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Sample records for adaptation physiology chair

  1. Physiological Motion Axis for the Seat of a Dynamic Office Chair.

    PubMed

    Kuster, Roman Peter; Bauer, Christoph Markus; Oetiker, Sarah; Kool, Jan

    2016-09-01

    The aim of this study was to determine and verify the optimal location of the motion axis (MA) for the seat of a dynamic office chair. A dynamic seat that supports pelvic motion may improve physical well-being and decrease the risk of sitting-associated disorders. However, office work requires an undisturbed view on the work task, which means a stable position of the upper trunk and head. Current dynamic office chairs do not fulfill this need. Consequently, a dynamic seat was adapted to the physiological kinematics of the human spine. Three-dimensional motion tracking in free sitting helped determine the physiological MA of the spine in the frontal plane. Three dynamic seats with physiological, lower, and higher MA were compared in stable upper body posture (thorax inclination) and seat support of pelvic motion (dynamic fitting accuracy). Spinal kinematics during sitting and walking were compared. The physiological MA was at the level of the 11th thoracic vertebra, causing minimal thorax inclination and high dynamic fitting accuracy. Spinal motion in active sitting and walking was similar. The physiological MA of the seat allows considerable lateral flexion of the spine similar to walking with a stable upper body posture and a high seat support of pelvic motion. The physiological MA enables lateral flexion of the spine, similar to walking, without affecting stable upper body posture, thus allowing active sitting while focusing on work. © 2016, Human Factors and Ergonomics Society.

  2. Physiological Motion Axis for the Seat of a Dynamic Office Chair

    PubMed Central

    Kuster, Roman Peter; Bauer, Christoph Markus; Oetiker, Sarah; Kool, Jan

    2016-01-01

    Objective The aim of this study was to determine and verify the optimal location of the motion axis (MA) for the seat of a dynamic office chair. Background A dynamic seat that supports pelvic motion may improve physical well-being and decrease the risk of sitting-associated disorders. However, office work requires an undisturbed view on the work task, which means a stable position of the upper trunk and head. Current dynamic office chairs do not fulfill this need. Consequently, a dynamic seat was adapted to the physiological kinematics of the human spine. Method Three-dimensional motion tracking in free sitting helped determine the physiological MA of the spine in the frontal plane. Three dynamic seats with physiological, lower, and higher MA were compared in stable upper body posture (thorax inclination) and seat support of pelvic motion (dynamic fitting accuracy). Spinal kinematics during sitting and walking were compared. Results The physiological MA was at the level of the 11th thoracic vertebra, causing minimal thorax inclination and high dynamic fitting accuracy. Spinal motion in active sitting and walking was similar. Conclusion The physiological MA of the seat allows considerable lateral flexion of the spine similar to walking with a stable upper body posture and a high seat support of pelvic motion. Application The physiological MA enables lateral flexion of the spine, similar to walking, without affecting stable upper body posture, thus allowing active sitting while focusing on work. PMID:27150530

  3. Wheel-chair driving improvement following visuo-manual prism adaptation.

    PubMed

    Jacquin-Courtois, Sophie; Rode, Gilles; Pisella, Laure; Boisson, Dominique; Rossetti, Yves

    2008-01-01

    Prism adaptation has been used for several years to improve several aspects of unilateral neglect. Parameters ranging from the classical neuropsychological tests to mental imagery or to tactile extinction have been successfully ameliorated following a brief period of adaptation to wedge prisms shifting the visual field to the right. However the potential therapeutic implications of this technique depend on the investigation of more functional and ecological parameters. Here we describe a patient with left hemiplegia and unilateral neglect who was impaired during wheel-chair navigation in the clinical unit. Following a brief adaptation period, this patient showed a sudden improvement of wheel-chair driving as well as of classical tests. The potential implications of prism adaptation for the rehabilitation of unilateral neglect are highlighted by the long duration of improvement obtained after a single adaptation session.

  4. Folding chair

    DOEpatents

    Cornell, Howell N.

    1985-08-20

    A foldable chair of the lawn chair type has ground-engaging front and rear legs, attached to and carrying a back frame and seat frame, the back frame and seat frame being pivotally attached to a spreader rod which extends beyond the back and seat frames to bear against one of the leg members when the chair is unfolded. A contact pad mounted on the extending portion of the spreader rod is formed as an externally-contoured bushing fit over the spreader rod and adapted to engage the leg member to restrict side-to-side movement of the spreader rod, with respect to the leg member, when the chair is unfolded.

  5. Physiological adaptation to space flight

    NASA Technical Reports Server (NTRS)

    Nicogossian, Arnauld E.; Sulzman, Frank M.; Gaiser, Karen K.; Teeter, Ronald C.

    1990-01-01

    In space, adaptive physiological changes have been observed in virtually all body systems, but how far these changes progress with time is not known. Their time course demonstrates variable patterns; some systems show evidence of gradual and progressive change. Biomedical postflight data have shown that a compensatory period of readaptation to one gravity is required after space flight, with longer intervals required for longer missions. Consistent readaptation trends include orthostatic intolerance and neurovestibular difficulties. For the long-duration missions of the exploration era, it is critical to determine the extent to which deleterious changes (e.g., bone loss and possible immunological changes) can be reversed upon return to earth. Radiation protection is another critical enabling element for missions beyond low earth orbit. Radiation exposure guidelines have not been established for exploration missions. Currently our experience is insufficient to prescribe countermeasures for the stay times associated with a lunar base or a mission to Mars. Artificial gravity may provide a solution, but the level and duration of exposure necessary to prevent deconditioning must be determined. Central issues for medical care in remote settings are preventive, diagnostic, and therapeutic care and the minimization of risk.

  6. Physiological adaptation to space flight

    NASA Technical Reports Server (NTRS)

    Nicogossian, Arnauld E.; Sulzman, Frank M.; Gaiser, Karen K.; Teeter, Ronald C.

    1990-01-01

    In space, adaptive physiological changes have been observed in virtually all body systems, but how far these changes progress with time is not known. Their time course demonstrates variable patterns; some systems show evidence of gradual and progressive change. Biomedical postflight data have shown that a compensatory period of readaptation to one gravity is required after space flight, with longer intervals required for longer missions. Consistent readaptation trends include orthostatic intolerance and neurovestibular difficulties. For the long-duration missions of the exploration era, it is critical to determine the extent to which deleterious changes (e.g., bone loss and possible immunological changes) can be reversed upon return to earth. Radiation protection is another critical enabling element for missions beyond low earth orbit. Radiation exposure guidelines have not been established for exploration missions. Currently our experience is insufficient to prescribe countermeasures for the stay times associated with a lunar base or a mission to Mars. Artificial gravity may provide a solution, but the level and duration of exposure necessary to prevent deconditioning must be determined. Central issues for medical care in remote settings are preventive, diagnostic, and therapeutic care and the minimization of risk.

  7. State Space Composition Technique for Intelligent Wheel Chair Adapting to Environment.

    NASA Astrophysics Data System (ADS)

    Hamagami, Tomoki; Hirata, Hironori

    This paper describes a state space composition technique for the adaptation to environment in the autonomous behavior of intelligent wheel chair (IWC).In the product like IWC with actual sensors, composing state space is difficult problem since environmental information can not be observed sufficiently from restricted sensor inputs.A lot of states observed from same environment position raise the fail of the learning and adaptation with active learning approach.In order to compensate for the effects of the sensor configuration, that is sensor position, angle and precision, a normalization processing of position detector is introduced.In sensor normalization process, IWC scans present environment via range sensors with executing spot-turn, and prepare scan-patterns of each sensor.Then the normalization process adjusts the phase and dynamic range of each pattern to the reference sensor scan-pattern, analyzing phase differences and scale factors of each pattern against reference pattern.Using phase difference and scale factors, automated state space composition is possible.From the simulation experiment with both artificial and real-worlddraft, the automated state space construction is confirmed as a practical approach for pre-processing for environment learning and adaptation.

  8. Physiologic adaptation to space - Space adaptation syndrome

    NASA Technical Reports Server (NTRS)

    Vanderploeg, J. M.

    1985-01-01

    The adaptive changes of the neurovestibular system to microgravity, which result in space motion sickness (SMS), are studied. A list of symptoms, which range from vomiting to drowsiness, is provided. The two patterns of symptom development, rapid and gradual, and the duration of the symptoms are described. The concept of sensory conflict and rearrangements to explain SMS is being investigated.

  9. Arm-crank propelled three-wheeled chair: physiological evaluation of the propulsion using one arm and both arm patterns.

    PubMed

    Mukherjee, G; Samanta, A

    2004-12-01

    Disabled people in India frequently use the arm-crank propelled three-wheeled chair (ACWC) for outdoor transportation. Two models of these chairs are commercially available: one is powered by cranking using one arm (ACWC-1) and the other uses both arms (ACWC-2). The purpose of the study was to compare the efficiency of the two types of propulsion with respect to the standard physiological responses and, consequent upon the findings, to recommend the use of a suitable one. The energetics of locomotion of the users at their freely chosen speed (FCS) were measured and compared with changes in the physiological parameters in the within-subject groups. The study was conducted in outdoor settings to simulate the actual locomotive conditions encountered by the users in their practical life. 14 males, who had been regular and proficient users of both propulsion systems for more than last six years and who had a history of paraplegia (below the 10th thoracic vertebra, n=11) and poliomyelitis (n=3) participated in the study. The subjects were required to propel the test chair (a combination of both the propulsion systems built in a single model) on an oval track of 358 m circumference at their FCS for 5 min; ambulatory data were collected during last 3 min of exercise and averaged. The FCS (m/min), heart rates (bpm) and oxygen uptake (l/min) were measured. Physiological cost index (b/m) oxygen consumption (ml/kg/min), oxygen cost (ml/kg/m) and net locomotor energy cost (kcal/kg/km) of the two sets of observations were derived and compared using a t-test for the paired observations. The FCS was significantly higher and the physiological parameters were lower with the ACWC-2 than with ACWC-1, except for heart rate and oxygen consumption, where the difference was not significant . It is concluded that two-arm use is more efficient and less physically demanding than one-arm use in the arm-crank propulsion system and that the former is more suitable for efficient ambulation.

  10. Resistance Training: Physiological Responses and Adaptations (Part 3 of 4).

    ERIC Educational Resources Information Center

    Fleck, Steven J.; Kraemer, William J.

    1988-01-01

    The physiological responses and adaptations which occur as a result of resistance training, such as cardiovascular responses, serum lipid count, body composition, and neural adaptations are discussed. Changes in the endocrine system are also described. (JL)

  11. Resistance Training: Physiological Responses and Adaptations (Part 3 of 4).

    ERIC Educational Resources Information Center

    Fleck, Steven J.; Kraemer, William J.

    1988-01-01

    The physiological responses and adaptations which occur as a result of resistance training, such as cardiovascular responses, serum lipid count, body composition, and neural adaptations are discussed. Changes in the endocrine system are also described. (JL)

  12. Infant epidermal skin physiology: adaptation after birth.

    PubMed

    Fluhr, J W; Darlenski, R; Lachmann, N; Baudouin, C; Msika, P; De Belilovsky, C; Hachem, J-P

    2012-03-01

    Functional and structural skin adaptation is a dynamic process which starts immediately after birth in humans and in mammalian skin in general. This adjustment to the extrauterine dry environment is accomplished in the first year of postnatal life of humans. To assess the dynamic changes in vivo after birth in the molecular composition and skin physiology parameters compared with older children and adults. The molecular composition of the stratum corneum (SC) and the water profile were investigated noninvasively by in vivo Raman confocal microscopy as a function of depth. Functional parameters including transepidermal water loss (characterizing epidermal permeability barrier), capacitance (as an indirect parameter for SC hydration) and skin surface pH were assessed noninvasively. The measurements were performed in 108 subjects divided into six age groups: full-term newborns (1-15 days), babies aged 5-6 weeks, babies aged 6±1 months, children aged 1-2 years, children aged 4-5 years and adults aged 20-35 years. We showed that skin acidification is still under development during the first weeks of life. While the basal epidermal barrier is competent immediately after birth, the SC is less hydrated in the first 2 weeks of postnatal life. Similar continuous decreasing water content towards the surface for all age groups was observed, whereas this gradient was lower for the newborns. Dynamic changes in the amounts of the natural moisturizing factor constituents were revealed in the period of infancy. We demonstrated the relation of formation of an acidic pH as well as underlying mechanisms in the induction of a fully hydrated SC over the first weeks of human life as a dynamic functional adaptation. © 2011 The Authors. BJD © 2011 British Association of Dermatologists.

  13. First Chair.

    ERIC Educational Resources Information Center

    Stewart, Donald C.

    1993-01-01

    A high school sophomore exceptionally talented on the violin is enraged and indignant when a less accomplished senior is given first chair in the school orchestra. After reacting rudely to the orchestra director and the principal, the girl discusses the situation with her supportive parents and resolves the problem. (JDD)

  14. Ergonomic Chairs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Findings published in the NASA Anthropometric Source Book by Johnson Space Center helped BodyBilt, Inc. to fashion controlled comfort chairs that lessen the harmful effects of gravity on seated workers. Crew members living aboard NASA's Skylab noted that in space the human posture differs from the normal posture caused by the tug of one gravity. There has been an alarming increase in back pain and muscle fatigue in workers, along with a dramatic escalation in repetitive stress injuries. BodyBilt's ergonomically-correct line of office chairs are targeted for the average worker that sits for prolonged periods, be it in the classroom or boardroom. Their roster of national clients lists such organizations as IBM, Microsoft, Texas Instruments, Hewlett-Packard, Eastman-Kodak, Boeing, Motorola, and Walt Disney Studios.

  15. Physiological Self-Regulation and Adaptive Automation

    NASA Technical Reports Server (NTRS)

    Prinzell, Lawrence J.; Pope, Alan T.; Freeman, Frederick G.

    2007-01-01

    Adaptive automation has been proposed as a solution to current problems of human-automation interaction. Past research has shown the potential of this advanced form of automation to enhance pilot engagement and lower cognitive workload. However, there have been concerns voiced regarding issues, such as automation surprises, associated with the use of adaptive automation. This study examined the use of psychophysiological self-regulation training with adaptive automation that may help pilots deal with these problems through the enhancement of cognitive resource management skills. Eighteen participants were assigned to 3 groups (self-regulation training, false feedback, and control) and performed resource management, monitoring, and tracking tasks from the Multiple Attribute Task Battery. The tracking task was cycled between 3 levels of task difficulty (automatic, adaptive aiding, manual) on the basis of the electroencephalogram-derived engagement index. The other two tasks remained in automatic mode that had a single automation failure. Those participants who had received self-regulation training performed significantly better and reported lower National Aeronautics and Space Administration Task Load Index scores than participants in the false feedback and control groups. The theoretical and practical implications of these results for adaptive automation are discussed.

  16. Physiological Self-Regulation and Adaptive Automation

    NASA Technical Reports Server (NTRS)

    Prinzell, Lawrence J.; Pope, Alan T.; Freeman, Frederick G.

    2007-01-01

    Adaptive automation has been proposed as a solution to current problems of human-automation interaction. Past research has shown the potential of this advanced form of automation to enhance pilot engagement and lower cognitive workload. However, there have been concerns voiced regarding issues, such as automation surprises, associated with the use of adaptive automation. This study examined the use of psychophysiological self-regulation training with adaptive automation that may help pilots deal with these problems through the enhancement of cognitive resource management skills. Eighteen participants were assigned to 3 groups (self-regulation training, false feedback, and control) and performed resource management, monitoring, and tracking tasks from the Multiple Attribute Task Battery. The tracking task was cycled between 3 levels of task difficulty (automatic, adaptive aiding, manual) on the basis of the electroencephalogram-derived engagement index. The other two tasks remained in automatic mode that had a single automation failure. Those participants who had received self-regulation training performed significantly better and reported lower National Aeronautics and Space Administration Task Load Index scores than participants in the false feedback and control groups. The theoretical and practical implications of these results for adaptive automation are discussed.

  17. Physiological adaptation of growth kinetics in activated sludge.

    PubMed

    Friedrich, M; Takács, I; Tränckner, J

    2015-11-15

    Physiological adaptation as it occurs in bacterial cells at variable environmental conditions influences characteristic properties of growth kinetics significantly. However, physiological adaptation to growth related parameters in activated sludge modelling is not yet recognised. Consequently these parameters are regarded to be constant. To investigate physiological adaptation in activated sludge the endogenous respiration in an aerobic degradation batch experiment and simultaneous to that the maximum possible respiration in an aerobic growth batch experiment was measured. The activated sludge samples were taken from full scale wastewater treatment plants with different sludge retention times (SRTs). It could be shown that the low SRT sludge adapts by growth optimisation (high maximum growth rate and high decay rate) to its particular environment where a high SRT sludge adapts by survival optimization (low maximum growth rate and low decay rate). Thereby, both the maximum specific growth rate and the decay rate vary in the same pattern and are strongly correlated to each other. To describe the physiological state of mixed cultures like activated sludge quantitatively a physiological state factor (PSF) is proposed as the ratio of the maximum specific growth rate and the decay rate. The PSF can be expressed as an exponential function with respect to the SRT.

  18. Physiological adaptation - Crew health in space

    NASA Technical Reports Server (NTRS)

    Brand, Susan

    1988-01-01

    The experiments planned for the Spacelab Life Sciences-1 (SLS-1) Shuttle mission, which is dedicated to investigating biomedical issues pertinent to the man's presence in space, are discussed. The areas of research will include human and animal experiments concerned with the cardiovascular system, the vestibular apparatus, and metabolic experiments related to renal endocrine function, hematology, immune system, and muscle and bone/calcium metabolism, with particular attention given to the physiological complications resulting from short-duration space flight and subsequent return to the 1-G environment. The hardware systems to be used on the SLS-1 mission represent prototypes of systems to be developed for the medical and research facilities of the Space Station. The results of the experiments will be used to address issues related to long-duration space flight required for the Space Station and interplanetary travels.

  19. Physiological adaptation - Crew health in space

    NASA Technical Reports Server (NTRS)

    Brand, Susan

    1988-01-01

    The experiments planned for the Spacelab Life Sciences-1 (SLS-1) Shuttle mission, which is dedicated to investigating biomedical issues pertinent to the man's presence in space, are discussed. The areas of research will include human and animal experiments concerned with the cardiovascular system, the vestibular apparatus, and metabolic experiments related to renal endocrine function, hematology, immune system, and muscle and bone/calcium metabolism, with particular attention given to the physiological complications resulting from short-duration space flight and subsequent return to the 1-G environment. The hardware systems to be used on the SLS-1 mission represent prototypes of systems to be developed for the medical and research facilities of the Space Station. The results of the experiments will be used to address issues related to long-duration space flight required for the Space Station and interplanetary travels.

  20. ADAPTIVE DATA ANALYSIS OF COMPLEX FLUCTUATIONS IN PHYSIOLOGIC TIME SERIES

    PubMed Central

    PENG, C.-K.; COSTA, MADALENA; GOLDBERGER, ARY L.

    2009-01-01

    We introduce a generic framework of dynamical complexity to understand and quantify fluctuations of physiologic time series. In particular, we discuss the importance of applying adaptive data analysis techniques, such as the empirical mode decomposition algorithm, to address the challenges of nonlinearity and nonstationarity that are typically exhibited in biological fluctuations. PMID:20041035

  1. Physiological adaptation to recurrent social stress of extraversion.

    PubMed

    Lu, Wei; Wang, Zhenhong

    2017-02-01

    The present studies examined the influence of extraversion on physiological reactivity, recovery, and physiological habituation-sensitization to repeated social stressors. In Study 1, subjective and physiological data were collected from 97 college students who were categorized as high (n = 51) and low (n = 46) on extraversion (NEO-FFI) across five laboratory stages: baseline, stress 1, poststress 1, stress 2, and poststress 2. Results indicated high extraversion (HE) participants exhibited relative lesser heart rate (HR) reactivity and respiratory sinus arrhythmia (RSA) withdrawals to, and more complete HR and RSA recovery after the first social stress, and also exhibited relative lesser HR reactivity to the second social stress. When repeatedly exposed to a social stressor, HE participants showed pronounced systolic blood pressure (SBP) adaptation, low extraversion (LE) participants displayed diastolic blood pressure (DBP) sensitization. In Study 2, data were collected from another 78 participants (HE: n = 40, LE: n = 38) across the same laboratory stages with speech performance videotaped. After controlling for the speech styles, Study 2 found the same HR response and SBP/DBP adaptation pattern across extraversion groups to social stress as Study 1 but not RSA reactivity. These findings suggest extraverts exhibit more adaptive physiological reactivity to recurrent social stressors, which thus might benefit their health. © 2016 Society for Psychophysiological Research.

