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Sample records for adaptive coping mechanisms

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

    PubMed

    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.

  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.

  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. 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…

  7. Adapting the Brief COPE for Chinese Adolescents with Visual Impairments

    ERIC Educational Resources Information Center

    Yuan, Wei; Zhang, Li-fang; Li, Bing

    2017-01-01

    Introduction: The present research pioneered the effort in assessing adolescents' coping with visual impairment through adapting the Brief COPE in an eastern context. The first study preliminarily explored the applicability of the Brief COPE to Chinese adolescent students with visual impairments. Based on the results, the Brief COPE was modified…

  8. Maladaptive Coping, Adaptive Coping, and Depressive Symptoms: Variations across Age and Depressive State

    PubMed Central

    Thompson, Renee J.; Mata, Jutta; Jaeggi, Susanne M.; Buschkuehl, Martin; Jonides, John; Gotlib, Ian H.

    2010-01-01

    Rumination has consistently been found to be associated with the onset and duration of major depressive episodes. Little research, however, has examined factors that may weaken the association between maladaptive coping, such as rumination, and depressive symptoms. In three samples of participants, including 149 never-depressed adolescent girls, 41 never-depressed women, and 39 depressed women, we examined whether generally adaptive forms of coping interacted with generally maladaptive coping to predict depressive symptoms. Age-appropriate measures of coping and depression were administered to participants in each sample. In never-depressed females, maladaptive coping / rumination were more strongly related to depressive symptoms in the presence of lower levels of adaptive coping. The relation between depression and maladaptive coping / rumination was weaker in the context of higher levels of adaptive coping. In contrast, for the depressed females, we found main effects for rumination and adaptive coping, with higher levels of rumination and lower levels of adaptive coping being associated with higher levels of depressive symptoms. The present findings highlight how adaptive coping and maladaptive coping, including rumination, differentially relate to each other and depressive symptoms depending on individuals’ current depressive state. PMID:20211463

  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. Is academic buoyancy anything more than adaptive coping?

    PubMed

    Putwain, David W; Connors, Liz; Symes, Wendy; Douglas-Osborn, Erica

    2012-05-01

    Academic buoyancy refers to a positive, constructive, and adaptive response to the types of challenges and setbacks experienced in a typical and everyday academic setting. In this project we examined whether academic buoyancy explained any additional variance in test anxiety over and above that explained by coping. Two hundred and ninety-eight students in their final two years of compulsory schooling completed self-report measures of academic buoyancy, coping, and test anxiety. Results suggested that buoyancy was inversely related to test anxiety and unrelated to coping. With the exception of test-irrelevant thoughts, test anxiety was positively related to avoidance coping and social support. Test-irrelevant thoughts were inversely related to task focus, unrelated to social support, and positively related to avoidance. A hierarchical regression analysis showed that academic buoyancy explained a significant additional proportion of variance in test anxiety when the variance for coping had already been accounted for. These findings suggest that academic buoyancy can be considered as a distinct construct from that of adaptive coping.

  11. Intolerance of Uncertainty and Coping Mechanisms in Nonclinical Young Subjects

    PubMed Central

    DORUK, Ali; DUGENCİ, Muharrem; ERSÖZ, Filiz; ÖZNUR, Taner

    2015-01-01

    Introduction We aimed to explore the relationship between intolerance of uncertainty (IU) and coping mechanisms in a nonclinical sample with the same age and educational level. Methods The Coping Orientations to Problems Experienced (COPE) scale was used to evaluate the coping mechanisms. The IU scale was used to evaluate IU situations. Results We found that the negative impact of uncertainty on the action in female students was greater than males. While female students used more planning, instrumental support, reinterpretation, religion, emotional support, venting, and mental disengagement coping styles, male students used more humor, denial, and alcohol/drug abuse coping styles. Subjects with psychological problems had higher IU scores and used some more coping mechanisms (restraint, acceptance, behavioral disengagement, and alcohol/drug abuse) than the others. Conclusion Our results suggest that healthy subjects use different coping styles and respond differently to uncertainty in both genders.

  12. Executive functioning and adaptive coping in healthy adults.

    PubMed

    Rodríguez Villegas, Ana Lilia; Salvador Cruz, Judith

    2015-01-01

    Middle-aged individuals encounter multiple environmental demands to which they must develop efficient solutions, thus making the study of executive functions and coping strategies within this age group important. This study evaluated the relationship between the planning and flexible organization of executive function with adaptive coping strategies (ACS) in adults aged 43 to 52 years old. The study included 104 participants, including 52 men and 52 women, with no history of neurological or psychiatric illnesses, diabetes, or hypertension. The participants engaged in the Tower of London(DX) (TOL(DX)) test, the Wisconsin Card-Sorting Test (WCST), and the Coping Strategies Inventory. A relationship was observed between the percentage of errors and conceptual-level responses (WCST) and the Problem Solving ACS. In a separate analysis performed on the men, a negative relationship was discovered between the WCST and the Emotional Expression ACS. In the female group, the dimensions of the WCST and the TOL(DX) were associated with the ACS Emotional Expression and Problem-Solving subscales and the maladaptive coping strategy Social Withdrawal subscale. The relationship between executive functioning and the ACS is multidimensional, complex, and different between men and women. This study adds a neuropsychological characterization of the relationship between executive functions and ACS with ecological validity. The study confirms a relationship between the flexible organization of executive function and the Problem-Solving ACS.

  13. 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.

  14. Interactions between Adaptive Coping and Drinking to Cope in Predicting Naturalistic Drinking and Drinking Following a Lab-Based Psychosocial Stressor

    PubMed Central

    Merrill, Jennifer E.; Thomas, Suzanne E.

    2012-01-01

    Using alcohol to cope (i.e., coping motivation) and general coping style both are theorized and demonstrated empirically to lead to problematic drinking. In the present study, we sought to examine whether these factors interact to predict alcohol use, both retrospectively reported and in the lab following a stressor task. Social drinkers (N=50, 50% women) received the Trier Social Stress Test (TSST), and then consumed beer under the guise of a taste-test. A Timeline Followback interview to assess past month alcohol use, the Drinking Motives Questionnaire (DMQ), and the COPE (to assess adaptive coping) were administered prior to the laboratory challenge. Multiple regression models were used to examine DMQ coping motives, adaptive coping, and their interaction as predictors of milliliters (mls) of beer consumed in a clinical laboratory setting. The association between coping motives and mls beer was positive at both high and low levels of adaptive coping, but at low levels of adaptive coping, this association was stronger. In contrast, there was no interaction between adaptive coping and coping motives in predicting quantity and frequency of drinking in the prior month. Findings suggest that stronger coping motives for drinking predict greater alcohol consumption following a stress provocation to a greater extent when an individual is lacking in adaptive coping strategies. As both general coping skills and coping motives for alcohol use are responsive to intervention, study of the conditions under which they exert unique and interactive effects is important. PMID:23254217

  15. 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.

  16. 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

  17. Coping with a changing soundscape: avoidance, adjustments and adaptations.

    PubMed

    Potvin, Dominique A

    2017-01-01

    Since the industrial age, background anthropogenic noise has become a pervasive feature of many habitable environments. This relatively recent environmental feature can be particularly challenging for organisms that use acoustic forms of communication due to its propensity for masking and decreasing the potential acoustic space of signals. Furthermore, anthropogenic noise may affect biological processes including animal interactions, physiological and behavioural responses to stimuli and cognitive development. However, animals' cognitive abilities may enable them to cope with high levels of anthropogenic noise through learning, the employment of acoustic and behavioural flexibility as well as the use of multi-modal sensory systems. We are only just beginning to understand how neural structures, endocrine systems and behaviour are mechanistically linked in these scenarios, providing us with information we can use to mitigate deleterious effects of pervasive noise on wildlife, along with highlighting the remarkable adaptability of animals to an increasingly anthropogenic world. In this review, I will focus mainly on birds, due to the amount of literature on the topic, and survey recent advancements made in two main spheres: (1) how anthropogenic noise affects cognitive processes and (2) how cognition enables animals to cope with increasingly noisy environments. I will be highlighting current gaps in our knowledge, such as how noise might impact behavioural traits such as predation, as well as how noise causes physical damage to neurotransmitters and affects stress levels, in order to direct future studies on this topic.

  18. 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.

  19. Integration of coping and social support perspectives: implications for the study of adaptation to chronic diseases.

    PubMed

    Schreurs, K M; de Ridder, D T

    1997-01-01

    In this article, empirical studies dealing with the relationship between coping and social support are discussed in order to identify promising themes for research on adaptation to chronic diseases. Although only few studies deal with this issue explicitly, the review reveals that four ways to study the relationship between coping and social support can be distinguished: (a) seeking social support as a coping strategy; (b) social support as a coping resource; (c) social support as dependent on the way individual patients cope; and (d) coping by a social system. It is argued that all four ways of integrating coping and social support contribute to a better understanding of adaptation to chronic diseases. However, exploring the interrelatedness of both concepts by studying social support as a coping resource and social support as dependent on the patient's own coping behavior appear to be especially fruitful in the short term, as they: (a) provide a better insight in the social determinants of coping, and (b) may help to clarify the way social support affects health and well-being.

  20. Effects of Self-Statements and Coping Strategies on Adaptational Outcomes of Stress.

    ERIC Educational Resources Information Center

    Uhlemann, Max R.; Plater, Sharon A.

    1989-01-01

    Examined effects of self-statements and coping strategies on adaptational outcomes of stress in female subjects (N=62). Results indicated self-statements did not discriminate significantly between individuals who effectively or ineffectively handled stressful encounters. Only information-seeking coping strategy showed a trend toward a significant…

  1. 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…

  2. 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…

  3. 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…

  4. 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…

  5. 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…

  6. Untangling the neurobiology of coping styles in rodents: Towards neural mechanisms underlying individual differences in disease susceptibility.

    PubMed

    de Boer, Sietse F; Buwalda, Bauke; Koolhaas, Jaap M

    2017-03-01

    Considerable individual differences exist in trait-like patterns of behavioral and physiological responses to salient environmental challenges. This individual variation in stress coping styles has an important functional role in terms of health and fitness. Hence, understanding the neural embedding of coping style variation is fundamental for biobehavioral neurosciences in probing individual disease susceptibility. This review outlines individual differences in trait-aggressiveness as an adaptive component of the natural sociobiology of rats and mice, and highlights that these reflect the general style of coping that varies from proactive (aggressive) to reactive (docile). We propose that this qualitative coping style can be disentangled into multiple quantitative behavioral domains, e.g., flexibility/impulse control, emotional reactivity and harm avoidance/reward processing, that each are encoded into selective neural circuitries. Since functioning of all these brain circuitries rely on fine-tuned serotonin signaling, autoinhibitory control mechanisms of serotonergic neuron (re)activity are crucial in orchestrating general coping style. Untangling the precise neuromolecular mechanisms of different coping styles will provide a roadmap for developing better therapeutic strategies of stress-related diseases.

  7. Coping with Information Overload as Adaptive Behavior in Competitive Debate.

    ERIC Educational Resources Information Center

    Dudczak, Craig A.

    When the amount of available information exceeds the ability of the user to process it, "information overload" is created. In an attempt to maintain some control over the quantity of arguments they may face, debaters have developed adaptive behavior, primarily through the generic argument--any argument within a "deliverative"…

  8. 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…

  9. 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…

  10. The adolescent Religious Coping Questionnaire. Translation and cultural adaptation of Pargament's RCOPE Scale for Polish adolescents.

    PubMed

    Talik, Elżbieta B

    2013-03-01

    The paper presents the process of translation and cultural adaptation of the Religious Coping Questionnaire (the RCOPE) by Pargament et al. (2000) for Polish adolescents. The work was driven by the necessity to obtain a structural and measurement equivalence between the American and Polish versions of the instrument. The Polish version was created at the Department of Clinical Psychology of Children and Adolescents at The John Paul II Catholic University of Lublin, Poland. The exploratory factor analysis with the Oblimin oblique rotation was carried out. The principal components method was used as an extraction method of common factors. The results provided input for constructing the scales. The Adolescent Religious Coping Questionnaire consists of 105 items, grouped in 16 scales, which reflects positive and negative religious coping strategies.

  11. 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

  12. Cultural adaptation of the Brief COPE for persons living with HIV/AIDS in southern India.

    PubMed

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

    2015-02-01

    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 yielded a 16 item scale with five 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.

  13. Adapting to and coping with the threat and impacts of climate change.

    PubMed

    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 adequately communicate and explain how a more psychological framing of the human dimensions of global environmental change can greatly inform and enhance effective and collaborative climate change adaptation and mitigation policies and research. An integrative framework is provided that identifies and considers important mediating and moderating parameters and processes relating to climate change adaptation, with particular emphasis given to environmental stress and stress and coping perspectives. This psychological perspective on climate change adaptation highlights crucial aspects of adaptation that have been neglected in the arena of climate change science. Of particular importance are intra-individual and social "psychological adaptation" processes that powerfully mediate public risk perceptions and understandings, effective coping responses and resilience, overt behavioral adjustment and change, and psychological and social impacts. This psychological window on climate change adaptation is arguably indispensable to genuinely multidisciplinary and interdisciplinary research and policy initiatives addressing the impacts of climate change.

  14. Multi-type Childhood Abuse, Strategies of Coping, and Psychological Adaptations in Young Adults

    PubMed Central

    Sesar, Kristina; Šimić, Nataša; Barišić, Marijana

    2010-01-01

    Aim To retrospectively analyze the rate of multi-type abuse in childhood and the effects of childhood abuse and type of coping strategies on the psychological adaptation of young adults in a sample form the student population of the University of Mostar. Methods The study was conducted on a convenience sample of 233 students from the University of Mostar (196 female and 37 male), with a median age of 20 (interquartile range, 2). Exposure to abuse was determined using the Child Maltreatment Scales for Adults, which assesses emotional, physical, and sexual abuse, neglect, and witnessing family violence. Psychological adaptation was explored by the Trauma Symptom Checklist, which assesses anxiety/depression, sexual problems, trauma symptoms, and somatic symptoms. Strategies of coping with stress were explored by the Coping Inventory for Stressful Situations. Results Multi-type abuse in childhood was experienced by 172 participants (74%) and all types of abuse by 11 (5%) participants. Emotional and physical maltreatment were the most frequent types of abuse and mostly occurred together with other types of abuse. Significant association was found between all types of abuse (r = 0.436-0.778, P < 0.050). Exposure to sexual abuse in childhood and coping strategies were significant predictors of anxiety/depression (R2 = 0.3553), traumatic symptoms (R2 = 0.2299), somatic symptoms (R2 = 0.2173), and sexual problems (R2 = 0.1550, P < 0.001). Conclusion Exposure to multi-type abuse in childhood is a traumatic experience with long-term negative effects. Problem-oriented coping strategies ensure a better psychosocial adaptation than emotion-oriented strategies. PMID:20960590

  15. 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.

  16. 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

    2012-12-07

    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'.

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

    PubMed

    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.

  18. Adaptation.

    PubMed

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  19. A comparison of the marginal adaptation of cathode-arc vapor-deposited titanium and cast base metal copings

    PubMed Central

    Wu, JC; Lai, LC; Sheets, CG; Earthman, J; Newcomb, R

    2011-01-01

    Statement of problem A new fabrication process has been developed where a titanium coping, which has a gold colored titanium nitride outer layer can be reliably fused to porcelain, but the marginal adaptation characteristics are still undetermined. Purpose The primary purpose of this study is to compare the rate of Clinically Acceptable Marginal Adaptation (CAMA-defined as a marginal gap mean ≤60 μm) of cathode-arc vapor-deposited titanium with the CAMA rate for the cast base metal copings. In addition, the study will evaluate the marginal gap scores themselves to assess their mean difference between the two study groups. Finally, the study will present two analyses of group differences in variability to support the contention that the titanium copings perform more consistently than their base metal counterparts. Material and methods Thirty-seven cathode-arc vapor-deposited titanium copings and 40 cast base metal copings were evaluated by computer-based image analysis using an optical microscope. The conventional lost wax technique was used to fabricate the 40 cast base metal copings that were 0.3 mm thick. The titanium copings were 0.3 mm thick and were formed by a collection of atomic titanium vapor onto a refractory die duplicate in a high vacuum chamber. Fifty vertical marginal gap measurements were collected from each of the 77 copings and the mean of these measurements was computed to form a gap score for each coping. Next, the gap score was compared to the 60 μm criterion to classify each coping as to whether it did or did not achieve Clinically Acceptable Marginal Adaption (CAMA). A comparison of the CAMA rates for each type of coping was used to address the primary purpose of this study. In addition, the gap scores themselves were used to test the (one-sided) hypothesis that the mean of the titanium gap scores is smaller than the mean of the base metal gap scores. Finally, the assertion that the titanium copings provide more consistency in their

  20. 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

  1. 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

  2. Maternal Coping Adaptations, Social Support and Transition Difficulties to Parenthood of First-Time Civilian and Military Mothers

    DTIC Science & Technology

    1992-12-01

    Social support and adaptation to the parent role in first-time adolescent mothers. Journal of Obstetric, Gynecologic, and Neonatal Nursing, 18(4), 327...NOV1𔄁s uS Maternal Coping Adaptations, Social Support and Transition Difficulties to Parenthood of First-time Civilian and Military Mothers 6. AUI HOr...Unlimited MICHAEL M. BRL.7KER, SMSgt, USAF Chief Administration S ELECTE JUN07 1993 A k 93-12634 97 !f C MATERNAL COPING ADAPTATIONS. SOCIAL SUPPORT AND

  3. 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…

  4. [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

  5. Coping and cognitive factors in adaptation to in vitro fertilization failure.

    PubMed

    Litt, M D; Tennen, H; Affleck, G; Klock, S

    1992-04-01

    Characteristics were identified that predict adaptation following an unsuccessful attempt at in vitro fertilization (IVF). Forty-one women and their husbands were interviewed and administered questionnaires prior to IVF and 2 weeks after notice of a positive or negative pregnancy test. Of the 36 couples who failed to conceive as a result of IVF, 6 of the women studied developed clinical depressive symptoms. Those women who reported poorest adaptation to IVF failure were more likely to have reported depressive symptoms prior to IVF, were more likely to have reported feeling a general loss of control over their lives as a result of infertility, tended to use escape as a coping strategy, and reported having felt some responsibility for their IVF failure. Dispositional optimism, as well as a sense of being partially responsible for the infertility, was protective of distress following IVF failure.

  6. Cultivating Resilience in Families Who Foster: Understanding How Families Cope and Adapt Over Time.

    PubMed

    Lietz, Cynthia A; Julien-Chinn, Francie J; Geiger, Jennifer M; Hayes Piel, Megan

    2016-12-01

    Families who foster offer essential care for children and youth when their own parents are unable to provide for their safety and well-being. Foster caregivers face many challenges including increased workload, emotional distress, and the difficulties associated with health and mental health problems that are more common in children in foster care. Despite these stressors, many families are able to sustain fostering while maintaining or enhancing functioning of their unit. This qualitative study applied an adaptational process model of family resilience that emerged in previous studies to examine narratives of persistent, long-term, and multiple fostering experiences. Data corroborated previous research in two ways. Family resilience was again described as a transactional process of coping and adaptation that evolves over time. This process was cultivated through the activation of 10 family strengths that are important in different ways, during varied phases.

  7. Adaptive and Maladaptive Coping Strategies in Adult Pathological Gamblers and Their Mediating Role with Anxious-Depressive Symptomatology.

    PubMed

    Jauregui, Paula; Onaindia, Jaione; Estévez, Ana

    2017-02-08

    Coping plays a central role in the appearance and persistence of pathological gambling. Anxious and depressive symptomatology also influence pathological gambling and are related to coping. This study aimed to analyze pathological gamblers' coping strategies and styles, as well as associated anxious and depressive symptomatology. The study sample included 167 male pathological gamblers (mean age = 39.29 years) and 107 non-gamblers (mean age = 33.43 years). Measures of gambling, coping, and anxious and depressive symptomatology were used. Results showed that pathological gamblers' scored higher in all the maladaptive coping strategies, problem- and emotion-focused disengagement, and disengagement subscales. These subscales also correlated with pathological gambling, and anxious and depressive symptomatology. Pathological gamblers also scored higher in emotional expression and emotion-focused engagement, with no differences in the rest of the adaptive coping strategies. Coping was also found to predict pathological gambling and anxious and depressive symptomatology. It was found that coping mediated the relationship between pathological gambling and anxious symptomatology when controlling for the effect of age. Specifically, social withdrawal and disengagement stood out as mediators. These results provide practical information for use in clinical settings with people diagnosed with pathological gambling.

  8. Promoting Adaptive Coping by Persons with HIV Disease: Evaluation of a Patient/Partner Intervention Model

    PubMed Central

    Fife, Betsy L.; Scott, Linda L.; Fineberg, Naomi S.; Zwickl, Beth E.

    2009-01-01

    This study evaluated an intervention to facilitate adaptive coping by persons living with HIV (PLWH), with the participation of their cohabiting partners as a dimension of the intervention. An experimental design with randomization was used, and 84 PLWH and their partners were recruited. The intervention was based on a psychosocial educational model that incorporated 4 two-hour sessions focused on communication, stress appraisal, adaptive coping strategies, and building social support. Both members of the dyad were included in each session. The comparison control included four supportive phone calls to the PLWH alone. Data were collected from both the PLWH and their partners in each of the two groups at baseline, immediately following the intervention, and 3 months and 6 months post-treatment. Data were analyzed using RM ANOVA, with change scores from the partner data being covariates. Findings indicated that the design was a feasible model, which demonstrated potential for the management of stress, and possibly problems such as adherence, in PLWH. A manual was developed as a part of this intervention and is currently available. PMID:18191771

  9. 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.

  10. 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

  11. Supportive Dyadic Coping and Psychological Adaptation in Couples Parenting Children with Autism Spectrum Disorder: The Role of Relationship Satisfaction.

    PubMed

    García-López, Cristina; Sarriá, Encarnación; Pozo, Pilar; Recio, Patricia

    2016-11-01

    In couples parenting children with Autism Spectrum Disorder (ASD), the partner becomes a primary source of support for addressing the additional parenting demands. The purpose of this study was to examine the associations between supportive dyadic coping and parental adaptation, and to assess the mediating role of relationship satisfaction between them. Seventy-six couples parenting children with ASD participated. Data were gathered through self-report questionnaires and an Actor-Partner Interdependence Mediation Model was used. Mothers' and fathers' supportive dyadic coping was related to both their own and partner's relationship satisfaction and parental adaptation. Findings also revealed the mediation role of relationship satisfaction, in the association between supportive dyadic coping and parental adaptation. The implications for research and clinical practice are discussed.

  12. 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.

  13. 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.

  14. [Autoprotective mechanisms in patients with schizophrenic psychoses--compensation and coping].

    PubMed

    Dittmann, J; Schüttler, R

    1990-12-01

    For a long time, the coping and compensatory mechanisms of patients with schizophrenic psychoses have mostly been neglected by the psychiatric research. We extended the six categories of coping mechanisms described in the Bonn Scale for the Assessment of Basic Symptoms (BSABS) by three further categories. With fifty schizophrenic patients in different stages of their disease semistructured interviews concerning these categories were done. The main sociodemographic and historical parameters were registered as well. Then the protocols of the interviews were analyzed, the coping strategies were quantified, and it was tried to disclose relations between the disease progress and sociodemographic parameters. Patients used to a certain degree of autonomy e. g. unmarried patients had--compared to less independent patients--stronger coping strategies. Patients with a strong interest for their disease and a positive opinion about neuroleptic therapy had--compared to patients without interest for their disease and/or negative opinion about neuroleptic therapy--stronger coping and compensatory psychisms. It is concluded that the coping strategies might be reinforced by influencing these parameters.

  15. Adaptive diagnosis of the bilinear mechanical systems

    NASA Astrophysics Data System (ADS)

    Gelman, L.; Gorpinich, S.; Thompson, C.

    2009-07-01

    A generic adaptive approach is proposed for diagnosis of the bilinear mechanical systems. The approach adapts the free oscillation method for bilinearity diagnosis of mechanical systems. The expediency of the adaptation is proved for a recognition feature, the decrement of the free oscillations. The developed adaptation consists of variation of the adaptive likelihood ratio of the decrement with variation of the resonance frequency of the bilinear system. It is shown that in the cases of the frequency-independent and the frequency-dependent internal damping, the adaptation is expedient. To investigate effectiveness of the adaptation in these cases, a numerical simulation was carried out. The simulation results show that use of the adaptation increases the total probability of the correct diagnosis of system bilinearity.

  16. 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%)…

  17. 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

  18. A novel mechanism of cone photoreceptor adaptation.

    PubMed

    Howlett, Marcus H C; Smith, Robert G; Kamermans, Maarten

    2017-04-01

    An animal's ability to survive depends on its sensory systems being able to adapt to a wide range of environmental conditions, by maximizing the information extracted and reducing the noise transmitted. The visual system does this by adapting to luminance and contrast. While luminance adaptation can begin at the retinal photoreceptors, contrast adaptation has been shown to start at later stages in the retina. Photoreceptors adapt to changes in luminance over multiple time scales ranging from tens of milliseconds to minutes, with the adaptive changes arising from processes within the phototransduction cascade. Here we show a new form of adaptation in cones that is independent of the phototransduction process. Rather, it is mediated by voltage-gated ion channels in the cone membrane and acts by changing the frequency response of cones such that their responses speed up as the membrane potential modulation depth increases and slow down as the membrane potential modulation depth decreases. This mechanism is effectively activated by high-contrast stimuli dominated by low frequencies such as natural stimuli. However, the more generally used Gaussian white noise stimuli were not effective since they did not modulate the cone membrane potential to the same extent. This new adaptive process had a time constant of less than a second. A critical component of the underlying mechanism is the hyperpolarization-activated current, Ih, as pharmacologically blocking it prevented the long- and mid- wavelength sensitive cone photoreceptors (L- and M-cones) from adapting. Consistent with this, short- wavelength sensitive cone photoreceptors (S-cones) did not show the adaptive response, and we found they also lacked a prominent Ih. The adaptive filtering mechanism identified here improves the information flow by removing higher-frequency noise during lower signal-to-noise ratio conditions, as occurs when contrast levels are low. Although this new adaptive mechanism can be driven by

  19. Maternal coping adaptations, social support, and transition difficulties to parenthood of first-time civilian and military mothers.

    PubMed

    Splonskowski, J M; Twiss, J J

    1995-01-01

    There is little research on whether the transient nature of the military family contributes to transition difficulty to parenthood or to the type of social supports utilized. Data were collected by mailed survey from a convenience sample of military and civilian mothers at 3 months after delivery. No significant differences were found in transition difficulty, maternal coping adaptations, or social support. Military mothers showed a trend toward utilizing more internal coping resources than did the civilian population. Military nurses may utilize the studies using civilian populations when considering nursing interventions to assist their military clients with transition difficulty to parenthood.

  20. Interpretation of illness in cancer survivors is associated with health-related variables and adaptive coping styles

    PubMed Central

    Büssing, Arndt; Fischer, Julia

    2009-01-01

    Background A patient's interpretation of illness may have an influence on the choice of coping strategies and decision making. We intended to analyze the meaning German cancer survivors would attribute to their disease, and investigated intercorrelations between the respective interpretations, health-related variables and adaptive coping strategies. Methods In an anonymous cross-sectional survey, we analyzed the interpretations of disease (according to Lipowski's eight 'meaning of illness' categories) in 387 patients with cancer (81% breast cancer). To make statements about their conceptual relationships with health-related variables, we correlated the 8 items of the 'Interpretation of Illness' questionnaire (IIQ) with health-related quality of life, anxiety/depression, fatigue, life satisfaction, and adaptive coping strategies. Results Most cancer survivors regarded their disease as a challenge (52%), others as value (38%) or even an interruption of life (irreparable loss; 35%); weakness/failure (5%) and punishment (3%) were rated the lowest. The fatalistic negative interpretations 'interruption/loss' and 'enemy/threat' were inversely correlated with mental health-related quality of life and life satisfaction, and positively with an escape-avoidance strategy, depression and anxiety. In contrast, positive disease interpretations (i.e., 'challenge' and 'value') correlated only with adaptive coping strategies. Physical health correlated with none of the disease interpretations. Conclusion Despite conceptual limitations, the 8-item schema could be regarded as a useful screening approach to identify patients at risk for reduced psychosocial functioning. PMID:19178733

  1. Stresses, coping mechanisms and job satisfaction in general practitioner registrars.

    PubMed Central

    Chambers, R; Wall, D; Campbell, I

    1996-01-01

    BACKGROUND: There is concern about the morale of general practitioner registrars. There may be stress-provoking factors that could be avoided or minimized. AIMS: The aims of the study were to assess the sources of stress and job satisfaction of general practitioner registrars, to compare registrars' job satisfaction with that of established principals using a recently published survey and to identify registrars' usual responses to stress. METHOD: A postal questionnaire survey was sent to all 143 general practitioner registrars in the West Midlands Region. The main measures were: self-rating scales of stresses associated with work and training; the Warr, Cook and Wall job satisfaction scale; and self-reported responses to stress. RESULTS: A total of 118 (83%) general practitioner registrars responded. The most potent sources of stress were family-job conflict, working for the Membership of the Royal College of General Practitioners, patients' unrealistic expectations and disruption of social life. Registrars practised good coping responses to stress. Registrars in this study had significantly greater job satisfaction than general practitioner principals in a 1993 survey for three out of 10 items measured (responsibility given, hours of work and the job as a whole) and significantly worse scores for three items (recognition for good work, rate of pay and variety of work). CONCLUSIONS: Registrars have additional stresses to those of established principals because they need to study for examinations, learn new tasks in general practice and carry out their service commitments at a stage in life when many are newly married or have a young family. Training in stress management for general practitioner registrars is recommended. PMID:8983252

  2. Adult Literacy Education Program Administrators' Perceptions of Occupational Stress and Coping Mechanisms

    ERIC Educational Resources Information Center

    Engelmann, Stephanie

    2014-01-01

    Job performance may be adversely affected by stress. Job stress is a primary contributor to serious physical and emotional health consequences. This quantitative study examined adult literacy program administrator perceptions of occupational stress and coping mechanisms related to job satisfaction, job efficacy, career longevity, and overall…

  3. 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.

  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. Coping Mechanisms Utah Agriculture Teachers Use to Manage Teaching Related Stress

    ERIC Educational Resources Information Center

    Lawver, Rebecca G.; Smith, Kasee L.

    2014-01-01

    The purpose of this study was to examine the level of occupational stress among Utah agriculture teachers, and to determine the coping mechanisms utilized to manage teaching related stressful events. Teachers were asked to rank their level of occupational stress according to the scale used by the American Psychological Association Stress in…

  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. Does peer mentoring work? Dental students assess its benefits as an adaptive coping strategy.

    PubMed

    Lopez, Naty; Johnson, Sara; Black, Nicki

    2010-11-01

    Dental students deal with various stressors while in dental school. While some develop adaptive coping skills, others may suffer from damaging effects of constant and increasing levels of stress. This study evaluated a peer mentoring program at a dental school in the Midwest to determine student perceptions of its benefits and to identify areas for improvement. Data were collected through a survey sent out to all dental classes online. The twenty-five-item survey was based on student responses during two focus groups held to elicit student assessment of the peer mentoring program. Sixty-six percent of the student body participated with representation from all four classes. Students find their peer mentoring program an effective tool in helping them deal with stress especially during transition phases of their curriculum, first into dental school and later from preclinic to the clinics. Having a mentor means easy access to an available person who can help students relieve anxieties about dental school. Experiencing dental school enables a student to serve as a mentor, so a non-dental student is seen as not effective. Peer mentoring needs to be loosely structured and flexible and should cover all years in the dental curriculum.

  8. Soft Thermal Sensor with Mechanical Adaptability.

    PubMed

    Yang, Hui; Qi, Dianpeng; Liu, Zhiyuan; Chandran, Bevita K; Wang, Ting; Yu, Jiancan; Chen, Xiaodong

    2016-11-01

    A soft thermal sensor with mechanical adaptability is fabricated by the combination of single-wall carbon nanotubes with carboxyl groups and self-healing polymers. This study demonstrates that this soft sensor has excellent thermal response and mechanical adaptability. It shows tremendous promise for improving the service life of soft artificial-intelligence robots and protecting thermally sensitive electronics from the risk of damage by high temperature.

  9. 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…

  10. Coping Repertoires of Families Adapting to Prolonged War-Induced Separations

    ERIC Educational Resources Information Center

    McCubbin, Hamilton I.; And Others

    1976-01-01

    Coping with husband absence, an enigma of family life in the military, stimulated questions as to how wives endure hardships engendered by war-induced separations. The investigators studied the adjustment of 47 families of servicemen missing in action. Findings are explained in terms of psychological and sociological theories of coping. (Author)

  11. 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

  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. The relationship between coping style and loneliness in adolescents: can "sad passivity" be adaptive?

