on coping strategies of the veterans with lower extremities amputation. Methods: In a double-blind randomized controlled clinical trial, 60 veterans with lower extremities amputation referring to Kowsar Orthotics and Prosthetics Center of Veterans Clinic in Tehran, Iran were recruited using convenience method and randomly assigned to intervention and control groups in 2013-2014. Lazarus and Folkman coping strategies questionnaire was used to collect the data. After completing the questionnaires in both groups, maladaptive behaviours were determined in the intervention group and an education program based on Roy’s adaptation model was implemented. After 2 months, both groups completed the questionnaires again. Data were analyzed using SPSS software. Results: Independent T-test showed that the score of the dimensions of coping strategies did not have a statistically significant difference between the intervention and control groups in the pre-intervention stage (P>0.05). This test showed a statistically significant difference between the two groups in the post-intervention stage in terms of the scores of different dimensions of coping strategies (P>0.05), except in dimensions of social support seeking and positive appraisal (P>0.05). Conclusion: The findings of this research indicated that the Roy’s adaptation model-guided education improved the majority of coping strategies in veterans with lower extremities amputation. It is recommended that further interventions based on Roy’s adaptation model should be performed to improve the coping of the veterans with lower extremities amputation. Trial Registration Number: IRCT2014081118763N1 PMID:27218110

  4. Stress: perceptions, manifestations, and coping mechanisms of student registered nurse anesthetists.

    PubMed

    Chipas, Anthony; Cordrey, Dan; Floyd, David; Grubbs, Lindsey; Miller, Sarah; Tyre, Brooks

    2012-08-01

    Stress is a response to change from the norm. Stress affects all individuals to varying degrees and can be positive, such as eustress, or negative, such as distress. The purpose of this qualitative, cross-sectional study was to investigate the stressors of the typical student registered nurse anesthetist (SRNA), with the objective of identifying trends in the perceptions, manifestations, and coping mechanisms of stress. An online (SurveyMonkey) questionnaire composed of 54 study-specific questions was developed to assess stress in the SRNA population. The questionnaire was sent to members of the American Association of Nurse Anesthetists via email invitation. The study yielded a sample of 1,282 SRNA participants. Analysis revealed statistically significant relationships between self-reported stress and negative outcomes, such as increased sick days, decreased health and wellness, and depression. The study demonstrated that SRNAs perceive their stress as above average, and it remains a central concern for them.

  5. Substance Abuse, Coping Strategies, Adaptive Skills and Behavioral and Emotional Problems in Clients with Mild to Borderline Intellectual Disability Admitted to a Treatment Facility: A Pilot Study

    ERIC Educational Resources Information Center

    Didden, Robert; Embregts, Petri; van der Toorn, Mirjam; Laarhoven, Nina

    2009-01-01

    Many clients with mild to borderline intellectual disability (ID) who are admitted to a treatment facility show serious problems in alcohol and/or drugs use. In the present case file study, we explored differences in coping strategies, adaptive skills and emotional and behavioral problems between clients who showed substance abuse and clients who…

  6. Viewing health expenditures, payment and coping mechanisms with an equity lens in Nigeria

    PubMed Central

    2013-01-01

    Background This paper examines socio-economic and geographic differences in payment and payment coping mechanisms for health services in southeast Nigeria. It shows the extent to which the poor and rural dwellers disproportionally bear the burden of health care costs and offers policy recommendations for improvements. Methods Questionnaires were used to collect data from 3071 randomly selected households in six communities in southeast Nigeria using a four week recall. The sample was divided into quintiles (Q1-Q5) using a socio-economic status (SES) index as well as into geographic groups (rural, peri-urban and urban). Tabulations and logistic regression were used to determine the relationships between payment and payment coping mechanisms and key independent variables. Q1/Q5 and rural/urban ratios were the measures of equity. Results Most of the respondents used out-of-pocket spending (OOPS) and own money to pay for healthcare. There was statistically significant geographic differences in the use of own money to pay for health services indicating more use among rural dwellers. Logistic regression showed statistically significant geographic differences in the use of both OOPS and own money when controlling for the effects of potential cofounders. Conclusions This study shows statistically significant geographic differences in the use of OOPS and own money to pay for health services. Though the SES differences were not statistically significant, they showed high equity ratios indicating more use among poor and rural dwellers. The high expenditure incurred on drugs alone highlights the need for expediting pro-poor interventions like exemptions and waivers aimed at improving access to health care for the vulnerable poor and rural dwellers. PMID:23497246

  7. Does coping help? A reexamination of the relation between coping and mental health.

    PubMed

    Aldwin, C M; Revenson, T A

    1987-08-01

    In a longitudinal community survey of 291 adults, we explored the relation between coping strategies and psychological symptoms. Respondents completed the revised Ways of Coping Scale (Folkman & Lazarus, 1985) for a self-named stressful episode. Factor analysis produced eight coping factors: three problem focused, four emotion focused, and one (support mobilization) that contained elements of both. Multiple regression analyses indicated bidirectionality in the relation between coping and psychological symptoms. Those in poorer mental health and under greater stress used less adaptive coping strategies, such as escapism, but coping efforts still affected mental health independent of prior symptom levels and degree of stress. We compared main versus interactive effects models of stress buffering. Main effects were confined primarily to the emotion-focused coping scales and showed little or negative impacts of coping on mental health; interactive effects, though small, were found with the problem-focused scales. The direction of the relation between problem-focused scales and symptoms may depend in part on perceived efficacy, or how the respondent thought he or she handled the problem. Implications for the measurement of adaptive coping mechanisms and their contextual appropriateness are discussed.

  8. Adapting to and Coping with the Threat and Impacts of Climate Change

    ERIC Educational Resources Information Center

    Reser, Joseph P.; Swim, Janet K.

    2011-01-01

    This article addresses the nature and challenge of adaptation in the context of global climate change. The complexity of "climate change" as threat, environmental stressor, risk domain, and impacting process with dramatic environmental and human consequences requires a synthesis of perspectives and models from diverse areas of psychology to…

  9. Coping with Spatial Heterogeneity and Temporal Variability in Resources and Risks: Adaptive Movement Behaviour by a Large Grazing Herbivore

    PubMed Central

    Martin, Jodie; Benhamou, Simon; Yoganand, K.; Owen-Smith, Norman

    2015-01-01

    Movement is a key mean for mobile species to cope with heterogeneous environments. While in herbivorous mammals large-scale migration has been widely investigated, fine-scale movement responses to local variations in resources and predation risk remain much less studied, especially in savannah environments. We developed a novel approach based on complementary movement metrics (residence time, frequency of visits and regularity of visits) to relate movement patterns of a savannah grazer, the blue wildebeest Connochaetes taurinus, to fine-scale variations in food availability, predation risk and water availability in the Kruger National Park, South Africa. Wildebeests spent more time in grazing lawns where the grass is of higher quality but shorter than in seep zones, where the grass is of lower quality but more abundant. Although the daily distances moved were longer during the wet season compared to the dry season, the daily net displacement was lower, and the residence time higher, indicating a more frequent occurrence of area-concentred searching. In contrast, during the late dry season the foraging sessions were more fragmented and wildebeests moved more frequently between foraging areas. Surprisingly, predation risk appeared to be the second factor, after water availability, influencing movement during the dry season, when resources are limiting and thus expected to influence movement more. Our approach, using complementary analyses of different movement metrics, provided an integrated view of changes in individual movement with varying environmental conditions and predation risk. It makes it possible to highlight the adaptive behavioral decisions made by wildebeest to cope with unpredictable environmental variations and provides insights for population conservation. PMID:25719494

  10. Coping with spatial heterogeneity and temporal variability in resources and risks: adaptive movement behaviour by a large grazing herbivore.

    PubMed

    Martin, Jodie; Benhamou, Simon; Yoganand, K; Owen-Smith, Norman

    2015-01-01

    Movement is a key mean for mobile species to cope with heterogeneous environments. While in herbivorous mammals large-scale migration has been widely investigated, fine-scale movement responses to local variations in resources and predation risk remain much less studied, especially in savannah environments. We developed a novel approach based on complementary movement metrics (residence time, frequency of visits and regularity of visits) to relate movement patterns of a savannah grazer, the blue wildebeest Connochaetes taurinus, to fine-scale variations in food availability, predation risk and water availability in the Kruger National Park, South Africa. Wildebeests spent more time in grazing lawns where the grass is of higher quality but shorter than in seep zones, where the grass is of lower quality but more abundant. Although the daily distances moved were longer during the wet season compared to the dry season, the daily net displacement was lower, and the residence time higher, indicating a more frequent occurrence of area-concentred searching. In contrast, during the late dry season the foraging sessions were more fragmented and wildebeests moved more frequently between foraging areas. Surprisingly, predation risk appeared to be the second factor, after water availability, influencing movement during the dry season, when resources are limiting and thus expected to influence movement more. Our approach, using complementary analyses of different movement metrics, provided an integrated view of changes in individual movement with varying environmental conditions and predation risk. It makes it possible to highlight the adaptive behavioral decisions made by wildebeest to cope with unpredictable environmental variations and provides insights for population conservation.

  11. Development of the Coping Flexibility Scale: Evidence for the Coping Flexibility Hypothesis

    ERIC Educational Resources Information Center

    Kato, Tsukasa

    2012-01-01

    "Coping flexibility" was defined as the ability to discontinue an ineffective coping strategy (i.e., evaluation coping) and produce and implement an alternative coping strategy (i.e., adaptive coping). The Coping Flexibility Scale (CFS) was developed on the basis of this definition. Five studies involving approximately 4,400 Japanese college…

  12. Individual and public-program adaptation: coping with heat waves in five cities in Canada.

    PubMed

    Alberini, Anna; Gans, Will; Alhassan, Mustapha

    2011-12-01

    Heat Alert and Response Systems (HARS) are currently undergoing testing and implementation in Canada. These programs seek to reduce the adverse health effects of heat waves on human health by issuing weather forecasts and warnings, informing individuals about possible protections from excessive heat, and providing such protections to vulnerable subpopulations and individuals at risk. For these programs to be designed effectively, it is important to know how individuals perceive the heat, what their experience with heat-related illness is, how they protect themselves from excessive heat, and how they acquire information about such protections. In September 2010, we conducted a survey of households in 5 cities in Canada to study these issues. At the time of the survey, these cities had not implemented heat outreach and response systems. The study results indicate that individuals' recollections of recent heat wave events were generally accurate. About 21% of the sample reported feeling unwell during the most recent heat spell, but these illnesses were generally minor. Only in 25 cases out of 243, these illnesses were confirmed or diagnosed by a health care professional. The rate at which our respondents reported heat-related illnesses was higher among those with cardiovascular and respiratory illnesses, was higher among younger respondents and bore no relationship with the availability of air conditioning at home. Most of the respondents indicated that they would not dismiss themselves as "not at risk" and that they would cope with excessive heat by staying in air conditioned environments and keeping well hydrated. Despite the absence of heat outreach and education programs in their city, our respondents at least a rough idea of how to take care of themselves. The presence of air conditioning and knowledge of cooling centers is location-specific, which provides opportunities for targeting HARS interventions.

  13. Individual and Public-Program Adaptation: Coping with Heat Waves in Five Cities in Canada

    PubMed Central

    Alberini, Anna; Gans, Will; Alhassan, Mustapha

    2011-01-01

    Heat Alert and Response Systems (HARS) are currently undergoing testing and implementation in Canada. These programs seek to reduce the adverse health effects of heat waves on human health by issuing weather forecasts and warnings, informing individuals about possible protections from excessive heat, and providing such protections to vulnerable subpopulations and individuals at risk. For these programs to be designed effectively, it is important to know how individuals perceive the heat, what their experience with heat-related illness is, how they protect themselves from excessive heat, and how they acquire information about such protections. In September 2010, we conducted a survey of households in 5 cities in Canada to study these issues. At the time of the survey, these cities had not implemented heat outreach and response systems. The study results indicate that individuals’ recollections of recent heat wave events were generally accurate. About 21% of the sample reported feeling unwell during the most recent heat spell, but these illnesses were generally minor. Only in 25 cases out of 243, these illnesses were confirmed or diagnosed by a health care professional. The rate at which our respondents reported heat-related illnesses was higher among those with cardiovascular and respiratory illnesses, was higher among younger respondents and bore no relationship with the availability of air conditioning at home. Most of the respondents indicated that they would not dismiss themselves as “not at risk” and that they would cope with excessive heat by staying in air conditioned environments and keeping well hydrated. Despite the absence of heat outreach and education programs in their city, our respondents at least a rough idea of how to take care of themselves. The presence of air conditioning and knowledge of cooling centers is location-specific, which provides opportunities for targeting HARS interventions. PMID:22408596

  14. Solution-adaptive finite element method in computational fracture mechanics

    NASA Technical Reports Server (NTRS)

    Min, J. B.; Bass, J. M.; Spradley, L. W.

    1993-01-01

    Some recent results obtained using solution-adaptive finite element method in linear elastic two-dimensional fracture mechanics problems are presented. The focus is on the basic issue of adaptive finite element method for validating the applications of new methodology to fracture mechanics problems by computing demonstration problems and comparing the stress intensity factors to analytical results.

  15. Parallel Adaptive Multi-Mechanics Simulations using Diablo

    SciTech Connect

    Parsons, D; Solberg, J

    2004-12-03

    Coupled multi-mechanics simulations (such as thermal-stress and fluidstructure interaction problems) are of substantial interest to engineering analysts. In addition, adaptive mesh refinement techniques present an attractive alternative to current mesh generation procedures and provide quantitative error bounds that can be used for model verification. This paper discusses spatially adaptive multi-mechanics implicit simulations using the Diablo computer code. (U)

  16. Do common mechanisms of adaptation mediate color discrimination and appearance? Contrast adaptation

    NASA Astrophysics Data System (ADS)

    Hillis, James M.; Brainard, David H.

    2007-08-01

    Are effects of background contrast on color appearance and sensitivity controlled by the same mechanism of adaptation? We examined the effects of background color contrast on color appearance and on color-difference sensitivity under well-matched conditions. We linked the data using Fechner's hypothesis that the rate of apparent stimulus change is proportional to sensitivity and examined a family of parametric models of adaptation. Our results show that both appearance and discrimination are consistent with the same mechanism of adaptation.

  17. Do common mechanisms of adaptation mediate color discrimination and appearance? Contrast adaptation.

    PubMed

    Hillis, James M; Brainard, David H

    2007-08-01

    Are effects of background contrast on color appearance and sensitivity controlled by the same mechanism of adaptation? We examined the effects of background color contrast on color appearance and on color-difference sensitivity under well-matched conditions. We linked the data using Fechner's hypothesis that the rate of apparent stimulus change is proportional to sensitivity and examined a family of parametric models of adaptation. Our results show that both appearance and discrimination are consistent with the same mechanism of adaptation.

  18. SAMCO: Society Adaptation for coping with Mountain risks in a global change COntext

    NASA Astrophysics Data System (ADS)

    Grandjean, Gilles; Bernardie, Severine; Malet, Jean-Philippe; Puissant, Anne; Houet, Thomas; Berger, Frederic; Fort, Monique; Pierre, Daniel

    2013-04-01

    The SAMCO project aims to develop a proactive resilience framework enhancing the overall resilience of societies on the impacts of mountain risks. The project aims to elaborate methodological tools to characterize and measure ecosystem and societal resilience from an operative perspective on three mountain representative case studies. To achieve this objective, the methodology is split in several points with (1) the definition of the potential impacts of global environmental changes (climate system, ecosystem e.g. land use, socio-economic system) on landslide hazards, (2) the analysis of these consequences in terms of vulnerability (e.g. changes in the location and characteristics of the impacted areas and level of their perturbation) and (3) the implementation of a methodology for quantitatively investigating and mapping indicators of mountain slope vulnerability exposed to several hazard types, and the development of a GIS-based demonstration platform. The strength and originality of the SAMCO project will be to combine different techniques, methodologies and models (multi-hazard assessment, risk evolution in time, vulnerability functional analysis, and governance strategies) and to gather various interdisciplinary expertises in earth sciences, environmental sciences, and social sciences. The multidisciplinary background of the members could potentially lead to the development of new concepts and emerging strategies for mountain hazard/risk adaptation. Research areas, characterized by a variety of environmental, economical and social settings, are severely affected by landslides, and have experienced significant land use modifications (reforestation, abandonment of traditional agricultural practices) and human interferences (urban expansion, ski resorts construction) over the last century.

  19. Mechanics and applications of pressure adaptive honeycomb

    NASA Astrophysics Data System (ADS)

    Vos, Roelof

    A novel adaptive aerostructure is presented that relies on certified aerospace materials and can therefore be applied in conventional passenger aircraft. This structure consists of a honeycomb material which' cells extend over a significant length perpendicular to the plane of the cells. Each of the cells contains an inelastic pouch (or bladder) that forms a circular tube when the cell forms a perfect hexagon. By changing the cell differential pressure (CDP) the stiffness of the honeycomb can be altered. Using an external force or the elastic force within the honeycomb material, the honeycomb can be deformed such that the cells deviate from their perfect-hexagonal shape. It can be shown that by increasing the CDP, the structure eventually returns to a perfect hexagon. By doing so, a fully embedded pneumatic actuator is created that can perform work and substitute conventional low-bandwidth flight control actuators. It is shown that two approaches can be taken to regulate the stiffness of this embedded actuator: (1) The first approach relies on the pouches having a fixed amount of air in them and stiffness is altered by a change in ambient pressure. Coupled to the ambient pressure-altitude cycle that aircraft encounter during each flight, this approach yields a true adaptive aerostructure that operates independently of pilot input and is controlled solely by the altitude the aircraft is flying at. (2) The second approach relies on a controlled constant CDP. This CDP could be supplied from one of the compressor stages of the engine as a form of bleed air. Because of the air-tight pouches there would essentially be no mass flow, meaning engine efficiency would not be significantly affected due to this application. By means of a valve system the pilot could have direct control over the pressure and, consequently, the stiffness of the structure. This allows for much higher CDPs (on the order of 1MPa) than could physically be achieved by relying on the ambient pressure

  20. Adaptation of the tendon to mechanical usage.

    PubMed

    Reeves, N D

    2006-01-01

    Tendons primarily function as contractile force transmitters, but their mechanical properties may change dependent upon their level of mechanical usage. Using an ultrasound-based technique we have assessed tendon mechanical properties in vivo in a number of conditions representing different levels of mechanical usage. Ageing alters tendon mechanical properties; stiffness and modulus were lower in older adults by 10 and 14%, respectively, compared to young adults. Increased levels of exercise loading in old age can however partly reverse this process, as tendon stiffness and modulus were found to increase by 65 and 69%, respectively. Complete unloading due to bed rest or spinal cord injury both reduce tendon stiffness and modulus, however, only chronic unloading due to spinal cord injury seems to cause tendon atrophy. Alterations in tendon mechanical properties due to changes in the levels loading have implications for the speed of force transmission, the muscle's operating range and the likelihood of tendon strain injury.

  1. Talking about death: implementing peer discussion as a coping mechanism to overcome fears about dissection, death, and dying.

    PubMed

    Kotzé, Sanet Henriët; Mole, Calvin Gerald

    2013-01-01

    Many studies have reported on the perceptions of medical students toward dissection. It is important to understand the feelings and symptoms experienced during dissection so that they can be adequately handled. Prior to dissection, first year students are given lectures on aspects of dissection, death and dying, and death rituals in various cultures. Two separate questionnaires, one given during the first week of dissection and another given one month into the program were then completed anonymously by dissection groups. The questions were designed to be open-ended, thereby encouraging group discussion amongst students. The questionnaires were used to determine the perception of students to dissection and to discover if these perceptions change during the dissection program. The first questionnaire revealed that students do experience fears and anxiety prior to and at the beginning of dissection; however, most of these fears dissipated by the time of the second questionnaire. One month into dissection students cited talking to peers as their main coping mechanism and fewer students mentioned emotional detachment from their cadaver as a coping mechanism, as was the case in the first questionnaire. Dissection was perceived as a positive experience by our student cohort and most students cited the main advantage of dissection as the ability to visualize organs in three dimensions. The comprehensive answers received from the students indicated that thorough discussion of feelings amongst peers occurred, introducing students to an important coping mechanism at an early stage of their learning.

  2. Managing Expectations: Results from Case Studies of US Water Utilities on Preparing for, Coping with, and Adapting to Extreme Events

    NASA Astrophysics Data System (ADS)

    Beller-Simms, N.; Metchis, K.

    2014-12-01

    Water utilities, reeling from increased impacts of successive extreme events such as floods, droughts, and derechos, are taking a more proactive role in preparing for future incursions. A recent study by Federal and water foundation investigators, reveals how six US water utilities and their regions prepared for, responded to, and coped with recent extreme weather and climate events and the lessons they are using to plan future adaptation and resilience activities. Two case studies will be highlighted. (1) Sonoma County, CA, has had alternating floods and severe droughts. In 2009, this area, home to competing water users, namely, agricultural crops, wineries, tourism, and fisheries faced a three-year drought, accompanied at the end by intense frosts. Competing uses of water threatened the grape harvest, endangered the fish industry and resulted in a series of regulations, and court cases. Five years later, new efforts by partners in the entire watershed have identified mutual opportunities for increased basin sustainability in the face of a changing climate. (2) Washington DC had a derecho in late June 2012, which curtailed water, communications, and power delivery during a record heat spell that impacted hundreds of thousands of residents and lasted over the height of the tourist-intensive July 4th holiday. Lessons from this event were applied three months later in anticipation of an approaching Superstorm Sandy. This study will help other communities in improving their resiliency in the face of future climate extremes. For example, this study revealed that (1) communities are planning with multiple types and occurrences of extreme events which are becoming more severe and frequent and are impacting communities that are expanding into more vulnerable areas and (2) decisions by one sector can not be made in a vacuum and require the scientific, sectoral and citizen communities to work towards sustainable solutions.

  3. Coping with Decline

    ERIC Educational Resources Information Center

    Boulding, Kenneth

    1977-01-01

    A quantitative decline is predicted because of the leveling off of industrial production and exhaustion of resources. Coping with these conditions requires flexibility and adaptability. Delusions of certainty zero in on catastrophe. (Author/MLF)

  4. A socio-ecological adaptive approach to contaminated mega-site management: From 'control and correct' to 'coping with change'

    NASA Astrophysics Data System (ADS)

    Schirmer, Mario; Lyon, Ken; Armstrong, James E.; Farrell, Katharine N.

    2012-01-01

    Mega-sites have a notable impact on surrounding ecological systems. At such sites there are substantial risks associated with complex socio-ecological interactions that are hard to characterize, let alone model and predict. While the urge to control and clean-up mega-sites (control and correct) is understandable, rather than setting a goal of cleaning up such sites, we suggest a more realistic response strategy is to address these massive and persistent sources of contamination by acknowledging their position as new features of the socio-ecological landscapes within which they are located. As it seems nearly impossible to clean up such sites, we argue for consideration of a 'coping with change' rather than a 'control and correct' approach. This strategy recognizes that the current management option for a mega-site, in light of its physical complexities and due to changing societal preferences, geochemical transformations, hydrogeology knowledge and remedial technology options may not remain optimal in future, and therefore needs to be continuously adapted, as community, ecology, technology and understanding change over time. This approach creates an opportunity to consider the relationship between a mega-site and its human and ecological environments in a different and more dynamic way. Our proposed approach relies on iterative adaptive management to incorporate mega-site management into the overall socio-ecological systems of the site's context. This approach effectively embeds mega-site management planning in a triple bottom line and environmental sustainability structure, rather than simply using single measures of success, such as contaminant-based guidelines. Recognizing that there is probably no best solution for managing a mega-site, we present a starting point for engaging constructively with this seemingly intractable issue. Therefore, we aim to initiate discussion about a new approach to mega-site management, in which the complexity of the problems posed

  5. A socio-ecological adaptive approach to contaminated mega-site management: from 'control and correct' to 'coping with change'.

    PubMed

    Schirmer, Mario; Lyon, Ken; Armstrong, James E; Farrell, Katharine N

    2012-01-01

    Mega-sites have a notable impact on surrounding ecological systems. At such sites there are substantial risks associated with complex socio-ecological interactions that are hard to characterize, let alone model and predict. While the urge to control and clean-up mega-sites (control and correct) is understandable, rather than setting a goal of cleaning up such sites, we suggest a more realistic response strategy is to address these massive and persistent sources of contamination by acknowledging their position as new features of the socio-ecological landscapes within which they are located. As it seems nearly impossible to clean up such sites, we argue for consideration of a 'coping with change' rather than a 'control and correct' approach. This strategy recognizes that the current management option for a mega-site, in light of its physical complexities and due to changing societal preferences, geochemical transformations, hydrogeology knowledge and remedial technology options may not remain optimal in future, and therefore needs to be continuously adapted, as community, ecology, technology and understanding change over time. This approach creates an opportunity to consider the relationship between a mega-site and its human and ecological environments in a different and more dynamic way. Our proposed approach relies on iterative adaptive management to incorporate mega-site management into the overall socio-ecological systems of the site's context. This approach effectively embeds mega-site management planning in a triple bottom line and environmental sustainability structure, rather than simply using single measures of success, such as contaminant-based guidelines. Recognizing that there is probably no best solution for managing a mega-site, we present a starting point for engaging constructively with this seemingly intractable issue. Therefore, we aim to initiate discussion about a new approach to mega-site management, in which the complexity of the problems posed

  6. A generic mechanism for adaptive growth rate regulation.

    PubMed

    Furusawa, Chikara; Kaneko, Kunihiko

    2008-01-01

    How can a microorganism adapt to a variety of environmental conditions despite the existence of a limited number of signal transduction mechanisms? We show that for any growing cells whose gene expression fluctuate stochastically, the adaptive cellular state is inevitably selected by noise, even without a specific signal transduction network for it. In general, changes in protein concentration in a cell are given by its synthesis minus dilution and degradation, both of which are proportional to the rate of cell growth. In an adaptive state with a higher growth speed, both terms are large and balanced. Under the presence of noise in gene expression, the adaptive state is less affected by stochasticity since both the synthesis and dilution terms are large, while for a nonadaptive state both the terms are smaller so that cells are easily kicked out of the original state by noise. Hence, escape time from a cellular state and the cellular growth rate are negatively correlated. This leads to a selection of adaptive states with higher growth rates, and model simulations confirm this selection to take place in general. The results suggest a general form of adaptation that has never been brought to light--a process that requires no specific mechanisms for sensory adaptation. The present scheme may help explain a wide range of cellular adaptive responses including the metabolic flux optimization for maximal cell growth.

  7. Mechanisms underlying neglect recovery after prism adaptation.

    PubMed

    Serino, Andrea; Angeli, Valentina; Frassinetti, Francesca; Làdavas, Elisabetta

    2006-01-01

    Prism adaptation (PA) has been demonstrated to be effective in improving hemispatial neglect. However not all patients seem to benefit from this procedure. Thus, the objective of the present work is to provide behavioural and neuroanatomical predictors of recovery by exploring the reorganization of low-order visuo-motor behaviour and high-order visuo-spatial representation induced by PA. To this end, 16 neglect patients (experimental group) were submitted to a PA treatment for 10 daily sessions. Neglect and oculo-motor responses were assessed before the treatment, 1 week, 1 and 3 months after the treatment. Eight control patients, who received general cognitive stimulation, were submitted to the same tests at the same time interval. The results showed that experimental patients obtained, as a consequence of PA, a long lasting neglect recovery, a reorganization of low-order visuo-motor behaviour during and after prism exposure (error reduction and after-effect, respectively) and a leftward deviation of oculo-motor responses. Importantly, the level of error reduction obtained in the first week of treatment was predictive of neglect recovery and the amelioration of oculo-motor responses, and the degree of eye movement deviation was positively related to neglect amelioration. Finally, the study of patients' neuroanatomical data showed that severe occipital lesions were associated with a lack of error reduction, poor neglect recovery and reduced oculo-motor system amelioration. In conclusion, the present results suggest that low-order visuo-motor reorganization induced by PA promotes a resetting of the oculo-motor system leading to an improvement in high-order visuo-spatial representation able to ameliorate neglect. PMID:16330055

  8. A synaptic mechanism for retinal adaptation to luminance and contrast.

    PubMed

    Jarsky, Tim; Cembrowski, Mark; Logan, Stephen M; Kath, William L; Riecke, Hermann; Demb, Jonathan B; Singer, Joshua H

    2011-07-27

    The gain of signaling in primary sensory circuits is matched to the stimulus intensity by the process of adaptation. Retinal neural circuits adapt to visual scene statistics, including the mean (background adaptation) and the temporal variance (contrast adaptation) of the light stimulus. The intrinsic properties of retinal bipolar cells and synapses contribute to background and contrast adaptation, but it is unclear whether both forms of adaptation depend on the same cellular mechanisms. Studies of bipolar cell synapses identified synaptic mechanisms of gain control, but the relevance of these mechanisms to visual processing is uncertain because of the historical focus on fast, phasic transmission rather than the tonic transmission evoked by ambient light. Here, we studied use-dependent regulation of bipolar cell synaptic transmission evoked by small, ongoing modulations of membrane potential (V(M)) in the physiological range. We made paired whole-cell recordings from rod bipolar (RB) and AII amacrine cells in a mouse retinal slice preparation. Quasi-white noise voltage commands modulated RB V(M) and evoked EPSCs in the AII. We mimicked changes in background luminance or contrast, respectively, by depolarizing the V(M) or increasing its variance. A linear systems analysis of synaptic transmission showed that increasing either the mean or the variance of the presynaptic V(M) reduced gain. Further electrophysiological and computational analyses demonstrated that adaptation to mean potential resulted from both Ca channel inactivation and vesicle depletion, whereas adaptation to variance resulted from vesicle depletion alone. Thus, background and contrast adaptation apparently depend in part on a common synaptic mechanism.

  9. Grandparents in a Parental or Near-Parental Role: Sources of Stress and Coping Mechanisms

    ERIC Educational Resources Information Center

    Lumpkin, James R.

    2008-01-01

    Although about 11% of grandparents are raising their grandchildren, a larger percentage provide a significant amount of care and serve in a near-parental role. Both parental and near-parental roles create stress. The stressors that these grandparents face and the strategies that they use to cope were investigated in this descriptive, exploratory…

  10. Stimuli-Responsive Mechanically Adaptive Polymer Nanocomposites

    PubMed Central

    Shanmuganathan, Kadhiravan; Capadona, Jeffrey R.; Rowan, Stuart J.; Weder, Christoph

    2010-01-01

    A new series of biomimetic stimuli-responsive nanocomposites, which change their mechanical properties upon exposure to physiological conditions, was prepared and investigated. The materials were produced by introducing percolating networks of cellulose nanofibers or “whiskers” derived from tunicates into poly(vinyl acetate) (PVAc), poly(butyl methacrylate) (PBMA), and blends of these polymers, with the objective of determining how the hydrophobicity and glass-transition temperature (Tg) of the polymer matrix affect the water-induced mechanically dynamic behavior. Below the Tg (~60–70 °C), the incorporation of whiskers (15.1 – 16.5% v/v) modestly increased the tensile storage moduli (E′) of the neat polymers from 0.6 to 3.8 GPa (PBMA) and from 2 to 5.2 GPa (PVAc). The reinforcement was much more dramatic above Tg, where E′ increased from 1.2 to 690 MPa (PVAc) and ~1 to 1.1 GPa (PBMA). Upon exposure to physiological conditions (immersion in artificial cerebrospinal fluid, ACSF, at 37 °C) all materials displayed a decrease of E′. The most significant contrast was seen in PVAc; for example the E′ of a 16.5% v/v PVAc/whisker nanocomposite decreased from 5.2 GPa to 12.7 MPa. Only a modest modulus decrease was measured for PBMA/whisker nanocomposite; here the E′ of a 15.1% v/v PBMA/whisker nanocomposite decreased from 3.8 to 1.2 GPa. A systematic investigation revealed that the magnitude of the mechanical contrast was related to the degree of swelling with ACSF, which was shown to increase with whisker content, temperature, and polarity of the matrix (PVAc > PBMA). The mechanical morphing of the new materials can be described in the framework of both the percolation and Halpin-Kardos models for nanocomposite reinforcement, and is the result of changing interactions among the nanoparticles and plasticization of the matrix upon swelling. PMID:20305827

  11. Interrelations between hydraulic and mechanical stress adaptations in woody plants.

    PubMed

    Christensen-Dalsgaard, Karen K; Ennos, A Roland; Fournier, Meriem

    2008-07-01

    The fields of plant water relations and plant biomechanics have traditionally been studied separately even though often the same tissues are responsible for water transport and mechanical support. There is now increasing evidence that hydraulic and mechanical adaptations may influence one another. We studied the changes in the hydraulic and mechanical properties of the wood along lateral roots of two species of buttressed trees. In these roots, the mechanical contstraints quantified by strain measurements are known to decrease distally. Further, we investigated the effect of mechanical loading on the vessel anatomy in these and four other species of tropical trees. We found that as the strain decreased, the wood became progressively less stiff and strong but the conductivity increased exponentially. This was reflected in that adaptations towards re-enforcing mechanically loaded areas resulted in xylem with fewer and smaller vessels. In addition a controlled growth experiment on three tree species showed that drought adaptation may results in plants with stronger and stiffer tissue. Our results indicate that hydraulic and mechanical stress adaptations may be interrelated, and so support recent studied suggesting that physiological responses are complex balances rather than pure optimisations.

  12. Root developmental adaptation to Fe toxicity: Mechanisms and management.

    PubMed

    Li, Guangjie; Kronzucker, Herbert J; Shi, Weiming

    2016-01-01

    Iron (Fe) is an essential microelement but is highly toxic when in excess. To cope with Fe excess, plants have evolved complex adaptive responses that include morphological and physiological modifications. The highly dynamic adjustments in overall root system architecture (RSA) determine root plasticity and allow plants to efficiently adapt to environmental constraints. However, the effects of Fe excess on RSA are poorly understood. Recently, we showed that excess Fe treatment in Arabidopsis not only directly impairs primary root (PR) growth but also arrests lateral root (LR) formation by acting at the tip of the growing primary root. Such a change is believed to help RSA adjust and restrict excessive Fe absorption in the part of the rhizosphere subject to acute toxicity while maintaining the absorption of other nutrients in the less stressed components of the root system. We further showed that the suppression of PR growth and LR formation under excess Fe is alleviated by K(+) addition, providing useful insight into the effectiveness of nutrient management to improve RSA and alleviate Fe toxicity symptoms in the field.

  13. Adaptive and Nonadaptive Help Seeking with Peer Harassment: An Integrative Perspective of Coping and Self-Regulation

    ERIC Educational Resources Information Center

    Newman, Richard S.

    2008-01-01

    When harassed by peers, elementary school students often face a dilemma of whether to ask their teacher for help. Assistance may be useful, and perhaps necessary. However, there can be social costs; children generally are expected to resolve interpersonal conflicts on their own. Two theoretical perspectives (i.e., coping and self-regulation)…

  14. Adaptive Coping Reduces the Impact of Community Violence Exposure on Violent Behavior among African American and Latino Male Adolescents

    ERIC Educational Resources Information Center

    Brady, Sonya S.; Gorman-Smith, Deborah; Henry, David B.; Tolan, Patrick H.

    2008-01-01

    This study examined whether coping moderated the impact of community violence exposure (CVE) on violent behavior among 285 urban African American and Latino adolescent males assessed annually across 5 years. Composites indicating overall CVE (having knowledge of others' victimization, witnessing violence, direct victimization) and approach to…

  15. CRISPR-Cas adaptation: insights into the mechanism of action.

    PubMed

    Amitai, Gil; Sorek, Rotem

    2016-02-01

    Since the first demonstration that CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against phages and plasmids, numerous studies have yielded key insights into the molecular mechanisms governing how these systems attack and degrade foreign DNA. However, the molecular mechanisms underlying the adaptation stage, in which new immunological memory is formed, have until recently represented a major unresolved question. In this Progress article, we discuss recent discoveries that have shown both how foreign DNA is identified by the CRISPR-Cas adaptation machinery and the molecular basis for its integration into the chromosome to form an immunological memory. Furthermore, we describe the roles of each of the specific CRISPR-Cas components that are involved in memory formation, and consider current models for their evolutionary origin.

  16. Never the Twain shall meet? Closing the gap between coping research and clinical intervention research.

    PubMed

    Coyne, J C; Racioppo, M W

    2000-06-01

    Two distinct literatures have contributed to a tremendous growth of interest in coping. The 1st consists of descriptive studies that have used coping checklists. This literature is in crisis because of its failure to yield substantive findings concerning the role of coping in adaptation that cannot be dismissed as truisms, trivia, or the product of a confounding of stress, coping, and distress. The 2nd literature concerns interventions to improve adaptation by enhancing coping. It provides evidence of the efficacy of intervention but provides little understanding of crucial ingredients, mechanisms of change, or barriers to maintaining gains. Both literatures would benefit from cross-fertilization. Process studies of interventions designed to improve coping provide an alternative to fruitless and potentially misleading correlational studies using checklists. Such studies might also aid in understanding and refining intervention strategies.

  17. When Do Adaptive Developmental Mechanisms Yield Maladaptive Outcomes?

    ERIC Educational Resources Information Center

    Frankenhuis, Willem E.; Del Giudice, Marco

    2012-01-01

    This article discusses 3 ways in which adaptive developmental mechanisms may produce maladaptive outcomes. First, natural selection may favor risky strategies that enhance fitness on average but which have detrimental consequences for a subset of individuals. Second, mismatch may result when organisms experience environmental change during…

  18. Coping mechanisms of some blind trainees engaging in agricultural rehabilitation in a Nigerian training centre for the blind.

    PubMed

    Olujide, Mukaila G; Ademokoya, Julius A

    2006-09-01

    This study was conducted to assess the coping mechanisms of some blind trainees engaged in agricultural activities at the Nigeria Training Centre for the Blind, Ogbomoso, Oyo State, Nigeria. The participants in this study were blind trainees and agricultural inspectors. Focus group discussions were used to elicit their feelings concerning their coping mechanisms with agricultural activities at the centre. In addition, a practical session, and participatory observation, was carried out to examine the trainees and their reactions to the agricultural training programmes. Findings revealed that the blind trainees could effectively undertake farming activities despite their disability. It was, however, noted that the facilities for agricultural training programme in the centre are not inadequate. Moreover, the study further discovered that the number of blind persons seeking agricultural training was far less than the expected intake for the centre. There were also more male than female trainees in the centre. Based on the findings, recommendations were made to improve the farming training programme for blind trainees at the centre. More facilities should be provided and efforts made to encourage more blind persons to use the centre. This will discourage begging and dependence, activities often engaged in by blind persons who have not been rehabilitated.

  19. NO-dependent mechanisms of adaptation to hypoxia.

    PubMed

    Malyshev, I Y; Zenina, T A; Golubeva, L Y; Saltykova, V A; Manukhina, E B; Mikoyan, V D; Kubrina, L N; Vanin, A F

    1999-01-01

    In studying NO-dependent mechanisms of resistance to hypoxia, it was shown that (1) acute hypoxia induces NO overproduction in brain and leaves unaffected NO production in liver of rats; (2) adaptation to hypoxia decreases NO production in liver and brain; and (3) adaptation to hypoxia prevents NO overproduction in brain and potentiates NO synthesis in liver in acute hypoxia. Dinitrosyl iron complex (DNIC, 200 microg/kg, single dose, iv), a NO donor, decreases the resistance of animals to acute hypoxia by 30%. Nomega-nitro-L-arginine (L-NNA, 50 mg/kg, single dose, ip), a NO synthase inhibitor, and diethyl dithiocarbamate (DETC, 200 mg/kg, single dose, iv), a NO trap, increases this parameter 1.3 and 2 times, respectively. Adaptation to hypoxia developed against a background of accumulation of heat shock protein HSP70 in liver and brain. A course of DNIC reproduced the antihypoxic effect of adaptation. A course of L-NNA during adaptation hampered both accumulation of HSP70 and development of the antihypoxic effect. Therefore, NO and the NO-dependent activation of HSP70 synthesis play important roles in adaptation to hypoxia. PMID:10369180

  20. Importance of plasticity and local adaptation for coping with changing salinity in coastal areas: a test case with barnacles in the Baltic Sea

    PubMed Central

    2014-01-01

    Background Salinity plays an important role in shaping coastal marine communities. Near-future climate predictions indicate that salinity will decrease in many shallow coastal areas due to increased precipitation; however, few studies have addressed this issue. The ability of ecosystems to cope with future changes will depend on species’ capacities to acclimatise or adapt to new environmental conditions. Here, we investigated the effects of a strong salinity gradient (the Baltic Sea system – Baltic, Kattegat, Skagerrak) on plasticity and adaptations in the euryhaline barnacle Balanus improvisus. We used a common-garden approach, where multiple batches of newly settled barnacles from each of three different geographical areas along the Skagerrak-Baltic salinity gradient were exposed to corresponding native salinities (6, 15 and 30 PSU), and phenotypic traits including mortality, growth, shell strength, condition index and reproductive maturity were recorded. Results We found that B. improvisus was highly euryhaline, but had highest growth and reproductive maturity at intermediate salinities. We also found that low salinity had negative effects on other fitness-related traits including initial growth and shell strength, although mortality was also lowest in low salinity. Overall, differences between populations in most measured traits were weak, indicating little local adaptation to salinity. Nonetheless, we observed some population-specific responses – notably that populations from high salinity grew stronger shells in their native salinity compared to the other populations, possibly indicating adaptation to differences in local predation pressure. Conclusions Our study shows that B. improvisus is an example of a true brackish-water species, and that plastic responses are more likely than evolutionary tracking in coping with future changes in coastal salinity. PMID:25038588

  1. First adaptation of coping power program as a classroom-based prevention intervention on aggressive behaviors among elementary school children.

    PubMed

    Muratori, Pietro; Bertacchi, Iacopo; Giuli, Consuelo; Lombardi, Lavinia; Bonetti, Silvia; Nocentini, Annalaura; Manfredi, Azzurra; Polidori, Lisa; Ruglioni, Laura; Milone, Annarita; Lochman, John E

    2015-04-01

    Children with high levels of aggressive behavior create a major management problem in school settings and interfere with the learning environment of their classmates. We report results from a group-randomized trial of a program aimed at preventing aggressive behaviors. The purpose of the current study, therefore, was to determine the extent to which an indicated prevention program, Coping Power Program, is capable of reducing behavioral problems and improving pro-social behavior when delivered as a universal classroom-based prevention intervention. Nine classes (five first grade and four second grade) were randomly assigned to intervention or control conditions. Findings showed a significant reduction in overall problematic behaviors and in inattention-hyperactivity problems for the intervention classes compared to the control classes. Students who received Coping Power Program intervention also showed more pro-social behaviors at postintervention. The implications of these findings for the implementation of strategies aimed at preventing aggressive behavior in school settings are discussed. PMID:24942813

  2. First adaptation of coping power program as a classroom-based prevention intervention on aggressive behaviors among elementary school children.

    PubMed

    Muratori, Pietro; Bertacchi, Iacopo; Giuli, Consuelo; Lombardi, Lavinia; Bonetti, Silvia; Nocentini, Annalaura; Manfredi, Azzurra; Polidori, Lisa; Ruglioni, Laura; Milone, Annarita; Lochman, John E

    2015-04-01

    Children with high levels of aggressive behavior create a major management problem in school settings and interfere with the learning environment of their classmates. We report results from a group-randomized trial of a program aimed at preventing aggressive behaviors. The purpose of the current study, therefore, was to determine the extent to which an indicated prevention program, Coping Power Program, is capable of reducing behavioral problems and improving pro-social behavior when delivered as a universal classroom-based prevention intervention. Nine classes (five first grade and four second grade) were randomly assigned to intervention or control conditions. Findings showed a significant reduction in overall problematic behaviors and in inattention-hyperactivity problems for the intervention classes compared to the control classes. Students who received Coping Power Program intervention also showed more pro-social behaviors at postintervention. The implications of these findings for the implementation of strategies aimed at preventing aggressive behavior in school settings are discussed.

  3. Chronic stress and brain plasticity: mechanisms underlying adaptive and maladaptive changes and implications for stress-related CNS disorders

    PubMed Central

    Radley, Jason; Morilak, David; Viau, Victor; Campeau, Serge

    2015-01-01

    Stress responses entail neuroendocrine, autonomic, and behavioral changes to promote effective coping with real or perceived threats to one’s safety. While these responses are critical for the survival of the individual, adverse effects of repeated exposure to stress are widely known to have deleterious effects on health. Thus, a considerable effort in the search for treatments to stress-related CNS disorders necessitates unraveling the brain mechanisms responsible for adaptation under acute conditions and their perturbations following chronic stress exposure. This paper is based upon a symposium from the 2014 International Behavioral Neuroscience Meeting, summarizing some recent advances in understanding the effects of stress on adaptive and maladaptive responses subserved by limbic forebrain networks. An important theme highlighted in this review is that the same networks mediating neuroendocrine, autonomic, and behavioral processes during adaptive coping also comprise targets of the effects of repeated stress exposure in the development of maladaptive states. Where possible, reference is made to the similarity of neurobiological substrates and effects observed following repeated exposure to stress in laboratory animals and the clinical features of stress-related disorders in humans. PMID:26116544

  4. Phenotypic Plasticity and Selection: Nonexclusive Mechanisms of Adaptation

    PubMed Central

    Grenier, S.; Barre, P.; Litrico, I.

    2016-01-01

    Selection and plasticity are two mechanisms that allow the adaptation of a population to a changing environment. Interaction between these nonexclusive mechanisms must be considered if we are to understand population survival. This review discusses the ways in which plasticity and selection can interact, based on a review of the literature on selection and phenotypic plasticity in the evolution of populations. The link between selection and phenotypic plasticity is analysed at the level of the individual. Plasticity can affect an individual's response to selection and so may modify the end result of genetic diversity evolution at population level. Genetic diversity increases the ability of populations or communities to adapt to new environmental conditions. Adaptive plasticity increases individual fitness. However this effect must be viewed from the perspective of the costs of plasticity, although these are not easy to estimate. It is becoming necessary to engage in new experimental research to demonstrate the combined effects of selection and plasticity for adaptation and their consequences on the evolution of genetic diversity. PMID:27313957

  5. Visual-adaptation-mechanism based underwater object extraction

    NASA Astrophysics Data System (ADS)

    Chen, Zhe; Wang, Huibin; Xu, Lizhong; Shen, Jie

    2014-03-01

    Due to the major obstacles originating from the strong light absorption and scattering in a dynamic underwater environment, underwater optical information acquisition and processing suffer from effects such as limited range, non-uniform lighting, low contrast, and diminished colors, causing it to become the bottleneck for marine scientific research and projects. After studying and generalizing the underwater biological visual mechanism, we explore its advantages in light adaption which helps animals to precisely sense the underwater scene and recognize their prey or enemies. Then, aiming to transform the significant advantage of the visual adaptation mechanism into underwater computer vision tasks, a novel knowledge-based information weighting fusion model is established for underwater object extraction. With this bionic model, the dynamical adaptability is given to the underwater object extraction task, making them more robust to the variability of the optical properties in different environments. The capability of the proposed method to adapt to the underwater optical environments is shown, and its outperformance for the object extraction is demonstrated by comparison experiments.

  6. Adaptive mechanism-based congestion control for networked systems

    NASA Astrophysics Data System (ADS)

    Liu, Zhi; Zhang, Yun; Chen, C. L. Philip

    2013-03-01

    In order to assure the communication quality in network systems with heavy traffic and limited bandwidth, a new ATRED (adaptive thresholds random early detection) congestion control algorithm is proposed for the congestion avoidance and resource management of network systems. Different to the traditional AQM (active queue management) algorithms, the control parameters of ATRED are not configured statically, but dynamically adjusted by the adaptive mechanism. By integrating with the adaptive strategy, ATRED alleviates the tuning difficulty of RED (random early detection) and shows a better control on the queue management, and achieve a more robust performance than RED under varying network conditions. Furthermore, a dynamic transmission control protocol-AQM control system using ATRED controller is introduced for the systematic analysis. It is proved that the stability of the network system can be guaranteed when the adaptive mechanism is finely designed. Simulation studies show the proposed ATRED algorithm achieves a good performance in varying network environments, which is superior to the RED and Gentle-RED algorithm, and providing more reliable service under varying network conditions.

  7. Mechanical signal transduction in skeletal muscle growth and adaptation.

    PubMed

    Tidball, James G

    2005-05-01

    The adaptability of skeletal muscle to changes in the mechanical environment has been well characterized at the tissue and system levels, but the mechanisms through which mechanical signals are transduced to chemical signals that influence muscle growth and metabolism remain largely unidentified. However, several findings have suggested that mechanical signal transduction in muscle may occur through signaling pathways that are shared with insulin-like growth factor (IGF)-I. The involvement of IGF-I-mediated signaling for mechanical signal transduction in muscle was originally suggested by the observations that muscle releases IGF-I on mechanical stimulation, that IGF-I is a potent agent for promoting muscle growth and affecting phenotype, and that IGF-I can function as an autocrine hormone in muscle. Accumulating evidence shows that at least two signaling pathways downstream of IGF-I binding can influence muscle growth and adaptation. Signaling via the calcineurin/nuclear factor of activated T-cell pathway has been shown to have a powerful influence on promoting the slow/type I phenotype in muscle but can also increase muscle mass. Neural stimulation of muscle can activate this pathway, although whether neural activation of the pathway can occur independent of mechanical activation or independent of IGF-I-mediated signaling remains to be explored. Signaling via the Akt/mammalian target of rapamycin pathway can also increase muscle growth, and recent findings show that activation of this pathway can occur as a response to mechanical stimulation applied directly to muscle cells, independent of signals derived from other cells. In addition, mechanical activation of mammalian target of rapamycin, Akt, and other downstream signals is apparently independent of autocrine factors, which suggests that activation of the mechanical pathway occurs independent of muscle-mediated IGF-I release.

  8. In vivo deployment of mechanically adaptive nanocomposites for intracortical microelectrodes

    PubMed Central

    Harris, J P; Hess, A E; Rowan, S J; Weder, C; Zorman, C A; Tyler, D J; Capadona, J R

    2012-01-01

    We recently introduced a series of stimuli-responsive, mechanically-adaptive polymer nanocomposites. Here, we report the first application of these bio-inspired materials as substrates for intracortical microelectrodes. Our hypothesis is that the ideal electrode should be initially stiff to facilitate minimal trauma during insertion into the cortex, yet becomes mechanically compliant to match the stiffness of the brain tissue and minimize forces exerted on the tissue, attenuating inflammation. Microprobes created from mechanically reinforced nanocomposites demonstrated a significant advantage compared to model microprobes composed of neat polymer only. The nanocomposite microprobes exhibit a higher storage modulus (E’ = ~5 GPa) than the neat polymer microprobes (E’ = ~2 GPa) and could sustain higher loads (~17 mN), facilitating penetration through the pia mater and insertion into the cerebral cortex of a rat. In contrast, the neat polymer microprobes mechanically failed under lower loads (~7 mN) before they were capable of inserting into cortical tissue. Further, we demonstrated the material’s ability to morph while in the rat cortex to more closely match the mechanical properties of the cortical tissue. Nanocomposite microprobes that were implanted into the rat cortex for up to 8 weeks demonstrated increased cell density at the microelectrode-tissue interface and a lack of tissue necrosis or excessive gliosis. This body of work introduces our nanocomposite-based microprobes as adaptive substrates for intracortical microelectrodes and potentially other biomedical applications. PMID:21654037

  9. In vivo deployment of mechanically adaptive nanocomposites for intracortical microelectrodes.

    PubMed

    Harris, J P; Hess, A E; Rowan, S J; Weder, C; Zorman, C A; Tyler, D J; Capadona, J R

    2011-08-01

    We recently introduced a series of stimuli-responsive, mechanically adaptive polymer nanocomposites. Here, we report the first application of these bio-inspired materials as substrates for intracortical microelectrodes. Our hypothesis is that the ideal electrode should be initially stiff to facilitate minimal trauma during insertion into the cortex, yet become mechanically compliant to match the stiffness of the brain tissue and minimize forces exerted on the tissue, attenuating inflammation. Microprobes created from mechanically reinforced nanocomposites demonstrated a significant advantage compared to model microprobes composed of neat polymer only. The nanocomposite microprobes exhibit a higher storage modulus (E' = ~5 GPa) than the neat polymer microprobes (E' = ~2 GPa) and can sustain higher loads (~12 mN), facilitating penetration through the pia mater and insertion into the cerebral cortex of a rat. In contrast, the neat polymer microprobes mechanically failed under lower loads (~7 mN) before they were capable of insertion into cortical tissue. Further, we demonstrated the material's ability to morph while in the rat cortex to more closely match the mechanical properties of the cortical tissue. Nanocomposite microprobes that were implanted into the rat cortex for up to eight weeks demonstrated increased cell density at the microelectrode-tissue interface and a lack of tissue necrosis or excessive gliosis. This body of work introduces our nanocomposite-based microprobes as adaptive substrates for intracortical microelectrodes and potentially for other biomedical applications.

  10. Selective brain cooling in Arabian oryx (Oryx leucoryx): a physiological mechanism for coping with aridity?

    PubMed

    Hetem, Robyn S; Strauss, W Maartin; Fick, Linda G; Maloney, Shane K; Meyer, Leith C R; Fuller, Andrea; Shobrak, Mohammed; Mitchell, Duncan

    2012-11-15

    Selective brain cooling is a thermoregulatory effector proposed to conserve body water and, as such, may help artiodactyls cope with aridity. We measured brain and carotid blood temperature, using implanted data loggers, in five Arabian oryx (Oryx leucoryx) in the desert of Saudi Arabia. On average, brain temperature was 0.24±0.05°C lower than carotid blood temperature for four oryx in April. Selective brain cooling was enhanced in our Arabian oryx compared with another species from the same genus (gemsbok Oryx gazella gazella) exposed to similar ambient temperatures but less aridity. Arabian oryx displayed a lower threshold (37.8±0.1°C vs 39.8±0.4°C), a higher frequency (87±6% vs 15±15%) and a higher maximum magnitude (1.2±0.2°C vs 0.5±0.3°C) of selective brain cooling than did gemsbok. The dominant male oryx displayed less selective brain cooling than did any of the other oryx, but selective brain cooling was enhanced in this oryx as conditions became hotter and drier. Enhanced selective brain cooling in Arabian oryx supports the hypothesis that selective brain cooling would bestow survival advantages for artiodactyl species inhabiting hot hyper-arid environments. PMID:22899527

  11. Explicit mentalizing mechanisms and their adaptive role in memory conformity.

    PubMed

    Wheeler, Rebecca; Allan, Kevin; Tsivilis, Dimitris; Martin, Douglas; Gabbert, Fiona

    2013-01-01

    Memory conformity occurs when an individual endorses what other individuals remember about past events. Research on memory conformity is currently dominated by a 'forensic' perspective, which views the phenomenon as inherently undesirable. This is because conformity not only distorts the accuracy of an individual's memory, but also produces false corroboration between individuals, effects that act to undermine criminal justice systems. There is growing awareness, however, that memory conformity may be interpreted more generally as an adaptive social behavior regulated by explicit mentalizing mechanisms. Here, we provide novel evidence in support of this emerging alternative theoretical perspective. We carried out a memory conformity experiment which revealed that explicit belief-simulation (i.e. using one's own beliefs to model what other people believe) systematically biases conformity towards like-minded individuals, even when there is no objective evidence that they have a more accurate memory than dissimilar individuals. We suggest that this bias is functional, i.e. adaptive, to the extent that it fosters trust, and hence cooperation, between in-group versus out-group individuals. We conclude that memory conformity is, in more fundamental terms, a highly desirable product of explicit mentalizing mechanisms that promote adaptive forms of social learning and cooperation.

  12. Application of flexure structures to active and adaptive opto-mechanical mechanisms

    NASA Astrophysics Data System (ADS)

    Zago, Lorenzo; Genequand, Pierre M.; Kjelberg, Ivar; Morschel, Joseph

    1997-03-01

    Active and adaptive structures, also commonly called 'smart' structures, combine in one integrated system various functions such as load carrying and structural function, mechanical (cinematic) functions, sensing, control and actuating. Originally developed for high accuracy opto-mechanical applications, CSEM's technology of flexure structures and flexible mechanisms is particularly suited to solve many structural and mechanical issues found in such active/adaptive mechanisms. The paper illustrates some recent flexure structures developments at CSEM and outlines the comprehensive know-how involved in this technology. This comprises in particular the elaboration of optimal design guidelines, related to the geometry, kinematics and dynamics issues (for instance, the minimization of spurious high frequency effects), the evaluation and predictability of all performance quantities relevant to the utilization of flexure structures in space (reliability, fatigue, static and dynamic modeling, etc.). material issues and manufacturing procedures.

  13. Mechanisms in Adaptive Feedback Control: Photoisomerization in a Liquid

    SciTech Connect

    Hoki, Kunihito; Brumer, Paul

    2005-10-14

    The underlying mechanism for Adaptive Feedback Control in the experimental photoisomerization of 3,3'-diethyl-2,2'-thiacyanine iodide (NK88) in methanol is exposed theoretically. With given laboratory limitations on laser output, the complicated electric fields are shown to achieve their targets in qualitatively simple ways. Further, control over the cis population without laser limitations reveals an incoherent pump-dump scenario as the optimal isomerization strategy. In neither case are there substantial contributions from quantum multiple-path interference or from nuclear wave packet coherence. Environmentally induced decoherence is shown to justify the use of a simplified theoretical model.

  14. Aneuploidy as a mechanism for stress-induced liver adaptation

    PubMed Central

    Duncan, Andrew W.; Hanlon Newell, Amy E.; Bi, Weimin; Finegold, Milton J.; Olson, Susan B.; Beaudet, Arthur L.; Grompe, Markus

    2012-01-01

    Over half of the mature hepatocytes in mice and humans are aneuploid and yet retain full ability to undergo mitosis. This observation has raised the question of whether this unusual somatic genetic variation evolved as an adaptive mechanism in response to hepatic injury. According to this model, hepatotoxic insults select for hepatocytes with specific numerical chromosome abnormalities, rendering them differentially resistant to injury. To test this hypothesis, we utilized a strain of mice heterozygous for a mutation in the homogentisic acid dioxygenase (Hgd) gene located on chromosome 16. Loss of the remaining Hgd allele protects from fumarylacetoacetate hydrolase (Fah) deficiency, a genetic liver disease model. When adult mice heterozygous for Hgd and lacking Fah were exposed to chronic liver damage, injury-resistant nodules consisting of Hgd-null hepatocytes rapidly emerged. To determine whether aneuploidy played a role in this phenomenon, array comparative genomic hybridization (aCGH) and metaphase karyotyping were performed. Strikingly, loss of chromosome 16 was dramatically enriched in all mice that became completely resistant to tyrosinemia-induced hepatic injury. The frequency of chromosome 16–specific aneuploidy was approximately 50%. This result indicates that selection of a specific aneuploid karyotype can result in the adaptation of hepatocytes to chronic liver injury. The extent to which aneuploidy promotes hepatic adaptation in humans remains under investigation. PMID:22863619

  15. Aneuploidy as a mechanism for stress-induced liver adaptation.

    PubMed

    Duncan, Andrew W; Hanlon Newell, Amy E; Bi, Weimin; Finegold, Milton J; Olson, Susan B; Beaudet, Arthur L; Grompe, Markus

    2012-09-01

    Over half of the mature hepatocytes in mice and humans are aneuploid and yet retain full ability to undergo mitosis. This observation has raised the question of whether this unusual somatic genetic variation evolved as an adaptive mechanism in response to hepatic injury. According to this model, hepatotoxic insults select for hepatocytes with specific numerical chromosome abnormalities, rendering them differentially resistant to injury. To test this hypothesis, we utilized a strain of mice heterozygous for a mutation in the homogentisic acid dioxygenase (Hgd) gene located on chromosome 16. Loss of the remaining Hgd allele protects from fumarylacetoacetate hydrolase (Fah) deficiency, a genetic liver disease model. When adult mice heterozygous for Hgd and lacking Fah were exposed to chronic liver damage, injury-resistant nodules consisting of Hgd-null hepatocytes rapidly emerged. To determine whether aneuploidy played a role in this phenomenon, array comparative genomic hybridization (aCGH) and metaphase karyotyping were performed. Strikingly, loss of chromosome 16 was dramatically enriched in all mice that became completely resistant to tyrosinemia-induced hepatic injury. The frequency of chromosome 16-specific aneuploidy was approximately 50%. This result indicates that selection of a specific aneuploid karyotype can result in the adaptation of hepatocytes to chronic liver injury. The extent to which aneuploidy promotes hepatic adaptation in humans remains under investigation.

  16. Coping with Temperature at the Warm Edge – Patterns of Thermal Adaptation in the Microbial Eukaryote Paramecium caudatum

    PubMed Central

    Krenek, Sascha; Petzoldt, Thomas; Berendonk, Thomas U.

    2012-01-01

    Background Ectothermic organisms are thought to be severely affected by global warming since their physiological performance is directly dependent on temperature. Latitudinal and temporal variations in mean temperatures force ectotherms to adapt to these complex environmental conditions. Studies investigating current patterns of thermal adaptation among populations of different latitudes allow a prediction of the potential impact of prospective increases in environmental temperatures on their fitness. Methodology/Principal Findings In this study, temperature reaction norms were ascertained among 18 genetically defined, natural clones of the microbial eukaryote Paramecium caudatum. These different clones have been isolated from 12 freshwater habitats along a latitudinal transect in Europe and from 3 tropical habitats (Indonesia). The sensitivity to increasing temperatures was estimated through the analysis of clone specific thermal tolerances and by relating those to current and predicted temperature data of their natural habitats. All investigated European clones seem to be thermal generalists with a broad thermal tolerance and similar optimum temperatures. The weak or missing co-variation of thermal tolerance with latitude does not imply local adaptation to thermal gradients; it rather suggests adaptive phenotypic plasticity among the whole European subpopulation. The tested Indonesian clones appear to be locally adapted to the less variable, tropical temperature regime and show higher tolerance limits, but lower tolerance breadths. Conclusions/Significance Due to the lack of local temperature adaptation within the European subpopulation, P. caudatum genotypes at the most southern edge of their geographic range seem to suffer from the predicted increase in magnitude and frequency of summer heat waves caused by climate change. PMID:22427799

  17. MECHANISMS OF STATIONARY PHASE MUTATION: A Decade of Adaptive Mutation

    PubMed Central

    Foster, P. L.