  2. Functional genomics of physiological plasticity and local adaptation in killifish.

    PubMed

    Whitehead, Andrew; Galvez, Fernando; Zhang, Shujun; Williams, Larissa M; Oleksiak, Marjorie F

    2011-01-01

    Evolutionary solutions to the physiological challenges of life in highly variable habitats can span the continuum from evolution of a cosmopolitan plastic phenotype to the evolution of locally adapted phenotypes. Killifish (Fundulus sp.) have evolved both highly plastic and locally adapted phenotypes within different selective contexts, providing a comparative system in which to explore the genomic underpinnings of physiological plasticity and adaptive variation. Importantly, extensive variation exists among populations and species for tolerance to a variety of stressors, and we exploit this variation in comparative studies to yield insights into the genomic basis of evolved phenotypic variation. Notably, species of Fundulus occupy the continuum of osmotic habitats from freshwater to marine and populations within Fundulus heteroclitus span far greater variation in pollution tolerance than across all species of fish. Here, we explore how transcriptome regulation underpins extreme physiological plasticity on osmotic shock and how genomic and transcriptomic variation is associated with locally evolved pollution tolerance. We show that F. heteroclitus quickly acclimate to extreme osmotic shock by mounting a dramatic rapid transcriptomic response including an early crisis control phase followed by a tissue remodeling phase involving many regulatory pathways. We also show that convergent evolution of locally adapted pollution tolerance involves complex patterns of gene expression and genome sequence variation, which is confounded with body-weight dependence for some genes. Similarly, exploiting the natural phenotypic variation associated with other established and emerging model organisms is likely to greatly accelerate the pace of discovery of the genomic basis of phenotypic variation.

  3. Physiological Adaptations to Resistance Training in Prepubertal Boys

    ERIC Educational Resources Information Center

    dos Santos Cunha, Giovani; Sant'anna, Marcelo Morganti; Cadore, Eduardo Lusa; de Oliveira, Norton Luis; dos Santos, Cinara Bos; Pinto, Ronei Silveira; Reischak-Oliveira, Alvaro

    2015-01-01

    Purpose: The purpose of this study was to investigate the physiological adaptations of resistance training (RT) in prepubertal boys. Methods: Eighteen healthy boys were divided into RT (n = 9, M[subscript age] = 10.4 ± 0.5 years) and control (CTR; n = 9, M[subscript age] = 10.9 ± 0.7 years) groups. The RT group underwent a resistance training…

  4. Physiological Adaptations to Resistance Training in Prepubertal Boys

    ERIC Educational Resources Information Center

    dos Santos Cunha, Giovani; Sant'anna, Marcelo Morganti; Cadore, Eduardo Lusa; de Oliveira, Norton Luis; dos Santos, Cinara Bos; Pinto, Ronei Silveira; Reischak-Oliveira, Alvaro

    2015-01-01

    Purpose: The purpose of this study was to investigate the physiological adaptations of resistance training (RT) in prepubertal boys. Methods: Eighteen healthy boys were divided into RT (n = 9, M[subscript age] = 10.4 ± 0.5 years) and control (CTR; n = 9, M[subscript age] = 10.9 ± 0.7 years) groups. The RT group underwent a resistance training…

  5. The role of mitochondrial respiration in physiological and evolutionary adaptation.

    PubMed

    Das, Jayatri

    2006-09-01

    Aerobic mitochondria serve as the power sources of eukaryotes by producing ATP through oxidative phosphorylation (OXPHOS). The enzymes involved in OXPHOS are multisubunit complexes encoded by both nuclear and mitochondrial DNA. Thus, regulation of respiration is necessarily a highly coordinated process that must organize production, assembly and function of mitochondria to meet an organism's energetic needs. Here I review the role of OXPHOS in metabolic adaptation and diversification of higher animals. On a physiological timescale, endocrine-initiated signaling pathways allow organisms to modulate respiratory enzyme concentration and function under changing environmental conditions. On an evolutionary timescale, mitochondrial enzymes are targets of natural selection, balancing cytonuclear coevolutionary constraints against physiological innovation. By synthesizing our knowledge of biochemistry, physiology and evolution of respiratory regulation, I propose that we can now explore questions at the interface of these fields, from molecular translation of environmental cues to selection on mitochondrial haplotype variation.

  6. Physiological adaptations to weight loss and factors favouring weight regain

    PubMed Central

    Greenway, F L

    2015-01-01

    Obesity is a major global health problem and predisposes individuals to several comorbidities that can affect life expectancy. Interventions based on lifestyle modification (for example, improved diet and exercise) are integral components in the management of obesity. However, although weight loss can be achieved through dietary restriction and/or increased physical activity, over the long term many individuals regain weight. The aim of this article is to review the research into the processes and mechanisms that underpin weight regain after weight loss and comment on future strategies to address them. Maintenance of body weight is regulated by the interaction of a number of processes, encompassing homoeostatic, environmental and behavioural factors. In homoeostatic regulation, the hypothalamus has a central role in integrating signals regarding food intake, energy balance and body weight, while an ‘obesogenic' environment and behavioural patterns exert effects on the amount and type of food intake and physical activity. The roles of other environmental factors are also now being considered, including sleep debt and iatrogenic effects of medications, many of which warrant further investigation. Unfortunately, physiological adaptations to weight loss favour weight regain. These changes include perturbations in the levels of circulating appetite-related hormones and energy homoeostasis, in addition to alterations in nutrient metabolism and subjective appetite. To maintain weight loss, individuals must adhere to behaviours that counteract physiological adaptations and other factors favouring weight regain. It is difficult to overcome physiology with behaviour. Weight loss medications and surgery change the physiology of body weight regulation and are the best chance for long-term success. An increased understanding of the physiology of weight loss and regain will underpin the development of future strategies to support overweight and obese individuals in their

  7. Physiological adaptations to weight loss and factors favouring weight regain.

    PubMed

    Greenway, F L

    2015-08-01

    Obesity is a major global health problem and predisposes individuals to several comorbidities that can affect life expectancy. Interventions based on lifestyle modification (for example, improved diet and exercise) are integral components in the management of obesity. However, although weight loss can be achieved through dietary restriction and/or increased physical activity, over the long term many individuals regain weight. The aim of this article is to review the research into the processes and mechanisms that underpin weight regain after weight loss and comment on future strategies to address them. Maintenance of body weight is regulated by the interaction of a number of processes, encompassing homoeostatic, environmental and behavioural factors. In homoeostatic regulation, the hypothalamus has a central role in integrating signals regarding food intake, energy balance and body weight, while an 'obesogenic' environment and behavioural patterns exert effects on the amount and type of food intake and physical activity. The roles of other environmental factors are also now being considered, including sleep debt and iatrogenic effects of medications, many of which warrant further investigation. Unfortunately, physiological adaptations to weight loss favour weight regain. These changes include perturbations in the levels of circulating appetite-related hormones and energy homoeostasis, in addition to alterations in nutrient metabolism and subjective appetite. To maintain weight loss, individuals must adhere to behaviours that counteract physiological adaptations and other factors favouring weight regain. It is difficult to overcome physiology with behaviour. Weight loss medications and surgery change the physiology of body weight regulation and are the best chance for long-term success. An increased understanding of the physiology of weight loss and regain will underpin the development of future strategies to support overweight and obese individuals in their efforts

  8. Mitochondrial adaptations to physiological vs. pathological cardiac hypertrophy

    PubMed Central

    Abel, E. Dale; Doenst, Torsten

    2011-01-01

    Cardiac hypertrophy is a stereotypic response of the heart to increased workload. The nature of the workload increase may vary depending on the stimulus (repetitive, chronic, pressure, or volume overload). If the heart fully adapts to the new loading condition, the hypertrophic response is considered physiological. If the hypertrophic response is associated with the ultimate development of contractile dysfunction and heart failure, the response is considered pathological. Although divergent signalling mechanisms may lead to these distinct patterns of hypertrophy, there is some overlap. Given the close relationship between workload and energy demand, any form of cardiac hypertrophy will impact the energy generation by mitochondria, which are the key organelles for cellular ATP production. Significant changes in the expression of nuclear and mitochondrially encoded transcripts that impact mitochondrial function as well as altered mitochondrial proteome composition and mitochondrial energetics have been described in various forms of cardiac hypertrophy. Here, we review mitochondrial alterations in pathological and physiological hypertrophy. We suggest that mitochondrial adaptations to pathological and physiological hypertrophy are distinct, and we shall review potential mechanisms that might account for these differences. PMID:21257612

  9. Mitochondrial adaptations to physiological vs. pathological cardiac hypertrophy.

    PubMed

    Abel, E Dale; Doenst, Torsten

    2011-05-01

    Cardiac hypertrophy is a stereotypic response of the heart to increased workload. The nature of the workload increase may vary depending on the stimulus (repetitive, chronic, pressure, or volume overload). If the heart fully adapts to the new loading condition, the hypertrophic response is considered physiological. If the hypertrophic response is associated with the ultimate development of contractile dysfunction and heart failure, the response is considered pathological. Although divergent signalling mechanisms may lead to these distinct patterns of hypertrophy, there is some overlap. Given the close relationship between workload and energy demand, any form of cardiac hypertrophy will impact the energy generation by mitochondria, which are the key organelles for cellular ATP production. Significant changes in the expression of nuclear and mitochondrially encoded transcripts that impact mitochondrial function as well as altered mitochondrial proteome composition and mitochondrial energetics have been described in various forms of cardiac hypertrophy. Here, we review mitochondrial alterations in pathological and physiological hypertrophy. We suggest that mitochondrial adaptations to pathological and physiological hypertrophy are distinct, and we shall review potential mechanisms that might account for these differences.

  10. Physiological adaptation of a mature adult walking the Alps.

    PubMed

    Ardigò, Luca P; Lippi, Giuseppe; Salvagno, Gian Luca; Schena, Federico

    2011-09-01

    Research on endurance locomotion has mainly focused on elite athletes rather than common middle-aged subjects. Our report describes the physiological and hematological adaptation of a healthy, active 62-year-old man who trekked alone along a 1300 km/3 month course of Alpine paths (Via Alpina). The following procedures were conducted: pre- and post-trekking and fortnightly field anthropometry (total and lean body mass), functional tests (isometric maximal voluntary force, spontaneous walking speed, relative metabolic cost, and peak oxygen consumption) and clinical chemistry/hematological measurements with laboratory instruments; daily self-administered effort measurements using portable devices along the route (walked distance, ascent, descent, time, metabolic consumption, and cost). Despite the tough trekking route, the subject completed the trek without any worsening of his performance, or any significant health or functional problems. In addition, his peak oxygen consumption increased by 13.2%. His successful adaptation may be attributed to his constant, repeated middle-intensity and extensive exercise and lengthy exposure to high altitude. The clinical chemistry/hematological measurements documented his physiological adaptation. In conclusion, we show how an active, middle-aged man can successfully face endurance trekking, not only without any harm to his health or functions but also with an increase in his capacity to support specific effort.

  11. Urban plant physiology: adaptation-mitigation strategies under permanent stress.

    PubMed

    Calfapietra, Carlo; Peñuelas, Josep; Niinemets, Ülo

    2015-02-01

    Urban environments that are stressful for plant function and growth will become increasingly widespread in future. In this opinion article, we define the concept of 'urban plant physiology', which focuses on plant responses and long term adaptations to urban conditions and on the capacity of urban vegetation to mitigate environmental hazards in urbanized settings such as air and soil pollution. Use of appropriate control treatments would allow for studies in urban environments to be comparable to expensive manipulative experiments. In this opinion article, we propose to couple two approaches, based either on environmental gradients or manipulated gradients, to develop the concept of urban plant physiology for assessing how single or multiple environmental factors affect the key environmental services provided by urban forests. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Nutrition and human physiological adaptations to space flight

    NASA Technical Reports Server (NTRS)

    Lane, H. W.; LeBlanc, A. D.; Putcha, L.; Whitson, P. A.

    1993-01-01

    Space flight provides a model for the study of healthy individuals undergoing unique stresses. This review focuses on how physiological adaptations to weightlessness may affect nutrient and food requirements in space. These adaptations include reductions in body water and plasma volume, which affect the renal and cardiovascular systems and thereby fluid and electrolyte requirements. Changes in muscle mass and function may affect requirements for energy, protein and amino acids. Changes in bone mass lead to increased urinary calcium concentrations, which may increase the risk of forming renal stones. Space motion sickness may influence putative changes in gastro-intestinal-hepatic function; neurosensory alterations may affect smell and taste. Some or all of these effects may be ameliorated through the use of specially designed dietary countermeasures.

  13. Tilting a wobbly chair

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2017-03-01

    If a small object is placed under the front leg of a chair, the chair tilts backwards. If the object is placed under a rear leg, the chair tilts sideways. The effect is surprising but can be analysed in terms of elementary physics.

  14. Tilting a Wobbly Chair

    ERIC Educational Resources Information Center

    Cross, Rod

    2017-01-01

    If a small object is placed under the front leg of a chair, the chair tilts backwards. If the object is placed under a rear leg, the chair tilts sideways. The effect is surprising but can be analysed in terms of elementary physics.

  15. Cytokine hypothesis of overtraining: a physiological adaptation to excessive stress?

    PubMed

    Smith, L L

    2000-02-01

    Overtraining syndrome (OTS) is a condition wherein an athlete is training excessively, yet performance deteriorates. This is usually accompanied by mood/behavior changes and a variety of biochemical and physiological alterations. Presently, there is no global hypothesis to account for OTS. The present paper will attempt to provide a unifying paradigm that will integrate previous research under the rubric of the cytokine hypothesis of overtraining. It is argued that high volume/intensity training, with insufficient rest, will produce muscle and/or skeletal and/or joint trauma. Circulating monocytes are then activated by injury-related cytokines, and in turn produce large quantities of proinflammatory IL-1beta, and/or IL-6, and/or TNF-alpha, producing systemic inflammation. Elevated circulating cytokines then co-ordinate the whole-body response by: a) communicating with the CNS and inducing a set of behaviors referred to as "sickness" behavior, which involves mood and behavior changes that support resolution of systemic inflammation: b) adjusting liver function, to support the up-regulation of gluconeogenesis, as well as de novo synthesis of acute phase proteins, and a concomitant hypercatabolic state; and c) impacting on immune function. Theoretically, OTS is viewed as the third stage of Selye's general adaptation syndrome, with the focus being on recovery/survival, and not adaptation, and is deemed to be "protective," occurring in response to excessive physical/physiological stress. Recommendations are made for potential markers of OTS, based on a systemic inflammatory condition.

  16. Physiological, behavioral and biochemical adaptations of intertidal fishes to hypoxia.

    PubMed

    Richards, Jeffrey G

    2011-01-15

    Hypoxia survival in fish requires a well-coordinated response to either secure more O(2) from the hypoxic environment or to limit the metabolic consequences of an O(2) restriction at the mitochondria. Although there is a considerable amount of information available on the physiological, behavioral, biochemical and molecular responses of fish to hypoxia, very little research has attempted to determine the adaptive value of these responses. This article will review current attempts to use the phylogenetically corrected comparative method to define physiological and behavioral adaptations to hypoxia in intertidal fish and further identify putatively adaptive biochemical traits that should be investigated in the future. In a group of marine fishes known as sculpins, from the family Cottidae, variation in hypoxia tolerance, measured as a critical O(2) tension (P(crit)), is primarily explained by variation in mass-specific gill surface area, red blood cell hemoglobin-O(2) binding affinity, and to a lesser extent variation in routine O(2) consumption rate (M(O(2))). The most hypoxia-tolerant sculpins consistently show aquatic surface respiration (ASR) and aerial emergence behavior during hypoxia exposure, but no phylogenetically independent relationship has been found between the thresholds for initiating these behaviors and P(crit). At O(2) levels below P(crit), hypoxia survival requires a rapid reorganization of cellular metabolism to suppress ATP consumption to match the limited capacity for O(2)-independent ATP production. Thus, it is reasonable to speculate that the degree of metabolic rate suppression and the quantity of stored fermentable fuel is strongly selected for in hypoxia-tolerant fishes; however, these assertions have not been tested in a phylogenetic comparative model.

  17. Membrane lipid unsaturation as physiological adaptation to animal longevity

    PubMed Central

    Naudí, Alba; Jové, Mariona; Ayala, Victòria; Portero-Otín, Manuel; Barja, Gustavo; Pamplona, Reinald

    2013-01-01

    The appearance of oxygen in the terrestrial atmosphere represented an important selective pressure for ancestral living organisms and contributed toward setting up the pace of evolutionary changes in structural and functional systems. The evolution of using oxygen for efficient energy production served as a driving force for the evolution of complex organisms. The redox reactions associated with its use were, however, responsible for the production of reactive species (derived from oxygen and lipids) with damaging effects due to oxidative chemical modifications of essential cellular components. Consequently, aerobic life required the emergence and selection of antioxidant defense systems. As a result, a high diversity in molecular and structural antioxidant defenses evolved. In the following paragraphs, we analyze the adaptation of biological membranes as a dynamic structural defense against reactive species evolved by animals. In particular, our goal is to describe the physiological mechanisms underlying the structural adaptation of cellular membranes to oxidative stress and to explain the meaning of this adaptive mechanism, and to review the state of the art about the link between membrane composition and longevity of animal species. PMID:24381560

  18. Respiratory physiology: adaptations to high-level exercise.

    PubMed

    McKenzie, Donald C

    2012-05-01

    Most exercise scientists would agree that the physiological determinants of peak endurance performance include the capacity to transport oxygen to the working muscle, diffusion from the muscle to the mitochondria, energy production and force generation, all influenced by signals from the central nervous system. In general, the capacity of the pulmonary system far exceeds the demands required for ventilation and gas exchange during exercise. Endurance training induces large and significant adaptations within the cardiovascular, musculoskeletal and haematological systems. However, the structural and functional properties of the lung and airways do not change in response to repetitive physical activity and, in elite athletes, the pulmonary system may become a limiting factor to exercise at sea level and altitude. As a consequence to this respiratory paradox, highly trained athletes may develop intrathoracic and extrathoracic obstruction, expiratory flow limitation, respiratory muscle fatigue and exercise-induced hypoxaemia. All of these maladaptations may influence performance.

  19. [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.