    PubMed

    Van Buskirk, A M; Duke, M P

    1991-06-01

    The authors' purpose in this paper was to examine how the use of the "sad passive" coping style may be related to adolescent self-reported loneliness. Subjects were asked to complete the revised UCLA Loneliness Scale (Russell, Peplau, & Cutrona, 1980) to determine self-reported loneliness and the Coping with Loneliness Questionnaire (CLQ; Rubenstein & Shaver, 1980) in order to examine coping styles. We hypothesized that those adolescents whose coping strategies fell into the category of sad passivity described by Rubenstein and Shaver would indicate greater loneliness than those adolescents whose coping strategies fell into other categories. Results indicated that sad passivity was used by both lonely and nonlonely adolescents, but that nonlonely youngsters resorted to this method only temporarily and in preparation for a more active coping style. Lonely teens, on the other hand, appeared to remain in the sad-passive mode to a maladaptive degree. These results were discussed in terms of their importance for theories of adolescent loneliness and for possible intervention strategies.

  14. 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

  15. Adaptation Mechanisms in the Evolution of Moss Defenses to Microbes

    PubMed Central

    Ponce de León, Inés; Montesano, Marcos

    2017-01-01

    Bryophytes, including mosses, liverworts and hornworts are early land plants that have evolved key adaptation mechanisms to cope with abiotic stresses and microorganisms. Microbial symbioses facilitated plant colonization of land by enhancing nutrient uptake leading to improved plant growth and fitness. In addition, early land plants acquired novel defense mechanisms to protect plant tissues from pre-existing microbial pathogens. Due to its evolutionary stage linking unicellular green algae to vascular plants, the non-vascular moss Physcomitrella patens is an interesting organism to explore the adaptation mechanisms developed in the evolution of plant defenses to microbes. Cellular and biochemical approaches, gene expression profiles, and functional analysis of genes by targeted gene disruption have revealed that several defense mechanisms against microbial pathogens are conserved between mosses and flowering plants. P. patens perceives pathogen associated molecular patterns by plasma membrane receptor(s) and transduces the signal through a MAP kinase (MAPK) cascade leading to the activation of cell wall associated defenses and expression of genes that encode proteins with different roles in plant resistance. After pathogen assault, P. patens also activates the production of ROS, induces a HR-like reaction and increases levels of some hormones. Furthermore, alternative metabolic pathways are present in P. patens leading to the production of a distinct metabolic scenario than flowering plants that could contribute to defense. P. patens has acquired genes by horizontal transfer from prokaryotes and fungi, and some of them could represent adaptive benefits for resistance to biotic stress. In this review, the current knowledge related to the evolution of plant defense responses against pathogens will be discussed, focusing on the latest advances made in the model plant P. patens. PMID:28360923

  16. Adaptation Mechanisms in the Evolution of Moss Defenses to Microbes.

    PubMed

    Ponce de León, Inés; Montesano, Marcos

    2017-01-01

    Bryophytes, including mosses, liverworts and hornworts are early land plants that have evolved key adaptation mechanisms to cope with abiotic stresses and microorganisms. Microbial symbioses facilitated plant colonization of land by enhancing nutrient uptake leading to improved plant growth and fitness. In addition, early land plants acquired novel defense mechanisms to protect plant tissues from pre-existing microbial pathogens. Due to its evolutionary stage linking unicellular green algae to vascular plants, the non-vascular moss Physcomitrella patens is an interesting organism to explore the adaptation mechanisms developed in the evolution of plant defenses to microbes. Cellular and biochemical approaches, gene expression profiles, and functional analysis of genes by targeted gene disruption have revealed that several defense mechanisms against microbial pathogens are conserved between mosses and flowering plants. P. patens perceives pathogen associated molecular patterns by plasma membrane receptor(s) and transduces the signal through a MAP kinase (MAPK) cascade leading to the activation of cell wall associated defenses and expression of genes that encode proteins with different roles in plant resistance. After pathogen assault, P. patens also activates the production of ROS, induces a HR-like reaction and increases levels of some hormones. Furthermore, alternative metabolic pathways are present in P. patens leading to the production of a distinct metabolic scenario than flowering plants that could contribute to defense. P. patens has acquired genes by horizontal transfer from prokaryotes and fungi, and some of them could represent adaptive benefits for resistance to biotic stress. In this review, the current knowledge related to the evolution of plant defense responses against pathogens will be discussed, focusing on the latest advances made in the model plant P. patens.

  17. Effects of single cortisol administrations on human affect reviewed: Coping with stress through adaptive regulation of automatic cognitive processing.

    PubMed

    Putman, Peter; Roelofs, Karin

    2011-05-01

    The human stress hormone cortisol may facilitate effective coping after psychological stress. In apparent agreement, administration of cortisol has been demonstrated to reduce fear in response to stressors. For anxious patients with phobias or posttraumatic stress disorder this has been ascribed to hypothetical inhibition of retrieval of traumatic memories. However, such stress-protective effects may also work via adaptive regulation of early cognitive processing of threatening information from the environment. This paper selectively reviews the available literature on effects of single cortisol administrations on affect and early cognitive processing of affectively significant information. The concluded working hypothesis is that immediate effects of high concentration of cortisol may facilitate stress-coping via inhibition of automatic processing of goal-irrelevant threatening information and through increased automatic approach-avoidance responses in early emotional processing. Limitations in the existing literature and suggestions for future directions are briefly discussed.

  18. 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.

  19. Inducing adaptive coping self-statements in children with learning disabilities through self-instruction training.

    PubMed

    Kamann, M P; Wong, B Y

    1993-11-01

    This study investigated the efficacy of a coping strategy in reducing math anxiety in children with learning disabilities (LD). The coping strategy was based on cognitive behavior modification (CBM). Twenty children from Grades 4 to 7 participated in the study. Half of them were children with LD and the remaining were normally achieving children. The dependent measures were self-talk data and performance data on math (fraction) problems. Pretest data indicated that normally achieving children produced substantially more positive self-talk than children with learning disabilities. Subsequent to training in the use of the CBM-based coping strategy, children with LD produced a comparable amount of positive self-talk at posttest as found in normally achieving children. Moreover, there was a moderate, positive correlation between increased positive self-talk and math performance among the children with LD. The results clearly indicated that the children with LD had learned to cope with their math anxiety via a CBM-based strategy. More generally, the results of the study suggest that CBM strategies can be effectively applied to the affective domain. This broader implication and the limitations of the study are discussed.

  20. [Strategies of Adaption, coping reactions and attempts of self-cure in Schizophrenes].

    PubMed

    Lange, H U

    1981-07-01

    Though already Kraepelin started to consider coping behavior, there has not been much interest in it. Besides a summary of the literature, evidence of the study of 616 patient histories and the exploration of 94 schizophrenes is reported. Whereas often speculative interpretations of the patients' behaviour from the sight of the therapists have predominated in publications as yet, here it is preferred - with the danger of listing rationalizations - to outline defense reactions the patients themselves mention. The coping behaviour is classified in groups of symptoms: global strategies, disorders of perception, delusion, disorders of self-awareness, cognitive, affective, and motorial disorders. The discrimination of primary psychotic and "defect" symptoms, however, is often difficult. Some problems of the evaluation of coping behaviour are discussed. Defense reactions are presumably present in all schizophrenic types at least sometimes in the course of the illness. The more abrupt the disease starts, the more inadequate the coping behaviour seems to be. A further investigation of these strategies might be worth while for theoretical und therapeutical reasons.

  1. Loss of adaptive mechanisms during aging.

    PubMed

    Adelman, R C

    1979-05-01

    Factors contributing to modifications in the capability for enzyme adaptation as an expression of aging are reviewed. Specific examples of altered enzyme adaptations during aging include the responses of hepatic glucokinase activity to glucose and hepatic tyrosine aminotransferase activity to starvation in Sprague-Dawley rats. These impaired enzyme adaptations apparently are not the consequence of alterations in hepatic function during aging. Instead, they reflect disturbances in extrahepatic hormonal regulatory mechanisms. Specific examples include modifications in the control of circulating levels of insulin glucagon, corticosteroids, and thyroid hormones. Age-dependent changes in the regulation of circulating levels of insulin probably originate within the impaired ability of pancreatic islets of Langerhans to secrete the hormone in response to glucose. The rationale for exploiting this experimental approach as a means to understand biological aging is discussed.

  2. Cognitive and coping mechanisms in the interplay between intimate partner violence and depression.

    PubMed

    Calvete, Esther; Corral, Susana; Estévez, Ana

    2007-12-01

    This study examined the association between intimate partner violence, maladaptive cognitive schemas, coping, and depression in a sample of 298 battered women. The results indicated that maladaptive cognitive schemas were associated with less use of primary and secondary engagement coping, and higher use of disengagement coping. In particular, cognitive schemas reflecting disconnection and rejection accounted for the association between psychological abuse and percentage of disengagement coping. In addition, disengagement coping partially mediated between cognitive schemas and depressive symptoms. Finally, the role of cognitive schemas as personal constraints that affect the choice of coping and the implications for interventions with victims are discussed.

  3. 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.

    PubMed

    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 did not. There were no differences in adaptive skills between groups. However, compared to clients without substance abuse, those who abused substances showed a more palliative coping style, and had more severe emotional and behavior problems such as anxiety/depression and intrusive thoughts and aggressive and antisocial behaviors. Implications for treatment are discussed.

  4. 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.

  5. 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.

  6. 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

  7. 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…

  8. Mechanisms of Sensorimotor Adaptation to Centrifugation

    NASA Technical Reports Server (NTRS)

    Paloski, W. H.; Wood, S. J.; Kaufman, G. D.

    1999-01-01

    We postulate that centripetal acceleration induced by centrifugation can be used as an inflight sensorimotor countermeasure to retain and/or promote appropriate crewmember responses to sustained changes in gravito-inertial force conditions. Active voluntary motion is required to promote vestibular system conditioning, and both visual and graviceptor sensory feedback are critical for evaluating internal representations of spatial orientation. The goal of our investigation is to use centrifugation to develop an analog to the conflicting visual/gravito-inertial force environment experienced during space flight, and to use voluntary head movements during centrifugation to study mechanisms of adaptation to altered gravity environments. We address the following two hypotheses: (1) Discordant canal-otolith feedback during head movements in a hypergravity tilted environment will cause a reorganization of the spatial processing required for multisensory integration and motor control, resulting in decreased postural stability upon return to normal gravity environment. (2) Adaptation to this "gravito-inertial tilt distortion" will result in a negative after-effect, and readaptation will be expressed by return of postural stability to baseline conditions. During the third year of our grant we concentrated on examining changes in balance control following 90-180 min of centrifugation at 1.4 9. We also began a control study in which we exposed subjects to 90 min of sustained roll tilt in a static (non-rotating) chair. This allowed us to examine adaptation to roll tilt without the hypergravity induced by centrifugation. To these ends, we addressed the question: Is gravity an internal calibration reference for postural control? The remainder of this report is limited to presenting preliminary findings from this study.

  9. Phenotypic plasticity: molecular mechanisms and adaptive significance.

    PubMed

    Kelly, Scott A; Panhuis, Tami M; Stoehr, Andrew M

    2012-04-01

    Phenotypic plasticity can be broadly defined as the ability of one genotype to produce more than one phenotype when exposed to different environments, as the modification of developmental events by the environment, or as the ability of an individual organism to alter its phenotype in response to changes in environmental conditions. Not surprisingly, the study of phenotypic plasticity is innately interdisciplinary and encompasses aspects of behavior, development, ecology, evolution, genetics, genomics, and multiple physiological systems at various levels of biological organization. From an ecological and evolutionary perspective, phenotypic plasticity may be a powerful means of adaptation and dramatic examples of phenotypic plasticity include predator avoidance, insect wing polymorphisms, the timing of metamorphosis in amphibians, osmoregulation in fishes, and alternative reproductive tactics in male vertebrates. From a human health perspective, documented examples of plasticity most commonly include the results of exercise, training, and/or dieting on human morphology and physiology. Regardless of the discipline, phenotypic plasticity has increasingly become the target of a plethora of investigations with the methodological approaches utilized ranging from the molecular to whole organsimal. In this article, we provide a brief historical outlook on phenotypic plasticity; examine its potential adaptive significance; emphasize recent molecular approaches that provide novel insight into underlying mechanisms, and highlight examples in fishes and insects. Finally, we highlight examples of phenotypic plasticity from a human health perspective and underscore the use of mouse models as a powerful tool in understanding the genetic architecture of phenotypic plasticity.

  10. 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…

  11. 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.

  12. [The impact of religious coping on adaptation strategy among the sick].

    PubMed

    Debout, Christophe

    2015-10-01

    The influence of religious practice on sick people's adaptation processes has been demonstrated in many studies. It is important for the clinical reasoning implemented by caregivers to integrate this aspect in a context defined by the principle of "laïcité" as understood in France.

  13. 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…

  14. Population differentiation in a Mediterranean relict shrub: the potential role of local adaptation for coping with climate change.

    PubMed

    Lázaro-Nogal, Ana; Matesanz, Silvia; Hallik, Lea; Krasnova, Alisa; Traveset, Anna; Valladares, Fernando

    2016-04-01

    Plants can respond to climate change by either migrating, adapting to the new conditions or going extinct. Relict plant species of limited distribution can be especially vulnerable as they are usually composed of small and isolated populations, which may reduce their ability to cope with rapidly changing environmental conditions. The aim of this study was to assess the vulnerability of Cneorum tricoccon L. (Cneoraceae), a Mediterranean relict shrub of limited distribution, to a future drier climate. We evaluated population differentiation in functional traits related to drought tolerance across seven representative populations of the species' range. We measured morphological and physiological traits in both the field and the greenhouse under three water availability levels. Large phenotypic differences among populations were found under field conditions. All populations responded plastically to simulated drought, but they differed in mean trait values as well as in the slope of the phenotypic response. Particularly, dry-edge populations exhibited multiple functional traits that favored drought tolerance, such as more sclerophyllous leaves, strong stomatal control but high photosynthetic rates, which increases water use efficiency (iWUE), and an enhanced ability to accumulate sugars as osmolytes. Although drought decreased RGR in all populations, this reduction was smaller for populations from the dry edge. Our results suggest that dry-edge populations of this relict species are well adapted to drought, which could potentially mitigate the species' extinction risk under drier scenarios. Dry-edge populations not only have a great conservation value but can also change expectations from current species' distribution models.

  15. 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

  16. 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

  17. Adapt, move or die - how will tropical coral reef fishes cope with ocean warming?

    PubMed

    Habary, Adam; Johansen, Jacob L; Nay, Tiffany J; Steffensen, John F; Rummer, Jodie L

    2017-02-01

    Previous studies hailed thermal tolerance and the capacity for organisms to acclimate and adapt as the primary pathways for species survival under climate change. Here we challenge this theory. Over the past decade, more than 365 tropical stenothermal fish species have been documented moving poleward, away from ocean warming hotspots where temperatures 2-3 °C above long-term annual means can compromise critical physiological processes. We examined the capacity of a model species - a thermally sensitive coral reef fish, Chromis viridis (Pomacentridae) - to use preference behaviour to regulate its body temperature. Movement could potentially circumvent the physiological stress response associated with elevated temperatures and may be a strategy relied upon before genetic adaptation can be effectuated. Individuals were maintained at one of six temperatures (23, 25, 27, 29, 31 and 33 °C) for at least 6 weeks. We compared the relative importance of acclimation temperature to changes in upper critical thermal limits, aerobic metabolic scope and thermal preference. While acclimation temperature positively affected the upper critical thermal limit, neither aerobic metabolic scope nor thermal preference exhibited such plasticity. Importantly, when given the choice to stay in a habitat reflecting their acclimation temperatures or relocate, fish acclimated to end-of-century predicted temperatures (i.e. 31 or 33 °C) preferentially sought out cooler temperatures, those equivalent to long-term summer averages in their natural habitats (~29 °C). This was also the temperature providing the greatest aerobic metabolic scope and body condition across all treatments. Consequently, acclimation can confer plasticity in some performance traits, but may be an unreliable indicator of the ultimate survival and distribution of mobile stenothermal species under global warming. Conversely, thermal preference can arise long before, and remain long after, the harmful effects of elevated

  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. 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.

  20. Ministry-Related Burnout and Stress Coping Mechanisms Among Assemblies of God-Ordained Clergy in Minnesota.

    PubMed

    Visker, Joseph D; Rider, Taylor; Humphers-Ginther, Anastasia

    2017-06-01

    Clergy members suffering from burnout face both personal and professional complications. This study assessed occupational burnout and stress coping mechanisms among ministers affiliated with the Assemblies of God, a denomination that has received little attention in previous burnout-related studies. A cross-sectional design was employed using two instruments with acceptable psychometric properties. Approximately 65 % of those surveyed were either suffering from burnout or on the verge of burnout. Statistical differences in coping mechanism use were found between those who were and were not experiencing some level of burnout. The results of this study add to the existing understanding of occupational burnout among clergy members and ways in which burnout may be alleviated.

  1. Gender differences in defense mechanisms, ways of coping with stress and sense of identity in adolescent suicide attempts.

    PubMed

    Foto-Özdemir, Dilşad; Akdemir, Devrim; Çuhadaroğlu-Çetin, Füsun

    2016-01-01

    The main aim of this study was to investigate the gender differences in defense mechanisms, ways of coping with stress and identity formation in relation to adolescent suicidal behavior. This study involved 64 adolescents between 12-17 years of age, who were admitted to the emergency service with a suicide attempt. They were evaluated with a semi-structured clinical interview (K-SADS), Ways of Coping Inventory (WCI), Defense Mechanisms Inventory (DMI) and Sense of Identity Assessment Form (SIAF). 60.9% (n = 39) of the adolescents were female, and 39.1% (n=25) were male. There were no statistically significant differences between the girls and the boys with respect to the clinical characteristics of the suicide attempt and the rate of psychiatric disorders. Of the 64 adolescents with suicide attempt, 47 (73.4%) had at least one, and 26 (40.6%) had more than one psychiatric disorder according to K-SADS. Disruptive behavior disorders were more frequent in males, whereas depression was more frequent in girls. The data indicated the importance of identity confusion, major depression and ADHD in adolescents with suicide attempt in both genders. 43.6% (n=17) of the girls and 36% (n=9) of the boys obtained scores higher than the cut-off point of SIAF indicating identity confusion. Professional help seeking and NSSI behaviors before the suicide attempt were more common in adolescents with identity confusion. While there were differences between genders with respect to the defense mechanisms used, no significant difference was found in terms of ways of coping. Evaluation of DMI scores revealed that the turning against object subscale score was significantly higher in boys compared to girls. While evaluating the adolescents at risk, their defense mechanisms, way of coping and sense of identity, as well as their psychiatric diagnosis should be assessed in detail in order to identify the suicidal thoughts and prevent possible suicide attempts.

  2. [Mechanisms of psychological adaptation of anesthesiologists-resuscitators to the stress-induced conditions of professional occupation and possibilities of their correction within a teaching process].

    PubMed

    Shchelkova, O Iu; Mazurok, V A

    2007-01-01

    High psychological tension results in the development of specific coping behavior. Ninety-six anesthesiologists, including 62 (64.6%) males and 34 (35.4%) females, were examined to reveal the mechanisms of psychological adaptation to stress-induced conditions of professional occupation. The respondents were ascertained to most frequently use cognitive, emotional, and behavioral constructive copings in settling stress situations. Nonadaptive copings most commonly contemplate a refusal to get over difficulties due to the lack of faith in power, to the underestimation of the importance of negative events, to passivity, isolation, etc., which is traditionally considered to be a manifestation of the emotional burnout syndrome in attendants. Psychological training within a teaching process may be regarded as a help to physicians in developing constructive coping strategies, training in self-diagnosis and self-help in the early manifestations of emotional burnout.

  3. 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.

  4. 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.

  5. 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.

  6. Neuronal Adaptive Mechanisms Underlying Intelligent Information Processing

    DTIC Science & Technology

    1982-05-01

    omuter Procram The program consists of three functional units: stimulus presentation and data collection, histogram generation and display, and benavioral...sequence for ten second trials of adaptation, conditioning, extinction, or delayed HS paradigms. Timing of stimuli can be generated • . .. -?’ _-, a’. Ah...are generated from the data and displayed four each on Mime 100 and VT105 video terminals. The histograms are averages of three trials and are

  7. Delivering organisational adaptation through legislative mechanisms: Evidence from the Adaptation Reporting Power (Climate Change Act 2008).

    PubMed

    Jude, S R; Drew, G H; Pollard, S J T; Rocks, S A; Jenkinson, K; Lamb, R

    2017-01-01

    There is increasing recognition that organisations, particularly in key infrastructure sectors, are potentially vulnerable to climate change and extreme weather events, and require organisational responses to ensure they are resilient and adaptive. However, detailed evidence of how adaptation is facilitated, implemented and reported, particularly through legislative mechanisms is lacking. The United Kingdom Climate Change Act (2008), introduced the Adaptation Reporting Power, enabling the Government to direct so-called reporting authorities to report their climate change risks and adaptation plans. We describe the authors' unique role and experience supporting the Department for Environment, Food and Rural Affairs (Defra) during the Adaptation Reporting Power's first round. An evaluation framework, used to review the adaptation reports, is presented alongside evidence on how the process provides new insights into adaptation activities and triggered organisational change in 78% of reporting authorities, including the embedding of climate risk and adaptation issues. The role of legislative mechanisms and risk-based approaches in driving and delivering adaptation is discussed alongside future research needs, including the development of organisational maturity models to determine resilient and well adapting organisations. The Adaptation Reporting Power process provides a basis for similar initiatives in other countries, although a clear engagement strategy to ensure buy-in to the process and research on its long-term legacy, including the potential merits of voluntary approaches, is required.

  8. Adaptive Finite-Element Computation In Fracture Mechanics

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    Report discusses recent progress in use of solution-adaptive finite-element computational methods to solve two-dimensional problems in linear elastic fracture mechanics. Method also shown extensible to three-dimensional problems.

  9. Gender differences in perception of psychosocial distress and coping mechanisms among infertile men and women in Saudi Arabia.

    PubMed

    Alosaimi, Fahad D; Bukhari, Mujahid; Altuwirqi, Maram; Habous, Mohamad; Madbouly, Khaled; Abotalib, Zeinab; Binsaleh, Saleh

    2017-04-01

    The objective of the study was to evaluate the differences in psychosocial distress and coping mechanisms among infertile men and women in Saudi Arabia (SA). We performed a cross-sectional study of infertile patients (206 women and 200 men) attending infertility clinics in three referral hospitals in Riyadh, SA. A semi-structured questionnaire was developed to assess socio-demographic, clinical and psychosocial variables. Infertility-related psychosocial pressures were reported in 79 (39.7%) male and 97 (47.3%) female participants (p = 0.123). Males suffered more from intrusive questions and pressure to conceive, remarry or get divorced, while females were stressed more from psychological and emotional exhaustion, marital discord, attitudes of mothers-in-law or society, and persistent desire by the husband to have children. To cope with infertility, females engaged more in religious activities (p < 0.001) and spoke more to someone regarding their problems (p < 0.001). To solve their infertility problems, 50% tried to find solutions via the internet, and 38.5% of males and 51% of females reported using alternative medicines (p = 0.012). The patients with infertility in SA face multiple psychosocial stressors related to their infertility, and cope differently based on the gender and culture-specific knowledge of infertility. The female participants were significantly more affected from psychosocial stressors and the persistent desire by their spouse to have children.

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

    PubMed Central

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

    2011-01-01

    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 owing to 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 (VM) 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 VM and evoked EPSCs in the AII. We mimicked changes in background luminance or contrast, respectively, by depolarizing the VM or increasing its variance. A linear systems analysis of synaptic transmission showed that increasing either the mean or the variance of the presynaptic VM 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. PMID:21795549

  11. 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.

  12. 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…

  13. Implementing Coping Power Adapted as a Universal Prevention Program in Italian Primary Schools: a Randomized Control Trial.

    PubMed

    Muratori, Pietro; Bertacchi, Iacopo; Giuli, Consuelo; Nocentini, Annalaura; Lochman, John E

    2016-09-24

    Behavioral problems in schools can cause serious harm to the emotional and social well-being of students and limit their ability to achieve their full academic potential. A prior pilot study on the universal application of Coping Power showed a significant decrease in the hyperactivity behaviors of five classes. The next step was to test whether Coping Power Universal could be successfully implemented by teachers in a variety of Italian schools. The sample involved 40 third- and fourth-grade classes (901 students) from public schools located in three Italian cities. Twenty classes were randomly assigned to Coping Power Universal, and 20 classes were randomly assigned to the control group, which received the strictly standard academic curriculum of Italian elementary schools. At each assessment period, the teachers completed the Strengths and Difficulties Questionnaire. The findings showed a significant reduction in hyperactive and inattention behaviors and conduct problems and emotional symptoms in the intervention classes compared with the control classes. This study suggests that Coping Power model can be delivered in school settings at both universal and targeted prevention levels and that in this multi-tiered prevention model, teachers can learn a set of intervention skills which can be delivered with flexibility, thus reducing some of the complexity and costs of schools using multiple interventions.

  14. 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

  15. Microwear, mechanics and the feeding adaptations of Australopithecus africanus.

    PubMed

    Strait, David S; Weber, Gerhard W; Constantino, Paul; Lucas, Peter W; Richmond, Brian G; Spencer, Mark A; Dechow, Paul C; Ross, Callum F; Grosse, Ian R; Wright, Barth W; Wood, Bernard A; Wang, Qian; Byron, Craig; Slice, Dennis E

    2012-01-01

    Recent studies of dental microwear and craniofacial mechanics have yielded contradictory interpretations regarding the feeding ecology and adaptations of Australopithecus africanus. As part of this debate, the methods used in the mechanical studies have been criticized. In particular, it has been claimed that finite element analysis has been poorly applied to this research question. This paper responds to some of these mechanical criticisms, highlights limitations of dental microwear analysis, and identifies avenues of future research.

  16. Paraventricular Hypothalamic Mechanisms of Chronic Stress Adaptation

    PubMed Central

    Herman, James P.; Tasker, Jeffrey G.

    2016-01-01

    The hypothalamic paraventricular nucleus (PVN) is the primary driver of hypothalamo–pituitary–adrenocortical (HPA) responses. At least part of the role of the PVN is managing the demands of chronic stress exposure. With repeated exposure to stress, hypophysiotrophic corticotropin-releasing hormone (CRH) neurons of the PVN display a remarkable cellular, synaptic, and connectional plasticity that serves to maximize the ability of the HPA axis to maintain response vigor and flexibility. At the cellular level, chronic stress enhances the production of CRH and its co-secretagogue arginine vasopressin and rearranges neurotransmitter receptor expression so as to maximize cellular excitability. There is also evidence to suggest that efficacy of local glucocorticoid feedback is reduced following chronic stress. At the level of the synapse, chronic stress enhances cellular excitability and reduces inhibitory tone. Finally, chronic stress causes a structural enhancement of excitatory innervation, increasing the density of glutamate and noradrenergic/adrenergic terminals on CRH neuronal cell somata and dendrites. Together, these neuroplastic changes favor the ability of the HPA axis to retain responsiveness even under conditions of considerable adversity. Thus, chronic stress appears able to drive PVN neurons via a number of convergent mechanisms, processes that may play a major role in HPA axis dysfunction seen in variety of stress-linked disease states. PMID:27843437

  17. 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

  18. 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.

  19. 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.

  20. Contingency-based emotional resilience: effort-based reward training and flexible coping lead to adaptive responses to uncertainty in male rats

    PubMed Central

    Lambert, Kelly G.; Hyer, Molly M.; Rzucidlo, Amanda A.; Bergeron, Timothy; Landis, Timothy; Bardi, Massimo

    2014-01-01

    Emotional resilience enhances an animal's ability to maintain physiological allostasis and adaptive responses in the midst of challenges ranging from cognitive uncertainty to chronic stress. In the current study, neurobiological factors related to strategic responses to uncertainty produced by prediction errors were investigated by initially profiling male rats as passive, active or flexible copers (n = 12 each group) and assigning to either a contingency-trained or non-contingency trained group. Animals were subsequently trained in a spatial learning task so that problem solving strategies in the final probe task, as well-various biomarkers of brain activation and plasticity in brain areas associated with cognition and emotional regulation, could be assessed. Additionally, fecal samples were collected to further determine markers of stress responsivity and emotional resilience. Results indicated that contingency-trained rats exhibited more adaptive responses in the probe trial (e.g., fewer interrupted grooming sequences and more targeted search strategies) than the noncontingent-trained rats; additionally, increased DHEA/CORT ratios were observed in the contingent-trained animals. Diminished activation of the habenula (i.e., fos-immunoreactivity) was correlated with resilience factors such as increased levels of DHEA metabolites during cognitive training. Of the three coping profiles, flexible copers exhibited enhanced neuroplasticity (i.e., increased dentate gyrus doublecortin-immunoreactivity) compared to the more consistently responding active and passive copers. Thus, in the current study, contingency training via effort-based reward (EBR) training, enhanced by a flexible coping style, provided neurobiological resilience and adaptive responses to prediction errors in the final probe trial. These findings have implications for psychiatric illnesses that are influenced by altered stress responses and decision-making abilities (e.g., depression). PMID:24808837

  1. 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…

  2. Prevalence of PTSD Symptoms and Depression and Level of Coping among the Victims of the Kashmir Conflict

    ERIC Educational Resources Information Center

    Yaswi, Arooj; Haque, Amber

    2008-01-01

    This study examined the prevalence of posttraumatic stress disorder (PTSD) symptoms, depression, and coping mechanisms among the adult civilian population in Indian Kashmir. The Everstine Trauma Response Index-Adapted, the Beck Depression Inventory, and the Coping Resources Inventory were used to assess the three domains. Independent-sample t…

  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. Operation Joint Guard (SFOR) Bosnia. Assessment of Operational Stress and Adaptive Coping Mechanisms of Soldiers

    DTIC Science & Technology

    1998-03-01

    Opportunities to contact home acted as a buffer for this stress. ATT phone banks and morale calls home alleviated some of the stress of being away from loved...objectives. Horizontal cohesion (peer group bonding) and vertical cohesion (bonding to unit leadership) were extremely important buffers to stress. Both...4.0 3.0 2.0 7.0 Form Number 7S612-S-88 SURVEY Ivf ^tWoRK1 322 Below are statements about life that people often feel different about. Please

  5. 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.

  6. Impaired Adaptive Response to Mechanical Overloading in Dystrophic Skeletal Muscle

    PubMed Central

    Joanne, Pierre; Hourdé, Christophe; Ochala, Julien; Caudéran, Yvain; Medja, Fadia; Vignaud, Alban; Mouisel, Etienne; Hadj-Said, Wahiba; Arandel, Ludovic; Garcia, Luis; Goyenvalle, Aurélie; Mounier, Rémi; Zibroba, Daria; Sakamato, Kei; Butler-Browne, Gillian; Agbulut, Onnik; Ferry, Arnaud

    2012-01-01

    Dystrophin contributes to force transmission and has a protein-scaffolding role for a variety of signaling complexes in skeletal muscle. In the present study, we tested the hypothesis that the muscle adaptive response following mechanical overloading (ML) would be decreased in MDX dystrophic muscle lacking dystrophin. We found that the gains in muscle maximal force production and fatigue resistance in response to ML were both reduced in MDX mice as compared to healthy mice. MDX muscle also exhibited decreased cellular and molecular muscle remodeling (hypertrophy and promotion of slower/oxidative fiber type) in response to ML, and altered intracellular signalings involved in muscle growth and maintenance (mTOR, myostatin, follistatin, AMPKα1, REDD1, atrogin-1, Bnip3). Moreover, dystrophin rescue via exon skipping restored the adaptive response to ML. Therefore our results demonstrate that the adaptive response in response to ML is impaired in dystrophic MDX muscle, most likely because of the dystrophin crucial role. PMID:22511986

  7. Effects of mechanical stimuli on adaptive remodeling of condylar cartilage.

    PubMed

    Sriram, D; Jones, A; Alatli-Burt, I; Darendeliler, M A

    2009-05-01

    Trabecular bone has been shown to be responsive to low-magnitude, high-frequency mechanical stimuli. This study aimed to assess the effects of these stimuli on condylar cartilage and its endochondral bone. Forty female 12-week-old C3H mice were divided into 3 groups: baseline control (killed at day 0), sham (killed at day 28 without exposure to mechanical stimuli), and experimental (killed following 28 days of exposure to mechanical stimuli). The experimental group was subjected to mechanical vibration of 30 Hz, for 20 minutes per day, 5 days per week, for 28 days. The specimens were analyzed by micro-computed tomography. The experimental group demonstrated a significant decrease in the volume of condylar cartilage and also a significant increase in bone histomorphometric parameters. The results suggest that the low-magnitude, high-frequency mechanical stimuli enhance adaptive remodeling of condylar cartilage, evidenced by the advent of endochondral bone replacing the hypertrophic cartilage.