    2010-01-01

    A decade of research on adaptive mutation has revealed a plethora of mutagenic mechanisms that may be important in evolution. The DNA synthesis associated with recombination could be an important source of spontaneous mutation in cells that are not proliferating. The movement of insertion elements can be responsive to environmental conditions. Insertion elements not only activate and inactivate genes, they also provide sequence homology that allows large-scale genomic rearrangements. Some conjugative plasmids can recombine with their host’s chromosome, and may acquire chromosomal genes that could then spread through the population and even to other species. Finally, a subpopulation of transient hypermutators could be a source of multiple variant alleles, providing a mechanism for rapid evolution under adverse conditions. PMID:10690404

  18. An Examination of the Role of Social Support, Coping Strategies, and Individual Characteristics in Students' Adaptation to College

    ERIC Educational Resources Information Center

    Bejerano, Arleen R.

    2014-01-01

    Adaptation, or adjustment, is a psycho-social process that occurs when an individual accepts and integrates into his or her life a transition from one situation to another situation (Schlossberg, 1981). Many individuals struggle with transitions because transitions involve changes in the environment, roles, routines, and/or ways of looking at the…

  19. Adaptive mechanisms of Campylobacter jejuni to erythromycin treatment

    PubMed Central

    2013-01-01

    Background Macrolide is the drug of choice to treat human campylobacteriosis, but Campylobacter resistance to this antibiotic is rising. The mechanisms employed by Campylobacter jejuni to adapt to erythromycin treatment remain unknown and are examined in this study. The transcriptomic response of C. jejuni NCTC 11168 to erythromycin (Ery) treatment was determined by competitive microarray hybridizations. Representative genes identified to be differentially expressed were further characterized by constructing mutants and assessing their involvement in antimicrobial susceptibility, oxidative stress tolerance, and chicken colonization. Results Following the treatment with an inhibitory dose of Ery, 139 genes were up-regulated and 119 were down-regulated. Many genes associated with flagellar biosynthesis and motility was up-regulated, while many genes involved in tricarboxylic acid cycle, electron transport, and ribonucleotide biosynthesis were down-regulated. Exposure to a sub-inhibitory dose of Ery resulted in differential expression of much fewer genes. Interestingly, two putative drug efflux operons (cj0309c-cj0310c and cj1173-cj1174) were up-regulated. Although mutation of the two operons did not alter the susceptibility of C. jejuni to antimicrobials, it reduced Campylobacter growth under high-level oxygen. Another notable finding is the consistent up-regulation of cj1169c-cj1170c, of which cj1170c encodes a known phosphokinase, an important regulatory protein in C. jejuni. Mutation of the cj1169c-cj1170c rendered C. jejuni less tolerant to atmospheric oxygen and reduced Campylobacter colonization and transmission in chickens. Conclusions These findings indicate that Ery treatment elicits a range of changes in C. jejuni transcriptome and affects the expression of genes important for in vitro and in vivo adaptation. Up-regulation of motility and down-regulation of energy metabolism likely facilitate Campylobacter to survive during Ery treatment. These findings

  20. A density-based adaptive quantum mechanical/molecular mechanical method.

    PubMed

    Waller, Mark P; Kumbhar, Sadhana; Yang, Jack

    2014-10-20

    We present a density-based adaptive quantum mechanical/molecular mechanical (DBA-QM/MM) method, whereby molecules can switch layers from the QM to the MM region and vice versa. The adaptive partitioning of the molecular system ensures that the layer assignment can change during the optimization procedure, that is, on the fly. The switch from a QM molecule to a MM molecule is determined if there is an absence of noncovalent interactions to any atom of the QM core region. The presence/absence of noncovalent interactions is determined by analysis of the reduced density gradient. Therefore, the location of the QM/MM boundary is based on physical arguments, and this neatly removes some empiricism inherent in previous adaptive QM/MM partitioning schemes. The DBA-QM/MM method is validated by using a water-in-water setup and an explicitly solvated L-alanyl-L-alanine dipeptide. PMID:24954803

  1. A density-based adaptive quantum mechanical/molecular mechanical method.

    PubMed

    Waller, Mark P; Kumbhar, Sadhana; Yang, Jack

    2014-10-20

    We present a density-based adaptive quantum mechanical/molecular mechanical (DBA-QM/MM) method, whereby molecules can switch layers from the QM to the MM region and vice versa. The adaptive partitioning of the molecular system ensures that the layer assignment can change during the optimization procedure, that is, on the fly. The switch from a QM molecule to a MM molecule is determined if there is an absence of noncovalent interactions to any atom of the QM core region. The presence/absence of noncovalent interactions is determined by analysis of the reduced density gradient. Therefore, the location of the QM/MM boundary is based on physical arguments, and this neatly removes some empiricism inherent in previous adaptive QM/MM partitioning schemes. The DBA-QM/MM method is validated by using a water-in-water setup and an explicitly solvated L-alanyl-L-alanine dipeptide.

  2. NaCl-induced physiological and biochemical adaptative mechanisms in the ornamental Myrtus communis L. plants.

    PubMed

    Acosta-Motos, José Ramón; Diaz-Vivancos, Pedro; Álvarez, Sara; Fernández-García, Nieves; Sánchez-Blanco, María Jesús; Hernández, José Antonio

    2015-07-01

    Physiological and biochemical changes in Myrtus communis L. plants after being subjected to different solutions of NaCl (44, and 88 mM) for up to 30 days (Phase I) and after recovery from the salinity period (Phase II) were studied. Myrtle plants showed salinity tolerance by displaying a series of adaptative mechanisms to cope with salt-stress, including controlled ion homeostasis, the increase in root/shoot ratio, the reduction of water potentials and stomatal conductance to limit water loss. In addition, they displayed different strategies to protect the photosynthetic machinery, including limiting toxic ion accumulation in leaves, increase in chlorophyll content, and changes in chlorophyll fluorescence parameters, leaf anatomy and increases in catalase activity. Anatomical modifications in leaves, including a decrease in spongy parenchyma and increased intercellular spaces, allow CO2 diffusion in a situation of reduced stomatal aperture. In spite of all these changes, salinity produced oxidative stress in myrtle plants as monitored by increases in oxidative stress parameter values. The post-recovery period is perceived as a new stress situation, as observed through effects on plant growth and alterations in non-photochemical quenching parameters and lipid peroxidation values.

  3. Neural Mechanisms Behind Identification of Leptokurtic Noise and Adaptive Behavioral Response.

    PubMed

    d'Acremont, Mathieu; Bossaerts, Peter

    2016-04-01

    Large-scale human interaction through, for example, financial markets causes ceaseless random changes in outcome variability, producing frequent and salient outliers that render the outcome distribution more peaked than the Gaussian distribution, and with longer tails. Here, we study how humans cope with this evolutionary novel leptokurtic noise, focusing on the neurobiological mechanisms that allow the brain, 1) to recognize the outliers as noise and 2) to regulate the control necessary for adaptive response. We used functional magnetic resonance imaging, while participants tracked a target whose movements were affected by leptokurtic noise. After initial overreaction and insufficient subsequent correction, participants improved performance significantly. Yet, persistently long reaction times pointed to continued need for vigilance and control. We ran a contrasting treatment where outliers reflected permanent moves of the target, as in traditional mean-shift paradigms. Importantly, outliers were equally frequent and salient. There, control was superior and reaction time was faster. We present a novel reinforcement learning model that fits observed choices better than the Bayes-optimal model. Only anterior insula discriminated between the 2 types of outliers. In both treatments, outliers initially activated an extensive bottom-up attention and belief network, followed by sustained engagement of the fronto-parietal control network.

  4. Neural Mechanisms Behind Identification of Leptokurtic Noise and Adaptive Behavioral Response

    PubMed Central

    d'Acremont, Mathieu; Bossaerts, Peter

    2016-01-01

    Large-scale human interaction through, for example, financial markets causes ceaseless random changes in outcome variability, producing frequent and salient outliers that render the outcome distribution more peaked than the Gaussian distribution, and with longer tails. Here, we study how humans cope with this evolutionary novel leptokurtic noise, focusing on the neurobiological mechanisms that allow the brain, 1) to recognize the outliers as noise and 2) to regulate the control necessary for adaptive response. We used functional magnetic resonance imaging, while participants tracked a target whose movements were affected by leptokurtic noise. After initial overreaction and insufficient subsequent correction, participants improved performance significantly. Yet, persistently long reaction times pointed to continued need for vigilance and control. We ran a contrasting treatment where outliers reflected permanent moves of the target, as in traditional mean-shift paradigms. Importantly, outliers were equally frequent and salient. There, control was superior and reaction time was faster. We present a novel reinforcement learning model that fits observed choices better than the Bayes-optimal model. Only anterior insula discriminated between the 2 types of outliers. In both treatments, outliers initially activated an extensive bottom-up attention and belief network, followed by sustained engagement of the fronto-parietal control network. PMID:26850528

  5. NaCl-induced physiological and biochemical adaptative mechanisms in the ornamental Myrtus communis L. plants.

    PubMed

    Acosta-Motos, José Ramón; Diaz-Vivancos, Pedro; Álvarez, Sara; Fernández-García, Nieves; Sánchez-Blanco, María Jesús; Hernández, José Antonio

    2015-07-01

    Physiological and biochemical changes in Myrtus communis L. plants after being subjected to different solutions of NaCl (44, and 88 mM) for up to 30 days (Phase I) and after recovery from the salinity period (Phase II) were studied. Myrtle plants showed salinity tolerance by displaying a series of adaptative mechanisms to cope with salt-stress, including controlled ion homeostasis, the increase in root/shoot ratio, the reduction of water potentials and stomatal conductance to limit water loss. In addition, they displayed different strategies to protect the photosynthetic machinery, including limiting toxic ion accumulation in leaves, increase in chlorophyll content, and changes in chlorophyll fluorescence parameters, leaf anatomy and increases in catalase activity. Anatomical modifications in leaves, including a decrease in spongy parenchyma and increased intercellular spaces, allow CO2 diffusion in a situation of reduced stomatal aperture. In spite of all these changes, salinity produced oxidative stress in myrtle plants as monitored by increases in oxidative stress parameter values. The post-recovery period is perceived as a new stress situation, as observed through effects on plant growth and alterations in non-photochemical quenching parameters and lipid peroxidation values. PMID:26074356

  6. Endocrine and Cognitive Adaptations to Cope with Stress in Immature Common Marmosets (Callithrix jacchus): Sex and Age Matter

    PubMed Central

    de Sousa, Maria Bernardete Cordeiro; Galvão, Ana Cecília de Menezes; Sales, Carla Jéssica Rodrigues; de Castro, Dijenaide Chaves; Galvão-Coelho, Nicole Leite

    2015-01-01

    Phenotypic sex differences in primates are associated with body differentiation during the early stages of life, expressed in both physiological and behavioral features. Hormones seem to play a pivotal role in creating a range of responses to meet environmental and social demands, resulting in better reactions to cope with challenges to survival and reproduction. Steroid hormones actively participate in neuroplasticity and steroids from both gonads and neurons seem to be involved in behavioral modulation in primates. Indirect evidence suggests the participation of sexual steroids in dimorphism of the stress response in common marmosets. This species is an important experimental model in psychiatry, and we found a dual profile for cortisol in the transition from juvenile to subadult, with females showing higher levels. Immature males and females at 6 and 9 months of age moved alone from the family group to a new cage, over a 21-day period, expressed distinct patterns of cortisol variation with respect to range and duration of response. Additional evidence showed that at 12 months of age, males and females buffered the hypothalamic–pituitary–adrenal axis during chronic stress. Moreover, chronic stressed juvenile marmoset males showed better cognitive performance in working memory tests and motivation when compared to those submitted to short-term stress living in family groups. Thus, as cortisol profile seems to be sexually dimorphic before adulthood, age and sex are critical variables to consider in approaches that require immature marmosets in their experimental protocols. Moreover, available cognitive tests should be scrutinized to allow better investigation of cognitive traits in this species. PMID:26648876

  7. Endocrine and Cognitive Adaptations to Cope with Stress in Immature Common Marmosets (Callithrix jacchus): Sex and Age Matter.

    PubMed

    de Sousa, Maria Bernardete Cordeiro; Galvão, Ana Cecília de Menezes; Sales, Carla Jéssica Rodrigues; de Castro, Dijenaide Chaves; Galvão-Coelho, Nicole Leite

    2015-01-01

    Phenotypic sex differences in primates are associated with body differentiation during the early stages of life, expressed in both physiological and behavioral features. Hormones seem to play a pivotal role in creating a range of responses to meet environmental and social demands, resulting in better reactions to cope with challenges to survival and reproduction. Steroid hormones actively participate in neuroplasticity and steroids from both gonads and neurons seem to be involved in behavioral modulation in primates. Indirect evidence suggests the participation of sexual steroids in dimorphism of the stress response in common marmosets. This species is an important experimental model in psychiatry, and we found a dual profile for cortisol in the transition from juvenile to subadult, with females showing higher levels. Immature males and females at 6 and 9 months of age moved alone from the family group to a new cage, over a 21-day period, expressed distinct patterns of cortisol variation with respect to range and duration of response. Additional evidence showed that at 12 months of age, males and females buffered the hypothalamic-pituitary-adrenal axis during chronic stress. Moreover, chronic stressed juvenile marmoset males showed better cognitive performance in working memory tests and motivation when compared to those submitted to short-term stress living in family groups. Thus, as cortisol profile seems to be sexually dimorphic before adulthood, age and sex are critical variables to consider in approaches that require immature marmosets in their experimental protocols. Moreover, available cognitive tests should be scrutinized to allow better investigation of cognitive traits in this species.

  8. Endocrine and Cognitive Adaptations to Cope with Stress in Immature Common Marmosets (Callithrix jacchus): Sex and Age Matter.

    PubMed

    de Sousa, Maria Bernardete Cordeiro; Galvão, Ana Cecília de Menezes; Sales, Carla Jéssica Rodrigues; de Castro, Dijenaide Chaves; Galvão-Coelho, Nicole Leite

    2015-01-01

    Phenotypic sex differences in primates are associated with body differentiation during the early stages of life, expressed in both physiological and behavioral features. Hormones seem to play a pivotal role in creating a range of responses to meet environmental and social demands, resulting in better reactions to cope with challenges to survival and reproduction. Steroid hormones actively participate in neuroplasticity and steroids from both gonads and neurons seem to be involved in behavioral modulation in primates. Indirect evidence suggests the participation of sexual steroids in dimorphism of the stress response in common marmosets. This species is an important experimental model in psychiatry, and we found a dual profile for cortisol in the transition from juvenile to subadult, with females showing higher levels. Immature males and females at 6 and 9 months of age moved alone from the family group to a new cage, over a 21-day period, expressed distinct patterns of cortisol variation with respect to range and duration of response. Additional evidence showed that at 12 months of age, males and females buffered the hypothalamic-pituitary-adrenal axis during chronic stress. Moreover, chronic stressed juvenile marmoset males showed better cognitive performance in working memory tests and motivation when compared to those submitted to short-term stress living in family groups. Thus, as cortisol profile seems to be sexually dimorphic before adulthood, age and sex are critical variables to consider in approaches that require immature marmosets in their experimental protocols. Moreover, available cognitive tests should be scrutinized to allow better investigation of cognitive traits in this species. PMID:26648876

  9. Coping among the caregivers of patients with schizophrenia

    PubMed Central

    Grover, Sandeep; Pradyumna; Chakrabarti, Subho

    2015-01-01

    Coping is understood as the process of managing external or internal demands that are considered as taxing or exceeding the resources of the person. There is no formal classification of coping strategies, and these are understood as adaptive versus maladaptive and problem focuses versus emotion-focused. Understanding the commonly used coping strategies in a particular group of subjects can provide valuable insights for designing interventions to reduce the stress. In this review, we look at the literature which is available with regards to the coping strategies used by the caregivers of patients with schizophrenia. Findings suggest that caregivers of patients with schizophrenia use mixed type of coping mechanisms to deal with the stress of caregiving. The coping strategies are shown to have association with variables such as caregiver burden, caregiving experience, expressed emotions, social support, psychological morbidity in the caregivers, quality of life of caregivers and psychopathology in patients. One of the major limitations of the literature is that there is a lot of variability in the assessment instruments used across different studies to assess coping. PMID:26257476

  10. Coping Skills Help Explain How Future-Oriented Adolescents Accrue Greater Well-Being Over Time.

    PubMed

    Chua, Li Wen; Milfont, Taciano L; Jose, Paul E

    2015-11-01

    Adolescents who endorse greater levels of future orientation report greater well-being over time, but we do not know the mechanism by which this happens. The present longitudinal study examined whether both adaptive as well as maladaptive coping strategies might explain how future orientation leads to ill-being and well-being over time in young New Zealanders. A sample of 1,774 preadolescents and early adolescents (51.9 % female) aged 10-15 years at Time 1 completed a self-report survey three times with 1 year intervals in between. Longitudinal mediation path models were constructed to determine whether and how maladaptive and adaptive coping strategies at Time 2 functioned as mediators between future orientation at Time 1 and ill-being and well-being at Time 3. Results showed that future orientation predicted lower maladaptive coping, which in turn predicted lower substance use and self-harming behavior. All three well-being outcomes (i.e., happiness with weight, vitality, and sleep) were consistently predicted by future orientation, and all three pathways were mediated by both lower maladaptive and higher adaptive coping strategies (with the exception of happiness with weight, which was mediated only by lower maladaptive coping). The results suggest that several pathways by which future orientation leads to greater well-being occurs through an increased use of adaptive coping, a decreased use of maladaptive coping, or both.

  11. Adaptive Changes of the Insig1/SREBP1/SCD1 Set Point Help Adipose Tissue to Cope With Increased Storage Demands of Obesity

    PubMed Central

    Carobbio, Stefania; Hagen, Rachel M.; Lelliott, Christopher J.; Slawik, Marc; Medina-Gomez, Gema; Tan, Chong-Yew; Sicard, Audrey; Atherton, Helen J.; Barbarroja, Nuria; Bjursell, Mikael; Bohlooly-Y, Mohammad; Virtue, Sam; Tuthill, Antoinette; Lefai, Etienne; Laville, Martine; Wu, Tingting; Considine, Robert V.; Vidal, Hubert; Langin, Dominique; Oresic, Matej; Tinahones, Francisco J.; Fernandez-Real, Jose Manuel; Griffin, Julian L.; Sethi, Jaswinder K.; López, Miguel; Vidal-Puig, Antonio

    2013-01-01

    The epidemic of obesity imposes unprecedented challenges on human adipose tissue (WAT) storage capacity that may benefit from adaptive mechanisms to maintain adipocyte functionality. Here, we demonstrate that changes in the regulatory feedback set point control of Insig1/SREBP1 represent an adaptive response that preserves WAT lipid homeostasis in obese and insulin-resistant states. In our experiments, we show that Insig1 mRNA expression decreases in WAT from mice with obesity-associated insulin resistance and from morbidly obese humans and in in vitro models of adipocyte insulin resistance. Insig1 downregulation is part of an adaptive response that promotes the maintenance of SREBP1 maturation and facilitates lipogenesis and availability of appropriate levels of fatty acid unsaturation, partially compensating the antilipogenic effect associated with insulin resistance. We describe for the first time the existence of this adaptive mechanism in WAT, which involves Insig1/SREBP1 and preserves the degree of lipid unsaturation under conditions of obesity-induced insulin resistance. These adaptive mechanisms contribute to maintain lipid desaturation through preferential SCD1 regulation and facilitate fat storage in WAT, despite on-going metabolic stress. PMID:23919961

  12. A genetic mechanism for Tibetan high-altitude adaptation

    PubMed Central

    Lorenzo, Felipe R; Huff, Chad; Myllymäki, Mikko; Olenchock, Benjamin; Swierczek, Sabina; Tashi, Tsewang; Gordeuk, Victor; Wuren, Tana; Ri-Li, Ge; McClain, Donald A; Khan, Tahsin M; Koul, Parvaiz A; Guchhait, Prasenjit; Salama, Mohamed E; Xing, Jinchuan; Semenza, Gregg L; Liberzon, Ella; Wilson, Andrew; Simonson, Tatum S; Jorde, Lynn B; Kaelin, William G; Koivunen, Peppi; Prchal, Josef T

    2015-01-01

    Tibetans do not exhibit increased hemoglobin concentration at high altitude. We describe a high-frequency missense mutation in the EGLN1 gene, which encodes prolyl hydroxylase 2 (PHD2), that contributes to this adaptive response. We show that a variant in EGLN1, c.[12C>G; 380G>C], contributes functionally to the Tibetan high-altitude phenotype. PHD2 triggers the degradation of hypoxia-inducible factors (HIFs), which mediate many physiological responses to hypoxia, including erythropoiesis. The PHD2 p.[Asp4Glu; Cys127Ser] variant exhibits a lower Km value for oxygen, suggesting that it promotes increased HIF degradation under hypoxic conditions. Whereas hypoxia stimulates the proliferation of wild-type erythroid progenitors, the proliferation of progenitors with the c.[12C>G; 380G>C] mutation in EGLN1 is significantly impaired under hypoxic culture conditions. We show that the c.[12C>G; 380G>C] mutation originated ~8,000 years ago on the same haplotype previously associated with adaptation to high altitude. The c.[12C>G; 380G>C] mutation abrogates hypoxia-induced and HIF-mediated augmentation of erythropoiesis, which provides a molecular mechanism for the observed protection of Tibetans from polycythemia at high altitude. PMID:25129147

  13. Adaptive information interactive mechanism for multi-UAV visual navigation

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Dai, Qionghai

    2012-06-01

    Multi-unmanned aerial vehicle (UAV) cooperative communication for visual navigation has recently generated significant concern. It has large amounts of visual information to be transmitted and processed among UAVs with realtime requirements. And the UAV clusters have self-organized, time-varying and high dynamic characteristics. Considering the above conditions, we propose an adaptive information interactive mechanism (AIIM) for multi-UAV visual navigation. In the mechanism, the function modules for UAV inter-communication interface are designed, the mobility-based link lifetime is established and the information interactive protocol is presented. Thus we combine the mobility of UAVs with the corresponding communication requirements to make effective information interaction for UAVs. Task-oriented distributed control is adopted to improve the collaboration flexibility in the multi-UAV visual navigation system. In order to timely obtain the necessary visual information, each UAV can cooperate with other relevant UAVs which meet some certain terms such as situation, task or environmental conditions. Simulation results are presented to show the validity of the proposed mechanism in terms of end-to-end delay and links stability.

  14. Mechanisms of Cardiopulmonary Adaptation to Microgravity. Part 1

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Session TA1 includes short reports covering: (1) Indices of Baroreceptor Reflex Sensitivity: The Use in Rehabilitation Medicine and Space Cardiology; (2) +Gz and +Gx Tolerance of Healthy Persons of Non-Flying Trades at Primary Selection of the Centrifuge; (3) Effect of Dry Immersion on Calf Blood Supply During Sustained Contraction and Upright Exercise in Man; (4) Cardiovascular and Valsalva Responses during Parabolic flight; (5) An Analysis of the Cardiovascular Responses under Hyper- and Hypo-Gravity Environments using a Mathematical model; (6) Effect of Very Gradual Onset Rate +Gz Exposures on the Cardiovascular System; and (7) NASA Specialized Center of Research and Training (NSCORT) in Integrated Physiology: Mechanisms of Physiological Adaptations to Microgravity.

  15. Adaptive Broadcasting Mechanism for Bandwidth Allocation in Mobile Services

    PubMed Central

    Horng, Gwo-Jiun; Wang, Chi-Hsuan; Chou, Chih-Lun

    2014-01-01

    This paper proposes a tree-based adaptive broadcasting (TAB) algorithm for data dissemination to improve data access efficiency. The proposed TAB algorithm first constructs a broadcast tree to determine the broadcast frequency of each data and splits the broadcast tree into some broadcast wood to generate the broadcast program. In addition, this paper develops an analytical model to derive the mean access latency of the generated broadcast program. In light of the derived results, both the index channel's bandwidth and the data channel's bandwidth can be optimally allocated to maximize bandwidth utilization. This paper presents experiments to help evaluate the effectiveness of the proposed strategy. From the experimental results, it can be seen that the proposed mechanism is feasible in practice. PMID:25057509

  16. Adaptive broadcasting mechanism for bandwidth allocation in mobile services.

    PubMed

    Horng, Gwo-Jiun; Wang, Chi-Hsuan; Chou, Chih-Lun

    2014-01-01

    This paper proposes a tree-based adaptive broadcasting (TAB) algorithm for data dissemination to improve data access efficiency. The proposed TAB algorithm first constructs a broadcast tree to determine the broadcast frequency of each data and splits the broadcast tree into some broadcast wood to generate the broadcast program. In addition, this paper develops an analytical model to derive the mean access latency of the generated broadcast program. In light of the derived results, both the index channel's bandwidth and the data channel's bandwidth can be optimally allocated to maximize bandwidth utilization. This paper presents experiments to help evaluate the effectiveness of the proposed strategy. From the experimental results, it can be seen that the proposed mechanism is feasible in practice.

  17. Synaptic mechanisms of adaptation and sensitization in the retina

    PubMed Central

    Nikolaev, Anton; Leung, Kin-Mei; Odermatt, Benjamin; Lagnado, Leon

    2014-01-01

    Sensory systems continually adjust the way stimuli are processed. What are the circuit mechanisms underlying this plasticity? We investigated how synapses in the retina of zebrafish adjust to changes in the temporal contrast of a visual stimulus by imaging activity in vivo. Following an increase in contrast, bipolar cell synapses with strong initial responses depressed, whereas synapses with weak initial responses facilitated. Depression and facilitation predominated in different strata of the inner retina, where bipolar cell output was anticorrelated with the activity of amacrine cell synapses providing inhibitory feedback. Pharmacological block of GABAergic feedback converted facilitating bipolar cell synapses into depressing ones. These results indicate that depression intrinsic to bipolar cell synapses causes adaptation of the ganglion cell response to contrast, whereas depression in amacrine cell synapses causes sensitization. Distinct microcircuits segregating to different layers of the retina can cause simultaneous increases or decreases in the gain of neural responses. PMID:23685718

  18. Stochastic retinal mechanisms of light adaptation and gain control.

    PubMed

    Rudd, M E; Brown, L G

    1996-01-01

    Under appropriate experimental conditions, the threshold intensity of a visual stimulus varies as the square-root of the background illuminance. This square-root law has been observed in both psychophysical threshold experiments and in measurements of the thresholds of individual ganglion cells. A signal detection theory developed in the 1940s by H. L. de Vries and A. Rose, and since elaborated by H. B. Barlow and others, explains the square-root law on the basis of 'noise' due to fluctuations in the number of photon absorptions per unit area and unit time at the cornea. An alternative account of the square-root law--and also other threshold-vs-intensity slopes--is founded on the assumption of physiological gain control (W. A. H. Rushton, Proc, Roy. Soc. (London) B 162, 20-46, 1965; W. S. Geisler, J. Physiol. (London) 312, 165-179, 1979). In this paper, a neural model of light adaptation and gain control is described that shows how these two accounts of the square-root law can be reconciled by a stochastic gain control mechanism whose gain depends on the photon fluctuation level. The process by which spikes are generated in a ganglion cell is modeled in terms of a stochastic integrate-and-fire mechanism; this model is used to quantitatively fit toad retinal ganglion cell threshold data. A psychophysical model is then outlined showing how a statistical observer could analyze the ganglion cell spike trains generated by 'signal' and 'noise' trials in order to statistically discriminate the two conditions. The model is also shown to account for some dynamic aspects of ganglion cell responses, including ON- and OFF-responses. The neural light adaptation model predicts that--under the proper conditions--brightness matching judgments will also be subject to a square-root law. Experimental tests of the model under superthreshold conditions are proposed.

  19. Deciphering the protein translation inhibition and coping mechanism of trichothecene toxin in resistant fungi.

    PubMed

    Kumari, Indu; Ahmed, Mushtaq; Akhter, Yusuf

    2016-09-01

    In modern times for combating the deleterious soil microbes for improved sustainable agricultural practices, there is a need to have a proper understanding of the plant-microbe interactions present in the rhizospheric microbiome of the plant roots. In the present study, the interactions of trichodermin with petidyltransferase centre of ribosomal complex was studied by molecular dynamics and in silico interaction methods to demonstrate its mechanism of action and to decipher the possible reason how it may inhibit protein synthesis at the ribosomal complex. Further we have illustrated how trichodermin resistance protein (60S ribosomal protein L3) helps to overcome the deleterious effects of trichothecene compounds like trichodermin. Normal mode analysis of trichodermin resistance protein and 25S rRNA that constitutes the petidyltransferase centre showed that the W-finger region of the protein moved towards 25S rRNA. Further analysis of molecular dynamics simulation time frames showed that several intermediate states of large motions of the protein molecules towards the 25S rRNA which finally blocks the binding pocket of the trichodermin. It indicated that this protein not only changes the local environment and conformation of the petidyltransferase centre but also restrain trichodermin from binding to the 25S rRNA at the petidyltransferase centre. PMID:27495375

  20. Block-adaptive quantum mechanics: an adaptive divide-and-conquer approach to interactive quantum chemistry.

    PubMed

    Bosson, Maël; Grudinin, Sergei; Redon, Stephane

    2013-03-01

    We present a novel Block-Adaptive Quantum Mechanics (BAQM) approach to interactive quantum chemistry. Although quantum chemistry models are known to be computationally demanding, we achieve interactive rates by focusing computational resources on the most active parts of the system. BAQM is based on a divide-and-conquer technique and constrains some nucleus positions and some electronic degrees of freedom on the fly to simplify the simulation. As a result, each time step may be performed significantly faster, which in turn may accelerate attraction to the neighboring local minima. By applying our approach to the nonself-consistent Atom Superposition and Electron Delocalization Molecular Orbital theory, we demonstrate interactive rates and efficient virtual prototyping for systems containing more than a thousand of atoms on a standard desktop computer.

  1. [Coping psychologically with amputation].

    PubMed

    Schulz, M

    2009-02-01

    An amputation is a "tragic event" in someone's biography which causes a dramatic change in the outer appearance, the loss of mobility, independence and self esteem. The following article is about how people learn to cope with this difficult situation; with the practical problems of everyday life as well as their emotional problems. It is important for the amputees to go through the different stages of mourning: The first stage is the rejection of the situation. Repression and denial of the loss protects the patient from emotional overstrain. Confrontation is the next step: emotionally as well as mentally. "How could it happen?", (understanding the reasons why ...) "What will my future be like?", "How will I cope?" (ability of coping) "Why did it happen to me?" (sense) The last stage of coping with the amputation is to accept and deal with the new situation and to build up new self-confidence. A successful process of coping leads to a new identity. If a person fails to adapt to the new situation, he will develop an inferiority complex and fall into a depression. He might also try to look for culprit and blame the situation on someone else. About two thirds of all amputees don't cope with their amputation and become depressive. 15% develop symptoms of anxiety. Therefore it is important to offer help. The patients should get together in self helping groups and talk about their experiences and problems. If they need more intensive and individual help, they should have the opportunity to contact a psychologist. During the process of coping with their amputation the patients often alternate between optimistic and pessimistic moods. Sometimes they fall back into a negative and resigned state of mind. This is natural and part of the process as long as they find their own way to a positive attitude and view of life. PMID:19259934

  2. [Insulin resistance as a mechanism of adaptation during human evolution].

    PubMed

    Ricart, W; Fernández-Real, J M

    2010-10-01

    The recent application of concepts of evolution to human disease is proving useful to understand certain pathophysiological mechanisms of different entities that span genomic alterations of immunity, respiratory and hormone function, and the circulatory and neural systems. However, effort has concentrated on explaining the keys to adaptation that define human metabolism and, since the early 1960s, several theories have been developed. This article reviews some of the hypotheses postulated in recent years on the potential benefit of insulin resistance and discusses the most recent knowledge. The concept of the thrifty gene seems to have been definitively refuted by current knowledge. The current paradigm describes an interaction between the metabolic and the immune systems resulting from their coevolution, promoted by evolutionary pressures triggered by fasting, infection and intake of different foods. The activation and regulation of these ancient mechanisms in integrated and interdependent areas defines insulin resistance as a survival strategy that is critical during fasting and in the fight against infection. The relationship with some components of the diet and, particularly, with the symbiotic intestinal microflora points to new paradigms in understanding the pathophysiology of obesity, metabolic syndrome and type 2 diabetes mellitus.

  3. Molecular mechanisms of Tetranychus urticae chemical adaptation in hop fields

    PubMed Central

    Piraneo, Tara G.; Bull, Jon; Morales, Mariany A.; Lavine, Laura C.; Walsh, Douglas B.; Zhu, Fang

    2015-01-01

    The two-spotted spider mite, Tetranychus urticae Koch is a major pest that feeds on >1,100 plant species. Many perennial crops including hop (Humulus lupulus) are routinely plagued by T. urticae infestations. Hop is a specialty crop in Pacific Northwest states, where 99% of all U.S. hops are produced. To suppress T. urticae, growers often apply various acaricides. Unfortunately T. urticae has been documented to quickly develop resistance to these acaricides which directly cause control failures. Here, we investigated resistance ratios and distribution of multiple resistance-associated mutations in field collected T. urticae samples compared with a susceptible population. Our research revealed that a mutation in the cytochrome b gene (G126S) in 35% tested T. urticae populations and a mutation in the voltage-gated sodium channel gene (F1538I) in 66.7% populations may contribute resistance to bifenazate and bifenthrin, respectively. No mutations were detected in Glutamate-gated chloride channel subunits tested, suggesting target site insensitivity may not be important in our hop T. urticae resistance to abamectin. However, P450-mediated detoxification was observed and is a putative mechanism for abamectin resistance. Molecular mechanisms of T. urticae chemical adaptation in hopyards is imperative new information that will help growers develop effective and sustainable management strategies. PMID:26621458

  4. Molecular mechanisms of Tetranychus urticae chemical adaptation in hop fields.

    PubMed

    Piraneo, Tara G; Bull, Jon; Morales, Mariany A; Lavine, Laura C; Walsh, Douglas B; Zhu, Fang

    2015-01-01

    The two-spotted spider mite, Tetranychus urticae Koch is a major pest that feeds on >1,100 plant species. Many perennial crops including hop (Humulus lupulus) are routinely plagued by T. urticae infestations. Hop is a specialty crop in Pacific Northwest states, where 99% of all U.S. hops are produced. To suppress T. urticae, growers often apply various acaricides. Unfortunately T. urticae has been documented to quickly develop resistance to these acaricides which directly cause control failures. Here, we investigated resistance ratios and distribution of multiple resistance-associated mutations in field collected T. urticae samples compared with a susceptible population. Our research revealed that a mutation in the cytochrome b gene (G126S) in 35% tested T. urticae populations and a mutation in the voltage-gated sodium channel gene (F1538I) in 66.7% populations may contribute resistance to bifenazate and bifenthrin, respectively. No mutations were detected in Glutamate-gated chloride channel subunits tested, suggesting target site insensitivity may not be important in our hop T. urticae resistance to abamectin. However, P450-mediated detoxification was observed and is a putative mechanism for abamectin resistance. Molecular mechanisms of T. urticae chemical adaptation in hopyards is imperative new information that will help growers develop effective and sustainable management strategies. PMID:26621458

  5. [Insulin resistance as a mechanism of adaptation during human evolution].

    PubMed

    Ricart, W; Fernández-Real, J M

    2010-10-01

    The recent application of concepts of evolution to human disease is proving useful to understand certain pathophysiological mechanisms of different entities that span genomic alterations of immunity, respiratory and hormone function, and the circulatory and neural systems. However, effort has concentrated on explaining the keys to adaptation that define human metabolism and, since the early 1960s, several theories have been developed. This article reviews some of the hypotheses postulated in recent years on the potential benefit of insulin resistance and discusses the most recent knowledge. The concept of the thrifty gene seems to have been definitively refuted by current knowledge. The current paradigm describes an interaction between the metabolic and the immune systems resulting from their coevolution, promoted by evolutionary pressures triggered by fasting, infection and intake of different foods. The activation and regulation of these ancient mechanisms in integrated and interdependent areas defines insulin resistance as a survival strategy that is critical during fasting and in the fight against infection. The relationship with some components of the diet and, particularly, with the symbiotic intestinal microflora points to new paradigms in understanding the pathophysiology of obesity, metabolic syndrome and type 2 diabetes mellitus. PMID:20675202

  6. Mechanisms of adaptive evolution. Darwinism and Lamarckism restated.

    PubMed

    Aboitiz, F

    1992-07-01

    This article discusses the conceptual basis of the different mechanisms of adaptive evolution. It is argued that only two such mechanisms may conceivably exist, Lamarckism and Darwinism. Darwinism is the fundamental process generating the diversity of species. Some aspects of the gene-centered approach to Darwinism are questioned, since they do not account for the generation of biological diversity. Diversity in biological design must be explained in relation to the diversity of interactions of organisms (or other higher-level units) with their environment. This aspect is usually overlooked in gene-centered views of evolution. A variant of the gene-selectionist approach has been proposed to account for the spread of cultural traits in human societies. Alternatively, I argue that social evolution is rather driven by what I call pseudo-Lamarckian inheritance. Finally, I argue that Lamarckian and pseudo-Lamarckian inheritance are just special cases of faithful replication which are found in the development of some higher-order units, such as multicellular organisms and human societies.

  7. Physiologically responsive, mechanically adaptive polymer optical fibers for optogenetics.

    PubMed

    Jorfi, Mehdi; Voirin, Guy; Foster, E Johan; Weder, Christoph

    2014-05-15

    The capability to deliver light to specific locations within the brain using optogenetic tools has opened up new possibilities in the field of neural interfacing. In this context, optical fibers are commonly inserted into the brain to activate or mute neurons using photosensitive proteins. While chronic optogenetic stimulation studies are just beginning to emerge, knowledge gathered in connection with electrophysiological implants suggests that the mechanical mismatch of conventional optical fibers and the cortical tissue may be a significant contributor to neuroinflammatory response. Here, we present the design and fabrication of physiologically responsive, mechanically adaptive optical fibers made of poly(vinyl alcohol) (PVA) that may mitigate this problem. Produced by a one-step wet-spinning process, the fibers display a tensile storage modulus E' of ∼7000  MPa in the dry state at 25°C and can thus readily be inserted into cortical tissue. Exposure to water causes a drastic reduction of E' to ∼35  MPa on account of modest swelling with the water. The optical properties at 470 and 590 were comparable with losses of 0.7±0.04  dB/cm at 470 nm and 0.6±0.1  dB/cm at 590 nm in the dry state and 1.1±0.1  dB/cm at 470 nm and 0.9±0.3  dB/cm at 590 nm in the wet state. The dry end of a partially switched fiber with a length of 10 cm was coupled with a light-emitting diode with an output of 10.1 mW to deliver light with a power density of >500  mW/cm2 from the wet end, which is more than sufficient to stimulate neurons in vivo. Thus, even without a low-refractive index cladding, the physiologically responsive, mechanically adaptive optical fibers presented here appear to be a very useful new tool for future optogenetic studies.

  8. The relationship between socio-demographic characteristics, family environment, and caregiver coping in families of children with cancer.

    PubMed

    Gage-Bouchard, Elizabeth A; Devine, Katie A; Heckler, Charles E

    2013-12-01

    The factors that influence caregiver coping mechanism preferences after a child's diagnosis with cancer are not fully understood. This study examines the relationship between caregivers' socio-demographic characteristics and the coping strategies they use to adapt to childhood cancer. Sixty caregivers of pediatric cancer patients completed a socio-demographic questionnaire, the Family Environment Scale, and the COPE inventory. There were no significant differences in family environment by income or education. Caregiver educational attainment was positively associated with use of planning and active coping styles, while income was not associated with caregiver coping style. Mothers were more likely than fathers to use active coping, instrumental support, religious coping, and emotional support. Men with lower education engaged in greater substance use coping and lower planning. The findings show that educational attainment and caregiver gender influence caregiver coping styles following a pediatric cancer diagnosis and suggest that educational attainment rather than financial resources drive the association between SES and coping. Programs that address educational gaps and teach caregivers planning and active coping skills may be beneficial for parents with lower educational attainment, particularly men.

  9. RNA Sequencing of Populus x canadensis Roots Identifies Key Molecular Mechanisms Underlying Physiological Adaption to Excess Zinc

    PubMed Central

    Ariani, Andrea; Di Baccio, Daniela; Romeo, Stefania; Lombardi, Lara; Andreucci, Andrea; Lux, Alexander; Horner, David Stephen; Sebastiani, Luca

    2015-01-01

    Populus x canadensis clone I-214 exhibits a general indicator phenotype in response to excess Zn, and a higher metal uptake in roots than in shoots with a reduced translocation to aerial parts under hydroponic conditions. This physiological adaptation seems mainly regulated by roots, although the molecular mechanisms that underlie these processes are still poorly understood. Here, differential expression analysis using RNA-sequencing technology was used to identify the molecular mechanisms involved in the response to excess Zn in root. In order to maximize specificity of detection of differentially expressed (DE) genes, we consider the intersection of genes identified by three distinct statistical approaches (61 up- and 19 down-regulated) and validate them by RT-qPCR, yielding an agreement of 93% between the two experimental techniques. Gene Ontology (GO) terms related to oxidation-reduction processes, transport and cellular iron ion homeostasis were enriched among DE genes, highlighting the importance of metal homeostasis in adaptation to excess Zn by P. x canadensis clone I-214. We identified the up-regulation of two Populus metal transporters (ZIP2 and NRAMP1) probably involved in metal uptake, and the down-regulation of a NAS4 gene involved in metal translocation. We identified also four Fe-homeostasis transcription factors (two bHLH38 genes, FIT and BTS) that were differentially expressed, probably for reducing Zn-induced Fe-deficiency. In particular, we suggest that the down-regulation of FIT transcription factor could be a mechanism to cope with Zn-induced Fe-deficiency in Populus. These results provide insight into the molecular mechanisms involved in adaption to excess Zn in Populus spp., but could also constitute a starting point for the identification and characterization of molecular markers or biotechnological targets for possible improvement of phytoremediation performances of poplar trees. PMID:25671786

  10. Cl- uptake mechanism in freshwater-adapted tilapia (Oreochromis mossambicus).

    PubMed

    Chang, I-Chi; Hwang, Pung-Pung

    2004-01-01

    In this study, the correlation between Cl(-) influx in freshwater tilapia and various transporters or enzymes, the Cl(-)/HCO(3)(-) exchanger, Na(+),K(+)-ATPase, V-type H(+)-ATPase, and carbonic anhydrase were examined. The inhibitors 2x10(-4) M ouabain (a Na(+),K(+)-ATPase inhibitor), 10(-5) M NEM (a V-type H(+)-ATPase inhibitor), 10(-2) M ACTZ (acetazolamide, a carbonic anhydrase inhibitor), and 6x10(-4) M DIDS (a Cl(-)/HCO(3)(-) exchanger inhibitor) caused 40%, 60%-80%, 40%-60%, and 40%-60% reduction in Cl(-) influx of freshwater tilapia, respectively. The inhibitor 2x10(-4) M ouabain also caused 50%-65% inhibition in gill Na(+),K(+)-ATPase activity. Western blot results showed that protein levels of gill Na(+),K(+)-ATPase, V-type H(+)-ATPase, and carbonic anhydrase in tilapia acclimated in low-Cl(-) freshwater were significantly higher than those acclimated to high-Cl(-) freshwater. Based on these data, we conclude that Na(+),K(+)-ATPase, V-H(+)-ATPase, the Cl(-)/HCO(3)(-) exchanger, and carbonic anhydrase may be involved in the active Cl(-) uptake mechanism in gills of freshwater-adapted tilapia. PMID:15286914

  11. The Role of Spirituality in Coping with Visual Impairment

    ERIC Educational Resources Information Center

    Yampolsky, Maya A.; Wittich, Walter; Webb, Gail; Overbury, Olga

    2008-01-01

    Spirituality and coping behaviors were measured in 85 individuals with visual impairments aged 23 to 97. A regression analysis indicated that the religious well-being subscale of the Spiritual Well-Being Scale is a significant predictor of adaptive coping behaviors, indicating that higher religious well-being facilitates adaptive coping. (Contains…

  12. Skeletal adaptation to external loads optimizes mechanical properties: fact or fiction

    NASA Technical Reports Server (NTRS)

    Turner, R. T.

    2001-01-01

    The skeleton adapts to a changing mechanical environment but the widely held concept that bone cells are programmed to respond to local mechanical loads to produce an optimal mechanical structure is not consistent with the high frequency of bone fractures. Instead, the author suggests that other important functions of bone compete with mechanical adaptation to determine structure. As a consequence of competing demands, bone architecture never achieves an optimal mechanical structure. c2001 Lippincott Williams & Wilkins, Inc.

  13. Differences in the catalytic mechanisms of mesophilic and thermophilic indole-3-glycerol phosphate synthase enzymes at their adaptive temperatures

    SciTech Connect

    Zaccardi, Margot J.; Mannweiler, Olga; Boehr, David D.

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer Catalytic mechanisms of thermophilic-mesophilic enzymes may differ. Black-Right-Pointing-Pointer Product release is rate-determining for thermophilic IGPS at low temperatures. Black-Right-Pointing-Pointer But at higher temperatures, proton transfer from the general acid is rate-limiting. Black-Right-Pointing-Pointer Rate-determining step is different still for mesophilic IGPS. Black-Right-Pointing-Pointer Both chemical and physical steps of catalysis are important for temperature adaptation. -- Abstract: Thermophilic enzymes tend to be less catalytically-active at lower temperatures relative to their mesophilic counterparts, despite having very similar crystal structures. An often cited hypothesis for this general observation is that thermostable enzymes have evolved a more rigid tertiary structure in order to cope with their more extreme, natural environment, but they are also less flexible at lower temperatures, leading to their lower catalytic activity under mesophilic conditions. An alternative hypothesis, however, is that complementary thermophilic-mesophilic enzyme pairs simply operate through different evolutionary-optimized catalytic mechanisms. In this communication, we present evidence that while the steps of the catalytic mechanisms for mesophilic and thermophilic indole-3-glycerol phosphate synthase (IGPS) enzymes are fundamentally similar, the identity of the rate-determining step changes as a function of temperature. Our findings indicate that while product release is rate-determining at 25 Degree-Sign C for thermophilic IGPS, near its adaptive temperature (75 Degree-Sign C), a proton transfer event, involving a general acid, becomes rate-determining. The rate-determining steps for thermophilic and mesophilic IGPS enzymes are also different at their respective, adaptive temperatures with the mesophilic IGPS-catalyzed reaction being rate-limited before irreversible CO{sub 2} release, and the thermophilic IGPS

  14. Development of the Coping Flexibility Scale: evidence for the coping flexibility hypothesis.

    PubMed

    Kato, Tsukasa

    2012-04-01

    Coping flexibility was defined as the ability to discontinue an ineffective coping strategy (i.e., evaluation coping) and produce and implement an alternative coping strategy (i.e., adaptive coping). The Coping Flexibility Scale (CFS) was developed on the basis of this definition. Five studies involving approximately 4,400 Japanese college students and employees were conducted to test the hypothesis that flexible coping produces more adaptive outcomes. Studies 1, 2, and 3 provided evidence of the reliability of the CFS scores as well as of its convergent and discriminant validity for Japanese samples. Study 4 further demonstrated that flexible coping was positively associated with improved psychological health, including reduced depression, anxiety, and distress. In Study 5, coping flexibility as measured by the CFS was associated with reduced future depression, even after controlling for the effects of other coping flexibility measures and popular coping strategies. Overall, these results suggest that a valid approach for assessing coping flexibility has been developed and that flexible coping can contribute to psychological health. The implications of these findings for clinical practice are discussed. PMID:22506909

  15. Viewpoints: feeding mechanics, diet, and dietary adaptations in early hominins.

    PubMed

    Daegling, David J; Judex, Stefan; Ozcivici, Engin; Ravosa, Matthew J; Taylor, Andrea B; Grine, Frederick E; Teaford, Mark F; Ungar, Peter S

    2013-07-01

    Inference of feeding adaptation in extinct species is challenging, and reconstructions of the paleobiology of our ancestors have utilized an array of analytical approaches. Comparative anatomy and finite element analysis assist in bracketing the range of capabilities in taxa, while microwear and isotopic analyses give glimpses of individual behavior in the past. These myriad approaches have limitations, but each contributes incrementally toward the recognition of adaptation in the hominin fossil record. Microwear and stable isotope analysis together suggest that australopiths are not united by a single, increasingly specialized dietary adaptation. Their traditional (i.e., morphological) characterization as "nutcrackers" may only apply to a single taxon, Paranthropus robustus. These inferences can be rejected if interpretation of microwear and isotopic data can be shown to be misguided or altogether erroneous. Alternatively, if these sources of inference are valid, it merely indicates that there are phylogenetic and developmental constraints on morphology. Inherently, finite element analysis is limited in its ability to identify adaptation in paleobiological contexts. Its application to the hominin fossil record to date demonstrates only that under similar loading conditions, the form of the stress field in the australopith facial skeleton differs from that in living primates. This observation, by itself, does not reveal feeding adaptation. Ontogenetic studies indicate that functional and evolutionary adaptation need not be conceptually isolated phenomena. Such a perspective helps to inject consideration of mechanobiological principles of bone formation into paleontological inferences. Finite element analysis must employ such principles to become an effective research tool in this context. PMID:23794331

  16. Mechanisms of motor adaptation in reactive balance control.

    PubMed

    Welch, Torrence D J; Ting, Lena H

    2014-01-01

    Balance control must be rapidly modified to provide stability in the face of environmental challenges. Although changes in reactive balance over repeated perturbations have been observed previously, only anticipatory postural adjustments preceding voluntary movements have been studied in the framework of motor adaptation and learning theory. Here, we hypothesized that adaptation occurs in task-level balance control during responses to perturbations due to central changes in the control of both anticipatory and reactive components of balance. Our adaptation paradigm consisted of a Training set of forward support-surface perturbations, a Reversal set of novel countermanding perturbations that reversed direction, and a Washout set identical to the Training set. Adaptation was characterized by a change in a motor variable from the beginning to the end of each set, the presence of aftereffects at the beginning of the Washout set when the novel perturbations were removed, and a return of the variable at the end of the Washout to a level comparable to the end of the Training set. Task-level balance performance was characterized by peak center of mass (CoM) excursion and velocity, which showed adaptive changes with repetitive trials. Only small changes in anticipatory postural control, characterized by body lean and background muscle activity were observed. Adaptation was found in the evoked long-latency muscular response, and also in the sensorimotor transformation mediating that response. Finally, in each set, temporal patterns of muscle activity converged towards an optimum predicted by a trade-off between maximizing motor performance and minimizing muscle activity. Our results suggest that adaptation in balance, as well as other motor tasks, is mediated by altering central sensitivity to perturbations and may be driven by energetic considerations. PMID:24810991

  17. A novel adaptation of a parent–child observational assessment tool for appraisals and coping in children exposed to acute trauma

    PubMed Central

    Marsac, Meghan L.; Kassam-Adams, Nancy

    2016-01-01

    Background Millions of children worldwide are exposed to acute potentially traumatic events (PTEs) annually. Many children and their families experience significant emotional distress and/or functional impairment following PTEs. While current research has begun to highlight a role for early appraisals and coping in promoting or preventing full recovery from PTEs, the exact nature of the relationships among appraisals, coping, and traumatic stress reactions as well as how appraisals and coping behaviors are influenced by the child's environment (e.g., parents) remains unclear; assessment tools that reach beyond self-report are needed to improve this understanding. Objective The objective of the current study is to describe the newly created Trauma Ambiguous Situations Tool (TAST; i.e., an observational child–parent interview and discussion task that allows assessment of appraisals, coping, and parent–child processes) and to report on initial feasibility and validation of TAST implemented with child–parent dyads in which children were exposed to a PTE. Method As part of a larger study on the role of biopsychosocial factors in posttraumatic stress reactions, children (aged 8–13) and parents (n=25 child–parent dyads) completed the TAST during the child's hospitalization for injury. Results Children and parents engaged well with the TAST. The time to administer the TAST was feasible, even in a peri-trauma context. The TAST solicited a wide array of appraisals (threat and neutral) and coping solutions (proactive and avoidant). Forced-choice and open-ended appraisal assessments provided unique information. The parent–child discussion portion of the TAST allowed for direct observation of parent–child processes and demonstrated parental influence on children's appraisals and coping solutions. Conclusions The TAST is a promising new research tool, which may help to explicate how parents influence their child's developing appraisals and coping solutions

  18. Tissue-specific defense and thermo-adaptive mechanisms of soybean seedlings under heat stress revealed by proteomic approach.

    PubMed

    Ahsan, Nagib; Donnart, Tifenn; Nouri, Mohammad-Zaman; Komatsu, Setsuko

    2010-08-01

    A comparative proteomic approach was employed to explore tissue-specific protein expression patterns in soybean seedlings under heat stress. The changes in the protein expression profiles of soybean seedling leaves, stems, and roots were analyzed after exposure to high temperatures. A total of 54, 35, and 61 differentially expressed proteins were identified from heat-treated leaves, stems, and roots, respectively. Differentially expressed heat shock proteins (HSPs) and proteins involved in antioxidant defense were mostly up-regulated, whereas proteins associated with photosynthesis, secondary metabolism, and amino acid and protein biosynthesis were down-regulated in response to heat stress. A group of proteins, specifically low molecular weight HSPs and HSP70, were up-regulated and expressed in a similar manner in all tissues. Proteomic analysis indicated that the responses of HSP70, CPN-60 beta, and ChsHSP were tissue specific, and this observation was validated by immunoblot analysis. The heat-responsive sHSPs were not induced by other stresses such as cold and hydrogen peroxide. Taken together, these results suggest that to cope with heat stress soybean seedlings operate tissue-specific defenses and adaptive mechanisms, whereas a common defense mechanism associated with the induction of several HSPs was employed in all three tissues. In addition, tissue-specific proteins may play a crucial role in defending each type of tissues against thermal stress.

  19. Coping with Demotivation: EFL Learners' Remotivation Processes

    ERIC Educational Resources Information Center

    Falout, Joseph

    2012-01-01

    When foreign language education is compulsory, competitive, or coercive, how learners cope with stress can determine outcomes, including value of the subject, persistence on task, and level of proficiency. The development of adaptive or maladaptive coping processes toward situated learning goals is influenced by learners' beliefs about themselves…

  20. Personality, Coping Style and Well-Being of Parents Rearing Children with Developmental Disabilities

    ERIC Educational Resources Information Center

    Glidden, L. M.; Billings, F. J.; Jobe, B. M.

    2006-01-01

    Background: Parents with children with developmental disabilities (DD) encounter a variety of stressors associated with rearing their children and must develop effective coping mechanisms in order to adapt successfully to these challenges. Previous research has failed to establish the role of parental individual differences in the reported use of…

  1. Stoichiometric imbalances between terrestrial decomposer communities and their resources: mechanisms and implications of microbial adaptations to their resources.

    PubMed

    Mooshammer, Maria; Wanek, Wolfgang; Zechmeister-Boltenstern, Sophie; Richter, Andreas

    2014-01-01

    Terrestrial microbial decomposer communities thrive on a wide range of organic matter types that rarely ever meet their elemental demands. In this review we synthesize the current state-of-the-art of microbial adaptations to resource stoichiometry, in order to gain a deeper understanding of the interactions between heterotrophic microbial communities and their chemical environment. The stoichiometric imbalance between microbial communities and their organic substrates generally decreases from wood to leaf litter and further to topsoil and subsoil organic matter. Microbial communities can respond to these imbalances in four ways: first, they adapt their biomass composition toward their resource in a non-homeostatic behavior. Such changes are, however, only moderate, and occur mainly because of changes in microbial community structure and less so due to cellular storage of elements in excess. Second, microbial communities can mobilize resources that meet their elemental demand by producing specific extracellular enzymes, which, in turn, is restricted by the C and N requirement for enzyme production itself. Third, microbes can regulate their element use efficiencies (ratio of element invested in growth over total element uptake), such that they release elements in excess depending on their demand (e.g., respiration and N mineralization). Fourth, diazotrophic bacteria and saprotrophic fungi may trigger the input of external N and P to decomposer communities. Theoretical considerations show that adjustments in element use efficiencies may be the most important mechanism by which microbes regulate their biomass stoichiometry. This review summarizes different views on how microbes cope with imbalanced supply of C, N and P, thereby providing a framework for integrating and linking microbial adaptation to resource imbalances to ecosystem scale fluxes across scales and ecosystems. PMID:24550895

  2. Stoichiometric imbalances between terrestrial decomposer communities and their resources: mechanisms and implications of microbial adaptations to their resources.

    PubMed

    Mooshammer, Maria; Wanek, Wolfgang; Zechmeister-Boltenstern, Sophie; Richter, Andreas

    2014-01-01

    Terrestrial microbial decomposer communities thrive on a wide range of organic matter types that rarely ever meet their elemental demands. In this review we synthesize the current state-of-the-art of microbial adaptations to resource stoichiometry, in order to gain a deeper understanding of the interactions between heterotrophic microbial communities and their chemical environment. The stoichiometric imbalance between microbial communities and their organic substrates generally decreases from wood to leaf litter and further to topsoil and subsoil organic matter. Microbial communities can respond to these imbalances in four ways: first, they adapt their biomass composition toward their resource in a non-homeostatic behavior. Such changes are, however, only moderate, and occur mainly because of changes in microbial community structure and less so due to cellular storage of elements in excess. Second, microbial communities can mobilize resources that meet their elemental demand by producing specific extracellular enzymes, which, in turn, is restricted by the C and N requirement for enzyme production itself. Third, microbes can regulate their element use efficiencies (ratio of element invested in growth over total element uptake), such that they release elements in excess depending on their demand (e.g., respiration and N mineralization). Fourth, diazotrophic bacteria and saprotrophic fungi may trigger the input of external N and P to decomposer communities. Theoretical considerations show that adjustments in element use efficiencies may be the most important mechanism by which microbes regulate their biomass stoichiometry. This review summarizes different views on how microbes cope with imbalanced supply of C, N and P, thereby providing a framework for integrating and linking microbial adaptation to resource imbalances to ecosystem scale fluxes across scales and ecosystems.

  3. Adaptive camouflage in the VIS and IR spectral range: main principles and mechanisms

    NASA Astrophysics Data System (ADS)

    Schwarz, Alexander

    2015-10-01

    This paper presents a survey of main applicable technical principles and mechanisms for adaptive camouflage in the visible (VIS) and infrared (IR) spectral ranges. All principles are described by their operation method and technical data such as the active spectral range, the degree and speed of adaptation, weight, power consumption, robustness, usability, lifetime, technology readiness level (TRL) etc.. The paper allows to compare the different principles and to assess them with regard to an application to an adaptive camouflage system.

  4. Adaptive finite element methods for two-dimensional problems in computational fracture mechanics

    NASA Technical Reports Server (NTRS)

    Min, J. B.; Bass, J. M.; Spradley, L. W.

    1994-01-01

    Some recent results obtained using solution-adaptive finite element methods in two-dimensional problems in linear elastic fracture mechanics are presented. The focus is on the basic issue of adaptive finite element methods for validating the new methodology by computing demonstration problems and comparing the stress intensity factors to analytical results.

  5. Mechanisms of Cardiopulmonary Adaptation to Microgravity. Part 2

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Session TP1 contains short reports concerning: (1) Autonomic Regulation of Circulation and Mechanical Function of Heart at Different Stages of 14th Month Space Flight; (2) Cardiovascular Oxygen Transport in Exercising Humans in Microgravity; (3) Venous Hemodynamic Changes Assessed by Air Plethysmography During a 16-Day Space Flight; (4) Respiratory Mechanics After 180 Days Space Mission (EUROMIR'95); (5) Assessment of the Sympathetic and the Parasympathetic Nervous Activity During Parabolic Flight by Pupillary Light Reflex; and(6) Vascular Response to Different Gravity.

  6. Contextual control of inhibition with reinforcement: Adaptation and timing mechanisms

    PubMed Central

    Bouton, Mark E.; Frohardt, Russell J.; Sunsay, Ceyhun; Waddell, Jaylyn; Morris, Richard W.

    2010-01-01

    Four experiments with rats studied the effects of switching the context after Pavlovian conditioning. In three conditioned suppression experiments, a large number of conditioning trials created “inhibition with reinforcement” (IWR), in which fear of the conditional stimulus (CS) reached a maximum and then declined despite continued CS – unconditional stimulus pairings. When IWR occurred, a context switch augmented fear of the CS; IWR and augmentation were highly correlated. Neither IWR nor augmentation resulted from inhibition of delay (IOD): In conditioned suppression, IWR and augmentation occurred without IOD (Experiment 3), and in appetitive conditioning (Experiment 4), IOD occurred without IWR or augmentation. IWR may occur in conditioned suppression because the animal adapts to fear of the CS in a context-specific manner. We discuss several implications. PMID:18426305

  7. Adaptive Power Saving Mechanism for 10 Gigabit Class PON Systems

    NASA Astrophysics Data System (ADS)

    Kubo, Ryogo; Kani, Jun-Ichi; Fujimoto, Yukihiro; Yoshimoto, Naoto; Kumozaki, Kiyomi

    This paper proposes a power saving mechanism with variable sleep period to reduce the power consumed by optical network units (ONUs) in passive optical network (PON) systems. In the PON systems based on time division multiplexing (TDM), sleep and periodic wake-up (SPW) control is an effective ONU power saving technique. However, the effectiveness of SPW control is fully realized only if the sleep period changes in accordance with the traffic conditions. This paper proposes an SPW control mechanism with variable sleep period. The proposed mechanism sets the sleep period according to traffic conditions, which greatly improves the power saving effect. In addition, the protocols needed between an optical line terminal (OLT) and ONUs are described on the assumption that the proposed mechanism is applied to 10 Gigabit (10G) class PON systems, i.e. IEEE 802.3av 10G-EPON and FSAN/ITU-T 10G-PON systems. The validity of the proposed mechanism is confirmed by numerical simulations.