  20. Dietary Antioxidants as Modifiers of Physiologic Adaptations to Exercise

    PubMed Central

    Mankowski, Robert T.; Anton, Stephen D.; Buford, Thomas W.; Leeuwenburgh, Christiaan

    2015-01-01

    Adaptive responses to exercise training (ET) are crucial in maintaining physiological homeostasis and health span. Exercise-induced aerobic bioenergetic reactions in mitochondria and cytosol increase production of reactive oxygen species (ROSs), where excess of ROS can be scavenged by enzymatic as well as non-enzymatic antioxidants to protect against deleterious oxidative stress. Free radicals, however, have recently been recognized as crucial signaling agents that promote adaptive mechanisms to ET, such as mitochondrial biogenesis, antioxidant (AO) enzyme activity defense system upregulation, insulin sensitivity, and glucose uptake in skeletal muscle. Commonly used non-enzymatic AO supplements, such as vitamins C and E, a-lipoic acid, and polyphenols, in combination with ET, have been proposed as ways to prevent exercise-induced oxidative stress and hence improve adaptation responses to endurance training. Preclinical and clinical studies to date have shown inconsistent results indicating either positive or negative effects of endurance training combined with different blends of AO supplements (mostly vitamins C and E and a-lipoic acid) on redox status, mitochondrial biogenesis pathways, and insulin sensitivity. Preclinical reports on ET combined with resveratrol, however, have shown consistent positive effects on exercise performance, mitochondrial biogenesis, and insulin sensitivity, with clinical trials reporting mixed effects. Relevant clinical studies have been few and have used inconsistent results and methodology (types of compounds, combinations, and supplementation time). The future studies would investigate the effects of specific antioxidants and other popular supplements, such as a-lipoic acid and resveratrol, on training effects in humans. Of particular importance are older adults who may be at higher risk of age-related increased oxidative stress, an impaired AO enzyme defense system, and comorbidities such as hypertension, insulin resistance, and

  1. Dietary Antioxidants as Modifiers of Physiologic Adaptations to Exercise.

    PubMed

    Mankowski, Robert T; Anton, Stephen D; Buford, Thomas W; Leeuwenburgh, Christiaan

    2015-09-01

    Adaptive responses to exercise training (ET) are crucial in maintaining physiologic homeostasis and health span. Exercise-induced aerobic bioenergetic reactions in the mitochondria and cytosol increase production of reactive oxygen species, where excess of reactive oxygen species can be scavenged by enzymatic and nonenzymatic antioxidants (AO) to protect against deleterious oxidative stress. Free radicals, however, have recently been recognized as crucial signaling agents that promote adaptive mechanisms to ET, such as mitochondrial biogenesis, AO enzyme activity defense system upregulation, insulin sensitivity, and glucose uptake in the skeletal muscle. Commonly used nonenzymatic AO supplements, such as vitamins C and E, α-lipoic acid, and polyphenols, in combination with ET, have been proposed as ways to prevent exercise-induced oxidative stress and hence improve adaptation responses to endurance training. During the PubMed search, we selected studies that examined and compared ET effects with and without administration of commonly used AO supplements. Preclinical and clinical studies to date have shown inconsistent results indicating either positive or negative effects of endurance training combined with different blends of AO supplements (mostly vitamins C and E and α-lipoic acid) on redox status, mitochondrial biogenesis pathways, and insulin sensitivity. Preclinical reports on ET combined with resveratrol, however, have shown consistent positive effects on exercise performance, mitochondrial biogenesis, and insulin sensitivity, with clinical trials reporting mixed effects. Relevant clinical studies have been few and have used inconsistent results and methodology (types of compounds, combinations, and supplementation time). The future studies should investigate the effects of specific AO and other popular supplements, such as α-lipoic acid and resveratrol, on training effects in humans. Of particular importance are older adults who may be at higher risk of

  2. 4 CFR 27.2 - The Chair, Vice Chair.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 4 Accounts 1 2011-01-01 2011-01-01 false The Chair, Vice Chair. 27.2 Section 27.2 Accounts...; ORGANIZATION § 27.2 The Chair, Vice Chair. The members of the Board shall select from among its membership a Chairperson, hereinafter the Chair, who shall serve as the chief executive and administrative officer of the...

  3. 4 CFR 27.2 - The Chair, Vice Chair.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 4 Accounts 1 2014-01-01 2013-01-01 true The Chair, Vice Chair. 27.2 Section 27.2 Accounts...; ORGANIZATION § 27.2 The Chair, Vice Chair. The members of the Board shall select from among its membership a Chairperson, hereinafter the Chair, who shall serve as the chief executive and administrative officer of the...

  4. 4 CFR 27.2 - The Chair, Vice Chair.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 4 Accounts 1 2013-01-01 2013-01-01 false The Chair, Vice Chair. 27.2 Section 27.2 Accounts...; ORGANIZATION § 27.2 The Chair, Vice Chair. The members of the Board shall select from among its membership a Chairperson, hereinafter the Chair, who shall serve as the chief executive and administrative officer of the...

  5. 4 CFR 27.2 - The Chair, Vice Chair.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 4 Accounts 1 2012-01-01 2012-01-01 false The Chair, Vice Chair. 27.2 Section 27.2 Accounts...; ORGANIZATION § 27.2 The Chair, Vice Chair. The members of the Board shall select from among its membership a Chairperson, hereinafter the Chair, who shall serve as the chief executive and administrative officer of the...

  6. The Supportive Chair.

    ERIC Educational Resources Information Center

    Rosbottom, Ronald C.

    1987-01-01

    Recommendations for chairs of college-level foreign language departments include: being supportive of the department; communicating fully and openly with faculty and staff; promoting grantsmanship; and encouraging staff and faculty. Recommendations for deans working with chairs and department heads include: consulting frequently and communicating…

  7. Transposition Musical Chairs

    ERIC Educational Resources Information Center

    Yankosky, Bill

    2008-01-01

    This article discusses a classroom activity in which students in a small-sized (n = 4) Abstract Algebra class were able to discover some properties related to permutations and transpositions by physically moving from chair to chair according to suggested guidelines. During the lesson students were able to determine ways to write a permutation as a…

  8. Exercise as a countermeasure for physiological adaptation to prolonged spaceflight

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.

    1996-01-01

    Exercise represents the primary countermeasure used during spaceflight to maintain or restore maximal aerobic capacity (VO2max), musculoskeletal structure, and orthostatic function. However, no single exercise or combination of prescriptions has proven entirely effective in restoring cardiovascular and musculoskeletal functions to preflight levels following prolonged spaceflight. As human spaceflight exposures increase in duration, assessment and development of various effective exercise-based protective procedures become paramount. This must involve improvement in specific countermeasure prescription as well as development of additional approaches that will allow space travelers greater flexibility and medical safety during long flights. Effective exercise prescription will be based on identification of basic physiological stimuli that maintain normal function in terrestrial gravity and understanding of how specific combinations of exercise characteristics e.g., duration, frequency, intensity, mode) can mimic these stimuli and affect the overall process of adaptation to microgravity. This can be accomplished only with greater emphasis of research on ground-based experiments. Future attention must be directed to improving exercise compliance while minimizing both crew time and the impact of the exercise on life-support resources.

  9. Exercise as a countermeasure for physiological adaptation to prolonged spaceflight

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.

    1996-01-01

    Exercise represents the primary countermeasure used during spaceflight to maintain or restore maximal aerobic capacity (VO2max), musculoskeletal structure, and orthostatic function. However, no single exercise or combination of prescriptions has proven entirely effective in restoring cardiovascular and musculoskeletal functions to preflight levels following prolonged spaceflight. As human spaceflight exposures increase in duration, assessment and development of various effective exercise-based protective procedures become paramount. This must involve improvement in specific countermeasure prescription as well as development of additional approaches that will allow space travelers greater flexibility and medical safety during long flights. Effective exercise prescription will be based on identification of basic physiological stimuli that maintain normal function in terrestrial gravity and understanding of how specific combinations of exercise characteristics e.g., duration, frequency, intensity, mode) can mimic these stimuli and affect the overall process of adaptation to microgravity. This can be accomplished only with greater emphasis of research on ground-based experiments. Future attention must be directed to improving exercise compliance while minimizing both crew time and the impact of the exercise on life-support resources.

  10. Chair Inserts for Preschoolers.

    ERIC Educational Resources Information Center

    Horn, Eva; And Others

    1987-01-01

    The article provides detailed procedures (with diagrams) for constructing cardboard chair inserts to meet the needs of preschool children with minimal to severe physical limitations. The inserts offer reduced expense and increased flexibility allowing a customized fit. (DB)

  11. 4 CFR 27.2 - The Chair, Vice Chair.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 4 Accounts 1 2010-01-01 2010-01-01 false The Chair, Vice Chair. 27.2 Section 27.2 Accounts GOVERNMENT ACCOUNTABILITY OFFICE GENERAL PROCEDURES GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL APPEALS BOARD; ORGANIZATION § 27.2 The Chair, Vice Chair. The members of the Board shall select from among its membership...

  12. Stress Reducing Chair

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Flogiston Chair incorporates NASA human factors in spacecraft design technology as well as information from NASA's Anthropometric Source Book. Designed by Brian V. Park, it provides a close approximation of the natural position a body assumes in weightless space. Its principal markets are information workers, designers, software developers, data processors, etc. It assists in maintaining concentration, is useful for relaxation and reality ventures. The chair may be fixed, rockable, or suspended from the ceiling.

  13. Resistance Training: Physiological Responses and Adaptations (Part 2 of 4).

    ERIC Educational Resources Information Center

    Fleck, Stephen J.; Kraerner, William J.

    1988-01-01

    Resistance training causes a variety of physiological reactions, including changes in muscle size, connective tissue size, and bone mineral content. This article summarizes data from a variety of studies and research. (JL)

  14. Resistance Training: Physiological Responses and Adaptations (Part 2 of 4).

    ERIC Educational Resources Information Center

    Fleck, Stephen J.; Kraerner, William J.

    1988-01-01

    Resistance training causes a variety of physiological reactions, including changes in muscle size, connective tissue size, and bone mineral content. This article summarizes data from a variety of studies and research. (JL)

  15. Skylab experiment M131: Rotating little chair

    NASA Technical Reports Server (NTRS)

    Evans, J. S.; Zitterkopf, D. L.; Konigsberg, R. L.; Blackburn, C. M.

    1977-01-01

    Physiological considerations suggest that the response of the vestibular system can be substantially modified during weightlessness and that such modifications affect susceptibility to motion sickness and to judgment of spatial localization. Evaluation of such effects requires measurement of responses to rotational accelerations before, during, and after exposure to conditions of prolonged zero-gravity. For this purpose, a precisely controlled rotating chair was designed, constructed, tested, and installed in the Skylab Orbital Workshop. The chair was used in three test modes to measure changes in the vestibular (balance) organs of the astronauts.

  16. Physiology of environmental adaptations and resource acquisition in cockroaches.

    PubMed

    Mullins, Donald E

    2015-01-07

    Cockroaches are a group of insects that evolved early in geological time. Because of their antiquity, they for the most part display generalized behavior and physiology and accordingly have frequently been used as model insects to examine physiological and biochemical mechanisms involved with water balance, nutrition, reproduction, genetics, and insecticide resistance. As a result, a considerable amount of information on these topics is available. However, there is much more to be learned by employing new protocols, microchemical analytical techniques, and molecular biology tools to explore many unanswered questions.

  17. Human Adaptation to Space: Space Physiology and Countermeasures

    NASA Technical Reports Server (NTRS)

    Fogarty, Jennifer

    2009-01-01

    This viewgraph presentation reviews human physiological responses to spaceflight, and the countermeasures taken to prevent adverse effects of manned space flight. The topics include: 1) Human Spaceflight Experience; 2) Human Response to Spaceflight; 3) ISS Expeditions 1-16; 4) Countermeasure; and 5) Biomedical Data;

  18. Effect of a care plan based on Roy adaptation model biological dimension on stroke patients' physiologic adaptation level.

    PubMed

    Alimohammadi, Nasrollah; Maleki, Bibi; Shahriari, Mohsen; Chitsaz, Ahmad

    2015-01-01

    Stroke is a stressful event with several functional, physical, psychological, social, and economic problems that affect individuals' different living balances. With coping strategies, patients try to control these problems and return to their natural life. The aim of this study is to investigate the effect of a care plan based on Roy adaptation model biological dimension on stroke patients' physiologic adaptation level. This study is a clinical trial in which 50 patients, affected by brain stroke and being admitted in the neurology ward of Kashani and Alzahra hospitals, were randomly assigned to control and study groups in Isfahan in 2013. Roy adaptation model care plan was administered in biological dimension in the form of four sessions and phone call follow-ups for 1 month. The forms related to Roy adaptation model were completed before and after intervention in the two groups. Chi-square test and t-test were used to analyze the data through SPSS 18. There was a significant difference in mean score of adaptation in physiological dimension in the study group after intervention (P < 0.001) compared to before intervention. Comparison of the mean scores of changes of adaptation in the patients affected by brain stroke in the study and control groups showed a significant increase in physiological dimension in the study group by 47.30 after intervention (P < 0.001). The results of study showed that Roy adaptation model biological dimension care plan can result in an increase in adaptation in patients with stroke in physiological dimension. Nurses can use this model for increasing patients' adaptation.

  19. Effect of a care plan based on Roy adaptation model biological dimension on stroke patients’ physiologic adaptation level

    PubMed Central

    Alimohammadi, Nasrollah; Maleki, Bibi; Shahriari, Mohsen; Chitsaz, Ahmad

    2015-01-01

    Background: Stroke is a stressful event with several functional, physical, psychological, social, and economic problems that affect individuals’ different living balances. With coping strategies, patients try to control these problems and return to their natural life. The aim of this study is to investigate the effect of a care plan based on Roy adaptation model biological dimension on stroke patients’ physiologic adaptation level. Materials and Methods: This study is a clinical trial in which 50 patients, affected by brain stroke and being admitted in the neurology ward of Kashani and Alzahra hospitals, were randomly assigned to control and study groups in Isfahan in 2013. Roy adaptation model care plan was administered in biological dimension in the form of four sessions and phone call follow-ups for 1 month. The forms related to Roy adaptation model were completed before and after intervention in the two groups. Chi-square test and t-test were used to analyze the data through SPSS 18. Results: There was a significant difference in mean score of adaptation in physiological dimension in the study group after intervention (P < 0.001) compared to before intervention. Comparison of the mean scores of changes of adaptation in the patients affected by brain stroke in the study and control groups showed a significant increase in physiological dimension in the study group by 47.30 after intervention (P < 0.001). Conclusions: The results of study showed that Roy adaptation model biological dimension care plan can result in an increase in adaptation in patients with stroke in physiological dimension. Nurses can use this model for increasing patients’ adaptation. PMID:25878708

  20. Chairing a Small Department.

    ERIC Educational Resources Information Center

    Bowker, Lee H.; Lynch, David M.

    Ten management problems for chairs of small departments in small colleges are discussed, along with problem-solving strategies for these administrators. Serious disagreements within a small and intimate department may create a country club culture in which differences are smoothed over and the personal idiosyncrasies of individual members are…

  1. Chair-ish.

    ERIC Educational Resources Information Center

    Greenman, Geri

    2000-01-01

    Presents an art assignment that helps students progress from color theory and the color wheel to understanding watercolor techniques. Explains that students apply their knowledge of watercolor techniques by using three of ten techniques to create different views of a chair in the Cubist style. (CMK)

  2. Chair-ish.

    ERIC Educational Resources Information Center

    Greenman, Geri

    2000-01-01

    Presents an art assignment that helps students progress from color theory and the color wheel to understanding watercolor techniques. Explains that students apply their knowledge of watercolor techniques by using three of ten techniques to create different views of a chair in the Cubist style. (CMK)

  3. Physiological Adaptations to Training in Competitive Swimming: A Systematic Review

    PubMed Central

    Costa, Mário J.; Balasekaran, Govindasamy; Vilas-Boas, J. Paulo; Barbosa, Tiago M.

    2015-01-01

    The purpose of this systematic review was to summarize longitudinal studies on swimming physiology and get implications for daily practice. A computerized search of databases according to the PRISMA statement was employed. Studies were screened for eligibility on inclusion criteria: (i) present two testing points; (ii) on swimming physiology; (iii) using adult elite swimmers; (iv) no case-studies or with small sample sizes. Two independent reviewers used a checklist to assess the methodological quality of the studies. Thirty-four studies selected for analysis were gathered into five main categories: blood composition (n=7), endocrine secretion (n=11), muscle biochemistry (n=7), cardiovascular response (n=8) and the energetic profile (n=14). The mean quality index was 10.58 ± 2.19 points demonstrating an almost perfect agreement between reviewers (K = 0.93). It can be concluded that the mixed findings in the literature are due to the diversity of the experimental designs. Micro variables obtained at the cellular or molecular level are sensitive measures and demonstrate overtraining signs and health symptoms. The improvement of macro variables (i.e. main physiological systems) is limited and may depend on the athletes’ training background and experience. PMID:26839618

  4. Physiological Adaptations to Training in Competitive Swimming: A Systematic Review.

    PubMed

    Costa, Mário J; Balasekaran, Govindasamy; Vilas-Boas, J Paulo; Barbosa, Tiago M

    2015-12-22

    The purpose of this systematic review was to summarize longitudinal studies on swimming physiology and get implications for daily practice. A computerized search of databases according to the PRISMA statement was employed. Studies were screened for eligibility on inclusion criteria: (i) present two testing points; (ii) on swimming physiology; (iii) using adult elite swimmers; (iv) no case-studies or with small sample sizes. Two independent reviewers used a checklist to assess the methodological quality of the studies. Thirty-four studies selected for analysis were gathered into five main categories: blood composition (n=7), endocrine secretion (n=11), muscle biochemistry (n=7), cardiovascular response (n=8) and the energetic profile (n=14). The mean quality index was 10.58 ± 2.19 points demonstrating an almost perfect agreement between reviewers (K = 0.93). It can be concluded that the mixed findings in the literature are due to the diversity of the experimental designs. Micro variables obtained at the cellular or molecular level are sensitive measures and demonstrate overtraining signs and health symptoms. The improvement of macro variables (i.e. main physiological systems) is limited and may depend on the athletes' training background and experience.

  5. Physiological adaptations and countermeasures associated with long-duration spaceflights

    NASA Technical Reports Server (NTRS)

    Tipton, C. M.; Hargens, A.

    1996-01-01

    Since 1961, there have been more than 165 flights involving several hundred individuals who have remained in a space environment from 15 min to more than a year. In addition, plans exist for humans to explore, colonize, and remain in microgravity for 1000 d or more. This symposium will address the current state of knowledge in select aspects associated with the cardiovascular, fluid and electrolytes, musculoskeletal, and the neuroendocrine and immune systems. The authors will focus on responses, mechanisms, and the appropriate countermeasures to minimize or prevent the physiological and biochemical consequences of a microgravity environment. Since exercise is frequently cited as a generic countermeasure, this topic will be covered in greater detail. Models for simulated microgravity conditions will be discussed in subsequent manuscripts, as will future directions for ground-based research.

  6. Physiological adaptations and countermeasures associated with long-duration spaceflights

    NASA Technical Reports Server (NTRS)

    Tipton, C. M.; Hargens, A.

    1996-01-01

    Since 1961, there have been more than 165 flights involving several hundred individuals who have remained in a space environment from 15 min to more than a year. In addition, plans exist for humans to explore, colonize, and remain in microgravity for 1000 d or more. This symposium will address the current state of knowledge in select aspects associated with the cardiovascular, fluid and electrolytes, musculoskeletal, and the neuroendocrine and immune systems. The authors will focus on responses, mechanisms, and the appropriate countermeasures to minimize or prevent the physiological and biochemical consequences of a microgravity environment. Since exercise is frequently cited as a generic countermeasure, this topic will be covered in greater detail. Models for simulated microgravity conditions will be discussed in subsequent manuscripts, as will future directions for ground-based research.

  7. Physiological adaptations and countermeasures associated with long-duration spaceflights.

    PubMed

    Tipton, C M; Hargens, A

    1996-08-01

    Since 1961, there have been more than 165 flights involving several hundred individuals who have remained in a space environment from 15 min to more than a year. In addition, plans exist for humans to explore, colonize, and remain in microgravity for 1000 d or more. This symposium will address the current state of knowledge in select aspects associated with the cardiovascular, fluid and electrolytes, musculoskeletal, and the neuroendocrine and immune systems. The authors will focus on responses, mechanisms, and the appropriate countermeasures to minimize or prevent the physiological and biochemical consequences of a microgravity environment. Since exercise is frequently cited as a generic countermeasure, this topic will be covered in greater detail. Models for simulated microgravity conditions will be discussed in subsequent manuscripts, as will future directions for ground-based research.

  8. Physiological and behavioral adaptations in bats living at high latitudes.

    PubMed

    Boyles, Justin G; McGuire, Liam P; Boyles, Esmarie; Reimer, Jesika P; Brooks, Christopher A C; Rutherford, Robert W; Rutherford, Teresa A; Whitaker, John O; McCracken, Gary F

    2016-10-15

    Widespread animals at the extremes of the species' distribution experience ecological constraints different than individuals in the core of the distribution. For example, small endotherms at very high latitudes face short summers with cool temperatures and a lack of true darkness. In particular, insectivorous bats at high latitudes may experience constraints because of their unique life history traits, and may have different energy requirements than bats at lower latitudes. To evaluate the extent of these differences, we estimated an energy budget and refueling rates for reproductively active female little brown bats (Myotis lucifugus) roosting in buildings in eastern Alaska (~63°N). Physiological parameters (torpor use and metabolic rates) and daily energy expenditures (25.7±5.3kJd(-1)) were similar to, or slightly lower than, conspecifics at lower latitudes. Northern little brown bats foraged for less time than southerly conspecifics, but measurements of plasma β-hydroxybutyrate concentrations suggest that northern bats refuel at a rate considerably higher than those to the south. It appears that high refueling rates (and therefore foraging intensity) involve a dietary shift to orb-weaver spiders, which are abundant and likely offer higher energetic benefit than the small, flying insects consumed by individuals in other parts of the distribution. Environmental factors may limit species' distributions, but our results provide an example of a population at the limit of their geographic range that has compensated for environmental challenges by adopting unique behavioral strategies while the underlying physiology (including daily energy expenditure) remains similar to populations at the core of the species' range. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Phenotyping for drought adaptation in wheat using physiological traits

    PubMed Central

    Monneveux, Philippe; Jing, Ruilian; Misra, Satish C.