  8. 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.

  9. 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

  10. 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.

  11. Phenotypic Plasticity and Selection: Nonexclusive Mechanisms of Adaptation.

    PubMed

    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.

  12. Adaptive mechanical-wetting lens actuated by ferrofluids

    NASA Astrophysics Data System (ADS)

    Cheng, Hui-Chuan; Xu, Su; Liu, Yifan; Levi, Shoshana; Wu, Shin-Tson

    2011-04-01

    We report an adaptive mechanical-wetting lens actuated by ferrofluids. The ferrofluids works like a piston to pump liquids in and out from the lens chamber, which in turn reshapes the lens curvature and changes the focal length. Both positive and negative lenses are demonstrated experimentally. The ferrofluid-actuated mechanical-wetting lens exhibits some attractive features, such as high resolution, fast response time, low power consumption, simple structure and electronic control, weak gravity effect, and low cost. Its potential applications in medical imaging, surveillance, and commercial electronics are foreseeable.

  13. The development of coping.

    PubMed

    Skinner, Ellen A; Zimmer-Gembeck, Melanie J

    2007-01-01

    Research on coping during childhood and adolescence is distinguished by its focus on how children deal with actual stressors in real-life contexts. Despite burgeoning literatures within age groups, studies on developmental differences and changes have proven difficult to integrate. Two recent advances promise progress toward a developmental framework. First, dual-process models that conceptualize coping as "regulation under stress" establish links to the development of emotional, attentional, and behavioral self-regulation and suggest constitutional underpinnings and social factors that shape coping development. Second, analyses of the functions of higher-order coping families allow identification of corresponding lower-order ways of coping that, despite their differences, are developmentally graded members of the same family. This emerging framework was used to integrate 44 studies reporting age differences or changes in coping from infancy through adolescence. Together, these advances outline a systems perspective in which, as regulatory subsystems are integrated, general mechanisms of coping accumulate developmentally, suggesting multiple directions for future research.

  14. 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

  15. Mechanisms of colour adaptation in the prawn Penaeus monodon.

    PubMed

    Wade, Nicholas M; Anderson, Mike; Sellars, Melony J; Tume, Ron K; Preston, Nigel P; Glencross, Brett D

    2012-01-15

    Exposure of prawns to dark- or light-coloured substrates is known to trigger a strong colour adaptation response through expansion or contraction of the colouration structures in the prawn hypodermis. Despite the difference in colour triggered by this adaptive response, total levels of the predominant carotenoid pigment, astaxanthin, are not modified, suggesting that another mechanism is regulating this phenomenon. Astaxanthin binds to a specific protein called crustacyanin (CRCN), and it is the interaction between the quantities of each of these compounds that produces the diverse range of colours seen in crustacean shells. In this study, we investigated the protein changes and genetic regulatory processes that occur in prawn hypodermal tissues during adaptation to black or white substrates. The amount of free astaxanthin was higher in animals adapted to dark substrate compared with those adapted to light substrate, and this difference was matched by a strong elevation of CRCN protein. However, there was no difference in the expression of CRCN genes either across the moult cycle or in response to background substrate colour. These results indicate that exposure to a dark-coloured substrate causes an accumulation of CRCN protein, bound with free astaxanthin, in the prawn hypodermis without modification of CRCN gene expression. On light-coloured substrates, levels of CRCN protein in the hypodermis are reduced, but the carotenoid is retained, undispersed in the hypodermal tissue, in an esterified form. Therefore, the abundance of CRCN protein affects the distribution of pigment in prawn hypodermal tissues, and is a crucial regulator of the colour adaptation response in prawns.

  16. 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…

  17. Novel pathogenetic mechanisms and structural adaptations in ischemic mitral regurgitation.

    PubMed

    Silbiger, Jeffrey J

    2013-10-01

    Ischemic mitral regurgitation (MR) is a common complication of myocardial infarction thought to result from leaflet tethering caused by displacement of the papillary muscles that occurs as the left ventricle remodels. The author explores the possibility that left atrial remodeling may also play a role in the pathogenesis of ischemic MR, through a novel mechanism: atriogenic leaflet tethering. When ischemic MR is hemodynamically significant, the left ventricle compensates by dilating to preserve forward output using the Starling mechanism. Left ventricular dilatation, however, worsens MR by increasing the mitral valve regurgitant orifice, leading to a vicious cycle in which MR begets more MR. The author proposes that several structural adaptations play a role in reducing ischemic MR. In contrast to the compensatory effects of left ventricular enlargement, these may reduce, rather than increase, its severity. The suggested adaptations involve the mitral valve leaflets, the papillary muscles, the mitral annulus, and the left ventricular false tendons. This review describes the potential role each may play in reducing ischemic MR. Therapies that exploit these adaptations are also discussed.

  18. 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.

  19. Mechanism of Thermal Adaptation in the Lactate Dehydrogenases.

    PubMed

    Peng, Huo-Lei; Egawa, Tsuyoshi; Chang, Eric; Deng, Hua; Callender, Robert

    2015-12-10

    The mechanism of thermal adaptation of enzyme function at the molecular level is poorly understood but is thought to lie within the structure of the protein or its dynamics. Our previous work on pig heart lactate dehydrogenase (phLDH) has determined very high resolution structures of the active site, via isotope edited IR studies, and has characterized its dynamical nature, via laser-induced temperature jump (T-jump) relaxation spectroscopy on the Michaelis complex. These particular probes are quite powerful at getting at the interplay between structure and dynamics in adaptation. Hence, we extend these studies to the psychrophilic protein cgLDH (Champsocephalus gunnari; 0 °C) and the extreme thermophile tmLDH (Thermotoga maritima LDH; 80 °C) for comparison to the mesophile phLDH (38-39 °C). Instead of the native substrate pyruvate, we utilize oxamate as a nonreactive substrate mimic for experimental reasons. Using isotope edited IR spectroscopy, we find small differences in the substate composition that arise from the detailed bonding patterns of oxamate within the active site of the three proteins; however, we find these differences insufficient to explain the mechanism of thermal adaptation. On the other hand, T-jump studies of reduced β-nicotinamide adenine dinucleotide (NADH) emission reveal that the most important parameter affecting thermal adaptation appears to be enzyme control of the specific kinetics and dynamics of protein motions that lie along the catalytic pathway. The relaxation rate of the motions scale as cgLDH > phLDH > tmLDH in a way that faithfully matches kcat of the three isozymes.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. Automated mechanical ventilation: adapting decision making to different disease states.

    PubMed

    Lozano-Zahonero, S; Gottlieb, D; Haberthür, C; Guttmann, J; Möller, K

    2011-03-01

    The purpose of the present study is to introduce a novel methodology for adapting and upgrading decision-making strategies concerning mechanical ventilation with respect to different disease states into our fuzzy-based expert system, AUTOPILOT-BT. The special features are: (1) Extraction of clinical knowledge in analogy to the daily routine. (2) An automated process to obtain the required information and to create fuzzy sets. (3) The controller employs the derived fuzzy rules to achieve the desired ventilation status. For demonstration this study focuses exclusively on the control of arterial CO(2) partial pressure (p(a)CO(2)). Clinical knowledge from 61 anesthesiologists was acquired using a questionnaire from which different disease-specific fuzzy sets were generated to control p(a)CO(2). For both, patients with healthy lung and with acute respiratory distress syndrome (ARDS) the fuzzy sets show different shapes. The fuzzy set "normal", i.e., "target p(a)CO(2) area", ranges from 35 to 39 mmHg for healthy lungs and from 39 to 43 mmHg for ARDS lungs. With the new fuzzy sets our AUTOPILOT-BT reaches the target p(a)CO(2) within maximal three consecutive changes of ventilator settings. Thus, clinical knowledge can be extended, updated, and the resulting mechanical ventilation therapies can be individually adapted, analyzed, and evaluated.

  9. Adaptive midlife defense mechanisms and late-life health.

    PubMed

    Malone, Johanna C; Cohen, Shiri; Liu, Sabrina R; Vaillant, George E; Waldinger, Robert J

    2013-07-01

    A growing body of research suggests that personality characteristics relate to physical health; however, this relation ship has primarily been tested in cross-sectional studies that have not followed the participants into old age. The present study utilizes data from a 70-year longitudinal study to prospectively examine the relationship between the adaptive defense mechanisms in midlife and objectively assessed physical health in late life. In addition to examining the direct effect, we test whether social support mediates this relation ship. The sample consisted of 90 men who were followed for over seven decades beginning in late adolescence. Health ratings from medical records were made at three time points (ages 70, 75, and 80). Defense mechanisms were coded from narratives by trained independent raters (Vaillant, Bond, & Vaillant, 1986). Independent raters assessed social supports between ages 50 and 70. More adaptive defenses in midlife were associated with better physical health at all three time points in late life. These relationships were partially mediated by social support. Findings are consistent with the theory that defense maturity is important for building social relationships, which in turn contribute to better late-life physical health. Psychological interventions aimed at improving these domains may be beneficial for physical health.

  10. The relationship between burnout and coping in adult and young offender center correctional officers: an exploratory investigation.

    PubMed

    Gould, Drew D; Watson, Shelley L; Price, Stephanie R; Valliant, Paul M

    2013-02-01

    High levels of occupational stress and burnout are costly for correctional services and their employees. Correctional officers report high levels of burnout, absenteeism, turnover, and poor physical health. The purpose of this study was to investigate the prevalence of burnout and the coping mechanisms used to buffer the effects of burnout within correctional centers. In the current study, 208 correctional officers from adult and young offender centers completed an online survey measuring burnout and coping strategies. Results from the Maslach Burnout Inventory-Human Services Survey (MBI-HSS) and the Brief Coping Orientation to Problems Experienced (COPE) Scale indicated that even though correctional center officers mostly used adaptive coping strategies, they still reported high levels of burnout. The results of this study suggest that there are variables other than coping strategies, such as gender and length of experience, that lead to the level of burnout as observed in correctional officers.

  11. A genetic mechanism for Tibetan high-altitude adaptation.

    PubMed

    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

    2014-09-01

    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 K(m) 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.

  12. Adaptive mechanical properties of topologically interlocking material systems

    NASA Astrophysics Data System (ADS)

    Khandelwal, S.; Siegmund, T.; Cipra, R. J.; Bolton, J. S.

    2015-04-01

    Topologically interlocked material systems are two-dimensional granular crystals created as ordered and adhesion-less assemblies of unit elements of the shape of platonic solids. The assembly resists transverse forces due to the interlocking geometric arrangement of the unit elements. Topologically interlocked material systems yet require an external constraint to provide resistance under the action of external load. Past work considered fixed and passive constraints only. The objective of the present study is to consider active and adaptive external constraints with the goal to achieve variable stiffness and energy absorption characteristics of the topologically interlocked material system through an active control of the in-plane constraint conditions. Experiments and corresponding model analysis are used to demonstrate control of system stiffness over a wide range, including negative stiffness, and energy absorption characteristics. The adaptive characteristics of the topologically interlocked material system are shown to solve conflicting requirements of simultaneously providing energy absorption while keeping loads controlled. Potential applications can be envisioned in smart structure enhanced response characteristics as desired in shock absorption, protective packaging and catching mechanisms.

  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. Multiple representations and mechanisms for visuomotor adaptation in young children.

    PubMed

    Tahej, Pierre-Karim; Ferrel-Chapus, Carole; Olivier, Isabelle; Ginhac, Dominique; Rolland, Jean-Pierre

    2012-12-01

    In this study, we utilized transformed spatial mappings to perturb visuomotor integration in 5-yr-old children and adults. The participants were asked to perform pointing movements under five different conditions of visuomotor rotation (from 0° to 180°), which were designed to reveal explicit vs. implicit representations as well as the mechanisms underlying the visual-motor mapping. Several tests allowed us to separately evaluate sensorimotor (i.e., the dynamic dimension of movement) and cognitive (i.e., the explicit representations of target position and the strategies used by the participants) representations of visuo-proprioceptive distortion. Our results indicate that children do not establish representations in the same manner as adults and that children exhibit multiple visuomotor representations. Sensorimotor representations were relatively precise, presumably due to the recovery of proprioceptive information and efferent copy. Furthermore, a bidirectional mechanism was used to re-map visual and motor spaces. In contrast, cognitive representations were supplied with visual information and followed a unidirectional visual-motor mapping. Therefore, it appears that sensorimotor mechanisms develop before the use of explicit strategies during development, and young children showed impaired visuomotor adaptation when confronted with large distortions.

  15. Mechanisms of adaptation in the intestinal parasite Giardia lamblia.

    PubMed

    Lujan, Hugo D

    2011-01-01

    Giardia lamblia, a parasite of humans, is a major source of waterborne diarrhoeal disease. Giardia is also an excellent system to study basic biochemical processes because it is a single-celled eukaryote with a small genome and its entire life cycle can be replicated in vitro. Giardia trophozoites undergo fundamental changes to survive outside the intestine of their host by differentiating into infective cysts. Encystation entails the synthesis, processing, transport, secretion and extracellular assembly of cyst wall components. To survive within the intestine, Giardia undergoes antigenic variation, a process by which the parasite continuously switches its major surface molecules, allowing the parasite to evade the host's immune response and produce chronic and recurrent infections. The objective of the present chapter is to provide a better understanding of the molecular mechanisms involved in adaptation and differentiation in Giardia, with a particular focus on the process of encystation and antigenic variation of this interesting micro-organism.

  16. 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.

  17. 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.

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

    PubMed

    Bosson, Maël; Grudinin, Sergei; Redon, Stephane

    2013-03-05

    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.

  19. [Heart failure due to ischemia--the adaptive mechanisms].

    PubMed

    Mitu, M; Mitu, F

    1999-01-01

    Chronic myocardial ischemia is the leading cause of disturbances in myocardial contractility (myocardial infarction) or hemodynamic overload upon the left ventricle. The heart reactions consist in a series of adaptative mechanisms in order to maintain its pump function: Frank-Starling mechanism, myocardial hypertrophy and neurohumoral activation. In heart failure, the cardiac output is maintained by an increase of the preload which enhances the contractility (Frank-Starling law). Myocardial ischemia influences the systolic and diastolic function. The decrease of cardiac output leads to neurohumoral responses which, in the initial stages of cardiac failure are compensatory; along with the progression of the disease, they exert adverse effects. Increased activity of the sympathetic nervous system induces high cardiac rates, chronotropic incompetence. Activation of the renin-angiotensin system held to myocardial and vascular hypertrophy, vasoconstriction, fluid retention. Endothelin is the most powerful vasoconstrictor; its plasmatic concentrations correlate with the severity of the disease. Vasodilator mediators released in cardiac failure are the natriuretic peptide, nitric oxide, dopamine, prostacicline, bradikinin.

  20. [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.

  1. 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

  2. RNA sequencing of Populus x canadensis roots identifies key molecular mechanisms underlying physiological adaption to excess zinc.

    PubMed

    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.

  3. Testing of the coping flexibility hypothesis based on the dual-process theory: Relationships between coping flexibility and depressive Symptoms.

    PubMed

    Kato, Tsukasa

    2015-12-15

    According to the dual-process theory of coping flexibility (Kato, 2012), coping flexibility is the ability to discontinue an ineffective coping strategy (i.e., evaluation coping process) and implement an alternative strategy (i.e., adaptive coping process). The coping flexibility hypothesis (CFH) proposes that the ability to engage in flexible coping is related to better psychological functioning and physical health, including less depression. I the present study, participants were 393 American Whites, 429 Australian Whites, and 496 Chinese, selected from the data pool of the 2013 Coping and Health Survey (see Kato, 2014b). They completed both the Coping Flexibility Scale (Kato, 2012), which is based on the dual-process theory of coping flexibility, and the Center for Epidemiologic Studies Depression Scale (CES-D). For all nationalities and genders, evaluation coping and adaptive coping were significantly correlated with lower levels of depressive symptoms. Structural equation modeling revealed that evaluation coping was associated with lower depressive symptoms for all nationalities and genders, whereas no significant relationships between adaptive coping and depressive symptoms were found for any nationalities. Our results partially supported that the CFH fits with the dual-process theory of coping flexibility.

  4. Molecular mechanisms underlying phosphate sensing, signaling, and adaptation in plants.

    PubMed

    Zhang, Zhaoliang; Liao, Hong; Lucas, William J

    2014-03-01

    As an essential plant macronutrient, the low availability of phosphorus (P) in most soils imposes serious limitation on crop production. Plants have evolved complex responsive and adaptive mechanisms for acquisition, remobilization and recycling of phosphate (Pi) to maintain P homeostasis. Spatio-temporal molecular, physiological, and biochemical Pi deficiency responses developed by plants are the consequence of local and systemic sensing and signaling pathways. Pi deficiency is sensed locally by the root system where hormones serve as important signaling components in terms of developmental reprogramming, leading to changes in root system architecture. Root-to-shoot and shoot-to-root signals, delivered through the xylem and phloem, respectively, involving Pi itself, hormones, miRNAs, mRNAs, and sucrose, serve to coordinate Pi deficiency responses at the whole-plant level. A combination of chromatin remodeling, transcriptional and posttranslational events contribute to globally regulating a wide range of Pi deficiency responses. In this review, recent advances are evaluated in terms of progress toward developing a comprehensive understanding of the molecular events underlying control over P homeostasis. Application of this knowledge, in terms of developing crop plants having enhanced attributes for P use efficiency, is discussed from the perspective of agricultural sustainability in the face of diminishing global P supplies.

  5. 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

  6. 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.

  7. [Mechanism of cytogenetic adaptive response induced by low dose radiation].

    PubMed

    Cai, L; Liu, S

    1990-11-01

    Cytogenetic observation on human lymphocytes indicated that pre-exposure of 10, 50 and 75 mGy X-rays could induced the adaptive response. Experimental results with different temperature treatment showed that the adaptive response induced by low dose radiation could be enhanced by 41 degrees C and 43 degrees C, but inhibited by 4 degrees C in addition the treatment by 41 degrees C for one hour could also cause the adaptive response as did low dose radiation. Results showed that adaptive response induced by low dose radiation (10 or 50 mGy X-rays) could be eliminated by the protein synthesis inhibitor, implying that the adaptive response is related with the metabolism of cells, especially with the production of certain protective proteins.

  8. 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…

  9. 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

  10. An Investigation of the Association Between Shame and Problem Gambling: The Mediating Role of Maladaptive Coping Motives.

    PubMed

    Schlagintweit, Hera E; Thompson, Kara; Goldstein, Abby L; Stewart, Sherry H

    2017-02-03

    Despite often being considered equivalent affective states, shame and guilt have differential associations with problem gambling with only shame showing a strong positive association with problem gambling. However, little is known about the mechanisms underlying the shame-problem gambling association. Further, shame and guilt are associated with distinct coping strategies, with shame motivating maladaptive coping (e.g., avoidance, escape) and guilt motivating adaptive coping (e.g., taking corrective action). This study aimed to examine whether maladaptive coping motives for gambling mediate the relationship between shame, but not guilt, and gambling problems. Participants were 196 (126 male) regular gamblers who completed a same and guilt scale, the Problem Gambling Severity Index, and a modified Gambling Motives Questionnaire, which assessed individual motives to engage in gambling for coping, enhancement, or social reasons. Results indicated that coping motives for gambling fully mediated the relationship between shame and problem gambling severity, but did not mediate the association between guilt and problem gambling severity. Experiencing shame contributes to problem gambling as a result of gambling to cope with negative affect. Cultivating more adaptive strategies to cope with shame may be effective in preventing and treating problem gambling.

  11. [Is secondary myocardial hypertrophy a physiological or pathological adaptive mechanism?].

    PubMed

    Krayenbühl, H P

    1982-08-01

    however not associated with normal myocardial structure because interstitial fibrosis evaluated from endomyocardial biopsies or biopsies obtained at surgery was found to be increased. Patients with depressed left ventricular contractility were characterized by having an abnormally high muscle fibre diameter. Normal function after surgery was not accompanied by normalization of myocardial structure: Interstitial fibrosis increased, fibrous content remained the same and cellular hypertrophy regressed incompletely regardless whether angiographic muscle mass had regressed to normal or remained still increased after surgery. In summary, the bulk of available functional and morphological data suggests that the occurrence of true physiological hypertrophy is probably limited to exercise conditioning and eventually to mild chronic mechanical overload. The more severe secondary hypertrophy such as in patients with aortic valve disease who undergo valve replacement, is not a physiological adaptation, but must be considered as a pathological process.

  12. Floods and health in Gambella region, Ethiopia: a qualitative assessment of the strengths and weaknesses of coping mechanisms

    PubMed Central

    Wakuma Abaya, Samson; Mandere, Nicodemus; Ewald, Göran

    2009-01-01

    Background Floods are the most frequent and devastating type of natural disaster worldwide, causing unprecedented deaths, diseases, and destruction of property and crops. Flooding has a greater impact in developing countries due to lack of sufficient disaster management structures and a lack of economic resources. Objective This study was conducted with the aim of contributing to the knowledge base of development strategies that reduce flood-related health risks in developing countries. The study focused particularly on assessing the flood risks and health-related issues in the Gambella region of Ethiopia; with the intent of producing relevant information to assist with the improvements in the efficacy of the current flood coping strategies in the region. Methods Data were gathered through interviews with 14 officers from different government and non-governmental organizations and a questionnaire survey given to 35 flood victims in Itang woreda. A qualitative approach was applied and the data were analyzed using content analysis. Results It was found that flooding is a common problem in Gambella region. The findings also indicate that the flood frequency and magnitude has increased rapidly during the last decade. The increase in floods was driven mainly by climate change and changes in land use, specifically deforestation. The reported main impacts of flooding on human health in Gambella region were deaths, injuries, and diseases such as malaria and diarrhea. Another notable consequence of flooding was crop destruction and subsequent malnutrition. Conclusions Three weaknesses that were identified in the current coping strategies for flood-related health impacts in Gambella region were a lack of flood-specific policy, absence of risk assessment, and weak institutional capacity. This study recommends new policy approaches that will increase the effectiveness of the current flood coping strategies to sustainably address the impact of flooding on human health. PMID

  13. 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…

  14. Adaptive Local Grid Refinement in Computational Fluid Mechanics.

    DTIC Science & Technology

    1987-11-01

    Adaptive mesh refinements in reservoir simulation applications (R.E. Ew- ing), Proceedings Intl. Conference on Accuracy Est. and Adaptive Refine... reservoir simulation (R.E. Ewing and .J.V. 1{oebbe), Innovati’ve Numerical Mlethods in Engineering, (R.P. Shaw, J. Pc- riaux, A. Chaudouet, J. Wu...Universities, Cheyenne, Wyoming, February 21, 1986, O 9. Finite element techniques for reservoir simulation , Fourth International Sym- posium on Numerical

  15. Evolution by flight and fight: diverse mechanisms of adaptation by actively motile microbes.

    PubMed

    Rendueles, Olaya; Velicer, Gregory J

    2017-02-01

    Evolutionary adaptation can be achieved by mechanisms accessible to all organisms, including faster growth and interference competition, but self-generated motility offers additional possibilities. We tested whether 55 populations of the bacterium Myxococcus xanthus that underwent selection for increased fitness at the leading edge of swarming colonies adapted by swarming faster toward unused resources or by other means. Populations adapted greatly but diversified markedly in both swarming phenotypes and apparent mechanisms of adaptation. Intriguingly, although many adapted populations swarm intrinsically faster than their ancestors, numerous others do not. Some populations evolved interference competition toward their ancestors, whereas others gained the ability to facultatively increase swarming rate specifically upon direct interaction with ancestral competitors. Our results both highlight the diverse range of mechanisms by which actively motile organisms can adapt evolutionarily and help to explain the high levels of swarming-phenotype diversity found in local soil populations of M. xanthus.

  16. Evolution by flight and fight: diverse mechanisms of adaptation by actively motile microbes

    PubMed Central

    Rendueles, Olaya; Velicer, Gregory J

    2017-01-01

    Evolutionary adaptation can be achieved by mechanisms accessible to all organisms, including faster growth and interference competition, but self-generated motility offers additional possibilities. We tested whether 55 populations of the bacterium Myxococcus xanthus that underwent selection for increased fitness at the leading edge of swarming colonies adapted by swarming faster toward unused resources or by other means. Populations adapted greatly but diversified markedly in both swarming phenotypes and apparent mechanisms of adaptation. Intriguingly, although many adapted populations swarm intrinsically faster than their ancestors, numerous others do not. Some populations evolved interference competition toward their ancestors, whereas others gained the ability to facultatively increase swarming rate specifically upon direct interaction with ancestral competitors. Our results both highlight the diverse range of mechanisms by which actively motile organisms can adapt evolutionarily and help to explain the high levels of swarming-phenotype diversity found in local soil populations of M. xanthus. PMID:27662568

  17. Family Functionality and Coping Attitudes of Patients with Bipolar Disorder.

    PubMed

    Çuhadar, Döndü; Savaş, Haluk Asuman; Ünal, Ahmet; Gökpınar, Fatma

    2015-10-01

    The coping of patients with prodromal syndromes prevents relapses, and the differences in coping strategies affect the results of bipolar disorder. The various functionality levels of bipolar disorder patients such as work, marital relations, parental abilities and social presentation are significantly related with how well they cope. The objective of this study was to determine the family functionality and coping attitudes of bipolar disorder patients. The study planned as a descriptive one was carried with 81 bipolar disorder patients. Personal description form, family assessment device and Coping Attitudes Scale were used as data acquisition tools. It was determined that the adaptive coping attitudes used most frequently by the patients were religious coping, positive reinterpretation, active coping, problem-focused coping and emotional focused coping, beneficial social support use, emotional social support use, planning, suppression of competing activities and restraint coping; maladaptive coping attitudes used most frequently by the patients were "focusing on the problem and venting of emotions and mental disengagement." It was determined that family functions affected the coping attitudes of patients and that the patients who evaluated family functions in a healthy manner made use of adaptive coping strategies more at a statistically significant level.

  18. Adaptation to mechanical load determines shape and properties of heart and circulation: the CircAdapt model.

    PubMed

    Arts, Theo; Delhaas, Tammo; Bovendeerd, Peter; Verbeek, Xander; Prinzen, Frits W

    2005-04-01

    With circulatory pathology, patient-specific simulation of hemodynamics is required to minimize invasiveness for diagnosis, treatment planning, and followup. We investigated the advantages of a smart combination of often already known hemodynamic principles. The CircAdapt model was designed to simulate beat-to-beat dynamics of the four-chamber heart with systemic and pulmonary circulation while incorporating a realistic relation between pressure-volume load and tissue mechanics and adaptation of tissues to mechanical load. Adaptation was modeled by rules, where a locally sensed signal results in a local action of the tissue. The applied rules were as follows: For blood vessel walls, 1) flow shear stress dilates the wall and 2) tensile stress thickens the wall; for myocardial tissue, 3) strain dilates the wall material, 4) larger maximum sarcomere length increases contractility, and 5) contractility increases wall mass. The circulation was composed of active and passive compliances and inertias. A realistic circulation developed by self-structuring through adaptation provided mean levels of systemic pressure and flow. Ability to simulate a wide variety of patient-specific circumstances was demonstrated by application of the same adaptation rules to the conditions of fetal circulation followed by a switch to the newborn circulation around birth. It was concluded that a few adaptation rules, directed to normalize mechanical load of the tissue, were sufficient to develop and maintain a realistic circulation automatically. Adaptation rules appear to be the key to reduce dramatically the number of input parameters for simulating circulation dynamics. The model may be used to simulate circulation pathology and to predict effects of treatment.

  19. 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.

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

    PubMed Central

    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

  1. Relationship Between Ways of Coping and Quality of Life in Married Women: Toward Mental Health Promotion

    PubMed Central

    Mirabzadeh, Arash; Baradaran Eftekhari, Monir; Setareh Forouzan, Ameneh; Sajadi, Homeira; Rafiee, Hassan

    2013-01-01

    Background Adaptive ways of coping with stress are as a major component of mental health and also this is considered as a key element in quality of life. Objectives The aim of this study was to investigate the relationship between quality of life and coping mechanisms in married women ages between 18-65 years in order to develop appropriate intervention programs to promote mental health. Patients and Methods This study was a part of interventional project to mental health promotion in married women that completed through a cross sectional studies using two standard questionnaires: Ways of Coping (WOC) and Quality of Life questionnaire (WHO, QOL-BREF). Results The most and the least used ways in coping with stress were Planful Problem Solving and Confronting Coping. Considering the quality of life, the most and the least scores were related to social dimension and mental health. Also women who have higher quality of life used more Positive Reappraisal way and less Escape-Avoidance way to deal with stress (P < 0.05). Conclusions It seems that implementation of an appropriate interventional program related to adaptive ways of coping in order to deal with stress is effective in mental health and quality of life promotion. PMID:24578846

  2. 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.

  3. Cosmological fluid mechanics with adaptively refined large eddy simulations

    NASA Astrophysics Data System (ADS)

    Schmidt, W.; Almgren, A. S.; Braun, H.; Engels, J. F.; Niemeyer, J. C.; Schulz, J.; Mekuria, R. R.; Aspden, A. J.; Bell, J. B.

    2014-06-01

    We investigate turbulence generated by cosmological structure formation by means of large eddy simulations using adaptive mesh refinement. In contrast to the widely used implicit large eddy simulations, which resolve a limited range of length-scales and treat the effect of turbulent velocity fluctuations below the grid scale solely by numerical dissipation, we apply a subgrid-scale model for the numerically unresolved fraction of the turbulence energy. For simulations with adaptive mesh refinement, we utilize a new methodology that allows us to adjust the scale-dependent energy variables in such a way that the sum of resolved and unresolved energies is globally conserved. We test our approach in simulations of randomly forced turbulence, a gravitationally bound cloud in a wind, and the Santa Barbara cluster. To treat inhomogeneous turbulence, we introduce an adaptive Kalman filtering technique that separates turbulent velocity fluctuations on resolved length-scales from the non-turbulent bulk flow. From the magnitude of the fluctuating component and the subgrid-scale turbulence energy, a total turbulent velocity dispersion of several 100 km s-1 is obtained for the Santa Barbara cluster, while the low-density gas outside the accretion shocks is nearly devoid of turbulence. The energy flux through the turbulent cascade and the dissipation rate predicted by the subgrid-scale model correspond to dynamical time-scales around 5 Gyr, independent of numerical resolution.

  4. Molecular mechanisms underlying thermal adaptation of xeric animals.

    PubMed

    Evgen'ev, M B; Garbuz, D G; Shilova, V Y; Zatsepina, O G

    2007-04-01

    For many years,we and our collaborators have investigated the adaptive role of heat shock proteins in different animals,including the representatives of homothermic and poikilothermic species that inhabit regions with contrasting thermal conditions. Adaptive evolution of the response to hyperthermia has led to different results depending upon the species. The thermal threshold of induction of heat shock proteins in desert thermophylic species is, as a rule, higher than in the species from less extreme climates. In addition,thermoresistant poikilothermic species often exhibit a certain level of heat shock proteins in cells even at a physiologically normal temperature. Furthermore,there is often a positive correlation between the characteristic temperature of the ecological niche of a given species and the amount of Hsp70-like proteins in the cells at normal temperature. Although in most cases adaptation to hyperthermia occurs without changes in the number of heat shock genes, these genes can be amplified in some xeric species. It was shown that mobile genetic elements may play an important role in the evolution and fine-tuning of the heat shock response system,and can be used for direct introduction of mutations in the promoter regions of these genes.

  5. 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.

  6. [The effect of coping and appraisal for coping on mental health and later coping].

    PubMed

    Takamoto, Masahiro; Aikawa, Atsushi

    2013-02-01

    This study examined the effect of coping and appraisal for coping on mental health and later coping in two longitudinal studies. In Study 1 (Time 1: n = 342, Time 2: n = 367) investigated the influence of selected coping and coping for appraisal on mental health and assumed coping. In Study 2 (Time 1: n = 161, Time 2: n = 154) investigated the influence of selected coping and coping for appraisal on mental health and later coping. The results indicated that coping and coping for appraisal affected mental health and later coping. However, the influence of the coping for appraisal was more limited than selected coping.

  7. Fundamental Advances in Inverse Mechanics Towards Self-Aware and Intrinsically Adaptable Structural Systems

    DTIC Science & Technology

    2014-11-30

    AFRL-OSR-VA-TR-2015-0007 FUNDAMENTAL ADVANCES IN INVERSE MECHANICS TOWARDS SELF-AWARE JOHN BRIGHAM UNIVERSITY OF PITTSBURGH Final Report 12/04/2014...TITLE AND SUBTITLE Fundamental Advances in Inverse Mechanics Towards Self-Aware and Intrinsically Adaptable Structural Systems 5a. CONTRACT NUMBER...methods for solving inverse problems related to smart morphable structures that can evaluate their current environment and then adapt accordingly to

  8. Mechanism for adaptive remodeling of the bacterial flagellar switch

    PubMed Central

    Lele, Pushkar P.; Branch, Richard W.; Nathan, Vedhavalli S. J.; Berg, Howard C.