  8. Adaptive Mechanisms for Treating Missing Information: A Simulation Study

    ERIC Educational Resources Information Center

    Garcia-Retamero, Rocio; Rieskamp, Jorg

    2008-01-01

    People often make inferences with incomplete information. Previous research has led to a mixed picture of how people treat missing information. To explain these results, the authors follow the Brunswikian perspective on human inference and hypothesize that the mechanism's accuracy for treating missing information depends on how it is distributed…

  9. Fluid Mechanics of Wing Adaptation for Separation Control

    NASA Technical Reports Server (NTRS)

    Chandrasekhara, M. S.; Wilder, M. C.; Carr, L. W.; Davis, Sanford S. (Technical Monitor)

    1997-01-01

    The unsteady fluid mechanics associated with use of a dynamically deforming leading edge airfoil for achieving compressible flow separation control has been experimentally studied. Changing the leading edge curvature at rapid rates dramatically alters the flow vorticity dynamics which is responsible for the many effects observed in the flow.

  10. [Adaptation mechanisms of alpine plants photosynthetic apparatus against adverse stress: a review].

    PubMed

    Wang, Yu-Ping; Gao, Hui-Hui; Liu, Yue-Shan; Mu, Ping; Yu, Xiao-Jun; An, Li-Zhe; Zhang, Feng

    2013-07-01

    Photosynthesis is one of the vital physiological processes easily affected by environmental changes. As a plant group growing in specific low temperature and strong irradiance environment, the photosynthetic apparatus of alpine plants have developed special morphologically and physiologically mechanisms in adapting to this extreme adverse environment. However, due to the high heterogeneity of habitats, there exist great differences in the photo-protection and adaptation mechanisms among different alpine plants. This paper reviewed the recent researches about the morphology and ultramicro-anatomical structure of the chloroplasts in photosynthetic apparatus of alpine plants and the photo-protection and adaptation mechanisms of the plants, and proposed the further research directions on the physiological adaptation of the photosynthesis of alpine plants.

  11. Mechanisms of β-cell functional adaptation to changes in workload.

    PubMed

    Wortham, M; Sander, M

    2016-09-01

    Insulin secretion must be tightly coupled to nutritional state to maintain blood glucose homeostasis. To this end, pancreatic β-cells sense and respond to changes in metabolic conditions, thereby anticipating insulin demands for a given physiological context. This is achieved in part through adjustments of nutrient metabolism, which is controlled at several levels including allosteric regulation, post-translational modifications, and altered expression of metabolic enzymes. In this review, we discuss mechanisms of β-cell metabolic and functional adaptation in the context of two physiological states that alter glucose-stimulated insulin secretion: fasting and insulin resistance. We review current knowledge of metabolic changes that occur in the β-cell during adaptation and specifically discuss transcriptional mechanisms that underlie β-cell adaptation. A more comprehensive understanding of how β-cells adapt to changes in nutrient state could identify mechanisms to be co-opted for therapeutically modulating insulin secretion in metabolic disease. PMID:27615135

  12. Personality and coping traits: A joint factor analysis.

    PubMed

    Ferguson, Eamonn

    2001-11-01

    OBJECTIVES: The main objective of this paper is to explore the structural similarities between Eysenck's model of personality and the dimensions of the dispositional COPE. Costa et al. {Costa P., Somerfield, M., & McCrae, R. (1996). Personality and coping: A reconceptualisation. In (pp. 44-61) Handbook of coping: Theory, research and applications. New York: Wiley} suggest that personality and coping behaviour are part of a continuum based on adaptation. If this is the case, there should be structural similarities between measures of personality and coping behaviour. This is tested using a joint factor analysis of personality and coping measures. DESIGN: Cross-sectional survey. METHODS: The EPQ-R and the dispositional COPE were administered to 154 participants, and the data were analysed using joint factor analysis and bivariate associations. RESULTS: The joint factor analysis indicated that these data were best explained by a four-factor model. One factor was primarily unrelated to personality. There was a COPE-neurotic-introvert factor (NI-COPE) containing coping behaviours such as denial, a COPE-extroversion (E-COPE) factor containing behaviours such as seeking social support and a COPE-psychoticism factor (P-COPE) containing behaviours such as alcohol use. This factor pattern, especially for NI- and E-COPE, was interpreted in terms of Gray's model of personality {Gray, J. A. (1987) The psychology of fear and stress. Cambridge: Cambridge University Press}. NI-, E-, and P-COPE were shown to be related, in a theoretically consistent manner, to perceived coping success and perceived coping functions. CONCLUSIONS: The results indicate that there are indeed conceptual links between models of personality and coping. It is argued that future research should focus on identifying coping 'trait complexes'. Implications for practice are discussed. PMID:12614507

  13. Genome and Transcriptome Analyses Provide Insight into the Euryhaline Adaptation Mechanism of Crassostrea gigas

    PubMed Central

    Zhang, Linlin; Li, Chunyan; Li, Li; She, Zhicai; Huang, Baoyu; Zhang, Guofan

    2013-01-01

    Background The Pacific oyster, Crassostrea gigas, has developed special mechanisms to regulate its osmotic balance to adapt to fluctuations of salinities in coastal zones. To understand the oyster’s euryhaline adaptation, we analyzed salt stress effectors metabolism pathways under different salinities (salt 5, 10, 15, 20, 25, 30 and 40 for 7 days) using transcriptome data, physiology experiment and quantitative real-time PCR. Results Transcriptome data uncovered 189, 480, 207 and 80 marker genes for monitoring physiology status of oysters and the environment conditions. Three known salt stress effectors (involving ion channels, aquaporins and free amino acids) were examined. The analysis of ion channels and aquaporins indicated that 7 days long-term salt stress inhibited voltage-gated Na+/K+ channel and aquaporin but increased calcium-activated K+ channel and Ca2+ channel. As the most important category of osmotic stress effector, we analyzed the oyster FAAs metabolism pathways (including taurine, glycine, alanine, beta-alanine, proline and arginine) and explained FAAs functional mechanism for oyster low salinity adaptation. FAAs metabolism key enzyme genes displayed expression differentiation in low salinity adapted individuals comparing with control which further indicated that FAAs played important roles for oyster salinity adaptation. A global metabolic pathway analysis (iPath) of oyster expanded genes displayed a co-expansion of FAAs metabolism in C. gigas compared with seven other species, suggesting oyster’s powerful ability regarding FAAs metabolism, allowing it to adapt to fluctuating salinities, which may be one important mechanism underlying euryhaline adaption in oyster. Additionally, using transcriptome data analysis, we uncovered salt stress transduction networks in C. gigas. Conclusions Our results represented oyster salt stress effectors functional mechanisms under salt stress conditions and explained the expansion of FAAs metabolism pathways as

  14. Spike initiating dynamics of the neuron with different adaptation mechanisms to extracellular electric fields

    NASA Astrophysics Data System (ADS)

    Yi, Guosheng; Wang, Jiang; Deng, Bin; Wei, Xile

    2015-05-01

    In this paper, we address how adaptation mediated by different biophysical mechanisms modulates neuronal spike initiating dynamics to extracellular electric fields. We incorporate two adaptation currents, i.e., voltage-sensitive potassium current (IM) and calcium-sensitive potassium current (IAHP), into a reduced two-compartment neuron model, and extensively investigate the modeling behavior to a range of electric fields. With phase plane analysis, it is shown whether neuron continues to spike depends on whether adaptation currents could be sufficiently activated to stabilize membrane potential at subthreshold voltages. With stability and bifurcation analysis, we find the steady-state spiking in the neuron with IM occurs through a Hopf bifurcation, whereas it is generated through a saddle-node on invariant circle (SNIC) bifurcation in the cases of IAHP or no adaptation. By identifying the biophysical basis for these dynamics, we observe that IM could alter the competitive outcomes between kinetically mismatched opposite currents to result in a Hopf bifurcation, while IAHP cannot alter these competitive outcomes. From this, we conclude that different modulations of spike initiating dynamics derive from the biophysical mechanism responsible for distinct adaptation currents. Our study suggests that the adaptation mediated by different mechanisms indeed has different effects on neuronal dynamics to electric field stimulus. It could contribute to uncover the underlying mechanism of how neuron encodes electric field signals.

  15. Use it or lose it: multiscale skeletal muscle adaptation to mechanical stimuli.

    PubMed

    Wisdom, Katrina M; Delp, Scott L; Kuhl, Ellen

    2015-04-01

    Skeletal muscle undergoes continuous turnover to adapt to changes in its mechanical environment. Overload increases muscle mass, whereas underload decreases muscle mass. These changes are correlated with, and enabled by, structural alterations across the molecular, subcellular, cellular, tissue, and organ scales. Despite extensive research on muscle adaptation at the individual scales, the interaction of the underlying mechanisms across the scales remains poorly understood. Here, we present a thorough review and a broad classification of multiscale muscle adaptation in response to a variety of mechanical stimuli. From this classification, we suggest that a mathematical model for skeletal muscle adaptation should include the four major stimuli, overstretch, understretch, overload, and underload, and the five key players in skeletal muscle adaptation, myosin heavy chain isoform, serial sarcomere number, parallel sarcomere number, pennation angle, and extracellular matrix composition. Including this information in multiscale computational models of muscle will shape our understanding of the interacting mechanisms of skeletal muscle adaptation across the scales. Ultimately, this will allow us to rationalize the design of exercise and rehabilitation programs, and improve the long-term success of interventional treatment in musculoskeletal disease.

  16. Review. Use it or lose it: Multiscale skeletal muscle adaptation to mechanical stimuli

    PubMed Central

    Wisdom, Katrina M.; Delp, Scott L.; Kuhl, Ellen

    2014-01-01

    Skeletal muscle undergoes continuous turnover to adapt to changes in its mechanical environment. Overload increases muscle mass, whereas underload decreases muscle mass. These changes are correlated with, and enabled by, structural alterations across the molecular, subcellular, cellular, tissue, and organ scales. Despite extensive research on muscle adaptation at the individual scales, the interaction of the underlying mechanisms across the scales remains poorly understood. Here we present a thorough review and a broad classification of multiscale muscle adaptation in response to a variety of mechanical stimuli. From this classification, we suggest that a mathematical model for skeletal muscle adaptation should include the four major stimuli, overstretch, understretch, overload, and underload, and the five key players in skeletal muscle adaptation, myosin heavy chain isoform, serial sarcomere number, parallel sarcomere number, pennation angle, and extracellular matrix composition. Including this information in multiscale computational models of muscle will shape our understanding of the interacting mechanisms of skeletal muscle adaptation across the scales. Ultimately, this will allow us to rationalize the design of exercise and rehabilitation programs, and improve the long-term success of interventional treatment in musculoskeletal disease. PMID:25199941

  17. Aortic pulse pressure homeostasis emerges from physiological adaptation of systemic arteries to local mechanical stresses.

    PubMed

    Nguyen, Phuc H; Tuzun, Egemen; Quick, Christopher M

    2016-09-01

    Aortic pulse pressure arises from the interaction of the heart, the systemic arterial system, and peripheral microcirculations. The complex interaction between hemodynamics and arterial remodeling precludes the ability to experimentally ascribe changes in aortic pulse pressure to particular adaptive responses. Therefore, the purpose of the present work was to use a human systemic arterial system model to test the hypothesis that pulse pressure homeostasis can emerge from physiological adaptation of systemic arteries to local mechanical stresses. First, we assumed a systemic arterial system that had a realistic topology consisting of 121 arterial segments. Then the relationships of pulsatile blood pressures and flows in arterial segments were characterized by standard pulse transmission equations. Finally, each arterial segment was assumed to remodel to local stresses following three simple rules: 1) increases in endothelial shear stress increases radius, 2) increases in wall circumferential stress increases wall thickness, and 3) increases in wall circumferential stress decreases wall stiffness. Simulation of adaptation by iteratively calculating pulsatile hemodynamics, mechanical stresses, and vascular remodeling led to a general behavior in response to mechanical perturbations: initial increases in pulse pressure led to increased arterial compliances, and decreases in pulse pressure led to decreased compliances. Consequently, vascular adaptation returned pulse pressures back toward baseline conditions. This behavior manifested when modeling physiological adaptive responses to changes in cardiac output, changes in peripheral resistances, and changes in local arterial radii. The present work, thus, revealed that pulse pressure homeostasis emerges from physiological adaptation of systemic arteries to local mechanical stresses.

  18. Molecular mechanisms underlying the exceptional adaptations of batoid fins

    PubMed Central

    Nakamura, Tetsuya; Klomp, Jeff; Pieretti, Joyce; Schneider, Igor; Gehrke, Andrew R.; Shubin, Neil H.

    2015-01-01

    Extreme novelties in the shape and size of paired fins are exemplified by extinct and extant cartilaginous and bony fishes. Pectoral fins of skates and rays, such as the little skate (Batoid, Leucoraja erinacea), show a strikingly unique morphology where the pectoral fin extends anteriorly to ultimately fuse with the head. This results in a morphology that essentially surrounds the body and is associated with the evolution of novel swimming mechanisms in the group. In an approach that extends from RNA sequencing to in situ hybridization to functional assays, we show that anterior and posterior portions of the pectoral fin have different genetic underpinnings: canonical genes of appendage development control posterior fin development via an apical ectodermal ridge (AER), whereas an alternative Homeobox (Hox)–Fibroblast growth factor (Fgf)–Wingless type MMTV integration site family (Wnt) genetic module in the anterior region creates an AER-like structure that drives anterior fin expansion. Finally, we show that GLI family zinc finger 3 (Gli3), which is an anterior repressor of tetrapod digits, is expressed in the posterior half of the pectoral fin of skate, shark, and zebrafish but in the anterior side of the pelvic fin. Taken together, these data point to both highly derived and deeply ancestral patterns of gene expression in skate pectoral fins, shedding light on the molecular mechanisms behind the evolution of novel fin morphologies. PMID:26644578

  19. Molecular mechanisms underlying the exceptional adaptations of batoid fins.

    PubMed

    Nakamura, Tetsuya; Klomp, Jeff; Pieretti, Joyce; Schneider, Igor; Gehrke, Andrew R; Shubin, Neil H

    2015-12-29

    Extreme novelties in the shape and size of paired fins are exemplified by extinct and extant cartilaginous and bony fishes. Pectoral fins of skates and rays, such as the little skate (Batoid, Leucoraja erinacea), show a strikingly unique morphology where the pectoral fin extends anteriorly to ultimately fuse with the head. This results in a morphology that essentially surrounds the body and is associated with the evolution of novel swimming mechanisms in the group. In an approach that extends from RNA sequencing to in situ hybridization to functional assays, we show that anterior and posterior portions of the pectoral fin have different genetic underpinnings: canonical genes of appendage development control posterior fin development via an apical ectodermal ridge (AER), whereas an alternative Homeobox (Hox)-Fibroblast growth factor (Fgf)-Wingless type MMTV integration site family (Wnt) genetic module in the anterior region creates an AER-like structure that drives anterior fin expansion. Finally, we show that GLI family zinc finger 3 (Gli3), which is an anterior repressor of tetrapod digits, is expressed in the posterior half of the pectoral fin of skate, shark, and zebrafish but in the anterior side of the pelvic fin. Taken together, these data point to both highly derived and deeply ancestral patterns of gene expression in skate pectoral fins, shedding light on the molecular mechanisms behind the evolution of novel fin morphologies. PMID:26644578

  20. Adaptation Mechanism of the Aspartate Receptor: Electrostatics of the Adaptation Subdomain Play a Key Role in Modulating Kinase Activity†

    PubMed Central

    Starrett, Diane J.; Falke, Joseph J.

    2010-01-01

    The aspartate receptor of the Escherichia coli and Salmonella typhimurium chemotaxis pathway generates a transmembrane signal that regulates the activity of the cytoplasmic kinase CheA. Previous studies have identified a region of the cytoplasmic domain that is critical to receptor adaptation and kinase regulation. This region, termed the adaptation subdomain, contains a high density of acidic residues, including specific glutamate residues that serve as receptor adaptation sites. However, the mechanism of signal propagation through this region remains poorly understood. This study uses site-directed mutagenesis to neutralize each acidic residue within the subdomain to probe the hypothesis that electrostatics in this region play a significant role in the mechanism of kinase activation and modulation. Each point mutant was tested for its ability to regulate chemotaxis in vivo and kinase activity in vitro. Four point mutants (D273N, E281Q, D288N, and E477Q) were found to superactivate the kinase relative to the wild-type receptor, and all four of these kinase-activating substitutions are located along the same intersubunit interface as the adaptation sites. These activating substitutions retained the wild-type ability of the attractant-occupied receptor to inhibit kinase activity. When combined in a quadruple mutant (D273N/E281Q/D288N/E477Q), the four charge-neutralizing substitutions locked the receptor in a kinase-superactivating state that could not be fully inactivated by the attractant. Similar lock-on character was observed for a charge reversal substitution, D273R. Together, these results implicate the electrostatic interactions at the intersubunit interface as a major player in signal transduction and kinase regulation. The negative charge in this region destabilizes the local structure in a way that enhances conformational dynamics, as detected by disulfide trapping, and this effect is reversed by charge neutralization of the adaptation sites. Finally, two

  1. Advances on molecular mechanism of the adaptive evolution of Chiroptera (bats).

    PubMed

    Yunpeng, Liang; Li, Yu

    2015-01-01

    As the second biggest animal group in mammals, Chiroptera (bats) demonstrates many unique adaptive features in terms of flight, echolocation, auditory acuity, feeding habit, hibernation and immune defense, providing an excellent system for understanding the molecular basis of how organisms adapt to the living environments encountered. In this review, we summarize the researches on the molecular mechanism of the adaptive evolution of Chiroptera, especially the recent researches at the genome levels, suggesting a far more complex evolutionary pattern and functional diversity than previously thought. In the future, along with the increasing numbers of Chiroptera species genomes available, new evolutionary patterns and functional divergence will be revealed, which can promote the further understanding of this animal group and the molecular mechanism of adaptive evolution.

  2. Adaptive implicit-explicit finite element algorithms for fluid mechanics problems

    NASA Technical Reports Server (NTRS)

    Tezduyar, T. E.; Liou, J.

    1988-01-01

    The adaptive implicit-explicit (AIE) approach is presented for the finite-element solution of various problems in computational fluid mechanics. In the AIE approach, the elements are dynamically (adaptively) arranged into differently treated groups. The differences in treatment could be based on considerations such as the cost efficiency, the type of spatial or temporal discretization employed, the choice of field equations, etc. Several numerical tests are performed to demonstrate that this approach can achieve substantial savings in CPU time and memory.

  3. Adaptive Spontaneous Transitions between Two Mechanisms of Numerical Averaging.

    PubMed

    Brezis, Noam; Bronfman, Zohar Z; Usher, Marius

    2015-01-01

    We investigated the mechanism with which humans estimate numerical averages. Participants were presented with 4, 8 or 16 (two-digit) numbers, serially and rapidly (2 numerals/second) and were instructed to convey the sequence average. As predicted by a dual, but not a single-component account, we found a non-monotonic influence of set-size on accuracy. Moreover, we observed a marked decrease in RT as set-size increases and RT-accuracy tradeoff in the 4-, but not in the 16-number condition. These results indicate that in accordance with the normative directive, participants spontaneously employ analytic/sequential thinking in the 4-number condition and intuitive/holistic thinking in the 16-number condition. When the presentation rate is extreme (10 items/sec) we find that, while performance still remains high, the estimations are now based on intuitive processing. The results are accounted for by a computational model postulating population-coding underlying intuitive-averaging and working-memory-mediated symbolic procedures underlying analytical-averaging, with flexible allocation between the two. PMID:26041580

  4. Adaptive Spontaneous Transitions between Two Mechanisms of Numerical Averaging

    PubMed Central

    Brezis, Noam; Bronfman, Zohar Z.; Usher, Marius

    2015-01-01

    We investigated the mechanism with which humans estimate numerical averages. Participants were presented with 4, 8 or 16 (two-digit) numbers, serially and rapidly (2 numerals/second) and were instructed to convey the sequence average. As predicted by a dual, but not a single-component account, we found a non-monotonic influence of set-size on accuracy. Moreover, we observed a marked decrease in RT as set-size increases and RT-accuracy tradeoff in the 4-, but not in the 16-number condition. These results indicate that in accordance with the normative directive, participants spontaneously employ analytic/sequential thinking in the 4-number condition and intuitive/holistic thinking in the 16-number condition. When the presentation rate is extreme (10 items/sec) we find that, while performance still remains high, the estimations are now based on intuitive processing. The results are accounted for by a computational model postulating population-coding underlying intuitive-averaging and working-memory-mediated symbolic procedures underlying analytical-averaging, with flexible allocation between the two. PMID:26041580

  5. Understanding Students' Adaptation to Graduate School: An Integration of Social Support Theory and Social Learning Theory

    ERIC Educational Resources Information Center

    Tsay, Crystal Han-Huei

    2012-01-01

    The contemporary business world demands adaptive individuals (Friedman & Wyman, 2005). Adaptation is essential for any life transition. It often involves developing coping mechanisms, strategies, and seeking of social support. Adaptation occurs in many settings from moving to a new culture, taking a new job, starting or finishing an…

  6. Personality and coping.

    PubMed

    Carver, Charles S; Connor-Smith, Jennifer

    2010-01-01

    Personality psychology addresses views of human nature and individual differences. Biological and goal-based views of human nature provide an especially useful basis for construing coping; the five-factor model of traits adds a useful set of individual differences. Coping-responses to adversity and to the distress that results-is categorized in many ways. Meta-analyses link optimism, extraversion, conscientiousness, and openness to more engagement coping; neuroticism to more disengagement coping; and optimism, conscientiousness, and agreeableness to less disengagement coping. Relations of traits to specific coping responses reveal a more nuanced picture. Several moderators of these associations also emerge: age, stressor severity, and temporal proximity between the coping activity and the coping report. Personality and coping play both independent and interactive roles in influencing physical and mental health. Recommendations are presented for ways future research can expand on the growing understanding of how personality and coping shape adjustment to stress.

  7. Indirect and direct associations between personality and psychological distress mediated by dispositional coping.

    PubMed

    Panayiotou, Georgia; Kokkinos, Constantinos M; Kapsou, Margarita

    2014-01-01

    The present study examines the association between coping and personality, by testing the hypothesis that dispositional coping mediates the relationship between personality and psychological distress. Canonical correlations evaluated the degree of the association among personality and coping dimensions in a community sample (N = 489) from Cyprus. Results partially support the hypothesized mediation model with Agreeableness predicting distress through the full mediation of avoidant coping, expression of negative feelings and active-positive coping. Partial mediation was found for Neuroticism and Openness. Canonical correlations deciphered how coping relates to the Big Five dimensions. Neuroticism was mostly associated with maladaptive coping, whereas Conscientiousness and Extraversion with adaptive coping.

  8. Psychosocial mechanisms of serotonin transporter’s genetic polymorphism in susceptibility to major depressive disorder: mediated by trait coping styles and interacted with life events

    PubMed Central

    Wang, Yanfang; Sun, Ning; Liu, Zhifen; Li, Xinrong; Yang, Chunxia; Zhang, Kerang

    2016-01-01

    The mechanism of 5-HTT genetic polymorphisms related susceptibility of major depressive disorder (MDD) has not been fully understood. Two hundred MDD patients and 199 control subjects were included. A model of two binary logistical regressions with and without controlling for different psychosocial variables, was applied to investigate the possible mediation effects of psychosocial factors in contribution of 5-HTT polymorphisms in MDD development. These psychosocial variables included personality, trait coping style, life events and social support. Then, contribution of interactions between 5-HTT polymorphisms and psychosocial factors in MDD was investigated by a stepwise logistical approach. The results indicated a significant association of 5-HTT LPR with the MDD indicence, but not of VNTR genotype variances with the MDD incidence without counting effects of psychosocial factors. The ss genotype of LPR demonstrated 2.50 (95% CI: 1.11-5.62) times higher odds to develop MDD than ll genotype (p=0.026). After including psychosocial variables, the odds ratio of 5-HTT LPR ss to ll genotype dropped to 1.30 times (95% CI: 0.41-4.10) and became non-significant (p=0.658). While psychosocial variables all showed significant contributions to MDD susceptibility. Our data suggested an intermediator role of this psychosocial variable in LPR genetic pathogenesis of MDD. Whereas, 5-HTT VNTR could significantly affect MDD outcome by interacting with life events (p=0.043). In conclusion, 5-HTT LPR and VNTR polymorphisms could affect MDD susceptibility through mediation by trait coping styles and interaction with severe life events, respectively. The genetic information of 5-HTT can be potentially helpful for diagnosis and further therapy. PMID:27158415

  9. Relations among stress, coping strategies, coping motives, alcohol consumption and related problems: a mediated moderation model.

    PubMed

    Corbin, William R; Farmer, Nicole M; Nolen-Hoekesma, Susan

    2013-04-01

    Although prominent models of alcohol use and abuse implicate stress as an important motivator of alcohol consumption, research has not consistently identified a relationship between stress and drinking outcomes. Presumably stress leads to heavier alcohol consumption and related problems primarily for individuals who lack other adaptive methods for coping effectively with stressful experiences. To test this hypothesis, we examined four adaptive coping approaches (active coping, planning, suppression of competing activities, and restraint), as predictors of alcohol use and related problems as well as moderators of relations between stress and drinking outcomes in an undergraduate population (N=225). Further, we examined coping motives for drinking as potential mediators of the effects of coping strategies as well as stress by coping strategy interactions. Analyses supported both restraint and suppression of competing activities as moderators of the influence of stress on alcohol use but not problems. The stress by restraint interaction was also evident in the prediction of coping motives, and coping motives were related to higher levels of both weekly drinking and alcohol-related problems. Finally, coping motives for drinking served to mediate the stress by restraint interaction on weekly drinking. Overall, these results suggest that efforts to suppress competing activities and restrain impulsive responses in the face of stress may reduce the risk for heavy drinking during the transition from high school to college.

  10. Innate and adaptive immunity in bacteria: mechanisms of programmed genetic variation to fight bacteriophages.

    PubMed

    Bikard, David; Marraffini, Luciano A

    2012-02-01

    Bacteria are constantly challenged by bacteriophages (viruses that infect bacteria), the most abundant microorganism on earth. Bacteria have evolved a variety of immunity mechanisms to resist bacteriophage infection. In response, bacteriophages can evolve counter-resistance mechanisms and launch a 'virus versus host' evolutionary arms race. In this context, rapid evolution is fundamental for the survival of the bacterial cell. Programmed genetic variation mechanisms at loci involved in immunity against bacteriophages generate diversity at a much faster rate than random point mutation and enable bacteria to quickly adapt and repel infection. Diversity-generating retroelements (DGRs) and phase variation mechanisms enhance the generic (innate) immune response against bacteriophages. On the other hand, the integration of small bacteriophage sequences in CRISPR loci provide bacteria with a virus-specific and sequence-specific adaptive immune response. Therefore, although using different molecular mechanisms, both prokaryotes and higher organisms rely on programmed genetic variation to increase genetic diversity and fight rapidly evolving infectious agents.

  11. Coping in Outdoor Recreation: Causes and Consequences of Crowding and Conflict among Community Residents.

    ERIC Educational Resources Information Center

    Manning, Robert E.; Valliere, William A.

    2001-01-01

    Explored coping mechanisms in outdoor recreation in response to crowing and conflict, measuring perceived changes in amounts and types of recreation use occurring at one national park and the extent to which park visitors adopted coping mechanisms. People near the park adopted coping mechanisms at relatively high levels. Coping related to…

  12. Controversies Regarding the Psychometric Properties of the Brief COPE: The Case of the Brazilian-Portuguese Version "COPE Breve".

    PubMed

    Brasileiro, Sarah V; Orsini, Mara R C A; Cavalcante, Julianna A; Bartholomeu, Daniel; Montiel, José M; Costa, Paulo S S; Costa, Luciane R

    2016-01-01

    The Brief Coping Orientation to Problems Experienced (COPE) inventory investigates the different ways in which people respond to stressful situations. Knowledge is lacking regarding the coping strategies and styles of people in developing countries, including Brazil. This study aimed to adapt and validate the Brief COPE to Brazilian Portuguese (named COPE Breve) by focusing on dispositional coping. For the cross-cultural adaptation, the original Brief COPE in English (28 items grouped into 14 subscales) was adapted according to a universalistic approach, following these steps: translation, synthesis, back-translation, analysis by an expert panel, and pretest with 30 participants. Then, 237 adults from the community health service responded to the COPE Breve. Psychometric analyses included reliability and exploratory factor analysis. Most of the 14 subscales from the original Brief COPE exhibited problems related to internal consistency. A Velicer's minimum average partial test (MAP) was performed and pointed out 3 factors. Exploratory factor analysis produced a revised 20-item version with a 3-factor solution: religion and positive reframing, distraction and external support. The psychometric properties of the COPE Breve with three factors were appropriate. Limitations of this study as well as suggestions for future studies are presented. The COPE Breve should be used in Brazilian clinics and investigations, but divergences in its psychometrics should be further explored in other contexts. PMID:27007646

  13. Controversies Regarding the Psychometric Properties of the Brief COPE: The Case of the Brazilian-Portuguese Version "COPE Breve".

    PubMed

    Brasileiro, Sarah V; Orsini, Mara R C A; Cavalcante, Julianna A; Bartholomeu, Daniel; Montiel, José M; Costa, Paulo S S; Costa, Luciane R

    2016-01-01

    The Brief Coping Orientation to Problems Experienced (COPE) inventory investigates the different ways in which people respond to stressful situations. Knowledge is lacking regarding the coping strategies and styles of people in developing countries, including Brazil. This study aimed to adapt and validate the Brief COPE to Brazilian Portuguese (named COPE Breve) by focusing on dispositional coping. For the cross-cultural adaptation, the original Brief COPE in English (28 items grouped into 14 subscales) was adapted according to a universalistic approach, following these steps: translation, synthesis, back-translation, analysis by an expert panel, and pretest with 30 participants. Then, 237 adults from the community health service responded to the COPE Breve. Psychometric analyses included reliability and exploratory factor analysis. Most of the 14 subscales from the original Brief COPE exhibited problems related to internal consistency. A Velicer's minimum average partial test (MAP) was performed and pointed out 3 factors. Exploratory factor analysis produced a revised 20-item version with a 3-factor solution: religion and positive reframing, distraction and external support. The psychometric properties of the COPE Breve with three factors were appropriate. Limitations of this study as well as suggestions for future studies are presented. The COPE Breve should be used in Brazilian clinics and investigations, but divergences in its psychometrics should be further explored in other contexts.

  14. Comparison of adaptive algorithms for the control of tonal disturbances in mechanical systems

    NASA Astrophysics Data System (ADS)

    Zilletti, M.; Elliott, S. J.; Cheer, J.

    2016-09-01

    This paper presents a study on the performance of adaptive control algorithms designed to reduce the vibration of mechanical systems excited by a harmonic disturbance. The mechanical system consists of a mass suspended on a spring and a damper. The system is equipped with a force actuator in parallel with the suspension. The control signal driving the actuator is generated by adjusting the amplitude and phase of a sinusoidal reference signal at the same frequency as the excitation. An adaptive feedforward control algorithm is used to adapt the amplitude and phase of the control signal, to minimise the mean square velocity of the mass. Two adaptation strategies are considered in which the control signal is either updated after each period of the oscillation or at every time sample. The first strategy is traditionally used in vibration control in helicopters for example; the second strategy is normally referred to as the filtered-x least mean square algorithm and is often used to control engine noise in cars. The two adaptation strategies are compared through a parametric study, which investigates the influence of the properties of both the mechanical system and the control system on the convergence speed of the two algorithms.

  15. Mechanism of HSV infection through soluble adapter-mediated virus bridging to the EGF receptor

    SciTech Connect

    Nakano, Kenji; Kobayashi, Masatoshi; Nakamura, Kei-ichiro; Nakanishi, Takeshi; Asano, Ryutaro; Kumagai, Izumi; Tahara, Hideaki; Kuwano, Michihiko; Cohen, Justus B.; Glorioso, Joseph C.

    2011-04-25

    Herpes simplex virus entry into cells requires the binding of envelope glycoprotein D (gD) to an entry receptor. Depending on the cell, entry occurs by different mechanisms, including fusion at the cell surface or endocytosis. Here we examined the entry mechanism through a non-HSV receptor mediated by a soluble bi-specific adapter protein composed of recognition elements for gD and the EGF receptor (EGFR). Virus entered into endosomes using either EGF or an EGFR-specific single chain antibody (scFv) for receptor recognition. Infection was less efficient with the EGF adapter which could be attributed to its weaker binding to a viral gD. Infection mediated by the scFv adapter was pH sensitive, indicating that gD-EGFR bridging alone was insufficient for capsid release from endosomes. We also show that the scFv adapter enhanced infection of EGFR-expressing tumor tissue in vivo. Our results indicate that adapters may retarget HSV infection without drastically changing the entry mechanism.

  16. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  17. Microbial community succession mechanism coupling with adaptive evolution of adsorption performance in chalcopyrite bioleaching.

    PubMed

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    The community succession mechanism of Acidithiobacillus sp. coupling with adaptive evolution of adsorption performance were systematically investigated. Specifically, the μmax of attached and free cells was increased and peak time was moved ahead, indicating both cell growth of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was promoted. In the mixed strains system, the domination courses of A. thiooxidans was dramatically shortened from 22th day to 15th day, although community structure finally approached to the normal system. Compared to A. ferrooxidans, more positive effects of adaptive evolution on cell growth of A. thiooxidans were shown in either single or mixed strains system. Moreover, higher concentrations of sulfate and ferric ions indicated that both sulfur and iron metabolism was enhanced, especially of A. thiooxidans. Consistently, copper ion production was improved from 65.5 to 88.5 mg/L. This new adaptive evolution and community succession mechanism may be useful for guiding similar bioleaching processes.

  18. FPGA-based adaptive backstepping fuzzy control for a micro-positioning Scott-Russell mechanism

    NASA Astrophysics Data System (ADS)

    Fung, Rong-Fong; Weng, Ming-Hong; Kung, Ying-Shieh

    2009-11-01

    This paper utilizes the field programmable gate array (FPGA) and Nios II embedded processor technologies to design a controller IC for a micro-positioning Scott-Russell (SR) mechanism, which is driven by a piezoelectric actuator (PA) and its hysteresis phenomenon is described by Bouc-Wen hysteresis model. For the controller design, the adaptive backstepping fuzzy control (ABFC) method is developed to compensate the PA's hysteresis and achieve the motion tracking control. The fuzzy logic method (FLM) is utilized to find the best adaptation gain of the adaptation law and control gain of the stabilization controls. This ABFC controller method can improve the transient and asymptotic tracking performances, and make the SR mechanism keep good working performance when external disturbances is added in the control system. Finally, we successfully apply the system-on-a-programmable-chip (SoPC) technologies to develop the motion controller IC, and achieve the advantages of reduced space, high performance and low cost.

  19. Evolution of time-keeping mechanisms: early emergence and adaptation to photoperiod.

    PubMed

    Hut, R A; Beersma, D G M

    2011-07-27

    Virtually all species have developed cellular oscillations and mechanisms that synchronize these cellular oscillations to environmental cycles. Such environmental cycles in biotic (e.g. food availability and predation risk) or abiotic (e.g. temperature and light) factors may occur on a daily, annual or tidal time scale. Internal timing mechanisms may facilitate behavioural or physiological adaptation to such changes in environmental conditions. These timing mechanisms commonly involve an internal molecular oscillator (a 'clock') that is synchronized ('entrained') to the environmental cycle by receptor mechanisms responding to relevant environmental signals ('Zeitgeber', i.e. German for time-giver). To understand the evolution of such timing mechanisms, we have to understand the mechanisms leading to selective advantage. Although major advances have been made in our understanding of the physiological and molecular mechanisms driving internal cycles (proximate questions), studies identifying mechanisms of natural selection on clock systems (ultimate questions) are rather limited. Here, we discuss the selective advantage of a circadian system and how its adaptation to day length variation may have a functional role in optimizing seasonal timing. We discuss various cases where selective advantages of circadian timing mechanisms have been shown and cases where temporarily loss of circadian timing may cause selective advantage. We suggest an explanation for why a circadian timing system has emerged in primitive life forms like cyanobacteria and we evaluate a possible molecular mechanism that enabled these bacteria to adapt to seasonal variation in day length. We further discuss how the role of the circadian system in photoperiodic time measurement may explain differential selection pressures on circadian period when species are exposed to changing climatic conditions (e.g. global warming) or when they expand their geographical range to different latitudes or altitudes.

  20. Metabolic insight into mechanisms of high-altitude adaptation in Tibetans.

    PubMed

    Ge, Ri-Li; Simonson, Tatum S; Cooksey, Robert C; Tanna, Uran; Qin, Ga; Huff, Chad D; Witherspoon, David J; Xing, Jinchuan; Zhengzhong, Bai; Prchal, Josef T; Jorde, Lynn B; McClain, Donald A

    2012-06-01

    Recent studies have identified genes involved in high-altitude adaptation in Tibetans. Genetic variants/haplotypes within regions containing three of these genes (EPAS1, EGLN1, and PPARA) are associated with relatively decreased hemoglobin levels observed in Tibetans at high altitude, providing corroborative evidence for genetic adaptation to this extreme environment. The mechanisms that afford adaptation to high-altitude hypoxia, however, remain unclear. Considering the strong metabolic demands imposed by hypoxia, we hypothesized that a shift in fuel preference to glucose oxidation and glycolysis at the expense of fatty acid oxidation would improve adaptation to decreased oxygen availability. Correlations between serum free fatty acid and lactate concentrations in Tibetan groups living at high altitude and putatively selected haplotypes provide insight into this hypothesis. An EPAS1 haplotype that exhibits a signal of positive selection is significantly associated with increased lactate concentration, the product of anaerobic glycolysis. Furthermore, the putatively advantageous PPARA haplotype is correlated with serum free fatty acid concentrations, suggesting a possible decrease in the activity of fatty acid oxidation. Although further studies are required to assess the molecular mechanisms underlying these patterns, these associations suggest that genetic adaptation to high altitude involves alteration in energy utilization pathways.

  1. Coping with Cold Sores

    MedlinePlus

    ... Here's Help White House Lunch Recipes Coping With Cold Sores KidsHealth > For Kids > Coping With Cold Sores ... sore." What's that? Adam wondered. What Is a Cold Sore? Cold sores are small blisters that is ...

  2. Perceptions of coping with non-disease-related life stress for women with osteoarthritis: a qualitative analysis

    PubMed Central

    Harris, Melissa L; Byles, Julie E; Townsend, Natalie; Loxton, Deborah

    2016-01-01

    Objective Coping with arthritis-related stress has been extensively studied. However, limited evidence exists regarding coping with stress extraneous to the disease (life stress). This study explored life stress and coping in a subset of older women with osteoarthritis from a larger longitudinal study. Setting An Australian regional university. Design This qualitative study involved semistructured telephone interviews. Potential participants were mailed a letter of invitation/participant information statement by the Australian Longitudinal Study on Women's Health (ALSWH). Invitations were sent out in small batches (primarily 10). Interviews were conducted until data saturation was achieved using a systematic process (n=19). Digitally recorded interviews were transcribed verbatim and deidentified. Data were thematically analysed. Participants Women who indicated being diagnosed or treated for arthritis in the previous 3 years in the fifth survey of the ALSWH (conducted in 2007) provided the sampling frame. Potential participants were randomly sampled by a blinded data manager using a random number generator. Results Coping with life stress involved both attitudinal coping processes developed early in life (ie, stoicism) and transient cognitive and support-based responses. Women also described a dualistic process involving a reduction in the ability to cope with ongoing stress over time, coupled with personal growth. Conclusions This is the first study to examine how individuals cope with non-arthritis-related stress. The findings add to the current understanding of stress and coping, and have implications regarding the prevention of arthritis in women. Importantly, this study highlighted the potential detrimental impact of persistent coping patterns developed early in life. Public health campaigns aimed at stress mitigation and facilitation of adaptive coping mechanisms in childhood and adolescence may assist with arthritis prevention. PMID:27188808

  3. A Complexity-Aware Video Adaptation Mechanism for Live Streaming Systems

    NASA Astrophysics Data System (ADS)

    Lu, Meng-Ting; Yao, Jason J.; Chen, Homer H.

    2007-12-01

    The paradigm shift of network design from performance-centric to constraint-centric has called for new signal processing techniques to deal with various aspects of resource-constrained communication and networking. In this paper, we consider the computational constraints of a multimedia communication system and propose a video adaptation mechanism for live video streaming of multiple channels. The video adaptation mechanism includes three salient features. First, it adjusts the computational resource of the streaming server block by block to provide a fine control of the encoding complexity. Second, as far as we know, it is the first mechanism to allocate the computational resource to multiple channels. Third, it utilizes a complexity-distortion model to determine the optimal coding parameter values to achieve global optimization. These techniques constitute the basic building blocks for a successful application of wireless and Internet video to digital home, surveillance, IPTV, and online games.

  4. A comparative study on Ca content and distribution in two Gesneriaceae species reveals distinctive mechanisms to cope with high rhizospheric soluble calcium.

    PubMed

    Li, Wenlong; Xu, Falun; Chen, Shixuan; Zhang, Zhennan; Zhao, Yan; Jin, Yukuan; Li, Meijing; Zhu, Yan; Liu, Yongxiu; Yang, Yi; Deng, Xin

    2014-01-01

    Excessive Ca is toxic to plants thus significantly affects plant growth and species distribution in Ca-rich karst areas. To understand how plants survive high Ca soil, laboratory experiments were established to compare the physiological responses and internal Ca distribution in organ, tissue, cell, and intracellular levels under different Ca levels for Lysionotus pauciflorus and Boea hygrometrica, two karst habitant Gesneriaceae species in Southwest China. In the controlled condition, L. pauciflorus could survive as high as 200 mM rhizospheric soluble Ca, attributed to a series of physiological responses and preferential storage that limited Ca accumulation in chloroplasts of palisade cells. In contrast, B. hygrometrica could survive only 20 mM rhizospheric soluble Ca, but accumulated a high level of internal Ca in both palisade and spongy cells without disturbance on photosynthetic activity. By phenotype screening of transgenic plants expressing high Ca-inducible genes from B. hygrometrica, the expression of BhDNAJC2 in A. thaliana was found to enhance plant growth and photosynthesis under high soluble Ca stress. BhDNAJC2 encodes a recently reported heat shock protein (HSP) 40 family DnaJ-domain protein. The Ca-resistant phenotype of BhDNAJC2 highlights the important role of chaperone-mediated protein quality control in Ca tolerance in B. hygrometrica. Taken together, our results revealed that distinctive mechanisms were employed in the two Gesneriaceae karst habitants to cope with a high Ca environment.

  5. A comparative study on Ca content and distribution in two Gesneriaceae species reveals distinctive mechanisms to cope with high rhizospheric soluble calcium

    PubMed Central

    Li, Wenlong; Xu, Falun; Chen, Shixuan; Zhang, Zhennan; Zhao, Yan; Jin, Yukuan; Li, Meijing; Zhu, Yan; Liu, Yongxiu; Yang, Yi; Deng, Xin

    2014-01-01

    Excessive Ca is toxic to plants thus significantly affects plant growth and species distribution in Ca-rich karst areas. To understand how plants survive high Ca soil, laboratory experiments were established to compare the physiological responses and internal Ca distribution in organ, tissue, cell, and intracellular levels under different Ca levels for Lysionotus pauciflorus and Boea hygrometrica, two karst habitant Gesneriaceae species in Southwest China. In the controlled condition, L. pauciflorus could survive as high as 200 mM rhizospheric soluble Ca, attributed to a series of physiological responses and preferential storage that limited Ca accumulation in chloroplasts of palisade cells. In contrast, B. hygrometrica could survive only 20 mM rhizospheric soluble Ca, but accumulated a high level of internal Ca in both palisade and spongy cells without disturbance on photosynthetic activity. By phenotype screening of transgenic plants expressing high Ca-inducible genes from B. hygrometrica, the expression of BhDNAJC2 in A. thaliana was found to enhance plant growth and photosynthesis under high soluble Ca stress. BhDNAJC2 encodes a recently reported heat shock protein (HSP) 40 family DnaJ-domain protein. The Ca-resistant phenotype of BhDNAJC2 highlights the important role of chaperone-mediated protein quality control in Ca tolerance in B. hygrometrica. Taken together, our results revealed that distinctive mechanisms were employed in the two Gesneriaceae karst habitants to cope with a high Ca environment. PMID:25477893

  6. Molecular mechanisms for mitochondrial adaptation to exercise training in skeletal muscle.

    PubMed

    Drake, Joshua C; Wilson, Rebecca J; Yan, Zhen

    2016-01-01

    Exercise training enhances physical performance and confers health benefits, largely through adaptations in skeletal muscle. Mitochondrial adaptation, encompassing coordinated improvements in quantity (content) and quality (structure and function), is increasingly recognized as a key factor in the beneficial outcomes of exercise training. Exercise training has long been known to promote mitochondrial biogenesis, but recent work has demonstrated that it has a profound impact on mitochondrial dynamics (fusion and fission) and clearance (mitophagy), as well. In this review, we discuss the various mechanisms through which exercise training promotes mitochondrial quantity and quality in skeletal muscle.

  7. The Role of Adaptation in Body Load-Regulating Mechanisms During Locomotion

    NASA Technical Reports Server (NTRS)

    Ruttley, Tara; Holt, Christopher; Mulavara, Ajitkumar; Bloomberg, Jacob

    2010-01-01

    Body loading is a fundamental parameter that modulates motor output during locomotion, and is especially important for controlling the generation of stepping patterns, dynamic balance, and termination of locomotion. Load receptors that regulate and control posture and stance in locomotion include the Golgi tendon organs and muscle spindles at the hip, knee, and ankle joints, and the Ruffini endings and the Pacinian corpuscles in the soles of the feet. Increased body weight support (BWS) during locomotion results in an immediate reorganization of locomotor control, such as a reduction in stance and double support duration and decreased hip, ankle, and knee angles during the gait cycle. Previous studies on the effect during exposure to increased BWS while walking showed a reduction in lower limb joint angles and gait cycle timing that represents a reorganization of locomotor control. Until now, no studies have investigated how locomotor control responds after a period of exposure to adaptive modification in the body load sensing system. The goal of this research was to determine the adaptive properties of body load-regulating mechanisms in locomotor control during locomotion. We hypothesized that body load-regulating mechanisms contribute to locomotor control, and adaptive changes in these load-regulating mechanisms require reorganization to maintain forward locomotion. Head-torso coordination, lower limb movement patterns, and gait cycle timing were evaluated before and after a 30-minute adaptation session during which subjects walked on a treadmill at 5.4 km/hr with 40% body weight support (BWS). Before and after the adaptation period, head-torso and lower limb 3D kinematic data were obtained while performing a goal directed task during locomotion with 0% BWS using a video-based motion analysis system, and gait cycle timing parameters were collected by foot switches positioned under the heel and toe of the subjects shoes. Subjects showed adaptive modification in

  8. Cross-domain adaptation reveals that a common mechanism computes stereoscopic (cyclopean) and luminance plaid motion.

    PubMed

    Bowd, C; Donnelly, M; Shorter, S; Patterson, R

    2000-01-01

    Across three experiments, this study investigated the visual processing of moving stereoscopic plaid patterns (plaids created with cyclopean components defined by moving binocular disparity embedded in a dynamic random-dot stereogram). Results showed that adaptation to a moving stereoscopic plaid or its components affected the perceived coherence of a luminance test plaid, and vice versa. Cross-domain adaptation suggests that stereoscopic and luminance motion signals feed into a common pattern-motion mechanism, consistent with the idea that stereoscopic motion signals are computed early in the motion processing stream.

  9. How to Cope with Bias While Adapting for Inclusion in Physical Education and Sports: A Judgment and Decision-Making Perspective

    ERIC Educational Resources Information Center

    Hutzler, Yeshayahu; Bar-Eli, Michael

    2013-01-01

    The purpose of this article is to describe a theoretical model and practice examples of judgment and decision making bias within the context of inclusion in physical education and sports. After presenting the context of adapting for inclusion, the theoretical roots of judgment and decision are described, and are linked to the practice of physical…

  10. Coping with Cancer.

    ERIC Educational Resources Information Center

    Manuel, Gerdenio M.; And Others

    Since the incidence of cancer in this country is high and the cancer survival rates are increasing, it is important to study coping strategies in cancer patients. As survival time lengthens, coping strategies that might affect the quality of a patient's life become increasingly important. A study was conducted to examine coping strategies in newly…

  11. Coping with Congenital Hand Differences

    PubMed Central

    Franzblau, Lauren E.; Chung, Kevin C.; Carlozzi, Noelle; Chin, Autumn Y. T.; Nellans, Kate W.; Waljee, Jennifer F.

    2015-01-01

    Purpose Although functional outcomes following reconstruction for congenital hand differences are frequently described, much less is known regarding children’s ability to cope with psychosocial effects of these conditions. We qualitatively explored stress and coping mechanisms among children following reconstructive surgery for congenital hand differences. Methods Forty patients and their parents participated in semi-structured interviews examining stress related to hand functioning and appearance, emotional responses to stress, and coping strategies. Interviews were audio-taped, transcribed, and analyzed thematically. A consensus taxonomy for classifying content evolved from comparisons of coding by two reviewers. Themes expressed by participants were studied for patterns of connection and grouped into broader categories. Results In this sample, 58% of children and 40% of parents reported stress related to congenital hand differences, attributed to functional deficits (61%), hand appearance (27%), social interactions (58%), and emotional reactions (46%). Among the 18 children who reported stress, 43% of parents were not aware of the presence of stress. Eight coping strategies emerged, including humor (12%), self-acceptance (21%), avoidance (27%), seeking external support (30%), concealment (30%), educating others (9%), support programs (21%) and religion (24%). Conclusions Although children with congenital hand differences often experience emotional stress related to functional limitations and aesthetic deformities, many apply positive coping mechanisms that enhance self-esteem and self-esteem. Clinicians caring for children with congenital hand differences should inform families about potential sources of stress in order to direct resources toward strengthening coping strategies and support systems. Level of Evidence Level IV-Case series PMID:25502854

  12. Adaptation of cardiac structure by mechanical feedback in the environment of the cell: a model study.

    PubMed Central

    Arts, T; Prinzen, F W; Snoeckx, L H; Rijcken, J M; Reneman, R S

    1994-01-01

    In the cardiac left ventricle during systole mechanical load of the myocardial fibers is distributed uniformly. A mechanism is proposed by which control of mechanical load is distributed over many individual control units acting in the environment of the cell. The mechanics of the equatorial region of the left ventricle was modeled by a thick-walled cylinder composed of 6-1500 shells of myocardial fiber material. In each shell a separate control unit was simulated. The direction of the cells was varied so that systolic fiber shortening approached a given optimum of 15%. End-diastolic sarcomere length was maintained at 2.1 microns. Regional early-systolic stretch and global contractility stimulated growth of cellular mass. If systolic shortening was more than normal the passive extracellular matrix stretched. The design of the load-controlling mechanism was derived from biological experiments showing that cellular processes are sensitive to mechanical deformation. After simulating a few hundred adaptation cycles, the macroscopic anatomical arrangement of helical pathways of the myocardial fibers formed automatically. If pump load of the ventricle was changed, wall thickness and cavity volume adapted physiologically. We propose that the cardiac anatomy may be defined and maintained by a multitude of control units for mechanical load, each acting in the cellular environment. Interestingly, feedback through fiber stress is not a compelling condition for such control. PMID:8038399

  13. Daylight Adaptive Shading Using Parametric Camshaft Mechanism for SOHO in Jakarta

    NASA Astrophysics Data System (ADS)

    Utama Sjarifudin, Firza; Justina, Laurensia

    2014-03-01

    This research analyzes SOHO (Small Office Home Office) which can adjust to the need of visual comfort for the users through natural daylighting and also can be adapted to standard requirements of 14 creative industry workspace in Jakartas. The method of the research is by simulating the SOHO unit with variation of shading opening angles in order to adapt to each unit. Analysis done to every shading opening angle to get the appropriate daylight intensity level which support the work activities in every unit for the whole day. In order for the shading to be able to adapt to the changing daylight condition, previously developed parametric camshaft mechanism was used. The study found that the visual comfort for SOHO with creative industries workers in Jakarta can be achieve by varying the shading opening angles between 15-75°.

  14. Terrain Adaptability Mechanism of Large Ruminants' Feet on the Kinematics View

    PubMed Central

    Zhang, Qun; Ding, Xilun; Xu, Kun

    2015-01-01

    Ruminants live in various parts of land. Similar cloven hooves assist ruminants in adapting to different ground environment during locomotion. This paper analyzes the general terrain adaptability of the feet of ruminants using kinematics of the equivalent mechanism model based on screw theory. Cloven hooves could adjust attitude by changing relative positions between two digits in swing phase. This function helps to choose better landing orientation. “Grasping” or “holding” a rock or other object on the ground passively provides extra adhesion force in stance phase. Ruminants could adjust the position of the metacarpophalangeal joint or metatarsophalangeal joint (MTP or MCP) with no relative motion between the tip of feet and the ground, which ensures the adhesion and dexterity in stance phase. These functions are derived from an example from chamois' feet and several assumptions, which are believed to demonstrate the foundation of adaptation of ruminants and ensure a stable and continuous movement. PMID:27019579

  15. Adaptive backstepping sliding mode control with fuzzy monitoring strategy for a kind of mechanical system.

    PubMed

    Song, Zhankui; Sun, Kaibiao

    2014-01-01

    A novel adaptive backstepping sliding mode control (ABSMC) law with fuzzy monitoring strategy is proposed for the tracking-control of a kind of nonlinear mechanical system. The proposed ABSMC scheme combining the sliding mode control and backstepping technique ensure that the occurrence of the sliding motion in finite-time and the trajectory of tracking-error converge to equilibrium point. To obtain a better perturbation rejection property, an adaptive control law is employed to compensate the lumped perturbation. Furthermore, we introduce fuzzy monitoring strategy to improve adaptive capacity and soften the control signal. The convergence and stability of the proposed control scheme are proved by using Lyaponov's method. Finally, numerical simulations demonstrate the effectiveness of the proposed control scheme.

  16. Mechanics of pressure-adaptive honeycomb and its application to wing morphing

    NASA Astrophysics Data System (ADS)

    Vos, Roelof; Barrett, Ron

    2011-09-01

    Current, highly active classes of adaptive materials have been considered for use in many different aerospace applications. From adaptive flight control surfaces to wing surfaces, shape-memory alloy (SMA), piezoelectric and electrorheological fluids are making their way into wings, stabilizers and rotor blades. Despite the benefits which can be seen in many classes of aircraft, some profound challenges are ever present, including low power and energy density, high power consumption, high development and installation costs and outright programmatic blockages due to a lack of a materials certification database on FAR 23/25 and 27/29 certified aircraft. Three years ago, a class of adaptive structure was developed to skirt these daunting challenges. This pressure-adaptive honeycomb (PAH) is capable of extremely high performance and is FAA/EASA certifiable because it employs well characterized materials arranged in ways that lend a high level of adaptivity to the structure. This study is centered on laying out the mechanics, analytical models and experimental test data describing this new form of adaptive material. A directionally biased PAH system using an external (spring) force acting on the PAH bending structure was examined. The paper discusses the mechanics of pressure adaptive honeycomb and describes a simple reduced order model that can be used to simplify the geometric model in a finite element environment. The model assumes that a variable stiffness honeycomb results in an overall deformation of the honeycomb. Strains in excess of 50% can be generated through this mechanism without encountering local material (yield) limits. It was also shown that the energy density of pressure-adaptive honeycomb is akin to that of shape-memory alloy, while exhibiting strains that are an order of magnitude greater with an energy efficiency close to 100%. Excellent correlation between theory and experiment is demonstrated in a number of tests. A proof-of-concept wing section

  17. Fibrin Networks Support Recurring Mechanical Loads by Adapting their Structure across Multiple Scales.

    PubMed

    Kurniawan, Nicholas A; Vos, Bart E; Biebricher, Andreas; Wuite, Gijs J L; Peterman, Erwin J G; Koenderink, Gijsje H

    2016-09-01

    Tissues and cells sustain recurring mechanical loads that span a wide range of loading amplitudes and timescales as a consequence of exposure to blood flow, muscle activity, and external impact. Both tissues and cells derive their mechanical strength from fibrous protein scaffolds, which typically have a complex hierarchical structure. In this study, we focus on a prototypical hierarchical biomaterial, fibrin, which is one of the most resilient naturally occurring biopolymers and forms the structural scaffold of blood clots. We show how fibrous networks composed of fibrin utilize irreversible changes in their hierarchical structure at different scales to maintain reversible stress stiffening up to large strains. To trace the origin of this paradoxical resilience, we systematically tuned the microstructural parameters of fibrin and used a combination of optical tweezers and fluorescence microscopy to measure the interactions of single fibrin fibers for the first time, to our knowledge. We demonstrate that fibrin networks adapt to moderate strains by remodeling at the network scale through the spontaneous formation of new bonds between fibers, whereas they adapt to high strains by plastic remodeling of the fibers themselves. This multiscale adaptation mechanism endows fibrin gels with the remarkable ability to sustain recurring loads due to shear flows and wound stretching. Our findings therefore reveal a microscopic mechanism by which tissues and cells can balance elastic nonlinearity and plasticity, and thus can provide microstructural insights into cell-driven remodeling of tissues. PMID:27602730

  18. The dynamics of the Π1 colour mechanism: further evidence for two sites of adaptation

    PubMed Central

    Augenstein, E. J.; Pugh, E. N.

    1977-01-01

    1. The visual pathway that determines Stiles's Π1 colour mechanism was isolated by the auxiliary field technique and studied under dynamic conditions of light adaptation and recovery by threshold measurements. 2. The time courses of adaptation to Π1-equated short wave-length (μ ≤ 500 nm) and long wave-length (μ ≥ 550 nm) fields are very distinct: a large and relatively long-enduring transient threshold elevation occurs at the onset of the long wave-length, but not of the short wave-length fields. 3. Similarly, the time courses of recovery from Π1-equated long and short wave-length fields are quite distinctive: a large and relatively long enduring transient (`transient tritanopia') occurs at the offset of the long wave-length, but not of the short wave-length fields. 4. The wave-lengths of the fields which cause the adaptation transients coincide with those shown previously (Pugh, 1976) to combine non-additively with μ = 430 nm fields in effecting Π1 adaptation. The failure of the time course of Π1 adaptation to be spectrally `univariant' combines with the failures of field-additivity to demonstrate that signals from the long and/or middle wave-length sensitive cones affect the adaptation state of the Π1 pathway. 5. The adaptation transients are not observed in the pathways that determine Π4 and Π5. Thus, instantaneous signals from the middle and/or long wave-length sensitive cones are not the cause of the transients. Rather the cause must lie in the path by which those cones transmit their signals to the Π1 pathway or in the Π1 pathway itself. 6. The off-transient can be diminished by adding an adequately intense short wave-length field to a long wave-length field that would normally cause it. The Π1 pathway must receive chromatically opponent signals. PMID:592192

  19. Functional Genomic Insights into Regulatory Mechanisms of High-Altitude Adaptation.

    PubMed

    Storz, Jay F; Cheviron, Zachary A

    2016-01-01

    Recent studies of indigenous human populations at high altitude have provided proof-of-principle that genome scans of DNA polymorphism can be used to identify candidate loci for hypoxia adaptation. When integrated with experimental analyses of physiological phenotypes, genome-wide surveys of DNA polymorphism and tissue-specific transcriptional profiles can provide insights into actual mechanisms of adaptation. It has been suggested that adaptive phenotypic evolution is largely mediated by cis-regulatory changes in genes that are located at integrative control points in regulatory networks. This hypothesis can be tested by conducting transcriptomic analyses of hypoxic signaling pathways in conjunction with experimental measures of vascular oxygen supply and metabolic pathway flux. Such studies may reveal whether the architecture of gene regulatory networks can be used to predict which loci (and which types of loci) are likely to be "hot spots" for adaptive physiological evolution. Functional genomic studies of deer mice (Peromyscus maniculatus) demonstrate how the integrated analysis of variation in tissue-specific transcriptomes, whole-animal physiological performance, and various subordinate traits can yield insights into the mechanistic underpinnings of high-altitude adaptation. PMID:27343092

  20. Post traumatic stress disorder and coping in a sample of adult survivors of the Italian earthquake.

    PubMed

    Cofini, V; Carbonelli, A; Cecilia, M R; Binkin, N; di Orio, F

    2015-09-30

    The aim was to investigate the prevalence of post traumatic stress disorder (PTSD) in people who had left their damaged homes and were still living in temporary housing more than a year after the April 2009 L'Aquila (Italy) earthquake. In addition, we evaluated the differences in coping strategies implemented by persons who had and who did not have PTSD. A cross-sectional prevalence study was carried out on a sample of 281 people aged >18 years and living in temporary housing after the earthquake. The questionnaires used include the Davidson Trauma Scale and the Brief Cope. The prevalence of PTSD was 43%. Women and the non-employed were more vulnerable to PTSD, while, age and level of education were not associated with PTSD. Those with PTSD symptoms often employed maladaptive coping strategies for dealing with earthquake and had the highest scores in the domains of denial, venting, behavioral disengagement, self-blame. By contrast, those without PTSD generally had more adaptive coping mechanisms. Adults who were living in temporary housing after the earthquake experienced high rates of PTSD. The difference in coping mechanisms between those who have PTSD and those who do not also suggests that they influence the likeliness of developing PTSD. PMID:26162658

  1. Post traumatic stress disorder and coping in a sample of adult survivors of the Italian earthquake.

    PubMed

    Cofini, V; Carbonelli, A; Cecilia, M R; Binkin, N; di Orio, F

    2015-09-30

    The aim was to investigate the prevalence of post traumatic stress disorder (PTSD) in people who had left their damaged homes and were still living in temporary housing more than a year after the April 2009 L'Aquila (Italy) earthquake. In addition, we evaluated the differences in coping strategies implemented by persons who had and who did not have PTSD. A cross-sectional prevalence study was carried out on a sample of 281 people aged >18 years and living in temporary housing after the earthquake. The questionnaires used include the Davidson Trauma Scale and the Brief Cope. The prevalence of PTSD was 43%. Women and the non-employed were more vulnerable to PTSD, while, age and level of education were not associated with PTSD. Those with PTSD symptoms often employed maladaptive coping strategies for dealing with earthquake and had the highest scores in the domains of denial, venting, behavioral disengagement, self-blame. By contrast, those without PTSD generally had more adaptive coping mechanisms. Adults who were living in temporary housing after the earthquake experienced high rates of PTSD. The difference in coping mechanisms between those who have PTSD and those who do not also suggests that they influence the likeliness of developing PTSD.