    2012-01-01

    Wheat (Triticum spp) is one of the first domesticated food crops. It represents the first source of calories (after rice) and an important source of proteins in developing countries. As a result of the Green Revolution, wheat yield sharply increased due to the use of improved varieties, irrigation, pesticides, and fertilizers. The rate of increase in world wheat production, however, slowed after 1980, except in China, India, and Pakistan. Being adapted to a wide range of moisture conditions, wheat is grown on more land area worldwide than any other crop, including in drought prone areas. In these marginal rain-fed environments where at least 60 m ha of wheat is grown, amount and distribution of rainfall are the predominant factors influencing yield variability. Intensive work has been carried out in the area of drought adaptation over the last decades. Breeding strategies for drought tolerance improvement include: definition of the target environment, choice and characterization of the testing environment, water stress management and characterization, and use of phenotyping traits with high heritability. The use of integrative traits, facilitated by the development and application of new technologies (thermal imaging, spectral reflectance, stable isotopes) is facilitating high throughput phenotyping and indirect selection, consequently favoring yield improvement in drought prone environments. PMID:23181021

  10. Phenotyping for drought adaptation in wheat using physiological traits.

    PubMed

    Monneveux, Philippe; Jing, Ruilian; Misra, Satish C

    2012-01-01

    Wheat (Triticum spp) is one of the first domesticated food crops. It represents the first source of calories (after rice) and an important source of proteins in developing countries. As a result of the Green Revolution, wheat yield sharply increased due to the use of improved varieties, irrigation, pesticides, and fertilizers. The rate of increase in world wheat production, however, slowed after 1980, except in China, India, and Pakistan. Being adapted to a wide range of moisture conditions, wheat is grown on more land area worldwide than any other crop, including in drought prone areas. In these marginal rain-fed environments where at least 60 m ha of wheat is grown, amount and distribution of rainfall are the predominant factors influencing yield variability. Intensive work has been carried out in the area of drought adaptation over the last decades. Breeding strategies for drought tolerance improvement include: definition of the target environment, choice and characterization of the testing environment, water stress management and characterization, and use of phenotyping traits with high heritability. The use of integrative traits, facilitated by the development and application of new technologies (thermal imaging, spectral reflectance, stable isotopes) is facilitating high throughput phenotyping and indirect selection, consequently favoring yield improvement in drought prone environments.

  11. Physiological and proteomic characterization of light adaptations in marine Synechococcus.

    PubMed

    Mackey, Katherine R M; Post, Anton F; McIlvin, Matthew R; Saito, Mak A

    2017-06-01

    Marine Synechococcus thrive over a range of light regimes in the ocean. We examined the proteomic, genomic and physiological responses of seven Synechococcus isolates to moderate irradiances (5-80 μE m(-2) s(-1) ), and show that Synechococcus spans a continuum of light responses ranging from low light optimized (LLO) to high light optimized (HLO). These light responses are linked to phylogeny and pigmentation. Marine sub-cluster 5.1A isolates with higher phycouribilin: phycoerythrobilin ratios fell toward the LLO end of the continuum, while sub-cluster 5.1B, 5.2 and estuarine Synechococcus with less phycouribilin fell toward the HLO end of the continuum. Global proteomes were highly responsive to light, with > 50% of abundant proteins varying more than twofold between the lowest and highest irradiance. All strains downregulated phycobilisome proteins with increasing irradiance. Regulation of proteins involved in photosynthetic electron transport, carbon fixation, oxidative stress protection (superoxide dismutases) and iron and nitrogen metabolism varied among strains, as did the number of high light inducible protein (Hlip) and DNA photolyase genes in their genomes. All but one LLO strain possessed the photoprotective orange carotenoid protein (OCP). The unique combinations of light responses in each strain gives rise to distinct photophysiological phenotypes that may affect Synechococcus distributions in the ocean. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Distribution, adaptation and physiological meaning of thiols from vertebrate hemoglobins.

    PubMed

    Reischl, Evaldo; Dafre, Alcir Luiz; Franco, Jeferson Luis; Wilhelm Filho, Danilo

    2007-01-01

    In the present review, the sequences of hemoglobins (Hb) of 267 adult vertebrate species belonging to eight major vertebrate taxa are examined for the presence and location of cysteinyl residues in an attempt at correlation with their ecophysiology. Essentially, all vertebrates have surface cysteinyl residues in Hb molecules whereby their thiol groups may become highly reactive. Thiol-rich Hbs may display eight or more thiols per tetramer. In vertebrates so far examined, the cysteinyl residues occur in 44 different sequence positions in alpha chains and 41 positions in beta chains. Most of them are conservatively located and occur in only a few positions in Teleostei, Aves and Mammalia, whereas they are dispersed in Amphibia. The internal cysteinyl residue alpha104 is ubiquitous in vertebrates. Residue beta93 is highly conserved in reptiles, birds and mammals. The number of cysteine residues per tetramer with solvent access varies in vertebrates, mammalians and bony fish having the lowest number of external residues, whereas nearly all external cysteine residues in Aves and Lepidosauria are of the surface crevice type. In cartilaginous fish, amphibians, Crocodylidae and fresh water turtles, a substantial portion of the solvent accessible thiols are of the totally external type. Recent evidence shows that some Hb thiol groups are highly reactive and undergo extensive and reversible S-thiolation, and that they may be implicated in interorgan redox equilibrium processes. Participation of thiol groups in nitric oxide ((*)NO) metabolism has also been proved. The evidence argues for a new physiologically relevant role for Hb via involvement in free radical and antioxidant metabolism.

  13. Physiological adaptation in noncompetitive rock climbers: good for aerobic fitness?

    PubMed

    Rodio, Angelo; Fattorini, Luigi; Rosponi, Alessandro; Quattrini, Filippo M; Marchetti, Marco

    2008-03-01

    The present investigation aimed to establish whether noncompetitive rock climbing fulfills sports medicine recommendations for maintaining a good level of aerobic fitness. The physiological profile of 13 rock climbers, 8 men (age, 43 +/- 8 years) and 5 women (age, 31 +/- 8 years) was assessed by means of laboratory tests. Maximal aerobic power (VO2peak) and ventilatory threshold (VT) were assessed using a cycloergometer incremental test. During outdoor rock face climbing, VO2 and heart rate (HR) were measured with a portable metabolimeter and the relative steady-state values (VO2 and HR during rock climbing) were computed. Blood lactate was measured during recovery. All data are presented as mean +/- SD. VO2 was 39.1 +/- 4.3 mL.kg.min in men and 39.7 +/- 5 mL.kg.min in women, while VT was 29.4 +/- 3.0 mL.kg.min in men and 28.8 +/- 4.6 mL.kg.min in women. The VO2 during rock climbing was 28.3 +/- 1.5 mL.kg.min in men and 27.5 +/- 3.7 mL.kg.min in women. The HR during rock climbing was 144 +/- 16 b.min in men and 164 +/- 13 b.min in women. The aerobic profile was classified from excellent to superior in accordance with the standards of the American College of Sports Medicine (ACSM). The exercise intensity (VO2 during rock climbing expressed as a percentage of VO2peak) was 70 +/- 6% in men and 72 +/- 8% in women. Moreover, the energy expenditure was 1000-1500 kcal per week. In conclusion, noncompetitive rock climbing has proved to be a typical aerobic activity. The intensity of exercise is comparable to that recommended by the American College of Sports Medicine to maintain good cardiorespiratory fitness.

  14. [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.

  15. 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

  16. 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.

  17. The lugworm Arenicola marina: A model of physiological adaptation to life in intertidal sediments

    NASA Astrophysics Data System (ADS)

    Zebe, E.; Schiedek, D.

    1996-03-01

    The results of more than two decades of intensive research on the physiological and biochemical features of the lugworm are reviewed with the aim of drawing a general and comprehensive picture of the adaptation of this species to the special conditions of living in the tidal zone, which may also hold true for the majority of invertebrates found in this habitat.

  18. Adaptation to Altitude as a Vehicle for Experiential Learning of Physiology by University Undergraduates

    ERIC Educational Resources Information Center

    Weigle, David S.; Buben, Amelia; Burke, Caitlin C.; Carroll, Nels D.; Cook, Brett M.; Davis, Benjamin S.; Dubowitz, Gerald; Fisher, Rian E.; Freeman, Timothy C.; Gibbons, Stephen M.; Hansen, Hale A.; Heys, Kimberly A.; Hopkins, Brittany; Jordan, Brittany L.; McElwain, Katherine L.; Powell, Frank L.; Reinhart, Katherine E.; Robbins, Charles D.; Summers, Cameron C.; Walker, Jennifer D.; Weber, Steven S.; Weinheimer, Caroline J.

    2007-01-01

    In this article, an experiential learning activity is described in which 19 university undergraduates made experimental observations on each other to explore physiological adaptations to high altitude. Following 2 wk of didactic sessions and baseline data collection at sea level, the group ascended to a research station at 12,500-ft elevation.…

  19. Adaptation to Altitude as a Vehicle for Experiential Learning of Physiology by University Undergraduates

    ERIC Educational Resources Information Center

    Weigle, David S.; Buben, Amelia; Burke, Caitlin C.; Carroll, Nels D.; Cook, Brett M.; Davis, Benjamin S.; Dubowitz, Gerald; Fisher, Rian E.; Freeman, Timothy C.; Gibbons, Stephen M.; Hansen, Hale A.; Heys, Kimberly A.; Hopkins, Brittany; Jordan, Brittany L.; McElwain, Katherine L.; Powell, Frank L.; Reinhart, Katherine E.; Robbins, Charles D.; Summers, Cameron C.; Walker, Jennifer D.; Weber, Steven S.; Weinheimer, Caroline J.

    2007-01-01

    In this article, an experiential learning activity is described in which 19 university undergraduates made experimental observations on each other to explore physiological adaptations to high altitude. Following 2 wk of didactic sessions and baseline data collection at sea level, the group ascended to a research station at 12,500-ft elevation.…

  20. Physiology of adaptation of first-year students to studies at higher educational institutions.

    PubMed

    Panikhina, A V

    2011-07-01

    Changes in anthropometric and hematological values and parameters of cardiovascular function indicated sufficiently effective adaptation of first-year students to studies at higher educational institutions. On the other hand, a certain strain of the physiological optimum caused by examination stress was found in the students.

  1. PHYCAA+: an optimized, adaptive procedure for measuring and controlling physiological noise in BOLD fMRI.

    PubMed

    Churchill, Nathan W; Strother, Stephen C

    2013-11-15

    The presence of physiological noise in functional MRI can greatly limit the sensitivity and accuracy of BOLD signal measurements, and produce significant false positives. There are two main types of physiological confounds: (1) high-variance signal in non-neuronal tissues of the brain including vascular tracts, sinuses and ventricles, and (2) physiological noise components which extend into gray matter tissue. These physiological effects may also be partially coupled with stimuli (and thus the BOLD response). To address these issues, we have developed PHYCAA+, a significantly improved version of the PHYCAA algorithm (Churchill et al., 2011) that (1) down-weights the variance of voxels in probable non-neuronal tissue, and (2) identifies the multivariate physiological noise subspace in gray matter that is linked to non-neuronal tissue. This model estimates physiological noise directly from EPI data, without requiring external measures of heartbeat and respiration, or manual selection of physiological components. The PHYCAA+ model significantly improves the prediction accuracy and reproducibility of single-subject analyses, compared to PHYCAA and a number of commonly-used physiological correction algorithms. Individual subject denoising with PHYCAA+ is independently validated by showing that it consistently increased between-subject activation overlap, and minimized false-positive signal in non gray-matter loci. The results are demonstrated for both block and fast single-event task designs, applied to standard univariate and adaptive multivariate analysis models. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Differential and Conditional Activation of PKC-Isoforms Dictates Cardiac Adaptation during Physiological to Pathological Hypertrophy

    PubMed Central

    Naskar, Shaon; Datta, Kaberi; Mitra, Arkadeep; Pathak, Kanchan; Datta, Ritwik; Bansal, Trisha; Sarkar, Sagartirtha

    2014-01-01

    A cardiac hypertrophy is defined as an increase in heart mass which may either be beneficial (physiological hypertrophy) or detrimental (pathological hypertrophy). This study was undertaken to establish the role of different protein kinase-C (PKC) isoforms in the regulation of cardiac adaptation during two types of cardiac hypertrophy. Phosphorylation of specific PKC-isoforms and expression of their downstream proteins were studied during physiological and pathological hypertrophy in 24 week male Balb/c mice (Mus musculus) models, by reverse transcriptase-PCR, western blot analysis and M-mode echocardiography for cardiac function analysis. PKC-δ was significantly induced during pathological hypertrophy while PKC-α was exclusively activated during physiological hypertrophy in our study. PKC-δ activation during pathological hypertrophy resulted in cardiomyocyte apoptosis leading to compromised cardiac function and on the other hand, activation of PKC-α during physiological hypertrophy promoted cardiomyocyte growth but down regulated cellular apoptotic load resulting in improved cardiac function. Reversal in PKC-isoform with induced activation of PKC-δ and simultaneous inhibition of phospho-PKC-α resulted in an efficient myocardium to deteriorate considerably resulting in compromised cardiac function during physiological hypertrophy via augmentation of apoptotic and fibrotic load. This is the first report where PKC-α and -δ have been shown to play crucial role in cardiac adaptation during physiological and pathological hypertrophy respectively thereby rendering compromised cardiac function to an otherwise efficient heart by conditional reversal of their activation. PMID:25116170

  3. Differential and conditional activation of PKC-isoforms dictates cardiac adaptation during physiological to pathological hypertrophy.

    PubMed

    Naskar, Shaon; Datta, Kaberi; Mitra, Arkadeep; Pathak, Kanchan; Datta, Ritwik; Bansal, Trisha; Sarkar, Sagartirtha

    2014-01-01

    A cardiac hypertrophy is defined as an increase in heart mass which may either be beneficial (physiological hypertrophy) or detrimental (pathological hypertrophy). This study was undertaken to establish the role of different protein kinase-C (PKC) isoforms in the regulation of cardiac adaptation during two types of cardiac hypertrophy. Phosphorylation of specific PKC-isoforms and expression of their downstream proteins were studied during physiological and pathological hypertrophy in 24 week male Balb/c mice (Mus musculus) models, by reverse transcriptase-PCR, western blot analysis and M-mode echocardiography for cardiac function analysis. PKC-δ was significantly induced during pathological hypertrophy while PKC-α was exclusively activated during physiological hypertrophy in our study. PKC-δ activation during pathological hypertrophy resulted in cardiomyocyte apoptosis leading to compromised cardiac function and on the other hand, activation of PKC-α during physiological hypertrophy promoted cardiomyocyte growth but down regulated cellular apoptotic load resulting in improved cardiac function. Reversal in PKC-isoform with induced activation of PKC-δ and simultaneous inhibition of phospho-PKC-α resulted in an efficient myocardium to deteriorate considerably resulting in compromised cardiac function during physiological hypertrophy via augmentation of apoptotic and fibrotic load. This is the first report where PKC-α and -δ have been shown to play crucial role in cardiac adaptation during physiological and pathological hypertrophy respectively thereby rendering compromised cardiac function to an otherwise efficient heart by conditional reversal of their activation.

  4. Principles of exercise physiology: responses to acute exercise and long-term adaptations to training.

    PubMed

    Rivera-Brown, Anita M; Frontera, Walter R

    2012-11-01

    Physical activity and fitness are associated with a lower prevalence of chronic diseases, such as heart disease, cancer, high blood pressure, and diabetes. This review discusses the body's response to an acute bout of exercise and long-term physiological adaptations to exercise training with an emphasis on endurance exercise. An overview is provided of skeletal muscle actions, muscle fiber types, and the major metabolic pathways involved in energy production. The importance of adequate fluid intake during exercise sessions to prevent impairments induced by dehydration on endurance exercise, muscular power, and strength is discussed. Physiological adaptations that result from regular exercise training such as increases in cardiorespiratory capacity and strength are mentioned. The review emphasizes the cardiovascular and metabolic adaptations that lead to improvements in maximal oxygen capacity.

  5. Shell funds chair

    NASA Astrophysics Data System (ADS)

    The Shell Companies Foundation, Inc., of Houston, Tex., has given $750,000 to the University of Texas at Austin to establish the Shell Distinguished Chair in Geophysics. The 5-year, $150,000-per-year grant will support the studies of John G. Sclater. Sclater, currently a professor at the Massachusetts Institute of Technology, has accepted a joint position that begins July 1 in the geological sciences department and in the Institute for Geophysics at UT Austin.Sclater's research into the formation of ocean basins has applications for understanding the way petroleum deposits mature. He has studied the reconstruction of movements of the continents and the subsidence of ocean basins. He is considered an expert in the interpretation of geothermal and seismic data.

  6. Primer for the Interim Chair

    ERIC Educational Resources Information Center

    Soltys, Stephen M.

    2011-01-01

    Objective: Being successful in the role of an Interim Chair requires an approach to transitional leadership that is different from that of individuals filling the Chair role permanently. This article reviews pertinent literature on the topic. Method: The author reviewed the literature, cited pertinent articles, and supplemented with personal…

  7. Primer for the Interim Chair

    ERIC Educational Resources Information Center

    Soltys, Stephen M.

    2011-01-01

    Objective: Being successful in the role of an Interim Chair requires an approach to transitional leadership that is different from that of individuals filling the Chair role permanently. This article reviews pertinent literature on the topic. Method: The author reviewed the literature, cited pertinent articles, and supplemented with personal…

  8. Adaptation and acclimation of aerobic exercise physiology in Lake Whitefish ecotypes (Coregonus clupeaformis).

    PubMed

    Dalziel, Anne C; Martin, Nicolas; Laporte, Martin; Guderley, Helga; Bernatchez, Louis

    2015-08-01

    The physiological mechanisms underlying local adaptation in natural populations of animals, and whether the same mechanisms contribute to adaptation and acclimation, are largely unknown. Therefore, we tested for evolutionary divergence in aerobic exercise physiology in laboratory bred, size-matched crosses of ancestral, benthic, normal Lake Whitefish (Coregonus clupeaformis) and derived, limnetic, more actively swimming "dwarf" ecotypes. We acclimated fish to constant swimming (emulating limnetic foraging) and control conditions (emulating normal activity levels) to simultaneously study phenotypic plasticity. We found extensive divergence between ecotypes: dwarf fish generally had constitutively higher values of traits related to oxygen transport (ventricle size) and use by skeletal muscle (percent oxidative muscle, mitochondrial content), and also evolved differential plasticity of mitochondrial function (Complex I activity and flux through Complexes I-IV and IV). The effects of swim training were less pronounced than differences among ecotypes and the traits which had a significant training effect (ventricle protein content, ventricle malate dehydrogenase activity, and muscle Complex V activity) did not differ among ecotypes. Only one trait, ventricle mass, varied in a similar manner with acclimation and adaptation and followed a pattern consistent with genetic accommodation. Overall, the physiological and biochemical mechanisms underlying acclimation and adaptation to swimming activity in Lake Whitefish differ.

  9. A 6-month analysis of training-intensity distribution and physiological adaptation in Ironman triathletes.

    PubMed

    Neal, Craig M; Hunter, Angus M; Galloway, Stuart D R

    2011-11-01

    In the present study, we analysed the training-intensity distribution and physiological adaptations over a 6-month period preceding an Ironman triathlon race. Ten athletes (mean ± s: age 43 ± 3 years, mass 78.3 ± 10.3 kg, stature 1.79 ± 0.05 m) participated in the study. The study consisted of three training periods (A, B, C), each of approximately 2 months' duration, and four testing weeks. Testing consisted of incremental tests to exhaustion for swimming, cycling and running, and assessments for anthropometry plus cardiovascular and pulmonary measures. The lactate threshold and the lactate turnpoint were used to demarcate three discipline-specific, exercise-intensity zones. The mean percentage of time spent in zones 1, 2, and 3 was 69 ± 9%, 25 ± 8%, and 6 ± 2% for periods A-C combined. Only modest physiological adaptation occurred throughout the 6-month period, with small to moderate effect sizes at best. Relationships between the training volume/training load and the training-intensity distribution with the changes in key measures of adaptation were weak and probably reflect differences in initial training status. Our results suggest that the effects of intensity distribution are small over short-term training periods and future experimental research is needed to clarify the potential impact of intensity distribution on physiological adaptation.