    2012-01-01

    The bacterial flagellar motor has been shown in previous work to adapt to changes in the steady-state concentration of the chemotaxis signaling molecule, CheY-P, by changing the FliM content. We show here that the number of FliM molecules in the motor and the fraction of FliM molecules that exchange depend on the direction of flagellar rotation, not on CheY-P binding per se. Our results are consistent with a model in which the structural differences associated with the direction of rotation modulate the strength of FliM binding. When the motor spins counterclockwise, FliM binding strengthens, the fraction of FliM molecules that exchanges decreases, and the ring content increases. The larger number of CheY-P binding sites enhances the motor’s sensitivity, i.e., the motor adapts. An interesting unresolved question is how additional copies of FliM might be accommodated. PMID:23169659

  9. 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.

  10. Network Adaptation Improves Temporal Representation of Naturalistic Stimuli in Drosophila Eye: II Mechanisms

    PubMed Central

    Wardill, Trevor J.; O'Kane, Cahir J.; de Polavieja, Gonzalo G.; Juusola, Mikko

    2009-01-01

    Retinal networks must adapt constantly to best present the ever changing visual world to the brain. Here we test the hypothesis that adaptation is a result of different mechanisms at several synaptic connections within the network. In a companion paper (Part I), we showed that adaptation in the photoreceptors (R1–R6) and large monopolar cells (LMC) of the Drosophila eye improves sensitivity to under-represented signals in seconds by enhancing both the amplitude and frequency distribution of LMCs' voltage responses to repeated naturalistic contrast series. In this paper, we show that such adaptation needs both the light-mediated conductance and feedback-mediated synaptic conductance. A faulty feedforward pathway in histamine receptor mutant flies speeds up the LMC output, mimicking extreme light adaptation. A faulty feedback pathway from L2 LMCs to photoreceptors slows down the LMC output, mimicking dark adaptation. These results underline the importance of network adaptation for efficient coding, and as a mechanism for selectively regulating the size and speed of signals in neurons. We suggest that concert action of many different mechanisms and neural connections are responsible for adaptation to visual stimuli. Further, our results demonstrate the need for detailed circuit reconstructions like that of the Drosophila lamina, to understand how networks process information. PMID:19180195

  11. Self-* and Adaptive Mechanisms for Large Scale Distributed Systems

    NASA Astrophysics Data System (ADS)

    Fragopoulou, P.; Mastroianni, C.; Montero, R.; Andrjezak, A.; Kondo, D.

    Large-scale distributed computing systems and infrastructure, such as Grids, P2P systems and desktop Grid platforms, are decentralized, pervasive, and composed of a large number of autonomous entities. The complexity of these systems is such that human administration is nearly impossible and centralized or hierarchical control is highly inefficient. These systems need to run on highly dynamic environments, where content, network topologies and workloads are continuously changing. Moreover, they are characterized by the high degree of volatility of their components and the need to provide efficient service management and to handle efficiently large amounts of data. This paper describes some of the areas for which adaptation emerges as a key feature, namely, the management of computational Grids, the self-management of desktop Grid platforms and the monitoring and healing of complex applications. It also elaborates on the use of bio-inspired algorithms to achieve self-management. Related future trends and challenges are described.

  12. 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.

  13. 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

    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.

  14. 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

  15. 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.

  16. 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…

  17. 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.

  18. 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.

  19. 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

  20. Adaptive-randomised self-calibration of electro-mechanical shutters for space imaging

    NASA Astrophysics Data System (ADS)

    De Cecco, Mariolino; Debei, Stefano; Zaccariotto, Mirco; Pertile, Marco

    2006-11-01

    This work describes the self-calibration of a high-precision open-loop mechanism. The self-calibration method is applied to a mechanical shutter for space applications, which was launched onboard the ESA-ROSETTA mission (launch: 2 March 2004). It is based on an adaptive 'model reference' and a 'randomised' search method which may be generalised to applications in which high performance and functionality are strongly interconnected. The method makes use of an adaptive 'model-reference' control approach [K.J. Astrom, B. Wittenmark, On self-tuning regulators Automatica 9 (1973) 185-199 [16]; K.J. Astrom, Theory and application of adaptive control, in: Proceedings of the Eighth IFAC World Conference, Kyoto, Japan, 1981 [17]; D.E. Seborg, S.L. Shah, T.F. Edgar, Adaptive control strategies for process control, AIChE Journal 6(32) (1986) 881-895 [18

  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. Restricted autoantigen recognition associated with deletional and adaptive regulatory mechanisms.

    PubMed

    Gebe, John A; Yue, Betty B; Unrath, Kelly A; Falk, Ben A; Nepom, Gerald T

    2009-07-01

    Autoimmune diabetes (T1D) is characterized by CD4(+) T cell reactivity to a variety of islet-associated Ags. At-risk individuals, genetically predisposed to T1D, often have similar T cell reactivity, but nevertheless fail to progress to clinically overt disease. To study the immune tolerance and regulatory environment permissive for such autoreactive T cells, we expressed TCR transgenes derived from two autoreactive human T cells, 4.13 and 164, in HLA-DR4 transgenic mice on a C57BL/6-derived "diabetes-resistant" background. Both TCR are responsive to an immunodominant epitope of glutamic acid decarboxylase 65(555-567), which is identical in sequence between humans and mice, is restricted by HLA-DR4, and is a naturally processed self Ag associated with T1D. Although both TCR use the identical Valpha and Vbeta genes, differing only in CDR3, we found stark differences in the mechanisms utilized in vivo in the maintenance of immune tolerance. A combination of thymic deletion (negative selection), TCR down-regulation, and peripheral activation-induced cell death dominated the phenotype of 164 T cells, which nevertheless still maintain their Ag responsiveness in the periphery. In contrast, 4.13 T cells are much less influenced by central and deletional tolerance mechanisms, and instead display a peripheral immune deviation including differentiation into IL-10-secreting Tr1 cells. These findings indicate a distinct set of regulatory alternatives for autoreactive T cells, even within a single highly restricted HLA-peptide-TCR recognition profile.

  3. The primary cilium is a self-adaptable, integrating nexus for mechanical stimuli and cellular signaling.

    PubMed

    Nguyen, An M; Young, Y-N; Jacobs, Christopher R

    2015-11-24

    Mechanosensation is crucial for cells to sense and respond to mechanical signals within their local environment. While adaptation allows a sensor to be conditioned by stimuli within the environment and enables its operation in a wide range of stimuli intensities, the mechanisms behind adaptation remain controversial in even the most extensively studied mechanosensor, bacterial mechanosensitive channels. Primary cilia are ubiquitous sensory organelles. They have emerged as mechanosensors across diverse tissues, including kidney, liver and the embryonic node, and deflect with mechanical stimuli. Here, we show that both mechanical and chemical stimuli can alter cilium stiffness. We found that exposure to flow stiffens the cilium, which deflects less in response to subsequent exposures to flow. We also found that through a process involving acetylation, the cell can biochemically regulate cilium stiffness. Finally, we show that this altered stiffness directly affects the responsiveness of the cell to mechanical signals. These results demonstrate a potential mechanism through which the cell can regulate its mechanosensing apparatus.

  4. 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.

  5. From models to rules: mechanization of reasoning as a way to cope with cognitive overloading in combinatorial problems.

    PubMed

    Cherubini, Paolo; Mazzocco, Alberto

    2004-07-01

    It is hypothesized that the transition from unfamiliar problems to familiar, well-learned problems coincides with the transition from a model-based style of reasoning to a rule-based style of reasoning; model-based style of reasoning helps understanding the problem structure, but can overload working memory when the number of models required increases; rule-based style of reasoning avoids cognitive overloading, at the cost of making individuals liable to mechanization errors. In Experiment 1, the number of models required to respond to a verification task affected response latencies with unfamiliar problems, but not with familiar problems, supporting the initial hypothesis. In Experiment 2, participants were prone to mechanization errors when confronted with slightly modified problems in the late stages of the experiment, supporting the hypothesis that they had developed a reasoning rule in the early stages and were blindly applying it. The findings suggest that model-based reasoning and rule-based reasoning serve different purposes and have different costs and benefits, are both available to human reasoners, and familiarization with a problem may induce the transition from the former to the latter. The findings also suggest that mechanization of reasoning may be the first step along a gradient of decreasing cognitive load, whose end-point is automatization, as discussed in theories of automatization of information processing.

  6. 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…

  7. 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

  8. 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.

  9. 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

  10. Optimism and coping strategies among Caucasian, Korean, and African American older women.

    PubMed

    Lee, Heesoon; Mason, Derek

    2013-01-01

    Coping strategies and optimism have significant effects on the health of older women. Culture affects coping behaviors used to deal with stress. We examined the relationship between optimism and coping strategies used to manage daily stress and health among community-dwelling Caucasian, Korean American, and African American women. Data were collected from 373 women over the age of 65. Results showed that each group used different coping strategies. The more optimistic used more problem-focused and adaptive copings, while the less optimistic employed more avoidant copings. Differences in cultural background and individual levels of optimism guided their coping strategies.

  11. Mechanism of spike frequency adaptation in substantia gelatinosa neurones of rat.

    PubMed

    Melnick, Igor V; Santos, Sónia F A; Safronov, Boris V

    2004-09-01

    Using tight-seal recordings from rat spinal cord slices, intracellular labelling and computer simulation, we analysed the mechanisms of spike frequency adaptation in substantia gelatinosa (SG) neurones. Adapting-firing neurones (AFNs) generated short bursts of spikes during sustained depolarization and were mostly found in lateral SG. The firing pattern and the shape of single spikes did not change after substitution of Ca2+ with Co2+, Mg2+ or Cd2+ indicating that Ca2+-dependent conductances do not contribute to adapting firing. Transient KA current was small and completely inactivated at resting potential suggesting that adapting firing was mainly generated by voltage-gated Na+ and delayed-rectifier K+ (KDR) currents. Although these currents were similar to those previously described in tonic-firing neurones (TFNs), we found that Na+ and KDR currents were smaller in AFNs. Discharge pattern in TFNs could be reversibly converted into that typical of AFNs in the presence of tetrodotoxin but not tetraethylammonium, suggesting that lower Na+ conductance is more critical for the appearance of firing adaptation. Intracellularly labelled AFNs showed specific morphological features and preserved long extensively branching axons, indicating that smaller Na+ conductance could not result from the axon cut. Computer simulation has further revealed that down-regulation of Na+ conductance represents an effective mechanism for the induction of firing adaptation. It is suggested that the cell-specific regulation of Na+ channel expression can be an important factor underlying the diversity of firing patterns in SG neurones.

  12. 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…

  13. 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.

  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. Structural and Functional Mechanisms of Adaptations of WrbA in Extremophilic Organisms

    DTIC Science & Technology

    2010-05-11

    Archaeoglobus fulgidus and the mesophile Escherichia coli were investigated to gain an understanding of the mechanisms by which proteins in extremophilic...hypcrthcrmoph’tieArchaeoglohns fidgidus and the mesophile EMiwruhia coli were investigated to gain an understanding of the mechanisms by which proteins in...extremophilic organisms adapt to high temperature. A model of the thermophilic enzyme was constructed based on the crystal structure of the mesophilic

  16. Adaptive behavior of bacterial mechanosensitive channels is coupled to membrane mechanics.

    PubMed

    Belyy, Vladislav; Kamaraju, Kishore; Akitake, Bradley; Anishkin, Andriy; Sukharev, Sergei

    2010-06-01

    Mechanosensitive channel of small conductance (MscS), a tension-driven osmolyte release valve residing in the inner membrane of Escherichia coli, exhibits a complex adaptive behavior, whereas its functional counterpart, mechanosensitive channel of large conductance (MscL), was generally considered nonadaptive. In this study, we show that both channels exhibit similar adaptation in excised patches, a process that is completely separable from inactivation prominent only in MscS. When a membrane patch is held under constant pressure, adaptation of both channels is manifested as a reversible current decline. Their dose-response curves recorded with 1-10-s ramps of pressure are shifted toward higher tension relative to the curves measured with series of pulses, indicating decreased tension sensitivity. Prolonged exposure of excised patches to subthreshold tensions further shifts activation curves for both MscS and MscL toward higher tension with similar magnitude and time course. Whole spheroplast MscS recordings performed with simultaneous imaging reveal activation curves with a midpoint tension of 7.8 mN/m and the slope corresponding to approximately 15-nm(2) in-plane expansion. Inactivation was retained in whole spheroplast mode, but no adaptation was observed. Similarly, whole spheroplast recordings of MscL (V23T mutant) indicated no adaptation, which was present in excised patches. MscS activities tried in spheroplast-attached mode showed no adaptation when the spheroplasts were intact, but permeabilized spheroplasts showed delayed adaptation, suggesting that the presence of membrane breaks or edges causes adaptation. We interpret this in the framework of the mechanics of the bilayer couple linking adaptation of channels in excised patches to the relaxation of the inner leaflet that is not in contact with the glass pipette. Relaxation of one leaflet results in asymmetric redistribution of tension in the bilayer that is less favorable for channel opening.

  17. 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

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

    PubMed Central

    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.

    2012-01-01

    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 acids 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 levels, 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. PMID:22503288

  19. A Neural Mechanism for Time-Window Separation Resolves Ambiguity of Adaptive Coding

    PubMed Central

    Hildebrandt, K. Jannis; Ronacher, Bernhard; Hennig, R. Matthias; Benda, Jan

    2015-01-01

    The senses of animals are confronted with changing environments and different contexts. Neural adaptation is one important tool to adjust sensitivity to varying intensity ranges. For instance, in a quiet night outdoors, our hearing is more sensitive than when we are confronted with the plurality of sounds in a large city during the day. However, adaptation also removes available information on absolute sound levels and may thus cause ambiguity. Experimental data on the trade-off between benefits and loss through adaptation is scarce and very few mechanisms have been proposed to resolve it. We present an example where adaptation is beneficial for one task—namely, the reliable encoding of the pattern of an acoustic signal—but detrimental for another—the localization of the same acoustic stimulus. With a combination of neurophysiological data, modeling, and behavioral tests, we show that adaptation in the periphery of the auditory pathway of grasshoppers enables intensity-invariant coding of amplitude modulations, but at the same time, degrades information available for sound localization. We demonstrate how focusing the response of localization neurons to the onset of relevant signals separates processing of localization and pattern information temporally. In this way, the ambiguity of adaptive coding can be circumvented and both absolute and relative levels can be processed using the same set of peripheral neurons. PMID:25761097

  20. Gradual mechanics-dependent adaptation of medial gastrocnemius activity during human walking

    PubMed Central

    Wellinghoff, Molly A.; Bunchman, Alison M.

    2013-01-01

    While performing a simple bouncing task, humans modify their preferred movement period and pattern of plantarflexor activity in response to changes in system mechanics. Over time, the preferred movement pattern gradually adapts toward the resonant frequency. The purpose of the present experiments was to determine whether humans undergo a similar process of gradually adapting their stride period and plantarflexor activity after a change in mechanical demand while walking. Participants walked on a treadmill while we measured stride period and plantarflexor activity (medial gastrocnemius and soleus). Plantarflexor activity during stance was divided into a storage phase (30–65% stance) and a return phase (65–100% stance) based on when the Achilles tendon has previously been shown to store and return mechanical energy. Participants walked either on constant inclines (0%, 1%, 5%, 9%) or on a variable incline (0–1%) for which they were unaware of the incline changes. For variable-incline trials, participants walked under both single-task and dual-task conditions in order to vary the cognitive load. Both stride period and plantarflexor activity increased at steeper inclines. During single-task walking, small changes in incline were followed by gradual adaptation of storage-phase medial gastrocnemius activity. However, this adaptation was not present during dual-task walking, indicating some level of cognitive involvement. The observed adaptation may be the result of using afferent feedback in order to optimize the contractile conditions of the plantarflexors during the stance phase. Such adaptation could serve to improve metabolic economy but may be limited in clinical populations with disrupted proprioception. PMID:24335207

  1. 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…

  2. 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…

  3. Academic Resourcefulness, Coping Strategies and Doubting in University Undergraduates

    ERIC Educational Resources Information Center

    Xuereb, Sharon

    2015-01-01

    This study hypothesised that academic resourcefulness and coping strategies would predict doubting amongst university undergraduates. Doubting refers to the serious consideration of prematurely withdrawing from university. It was predicted that mature students would report higher levels of academic resourcefulness and adaptive coping strategies,…

  4. 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…

  5. Establishing a Career: Developmental Tasks and Coping Responses.

    ERIC Educational Resources Information Center

    Dix, Janet E.; Savickas, Mark L.

    1995-01-01

    The critical incidents technique was used with 50 workers successfully coping with career establishment. The workers identified behaviors used to cope with six tasks: organizational adaptation, position performance, work habits/attitudes, coworker relations, advancement, and career choice/plans. Responses were organized into patterns of coping…

  6. 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…

  7. 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.

  8. Adaptively Adjusted Event-Triggering Mechanism on Fault Detection for Networked Control Systems.

    PubMed

    Wang, Yu-Long; Lim, Cheng-Chew; Shi, Peng

    2016-12-08

    This paper studies the problem of adaptively adjusted event-triggering mechanism-based fault detection for a class of discrete-time networked control system (NCS) with applications to aircraft dynamics. By taking into account the fault occurrence detection progress and the fault occurrence probability, and introducing an adaptively adjusted event-triggering parameter, a novel event-triggering mechanism is proposed to achieve the efficient utilization of the communication network bandwidth. Both the sensor-to-control station and the control station-to-actuator network-induced delays are taken into account. The event-triggered sensor and the event-triggered control station are utilized simultaneously to establish new network-based closed-loop models for the NCS subject to faults. Based on the established models, the event-triggered simultaneous design of fault detection filter (FDF) and controller is presented. A new algorithm for handling the adaptively adjusted event-triggering parameter is proposed. Performance analysis verifies the effectiveness of the adaptively adjusted event-triggering mechanism, and the simultaneous design of FDF and controller.

  9. A Quasi-ARX Neural Network with Switching Mechanism to Adaptive Control of Nonlinear Systems

    NASA Astrophysics Data System (ADS)

    Wang, Lan; Cheng, Yu; Hu, Jinglu

    This paper introduces an improved quasi-ARX neural network and discusses its application to adaptive control of nonlinear systems. A switching mechanism is employed to improve the performance of the quasi-ARX neural network prediction model which has linear and nonlinear parts. An adaptive controller for a nonlinear system is established based on the proposed prediction model and some stability analysis of the control system is shown. Simulations are given to show the effectiveness of the proposed method both on stability and accuracy.

  10. 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

  11. [Mechanisms of natural variability at adaptation of human physiological systems to conditions of space flight].

    PubMed

    Larina, I M; Nosovskiĭ, A M; Grigor'ev, A I

    2012-01-01

    This article analyzes the physiological data using the principle of invariant relationships, to reveal the mechanisms of adaptive variability. It was used physical-chemical, biochemical, and hormonal blood parameters of cosmonauts who have committed short-term and long space flights. These results suggest that application of the methods of fractal geometry to quantitative estimates of homeostasis allows to allocate the processes depending on the increase/decrease of adaptive variability and fix the state of stability or instability of certain physiological regulatory subsystems, due to mobility and to reduce the level of stability which remains stable internal structure of relationships throughout the body.

  12. Mechanisms of cell protection by adaptation to chronic and acute hypoxia: molecular biology and clinical practice.

    PubMed

    Corbucci, G G; Marchi, A; Lettieri, B; Luongo, C

    2005-11-01

    Several experimental and clinical studies have shown that specific biochemical and molecular pathways are involved in the myocardial and skeletal muscle cell tolerance to acute and/or chronic hypoxic injury. A number of different factors were proposed to play a role in the preservation of tissue viability, but to a few of them a pivotal role in the adaptive mechanisms to hypoxic stimuli could be ascribed. Starting from the observation that mitochondrial electron transport chain (ETC) enzymic complexes are the targets of oxygen reduced availability, most of data are compatible with a mechanism of enzymic adaptation in which the nitric oxide (NO) generation plays the major role. If the partial and reversible NO-induced inhibition of ETC enzymic complexes represents the most rapid and prominent adaptive mechanism in counteracting the damaging effects of hypoxia, the sarcolemmal and mitochondrial K+(ATP) channels activation results to be closely involved in cytoprotection. This process is depending on protein kinase C (PKC) isoform activation triggered by reactive oxygen species (ROS) generation, adenosine triphosphate (ATP) depletion and Ca++ overload. It is well known that all these factors are present in hypoxia-induced oxidative damage and mitochondrial Ca++ altered pools represent powerful stimuli in the damaging processes. The activation of mitochondrial K+(ATP) channels leads to a significant reduction of Ca++ influx and attenuation of mitochondrial Ca++ overload. Closely linked to these adaptive changes signal transduction pathways are involved in the nuclear DNA damage and repair mechanisms. On this context, an essential role is played by the hypoxia-induced factor-1alpha (HIF-1alpha) in terms of key transcription factor involved in oxygen-dependent gene regulation. The knowledge of the biochemical and molecular sequences involved in these adaptive processes call for a re-evaluation of the therapeutic approach to hypoxia-induced pathologies. On this light

  13. Theory of psychological adaptive modes.

    PubMed

    Lehti, Juha

    2016-05-01

    When an individual is facing a stressor and normal stress-response mechanism cannot guarantee sufficient adaptation, special emotional states, adaptive modes, are activated (for example a depressive reaction). Adaptive modes are involuntary states of mind, they are of comprehensive nature, they interfere with normal functioning, and they cannot be repressed or controlled the same way as many emotions. Their transformational nature differentiates them from other emotional states. The object of the adaptive mode is to optimize the problem-solving abilities according to the situation that has provoked the mode. Cognitions and emotions during the adaptive mode are different than in a normal mental state. These altered cognitions and emotional reactions guide the individual to use the correct coping skills in order to deal with the stressor. Successful adaptation will cause the adaptive mode to fade off since the adaptive mode is no longer necessary, and the process as a whole will lead to raised well-being. However, if the adaptation process is inadequate, then the transformation period is prolonged, and the adaptive mode will turn into a dysfunctional state. Many psychiatric disorders are such maladaptive processes. The maladaptive processes can be turned into functional ones by using adaptive skills that are used in functional adaptive processes.

  14. Adaptive response in animals exposed to non-ionizing radiofrequency fields: some underlying mechanisms.

    PubMed

    Cao, Yi; Tong, Jian

    2014-04-22

    During the last few years, our research group has been investigating the phenomenon of adaptive response in animals exposed to non-ionizing radiofrequency fields. The results from several separate studies indicated a significant increase in survival, decreases in genetic damage as well as oxidative damage and, alterations in several cellular processes in mice pre-exposed to radiofrequency fields and subsequently subjected to sub-lethal or lethal doses of γ-radiation or injected with bleomycin, a radiomimetic chemical mutagen. These observations indicated the induction of adaptive response providing the animals the ability to resist subsequent damage. Similar studies conducted by independent researchers in mice and rats have supported our observation on increased survival. In this paper, we have presented a brief review of all of our own and other independent investigations on radiofrequency fields-induced adaptive response and some underlying mechanisms discussed.

  15. 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°.

  16. 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

  17. fMRI study of the role of glutamate NMDA receptor in the olfactory adaptation in rats: Insights into cellular and molecular mechanisms of olfactory adaptation.

    PubMed

    Zhao, Fuqiang; Wang, Xiaohai; Zariwala, Hatim A; Uslaner, Jason M; Houghton, Andrea K; Evelhoch, Jeffrey L; Hostetler, Eric; Winkelmann, Christopher T; Hines, Catherine D G

    2017-02-03

    Olfactory adaptation, characterized by attenuation of response to repeated odor stimulations or continuous odor exposure, is an intrinsic feature of olfactory processing. Adaptation can be induced by either "synaptic depression" due to depletion of neurotransmitters, or "enhanced inhibition" onto principle neurons by local inhibitory interneurons in olfactory structures. It is not clear which mechanism plays a major role in olfactory adaptation. More importantly, molecular sources of enhanced inhibition have not been identified. In this study, olfactory responses to either repeated 40-s stimulations with interstimulus intervals (ISI) of 140-s or 30-min, or a single prolonged 200-s stimulus were measured by fMRI in different naïve rats. Olfactory adaptations in the olfactory bulb (OB), anterior olfactory nucleus (AON), and piriform cortex (PC) were observed only with repeated 40-s odor stimulations, and no olfactory adaptations were detected during the prolonged 200-s stimulation. Interestingly, in responses to repeated 40-s odor stimulations in the PC, the first odor stimulation induced positive activations, and odor stimulations under adapted condition induced negative activations. The negative activations suggest that "sparse coding" and "global inhibition" are the characteristics of olfactory processing in PC, and the global inhibition manifests only under an adapted condition, not a naïve condition. Further, we found that these adaptations were NMDA receptor dependent; an NMDA receptor antagonist (MK801) blocked the adaptations. Based on the mechanism that glutamate NMDA receptor plays a role in the inhibition onto principle neurons by interneurons, our data suggest that the olfactory adaptations are caused by enhanced inhibition from interneurons. Combined with the necessity of the interruption of odor stimulation to observe the adaptations, the molecular source for the enhanced inhibition is most likely an increased glutamate release from presynaptic

  18. 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

  19. Adaptive vision-based control of a motor-toggle mechanism: Simulations and experiments

    NASA Astrophysics Data System (ADS)

    Chuang, Chin-Wen; Huang, Ming-Shyan; Chen, Kun-Yung; Fung, Rong-Fong

    2008-05-01

    The dynamic motion of an adaptive visual servoing feedback-controlled punching machine, which is made up by a toggle mechanism driven by a permanent magnet (PM) synchronous servomotor, is studied numerically and experimentally. First, Hamilton's principle, Lagrange multiplier, geometric constraints and partitioning method are employed to derive its dynamic equations for numerical simulations. To satisfy the demand of the machine performance, adaptive controller by using stability analysis with inertia-related Lyapunov function is designed to control the slider responses. Different from the previous studies, the vision servo system of a non-contact measurement of a charge-coupled device (CCD) camera is employed to measure the shape patterns as output states instead of using the expensive linear scale or encoder of the motor-mechanism system. Finally, the stable and robust control performances of an adaptive controller by the Lyapunov stable theory for a motor-toggle mechanism with external disturbances are proposed. A combination of the visual servoing measurement system and the motion control system are established experimentally for the motor-toggle mechanism system. From the agreements between numerical simulations and experimental results, it is demonstrated that the proposed controller, by use of machine vision, is robust to external disturbances for a punching machine system.

  20. 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

    2016-09-06

    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.

  1. Short-term saccadic adaptation in the macaque monkey: a binocular mechanism

    PubMed Central

    Schultz, K. P.

    2013-01-01

    Saccadic eye movements are rapid transfers of gaze between objects of interest. Their duration is too short for the visual system to be able to follow their progress in time. Adaptive mechanisms constantly recalibrate the saccadic responses by detecting how close the landings are to the selected targets. The double-step saccadic paradigm is a common method to simulate alterations in saccadic gain. While the subject is responding to a first target shift, a second shift is introduced in the middle of this movement, which masks it from visual detection. The error in landing introduced by the second shift is interpreted by the brain as an error in the programming of the initial response, with gradual gain changes aimed at compensating the apparent sensorimotor mismatch. A second shift applied dichoptically to only one eye introduces disconjugate landing errors between the two eyes. A monocular adaptive system would independently modify only the gain of the eye exposed to the second shift in order to reestablish binocular alignment. Our results support a binocular mechanism. A version-based saccadic adaptive process detects postsaccadic version errors and generates compensatory conjugate gain alterations. A vergence-based saccadic adaptive process detects postsaccadic disparity errors and generates corrective nonvisual disparity signals that are sent to the vergence system to regain binocularity. This results in striking dynamical similarities between visually driven combined saccade-vergence gaze transfers, where the disparity is given by the visual targets, and the double-step adaptive disconjugate responses, where an adaptive disparity signal is generated internally by the saccadic system. PMID:23076111

  2. Testing the efficacy of culturally adapted coping skills training for Chinese American immigrants with type 2 diabetes using community-based participatory research.

    PubMed

    Chesla, Catherine A; Chun, Kevin M; Kwan, Christine M L; Mullan, Joseph T; Kwong, Yulanda; Hsu, Lydia; Huang, Peggy; Strycker, Lisa A; Shum, Tina; To, Diana; Kao, Rudy; Waters, Catherine M

    2013-08-01

    Chinese Americans demonstrate greater prevalence of diabetes than non-Hispanic whites and find standard diabetes care disregards their cultural health beliefs. Academic researchers and Chinatown agencies collaborated to culturally adapt and test an efficacious cognitive-behavioral intervention using community-based participatory research. Using a delayed-treatment repeated-measures design, 145 adult Chinese immigrants with Type 2 diabetes completed treatment. Immediate benefits of treatment were evident in the improvement (p < .05) in diabetes self-efficacy, diabetes knowledge, bicultural efficacy, family emotional and instrumental support, diabetes quality of life, and diabetes distress. Prolonged benefits were evident in all changed variables 2 months post-intervention. The CBPR approach enabled the development of a culturally acceptable, efficacious behavioral intervention, and provides a model for working with communities that demonstrate health disparities.

  3. Adaptation as a mechanism for gain control in cockroach ON and OFF olfactory receptor neurons.

    PubMed

    Burgstaller, Maria; Tichy, Harald

    2012-02-01

    In many sensory systems adaptation acts as a gain control mechanism that optimizes sensory performance by trading increased sensitivity to low stimulus intensity for decreased sensitivity to high stimulus intensity. Adaptation of insect antennal olfactory receptor neurons (ORNs) has been studied for strong odour concentrations, either pulsed or constant. Here, we report that during slowly oscillating changes in the concentration of the odour of lemon oil, the ON and OFF ORNs on the antenna of the cockroach Periplaneta americana adapt to the actual odour concentration and the rate at which concentration changes. When odour concentration oscillates rapidly with brief periods, adaptation improves gain for instantaneous odour concentration and reduces gain for the rate of concentration change. Conversely, when odour concentration oscillates slowly with long periods, adaptation increases gain for the rate of change at the expense of instantaneous concentration. Without this gain control the ON and OFF ORNs would, at brief oscillation periods, soon reach their saturation level and become insensitive to further concentration increments and decrements. At long oscillation periods, on the other hand, the cue would simply be that the discharge begins to change. Because of the high gain for the rate of change, the cockroach will receive creeping changes in odour concentration, even if they persist in one direction. Gain control permits a high degree of precision at small rates when it counts most, without sacrificing the range of detection and without extending the measuring scale.

  4. Deciphering the salinity adaptation mechanism in Penicilliopsis clavariiformis AP, a rare salt tolerant fungus from mangrove.

    PubMed

    Kashyap, Prem Lal; Rai, Anuradha; Singh, Ruchi; Chakdar, Hillol; Kumar, Sudheer; Srivastava, Alok Kumar

    2016-07-01

    Penicilliopsis clavariiformis AP, a rare salt tolerant fungus reported for the first time from India was identified through polyphasic taxonomy. Scanning electron microscopy showed that the fungus has unique features such as biverticillate penicilli bearing masses of oval to ellipsoidal conidia. The fungus has been characterized for salt tolerance and to understand the relevance of central carbon metabolism in salt stress adaptation. It showed optimal growth at 24 °C and able to tolerate up to 10% (w/v) NaCl. To understand the mechanism of adaptation to high salinity, activities of the key enzymes regulating glycolysis, pentose phosphate pathway, and tricarboxylic acid cycle were investigated under normal (0% NaCl) and saline stress environment (10% NaCl). The results revealed a re-routing of carbon metabolism away from glycolysis to the pentose phosphate pathway (PPP), served as a cellular stress-resistance mechanism in fungi under saline environment. The detection and significant expression of fungus genes (Hsp98, Hsp60, HTB, and RHO) under saline stress suggest that these halotolerance conferring genes from the fungus could have a role in fungus protection and adaptation under saline environment. Overall, the present findings indicate that the rearrangement of the metabolic fluxes distribution and stress related genes play an important role in cell survival and adaptation under saline environment.

  5. 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.

  6. Mycobacterial escape from macrophage phagosomes to the cytoplasm represents an alternate adaptation mechanism

    PubMed Central

    Jamwal, Shilpa V.; Mehrotra, Parul; Singh, Archana; Siddiqui, Zaved; Basu, Atanu; Rao, Kanury V.S.