  2. Mechanical Strain Causes Adaptive Change in Bronchial Fibroblasts Enhancing Profibrotic and Inflammatory Responses

    PubMed Central

    Manuyakorn, Wiparat; Smart, David E.; Noto, Antonio; Bucchieri, Fabio; Haitchi, Hans Michael; Holgate, Stephen T.; Howarth, Peter H.; Davies, Donna E.

    2016-01-01

    Asthma is characterized by periodic episodes of bronchoconstriction and reversible airway obstruction; these symptoms are attributable to a number of factors including increased mass and reactivity of bronchial smooth muscle and extracellular matrix (ECM) in asthmatic airways. Literature has suggested changes in cell responses and signaling can be elicited via modulation of mechanical stress acting upon them, potentially affecting the microenvironment of the cell. In this study, we hypothesized that mechanical strain directly affects the (myo)fibroblast phenotype in asthma. Therefore, we characterized responses of bronchial fibroblasts, from 6 normal and 11 asthmatic non-smoking volunteers, exposed to cyclical mechanical strain using flexible silastic membranes. Samples were analyzed for proteoglycans, α-smooth muscle actin (αSMA), collagens I and III, matrix metalloproteinase (MMP) 2 & 9 and interleukin-8 (IL-8) by qRT-PCR, Western blot, zymography and ELISA. Mechanical strain caused a decrease in αSMA mRNA but no change in either αSMA protein or proteoglycan expression. In contrast the inflammatory mediator IL-8, MMPs and interstitial collagens were increased at both the transcriptional and protein level. The results demonstrate an adaptive response of bronchial fibroblasts to mechanical strain, irrespective of donor. The adaptation involves cytoskeletal rearrangement, matrix remodelling and inflammatory cytokine release. These results suggest that mechanical strain could contribute to disease progression in asthma by promoting inflammation and remodelling responses. PMID:27101406

  3. Adaptation of an industrial application for an instructional laboratory in mechanical vibrations

    SciTech Connect

    Whiteman, W.E. )

    1990-01-01

    Extensive theoretical treatment is given to damping as the process of energy dissipation during mechanical vibration. The challenge in the classroom is to adequately convey this concept and extend it by teaching students practical applications in engineering analysis and design. Students are motivated by real-world problems; applying these types of problems with strong instructional classroom content significantly enhances the learning environment. This paper proposes the adaptation of an actual research project to a simple, yet innovative, mechanical vibrations laboratory. The adapted project involves an ongoing effort at the Los Alamos National Laboratory to investigate damping factors of various alloys used in military tank munitions. The kinetic-energy penetrators used in these tank rounds are cylindrical in shape and are a major class of weapons designed to defeat heavy armor. Unwanted transverse oscillations of these penetrators degrade the accuracy of the rounds and may lead to glancing blows off the target. 5 refs., 3 figs.

  4. Rule-based mechanisms of learning for intelligent adaptive flight control

    NASA Technical Reports Server (NTRS)

    Handelman, David A.; Stengel, Robert F.

    1990-01-01

    How certain aspects of human learning can be used to characterize learning in intelligent adaptive control systems is investigated. Reflexive and declarative memory and learning are described. It is shown that model-based systems-theoretic adaptive control methods exhibit attributes of reflexive learning, whereas the problem-solving capabilities of knowledge-based systems of artificial intelligence are naturally suited for implementing declarative learning. Issues related to learning in knowledge-based control systems are addressed, with particular attention given to rule-based systems. A mechanism for real-time rule-based knowledge acquisition is suggested, and utilization of this mechanism within the context of failure diagnosis for fault-tolerant flight control is demonstrated.

  5. Coping styles of older adults with ostomies.

    PubMed

    Reynaud, Sheila Normand; Meeker, Bonnie Juve'

    2002-05-01

    Various clinical studies throughout the years have shown that individuals with ostomies are a unique group facing adjustment demands. One of the most important challenges for an individual with an ostomy is coping with the physiological and psychological changes. The purpose of this study was to describe coping styles of older adults after undergoing ostomy surgery and to explore its helpfulness in dealing with the stressors related to having an ostomy. Lazarus and Folkman's theory on stress and coping was used as the framework to guide this study. A sample of 27 participants ranging from age 50 to 84 years was obtained from an ostomy association in southeastern Louisiana. Participants were asked to complete a demographic data form and the Revised Jalowiec Coping Scale. This revised scale measured eight coping styles related to Use and Effectiveness. Findings revealed significant differences existed among the means of the eight measures for both Use and Effectiveness at p < .01. Results demonstrated that the optimistic and self-reliant styles of coping were the most frequently used as effective styles for coping with an ostomy. This indicated a positive outlook and dependence on oneself rather than dependence on others when coping with the stressors of having an ostomy. There were no statistically significant differences related to gender or ostomy type. Also, aging did not appear to be a factor when considering coping styles of older adults with ostomies. The nursing role should include assessment of the individual preoperatively to identify fears, concerns, and stressors related to having an ostomy. Also, nurses can provide education on disease management, assist with identification of ineffective coping mechanisms, and promote effective coping skills and stress management techniques.

  6. Preferential Osmolyte Accumulation: a Mechanism of Osmotic Stress Adaptation in Diazotrophic Bacteria

    PubMed Central

    Madkour, Magdy A.; Smith, Linda Tombras; Smith, Gary M.

    1990-01-01

    A common cellular mechanism of osmotic-stress adaptation is the intracellular accumulation of organic solutes (osmolytes). We investigated the mechanism of osmotic adaptation in the diazotrophic bacteria Azotobacter chroococcum, Azospirillum brasilense, and Klebsiella pneumoniae, which are adversely affected by high osmotic strength (i.e., soil salinity and/or drought). We used natural-abundance 13C nuclear magnetic resonance spectroscopy to identify all the osmolytes accumulating in these strains during osmotic stress generated by 0.5 M NaCl. Evidence is presented for the accumulation of trehalose and glutamate in Azotobacter chroococcum ZSM4, proline and glutamate in Azospirillum brasilense SHS6, and trehalose and proline in K. pneumoniae. Glycine betaine was accumulated in all strains grown in culture media containing yeast extract as the sole nitrogen source. Alternative nitrogen sources (e.g., NH4Cl or casamino acids) in the culture medium did not result in measurable glycine betaine accumulation. We suggest that the mechanism of osmotic adaptation in these organisms entails the accumulation of osmolytes in hyperosmotically stressed cells resulting from either enhanced uptake from the medium (of glycine betaine, proline, and glutamate) or increased net biosynthesis (of trehalose, proline, and glutamate) or both. The preferred osmolyte in Azotobacter chroococcum ZSM4 shifted from glutamate to trehalose as a consequence of a prolonged osmotic stress. Also, the dominant osmolyte in Azospirillum brasilense SHS6 shifted from glutamate to proline accumulation as the osmotic strength of the medium increased. PMID:16348295

  7. Strategies for adding adaptive learning mechanisms to rule-based diagnostic expert systems

    NASA Technical Reports Server (NTRS)

    Stclair, D. C.; Sabharwal, C. L.; Bond, W. E.; Hacke, Keith

    1988-01-01

    Rule-based diagnostic expert systems can be used to perform many of the diagnostic chores necessary in today's complex space systems. These expert systems typically take a set of symptoms as input and produce diagnostic advice as output. The primary objective of such expert systems is to provide accurate and comprehensive advice which can be used to help return the space system in question to nominal operation. The development and maintenance of diagnostic expert systems is time and labor intensive since the services of both knowledge engineer(s) and domain expert(s) are required. The use of adaptive learning mechanisms to increment evaluate and refine rules promises to reduce both time and labor costs associated with such systems. This paper describes the basic adaptive learning mechanisms of strengthening, weakening, generalization, discrimination, and discovery. Next basic strategies are discussed for adding these learning mechanisms to rule-based diagnostic expert systems. These strategies support the incremental evaluation and refinement of rules in the knowledge base by comparing the set of advice given by the expert system (A) with the correct diagnosis (C). Techniques are described for selecting those rules in the in the knowledge base which should participate in adaptive learning. The strategies presented may be used with a wide variety of learning algorithms. Further, these strategies are applicable to a large number of rule-based diagnostic expert systems. They may be used to provide either immediate or deferred updating of the knowledge base.

  8. An epidemic spreading model on adaptive scale-free networks with feedback mechanism

    NASA Astrophysics Data System (ADS)

    Li, Tao; Liu, Xiongding; Wu, Jie; Wan, Chen; Guan, Zhi-Hong; Wang, Yuanmei

    2016-05-01

    A SIRS epidemic model with feedback mechanism on adaptive scale-free networks is presented. Using the mean field theory the spreading dynamics of the epidemic is studied in detail. The basic reproductive number and equilibriums are derived. Theoretical results indicate that the basic reproductive number is significantly dependent on the topology of the underlying networks. The existence of equilibriums is determined by the basic reproductive number. The global stability of disease-free equilibrium and the epidemic permanence are proved in detail. The feedback mechanism cannot change the basic reproductive number, but it can reduce the endemic level and weaken the epidemic spreading. Numerical simulations confirmed the analytical results.

  9. Mechanisms of Host Receptor Adaptation by Severe Acute Respiratory Syndrome Coronavirus

    SciTech Connect

    Wu, Kailang; Peng, Guiqing; Wilken, Matthew; Geraghty, Robert J.; Li, Fang

    2012-12-10

    The severe acute respiratory syndrome coronavirus (SARS-CoV) from palm civets has twice evolved the capacity to infect humans by gaining binding affinity for human receptor angiotensin-converting enzyme 2 (ACE2). Numerous mutations have been identified in the receptor-binding domain (RBD) of different SARS-CoV strains isolated from humans or civets. Why these mutations were naturally selected or how SARS-CoV evolved to adapt to different host receptors has been poorly understood, presenting evolutionary and epidemic conundrums. In this study, we investigated the impact of these mutations on receptor recognition, an important determinant of SARS-CoV infection and pathogenesis. Using a combination of biochemical, functional, and crystallographic approaches, we elucidated the molecular and structural mechanisms of each of these naturally selected RBD mutations. These mutations either strengthen favorable interactions or reduce unfavorable interactions with two virus-binding hot spots on ACE2, and by doing so, they enhance viral interactions with either human (hACE2) or civet (cACE2) ACE2. Therefore, these mutations were viral adaptations to either hACE2 or cACE2. To corroborate the above analysis, we designed and characterized two optimized RBDs. The human-optimized RBD contains all of the hACE2-adapted residues (Phe-442, Phe-472, Asn-479, Asp-480, and Thr-487) and possesses exceptionally high affinity for hACE2 but relative low affinity for cACE2. The civet-optimized RBD contains all of the cACE2-adapted residues (Tyr-442, Pro-472, Arg-479, Gly-480, and Thr-487) and possesses exceptionally high affinity for cACE2 and also substantial affinity for hACE2. These results not only illustrate the detailed mechanisms of host receptor adaptation by SARS-CoV but also provide a molecular and structural basis for tracking future SARS-CoV evolution in animals.

  10. A Qualitative Analysis of the Coping Strategies of Substitute Teachers

    ERIC Educational Resources Information Center

    Vorell, Matthew S.

    2011-01-01

    This study distinguishes whether substitute teachers enact coping strategies that mitigate the source of work-related stress (problem-centered) or coping strategies that enable them to adapt to stress created by work-related stressors (avoidance-centered). The author gathered data for this analysis by conducting 37 in-depth interviews with…

  11. Control Beliefs, Coping Efforts, and Adjustment to Chronic Pain.

    ERIC Educational Resources Information Center

    Jensen, Mark P.; Karoly, Paul

    1991-01-01

    Examined adaptation to chronic pain in 118 patients. Control appraisals, ignoring pain, using coping self-statements, and increasing activities were positively related to psychological functioning. Control appraisals, diverting attention, ignoring pain, and using coping self-statements were positively related to activity level for patients…

  12. Coping in Dual-Employed Families: Spousal Differences.

    ERIC Educational Resources Information Center

    Skinner, Denise A.; McCubbin, Hamilton I.

    The Dual Employed Coping Scales (DECS) were developed to measure coping behaviors and patterns of dual-employed families. The original DECS (58 self-report items) was administered to a sample of 60 individuals in dual-employed families. In another study, in which 69 dual-employed couples completed the DECS and the Family Adaptability and Cohesion…

  13. Coping Behavior: Implications for Disabled Infants and Toddlers.

    ERIC Educational Resources Information Center

    Williamson, G. Gordon; And Others

    1989-01-01

    This study investigated differences between coping behavior of 25 developmentally disabled and 25 nondisabled children (age 4-34 months) from lower- and middle-income family backgrounds. Assessment of three adaptive-coping behaviors (sensorimotor organization, reactive behavior, and self-initiated behavior) indicated that nondisabled children…

  14. Teacher Stress and Coping Strategies: A National Snapshot

    ERIC Educational Resources Information Center

    Richards, Jan

    2012-01-01

    This national survey of 1,201 kindergarten through Grade-12-U.S. teachers focused on three related areas: (1) sources of teacher stress, (2) manifestations of stress, and (3) suggested coping strategies. The survey instrument was adapted from the Teacher Stress Inventory and the Coping Scale for Adults. Results indicated that teachers nationwide…

  15. Optimism, Social Comparisons, and Coping with Vision Loss in Israel

    ERIC Educational Resources Information Center

    Ben-Zur, Hasida; Debi, Zoharit

    2005-01-01

    This study of 90 adults (aged 55?80) who lost their vision assessed their dispositional optimism, social comparisons, coping strategies, and wellbeing. The findings suggest that optimism and positive social comparisons play an important role in stimulating the motivation to cope adaptively with vision loss and that enhancing optimism and social…

  16. Gene duplication as a mechanism of genomic adaptation to a changing environment

    PubMed Central

    Kondrashov, Fyodor A.

    2012-01-01

    A subject of extensive study in evolutionary theory has been the issue of how neutral, redundant copies can be maintained in the genome for long periods of time. Concurrently, examples of adaptive gene duplications to various environmental conditions in different species have been described. At this point, it is too early to tell whether or not a substantial fraction of gene copies have initially achieved fixation by positive selection for increased dosage. Nevertheless, enough examples have accumulated in the literature that such a possibility should be considered. Here, I review the recent examples of adaptive gene duplications and make an attempt to draw generalizations on what types of genes may be particularly prone to be selected for under certain environmental conditions. The identification of copy-number variation in ecological field studies of species adapting to stressful or novel environmental conditions may improve our understanding of gene duplications as a mechanism of adaptation and its relevance to the long-term persistence of gene duplications. PMID:22977152

  17. The adaptation of the cerebral circulation to pregnancy: mechanisms and consequences

    PubMed Central

    Cipolla, Marilyn J

    2013-01-01

    The adaptation of the cerebral circulation to pregnancy is unique from other vascular beds. Most notably, the growth and vasodilatory response to high levels of circulating growth factors and cytokines that promote substantial hemodynamic changes in other vascular beds is limited in the cerebral circulation. This is accomplished through several mechanisms, including downregulation of key receptors and transcription factors, and production of circulating factors that counteract the vasodilatory effects of vascular endothelial growth factor (VEGF) and placental growth factor. Pregnancy both prevents and reverses hypertensive inward remodeling of cerebral arteries, possibly through downregulation of the angiotensin type 1 receptor. The blood–brain barrier (BBB) importantly adapts to pregnancy by preventing the passage of seizure provoking serum into the brain and limiting the permeability effects of VEGF that is more highly expressed in cerebral vasculature during pregnancy. While the adaptation of the cerebral circulation to pregnancy provides for relatively normal cerebral blood flow and BBB properties in the face of substantial cardiovascular changes and high levels of circulating factors, under pathologic conditions, these adaptations appear to promote greater brain injury, including edema formation during acute hypertension, and greater sensitivity to bacterial endotoxin. PMID:23321787

  18. Effects of potassium and sodium supply on drought-adaptive mechanisms in Eucalyptus grandis plantations.

    PubMed

    Battie-Laclau, Patricia; Laclau, Jean-Paul; Domec, Jean-Christophe; Christina, Mathias; Bouillet, Jean-Pierre; de Cassia Piccolo, Marisa; de Moraes Gonçalves, José Leonardo; e Moreira, Rildo Moreira; Krusche, Alex Vladimir; Bouvet, Jean-Marc; Nouvellon, Yann

    2014-07-01

    A basic understanding of nutrition effects on the mechanisms involved in tree response to drought is essential under a future drier climate. A large-scale throughfall exclusion experiment was set up in Brazil to gain an insight into the effects of potassium (K) and sodium (Na) nutrition on tree structural and physiological adjustments to water deficit. Regardless of the water supply, K and Na supply greatly increased growth and leaf area index (LAI) of Eucalyptus grandis trees over the first 3 yr after planting. Excluding 37% of throughfall reduced above-ground biomass accumulation in the third year after planting for K- supplied trees only. E. grandis trees were scarcely sensitive to drought as a result of the utilization of water stored in deep soil layers after clear-cutting the previous plantation. Trees coped with water restriction through stomatal closure (isohydrodynamic behavior), osmotic adjustment and decrease in LAI. Additionally, droughted trees showed higher phloem sap sugar concentrations. K and Na supply increased maximum stomatal conductance, and the high water requirements of fertilized trees increased water stress during dry periods. Fertilization regimes should be revisited in a future drier climate in order to find the right balance between improving tree growth and limiting water shortage. PMID:24725318

  19. Environmentally-controlled microtensile testing of mechanically-adaptive polymer nanocomposites for ex vivo characterization.

    PubMed

    Hess, Allison E; Potter, Kelsey A; Tyler, Dustin J; Zorman, Christian A; Capadona, Jeffrey R

    2013-08-20

    Implantable microdevices are gaining significant attention for several biomedical applications. Such devices have been made from a range of materials, each offering its own advantages and shortcomings. Most prominently, due to the microscale device dimensions, a high modulus is required to facilitate implantation into living tissue. Conversely, the stiffness of the device should match the surrounding tissue to minimize induced local strain. Therefore, we recently developed a new class of bio-inspired materials to meet these requirements by responding to environmental stimuli with a change in mechanical properties. Specifically, our poly(vinyl acetate)-based nanocomposite (PVAc-NC) displays a reduction in stiffness when exposed to water and elevated temperatures (e.g. body temperature). Unfortunately, few methods exist to quantify the stiffness of materials in vivo, and mechanical testing outside of the physiological environment often requires large samples inappropriate for implantation. Further, stimuli-responsive materials may quickly recover their initial stiffness after explantation. Therefore, we have developed a method by which the mechanical properties of implanted microsamples can be measured ex vivo, with simulated physiological conditions maintained using moisture and temperature control. To this end, a custom microtensile tester was designed to accommodate microscale samples with widely-varying Young's moduli (range of 10 MPa to 5 GPa). As our interests are in the application of PVAc-NC as a biologically-adaptable neural probe substrate, a tool capable of mechanical characterization of samples at the microscale was necessary. This tool was adapted to provide humidity and temperature control, which minimized sample drying and cooling. As a result, the mechanical characteristics of the explanted sample closely reflect those of the sample just prior to explantation. The overall goal of this method is to quantitatively assess the in vivo mechanical

  20. Design of a knee joint mechanism that adapts to individual physiology.

    PubMed

    Jiun-Yih Kuan; Pasch, Kenneth A; Herr, Hugh M

    2014-01-01

    This paper describes the design of a new knee joint mechanism, called the Adaptive Coupling Joint (ACJ). The new mechanism has an adaptive trajectory of the center of rotations (COR) that automatically matches those of the attached biological joint. The detailed design is presented as well as characterization results of the ACJ. Conventional exoskeleton and assistive devices usually consider limb joints as a one to three degrees of freedom (DOFs) joint synthesized by multiple one-DOF hinge joints in a single plane. However, the biological joints are complex and usually rotate with respect to a changing COR. As a result, the mismatch between limb joint motion and mechanical interface motion can lead to forces that cause undesired ligament and muscle length changes and internal mechanical changes. These undesired changes contribute to discomfort, as well as to the slippage and sluggish interaction between humans and devices. It is shown that the ACJ can transmit planetary torques from either active or passive devices to the limbs without altering the normal biological joint motion. PMID:25570389

  1. Design of a knee joint mechanism that adapts to individual physiology.

    PubMed

    Jiun-Yih Kuan; Pasch, Kenneth A; Herr, Hugh M

    2014-01-01

    This paper describes the design of a new knee joint mechanism, called the Adaptive Coupling Joint (ACJ). The new mechanism has an adaptive trajectory of the center of rotations (COR) that automatically matches those of the attached biological joint. The detailed design is presented as well as characterization results of the ACJ. Conventional exoskeleton and assistive devices usually consider limb joints as a one to three degrees of freedom (DOFs) joint synthesized by multiple one-DOF hinge joints in a single plane. However, the biological joints are complex and usually rotate with respect to a changing COR. As a result, the mismatch between limb joint motion and mechanical interface motion can lead to forces that cause undesired ligament and muscle length changes and internal mechanical changes. These undesired changes contribute to discomfort, as well as to the slippage and sluggish interaction between humans and devices. It is shown that the ACJ can transmit planetary torques from either active or passive devices to the limbs without altering the normal biological joint motion.

  2. Tissue mechanics govern the rapidly adapting and symmetrical response to touch.

    PubMed

    Eastwood, Amy L; Sanzeni, Alessandro; Petzold, Bryan C; Park, Sung-Jin; Vergassola, Massimo; Pruitt, Beth L; Goodman, Miriam B

    2015-12-15

    Interactions with the physical world are deeply rooted in our sense of touch and depend on ensembles of somatosensory neurons that invade and innervate the skin. Somatosensory neurons convert the mechanical energy delivered in each touch into excitatory membrane currents carried by mechanoelectrical transduction (MeT) channels. Pacinian corpuscles in mammals and touch receptor neurons (TRNs) in Caenorhabditis elegans nematodes are embedded in distinctive specialized accessory structures, have low thresholds for activation, and adapt rapidly to the application and removal of mechanical loads. Recently, many of the protein partners that form native MeT channels in these and other somatosensory neurons have been identified. However, the biophysical mechanism of symmetric responses to the onset and offset of mechanical stimulation has eluded understanding for decades. Moreover, it is not known whether applied force or the resulting indentation activate MeT channels. Here, we introduce a system for simultaneously recording membrane current, applied force, and the resulting indentation in living C. elegans (Feedback-controlled Application of mechanical Loads Combined with in vivo Neurophysiology, FALCON) and use it, together with modeling, to study these questions. We show that current amplitude increases with indentation, not force, and that fast stimuli evoke larger currents than slower stimuli producing the same or smaller indentation. A model linking body indentation to MeT channel activation through an embedded viscoelastic element reproduces the experimental findings, predicts that the TRNs function as a band-pass mechanical filter, and provides a general mechanism for symmetrical and rapidly adapting MeT channel activation relevant to somatosensory neurons across phyla and submodalities.

  3. Tissue mechanics govern the rapidly adapting and symmetrical response to touch

    PubMed Central

    Eastwood, Amy L.; Sanzeni, Alessandro; Petzold, Bryan C.; Park, Sung-Jin; Vergassola, Massimo; Pruitt, Beth L.

    2015-01-01

    Interactions with the physical world are deeply rooted in our sense of touch and depend on ensembles of somatosensory neurons that invade and innervate the skin. Somatosensory neurons convert the mechanical energy delivered in each touch into excitatory membrane currents carried by mechanoelectrical transduction (MeT) channels. Pacinian corpuscles in mammals and touch receptor neurons (TRNs) in Caenorhabditis elegans nematodes are embedded in distinctive specialized accessory structures, have low thresholds for activation, and adapt rapidly to the application and removal of mechanical loads. Recently, many of the protein partners that form native MeT channels in these and other somatosensory neurons have been identified. However, the biophysical mechanism of symmetric responses to the onset and offset of mechanical stimulation has eluded understanding for decades. Moreover, it is not known whether applied force or the resulting indentation activate MeT channels. Here, we introduce a system for simultaneously recording membrane current, applied force, and the resulting indentation in living C. elegans (Feedback-controlled Application of mechanical Loads Combined with in vivo Neurophysiology, FALCON) and use it, together with modeling, to study these questions. We show that current amplitude increases with indentation, not force, and that fast stimuli evoke larger currents than slower stimuli producing the same or smaller indentation. A model linking body indentation to MeT channel activation through an embedded viscoelastic element reproduces the experimental findings, predicts that the TRNs function as a band-pass mechanical filter, and provides a general mechanism for symmetrical and rapidly adapting MeT channel activation relevant to somatosensory neurons across phyla and submodalities. PMID:26627717

  4. Genomic and transcriptomic analysis of NDM-1 Klebsiella pneumoniae in spaceflight reveal mechanisms underlying environmental adaptability.

    PubMed

    Li, Jia; Liu, Fei; Wang, Qi; Ge, Pupu; Woo, Patrick C Y; Yan, Jinghua; Zhao, Yanlin; Gao, George F; Liu, Cui Hua; Liu, Changting

    2014-01-01

    The emergence and rapid spread of New Delhi Metallo-beta-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae strains has caused a great concern worldwide. To better understand the mechanisms underlying environmental adaptation of those highly drug-resistant K. pneumoniae strains, we took advantage of the China's Shenzhou 10 spacecraft mission to conduct comparative genomic and transcriptomic analysis of a NDM-1 K. pneumoniae strain (ATCC BAA-2146) being cultivated under different conditions. The samples were recovered from semisolid medium placed on the ground (D strain), in simulated space condition (M strain), or in Shenzhou 10 spacecraft (T strain) for analysis. Our data revealed multiple variations underlying pathogen adaptation into different environments in terms of changes in morphology, H2O2 tolerance and biofilm formation ability, genomic stability and regulation of metabolic pathways. Additionally, we found a few non-coding RNAs to be differentially regulated. The results are helpful for better understanding the adaptive mechanisms of drug-resistant bacterial pathogens. PMID:25163721

  5. Genomic and transcriptomic analysis of NDM-1 Klebsiella pneumoniae in spaceflight reveal mechanisms underlying environmental adaptability

    PubMed Central

    Li, Jia; Liu, Fei; Wang, Qi; Ge, Pupu; Woo, Patrick C. Y.; Yan, Jinghua; Zhao, Yanlin; Gao, George F.; Liu, Cui Hua; Liu, Changting

    2014-01-01

    The emergence and rapid spread of New Delhi Metallo-beta-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae strains has caused a great concern worldwide. To better understand the mechanisms underlying environmental adaptation of those highly drug-resistant K. pneumoniae strains, we took advantage of the China's Shenzhou 10 spacecraft mission to conduct comparative genomic and transcriptomic analysis of a NDM-1 K. pneumoniae strain (ATCC BAA-2146) being cultivated under different conditions. The samples were recovered from semisolid medium placed on the ground (D strain), in simulated space condition (M strain), or in Shenzhou 10 spacecraft (T strain) for analysis. Our data revealed multiple variations underlying pathogen adaptation into different environments in terms of changes in morphology, H2O2 tolerance and biofilm formation ability, genomic stability and regulation of metabolic pathways. Additionally, we found a few non-coding RNAs to be differentially regulated. The results are helpful for better understanding the adaptive mechanisms of drug-resistant bacterial pathogens. PMID:25163721

  6. Cultural variation in Africa: role of mechanisms of transmission and adaptation.

    PubMed Central

    Guglielmino, C R; Viganotti, C; Hewlett, B; Cavalli-Sforza, L L

    1995-01-01

    Cultural inheritance can be considered as a mechanism of adaptation made possible by communication, which has reached its greatest development in humans and can allow long-term conservation or rapid change of culturally transmissible traits depending on circumstances and needs. Conservativeness/flexibility is largely modulated by mechanisms of sociocultural transmission. An analysis was carried out by testing the fit of three models to 47 cultural traits (classified in six groups) in 277 African societies. Model A (demic diffusion) is conservation over generations, as shown by correlations of cultural traits with language, used as a measure of historical connection. Model B (environmental adaptation) is measured by correlation to the natural environment. Model C (cultural diffusion) is the spread to neighbors by social contact in an epidemic-like fashion and was tested by measuring the tightness of geographic clustering of the traits. Most traits examined, in particular those affecting family structure and kinship, showed great conservation over generations, as shown by the fit of model A. They are most probably transmitted by family members. This is in agreement with the theoretical demonstration that cultural transmission in the family (vertical) is the most conservative one. Some traits show environmental effects, indicating the importance of adaptation to physical environment. Only a few of the 47 traits showed tight geographic clustering indicating that their spread to nearest neighbors follows model C, as is usually the case for transmission among unrelated people (called horizontal transmission). PMID:11607569

  7. Molecular Adaptation Mechanisms Employed by Ethanologenic Bacteria in Response to Lignocellulose-derived Inhibitory Compounds

    PubMed Central

    Ibraheem, Omodele; Ndimba, Bongani K.

    2013-01-01

    Current international interest in finding alternative sources of energy to the diminishing supplies of fossil fuels has encouraged research efforts in improving biofuel production technologies. In countries which lack sufficient food, the use of sustainable lignocellulosic feedstocks, for the production of bioethanol, is an attractive option. In the pre-treatment of lignocellulosic feedstocks for ethanol production, various chemicals and/or enzymatic processes are employed. These methods generally result in a range of fermentable sugars, which are subjected to microbial fermentation and distillation to produce bioethanol. However, these methods also produce compounds that are inhibitory to the microbial fermentation process. These compounds include products of sugar dehydration and lignin depolymerisation, such as organic acids, derivatised furaldehydes and phenolic acids. These compounds are known to have a severe negative impact on the ethanologenic microorganisms involved in the fermentation process by compromising the integrity of their cell membranes, inhibiting essential enzymes and negatively interact with their DNA/RNA. It is therefore important to understand the molecular mechanisms of these inhibitions, and the mechanisms by which these microorganisms show increased adaptation to such inhibitors. Presented here is a concise overview of the molecular adaptation mechanisms of ethanologenic bacteria in response to lignocellulose-derived inhibitory compounds. These include general stress response and tolerance mechanisms, which are typically those that maintain intracellular pH homeostasis and cell membrane integrity, activation/regulation of global stress responses and inhibitor substrate-specific degradation pathways. We anticipate that understanding these adaptation responses will be essential in the design of 'intelligent' metabolic engineering strategies for the generation of hyper-tolerant fermentation bacteria strains. PMID:23847442

  8. Molecular adaptation mechanisms employed by ethanologenic bacteria in response to lignocellulose-derived inhibitory compounds.

    PubMed

    Ibraheem, Omodele; Ndimba, Bongani K

    2013-01-01

    Current international interest in finding alternative sources of energy to the diminishing supplies of fossil fuels has encouraged research efforts in improving biofuel production technologies. In countries which lack sufficient food, the use of sustainable lignocellulosic feedstocks, for the production of bioethanol, is an attractive option. In the pre-treatment of lignocellulosic feedstocks for ethanol production, various chemicals and/or enzymatic processes are employed. These methods generally result in a range of fermentable sugars, which are subjected to microbial fermentation and distillation to produce bioethanol. However, these methods also produce compounds that are inhibitory to the microbial fermentation process. These compounds include products of sugar dehydration and lignin depolymerisation, such as organic acids, derivatised furaldehydes and phenolic acids. These compounds are known to have a severe negative impact on the ethanologenic microorganisms involved in the fermentation process by compromising the integrity of their cell membranes, inhibiting essential enzymes and negatively interact with their DNA/RNA. It is therefore important to understand the molecular mechanisms of these inhibitions, and the mechanisms by which these microorganisms show increased adaptation to such inhibitors. Presented here is a concise overview of the molecular adaptation mechanisms of ethanologenic bacteria in response to lignocellulose-derived inhibitory compounds. These include general stress response and tolerance mechanisms, which are typically those that maintain intracellular pH homeostasis and cell membrane integrity, activation/regulation of global stress responses and inhibitor substrate-specific degradation pathways. We anticipate that understanding these adaptation responses will be essential in the design of 'intelligent' metabolic engineering strategies for the generation of hyper-tolerant fermentation bacteria strains. PMID:23847442

  9. L-ALLIANCE: a mechanism for adaptive action selection in heterogeneous multi-robot teams

    SciTech Connect

    Parker, L.E.

    1995-11-01

    In practical applications of robotics, it is usually quite difficult, if not impossible, for the system designer to fully predict the environmental states in which the robots will operate. The complexity of the problem is further increased when dealing with teams of robots which themselves may be incompletely known and characterized in advance. It is thus highly desirable for robot teams to be able to adapt their performance during the mission due to changes in the environment, or to changes in other robot team members. In previous work, we introduced a behavior-based mechanism called the ALLIANCE architecture -- that facilitates the fault tolerant cooperative control of multi-robot teams. However, this previous work did not address the issue of how to dynamically update the control parameters during a mission to adapt to ongoing changes in the environment or in the robot team, and to ensure the efficiency of the collective team actions. In this paper, we address this issue by proposing the L-ALLIANCE mechanism, which defines an automated method whereby robots can use knowledge learned from previous experience to continually improve their collective action selection when working on missions composed of loosely coupled, discrete subtasks. This ability to dynamically update robotic control parameters provides a number of distinct advantages: it alleviates the need for human tuning of control parameters, it facilitates the use of custom-designed multi-robot teams for any given application, it improves the efficiency of the mission performance, and It allows robots to continually adapt their performance over time due to changes in the robot team and/or the environment. We describe the L-ALLIANCE mechanism, present the results of various alternative update strategies we investigated, present the formal model of the L-ALLIANCE mechanism, and present the results of a simple proof of concept implementation on a small team of heterogeneous mobile robots.

  10. Farmer Health and Adaptive Capacity in the Face of Climate Change and Variability. Part 1: Health as a Contributor to Adaptive Capacity and as an Outcome from Pressures Coping with Climate Related Adversities

    PubMed Central

    Berry, Helen L.; Hogan, Anthony; Ng, Suan Peng; Parkinson, Anne

    2011-01-01

    This paper examines the role farmers’ health plays as an element of adaptive capacity. The study examines which of twenty aspects of adaptation may be related to overall health outcomes, controlling for demographic and on-farm-factors in health problems. The analysis is based on 3,993 farmers’ responses to a national survey of climate risk and adaptation. Hierarchical linear regression modelling was used examine the extent to which, in a multivariate analysis, the use of adaptive practices was predictively associated with self-assessed health, taking into account the farmer’s rating of whether their health was a barrier to undertaking farm work. We present two models, one excluding pre-existing health (model 1) and one including pre-existing health (model 2). The first model accounted for 21% of the variance. In this model better health was most strongly predicted by an absence of on-farm risk, greater financial viability, greater debt pressures, younger age and a desire to continue farming. Social capital (trust and reciprocity) was moderately associated with health as was the intention to adopt more sustainable practices. The second model (including the farmers’ health as a barrier to undertaking farm work) accounted for 43% of the variance. Better health outcomes were most strongly explained, in order of magnitude, by the absence of pre-existing health problems, greater access to social support, greater financial viability, greater debt pressures, a desire to continue farming and the condition of on-farm resources. Model 2 was a more parsimonious model (only nine predictors, compared with 15 in model 1), and explained twice as much variance in health outcomes. These results suggest that (i) pre-existing health problems are a very important factor to consider when designing adaptation programs and policies and (ii) these problems may mediate or modify the relationship between adaptation and health. PMID:22073027

  11. Farmer health and adaptive capacity in the face of climate change and variability. Part 1: Health as a contributor to adaptive capacity and as an outcome from pressures coping with climate related adversities.

    PubMed

    Berry, Helen L; Hogan, Anthony; Ng, Suan Peng; Parkinson, Anne

    2011-10-01

    This paper examines the role farmers' health plays as an element of adaptive capacity. The study examines which of twenty aspects of adaptation may be related to overall health outcomes, controlling for demographic and on-farm-factors in health problems. The analysis is based on 3,993 farmers' responses to a national survey of climate risk and adaptation. Hierarchical linear regression modelling was used examine the extent to which, in a multivariate analysis, the use of adaptive practices was predictively associated with self-assessed health, taking into account the farmer's rating of whether their health was a barrier to undertaking farm work. We present two models, one excluding pre-existing health (model 1) and one including pre-existing health (model 2). The first model accounted for 21% of the variance. In this model better health was most strongly predicted by an absence of on-farm risk, greater financial viability, greater debt pressures, younger age and a desire to continue farming. Social capital (trust and reciprocity) was moderately associated with health as was the intention to adopt more sustainable practices. The second model (including the farmers' health as a barrier to undertaking farm work) accounted for 43% of the variance. Better health outcomes were most strongly explained, in order of magnitude, by the absence of pre-existing health problems, greater access to social support, greater financial viability, greater debt pressures, a desire to continue farming and the condition of on-farm resources. Model 2 was a more parsimonious model (only nine predictors, compared with 15 in model 1), and explained twice as much variance in health outcomes. These results suggest that (i) pre-existing health problems are a very important factor to consider when designing adaptation programs and policies and (ii) these problems may mediate or modify the relationship between adaptation and health.

  12. COMET-AR User's Manual: COmputational MEchanics Testbed with Adaptive Refinement

    NASA Technical Reports Server (NTRS)

    Moas, E. (Editor)

    1997-01-01

    The COMET-AR User's Manual provides a reference manual for the Computational Structural Mechanics Testbed with Adaptive Refinement (COMET-AR), a software system developed jointly by Lockheed Palo Alto Research Laboratory and NASA Langley Research Center under contract NAS1-18444. The COMET-AR system is an extended version of an earlier finite element based structural analysis system called COMET, also developed by Lockheed and NASA. The primary extensions are the adaptive mesh refinement capabilities and a new "object-like" database interface that makes COMET-AR easier to extend further. This User's Manual provides a detailed description of the user interface to COMET-AR from the viewpoint of a structural analyst.

  13. Behavioral and neural Darwinism: selectionist function and mechanism in adaptive behavior dynamics.

    PubMed

    McDowell, J J

    2010-05-01

    An evolutionary theory of behavior dynamics and a theory of neuronal group selection share a common selectionist framework. The theory of behavior dynamics instantiates abstractly the idea that behavior is selected by its consequences. It implements Darwinian principles of selection, reproduction, and mutation to generate adaptive behavior in virtual organisms. The behavior generated by the theory has been shown to be quantitatively indistinguishable from that of live organisms. The theory of neuronal group selection suggests a mechanism whereby the abstract principles of the evolutionary theory may be implemented in the nervous systems of biological organisms. According to this theory, groups of neurons subserving behavior may be selected by synaptic modifications that occur when the consequences of behavior activate value systems in the brain. Together, these theories constitute a framework for a comprehensive account of adaptive behavior that extends from brain function to the behavior of whole organisms in quantitative detail.

  14. Lessons in Fundamental Mechanisms and Diverse Adaptations from the 2015 Bacterial Locomotion and Signal Transduction Meeting

    PubMed Central

    Prüβ, Birgit M.; Liu, Jun; Higgs, Penelope I.

    2015-01-01

    In response to rapid changes in their environment, bacteria control a number of processes, including motility, cell division, biofilm formation, and virulence. Research presented in January 2015 at the biennial Bacterial Locomotion and Signal Transduction (BLAST) meeting in Tucson, AZ, illustrates the elegant complexity of the nanoarrays, nanomachines, and networks of interacting proteins that mediate such processes. Studies employing an array of biophysical, genetic, cell biology, and mathematical methods are providing an increasingly detailed understanding of the mechanisms of these systems within well-studied bacteria. Furthermore, comparisons of these processes in diverse bacterial species are providing insight into novel regulatory and functional mechanisms. This review summarizes research presented at the BLAST meeting on these fundamental mechanisms and diverse adaptations, including findings of importance for applications involving bacteria of medical or agricultural relevance. PMID:26195592

  15. Fine-scale temporal adaptation within a salmonid population: mechanism and consequences.

    PubMed

    Gharrett, Anthony J; Joyce, John; Smoker, William W

    2013-09-01

    We demonstrate a clear example of local adaptation of seasonal timing of spawning and embryo development. The consequence is a population of pink salmon that is segmented into spawning groups that use the same limited habitat. We synthesize published observations with results of new analyses to demonstrate that genetic variation of these traits results in survival differentials related to that variation, and that density-dependent embryo mortality and seasonally variable juvenile mortality are a mechanism of selection. Most examples of local adaptation in natural systems depend on observed correlations between environments and fitness traits, but do not fully demonstrate local adaptation: that the trait is genetically determined, exhibits different fitness in common environments or across different environments, and its variation is mechanistically connected to fitness differences. The geographic or temporal scales of local adaptation often remain obscure. Here, we show that heritable, fine-scale differences of timing of reproductive migration in a pink salmon (Oncorhynchus gorbuscha) resulted in temporal structure that persisted several generations; the differences enable a density-dependent population to pack more spawners into limited spawning habitat, that is, enhance its fitness. A balanced trade-off of survivals results because embryos from early-migrating fish have a lower freshwater survival (harsh early physical conditions and disturbance by late spawners), but emigrant fry from late-migrating fish have lower marine survivals (timing of their vernal emergence into the estuarine environment). Such fine-scale local adaptations increase the genetic portfolio of the populations and may provide a buffer against the impacts of climate change.

  16. Personality, life events and coping in the oldest-old.

    PubMed

    Martin, P; Poon, L W; Clayton, G M; Lee, H S; Fulks, J S; Johnson, M A

    1992-01-01

    This paper compares older adults in their sixties, eighties, and 100s on personality, experience of life events, and coping. A secondary goal was to test a structural model of adaptation. Participants (165) filled out a personality inventory, life-event lists, and coping and mental health measures. Results revealed differences in personality: centenarians scored higher on dominance, suspiciousness, and imagination. While centenarians scored lower on active behavioral coping than other age groups, they used cognitive strategies when coping with health and family events. Results from the structural equation model indicated that extraversion and anxiety predicted morale and mental health.

  17. The Interplay Between Strategic And Adaptive Control Mechanisms In Plastic Recalibration Of Locomotor Function

    NASA Technical Reports Server (NTRS)

    Richards, J. T.; Mulavara, A. P.; Bloomberg, J. J.

    2006-01-01

    We have previously shown that viewing simulated rotary self-motion during treadmill locomotion causes immediate strategic modifications (Richards et al. 2004) as well as an after effect reflecting adaptive modification of the control of position and trajectory during over-ground locomotion (Mulavara et al. 2005). The process of sensorimotor adaptation is comprised of both strategic and adaptive control mechanisms. Strategic control involves cognitive, on-line corrections to limb movements once one is aware of a sensory discordance. Over an extended period of exposure to the sensory discordance, new strategic sensorimotor coordination patterns are reinforced until they become more automatic, and therefore adaptive, in nature. The objective of this study was to investigate how strategic changes in trunk control during exposure to simulated rotary self-motion during treadmill walking influences adaptive modification of locomotor heading direction during over-ground stepping. Subjects (n = 10) walked on a motorized linear treadmill while viewing a wide field-of-view virtual scene for 24 minutes. The scene was static for the first 4 minutes and then, for the last 20 minutes, depicted constant rate self-motion equivalent to walking in a counter-clockwise, circular path around the perimeter of a room. Subjects performed five stepping trials both before and after the exposure period to assess after effects. Results from our previous study showed a significant change in heading direction (HD) during post-exposure step tests that was opposite the direction in which the scene rotated during the adaptation period. For the present study, we quantified strategic modifications in trunk movement control during scene exposure using normalized root mean square (R(sub p)) variation of the subject's 3D trunk positions and normalized sum of standard deviations (R(sub o)) variation of 3D trunk orientations during scene rotation relative to that during static scene presentation

  18. Multiple symbiont acquisition strategies as an adaptive mechanism in the coral Stylophora pistillata.

    PubMed

    Byler, Kristen A; Carmi-Veal, Maya; Fine, Maoz; Goulet, Tamar L

    2013-01-01

    In obligate symbioses, the host's survival relies on the successful acquisition and maintenance of symbionts. Symbionts can either be transferred from parent to offspring via direct inheritance (vertical transmission) or acquired anew each generation from the environment (horizontal transmission). With vertical symbiont transmission, progeny benefit by not having to search for their obligate symbionts, and, with symbiont inheritance, a mechanism exists for perpetuating advantageous symbionts. But, if the progeny encounter an environment that differs from that of their parent, they may be disadvantaged if the inherited symbionts prove suboptimal. Conversely, while in horizontal symbiont acquisition host survival hinges on an unpredictable symbiont source, an individual host may acquire genetically diverse symbionts well suited to any given environment. In horizontal acquisition, however, a potentially advantageous symbiont will not be transmitted to subsequent generations. Adaptation in obligate symbioses may require mechanisms for both novel symbiont acquisition and symbiont inheritance. Using denaturing-gradient gel electrophoresis and real-time PCR, we identified the dinoflagellate symbionts (genus Symbiodinium) hosted by the Red Sea coral Stylophora pistillata throughout its ontogenesis and over depth. We present evidence that S. pistillata juvenile colonies may utilize both vertical and horizontal symbiont acquisition strategies. By releasing progeny with maternally derived symbionts, that are also capable of subsequent horizontal symbiont acquisition, coral colonies may acquire physiologically advantageous novel symbionts that are then perpetuated via vertical transmission to subsequent generations. With symbiont inheritance, natural selection can act upon the symbiotic variability, providing a mechanism for coral adaptation.

  19. The estimated mechanical advantage of the prosimian ankle joint musculature, and implications for locomotor adaptation.

    PubMed

    Goto, Ryosuke; Kumakura, Hiroo

    2013-05-01

    In this study we compared the power arm lengths and mechanical advantages attributed to 12 lower leg muscles across three prosimian species. The origins and insertions of the lower leg muscles in Garnett's galago, the ring-tailed lemur, and the slow loris were quantified and correlated with positional behaviour. The ankle joint of the galago has a speed-oriented mechanical system, in contrast to that of the slow loris, which exhibits more power-oriented mechanics. The lemur ankle joint exhibited intermediate power arm lengths and an intermediate mechanical advantage relative to the other primates. This result suggests that the mechanical differences in the ankle between the galago and the lemur, taxa that exhibit similar locomotory repertoires, reflect a difference in the kinematics and kinetics of leaping (i.e. generalised vs. specialised leapers). In contrast to leaping primates, lorises have developed a more power-oriented mechanical system as a foot adaptation for positional behaviours such as bridging or cantilevering in their arboreal habitat. PMID:23489408

  20. The estimated mechanical advantage of the prosimian ankle joint musculature, and implications for locomotor adaptation.

    PubMed

    Goto, Ryosuke; Kumakura, Hiroo

    2013-05-01

    In this study we compared the power arm lengths and mechanical advantages attributed to 12 lower leg muscles across three prosimian species. The origins and insertions of the lower leg muscles in Garnett's galago, the ring-tailed lemur, and the slow loris were quantified and correlated with positional behaviour. The ankle joint of the galago has a speed-oriented mechanical system, in contrast to that of the slow loris, which exhibits more power-oriented mechanics. The lemur ankle joint exhibited intermediate power arm lengths and an intermediate mechanical advantage relative to the other primates. This result suggests that the mechanical differences in the ankle between the galago and the lemur, taxa that exhibit similar locomotory repertoires, reflect a difference in the kinematics and kinetics of leaping (i.e. generalised vs. specialised leapers). In contrast to leaping primates, lorises have developed a more power-oriented mechanical system as a foot adaptation for positional behaviours such as bridging or cantilevering in their arboreal habitat.

  1. Mechanisms of Regulation of Olfactory Transduction and Adaptation in the Olfactory Cilium

    PubMed Central

    Antunes, Gabriela; Sebastião, Ana Maria; Simoes de Souza, Fabio Marques

    2014-01-01

    Olfactory adaptation is a fundamental process for the functioning of the olfactory system, but the underlying mechanisms regulating its occurrence in intact olfactory sensory neurons (OSNs) are not fully understood. In this work, we have combined stochastic computational modeling and a systematic pharmacological study of different signaling pathways to investigate their impact during short-term adaptation (STA). We used odorant stimulation and electroolfactogram (EOG) recordings of the olfactory epithelium treated with pharmacological blockers to study the molecular mechanisms regulating the occurrence of adaptation in OSNs. EOG responses to paired-pulses of odorants showed that inhibition of phosphodiesterases (PDEs) and phosphatases enhanced the levels of STA in the olfactory epithelium, and this effect was mimicked by blocking vesicle exocytosis and reduced by blocking cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) and vesicle endocytosis. These results suggest that G-coupled receptors (GPCRs) cycling is involved with the occurrence of STA. To gain insights on the dynamical aspects of this process, we developed a stochastic computational model. The model consists of the olfactory transduction currents mediated by the cyclic nucleotide gated (CNG) channels and calcium ion (Ca2+)-activated chloride (CAC) channels, and the dynamics of their respective ligands, cAMP and Ca2+, and it simulates the EOG results obtained under different experimental conditions through changes in the amplitude and duration of cAMP and Ca2+ response, two second messengers implicated with STA occurrence. The model reproduced the experimental data for each pharmacological treatment and provided a mechanistic explanation for the action of GPCR cycling in the levels of second messengers modulating the levels of STA. All together, these experimental and theoretical results indicate the existence of a mechanism of regulation of STA by signaling pathways that control GPCR

  2. The Contribution of Experimental in vivo Models to Understanding the Mechanisms of Adaptation to Mechanical Loading in Bone

    PubMed Central

    Meakin, Lee B.; Price, Joanna S.; Lanyon, Lance E.

    2014-01-01

    Changing loading regimens by natural means such as exercise, with or without interference such as osteotomy, has provided useful information on the structure:function relationship in bone tissue. However, the greatest precision in defining those aspects of the overall strain environment that influence modeling and remodeling behavior has been achieved by relating quantified changes in bone architecture to quantified changes in bones’ strain environment produced by direct, controlled artificial bone loading. Jiri Hert introduced the technique of artificial loading of bones in vivo with external devices in the 1960s using an electromechanical device to load rabbit tibiae through transfixing stainless steel pins. Quantifying natural bone strains during locomotion by attaching electrical resistance strain gages to bone surfaces was introduced by Lanyon, also in the 1960s. These studies in a variety of bones in a number of species demonstrated remarkable uniformity in the peak strains and maximum strain rates experienced. Experiments combining strain gage instrumentation with artificial loading in sheep, pigs, roosters, turkeys, rats, and mice has yielded significant insight into the control of strain-related adaptive (re)modeling. This diversity of approach has been largely superseded by non-invasive transcutaneous loading in rats and mice, which is now the model of choice for many studies. Together such studies have demonstrated that over the physiological strain range, bone’s mechanically adaptive processes are responsive to dynamic but not static strains; the size and nature of the adaptive response controlling bone mass is linearly related to the peak loads encountered; the strain-related response is preferentially sensitive to high strain rates and unresponsive to static ones; is most responsive to unusual strain distributions; is maximized by remarkably few strain cycles, and that these are most effective when interrupted by short periods of rest between them

  3. Psychotic symptoms, functioning and coping in adolescents with mental illness

    PubMed Central

    2014-01-01

    Background Psychotic symptoms in the context of psychiatric disorders are associated with poor functional outcomes. Environmental stressors are important in the development of psychosis; however, distress may only be pathogenic when it exceeds an individual’s ability to cope with it. Therefore, one interesting factor regarding poor functional outcomes in patients with psychotic symptoms may be poor coping. This paper aimed to address the question whether 1) psychotic symptoms are associated with poorer functioning and 2) whether poor coping moderated the association. Methods In a clinical case-clinical control study of 106 newly-referred adolescent patients with non-psychotic psychiatric disorders, coping was investigated using the Adolescents Coping Scale. Severity of impairment in socio-occupational functioning was assessed with the Children’s Global Assessment Scale. Results Patients with non-psychotic psychiatric disorders and additional psychotic symptoms (N = 50) had poorer functioning and were more likely to use avoidance-oriented coping compared to patients with non-psychotic psychiatric disorders without psychotic symptoms (N = 56). No differences were found with respect to approach-oriented coping. When stratifying for poor/good coping, only those adolescent patients with psychotic symptoms who applied poor coping (i.e. less use of approach-oriented coping styles [OR 0.24, p < 0.015] and more use of avoidance-oriented coping [OR 0.23, p < 0.034]) had poorer functioning. However, these interactions were not significant. Conclusions Non-adaptive coping and poorer functioning were more often present in adolescents with non-psychotic psychiatric disorders and additional psychotic symptoms. Due to small subgroups, our analyses could not give definitive conclusions about the question whether coping moderated the association between psychotic symptoms and functioning. Improvement of coping skills may form an important target for intervention

  4. Hybrid numerical method with adaptive overlapping meshes for solving nonstationary problems in continuum mechanics

    NASA Astrophysics Data System (ADS)

    Burago, N. G.; Nikitin, I. S.; Yakushev, V. L.

    2016-06-01

    Techniques that improve the accuracy of numerical solutions and reduce their computational costs are discussed as applied to continuum mechanics problems with complex time-varying geometry. The approach combines shock-capturing computations with the following methods: (1) overlapping meshes for specifying complex geometry; (2) elastic arbitrarily moving adaptive meshes for minimizing the approximation errors near shock waves, boundary layers, contact discontinuities, and moving boundaries; (3) matrix-free implementation of efficient iterative and explicit-implicit finite element schemes; (4) balancing viscosity (version of the stabilized Petrov-Galerkin method); (5) exponential adjustment of physical viscosity coefficients; and (6) stepwise correction of solutions for providing their monotonicity and conservativeness.

  5. Coping Strategy Use, Personality, and Adjustment of Parents Rearing Children with Developmental Disabilities

    ERIC Educational Resources Information Center

    Glidden, L. M.; Natcher, A. L.

    2009-01-01

    Background: Parents rearing children with developmental disabilities encounter stressors that require coping and adaptation. In Glidden et al. 2006, the use of problem-focused coping strategies was more often associated with positive adjustment outcomes than was the use of emotion-focused coping strategies, and parental personality was shown to…

  6. The Impact of Childhood Cancer: A Two-Factor Model of Coping.

    ERIC Educational Resources Information Center

    Zevon, Michael A.; Armstrong, Gordon D.

    A review of existing stress and coping models and an analysis of the distress caused by childhood cancer suggest that a broader conceptualization of coping that includes "pleasure management" is needed. Presently, successful coping is identified as the employment of strategies which allow the individual to adapt to stress. Traditional stress…

  7. Matrix Metalloproteinases in a Sea Urchin Ligament with Adaptable Mechanical Properties

    PubMed Central

    Ribeiro, Ana R.; Barbaglio, Alice; Oliveira, Maria J.; Ribeiro, Cristina C.; Wilkie, Iain C.; Candia Carnevali, Maria D.; Barbosa, Mário A.

    2012-01-01

    Mutable collagenous tissues (MCTs) of echinoderms show reversible changes in tensile properties (mutability) that are initiated and modulated by the nervous system via the activities of cells known as juxtaligamental cells. The molecular mechanism underpinning this mechanical adaptability has still to be elucidated. Adaptable connective tissues are also present in mammals, most notably in the uterine cervix, in which changes in stiffness result partly from changes in the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). There have been no attempts to assess the potential involvement of MMPs in the echinoderm mutability phenomenon, apart from studies dealing with a process whose relationship to the latter is uncertain. In this investigation we used the compass depressor ligaments (CDLs) of the sea-urchin Paracentrotus lividus. The effect of a synthetic MMP inhibitor - galardin - on the biomechanical properties of CDLs in different mechanical states (“standard”, “compliant” and “stiff”) was evaluated by dynamic mechanical analysis, and the presence of MMPs in normal and galardin-treated CDLs was determined semi-quantitatively by gelatin zymography. Galardin reversibly increased the stiffness and storage modulus of CDLs in all three states, although its effect was significantly lower in stiff than in standard or compliant CDLs. Gelatin zymography revealed a progressive increase in total gelatinolytic activity between the compliant, standard and stiff states, which was possibly due primarily to higher molecular weight components resulting from the inhibition and degradation of MMPs. Galardin caused no change in the gelatinolytic activity of stiff CDLs, a pronounced and statistically significant reduction in that of standard CDLs, and a pronounced, but not statistically significant, reduction in that of compliant CDLs. Our results provide evidence that MMPs may contribute to the variable tensility of the

  8. Stress, sex and neural adaptation to a changing environment: mechanisms of neuronal remodeling

    PubMed Central

    McEwen, Bruce S.

    2010-01-01

    The adult brain is much more resilient and adaptable than previously believed, and adaptive structural plasticity involves growth and shrinkage of dendritic trees, turnover of synapses and limited amounts of neurogenesis in the forebrain, especially the dentate gyrus of the hippocampal formation. Stress and sex hormones help to mediate adaptive structural plasticity, which has been extensively investigated in hippocampus and to a lesser extent in prefrontal cortex and amygdala, all brain regions that are involved in cognitive and emotional functions. Stress and sex hormones exert their effects on brain structural remodeling through both classical genomic as well as non-genomic mechanisms, and they do so in collaboration with neurotransmitters and other intra- and extracellular mediators. This review will illustrate the actions of estrogen on synapse formation in the hippocampus and the process of stress-induced remodelling of dendrites and synapses in the hippocampus, amygdala and prefrontal cortex. The influence of early developmental epigenetic events, such as early life stress and brain sexual differentiation, is noted along with the interactions between sex hormones and the effects of stress on the brain. Because hormones influence brain structure and function and because hormone secretion is governed by the brain, applied molecular neuroscience techniques can begin to reveal the role of hormones in brain-related disorders and the treatment of these diseases. A better understanding of hormone-brain interactions should promote more flexible approaches to the treatment of psychiatric disorders, as well as their prevention through both behavioral and pharmaceutical interventions. PMID:20840167

  9. Integrated approach for studying adaptation mechanisms in the human somatosensory cortical network.

    PubMed

    Venkatesan, Lalit; Barlow, Steven M; Popescu, Mihai; Popescu, Anda

    2014-11-01

    Magnetoencephalography and independent component analysis (ICA) was utilized to study and characterize neural adaptation in the somatosensory cortical network. Repetitive punctate tactile stimuli were applied unilaterally to the dominant hand and face using a custom-built pneumatic stimulator called the TAC-Cell. ICA-based source estimation from the evoked neuromagnetic responses indicated cortical activity in the contralateral primary somatosensory cortex (SI) for face stimulation, while hand stimulation resulted in robust contralateral SI and posterior parietal cortex (PPC) activation. Activity was also observed in the secondary somatosensory cortical area (SII) with reduced amplitude and higher variability across subjects. There was a significant difference in adaptation rate between SI and higher-order somatosensory cortices for hand stimulation. Adaptation was significantly dependent on stimulus frequency and pulse index within the stimulus train for both hand and face stimulation. The peak latency of the activity was significantly dependent on stimulation site (hand vs. face) and cortical area (SI vs. PPC). The difference in the peak latency of activity in SI and PPC is presumed to reflect a hierarchical serial-processing mechanism in the somatosensory cortex.

  10. Adaptive Transgenerational Plasticity in Plants: Case Studies, Mechanisms, and Implications for Natural Populations

    PubMed Central

    Herman, Jacob J.; Sultan, Sonia E.

    2011-01-01

    Plants respond to environmental conditions not only by plastic changes to their own development and physiology, but also by altering the phenotypes expressed by their offspring. This transgenerational plasticity was initially considered to entail only negative effects of stressful parental environments, such as production of smaller seeds by resource- or temperature-stressed parent plants, and was therefore viewed as environmental noise. Recent evolutionary ecology studies have shown that in some cases, these inherited environmental effects can include specific growth adjustments that are functionally adaptive to the parental conditions that induced them, which can range from contrasting states of controlled laboratory environments to the complex habitat variation encountered by natural plant populations. Preliminary findings suggest that adaptive transgenerational effects can be transmitted by means of diverse mechanisms including changes to seed provisioning and biochemistry, and epigenetic modifications such as DNA methylation that can persist across multiple generations. These non-genetically inherited adaptations can influence the ecological breadth and evolutionary dynamics of plant taxa and promote the spread of invasive plants. Interdisciplinary studies that join mechanistic and evolutionary ecology approaches will be an important source of future insights. PMID:22639624

  11. The Depression Coping Questionnaire.

    ERIC Educational Resources Information Center

    Kleinke, Chris L.

    College students (N=396), chronic pain patients (N=319), and schizophrenic veterans (N=43) completed the Depression Coping Questionnaire (DCQ) and the Beck Depression Inventory (BDI). Factor analysis of the DCQ identified eleven coping responses: social support, problem solving, self-blame/escape, aggression, indulgence, activities, medication,…

  12. Women's experiences of coping with pregnancy termination for fetal abnormality.

    PubMed

    Lafarge, Caroline; Mitchell, Kathryn; Fox, Pauline

    2013-07-01

    Pregnancy termination for fetal abnormality (TFA) can have significant psychological consequences. Most previous research has been focused on measuring the psychological outcomes of TFA, and little is known about the coping strategies involved. In this article, we report on women's coping strategies used during and after the procedure. Our account is based on experiences of 27 women who completed an online survey. We analyzed the data using interpretative phenomenological analysis. Coping comprised four structures, consistent across time points: support, acceptance, avoidance, and meaning attribution. Women mostly used adaptive coping strategies but reported inadequacies in aftercare, which challenged their resources. The study's findings indicate the need to provide sensitive, nondirective care rooted in the acknowledgment of the unique nature of TFA. Enabling women to reciprocate for emotional support, promoting adaptive coping strategies, highlighting the potential value of spending time with the baby, and providing long-term support (including during subsequent pregnancies) might promote psychological adjustment to TFA.