  10. [The physiological analysis of cross adaptation to regular cold exposure and physical activities].

    PubMed

    Son'kin, V D; Iakushkin, A V; Akimov, E B; Andreev, R S; Kalenov, Iu N; Kozlov, A V

    2014-01-01

    Research is devoted to the comparative analysis of results of cold adaptation and physical training. The adaptive shifts occurring in an organism under the influence of a hardening (douche by a cold shower 2 times a day 2 minutes long within 6 weeks) and running training on the treadmill (30 minutes at 70-80% of individual VO2max, 3 times a week, within 6 weeks) were compared at 6 the same subjects. The interval between the two cycles of training was no less than 3 months. The indicators registered during ramp test and standard cold exposure test before and after each cycle of trainings were compared. It is shown that patterns of adaptive shifts at adaptation to factors of various modality strongly differ. Shifts at adaptation to physical activities were as a whole more expressed, than at adaptation to regular cold exposition. An individual variety of adaptive reactions suggests the feasibility of developing new approaches to the theory of the adaptation, connected with studying of physiological individuality.

  11. Rising from a chair. Influence of age and chair design.

    PubMed

    Wheeler, J; Woodward, C; Ucovich, R L; Perry, J; Walker, J M

    1985-01-01

    We studied the effect of age on the act of rising from a standard armchair in a younger (means = 24 years) and an older (means = 75 years) group of healthy adult women. Rising from a standard armchair and an armchair specially designed for comfort in sitting of the elderly was studied in the older group to determine the influence of the special chair. We used electrogoniometry, EMG, and videotape analysis to record the activity for both groups. The older group placed their feet farther back and showed greater vastus lateralis muscle activity than did the younger group to rise from the standard chair. These results suggest that rising from the standard chair was more difficult for the older than for the younger group. In the special chair, the older subjects showed even more vastus lateralis muscle activity, greater knee flexion, and greater trunk forward lean. Rising from the special chair, therefore, appeared to be more difficult than rising from a standard chair; this finding suggests that both comfort and function must be considered in chair selection for certain groups.

  12. Exploring physiological plasticity and local thermal adaptation in an intertidal crab along a latitudinal cline.

    PubMed

    Gaitán-Espitia, Juan Diego; Bacigalupe, Leonardo D; Opitz, Tania; Lagos, Nelson A; Osores, Sebastián; Lardies, Marco A

    2017-08-01

    Intertidal organisms have evolved physiological mechanisms that enable them to maintain performance and survive during periods of severe environmental stress with temperatures close to their tolerance limits. The level of these adaptive responses in thermal physiology can vary among populations of broadly distributed species depending on their particular environmental context and genetic backgrounds. Here we examined thermal performances and reaction norms for metabolic rate (MR) and heart rate (HR) of seven populations of the porcelanid crab Petrolisthes violaceus from markedly different thermal environments across the latitudinal gradient of ~3000km. Physiological responses of this intertidal crab under common-garden conditions suggest the absence of local thermal adaptation along the geographic gradient (i.e., lack of latitudinal compensation). Moreover, thermal physiological sensitivities and performances in response to increased temperatures evidenced the existence of some level of: i) metabolic rate control or depression during warm temperature exposures; and ii) homeostasis/canalization (i.e., absence or low levels of plasticity) in physiological traits that may reflect some sort of buffering mechanism in most of the populations. Nevertheless, our results indicate that elevated temperatures can reduce cardiac function but not metabolic rate in high latitude crabs. The lack of congruence between HR and MR supports the idea that energy metabolism in marine invertebrates cannot be inferred from HR and different conclusions regarding geographic differentiation in energy metabolism can be obtained from both physiological traits. Integrating thermal physiology and species range extent can contribute to a better understanding of the likely effects of climate change on natural populations of marine ectotherms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Genetic and physiological basis of adaptive salt tolerance divergence between coastal and inland Mimulus guttatus.

    PubMed

    Lowry, David B; Hall, Megan C; Salt, David E; Willis, John H

    2009-08-01

    Local adaptation is a well-established phenomenon whereby habitat-mediated natural selection drives the differentiation of populations. However, little is known about how specific traits and loci combine to cause local adaptation. Here, we conducted a set of experiments to determine which physiological mechanisms contribute to locally adaptive divergence in salt tolerance between coastal perennial and inland annual ecotypes of Mimulus guttatus. Quantitative trait locus (QTL) mapping was used to discover loci involved in salt spray tolerance and leaf sodium (Na(+)) concentration. To determine whether these QTLs confer fitness in the field, we examined their effects in reciprocal transplant experiments using recombinant inbred lines (RILs). Coastal plants had constitutively higher leaf Na(+) concentrations and greater levels of tissue tolerance, but no difference in osmotic stress tolerance. Three QTLs contributed to salt spray tolerance and two QTLs to leaf Na(+) concentration. All three salt-spray tolerance QTLs had a significant fitness effects at the coastal field site but no effects inland. Leaf Na(+) QTLs had no detectable fitness effects in the field. * Physiological results are consistent with adaptation of coastal populations to salt spray and soil salinity. Field results suggest that there may not be trade-offs across habitats for alleles involved in local salt spray adaptations.

  14. Hypoxia Inducible Factor Pathway and Physiological Adaptation: A Cell Survival Pathway?

    PubMed

    Kumar, Hemant; Choi, Dong-Kug

    2015-01-01

    Oxygen homeostasis reflects the constant body requirement to generate energy. Hypoxia (0.1-1% O2), physioxia or physoxia (∼1-13%), and normoxia (∼20%) are terms used to define oxygen concentration in the cellular environment. A decrease in oxygen (hypoxia) or excess oxygen (hyperoxia) could be deleterious for cellular adaptation and survival. Hypoxia can occur under both physiological (e.g., exercise, embryonic development, underwater diving, or high altitude) and pathological conditions (e.g., inflammation, solid tumor formation, lung disease, or myocardial infarction). Hypoxia plays a key role in the pathophysiology of heart disease, cancers, stroke, and other causes of mortality. Hypoxia inducible factor(s) (HIFs) are key oxygen sensors that mediate the ability of the cell to cope with decreased oxygen tension. These transcription factors regulate cellular adaptation to hypoxia and protect cells by responding acutely and inducing production of endogenous metabolites and proteins to promptly regulate metabolic pathways. Here, we review the role of the HIF pathway as a metabolic adaptation pathway and how this pathway plays a role in cell survival. We emphasize the roles of the HIF pathway in physiological adaptation, cell death, pH regulation, and adaptation during exercise.

  15. Physiological adaptations to interval training and the role of exercise intensity.

    PubMed

    MacInnis, Martin J; Gibala, Martin J

    2017-05-01

    Interval exercise typically involves repeated bouts of relatively intense exercise interspersed by short periods of recovery. A common classification scheme subdivides this method into high-intensity interval training (HIIT; 'near maximal' efforts) and sprint interval training (SIT; 'supramaximal' efforts). Both forms of interval training induce the classic physiological adaptations characteristic of moderate-intensity continuous training (MICT) such as increased aerobic capacity (V̇O2 max ) and mitochondrial content. This brief review considers the role of exercise intensity in mediating physiological adaptations to training, with a focus on the capacity for aerobic energy metabolism. With respect to skeletal muscle adaptations, cellular stress and the resultant metabolic signals for mitochondrial biogenesis depend largely on exercise intensity, with limited work suggesting that increases in mitochondrial content are superior after HIIT compared to MICT, at least when matched-work comparisons are made within the same individual. It is well established that SIT increases mitochondrial content to a similar extent to MICT despite a reduced exercise volume. At the whole-body level, V̇O2 max is generally increased more by HIIT than MICT for a given training volume, whereas SIT and MICT similarly improve V̇O2 max despite differences in training volume. There is less evidence available regarding the role of exercise intensity in mediating changes in skeletal muscle capillary density, maximum stroke volume and cardiac output, and blood volume. Furthermore, the interactions between intensity and duration and frequency have not been thoroughly explored. While interval training is clearly a potent stimulus for physiological remodelling in humans, the integrative response to this type of exercise warrants further attention, especially in comparison to traditional endurance training. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  16. Predicting organismal vulnerability to climate warming: roles of behaviour, physiology and adaptation

    PubMed Central

    Huey, Raymond B.; Kearney, Michael R.; Krockenberger, Andrew; Holtum, Joseph A. M.; Jess, Mellissa; Williams, Stephen E.

    2012-01-01

    A recently developed integrative framework proposes that the vulnerability of a species to environmental change depends on the species' exposure and sensitivity to environmental change, its resilience to perturbations and its potential to adapt to change. These vulnerability criteria require behavioural, physiological and genetic data. With this information in hand, biologists can predict organisms most at risk from environmental change. Biologists and managers can then target organisms and habitats most at risk. Unfortunately, the required data (e.g. optimal physiological temperatures) are rarely available. Here, we evaluate the reliability of potential proxies (e.g. critical temperatures) that are often available for some groups. Several proxies for ectotherms are promising, but analogous ones for endotherms are lacking. We also develop a simple graphical model of how behavioural thermoregulation, acclimation and adaptation may interact to influence vulnerability over time. After considering this model together with the proxies available for physiological sensitivity to climate change, we conclude that ectotherms sharing vulnerability traits seem concentrated in lowland tropical forests. Their vulnerability may be exacerbated by negative biotic interactions. Whether tropical forest (or other) species can adapt to warming environments is unclear, as genetic and selective data are scant. Nevertheless, the prospects for tropical forest ectotherms appear grim. PMID:22566674

  17. Sexually dimorphic adaptations in basal maternal stress physiology during pregnancy and implications for fetal development.

    PubMed

    Giesbrecht, Gerald F; Campbell, Tavis; Letourneau, Nicole

    2015-06-01

    There is clear evidence of reciprocal exchange of information between the mother and fetus during pregnancy but the majority of research in this area has focussed on the fetus as a recipient of signals from the mother. Specifically, physiological signals produced by the maternal stress systems in response to the environment may carry valuable information about the state of the external world. Prenatal stress produces sex-specific adaptations within fetal physiology that have pervasive and long-lasting effects on development. Little is known, however, about the effects of sex-specific fetal signals on maternal adaptations to pregnancy. The current prospective study examined sexually dimorphic adaptations within maternal stress physiology, including the hypothalamic-adrenal-pituitary (HPA) axis and the autonomic nervous system (ANS) and associations with fetal growth. Using diurnal suites of saliva collected in early and late pregnancy, we demonstrate that basal cortisol and salivary alpha-amylase (sAA) differ by fetal sex. Women carrying female fetuses displayed greater autonomic arousal and flatter (but more elevated) diurnal cortisol patterns compared to women carrying males. Women with flatter daytime cortisol trajectories and more blunted sAA awakening responses also had infants with lower birth weight. These maternal adaptations are consistent with sexually dimorphic fetal developmental/evolutionary adaptation strategies that favor growth for males and conservation of resources for females. The findings provide new evidence to suggest that the fetus contributes to maternal HPA axis and ANS regulation during pregnancy and that these systems also contribute to the regulation of fetal growth.

  18. Actions of Prolactin in the Brain: From Physiological Adaptations to Stress and Neurogenesis to Psychopathology

    PubMed Central

    Torner, Luz

    2016-01-01

    Prolactin (PRL) is one of the most versatile hormones known. It is considered an adaptive hormone due to the key roles it plays in the modulation of the stress response and during pregnancy and lactation. Within the brain, PRL acts as a neuropeptide to promote physiological responses related to reproduction, stress adaptation, neurogenesis, and neuroprotection. The action of PRL on the nervous system contributes to the wide array of changes that occur in the female brain during pregnancy and result in the attenuation of the hypothalamic–pituitary–adrenal axis. Together, all these changes promote behavioral and physiological adaptations of the new mother to enable reproductive success. Brain adaptations driven by PRL are also important for the regulation of maternal emotionality and well-being. PRL also affects the male brain during the stress response, but its effects have been less studied. PRL regulates neurogenesis both in the subventricular zone and in the hippocampus. Therefore, alterations in the PRL system due to stress or exposure to substances that reduce neurogenesis or other conditions, could contribute to maladaptive responses and pathological behavioral outcomes. Here, we review the PRL system and the role it plays in the modulation of stress response and emotion regulation. We discuss the effects of PRL on neurogenesis and neuroprotection, the putative neuronal mechanisms underlying these effects, and their contribution to the onset of psychopathological states such as depression. PMID:27065946

  19. Boldness behavior and stress physiology in a novel urban environment suggest rapid correlated evolutionary adaptation

    PubMed Central

    Cardoso, Gonçalo C.; Whittaker, Danielle J.; Campbell-Nelson, Samuel; Robertson, Kyle W.; Ketterson, Ellen D.

    2012-01-01

    Novel or changing environments expose animals to diverse stressors that likely require coordinated hormonal and behavioral adaptations. Predicted adaptations to urban environments include attenuated physiological responses to stressors and bolder exploratory behaviors, but few studies to date have evaluated the impact of urban life on codivergence of these hormonal and behavioral traits in natural systems. Here, we demonstrate rapid adaptive shifts in both stress physiology and correlated boldness behaviors in a songbird, the dark-eyed junco, following its colonization of a novel urban environment. We compared elevation in corticosterone (CORT) in response to handling and flight initiation distances in birds from a recently established urban population in San Diego, California to birds from a nearby wildland population in the species' ancestral montane breeding range. We also measured CORT and exploratory behavior in birds raised from early life in a captive common garden study. We found persistent population differences for both reduced CORT responses and bolder exploratory behavior in birds from the colonist population, as well as significant negative covariation between maximum CORT and exploratory behavior. Although early developmental effects cannot be ruled out, these results suggest contemporary adaptive evolution of correlated hormonal and behavioral traits associated with colonization of an urban habitat. PMID:22936840

  20. Process- and controller-adaptations determine the physiological effects of cold acclimation.

    PubMed

    Werner, Jürgen

    2008-09-01

    Experimental results on physiological effects of cold adaptation seem confusing and apparently incompatible with one another. This paper will explain that a substantial part of such a variety of results may be deduced from a common functional concept. A core/shell treatment ("model") of the thermoregulatory system is used with mean body temperature as the controlled variable. Adaptation, as a higher control level, is introduced into the system. Due to persistent stressors, either the (heat transfer) process or the controller properties (parameters) are adjusted (or both). It is convenient to call the one "process adaptation" and the other "controller adaptation". The most commonly demonstrated effect of autonomic cold acclimation is a change in the controller threshold. The analysis shows that this necessarily means a lowering of body temperature because of a lowered metabolic rate. This explains experimental results on both Europeans in the climatic chamber and Australian Aborigines in a natural environment. Exclusive autonomic process adaptation occurs in the form of a better insulation. The analysis explains why the post-adaptive steady-state can only be achieved, if the controller system reduces metabolism and why in spite of this the new state is inevitably characterized by a rise in body temperature. If both process and controller adaptations are simultaneously present, there may be not any change of body temperature at all, e.g., as demonstrated in animal experiments. Whether this kind of adaptation delivers a decrease, an increase or no change of mean body temperature, depends on the proportion of process and controller adaptation.

  1. Common-garden studies on adaptive radiation of photosynthetic physiology among Hawaiian lobeliads

    PubMed Central

    Givnish, Thomas J.; Montgomery, Rebecca A.

    2014-01-01

    Species in an adaptive radiation often occupy different habitats so that individuals of each species develop under different conditions. Showing that a radiation is adaptive thus requires evidence that taxa have diverged genetically and that each has an ecological advantage in using particular habitats or resources, taking into account both phenotypic plasticity and phylogenetic relationships among species. Here, we use a common-garden experiment to show that representative species of Hawaiian lobeliads have diverged adaptively in their leaf-level photosynthetic light responses. Across species, plants genetically shifted their photosynthetic physiology with native light regime in accord with theoretical predictions and exhibited adaptive crossover in net carbon gain—that is, species native to a given light regime outperformed others only under conditions similar to those they occupy in the field, with the rank order of species based on photosynthesis per unit leaf mass changing with light level. These findings make a powerful case for adaptation of photosynthetic light responses to native light regimes and, combined with our earlier field studies, provide the strongest demonstration to date for the evolution of divergent adaptations for energy capture in any group of closely related plants. PMID:24478303

  2. Common-garden studies on adaptive radiation of photosynthetic physiology among Hawaiian lobeliads.

    PubMed

    Givnish, Thomas J; Montgomery, Rebecca A

    2014-03-22

    Species in an adaptive radiation often occupy different habitats so that individuals of each species develop under different conditions. Showing that a radiation is adaptive thus requires evidence that taxa have diverged genetically and that each has an ecological advantage in using particular habitats or resources, taking into account both phenotypic plasticity and phylogenetic relationships among species. Here, we use a common-garden experiment to show that representative species of Hawaiian lobeliads have diverged adaptively in their leaf-level photosynthetic light responses. Across species, plants genetically shifted their photosynthetic physiology with native light regime in accord with theoretical predictions and exhibited adaptive crossover in net carbon gain-that is, species native to a given light regime outperformed others only under conditions similar to those they occupy in the field, with the rank order of species based on photosynthesis per unit leaf mass changing with light level. These findings make a powerful case for adaptation of photosynthetic light responses to native light regimes and, combined with our earlier field studies, provide the strongest demonstration to date for the evolution of divergent adaptations for energy capture in any group of closely related plants.

  3. Physiology

    ERIC Educational Resources Information Center

    Kay, Ian

    2008-01-01

    Underlying recent developments in health care and new treatments for disease are advances in basic medical sciences. This edition of "Webwatch" focuses on sites dealing with basic medical sciences, with particular attention given to physiology. There is a vast amount of information on the web related to physiology. The sites that are included here…

  4. Physiology

    ERIC Educational Resources Information Center

    Kay, Ian

    2008-01-01

    Underlying recent developments in health care and new treatments for disease are advances in basic medical sciences. This edition of "Webwatch" focuses on sites dealing with basic medical sciences, with particular attention given to physiology. There is a vast amount of information on the web related to physiology. The sites that are included here…

  5. Myosin heavy chain and physiological adaptation of the rat diaphragm in elastase-induced emphysema

    PubMed Central

    Kim, Dong Kwan; Zhu, Jianliang; Kozyak, Benjamin W; Burkman, James M; Rubinstein, Neal A; Lankford, Edward B; Stedman, Hansell H; Nguyen, Taitan; Levine, Sanford; Shrager, Joseph B

    2003-01-01

    Background Several physiological adaptations occur in the respiratory muscles in rodent models of elastase-induced emphysema. Although the contractile properties of the diaphragm are altered in a way that suggests expression of slower isoforms of myosin heavy chain (MHC), it has been difficult to demonstrate a shift in MHCs in an animal model that corresponds to the shift toward slower MHCs seen in human emphysema. Methods We sought to identify MHC and corresponding physiological changes in the diaphragms of rats with elastase-induced emphysema. Nine rats with emphysema and 11 control rats were studied 10 months after instillation with elastase. MHC isoform composition was determined by both reverse transcriptase polymerase chain reaction (RT-PCR) and immunocytochemistry by using specific probes able to identify all known adult isoforms. Physiological adaptation was studied on diaphragm strips stimulated in vitro. Results In addition to confirming that emphysematous diaphragm has a decreased fatigability, we identified a significantly longer time-to-peak-tension (63.9 ± 2.7 ms versus 53.9 ± 2.4 ms). At both the RNA (RT-PCR) and protein (immunocytochemistry) levels, we found a significant decrease in the fastest, MHC isoform (IIb) in emphysema. Conclusion This is the first demonstration of MHC shifts and corresponding physiological changes in the diaphragm in an animal model of emphysema. It is established that rodent emphysema, like human emphysema, does result in a physiologically significant shift toward slower diaphragmatic MHC isoforms. In the rat, this occurs at the faster end of the MHC spectrum than in humans. PMID:12617755

  6. Volunteer Interacting with a Rotating Chair Demonstration

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Brad McLain for the Space Biology Museum Network spins a volunteer in a rotating chair to illustrate how dependent the human vestibular system is on visual cues. The volunteer's thumbs indicate which way she thinks she is turning. Similar tests are conducted on astronauts to study how they adapt to space and readapt to Earth. The activity was part of the Space Research and You education event held by NASA's Office of Biological and Physical Research on June 25, 2002, in Arlington, VA, to highlight the research that will be conducted on STS-107.