    2016-01-01

    Survival of Mycobacterium tuberculosis (Mtb) within the host macrophage is mediated through pathogen-dependent inhibition of phagosome-lysosome fusion, which enables bacteria to persist within the immature phagosomal compartment. By employing ultrastructural examination of different field isolates supported by biochemical analysis, we found that some of the Mtb strains were in fact poorly adapted for subsistence within endocytic vesicles of infected macrophages. Instead, through a mechanism involving activation of host cytosolic phospholipase A2, these bacteria rapidly escaped from phagosomes, and established residence in the cytoplasm of the host cell. Interestingly, by facilitating an enhanced suppression of host cellular autophagy, this translocation served as an alternate virulence acquisition mechanism. Thus, our studies reveal plasticity in the adaptation strategies employed by Mtb, for survival in the host macrophage. PMID:26980157

  7. Gender Roles and Coping.

    ERIC Educational Resources Information Center

    Patterson, Joan M.; McCubbin, Hamilton I.

    1984-01-01

    Examined the relationship of gender-role orientation and specific behavioral coping responses of wives (N=82) experiencing a long-term separation from their military spouses. Results showed that an androgynous gender-role orientation was significantly associated with four of the five coping patterns identified as helpful to wives managing a…

  8. 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…

  9. Subverting the adaptive immune resistance mechanism to improve clinical responses to immune checkpoint blockade therapy

    PubMed Central

    Kim, Young J

    2015-01-01

    The correlation between tumor-infiltrating lymphocyte (TIL)-expression of programmed cell death ligand 1 (PD-L1) and clinical responsiveness to the PD-1 blocking antibody nivolumab implicates adaptive immune evasion mechanisms in cancer. We review our findings that tumor cell PD-L1 expression is induced by interferon γ (IFNγ) producing TILs. We provide a mechanistic rationale for combining IFNγ+ T helper type 1 (Th1)-inducing cancer vaccines with PD-1 immune checkpoint blockade. PMID:25964860

  10. Adaptive kanban control mechanism for a single-stage hybrid system

    NASA Astrophysics Data System (ADS)

    Korugan, Aybek; Gupta, Surendra M.

    2002-02-01

    In this paper, we consider a hybrid manufacturing system with two discrete production lines. Here the output of either production line can satisfy the demand for the same type of product without any penalties. The interarrival times for demand occurrences and service completions are exponentially distributed i.i.d. variables. In order to control this type of manufacturing system we suggest a single stage pull type control mechanism with adaptive kanbans and state independent routing of the production information.

  11. Coping with stalking.

    PubMed

    Amar, Angela Frederick; Alexy, Eileen M

    2010-01-01

    Stalking is a serious public health and societal concern affecting the college population. Although numerous studies illustrate the physical and mental effects of stalking, literature addressing how individuals cope with this phenomenon is lacking. The purpose of this study was to describe stalking experiences of college students and the coping strategies used to manage stalking. In this descriptive study, 262 college students completed an online survey that included a stalking questionnaire and coping survey. Slightly more than one-fourth of the sample (n = 69) reported experiencing stalking victimization. Results indicated that the most common coping strategies employed were: ignoring the problem, minimizing the problem, distancing, detaching or depersonalizing, using verbal escape tactics, attempting to end the relationship, controlling the interaction, and restricting accessibility. Implications for refining current practice and research on coping strategies and stalking are suggested.

  12. 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.

  13. 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

  14. 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.

  15. Potential mechanisms for a role of metabolic stress in hypertrophic adaptations to resistance training.

    PubMed

    Schoenfeld, Brad J

    2013-03-01

    It is well established that regimented resistance training can promote increases in muscle hypertrophy. The prevailing body of research indicates that mechanical stress is the primary impetus for this adaptive response and studies show that mechanical stress alone can initiate anabolic signalling. Given the dominant role of mechanical stress in muscle growth, the question arises as to whether other factors may enhance the post-exercise hypertrophic response. Several researchers have proposed that exercise-induced metabolic stress may in fact confer such an anabolic effect and some have even suggested that metabolite accumulation may be more important than high force development in optimizing muscle growth. Metabolic stress pursuant to traditional resistance training manifests as a result of exercise that relies on anaerobic glycolysis for adenosine triphosphate production. This, in turn, causes the subsequent accumulation of metabolites, particularly lactate and H(+). Acute muscle hypoxia associated with such training methods may further heighten metabolic buildup. Therefore, the purpose of this paper will be to review the emerging body of research suggesting a role for exercise-induced metabolic stress in maximizing muscle development and present insights as to the potential mechanisms by which these hypertrophic adaptations may occur. These mechanisms include increased fibre recruitment, elevated systemic hormonal production, alterations in local myokines, heightened production of reactive oxygen species and cell swelling. Recommendations are provided for potential areas of future research on the subject.

  16. 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.

  17. 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.

  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.

  19. Can use of positive religious coping predict greater distress? An examination of Army soldiers on deployment.

    PubMed

    Cornish, Marilyn A; Lannin, Daniel G; Wade, Nathaniel G; Martinez, Melisa

    2017-04-01

    Although positive religious coping is generally viewed as an adaptive, functional coping pattern, some studies have actually found positive religious coping to be associated with more distress in military populations. In the current study, we examined the role of positive religious coping on distress across 2 time points. Participants in this study were 192 Army soldiers (men = 90.4%) who were stationed in Iraq for a 1-year deployment in 2005. Using structural equation modeling, we conducted a cross-lag analysis of positive religious coping and distress. Results indicated that greater use of positive religious coping significantly predicted greater distress 1 month later, whereas distress at T1 did not predict positive religious coping 1 month later. Combat exposure was also a significant predictor of distress 1 month later. Implications of these results include the need to inquire about clients' use of religious coping and whether such coping methods are having the desired effect for them. (PsycINFO Database Record

  20. The regulating role of negative emotions in children's coping with peer rejection.

    PubMed

    Goodman, Kimberly L; Southam-Gerow, Michael A

    2010-10-01

    This study examined the role of emotions as predictors of children's coping responses to peer rejection experiences. Children ages 7-12 (N = 79) completed questionnaires to assess emotional and coping responses to peer rejection scenarios. This study examined three coping factors specific to peer rejection (positive reappraisal, ruminative coping, and aggressive coping) and examined results separately for two negative peer experiences (teasing and exclusion). Children's emotions predicted coping responses after controlling for peer experiences. Specifically, anger was associated with aggressive coping, whereas sadness was associated with ruminative coping, supporting theory that emotions have distinct motivational-behavioral properties. Peer experiences were also important, as victimization was associated with aggressive coping, and receipt of prosocial peer behaviors was associated with positive reappraisal. These findings provide an empirical foundation for future research and the development of interventions to facilitate adaptive reactions to peer rejection.

  1. TATA Box Insertion Provides a Selection Mechanism Underpinning Adaptations to Fe Deficiency1[OPEN

    PubMed Central

    Zhang, Meiling; Lv, Yuanda; Wang, Yi; Shen, Fei; Han, Zhenyun; Zhang, Xinzhong; Xu, Xuefeng; Han, Zhenhai

    2017-01-01

    Intraspecific genetic variation is essential for the responses and adaption of plants to evolutionary challenges, such as changing environmental conditions. The development of the Earth’s aerobic atmosphere has increased the demand for iron (Fe) in organisms, and Fe deficiency has become a limiting environmental factor for plant growth. Here, we demonstrate that genus Malus adapt to Fe deficiency through modification of the Iron-Regulated Transporter1 (IRT1) promoter. Specifically, an IRT1 mutant allele with a TATA-box insertion in the promoter region upstream of the coding region exhibited increased IRT1 expression. The altered IRT1 promoter is responsible for enhancing Fe uptake. Increasing the number of synthetic repeat TATA-boxes correlates with increased promoter activity. Furthermore, we demonstrate that the insertion of the TATA-box correlates with an increase in transcriptional activation via specific binding of the transcription factor IID (MDP0000939369). Taken together, these results indicate that an allelic insertion of a TATA-box in a gene promoter has allowed apple to adapt to the selective pressure posed by Fe deficiency. More broadly, this study reveals a new mechanism for enhancing gene expression to help plants adapt to different environments, providing new insights into molecular genetic divergence in plants. PMID:27881725

  2. TATA Box Insertion Provides a Selection Mechanism Underpinning Adaptations to Fe Deficiency.

    PubMed

    Zhang, Meiling; Lv, Yuanda; Wang, Yi; Rose, Jocelyn K C; Shen, Fei; Han, Zhenyun; Zhang, Xinzhong; Xu, Xuefeng; Wu, Ting; Han, Zhenhai

    2017-01-01

    Intraspecific genetic variation is essential for the responses and adaption of plants to evolutionary challenges, such as changing environmental conditions. The development of the Earth's aerobic atmosphere has increased the demand for iron (Fe) in organisms, and Fe deficiency has become a limiting environmental factor for plant growth. Here, we demonstrate that genus Malus adapt to Fe deficiency through modification of the Iron-Regulated Transporter1 (IRT1) promoter. Specifically, an IRT1 mutant allele with a TATA-box insertion in the promoter region upstream of the coding region exhibited increased IRT1 expression. The altered IRT1 promoter is responsible for enhancing Fe uptake. Increasing the number of synthetic repeat TATA-boxes correlates with increased promoter activity. Furthermore, we demonstrate that the insertion of the TATA-box correlates with an increase in transcriptional activation via specific binding of the transcription factor IID (MDP0000939369). Taken together, these results indicate that an allelic insertion of a TATA-box in a gene promoter has allowed apple to adapt to the selective pressure posed by Fe deficiency. More broadly, this study reveals a new mechanism for enhancing gene expression to help plants adapt to different environments, providing new insights into molecular genetic divergence in plants.

  3. 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

  4. Mechanisms by Which Phenotypic Plasticity Affects Adaptive Divergence and Ecological Speciation.

    PubMed

    Nonaka, Etsuko; Svanbäck, Richard; Thibert-Plante, Xavier; Englund, Göran; Brännström, Åke

    2015-11-01

    Phenotypic plasticity is the ability of one genotype to produce different phenotypes depending on environmental conditions. Several conceptual models emphasize the role of plasticity in promoting reproductive isolation and, ultimately, speciation in populations that forage on two or more resources. These models predict that plasticity plays a critical role in the early stages of speciation, prior to genetic divergence, by facilitating fast phenotypic divergence. The ability to plastically express alternative phenotypes may, however, interfere with the early phase of the formation of reproductive barriers, especially in the absence of geographic barriers. Here, we quantitatively investigate mechanisms under which plasticity can influence progress toward adaptive genetic diversification and ecological speciation. We use a stochastic, individual-based model of a predator-prey system incorporating sexual reproduction and mate choice in the predator. Our results show that evolving plasticity promotes the evolution of reproductive isolation under diversifying environments when individuals are able to correctly select a more profitable habitat with respect to their phenotypes (i.e., adaptive habitat choice) and to assortatively mate with relatively similar phenotypes. On the other hand, plasticity facilitates the evolution of plastic generalists when individuals have a limited capacity for adaptive habitat choice. We conclude that plasticity can accelerate the evolution of a reproductive barrier toward adaptive diversification and ecological speciation through enhanced phenotypic differentiation between diverging phenotypes.

  5. Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization

    PubMed Central

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

    2013-01-01

    Implantable microdevices are gaining significant attention for several biomedical applications1-4. Such devices have been made from a range of materials, each offering its own advantages and shortcomings5,6. 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 strain7-9. 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 properties10-14. 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 vivo15, 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 control13,16,17. To this end, a custom microtensile tester was designed to accommodate microscale samples13,17 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 cooling17. 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

  6. 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.

  7. 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

  8. 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.

  9. Adapt, Recycle, and Move on: Proteostasis and Trafficking Mechanisms in Melanoma

    PubMed Central

    Demirsoy, Seyma; Martin, Shaun; Maes, Hannelore; Agostinis, Patrizia

    2016-01-01

    Melanoma has emerged as a paradigm of a highly aggressive and plastic cancer, capable to co-opt the tumor stroma in order to adapt to the hostile microenvironment, suppress immunosurveillance mechanisms, and disseminate. In particular, oncogene- and aneuploidy-driven dysregulations of proteostasis in melanoma cells impose a rewiring of central proteostatic processes, such as the heat shock and unfolded protein responses, autophagy, and the endo-lysosomal system, to avoid proteotoxicity. Research over the past decade has indicated that alterations in key nodes of these proteostasis pathways act in conjunction with crucial oncogenic drivers to increase intrinsic adaptations of melanoma cells against proteotoxic stress, modulate the high metabolic demand of these cancer cells and the interface with other stromal cells, through the heightened release of soluble factors or exosomes. Here, we overview and discuss how key proteostasis pathways and vesicular trafficking mechanisms are turned into vital conduits of melanoma progression, by supporting cancer cell’s adaptation to the microenvironment, limiting or modulating the ability to respond to therapy and fueling melanoma dissemination. PMID:27896217

  10. 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

    2014-08-28

    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.

  11. Adapt, Recycle, and Move on: Proteostasis and Trafficking Mechanisms in Melanoma.

    PubMed

    Demirsoy, Seyma; Martin, Shaun; Maes, Hannelore; Agostinis, Patrizia

    2016-01-01

    Melanoma has emerged as a paradigm of a highly aggressive and plastic cancer, capable to co-opt the tumor stroma in order to adapt to the hostile microenvironment, suppress immunosurveillance mechanisms, and disseminate. In particular, oncogene- and aneuploidy-driven dysregulations of proteostasis in melanoma cells impose a rewiring of central proteostatic processes, such as the heat shock and unfolded protein responses, autophagy, and the endo-lysosomal system, to avoid proteotoxicity. Research over the past decade has indicated that alterations in key nodes of these proteostasis pathways act in conjunction with crucial oncogenic drivers to increase intrinsic adaptations of melanoma cells against proteotoxic stress, modulate the high metabolic demand of these cancer cells and the interface with other stromal cells, through the heightened release of soluble factors or exosomes. Here, we overview and discuss how key proteostasis pathways and vesicular trafficking mechanisms are turned into vital conduits of melanoma progression, by supporting cancer cell's adaptation to the microenvironment, limiting or modulating the ability to respond to therapy and fueling melanoma dissemination.

  12. 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

  13. 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

  14. Coding and adaptation during mechanical stimulation in the leech nervous system.

    PubMed

    Pinato, G; Torre, V

    2000-12-15

    The experiments described here were designed to characterise sensory coding and adaptation during mechanical stimulation in the leech (Hirudo medicinalis). A chain of three ganglia and a segment of the body wall connected to the central ganglion were used. Eight extracellular suction pipettes and one or two intracellular electrodes were used to record action potentials from all mechanosensory neurones of the three ganglia. When the skin of the body wall was briefly touched with a filament exerting a force of about 2 mN, touch (T) cells in the central ganglion, but also those in adjacent ganglia (i.e. anterior and posterior), fired one or two action potentials. However, the threshold for action potential initiation was lower for T cells in the central ganglion than for those in adjacent ganglia. The timing of the first evoked action potential in a T cell was very reproducible with a jitter often lower than 100 us. Action potentials in T cells were not significantly correlated. When the force exerted by the filament was increased above 20 mN, pressure (P) cells in the central and neighbouring ganglia fired action potentials. Action potentials in P cells usually followed those evoked in T cells with a delay of about 20 ms and had a larger jitter of 0.5-10 ms. With stronger stimulations exceeding 50 mN, noxious (N) cells also fired action potentials. With such stimulations the majority of mechanosensory neurones in the three ganglia fired action potentials. The spatial properties of the whole receptive field of the mechanosensory neurones were explored by touching different parts of the skin. When the mechanical stimulation was applied for a longer time, i.e. 1 s, only P cells in the central ganglion continued to fire action potentials. P cells in neighbouring ganglia fully adapted after firing two or three action potentials.P cells in adjacent ganglia, having fully adapted to a steady mechanical stimulation of one part of the skin, fired action potentials following

  15. Network Bursting Dynamics in Excitatory Cortical Neuron Cultures Results from the Combination of Different Adaptive Mechanism

    PubMed Central

    Masquelier, Timothée; Deco, Gustavo

    2013-01-01

    In the brain, synchronization among cells of an assembly is a common phenomenon, and thought to be functionally relevant. Here we used an in vitro experimental model of cell assemblies, cortical cultures, combined with numerical simulations of a spiking neural network (SNN) to investigate how and why spontaneous synchronization occurs. In order to deal with excitation only, we pharmacologically blocked GABAAergic transmission using bicuculline. Synchronous events in cortical cultures tend to involve almost every cell and to display relatively constant durations. We have thus named these “network spikes” (NS). The inter-NS-intervals (INSIs) proved to be a more interesting phenomenon. In most cortical cultures NSs typically come in series or bursts (“bursts of NSs”, BNS), with short (∼1 s) INSIs and separated by long silent intervals (tens of s), which leads to bimodal INSI distributions. This suggests that a facilitating mechanism is at work, presumably short-term synaptic facilitation, as well as two fatigue mechanisms: one with a short timescale, presumably short-term synaptic depression, and another one with a longer timescale, presumably cellular adaptation. We thus incorporated these three mechanisms into the SNN, which, indeed, produced realistic BNSs. Next, we systematically varied the recurrent excitation for various adaptation timescales. Strong excitability led to frequent, quasi-periodic BNSs (CV∼0), and weak excitability led to rare BNSs, approaching a Poisson process (CV∼1). Experimental cultures appear to operate within an intermediate weakly-synchronized regime (CV∼0.5), with an adaptation timescale in the 2–8 s range, and well described by a Poisson-with-refractory-period model. Taken together, our results demonstrate that the INSI statistics are indeed informative: they allowed us to infer the mechanisms at work, and many parameters that we cannot access experimentally. PMID:24146781

  16. 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.

  17. 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

  18. 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.

  19. Network bursting dynamics in excitatory cortical neuron cultures results from the combination of different adaptive mechanisms.

    PubMed

    Masquelier, Timothée; Deco, Gustavo

    2013-01-01

    In the brain, synchronization among cells of an assembly is a common phenomenon, and thought to be functionally relevant. Here we used an in vitro experimental model of cell assemblies, cortical cultures, combined with numerical simulations of a spiking neural network (SNN) to investigate how and why spontaneous synchronization occurs. In order to deal with excitation only, we pharmacologically blocked GABAAergic transmission using bicuculline. Synchronous events in cortical cultures tend to involve almost every cell and to display relatively constant durations. We have thus named these "network spikes" (NS). The inter-NS-intervals (INSIs) proved to be a more interesting phenomenon. In most cortical cultures NSs typically come in series or bursts ("bursts of NSs", BNS), with short (~1 s) INSIs and separated by long silent intervals (tens of s), which leads to bimodal INSI distributions. This suggests that a facilitating mechanism is at work, presumably short-term synaptic facilitation, as well as two fatigue mechanisms: one with a short timescale, presumably short-term synaptic depression, and another one with a longer timescale, presumably cellular adaptation. We thus incorporated these three mechanisms into the SNN, which, indeed, produced realistic BNSs. Next, we systematically varied the recurrent excitation for various adaptation timescales. Strong excitability led to frequent, quasi-periodic BNSs (CV~0), and weak excitability led to rare BNSs, approaching a Poisson process (CV~1). Experimental cultures appear to operate within an intermediate weakly-synchronized regime (CV~0.5), with an adaptation timescale in the 2-8 s range, and well described by a Poisson-with-refractory-period model. Taken together, our results demonstrate that the INSI statistics are indeed informative: they allowed us to infer the mechanisms at work, and many parameters that we cannot access experimentally.

  20. Mechanisms of adaptation in a predator-prey arms race: TTX-resistant sodium channels.

    PubMed

    Geffeney, Shana; Brodie, Edmund D; Ruben, Peter C; Brodie, Edmund D

    2002-08-23

    Populations of the garter snake Thamnophis sirtalis have evolved geographically variable resistance to tetrodotoxin (TTX) in a coevolutionary arms race with their toxic prey, newts of the genus Taricha. Here, we identify a physiological mechanism, the expression of TTX-resistant sodium channels in skeletal muscle, responsible for adaptive diversification in whole-animal resistance. Both individual and population differences in the ability of skeletal muscle fibers to function in the presence of TTX correlate closely with whole-animal measures of TTX resistance. Demonstration of individual variation in an essential physiological function responsible for the adaptive differences among populations is a step toward linking the selective consequences of coevolutionary interactions to geographic and phylogenetic patterns of diversity.

  1. 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.

  2. 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.

  3. Feed-forward mechanisms: addiction-like behavioral and molecular adaptations in overeating.

    PubMed

    Alsiö, Johan; Olszewski, Pawel K; Levine, Allen S; Schiöth, Helgi B

    2012-04-01

    Food reward, not hunger, is the main driving force behind eating in the modern obesogenic environment. Palatable foods, generally calorie-dense and rich in sugar/fat, are thus readily overconsumed despite the resulting health consequences. Important advances have been made to explain mechanisms underlying excessive consumption as an immediate response to presentation of rewarding tastants. However, our understanding of long-term neural adaptations to food reward that oftentimes persist during even a prolonged absence of palatable food and contribute to the reinstatement of compulsive overeating of high-fat high-sugar diets, is much more limited. Here we discuss the evidence from animal and human studies for neural and molecular adaptations in both homeostatic and non-homeostatic appetite regulation that may underlie the formation of a "feed-forward" system, sensitive to palatable food and propelling the individual from a basic preference for palatable diets to food craving and compulsive, addiction-like eating behavior.

  4. The Role of Training in the Development of Adaptive Mechanisms in Freedivers

    PubMed Central

    Ostrowski, Andrzej; Strzała, Marek; Stanula, Arkadiusz; Juszkiewicz, Mirosław; Pilch, Wanda; Maszczyk, Adam

    2012-01-01

    Freediving is a sport in which athletes aim to achieve the longest or the deepest breath-hold dive. Divers are at risk of gradually increasing hypoxia and hypercapnia due to a long time spent underwater and additionally of increasing hyperoxia while depth diving. Exceeding the limits of hypoxia endurance leads to loss of consciousness or even to death whithout immediate first aid. Often enhanced world records indicate the ability to shape specific to the discipline adaptive mechanisms of cardio-pulmonary system which are individually conditioned. During stay underwater heartbeats decelerating called bradycardia, increase in blood pressure, peripheral blood vessels narrowing and blood centralization in freediver’s organism. These mechanisms enhance blood oxygen management as well as transporting it first of all to essential for survival organs, i.e. brain and heart. These mechanisms are supported by spleen and adrenal glands hormonal reactions. PMID:23487544

  5. 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

  6. 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)

  7. 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)

  8. Coping with Transitions.

    ERIC Educational Resources Information Center

    Bendersky, Nora; And Others

    1984-01-01

    Describes a workshop for nine South American students at the Hebrew University of Jerusalem. The two-day session focussed on exploring coping behaviors that could help students adjust to transitions. (JAC)

  9. 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

  10. 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

  11. The complex distribution of arterial system mechanical properties, pulsatile hemodynamics, and vascular stresses emerges from three simple adaptive rules.

    PubMed

    Nguyen, Phuc H; Coquis-Knezek, Sarah F; Mohiuddin, Mohammad W; Tuzun, Egemen; Quick, Christopher M

    2015-03-01

    Arterial mechanical properties, pulsatile hemodynamic variables, and mechanical vascular stresses vary significantly throughout the systemic arterial system. Although the fundamental principles governing pulsatile hemodynamics in elastic arteries are widely accepted, a set of rules governing stress-induced adaptation of mechanical properties can only be indirectly inferred from experimental studies. Previously reported mathematical models have assumed mechanical properties adapt to achieve an assumed target stress "set point." Simultaneous prediction of the mechanical properties, hemodynamics, and stresses, however, requires that equilibrium stresses are not assumed a priori. Therefore, the purpose of this work was to use a "balance point" approach to identify the simplest set of universal adaptation rules that simultaneously predict observed mechanical properties, hemodynamics, and stresses throughout the human systemic arterial system. First, we employed a classical systemic arterial system model with 121 arterial segments and removed all parameter values except vessel lengths and peripheral resistances. We then assumed vessel radii increase with endothelial shear stress, wall thicknesses increase with circumferential wall stress, and material stiffnesses decrease with circumferential wall stress. Parameters characterizing adaptive responses were assumed to be identical in all arterial segments. Iteratively predicting local mechanical properties, hemodynamics, and stresses reproduced five trends observed when traversing away from the aortic root towards the periphery: decrease in lumen radii, wall thicknesses, and pulsatile flows and increase in wall stiffnesses and pulsatile pressures. The extraordinary complexity of the systemic arterial system can thus arise from independent adaptation of vessels to local stresses characterized by three simple adaptive rules.

  12. 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

  13. MOLECULAR MECHANISMS FOR ADAPTIVE TOLERANCE AND OTHER T CELL ANERGY MODELS

    PubMed Central

    Choi, Seeyoung; Schwartz, Ronald H.

    2007-01-01

    Since the original description of T cell anergy in CD4 clones from mice and humans, a number of different unresponsive states have been described, both in vivo and in vitro, that have been called anergic. While initial attempts were made to understand the similarities between the different models, it has now become clear from biochemical experiments that many of them have different molecular mechanisms underlying their unresponsiveness. In this review we will detail our own work on the in vivo model referred to as adaptive tolerance and then attempt to compare this biochemical state to the multitude of other states that have been described in the literature. PMID:17400472

  14. Photorespiration and carbon concentrating mechanisms: two adaptations to high O2, low CO2 conditions.

    PubMed

    Moroney, James V; Jungnick, Nadine; Dimario, Robert J; Longstreth, David J

    2013-11-01

    This review presents an overview of the two ways that cyanobacteria, algae, and plants have adapted to high O2 and low CO2 concentrations in the environment. First, the process of photorespiration enables photosynthetic organisms to recycle phosphoglycolate formed by the oxygenase reaction catalyzed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Second, there are a number of carbon concentrating mechanisms that increase the CO2 concentration around Rubisco which increases the carboxylase reaction enhancing CO2 fixation. This review also presents possibilities for the beneficial modification of these processes with the goal of improving future crop yields.

  15. 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.

  16. 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

  17. Pooled ecotype sequencing reveals candidate genetic mechanisms for adaptive differentiation and reproductive isolation.

    PubMed

    Gould, Billie A; Chen, Yani; Lowry, David B

    2017-01-01

    The early stages of speciation are often characterized by the formation of partially reproductively isolated ecotypes, which evolve as a by-product of divergent selective forces that are endemic to different habitats. Identifying the genomic regions, genes and ultimately functional polymorphisms that are involved in the processes of ecotype formation is inherently challenging, as there are likely to be many different loci involved in the process. To localize candidate regions of the genome contributing to ecotype formation, we conducted whole-genome pooled sequencing (pool-seq) with 47 coastal perennial and 50 inland annual populations of the yellow monkeyflower, Mimulus guttatus. Coastal perennial and inland annual ecotypes of M. guttatus have previously been shown to be ecologically reproductively isolated and highly locally adapted to their respective habitats. Our pool-seq results found allelic differentiation between the ecotypes for two chromosomal inversions, suggesting that frequencies of inversion heterokaryotypes are strongly differentiated between the ecotypes. Further, there were elevated levels of nonsynonymous change across chromosomal inversions. Across the genome, we identified multiple strong candidate genes potentially driving the morphological, life history and salt tolerance differences between the ecotypes. Several candidate genes coincide with previously identified quantitative trait locus regions and also show a signature of recent natural selection. Overall, the results of our study add to growing support for a major role of chromosomal inversions in adaptation and speciation and provide new insights into the genetic mechanisms underlying classic plant ecotype adaptations to wet and dry habitats.

  18. Shading and texture: separate information channels with a common adaptation mechanism?

    PubMed

    Georgeson, Mark A; Schofield, Andrew J

    2002-01-01

    We outline a scheme for the way in which early vision may handle information about shading (luminance modulation, LM) and texture (contrast modulation, CM). Previous work on the detection of gratings has found no sub-threshold summation, and no cross-adaptation, between LM and CM patterns. This strongly implied separate channels for the detection of LM and CM structure. However, we now report experiments in which adapting to LM (or CM) gratings creates tilt aftereffects of similar magnitude on both LM and CM test gratings, and reduces the perceived strength (modulation depth) of LM and CM gratings to a similar extent. This transfer of aftereffects between LM and CM might suggest a second stage of processing at which LM and CM information is integrated. The nature of this integration, however, is unclear and several simple predictions are not fulfilled. Firstly, one might expect the integration stage to lose identity information about whether the pattern was LM or CM. We show instead that the identity of barely detectable LM and CM patterns is not lost. Secondly, when LM and CM gratings are combined in-phase or out-of-phase we find no evidence for cancellation, nor for 'phase-blindness'. These results suggest that information about LM and CM is not pooled or merged--shading is not confused with texture variation. We suggest that LM and CM signals are carried by separate channels, but they share a common adaptation mechanism that accounts for the almost complete transfer of perceptual aftereffects.

  19. Immunological mechanisms of adaptation to the low-weight chemical compounds in ontogenesis.

    PubMed

    Glushkov, A N

    2003-09-01

    It is postulated that adaptation to the low-weight chemical compounds includes six consistent ontogenetic periods: the reciprocal selection of the marriage partners; the maturation of the gametes; the formation of the zygote; the development of the fetus; the birth and nursing of the child; and the sexual maturation of a human being. The main immunological parts of adaptation are: the antibodies to the low-weight xeno- and endobiotics; the reciprocal immune-like recognition of the maternal and paternal gametes; and the maternal immune reaction on the paternal histocompatibility antigens of the fetus. The main immunological mechanisms of adaptation are: the promotion of the selectivity in the smell recognition of the marriage partners by the antibodies to the xeno- and endobiotics expanding the individual spectrum of their metabolites; the inhibition of the xenobiotic genotoxic action on the gametes, fetus and child by the antibodies; the prevention of the development of gene-damaged gametes and fetus by antibodies to the sexual hormones; and the immune preservation (elimination) of the heterozygote (homozygote) fetus.

  20. An Exploration of Stressful Life Events, Illness, and Coping among the Rural Elderly.

    ERIC Educational Resources Information Center

    Preston, Deborah Bray; Mansfield, Phyllis Kernoff

    1984-01-01

    Explores the relationship between stressful life events, coping mechanisms, and illness in 200 rural elderly. Cluster analysis produced four groups with different degress of stress, health, and coping patterns. Groups with the highest stress experienced the poorest health. (JAC)

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

    PubMed Central

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

    2011-01-01

    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

  2. Temperature dependence of rapidly adapting mechanically activated currents in rat dorsal root ganglion neurons.

    PubMed

    Jia, Zhanfeng; Ling, Jennifer; Gu, Jianguo G

    2012-08-01

    Rapidly adapting mechanically activated channels (RA) are expressed on somatosensory neurons and thought to play a role in mechanical transduction. Because mechanical sensations can be significantly affected by temperatures, we examined thermal sensitivity of RA currents in cultured dorsal root ganglion (DRG) neurons to see if RA channel activity is highly temperature-dependent. RA currents were evoked from DRG neurons by membrane displacements and recorded by the whole-cell patch-clamp recording technique. We found that RA currents were significantly enhanced by warming temperatures from 22 to 32 °C and reduced by cooling temperatures from 24 to 14 °C. RA channel activation exhibited steep temperature-dependence with a large temperature coefficient (Q10>5) and a high activation energy (Ea>30 kcal/mol). We further showed that RA channel activation by mechanical stimulation led to membrane depolarization, which could result in action potential firing at 22 °C or 32 °C but not at 14 °C. Taken together, our results provide the measurements of thermal dynamics and activation energy of RA channels, and suggest that a high energy barrier is present for RA channels to open. These findings are in agreement with temperature sensitivity of mechanical sensations in mammals.

  3. 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

  4. 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.

  5. 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.…

  6. 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

  7. [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.

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

    PubMed Central

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

    2012-01-01

    The hypothesis is that 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 minutes 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 the nanocomposite. The glial scar response to the compliant nanocomposite was less vigorous than 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

  9. A Mobility-Aware Adaptive Duty Cycling Mechanism for Tracking Objects during Tunnel Excavation

    PubMed Central

    Kim, Taesik; Min, Hong; Jung, Jinman

    2017-01-01

    Tunnel construction workers face many dangers while working under dark conditions, with difficult access and egress, and many potential hazards. To enhance safety at tunnel construction sites, low latency tracking of mobile objects (e.g., heavy-duty equipment) and construction workers is critical for managing the dangerous construction environment. Wireless Sensor Networks (WSNs) are the basis for a widely used technology for monitoring the environment because of their energy-efficiency and scalability. However, their use involves an inherent point-to-point delay caused by duty cycling mechanisms that can result in a significant rise in the delivery latency for tracking mobile objects. To overcome this issue, we proposed a mobility-aware adaptive duty cycling mechanism for the WSNs based on object mobility. For the evaluation, we tested this mechanism for mobile object tracking at a tunnel excavation site. The evaluation results showed that the proposed mechanism could track mobile objects with low latency while they were moving, and could reduce energy consumption by increasing sleep time while the objects were immobile. PMID:28241473

  10. A Mobility-Aware Adaptive Duty Cycling Mechanism for Tracking Objects during Tunnel Excavation.

    PubMed

    Kim, Taesik; Min, Hong; Jung, Jinman

    2017-02-23

    Tunnel construction workers face many dangers while working under dark conditions, with difficult access and egress, and many potential hazards. To enhance safety at tunnel construction sites, low latency tracking of mobile objects (e.g., heavy-duty equipment) and construction workers is critical for managing the dangerous construction environment. Wireless Sensor Networks (WSNs) are the basis for a widely used technology for monitoring the environment because of their energy-efficiency and scalability. However, their use involves an inherent point-to-point delay caused by duty cycling mechanisms that can result in a significant rise in the delivery latency for tracking mobile objects. To overcome this issue, we proposed a mobility-aware adaptive duty cycling mechanism for the WSNs based on object mobility. For the evaluation, we tested this mechanism for mobile object tracking at a tunnel excavation site. The evaluation results showed that the proposed mechanism could track mobile objects with low latency while they were moving, and could reduce energy consumption by increasing sleep time while the objects were immobile.