  13. Evidence for a common motion mechanism of luminance-modulated and contrast-modulated patterns: selective adaptation.

    PubMed

    Turano, K

    1991-01-01

    Selective adaptation effects were measured with contrast-modulated patterns and sine-wave gratings in order to determine the extent to which the two patterns are processed by common mechanisms. Direction-specific adaptation effects were measured for a contrast-modulated adapting pattern and a test pattern. The contrast-modulated adapting pattern was composed of a sine-wave grating of 8 cycles deg-1 whose contrast was spatially modulated by a sinusoid of 1 cycle deg-1 at one of four levels: 100%, 60%, 30%, or 0%. The results showed that contrast-modulation thresholds for contrast-modulated gratings were raised by 0.3 to 0.5 log units following adaptation to a contrast-modulated grating moving in the same direction as the test pattern, relative to thresholds obtained following adaptation to a contrast-modulated grafting moving in the opposite direction. Cross-adaptation effects were also measured with a sine-wave adapting pattern and a contrast-modulated test pattern. The sine-wave adapting pattern was a sine-wave grating of 1 cycle deg-1 whose contrast was set to one of three levels: 16.4%, 1.25%, or 0%. The contrast-modulated test pattern was a sine-wave grating of 8 cycles deg-1 whose contrast was modulated by a sinusoid of 1 cycle deg-1. The results revealed that contrast-modulation thresholds for contrast-modulated gratings were raised by approximately 0.25 log units following adaptation to moving sine-wave gratings, relative to thresholds obtained following adaptation to a uniform field. Cross-adaptation effects were also obtained with a contrast-modulated adapting pattern and a sine-wave test pattern. The results support the view that signals generated from luminance-domain stimuli and from contrast-domain stimuli are processed by a common motion mechanism.

  14. Adaptations for economical bipedal running: the effect of limb structure on three-dimensional joint mechanics.

    PubMed

    Rubenson, Jonas; Lloyd, David G; Heliams, Denham B; Besier, Thor F; Fournier, Paul A

    2011-05-01

    The purpose of this study was to examine the mechanical adaptations linked to economical locomotion in cursorial bipeds. We addressed this question by comparing mass-matched humans and avian bipeds (ostriches), which exhibit marked differences in limb structure and running economy. We hypothesized that the nearly 50 per cent lower energy cost of running in ostriches is a result of: (i) lower limb-swing mechanical power, (ii) greater stance-phase storage and release of elastic energy, and (iii) lower total muscle power output. To test these hypotheses, we used three-dimensional joint mechanical measurements and a simple model to estimate the elastic and muscle contributions to joint work and power. Contradictory to our first hypothesis, we found that ostriches and humans generate the same amounts of mechanical power to swing the limbs at a similar self-selected running speed, indicating that limb swing probably does not contribute to the difference in energy cost of running between these species. In contrast, we estimated that ostriches generate 120 per cent more stance-phase mechanical joint power via release of elastic energy compared with humans. This elastic mechanical power occurs nearly exclusively at the tarsometatarso-phalangeal joint, demonstrating a shift of mechanical power generation to distal joints compared with humans. We also estimated that positive muscle fibre power is 35 per cent lower in ostriches compared with humans, and is accounted for primarily by higher capacity for storage and release of elastic energy. Furthermore, our analysis revealed much larger frontal and internal/external rotation joint loads during ostrich running than in humans. Together, these findings support the hypothesis that a primary limb structure specialization linked to economical running in cursorial species is an elevated storage and release of elastic energy in tendon. In the ostrich, energy-saving specializations may also include passive frontal and internal

  15. Investigating coping strategies and social support among Canadian melanoma patients: A survey approach.

    PubMed

    Kalbfleisch, Melanie; Cyr, Annette; Gregorio, Nancy; Nyhof-Young, Joyce

    2015-01-01

    Complex support needs are involved in coping with a diagnosis of melanoma. The purpose of this study was to determine the perceived social support levels and utilization of adaptive and maladaptive coping strategies by Canadian melanoma patients. The impact of social support level on coping strategy utilization was also examined. Social support and coping strategies were assessed using the Medical Outcomes Study Social Support Survey (MOS-SSS) and the 28-item Brief COPE, respectively. Perceived levels of emotional/informational support were significantly lower than affectionate support and positive social interaction. Acceptance, active coping, and use of emotional support were the most frequently utilized coping strategies. Patients with higher perceived levels of social support had significantly higher adaptive coping scores than patients with lower levels of social support. Health care professionals have an important role in promoting awareness of and access to emotional and informational support resources in order to improve perceived social support levels. PMID:26642495

  16. Endurance athletes' coping function use during competitive suffering episodes.

    PubMed

    Evans, Michael Blair; Hoar, Sharleen D; Gebotys, Robert J; Marchesin, Courtney A

    2014-01-01

    Endurance athletes who realise that they are falling short of important personal goals during competition are expected to experience competitive suffering. As a negative affective state with implications for performance and personal experiences, it is important to understand how endurance athletes cope with competitive suffering. Thus, the purpose of this study was to investigate differences in athletes' momentary coping function use over time during a competitive suffering episode. Twenty-six runners (mean age: 35.8 years) completed a 5-km running time trial that evoked an experience of competitive suffering using false failure-oriented feedback. Momentary assessments of goal attainment feelings and coping function use were completed immediately following the running time trial using video-mediated recall. Pooled time series analysis was used to predict coping function use across several points in time (i.e. earlier and later stages of a competitive suffering episode) and at different ratings of goal attainment feelings. Analyses revealed that negative feelings about goal attainment moderately predicted problem-focused coping use, and strongly predicted emotion-focused coping use. Although it was not predicted by goal attainment feelings, avoidance coping use was decreased over time throughout suffering episodes. Overall, this study supports propositions that the coping process is continually adapted to competitive demands and identifies the roles of distinct coping functions within the total coping effort.

  17. Visual motion aftereffects arise from a cascade of two isomorphic adaptation mechanisms

    PubMed Central

    Stocker, Alan A.; Simoncelli, Eero P.

    2013-01-01

    Prolonged exposure to a moving stimulus can substantially alter the perceived velocity (both speed and direction) of subsequently presented stimuli. Here, we show that these changes can be parsimoniously explained with a model that combines the effects of two isomorphic adaptation mechanisms, one nondirectional and one directional. Each produces a pattern of velocity biases that serves as an observable “signature” of the corresponding mechanism. The net effect on perceived velocity is a superposition of these two signatures. By examining human velocity judgments in the context of different adaptor velocities, we are able to separate these two signatures. The model fits the data well, successfully predicts subjects’ behavior in an additional experiment using a nondirectional adaptor, and is in agreement with a variety of previous experimental results. As such, the model provides a unifying explanation for the diversity of motion aftereffects. PMID:19761342

  18. Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid

    PubMed Central

    Giannattasio, Sergio; Guaragnella, Nicoletta; Ždralević, Maša; Marra, Ersilia

    2013-01-01

    Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications. PMID:23430312

  19. Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid.

    PubMed

    Giannattasio, Sergio; Guaragnella, Nicoletta; Zdralević, Maša; Marra, Ersilia

    2013-01-01

    Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications. PMID:23430312

  20. Poly(ethylene glycol) Hydrogels with Adaptable Mechanical and Degradation Properties for Use in Biomedical Applicationsa

    PubMed Central

    Parlato, Matthew; Reichert, Sarah; Barney, Neal

    2014-01-01

    Requirements of hydrogels for drug delivery, wound dressings, and surgical implantation can be extensive, including suitable mechanical properties and tailorable degradation time frames. Herein, an adaptable PEG-based hydrogel, whose mechanical properties and degradation rate can be systematically adjusted to meet these criteria by altering simple variables such as the PEG molecular weight, is described. The performance of these hydrogels in three physical manipulations (pushing, pulling, and folding), representative of manipulations that they may undergo during typical biomedical use, is also assessed. While not all of these formulations can withstand these manipulations, a subset did, and it is intended to further optimize these formulations for specific clinical applications. Additionally, the outcomes of the physical manipulation tests indicate that simply having a high modulus does not correlate with biomedical applicability. PMID:24949497

  1. Adaptation of Gabor filters for simulation of human preattentive mechanism for a mobile robot

    NASA Astrophysics Data System (ADS)

    Kulkarni, Naren; Naghdy, Golshah A.

    1993-08-01

    Vision guided mobile robot navigation is complex and requires analysis of tremendous amounts of information in real time. In order to simplify the task and reduce the amount of information, human preattentive mechanism can be adapted [Nag90]. During the preattentive search the scene is analyzed rapidly but in sufficient detail for the attention to be focused on the `area of interest.' The `area of interest' can further be scrutinized in more detail for recognition purposes. This `area of interest' can be a text message to facilitate navigation. Gabor filters and an automated turning mechanism are used to isolate the `area of interest.' These regions are subsequently processed with optimal spatial resolution for perception tasks. This method has clear advantages over the global operators in that, after an initial search, it scans each region of interest with optimum resolution. This reduces the volume of information for recognition stages and ensures that no region is over or under estimated.

  2. Influence of background size, luminance and eccentricity on different adaptation mechanisms.

    PubMed

    Gloriani, Alejandro H; Matesanz, Beatriz M; Barrionuevo, Pablo A; Arranz, Isabel; Issolio, Luis; Mar, Santiago; Aparicio, Juan A

    2016-08-01

    Mechanisms of light adaptation have been traditionally explained with reference to psychophysical experimentation. However, the neural substrata involved in those mechanisms remain to be elucidated. Our study analyzed links between psychophysical measurements and retinal physiological evidence with consideration for the phenomena of rod-cone interactions, photon noise, and spatial summation. Threshold test luminances were obtained with steady background fields at mesopic and photopic light levels (i.e., 0.06-110cd/m(2)) for retinal eccentricities from 0° to 15° using three combinations of background/test field sizes (i.e., 10°/2°, 10°/0.45°, and 1°/0.45°). A two-channel Maxwellian view optical system was employed to eliminate pupil effects on the measured thresholds. A model based on visual mechanisms that were described in the literature was optimized to fit the measured luminance thresholds in all experimental conditions. Our results can be described by a combination of visual mechanisms. We determined how spatial summation changed with eccentricity and how subtractive adaptation changed with eccentricity and background field size. According to our model, photon noise plays a significant role to explain contrast detection thresholds measured with the 1/0.45° background/test size combination at mesopic luminances and at off-axis eccentricities. In these conditions, our data reflect the presence of rod-cone interaction for eccentricities between 6° and 9° and luminances between 0.6 and 5cd/m(2). In spite of the increasing noise effects with eccentricity, results also show that the visual system tends to maintain a constant signal-to-noise ratio in the off-axis detection task over the whole mesopic range.

  3. Coping profiles characterize individual flourishing, languishing, and depression.

    PubMed

    Faulk, Kathryn E; Gloria, Christian T; Steinhardt, Mary A

    2013-01-01

    According to the broaden-and-build theory of positive emotions, negative emotions narrow one's thought-action repertoire. In contrast, positive emotions have a broadening effect, expanding cognitive capacity, increasing potential coping strategies that come to mind, and enhancing decision-making, reaction, and adaptation to adversity. Fredrickson and Losada determined that a positivity ratio - the ratio of experienced positive to negative emotions - at or above 2.9 promotes human flourishing. A ratio below 2.9 is indicative of languishing individuals, whereas a ratio below 1.0 is a marker of depression. This study examined whether adaptive and maladaptive coping profiles differentiated those who flourish, languish, or are depressed in two convenience samples - military spouses (n =367) and public school teachers (n=267). Results were consistent with the theoretical predictions, as coping profiles of the groups differed significantly, with flourishing individuals favoring adaptive coping strategies more than those who were languishing or depressed. Conversely, depressed individuals reported greater use of maladaptive coping strategies than those who were languishing or flourishing. These results provide further empirical support for the mathematical model of Fredrickson and Losada, as the set of positivity criteria were predictive of coping profiles in two samples where successful coping and adaptation are important. PMID:22853921

  4. Marginal adaptation of class V composite restorations submitted to thermal and mechanical cycling

    PubMed Central

    CASSELLI, Denise Sá Maia; FARIA-E-SILVA, André Luis; CASSELLI, Henrique; MARTINS, Luis Roberto Marcondes

    2013-01-01

    Objective: This study evaluated the effect of the margin location and an adhesive system on the marginal adaptation of composite restorations. Material and Methods: Class V cavities were prepared in bovine teeth with the gingival margin on the dentin and the incisal margin on the enamel. The cavities were restored with a micro-hybrid composite resin using an etch-and-rinse [Single Bond 2 (SB)] or a self-etching adhesive [Clearfil SE Bond (CL)]. After finishing and polishing the restorations, epoxy replicas were prepared. The marginal adaptation was analyzed using scanning electronic microscopy (SEM, 500 x magnification). The higher gap width in each margin was recorded (T0). After the first evaluation, the samples were submitted to thermal cycling (2,000 cycles of 5ºC±2ºC followed by 55ºC±2ºC - T1) and mechanical cycling (100,000 cycles of 50 kN and 2 Hz - T2). Replicas of samples were rebuilt after each cycling and analyzed under SEM. The data were submitted to Mann-Whitney, Wilcoxon and Friedman testing (a=0.05). Results: The SB presented higher gaps in the dentin than the enamel, while there was no difference between the substrate for the CL. In the dentin, the CL showed better marginal sealing than the SB. The opposite occurred in the enamel. There were no significant differences between the baseline, thermal and mechanical cycling for any experimental condition. Conclusions: The outcomes of the present study showed that the adhesive system and margin location have an important effect on the marginal adaptation of composite restorations. PMID:23559115

  5. A Dopamine- and Protein Kinase A-Dependent Mechanism for Network Adaptation in Retinal Ganglion Cells

    PubMed Central

    Vaquero, C. F.; Pignatelli, A.; Partida, G. J.; Ishida, A. T.

    2011-01-01

    Vertebrates can detect light intensity changes in vastly different photic environments, in part, because post-receptoral neurons undergo “network adaptation”. Previous data implicated dopaminergic, cAMP-dependent inhibition of retinal ganglion cells in this process, yet left unclear how this occurs, and whether this occurs in darkness versus light. To test for light- and dopamine-dependent changes in ganglion cell cAMP levels in situ, we immunostained dark- and light-adapted retinas with anti-cAMP antisera, in the presence and absence of various dopamine receptor ligands. To test for direct effects of dopamine receptor ligands and membrane-permeable protein kinase ligands on ganglion cell excitability, we recorded spikes from isolated ganglion cells in perforated-patch whole-cell mode, before and during application of these agents by microperfusion. Our immunostainings show that light, endogenous dopamine, and exogenous dopamine elevate ganglion cell cAMP levels in situ by activating D1-type dopamine receptors. Our spike recordings show that D1-type agonists and 8-bromo cAMP reduce spike frequency and curtail sustained spike firing, and that these effects entail protein kinase A activation. These effects resemble those of background light on ganglion cell responses to light flashes. Network adaptation could thus be produced, to some extent, by dopaminergic modulation of ganglion cell spike generation, a mechanism distinct from modulation of transmitter release onto ganglion cells or of transmitter-gated currents in ganglion cells. Combining these observations, with results obtained in studies of photoreceptor, bipolar, and horizontal cells, indicates that all three layers of neurons in the retina are equipped with mechanisms for adaptation to ambient light. PMID:11606650

  6. [PROTEOMIC ANALYSIS OF ADAPTIVE MECHANISMS TO SALINITY STRESS IN MARINE GASTROPODS LITTORINA SAXATILIS].

    PubMed

    Muraeva, O A; Maltseva, A L; Mikhailova, N A; Granovitch, A I

    2015-01-01

    Salinity is one of the most important abiotic environmental factors affecting marine animals. If salinity deviate from optimum, adaptive mechanisms switch on to maintain organism's physiological activity. In this study, the reaction of the snails Littorina saxatilis from natural habitats and in response to experimental salinity decreasing was analyzed on proteomic level. The isolation of all snails inside their shells and gradually declining mortality was observed under acute experimental salinity decrease (down to 10 per hundred). Proteomic changes were evaluated in the surviving experimental mollusks compared to control individual using differential 2D gel-electrophoresis (DIGE) and subsequent LC-MS/MS-identification of proteins. Approximately 10% of analyzed proteins underwent up- or down regulation during the experiment. Proteins of folding, antioxidant response, intercellular matrix, cell adhesion, cell signaling and metabolic enzymes were identified among them. Proteome changes observed in experimental hypoosmotic stress partially reproduced in the proteomes of mollusks that live in conditions of natural freshening (estuaries). Possible mechanisms involved in the adaptation process of L. saxatilis individuals to hypo-osmotic stress are discussed. PMID:26995971

  7. Acclimation of leaf cohorts expanded under light and water stresses: an adaptive mechanism of Eucryphia cordifolia to face changes in climatic conditions?

    PubMed

    Morales, Loreto V; Coopman, Rafael E; Rojas, Roke; Escandón, Antonio B; Flexas, Jaume; Galmés, Jeroni; García-Plazaola, José I; Gago, Jorge; Cabrera, Hernán M; Corcuera, Luis J

    2014-12-01

    Eucryphia cordifolia Cav. is a long-lived evergreen tree species, commonly found as a canopy emergent tree in the Chilean temperate rain forest. This species displays successive leaf cohorts throughout the entire growing season. Thus, full leaf expansion occurs under different environmental conditions during growing such as air temperature, vapor pressure deficit and the progress of moderate water stress (WS). These climate variations can be reflected as differences in anatomical and physiological characteristics among leaf cohorts. Thus, we investigated the potential adaptive role of different co-existing leaf cohorts in seedlings grown under shade, drought stress or a combination of the two. Photosynthetic and anatomical traits were measured in the first displayed leaf cohort and in a subsequent leaf cohort generated during the mid-season. Although most anatomical and photosynthetic pigments did not vary between cohorts, photosynthetic acclimation did occur in the leaf cohort and was mainly driven by biochemical processes such as leaf nitrogen content, Rubisco carboxylation capacity and maximal Photosystem II electron transport rather than CO2 diffusion conductance. Cohort acclimation could be relevant in the context of climate change, as this temperate rainforest will likely face some degree of summer WS even under low light conditions. We suggest that the acclimation of the photosynthetic capacity among current leaf cohorts represents a well-tuned mechanism helping E. cordifolia seedlings to face a single stress like shade or drought stress, but is insufficient to cope with simultaneous stresses.

  8. A comparative study of marginal fit of copings prepared with various techniques on different implant abutments.

    PubMed

    Koç, Esra; Öngül, Değer; Şermet, Bülent

    2016-01-01

    This study evaluated fabrication techniques of recently introduced all-ceramic copings' marginal adaptation on two different implant abutments with different finish lines. Five different copings were prepared (Casted chrome-cobalt metal coping, Zirkonzahn, Cercon, In Ceram Alumina and IPS e.max Press) on two cementable implant abutments with two marginal designs. Ten samples for each coping group were prepared (totally 100 samples). Copings were cemented to implant abutments and marginal gap measurements were done from 24 points with stereomicroscope and the datas were analyzed by the Kruskal-Wallis test before cementation. Cercon copings showed the lowest marginal fit scores and metal copings showed the highest scores. After cementation, all marginal gap values have been increased. All marginal gap values obtained from crown copings can be considered in clinically acceptable limits (<120 µm) except metal copings after cementation on abutment with 135 degrees shoulder group (123 µm).

  9. A comparative study of marginal fit of copings prepared with various techniques on different implant abutments.

    PubMed

    Koç, Esra; Öngül, Değer; Şermet, Bülent

    2016-01-01

    This study evaluated fabrication techniques of recently introduced all-ceramic copings' marginal adaptation on two different implant abutments with different finish lines. Five different copings were prepared (Casted chrome-cobalt metal coping, Zirkonzahn, Cercon, In Ceram Alumina and IPS e.max Press) on two cementable implant abutments with two marginal designs. Ten samples for each coping group were prepared (totally 100 samples). Copings were cemented to implant abutments and marginal gap measurements were done from 24 points with stereomicroscope and the datas were analyzed by the Kruskal-Wallis test before cementation. Cercon copings showed the lowest marginal fit scores and metal copings showed the highest scores. After cementation, all marginal gap values have been increased. All marginal gap values obtained from crown copings can be considered in clinically acceptable limits (<120 µm) except metal copings after cementation on abutment with 135 degrees shoulder group (123 µm). PMID:27252001

  10. Controversies Regarding the Psychometric Properties of the Brief COPE: The Case of the Brazilian-Portuguese Version “COPE Breve”

    PubMed Central

    Orsini, Mara R. C. A.; Bartholomeu, Daniel; Montiel, José M.

    2016-01-01

    The Brief Coping Orientation to Problems Experienced (COPE) inventory investigates the different ways in which people respond to stressful situations. Knowledge is lacking regarding the coping strategies and styles of people in developing countries, including Brazil. This study aimed to adapt and validate the Brief COPE to Brazilian Portuguese (named COPE Breve) by focusing on dispositional coping. For the cross-cultural adaptation, the original Brief COPE in English (28 items grouped into 14 subscales) was adapted according to a universalistic approach, following these steps: translation, synthesis, back-translation, analysis by an expert panel, and pretest with 30 participants. Then, 237 adults from the community health service responded to the COPE Breve. Psychometric analyses included reliability and exploratory factor analysis. Most of the 14 subscales from the original Brief COPE exhibited problems related to internal consistency. A Velicer's minimum average partial test (MAP) was performed and pointed out 3 factors. Exploratory factor analysis produced a revised 20-item version with a 3-factor solution: religion and positive reframing, distraction and external support. The psychometric properties of the COPE Breve with three factors were appropriate. Limitations of this study as well as suggestions for future studies are presented. The COPE Breve should be used in Brazilian clinics and investigations, but divergences in its psychometrics should be further explored in other contexts. PMID:27007646

  11. Adaptedness and coping in dysphagic students.

    PubMed

    Gustafsson, B; Theorell, T

    1995-01-01

    Using a definition based on Bowlby and Pörn, an effort is made to interpret adaptedness and coping in 87 dysphagic students (corresponding to a prevalence of dysphagia in 9% of the boys and 12% of the girls) found in a screening study utilizing a questionnaire. Coping patterns and methods of adaptation were explored in a telephone interview with dysphagic students. Those who stated that their dysphagia influenced their daily living were classified as subjectively maladapted (S-maladapted; n = 9). Compared with the S-adapted students, the S-maladapted students reported more defects in ability to eat, more inappropriate beliefs about the causes and management of dysphagia, and greater desires regarding eating than S-adapted students (p < 0.05). The environmental conditions more often impaired the eating ability in S-maladapted students (p < 0.05). Anxiety at mealtime was reported more frequently than in S-adapted students (p < 0.05). Every second S-maladapted student had reduced self-esteem because of dysphagia (p < 0.05). The S-maladapted students had talked about their dysphagia with parents and/or friends and visited a school physician because of dysphagia more often than S-adapted students (p < 0.05). Two of 9 students felt confirmed by the physician and experienced help. There was concordance between the students' own beliefs regarding the causes of dysphagia and corresponding coping strategy. PMID:7600858

  12. Adaptedness and coping in dysphagic students.

    PubMed

    Gustafsson, B; Theorell, T

    1995-01-01

    Using a definition based on Bowlby and Pörn, an effort is made to interpret adaptedness and coping in 87 dysphagic students (corresponding to a prevalence of dysphagia in 9% of the boys and 12% of the girls) found in a screening study utilizing a questionnaire. Coping patterns and methods of adaptation were explored in a telephone interview with dysphagic students. Those who stated that their dysphagia influenced their daily living were classified as subjectively maladapted (S-maladapted; n = 9). Compared with the S-adapted students, the S-maladapted students reported more defects in ability to eat, more inappropriate beliefs about the causes and management of dysphagia, and greater desires regarding eating than S-adapted students (p < 0.05). The environmental conditions more often impaired the eating ability in S-maladapted students (p < 0.05). Anxiety at mealtime was reported more frequently than in S-adapted students (p < 0.05). Every second S-maladapted student had reduced self-esteem because of dysphagia (p < 0.05). The S-maladapted students had talked about their dysphagia with parents and/or friends and visited a school physician because of dysphagia more often than S-adapted students (p < 0.05). Two of 9 students felt confirmed by the physician and experienced help. There was concordance between the students' own beliefs regarding the causes of dysphagia and corresponding coping strategy.

  13. Mechanically adaptive intracortical implants improve the proximity of neuronal cell bodies

    NASA Astrophysics Data System (ADS)

    Harris, J. P.; Capadona, J. R.; Miller, R. H.; Healy, B. C.; Shanmuganathan, K.; Rowan, S. J.; Weder, C.; Tyler, D. J.

    2011-10-01

    The hypothesis is that the mechanical mismatch between brain tissue and microelectrodes influences the inflammatory response. Our unique, mechanically adaptive polymer nanocomposite enabled this study within the cerebral cortex of rats. The initial tensile storage modulus of 5 GPa decreases to 12 MPa within 15 min under physiological conditions. The response to the nanocomposite was compared to surface-matched, stiffer implants of traditional wires (411 GPa) coated with the identical polymer substrate and implanted on the contralateral side. Both implants were tethered. Fluorescent immunohistochemistry labeling examined neurons, intermediate filaments, macrophages, microglia and proteoglycans. We demonstrate, for the first time, a system that decouples the mechanical and surface chemistry components of the neural response. The neuronal nuclei density within 100 µm of the device at four weeks post-implantation was greater for the compliant nanocomposite compared to the stiff wire. At eight weeks post-implantation, the neuronal nuclei density around the nanocomposite was maintained, but the density around the wire recovered to match that of the nanocomposite. The glial scar response to the compliant nanocomposite was less vigorous than it was to the stiffer wire. The results suggest that mechanically associated factors such as proteoglycans and intermediate filaments are important modulators of the response of the compliant nanocomposite.

  14. Mechanically adaptive intracortical implants improve the proximity of neuronal cell bodies.

    PubMed

    Harris, J P; Capadona, J R; Miller, R H; Healy, B C; Shanmuganathan, K; Rowan, S J; Weder, C; Tyler, D J

    2011-12-01

    The hypothesis is that the mechanical mismatch between brain tissue and microelectrodes influences the inflammatory response. Our unique, mechanically adaptive polymer nanocomposite enabled this study within the cerebral cortex of rats. The initial tensile storage modulus of 5 GPa decreases to 12 MPa within 15 min under physiological conditions. The response to the nanocomposite was compared to surface-matched, stiffer implants of traditional wires (411 GPa) coated with the identical polymer substrate and implanted on the contralateral side. Both implants were tethered. Fluorescent immunohistochemistry labeling examined neurons, intermediate filaments, macrophages, microglia and proteoglycans. We demonstrate, for the first time, a system that decouples the mechanical and surface chemistry components of the neural response. The neuronal nuclei density within 100 µm of the device at four weeks post-implantation was greater for the compliant nanocomposite compared to the stiff wire. At eight weeks post-implantation, the neuronal nuclei density around the nanocomposite was maintained, but the density around the wire recovered to match that of the nanocomposite. The glial scar response to the compliant nanocomposite was less vigorous than it was to the stiffer wire. The results suggest that mechanically associated factors such as proteoglycans and intermediate filaments are important modulators of the response of the compliant nanocomposite. PMID:22049097

  15. Molecular Mechanisms Mediating the Adaptive Regulation of Intestinal Riboflavin Uptake Process.

    PubMed

    Subramanian, Veedamali S; Ghosal, Abhisek; Kapadia, Rubina; Nabokina, Svetlana M; Said, Hamid M

    2015-01-01

    The intestinal absorption process of vitamin B2 (riboflavin, RF) is carrier-mediated, and all three known human RF transporters, i.e., hRFVT-1, -2, and -3 (products of the SLC52A1, 2 & 3 genes, respectively) are expressed in the gut. We have previously shown that the intestinal RF uptake process is adaptively regulated by substrate level, but little is known about the molecular mechanism(s) involved. Using human intestinal epithelial NCM460 cells maintained under RF deficient and over-supplemented (OS) conditions, we now show that the induction in RF uptake in RF deficiency is associated with an increase in expression of the hRFVT-2 & -3 (but not hRFVT-1) at the protein and mRNA levels. Focusing on hRFVT-3, the predominant transporter in the intestine, we also observed an increase in the level of expression of its hnRNA and activity of its promoter in the RF deficiency state. An increase in the level of expression of the nuclear factor Sp1 (which is important for activity of the SLC52A3 promoter) was observed in RF deficiency, while mutating the Sp1/GC site in the SLC52A3 promoter drastically decreased the level of induction in SLC52A3 promoter activity in RF deficiency. We also observed specific epigenetic changes in the SLC52A3 promoter in RF deficiency. Finally, an increase in hRFVT-3 protein expression at the cell surface was observed in RF deficiency. Results of these investigations show, for the first time, that transcriptional and post-transcriptional mechanisms are involved in the adaptive regulation of intestinal RF uptake by the prevailing substrate level.

  16. Molecular Mechanisms Mediating the Adaptive Regulation of Intestinal Riboflavin Uptake Process

    PubMed Central

    Subramanian, Veedamali S.; Ghosal, Abhisek; Kapadia, Rubina; Nabokina, Svetlana M.; Said, Hamid M.

    2015-01-01

    The intestinal absorption process of vitamin B2 (riboflavin, RF) is carrier-mediated, and all three known human RF transporters, i.e., hRFVT-1, -2, and -3 (products of the SLC52A1, 2 & 3 genes, respectively) are expressed in the gut. We have previously shown that the intestinal RF uptake process is adaptively regulated by substrate level, but little is known about the molecular mechanism(s) involved. Using human intestinal epithelial NCM460 cells maintained under RF deficient and over-supplemented (OS) conditions, we now show that the induction in RF uptake in RF deficiency is associated with an increase in expression of the hRFVT-2 & -3 (but not hRFVT-1) at the protein and mRNA levels. Focusing on hRFVT-3, the predominant transporter in the intestine, we also observed an increase in the level of expression of its hnRNA and activity of its promoter in the RF deficiency state. An increase in the level of expression of the nuclear factor Sp1 (which is important for activity of the SLC52A3 promoter) was observed in RF deficiency, while mutating the Sp1/GC site in the SLC52A3 promoter drastically decreased the level of induction in SLC52A3 promoter activity in RF deficiency. We also observed specific epigenetic changes in the SLC52A3 promoter in RF deficiency. Finally, an increase in hRFVT-3 protein expression at the cell surface was observed in RF deficiency. Results of these investigations show, for the first time, that transcriptional and post-transcriptional mechanisms are involved in the adaptive regulation of intestinal RF uptake by the prevailing substrate level. PMID:26121134

  17. Influence of resveratrol release on the tissue response to mechanically adaptive cortical implants.

    PubMed

    Nguyen, Jessica K; Jorfi, Mehdi; Buchanan, Kelly L; Park, Daniel J; Foster, E Johan; Tyler, Dustin J; Rowan, Stuart J; Weder, Christoph; Capadona, Jeffrey R

    2016-01-01

    The stability and longevity of recordings obtained from intracortical microelectrodes continues to remain an area of concern for neural interfacing applications. The limited longevity of microelectrode performance has been associated with the integrity of the blood brain barrier (BBB) and the neuroinflammatory response to the microelectrode. Here, we report the investigation of an additive approach that targets both mechanical and chemical factors believed to contribute to chronic BBB instability and the neuroinflammatory response associated with implanted intracortical microelectrodes. The implants investigated were based on a mechanically adaptive, compliant nanocomposite (NC), which reduces the tissue response and tissue strain. This material was doped with various concentrations of the antioxidant resveratrol with the objective of local and rapid delivery. In vitro analysis of resveratrol release, antioxidant activity, and cytotoxicity suggested that a resveratrol content of 0.01% was optimal for in vivo assessment. Thus, probes made from the neat NC reference and probes containing resveratrol (NC Res) were implanted into the cortical tissue of rats for up to sixteen weeks. Histochemical analysis suggested that at three days post-implantation, neither materials nor therapeutic approaches (independently or in combination) could alter the initial wound healing response. However, at two weeks post-implantation, the NC Res implant showed a reduction in activated microglia/macrophages and improvement in neuron density at the tissue-implant interface when compared to the neat NC reference. However, sixteen weeks post-implantation, when the antioxidant was exhausted, NC Res and the neat NC reference exhibited similar tissue responses. The data show that NC Res provides short-term, short-lived benefits due to the antioxidant release, and a long-term reduction in neuroinflammation on account of is mechanical adaptive, compliant nature. Together, these results

  18. Influence of resveratrol release on the tissue response to mechanically adaptive cortical implants.

    PubMed

    Nguyen, Jessica K; Jorfi, Mehdi; Buchanan, Kelly L; Park, Daniel J; Foster, E Johan; Tyler, Dustin J; Rowan, Stuart J; Weder, Christoph; Capadona, Jeffrey R

    2016-01-01

    The stability and longevity of recordings obtained from intracortical microelectrodes continues to remain an area of concern for neural interfacing applications. The limited longevity of microelectrode performance has been associated with the integrity of the blood brain barrier (BBB) and the neuroinflammatory response to the microelectrode. Here, we report the investigation of an additive approach that targets both mechanical and chemical factors believed to contribute to chronic BBB instability and the neuroinflammatory response associated with implanted intracortical microelectrodes. The implants investigated were based on a mechanically adaptive, compliant nanocomposite (NC), which reduces the tissue response and tissue strain. This material was doped with various concentrations of the antioxidant resveratrol with the objective of local and rapid delivery. In vitro analysis of resveratrol release, antioxidant activity, and cytotoxicity suggested that a resveratrol content of 0.01% was optimal for in vivo assessment. Thus, probes made from the neat NC reference and probes containing resveratrol (NC Res) were implanted into the cortical tissue of rats for up to sixteen weeks. Histochemical analysis suggested that at three days post-implantation, neither materials nor therapeutic approaches (independently or in combination) could alter the initial wound healing response. However, at two weeks post-implantation, the NC Res implant showed a reduction in activated microglia/macrophages and improvement in neuron density at the tissue-implant interface when compared to the neat NC reference. However, sixteen weeks post-implantation, when the antioxidant was exhausted, NC Res and the neat NC reference exhibited similar tissue responses. The data show that NC Res provides short-term, short-lived benefits due to the antioxidant release, and a long-term reduction in neuroinflammation on account of is mechanical adaptive, compliant nature. Together, these results

  19. Interrelatedness of Proactive Coping, Reactive Coping, and Learned Resourcefulness

    ERIC Educational Resources Information Center

    Moring, John; Fuhrman, Robert; Zauszniewski, Jaclene A.

    2011-01-01

    Research has identified that coping strategies used by individuals depend on temporal locations of stressors. Dispositional attributes are also identified as predictors of coping. The current study identified commonalities of proactive coping, reactive coping, and learned resourcefulness measures. The analysis yielded three factors reflective of…

  20. How Older Female Spouses Cope with Partners' Coronary Artery Bypass Graft Surgery

    PubMed Central

    Marnocha, Suzanne; Marnocha, Mark

    2013-01-01

    This research sought to better understand how older female spouses cope with a partner's coronary artery bypass graft surgery and to explore coping's relationships with life-change stress, cognitive appraisal, resilience, social support, and aspects of spouse's surgery. A sample of 96 women, aged from 55 to 81 years, completed surveys after their partner's surgery. Folkman and Lazarus' ways of coping (WCQ) scales yielded two factors in this sample—reactive coping and adaptive coping. Reactive coping, including more emotion-focused ways of coping from the WCQ, was associated only with more time spent anticipating spouses' surgeries. Women described the greatest use of ways of coping labeled adaptive, which in turn had significant relationships with greater resilience, social support, and positive appraisal of the surgical experience. Stepwise multiple regression found greater resilience, more frequent religious participation, and fewer children to be distinct predictors of adaptive coping. Nursing staff are encouraged to accept and normalize reactive coping, while facilitating adaptive coping with surgical stresses. PMID:23634299

  1. Mechanisms Underlying Adaptation to Life in Hydrogen Sulfide–Rich Environments

    PubMed Central

    Kelley, Joanna L.; Arias-Rodriguez, Lenin; Patacsil Martin, Dorrelyn; Yee, Muh-Ching; Bustamante, Carlos D.; Tobler, Michael

    2016-01-01

    Hydrogen sulfide (H2S) is a potent toxicant interfering with oxidative phosphorylation in mitochondria and creating extreme environmental conditions in aquatic ecosystems. The mechanistic basis of adaptation to perpetual exposure to H2S remains poorly understood. We investigated evolutionarily independent lineages of livebearing fishes that have colonized and adapted to springs rich in H2S and compared their genome-wide gene expression patterns with closely related lineages from adjacent, nonsulfidic streams. Significant differences in gene expression were uncovered between all sulfidic and nonsulfidic population pairs. Variation in the number of differentially expressed genes among population pairs corresponded to differences in divergence times and rates of gene flow, which is consistent with neutral drift driving a substantial portion of gene expression variation among populations. Accordingly, there was little evidence for convergent evolution shaping large-scale gene expression patterns among independent sulfide spring populations. Nonetheless, we identified a small number of genes that was consistently differentially expressed in the same direction in all sulfidic and nonsulfidic population pairs. Functional annotation of shared differentially expressed genes indicated upregulation of genes associated with enzymatic H2S detoxification and transport of oxidized sulfur species, oxidative phosphorylation, energy metabolism, and pathways involved in responses to oxidative stress. Overall, our results suggest that modification of processes associated with H2S detoxification and toxicity likely complement each other to mediate elevated H2S tolerance in sulfide spring fishes. Our analyses allow for the development of novel hypotheses about biochemical and physiological mechanisms of adaptation to extreme environments. PMID:26861137

  2. Mechanisms Underlying Adaptation to Life in Hydrogen Sulfide-Rich Environments.

    PubMed

    Kelley, Joanna L; Arias-Rodriguez, Lenin; Patacsil Martin, Dorrelyn; Yee, Muh-Ching; Bustamante, Carlos D; Tobler, Michael

    2016-06-01

    Hydrogen sulfide (H2S) is a potent toxicant interfering with oxidative phosphorylation in mitochondria and creating extreme environmental conditions in aquatic ecosystems. The mechanistic basis of adaptation to perpetual exposure to H2S remains poorly understood. We investigated evolutionarily independent lineages of livebearing fishes that have colonized and adapted to springs rich in H2S and compared their genome-wide gene expression patterns with closely related lineages from adjacent, nonsulfidic streams. Significant differences in gene expression were uncovered between all sulfidic and nonsulfidic population pairs. Variation in the number of differentially expressed genes among population pairs corresponded to differences in divergence times and rates of gene flow, which is consistent with neutral drift driving a substantial portion of gene expression variation among populations. Accordingly, there was little evidence for convergent evolution shaping large-scale gene expression patterns among independent sulfide spring populations. Nonetheless, we identified a small number of genes that was consistently differentially expressed in the same direction in all sulfidic and nonsulfidic population pairs. Functional annotation of shared differentially expressed genes indicated upregulation of genes associated with enzymatic H2S detoxification and transport of oxidized sulfur species, oxidative phosphorylation, energy metabolism, and pathways involved in responses to oxidative stress. Overall, our results suggest that modification of processes associated with H2S detoxification and toxicity likely complement each other to mediate elevated H2S tolerance in sulfide spring fishes. Our analyses allow for the development of novel hypotheses about biochemical and physiological mechanisms of adaptation to extreme environments.

  3. Tobacco Smoking in Adolescence Predicts Maladaptive Coping Styles in Adulthood

    PubMed Central

    2013-01-01

    Introduction: To examine the extent to which cigarette smoking in adolescence is associated with maladaptive versus adaptive coping behaviors in adulthood. Method: The data came from a longitudinal study of New Zealand adolescents followed into adulthood at age 32 years. Using structural equation modeling (SEM), we examined the predictive association between daily smoking of cigarettes and symptoms of tobacco dependence from 18 to 26 years of age and later coping at age 32 years. We included pathways from childhood family disadvantage in addition to both adolescent stress–worry and adult coping in the model. Results: SEM revealed that cigarette smoking had a small but direct inverse effect on later adaptive coping (−.14) and a direct effect on maladaptive coping (.23) independent of the relationships between adolescent coping and stress–worry and later adult coping. Conclusions: The findings are consistent with the hypothesis that tobacco smoking may inhibit the development of self-efficacy or one’s ability to act with appropriate coping behaviors in any given situation. PMID:23817581

  4. An Adaptive Jitter Mechanism for Reactive Route Discovery in Sensor Networks

    PubMed Central

    Cordero, Juan Antonio; Yi, Jiazi; Clausen, Thomas

    2014-01-01

    This paper analyses the impact of jitter when applied to route discovery in reactive (on-demand) routing protocols. In multi-hop non-synchronized wireless networks, jitter—a small, random variation in the timing of message emission—is commonly employed, as a means to avoid collisions of simultaneous transmissions by adjacent routers over the same channel. In a reactive routing protocol for sensor and ad hoc networks, jitter is recommended during the route discovery process, specifically, during the network-wide flooding of route request messages, in order to avoid collisions. Commonly, a simple uniform jitter is recommended. Alas, this is not without drawbacks: when applying uniform jitter to the route discovery process, an effect called delay inversion is observed. This paper, first, studies and quantifies this delay inversion effect. Second, this paper proposes an adaptive jitter mechanism, designed to alleviate the delay inversion effect and thereby to reduce the route discovery overhead and (ultimately) allow the routing protocol to find more optimal paths, as compared to uniform jitter. This paper presents both analytical and simulation studies, showing that the proposed adaptive jitter can effectively decrease the cost of route discovery and increase the path quality. PMID:25111238

  5. Integrity of the osteocyte bone cell network in osteoporotic fracture: Implications for mechanical load adaptation

    NASA Astrophysics Data System (ADS)

    Kuliwaba, J. S.; Truong, L.; Codrington, J. D.; Fazzalari, N. L.

    2010-06-01

    The human skeleton has the ability to modify its material composition and structure to accommodate loads through adaptive modelling and remodelling. The osteocyte cell network is now considered to be central to the regulation of skeletal homeostasis; however, very little is known of the integrity of the osteocyte cell network in osteoporotic fragility fracture. This study was designed to characterise osteocyte morphology, the extent of osteocyte cell apoptosis and expression of sclerostin protein (a negative regulator of bone formation) in trabecular bone from the intertrochanteric region of the proximal femur, for postmenopausal women with fragility hip fracture compared to age-matched women who had not sustained fragility fracture. Osteocyte morphology (osteocyte, empty lacunar, and total lacunar densities) and the degree of osteocyte apoptosis (percent caspase-3 positive osteocyte lacunae) were similar between the fracture patients and non-fracture women. The fragility hip fracture patients had a lower proportion of sclerostin-positive osteocyte lacunae in comparison to sclerostin-negative osteocyte lacunae, in contrast to similar percent sclerostin-positive/sclerostin-negative lacunae for non-fracture women. The unexpected finding of decreased sclerostin expression in trabecular bone osteocytes from fracture cases may be indicative of elevated bone turnover and under-mineralisation, characteristic of postmenopausal osteoporosis. Further, altered osteocytic expression of sclerostin may be involved in the mechano-responsiveness of bone. Optimal function of the osteocyte cell network is likely to be a critical determinant of bone strength, acting via mechanical load adaptation, and thus contributing to osteoporotic fracture risk.

  6. Mechanisms of adaptation to chronic respiratory acidosis in the rabbit proximal tubule.

    PubMed Central

    Krapf, R

    1989-01-01

    The hyperbicarbonatemia of chronic respiratory acidosis is maintained by enhanced bicarbonate reabsorption in the proximal tubule. To investigate the cellular mechanisms involved in this adaptation, cell and luminal pH were measured microfluorometrically using (2",7')-bis(carboxyethyl)-(5,6)-carboxyfluorescein in isolated, microperfused S2 proximal convoluted tubules from control and acidotic rabbits. Chronic respiratory acidosis was induced by exposure to 10% CO2 for 52-56 h. Tubules from acidotic rabbits had a significantly lower luminal pH after 1-mm perfused length (7.03 +/- 0.09 vs. 7.26 +/- 0.06 in controls, perfusion rate = 10 nl/min). Chronic respiratory acidosis increased the initial rate of cell acidification (dpHi/dt) in response to luminal sodium removal by 63% and in response to lowering luminal pH (7.4-6.8) by 69%. Chronic respiratory acidosis also increased dpHi/dt in response to peritubular sodium removal by 63% and in response to lowering peritubular pH by 73%. In conclusion, chronic respiratory acidosis induces a parallel increase in the rates of the luminal Na/H antiporter and the basolateral Na/(HCO3)3 cotransporter. Therefore, the enhanced proximal tubule reabsorption of bicarbonate in chronic respiratory acidosis may be, at least in part, mediated by a parallel adaptation of these transporters. PMID:2537851

  7. Differential gene retention as an evolutionary mechanism to generate biodiversity and adaptation in yeasts.

    PubMed

    Morel, Guillaume; Sterck, Lieven; Swennen, Dominique; Marcet-Houben, Marina; Onesime, Djamila; Levasseur, Anthony; Jacques, Noémie; Mallet, Sandrine; Couloux, Arnaux; Labadie, Karine; Amselem, Joëlle; Beckerich, Jean-Marie; Henrissat, Bernard; Van de Peer, Yves; Wincker, Patrick; Souciet, Jean-Luc; Gabaldón, Toni; Tinsley, Colin R; Casaregola, Serge

    2015-06-25

    The evolutionary history of the characters underlying the adaptation of microorganisms to food and biotechnological uses is poorly understood. We undertook comparative genomics to investigate evolutionary relationships of the dairy yeast Geotrichum candidum within Saccharomycotina. Surprisingly, a remarkable proportion of genes showed discordant phylogenies, clustering with the filamentous fungus subphylum (Pezizomycotina), rather than the yeast subphylum (Saccharomycotina), of the Ascomycota. These genes appear not to be the result of Horizontal Gene Transfer (HGT), but to have been specifically retained by G. candidum after the filamentous fungi-yeasts split concomitant with the yeasts' genome contraction. We refer to these genes as SRAGs (Specifically Retained Ancestral Genes), having been lost by all or nearly all other yeasts, and thus contributing to the phenotypic specificity of lineages. SRAG functions include lipases consistent with a role in cheese making and novel endoglucanases associated with degradation of plant material. Similar gene retention was observed in three other distantly related yeasts representative of this ecologically diverse subphylum. The phenomenon thus appears to be widespread in the Saccharomycotina and argues that, alongside neo-functionalization following gene duplication and HGT, specific gene retention must be recognized as an important mechanism for generation of biodiversity and adaptation in yeasts.

  8. Indirect adaptive output feedback control of a biorobotic AUV using pectoral-like mechanical fins.

    PubMed

    Naik, Mugdha S; Singh, Sahjendra N; Mittal, Rajat

    2009-06-01

    This paper treats the question of servoregulation of autonomous underwater vehicles (AUVs) in the yaw plane using pectoral-like mechanical fins. The fins attached to the vehicle have oscillatory swaying and yawing motion. The bias angle of the angular motion of the fin is used for the purpose of control. Of course, the design approach considered here is applicable to AUVs for other choices of oscillation patterns of the fins, which produce periodic forces and moments. It is assumed that the vehicle parameters, hydrodynamic coefficients, as well the fin forces and moments are unknown. For the trajectory control of the yaw angle, a sampled-data indirect adaptive control system using output (yaw angle) feedback is derived. The control system has a modular structure, which includes a parameter identifier and a stabilizer. For the control law derivation, an internal model of the exosignals (reference signal (constant or ramp) and constant disturbance) is included. Unlike the direct adaptive control scheme, the derived control law is applicable to minimum as well as nonminimum phase biorobotic AUVs (BAUVs). This is important, because for most of the fin locations on the vehicle, the model is a nonminimum phase. In the closed-loop system, the yaw angle trajectory tracking error converges to zero and the remaining state variables remain bounded. Simulation results are presented which show that the derived modular control system accomplishes precise set point yaw angle control and turning maneuvers in spite of the uncertainties in the system parameters using only yaw angle feedback.

  9. Integrated physiological mechanisms of exercise performance, adaptation, and maladaptation to heat stress.

    PubMed

    Sawka, Michael N; Leon, Lisa R; Montain, Scott J; Sonna, Larry A

    2011-10-01

    This article emphasizes significant recent advances regarding heat stress and its impact on exercise performance, adaptations, fluid electrolyte imbalances, and pathophysiology. During exercise-heat stress, the physiological burden of supporting high skin blood flow and high sweating rates can impose considerable cardiovascular strain and initiate a cascade of pathophysiological events leading to heat stroke. We examine the association between heat stress, particularly high skin temperature, on diminishing cardiovascular/aerobic reserves as well as increasing relative intensity and perceptual cues that degrade aerobic exercise performance. We discuss novel systemic (heat acclimation) and cellular (acquired thermal tolerance) adaptations that improve performance in hot and temperate environments and protect organs from heat stroke as well as other dissimilar stresses. We delineate how heat stroke evolves from gut underperfusion/ischemia causing endotoxin release or the release of mitochondrial DNA fragments in response to cell necrosis, to mediate a systemic inflammatory syndrome inducing coagulopathies, immune dysfunction, cytokine modulation, and multiorgan damage and failure. We discuss how an inflammatory response that induces simultaneous fever and/or prior exposure to a pathogen (e.g., viral infection) that deactivates molecular protective mechanisms interacts synergistically with the hyperthermia of exercise to perhaps explain heat stroke cases reported in low-risk populations performing routine activities. Importantly, we question the "traditional" notion that high core temperature is the critical mediator of exercise performance degradation and heat stroke. Published 2011. This article is a U.S. Government work and is in the public domain in the USA. PMID:23733692

  10. Intra-plastid protein trafficking; how plant cells adapted prokaryotic mechanisms to the eukaryotic condition

    PubMed Central

    Celedon, Jose M.; Cline, Kenneth

    2012-01-01

    Protein trafficking and localization in plastids involves a complex interplay between ancient (prokaryotic) and novel (eukaryotic) translocases and targeting machineries. During evolution, ancient systems acquired new functions and novel translocation machineries were developed to facilitate the correct localization of nuclear encoded proteins targeted to the chloroplast. Because of its post-translational nature, targeting and integration of membrane proteins posed the biggest challenge to the organelle to avoid aggregation in the aqueous compartments. Soluble proteins faced a different kind of problem since some had to be transported across three membranes to reach their destination. Early studies suggested that chloroplasts addressed these issues by adapting ancient-prokaryotic machineries and integrating them with novel-eukaryotic systems, a process called ‘conservative sorting’. In the last decade, detailed biochemical, genetic, and structural studies have unraveled the mechanisms of protein targeting and localization in chloroplasts, suggesting a highly integrated scheme where ancient and novel systems collaborate at different stages of the process. In this review we focus on the differences and similarities between chloroplast ancestral translocases and their prokaryotic relatives to highlight known modifications that adapted them to the eukaryotic situation. PMID:22750312

  11. Integrated physiological mechanisms of exercise performance, adaptation, and maladaptation to heat stress.

    PubMed

    Sawka, Michael N; Leon, Lisa R; Montain, Scott J; Sonna, Larry A

    2011-10-01

    This article emphasizes significant recent advances regarding heat stress and its impact on exercise performance, adaptations, fluid electrolyte imbalances, and pathophysiology. During exercise-heat stress, the physiological burden of supporting high skin blood flow and high sweating rates can impose considerable cardiovascular strain and initiate a cascade of pathophysiological events leading to heat stroke. We examine the association between heat stress, particularly high skin temperature, on diminishing cardiovascular/aerobic reserves as well as increasing relative intensity and perceptual cues that degrade aerobic exercise performance. We discuss novel systemic (heat acclimation) and cellular (acquired thermal tolerance) adaptations that improve performance in hot and temperate environments and protect organs from heat stroke as well as other dissimilar stresses. We delineate how heat stroke evolves from gut underperfusion/ischemia causing endotoxin release or the release of mitochondrial DNA fragments in response to cell necrosis, to mediate a systemic inflammatory syndrome inducing coagulopathies, immune dysfunction, cytokine modulation, and multiorgan damage and failure. We discuss how an inflammatory response that induces simultaneous fever and/or prior exposure to a pathogen (e.g., viral infection) that deactivates molecular protective mechanisms interacts synergistically with the hyperthermia of exercise to perhaps explain heat stroke cases reported in low-risk populations performing routine activities. Importantly, we question the "traditional" notion that high core temperature is the critical mediator of exercise performance degradation and heat stroke. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

  12. Self-Adaptive Image Reconstruction Inspired by Insect Compound Eye Mechanism

    PubMed Central

    Zhang, Jiahua; Shi, Aiye; Wang, Xin; Bian, Linjie; Huang, Fengchen; Xu, Lizhong

    2012-01-01

    Inspired by the mechanism of imaging and adaptation to luminosity in insect compound eyes (ICE), we propose an ICE-based adaptive reconstruction method (ARM-ICE), which can adjust the sampling vision field of image according to the environment light intensity. The target scene can be compressive, sampled independently with multichannel through ARM-ICE. Meanwhile, ARM-ICE can regulate the visual field of sampling to control imaging according to the environment light intensity. Based on the compressed sensing joint sparse model (JSM-1), we establish an information processing system of ARM-ICE. The simulation of a four-channel ARM-ICE system shows that the new method improves the peak signal-to-noise ratio (PSNR) and resolution of the reconstructed target scene under two different cases of light intensity. Furthermore, there is no distinct block effect in the result, and the edge of the reconstructed image is smoother than that obtained by the other two reconstruction methods in this work. PMID:23365615

  13. Non-Invasive Investigation of Bone Adaptation in Humans to Mechanical Loading

    NASA Technical Reports Server (NTRS)

    Whalen, R.

    1999-01-01

    Experimental studies have identified peak cyclic forces, number of loading cycles, and loading rate as contributors to the regulation of bone metabolism. We have proposed a theoretical model that relates bone density to a mechanical stimulus derived from average daily cumulative peak cyclic 'effective' tissue stresses. In order to develop a non-invasive experimental model to test the theoretical model we need to: (1) monitor daily cumulative loading on a bone, (2) compute the internal stress state(s) resulting from the imposed loading, and (3) image volumetric bone density accurately, precisely, and reproducibly within small contiguous volumes throughout the bone. We have chosen the calcaneus (heel) as an experimental model bone site because it is loaded by ligament, tendon and joint contact forces in equilibrium with daily ground reaction forces that we can measure; it is a peripheral bone site and therefore more easily and accurately imaged with computed tomography; it is composed primarily of cancellous bone; and it is a relevant site for monitoring bone loss and adaptation in astronauts and the general population. This paper presents an overview of our recent advances in the areas of monitoring daily ground reaction forces, biomechanical modeling of the forces on the calcaneus during gait, mathematical modeling of calcaneal bone adaptation in response to cumulative daily activity, accurate and precise imaging of the calcaneus with quantitative computed tomography (QCT), and application to long duration space flight.

  14. Intra-plastid protein trafficking: how plant cells adapted prokaryotic mechanisms to the eukaryotic condition.

    PubMed

    Celedon, Jose M; Cline, Kenneth

    2013-02-01

    Protein trafficking and localization in plastids involve a complex interplay between ancient (prokaryotic) and novel (eukaryotic) translocases and targeting machineries. During evolution, ancient systems acquired new functions and novel translocation machineries were developed to facilitate the correct localization of nuclear encoded proteins targeted to the chloroplast. Because of its post-translational nature, targeting and integration of membrane proteins posed the biggest challenge to the organelle to avoid aggregation in the aqueous compartments. Soluble proteins faced a different kind of problem since some had to be transported across three membranes to reach their destination. Early studies suggested that chloroplasts addressed these issues by adapting ancient-prokaryotic machineries and integrating them with novel-eukaryotic systems, a process called 'conservative sorting'. In the last decade, detailed biochemical, genetic, and structural studies have unraveled the mechanisms of protein targeting and localization in chloroplasts, suggesting a highly integrated scheme where ancient and novel systems collaborate at different stages of the process. In this review we focus on the differences and similarities between chloroplast ancestral translocases and their prokaryotic relatives to highlight known modifications that adapted them to the eukaryotic situation. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.

  15. Effects of mechanical forces on maintenance and adaptation of form in trabecular bone

    NASA Astrophysics Data System (ADS)

    Huiskes, Rik; Ruimerman, Ronald; van Lenthe, G. Harry; Janssen, Jan D.

    2000-06-01

    The architecture of trabecular bone, the porous bone found in the spine and at articulating joints, provides the requirements for optimal load transfer, by pairing suitable strength and stiffness to minimal weight according to rules of mathematical design. But, as it is unlikely that the architecture is fully pre-programmed in the genes, how are the bone cells informed about these rules, which so obviously dictate architecture? A relationship exists between bone architecture and mechanical usage-while strenuous exercise increases bone mass, disuse, as in microgravity and inactivity, reduces it. Bone resorption cells (osteoclasts) and bone formation cells (osteoblasts) normally balance bone mass in a coupled homeostatic process of remodelling, which renews some 25% of trabecular bone volume per year. Here we present a computational model of the metabolic process in bone that confirms that cell coupling is governed by feedback from mechanical load transfer.This model can explain the emergence and maintenance of trabecular architecture as an optimal mechanical structure, as well as its adaptation to alternative external loads.

  16. [Strategies and mechanisms of soil springtails in adapting lower temperature environment: research progress].

    PubMed

    Liu, Jing; Wang, Yun-Biao; Wu, Dong-Hui

    2012-12-01

    Low temperature and drought are the main environmental factors threatening the animals living in arctic area and cold temperate regions. To adapt the severe environment, the animals should adopt appropriate strategies. As a group of arthopods with freeze-avoiding strategy, soil springtails have the similar ecological mechanisms and modes of cold resistance/tolerance as insects, manifesting in the cold acclimation and drought tolerance to decrease the damage of ice crystal formation. During cold acclimation, there are a rapid increase of glycerol, a rapid decrease of fucose and glucose, and the production of anti-freeze proteins (AFP) , and exists the inter-transformation of different kinds of lipids to improve the flow of cell membrane to protect the cell from low temperature injury. In addition, soil springtails have their own specific modes and mechanisms to tolerate low temperature stress, mainly the vertical migration under the protection of snow cover and the excretion of ice nucleator from haemolymph, illustrating that it's of significance to research the cryobiology of soil springtails. This paper summarized the modes and mechanisms of soil springtails in tolerating low temperature environment, reviewed the research progress on the eco-physiology of the springtails, discussed the existing problems of the researches on the low temperature tolerance of the springtails, and prospected the research directions of the springtails low temperature ecology under the background of global change. PMID:23479899

  17. Mechano-adaptive sensory mechanism of α-catenin under tension

    PubMed Central

    Maki, Koichiro; Han, Sung-Woong; Hirano, Yoshinori; Yonemura, Shigenobu; Hakoshima, Toshio; Adachi, Taiji

    2016-01-01

    The contractile forces in individual cells drive the tissue processes, such as morphogenesis and wound healing, and maintain tissue integrity. In these processes, α-catenin molecule acts as a tension sensor at cadherin-based adherens junctions (AJs), accelerating the positive feedback of intercellular tension. Under tension, α-catenin is activated to recruit vinculin, which recruits actin filaments to AJs. In this study, we revealed how α-catenin retains its activated state while avoiding unfolding under tension. Using single-molecule force spectroscopy employing atomic force microscopy (AFM), we found that mechanically activated α-catenin fragment had higher mechanical stability than a non-activated fragment. The results of our experiments using mutated and segmented fragments showed that the key intramolecular interactions acted as a conformational switch. We also found that the conformation of α-catenin was reinforced by vinculin binding. We demonstrate that α-catenin adaptively changes its conformation under tension to a stable intermediate state, binds to vinculin, and finally settles into a more stable state reinforced by vinculin binding. Our data suggest that the plastic characteristics of α-catenin, revealed in response to both mechanical and biochemical cues, enable the functional-structural dynamics at the cellular and tissue levels. PMID:27109499

  18. Genomic Mechanisms Accounting for the Adaptation to Parasitism in Nematode-Trapping Fungi

    PubMed Central

    Meerupati, Tejashwari; Andersson, Karl-Magnus; Friman, Eva; Kumar, Dharmendra; Tunlid, Anders; Ahrén, Dag

    2013-01-01

    Orbiliomycetes is one of the earliest diverging branches of the filamentous ascomycetes. The class contains nematode-trapping fungi that form unique infection structures, called traps, to capture and kill free-living nematodes. The traps have evolved differently along several lineages and include adhesive traps (knobs, nets or branches) and constricting rings. We show, by genome sequencing of the knob-forming species Monacrosporium haptotylum and comparison with the net-forming species Arthrobotrys oligospora, that two genomic mechanisms are likely to have been important for the adaptation to parasitism in these fungi. Firstly, the expansion of protein domain families and the large number of species-specific genes indicated that gene duplication followed by functional diversification had a major role in the evolution of the nematode-trapping fungi. Gene expression indicated that many of these genes are important for pathogenicity. Secondly, gene expression of orthologs between the two fungi during infection indicated that differential regulation was an important mechanism for the evolution of parasitism in nematode-trapping fungi. Many of the highly expressed and highly upregulated M. haptotylum transcripts during the early stages of nematode infection were species-specific and encoded small secreted proteins (SSPs) that were affected by repeat-induced point mutations (RIP). An active RIP mechanism was revealed by lack of repeats, dinucleotide bias in repeats and genes, low proportion of recent gene duplicates, and reduction of recent gene family expansions. The high expression and rapid divergence of SSPs indicate a striking similarity in the infection mechanisms of nematode-trapping fungi and plant and insect pathogens from the crown groups of the filamentous ascomycetes (Pezizomycotina). The patterns of gene family expansions in the nematode-trapping fungi were more similar to plant pathogens than to insect and animal pathogens. The observation of RIP activity

  19. Genomic mechanisms accounting for the adaptation to parasitism in nematode-trapping fungi.

    PubMed

    Meerupati, Tejashwari; Andersson, Karl-Magnus; Friman, Eva; Kumar, Dharmendra; Tunlid, Anders; Ahrén, Dag

    2013-11-01

    Orbiliomycetes is one of the earliest diverging branches of the filamentous ascomycetes. The class contains nematode-trapping fungi that form unique infection structures, called traps, to capture and kill free-living nematodes. The traps have evolved differently along several lineages and include adhesive traps (knobs, nets or branches) and constricting rings. We show, by genome sequencing of the knob-forming species Monacrosporium haptotylum and comparison with the net-forming species Arthrobotrys oligospora, that two genomic mechanisms are likely to have been important for the adaptation to parasitism in these fungi. Firstly, the expansion of protein domain families and the large number of species-specific genes indicated that gene duplication followed by functional diversification had a major role in the evolution of the nematode-trapping fungi. Gene expression indicated that many of these genes are important for pathogenicity. Secondly, gene expression of orthologs between the two fungi during infection indicated that differential regulation was an important mechanism for the evolution of parasitism in nematode-trapping fungi. Many of the highly expressed and highly upregulated M. haptotylum transcripts during the early stages of nematode infection were species-specific and encoded small secreted proteins (SSPs) that were affected by repeat-induced point mutations (RIP). An active RIP mechanism was revealed by lack of repeats, dinucleotide bias in repeats and genes, low proportion of recent gene duplicates, and reduction of recent gene family expansions. The high expression and rapid divergence of SSPs indicate a striking similarity in the infection mechanisms of nematode-trapping fungi and plant and insect pathogens from the crown groups of the filamentous ascomycetes (Pezizomycotina). The patterns of gene family expansions in the nematode-trapping fungi were more similar to plant pathogens than to insect and animal pathogens. The observation of RIP activity

  20. Helping Teens Cope.

    ERIC Educational Resources Information Center

    Jones, Jami I.