  7. King of the mountains: Tibetan and Sherpa physiological adaptations for life at high altitude.

    PubMed

    Gilbert-Kawai, Edward T; Milledge, James S; Grocott, Michael P W; Martin, Daniel S

    2014-11-01

    Anecdotal evidence surrounding Tibetans' and Sherpas' exceptional tolerance to hypobaric hypoxia has been recorded since the beginning of high-altitude exploration. These populations have successfully lived and reproduced at high altitude for hundreds of generations with hypoxia as a constant evolutionary pressure. Consequently, they are likely to have undergone natural selection toward a genotype (and phenotype) tending to offer beneficial adaptation to sustained hypoxia. With the advent of translational human hypoxic research, in which genotype/phenotype studies of healthy individuals at high altitude may be of benefit to hypoxemic critically ill patients in a hospital setting, high-altitude natives may provide a valuable and intriguing model. The aim of this review is to provide a comprehensive summary of the scientific literature encompassing Tibetan and Sherpa physiological adaptations to a high-altitude residence. The review demonstrates the extent to which evolutionary pressure has refined the physiology of this high-altitude population. Furthermore, although many physiological differences between highlanders and lowlanders have been found, it also suggests many more potential avenues of investigation. ©2014 Int. Union Physiol. Sci./Am. Physiol. Soc.

  8. Eco-physiological adaptation shapes the response of calcifying algae to nutrient limitation.

    PubMed

    Šupraha, Luka; Gerecht, Andrea C; Probert, Ian; Henderiks, Jorijntje

    2015-11-12

    The steady increase in global ocean temperature will most likely lead to nutrient limitation in the photic zone. This will impact the physiology of marine algae, including the globally important calcifying coccolithophores. Understanding their adaptive patterns is essential for modelling carbon production in a low-nutrient ocean. We investigated the physiology of Helicosphaera carteri, a representative of the abundant but under-investigated flagellated functional group of coccolithophores. Two strains isolated from contrasting nutrient regimes (South Atlantic and Mediterranean Sea) were grown in phosphorus-replete and phosphorus-limited batch cultures. While growing exponentially in a phosphorus-replete medium, the Mediterranean strain exhibited on average 24% lower growth rate, 36% larger coccosphere volume and 21% lower particulate inorganic carbon (PIC) production than the Atlantic strain. Under phosphorus limitation, the same strain was capable of reaching a 2.6 times higher cell density than the Atlantic strain due to lower phosphorus requirements. These results suggest that local physiological adaptation can define the performance of this species under nutrient limitation.

  9. Eco-physiological adaptation shapes the response of calcifying algae to nutrient limitation

    NASA Astrophysics Data System (ADS)

    Šupraha, Luka; Gerecht, Andrea C.; Probert, Ian; Henderiks, Jorijntje

    2015-11-01

    The steady increase in global ocean temperature will most likely lead to nutrient limitation in the photic zone. This will impact the physiology of marine algae, including the globally important calcifying coccolithophores. Understanding their adaptive patterns is essential for modelling carbon production in a low-nutrient ocean. We investigated the physiology of Helicosphaera carteri, a representative of the abundant but under-investigated flagellated functional group of coccolithophores. Two strains isolated from contrasting nutrient regimes (South Atlantic and Mediterranean Sea) were grown in phosphorus-replete and phosphorus-limited batch cultures. While growing exponentially in a phosphorus-replete medium, the Mediterranean strain exhibited on average 24% lower growth rate, 36% larger coccosphere volume and 21% lower particulate inorganic carbon (PIC) production than the Atlantic strain. Under phosphorus limitation, the same strain was capable of reaching a 2.6 times higher cell density than the Atlantic strain due to lower phosphorus requirements. These results suggest that local physiological adaptation can define the performance of this species under nutrient limitation.

  10. Biochemical and physiological adaptations in the estuarine crab Neohelice granulata during salinity acclimation.

    PubMed

    Bianchini, Adalto; Lauer, Mariana Machado; Nery, Luiz Eduardo Maia; Colares, Elton Pinto; Monserrat, José María; Dos Santos Filho, Euclydes Antônio

    2008-11-01

    Neohelice granulata (Chasmagnathus granulatus) is an intertidal crab species living in salt marshes from estuaries and lagoons along the Atlantic coast of South America. It is a key species in these environments because it is responsible for energy transfer from producers to consumers. In order to deal with the extremely marked environmental salinity changes occurring in salt marshes, N. granulata shows important and interesting structural, biochemical, and physiological adaptations at the gills level. These adaptations characterize this crab as a euryhaline species, tolerating environmental salinities ranging from very diluted media to concentrated seawater. These characteristics had led to its use as an animal model to study estuarine adaptations in crustaceans. Therefore, the present review focuses on the influence of environmental salinity on N. granulata responses at the ecological, organismic and molecular levels. Aspects covered include salinity tolerance, osmo- and ionoregulatory patterns, morphological and structural adaptations at the gills, and mechanisms of ion transport and their regulation at the gills level during environmental salinity acclimation. Finally, this review compiles information on the effects of some environmental pollutants on iono- and osmoregulatory adaptations showed by N. granulata.

  11. Global transcriptional, physiological and metabolite analyses of Desulfovibrio vulgaris Hildenborough responses to salt adaptation

    SciTech Connect

    He, Z.; Zhou, A.; Baidoo, E.; He, Q.; Joachimiak, M. P.; Benke, P.; Phan, R.; Mukhopadhyay, A.; Hemme, C.L.; Huang, K.; Alm, E.J.; Fields, M.W.; Wall, J.; Stahl, D.; Hazen, T.C.; Keasling, J.D.; Arkin, A.P.; Zhou, J.

    2009-12-01

    The response of Desulfovibrio vulgaris Hildenborough to salt adaptation (long-term NaCl exposure) was examined by physiological, global transcriptional, and metabolite analyses. The growth of D. vulgaris was inhibited by high levels of NaCl, and the growth inhibition could be relieved by the addition of exogenous amino acids (e.g., glutamate, alanine, tryptophan) or yeast extract. Salt adaptation induced the expression of genes involved in amino acid biosynthesis and transport, electron transfer, hydrogen oxidation, and general stress responses (e.g., heat shock proteins, phage shock proteins, and oxidative stress response proteins). Genes involved in carbon metabolism, cell motility, and phage structures were repressed. Comparison of transcriptomic profiles of D. vulgaris responses to salt adaptation with those of salt shock (short-term NaCl exposure) showed some similarity as well as a significant difference. Metabolite assays showed that glutamate and alanine were accumulated under salt adaptation, suggesting that they may be used as osmoprotectants in D. vulgaris. A conceptual model is proposed to link the observed results to currently available knowledge for further understanding the mechanisms of D. vulgaris adaptation to elevated NaCl.

  12. Global transcriptional, physiological, and metabolite analyses of the responses of Desulfovibrio vulgaris hildenborough to salt adaptation.

    PubMed

    He, Zhili; Zhou, Aifen; Baidoo, Edward; He, Qiang; Joachimiak, Marcin P; Benke, Peter; Phan, Richard; Mukhopadhyay, Aindrila; Hemme, Christopher L; Huang, Katherine; Alm, Eric J; Fields, Matthew W; Wall, Judy; Stahl, David; Hazen, Terry C; Keasling, Jay D; Arkin, Adam P; Zhou, Jizhong

    2010-03-01

    The response of Desulfovibrio vulgaris Hildenborough to salt adaptation (long-term NaCl exposure) was examined by performing physiological, global transcriptional, and metabolite analyses. Salt adaptation was reflected by increased expression of genes involved in amino acid biosynthesis and transport, electron transfer, hydrogen oxidation, and general stress responses (e.g., heat shock proteins, phage shock proteins, and oxidative stress response proteins). The expression of genes involved in carbon metabolism, cell growth, and phage structures was decreased. Transcriptome profiles of D. vulgaris responses to salt adaptation were compared with transcriptome profiles of D. vulgaris responses to salt shock (short-term NaCl exposure). Metabolite assays showed that glutamate and alanine accumulated under salt adaptation conditions, suggesting that these amino acids may be used as osmoprotectants in D. vulgaris. Addition of amino acids (glutamate, alanine, and tryptophan) or yeast extract to the growth medium relieved salt-related growth inhibition. A conceptual model that links the observed results to currently available knowledge is proposed to increase our understanding of the mechanisms of D. vulgaris adaptation to elevated NaCl levels.

  13. Short-term adaptation to a simple motor task: a physiological process preserved in multiple sclerosis.

    PubMed

    Mancini, L; Ciccarelli, O; Manfredonia, F; Thornton, J S; Agosta, F; Barkhof, F; Beckmann, C; De Stefano, N; Enzinger, C; Fazekas, F; Filippi, M; Gass, A; Hirsch, J G; Johansen-Berg, H; Kappos, L; Korteweg, T; Manson, S C; Marino, S; Matthews, P M; Montalban, X; Palace, J; Polman, C; Rocca, M; Ropele, S; Rovira, A; Wegner, C; Friston, K; Thompson, A; Yousry, T

    2009-04-01

    Short-term adaptation indicates the attenuation of the functional MRI (fMRI) response during repeated task execution. It is considered to be a physiological process, but it is unknown whether short-term adaptation changes significantly in patients with brain disorders, such as multiple sclerosis (MS). In order to investigate short-term adaptation during a repeated right-hand tapping task in both controls and in patients with MS, we analyzed the fMRI data collected in a large cohort of controls and MS patients who were recruited into a multi-centre European fMRI study. Four fMRI runs were acquired for each of the 55 controls and 56 MS patients at baseline and 33 controls and 26 MS patients at 1-year follow-up. The externally cued (1 Hz) right hand tapping movement was limited to 3 cm amplitude by using at all sites (7 at baseline and 6 at follow-up) identically manufactured wooden frames. No significant differences in cerebral activation were found between sites. Furthermore, our results showed linear response adaptation (i.e. reduced activation) from run 1 to run 4 (over a 25 minute period) in the primary motor area (contralateral more than ipsilateral), in the supplementary motor area and in the primary sensory cortex, sensory-motor cortex and cerebellum, bilaterally. This linear activation decay was the same in both control and patient groups, did not change between baseline and 1-year follow-up and was not influenced by the modest disease progression observed over 1 year. These findings confirm that the short-term adaptation to a simple motor task is a physiological process which is preserved in MS.

  14. 21 CFR 882.4125 - Neurosurgical chair.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neurosurgical chair. 882.4125 Section 882.4125...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4125 Neurosurgical chair. (a) Identification. A neurosurgical chair is an operating room chair used to position and support a patient during...

  15. 21 CFR 882.4125 - Neurosurgical chair.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Neurosurgical chair. 882.4125 Section 882.4125...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4125 Neurosurgical chair. (a) Identification. A neurosurgical chair is an operating room chair used to position and support a patient during...

  16. 21 CFR 882.4125 - Neurosurgical chair.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Neurosurgical chair. 882.4125 Section 882.4125...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4125 Neurosurgical chair. (a) Identification. A neurosurgical chair is an operating room chair used to position and support a patient during...

  17. 21 CFR 882.4125 - Neurosurgical chair.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical chair. 882.4125 Section 882.4125...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4125 Neurosurgical chair. (a) Identification. A neurosurgical chair is an operating room chair used to position and support a patient during...

  18. 21 CFR 882.4125 - Neurosurgical chair.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Neurosurgical chair. 882.4125 Section 882.4125...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4125 Neurosurgical chair. (a) Identification. A neurosurgical chair is an operating room chair used to position and support a patient during...

  19. Women Chairs in Psychiatry: A Collective Reflection

    ERIC Educational Resources Information Center

    Vaidya, Nutan Atre

    2006-01-01

    Objective: This article describes the experiences of women chairs in psychiatry. Method: All women chairs in psychiatry were contacted by the author to share their personal experiences as chair. Seven out of 10 chairs accepted the invitation. A similar invitation was extended to a few female and male academics. Conclusions: Women in chair…

  20. Match and mismatch: conservation physiology, nutritional ecology and the timescales of biological adaptation

    PubMed Central

    Raubenheimer, David; Simpson, Stephen J.; Tait, Alice H.

    2012-01-01

    Conservation physiology (CP) and nutritional ecology (NE) are both integrative sciences that share the fundamental aim of understanding the patterns, mechanisms and consequences of animal responses to changing environments. Here, we explore the high-level similarities and differences between CP and NE, identifying as central themes to both fields the multiple timescales over which animals adapt (and fail to adapt) to their environments, and the need for integrative models to study these processes. At one extreme are the short-term regulatory responses that modulate the state of animals in relation to the environment, which are variously considered under the concepts of homeostasis, homeorhesis, enantiostasis, heterostasis and allostasis. In the longer term are developmental responses, including phenotypic plasticity and transgenerational effects mediated by non-genomic influences such as parental physiology, epigenetic effects and cultural learning. Over a longer timescale still are the cumulative genetic changes that take place in Darwinian evolution. We present examples showing how the adaptive responses of animals across these timescales have been represented in an integrative framework from NE, the geometric framework (GF) for nutrition, and close with an illustration of how GF can be applied to the central issue in CP, animal conservation. PMID:22566672

  1. Match and mismatch: conservation physiology, nutritional ecology and the timescales of biological adaptation.

    PubMed

    Raubenheimer, David; Simpson, Stephen J; Tait, Alice H

    2012-06-19

    Conservation physiology (CP) and nutritional ecology (NE) are both integrative sciences that share the fundamental aim of understanding the patterns, mechanisms and consequences of animal responses to changing environments. Here, we explore the high-level similarities and differences between CP and NE, identifying as central themes to both fields the multiple timescales over which animals adapt (and fail to adapt) to their environments, and the need for integrative models to study these processes. At one extreme are the short-term regulatory responses that modulate the state of animals in relation to the environment, which are variously considered under the concepts of homeostasis, homeorhesis, enantiostasis, heterostasis and allostasis. In the longer term are developmental responses, including phenotypic plasticity and transgenerational effects mediated by non-genomic influences such as parental physiology, epigenetic effects and cultural learning. Over a longer timescale still are the cumulative genetic changes that take place in Darwinian evolution. We present examples showing how the adaptive responses of animals across these timescales have been represented in an integrative framework from NE, the geometric framework (GF) for nutrition, and close with an illustration of how GF can be applied to the central issue in CP, animal conservation.

  2. What Has Natural Variation Taught Us about Plant Development, Physiology, and Adaptation?

    PubMed Central

    Alonso-Blanco, Carlos; Aarts, Mark G.M.; Bentsink, Leonie; Keurentjes, Joost J.B.; Reymond, Matthieu; Vreugdenhil, Dick; Koornneef, Maarten

    2009-01-01

    Nearly 100 genes and functional polymorphisms underlying natural variation in plant development and physiology have been identified. In crop plants, these include genes involved in domestication traits, such as those related to plant architecture, fruit and seed structure and morphology, as well as yield and quality traits improved by subsequent crop breeding. In wild plants, comparable traits have been dissected mainly in Arabidopsis thaliana. In this review, we discuss the major contributions of the analysis of natural variation to our understanding of plant development and physiology, focusing in particular on the timing of germination and flowering, plant growth and morphology, primary metabolism, and mineral accumulation. Overall, functional polymorphisms appear in all types of genes and gene regions, and they may have multiple mutational causes. However, understanding this diversity in relation to adaptation and environmental variation is a challenge for which tools are now available. PMID:19574434

  3. Reliable emotion recognition system based on dynamic adaptive fusion of forehead biopotentials and physiological signals.

    PubMed

    Khezri, Mahdi; Firoozabadi, Mohammad; Sharafat, Ahmad Reza

    2015-11-01

    In this study, we proposed a new adaptive method for fusing multiple emotional modalities to improve the performance of the emotion recognition system. Three-channel forehead biosignals along with peripheral physiological measurements (blood volume pressure, skin conductance, and interbeat intervals) were utilized as emotional modalities. Six basic emotions, i.e., anger, sadness, fear, disgust, happiness, and surprise were elicited by displaying preselected video clips for each of the 25 participants in the experiment; the physiological signals were collected simultaneously. In our multimodal emotion recognition system, recorded signals with the formation of several classification units identified the emotions independently. Then the results were fused using the adaptive weighted linear model to produce the final result. Each classification unit is assigned a weight that is determined dynamically by considering the performance of the units during the testing phase and the training phase results. This dynamic weighting scheme enables the emotion recognition system to adapt itself to each new user. The results showed that the suggested method outperformed conventional fusion of the features and classification units using the majority voting method. In addition, a considerable improvement, compared to the systems that used the static weighting schemes for fusing classification units, was also shown. Using support vector machine (SVM) and k-nearest neighbors (KNN) classifiers, the overall classification accuracies of 84.7% and 80% were obtained in identifying the emotions, respectively. In addition, applying the forehead or physiological signals in the proposed scheme indicates that designing a reliable emotion recognition system is feasible without the need for additional emotional modalities.

  4. Behavioural and physiological adaptations to low-temperature environments in the common frog, Rana temporaria.

    PubMed

    Muir, Anna P; Biek, Roman; Mable, Barbara K

    2014-05-23

    Extreme environments can impose strong ecological and evolutionary pressures at a local level. Ectotherms are particularly sensitive to low-temperature environments, which can result in a reduced activity period, slowed physiological processes and increased exposure to sub-zero temperatures. The aim of this study was to assess the behavioural and physiological responses that facilitate survival in low-temperature environments. In particular, we asked: 1) do high-altitude common frog (Rana temporaria) adults extend the time available for larval growth by breeding at lower temperatures than low-altitude individuals?; and 2) do tadpoles sampled from high-altitude sites differ physiologically from those from low-altitude sites, in terms of routine metabolic rate (RMR) and freeze tolerance? Breeding date was assessed as the first day of spawn observation and local temperature recorded for five, paired high- and low-altitude R. temporaria breeding sites in Scotland. Spawn was collected and tadpoles raised in a common laboratory environment, where RMR was measured as oxygen consumed using a closed respiratory tube system. Freeze tolerance was measured as survival following slow cooling to the point when all container water had frozen. We found that breeding did not occur below 5°C at any site and there was no significant relationship between breeding temperature and altitude, leading to a delay in spawning of five days for every 100 m increase in altitude. The relationship between altitude and RMR varied by mountain but was lower for individuals sampled from high- than low-altitude sites within the three mountains with the highest high-altitude sites (≥900 m). In contrast, individuals sampled from low-altitudes survived freezing significantly better than those from high-altitudes, across all mountains. Our results suggest that adults at high-altitude do not show behavioural adaptations in terms of breeding at lower temperatures. However, tadpoles appear to have the

  5. Influence of dietary nitrate supplementation on physiological and muscle metabolic adaptations to sprint interval training.

    PubMed

    Thompson, Christopher; Wylie, Lee J; Blackwell, Jamie R; Fulford, Jonathan; Black, Matthew I; Kelly, James; McDonagh, Sinead T J; Carter, James; Bailey, Stephen J; Vanhatalo, Anni; Jones, Andrew M

    2017-03-01

    We hypothesized that 4 wk of dietary nitrate supplementation would enhance exercise performance and muscle metabolic adaptations to sprint interval training (SIT). Thirty-six recreationally active subjects, matched on key variables at baseline, completed a series of exercise tests before and following a 4-wk period in which they were allocated to one of the following groups: 1) SIT and [Formula: see text]-depleted beetroot juice as a placebo (SIT+PL); 2) SIT and [Formula: see text]-rich beetroot juice (~13 mmol [Formula: see text]/day; SIT+BR); or 3) no training and [Formula: see text]-rich beetroot juice (NT+BR). During moderate-intensity exercise, pulmonary oxygen uptake was reduced by 4% following 4 wk of SIT+BR and NT+BR (P < 0.05) but not SIT+PL. The peak work rate attained during incremental exercise increased more in SIT+BR than in SIT+PL (P < 0.05) or NT+BR (P < 0.001). The reduction in muscle and blood [lactate] and the increase in muscle pH from preintervention to postintervention were greater at 3 min of severe-intensity exercise in SIT+BR compared with SIT+PL and NT+BR (P < 0.05). However, the change in severe-intensity exercise performance was not different between SIT+BR and SIT+PL (P > 0.05). The relative proportion of type IIx muscle fibers in the vastus lateralis muscle was reduced in SIT+BR only (P < 0.05). These findings suggest that BR supplementation may enhance some aspects of the physiological adaptations to SIT.NEW & NOTEWORTHY We investigated the influence of nitrate-rich and nitrate-depleted beetroot juice on the muscle metabolic and physiological adaptations to 4 wk of sprint interval training. Compared with placebo, dietary nitrate supplementation reduced the O2 cost of submaximal exercise, resulted in greater improvement in incremental (but not severe-intensity) exercise performance, and augmented some muscle metabolic adaptations to training. Nitrate supplementation may facilitate some of the physiological responses to sprint interval

  6. Human physiological adaptation to extended Space Flight and its implications for Space Station

    NASA Technical Reports Server (NTRS)

    Kutyna, F. A.; Shumate, W. H.