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

    PubMed Central

    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.

    2015-01-01

    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

  12. 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

  13. 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.

  14. Self-adaptive image reconstruction inspired by insect compound eye mechanism.

    PubMed

    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.

  15. 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.

  16. 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.

  17. 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

  18. On rate-dependent mechanical model for adaptive magnetorheological elastomer base isolator

    NASA Astrophysics Data System (ADS)

    Li, Yancheng; Li, Jianchun

    2017-04-01

    This paper presents research on the phenomenological model of an adaptive base isolator. The adaptive base isolator is made of field-dependent magnetorheological elastomer (MRE) which can alter its physical property under application of magnetic field. Experimental testing demonstrated that the developed MRE base isolator possesses an amazing ability to vary its stiffness under applied magnetic field. However, several challenges have been encountered when it comes modeling such novel device. For example, under a large deformation, the MRE base isolator exhibits a clear strain stiffening effect and this behavior escalates with the increasing of applied current. In addition, the MRE base isolator has also shown typical rate-dependent behavior. Following a review on mechanical models for viscos-elastic rubber devices, a novel rate-dependent model is proposed in this paper to capture the behavior of the new MRE base isolator. To develop a generalized model, the proposed model was evaluated using its performance under random displacement input and a seismic input. It shows that the proposed rate-dependent model can successfully describe the complex behavior of the device.

  19. 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.

  20. 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.

  1. 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.

  2. An adaptive jitter mechanism for reactive route discovery in sensor networks.

    PubMed

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

    2014-08-08

    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.

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

    PubMed Central

    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

    2015-01-01

    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. PMID:26108467

  4. 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

  5. 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.

  6. Mechano-adaptive sensory mechanism of α-catenin under tension

    NASA Astrophysics Data System (ADS)

    Maki, Koichiro; Han, Sung-Woong; Hirano, Yoshinori; Yonemura, Shigenobu; Hakoshima, Toshio; Adachi, Taiji

    2016-04-01

    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.

  7. 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

  8. [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.

  9. 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.…

  10. 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

  11. 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…

  12. 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

  13. 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

  14. [Interrupted alcohol treatment and liver: free radical homeostasis, nitric oxide, adaptive mechanisms].

    PubMed

    Miskevich, D A; Borodinskiĭ, A N; Petushok, N E; Konovalenko, O V; Lelevich, V V

    2006-01-01

    Alcohol administration can result in liver damage. Reactive oxygen species (ROS), nitric oxide (NO) and their interaction are crucial factors in this process. The aim of work was to investigate, free radical state and mechanisms of adaptation of the antioxidant system (AOS) to stress, caused by interrupted alcohol intake. Repeated cycles of alcoholization caused an imbalance between production and utilization of various ROS. This imbalance was due to impairments in the system superoxide dismutase/catalase. Nevertheless, in most experimental groups there was clear reduction of lipid peroxidation (LPO) products evaluated by thiobarbituric acid reactive substances. This might be attributed to the antioxidant effect of NO. However, there was an increased level of transaminases in blood plasma. After 28 days of this experimental scheme all the parameters studied normalized.

  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. Coping with Aging and Amputation

    MedlinePlus

    ... Center > Coping With Aging and Amputation Coping With Aging and Amputation Web Development February 15, 2015 Senior ... Though we don’t have much control over aging, we do have some power over the way ...

  17. Coping with Fear of Recurrence

    MedlinePlus

    ... With Fear of Recurrence Request Permissions Coping With Fear of Recurrence Approved by the Cancer.Net Editorial ... affects your life. Tips for coping with the fear of recurrence Living with uncertainty is never easy. ...

  18. Coping with Traumatic Stress Reactions

    MedlinePlus

    ... Estrés Traumático | Ver todos When trauma survivors take direct action to cope with their stress reactions, they ... impact of trauma on your life and taking direct action to improve things. Active coping occurs even ...

  19. 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…

  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 Central

    Kennington, W. J.; Tomkins, J. L.; Berry, O.; Whiting, S.; Meekan, M. G.; Mitchell, N. J.

    2016-01-01

    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. Immune evasion by cytomegalovirus--survival strategies of a highly adapted opportunist.

    PubMed

    Hengel, H; Brune, W; Koszinowski, U H

    1998-05-01

    Slowly replicating, species-specific and complex DNA viruses, such as cytomegaloviruses (CMVs), which code for > 200 antigenic proteins, should be easy prey to the host's immune system. Yet, CMVs are amazingly adapted opportunists that cope with multiple immune responses. Frequently, CMVs exploit immune mechanisms generated by the host. These strategies secure the persistence of CMVs and provide opportunities to spread to naive individuals.

  3. The Mechanism of Adaptation of Breast Cancer Cells to Hypoxia: Role of AMPK/mTOR Signaling Pathway.

    PubMed

    Sorokin, D V; Scherbakov, A M; Yakushina, I A; Semina, S E; Gudkova, M V; Krasil'nikov, M A

    2016-02-01

    We studied the mechanisms of adaptation of human breast cancer cells MCF-7 to hypoxia and analyzed the role of AMPK/mTOR signaling pathway in the maintenance of cell proliferation under hypoxic conditions. It was found that long-term culturing (30 days or more) of MCF-7 cells under hypoxic conditions induced their partial adaptation to hypoxia. Cell adaptation to hypoxia was associated with attenuation of hypoxia-dependent AMPK induction with simultaneous constitutive activation of mTOR and Akt. These findings suggest that these proteins can be promising targets for targeted therapy of tumors developing under hypoxic conditions.

  4. Coping with jealousy: the association between maladaptive aspects of jealousy and drinking problems is mediated by drinking to cope.

    PubMed

    Dibello, Angelo M; Neighbors, Clayton; Rodriguez, Lindsey M; Lindgren, Kristen

    2014-01-01

    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 was 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.

  5. Adaptive Redox Response of Mesenchymal Stromal Cells to Stimulation with Lipopolysaccharide Inflammagen: Mechanisms of Remodeling of Tissue Barriers in Sepsis

    DTIC Science & Technology

    2013-03-08

    Mechanisms of Remodeling of Tissue Barriers in Sepsis Nikolai V. Gorbunov1*, Bradley R. Garrison1, Dennis P. McDaniel2, Min Zhai1, Pei-Jyun Liao1... sepsis [2, 5]. This problem leads to the searching for other potential mechanisms that could produce adverse effects on host metabolome resulting...understanding of the basic cellular mechanisms implicated in redox adaptive responses in 16 tissue barriers. This particular area of the molecular

  6. Coping Style and Quality of Life in Elderly Patients with Vision Disturbances

    PubMed Central

    Oles, Maria

    2014-01-01

    Purpose. This study aims at evaluating coping style and quality of life in patients with glaucoma and cataract. Methods. The participants were patients (N = 237, 130F; mean age: M = 67,8; SD = 9,5) with low vision caused by cataract (N = 188) and glaucoma (N = 49) who answered the Quality of Life Questionnaire (QOLQ) by Schalock and Keith. The participants were divided by means of cluster analysis (k-means) according to coping styles measured by CISS (Endler and Parker) into three groups: (1) high mobilization for coping, (2) task-oriented coping, and (3) low mobilization for coping. Results. In all the group, a general quality of life was moderately lowered; however, in task-oriented group it was relatively high. Moreover, task-oriented group had significantly lower level of anxiety (STAI), hopelessness (HS), and loneliness (UCLA LS-R) and higher level of self-esteem (SES) in comparison to the patients from high mobilization and low mobilization for coping. Conclusions. In an old age, adaptive coping with vision disturbances does not necessarily mean flexibility in combining all coping styles, but rather task-oriented coping and an ability to use social support. Extreme mobilization for coping seems not adaptive similarly like low mobilization for coping because it violates balance between environmental requirements and personal resources. PMID:25215225

  7. 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…

  8. 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…

  9. 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

  10. A model of stereocilia adaptation based on single molecule mechanical studies of myosin I.

    PubMed Central

    Batters, Christopher; Wallace, Mark I; Coluccio, Lynne M; Molloy, Justin E

    2004-01-01

    We have used an optical tweezers-based apparatus to perform single molecule mechanical experiments using the unconventional myosins, Myo1b and Myo1c. The single-headed nature and slow ATPase kinetics of these myosins make them ideal for detailed studies of the molecular mechanism of force generation by acto-myosin. Myo1c exhibits several features that have not been seen using fast skeletal muscle myosin II. (i) The working stroke occurs in two, distinct phases, producing an initial 3 nm and then a further 1.5 nm of movement. (ii) Two types of binding interaction were observed: short-lived ATP-independent binding events that produced no movement and longer-lived, ATP-dependent events that produced a full working stroke. The stiffness of both types of interaction was similar. (iii) In a new type of experiment, using feedback to apply controlled displacements to a single acto-myosin cross-bridge, we found abrupt changes in force during attachment of the acto-Myo1b cross-bridge, a result that is consistent with the classical 'T2' behaviour of single muscle fibres. Given that these myosins might exhibit the classical T2 behaviour, we propose a new model to explain the slow phase of sensory adaptation of the hair cells of the inner ear. PMID:15647165

  11. A review of visual perception mechanisms that regulate rapid adaptive camouflage in cuttlefish.

    PubMed

    Chiao, Chuan-Chin; Chubb, Charles; Hanlon, Roger T

    2015-09-01

    We review recent research on the visual mechanisms of rapid adaptive camouflage in cuttlefish. These neurophysiologically complex marine invertebrates can camouflage themselves against almost any background, yet their ability to quickly (0.5-2 s) alter their body patterns on different visual backgrounds poses a vexing challenge: how to pick the correct body pattern amongst their repertoire. The ability of cuttlefish to change appropriately requires a visual system that can rapidly assess complex visual scenes and produce the motor responses-the neurally controlled body patterns-that achieve camouflage. Using specifically designed visual backgrounds and assessing the corresponding body patterns quantitatively, we and others have uncovered several aspects of scene variation that are important in regulating cuttlefish patterning responses. These include spatial scale of background pattern, background intensity, background contrast, object edge properties, object contrast polarity, object depth, and the presence of 3D objects. Moreover, arm postures and skin papillae are also regulated visually for additional aspects of concealment. By integrating these visual cues, cuttlefish are able to rapidly select appropriate body patterns for concealment throughout diverse natural environments. This sensorimotor approach of studying cuttlefish camouflage thus provides unique insights into the mechanisms of visual perception in an invertebrate image-forming eye.

  12. 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.

  13. 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.

  14. Do common mechanisms of adaptation mediate color discrimination and appearance? Uniform backgrounds

    NASA Astrophysics Data System (ADS)

    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.

  15. 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.

  16. 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

  17. Connexin 43 hemichannel opening associated with Prostaglandin E(2) release is adaptively regulated by mechanical stimulation.

    PubMed

    Burra, Sirisha; Jiang, Jean X

    2009-05-01

    Osteocytes present in the bone are known to be the major mechanosensory cells. Their involvement in mechanoregulation of bone remodeling is not yet clear. Osteocytes are connected with each other through gap junctions formed by Connexin 43 (Cx43). Apart from forming gap junctions, Cx43 in osteocytes is also present in the form of hemichannels. Recently, we have developed a unique antibody that specifically blocks hemichannels and does not have any effect on gap junctions. Cx43 hemichannels present in osteocytes of the bone are mechanosensory in nature as they open when subjected to mechanical stimulation in the form of fluid flow shear stress (FFSS). Opening of Cx43 hemichannels results in the release of molecules like Prostaglandin E(2) (PGE(2)) that are involved in bone remodeling. Our recent report shows that the opening of Cx43 hemichannels depends on the magnitude and duration of shear stress. When osteocytes are subjected to FFSS followed by a brief rest and reapplication of FFSS, it led to further increase in opening of Cx43 hemichannels. Application of continuous FFSS for longer periods of time (24 hrs) results in decreased opening of hemichannels. These results show that Cx43 hemichannels are adaptive in response to mechanical stimulation, possibly to regulate the release PGE(2) during bone remodeling.

  18. 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)…

  19. The adapted augmented Lagrangian method: a new method for the resolution of the mechanical frictional contact problem

    NASA Astrophysics Data System (ADS)

    Bussetta, Philippe; Marceau, Daniel; Ponthot, Jean-Philippe

    2012-02-01

    The aim of this work is to propose a new numerical method for solving the mechanical frictional contact problem in the general case of multi-bodies in a three dimensional space. This method is called adapted augmented Lagrangian method (AALM) and can be used in a multi-physical context (like thermo-electro-mechanical fields problems). This paper presents this new method and its advantages over other classical methods such as penalty method (PM), adapted penalty method (APM) and, augmented Lagrangian method (ALM). In addition, the efficiency and the reliability of the AALM are proved with some academic problems and an industrial thermo-electromechanical problem.

  20. Adult Coping with Childhood Sexual Abuse: A Theoretical and Empirical Review

    PubMed Central

    Walsh, Kate; Fortier, Michelle A.; DiLillo, David

    2009-01-01

    Coping has been suggested as an important element in understanding the long-term functioning of individuals with a history of child sexual abuse (CSA). The present review synthesizes the literature on coping with CSA, first by examining theories of coping with trauma, and, second by examining how these theories have been applied to studies of coping in samples of CSA victims. Thirty-nine studies were reviewed, including eleven descriptive studies of the coping strategies employed by individuals with a history of CSA, eighteen correlational studies of the relationship between coping strategies and long-term functioning of CSA victims, and ten investigations in which coping was examined as a mediational factor in relation to long-term outcomes. These studies provide initial information regarding early sexual abuse and subsequent coping processes. However, this literature is limited by several theoretical and methodological issues, including a failure to specify the process of coping as it occurs, a disparity between theory and research, and limited applicability to clinical practice. Future directions of research are discussed and include the need to understand coping as a process, identification of coping in relation to adaptive outcomes, and considerations of more complex mediational and moderational processes in the study of coping with CSA. PMID:20161502

  1. 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

  2. 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

  3. Conforming and nonconforming personality and stress coping styles in combat athletes

    PubMed Central

    Sawicki, Bogusław; Mazurek-Kusiak, Anna; Hawlena, Joanna

    2016-01-01

    Abstract The main objective of this study was to investigate whether the personality dimension of conformism/nonconformism was a predictor of stress coping styles in athletes training combat sports, and to present the characteristics of this personality dimension in the context of the competitors’ adaptive/innovative sport performance. Scores of 346 males practising combat sports such as kick boxing, MMA, thai boxing, boxing and wrestling were analyzed. The participants completed the Creative Behaviour Questionnaire (KANH III) measuring the conformity/nonconformity personality dimension and the Coping Inventory for Stressful Situations (CISS) measuring stress coping styles. The comparative analyses were conducted only for the groups of conformists and nonconformists. Differences in stress coping styles between conformists and nonconformists training combat sports were found as nonconformists tended to prefer the task-oriented coping style. Conclusively, a higher rate of nonconformity was associated with increasingly frequent occurrence of task-oriented coping and decreasingly frequent emotion-oriented coping. PMID:28149386

  4. Conforming and nonconforming personality and stress coping styles in combat athletes.

    PubMed

    Bernacka, Ryszarda Ewa; Sawicki, Bogusław; Mazurek-Kusiak, Anna; Hawlena, Joanna

    2016-06-01

    The main objective of this study was to investigate whether the personality dimension of conformism/nonconformism was a predictor of stress coping styles in athletes training combat sports, and to present the characteristics of this personality dimension in the context of the competitors' adaptive/innovative sport performance. Scores of 346 males practising combat sports such as kick boxing, MMA, thai boxing, boxing and wrestling were analyzed. The participants completed the Creative Behaviour Questionnaire (KANH III) measuring the conformity/nonconformity personality dimension and the Coping Inventory for Stressful Situations (CISS) measuring stress coping styles. The comparative analyses were conducted only for the groups of conformists and nonconformists. Differences in stress coping styles between conformists and nonconformists training combat sports were found as nonconformists tended to prefer the task-oriented coping style. Conclusively, a higher rate of nonconformity was associated with increasingly frequent occurrence of task-oriented coping and decreasingly frequent emotion-oriented coping.

  5. Impact of age, and cognitive and coping resources on coping.

    PubMed

    Trouillet, Raphaël; Doan-Van-Hay, Loane-Martine; Launay, Michel; Martin, Sophie

    2011-12-01

    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 using French versions of the Perceived Stress Scale, General Self-Efficacy Scale, and Way of Coping Checklist. Cognitive assessments comprised the WAIS III digit-span subtest and the Trail Making Test parts A and B. In multivariate analyses, neither working-memory nor mental-flexibility deficit predicted problem-focused coping. Age was found to predict only problem-focused coping. Self-efficacy predicted problem-focused coping, and perceived stress predicted emotion-focused coping. Our results confirmed that use of an emotion-focused coping style would not significantly change with age. Problem-focused coping increases with age and depends primarily on participants' confidence in their ability to successfully solve problems (i.e., self-efficacy).

  6. Time scale matters: genetic analysis does not support adaptation-by-time as the mechanism for adaptive seasonal declines in kokanee reproductive life span

    PubMed Central

    Morbey, Yolanda E; Jensen, Evelyn L; Russello, Michael A

    2014-01-01

    Seasonal declines of fitness-related traits are often attributed to environmental effects or individual-level decisions about reproductive timing and effort, but genetic variation may also play a role. In populations of Pacific salmon (Oncorhynchus spp.), seasonal declines in reproductive life span have been attributed to adaptation-by-time, in which divergent selection for different traits occurs among reproductively isolated temporal components of a population. We evaluated this hypothesis in kokanee (freshwater obligate Oncorhynchus nerka) by testing for temporal genetic structure in neutral and circadian-linked loci. We detected no genetic differences in presumably neutral loci among kokanee with different arrival and maturation dates within a spawning season. Similarly, we detected no temporal genetic structure in OtsClock1b, Omy1009uw, or OmyFbxw11, candidate loci associated with circadian function. The genetic evidence from this study and others indicates a lack of support for adaptation-by-time as an important evolutionary mechanism underlying seasonal declines in reproductive life span and a need for greater consideration of other mechanisms such as time-dependent, adaptive adjustment of reproductive effort. PMID:25478160

  7. Proactive coping and gambling disorder among young men.

    PubMed

    Sleczka, Pawel; Braun, Barbara; Grüne, Bettina; Bühringer, Gerhard; Kraus, Ludwig

    2016-12-01

    Objectives Male sex, young age, and frequent gambling are considered as risk factors for gambling disorder (GD) and stress might be one of the triggers of gambling behavior among problem gamblers. Conversely, well-developed coping with stress might counteract gambling problems. The Proactive Coping Theory provides a promising approach for the further development of preventive and treatment measures. The objective of the study was to investigate different facets of proactive coping (PC) in young male gamblers. Methods Young men from Bavaria were recruited via the Munich citizens' registry (n = 2,588) and Facebook invitations (n = 105). In total, 173 out of 398 individuals were positively screened for frequent gambling and/or signs of related problems and completed the baseline questionnaire of the Munich Leisure-time Study. Factors investigated include gambling problems, PC, impulsiveness, social support, and psychological distress. Results Gambling problems were associated with lower levels of preventive coping as well as of adaptive reaction delay. The associations were also significant when controlled for impulsiveness and general psychological distress. Preventive coping moderated the association between social support and gambling problems. Discussion and conclusions Young men with gambling problems less frequently prevent the occurrence of stressors and more often react hasty when these occur. While the investigated group reported good social support, this factor was negatively associated with GD only among individuals with good preventive coping. Preventive coping poses a useful construct for selective prevention and treatment as it can be modified in professional interventions.

  8. Proactive coping and gambling disorder among young men

    PubMed Central

    Sleczka, Pawel; Braun, Barbara; Grüne, Bettina; Bühringer, Gerhard; Kraus, Ludwig

    2016-01-01

    Objectives Male sex, young age, and frequent gambling are considered as risk factors for gambling disorder (GD) and stress might be one of the triggers of gambling behavior among problem gamblers. Conversely, well-developed coping with stress might counteract gambling problems. The Proactive Coping Theory provides a promising approach for the further development of preventive and treatment measures. The objective of the study was to investigate different facets of proactive coping (PC) in young male gamblers. Methods Young men from Bavaria were recruited via the Munich citizens’ registry (n = 2,588) and Facebook invitations (n = 105). In total, 173 out of 398 individuals were positively screened for frequent gambling and/or signs of related problems and completed the baseline questionnaire of the Munich Leisure-time Study. Factors investigated include gambling problems, PC, impulsiveness, social support, and psychological distress. Results Gambling problems were associated with lower levels of preventive coping as well as of adaptive reaction delay. The associations were also significant when controlled for impulsiveness and general psychological distress. Preventive coping moderated the association between social support and gambling problems. Discussion and conclusions Young men with gambling problems less frequently prevent the occurrence of stressors and more often react hasty when these occur. While the investigated group reported good social support, this factor was negatively associated with GD only among individuals with good preventive coping. Preventive coping poses a useful construct for selective prevention and treatment as it can be modified in professional interventions. PMID:27838919

  9. Saccade adaptation abnormalities implicate dysfunction of cerebellar-dependent learning mechanisms in Autism Spectrum Disorders (ASD).

    PubMed

    Mosconi, Matthew W; Luna, Beatriz; Kay-Stacey, Margaret; Nowinski, Caralynn V; Rubin, Leah H; Scudder, Charles; Minshew, Nancy; Sweeney, John A

    2013-01-01

    The cerebellar vermis (lobules VI-VII) has been implicated in both postmortem and neuroimaging studies of autism spectrum disorders (ASD). This region maintains the consistent accuracy of saccadic eye movements and plays an especially important role in correcting systematic errors in saccade amplitudes such as those induced by adaptation paradigms. Saccade adaptation paradigms have not yet been used to study ASD. Fifty-six individuals with ASD and 53 age-matched healthy controls performed an intrasaccadic target displacement task known to elicit saccadic adaptation reflected in an amplitude reduction. The rate of amplitude reduction and the variability of saccade amplitude across 180 adaptation trials were examined. Individuals with ASD adapted slower than healthy controls, and demonstrated more variability of their saccade amplitudes across trials prior to, during and after adaptation. Thirty percent of individuals with ASD did not significantly adapt, whereas only 6% of healthy controls failed to adapt. Adaptation rate and amplitude variability impairments were related to performance on a traditional neuropsychological test of manual motor control. The profile of impaired adaptation and reduced consistency of saccade accuracy indicates reduced neural plasticity within learning circuits of the oculomotor vermis that impedes the fine-tuning of motor behavior in ASD. These data provide functional evidence of abnormality in the cerebellar vermis that converges with previous reports of cellular and gross anatomic dysmorphology of this brain region in ASD.

  10. Role of extracellular matrix in adaptation of tendon and skeletal muscle to mechanical loading.

    PubMed

    Kjaer, Michael

    2004-04-01

    The extracellular matrix (ECM), and especially the connective tissue with its collagen, links tissues of the body together and plays an important role in the force transmission and tissue structure maintenance especially in tendons, ligaments, bone, and muscle. The ECM turnover is influenced by physical activity, and both collagen synthesis and degrading metalloprotease enzymes increase with mechanical loading. Both transcription and posttranslational modifications, as well as local and systemic release of growth factors, are enhanced following exercise. For tendons, metabolic activity, circulatory responses, and collagen turnover are demonstrated to be more pronounced in humans than hitherto thought. Conversely, inactivity markedly decreases collagen turnover in both tendon and muscle. Chronic loading in the form of physical training leads both to increased collagen turnover as well as, dependent on the type of collagen in question, some degree of net collagen synthesis. These changes will modify the mechanical properties and the viscoelastic characteristics of the tissue, decrease its stress, and likely make it more load resistant. Cross-linking in connective tissue involves an intimate, enzymatical interplay between collagen synthesis and ECM proteoglycan components during growth and maturation and influences the collagen-derived functional properties of the tissue. With aging, glycation contributes to additional cross-linking which modifies tissue stiffness. Physiological signaling pathways from mechanical loading to changes in ECM most likely involve feedback signaling that results in rapid alterations in the mechanical properties of the ECM. In developing skeletal muscle, an important interplay between muscle cells and the ECM is present, and some evidence from adult human muscle suggests common signaling pathways to stimulate contractile and ECM components. Unaccostumed overloading responses suggest an important role of ECM in the adaptation of myofibrillar

  11. 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.

  12. 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

  13. An alkaline active xylanase: insights into mechanisms of high pH catalytic adaptation.

    PubMed

    Mamo, Gashaw; Thunnissen, Marjolein; Hatti-Kaul, Rajni; Mattiasson, Bo

    2009-09-01

    The alkaliphilic bacterium, Bacillus halodurans S7, produces an alkaline active xylanase (EC 3.2.1.8), which differs from many other xylanases in being operationally stable under alkaline conditions as well as at elevated temperature. Compared to non-alkaline active xylanases, this enzyme has a high percent composition of acidic amino acids which results in high ratio of negatively to positively charged residues. A positive correlation was observed between the charge ratio and the pH optima of xylanases. The recombinant xylanase was crystallized using a hanging drop diffusion method. The crystals belong to the space group P2(1)2(1)2(1) and the structure was determined at a resolution of 2.1 A. The enzyme has the common eight-fold TIM-barrel structure of family 10 xylanases; however, unlike non-alkaline active xylanases, it has a highly negatively charged surface and a deeper active site cleft. Mutational analysis of non-conserved amino acids which are close to the acid/base residue has shown that Val169, Ile170 and Asp171 are important to hydrolyze xylan at high pH. Unlike the wild type xylanase which has optimum pH at 9-9.5, the triple mutant xylanase (V169A, I170F and D171N), which was constructed using sequence information of alkaline sensitive xylanses was optimally active around pH 7. Compared to non-alkaline active xylanases, the alkaline active xylanases have highly acidic surfaces and fewer solvent exposed alkali labile residues. Based on these results obtained from sequence, structural and mutational analysis, the possible mechanisms of high pH stability and catalysis are discussed. This will provide useful information to understand the mechanism of high pH adaptation and engineering of enzymes that can be operationally stable at high pH.

  14. Feedback of mechanical effectiveness induces adaptations in motor modules during cycling

    PubMed Central

    De Marchis, Cristiano; Schmid, Maurizio; Bibbo, Daniele; Castronovo, Anna Margherita; D'Alessio, Tommaso; Conforto, Silvia

    2013-01-01

    Recent studies have reported evidence that the motor system may rely on a modular organization, even if this behavior has yet to be confirmed during motor adaptation. The aim of the present study is to investigate the modular motor control mechanisms underlying the execution of pedaling by untrained subjects in different biomechanical conditions. We use the muscle synergies framework to characterize the muscle coordination of 11 subjects pedaling under two different conditions. The first one consists of a pedaling exercise with a strategy freely chosen by the subjects (Preferred Pedaling Technique, PPT), while the second condition constrains the gesture by means of a real time visual feedback of mechanical effectiveness (Effective Pedaling Technique, EPT). Pedal forces, recorded using a pair of instrumented pedals, were used to calculate the Index of Effectiveness (IE). EMG signals were recorded from eight muscles of the dominant leg and Non-negative Matrix Factorization (NMF) was applied for the extraction of muscle synergies. All the synergy vectors, extracted cycle by cycle for each subject, were pooled across subjects and conditions and underwent a 2-dimensional Sammon's non-linear mapping. Seven representative clusters were identified on the Sammon's projection, and the corresponding eight-dimensional synergy vectors were used to reconstruct the repertoire of muscle activation for all subjects and all pedaling conditions (VAF > 0.8 for each individual muscle pattern). Only 5 out of the 7 identified modules were used by the subjects during the PPT pedaling condition, while 2 additional modules were found specific for the pedaling condition EPT. The temporal recruitment of three identified modules was highly correlated with IE. The structure of the identified modules was found similar to that extracted in other studies of human walking, partly confirming the existence of shared and task specific muscle synergies, and providing further evidence on the modularity

  15. 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.

  16. 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

  17. 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.

  18. Reproductive trade-offs in extant hunter-gatherers suggest adaptive mechanism for the Neolithic expansion.

    PubMed

    Page, Abigail E; Viguier, Sylvain; Dyble, Mark; Smith, Daniel; Chaudhary, Nikhil; Salali, Gul Deniz; Thompson, James; Vinicius, Lucio; Mace, Ruth; Migliano, Andrea Bamberg

    2016-04-26

    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.

  19. 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.

  20. Facets and mechanisms of adaptive pain behavior: predictive regulation and action

    PubMed Central

    Morrison, India; Perini, Irene; Dunham, James

    2013-01-01

    Neural mechanisms underlying nociception and pain perception are considered to serve the ultimate goal of limiting tissue damage. However, since pain usually occurs in complex environments and situations that call for elaborate control over behavior, simple avoidance is insufficient to explain a range of mammalian pain responses, especially in the presence of competing goals. In this integrative review we propose a Predictive Regulation and Action (PRA) model of acute pain processing. It emphasizes evidence that the nervous system is organized to anticipate potential pain and to adjust behavior before the risk of tissue damage becomes critical. Regulatory processes occur on many levels, and can be dynamically influenced by local interactions or by modulation from other brain areas in the network. The PRA model centers on neural substrates supporting the predictive nature of pain processing, as well as on finely-calibrated yet versatile regulatory processes that ultimately affect behavior. We outline several operational categories of pain behavior, from spinally-mediated reflexes to adaptive voluntary action, situated at various neural levels. An implication is that neural processes that track potential tissue damage in terms of behavioral consequences are an integral part of pain perception. PMID:24348358

  1. 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

  2. Adaptation and detoxification mechanisms of Vetiver grass (Chrysopogon zizanioides) growing on gold mine tailings.

    PubMed

    Melato, F A; Mokgalaka, N S; McCrindle, R I

    2016-01-01

    Vetiver grass (Chrysopogon zizanioides) was investigated for its potential use in the rehabilitation of gold mine tailings, its ability to extract and accumulate toxic metals from the tailings and its metal tolerant strategies. Vetiver grass was grown on gold mine tailings soil, in a hothouse, and monitored for sixteen weeks. The mine tailings were highly acidic and had high electrical conductivity. Vetiver grass was able to grow and adapt well on gold mine tailings. The results showed that Vetiver grass accumulated large amounts of metals in the roots and restricted their translocation to the shoots. This was confirmed by the bioconcentration factor of Zn, Cu, and Ni of >1 and the translocation factor of <1 for all the metals. This study revealed the defense mechanisms employed by Vetiver grass against metal stress that include: chelation of toxic metals by phenolics, glutathione S-tranferase, and low molecular weight thiols; sequestration and accumulation of metals within the cell wall that was revealed by the scanning electron microscopy that showed closure of stomata and thickened cell wall and was confirmed by high content of cell wall bound phenolics. Metal induced reactive oxygen species are reduced or eliminated by catalase, superoxide dismutase and peroxidase dismutase.

  3. 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

  4. The local enhancement conundrum: in search of the adaptive value of a social learning mechanism.

    PubMed

    Arbilly, Michal; Laland, Kevin N

    2014-02-01

    Social learning mechanisms are widely thought to vary in their degree of complexity as well as in their prevalence in the natural world. While learning the properties of a stimulus that generalize to similar stimuli at other locations (stimulus enhancement) prima facie appears more useful to an animal than learning about a specific stimulus at a specific location (local enhancement), empirical evidence suggests that the latter is much more widespread in nature. Simulating populations engaged in a producer-scrounger game, we sought to deploy mathematical models to identify the adaptive benefits of reliance on local enhancement and/or stimulus enhancement, and the alternative conditions favoring their evolution. Surprisingly, we found that while stimulus enhancement readily evolves, local enhancement is advantageous only under highly restricted conditions: when generalization of information was made unreliable or when error in social learning was high. Our results generate a conundrum over how seemingly conflicting empirical and theoretical findings can be reconciled. Perhaps the prevalence of local enhancement in nature is due to stimulus enhancement costs independent of the learning task itself (e.g. predation risk), perhaps natural habitats are often characterized by unreliable yet highly rewarding payoffs, or perhaps local enhancement occurs less frequently, and stimulus enhancement more frequently, than widely believed.