    2003-01-01

    Considers the role of school library media specialists in helping teens cope with developmental and emotional challenges. Discusses resiliency research, and opportunities to develop programs and services especially for middle school and high school at-risk teens. (LRW)

  1. Coping with College Stress

    MedlinePlus

    ... gov/news/fullstory_160792.html Coping With College Stress Parents can help make the transition easier for ... 5, 2016 MONDAY, Sept. 5, 2016 (HealthDay News) -- Stress and anxiety are common among new college students, ...

  2. Coping with the Unthinkable.

    ERIC Educational Resources Information Center

    Scholzman, Steven C.

    2001-01-01

    Describes the symptoms of posttraumatic stress disorder in students. Suggests ways that teachers can help students cope with catastrophic events such as the September 11 terrorist attack on the World Trade Center and the Pentagon. (PKP)

  3. Coping with Feelings

    MedlinePlus

    ... coping with emotions Learn more about these emotions: Fear After any illness, it's normal to feel afraid ... life. Every heart patient has some degree of fear, but if your fear is overwhelming, it can ...

  4. Coping with the Crunch.

    ERIC Educational Resources Information Center

    Sturgeon, Julie

    2000-01-01

    Examines housing strategies several college facilities managers used to cope with the problem of overcrowded residence halls. Also highlighted are tips to help facilities managers determine if their solution is to build additional housing. (GR)

  5. Grid coupling mechanism in the semi-implicit adaptive Multi-Level Multi-Domain method

    NASA Astrophysics Data System (ADS)

    Innocenti, M. E.; Tronci, C.; Markidis, S.; Lapenta, G.

    2016-05-01

    The Multi-Level Multi-Domain (MLMD) method is a semi-implicit adaptive method for Particle-In-Cell plasma simulations. It has been demonstrated in the past in simulations of Maxwellian plasmas, electrostatic and electromagnetic instabilities, plasma expansion in vacuum, magnetic reconnection [1, 2, 3]. In multiple occasions, it has been commented on the coupling between the coarse and the refined grid solutions. The coupling mechanism itself, however, has never been explored in depth. Here, we investigate the theoretical bases of grid coupling in the MLMD system. We obtain an evolution law for the electric field solution in the overlap area of the MLMD system which highlights a dependance on the densities and currents from both the coarse and the refined grid, rather than from the coarse grid alone: grid coupling is obtained via densities and currents.

  6. Ca2+-dependent regulations and signaling in skeletal muscle: from electro-mechanical coupling to adaptation.

    PubMed

    Gehlert, Sebastian; Bloch, Wilhelm; Suhr, Frank

    2015-01-05

    Calcium (Ca2+) plays a pivotal role in almost all cellular processes and ensures the functionality of an organism. In skeletal muscle fibers, Ca(2+) is critically involved in the innervation of skeletal muscle fibers that results in the exertion of an action potential along the muscle fiber membrane, the prerequisite for skeletal muscle contraction. Furthermore and among others, Ca(2+) regulates also intracellular processes, such as myosin-actin cross bridging, protein synthesis, protein degradation and fiber type shifting by the control of Ca(2+)-sensitive proteases and transcription factors, as well as mitochondrial adaptations, plasticity and respiration. These data highlight the overwhelming significance of Ca(2+) ions for the integrity of skeletal muscle tissue. In this review, we address the major functions of Ca(2+) ions in adult muscle but also highlight recent findings of critical Ca(2+)-dependent mechanisms essential for skeletal muscle-regulation and maintenance.

  7. Ca2+-Dependent Regulations and Signaling in Skeletal Muscle: From Electro-Mechanical Coupling to Adaptation

    PubMed Central

    Gehlert, Sebastian; Bloch, Wilhelm; Suhr, Frank

    2015-01-01

    Calcium (Ca2+) plays a pivotal role in almost all cellular processes and ensures the functionality of an organism. In skeletal muscle fibers, Ca2+ is critically involved in the innervation of skeletal muscle fibers that results in the exertion of an action potential along the muscle fiber membrane, the prerequisite for skeletal muscle contraction. Furthermore and among others, Ca2+ regulates also intracellular processes, such as myosin-actin cross bridging, protein synthesis, protein degradation and fiber type shifting by the control of Ca2+-sensitive proteases and transcription factors, as well as mitochondrial adaptations, plasticity and respiration. These data highlight the overwhelming significance of Ca2+ ions for the integrity of skeletal muscle tissue. In this review, we address the major functions of Ca2+ ions in adult muscle but also highlight recent findings of critical Ca2+-dependent mechanisms essential for skeletal muscle-regulation and maintenance. PMID:25569087

  8. Mechanisms and implications of adaptive immune responses after traumatic spinal cord injury

    PubMed Central

    Ankeny, Daniel P.; Popovich, Phillip G.

    2009-01-01

    Traumatic spinal cord injury (SCI) in mammals causes widespread glial activation and recruitment to the CNS of innate (e.g., neutrophils, monocytes) and adaptive (e.g., T and B lymphocytes) immune cells. To date, most studies have sought to understand or manipulate the post-traumatic functions of astrocytes, microglia, neutrophils or monocytes. Significantly less is known about the consequences of SCI-induced lymphocyte activation. Yet, emerging data suggest that T and B cells are activated by SCI and play significant roles in shaping post-traumatic inflammation and downstream cascades of neurodegeneration and repair. Here, we provide neurobiologists with a timely review of the mechanisms and implications of SCI-induced lymphocyte activation, including a discussion of different experimental strategies that have been designed to manipulate lymphocyte function for therapeutic gain. PMID:18674593

  9. Ca2+-dependent regulations and signaling in skeletal muscle: from electro-mechanical coupling to adaptation.

    PubMed

    Gehlert, Sebastian; Bloch, Wilhelm; Suhr, Frank

    2015-01-01

    Calcium (Ca2+) plays a pivotal role in almost all cellular processes and ensures the functionality of an organism. In skeletal muscle fibers, Ca(2+) is critically involved in the innervation of skeletal muscle fibers that results in the exertion of an action potential along the muscle fiber membrane, the prerequisite for skeletal muscle contraction. Furthermore and among others, Ca(2+) regulates also intracellular processes, such as myosin-actin cross bridging, protein synthesis, protein degradation and fiber type shifting by the control of Ca(2+)-sensitive proteases and transcription factors, as well as mitochondrial adaptations, plasticity and respiration. These data highlight the overwhelming significance of Ca(2+) ions for the integrity of skeletal muscle tissue. In this review, we address the major functions of Ca(2+) ions in adult muscle but also highlight recent findings of critical Ca(2+)-dependent mechanisms essential for skeletal muscle-regulation and maintenance. PMID:25569087

  10. Genome analysis of three Pneumocystis species reveals adaptation mechanisms to life exclusively in mammalian hosts.

    PubMed

    Ma, Liang; Chen, Zehua; Huang, Da Wei; Kutty, Geetha; Ishihara, Mayumi; Wang, Honghui; Abouelleil, Amr; Bishop, Lisa; Davey, Emma; Deng, Rebecca; Deng, Xilong; Fan, Lin; Fantoni, Giovanna; Fitzgerald, Michael; Gogineni, Emile; Goldberg, Jonathan M; Handley, Grace; Hu, Xiaojun; Huber, Charles; Jiao, Xiaoli; Jones, Kristine; Levin, Joshua Z; Liu, Yueqin; Macdonald, Pendexter; Melnikov, Alexandre; Raley, Castle; Sassi, Monica; Sherman, Brad T; Song, Xiaohong; Sykes, Sean; Tran, Bao; Walsh, Laura; Xia, Yun; Yang, Jun; Young, Sarah; Zeng, Qiandong; Zheng, Xin; Stephens, Robert; Nusbaum, Chad; Birren, Bruce W; Azadi, Parastoo; Lempicki, Richard A; Cuomo, Christina A; Kovacs, Joseph A

    2016-01-01

    Pneumocystis jirovecii is a major cause of life-threatening pneumonia in immunosuppressed patients including transplant recipients and those with HIV/AIDS, yet surprisingly little is known about the biology of this fungal pathogen. Here we report near complete genome assemblies for three Pneumocystis species that infect humans, rats and mice. Pneumocystis genomes are highly compact relative to other fungi, with substantial reductions of ribosomal RNA genes, transporters, transcription factors and many metabolic pathways, but contain expansions of surface proteins, especially a unique and complex surface glycoprotein superfamily, as well as proteases and RNA processing proteins. Unexpectedly, the key fungal cell wall components chitin and outer chain N-mannans are absent, based on genome content and experimental validation. Our findings suggest that Pneumocystis has developed unique mechanisms of adaptation to life exclusively in mammalian hosts, including dependence on the lungs for gas and nutrients and highly efficient strategies to escape both host innate and acquired immune defenses. PMID:26899007

  11. Genome analysis of three Pneumocystis species reveals adaptation mechanisms to life exclusively in mammalian hosts

    PubMed Central

    Ma, Liang; Chen, Zehua; Huang, Da Wei; Kutty, Geetha; Ishihara, Mayumi; Wang, Honghui; Abouelleil, Amr; Bishop, Lisa; Davey, Emma; Deng, Rebecca; Deng, Xilong; Fan, Lin; Fantoni, Giovanna; Fitzgerald, Michael; Gogineni, Emile; Goldberg, Jonathan M.; Handley, Grace; Hu, Xiaojun; Huber, Charles; Jiao, Xiaoli; Jones, Kristine; Levin, Joshua Z.; Liu, Yueqin; Macdonald, Pendexter; Melnikov, Alexandre; Raley, Castle; Sassi, Monica; Sherman, Brad T.; Song, Xiaohong; Sykes, Sean; Tran, Bao; Walsh, Laura; Xia, Yun; Yang, Jun; Young, Sarah; Zeng, Qiandong; Zheng, Xin; Stephens, Robert; Nusbaum, Chad; Birren, Bruce W.; Azadi, Parastoo; Lempicki, Richard A.; Cuomo, Christina A.; Kovacs, Joseph A.

    2016-01-01

    Pneumocystis jirovecii is a major cause of life-threatening pneumonia in immunosuppressed patients including transplant recipients and those with HIV/AIDS, yet surprisingly little is known about the biology of this fungal pathogen. Here we report near complete genome assemblies for three Pneumocystis species that infect humans, rats and mice. Pneumocystis genomes are highly compact relative to other fungi, with substantial reductions of ribosomal RNA genes, transporters, transcription factors and many metabolic pathways, but contain expansions of surface proteins, especially a unique and complex surface glycoprotein superfamily, as well as proteases and RNA processing proteins. Unexpectedly, the key fungal cell wall components chitin and outer chain N-mannans are absent, based on genome content and experimental validation. Our findings suggest that Pneumocystis has developed unique mechanisms of adaptation to life exclusively in mammalian hosts, including dependence on the lungs for gas and nutrients and highly efficient strategies to escape both host innate and acquired immune defenses. PMID:26899007

  12. Caregivers--Who Copes How?

    ERIC Educational Resources Information Center

    Chappell, Neena L.; Dujela, Carren

    2009-01-01

    Within gerontological caregiving research, there is a major emphasis on stresses and burdens of this role. Yet there has been little attention directed toward the coping strategies that caregivers engage in to cope with this role and the factors that influence their adoption of different coping strategies. This article examines coping strategies…

  13. Adapting Vocational Psychology To Cope with Change.

    ERIC Educational Resources Information Center

    Hesketh, Beryl

    2001-01-01

    The interdisciplinary tradition of vocational psychology is a strength, but it has been slow to respond to technology. Strategic issues to be addressed include implications of human genome research, inclusion of goal setting and metacognition in career development, virtual work organizations, and time as an important dimension of career research.…

  14. Time Course of Pathogenic and Adaptation Mechanisms in Cystinotic Mouse Kidneys

    PubMed Central

    Gaide Chevronnay, Héloïse P.; Janssens, Virginie; Van Der Smissen, Patrick; N’Kuli, Francisca; Nevo, Nathalie; Guiot, Yves; Levtchenko, Elena; Marbaix, Etienne; Pierreux, Christophe E.; Cherqui, Stéphanie; Antignac, Corinne; Courtoy, Pierre J.

    2014-01-01

    Cystinosis, a main cause of Fanconi syndrome, is reproduced in congenic C57BL/6 cystinosin knockout (KO) mice. To identify the sequence of pathogenic and adaptation mechanisms of nephropathic cystinosis, we defined the onset of Fanconi syndrome in KO mice between 3 and 6 months of age and analyzed the correlation with structural and functional changes in proximal tubular cells (PTCs), with focus on endocytosis of ultrafiltrated disulfide-rich proteins as a key source of cystine. Despite considerable variation between mice at the same age, typical event sequences were delineated. At the cellular level, amorphous lysosomal inclusions preceded cystine crystals and eventual atrophy without crystals. At the nephron level, lesions started at the glomerulotubular junction and then extended distally. In situ hybridization and immunofluorescence revealed progressive loss of expression of megalin, cubilin, sodium-glucose cotransporter 2, and type IIa sodium-dependent phosphate cotransporter, suggesting apical dedifferentiation accounting for Fanconi syndrome before atrophy. Injection of labeled proteins revealed that defective endocytosis in S1 PTCs led to partial compensatory uptake by S3 PTCs, suggesting displacement of endocytic load and injury by disulfide-rich cargo. Increased PTC apoptosis allowed luminal shedding of cystine crystals and was partially compensated for by tubular proliferation. We conclude that lysosomal storage triggered by soluble cystine accumulation induces apical PTC dedifferentiation, which causes transfer of the harmful load of disulfide-rich proteins to more distal cells, possibly explaining longitudinal progression of swan-neck lesions. Furthermore, our results suggest that subsequent adaptation mechanisms include lysosomal clearance of free and crystalline cystine into urine and ongoing tissue repair. PMID:24525030

  15. Adaptive response of bacteria: Multiple hurdles, cross-tolerance and tools to illustrate underlying mechanisms

    NASA Astrophysics Data System (ADS)

    Paramythiotis, Spyridon; Skandamis, Panagiotis N.

    2015-01-01

    A basic principle in the bacterial resistance against lethal stresses is that exposure of microbial cells to a sublethal hurdle (e.g., pH 5.0, 3% NaCl, or 48°C) may induce resistance to lethal level of the same or different stress. The latter is called "cross-tolerance" and the bacteria experiencing such situations are termed "stress-hardened". The majority of scientific reports on the adaptive responses of bacteria to stresses have recently addressed the need to elucidate the underlying mechanisms controlling bacterial stress response. This in turn, will assist in the efficient application of the multiple hurdle approach, e.g., by selecting specific sanitizers, combining stress treatments or antimicrobials, especially in mild processing, against specific cellular targets, eliminating the possibility of the development of stress adapted cells. Common scientific approaches for studying the link between phenotype (e.g., inactivation, survival, or growth) and physiology is the assessment of global transcriptional changes (up- or down-regulation) or those of certain genes, as well as of proteins involved in certain metabolic pathways, occurring during exposure to stress. This may also be performed in parallel to comparative evaluation of the phenotypic response of wild and mutant strains. The post-genomics research on foodborne pathogens has extended our knowledge beyond their phenotypic behavior and may offer mechanistic insights in the following: (i) the top-down approach (induction), which is the search of the underlying mechanisms (low level) responsible for a specific phenotype based on "-omic" studies; and (ii) the bottom-up approach (deduction), which starts from intracellular level and forms a mechanistic (functional) basis for the cellular response. All these may eventually enable the development of mechanistic microbial models and efficient strategies for controlling survival and growth of pathogens in foods.

  16. Time course of pathogenic and adaptation mechanisms in cystinotic mouse kidneys.

    PubMed

    Gaide Chevronnay, Héloïse P; Janssens, Virginie; Van Der Smissen, Patrick; N'Kuli, Francisca; Nevo, Nathalie; Guiot, Yves; Levtchenko, Elena; Marbaix, Etienne; Pierreux, Christophe E; Cherqui, Stéphanie; Antignac, Corinne; Courtoy, Pierre J

    2014-06-01

    Cystinosis, a main cause of Fanconi syndrome, is reproduced in congenic C57BL/6 cystinosin knockout (KO) mice. To identify the sequence of pathogenic and adaptation mechanisms of nephropathic cystinosis, we defined the onset of Fanconi syndrome in KO mice between 3 and 6 months of age and analyzed the correlation with structural and functional changes in proximal tubular cells (PTCs), with focus on endocytosis of ultrafiltrated disulfide-rich proteins as a key source of cystine. Despite considerable variation between mice at the same age, typical event sequences were delineated. At the cellular level, amorphous lysosomal inclusions preceded cystine crystals and eventual atrophy without crystals. At the nephron level, lesions started at the glomerulotubular junction and then extended distally. In situ hybridization and immunofluorescence revealed progressive loss of expression of megalin, cubilin, sodium-glucose cotransporter 2, and type IIa sodium-dependent phosphate cotransporter, suggesting apical dedifferentiation accounting for Fanconi syndrome before atrophy. Injection of labeled proteins revealed that defective endocytosis in S1 PTCs led to partial compensatory uptake by S3 PTCs, suggesting displacement of endocytic load and injury by disulfide-rich cargo. Increased PTC apoptosis allowed luminal shedding of cystine crystals and was partially compensated for by tubular proliferation. We conclude that lysosomal storage triggered by soluble cystine accumulation induces apical PTC dedifferentiation, which causes transfer of the harmful load of disulfide-rich proteins to more distal cells, possibly explaining longitudinal progression of swan-neck lesions. Furthermore, our results suggest that subsequent adaptation mechanisms include lysosomal clearance of free and crystalline cystine into urine and ongoing tissue repair. PMID:24525030

  17. Comparison of human turning gait with the mechanical performance of lower limb prosthetic transverse rotation adapters.

    PubMed

    Flick, K C; Orendurff, M S; Berge, J S; Segal, A D; Klute, G K

    2005-04-01

    Given the importance of minimizing transverse plane shear stress on soft tissue, several transverse rotational adapters (TRAs) are available for incorporation in lower limb prostheses. This study compares kinetic and kinematic data from human subjects during straight and turning gaits to the mechanical performance of several TRAs. Physiological data were collected from three individuals walking straight and turning at self-selected speeds around a 1 m radius circle. The average peak torques and range of motion for normal subjects while turning were 8.2 Nm and 26 degrees (outside leg), 11.8Nm and 20 degrees (inside leg), and 11.4 Nm and 20 degrees (right leg) during straight gait. Each TRA was mechanically tested without axial loading in a servo-hydraulic material testing system (MTS) over its rotational range at 0.5 dergrees/s and 60 degrees/s. The TRAs with axial compression were also tested at 0.5 degrees/s under a 736N (75kg mass) axial load. Applying these torques to the different TRAs yielded 3 to 35 degrees rotation, depending on the elastomer installed. Some TRAs had nearly constant stiffness, while others stiffened with rotation. The TRAs also varied in their average maximum stiffness from 0.4Nm/degree to 2.7Nm/degrees. Normal subjects exhibit interior vs. exterior asymmetrical torques and displacements; however, only one of the TRAs is designed to allow asymmetrical stiffness, and none have asymmetric ranges. Prosthetists and physicians can use these data to better interpret amputees' qualitative remarks and to prescribe the correct TRA and/or elastomer. This information also forms a basis for further design and development of novel torque absorbing prosthetic adapters.

  18. Relationship Between Resilience and Coping Strategies in Competitive Sport.

    PubMed

    Secades, Xabel García; Molinero, Olga; Salguero, Alfonso; Barquín, Roberto Ruíz; de la Vega, Ricardo; Márquez, Sara

    2016-02-01

    Resilience is important in sport performers to withstand the pressure they experience. This study analyzed the relationship among resilient qualities and coping strategies in 235 Spanish athletes (126 males, 109 females; M age = 20.7 yr) who practiced different sports (79.1% team sports, 20.9% individual sports). They were evaluated at the beginning of the last competitive mesocycle and after an important competition. Coping strategies and level of resilient qualities were measured by the Coping Inventory for Competitive Sport and the Resilience Scale. There was no significant difference in resilience scores between evaluations performed during the last mesocycle or competition. A significant increase occurred in the scores for emotion-oriented and distraction-oriented coping during competition. Resilience scores correlated positively to task-oriented coping and negatively to disengagement- and distraction-oriented coping during both periods. Analysis of variance indicated that athletes with high individual resilient qualities reached higher scores in task-oriented coping, using to a lower extent disengagement- and distraction-oriented coping. Results obtained suggest that resilient characteristics may associate in athletes to the use of more potentially adaptative coping strategies.

  19. Relationship Between Resilience and Coping Strategies in Competitive Sport.

    PubMed

    Secades, Xabel García; Molinero, Olga; Salguero, Alfonso; Barquín, Roberto Ruíz; de la Vega, Ricardo; Márquez, Sara

    2016-02-01

    Resilience is important in sport performers to withstand the pressure they experience. This study analyzed the relationship among resilient qualities and coping strategies in 235 Spanish athletes (126 males, 109 females; M age = 20.7 yr) who practiced different sports (79.1% team sports, 20.9% individual sports). They were evaluated at the beginning of the last competitive mesocycle and after an important competition. Coping strategies and level of resilient qualities were measured by the Coping Inventory for Competitive Sport and the Resilience Scale. There was no significant difference in resilience scores between evaluations performed during the last mesocycle or competition. A significant increase occurred in the scores for emotion-oriented and distraction-oriented coping during competition. Resilience scores correlated positively to task-oriented coping and negatively to disengagement- and distraction-oriented coping during both periods. Analysis of variance indicated that athletes with high individual resilient qualities reached higher scores in task-oriented coping, using to a lower extent disengagement- and distraction-oriented coping. Results obtained suggest that resilient characteristics may associate in athletes to the use of more potentially adaptative coping strategies. PMID:27420325

  20. Heritable variation in heat shock gene expression: a potential mechanism for adaptation to thermal stress in embryos of sea turtles.

    PubMed

    Tedeschi, J N; Kennington, W J; Tomkins, J L; Berry, O; Whiting, S; Meekan, M G; Mitchell, N J

    2016-01-13

    The capacity of species to respond adaptively to warming temperatures will be key to their survival in the Anthropocene. The embryos of egg-laying species such as sea turtles have limited behavioural means for avoiding high nest temperatures, and responses at the physiological level may be critical to coping with predicted global temperature increases. Using the loggerhead sea turtle (Caretta caretta) as a model, we used quantitative PCR to characterise variation in the expression response of heat-shock genes (hsp60, hsp70 and hsp90; molecular chaperones involved in cellular stress response) to an acute non-lethal heat shock. We show significant variation in gene expression at the clutch and population levels for some, but not all hsp genes. Using pedigree information, we estimated heritabilities of the expression response of hsp genes to heat shock and demonstrated both maternal and additive genetic effects. This is the first evidence that the heat-shock response is heritable in sea turtles and operates at the embryonic stage in any reptile. The presence of heritable variation in the expression of key thermotolerance genes is necessary for sea turtles to adapt at a molecular level to warming incubation environments.

  1. Heritable variation in heat shock gene expression: a potential mechanism for adaptation to thermal stress in embryos of sea turtles.

    PubMed

    Tedeschi, J N; Kennington, W J; Tomkins, J L; Berry, O; Whiting, S; Meekan, M G; Mitchell, N J

    2016-01-13

    The capacity of species to respond adaptively to warming temperatures will be key to their survival in the Anthropocene. The embryos of egg-laying species such as sea turtles have limited behavioural means for avoiding high nest temperatures, and responses at the physiological level may be critical to coping with predicted global temperature increases. Using the loggerhead sea turtle (Caretta caretta) as a model, we used quantitative PCR to characterise variation in the expression response of heat-shock genes (hsp60, hsp70 and hsp90; molecular chaperones involved in cellular stress response) to an acute non-lethal heat shock. We show significant variation in gene expression at the clutch and population levels for some, but not all hsp genes. Using pedigree information, we estimated heritabilities of the expression response of hsp genes to heat shock and demonstrated both maternal and additive genetic effects. This is the first evidence that the heat-shock response is heritable in sea turtles and operates at the embryonic stage in any reptile. The presence of heritable variation in the expression of key thermotolerance genes is necessary for sea turtles to adapt at a molecular level to warming incubation environments. PMID:26763709

  2. Regulated cell death and adaptive stress responses.

    PubMed

    Galluzzi, Lorenzo; Bravo-San Pedro, José Manuel; Kepp, Oliver; Kroemer, Guido

    2016-06-01

    Eukaryotic cells react to potentially dangerous perturbations of the intracellular or extracellular microenvironment by activating rapid (transcription-independent) mechanisms that attempt to restore homeostasis. If such perturbations persist, cells may still try to cope with stress by activating delayed and robust (transcription-dependent) adaptive systems, or they may actively engage in cellular suicide. This regulated form of cell death can manifest with various morphological, biochemical and immunological correlates, and constitutes an ultimate attempt of stressed cells to maintain organismal homeostasis. Here, we dissect the general organization of adaptive cellular responses to stress, their intimate connection with regulated cell death, and how the latter operates for the preservation of organismal homeostasis.

  3. The Coexistence of Coping Resources and Specific Coping Styles in Stress: Evidence from Full Information Item Bifactor Analysis

    PubMed Central

    Cui, Meng; Wu, Qing; Zhu, Xia; Miao, Danmin; Zhang, Yan; Feng, Xi; Xiao, Wei

    2014-01-01

    Background Knowledge of coping styles is useful in clinical diagnosis and suggesting specific therapeutic interventions. However, the latent structures and relationships between different aspects of coping styles have not been fully clarified. A full information item bifactor model will be beneficial to future research. Objective One goal of this study is identification of the best fit statistical model of coping styles. A second goal is entails extended analyses of latent relationships among different coping styles. In general, such research should offer greater understanding of the mechanisms of coping styles and provide insights into coping with stress. Methods Coping Styles Questionnaire (CSQ) and Generalized Self-Efficacy Scale (GSES) were administrated to officers suffering from military stress. Confirmatory Factor Analyses was performed to indentify the best fit model. A hierarchical item response model (bifactor model) was adopted to analyze the data. Additionally, correlations among coping styles and self-efficacy were compared using both original and bifactor models. Results Results showed a bifactor model best fit the data. Item loadings on general and specific factors varied among different coping styles. All items loaded significantly on the general factor, and most items also had moderate to large loadings on specific factors. The correlation between coping styles and self-efficacy and the correlation among different coping styles changed significantly after extracting the general factor of coping stress using bifactor analysis. This was seen in changes from positive (r = 0.714, p<0.01) correlation to negative (r = −0.335, p<0.01) and also from negative (r = −0.296, p<0.01) to positive (r = 0.331, p<0.01). Conclusion Our results reveal that coping styles have a bifactor structure. They also provide direct evidence of coexisting coping resources and styles. This further clarifies that dimensions of coping styles should include

  4. Animal activity around the clock with no overt circadian rhythms: patterns, mechanisms and adaptive value.

    PubMed

    Bloch, Guy; Barnes, Brian M; Gerkema, Menno P; Helm, Barbara

    2013-08-22

    Circadian rhythms are ubiquitous in many organisms. Animals that are forced to be active around the clock typically show reduced performance, health and survival. Nevertheless, we review evidence of animals showing prolonged intervals of activity with attenuated or nil overt circadian rhythms and no apparent ill effects. We show that around-the-clock and ultradian activity patterns are more common than is generally appreciated, particularly in herbivores, in animals inhabiting polar regions and habitats with constant physical environments, in animals during specific life-history stages (such as migration or reproduction), and in highly social animals. The underlying mechanisms are diverse, but studies suggest that some circadian pacemakers continue to measure time in animals active around the clock. The prevalence of around-the-clock activity in diverse animals and habitats, and an apparent diversity of underlying mechanisms, are consistent with convergent evolution. We suggest that the basic organizational principles of the circadian system and its complexity encompass the potential for chronobiological plasticity. There may be trade-offs between benefits of persistent daily rhythms versus plasticity, which for reasons still poorly understood make overt daily arrhythmicity functionally adaptive only in selected habitats and for selected lifestyles.

  5. Multifractal entropy based adaptive multiwavelet construction and its application for mechanical compound-fault diagnosis

    NASA Astrophysics Data System (ADS)

    He, Shuilong; Chen, Jinglong; Zhou, Zitong; Zi, Yanyang; Wang, Yanxue; Wang, Xiaodong

    2016-08-01

    Compound-fault diagnosis of mechanical equipment is still challenging at present because of its complexity, multiplicity and non-stationarity. In this work, an adaptive redundant multiwavelet packet (ARMP) method is proposed for the compound-fault diagnosis. Multiwavelet transform has two or more base functions and many excellent properties, making it suitable for detecting all the features of compound-fault simultaneously. However, on the other hand, the fixed basis function used in multiwavelet transform may decrease the accuracy of fault extraction; what's more, the multi-resolution analysis of multiwavelet transform in low frequency band may also leave out the useful features. Thus, the minimum sum of normalized multifractal entropy is adopted as the optimization criteria for the proposed ARMP method, while the relative energy ratio of the characteristic frequency is utilized as an effective way in automatically selecting the sensitive frequency bands. Then, The ARMP technique combined with Hilbert transform demodulation analysis is then applied to detect the compound-fault of bevel gearbox and planetary gearbox. The results verify that the proposed method can effectively identify and detect the compound-fault of mechanical equipment.

  6. Animal activity around the clock with no overt circadian rhythms: patterns, mechanisms and adaptive value

    PubMed Central

    Bloch, Guy; Barnes, Brian M.; Gerkema, Menno P.; Helm, Barbara

    2013-01-01

    Circadian rhythms are ubiquitous in many organisms. Animals that are forced to be active around the clock typically show reduced performance, health and survival. Nevertheless, we review evidence of animals showing prolonged intervals of activity with attenuated or nil overt circadian rhythms and no apparent ill effects. We show that around-the-clock and ultradian activity patterns are more common than is generally appreciated, particularly in herbivores, in animals inhabiting polar regions and habitats with constant physical environments, in animals during specific life-history stages (such as migration or reproduction), and in highly social animals. The underlying mechanisms are diverse, but studies suggest that some circadian pacemakers continue to measure time in animals active around the clock. The prevalence of around-the-clock activity in diverse animals and habitats, and an apparent diversity of underlying mechanisms, are consistent with convergent evolution. We suggest that the basic organizational principles of the circadian system and its complexity encompass the potential for chronobiological plasticity. There may be trade-offs between benefits of persistent daily rhythms versus plasticity, which for reasons still poorly understood make overt daily arrhythmicity functionally adaptive only in selected habitats and for selected lifestyles. PMID:23825202

  7. Do common mechanisms of adaptation mediate color discrimination and appearance? Uniform backgrounds.

    PubMed

    Hillis, James M; Brainard, David H

    2005-10-01

    Color vision is useful for detecting surface boundaries and identifying objects. Are the signals used to perform these two functions processed by common mechanisms, or has the visual system optimized its processing separately for each task? We measured the effect of mean chromaticity and luminance on color discriminability and on color appearance under well-matched stimulus conditions. In the discrimination experiments, a pedestal spot was presented in one interval and a pedestal + test in a second. Observers indicated which interval contained the test. In the appearance experiments, observers matched the appearance of test spots across a change in background. We analyzed the data using a variant of Fechner's proposal, that the rate of apparent stimulus change is proportional to visual sensitivity. We found that saturating visual response functions together with a model of adaptation that included multiplicative gain control and a subtractive term accounted for data from both tasks. This result suggests that effects of the contexts we studied on color appearance and discriminability are controlled by the same underlying mechanism.

  8. Physiological and genetic control mechanisms for plant adaptation to high temperature and elevated CO2

    SciTech Connect

    Zeiger, Eduardo

    2001-02-01

    Acclimations of the stomatal response to CO2 were characterized. Stomata from the model plant used, Vicia faba, are very sensitive to ambient CO2 when grown in growth chambers as compared to stomata from green house grown leaves. The different CO2 sensitivities of growth chamber and green house grown guard cells was confirmed by reciprocal transfer experiments. Stomata acclimated to their new environment and acquired the CO2 sensitivity typical of that environment. A mechanism for CO2 sensing was also characterized. Results show that CO2 concentration alters the concentration of zeaxanthin in the guard cell chloroplast, thus modifying the light response of the guard cells. This mechanism accounts for the well characterized interactions of light and CO2 in the stomatal responses. The xanthophyll cycle in the stomata of the facultative CAM plant, Mesembryanthemum crystallinum, was characterized. In the C3 mode, zeaxanthin is formed in the light and stomata open. Upon induction of the CAM mode, zeaxanthin synthesis is blocked and stomata no longer respond to light. These results implicate the regulation of the xanthophyll cycle of guard cells in the CAM adaptation.

  9. Animal activity around the clock with no overt circadian rhythms: patterns, mechanisms and adaptive value.

    PubMed

    Bloch, Guy; Barnes, Brian M; Gerkema, Menno P; Helm, Barbara

    2013-08-22

    Circadian rhythms are ubiquitous in many organisms. Animals that are forced to be active around the clock typically show reduced performance, health and survival. Nevertheless, we review evidence of animals showing prolonged intervals of activity with attenuated or nil overt circadian rhythms and no apparent ill effects. We show that around-the-clock and ultradian activity patterns are more common than is generally appreciated, particularly in herbivores, in animals inhabiting polar regions and habitats with constant physical environments, in animals during specific life-history stages (such as migration or reproduction), and in highly social animals. The underlying mechanisms are diverse, but studies suggest that some circadian pacemakers continue to measure time in animals active around the clock. The prevalence of around-the-clock activity in diverse animals and habitats, and an apparent diversity of underlying mechanisms, are consistent with convergent evolution. We suggest that the basic organizational principles of the circadian system and its complexity encompass the potential for chronobiological plasticity. There may be trade-offs between benefits of persistent daily rhythms versus plasticity, which for reasons still poorly understood make overt daily arrhythmicity functionally adaptive only in selected habitats and for selected lifestyles. PMID:23825202

  10. Evolution of the fruit endocarp: molecular mechanisms underlying adaptations in seed protection and dispersal strategies

    PubMed Central

    Dardick, Chris; Callahan, Ann M.

    2014-01-01

    Plant evolution is largely driven by adaptations in seed protection and dispersal strategies that allow diversification into new niches. This is evident by the tremendous variation in flowering and fruiting structures present both across and within different plant lineages. Within a single plant family a staggering variety of fruit types can be found such as fleshy fruits including berries, pomes, and drupes and dry fruit structures like achenes, capsules, and follicles. What are the evolutionary mechanisms that enable such dramatic shifts to occur in a relatively short period of time? This remains a fundamental question of plant biology today. On the surface it seems that these extreme differences in form and function must be the consequence of very different developmental programs that require unique sets of genes. Yet as we begin to decipher the molecular and genetic basis underlying fruit form it is becoming apparent that simple genetic changes in key developmental regulatory genes can have profound anatomical effects. In this review, we discuss recent advances in understanding the molecular mechanisms of fruit endocarp tissue differentiation that have contributed to species diversification within three plant lineages. PMID:25009543

  11. Evidence for Retromutagenesis as a Mechanism for Adaptive Mutation in Escherichia coli

    PubMed Central

    Morreall, Jordan; Kim, Alice; Liu, Yuan; Degtyareva, Natalya; Weiss, Bernard; Doetsch, Paul W.

    2015-01-01

    Adaptive mutation refers to the continuous outgrowth of new mutants from a non-dividing cell population during selection, in apparent violation of the neo-Darwinian principle that mutation precedes selection. One explanation is that of retromutagenesis, in which a DNA lesion causes a transcriptional mutation that yields a mutant protein, allowing escape from selection. This enables a round of DNA replication that establishes heritability. Because the model requires that gene expression precedes DNA replication, it predicts that during selection, new mutants will arise from damage only to the transcribed DNA strand. As a test, we used a lacZ amber mutant of Escherichia coli that can revert by nitrous acid-induced deamination of adenine residues on either strand of the TAG stop codon, each causing different DNA mutations. When stationary-phase, mutagenized cells were grown in rich broth before being plated on lactose-selective media, only non-transcribed strand mutations appeared in the revertants. This result was consistent with the known high sensitivity to deamination of the single-stranded DNA in a transcription bubble, and it provided an important control because it demonstrated that the genetic system we would use to detect transcribed-strand mutations could also detect a bias toward the non-transcribed strand. When residual lacZ transcription was blocked beforehand by catabolite repression, both strands were mutated about equally, but if revertants were selected immediately after nitrous acid exposure, transcribed-strand mutations predominated among the revertants, implicating retromutagenesis as the mechanism. This result was not affected by gene orientation. Retromutagenesis is apt to be a universal method of evolutionary adaptation, which enables the emergence of new mutants from mutations acquired during counterselection rather than beforehand, and it may have roles in processes as diverse as the development of antibiotic resistance and neoplasia. PMID

  12. Evidence for Retromutagenesis as a Mechanism for Adaptive Mutation in Escherichia coli.

    PubMed

    Morreall, Jordan; Kim, Alice; Liu, Yuan; Degtyareva, Natalya; Weiss, Bernard; Doetsch, Paul W

    2015-08-01

    Adaptive mutation refers to the continuous outgrowth of new mutants from a non-dividing cell population during selection, in apparent violation of the neo-Darwinian principle that mutation precedes selection. One explanation is that of retromutagenesis, in which a DNA lesion causes a transcriptional mutation that yields a mutant protein, allowing escape from selection. This enables a round of DNA replication that establishes heritability. Because the model requires that gene expression precedes DNA replication, it predicts that during selection, new mutants will arise from damage only to the transcribed DNA strand. As a test, we used a lacZ amber mutant of Escherichia coli that can revert by nitrous acid-induced deamination of adenine residues on either strand of the TAG stop codon, each causing different DNA mutations. When stationary-phase, mutagenized cells were grown in rich broth before being plated on lactose-selective media, only non-transcribed strand mutations appeared in the revertants. This result was consistent with the known high sensitivity to deamination of the single-stranded DNA in a transcription bubble, and it provided an important control because it demonstrated that the genetic system we would use to detect transcribed-strand mutations could also detect a bias toward the non-transcribed strand. When residual lacZ transcription was blocked beforehand by catabolite repression, both strands were mutated about equally, but if revertants were selected immediately after nitrous acid exposure, transcribed-strand mutations predominated among the revertants, implicating retromutagenesis as the mechanism. This result was not affected by gene orientation. Retromutagenesis is apt to be a universal method of evolutionary adaptation, which enables the emergence of new mutants from mutations acquired during counterselection rather than beforehand, and it may have roles in processes as diverse as the development of antibiotic resistance and neoplasia. PMID

  13. Psychosocial variables associated with coping of HIV-positive women diagnosed during pregnancy.

    PubMed

    Kotzé, Marinda; Visser, Maretha; Makin, Jenny; Sikkema, Kathleen; Forsyth, Brian

    2013-02-01

    To identify psychosocial variables related to the use of coping strategies by HIV-positive South African women diagnosed during pregnancy, structured interviews were conducted with 224 HIV-positive women at antenatal clinics over a period of 2 years. Two coping styles, active and avoidant coping, were assessed using an adapted version of the Brief COPE. Psychosocial variables associated with changes in coping over time were identified with mixed linear analysis. Increases in active coping were associated with decreasing levels of internalized stigma and depression, increasing self-esteem and positive social support, knowing someone who is living with HIV, being physically healthy and living above the poverty line. Increases in avoidant coping were associated with increasing internalized stigma and depression, lower levels of self-esteem, HIV-knowledge and lower levels of education. Recommendations are made for psychological support services to strengthen women's ability to cope and enhance their health and that of their infants.

  14. Structures and Mechanisms Design Concepts for Adaptive Deployable Entry Placement Technology

    NASA Technical Reports Server (NTRS)

    Yount, Bryan C.; Arnold, James O.; Gage, Peter J.; Mockelman, Jeffrey; Venkatapathy, Ethiraj

    2012-01-01

    System studies have shown that large deployable aerodynamic decelerators such as the Adaptive Deployable Entry and Placement Technology (ADEPT) concept can revolutionize future robotic and human exploration missions involving atmospheric entry, descent and landing by significantly reducing the maximum heating rate, total heat load, and deceleration loads experienced by the spacecraft during entry [1-3]. ADEPT and the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) [4] share the approach of stowing the entry system in the shroud of the launch vehicle and deploying it to a much larger diameter prior to entry. The ADEPT concept provides a low ballistic coefficient for planetary entry by employing an umbrella-like deployable structure consisting of ribs, struts and a fabric cover that form an aerodynamic decelerator capable of undergoing hypersonic flight. The ADEPT "skin" is a 3-D woven carbon cloth that serves as a thermal protection system (TPS) and as a structural surface that transfers aerodynamic forces to the underlying ribs [5]. This paper focuses on design activities associated with integrating ADEPT components (cloth, ribs, struts and mechanisms) into a system that can function across all configurations and environments of a typical mission concept: stowed during launch, in-space deployment, entry, descent, parachute deployment and separation from the landing payload. The baseline structures and mechanisms were selected via trade studies conducted during the summer and fall of 2012. They are now being incorporated into the design of a ground test article (GTA) that will be fabricated in 2013. It will be used to evaluate retention of the stowed configuration in a launch environment, mechanism operation for release, deployment and locking, and static strength of the deployed decelerator. Of particular interest are the carbon cloth interfaces, underlying hot structure, (Advanced Carbon- Carbon ribs) and other structural components (nose cap, struts, and

  15. Mechanisms underlying the early phase of spike frequency adaptation in mouse spinal motoneurones.

    PubMed

    Miles, G B; Dai, Y; Brownstone, R M

    2005-07-15

    Spike frequency adaptation (SFA) is a fundamental property of repetitive firing in motoneurones (MNs). Early SFA (occurring over several hundred milliseconds) is thought to be important in the initiation of muscular contraction. To date the mechanisms underlying SFA in spinal MNs remain unclear. In the present study, we used both whole-cell patch-clamp recordings of MNs in lumbar spinal cord slices prepared from motor functionally mature mice and computer modelling of spinal MNs to investigate the mechanisms underlying SFA. Pharmacological blocking agents applied during whole-cell recordings in current-clamp mode demonstrated that the medium AHP conductance (apamin), BK-type Ca2+ -dependent K+ channels (iberiotoxin), voltage-activated Ca2+ channels (CdCl2), M-current (linopirdine) and persistent Na+ currents (riluzole) are all unnecessary for SFA. Measurements of Na+ channel availability including action potential amplitude, action potential threshold and maximum depolarization rate of the action potential were found to correlate with instantaneous firing frequency suggesting that the availability of fast, inactivating Na+ channels is involved in SFA. Characterization of this Na+ conductance in voltage-clamp mode demonstrated that it undergoes slow inactivation with a time course similar to that of SFA. When experimentally measured parameters for the fast, inactivating Na+ conductance (including slow inactivation) were incorporated into a MN model, SFA could be faithfully reproduced. The removal of slow inactivation from this model was sufficient to remove SFA. These data indicate that slow inactivation of the fast, inactivating Na+ conductance is likely to be the key mechanism underlying early SFA in spinal MNs.

  16. Ultrastructural and biochemical characterization of mechanically adaptable collagenous structures in the edible sea urchin Paracentrotus lividus.

    PubMed

    Barbaglio, Alice; Tricarico, Serena; Ribeiro, Ana R; Di Benedetto, Cristiano; Barbato, Marta; Dessì, Desirèe; Fugnanesi, Valeria; Magni, Stefano; Mosca, Fabio; Sugni, Michela; Bonasoro, Francesco; Barbosa, Mario A; Wilkie, Iain C; Candia Carnevali, M Daniela

    2015-06-01

    The viscoelastic properties of vertebrate connective tissues rarely undergo significant changes within physiological timescales, the only major exception being the reversible destiffening of the mammalian uterine cervix at the end of pregnancy. In contrast to this, the connective tissues of echinoderms (sea urchins, starfish, sea cucumbers, etc.) can switch reversibly between stiff and compliant conditions in timescales of around a second to minutes. Elucidation of the molecular mechanism underlying such mutability has implications for the zoological, ecological and evolutionary field. Important information could also arise for veterinary and biomedical sciences, particularly regarding the pathological plasticization or stiffening of connective tissue structures. In the present investigation we analyzed aspects of the ultrastructure and biochemistry in two representative models, the compass depressor ligament and the peristomial membrane of the edible sea urchin Paracentrotus lividus, compared in three different mechanical states. The results provide further evidence that the mechanical adaptability of echinoderm connective tissues does not necessarily imply changes in the collagen fibrils themselves. The higher glycosaminoglycan (GAG) content registered in the peristomial membrane with respect to the compass depressor ligament suggests a diverse role of these molecules in the two mutable collagenous tissues. The possible involvement of GAG in the mutability phenomenon will need further clarification. During the shift from a compliant to a standard condition, significant changes in GAG content were detected only in the compass depressor ligament. Similarities in terms of ultrastructure (collagen fibrillar assembling) and biochemistry (two alpha chains) were found between the two models and mammalian collagen. Nevertheless, differences in collagen immunoreactivity, alpha chain migration on SDS-PAGE and BLAST alignment highlighted the uniqueness of sea urchin

  17. Alma: coping with culture, poverty, and disability.

    PubMed

    Blanche, E I

    1996-04-01

    This article raises questions about the ways culture affects the nature of health care services. By examining the life story of Alma, a Central American woman who has a daughter with disabilities; her interactions with health care providers; and my own assumptions about cultural differences, I note the impact of cultural differences on coping and adaptation in Alma and in the health care system when working with poor, non-English-speaking clients.

  18. A review of adaptive mechanisms in cell responses towards oxidative stress caused by dental resin monomers.

    PubMed

    Krifka, Stephanie; Spagnuolo, Gianrico; Schmalz, Gottfried; Schweikl, Helmut

    2013-06-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. Monomers like triethylene glycol dimethacrylate (TEGDMA) or 2-hydroxylethyl methacrylate (HEMA) are cytotoxic via apoptosis, induce genotoxic effects, and delay the cell cycle. Monomers also influence the response of cells of the innate immune system, inhibit specific odontoblast cell functions, or delay the odontogenic differentiation and mineralization processes in pulp-derived cells including stem cells. These observations indicate that resin monomers act as environmental stressors which inevitably disturb regulatory cellular networks through interference with signal transduction pathways. We hypothesize that an understanding of the cellular mechanisms underlying these phenomena will provide a better estimation of the consequences associated with dental therapy using composite materials, and lead to innovative therapeutic strategies and improved materials being used at tissue interfaces within the oral cavity. Current findings strongly suggest that monomers enhance the formation of reactive oxygen species (ROS), which is most likely the cause of biological reactions activated by dental composites and resin monomers. The aim of the present review manuscript is to discuss adaptive cell responses to oxidative stress caused by monomers. The particular significance of a tightly controlled network of non-enzymatic as well as enzymatic antioxidants for the regulation of cellular redox homeostasis and antioxidant defense in monomer-exposed cells will be addressed. The expression of ROS-metabolizing antioxidant enzymes like superoxide dismutase (SOD1), glutathione peroxidase (GPx1/2), and catalase in cells exposed to monomers will be discussed with particular emphasis on the role

  19. A review of adaptive mechanisms in cell responses towards oxidative stress caused by dental resin monomers.

    PubMed

    Krifka, Stephanie; Spagnuolo, Gianrico; Schmalz, Gottfried; Schweikl, Helmut

    2013-06-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. Monomers like triethylene glycol dimethacrylate (TEGDMA) or 2-hydroxylethyl methacrylate (HEMA) are cytotoxic via apoptosis, induce genotoxic effects, and delay the cell cycle. Monomers also influence the response of cells of the innate immune system, inhibit specific odontoblast cell functions, or delay the odontogenic differentiation and mineralization processes in pulp-derived cells including stem cells. These observations indicate that resin monomers act as environmental stressors which inevitably disturb regulatory cellular networks through interference with signal transduction pathways. We hypothesize that an understanding of the cellular mechanisms underlying these phenomena will provide a better estimation of the consequences associated with dental therapy using composite materials, and lead to innovative therapeutic strategies and improved materials being used at tissue interfaces within the oral cavity. Current findings strongly suggest that monomers enhance the formation of reactive oxygen species (ROS), which is most likely the cause of biological reactions activated by dental composites and resin monomers. The aim of the present review manuscript is to discuss adaptive cell responses to oxidative stress caused by monomers. The particular significance of a tightly controlled network of non-enzymatic as well as enzymatic antioxidants for the regulation of cellular redox homeostasis and antioxidant defense in monomer-exposed cells will be addressed. The expression of ROS-metabolizing antioxidant enzymes like superoxide dismutase (SOD1), glutathione peroxidase (GPx1/2), and catalase in cells exposed to monomers will be discussed with particular emphasis on the role

  20. How they cope: a qualitative study of the coping skills of hospice volunteers.

    PubMed

    Brown, Mary V

    2011-09-01

    The purpose of this phenomenological study was to examine the coping techniques utilized by hospice volunteers. Individual semi-structured interviews were conducted with 15 hospice volunteers who had at least 1 year of experience, working as a hospice volunteer with direct patient care. The interviews were digitally recorded, transcribed, and analyzed utilizing qualitative research methods. The results indicated the volunteers used problem-focused coping (seeking advice from members of the hospice interdisciplinary team), emotion-focused coping (talking with others, going to funerals), meaning making through appraisal (religious beliefs, downward comparison), and physical techniques (walking, deep breathing). The most significant coping mechanism utilized for the volunteer was talking with the volunteer coordinator. Implications for hospice volunteer coordinators are also discussed. PMID:21262760

  1. The Influence of Emotional Intelligence (EI) on Coping and Mental Health in Adolescence: Divergent Roles for Trait and Ability EI

    ERIC Educational Resources Information Center

    Davis, Sarah K.; Humphrey, Neil

    2012-01-01

    Theoretically, trait and ability emotional intelligence (EI) should mobilise coping processes to promote adaptation, plausibly operating as personal resources determining choice and/or implementation of coping style. However, there is a dearth of research deconstructing if/how EI impacts mental health via multiple coping strategies in adolescence.…

  2. Coping With Stress Strategies in HIV-infected Iranian Patients.

    PubMed

    Mahmoudi, Maryam; Dehdari, Tahereh; Shojaeezadeh, Davoud; Abbasian, Ladan

    2015-01-01

    Stress has significant adverse impacts on health outcomes of HIV-infected patients. Our study explored coping with stress strategies by HIV-infected Iranian patients. A qualitative content analysis study was conducted at the Consultation Clinic of HIV at the Imam Khomeini Hospital in Tehran, Iran in 2012. Twenty-six semi-structured in-depth interviews were done. Participants were asked about coping strategies for stress. After the first interview, continuous analysis of data was started and continued up to data saturation. Results showed that participants used two categories of strategies (emotion-based coping and problem-based coping) to cope with stress. Emotion-based coping had two sub-themes: adaptive and maladaptive. The problem-based coping category had three sub-themes: participation in education sessions, adherence to medication, and efforts to maintain a healthy lifestyle. Explanations of different strategies available to HIV-infected patients to cope with stress may help develop tailored interventions to improve the psychological conditions of people living with HIV.

  3. Use of Ultrasound to Monitor Biceps Femoris Mechanical Adaptations after Injury in a Professional Soccer Player

    PubMed Central

    Kellis, Eleftherios; Galanis, Nikiforos; Chrysanthou, Chrysanthos; Kofotolis, Nikolaos

    2016-01-01

    This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (BF) architecture of aprofessional soccer player with acute first-time hamstring strain. The player followed a 14 session physiotherapy treatment until return to sport. The pennation angle and aponeurosis strain of the long head of the biceps femoris (BF) were monitored at 6 occasions (up until 1 year) after injury. The size of the scar / hematoma was reduced by 63.56% (length) and 67.9% (width) after the intervention and it was almost non-traceable one year after injury. The pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. In contrast, pennation angle of fascicles located away from the injury site were relatively unaffected. The treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of MVC moment and remained similar one year after the intervention. This study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention. Key points Changes in fascicle orientation after biceps femoris mild tear were reduced after a 28 day intervention and remained similar one year after injury. Tendon/aponeurosis strain per unit of moment of force decreased during the course of the therapeutic intervention. Future studies could utilize ultrasonography to monitor mechanical responses after various types of hamstring injury and interventions in order to improve criteria for a safe return to sport. PMID:26957929

  4. Early-Life Stress, HPA Axis Adaptation, and Mechanisms Contributing to Later Health Outcomes

    PubMed Central

    Maniam, Jayanthi; Antoniadis, Christopher; Morris, Margaret J.

    2014-01-01

    Stress activates the hypothalamic–pituitary–adrenal (HPA) axis, which then modulates the degree of adaptation and response to a later stressor. It is known that early-life stress can impact on later health but less is known about how early-life stress impairs HPA axis activity, contributing to maladaptation of the stress–response system. Early-life stress exposure (either prenatally or in the early postnatal period) can impact developmental pathways resulting in lasting structural and regulatory changes that predispose to adulthood disease. Epidemiological, clinical, and experimental studies have demonstrated that early-life stress produces long term hyper-responsiveness to stress with exaggerated circulating glucocorticoids, and enhanced anxiety and depression-like behaviors. Recently, evidence has emerged on early-life stress-induced metabolic derangements, for example hyperinsulinemia and altered insulin sensitivity on exposure to a high energy diet later in life. This draws our attention to the contribution of later environment to disease vulnerability. Early-life stress can alter the expression of genes in peripheral tissues, such as the glucocorticoid receptor and 11-beta hydroxysteroid dehydrogenase (11β-HSD1). We propose that interactions between altered HPA axis activity and liver 11β-HSD1 modulates both tissue and circulating glucocorticoid availability, with adverse metabolic consequences. This review discusses the potential mechanisms underlying early-life stress-induced maladaptation of the HPA axis, and its subsequent effects on energy utilization and expenditure. The effects of positive later environments as a means of ameliorating early-life stress-induced health deficits, and proposed mechanisms underpinning the interaction between early-life stress and subsequent detrimental environmental exposures on metabolic risk will be outlined. Limitations in current methodology linking early-life stress and later health outcomes will also be

  5. Use of Ultrasound to Monitor Biceps Femoris Mechanical Adaptations after Injury in a Professional Soccer Player.

    PubMed

    Kellis, Eleftherios; Galanis, Nikiforos; Chrysanthou, Chrysanthos; Kofotolis, Nikolaos

    2016-03-01

    This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (BF) architecture of aprofessional soccer player with acute first-time hamstring strain. The player followed a 14 session physiotherapy treatment until return to sport. The pennation angle and aponeurosis strain of the long head of the biceps femoris (BF) were monitored at 6 occasions (up until 1 year) after injury. The size of the scar / hematoma was reduced by 63.56% (length) and 67.9% (width) after the intervention and it was almost non-traceable one year after injury. The pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. In contrast, pennation angle of fascicles located away from the injury site were relatively unaffected. The treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of MVC moment and remained similar one year after the intervention. This study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention. Key pointsChanges in fascicle orientation after biceps femoris mild tear were reduced after a 28 day intervention and remained similar one year after injury.Tendon/aponeurosis strain per unit of moment of force decreased during the course of the therapeutic intervention.Future studies could utilize ultrasonography to monitor mechanical responses after various types of hamstring injury and interventions in order to improve criteria for a safe return to sport. PMID:26957929

  6. Oxygen sensing by the carotid body: mechanisms and role in adaptation to hypoxia.

    PubMed

    López-Barneo, José; González-Rodríguez, Patricia; Gao, Lin; Fernández-Agüera, M Carmen; Pardal, Ricardo; Ortega-Sáenz, Patricia

    2016-04-15

    Oxygen (O2) is fundamental for cell and whole-body homeostasis. Our understanding of the adaptive processes that take place in response to a lack of O2(hypoxia) has progressed significantly in recent years. The carotid body (CB) is the main arterial chemoreceptor that mediates the acute cardiorespiratory reflexes (hyperventilation and sympathetic activation) triggered by hypoxia. The CB is composed of clusters of cells (glomeruli) in close contact with blood vessels and nerve fibers. Glomus cells, the O2-sensitive elements in the CB, are neuron-like cells that contain O2-sensitive K(+)channels, which are inhibited by hypoxia. This leads to cell depolarization, Ca(2+)entry, and the release of transmitters to activate sensory fibers terminating at the respiratory center. The mechanism whereby O2modulates K(+)channels has remained elusive, although several appealing hypotheses have been postulated. Recent data suggest that mitochondria complex I signaling to membrane K(+)channels plays a fundamental role in acute O2sensing. CB activation during exposure to low Po2is also necessary for acclimatization to chronic hypoxia. CB growth during sustained hypoxia depends on the activation of a resident population of stem cells, which are also activated by transmitters released from the O2-sensitive glomus cells. These advances should foster further studies on the role of CB dysfunction in the pathogenesis of highly prevalent human diseases.

  7. Adaptive Physiological Response to Perceived Scarcity as a Mechanism of Sensory Modulation of Life Span

    PubMed Central

    Waterson, Michael J.; Chan, Tammy P.

    2015-01-01

    Chemosensation is a potent modulator of organismal physiology and longevity. In Drosophila, loss of recognition of diverse tastants has significant and bidirectional life-span effects. Recently published results revealed that when flies were unable to taste water, they increased its internal generation, which may have subsequently altered life span. To determine whether similar adaptive responses occur in other contexts, we explored the impact of sensory deficiency of other metabolically important molecules. Trehalose is a major circulating carbohydrate in the fly that is recognized by the gustatory receptor Gr5a. Gr5a mutant flies are short lived, and we found that they specifically increased whole-body and circulating levels of trehalose, but not other carbohydrates, likely through upregulation of de novo synthesis. dILP2 transcript levels were increased in Gr5a mutants, a possible response intended to reduce hypertrehalosemia, and likely a contributing factor to their reduced life span. Together, these data suggest that compensatory physiological responses to perceived environmental scarcity, which are designed to alleviate the ostensive shortage, may be a common outcome of sensory manipulation. We suggest that future investigations into the mechanisms underlying sensory modulation of aging may benefit by focusing on direct or indirect consequences of physiological changes that are designed to correct perceived disparity with the environment. PMID:25878032

  8. Toward a mechanics of adaptive behavior: evolutionary dynamics and matching theory statics.

    PubMed

    McDowell, J J; Popa, Andrei

    2010-09-01

    One theory of behavior dynamics instantiates the idea that behavior evolves in response to selection pressure from the environment in the form of reinforcement. This computational theory implements Darwinian principles of selection, reproduction, and mutation, which operate on a population of potential behaviors by means of a genetic algorithm. The behavior of virtual organisms animated by this theory may be studied in any experimental environment. The evolutionary theory was tested by comparing the steady-state behavior it generated on concurrent schedules to the description of steady state behavior provided by modern matching theory. Ensemble fits of modern matching theory that enforced its constant-k requirement and the parametric identities required by its equations, accounted for large proportions of data variance, left random residuals, and yielded parameter estimates with values and properties similar to those obtained in experiments with live organisms. These results indicate that the dynamics of the evolutionary theory and the statics of modern matching theory together constitute a good candidate for a mechanics of adaptive behavior.

  9. Toward a Mechanics of Adaptive Behavior: Evolutionary Dynamics and Matching Theory Statics

    PubMed Central

    McDowell, J.J; Popa, Andrei

    2010-01-01

    One theory of behavior dynamics instantiates the idea that behavior evolves in response to selection pressure from the environment in the form of reinforcement. This computational theory implements Darwinian principles of selection, reproduction, and mutation, which operate on a population of potential behaviors by means of a genetic algorithm. The behavior of virtual organisms animated by this theory may be studied in any experimental environment. The evolutionary theory was tested by comparing the steady-state behavior it generated on concurrent schedules to the description of steady state behavior provided by modern matching theory. Ensemble fits of modern matching theory that enforced its constant-k requirement and the parametric identities required by its equations, accounted for large proportions of data variance, left random residuals, and yielded parameter estimates with values and properties similar to those obtained in experiments with live organisms. These results indicate that the dynamics of the evolutionary theory and the statics of modern matching theory together constitute a good candidate for a mechanics of adaptive behavior. PMID:21451751

  10. Exploration of intraclonal adaptation mechanisms of Pseudomonas brassicacearum facing cadmium toxicity

    PubMed Central

    Pagès, Delphine; Sanchez, Lisa; Conrod, Sandrine; Gidrol, Xavier; Fekete, Agnes; Schmitt-Kopplin, Philippe; Heulin, Thierry; Achouak, Wafa

    2007-01-01

    Pseudomonas brassicacearum forms phenotypic variants in vitro as well as in planta during root colonization under natural conditions, leading to subpopulations (phase I and II cells) that differ in colony morphology and production of exoenzymes/secondary metabolites. The maximal concentration of cadmium allowing both variants growth was 25 μM; however, phase II cells accumulated fivefold higher Cd than phase I cells, even though both variants showed the same growth rate and kinetics, comprising a long stasis period (50 h). The whole transcriptome analysis of both variants in response to Cd was investigated using the home-made DNA microarrays. This analysis revealed completely different adaptation mechanisms developed by each variant to withstand and grow in the presence of the toxic. A re-organization of the cell wall to limit Cd entrance was noticed for phase I cells, as genes encoding levan exopolymers were downregulated at the expense of an upregulation of genes encoding alginate, and an upregulation of transporters such as cadA, and a downregulation of copper transporters. Phase II cells were unable to prevent Cd entrance and recruited genes under the control of oxyR and soxR regulation to face osmotic and oxidant stresses generated by Cd. Putrescine and spermidine metabolism appeared to play a central role in Cd tolerance. Microarray data were validated by biological analyses such as motility, oxidative stress assay, metabolite profiling with ICR-FT/MS and UPLC, capillary electrophoresis analysis of biogenic amines. PMID:17922765

  11. Adaptive Physiological Response to Perceived Scarcity as a Mechanism of Sensory Modulation of Life Span.

    PubMed

    Waterson, Michael J; Chan, Tammy P; Pletcher, Scott D

    2015-09-01

    Chemosensation is a potent modulator of organismal physiology and longevity. In Drosophila, loss of recognition of diverse tastants has significant and bidirectional life-span effects. Recently published results revealed that when flies were unable to taste water, they increased its internal generation, which may have subsequently altered life span. To determine whether similar adaptive responses occur in other contexts, we explored the impact of sensory deficiency of other metabolically important molecules. Trehalose is a major circulating carbohydrate in the fly that is recognized by the gustatory receptor Gr5a. Gr5a mutant flies are short lived, and we found that they specifically increased whole-body and circulating levels of trehalose, but not other carbohydrates, likely through upregulation of de novo synthesis. dILP2 transcript levels were increased in Gr5a mutants, a possible response intended to reduce hypertrehalosemia, and likely a contributing factor to their reduced life span. Together, these data suggest that compensatory physiological responses to perceived environmental scarcity, which are designed to alleviate the ostensive shortage, may be a common outcome of sensory manipulation. We suggest that future investigations into the mechanisms underlying sensory modulation of aging may benefit by focusing on direct or indirect consequences of physiological changes that are designed to correct perceived disparity with the environment. PMID:25878032

  12. Mechanisms and evolution of synchronous chorusing: emergent properties and adaptive functions in Neoconocephalus katydids (Orthoptera: Tettigoniidae).