    1985-01-01

    Current work evaluating short-term space flight physiological data on the homeostatic changes due to weightlessness is presented as a means of anticipating Space Station long-term effects. An integrated systems analysis of current data shows a vestibulo-sensory adaptation within days; a loss of body mass, fluids, and electrolytes, stabilizing in a month; and a loss in red cell mass over a month. But bone demineralization which did not level off is seen as the biggest concern. Computer algorithms have been developed to simulate the human adaptation to weightlessness. So far these paradigms have been backed up by flight data and it is hoped that they will provide valuable information for future Space Station design. A series of explanatory schematics is attached.

  7. Human physiological adaptation to extended Space Flight and its implications for Space Station

    NASA Technical Reports Server (NTRS)

    Kutyna, F. A.; Shumate, W. H.

    1985-01-01

    Current work evaluating short-term space flight physiological data on the homeostatic changes due to weightlessness is presented as a means of anticipating Space Station long-term effects. An integrated systems analysis of current data shows a vestibulo-sensory adaptation within days; a loss of body mass, fluids, and electrolytes, stabilizing in a month; and a loss in red cell mass over a month. But bone demineralization which did not level off is seen as the biggest concern. Computer algorithms have been developed to simulate the human adaptation to weightlessness. So far these paradigms have been backed up by flight data and it is hoped that they will provide valuable information for future Space Station design. A series of explanatory schematics is attached.

  8. Physiological adaptation along environmental gradients and replicated hybrid zone structure in swordtails (Teleostei: Xiphophorus).

    PubMed

    Culumber, Z W; Shepard, D B; Coleman, S W; Rosenthal, G G; Tobler, M

    2012-09-01

    Local adaptation is often invoked to explain hybrid zone structure, but empirical evidence of this is generally rare. Hybrid zones between two poeciliid fishes, Xiphophorus birchmanni and X. malinche, occur in multiple tributaries with independent replication of upstream-to-downstream gradients in morphology and allele frequencies. Ecological niche modelling revealed that temperature is a central predictive factor in the spatial distribution of pure parental species and their hybrids and explains spatial and temporal variation in the frequency of neutral genetic markers in hybrid populations. Among populations of parentals and hybrids, both thermal tolerance and heat-shock protein expression vary strongly, indicating that spatial and temporal structure is likely driven by adaptation to local thermal environments. Therefore, hybrid zone structure is strongly influenced by interspecific differences in physiological mechanisms for coping with the thermal environment.

  9. Local Adaptation to Altitude Underlies Divergent Thermal Physiology in Tropical Killifishes of the Genus Aphyosemion

    PubMed Central

    McKenzie, David J.; Estivales, Guillan; Svendsen, Jon C.; Steffensen, John F.; Agnèse, Jean-François

    2013-01-01

    In watersheds of equatorial West Africa, monophyletic groups of killifish species (genus Aphyosemion) occur in discrete altitudinal ranges, low altitude species (LA, sea level to ∼350 m) or high altitude species (HA, 350 to 900 m). We investigated the hypothesis that local adaptation to altitude by the LA and HA species would be revealed as divergent effects of temperature on their physiological energetics. Two species from each group (mass ∼350 mg) were acclimated to 19, 25 and 28°C, with 19 and 28°C estimated to be outside the thermal envelope for LA or HA, respectively, in the wild. Wild-caught animals (F0 generation) were compared with animals raised in captivity at 25°C (F1 generation) to investigate the contribution of adaptation versus plasticity. Temperature significantly increased routine metabolic rate in all groups and generations. However, LA and HA species differed in the effects of temperature on their ability to process a meal. At 25°C, the specific dynamic action (SDA) response was completed within 8 h in all groups, but acclimation to temperatures beyond the thermal envelope caused profound declines in SDA performance. At 19°C, the LA required ∼14 h to complete the SDA, whereas the HA required only ∼7 h. The opposite effect was observed at 28°C. This effect was evident in both F0 and F1. Reaction norms for effects of temperature on SDA therefore revealed a trade-off, with superior performance at warmer temperatures by LA being associated with inferior performance at cooler temperatures, and vice-versa in HA. The data indicate that divergent physiological responses to temperature in the LA and HA species reflect local adaptation to the thermal regime in their habitat, and that local adaptation to one thermal environment trades off against performance in another. PMID:23349857

  10. Local adaptation to altitude underlies divergent thermal physiology in tropical killifishes of the genus Aphyosemion.

    PubMed

    McKenzie, David J; Estivales, Guillan; Svendsen, Jon C; Steffensen, John F; Agnèse, Jean-François

    2013-01-01

    In watersheds of equatorial West Africa, monophyletic groups of killifish species (genus Aphyosemion) occur in discrete altitudinal ranges, low altitude species (LA, sea level to ∼350 m) or high altitude species (HA, 350 to 900 m). We investigated the hypothesis that local adaptation to altitude by the LA and HA species would be revealed as divergent effects of temperature on their physiological energetics. Two species from each group (mass ∼350 mg) were acclimated to 19, 25 and 28°C, with 19 and 28°C estimated to be outside the thermal envelope for LA or HA, respectively, in the wild. Wild-caught animals (F0 generation) were compared with animals raised in captivity at 25°C (F1 generation) to investigate the contribution of adaptation versus plasticity. Temperature significantly increased routine metabolic rate in all groups and generations. However, LA and HA species differed in the effects of temperature on their ability to process a meal. At 25°C, the specific dynamic action (SDA) response was completed within 8 h in all groups, but acclimation to temperatures beyond the thermal envelope caused profound declines in SDA performance. At 19°C, the LA required ∼14 h to complete the SDA, whereas the HA required only ∼7 h. The opposite effect was observed at 28°C. This effect was evident in both F0 and F1. Reaction norms for effects of temperature on SDA therefore revealed a trade-off, with superior performance at warmer temperatures by LA being associated with inferior performance at cooler temperatures, and vice-versa in HA. The data indicate that divergent physiological responses to temperature in the LA and HA species reflect local adaptation to the thermal regime in their habitat, and that local adaptation to one thermal environment trades off against performance in another.

  11. Background adaptation and water acidification affect pigmentation and stress physiology of tilapia, Oreochromis mossambicus.

    PubMed

    van der Salm, A L; Spanings, F A T; Gresnigt, R; Bonga, S E Wendelaar; Flik, G

    2005-10-01

    The ability to adjust skin darkness to the background is a common phenomenon in fish. The hormone alpha-melanophore-stimulating hormone (alphaMSH) enhances skin darkening. In Mozambique tilapia, Oreochromis mossambicus L., alphaMSH acts as a corticotropic hormone during adaptation to water with a low pH, in addition to its role in skin colouration. In the current study, we investigated the responses of this fish to these two environmental challenges when it is exposed to both simultaneously. The skin darkening of tilapia on a black background and the lightening on grey and white backgrounds are compromised in water with a low pH, indicating that the two vastly different processes both rely on alphaMSH-regulatory mechanisms. If the water is acidified after 25 days of undisturbed background adaptation, fish showed a transient pigmentation change but recovered after two days and continued the adaptation of their skin darkness to match the background. Black backgrounds are experienced by tilapia as more stressful than grey or white backgrounds both in neutral and in low pH water. A decrease of water pH from 7.8 to 4.5 applied over a two-day period was not experienced as stressful when combined with background adaptation, based on unchanged plasma pH and plasma alphaMSH, and Na levels. However, when water pH was lowered after 25 days of undisturbed background adaptation, particularly alphaMSH levels increased chronically. In these fish, plasma pH and Na levels had decreased, indicating a reduced capacity to maintain ion-homeostasis, implicating that the fish indeed experience stress. We conclude that simultaneous exposure to these two types of stressor has a lower impact on the physiology of tilapia than subsequent exposure to the stressors.

  12. High sustained +Gz acceleration: physiological adaptation to high-G tolerance

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.

    1998-01-01

    Since the early 1940s, a significant volume of research has been conducted in an effort to describe the impact of acute exposures to high-G acceleration on cardiovascular mechanisms responsible to maintaining cerebral perfusion and conscious in high performance aircraft pilots during aerial combat maneuvers. The value of understanding hemodynamic characteristics that underlie G-induced loss of consciousness has been instrumental in the evolution of optimal technology development (e.g., G-suits, positive pressure breathing, COMBAT EDGE, etc.) and pilot training (e.g., anti-G straining maneuvers). Although the emphasis of research has been placed on the development of protection against acute high +Gz acceleration effects, recent observations suggest that adaptation of cardiovascular mechanism associated with blood pressure regulation may contribute to a protective 'G-training' effect. Regular training at high G enhances G tolerance in humans, rats, guinea pigs, and dogs while prolonged layoff from exposure in high G profiles (G-layoff) can result in reduced G endurance. It seems probable that adaptations in physiological functions following chronically-repeated high G exposure (G training) or G-layoff could have significant impacts on performance during sustained high-G acceleration since protective technology such as G-suits and anit-G straining maneuvers are applied consistently during these periods of training. The purpose of this paper is to present a review of new data from three experiments that support the notion that repeated exposure on a regular basis to high sustained +Gz acceleration induces significant physiological adaptations which are associated with improved blood pressure regulation and subsequent protection of cerebral perfusion during orthostatic challenges.

  13. High sustained +Gz acceleration: physiological adaptation to high-G tolerance.

    PubMed

    Convertino, V A

    1998-07-01

    Since the early 1940s, a significant volume of research has been conducted in an effort to describe the impact of acute exposures to high-G acceleration on cardiovascular mechanisms responsible to maintaining cerebral perfusion and conscious in high performance aircraft pilots during aerial combat maneuvers. The value of understanding hemodynamic characteristics that underlie G-induced loss of consciousness has been instrumental in the evolution of optimal technology development (e.g., G-suits, positive pressure breathing, COMBAT EDGE, etc.) and pilot training (e.g., anti-G straining maneuvers). Although the emphasis of research has been placed on the development of protection against acute high +Gz acceleration effects, recent observations suggest that adaptation of cardiovascular mechanism associated with blood pressure regulation may contribute to a protective 'G-training' effect. Regular training at high G enhances G tolerance in humans, rats, guinea pigs, and dogs while prolonged layoff from exposure in high G profiles (G-layoff) can result in reduced G endurance. It seems probable that adaptations in physiological functions following chronically-repeated high G exposure (G training) or G-layoff could have significant impacts on performance during sustained high-G acceleration since protective technology such as G-suits and anit-G straining maneuvers are applied consistently during these periods of training. The purpose of this paper is to present a review of new data from three experiments that support the notion that repeated exposure on a regular basis to high sustained +Gz acceleration induces significant physiological adaptations which are associated with improved blood pressure regulation and subsequent protection of cerebral perfusion during orthostatic challenges.

  14. High sustained +Gz acceleration: physiological adaptation to high-G tolerance

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.

    1998-01-01

    Since the early 1940s, a significant volume of research has been conducted in an effort to describe the impact of acute exposures to high-G acceleration on cardiovascular mechanisms responsible to maintaining cerebral perfusion and conscious in high performance aircraft pilots during aerial combat maneuvers. The value of understanding hemodynamic characteristics that underlie G-induced loss of consciousness has been instrumental in the evolution of optimal technology development (e.g., G-suits, positive pressure breathing, COMBAT EDGE, etc.) and pilot training (e.g., anti-G straining maneuvers). Although the emphasis of research has been placed on the development of protection against acute high +Gz acceleration effects, recent observations suggest that adaptation of cardiovascular mechanism associated with blood pressure regulation may contribute to a protective 'G-training' effect. Regular training at high G enhances G tolerance in humans, rats, guinea pigs, and dogs while prolonged layoff from exposure in high G profiles (G-layoff) can result in reduced G endurance. It seems probable that adaptations in physiological functions following chronically-repeated high G exposure (G training) or G-layoff could have significant impacts on performance during sustained high-G acceleration since protective technology such as G-suits and anit-G straining maneuvers are applied consistently during these periods of training. The purpose of this paper is to present a review of new data from three experiments that support the notion that repeated exposure on a regular basis to high sustained +Gz acceleration induces significant physiological adaptations which are associated with improved blood pressure regulation and subsequent protection of cerebral perfusion during orthostatic challenges.

  15. Publication Productivity of Orthopaedic Surgery Chairs.

    PubMed

    Zelle, Boris A; Weathers, Michael A; Fajardo, Roberto J; Haghshenas, Varan; Bhandari, Mohit

    2017-06-21

    As academic leaders, orthopaedic chairs represent role models for scholarly activities. Despite the importance of journal publications as a measure of scholarly activity, data on the publication productivity of orthopaedic chairs remain limited. The goals of this study were to record the publication productivity of orthopaedic chairs and evaluate the extent to which they maintained their scholarly activity while serving as chairs. The chairs of all orthopaedic residency programs in the United States were identified through the Accreditation Council for Graduate Medical Education (ACGME) web site, and were confirmed by information found on the web site of each orthopaedic program that was included in the study. University and non-university chairs were defined based on affiliation of the program with a medical school. The publication records of the program chairs were retrieved through the Scopus database. During the 7 years prior to their appointment to chair, the mean number of total publications was significantly higher for university chairs (n = 58.6, range 0 to 217) than for non-university chairs (n = 29.1, range 0 to 13) (p = 0.003). The mean number of publications per year during the 7 years leading up to the chair position was 4.66 (range, 0 to 25) for the university chairs, and 2.29 (range, 0 to 10.9) for the non-university group (p = 0.02). While serving as chair, the mean number of publications per year significantly decreased among the university chairs to 3.75 (range, 0 to 32.8; p = 0.015), whereas no significant change was observed among non-university chairs. The mean percentage of first authorships was not significantly different between university and non-university chairs. Both groups showed significant declines in first authorships while serving as chair. At the time of becoming chair, the average university chair had published approximately 60 manuscripts, whereas the average non-university chair had published approximately 30 manuscripts. While

  16. Adaptation to shift work: physiologically based modeling of the effects of lighting and shifts' start time.

    PubMed

    Postnova, Svetlana; Robinson, Peter A; Postnov, Dmitry D

    2013-01-01

    Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers' sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n = 8) in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers' adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21:00 instead of 00:00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters.

  17. Interval versus continuous training with identical workload: physiological and aerobic capacity adaptations.

    PubMed

    de Araujo, G G; Gobatto, C A; Marcos-Pereira, M; Dos Reis, I G M; Verlengia, R

    2015-01-01

    The interval model training has been more recommended to promote aerobic adaptations due to recovery period that enables the execution of elevated intensity and as consequence, higher workload in relation to continuous training. However, the physiological and aerobic capacity adaptations in interval training with identical workload to continuous are still uncertain. The purpose was to characterize the effects of chronic and acute biomarkers adaptations and aerobic capacity in interval and continuous protocols with equivalent load. Fifty Wistar rats were divided in three groups: Continuous training (GTC), interval training (GTI) and control (CG). The running training lasted 8 weeks (wk) and was based at Anaerobic Threshold (AT) velocity. GTI showed glycogen super-compensation (mg/100 mg) 48 h after training session in relation to CG and GTC (GTI red gastrocnemius (RG)=1.41+/-0.16; GTI white gastrocnemius (WG)=1.78+/-0.20; GTI soleus (S)=0.26+/-0.01; GTI liver (L)=2.72+/-0.36; GTC RG=0.42+/-0.17; GTC WG=0.54+/-0.22; GTC S=0.100+/-0.01; GTC L=1.12+/-0.24; CG RG=0.32+/-0.05; CG WG=0.65+/-0.17; CG S=0.14+/-0.01; CG L=2.28+/-0.33). The volume performed by GTI was higher than GTC. The aerobic capacity reduced 11 % after experimental period in GTC when compared to GTI, but this change was insignificant (19.6+/-5.4 m/min; 17.7+/-2.5 m/min, effect size = 0.59). Free fatty acids and glucose concentration did not show statistical differences among the groups. Corticosterone concentration increased in acute condition for GTI and GTC. Testosterone concentration reduced 71 % in GTC immediately after the exercise in comparison to CG. The GTI allowed positive adaptations when compared to GTC in relation to: glycogen super-compensation, training volume performed and anabolic condition. However, the GTI not improved the aerobic performance.

  18. Adaptation to Shift Work: Physiologically Based Modeling of the Effects of Lighting and Shifts’ Start Time

    PubMed Central

    Postnova, Svetlana; Robinson, Peter A.; Postnov, Dmitry D.

    2013-01-01

    Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers’ sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n = 8) in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers’ adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21∶00 instead of 00∶00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters. PMID:23308206

  19. Eco-physiological adaptation of dominant tree species at two contrasting karst habitats in southwestern China.

    PubMed

    Zhang, Shouren; Fan, Dayong; Wu, Qian; Yan, Hui; Xu, Xinwu

    2013-01-01

    The purpose of this study was to investigate the eco-physiological adaptation of indigenous woody species to their habitats in karst areas of southwestern China. Two contrasting forest habitats were studied: a degraded habitat in Daxiagu and a well-developed habitat in Tianlongshan, and the eco-physiological characteristics of the trees were measured for three growth seasons. Photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr) of the tree species in Daxiagu were 2-3 times higher than those in Tianlongshan under ambient conditions. However, this habitat effect was not significant when measurements were taken under controlled conditions. Under controlled conditions, Pn, gs, and Tr of the deciduous species were markedly higher than those for the evergreen species. Habitat had no significant effect on water use efficiency (WUE) or photochemical characteristics of PSII. The stomatal sensitivity of woody species in the degraded habitat was much higher than that in the well-developed habitat. Similarly, the leaf total nitrogen (N) and phosphorus (P) contents expressed on the basis of either dry mass or leaf area were also much higher in Daxiagu than they were in Tianlongshan. The mass-based leaf total N content of deciduous species was much higher than that of evergreen species, while leaf area-based total N and P contents of evergreens were significantly higher than those of deciduous species. The photosynthetic nitrogen- and phosphorus-use efficiencies (PNUE and PPUE) of deciduous species were much higher than those of evergreens. Further, the PPUE of the woody species in Tianlongshan was much higher than that  of the woody species in Daxiagu. The results from three growth seasons imply that the tree species were able to adapt well to their growth habitats. Furthermore, it seems that so-called "temporary drought stress" may not occur, or may not be severe for most woody plants in karst areas of southwestern China.