  5. 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

  6. Sensori-motor integration during stance: time adaptation of control mechanisms on adding or removing vision.

    PubMed

    Sozzi, Stefania; Monti, Alberto; De Nunzio, Alessandro Marco; Do, Manh-Cuong; Schieppati, Marco

    2011-04-01

    Sudden addition or removal of visual information can be particularly critical to balance control. The promptness of adaptation of stance control mechanisms is quantified by the latency at which body oscillation and postural muscle activity vary after a shift in visual condition. In the present study, volunteers stood on a force platform with feet parallel or in tandem. Shifts in visual condition were produced by electronic spectacles. Ground reaction force (center of foot pressure, CoP) and EMG of leg postural muscles were acquired, and latency of CoP and EMG changes estimated by t-tests on the averaged traces. Time-to-reach steady-state was estimated by means of an exponential model. On allowing or occluding vision, decrements and increments in CoP position and oscillation occurred within about 2s. These were preceded by changes in muscle activity, regardless of visual-shift direction, foot position or front or rear leg in tandem. These time intervals were longer than simple reaction-time responses. The time course of recovery to steady-state was about 3s, shorter for oscillation than position. The capacity of modifying balance control at very short intervals both during quiet standing and under more critical balance conditions speaks in favor of a necessary coupling between vision, postural reference, and postural muscle activity, and of the swiftness of this sensory reweighing process.

  7. Endocrine mechanisms of seasonal adaptation in small mammals: from early results to present understanding.

    PubMed

    Scherbarth, Frank; Steinlechner, Stephan

    2010-10-01

    Seasonal adaptation is widespread among mammals of temperate and polar latitudes. The changes in physiology, morphology and behaviour are controlled by the photoneuroendocrine system that, as a first step, translates day lengths into a hormonal signal (melatonin). Decoding of the humoral melatonin signal, i.e. responses on the cellular level to slight alterations in signal duration, represents the prerequisite for appropriate timing of winter acclimatization in photoperiodic animals. Corresponding to the diversity of affected traits, several hormone systems are involved in the regulation downstream of the neural integration of photoperiodic time measurement. Results from recent studies provide new insights into seasonal control of reproduction and energy balance. Most intriguingly, the availability of thyroid hormone within hypothalamic key regions, which is a crucial determinant of seasonal transitions, appears to be regulated by hormone secretion from the pars tuberalis of the pituitary gland. This proposed neuroendocrine pathway contradicts the common view of the pituitary as a gland that acts downstream of the hypothalamus. In the present overview of (neuro)endocrine mechanisms underlying seasonal acclimatization, we are focusing on the dwarf hamster Phodopus sungorus (long-day breeder) that is known for large amplitudes in seasonal changes. However, important findings in other mammalian species such as Syrian hamsters and sheep (short-day breeder) are considered as well.

  8. 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.

  9. 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…

  10. Coping Styles of Female Adolescent Cancer Patients with Potential Fertility Loss

    PubMed Central

    Murphy, Devin; Knapp, Caprice A.; Christie, Juliette; Phares, Vicky; Wells, Kristen J.

    2013-01-01

    Purpose The purpose of this qualitative study was to assess the coping styles of female adolescent cancer patients regarding potential loss of fertility. Expectations and desires for the future, coping styles in typical adolescence, and coping styles when faced with potential loss of fertility due to cancer treatment are discussed. Methods Female adolescents diagnosed with cancer aged 12–18 years at study (N=14) were administered a 10-item values clarification tool to pilot test the readability and relevance of the items on reproductive concerns, followed by a cognitive debriefing interview asking participants how they would respond to each item. These qualitative responses were assessed for coping style type using the constant comparative approach. Results All adolescent participants reported having a strong desire for biological children in the future. Reactions to questions regarding the loss of fertility fell into two categories of coping styles: emotion-focused coping or problem-focused (engagement) coping. Within emotion-focused coping, there were three distinct styles: externalizing attribution style, internalizing attribution style, and repressive adaptation. Problem-focused coping adolescents displayed optimism. Conclusion Successful interventions aimed at promoting adaptive coping styles should seek to uncover adolescents' values about future parenthood and reproduction. Development of an age-appropriate assessment to stimulate dialogue regarding fertility and initiate an adolescent's cognitive processing of potential fertility loss is warranted. PMID:23781403

  11. 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.

  12. Examining behavioural coping strategies as mediators between work-family conflict and psychological distress.

    PubMed

    Aazami, Sanaz; Shamsuddin, Khadijah; Akmal, Syaqirah

    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.

  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. [Urbanization mechanisms in bird species: population systems transformations or adaptations at the individual level?].

    PubMed

    Fridman, V S; Eremkin, G S; Zakharova-Kubareva, N Iu

    2008-01-01

    The present research deals with urbanization of wild bird and mammal species. Forms and mechanisms of population steadiness in the urban landscape have been examined. The urbanization process turned out to be a directed change of the population system forming de novo in the urbolandscape leading to a sustainable organization peculiar for the particular environment. The population organization of different types in urbolandscape is found to provide its stability under conditions of directed and fast changes accompanied with instability and heterogenous structure of habitats. It is shown that the same type of population organization meets the corresponding demands among different species settling in the urban environment. Its features are "openness" and "flowage" of the groups, far order of settlement levels and other units of population system, constant movements of the individuals between the groups as a respond to the signals of urboenvironment significant changes. The "urban" variant of the population system organization turns out to be opposite to that of the same species in the non-urban habitats. After formation of the urban types by the species and successful developing of the town, the urban population becomes separated from the maternal local population and begins to exist independently in the urban landscape. The variety of adaptation aberrations in ecology, behavior, and mode of life of urban birds is the population system stability function in the urban landscape and is not a results of individual selection. It is shown that the urbanization process of the species goes firstly on the population level being the system structure transformation developed by the species towards the most stable state in the town (city) territory. Only after the appearance of stable urban population, the urban individuals show the rapid growth of different changes in ecology, behavior, mode of life that was traditionally described by naturalists as species adaptation to the

  15. 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…

  16. Coping Characteristics of Primary Caregivers for Speech-Language Disabled Preschoolers.

    ERIC Educational Resources Information Center

    Vaughan, Lollie; Saniga, Richard D.

    1998-01-01

    A study that investigated the coping strategies of 20 females with children (ages birth-4) with speech and language impairments found that most utilized effective coping strategies. Adaptive behaviors included liking the company of other people, feeling liked by others, awareness of the feelings of others, and a sense of happiness. (Author/CR)

  17. 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…

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. The changing brain--insights into the mechanisms of neural and behavioral adaptation to the environment.

    PubMed

    Bergersen, L H; Bramham, C R; Hugdahl, K; Sander, M; Storm-Mathisen, J

    2013-09-05

    The Kavli Prize in Neuroscience was awarded for the third time in September 2012, by the Norwegian Academy of Science and Letters in Oslo. The accompanying Kavli Prize Symposium on Neuroscience, held in Bergen and Trondheim, was a showcase of excellence in neuroscience research. The common theme of the Symposium presentations was the mechanisms by which animals adapt to their environment. The symposium speakers--Michael Greenberg, Erin Schuman, Chiara Cirelli, Michael Meaney, Catherine Dulac, Hopi Hoekstra, and Stanislas Dehaene--covered topics ranging from the molecular and cellular levels to the systems level and behavior. Thus a single amino acid change in a transcriptional repressor can disrupt gene regulation through neural activity (Greenberg). Deep sequencing analysis of the neuropil transcriptome indicates that a large fraction of the synaptic proteome is synthesized in situ in axons and dendrites, permitting local regulation (Schuman). The nature of the 'reset' function that makes animals dependent of sleep is being revealed (Cirelli). Maternal behavior can cause changes in gene expression that stably modify behavior in the offspring (Meaney). Removal of a single sensory channel protein in the vomero-nasal organ can switch off male-specific and switch on female-specific innate behavior of mice in response to environmental stimulation (Dulac). Innate behaviors can be stably transmitted from parent to offspring through generations even when those behaviors cannot be expressed, as illustrated by the elaborate burrowing behavior in a rodent species, in which independent genetic regions regulate distinct modules of the burrowing pattern (Hoekstra). Finally, at the other extreme of the nature-nurture scale, functional magnetic resonance imaging (fMRI) analysis in children and adults identified a brain area specifically involved in reading (Dehaene). As the area must originally have developed for a purpose other than reading, such as shape recognition, this

  4. The Cellie Coping Kit for Sickle Cell Disease: Initial acceptability and feasibility

    PubMed Central

    Marsac, Meghan L.; Klingbeil, Olivia G.; Hildenbrand, Aimee K.; Alderfer, Melissa A.; Kassam-Adams, Nancy; Smith-Whitley, Kim; Barakat, Lamia P.

    2014-01-01

    Sickle Cell Disease (SCD) and its treatment can place physical and psychosocial strain on children and their families, underlining the need for behavioral and emotional support. Much of SCD is often managed at home, which may prevent children from obtaining supportive services from medical and psychosocial teams. Children with SCD report a restricted number of coping strategies specific to managing SCD and may benefit from education on adaptive coping. To address this unmet need, a coping tool for children with cancer (Cellie Cancer Coping Kit) was adapted for children with SCD. The Cellie Coping Kit for SCD (Cellie Coping Kit) includes a stuffed “Cellie” toy, coping cards for children, and a book for caregivers. This study sought to assess the acceptability and feasibility of an intervention utilizing the Cellie Coping Kit. Fifteen children with SCD (ages 6-14) and their caregivers participated in a baseline assessment including semi-structured interviews to examine SCD-related stressors and coping strategies. Next, families received a brief introduction to the Cellie Coping Kit and were provided with a kit to use independently over the next four weeks before completing a follow-up assessment. Results indicated strong intervention acceptability overall. While families reported using and learning information and skills from the Cellie Coping Kit, several challenges were identified (e.g., child's living situation, busy schedules). The Cellie Coping Kit is a promising tool to support children with SCD and their families. Future research should examine whether use of the Cellie Coping Kit impacts behavioral change and improved health outcomes. PMID:25664228

  5. 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

  6. 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.

  7. 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,…

  8. 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.

  9. Visual Adaptation

    PubMed Central

    Webster, Michael A.

    2015-01-01

    Sensory systems continuously mold themselves to the widely varying contexts in which they must operate. Studies of these adaptations have played a long and central role in vision science. In part this is because the specific adaptations remain a powerful tool for dissecting vision, by exposing the mechanisms that are adapting. That is, “if it adapts, it's there.” Many insights about vision have come from using adaptation in this way, as a method. A second important trend has been the realization that the processes of adaptation are themselves essential to how vision works, and thus are likely to operate at all levels. That is, “if it's there, it adapts.” This has focused interest on the mechanisms of adaptation as the target rather than the probe. Together both approaches have led to an emerging insight of adaptation as a fundamental and ubiquitous coding strategy impacting all aspects of how we see. PMID:26858985

  10. Effectively Coping With Task Stress: A Study of the Validity of the Trait Emotional Intelligence Questionnaire-Short Form (TEIQue-SF).

    PubMed

    O'Connor, Peter; Nguyen, Jessica; Anglim, Jeromy

    2016-10-03

    In this study, we investigated the validity of the Trait Emotional Intelligence Questionnaire-Short Form (TEIQue-SF; Petrides, 2009) in the context of task-induced stress. We used a total sample of 225 volunteers to investigate (a) the incremental validity of the TEIQue-SF over other predictors of coping with task-induced stress, and (b) the construct validity of the TEIQue-SF by examining the mechanisms via which scores from the TEIQue-SF predict coping outcomes. Results demonstrated that the TEIQue-SF possessed incremental validity over the Big Five personality traits in the prediction of emotion-focused coping. Results also provided support for the construct validity of the TEIQue-SF by demonstrating that this measure predicted adaptive coping via emotion-focused channels. Specifically, results showed that, following a task stressor, the TEIQue-SF predicted low negative affect and high task performance via high levels of emotion-focused coping. Consistent with the purported theoretical nature of the trait emotional intelligence (EI) construct, trait EI as assessed by the TEIQue-SF primarily enhances affect and performance in stressful situations by regulating negative emotions.

  11. Mechanisms of cellular adaptation to quantum dots--the role of glutathione and transcription factor EB.

    PubMed

    Neibert, Kevin D; Maysinger, Dusica

    2012-05-01

    Cellular adaptation is the dynamic response of a cell to adverse changes in its intra/extra cellular environment. The aims of this study were to investigate the role of: (i) the glutathione antioxidant system, and (ii) the transcription factor EB (TFEB), a newly revealed master regulator of lysosome biogenesis, in cellular adaptation to nanoparticle-induced oxidative stress. Intracellular concentrations of glutathione species and activation of TFEB were assessed in rat pheochromocytoma (PC12) cells following treatment with uncapped CdTe quantum dots (QDs), using biochemical, live cell fluorescence and immunocytochemical techniques. Exposure to toxic concentrations of QDs resulted in a significant enhancement of intracellular glutathione concentrations, redistribution of glutathione species and a progressive translocation and activation of TFEB. These changes were associated with an enlargement of the cellular lysosomal compartment. Together, these processes appear to have an adaptive character, and thereby participate in the adaptive cellular response to toxic nanoparticles.

  12. Neural adaptations to resistive exercise: mechanisms and recommendations for training practices.

    PubMed

    Gabriel, David A; Kamen, Gary; Frost, Gail

    2006-01-01

    It is generally accepted that neural factors play an important role in muscle strength gains. This article reviews the neural adaptations in strength, with the goal of laying the foundations for practical applications in sports medicine and rehabilitation. An increase in muscular strength without noticeable hypertrophy is the first line of evidence for neural involvement in acquisition of muscular strength. The use of surface electromyographic (SEMG) techniques reveal that strength gains in the early phase of a training regimen are associated with an increase in the amplitude of SEMG activity. This has been interpreted as an increase in neural drive, which denotes the magnitude of efferent neural output from the CNS to active muscle fibres. However, SEMG activity is a global measure of muscle activity. Underlying alterations in SEMG activity are changes in motor unit firing patterns as measured by indwelling (wire or needle) electrodes. Some studies have reported a transient increase in motor unit firing rate. Training-related increases in the rate of tension development have also been linked with an increased probability of doublet firing in individual motor units. A doublet is a very short interspike interval in a motor unit train, and usually occurs at the onset of a muscular contraction. Motor unit synchronisation is another possible mechanism for increases in muscle strength, but has yet to be definitely demonstrated. There are several lines of evidence for central control of training-related adaptation to resistive exercise. Mental practice using imagined contractions has been shown to increase the excitability of the cortical areas involved in movement and motion planning. However, training using imagined contractions is unlikely to be as effective as physical training, and it may be more applicable to rehabilitation. Retention of strength gains after dissipation of physiological effects demonstrates a strong practice effect. Bilateral contractions are

  13. 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.

  14. 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.

  15. Quantification of Internal Stress-Strain Fields in Human Tendon: Unraveling the Mechanisms that Underlie Regional Tendon Adaptations and Mal-Adaptations to Mechanical Loading and the Effectiveness of Therapeutic Eccentric Exercise

    PubMed Central

    Maganaris, Constantinos N.; Chatzistergos, Panagiotis; Reeves, Neil D.; Narici, Marco V.

    2017-01-01

    By virtue of their anatomical location between muscles and bones, tendons make it possible to transform contractile force to joint rotation and locomotion. However, tendons do not behave as rigid links, but exhibit viscoelastic tensile properties, thereby affecting the length and contractile force in the in-series muscle, but also storing and releasing elastic stain energy as some tendons are stretched and recoiled in a cyclic manner during locomotion. In the late 90s, advancements were made in the application of ultrasound scanning that allowed quantifying the tensile deformability and mechanical properties of human tendons in vivo. Since then, the main principles of the ultrasound-based method have been applied by numerous research groups throughout the world and showed that tendons increase their tensile stiffness in response to exercise training and chronic mechanical loading, in general, by increasing their size and improving their intrinsic material. It is often assumed that these changes occur homogenously, in the entire body of the tendon, but recent findings indicate that the adaptations may in fact take place in some but not all tendon regions. The present review focuses on these regional adaptability features and highlights two paradigms where they are particularly evident: (a) Chronic mechanical loading in healthy tendons, and (b) tendinopathy. In the former loading paradigm, local tendon adaptations indicate that certain regions may “see,” and therefore adapt to, increased levels of stress. In the latter paradigm, local pathological features indicate that certain tendon regions may be “stress-shielded” and degenerate over time. Eccentric exercise protocols have successfully been used in the management of tendinopathy, without much sound understanding of the mechanisms underpinning their effectiveness. For insertional tendinopathy, in particular, it is possible that the effectiveness of a loading/rehabilitation protocol depends on the topography

  16. Females' coping styles and control over poker machine gambling.

    PubMed

    Scannell, E D; Quirk, M M; Smith, K; Maddern, R; Dickerson, M

    2000-01-01

    An investigation of the relationship between impaired control over gambling, coping strategies, and demographic variables was conducted by surveying female poker machine players (N = 163) in their gaming venues. Metropolitan (n = 14) and regional (n = 6) gaming venues in Victoria, Australia participated. Control over gambling was measured using the Impaired Control Over Gambling Scale (Baron & Dickerson, 1994). Coping strategies were measured using (Folkman et al., 1986) adaptation of the Revised Ways of Coping Checklist (Vitaliano et al., 1985). MANOVA supported the hypothesis that the lower the control over gambling the greater the reliance on emotion-focused coping (blamed self, wishful thinking, avoidance) with F = 9.92, 13.35, 14.04 respectively, all significant at p <.001. MANOVA failed to supported the hypothesis that problem-focused strategies (problem focus, seek social support) would be significantly related to control over gambling with F =.82 and.21 respectively. Control over gambling was not related to age, employment, relationship status, education, or distress from significant life events, further supporting the relationship between control and coping strategies. Ways in which coping styles might be related to pathological gambling are discussed.

  17. School Principals' Emotional Coping Process

    ERIC Educational Resources Information Center

    Poirel, Emmanuel; Yvon, Frédéric

    2014-01-01

    The present study examines the emotional coping of school principals in Quebec. Emotional coping was measured by stimulated recall; six principals were filmed during a working day and presented a week later with their video showing stressful encounters. The results show that school principals experience anger because of reproaches from staff…

  18. 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,…

  19. Relationships Among Positive Emotions, Coping, Resilience and Mental Health.

    PubMed

    Gloria, Christian T; Steinhardt, Mary A

    2016-04-01

    The broaden-and-build theory of positive emotions suggests that positive emotions can widen the range of potential coping strategies that come to mind and subsequently enhance one's resilience against stress. Studies have shown that high stress, especially chronic levels of stress, strongly contributes to the development of anxiety and depressive symptoms. However, researchers have also found that individuals who possess high levels of resilience are protected from stress and thus report lower levels of anxiety and depressive symptoms. Using a sample of 200 postdoctoral research fellows, the present study examined if (a) positive emotions were associated with greater resilience, (b) coping strategies mediated the link between positive emotions and resilience and (c) resilience moderated the influence of stress on trait anxiety and depressive symptoms. Results support the broaden-and-build theory in that positive emotions may enhance resilience directly as well as indirectly through the mediating role of coping strategies-particularly via adaptive coping. Resilience also moderated the association of stress with trait anxiety and depressive symptoms. Although stress is unavoidable and its influences on anxiety and depressive symptoms are undeniable, the likelihood of postdocs developing anxiety or depressive symptoms may be reduced by implementing programmes designed to increase positive emotions, adaptive coping strategies and resilience.

  20. 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

  1. Personality and coping: a context for examining celebrity worship and mental health.

    PubMed

    Maltby, John; Day, Liza; McCutcheon, Lynn E; Gillett, Raphael; Houran, James; Ashe, Diane D

    2004-11-01

    The adaptational-continuum model of personality and coping suggests a useful context for research areas that emphasize both personality and coping. The present paper used Ferguson's (2001) model integrating personality and coping factors to further conceptualize findings around celebrity worship. Three hundred and seventy-two respondents completed measures of celebrity worship, personality, coping style, general health, stress, positive and negative affect and life satisfaction. Celebrity worship for intense-personal reasons is associated with poorer mental heath and this relationship can be understood within the dimensions of neuroticism and a coping style that suggests disengagement. Such findings suggest the utility of examining the relationship between celebrity worship and mental health within both personality and coping variables, which have practical implications for understanding and addressing mental health problems that may occur as the result of engaging in celebrity worship for intense-personal reasons.

  2. 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.

  3. Coping with coping strategies: how distributed teams and their members deal with the stress of distance, time zones and culture.

    PubMed

    Nurmi, Niina

    2011-04-01

    The changing world of work is increasing demands on workers through greater need for flexibility in global collaboration. This multiple-case study uses a qualitative research approach to study context-specific job stressors and coping in ten geographically distributed work teams. Results demonstrate the complex and dynamic nature of the stress-coping process and how coping strategies, adapted to manage stress-evoking uncertainty and ambiguity in distributed work, created secondary sources of psychological strain to individuals. The main strategies for managing the uncertainty and ambiguity in the studied teams were extensive emailing, travelling to face-to-face meetings and extending workdays to collaborate simultaneously across time zones. Continuously used, these coping strategies created work overload and strain. Experienced workers, who had good self-management skills, succeeded in coping with these secondary sources of strain by prioritizing and setting clear limits for workload. Less-experienced workers were overloaded and needed more social support from their leaders and teammates. The study proposes that distributed team members rely heavily on individual coping resources, because spatial and temporal distance hinders or even precludes the mobilization of social resources related to emotional, instrumental and informational social support.

  4. 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.

  5. Effect of insulin-induced hypoglycaemia on the peripheral nervous system: focus on adaptive mechanisms, pathogenesis and histopathological changes.

    PubMed

    Jensen, V F H; Mølck, A-M; Bøgh, I B; Lykkesfeldt, J

    2014-08-01

    Insulin-induced hypoglycaemia (IIH) is a common acute side effect in type 1 and type 2 diabetic patients, especially during intensive insulin therapy. The peripheral nervous system (PNS) depends on glucose as its primary energy source during normoglycaemia and, consequently, it may be particularly susceptible to IIH damage. Possible mechanisms for adaption of the PNS to IIH include increased glucose uptake, utilisation of alternative energy substrates and the use of Schwann cell glycogen as a local glucose reserve. However, these potential adaptive mechanisms become insufficient when the hypoglycaemic state exceeds a certain level of severity and duration, resulting in a sensory-motor neuropathy with associated skeletal muscle atrophy. Large myelinated motor fibres appear to be particularly vulnerable. Thus, although the PNS is not an obligate glucose consumer, as is the brain, it appears to be more prone to IIH than the central nervous system when hypoglycaemia is not severe (blood glucose level ≤ 2 mm), possibly reflecting a preferential protection of the brain during periods of inadequate glucose availability. With a primary focus on evidence from experimental animal studies investigating nondiabetic IIH, the present review discusses the effect of IIH on the PNS with a focus on adaptive mechanisms, pathogenesis and histological changes.

  6. 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.

  7. The Neural Mechanism Exploration of Adaptive Motor Control: Dynamical Economic Cell Allocation in the Primary Motor Cortex.

    PubMed

    Li, Wei; Guo, Yangyang; Fan, Jing; Ma, Chaolin; Ma, Xuan; Chen, Xi; He, Jiping

    2016-06-14

    Adaptive flexibility is of significance for the smooth and efficient movements in goal attainment. However, the underlying work mechanism of the cerebral cortex in adaptive motor control still remains unclear. How does the cerebral cortex organize and coordinate the activity of a large population of cells in the implementation of various motor strategies? To explore this issue, single-unit activities from the M1 region and kinematic data were recorded simultaneously in monkeys performing 3D reach-to-grasp tasks with different perturbations. Varying motor control strategies were employed and achieved in different perturbed tasks, via the dynamic allocation of cells to modulate specific movement parameters. An economic principle was proposed for the first time to describe a basic rule for cell allocation in the primary motor cortex. This principle, defined as the Dynamic Economic Cell Allocation Mechanism (DECAM), guarantees benefit maximization in cell allocation under limited neuronal resources, and avoids committing resources to uneconomic investments for unreliable factors with no or little revenue. That is to say, the cells recruited are always preferentially allocated to those factors with reliable return; otherwise, the cells are dispatched to respond to other factors about task. The findings of this study might partially reveal the working mechanisms underlying the role of the cerebral cortex in adaptive motor control, wherein is also of significance for the design of future intelligent brain-machine interfaces and rehabilitation device.

  8. Relationship between coping flexibility and the risk of depression in Indian adults.

    PubMed

    Kato, Tsukasa

    2016-12-01

    According to the dual-process theory of coping flexibility, coping flexibility is the ability to discontinue an ineffective coping strategy and produce and implement an alternative coping strategy. In order to test the coping flexibility hypothesis, which posits that flexible coping produces adaptive outcomes, the relationship between coping flexibility and the risk of depression was examined in the context of Indian adults. Participants (150 men and 150 women) answered questionnaires measuring coping flexibility and depressive symptoms. The risk of depression was assessed using a Patient Health Questionnaire-9 score of 10 and a Center for Epidemiologic Studies' Depression Scale score of 16 as cut-off points. Logistic regression analyses of the score cut-off points revealed that higher levels of coping flexibility were associated with lower risks of depression, after controlling for the effects of gender, age, and marital status. Overall, the coping flexibility hypothesis was supported in this Indian adult sample. These findings might contribute to preventing recurrent depression and to attenuating depressive symptoms.

  9. Root transcriptomes of two acidic soil adapted Indica rice genotypes suggest diverse and complex mechanism of low phosphorus tolerance.

    PubMed

    Tyagi, Wricha; Rai, Mayank

    2017-03-01

    Low phosphorus (P) tolerance in rice is a biologically and agronomically important character. Low P tolerant Indica-type rice genotypes, Sahbhagi Dhan (SD) and Chakhao Poreiton (CP), are adapted to acidic soils and show variable response to low P levels. Using RNAseq approach, transcriptome data was generated from roots of SD and CP after 15 days of low P treatment to understand differences and similarities at molecular level. In response to low P, number of genes up-regulated (1318) was more when compared with down-regulated genes (761). Eight hundred twenty-one genes found to be significantly regulated between SD and CP in response to low P. De novo assembly using plant database led to further identification of 1535 novel transcripts. Functional annotation of significantly expressed genes suggests two distinct methods of low P tolerance. While root system architecture in SD works through serine-threonine kinase PSTOL1, suberin-mediated cell wall modification seems to be key in CP. The transcription data indicated that CP relies more on releasing its internally bound Pi and coping with low P levels by transcriptional and translational modifications and using dehydration response-based signals. Role of P transporters seems to be vital in response to low P in CP while sugar- and auxin-mediated pathway seems to be preferred in SD. At least six small RNA clusters overlap with transcripts highly expressed under low P, suggesting role of RNA super clusters in nutrient response in plants. These results help us to understand and thereby devise better strategy to enhance low P tolerance in Indica-type rice.

  10. A striking reduction of simple loudness adaptation in autism.

    PubMed

    Lawson, Rebecca P; Aylward, Jessica; White, Sarah; Rees, Geraint

    2015-11-05

    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.

  11. 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

  12. [The cellular mechanisms of exercise adaptation from the perspective of skeletal muscle plasticity].

    PubMed

    Sun, Yi; Ding, Shu-Zhe

    2014-10-01

    As highly plastic tissue, skeletal muscle adapts to stressors such as exercise. Reasonable amount of exercise is known to play a role in the prevention of cardiovascular diseases, diabetes and cancer. However, in the field of Exercise Physiology, the debate has been on for a while as to which kind of exercise is more effective in health promotion. In this review, the authors contrast and compare the signaling pathways mediated by different types of exercise, and boldly speculate the intrinsic similarities and discrepancies among them, hoping to enrich the theoretical frames of exercise adaptation, as well as provide effective exercise regimen to the public.

  13. Evolution of the fruit endocarp: molecular mechanisms underlying adaptations in seed protection and dispersal strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 f...

  14. Biomolecular Mechanism, Cloning, Sequencing and Analysis of Adaptive Reflection cDNAs and Proteins from Squid

    DTIC Science & Technology

    2010-05-03

    drivers of these adaptive changes in reflectance that we will investigate include electromotive ion fluxes, pH change and exposures to metal ions and...found in L. pealeii. As is the case for the other reflectin proteins (16), Ref-Lp1 and 2 contain a series of conserved subdomains (SDs). Ref-Lp1

  15. Adaptive multisource streaming in heterogeneous peer-to-peer networks

    NASA Astrophysics Data System (ADS)

    Agarwal, Vikash; Rejaie, Reza

    2005-01-01

    This paper presents design and evaluation of an adaptive streaming mechanism from multiple senders to a single receiver in Peer-to-Peer (P2P) networks, called P2P Adaptive Layered Streaming, or PALS. PALS is a receiver-driven mechanism. It enables a receiver peer to orchestrate quality adaptive streaming of a single, layer encoded video stream from multiple congestion controlled senders, and is able to support a spectrum of non-interactive streaming applications. The primary challenge in design of a multi-source streaming mechanism is that available bandwidth from each peer is not known a priori, and could significantly change during a session. In PALS, the receiver periodically performs quality adaptation based on aggregate bandwidth from all senders to determine (i) overall quality (i.e. number of layers) that can be collectively delivered from all senders, and more importantly (ii) specific subset of packets that should be delivered by each sender in order to gracefully cope with any sudden change in its bandwidth. Our detailed simulation-based evaluations illustrate that PALS can effectively cope with several angles of dynamics in the system including: bandwidth variations, peer participation, and partially available content at different peers. We also demonstrate the importance of coordination among senders and examine key design tradeoffs for the PALS mechanism.

  16. Adaptive multisource streaming in heterogeneous peer-to-peer networks

    NASA Astrophysics Data System (ADS)

    Agarwal, Vikash; Rejaie, Reza

    2004-12-01

    This paper presents design and evaluation of an adaptive streaming mechanism from multiple senders to a single receiver in Peer-to-Peer (P2P) networks, called P2P Adaptive Layered Streaming, or PALS. PALS is a receiver-driven mechanism. It enables a receiver peer to orchestrate quality adaptive streaming of a single, layer encoded video stream from multiple congestion controlled senders, and is able to support a spectrum of non-interactive streaming applications. The primary challenge in design of a multi-source streaming mechanism is that available bandwidth from each peer is not known a priori, and could significantly change during a session. In PALS, the receiver periodically performs quality adaptation based on aggregate bandwidth from all senders to determine (i) overall quality (i.e. number of layers) that can be collectively delivered from all senders, and more importantly (ii) specific subset of packets that should be delivered by each sender in order to gracefully cope with any sudden change in its bandwidth. Our detailed simulation-based evaluations illustrate that PALS can effectively cope with several angles of dynamics in the system including: bandwidth variations, peer participation, and partially available content at different peers. We also demonstrate the importance of coordination among senders and examine key design tradeoffs for the PALS mechanism.

  17. A Mathematical Model of the Olfactory Bulb for the Selective Adaptation Mechanism in the Rodent Olfactory System.

    PubMed

    Soh, Zu; Nishikawa, Shinya; Kurita, Yuichi; Takiguchi, Noboru; Tsuji, Toshio

    2016-01-01

    To predict the odor quality of an odorant mixture, the interaction between odorants must be taken into account. Previously, an experiment in which mice discriminated between odorant mixtures identified a selective adaptation mechanism in the olfactory system. This paper proposes an olfactory model for odorant mixtures that can account for selective adaptation in terms of neural activity. The proposed model uses the spatial activity pattern of the mitral layer obtained from model simulations to predict the perceptual similarity between odors. Measured glomerular activity patterns are used as input to the model. The neural interaction between mitral cells and granular cells is then simulated, and a dissimilarity index between odors is defined using the activity patterns of the mitral layer. An odor set composed of three odorants is used to test the ability of the model. Simulations are performed based on the odor discrimination experiment on mice. As a result, we observe that part of the neural activity in the glomerular layer is enhanced in the mitral layer, whereas another part is suppressed. We find that the dissimilarity index strongly correlates with the odor discrimination rate of mice: r = 0.88 (p = 0.019). We conclude that our model has the ability to predict the perceptual similarity of odorant mixtures. In addition, the model also accounts for selective adaptation via the odor discrimination rate, and the enhancement and inhibition in the mitral layer may be related to this selective adaptation.