    PubMed

    Greenfield, Michael D; Schul, Johannes

    2008-08-01

    Synchronous interactions arise in various animal species that rhythmically broadcast acoustic, vibratory, and visual signals. These interactions are characterized by a coincidence in both rate and phase of the rhythms of neighboring signalers. Theory predicts several ways in which synchronized rhythms may specifically benefit the interacting signalers. However, synchrony may also arise as an emergent property, a default phenomenon that is neither preferred by conspecific receivers evaluating the signals nor advantageous to the signalers themselves. Here, we examine several well-studied cases of acoustic synchrony in Neoconocephalus katydids (Orthoptera: Tettigoniidae), a New World genus wherein males broadcast loud advertisement songs. We report that call synchrony found in N. spiza and N. nebrascensis results from two rather different mechanisms of rhythm adjustment. Moreover, synchrony in the former species appears to represent an incidental byproduct of signal competition between evenly matched males, whereas in the latter species synchrony functions as a specific adaptation in which cooperating males ensure that critical call features can be perceived by females. We discuss the separate evolutionary trajectories that may have led to similar outcomes, synchronous chorusing by advertising males, in these closely related species. PMID:18729657

  13. From tetrapods to primates: conserved developmental mechanisms in diverging ecological adaptations.

    PubMed

    Aboitiz, Francisco; Montiel, Juan F

    2012-01-01

    Primates are endowed with a brain about twice the size that of a mammal with the same body size, and humans have the largest brain relative to body size of all animals. This increase in brain size may be related to the acquisition of higher cognitive skills that permitted more complex social interactions, the evolution of culture, and the eventual ability to manipulate the environment. Nevertheless, in its internal structure, the primate brain shares a very conserved design with other mammals, being covered by a six-layered neocortex that, although expands disproportionately to other brain components, it does so following relatively well-defined allometric trends. Thus, the most fundamental events generating the basic design of the primate and human brain took place before the appearance of the first primate-like animal. Presumably, the earliest mammals already displayed a brain morphology radically different from that of their ancestors and that of their sister group, the reptiles, being characterized by the presence of an incipient neocortex that underwent an explosive growth in subsequent mammal evolution. In this chapter, we propose an integrative hypothesis for the origin of the mammalian neocortex, by considering the developmental modifications, functional networks, and ecological adaptations involved in the generation of this structure during the cretaceous period. Subsequently, the expansion of the primate brain is proposed to have relied on the amplification of the same, or very similar, developmental mechanisms as those involved in its primary origins, even in different ecological settings. PMID:22230620

  14. Reproductive trade-offs in extant hunter-gatherers suggest adaptive mechanism for the Neolithic expansion

    PubMed Central

    Viguier, Sylvain; Dyble, Mark; Smith, Daniel; Salali, Gul Deniz; Thompson, James; Vinicius, Lucio; Migliano, Andrea Bamberg

    2016-01-01

    The Neolithic demographic transition remains a paradox, because it is associated with both higher rates of population growth and increased morbidity and mortality rates. Here we reconcile the conflicting evidence by proposing that the spread of agriculture involved a life history quality–quantity trade-off whereby mothers traded offspring survival for increased fertility, achieving greater reproductive success despite deteriorating health. We test this hypothesis by investigating fertility, mortality, health, and overall reproductive success in Agta hunter-gatherers whose camps exhibit variable levels of sedentarization, mobility, and involvement in agricultural activities. We conducted blood composition tests in 345 Agta and found that viral and helminthic infections as well as child mortality rates were significantly increased with sedentarization. Nonetheless, both age-controlled fertility and overall reproductive success were positively affected by sedentarization and participation in cultivation. Thus, we provide the first empirical evidence, to our knowledge, of an adaptive mechanism in foragers that reconciles the decline in health and child survival with the observed demographic expansion during the Neolithic. PMID:27071109

  15. Hormonal Contraception and HIV-1 Infection: Medroxyprogesterone Acetate Suppresses Innate and Adaptive Immune Mechanisms

    PubMed Central

    Huijbregts, Richard P. H.; Helton, E. Scott; Michel, Katherine G.; Sabbaj, Steffanie; Richter, Holly E.; Goepfert, Paul A.

    2013-01-01

    Recent observational studies indicate an association between the use of hormonal contraceptives and acquisition and transmission of HIV-1. The biological and immunological mechanisms underlying the observed association are unknown. Depot medroxyprogesterone acetate (DMPA) is a progestin-only injectable contraceptive that is commonly used in regions with high HIV-1 prevalence. Here we show that medroxyprogesterone acetate (MPA) suppresses the production of key regulators of cellular and humoral immunity involved in orchestrating the immune response to invading pathogens. MPA inhibited the production of interferon (IFN)-γ, IL-2, IL-4, IL-6, IL-12, TNFα, macrophage inflammatory protein-1α (MIP-1α), and other cytokines and chemokines by peripheral blood cells and activated T cells and reduced the production of IFNα and TNFα by plasmacytoid dendritic cells in response to Toll-like receptor-7, -8, and -9 ligands. Women using DMPA displayed lower levels of IFNα in plasma and genital secretions compared with controls with no hormonal contraception. In addition, MPA prevented the down-regulation of HIV-1 coreceptors CXCR4 and CCR5 on the surface of T cells after activation and increased HIV-1 replication in activated peripheral blood mononuclear cell cultures. The presented results suggest that MPA suppresses both innate and adaptive arms of the immune system resulting in a reduction of host resistance to invading pathogens. PMID:23354099

  16. Stress in College Athletics: Causes, Consequences, Coping.

    ERIC Educational Resources Information Center

    Humphrey, James H.; Yow, Deborah A.; Bowden, William W.

    This book addresses the causes and consequences of stress in college sports and offers effective coping mechanisms to help individuals understand and control stressors and emotions in their environment. The chapters are: (1) "Understanding Stress"; (2) "Perceptions of Stress in College Athletics"; (3) "Stress among College Athletes"; (4) "Stress…

  17. Learner Characteristic Based Learning Effort Curve Mode: The Core Mechanism on Developing Personalized Adaptive E-Learning Platform

    ERIC Educational Resources Information Center

    Hsu, Pi-Shan

    2012-01-01

    This study aims to develop the core mechanism for realizing the development of personalized adaptive e-learning platform, which is based on the previous learning effort curve research and takes into account the learner characteristics of learning style and self-efficacy. 125 university students from Taiwan are classified into 16 groups according…

  18. Bacterial economics: adaptation to stress conditions via stage-wise changes in the response mechanism.

    PubMed

    Baranyi, J; Metris, A; George, S M

    2015-02-01

    Common features of microbial adaptation are analysed with mathematical models and extended to stress conditions when the bacterial population declines before growing again. A parallel is drawn between bacterial and human communities in terms of non-mutation-based adaptation (acclimation) to stress. For a case study, the behaviour of Escherichia coli under osmotic stress, is detailed. It is suggested that stress modelling adaptation should be the focus of further developments in predictive food microbiology.

  19. Impact of Age, and Cognitive and Coping Resources on Coping

    ERIC Educational Resources Information Center

    Trouillet, Raphael; Doan-Van-Hay, Loane-Martine; Launay, Michel; Martin, Sophie

    2011-01-01

    To explore the predictive value of cognitive and coping resources for problem- and emotion-focused coping with age, we collected data from community-dwelling adults between 20 and 90 years old. We hypothesized that age, perceived stress, self-efficacy, working-memory capacity, and mental flexibility were predictors of coping. We collected data…

  20. Curcumin-releasing mechanically adaptive intracortical implants improve the proximal neuronal density and blood-brain barrier stability.

    PubMed

    Potter, Kelsey A; Jorfi, Mehdi; Householder, Kyle T; Foster, E Johan; Weder, Christoph; Capadona, Jeffrey R

    2014-05-01

    The cellular and molecular mechanisms by which neuroinflammatory pathways respond to and propagate the reactive tissue response to intracortical microelectrodes remain active areas of research. We previously demonstrated that both the mechanical mismatch between rigid implants and the much softer brain tissue, as well as oxidative stress, contribute to the neurodegenerative reactive tissue response to intracortical implants. In this study, we utilize physiologically responsive, mechanically adaptive polymer implants based on poly(vinyl alcohol) (PVA), with the capability to also locally administer the antioxidant curcumin. The goal of this study is to investigate if the combination of two independently effective mechanisms - softening of the implant and antioxidant release - leads to synergistic effects in vivo. Over the first 4weeks of the implantation, curcumin-releasing, mechanically adaptive implants were associated with higher neuron survival and a more stable blood-brain barrier at the implant-tissue interface than the neat PVA controls. 12weeks post-implantation, the benefits of the curcumin release were lost, and both sets of compliant materials (with and without curcumin) had no statistically significant differences in neuronal density distribution profiles. Overall, however, the curcumin-releasing softening polymer implants cause minimal implant-mediated neuroinflammation, and embody the new concept of localized drug delivery from mechanically adaptive intracortical implants.

  1. Vestibulospinal adaptation to microgravity

    NASA Technical Reports Server (NTRS)

    Paloski, W. H.

    1998-01-01

    Human balance control is known to be transiently disrupted after spaceflight; however, the mechanisms responsible for postflight postural ataxia are still under investigation. In this report, we propose a conceptual model of vestibulospinal adaptation based on theoretical adaptive control concepts and supported by the results from a comprehensive study of balance control recovery after spaceflight. The conceptual model predicts that immediately after spaceflight the balance control system of a returning astronaut does not expect to receive gravity-induced afferent inputs and that descending vestibulospinal control of balance is disrupted until the central nervous system is able to cope with the newly available vestibular otolith information. Predictions of the model are tested using data from a study of the neurosensory control of balance in astronauts immediately after landing. In that study, the mechanisms of sensorimotor balance control were assessed under normal, reduced, and/or altered (sway-referenced) visual and somatosensory input conditions. We conclude that the adaptive control model accurately describes the neurobehavioral responses to spaceflight and that similar models of altered sensory, motor, or environmental constraints are needed clinically to predict responses that patients with sensorimotor pathologies may have to various visual-vestibular or changing stimulus environments.

  2. Coping with Jealousy: The Association between Maladaptive Aspects of Jealousy and Drinking Problems are Mediated by Drinking to Cope

    PubMed Central

    DiBello, Angelo M.; Neighbors, Clayton; Rodriguez, Lindsey M.; Lindgren, Kristen

    2013-01-01

    Previous research has shown that both alcohol use and jealousy are related to negative relationship outcomes. Little work, however, has examined direct associations between alcohol use and jealousy. The current study aimed to build upon existing research examining alcohol use and jealousy. More specifically, findings from current jealousy literature indicate that jealousy is a multifaceted construct with both maladaptive and adaptive aspects. The current study examined the association between maladaptive and adaptive feelings of jealousy and alcohol-related problems in the context of drinking to cope. Given the relationship between coping motives and alcohol-related problems, our primary interest was in predicting alcohol-related problems, but alcohol consumption was also investigated. Undergraduate students at a large Northwestern university (N = 657) in the US participated in the study. They completed measures of jealousy, drinking to cope, alcohol use, and alcohol-related problems. Analyses examined associations between jealousy subscales, alcohol use, drinking to cope, and drinking problems. Results indicated that drinking to cope mediated the association between some, but not all, aspects of jealousy and problems with alcohol use. In particular, the more negative or maladaptive aspects of jealousy were related to drinking to cope and drinking problems, while the more adaptive aspects were not, suggesting a more complex view of jealousy than previously understood. PMID:24138965

  3. Coping with Crises.

    ERIC Educational Resources Information Center

    Hawkins, Janet

    1982-01-01

    Coping with Crises is a home economics course in a rural school in Missouri. It includes experiences designed to increase the individual's ability to deal with stress and covers communication, popularity, loneliness, divorce, death and dying, mental illness, and rejection. (SK)

  4. Coping with Computing Success.

    ERIC Educational Resources Information Center

    Breslin, Richard D.

    Elements of computing success of Iona College, the challenges it currently faces, and the strategies conceived to cope with future computing needs are discussed. The college has mandated computer literacy for students and offers nine degrees in the computerized information system/management information system areas. Since planning is needed in…

  5. Coping by Caring.

    ERIC Educational Resources Information Center

    Lidstone, Sheila S.

    1992-01-01

    Describes a Texas elementary school's efforts to cope with the special needs of Kenneth, a fourth grader slowly dying of kidney cancer. Besides learning their subjects like other students, Kenneth's classmates learned how to care. Every student volunteered to be Kenneth's assistant and was enriched by the boy's positive attitude and determination…

  6. Incarceration, Coping, and Support.

    ERIC Educational Resources Information Center

    Carlson, Bonnie E.; Cervera, Neil J.

    1991-01-01

    Examined effects of incarceration on family life among 63 inmates and 38 inmate wives. Contrasted those who participated in Family Reunion (conjugal visits) Program with nonparticipants. Found that coping was in normal range for both groups of inmates and wives and, except for measures of wives' passive appraisal, did not differ according to…

  7. Coping with Traumatic Loss.

    ERIC Educational Resources Information Center

    Tramonte, Michael R.

    This workshop seeks to train persons interested in counseling those who have suffered traumatic loss. The training comes about in part by the participants' introspection into their own past trauma reactions and the coping strategies they used. They also learn from the shared experiences of other participants. The goals of this workshop are to 1)…

  8. Coping strategies of children with faecal incontinence.

    PubMed

    Ludman, L; Spitz, L

    1996-04-01

    As part of a study concerning the psychosocial adjustment of 160 children treated for anorectal anomalies, the authors investigated the ways in which the children coped with faecal incontinence (FIC). At the time of assessment, the children were 6 to 18 years of age. Portions of the in-depth interviews with the children and their parents covered questions about methods of managing and coping with FIC at home, socially, and at school. In addition, information was obtained about child and family characteristics that have been shown to contribute to the ability to adapt to chronic health problems. The ways in which the children dealt with their problems could be grouped into three distinct phases and were different for boys and girls. In phase 1, around 6 to 7 years of age, boys were largely unaware of the unsocial nature of their condition; the girls were sensitive and withdrawn. In phase 2, between 8 and 11 years of age, boys used overt denial, girls used secretiveness. Phase 3, from around 12 years into adolescence, for both sexes was marked by continued covert denial and eventual acceptance of their disability. The coping strategies reflected a complex interrelationship between characteristics of the child, the family, the social environment, and the unsocial and embarrassing nature of FIC. The findings showed that coping with FIC has potentially severely disruptive implications for the overall development of the child. PMID:8801314

  9. Coping Styles of Individuals at Clinical High Risk for Developing Psychosis

    PubMed Central

    Jalbrzikowski, Maria; Sugar, Catherine A.; Zinberg, Jamie; Bachman, Peter; Cannon, Tyrone D.; Bearden, Carrie E.

    2012-01-01

    Aim There is a wealth of evidence suggesting that patients with schizophrenia tend to respond to life stressors using less effective coping skills, which are in turn related to poor outcome. However, the contribution of coping strategies to outcome in youth at clinical high risk (CHR) for developing psychosis has not been investigated. Methods This longitudinal study followed CHR youth over a twelve-month period, using the Brief COPE questionnaire. CHR subjects (n=88) were compared at baseline to a healthy control sample (n=53), and then mixed models were used to explore the relationship of coping strategies to clinical and psychosocial outcomes in CHR subjects over time (n=102). Results Cross-sectional analyses revealed that, in comparison to healthy controls, CHR youth reported using more maladaptive coping strategies (p<.001) and fewer adaptive coping strategies (p<.01). Longitudinal analyses within the CHR group showed significant decreases in maladaptive coping and symptom severity over time, with corresponding improvements in social and role functioning. Adaptive coping was associated with better concurrent social functioning and less severe symptomatology (both p<.001). Over time, more maladaptive coping was associated with more severe positive and negative symptoms (both p < .005). Conclusions Youth at-risk for psychosis report using fewer adaptive and more maladaptive coping strategies relative to healthy controls. Over one year follow-up, more adaptive coping styles are associated with less severe clinical symptomatology and better social functioning. These findings suggest that teaching adaptive coping styles may be an important target for intervention in youth at high risk for psychosis. PMID:23164368

  10. Children's Coping with Academic Failure

    ERIC Educational Resources Information Center

    Raftery-Helmer, Jacquelyn N.; Grolnick, Wendy S.

    2016-01-01

    There is little consensus on how to conceptualize coping after perceived failure and less is known about the contextual resources that may support or undermine the use of specific coping strategies. This study examined parenting in relation to coping using the framework of self-determination theory and examined the motivational processes through…

  11. Children Coping with Chronic Illness.

    ERIC Educational Resources Information Center

    Perez, Lissette M.

    Children who live with chronic illness are confronted with challenges that frequently force them to cope in myriad ways. The ways in which children face chronic illness are summarized in this literature review. Also covered, are how the effects of family can influence coping strategies and how family members, especially parents, cope with their…

  12. At Home with MS: Adapting Your Environment

    MedlinePlus

    ... of things you almost never need. Your storage adaptations may include hanging baskets, rolling storage carts, peg ... living at home with a disability. n Any adaptation or renovation to help you cope with MS ...

  13. Design of an Adaptive Power Regulation Mechanism and a Nozzle for a Hydroelectric Power Plant Turbine Test Rig

    NASA Astrophysics Data System (ADS)

    Mert, Burak; Aytac, Zeynep; Tascioglu, Yigit; Celebioglu, Kutay; Aradag, Selin; ETU Hydro Research Center Team

    2014-11-01

    This study deals with the design of a power regulation mechanism for a Hydroelectric Power Plant (HEPP) model turbine test system which is designed to test Francis type hydroturbines up to 2 MW power with varying head and flow(discharge) values. Unlike the tailor made regulation mechanisms of full-sized, functional HEPPs; the design for the test system must be easily adapted to various turbines that are to be tested. In order to achieve this adaptability, a dynamic simulation model is constructed in MATLAB/Simulink SimMechanics. This model acquires geometric data and hydraulic loading data of the regulation system from Autodesk Inventor CAD models and Computational Fluid Dynamics (CFD) analysis respectively. The dynamic model is explained and case studies of two different HEPPs are performed for validation. CFD aided design of the turbine guide vanes, which is used as input for the dynamic model, is also presented. This research is financially supported by Turkish Ministry of Development.

  14. Innate and adaptive T cells in asthmatic patients: Relationship to severity and disease mechanisms

    PubMed Central

    Hinks, Timothy S.C.; Zhou, Xiaoying; Staples, Karl J.; Dimitrov, Borislav D.; Manta, Alexander; Petrossian, Tanya; Lum, Pek Y.; Smith, Caroline G.; Ward, Jon A.; Howarth, Peter H.; Walls, Andrew F.; Gadola, Stephan D.; Djukanović, Ratko

    2015-01-01

    Background Asthma is a chronic inflammatory disease involving diverse cells and mediators whose interconnectivity and relationships to asthma severity are unclear. Objective We performed a comprehensive assessment of TH17 cells, regulatory T cells, mucosal-associated invariant T (MAIT) cells, other T-cell subsets, and granulocyte mediators in asthmatic patients. Methods Sixty patients with mild-to-severe asthma and 24 control subjects underwent detailed clinical assessment and provided induced sputum, endobronchial biopsy, bronchoalveolar lavage, and blood samples. Adaptive and invariant T-cell subsets, cytokines, mast cells, and basophil mediators were analyzed. Results Significant heterogeneity of T-cell phenotypes was observed, with levels of IL-13–secreting T cells and type 2 cytokines increased at some, but not all, asthma severities. TH17 cells and γδ-17 cells, proposed drivers of neutrophilic inflammation, were not strongly associated with asthma, even in severe neutrophilic forms. MAIT cell frequencies were strikingly reduced in both blood and lung tissue in relation to corticosteroid therapy and vitamin D levels, especially in patients with severe asthma in whom bronchoalveolar lavage regulatory T-cell numbers were also reduced. Bayesian network analysis identified complex relationships between pathobiologic and clinical parameters. Topological data analysis identified 6 novel clusters that are associated with diverse underlying disease mechanisms, with increased mast cell mediator levels in patients with severe asthma both in its atopic (type 2 cytokine–high) and nonatopic forms. Conclusion The evidence for a role for TH17 cells in patients with severe asthma is limited. Severe asthma is associated with a striking deficiency of MAIT cells and high mast cell mediator levels. This study provides proof of concept for disease mechanistic networks in asthmatic patients with clusters that could inform the development of new therapies. PMID:25746968

  15. Agricultural Intensification as a Mechanism of Adaptation to Climate Change Impacts

    NASA Astrophysics Data System (ADS)

    Kyle, P.; Calvin, K. V.; le Page, Y.; Patel, P.; West, T. O.; Wise, M. A.

    2015-12-01

    The research, policy, and NGO communities have devoted significant attention to the potential for agricultural intensification, or closure of "yield gaps," to alleviate future global hunger, poverty, climate change impacts, and other threats. However, because the research to this point has focused on biophysically attainable yields—assuming optimal choices under ideal conditions—the presently available work has not yet addressed the likely responses of the agricultural sector to real-world conditions in the future. This study investigates endogenous agricultural intensification in response to global climate change impacts—that is, intensification independent of policies or other exogenous interventions to promote yield gap closure. The framework for the analysis is a set of scenarios to 2100 in the GCAM global integrated assessment model, enhanced to include endogenous irrigation, fertilizer application, and yields, in each of 283 land use regions, with maximum yields based on the 95th percentile of attainable yields in a recent global assessment. We assess three levels of agricultural climate impacts, using recent global gridded crop model datasets: none, low (LPJmL), and high (Pegasus). Applying formulations for decomposition of climate change impacts response developed in prior AgMIP work, we find that at the global level, availability of high-yielding technologies mitigates price shocks and shifts the agricultural sector's climate response modestly towards intensification, away from cropland expansion and reduced production. At the regional level, the behavior is more complex; nevertheless, availability of high-yielding production technologies enhances the inter-regional shifts in agricultural production that are induced by climate change, complemented by commensurate changes in trade patterns. The results highlight the importance of policies to facilitate yield gap closure and inter-regional trade as mechanisms for adapting to climate change

  16. Adaptation of the Black Yeast Wangiella dermatitidis to Ionizing Radiation: Molecular and Cellular Mechanisms

    PubMed Central

    Robertson, Kelly L.; Mostaghim, Anahita; Cuomo, Christina A.; Soto, Carissa M.; Lebedev, Nikolai; Bailey, Robert F.; Wang, Zheng

    2012-01-01

    Observations of enhanced growth of melanized fungi under low-dose ionizing radiation in the laboratory and in the damaged Chernobyl nuclear reactor suggest they have adapted the ability to survive or even benefit from exposure to ionizing radiation. However, the cellular and molecular mechanism of fungal responses to such radiation remains poorly understood. Using the black yeast Wangiella dermatitidis as a model, we confirmed that ionizing radiation enhanced cell growth by increasing cell division and cell size. Using RNA-seq technology, we compared the transcriptomic profiles of the wild type and the melanin-deficient wdpks1 mutant under irradiation and non-irradiation conditions. It was found that more than 3000 genes were differentially expressed when these two strains were constantly exposed to a low dose of ionizing radiation and that half were regulated at least two fold in either direction. Functional analysis indicated that many genes for amino acid and carbohydrate metabolism and cell cycle progression were down-regulated and that a number of antioxidant genes and genes affecting membrane fluidity were up-regulated in both irradiated strains. However, the expression of ribosomal biogenesis genes was significantly up-regulated in the irradiated wild-type strain but not in the irradiated wdpks1 mutant, implying that melanin might help to contribute radiation energy for protein translation. Furthermore, we demonstrated that long-term exposure to low doses of radiation significantly increased survivability of both the wild-type and the wdpks1 mutant, which was correlated with reduced levels of reactive oxygen species (ROS), increased production of carotenoid and induced expression of genes encoding translesion DNA synthesis. Our results represent the first functional genomic study of how melanized fungal cells respond to low dose ionizing radiation and provide clues for the identification of biological processes, molecular pathways and individual genes

  17. The extraordinary joint material of an articulated coralline alga. I. Mechanical characterization of a key adaptation.

    PubMed

    Denny, Mark W; King, Felicia A

    2016-06-15

    Flexibility is key to survival for seaweeds exposed to the extreme hydrodynamic environment of wave-washed rocky shores. This poses a problem for coralline algae, whose calcified cell walls make them rigid. Through the course of evolution, erect coralline algae have solved this problem by incorporating joints (genicula) into their morphology, allowing their fronds to be as flexible as those of uncalcified seaweeds. To provide the flexibility required by this structural innovation, the joint material of Calliarthron cheilosporioides, a representative articulated coralline alga, relies on an extraordinary tissue that is stronger, more extensible and more fatigue resistant than the tissue of other algal fronds. Here, we report on experiments that reveal the viscoelastic properties of this material. On the one hand, its compliance is independent of the rate of deformation across a wide range of deformation rates, a characteristic of elastic solids. This deformation rate independence allows joints to maintain their flexibility when loaded by the unpredictable - and often rapidly imposed - hydrodynamic force of breaking waves. On the other hand, the genicular material has viscous characteristics that similarly augment its function. The genicular material dissipates much of the energy absorbed as a joint is deformed during cyclic wave loading, which potentially reduces the chance of failure by fatigue, and the material accrues a limited amount of deformation through time. This limited creep increases the flexibility of the joints while preventing them from gradually stretching to the point of failure. These new findings provide the basis for understanding how the microscale architecture of genicular cell walls results in the adaptive mechanical properties of coralline algal joints. PMID:27307541

  18. The extraordinary joint material of an articulated coralline alga. I. Mechanical characterization of a key adaptation.

    PubMed

    Denny, Mark W; King, Felicia A

    2016-06-15

    Flexibility is key to survival for seaweeds exposed to the extreme hydrodynamic environment of wave-washed rocky shores. This poses a problem for coralline algae, whose calcified cell walls make them rigid. Through the course of evolution, erect coralline algae have solved this problem by incorporating joints (genicula) into their morphology, allowing their fronds to be as flexible as those of uncalcified seaweeds. To provide the flexibility required by this structural innovation, the joint material of Calliarthron cheilosporioides, a representative articulated coralline alga, relies on an extraordinary tissue that is stronger, more extensible and more fatigue resistant than the tissue of other algal fronds. Here, we report on experiments that reveal the viscoelastic properties of this material. On the one hand, its compliance is independent of the rate of deformation across a wide range of deformation rates, a characteristic of elastic solids. This deformation rate independence allows joints to maintain their flexibility when loaded by the unpredictable - and often rapidly imposed - hydrodynamic force of breaking waves. On the other hand, the genicular material has viscous characteristics that similarly augment its function. The genicular material dissipates much of the energy absorbed as a joint is deformed during cyclic wave loading, which potentially reduces the chance of failure by fatigue, and the material accrues a limited amount of deformation through time. This limited creep increases the flexibility of the joints while preventing them from gradually stretching to the point of failure. These new findings provide the basis for understanding how the microscale architecture of genicular cell walls results in the adaptive mechanical properties of coralline algal joints.

  19. Molecular adaptations in Antarctic fish and bacteria

    NASA Astrophysics Data System (ADS)

    Russo, Roberta; Riccio, Alessia; di Prisco, Guido; Verde, Cinzia; Giordano, Daniela

    2010-08-01

    Marine organisms, living in the cold waters of the Southern Ocean, are exposed to high oxygen concentrations. Cold-adapted organisms have developed networks of defence mechanisms to protect themselves against oxidative stress. The dominant suborder Notothenioidei of the Southern Ocean is one of the most interesting models, within vertebrates, to study the evolutionary biological responses to extreme environment. Within bacteria, the psychrophilic Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 gives the opportunity to explore the cellular strategies adopted in vivo by cold-adapted microorganisms to cope with cold and high oxygen concentration. Understanding the molecular mechanisms underlying how a range of Antarctic organisms have responded to climate change in the past will enable predictions as to how they and other species will adapt to global climate change, in terms of physiological function, distribution patterns and ecosystem balance.

  20. Black Canadians' Coping Responses to Racial Discrimination

    ERIC Educational Resources Information Center

    Joseph, Justine; Kuo, Ben C. H.

    2009-01-01

    On the basis of a cultural coping framework, the present study examined coping responses to racial discrimination among 190 Black Canadians. The study assessed the respondents' coping with both general (i.e., problem- and emotion-focused coping) and Africultural coping strategies (i.e., spiritual-centered, collective, and ritual-centered coping)…

  1. Physiological and Neural Adaptations to Eccentric Exercise: Mechanisms and Considerations for Training

    PubMed Central

    Hedayatpour, Nosratollah; Falla, Deborah

    2015-01-01

    Eccentric exercise is characterized by initial unfavorable effects such as subcellular muscle damage, pain, reduced fiber excitability, and initial muscle weakness. However, stretch combined with overload, as in eccentric contractions, is an effective stimulus for inducing physiological and neural adaptations to training. Eccentric exercise-induced adaptations include muscle hypertrophy, increased cortical activity, and changes in motor unit behavior, all of which contribute to improved muscle function. In this brief review, neuromuscular adaptations to different forms of exercise are reviewed, the positive training effects of eccentric exercise are presented, and the implications for training are considered. PMID:26543850

  2. Physiological and Neural Adaptations to Eccentric Exercise: Mechanisms and Considerations for Training.

    PubMed

    Hedayatpour, Nosratollah; Falla, Deborah

    2015-01-01

    Eccentric exercise is characterized by initial unfavorable effects such as subcellular muscle damage, pain, reduced fiber excitability, and initial muscle weakness. However, stretch combined with overload, as in eccentric contractions, is an effective stimulus for inducing physiological and neural adaptations to training. Eccentric exercise-induced adaptations include muscle hypertrophy, increased cortical activity, and changes in motor unit behavior, all of which contribute to improved muscle function. In this brief review, neuromuscular adaptations to different forms of exercise are reviewed, the positive training effects of eccentric exercise are presented, and the implications for training are considered.

  3. Dissociation of equilibrium points for color-discrimination and color-appearance mechanisms in incomplete chromatic adaptation.

    PubMed

    Sato, Tomoharu; Nagai, Takehiro; Kuriki, Ichiro; Nakauchi, Shigeki

    2016-03-01

    We compared the color-discrimination thresholds and supra-threshold color differences (STCDs) obtained in complete chromatic adaptation (gray) and incomplete chromatic adaptation (red). The color-difference profiles were examined by evaluating the perceptual distances between various color pairs using maximum likelihood difference scaling. In the gray condition, the chromaticities corresponding with the smallest threshold and the largest color difference were almost identical. In contrast, in the red condition, they were dissociated. The peaks of the sensitivity functions derived from the color-discrimination thresholds and STCDs along the L-M axis were systematically different between the adaptation conditions. These results suggest that the color signals involved in color discrimination and STCD tasks are controlled by separate mechanisms with different characteristic properties.

  4. Adaptations and mechanisms of human heat acclimation: Applications for competitive athletes and sports.

    PubMed

    Périard, J D; Racinais, S; Sawka, M N

    2015-06-01

    Exercise heat acclimation induces physiological adaptations that improve thermoregulation, attenuate physiological strain, reduce the risk of serious heat illness, and improve aerobic performance in warm-hot environments and potentially in temperate environments. The adaptations include improved sweating, improved skin blood flow, lowered body temperatures, reduced cardiovascular strain, improved fluid balance, altered metabolism, and enhanced cellular protection. The magnitudes of adaptations are determined by the intensity, duration, frequency, and number of heat exposures, as well as the environmental conditions (i.e., dry or humid heat). Evidence is emerging that controlled hyperthermia regimens where a target core temperature is maintained, enable more rapid and complete adaptations relative to the traditional constant work rate exercise heat acclimation regimens. Furthermore, inducing heat acclimation outdoors in a natural field setting may provide more specific adaptations based on direct exposure to the exact environmental and exercise conditions to be encountered during competition. This review initially examines the physiological adaptations associated with heat acclimation induction regimens, and subsequently emphasizes their application to competitive athletes and sports. PMID:25943654

  5. Adaptations and mechanisms of human heat acclimation: Applications for competitive athletes and sports.

    PubMed

    Périard, J D; Racinais, S; Sawka, M N

    2015-06-01

    Exercise heat acclimation induces physiological adaptations that improve thermoregulation, attenuate physiological strain, reduce the risk of serious heat illness, and improve aerobic performance in warm-hot environments and potentially in temperate environments. The adaptations include improved sweating, improved skin blood flow, lowered body temperatures, reduced cardiovascular strain, improved fluid balance, altered metabolism, and enhanced cellular protection. The magnitudes of adaptations are determined by the intensity, duration, frequency, and number of heat exposures, as well as the environmental conditions (i.e., dry or humid heat). Evidence is emerging that controlled hyperthermia regimens where a target core temperature is maintained, enable more rapid and complete adaptations relative to the traditional constant work rate exercise heat acclimation regimens. Furthermore, inducing heat acclimation outdoors in a natural field setting may provide more specific adaptations based on direct exposure to the exact environmental and exercise conditions to be encountered during competition. This review initially examines the physiological adaptations associated with heat acclimation induction regimens, and subsequently emphasizes their application to competitive athletes and sports.

  6. Development of the PROMIS® Coping Expectancies of Smoking Item Banks

    PubMed Central

    Edelen, Maria Orlando; Tucker, Joan S.; Stucky, Brian D.; Hansen, Mark; Cai, Li

    2014-01-01

    Objective: Smoking is a coping strategy for many smokers who then have difficulty finding new ways to cope with negative affect when they quit. This paper describes analyses conducted to develop and evaluate item banks for assessing the coping expectancies of smoking for daily and nondaily smokers. Methods: Using data from a large sample of daily (N = 4,201) and nondaily (N = 1,183) smokers, we conducted a series of item factor analyses, item response theory analyses, and differential item functioning (DIF) analyses (according to gender, age, and ethnicity) to arrive at a unidimensional set of items for daily and nondaily smokers. We also evaluated performance of short forms (SFs) and computer adaptive tests (CATs) for assessing coping expectancies of smoking. Results: For both daily and nondaily smokers, the unidimensional Coping Expectancies item banks (21 items) are relatively DIF free and are highly reliable (0.96 and 0.97, respectively). A common 4-item SF for daily and nondaily smokers also showed good reliability (0.85). Adaptive tests required an average of 4.3 and 3.7 items for simulated daily and nondaily respondents, respectively, and achieved reliabilities of 0.91 for both when the maximum test length was 10 items. Conclusions: This research provides a new set of items that can be used to reliably assess coping expectancies of smoking, through a SF, CAT, or a tailored set selected for a specific research purpose. PMID:25118227

  7. Coping behaviour after shipwreck.

    PubMed

    Henderson, S; Bostock, T

    1977-07-01

    A description is given of the coping behaviour of seven men who survived a shipwreck and were not rescued until 13 days later. The principal behaviours shown by the men were attachment ideation, drive to survive, modelling, prayer and hope. Particular attention is paid to the first of these, and consideration given to its likely origins in behavioural evolution. It is proposed as a hitherto inadequately recognized coping behaviour. A follow-up examination 12 to 24 months later showed that five of the seven men available had developed substantial psychiatric disorder, while by contrast one was not only well but claimed to have been enriched by the experience. Exposure to extreme adversity or disaster may have long-term effects on mental health. Further longitudinal studies of disaster victims are necessary for the design of informed after-care.

  8. Diversity of CRISPR-Cas-Mediated Mechanisms of Adaptive Immunity in Prokaryotes and Their Application in Biotechnology.

    PubMed

    Savitskaya, E E; Musharova, O S; Severinov, K V

    2016-07-01

    CRISPR-Cas systems of adaptive immunity in prokaryotes consist of CRISPR arrays (clusters of short repeated genomic DNA fragments separated by unique spacer sequences) and cas (CRISPR-associated) genes that provide cells with resistance against bacteriophages and plasmids containing protospacers, i.e. sequences complementary to CRISPR array spacers. CRISPR-Cas systems are responsible for two different cellular phenomena: CRISPR adaptation and CRISPR interference. CRISPR adaptation is cell genome modification by integration of new spacers that represents a unique case of Lamarckian inheritance. CRISPR interference involves specific recognition of protospacers in foreign DNA followed by introduction of breaks into this DNA and its destruction. According to the mechanisms of action, CRISPR-Cas systems have been subdivided into two classes, five types, and numerous subtypes. The development of techniques based on CRISPR interference mediated by the Type II system Cas9 protein has revolutionized the field of genome editing because it allows selective, efficient, and relatively simple introduction of directed breaks into target DNA loci. However, practical applications of CRISPR-Cas systems are not limited only to genome editing. In this review, we focus on the variety of CRISPR interference and CRISPR adaptation mechanisms and their prospective use in biotechnology. PMID:27449612

  9. Chronic sorrow and coping in families of children with epilepsy.

    PubMed

    Hobdell, Elizabeth F; Grant, Mitzie L; Valencia, Ignacio; Mare, Jane; Kothare, Sanjeev V; Legido, Agustin; Khurana, Divya S

    2007-04-01

    Epilepsy, a common problem in child neurology, affects the entire family. There is a potential for such psychosocial consequences as parental chronic sorrow and alterations in coping. In this study, 67 parents completed brief questionnaires about their sorrow and coping styles. Results demonstrated chronic sorrow as measured by the Adapted Burke Questionnaire (10.45 +/- 7.9). Interestingly, the total score was not significantly different between parents of children with refractory and nonrefractory epilepsy or parents of children with comorbid or without comorbid conditions. Selection of the individual item disbelief, however, was significantly increased in parents of children with nonrefractory epilepsy, and selection of the item anger was significantly increased in parents of children with comorbid conditions. Parental coping styles were similar to those reported in the normative data for the instrument used, the Coping Health Inventory for Parents (CHIP). The correlation between chronic sorrow and coping was significant between the grief component of sorrow and Coping Pattern II of the CHIP. Implications for practice include earlier identification of parental feelings of sorrow and coping styles, which may contribute to a positive outcome. PMID:17477221

  10. Adaptive mechanisms of insect pests against plant protease inhibitors and future prospects related to crop protection: a review.

    PubMed

    Macedo, Maria L R; de Oliveira, Caio F R; Costa, Poliene M; Castelhano, Elaine C; Silva-Filho, Marcio C

    2015-01-01

    The overwhelming demand for food requires the application of technology on field. An important issue that limits the productivity of crops is related to insect attacks. Hence, several studies have evaluated the application of different compounds to reduce the field losses, especially insecticide compounds from plant sources. Among them, plant protease inhibitors (PIs) have been studied in both basic and applied researches, displaying positive results in control of some insects. However, certain species are able to bypass the insecticide effects exerted by PIs. In this review, we disclosed the adaptive mechanisms showed by lepidopteran and coleopteran insects, the most expressive insect orders related to crop predation. The structural aspects involved in adaptation mechanisms are presented as well as the newest alternatives for pest control. The application of biotechnological tools in crop protection will be mandatory in agriculture, and it will be up to researchers to find the best candidates for effective control in long-term. PMID:25329404

  11. Insights into Mechanisms and Proteomic Characterisation of Pseudomonas aeruginosa Adaptation to a Novel Antimicrobial Substance

    PubMed Central

    Cierniak, Peter; Jübner, Martin; Müller, Stefan; Bender, Katja

    2013-01-01

    Antibiotic resistance has been reported since the introduction of synthetic antibiotics. Bacteria, such as one of the most common nosocomial pathogens P. aeruginosa, adapt quickly to changing environmental conditions, due to their short generation time. Thus microevolutional changes can be monitored in situ. In this study, the microevolutional process of Pseudomonas aeruginosa PAO1 resistance against a recently developed novel antibacterial zinc Schiff-base (ZSB) was investigated at the proteome level. After extended exposure to ZSB the passaged strain differed in tolerance against ZSB, with the adapted P. aeruginosa PAO1 exhibiting 1.6 times higher minimal inhibitory concentration. Using Two-dimensional Difference Gel Electrophoresis, the changes in the proteome of ZSB adapted P. aeruginosa PAO1 were examined by comparison with the non-adapted P. aeruginosa PAO1. The proteome of the adapted P. aeruginosa PAO1 strain differed significantly from the non-adapted in the abundance of two proteins when both strains were grown under stressing conditions. One protein could be identified as the outer membrane protein D that plays a role in uptake of basic amino acids as well as in carbapeneme resistance. The second protein has been identified as alkyl peroxide reductase subunit F. Our data indicated a slight increase in abundance of alkyl peroxide reductase F (AhpF) in the case of ZSB passaged P. aeruginosa PAO1. Higher abundance of Ahp has been discussed in the literature as a promoter of accelerated detoxification of benzene derivatives. The observed up-regulated AhpF thus appears to be connected to an increased tolerance against ZSB. Changes in the abundance of proteins connected to oxidative stress were also found after short-time exposure of P. aeruginosa PAO1 to the ZSB. Furthermore, adapted P. aeruginosa PAO1 showed increased tolerance against hydrogen peroxide and, in addition, showed accelerated degradation of ZSB, as determined by HPLC measurements. PMID:23869205

  12. Examining Behavioural Coping Strategies as Mediators between Work-Family Conflict and Psychological Distress

    PubMed Central

    Shamsuddin, Khadijah

    2015-01-01

    We examined the mediating role of behavioral coping strategies in the association between work-family conflict and psychological distress. In particular, we examined the two directions of work-family conflict, namely, work interference into family and family interference into work. Furthermore, two coping styles in this study were adaptive and maladaptive coping strategies. This cross-sectional study was conducted among 429 Malaysian working women using self-reported data. The results of mediational analysis in the present study showed that adaptive coping strategy does not significantly mediate the effect of work-family conflict on psychological distress. However, maladaptive coping strategies significantly mediate the effect of work-family conflict on psychological distress. These results show that adaptive coping strategies, which aimed to improve the stressful situation, are not effective in managing stressor such as work-family conflict. We found that experiencing interrole conflict steers employees toward frequent use of maladaptive coping strategies which in turn lead to psychological distress. Interventions targeted at improvement of coping skills which are according to individual's needs and expectation may help working women to balance work and family demands. The important issue is to keep in mind that effective coping strategies are to control the situations not to eliminate work-family conflict. PMID:25695097

  13. Mindfulness Training Improves Problem-Focused Coping in Psychology and Medical Students: Results from a Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Halland, E.; De Vibe, M.; Solhaug, I.; Friborg, O.; Rosenvinge, J. H.; Tyssen, R.; Sørlie, T.; Bjørndal, A.

    2015-01-01

    Background: Students of clinical psychology and medicine experience high levels of mental distress and low levels of life satisfaction. Using adaptive coping strategies can modify the negative effect of stressors on health. Mindfulness, it has been claimed, more adaptive coping with stress, yet few studies have investigated whether mindfulness…

  14. Mechanical, hormonal, and hypertrophic adaptations to 10 weeks of eccentric and stretch-shortening cycle exercise training in old males.

    PubMed

    Váczi, Márk; Nagy, Szilvia A; Kőszegi, Tamás; Ambrus, Míra; Bogner, Péter; Perlaki, Gábor; Orsi, Gergely; Tóth, Katalin; Hortobágyi, Tibor

    2014-10-01

    The growth promoting effects of eccentric (ECC) contractions are well documented but it is unknown if the rate of stretch per se plays a role in such muscular responses in healthy aging human skeletal muscle. We tested the hypothesis that exercise training of the quadriceps muscle with low rate ECC and high rate ECC contractions in the form of stretch-shortening cycles (SSCs) but at equal total mechanical work would produce rate-specific adaptations in healthy old males age 60-70. Both training programs produced similar improvements in maximal voluntary isometric (6%) and ECC torque (23%) and stretch-shortening cycle function (reduced contraction duration [24%] and enhanced elastic energy storage [12%]) (p<0.05). The rate of torque development increased 30% only after SSC exercise (p<0.05). Resting testosterone and cortisol levels were unchanged but after each program the acute exercise-induced cortisol levels were 12-15% lower (p<0.05). Both programs increased quadriceps size 2.5% (p<0.05). It is concluded that both ECC and SSC exercise training produces favorable adaptations in healthy old males' quadriceps muscle. Although the rate of muscle tension during the SSC vs. ECC contractions was about 4-fold greater, the total mechanical work seems to regulate the hypetrophic, hormonal, and most of the mechanical adaptations. However, SSC exercise was uniquely effective in improving a key deficiency of aging muscle, i.e., its ability to produce force rapidly.

  15. Chaos control of the micro-electro-mechanical resonator by using adaptive dynamic surface technology with extended state observer

    NASA Astrophysics Data System (ADS)

    Luo, Shaohua; Sun, Quanping; Cheng, Wei

    2016-04-01

    This paper addresses chaos control of the micro-electro- mechanical resonator by using adaptive dynamic surface technology with extended state observer. To reveal the mechanism of the micro- electro-mechanical resonator, the phase diagrams and corresponding time histories are given to research the nonlinear dynamics and chaotic behavior, and Homoclinic and heteroclinic chaos which relate closely with the appearance of chaos are presented based on the potential function. To eliminate the effect of chaos, an adaptive dynamic surface control scheme with extended state observer is designed to convert random motion into regular motion without precise system model parameters and measured variables. Putting tracking differentiator into chaos controller solves the `explosion of complexity' of backstepping and poor precision of the first-order filters. Meanwhile, to obtain high performance, a neural network with adaptive law is employed to approximate unknown nonlinear function in the process of controller design. The boundedness of all the signals of the closed-loop system is proved in theoretical analysis. Finally, numerical simulations are executed and extensive results illustrate effectiveness and robustness of the proposed scheme.

  16. Mechanism of Cell Culture Adaptation of an Enteric Calicivirus, the Porcine Sapovirus Cowden Strain

    PubMed Central

    Lu, Zhongyan; Yokoyama, Masaru; Chen, Ning; Oka, Tomoichiro; Jung, Kwonil; Chang, Kyeong-Ok; Annamalai, Thavamathi

    2015-01-01

    ABSTRACT The porcine sapovirus (SaV) (PoSaV) Cowden strain is one of only a few culturable enteric caliciviruses. Compared to the wild-type (WT) PoSaV Cowden strain, tissue culture-adapted (TC) PoSaV has two conserved amino acid substitutions in the RNA-dependent RNA polymerase (RdRp) and six in the capsid protein (VP1). By using the reverse-genetics system, we identified that 4 amino acid substitutions in VP1 (residues 178, 289, 324, and 328), but not the substitutions in the RdRp region, were critical for the cell culture adaptation of the PoSaV Cowden strain. The other two substitutions in VP1 (residues 291 and 295) reduced virus replication in vitro. Three-dimensional (3D) structural analysis of VP1 showed that residue 178 was located near the dimer-dimer interface, which may affect VP1 assembly and oligomerization; residues 289, 291, 324, and 328 were located at protruding subdomain 2 (P2) of VP1, which may influence virus binding to cellular receptors; and residue 295 was located at the interface of two monomeric VP1 proteins, which may influence VP1 dimerization. Although reversion of the mutation at residue 291 or 295 from that of the TC strain to that of the WT reduced virus replication in vitro, it enhanced virus replication in vivo, and the revertants induced higher-level serum and mucosal antibody responses than those induced by the TC PoSaV Cowden strain. Our findings reveal the molecular basis for PoSaV adaptation to cell culture. These findings may provide new, critical information for the cell culture adaptation of other PoSaV strains and human SaVs or noroviruses. IMPORTANCE The tissue culture-adapted porcine sapovirus Cowden strain is one of only a few culturable enteric caliciviruses. We discovered that 4 amino acid substitutions in VP1 (residues 178, 289, 324, and 328) were critical for its adaptation to LLC-PK cells. Two substitutions in VP1 (residues 291 and 295) reduced virus replication in vitro but enhanced virus replication and induced

  17. Illness Adaptation: Clarifying the Concept and Validating a Scale.

    ERIC Educational Resources Information Center

    Young, Rosalie F.; Kahana, Eva

    Traditionally, coping and adaptation have been considered synonymous in individual's responses to illness and other stressful situations. The Illness Adaptation Scale (IAS) is a 12-item instrument which was designed to assess adaptational outcomes in illness situations as well as four coping modes (instrumental-self oriented, instrumental-other…

  18. Age and Gender Differences in Coping Style across Various Problems: Omani Adolescents' Perspective

    ERIC Educational Resources Information Center

    Al-Bahrani, Muna; Aldhafri, Said; Alkharusi, Hussain; Kazem, Ali; Alzubiadi, Abdulqawi

    2013-01-01

    This study examines adolescents' coping styles, with relation to their gender and age and level, of six types of problems. The participants were 1843 adolescents (51.7% female and 48.3% male) from the Sultanate of Oman with a mean age of 15.75. Two scales examining general adaptive and maladaptive coping styles and levels of school, economic,…

  19. The Development and Psychometric Evaluation of the Brief Resilient Coping Scale

    ERIC Educational Resources Information Center

    Sinclair, Vaughn G.; Wallston, Kenneth A.

    2004-01-01

    This article introduces the Brief Resilient Coping Scale (BRCS), a 4-item measure designed to capture tendencies to cope with stress in a highly adaptive manner. Two samples of individuals with rheumatoid arthritis (ns = 90 and 140) provide evidence for the reliability and validity of the BRCS. The BRCS has adequate internal consistency and…

  20. Stress Constellations and Coping Styles of Older Adults with Age-Related Visual Impairment

    ERIC Educational Resources Information Center

    Lee, Kyoung Othelia; Brennan, Mark

    2006-01-01

    Narrative data from two earlier studies of adaptation to age-related visual impairment were examined for constellations of stressors and coping styles. In the course of previous qualitative analyses, the researchers identified stress and coping codes according to behavioral, psychological, and social domains using a grounded theory approach. In…

  1. Predictive Factors for the Uptake of Coping Strategies by Spousal Dementia Caregivers: A Systematic Review.

    PubMed

    Roche, Lauren; MacCann, Carolyn; Croot, Karen

    2016-01-01

    An understanding of spousal dementia caregivers' coping strategies and their predictive factors is imperative for caregivers' well-being. Although several reviews have explored the relationship between coping strategies and outcomes, no review has investigated factors that predict caregivers' use of one type of coping strategy over another. The current review aimed to identify factors that predict caregivers' coping strategies. Within this, we attempted to identify caregivers who are more likely to adopt dysfunctional coping strategies and be at risk of adverse outcomes. Several electronic databases were systematically searched. Twenty-one studies were eligible for review, describing 18 caregiver and care-recipient factors related to the 3 coping strategies. No factors were classified "predictive," however, 16 factors were "potentially predictive." Younger, more highly educated caregivers with greater emotional supports and knowledge of dementia were associated with solution-focused coping. Younger, less educated caregivers were associated with emotional support/acceptance-based coping strategies. Whereas nonwhite caregivers with less emotional supports caregiving for persons with more behavioral problems were associated with dysfunctional coping strategies. Enhancing caregiver self-efficacy, knowledge of dementia, improving social supports, linking to support groups, managing behavioral problems, as well as coaching adaptive coping strategies while flagging caregivers at risk for dysfunctional coping may improve outcomes for caregivers. PMID:26485497

  2. Predictive Factors for the Uptake of Coping Strategies by Spousal Dementia Caregivers: A Systematic Review.

    PubMed

    Roche, Lauren; MacCann, Carolyn; Croot, Karen

    2016-01-01

    An understanding of spousal dementia caregivers' coping strategies and their predictive factors is imperative for caregivers' well-being. Although several reviews have explored the relationship between coping strategies and outcomes, no review has investigated factors that predict caregivers' use of one type of coping strategy over another. The current review aimed to identify factors that predict caregivers' coping strategies. Within this, we attempted to identify caregivers who are more likely to adopt dysfunctional coping strategies and be at risk of adverse outcomes. Several electronic databases were systematically searched. Twenty-one studies were eligible for review, describing 18 caregiver and care-recipient factors related to the 3 coping strategies. No factors were classified "predictive," however, 16 factors were "potentially predictive." Younger, more highly educated caregivers with greater emotional supports and knowledge of dementia were associated with solution-focused coping. Younger, less educated caregivers were associated with emotional support/acceptance-based coping strategies. Whereas nonwhite caregivers with less emotional supports caregiving for persons with more behavioral problems were associated with dysfunctional coping strategies. Enhancing caregiver self-efficacy, knowledge of dementia, improving social supports, linking to support groups, managing behavioral problems, as well as coaching adaptive coping strategies while flagging caregivers at risk for dysfunctional coping may improve outcomes for caregivers.

  3. Coping strategies in a sample of anxiety patients: factorial analysis and associations with psychopathology

    PubMed Central

    Pozzi, Gino; Frustaci, Alessandra; Tedeschi, Daniela; Solaroli, Silvia; Grandinetti, Paolo; Di Nicola, Marco; Janiri, Luigi

    2015-01-01

    Background The relationship between coping styles and mental disorders has received considerable attention and instruments have been developed to assess coping strategies. The measurement by means of category systems has been criticized and a functional hierarchy of action types linked to the adaptive processes is preferred. We aimed to determine which factors may exist within the Brief-COPE (Brief Coping Orientation to Problems Experienced – COPE – Inventory) in an Italian sample of patients with anxiety disorders; and if these factors correlate with the severity of psychopathology or with other characteristics. Methods A total sample of 148 patients was recruited. The Brief-COPE inventory, the Symptom Check List 90-Revised, the Penn State Worry Questionnaire, the Zung Anxiety Status Inventory and the Zung Self-Rating Anxiety Scale were administered. Results Factor analysis of the Brief-COPE yielded nine factors accounting for 65.48% of the variance. Patients scored higher on Searching Support, followed by Acceptance, Changing Perspective, and Problem Solving. Associations between measures of psychopathology and factors of coping strategies, mostly Searching support and Avoidance, were found. Conclusions Data of the present study support a nine-factor structure of the Brief-COPE that includes five broad dimensions of coping. Psychopathology was mostly related to Searching support and Avoidance factors, showing that these strategies may reflect ineffective ways of coping; Problem solving and Changing perspective could be a valid approach to moderate anxiety/depression symptoms and psychopathology in general. PMID:26356192

  4. Effect of restorative technique and thermal/mechanical treatment on marginal adaptation and compressive strength of esthetic restorations.

    PubMed

    de Paula, Andréia Bolzan; Duque, Cristiane; Correr-Sobrinho, Lourenço; Puppin-Rontani, Regina M

    2008-01-01

    This study evaluated the compressive strength and marginal adaptation of composite onlays using indirect and direct techniques after thermal and mechanical cycling. Onlay standardized cavities were prepared in 50 permanent molars and restored with Z-250 resin composite using indirect (IRT) or direct (DRT) restorative techniques. The restorations were either submitted or not submitted to thermal (500 cycles, 5 degrees to 55 degrees C) and mechanical cycling (50,000 cycles, 50N). The teeth were distributed to five groups (n=10): G1-IRT/cycling; G2-IRT/no cycling; G3-DRT/cycling; G4-DRT/no cycling and G5 (control group)-sound teeth. All prepared teeth were stored in 100% relative humidity at 37 degrees C for 24 hours, followed by finishing with Sof-Lex discs. A caries detector solution was applied on the tooth-restoration interface of all teeth for five seconds, followed by washing and drying. Four digital photographs were taken of each tooth surface. The extent of gaps was measured using standard software (Image Tool 3.0). All groups were submitted to compression testing in a universal testing machine (INSTRON) at a crosshead speed of 1 mm/minute until failure. The compressive strength (CS) and marginal adaptation data were submitted to ANOVA and Tukey test (p<0.05). For both evaluation criteria (compressive strength and marginal adaptation), there were no statistically significant differences among the restorative techniques. Deterioration over time was observed for both types of restorations. However, the prevalence of catastrophic fractures increased among direct restorations. The application of thermal/mechanical cycling only influenced marginal adaptation.

  5. Costs, benefits and redundant mechanisms of adaption to chronic low-dose stress in yeast

    PubMed Central

    Markiewicz-Potoczny, Marta; Lydall, David

    2016-01-01

    ABSTRACT All organisms live in changeable, stressful environments. It has been reported that exposure to low-dose stresses or poisons can improve fitness. However, examining the effects of chronic low-dose chemical exposure is challenging. To address this issue we used temperature sensitive mutations affecting the yeast cell division cycle to induce low-dose stress for 40 generation times, or more. We examined cdc13-1 mutants, defective in telomere function, and cdc15-2 mutants, defective in mitotic kinase activity. We found that each stress induced similar adaptive responses. Stress-exposed cells became resistant to higher levels of stress but less fit, in comparison with unstressed cells, in conditions of low stress. The costs and benefits of adaptation to chronic stress were reversible. In the cdc13-1 context we tested the effects of Rad9, a central player in the response to telomere defects, Exo1, a nuclease that degrades defective telomeres, and Msn2 and Msn4, 2 transcription factors that contribute to the environmental stress response. We also observed, as expected, that Rad9 and Exo1 modulated the response of cells to stress. In addition we observed that adaptation to stress could still occur in these contexts, with associated costs and benefits. We conclude that functionally redundant cellular networks control the adaptive responses to low dose chronic stress. Our data suggests that if organisms adapt to low dose stress it is helpful if stress continues or increases but harmful should stress levels reduce. PMID:27628486

  6. An adaptive quantum mechanics/molecular mechanics method for the infrared spectrum of water: incorporation of the quantum effect between solute and solvent.

    PubMed

    Watanabe, Hiroshi C; Banno, Misa; Sakurai, Minoru

    2016-03-14

    Quantum effects in solute-solvent interactions, such as the many-body effect and the dipole-induced dipole, are known to be critical factors influencing the infrared spectra of species in the liquid phase. For accurate spectrum evaluation, the surrounding solvent molecules, in addition to the solute of interest, should be treated using a quantum mechanical method. However, conventional quantum mechanics/molecular mechanics (QM/MM) methods cannot handle free QM solvent molecules during molecular dynamics (MD) simulation because of the diffusion problem. To deal with this problem, we have previously proposed an adaptive QM/MM "size-consistent multipartitioning (SCMP) method". In the present study, as the first application of the SCMP method, we demonstrate the reproduction of the infrared spectrum of liquid-phase water, and evaluate the quantum effect in comparison with conventional QM/MM simulations.