  18. A Mathematical Model of the Olfactory Bulb for the Selective Adaptation Mechanism in the Rodent Olfactory System

    PubMed Central

    Nishikawa, Shinya; Kurita, Yuichi; Takiguchi, Noboru; Tsuji, Toshio

    2016-01-01

    To predict the odor quality of an odorant mixture, the interaction between odorants must be taken into account. Previously, an experiment in which mice discriminated between odorant mixtures identified a selective adaptation mechanism in the olfactory system. This paper proposes an olfactory model for odorant mixtures that can account for selective adaptation in terms of neural activity. The proposed model uses the spatial activity pattern of the mitral layer obtained from model simulations to predict the perceptual similarity between odors. Measured glomerular activity patterns are used as input to the model. The neural interaction between mitral cells and granular cells is then simulated, and a dissimilarity index between odors is defined using the activity patterns of the mitral layer. An odor set composed of three odorants is used to test the ability of the model. Simulations are performed based on the odor discrimination experiment on mice. As a result, we observe that part of the neural activity in the glomerular layer is enhanced in the mitral layer, whereas another part is suppressed. We find that the dissimilarity index strongly correlates with the odor discrimination rate of mice: r = 0.88 (p = 0.019). We conclude that our model has the ability to predict the perceptual similarity of odorant mixtures. In addition, the model also accounts for selective adaptation via the odor discrimination rate, and the enhancement and inhibition in the mitral layer may be related to this selective adaptation. PMID:27992433

  19. Multiple adaptive mechanisms affect asparagine synthetase substrate availability in asparaginase-resistant MOLT-4 human leukaemia cells.

    PubMed Central

    Aslanian, A M; Kilberg, M S

    2001-01-01

    Childhood acute lymphoblastic leukaemia is treated by combination chemotherapy with a number of drugs, almost always including the enzyme L-asparaginase (ASNase). Although the initial remission rate is quite high, relapse and associated drug resistance remain a problem. In vitro studies have demonstrated an adaptive increase in asparagine synthetase (AS) expression in ASNase-resistant cells, which is believed to permit ASNase-resistant human leukaemia cells to survive in vivo. The present results, obtained with ASNase-sensitive and -resistant human MOLT-4 leukaemia cell lines, illustrate that several other adaptive processes occur to provide sufficient amounts of the AS substrates, aspartate and glutamine, required to support this increased enzymic activity. In both cell populations, aspartate is derived almost exclusively from intracellular sources, whereas the necessary glutamine arises from both intracellular and extracellular sources. Transport of glutamine into ASNase-resistant cells is significantly enhanced compared with the parental cells, whereas amino acid efflux (e.g. asparagine) is reduced. Most of the adaptive change for the amino acid transporters, Systems A, ASC and L, is rapidly (12 h) reversed following ASNase removal. The enzymic activity of glutamine synthetase is also enhanced in ASNase-resistant cells by a post-transcriptional mechanism. The results demonstrate that there are several sites of metabolic adaptation in ASNase-treated leukaemia cells that serve to promote the replenishment of both glutamine and asparagine. PMID:11485552

  20. 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

  1. 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.

  2. 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

  3. [Preface to special issue: "Molecular mechanism of the adaptation of terrestrial plants to gravity environment on Earth"].

    PubMed

    Kamisaka, Seiichiro

    2003-08-01

    Organisms borne in the primitive sea about 30 million years ago had evolved in water without a large influence of gravity on earth. About 4 million years ago, the first terrestrial organisms, plants appeared on the land from the sea. The terrestrial plants have adapted to and evolved on the land environment so that they can extend their roots downward in soil and their shoots upward against 1 g gravity. At least two functions that were acquired during the process of evolution helped the terrestrial plants to adapt to gravity environment on earth. One is gravitropism. The other is the reinforcement of the cell wall, particularly the secondary cell wall. In the present feature articles, the molecular mechanism of the adaptation of terrestrial plants to gravity environment on earth will be reviewed, paying special attention to the mechanism of the genetic control of the signaling of gravity stimulus in gravitropism, automorphogenesis, genes involved in auxin transport, gravity effect on cell wall properties and gravimorphogenesis in terrestrial plants.

  4. Correlation of digital health use and chronic pain coping strategies

    PubMed Central

    Duarte, Cassandra; Baird, Janette; Patry, Emily J.; Green, Traci C.

    2016-01-01

    Background Digital health is an increasingly popular tool for patient engagement, having shown great success in arenas such as medication adherence, management of chronic conditions, and patient safety. Given the growth of chronic pain diagnoses, it is imperative to find new technologies to improve care for this particular population. Little research has catalogued the use of digital health in the chronic pain patient population. This manuscript’s objective was to describe current patterns of digital health usage among chronic pain patients and how digital health use correlates with health care utilization and health outcomes. Methods A cross-sectional survey was administered to patients with a self-identified chronic pain diagnosis participating in ‘Patients Like Me’® (PLM), an organization that directly collects data from patients experiencing chronic health conditions, with emphasis on patient-centered outcomes and experiences interacting with the health care system. Validated measures of healthcare utilization, chronic pain management, and digital health use were adapted for the survey. Digital health was defined as the use of online sites, social media, and mobile phone applications before, during, or after healthcare utilization. Descriptive statistics, chi square tests, logistic regression, and linear regression were used as appropriate for analysis. Results Among 565 respondents (mean age 51.3, 87.2% female, 45.7% publicly insured), most participants (89.5%) reported some digital health use. Females and users below the age of 50 were more likely to use multiple forms of digital health. Healthcare utilization, education level, and race/ethnicity did not correlate with digital health use. Patients using more types of digital health reported significantly higher levels of pain coping skills in the realms of social support, relaxation, and exercise. Conclusions Digital health use is common among a wide range of patients with chronic pain diagnoses. The

  5. Noncertainty equivalent nonlinear adaptive control and its applications to mechanical and aerospace systems

    NASA Astrophysics Data System (ADS)

    Seo, Dong Eun

    Adaptive control has long focused on establishing stable adaptive control methods for various nonlinear systems. Existing methods are mostly based on the certainty equivalence principle which states that the controller structure developed in the deterministic case (without uncertain system parameters) can be used for controlling the uncertain system along by adopting a carefully determined parameter estimator. Thus, the overall performance of the regulating/tracking control depends on the performance of the parameter estimator, which often results in the poor closed-loop performance compared with the deterministic control because the parameter estimate can exhibit wide variations compared to their true values in general. In this dissertation, we introduce a new adaptive control method for nonlinear systems where unknown parameters are estimated to within an attracting manifold and the proposed control method always asymptotically recovers the closed-loop error dynamics of the deterministic case control system. Thus, the overall performance of this new adaptive control method is comparable to that of the deterministic control method, something that is usually impossible to obtain with the certainty equivalent control method. We apply the noncertainty equivalent adaptive control to study application arising in the n degree of freedom (DOF) robot control problem and spacecraft attitude control. Especially, in the context of the spacecraft attitude control problem, we developed a new attitude observer that also utilizes an attracting manifold, while ensuring that the estimated attitude matrix confirms at all instants to the special group of rotation matrices SO(3). As a result, we demonstrate for the first time a separation property of the nonlinear attitude control problem in terms of the observer/controller based closed-loop system. For both the robotic and spacecraft attitude control problems, detailed derivations for the controller design and accompanying stability

  6. Conceptualization and Measurement of Coping During Adolescence: A Review of the Literature

    PubMed Central

    Garcia, Carolyn

    2010-01-01

    Purpose The purpose of this review was to examine the conceptualization and measurement of coping in adolescent research. Design A review of the literature published and abstracted in four scientific databases was undertaken between July 2008 and June 2009 with the following key words: adolescent(s), cope/coping, stress(ors), and adaptation/psychological. Methods A total of 367 articles were initially identified, and review of published abstracts yielded 104 empirical articles to retrieve and examine more closely for inclusion. Criteria for inclusion in the review were that the study (a) measured coping, (b) presented original data, (c) primarily targeted adolescent participants, (d) was reported in English, and (e) was published between 1998 and June 2009. Fifty-nine subsequent articles were organized using a matrix approach that facilitated cross-study comparisons of purpose, sample, and dependent variables. Findings Fewer than half of the studies reviewed included a specific statement defining coping. Instead, many authors described coping in the context of stress response by identifying particular types or ways of coping or naming specific coping strategies used. The theoretical frameworks guiding examination of coping varied across studies. A range of measures, congruent with adolescent developmental processes, were used to assess adolescent coping. A wide range of stress-related risks or conditions were examined, including psychological stressors such as eating disorders, suicidal ideation, and depression; physical stressors such as chronic illness, HIV infection, sports participation, violence, or sexual abuse; familial stressors such as domestic violence or interparental conflict; social stressors such as romantic relationships or difficulties in settings such as school, prison, or a homeless shelter; and societal stressors such as discrimination. Conclusions Coping is an important construct in understanding how adolescents react to the extensive stressors

  7. 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

  8. Adaptive engineering of a hyperthermophilic archaeon on CO and discovering the underlying mechanism by multi-omics analysis.

    PubMed

    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

    2016-03-15

    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.

  9. Vocal learning beyond imitation: mechanisms of adaptive vocal development in songbirds and human infants.

    PubMed

    Tchernichovski, Ofer; Marcus, Gary

    2014-10-01

    Studies of vocal learning in songbirds typically focus on the acquisition of sensory templates for song imitation and on the consequent process of matching song production to templates. However, functional vocal development also requires the capacity to adaptively diverge from sensory templates, and to flexibly assemble vocal units. Examples of adaptive divergence include the corrective imitation of abnormal songs, and the decreased tendency to copy over-abundant syllables. Such frequency-dependent effects might mirror tradeoffs between the assimilation of group identity (culture) while establishing individual and flexibly expressive songs. Intriguingly, although the requirements for vocal plasticity vary across songbirds, and more so between birdsong and language, the capacity to flexibly assemble vocal sounds develops in a similar, stepwise manner across species. Therefore, universal features of vocal learning go well beyond the capacity to imitate.

  10. 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.

  11. Adaptation of the Black Yeast Wangiella dermatitidis to Ionizing Radiation: Molecular and Cellular Mechanisms

    DTIC Science & Technology

    2012-11-01

    laboratory and in the damaged Chernobyl nuclear reactor suggest they have adapted the ability to survive or even benefit from exposure to ionizing...damaged nuclear reactor at Chernobyl , which are constantly exposed to ionizing radiation, harbor large of amounts of microorganisms, including fungal...species [3,4]. Furthermore, Zhdanova et al. reported that beta and gamma radiation promoted directional growth of fungi isolated from the Chernobyl

  12. Adaptation and Regulation of the Transduction Mechanism in Vestibular Hair Cells.

    DTIC Science & Technology

    1991-12-02

    tion channels. Optical tweezers and video -enhanced differen- posed to mediate adaptation. tial interference contrast optics provide high effciency and...AD-A255 217 ANNUAL REPORT R&T CODE : 441m804---01 DATE: 2 DEC 1991 FINAL REPORT ON CONTRACT N00014-88-K-0078 PRINCIPAL INVESTIGATOR: David P. Corey...affected the rates, but affected slipping more than INclimbing, thereby offering a test of the hypothesis. In high calcium, slipping is faster, tension is

  13. 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.

  14. 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

  15. Mechanisms of macrophage migration inhibitory factor (MIF)-dependent tumor microenvironmental adaptation

    PubMed Central

    Rendon, Beatriz E.; Willer, Sharon S.; Zundel, Wayne; Mitchell, Robert A.

    2009-01-01

    Since its activity was first reported in the mid-1960s, macrophage migration inhibitory factor (MIF) has gone from a cytokine activity modulating monocyte motility to a pleiotropic regulator of a vast array of cellular and biological processes. Studies in recent years suggest that MIF contributes to malignant disease progression on several different levels. Both circulating and intracellular MIF protein levels are elevated in cancer patients and MIF expression reportedly correlates with stage, metastatic spread and disease-free survival. Additionally, MIF expression positively correlates with angiogenic growth factor expression, microvessel density and tumor-associated neovascularization. Not coincidentally, MIF has recently been shown to contribute to tumoral hypoxic adaptation by promoting hypoxia-induced HIF-1α stabilization. Intriguingly, hypoxia is a strong regulator of MIF expression and secretion, suggesting that hypoxia-induced MIF acts as an amplifying factor for both hypoxia and normoxia-associated angiogenic growth factor expression in human malignancies. Combined, these findings suggest that MIF overexpression contributes to tumoral hypoxic adaptation and, by extension, therapeutic responsiveness and disease prognosis. This review summarizes recent literature on the contributions of MIF to tumor-associated angiogenic growth factor expression, neovascularization and hypoxic adaptation. We also will review recent efforts aimed at identifying and employing small-molecule antagonists of MIF as a novel approach to cancer therapeutics. PMID:19186177

  16. Coping with climate change

    USGS Publications Warehouse

    Prato, Tony; Fagre, Daniel B.

    2006-01-01

    Climate is not the only factor in the deterioration of natural systems.We are making big changes to the landscape, altering land use and land cover in major ways. These changes combined present a challenge to environmental management. Adaptive management is a scientific approach to managing the adverse impacts of climate and landscape change.

  17. Coping with cancer -- hair loss

    MedlinePlus

    ... gov/ency/patientinstructions/000914.htm Coping with cancer - hair loss To use the sharing features on this ... lose your hair. Why Cancer Treatments can Cause Hair Loss Many chemotherapy drugs attack fast-growing cells. ...

  18. Validation of the Mindful Coping Scale

    ERIC Educational Resources Information Center

    Tharaldsen, Kjersti B.; Bru, Edvin

    2011-01-01

    The aim of this research is to develop and validate a self-report measure of mindfulness and coping, the mindful coping scale (MCS). Dimensions of mindful coping were theoretically deduced from mindfulness theory and coping theory. The MCS was empirically evaluated by use of factor analyses, reliability testing and nomological network validation.…

  19. Self-esteem and styles of coping with stress versus strategies of planning in people with psychopathic personality disorders

    PubMed Central

    Pastwa-Wojciechowska, Beata; KaŸmierczak, Maria; Błażek, Magdalena

    2012-01-01

    Summary Background Psychopathy is a notion that has been difficult to define. The operational definition of psychopathy by Hare is one of the most commonly used in psychology and it is usually identified with the scale used to measure this type of personality, which is the Psychopathy Checklist - Revision (PCL-R). PCL-R is composed of two factors: Factor 1 describes a constellation of psychopathic traits considered by many clinicians to be basic for this type of personality, and Factor 2 describes types of behaviour indicating impulsiveness, lack of stability and antisocial lifestyle. The aim of the research was to verify a hypothesis that people with psychopathic personality disorders are characterised by high self-esteem, unconstructive strategies of planning actions and non-adaptive styles of coping with stress. Material/Methods The group of participants included 30 people at the age of 22–36 convicted with a legally binding sentence. Methods were: 1. The Psychopathy Checklist-Revision (PCL-R); 2. Antisocial Personality Questionnaire (APQ); 3. Coping Inventory for Stressful Situations (CISS); 4. Generalised Self-Efficacy Scale (GSES). Results The participants were diagnosed as psychopaths (PCL-R), and more specifically – as primary psychopaths (APQ). They revealed a grandiose sense of self-worth, increased self-control, impulsive style of functioning, perceived high self-efficacy (which might be considered as a defence mechanism). Psychopaths prefer a coping style focused on emotions and avoidance. Conclusions The hypothesis was confirmed, that people with psychopathic personality disorders are characterised by high self-esteem, unconstructive strategies of planning actions and non-adaptive styles of coping with stress. PMID:22293875

  20. Coping Styles and Alcohol Dependence among Homeless People

    PubMed Central

    Opalach, Cezary; Romaszko, Jerzy; Jaracz, Marcin; Kuchta, Robert; Borkowska, Alina; Buciński, Adam

    2016-01-01

    Background and Objectives The ways in which homeless individuals cope with stress may differ from those relied upon by the members of the general population and these differences may either be the result or the cause of their living conditions. The aim of the study was to determine the preferred coping style among the homeless and its relationship with alcohol dependence. Methods The study included 78 homeless individuals and involved the collection of demographic, sociological, psychological and medical data from each participant. Coping styles relied upon when dealing with stressful situations were assessed using a Polish adaptation of the Coping Inventory for Stressful Situations. Alcohol dependence was assessed using the Michigan Alcoholism Screening Test (MAST) and a quantitative analysis of alcohol consumption. Results Men accounted for 91.93% of the study population. Nearly 75% of the subjects met the alcohol dependence criterion. Significant relationships were observed between the individual's age, preferred coping style and alcohol consumption level. As an individual’s age increased, the use of emotion-oriented coping styles decreased, while an increase in alcohol consumption was associated with a more frequent use of emotion- and avoidance-oriented strategies. Conclusions The findings of this study, similarly to those of many other studies of homeless individuals but investigating other areas (e.g. epidemiology of tuberculosis and traumatic injuries), are an exaggerated representation of associations observed in the general population. The results describe a group of people living on the margins of the society, often suffering from extremely advanced alcoholism, with clear evident psychodegradation. The presence of specific ways of coping with stress related to excessive alcohol consumption in this group of individuals may interfere with active participation in support programmes provided for the homeless and may further exacerbate their problems. PMID

  1. [Advances in molecular mechanisms of adaptive immunity mediated by type I-E CRISPR/Cas system--A review].

    PubMed

    Sun, Dongchang; Qiu, Juanping

    2016-01-04

    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.

  2. 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.

  3. Coping Strategies and Psychological Outcomes: The Moderating Effects of Personal Resiliency.

    PubMed

    Smith, Martin M; Saklofske, Donald H; Keefer, Kateryna V; Tremblay, Paul F

    2016-01-01

    Certain coping strategies alleviate stress and promote positive psychological outcomes, whereas others exacerbate stress and promote negative psychological outcomes. However, the efficacy of any given coping strategy may also depend on personal resiliency. This study examined whether personal resiliency moderated the effects of task-oriented, avoidance-oriented, and emotion-oriented coping strategies on measures of depression, anxiety, stress, positive affect, negative affect, and satisfaction with life. Results (N = 424 undergraduates) showed higher personal resiliency was associated with greater use of task-oriented coping strategies, which were in turn associated with more adaptive outcomes, and less reliance on nonconstructive emotion-oriented strategies, which in turn were associated with poorer psychological outcomes. In addition, individual differences in personal resiliency moderated the effects of task-oriented coping on negative affect and of emotion-oriented coping on negative affect and depression. Specifically, proactive task-oriented coping was associated with greater negative affect for people lower in personal resiliency. Moreover, high personal resiliency attenuated the negative effects of emotion-oriented coping on depression and negative affect. The effects of avoidance-oriented coping were mixed and were not associated with or dependent on levels of personal resiliency.

  4. 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

  5. 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

  6. Mixed Emotions and Coping: The Benefits of Secondary Emotions

    PubMed Central

    Braniecka, Anna; Trzebińska, Ewa; Dowgiert, Aneta; Wytykowska, Agata

    2014-01-01

    The existing empirical literature suggests that during difficult situations, the concurrent experience of positive and negative affects may be ideal for ensuring successful adaptation and well-being. However, different patterns of mixed emotions may have different adaptive consequences. The present research tested the proposition that experiencing a pattern of secondary mixed emotion (i.e., secondary emotion that embrace both positive and negative affects) more greatly promotes adaptive coping than experiencing two other patterns of mixed emotional experiences: simultaneous (i.e., two emotions of opposing affects taking place at the same time) and sequential (i.e., two emotions of opposing affects switching back and forth). Support for this hypothesis was obtained from two experiments (Studies 1 and 2) and a longitudinal survey (Study 3). The results revealed that secondary mixed emotions predominate over sequential and simultaneous mixed emotional experiences in promoting adaptive coping through fostering the motivational and informative functions of emotions; this is done by providing solution-oriented actions rather than avoidance, faster decisions regarding coping strategies (Study 1), easier access to self-knowledge, and better narrative organization (Study 2). Furthermore, individuals characterized as being prone to feeling secondary mixed emotions were more resilient to stress caused by transitions than those who were characterized as being prone to feeling opposing emotions separately (Study 3). Taken together, the preliminary results indicate that the pattern of secondary mixed emotion provides individuals with a higher capacity to handle adversity than the other two patterns of mixed emotional experience. PMID:25084461

  7. Mixed emotions and coping: the benefits of secondary emotions.

    PubMed

    Braniecka, Anna; Trzebińska, Ewa; Dowgiert, Aneta; Wytykowska, Agata

    2014-01-01

    The existing empirical literature suggests that during difficult situations, the concurrent experience of positive and negative affects may be ideal for ensuring successful adaptation and well-being. However, different patterns of mixed emotions may have different adaptive consequences. The present research tested the proposition that experiencing a pattern of secondary mixed emotion (i.e., secondary emotion that embrace both positive and negative affects) more greatly promotes adaptive coping than experiencing two other patterns of mixed emotional experiences: simultaneous (i.e., two emotions of opposing affects taking place at the same time) and sequential (i.e., two emotions of opposing affects switching back and forth). Support for this hypothesis was obtained from two experiments (Studies 1 and 2) and a longitudinal survey (Study 3). The results revealed that secondary mixed emotions predominate over sequential and simultaneous mixed emotional experiences in promoting adaptive coping through fostering the motivational and informative functions of emotions; this is done by providing solution-oriented actions rather than avoidance, faster decisions regarding coping strategies (Study 1), easier access to self-knowledge, and better narrative organization (Study 2). Furthermore, individuals characterized as being prone to feeling secondary mixed emotions were more resilient to stress caused by transitions than those who were characterized as being prone to feeling opposing emotions separately (Study 3). Taken together, the preliminary results indicate that the pattern of secondary mixed emotion provides individuals with a higher capacity to handle adversity than the other two patterns of mixed emotional experience.

  8. Cellular mechanisms of adaptive myelination: bridging the gap between animal studies and human cognition.

    PubMed

    Bujalka, Helena; Emery, Ben

    2017-04-01

    Voelker and colleagues propose that we may illuminate learning-associated phenomena such as generalization by considering white matter plasticity. Consistent with this idea, human neuroimaging studies reveal learning-induced changes in adult white matter. Animal studies reveal that some forms of learning induce, and are dependent on, generation of new oligodendrocytes. Nevertheless, it remains unclear which alterations to myelin structure are most relevant to learning, and humans and rodents may profoundly differ in their capacity for oligodendrogenesis in adulthood. A full understanding of these issues will be critical to appreciating the role of adaptive myelination in human neuroplasticity.

  9. The relationship between cognitive dysfunction and coping abilities in schizophrenia.

    PubMed

    Wilder-Willis, Kelly E; Shear, Paula K; Steffen, John J; Borkin, Joyce

    2002-06-01

    Cognitive dysfunction is a core feature of schizophrenia [Psychiatr. Clin. North Am., 16 (1993) 295; Psychopharmacology: The fourth generation of progress, Raven Press, New York (1995) 1171; Clinical Neuropsychology, Oxford University Press, New York (1993) 449] and is related to psychosocial functioning in this population [Am. J. Psychiatry, 153 (1996) 321]. It is unclear whether cognitive dysfunction is related to specific areas of functioning in schizophrenia, such as coping abilities. Individuals with schizophrenia have deficient coping skills, which may contribute to their difficulties dealing with stressors [Am. J. Orthopsychiatry, 62 (1992) 117; J. Abnorm. Psychol., 82 (1986) 189]. The current study examined the relationship between coping abilities and cognitive dysfunction in a community sample of individuals with schizophrenia. It was hypothesized that executive dysfunction and mnemonic impairments would be positively related to deficiencies in active coping efforts involving problem solving and self-initiation (e.g. advocating for oneself and others with mental illness and becoming involved in meaningful activities, such as work), independent of the contributions of the general intellectual deficits associated with the disorder and psychiatric symptoms. The results indicated that both executive dysfunction and mnemonic impairments were related to decreased usage of active coping mechanisms after controlling for general intellectual deficits. Further, recognition memory made independent contributions to the prediction of coping involving action and help seeking after controlling for the effects of negative symptoms. These findings suggest that individuals with schizophrenia may be less flexible in their use of coping strategies, which may in turn contribute to their difficulties in coping with mental illness and its consequences.

  10. Integrated Physiological, Proteomic, and Metabolomic Analysis of Ultra Violet (UV) Stress Responses and Adaptation Mechanisms in Pinus radiata.

    PubMed

    Pascual, Jesús; Cañal, María Jesús; Escandón, Mónica; Meijón, Mónica; Weckwerth, Wolfram; Valledor, Luis

    2017-03-01

    Globally expected changes in environmental conditions, especially the increase of UV irradiation, necessitate extending our knowledge of the mechanisms mediating tree species adaptation to this stress. This is crucial for designing new strategies to maintain future forest productivity. Studies focused on environmentally realistic dosages of UV irradiation in forest species are scarce. Pinus spp. are commercially relevant trees and not much is known about their adaptation to UV. In this work, UV treatment and recovery of Pinus radiata plants with dosages mimicking future scenarios, based on current models of UV radiation, were performed in a time-dependent manner. The combined metabolome and proteome analysis were complemented with measurements of + physiological parameters and gene expression. Sparse PLS analysis revealed complex molecular interaction networks of molecular and physiological data. Early responses prevented phototoxicity by reducing photosystem activity and the electron transfer chain together with the accumulation of photoprotectors and photorespiration. Apart from the reduction in photosynthesis as consequence of the direct UV damage on the photosystems, the primary metabolism was rearranged to deal with the oxidative stress while minimizing ROS production. New protein kinases and proteases related to signaling, coordination, and regulation of UV stress responses were revealed. All these processes demonstrate a complex molecular interaction network extending the current knowledge on UV-stress adaptation in pine.

  11. 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

  12. 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.

  13. 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

  14. Stochastic slowly adapting ionic currents may provide a decorrelation mechanism for neural oscillators by causing wander in the intrinsic period.

    PubMed

    Norman, Sharon E; Butera, Robert J; Canavier, Carmen C

    2016-09-01

    Oscillatory neurons integrate their synaptic inputs in fundamentally different ways than normally quiescent neurons. We show that the oscillation period of invertebrate endogenous pacemaker neurons wanders, producing random fluctuations in the interspike intervals (ISI) on a time scale of seconds to minutes, which decorrelates pairs of neurons in hybrid circuits constructed using the dynamic clamp. The autocorrelation of the ISI sequence remained high for many ISIs, but the autocorrelation of the ΔISI series had on average a single nonzero value, which was negative at a lag of one interval. We reproduced these results using a simple integrate and fire (IF) model with a stochastic population of channels carrying an adaptation current with a stochastic component that was integrated with a slow time scale, suggesting that a similar population of channels underlies the observed wander in the period. Using autoregressive integrated moving average (ARIMA) models, we found that a single integrator and a single moving average with a negative coefficient could simulate both the experimental data and the IF model. Feeding white noise into an integrator with a slow time constant is sufficient to produce the autocorrelation structure of the ISI series. Moreover, the moving average clearly accounted for the autocorrelation structure of the ΔISI series and is biophysically implemented in the IF model using slow stochastic adaptation. The observed autocorrelation structure may be a neural signature of slow stochastic adaptation, and wander generated in this manner may be a general mechanism for limiting episodes of synchronized activity in the nervous system.

  15. Structural Insight into and Mutational Analysis of Family 11 Xylanases: Implications for Mechanisms of Higher pH Catalytic Adaptation

    PubMed Central

    Bai, Wenqin; Zhou, Cheng; Zhao, Yueju; Wang, Qinhong; Ma, Yanhe

    2015-01-01

    To understand the molecular basis of higher pH catalytic adaptation of family 11 xylanases, we compared the structures of alkaline, neutral, and acidic active xylanases and analyzed mutants of xylanase Xyn11A-LC from alkalophilic Bacillus sp. SN5. It was revealed that alkaline active xylanases have increased charged residue content, an increased ratio of negatively to positively charged residues, and decreased Ser, Thr, and Tyr residue content relative to non-alkaline active counterparts. Between strands β6 and β7, alkaline xylanases substitute an α-helix for a coil or turn found in their non-alkaline counterparts. Compared with non-alkaline xylanases, alkaline active enzymes have an inserted stretch of seven amino acids rich in charged residues, which may be beneficial for xylanase function in alkaline conditions. Positively charged residues on the molecular surface and ionic bonds may play important roles in higher pH catalytic adaptation of family 11 xylanases. By structure comparison, sequence alignment and mutational analysis, six amino acids (Glu16, Trp18, Asn44, Leu46, Arg48, and Ser187, numbering based on Xyn11A-LC) adjacent to the acid/base catalyst were found to be responsible for xylanase function in higher pH conditions. Our results will contribute to understanding the molecular mechanisms of higher pH catalytic adaptation in family 11 xylanases and engineering xylanases to suit industrial applications. PMID:26161643

  16. The Development of a New Sport-Specific Classification of Coping and a Meta-Analysis of the Relationship between Different Coping Strategies and Moderators on Sporting Outcomes

    PubMed Central

    Nicholls, Adam R.; Taylor, Natalie J.; Carroll, Sean; Perry, John L.

    2016-01-01

    There is an ever growing coping and sports performance literature, with researchers using many different methods to assess performance and different classifications of coping. As such, it makes it difficult to compare studies and therefore identify how coping is related to performance. Furthermore, there are no quantitative syntheses of the results from these studies. A quantitative synthesis would facilitate a more comprehensive understanding of how coping is associated with athletic performance. In order to accurately compare studies, our first aim was to develop a new coping classification that would make this possible. Firstly, we reviewed the strengths and limitations of the different coping classifications and then identified the commonalities and differences between such classifications. We opted for a three-factor classification of coping, because the evidence suggests that a three-factor classification provides a superior model fit to two-factor approaches. Our new classification of coping was based on an existing model from the developmental literature, which received an excellent model fit. We made some adaptations, however, as our classification was intended for an athletic population. As such, we classified coping as mastery (i.e., controlling the situation and eliminating the stressor), internal regulation (i.e., managing internal stress responses), or goal withdrawal (i.e., ceasing efforts toward goal attainment). Undertaking a meta-analysis, our second aim was to identify which coping strategies correlated with sports performance and whether this relationship varied according to moderator variables. Articles were sourced from online electronic databases and manual journal searches. PRISMA guidelines were used to search, select, and synthesize relevant studies. Random effects meta-analyses were performed to identify associations between coping classification and sport performance. Q, I2, and R2 values assessed heterogeneity. Eighteen published

  17. Adaptive mechanisms during food restriction in Acomys russatus: the use of torpor for desert survival.

    PubMed

    Ehrhardt, N; Heldmaier, G; Exner, C

    2005-04-01

    The golden spiny mouse (Acomys russatus) is an omnivorous desert rodent that does not store food, but can store large amounts of body fat. Thus, it provides a good animal model to study physiological and behavioural adaptations to changes in food availability. The aim of this study was to investigate the time course of metabolic and behavioural responses to prolonged food restriction. Spiny mice were kept at an ambient temperature of 27 degrees C and for 3 weeks their food was reduced individually to 30% of their previous ad libitum food intake. When fed ad libitum, their average metabolic rate was 82.77+/-3.72 ml O(2) h(-1) during the photophase and 111.19+/-4.30 ml O(2) h(-1) during the scotophase. During food restriction they displayed episodes of daily torpor when the minimal metabolic rate gradually decreased to 16.07+/-1.07 ml O(2) h(-1), i.e. a metabolic rate depression of approximately 83%. During the hypometabolic bouts the minimum average body temperature T(b), decreased gradually from 32.6+/-0.1 degrees C to 29.0+/-0.4 degrees C, with increasing duration of consecutive bouts. In parallel, the animals increased their activity during the remaining daytime. Torpor as well as hyperactivity was suppressed immediately by refeeding. Thus golden spiny mice used two simultaneous strategies to adapt to shortened food supply, namely energysaving torpor during their resting period and an increase in locomotor activity pattern during their activity period.

  18. 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

  19. 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.

  20. 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

  1. Comparing residue clusters from thermophilic and mesophilic enzymes reveals adaptive mechanisms

    SciTech Connect

    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. 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.

  2. Comparing residue clusters from thermophilic and mesophilic enzymes reveals adaptive mechanisms

    DOE PAGES

    Sammond, Deanne W.; Kastelowitz, Noah; Himmel, Michael E.; ...

    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

  3. A murine skeletal adaptation that significantly increases cortical bone mechanical properties. Implications for human skeletal fragility.

    PubMed Central

    Bonadio, J; Jepsen, K J; Mansoura, M K; Jaenisch, R; Kuhn, J L; Goldstein, S A

    1993-01-01

    Mov13 mice carry a provirus that prevents transcription initiation of the alpha 1(I) collagen gene. Mutant mice homozygous for the null mutation produce no type I collagen and die at mid-gestation, whereas heterozygotes survive to adulthood. Dermal fibroblasts from heterozygous mice produce approximately 50% less type I collagen than normal littermates, and the partial deficiency in collagen production results in a phenotype similar to osteogenesis imperfecta type I (an inherited form of skeletal fragility). In this study, we have identified an adaptation of Mov13 skeletal tissue that significantly improves the bending strength of long bone. The adaptive response occurred over a 2-mo period, during which time a small number of newly proliferated osteogenic cells produced a significant amount of matrix components and thus generated new bone along periosteal surfaces. New bone deposition resulted in a measurable increase in cross-sectional geometry which, in turn, led to a dramatic increase in long bone bending strength. Images PMID:8408623

  4. 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; Paweł