  7. Light and dark adaptation mechanisms in the compound eyes of Myrmecia ants that occupy discrete temporal niches.

    PubMed

    Narendra, Ajay; Greiner, Birgit; Ribi, Willi A; Zeil, Jochen

    2016-08-15

    Ants of the Australian genus Myrmecia partition their foraging niche temporally, allowing them to be sympatric with overlapping foraging requirements. We used histological techniques to study the light and dark adaptation mechanisms in the compound eyes of diurnal (Myrmecia croslandi), crepuscular (M. tarsata, M. nigriceps) and nocturnal ants (M. pyriformis). We found that, except in the day-active species, all ants have a variable primary pigment cell pupil that constricts the crystalline cone in bright light to control for light flux. We show for the nocturnal M. pyriformis that the constriction of the crystalline cone by the primary pigment cells is light dependent whereas the opening of the aperture is regulated by an endogenous rhythm. In addition, in the light-adapted eyes of all species, the retinular cell pigment granules radially migrate towards the rhabdom, a process that in both the day-active M. croslandi and the night-active M. pyriformis is driven by ambient light intensity. Visual system properties thus do not restrict crepuscular and night-active ants to their temporal foraging niche, while day-active ants require high light intensities to operate. We discuss the ecological significance of these adaptation mechanisms and their role in temporal niche partitioning. PMID:27535985

  8. Transcriptomes reveal the genetic mechanisms underlying ionic regulatory adaptations to salt in the crab-eating frog

    PubMed Central

    Shao, Yong; Wang, Li-Jun; Zhong, Li; Hong, Mei-Ling; Chen, Hong-Man; Murphy, Robert W.; Wu, Dong-Dong; Zhang, Ya-Ping; Che, Jing

    2015-01-01

    The crab-eating frog, Fejervarya cancrivora, is the only frog that lives near seas. It tolerates increased environmental concentrations of sodium, chloride and potassium partly by raising ion and urea levels in its blood plasma. The molecular mechanism of the adaptation remains rarely documented. Herein, we analyze transcriptomes of the crab-eating frog and its closely related saline-intolerant species, F. limnocharis, to explore the molecular basis of adaptations to such extreme environmental conditions. Analyses reveal the potential genetic mechanism underlying the adaptation to salinity for the crab-eating frog. Genes in categories associated with ion transport appear to have evolved rapidly in F. cancrivora. Both positively selected and differentially expressed genes exhibit enrichment in the GO category regulation of renal sodium excretion. In this category, the positively selected sites of ANPEP and AVPR2 encode CD13 and V2 receptors, respectively; they fall precisely on conserved domains. More differentially expressed rapidly evolved genes occur in the kidney of F. cancrivora than in F. limnocharis. Four genes involved in the regulation of body fluid levels show signs of positive selection and increased expression. Significant up-regulation occurs in several genes of F. cancrivora associated with renin-angiotensin system and aldosterone-regulated sodium reabsorption pathways, which relate to osmotic regulation. PMID:26619819

  9. A striking reduction of simple loudness adaptation in autism

    PubMed Central

    Lawson, Rebecca P.; Aylward, Jessica; White, Sarah; Rees, Geraint

    2015-01-01

    Reports of sensory disturbance, such as loudness sensitivity or sound intolerance, are ubiquitous in Autism Spectrum Disorder (ASD) but a mechanistic explanation for these perceptual differences is lacking. Here we tested adaptation to loudness, a process that regulates incoming sensory input, in adults with ASD and matched controls. Simple loudness adaptation (SLA) is a fundamental adaptive process that reduces the subjective loudness of quiet steady-state sounds in the environment over time, whereas induced loudness adaptation (ILA) is a means of generating a reduction in the perceived volume of louder sounds. ASD participants showed a striking reduction in magnitude and rate of SLA relative to age and ability-matched typical adults, but in contrast ILA remained intact. Furthermore, rate of SLA predicted sensory sensitivity coping strategies in the ASD group. These results provide the first evidence that compromised neural mechanisms governing fundamental adaptive processes might account for sound sensitivity in ASD. PMID:26537694

  10. Robust adaptive control modeling of human arm movements subject to altered gravity and mechanical loads

    NASA Astrophysics Data System (ADS)

    Tryfonidis, Michail

    It has been observed that during orbital spaceflight the absence of gravitation related sensory inputs causes incongruence between the expected and the actual sensory feedback resulting from voluntary movements. This incongruence results in a reinterpretation or neglect of gravity-induced sensory input signals. Over time, new internal models develop, gradually compensating for the loss of spatial reference. The study of adaptation of goal-directed movements is the main focus of this thesis. The hypothesis is that during the adaptive learning process the neural connections behave in ways that can be described by an adaptive control method. The investigation presented in this thesis includes two different sets of experiments. A series of dart throwing experiments took place onboard the space station Mir. Experiments also took place at the Biomechanics lab at MIT, where the subjects performed a series of continuous trajectory tracking movements while a planar robotic manipulandum exerted external torques on the subjects' moving arms. The experimental hypothesis for both experiments is that during the first few trials the subjects will perform poorly trying to follow a prescribed trajectory, or trying to hit a target. A theoretical framework is developed that is a modification of the sliding control method used in robotics. The new control framework is an attempt to explain the adaptive behavior of the subjects. Numerical simulations of the proposed framework are compared with experimental results and predictions from competitive models. The proposed control methodology extends the results of the sliding mode theory to human motor control. The resulting adaptive control model of the motor system is robust to external dynamics, even those of negative gain, uses only position and velocity feedback, and achieves bounded steady-state error without explicit knowledge of the system's nonlinearities. In addition, the experimental and modeling results demonstrate that

  11. On Everyday Stress and Coping Strategies among Elementary School Children

    ERIC Educational Resources Information Center

    Sotardi, Valerie A.

    2013-01-01

    Elementary school students are confronted with a variety of everyday challenges ranging from comprehension obstacles to interpersonal conflict. Learning to cope effectively with moments of tension is an important part of a child's education because adaptation to stress is likely to influence academic and developmental success. However,…

  12. Flexible Applications of the Coping Cat Program for Anxious Youth

    ERIC Educational Resources Information Center

    Beidas, Rinad S.; Benjamin, Courtney L.; Puleo, Connor M.; Edmunds, Julie M.; Kendall, Philip C.

    2010-01-01

    The current article offers suggestions for ways to adapt empirically supported treatments (ESTs). A specific manualized EST (Coping Cat; Kendall & Hedtke, 2006a) is used to illustrate the concept of "flexibility within fidelity" (Kendall & Beidas, 2007; Kendall, Gosch, Furr, & Sood, 2008). Flexibility within fidelity stresses the importance of…

  13. Stress and coping research. Methodological challenges, theoretical advances, and clinical applications.

    PubMed

    Somerfield, M R; McCrae, R R

    2000-06-01

    Coping is among the most widely studied topics in contemporary psychology. However, the explosion of interest in coping has yielded little and the field is in crisis. This section offers a survey of the state of the art in theory and research on stress and adaptational processes. The four core articles in the section take up, respectively, problems in research design, the neglect of unconscious reactions to stress, the selection of adaptational outcomes, and the link between research on adaptational processes and clinical practice. The final article by Richard S. Lazarus offers a commentary. The present introduction provides the historical backdrop for the section. Then, after a brief overview of research on adaptational processes, the authors summarize the scope and yield of coping research and preview the four core articles in the section. The strengths and limits of individual coping efforts and the need for realistic expectations and redoubled efforts are discussed.

  14. Coping with racial discrimination: the role of substance use.

    PubMed

    Gerrard, Meg; Stock, Michelle L; Roberts, Megan E; Gibbons, Frederick X; O'Hara, Ross E; Weng, Chih-Yuan; Wills, Thomas A

    2012-09-01

    Three studies tested the hypothesis that the relation between perceived racial discrimination and substance use reported in previous research is moderated by use of substances as a coping mechanism. Studies 1 and 2 were experimental studies of African American adolescents' and young adults' reactions to a discrimination experience. Results revealed that those who endorsed substance use-as-coping reported more willingness to use substances after experiencing discrimination. Study 3 was a prospective study of the relation between perceived discrimination and substance use over an 8-year period in African American adolescents. Results demonstrated that discrimination is associated with increases in substance use, but only among adolescents who endorse substance use-as-coping. Together, these three studies provide evidence that experiencing discrimination has both short- and long-term detrimental effects on African Americans' substance use, but significantly more so for those who adopt a pattern of using substances as a coping mechanism.

  15. Adaptive engineering of a hyperthermophilic archaeon on CO and discovering the underlying mechanism by multi-omics analysis

    PubMed Central

    Lee, Seong Hyuk; Kim, Min-Sik; Lee, Jae-Hak; Kim, Tae Wan; Bae, Seung Seob; Lee, Sung-Mok; Jung, Hae Chang; Yang, Tae-Jun; Choi, Ae Ran; Cho, Yong-Jun; Lee, Jung-Hyun; Kwon, Kae Kyoung; Lee, Hyun Sook; Kang, Sung Gyun

    2016-01-01

    The hyperthermophilic archaeon Thermococcus onnurineus NA1 can grow and produce H2 on carbon monoxide (CO) and its H2 production rates have been improved through metabolic engineering. In this study, we applied adaptive evolution to enhance H2 productivity. After over 150 serial transfers onto CO medium, cell density, CO consumption rate and H2 production rate increased. The underlying mechanism for those physiological changes could be explained by using multi-omics approaches including genomic, transcriptomic and epigenomic analyses. A putative transcriptional regulator was newly identified to regulate the expression levels of genes related to CO oxidation. Transcriptome analysis revealed significant changes in the transcript levels of genes belonging to the categories of transcription, translation and energy metabolism. Our study presents the first genome-scale methylation pattern of hyperthermophilic archaea. Adaptive evolution led to highly enhanced H2 productivity at high CO flow rates using synthesis gas produced from coal gasification. PMID:26975345

  16. Mechanisms of thermal adaptation revealed from the genomes of the Antarctic

    SciTech Connect

    Saunders, Neil F.W.; Thomas, Torsten; Curmi, Paul M.G.; Mattick, John S.; Kuczek, Elizabeth; Slade, Rob; Davis, John; Franzmann, Peter; Boone, David; Rusterholtz, Karl; Feldman, Robert; Gates, Chris; Bench, Shellie; Sowers, Kevin; Kadner, Kristen; Aerts, Andrea; Dehal, Paramvir; Detter, Chris; Glavina, Tijana; Lucas, Susan; Richardson, Paul; Larimer, Frank; Hauser , Frank; Hauser, Loren; Land, Miriam; Cavicchioli, Richard

    2003-03-01

    We generated draft genome sequences for two cold-adapted Archaea, Methanogenium frigidum and Methanococcoides burtonii, to identify genotypic characteristics that distinguish them from Archaea with a higher optimal growth temperature (OGT). Comparative genomics revealed trends in amino acid and tRNA composition, and structural features of proteins. Proteins from the cold-adapted Archaea are characterized by a higher content of non-charged polar amino acids, particularly Gln and Thr and a lower content of hydrophobic amino acids, particularly Leu. Sequence data from nine methanogen genomes (OGT 15-98 C) was used to generate 1 111 modeled protein structures. Analysis of the models from the cold-adapted Archaea showed a strong tendency in the solvent accessible area for more Gln, Thr an hydrophobic residues and fewer charged residues. A cold shock domain (CSD) protein (CspA homolog) was identified in M. frigidum, two hypothetical proteins with CSD-folds in M. burtonii, and a unique winged helix DNA-binding domain protein in M. burtonii. This suggests that these types of nucleic acid binding proteins have a critical role in cold-adapted Archaea. Structural analysis of tRNA sequences from the Archaea indicated that GC content is the major factor influencing tRNA stability in hyperthermophiles, but not in the psychrophiles, mesophiles or moderate thermophiles. Below an OGT of 60 C, the GC content in tRNA was largely unchanged, indicating that any requirement for flexibility of tRNA in psychrophiles is mediated by other means. This is the first time that comparisons have been performed with genome data from Archaea spanning the growth temperature extremes from psychrophiles to hyperthermophiles.

  17. Studying citizen science through adaptive management and learning feedbacks as mechanisms for improving conservation.

    PubMed

    Jordan, Rebecca; Gray, Steven; Sorensen, Amanda; Newman, Greg; Mellor, David; Newman, Greg; Hmelo-Silver, Cindy; LaDeau, Shannon; Biehler, Dawn; Crall, Alycia

    2016-06-01

    Citizen science has generated a growing interest among scientists and community groups, and citizen science programs have been created specifically for conservation. We examined collaborative science, a highly interactive form of citizen science, which we developed within a theoretically informed framework. In this essay, we focused on 2 aspects of our framework: social learning and adaptive management. Social learning, in contrast to individual-based learning, stresses collaborative and generative insight making and is well-suited for adaptive management. Adaptive-management integrates feedback loops that are informed by what is learned and is guided by iterative decision making. Participants engaged in citizen science are able to add to what they are learning through primary data collection, which can result in the real-time information that is often necessary for conservation. Our work is particularly timely because research publications consistently report a lack of established frameworks and evaluation plans to address the extent of conservation outcomes in citizen science. To illustrate how our framework supports conservation through citizen science, we examined how 2 programs enacted our collaborative science framework. Further, we inspected preliminary conservation outcomes of our case-study programs. These programs, despite their recent implementation, are demonstrating promise with regard to positive conservation outcomes. To date, they are independently earning funds to support research, earning buy-in from local partners to engage in experimentation, and, in the absence of leading scientists, are collecting data to test ideas. We argue that this success is due to citizen scientists being organized around local issues and engaging in iterative, collaborative, and adaptive learning.

  18. Studying citizen science through adaptive management and learning feedbacks as mechanisms for improving conservation.

    PubMed

    Jordan, Rebecca; Gray, Steven; Sorensen, Amanda; Newman, Greg; Mellor, David; Newman, Greg; Hmelo-Silver, Cindy; LaDeau, Shannon; Biehler, Dawn; Crall, Alycia

    2016-06-01

    Citizen science has generated a growing interest among scientists and community groups, and citizen science programs have been created specifically for conservation. We examined collaborative science, a highly interactive form of citizen science, which we developed within a theoretically informed framework. In this essay, we focused on 2 aspects of our framework: social learning and adaptive management. Social learning, in contrast to individual-based learning, stresses collaborative and generative insight making and is well-suited for adaptive management. Adaptive-management integrates feedback loops that are informed by what is learned and is guided by iterative decision making. Participants engaged in citizen science are able to add to what they are learning through primary data collection, which can result in the real-time information that is often necessary for conservation. Our work is particularly timely because research publications consistently report a lack of established frameworks and evaluation plans to address the extent of conservation outcomes in citizen science. To illustrate how our framework supports conservation through citizen science, we examined how 2 programs enacted our collaborative science framework. Further, we inspected preliminary conservation outcomes of our case-study programs. These programs, despite their recent implementation, are demonstrating promise with regard to positive conservation outcomes. To date, they are independently earning funds to support research, earning buy-in from local partners to engage in experimentation, and, in the absence of leading scientists, are collecting data to test ideas. We argue that this success is due to citizen scientists being organized around local issues and engaging in iterative, collaborative, and adaptive learning. PMID:26585836

  19. Placental, Matrilineal, and Epigenetic Mechanisms Promoting Environmentally Adaptive Development of the Mammalian Brain

    PubMed Central

    Broad, Kevin D.; Rocha-Ferreira, Eridan; Hristova, Mariya

    2016-01-01

    The evolution of intrauterine development, vivipary, and placentation in eutherian mammals has introduced new possibilities and constraints in the regulation of neural plasticity and development which promote neural function that is adaptive to the environment that a developing brain is likely to encounter in the future. A range of evolutionary adaptations associated with placentation transfers disproportionate control of this process to the matriline, a period unique in mammalian development in that there are three matrilineal genomes interacting in the same organism at the same time (maternal, foetal, and postmeiotic oocytes). The interactions between the maternal and developing foetal hypothalamus and placenta can provide a template by which a mother can transmit potentially adaptive information concerning potential future environmental conditions to the developing brain. In conjunction with genomic imprinting, it also provides a template to integrate epigenetic information from both maternal and paternal lineages. Placentation also hands ultimate control of genomic imprinting and intergenerational epigenetic information transfer to the matriline as epigenetic markers undergo erasure and reprogramming in the developing oocyte. These developments, in conjunction with an expanded neocortex, provide a unique evolutionary template by which matrilineal transfer of maternal care, resources, and culture can be used to promote brain development and infant survival. PMID:27069693

  20. Coping as Part of Motivational Resilience in School: A Multidimensional Measure of Families, Allocations, and Profiles of Academic Coping

    ERIC Educational Resources Information Center

    Skinner, Ellen; Pitzer, Jennifer; Steele, Joel

    2013-01-01

    A study was designed to examine a multidimensional measure of children's coping in the academic domain as part of a larger model of motivational resilience. Using items tapping multiple ways of dealing with academic problems, including five adaptive ways (strategizing, help-seeking, comfort-seeking, self-encouragement, and commitment) and six…

  1. En las Manos de Dios [in God’s Hands]: Religious and Other Forms of Coping Among Latinos With Arthritis

    PubMed Central

    Abraído-Lanza, Ana F.; Vásquez, Elizabeth; Echeverría, Sandra E.

    2013-01-01

    This study tested a theoretical model concerning religious, passive, and active coping; pain; and psychological adjustment among a sample of 200 Latinos with arthritis. Respondents reported using high levels of religious coping. A path analysis indicated that religious coping was correlated with active but not with passive coping. Religious coping was directly related to psychological well-being. Passive coping was associated with greater pain and worse adjustment. The effects of active coping on pain, depression, and psychological well-being were entirely indirect, mediated by acceptance of illness and self-efficacy. These findings warrant more research on the mechanisms that mediate the relationship between coping and health. This study contributes to a growing literature on religious coping among people with chronic illness, as well as contributing to a historically under-studied ethnic group. PMID:14756618

  2. Utilizing Matrix-Filler Interactions in the Design of Stimuli-Responsive, Mechanically-Adaptive Electrospun Composites

    NASA Astrophysics Data System (ADS)

    Wanasekara, Nandula; Stone, David; Wnek, Gary; Korley, Lashanda

    2013-03-01

    A new class of all-organic, stimuli-responsive and mechanically-adaptive electrospun nanocomposites, which have the ability to alter their stiffness upon hydration, were developed. These materials were fabricated by incorporating an electrospun mat of poly(vinyl alcohol) (PVA) as the filler in a polymeric matrix consisting of either poly(vinyl acetate) (PVAc) or ethylene oxide-epicholorohydrin copolymer (EO-EPI). The incorporation of high stiffness, high aspect ratio PVA filler mat significantly enhanced the tensile storage modulus of EO-EPI based composites, while modulus enhancement was only noticed above the glass transition for PVAc-based composites. Composite materials based on a rubbery EO-EPI host polymer and PVA filler exhibit an irreversible reduction by a factor of 12 of the tensile modulus upon hydration. In contrast, composites comprised of PVAc show a reversible reduction of modulus by a factor of 280 upon water uptake. The mechanical morphing of the electrospun composites is the result of the filler crystallinity, and matrix-filler interactions facilitated by the surface hydroxyl groups of the PVA filler. The choice of polymer matrix and electrospun nanofiber fillers allow control of matrix-filler interactions in a new series of all-organic composites to achieve desired stimuli-responsiveness and mechanical-adaptability upon exposure to various stimuli.

  3. Adaptive coupling between damage mechanics and peridynamics: A route for objective simulation of material degradation up to complete failure

    NASA Astrophysics Data System (ADS)

    Han, Fei; Lubineau, Gilles; Azdoud, Yan

    2016-09-01

    The objective (mesh-independent) simulation of evolving discontinuities, such as cracks, remains a challenge. Current techniques are highly complex or involve intractable computational costs, making simulations up to complete failure difficult. We propose a framework as a new route toward solving this problem that adaptively couples local-continuum damage mechanics with peridynamics to objectively simulate all the steps that lead to material failure: damage nucleation, crack formation and propagation. Local-continuum damage mechanics successfully describes the degradation related to dispersed microdefects before the formation of a macrocrack. However, when damage localizes, it suffers spurious mesh dependency, making the simulation of macrocracks challenging. On the other hand, the peridynamic theory is promising for the simulation of fractures, as it naturally allows discontinuities in the displacement field. Here, we present a hybrid local-continuum damage/peridynamic model. Local-continuum damage mechanics is used to describe "volume" damage before localization. Once localization is detected at a point, the remaining part of the energy is dissipated through an adaptive peridynamic model capable of the transition to a "surface" degradation, typically a crack. We believe that this framework, which actually mimics the real physical process of crack formation, is the first bridge between continuum damage theories and peridynamics. Two-dimensional numerical examples are used to illustrate that an objective simulation of material failure can be achieved by this method.

  4. [Advances in molecular mechanisms of adaptive immunity mediated by type I-E CRISPR/Cas system--A review].

    PubMed

    Sun, Dongchang; Qiu, Juanping

    2016-01-01

    To better adapt to the environment, prokaryocyte can take up exogenous genes (from bacteriophages, plasmids or genomes of other species) through horizontal gene transfer. Accompanied by the acquisition of exogenous genes, prokaryocyte is challenged by the invasion of 'selfish genes'. Therefore, to protect against the risk of gene transfer, prokaryocyte needs to establish mechanisms for selectively taking up or degrading exogenous DNA. In recent years, researchers discovered an adaptive immunity, which is mediated by the small RNA guided DNA degradation, prevents the invasion of exogenous genes in prokaryocyte. During the immune process, partial DNA fragments are firstly integrated.to the clustered regularly interspaced short palindromic repeats (CRISPR) located within the genome DNA, and then the mature CRISPR RNA transcript and the CRISPR associated proteins (Cas) form a complex CRISPR/Cas for degrading exogenous DNA. In this review, we will first briefly describe the CRISPR/Cas systems and then mainly focus on the recent advances of the function mechanism and the regulation mechanism of the type I-E CRISPR/Cas system in Escherichia coli.

  5. An empirically derived hierarchy of adaptive mechanisms and its usefulness as a potential diagnostic axis.

    PubMed

    Vaillant, G E

    1985-01-01

    This report empirically examines the utility of the model of ego mechanisms of defense to explain psychological resilience in 307 middle aged men with socially disadvantaged childhoods. The sample has been prospectively followed for forty years. The model arranges defense mechanisms along a hierarchy reflecting severity of psychopathology and hypothetical immaturity. The value of this hierarchy of defenses in relation to diagnosis is discussed.

  6. Ventricular structure, function, and mechanics at high altitude: chronic remodeling in Sherpa vs. short-term lowlander adaptation.

    PubMed

    Stembridge, Mike; Ainslie, Philip N; Hughes, Michael G; Stöhr, Eric J; Cotter, James D; Nio, Amanda Q X; Shave, Rob

    2014-08-01

    Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged exposure in Sherpa, a highly adapted HA population. To investigate short-term adaptation and potential long-term cardiac remodeling, we studied ventricular structure and function in Sherpa at 5,050 m (n = 11; 31 ± 13 yr; mass 68 ± 10 kg; height 169 ± 6 cm) and lowlanders at sea level (SL) and following 10 ± 3 days at 5,050 m (n = 9; 34 ± 7 yr; mass 82 ± 10 kg; height 177 ± 6 cm) using conventional and speckle-tracking echocardiography. At HA, PASP was higher in Sherpa and lowlanders compared with lowlanders at SL (both P < 0.05). Sherpa had smaller right-ventricular (RV) and LV stroke volumes than lowlanders at SL with lower RV systolic strain (P < 0.05) but similar LV systolic mechanics. In contrast to LV systolic mechanics, LV diastolic, untwisting velocity was significantly lower in Sherpa compared with lowlanders at both SL and HA. After partial acclimatization, lowlanders demonstrated no change in the RV end-diastolic area; however, both RV strain and LV end-diastolic volume were reduced. In conclusion, short-term hypoxia induced a reduction in RV systolic function that was also evident in Sherpa following chronic exposure. We propose that this was consequent to a persistently higher PASP. In contrast to the RV, remodeling of LV volumes and normalization of systolic mechanics indicate structural and functional adaptation to HA. However, altered LV diastolic relaxation after chronic hypoxic exposure may reflect differential remodeling of systolic and diastolic LV function.

  7. Genome Sequencing of the Perciform Fish Larimichthys crocea Provides Insights into Molecular and Genetic Mechanisms of Stress Adaptation

    PubMed Central

    Shi, Qiong; Zhu, Lv-Yun; Li, Ting; Ding, Yang; Nie, Li; Li, Qiuhua; Dong, Wei-ren; Jiang, Liang; Sun, Bing; Zhang, XinHui; Li, Mingyu; Zhang, Hai-Qi; Xie, ShangBo; Zhu, YaBing; Jiang, XuanTing; Wang, Xianhui; Mu, Pengfei; Chen, Wei; Yue, Zhen; Wang, Zhuo; Wang, Jun; Shao, Jian-Zhong; Chen, Xinhua

    2015-01-01

    The large yellow croaker Larimichthys crocea (L. crocea) is one of the most economically important marine fish in China and East Asian countries. It also exhibits peculiar behavioral and physiological characteristics, especially sensitive to various environmental stresses, such as hypoxia and air exposure. These traits may render L. crocea a good model for investigating the response mechanisms to environmental stress. To understand the molecular and genetic mechanisms underlying the adaptation and response of L. crocea to environmental stress, we sequenced and assembled the genome of L. crocea using a bacterial artificial chromosome and whole-genome shotgun hierarchical strategy. The final genome assembly was 679 Mb, with a contig N50 of 63.11 kb and a scaffold N50 of 1.03 Mb, containing 25,401 protein-coding genes. Gene families underlying adaptive behaviours, such as vision-related crystallins, olfactory receptors, and auditory sense-related genes, were significantly expanded in the genome of L. crocea relative to those of other vertebrates. Transcriptome analyses of the hypoxia-exposed L. crocea brain revealed new aspects of neuro-endocrine-immune/metabolism regulatory networks that may help the fish to avoid cerebral inflammatory injury and maintain energy balance under hypoxia. Proteomics data demonstrate that skin mucus of the air-exposed L. crocea had a complex composition, with an unexpectedly high number of proteins (3,209), suggesting its multiple protective mechanisms involved in antioxidant functions, oxygen transport, immune defence, and osmotic and ionic regulation. Our results reveal the molecular and genetic basis of fish adaptation and response to hypoxia and air exposure. The data generated by this study will provide valuable resources for the genetic improvement of stress resistance and yield potential in L. crocea. PMID:25835551

  8. [Coping with crisis as an important factor in the rehabilitation process].

    PubMed

    Clemens, K; Hack, E; Sülzer, A; Schottmann, J

    2008-03-01

    Accidents and serious illnesses are inevitably associated with an emotional crisis, based on the fact that they are followed by significant consequences. Coping with this crisis requires enormous mental adaptation. This active coping process is typically characterised by three phases: the shock phase, the coping phase in the narrow sense and the phase of successful coping versus chronification. In order to ensure a positive rehabilitation process, successful coping with the illness is necessary. It is therefore absolutely crucial to analyse individual coping styles and possible obstacles thoroughly from a psychological point of view. In order to prevent a process of chronification, relevant psychosocial factors should be considered along with the medical and occupational aspects early in the rehabilitation process. Ultimately, psychological stability is the prerequisite for successful rehabilitation.

  9. Intergenerational Child Abuse and Coping

    ERIC Educational Resources Information Center

    Robboy, Juliet; Anderson, Kristen G.

    2011-01-01

    Many studies have investigated the consequences of child sexual abuse (CSA) but few have examined the intergenerational effects of poly-victimization and maladaptive coping. The purpose of this investigation was to examine patterns of maltreatment and maladaptive coping among second-generation CSA survivors. It is hypothesized that: (a) maternal…

  10. Coping Resources of College Students.

    ERIC Educational Resources Information Center

    Hammer, Allen L.

    Coping resources are what people bring to situations (as opposed to what they do) that enable them to deal with stressors more effectively, allow them to recover faster, or experience fewer or less intense symptoms upon exposure to stressors. The Coping Resources Inventory (CRI) measures resources in the following domains: cognitive, social,…

  11. Cold adaptation mechanisms in the ghost moth Hepialus xiaojinensis: Metabolic regulation and thermal compensation.

    PubMed

    Zhu, Wei; Zhang, Huan; Li, Xuan; Meng, Qian; Shu, Ruihao; Wang, Menglong; Zhou, Guiling; Wang, Hongtuo; Miao, Lin; Zhang, Jihong; Qin, Qilian

    2016-02-01

    Ghost moths (Lepidoptera: Hepialidae) are cold-adapted stenothermal species inhabiting alpine meadows on the Tibetan Plateau. They have an optimal developmental temperature of 12-16 °C but can maintain feeding and growth at 0 °C. Their survival strategies have received little attention, but these insects are a promising model for environmental adaptation. Here, biochemical adaptations and energy metabolism in response to cold were investigated in larvae of the ghost moth Hepialus xiaojinensis. Metabolic rate and respiratory quotient decreased dramatically with decreasing temperature (15-4 °C), suggesting that the energy metabolism of ghost moths, especially glycometabolism, was sensitive to cold. However, the metabolic rate at 4 °C increased with the duration of cold exposure, indicating thermal compensation to sustain energy budgets under cold conditions. Underlying regulation strategies were studied by analyzing metabolic differences between cold-acclimated (4 °C for 48 h) and control larvae (15 °C). In cold-acclimated larvae, the energy generating pathways of carbohydrates, instead of the overall consumption of carbohydrates, was compensated in the fat body by improving the transcription of related enzymes. The mobilization of lipids was also promoted, with higher diacylglycerol, monoacylglycerol and free fatty acid content in hemolymph. These results indicated that cold acclimation induced a reorganization on metabolic structure to prioritise energy metabolism. Within the aerobic process, flux throughout the tricarboxylic acid (TCA) cycle was encouraged in the fat body, and the activity of α-ketoglutarate dehydrogenase was the likely compensation target. Increased mitochondrial cristae density was observed in the midgut of cold-acclimated larvae. The thermal compensation strategies in this ghost moth span the entire process of energy metabolism, including degration of metabolic substrate, TCA cycle and oxidative phosphorylation, and from an energy budget

  12. The process of coping following child sexual abuse:a qualitative study.

    PubMed

    Oaksford, Karen; Frude, Neil

    2003-01-01

    This research employed both quantitative and qualitative approaches to studying the immediate and long-term coping strategies adopted by survivors of child sexual abuse, focusing on how strategies evolve over time. Qualitative findings showed that coping with child sexual abuse is not static, but changes over time. The narratives of these nonclinical survivors suggest that an adaptive outcome may be associated with a particular evolution of strategies across time, i.e., survivors reported coping predominantly by engaging in psychological escape methods initially, and then adopting cognitive appraisal and positive reframing strategies in the longer term. It appears that coping processes can affect psychological outcome following child sexual abuse. This study offers insight into the evolution of coping methods associated with an adaptive outcome.

  13. Coping behavior in normal and clinical samples: more similarities than differences?

    PubMed

    Seiffge-Krenke, I

    1993-09-01

    In our studies we tried to integrate a developmental and a clinical perspective on coping and adaptation in adolescence. Starting with a review of the author's own research, involving over 3000 12- to 20-year-olds from various cultures, the problems typical of this developmental phase and the ways of coping with these normative demands are presented. The results show that coping skills of young people in dealing with age-specific problems have so far been considerably underestimated. Their response to problems stemming from different developmental fields such as parents, peers, school or future involved three main modes of coping: Active Coping, Internal Coping and Withdrawal. Withdrawal was employed very rarely and only for certain types of problems. Age, gender and problem-specific effects in coping were found. Whereas normal adolescents most frequently choose to cope with difficulties actively by means of social resources and to think out possible solutions, risk populations appear to have a more ambivalent pattern of coping strategies with high functionality and high dysfunctionality. Even their appraisal of problems is already disturbed; they feel more readily threatened by everyday problem situations and respond more uniformly with withdrawal. Finally, similarities between the female coping style in normal samples and the more pronounced ambivalent pattern in clinical samples were discussed and related to psychopathology. PMID:8282899

  14. Mechanisms Underlying Adaptation of Respiratory Network Activity to Modulatory Stimuli in the Mouse Embryo

    PubMed Central

    Chevalier, Marc; De Sa, Rafaël; Cardoit, Laura; Thoby-Brisson, Muriel

    2016-01-01

    Breathing is a rhythmic behavior that requires organized contractions of respiratory effector muscles. This behavior must adapt to constantly changing conditions in order to ensure homeostasis, proper body oxygenation, and CO2/pH regulation. Respiratory rhythmogenesis is controlled by neural networks located in the brainstem. One area considered to be essential for generating the inspiratory phase of the respiratory rhythm is the preBötzinger complex (preBötC). Rhythmogenesis emerges from this network through the interplay between the activation of intrinsic cellular properties (pacemaker properties) and intercellular synaptic connections. Respiratory activity continuously changes under the impact of numerous modulatory substances depending on organismal needs and environmental conditions. The preBötC network has been shown to become active during the last third of gestation. But only little is known regarding the modulation of inspiratory rhythmicity at embryonic stages and even less on a possible role of pacemaker neurons in this functional flexibility during the prenatal period. By combining electrophysiology and calcium imaging performed on embryonic brainstem slice preparations, we provide evidence showing that embryonic inspiratory pacemaker neurons are already intrinsically sensitive to neuromodulation and external conditions (i.e., temperature) affecting respiratory network activity, suggesting a potential role of pacemaker neurons in mediating rhythm adaptation to modulatory stimuli in the embryo. PMID:27239348

  15. Comparing Residue Clusters from Thermophilic and Mesophilic Enzymes Reveals Adaptive Mechanisms

    PubMed Central

    Sammond, Deanne W.; Kastelowitz, Noah; Himmel, Michael E.; Yin, Hang; Crowley, Michael F.; Bomble, Yannick J.

    2016-01-01

    Understanding how proteins adapt to function at high temperatures is important for deciphering the energetics that dictate protein stability and folding. While multiple principles important for thermostability have been identified, we lack a unified understanding of how internal protein structural and chemical environment determine qualitative or quantitative impact of evolutionary mutations. In this work we compare equivalent clusters of spatially neighboring residues between paired thermophilic and mesophilic homologues to evaluate adaptations under the selective pressure of high temperature. We find the residue clusters in thermophilic enzymes generally display improved atomic packing compared to mesophilic enzymes, in agreement with previous research. Unlike residue clusters from mesophilic enzymes, however, thermophilic residue clusters do not have significant cavities. In addition, anchor residues found in many clusters are highly conserved with respect to atomic packing between both thermophilic and mesophilic enzymes. Thus the improvements in atomic packing observed in thermophilic homologues are not derived from these anchor residues but from neighboring positions, which may serve to expand optimized protein core regions. PMID:26741367

  16. Comparing residue clusters from thermophilic and mesophilic enzymes reveals adaptive mechanisms

    DOE PAGES

    Sammond, Deanne W.; Kastelowitz, Noah; Himmel, Michael E.; Yin, Hang; Crowley, Michael F.; Bomble, Yannick J.

    2016-01-07

    Understanding how proteins adapt to function at high temperatures is important for deciphering the energetics that dictate protein stability and folding. While multiple principles important for thermostability have been identified, we lack a unified understanding of how internal protein structural and chemical environment determine qualitative or quantitative impact of evolutionary mutations. In this work we compare equivalent clusters of spatially neighboring residues between paired thermophilic and mesophilic homologues to evaluate adaptations under the selective pressure of high temperature. We find the residue clusters in thermophilic enzymes generally display improved atomic packing compared to mesophilic enzymes, in agreement with previous research.more » Unlike residue clusters from mesophilic enzymes, however, thermophilic residue clusters do not have significant cavities. In addition, anchor residues found in many clusters are highly conserved with respect to atomic packing between both thermophilic and mesophilic enzymes. As a result, the improvements in atomic packing observed in thermophilic homologues are not derived from these anchor residues but from neighboring positions, which may serve to expand optimized protein core regions.« less

  17. MTPA control of mechanical sensorless IPMSM based on adaptive nonlinear control.

    PubMed

    Najjar-Khodabakhsh, Abbas; Soltani, Jafar

    2016-03-01

    In this paper, an adaptive nonlinear control scheme has been proposed for implementing maximum torque per ampere (MTPA) control strategy corresponding to interior permanent magnet synchronous motor (IPMSM) drive. This control scheme is developed in the rotor d-q axis reference frame using adaptive input-output state feedback linearization (AIOFL) method. The drive system control stability is supported by Lyapunov theory. The motor inductances are online estimated by an estimation law obtained by AIOFL. The estimation errors of these parameters are proved to be asymptotically converged to zero. Based on minimizing the motor current amplitude, the MTPA control strategy is performed by using the nonlinear optimization technique while considering the online reference torque. The motor reference torque is generated by a conventional rotor speed PI controller. By performing MTPA control strategy, the generated online motor d-q reference currents were used in AIOFL controller to obtain the SV-PWM reference voltages and the online estimation of the motor d-q inductances. In addition, the stator resistance is online estimated using a conventional PI controller. Moreover, the rotor position is detected using the online estimation of the stator flux and online estimation of the motor q-axis inductance. Simulation and experimental results obtained prove the effectiveness and the capability of the proposed control method. PMID:26830002

  18. Genomic analysis identified a potential novel molecular mechanism for high-altitude adaptation in sheep at the Himalayas

    PubMed Central

    Gorkhali, Neena Amatya; Dong, Kunzhe; Yang, Min; Song, Shen; Kader, Adiljian; Shrestha, Bhola Shankar; He, Xiaohong; Zhao, Qianjun; Pu, Yabin; Li, Xiangchen; Kijas, James; Guan, Weijun; Han, Jianlin; Jiang, Lin; Ma, Yuehui

    2016-01-01

    Sheep has successfully adapted to the extreme high-altitude Himalayan region. To identify genes underlying such adaptation, we genotyped genome-wide single nucleotide polymorphisms (SNPs) of four major sheep breeds living at different altitudes in Nepal and downloaded SNP array data from additional Asian and Middle East breeds. Using a di value-based genomic comparison between four high-altitude and eight lowland Asian breeds, we discovered the most differentiated variants at the locus of FGF-7 (Keratinocyte growth factor-7), which was previously reported as a good protective candidate for pulmonary injuries. We further found a SNP upstream of FGF-7 that appears to contribute to the divergence signature. First, the SNP occurred at an extremely conserved site. Second, the SNP showed an increasing allele frequency with the elevated altitude in Nepalese sheep. Third, the electrophoretic mobility shift assays (EMSA) analysis using human lung cancer cells revealed the allele-specific DNA-protein interactions. We thus hypothesized that FGF-7 gene potentially enhances lung function by regulating its expression level in high-altitude sheep through altering its binding of specific transcription factors. Especially, FGF-7 gene was not implicated in previous studies of other high-altitude species, suggesting a potential novel adaptive mechanism to high altitude in sheep at the Himalayas. PMID:27444145

  19. An Adaptive Compensation Algorithm for Temperature Drift of Micro-Electro-Mechanical Systems Gyroscopes Using a Strong Tracking Kalman Filter

    PubMed Central

    Feng, Yibo; Li, Xisheng; Zhang, Xiaojuan

    2015-01-01

    We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS) gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF), the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to −2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation. PMID:25985165

  20. An adaptive compensation algorithm for temperature drift of micro-electro-mechanical systems gyroscopes using a strong tracking Kalman filter.

    PubMed

    Feng, Yibo; Li, Xisheng; Zhang, Xiaojuan

    2015-01-01

    We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS) gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF), the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to -2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation. PMID:25985165

  1. An adaptive compensation algorithm for temperature drift of micro-electro-mechanical systems gyroscopes using a strong tracking Kalman filter.

    PubMed

    Feng, Yibo; Li, Xisheng; Zhang, Xiaojuan

    2015-05-13

    We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS) gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF), the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to -2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation.

  2. [Coping with chronic disease].

    PubMed

    Bachmann, Silke

    2014-03-26

    Patients suffering form chronic diseases have to deal with several problems, the illness itself only being one of them. Health care providers have to undergo a paradigm shift to be able to meet the new challenges which differ from those in acute care. From the patient's perspective, coping with a chronic disease is not a limited process, but encompasses different, often recurring phases (trajectory model). The treating physician's support may comprise the offering of information on general and specific stress factors (physical, emotional, social), empathy, respecting the individual's expertise and activating a patient's resources and self-efficacy. The amount of support given is limited by the treating physician's expert knowledge in this area. Physicians should respect their own limits and involve specialists, supervision or Balint groups.

  3. Coping With Droughts

    NASA Astrophysics Data System (ADS)

    Zaporozec, Alexander

    This book is a collection of selected papers from the NATO Advanced Study Institute on Droughts entitled “Drought Impact Control Technology,” held at the National Laboratory of Civil Engineering in Lisbon, Portugal, in June 1980. The editors of the book have chosen a nontraditional but successful approach to presenting the papers. Instead of including a verbatim proceedings of the institute, they assembled 21 papers presented by 14 of the institute's lecturers, reshaped and synthesized them, and supplemented them by five new papers that cover obvious gaps in topics. The result is enlightening reading and a more or less complete presentation of the subject. The edited material in the book was arranged around three central themes related to efforts needed to cope with or manage the droughts. In the process, the identity of individual contributors has been preserved.

  4. Nonaggressive and adapted social cognition is controlled by the interplay between noradrenergic and nicotinic receptor mechanisms in the prefrontal cortex

    PubMed Central

    Coura, Renata S.; Cressant, Arnaud; Xia, Jing; de Chaumont, Fabrice; Olivo-Marin, Jean Christophe; Pelloux, Yann; Dalley, Jeffrey W.; Granon, Sylvie

    2013-01-01

    Social animals establish flexible behaviors and integrated decision-making processes to adapt to social environments. Such behaviors are impaired in all major neuropsychiatric disorders and depend on the prefrontal cortex (PFC). We previously showed that nicotinic acetylcholine receptors (nAChRs) and norepinephrine (NE) in the PFC are necessary for mice to show adapted social cognition. Here, we investigated how the cholinergic and NE systems converge within the PFC to modulate social behavior. We used a social interaction task (SIT) in C57BL/6 mice and mice lacking β2*nAChRs (β2−/− mice), making use of dedicated software to analyze >20 social sequences and pinpoint social decisions. We performed specific PFC NE depletions before SIT and measured monoamines and acetylcholine (ACh) levels in limbic corticostriatal circuitry. After PFC-NE depletion, C57BL/6 mice exhibited impoverished and more rigid social behavior and were 6-fold more aggressive than sham-lesioned animals, whereas β2−/− mice showed unimpaired social behavior. Our biochemical measures suggest a critical involvement of DA in SIT. In addition, we show that the balance between basal levels of monoamines and of ACh modulates aggressiveness and this modulation requires functional β2*nAChRs. These findings demonstrate the critical interplay between prefrontal NE and nAChRs for the development of adapted and nonaggressive social cognition.—Coura, R. S., Cressant, A., Xia, J., de Chaumont, F., Olivo-Marin, J. C., Pelloux, Y., Dalley, J. W., Granon, S. Nonaggressive and adapted social cognition is controlled by the interplay between noradrenergic and nicotinic receptor mechanisms in the prefrontal cortex. PMID:23882123

  5. The Genome Sequence of the North-European Cucumber (Cucumis sativus L.) Unravels Evolutionary Adaptation Mechanisms in Plants

    PubMed Central

    Wóycicki, Rafał; Witkowicz, Justyna; Gawroński, Piotr; Dąbrowska, Joanna; Lomsadze, Alexandre; Pawełkowicz, Magdalena; Siedlecka, Ewa; Yagi, Kohei; Pląder, Wojciech; Seroczyńska, Anna; Śmiech, Mieczysław; Gutman, Wojciech; Niemirowicz-Szczytt, Katarzyna; Bartoszewski, Grzegorz; Tagashira, Norikazu; Hoshi, Yoshikazu; Borodovsky, Mark; Karpiński, Stanisław; Malepszy, Stefan; Przybecki, Zbigniew

    2011-01-01

    Cucumber (Cucumis sativus L.), a widely cultivated crop, has originated from Eastern Himalayas and secondary domestication regions includes highly divergent climate conditions e.g. temperate and subtropical. We wanted to uncover adaptive genome differences between the cucumber cultivars and what sort of evolutionary molecular mechanisms regulate genetic adaptation of plants to different ecosystems and organism biodiversity. Here we present the draft genome sequence of the Cucumis sativus genome of the North-European Borszczagowski cultivar (line B10) and comparative genomics studies with the known genomes of: C. sativus (Chinese cultivar – Chinese Long (line 9930)), Arabidopsis thaliana, Populus trichocarpa and Oryza sativa. Cucumber genomes show extensive chromosomal rearrangements, distinct differences in quantity of the particular genes (e.g. involved in photosynthesis, respiration, sugar metabolism, chlorophyll degradation, regulation of gene expression, photooxidative stress tolerance, higher non-optimal temperatures tolerance and ammonium ion assimilation) as well as in distributions of abscisic acid-, dehydration- and ethylene-responsive cis-regulatory elements (CREs) in promoters of orthologous group of genes, which lead to the specific adaptation features. Abscisic acid treatment of non-acclimated Arabidopsis and C. sativus seedlings induced moderate freezing tolerance in Arabidopsis but not in C. sativus. This experiment together with analysis of abscisic acid-specific CRE distributions give a clue why C. sativus is much more susceptible to moderate freezing stresses than A. thaliana. Comparative analysis of all the five genomes showed that, each species and/or cultivars has a specific profile of CRE content in promoters of orthologous genes. Our results constitute the substantial and original resource for the basic and applied research on environmental adaptations of plants, which could facilitate creation of new crops with improved growth and yield in

  6. Full-Body Gaze Control Mechanisms Elicited During Locomotion: Effects Of VOR Adaptation

    NASA Technical Reports Server (NTRS)

    Mulavara, A. P.; Houser, J.; Peters, B.; Miller, C.; Richards, J.; Marshburn, A.; Brady, R.; Cohen, H.; Bloomberg, J. J.

    2004-01-01

    Control of locomotion requires precise interaction between several sensorimotor subsystems. During locomotion the performer must satisfy two performance criteria: maintain stable forward translation and to stabilize gaze (McDonald, et al., 1997). Precise coordination demands integration of multiple sensorimotor subsystems for fulfilling both criteria. In order to test the general hypothesis that the whole body can serve as an integrated gaze stabilization system, we have previously investigated how the multiple, interdependent full-body sensorimotor subsystems respond to changes in gaze stabilization task constraints during locomotion (Mulavara and Bloomberg, 2003). The results suggest that the full body contributes to gaze stabilization during locomotion, and that its different functional elements respond to changes in visual task constraints. The goal of this study was to determine how the multiple, interdependent, full-body sensorimotor subsystems aiding gaze stabilization during locomotion are functionally coordinated after the vestibulo-ocular reflex (VOR) gain has been altered. We investigated the potential of adaptive remodeling of the full-body gaze control system following exposure to visual-vestibular conflict known to adaptively reduce the VOR. Subjects (n=14) walked (6.4 km/h) on the treadmill before and after they were exposed to 0.5X manifying lenses worn for 30 minutes during self-generated sinusoidal vertical head rotations performed while seated. In this study we measured: temporal parameters of gait, full body sagittal plane segmental kinematics of the head, trunk, thigh, shank and foot, accelerations along the vertical axis at the head and the shank, and the vertical forces acting on the support surface. Results indicate that, following exposure to the 0.5X minifying lenses, there was a significant increase in the duration of stance and stride times, alteration in the amplitude of head movement with respect to space and a significant increase in

  7. Mechanisms of mindfulness: The dynamics of affective adaptation during open monitoring.

    PubMed

    Uusberg, Helen; Uusberg, Andero; Talpsep, Teri; Paaver, Marika

    2016-07-01

    Mindfulness - the nonjudgmental awareness of the present experience - is thought to facilitate affective adaptation through increased exposure to emotions and faster extinction of habitual responses. To test this framework, the amplification of the Late Positive Potential (LPP) by negative relative to neutral images was analyzed across stimulus repetitions while 37 novices performed an open monitoring mindfulness exercise. Compared to two active control conditions where attention was either diverted to a distracting task or the stimuli were attended without mindfulness instructions, open monitoring enhanced the initial LPP response to negative stimuli, indicating increased emotional exposure. Across successive repetitions, mindfulness reduced and ultimately removed the affective LPP amplification, suggesting extinction of habitual emotional reactions. This effect arose from reduced negative as well enlarged neutral LPPs. Unlike stimuli from control conditions, the images previously viewed with mindfulness instructions did not elicit affective LPP amplification during subsequent re-exposure, suggesting reconsolidation of stimulus meaning.

  8. Mechanisms of mindfulness: The dynamics of affective adaptation during open monitoring.

    PubMed

    Uusberg, Helen; Uusberg, Andero; Talpsep, Teri; Paaver, Marika

    2016-07-01

    Mindfulness - the nonjudgmental awareness of the present experience - is thought to facilitate affective adaptation through increased exposure to emotions and faster extinction of habitual responses. To test this framework, the amplification of the Late Positive Potential (LPP) by negative relative to neutral images was analyzed across stimulus repetitions while 37 novices performed an open monitoring mindfulness exercise. Compared to two active control conditions where attention was either diverted to a distracting task or the stimuli were attended without mindfulness instructions, open monitoring enhanced the initial LPP response to negative stimuli, indicating increased emotional exposure. Across successive repetitions, mindfulness reduced and ultimately removed the affective LPP amplification, suggesting extinction of habitual emotional reactions. This effect arose from reduced negative as well enlarged neutral LPPs. Unlike stimuli from control conditions, the images previously viewed with mindfulness instructions did not elicit affective LPP amplification during subsequent re-exposure, suggesting reconsolidation of stimulus meaning. PMID:27211913

  9. Coping with Overload and Stress: Men and Women in Dual-Earner Families

    ERIC Educational Resources Information Center

    Higgins, Chris A.; Duxbury, Linda E.; Lyons, Sean T.

    2010-01-01

    This study tested gender differences in a model positing relationships between work and family demands, overload, 4 coping mechanisms, and stress. The coping mechanisms were hypothesized to moderate the relationship between overload and stress. The sample consisted of 1,404 men and 1,623 women in dual-earner families. Respondents relied on 2…

  10. Short-term training for explosive strength causes neural and mechanical adaptations.

    PubMed

    Tillin, Neale A; Pain, Matthew T G; Folland, Jonathan P

    2012-05-01

    This study investigated the neural and peripheral adaptations to short-term training for explosive force production. Ten men trained the knee extensors with unilateral explosive isometric contractions (1 s 'fast and hard') for 4 weeks. Before and after training, force was recorded at 50-ms intervals from force onset (F(50), F(100) and F(150)) during both voluntary and involuntary (supramaximal evoked octet; eight pulses at 300 Hz) explosive isometric contractions. Neural drive during the explosive voluntary contractions was measured with the ratio of voluntary/octet force, and average EMG normalized to the peak-to-peak M-wave of the three superficial quadriceps. Maximal voluntary force (MVF) was also measured, and ultrasonic images of the vastus lateralis were recorded during ramped contractions to assess muscle-tendon unit stiffness between 50 and 90% MVF. There was an increase in voluntary F(50) (+54%), F(100) (+15%) and F(150) (+14%) and in octet F(50) (+7%) and F(100) (+10%). Voluntary F(100) and F(150), and octet F(50) and F(100) increased proportionally with MVF (+11%). However, the increase in voluntary F(50) was +37% even after normalization to MVF, and coincided with a 42% increase in both voluntary/octet force and agonist-normalized EMG over the first 50 ms. Muscle-tendon unit stiffness between 50 and 90% MVF also increased. In conclusion, enhanced agonist neural drive and MVF accounted for improved explosive voluntary force production in the early and late phases of the contraction, respectively. The increases in explosive octet force and muscle-tendon unit stiffness provide novel evidence of peripheral adaptations within merely 4 weeks of training for explosive force production.

  11. Adaptive Breast Radiation Therapy Using Modeling of Tissue Mechanics: A Breast Tissue Segmentation Study

    SciTech Connect

    Juneja, Prabhjot; Harris, Emma J.; Kirby, Anna M.; Evans, Philip M.

    2012-11-01

    Purpose: To validate and compare the accuracy of breast tissue segmentation methods applied to computed tomography (CT) scans used for radiation therapy planning and to study the effect of tissue distribution on the segmentation accuracy for the purpose of developing models for use in adaptive breast radiation therapy. Methods and Materials: Twenty-four patients receiving postlumpectomy radiation therapy for breast cancer underwent CT imaging in prone and supine positions. The whole-breast clinical target volume was outlined. Clinical target volumes were segmented into fibroglandular and fatty tissue using the following algorithms: physical density thresholding; interactive thresholding; fuzzy c-means with 3 classes (FCM3) and 4 classes (FCM4); and k-means. The segmentation algorithms were evaluated in 2 stages: first, an approach based on the assumption that the breast composition should be the same in both prone and supine position; and second, comparison of segmentation with tissue outlines from 3 experts using the Dice similarity coefficient (DSC). Breast datasets were grouped into nonsparse and sparse fibroglandular tissue distributions according to expert assessment and used to assess the accuracy of the segmentation methods and the agreement between experts. Results: Prone and supine breast composition analysis showed differences between the methods. Validation against expert outlines found significant differences (P<.001) between FCM3 and FCM4. Fuzzy c-means with 3 classes generated segmentation results (mean DSC = 0.70) closest to the experts' outlines. There was good agreement (mean DSC = 0.85) among experts for breast tissue outlining. Segmentation accuracy and expert agreement was significantly higher (P<.005) in the nonsparse group than in the sparse group. Conclusions: The FCM3 gave the most accurate segmentation of breast tissues on CT data and could therefore be used in adaptive radiation therapy-based on tissue modeling. Breast tissue segmentation

  12. Adaptation of ovarian cancer cells to the peritoneal environment: Multiple mechanisms of the developmental patterning gene HOXA9

    PubMed Central

    Ko, Song Yi; Naora, Honami

    2015-01-01

    The lethality of ovarian cancer stems from its propensity to involve the peritoneal cavity. However, the mechanisms that enable ovarian cancer cells to readily adapt to the peritoneal environment are not well understood. Here, we describe our recent studies in which we identified the mechanisms by which the transcription factor encoded by the patterning gene HOXA9 promotes the aggressive behavior of ovarian cancer. Firstly, we identified that HOXA9 promotes ovarian tumor growth and angiogenesis by activating the gene encoding transforming growth factor-β2 (TGF-β2), which in turn stimulates peritoneal fibroblasts and mesenchymal stem cells to acquire features of cancer-associated fibroblasts. Secondly, by inducing TGF-β2 and chemokine (C-C motif) ligand 2, HOXA9 stimulates peritoneal macrophages to acquire an immunosuppressive phenotype. Thirdly, HOXA9 stimulates attachment of ovarian cancer cells to peritoneal mesothelial cells by inducing expression of P-cadherin. By inducing P-cadherin, HOXA9 also enables floating cancer cells in the peritoneal cavity to form aggregates and escape anoikis. Together, our studies demonstrate that HOXA9 enables ovarian cancer cells to adapt to the peritoneal environment and ‘educates’ different types of stromal cells to become permissive for tumor growth. Our studies provide new insights into the regulation of tumor-stroma interactions in ovarian cancer and implicate several key effector molecules as candidate therapeutic targets. PMID:26000332

  13. Tenderization effect of cold-adapted collagenolytic protease MCP-01 on beef meat at low temperature and its mechanism.

    PubMed

    Zhao, Guo-Yan; Zhou, Ming-Yang; Zhao, Hui-Lin; Chen, Xiu-Lan; Xie, Bin-Bin; Zhang, Xi-Ying; He, Hai-Lun; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2012-10-15

    The enzymes currently used to increase meat tenderness are all mesophilic or thermophilic proteases. This study provides insight into the tenderization effect and the mechanism of a cold-adapted collagenolytic enzyme MCP-01 on beef meat at low temperatures. MCP-01 (10 U of caseinolytic activity) reduced the meat shear force by 23% and increased the relative myofibrillar fragmentation index of the meat by 91.7% at 4 °C, and it also kept the fresh colour and moisture of the meat. Compared to the commercially used tenderizers papain and bromelain, MCP-01 showed a unique tenderization mechanism. MCP-01 had a strong selectivity for degrading collagen at 4 °C, showed a distinct digestion pattern on the myofibrillar proteins, and had a different disruption pattern on the muscle fibres under scanning electron micrograph. These results suggest that the cold-adapted collagenolytic protease MCP-01 may be promising for use as a meat tenderizer at low and moderate temperatures. PMID:23442615

  14. Tenderization effect of cold-adapted collagenolytic protease MCP-01 on beef meat at low temperature and its mechanism.

    PubMed

    Zhao, Guo-Yan; Zhou, Ming-Yang; Zhao, Hui-Lin; Chen, Xiu-Lan; Xie, Bin-Bin; Zhang, Xi-Ying; He, Hai-Lun; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2012-10-15

    The enzymes currently used to increase meat tenderness are all mesophilic or thermophilic proteases. This study provides insight into the tenderization effect and the mechanism of a cold-adapted collagenolytic enzyme MCP-01 on beef meat at low temperatures. MCP-01 (10 U of caseinolytic activity) reduced the meat shear force by 23% and increased the relative myofibrillar fragmentation index of the meat by 91.7% at 4 °C, and it also kept the fresh colour and moisture of the meat. Compared to the commercially used tenderizers papain and bromelain, MCP-01 showed a unique tenderization mechanism. MCP-01 had a strong selectivity for degrading collagen at 4 °C, showed a distinct digestion pattern on the myofibrillar proteins, and had a different disruption pattern on the muscle fibres under scanning electron micrograph. These results suggest that the cold-adapted collagenolytic protease MCP-01 may be promising for use as a meat tenderizer at low and moderate temperatures.

  15. Performance enhanced design of chaos controller for the mechanical centrifugal flywheel governor system via adaptive dynamic surface control

    NASA Astrophysics Data System (ADS)

    Luo, Shaohua; Hou, Zhiwei; Zhang, Tao

    2016-09-01

    This paper addresses chaos suppression of the mechanical centrifugal flywheel governor system with output constraint and fully unknown parameters via adaptive dynamic surface control. To have a certain understanding of chaotic nature of the mechanical centrifugal flywheel governor system and subsequently design its controller, the useful tools like the phase diagrams and corresponding time histories are employed. By using tangent barrier Lyapunov function, a dynamic surface control scheme with neural network and tracking differentiator is developed to transform chaos oscillation into regular motion and the output constraint rule is not broken in whole process. Plugging second-order tracking differentiator into chaos controller tackles the "explosion of complexity" of backstepping and improves the accuracy in contrast with the first-order filter. Meanwhile, Chebyshev neural network with adaptive law whose input only depends on a subset of Chebyshev polynomials is derived to learn the behavior of unknown dynamics. The boundedness of all signals of the closed-loop system is verified in stability analysis. Finally, the results of numerical simulations illustrate effectiveness and exhibit the superior performance of the proposed scheme by comparing with the existing ADSC method.

  16. Examining the Coping Response to Peer Relational Aggression Victimization

    PubMed Central

    Gomes, Melissa M.

    2011-01-01

    Purpose. Relational aggression, rumor spreading, backstabbing, and social isolation, is psychologically damaging for adolescent girls. The purpose of this study was to provide an explanation of victimization response after experiencing peer relational aggression victimization. Methods. Grounded theory techniques were used to gain an understanding of the victimization experience and the coping responses used. Findings. A theory of coping after experiencing peer relational aggression victimization was generated. Girls voiced feelings of hurt and anger after the experience and expressed the following ways of coping as a result: distancing from others, retaliation against the aggressor, discussing their feelings with friends and family, writing their feelings down, and/or confronting the aggressor. Clinical Implications. Nurses should be aware of the phenomenon and asses, for incidences of relational aggression victimization so that they may provide strategies to assist the adolescent and her family with positive coping mechanisms in order to prevent maladaptive responses. PMID:21994828

  17. A Bayesian Tutoring System for Newtonian Mechanics: Can It Adapt to Different Learners?

    ERIC Educational Resources Information Center

    Pek, Peng-Kiat; Poh, Kim-Leng

    2004-01-01

    Newtonian mechanics is a core module in technology courses, but is difficult for many students to learn. Computerized tutoring can assist the teachers to provide individualized instruction. This article presents the application of decision theory to develop a tutoring system, "iTutor", to select optimal tutoring actions under uncertainty of…

  18. Mechanisms of psychological resiliency in women after mastectomy

    PubMed Central

    Sęk, Helena; Ziarko, Michał; Marzec, Marta

    2012-01-01

    Aim of the study To investigate into the mechanisms of resiliency in women after mastectomy. We hypothesized that the mechanism of resiliency in women with breast cancer would involve facilitation of adaptive coping strategies and inhibition of maladaptive strategies. We tested a mediational model in which resiliency was related to satisfaction with life through coping strategies. Material and methods Thirty women after mastectomy aged 28–69 years (M = 53.23, SD = 9.00) completed the Ego Resiliency Scale, Mental Adjustment to Cancer Scale, and Satisfaction with Life Scale. Results The bootstrapping technique revealed that there were significant indirect effects for positive reframing (95% CI: 0.01–0.36), hopelessness/helplessness (95% CI: 0.18–0.83) and anxious preoccupation (95% CI: 0.001–0.55) but not for fighting spirit. The models explained up to 33% of the variance in satisfaction with life. Conclusions Coping strategies fully explain the effect of resiliency on satisfaction with life in women after mastectomy. This finding provides additional evidence of the fundamental role of coping strategies in the mechanisms of resiliency. We obtained similar results in patients with type II diabetes and rheumatoid arthritis. The lack of significant associations of fighting spirit with resiliency suggests that this coping strategy may be beneficial for somatic health but its contribution to the mechanisms of psychological resiliency is complex. PMID:23788906

  19. Effects of gadolinium and tetrodotoxin on the response of slowly adapting type I mechanoreceptors to mechanical stimulation in frog dorsal skin.

    PubMed

    Takeda, Mamoru; Nishikawa, Toshimi; Sato, Sumie; Aiyama, Shigeo; Matsumoto, Shigeji

    2003-12-01

    To elucidate the excitatory mechanism of mechanoreceptors innervating the frog skin, we examined the effects of gadolinium (Gd3+) and tetrodotoxin (TTX) on the response of single-unit activity of slowly adapting type I mechanoreceptors to mechanical stimulation topically applied to the receptive field (RF). Recordings were made from 46 fibers responding to mechanical stimulation with von Frey hairs, which caused an irregular firing pattern with slow adaptation. Application of a mechanically gated channel blocker, Gd3+ (30 microM), and a Na+ channel blocker, TTX (3 microM), caused the suppression of discharge rates, which was characterized by the conversion of a slowly adapting to a rapidly adapting discharge pattern. The administration of a high-voltage-activated (HVA) Ca2+ channel blocker, Cd2+ (100 microm), inhibited the unit discharge and caused the conversion of a slowly adapting to a rapidly adapting discharge pattern. Tonic discharges evoked by anodal electrical stimulation were inhibited by the application of Gd3+ or TTX. Electron microscopic examination showed that the cytoplasm of Merkel cells seen in the RF contained numerous Merkel granules. These results suggest that the excitatory mechanism of frog cutaneous mechanoreceptors may be mediated by the activation of Gd(3+)-sensitive stretch-activated channels in the Merkel cell-neurite complex, which are related to the Na+ influx via voltage-gated Na+ channels and/or the Ca2+ influx through HVA Ca2+ channels. PMID:14641651

  20. Adolescent vulnerability and the distress of rejection: Associations of adjustment problems and gender with control, emotions, and coping.

    PubMed

    Zimmer-Gembeck, Melanie J; Skinner, Ellen A

    2015-12-01

    We examined adjustment problems as risks for patterns of emotions, appraisals, and coping with rejection, and explored whether these processes could account for sex (boy/girl) differences in coping. Young adolescents (N = 669, grades 6-8) completed questionnaires, which assessed responses to peer rejection threat with two short scenarios. Using structural equation modeling to test a multivariate process model, adolescents with heightened social anxiety had the most maladaptive responses to rejection threat, including elevated emotional reactions, more self-blame, and coping using more social isolation, rumination and opposition. Adolescents reporting more depressive symptoms felt less control and anticipated using less adaptive coping (less support seeking, distraction, and negotiation), whereas aggressive adolescents responded with more anger and coped via opposition. Moreover, as anticipated, sex differences in coping, symptoms, emotions, and appraisals were found. However, coping differences between boys and girls were mostly nonsignificant after accounting for symptoms, aggression, emotional reactions, and appraisals.