  20. Cornu cervi pantotrichum supplementation improves physiological adaptions during intensive endurance training

    PubMed Central

    HUANG, Wen-Ching; HUANG, Chi-Chang; CHUANG, Hsiao-Li; CHIU, Chien-Chao; CHEN, Wen-Chyuan; HSU, Mei-Chich

    2017-01-01

    Cornu cervi pantotrichum (CCP), used in traditional Chinese medicine, is a well-known yang-invigorating agent with multifunctional bioactivities. We previously showed, through an acute exercise challenge, that short-term CCP supplementation improved physical activities and fatigue-associated biochemical indices. Questions about the long-term effects of CCP treatment on exercise performance and physical fatigue, as well as safety, with intensive exercise training need further research. ICR-strain mice were randomly assigned to three groups: (1) sedentary control and vehicle treatment (SC); (2) exercise training with vehicle treatment (ET); and (3) ET with CCP treatment at 4,108 mg/kg/day (ET+CCP). We assessed the physical performance, body compositions, and serum levels of lactate, ammonia, glucose and creatine kinase (CK) after an acute exercise challenge. The ET and ET+CCP groups had significantly increased grip strength and endurance swimming time, and decreased serum lactate and ammonia levels after the acute exercise challenge than the SC group. Moreover, serum ammonia and CK levels in the ET+CCP group were significantly decreased when compared to that of the ET only group. In regard to the body composition, the ET+CCP group inhibits the decrease in fat tissue, and related biochemical changes induced by the high intensity endurance training CCP supplementation combined with high-intensity endurance exercise could significantly improve the physiological adaptions related to fatigue or energy consumption and maintain the fat composition when compared to treatment with training only. Therefore, CCP may potentially improve the physiological adaptions in intensive exercise training. PMID:28163267

  1. Eco-physiological adaptation of dominant tree species at two contrasting karst habitats in southwestern China

    PubMed Central

    Wu, Qian; Yan, Hui; Xu, Xinwu

    2013-01-01

    The purpose of this study was to investigate the eco-physiological adaptation of indigenous woody species to their habitats in karst areas of southwestern China. Two contrasting forest habitats were studied: a degraded habitat in Daxiagu and a well-developed habitat in Tianlongshan, and the eco-physiological characteristics of the trees were measured for three growth seasons. Photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr) of the tree species in Daxiagu were 2-3 times higher than those in Tianlongshan under ambient conditions. However, this habitat effect was not significant when measurements were taken under controlled conditions. Under controlled conditions, Pn, gs, and Tr of the deciduous species were markedly higher than those for the evergreen species. Habitat had no significant effect on water use efficiency (WUE) or photochemical characteristics of PSII. The stomatal sensitivity of woody species in the degraded habitat was much higher than that in the well-developed habitat. Similarly, the leaf total nitrogen (N) and phosphorus (P) contents expressed on the basis of either dry mass or leaf area were also much higher in Daxiagu than they were in Tianlongshan. The mass-based leaf total N content of deciduous species was much higher than that of evergreen species, while leaf area-based total N and P contents of evergreens were significantly higher than those of deciduous species. The photosynthetic nitrogen- and phosphorus-use efficiencies (PNUE and PPUE) of deciduous species were much higher than those of evergreens. Further, the PPUE of the woody species in Tianlongshan was much higher than that  of the woody species in Daxiagu. The results from three growth seasons imply that the tree species were able to adapt well to their growth habitats. Furthermore, it seems that so-called “temporary drought stress” may not occur, or may not be severe for most woody plants in karst areas of southwestern China. PMID:24555059

  2. Predicting animal δ18O: Accounting for diet and physiological adaptation

    NASA Astrophysics Data System (ADS)

    Kohn, Matthew J.

    1996-12-01

    Theoretical predictions and measured isotope variations indicate that diet and physiological adaptation have a significant impact on animals δ18O and cannot be ignored. A generalized model is therefore developed for the prediction of animal body water and phosphate δ18O to incorporate these factors quantitatively. Application of the model reproduces most published compositions and compositional trends for mammals and birds. A moderate dependence of animal δ18O on humidity is predicted for drought-tolerant animals, and the correlation between humidity and North American deer bone composition as corrected for local meteoric water is predicted within the scatter of the data. In contrast to an observed strong correlation between kangaroo δ18O and humidity (Δδ18O/Δh ∼ 2.5± 0.4‰/10%r.h.), the predicted humidity dependence is only 1.3 - 1.7‰/10% r.h., and it is inferred that drinking water in hot dry areas of Australia is enriched in 18O over rainwater. Differences in physiology and water turnover readily explain the observed differences in δ18O for several herbivore genera in East Africa, excepting antelopes. Antelope models are more sensitive to biological fractionations, and adjustments to the flux of transcutaneous water vapor within experimentally measured ranges allows their δ18O values to be matched. Models of the seasonal changes of forage composition for two regions with dissimilar climates show that significant seasonal variations in animal isotope composition are expected, and that animals with different physiologies and diets track climate differently. Analysis of different genera with disparate sensitivities to surface water and humidity will allow the most accurate quantification of past climate changes.

  3. 21 CFR 886.1140 - Ophthalmic chair.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic chair. 886.1140 Section 886.1140 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1140 Ophthalmic chair. (a) Identification. An ophthalmic chair is an AC-powered or manual device with adjustable positioning in which a patient is to sit...

  4. 21 CFR 886.1140 - Ophthalmic chair.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic chair. 886.1140 Section 886.1140 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1140 Ophthalmic chair. (a) Identification. An ophthalmic chair is an AC-powered or manual device with adjustable positioning in which a patient is to sit...

  5. 21 CFR 886.1140 - Ophthalmic chair.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic chair. 886.1140 Section 886.1140 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1140 Ophthalmic chair. (a) Identification. An ophthalmic chair is an AC-powered or manual device with adjustable positioning in which a patient is to sit...

  6. 21 CFR 886.1140 - Ophthalmic chair.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic chair. 886.1140 Section 886.1140 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1140 Ophthalmic chair. (a) Identification. An ophthalmic chair is an AC-powered or manual device with adjustable positioning in which a patient is to sit...

  7. A Tool Kit for New Chairs

    ERIC Educational Resources Information Center

    Munro, Stuart

    2006-01-01

    Many chairs come to their position without the benefit of previous experience in the role of leading an academic department. The American Association of Chairs of Departments of Psychiatry (AACDP) identified the need for a manual designed to help a new chair get started. The "tool kit" that emerged contains sections that describe the AACDP,…

  8. 21 CFR 886.1140 - Ophthalmic chair.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic chair. 886.1140 Section 886.1140 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1140 Ophthalmic chair. (a) Identification. An ophthalmic chair is an AC-powered or manual device with adjustable positioning in which a patient is to sit...

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

    PubMed

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

    2011-10-01

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

  10. Physiological adaptation of an Antarctic Na+/K+-ATPase to the cold.

    PubMed

    Galarza-Muñoz, Gaddiel; Soto-Morales, Sonia I; Holmgren, Miguel; Rosenthal, Joshua J C

    2011-07-01

    Because enzymatic activity is strongly suppressed by the cold, polar poikilotherms face significant adaptive challenges. For example, at 0°C the catalytic activity of a typical enzyme from a temperate organism is reduced by more than 90%. Enzymes embedded in the plasma membrane, such as the Na(+)/K(+)-ATPase, may be even more susceptible to the cold because of thermal effects on the lipid bilayer. Accordingly, adaptive changes in response to the cold may include adjustments to the enzyme or the surrounding lipid environment, or synergistic changes to both. To assess the contribution of the enzyme itself, we cloned orthologous Na(+)/K(+)-ATPase α-subunits from an Antarctic (Pareledone sp.; -1.8°C) and a temperate octopus (Octopus bimaculatus; ∼18°C), and compared their turnover rates and temperature sensitivities in a heterologous expression system. The primary sequences of the two pumps were found to be highly similar (97% identity), with most differences being conservative changes involving hydrophobic residues. The physiology of the pumps was studied using an electrophysiological approach in intact Xenopus oocytes. The voltage dependence of the pumps was equivalent. However, at room temperature the maximum turnover rate of the Antarctic pump was found to be 25% higher than that of the temperate pump. In addition, the Antarctic pump exhibited a lower temperature sensitivity, leading to significantly higher relative activity at lower temperatures. Orthologous Na(+)/K(+) pumps were then isolated from two tropical and two Arctic octopus. The temperature sensitivities of these pumps closely matched those of the temperate and Antarctic pumps, respectively. Thus, reduced thermal sensitivity appears to be a common mechanism driving cold adaptation in the Na(+)/K(+)-ATPase.

  11. Physiological adaptation of an Antarctic Na+/K+-ATPase to the cold

    PubMed Central

    Galarza-Muñoz, Gaddiel; Soto-Morales, Sonia I.; Holmgren, Miguel; Rosenthal, Joshua J. C.

    2011-01-01

    SUMMARY Because enzymatic activity is strongly suppressed by the cold, polar poikilotherms face significant adaptive challenges. For example, at 0°C the catalytic activity of a typical enzyme from a temperate organism is reduced by more than 90%. Enzymes embedded in the plasma membrane, such as the Na+/K+-ATPase, may be even more susceptible to the cold because of thermal effects on the lipid bilayer. Accordingly, adaptive changes in response to the cold may include adjustments to the enzyme or the surrounding lipid environment, or synergistic changes to both. To assess the contribution of the enzyme itself, we cloned orthologous Na+/K+-ATPase α-subunits from an Antarctic (Pareledone sp.; –1.8°C) and a temperate octopus (Octopus bimaculatus; ∼18°C), and compared their turnover rates and temperature sensitivities in a heterologous expression system. The primary sequences of the two pumps were found to be highly similar (97% identity), with most differences being conservative changes involving hydrophobic residues. The physiology of the pumps was studied using an electrophysiological approach in intact Xenopus oocytes. The voltage dependence of the pumps was equivalent. However, at room temperature the maximum turnover rate of the Antarctic pump was found to be 25% higher than that of the temperate pump. In addition, the Antarctic pump exhibited a lower temperature sensitivity, leading to significantly higher relative activity at lower temperatures. Orthologous Na+/K+ pumps were then isolated from two tropical and two Arctic octopus. The temperature sensitivities of these pumps closely matched those of the temperate and Antarctic pumps, respectively. Thus, reduced thermal sensitivity appears to be a common mechanism driving cold adaptation in the Na+/K+-ATPase. PMID:21653810

  12. Chair design and the anesthesia provider.

    PubMed

    Petty, W C

    1996-06-01

    Anesthesia providers spend a considerable amount of time sitting in poorly designed chairs. In the majority of hospitals, anesthesia providers are reluctant to request ergonomically designed chairs for the operating room. Multiple studies have given conclusive evidence that properly designed chairs reduce low back pain, improve lower extremity circulation, and relieve muscle tension, thus increasing overall comfort. Continual use of poorly designed chairs and stools in the operating room will cause eventual health complaints. Ergonomically designed chairs will be a wise purchase for the anesthesia provider, especially those who are aging or have physical complaints related to the back, muscle tension, and other lower extremity problems.

  13. Robotic chair at steep and narrow stairways

    NASA Astrophysics Data System (ADS)

    Imazato, Masahiro; Yamaguchi, Masahiro; Moromugi, Shunji; Ishimatsu, Takakazu

    2007-12-01

    A robotic chair is developed to support mobility of elderly and disabled people living in the house where steep and narrow stairways are installed. In order to deal with such mobility problem the developed robotic chair has a compact original configuration. The robotic chair vertically moves by actuation of electric cylinders and horizontally moves by push-pull operation given by a care-giver. In order to navigate safely every action of the chair is checked by the operator. Up-and-down motions of the robotic chair on the stairway are executed through combinations of motor and cylinder actuations. Performance of the robotic chair was evaluated through two kinds of experiments. The excellent ability of the robotic chair could be confirmed through these experiments.

  14. Genetic dissection of the Arabidopsis spaceflight transcriptome: Are some responses dispensable for the physiological adaptation of plants to spaceflight?

    PubMed Central

    Sng, Natasha J.; Zupanska, Agata K.; Krishnamurthy, Aparna; Schultz, Eric R.; Ferl, Robert J.

    2017-01-01

    Experimentation on the International Space Station has reached the stage where repeated and nuanced transcriptome studies are beginning to illuminate the structural and metabolic differences between plants grown in space compared to plants on the Earth. Genes that are important in establishing the spaceflight responses are being identified, their roles in spaceflight physiological adaptation are increasingly understood, and the fact that different genotypes adapt differently is recognized. However, the basic question of whether these spaceflight responses are actually required for survival has yet to be posed, and the fundamental notion that spaceflight responses may be non-adaptive has yet to be explored. Therefore the experiments presented here were designed to ask if portions of the plant spaceflight response can be genetically removed without causing loss of spaceflight survival and without causing increased stress responses. The CARA experiment compared the spaceflight transcriptome responses in the root tips of two Arabidopsis ecotypes, Col-0 and WS, as well as that of a PhyD mutant of Col-0. When grown with the ambient light of the ISS, phyD plants displayed a significantly reduced spaceflight transcriptome response compared to Col-0, suggesting that altering the activity of a single gene can actually improve spaceflight adaptation by reducing the transcriptome cost of physiological adaptation. The WS genotype showed an even simpler spaceflight transcriptome response in the ambient light of the ISS, more broadly indicating that the plant genotype can be manipulated to reduce the cost of spaceflight adaptation, as measured by transcriptional response. These differential genotypic responses suggest that genetic manipulation could further reduce, or perhaps eliminate the metabolic cost of spaceflight adaptation. When plants were germinated and then left in the dark on the ISS, the WS genotype actually mounted a larger transcriptome response than Col-0

  15. Facilitated physiological adaptation to prolonged circadian disruption through dietary supplementation with essence of chicken.

    PubMed

    Wu, Tao; Yao, Cencen; Tsang, Fai; Huang, Liangfeng; Zhang, Wanjing; Jiang, Jianguo; Mao, Youxiang; Shao, Yujian; Kong, Boda; Singh, Paramjeet; Fu, Zhengwei

    2015-01-01

    Synchrony between circadian and metabolic processes is critical to the maintenance of energy homeostasis. Studies on essence of chicken (EC), a chicken meat extract rich in proteins, amino acids and peptides, showed its effectiveness in alleviating fatigue and promoting metabolism. A recent study revealed that it facilitated the re-entrainment of clock genes (Bmal1, Cry1, Dec1, Per1 and Per2) in the pineal gland and liver in a rat model of circadian disruption. Here, we investigated the role of EC-facilitated circadian synchrony in the maintenance of the energy homeostasis using a mouse model of prolonged circadian disruption. Prolonged circadian disruption (12 weeks) resulted in hepatic maladaptation, manifested by a mild but significant (p < 0.05) hepatomegaly, accompanied by disturbed hepatic lipid metabolism and liver injury (indicated by increased circulating hepatic enzymes). Evidently, there was marked elevations of hepatic inflammatory mediators (interleukin-1beta and interleukin-6), suggesting an underlying inflammation leading to the hepatic injury and functional impairment. Importantly, the disruption paradigm caused the decoupling between key metabolic regulators (e.g. mTOR and AMPK) and hepatic clock genes (Per1, Cry1, Dec1, Bmal1). Further, we showed that the loss of circadian synchrony between the master and hepatic clock genes (Per1, Cry1, Dec1, Bmal1) could be the underlying cause of the maladaptation. When supplemented with EC, the functional impairment and inflammation were abolished. The protective effects could be linked to its effectiveness in maintaining the synchrony between the master and hepatic clocks, and the resultant improved coupling of the circadian oscillators (Per1, Cry1, Dec1, Bmal1) and metabolic regulators (mTOR, AMPK). Overall, EC supplementation promoted the physiological adaptation to the prolonged circadian disruption through facilitation of endogenous circadian synchrony and the coupling of circadian oscillators and

  16. Physiological adaptations to soccer specific endurance training in professional youth soccer players

    PubMed Central

    McMillan, K; Helgerud, J; Macdonald, R; Hoff, J

    2005-01-01

    Background: Improved oxygen uptake improves soccer performance as regards distance covered, involvements with the ball, and number of sprints. Large improvements in oxygen uptake have been shown using interval running. A similar physiological load arising from interval running could be obtained using the soccer ball in training. Objectives: The main aim was to study physiological adaptations to a 10 week high intensity aerobic interval training program performed by professional youth soccer players, using a soccer specific ball dribbling track. Methods: Eleven youth soccer players with a mean (SD) age of 16.9 (0.4) years performed high intensity aerobic interval training sessions twice per week for 10 weeks in addition to normal soccer training. The specific aerobic training consisted of four sets of 4 min work periods dribbling a soccer ball around a specially designed track at 90–95% of maximal heart frequency, with a 3 min recovery jog at 70% of maximal heart frequency between intervals. Results: Mean Vo2max improved significantly from 63.4 (5.6) to 69.8 (6.6) ml kg–1 min–1, or 183.3 (13.2) to 201.5 (16.2) ml kg–0.75 min–1 (p<0.001). Squat jump and counter movement jump height increased significantly from 37.7 (6.2) to 40.3 (6.1) cm and 52.0 (4.0) to 53.4 (4.2) cm, respectively (p<0.05). No significant changes in body mass, running economy, rate of force development, or 10 m sprint times occurred. Conclusion: Performing high intensity 4 min intervals dribbling a soccer ball around a specially designed track together with regular soccer training is effective for improving the Vo2max of soccer players, with no negative interference effects on strength, jumping ability, and sprinting performance. PMID:15849290

  17. Physiological right ventricular adaptation in elite athletes of African and Afro-Caribbean origin.

    PubMed

    Zaidi, Abbas; Ghani, Saqib; Sharma, Rajan; Oxborough, David; Panoulas, Vasileios F; Sheikh, Nabeel; Gati, Sabiha; Papadakis, Michael; Sharma, Sanjay

    2013-04-30

    Regular, intensive exercise results in physiological biventricular cardiac adaptation. Ethnicity is an established determinant of left ventricular remodeling; black athletes (BAs) exhibit more profound LV hypertrophy than white athletes (WAs). Right ventricular (RV) remodeling has not been characterized in BAs, although the issue is pertinent because BAs commonly exhibit ECG anomalies that resemble arrhythmogenic RV cardiomyopathy. Between 2006 and 2012, 300 consecutive BAs (n=243 males) from 25 sporting disciplines were evaluated by use of ECG and echocardiography. Results were compared with 375 WAs and 153 sedentary control subjects (n=69 blacks). There were no ethnic differences between RV parameters in control subjects. Both BAs and WAs exhibited greater RV dimensions than control subjects. RV dimensions were marginally smaller in BAs than in WAs (proximal outflow tract, 30.9±5.5 versus 32.8±5.3 mm, P<0.001; longitudinal dimension, 86.6±9.5 versus 89.8±9.6 mm, P<0.001), although only 2.3% of variation was attributable to ethnicity. RV enlargement compatible with diagnostic criteria for arrhythmogenic RV cardiomyopathy was frequently observed (proximal outflow tract ≥32 mm; 45.0% of BAs, 58.5% of WAs). Anterior T-wave inversion was present in 14.3% of BAs versus 3.7% of WAs (P<0.001). Marked RV enlargement with concomitant anterior T-wave inversion was observed in 3.0% of BAs versus 0.3% of WAs (P=0.005). Further investigation did not diagnose arrhythmogenic RV cardiomyopathy in any athlete. Physiological RV enlargement is commonly observed in both black and white athletes. The impact of ethnicity is minimal, which obviates the need for race-specific RV reference values. However, in the context of frequent ECG repolarization anomalies in BAs, the potential for erroneous diagnosis of arrhythmogenic RV cardiomyopathy is considerably greater in this ethnic group.

  18. Membrane Composition Changes and Physiological Adaptation by Streptococcus mutans Signal Recognition Particle Pathway Mutants▿

    PubMed Central

    Hasona, Adnan; Zuobi-Hasona, Kheir; Crowley, Paula J.; Abranches, Jacqueline; Ruelf, Michael A.; Bleiweis, Arnold S.; Brady, L. Jeannine

    2007-01-01

    Previously, we presented evidence that the oral cariogenic species Streptococcus mutans remains viable but physiologically impaired and sensitive to environmental stress when genes encoding the minimal conserved bacterial signal recognition particle (SRP) elements are inactivated. Two-dimensional gel electrophoresis of isolated membrane fractions from strain UA159 and three mutants (Δffh, ΔscRNA, and ΔftsY) grown at pH 7.0 or pH 5.0 allowed us to obtain insight into the adaptation process and the identities of potential SRP substrates. Mutant membrane preparations contained increased amounts of the chaperones DnaK and GroES and ClpP protease but decreased amounts of transcription- and translation-related proteins, the β subunit of ATPase, HPr, and several metabolic and glycolytic enzymes. Therefore, the acid sensitivity of SRP mutants might be caused in part by diminished ATPase activity, as well as the absence of an efficient mechanism for supplying ATP quickly at the site of proton elimination. Decreased amounts of LuxS were also observed in all mutant membranes. To further define physiological changes that occur upon disruption of the SRP pathway, we studied global gene expression in S. mutans UA159 (parent strain) and AH333 (Δffh mutant) using microarray analysis. Transcriptome analysis revealed up-regulation of 81 genes, including genes encoding chaperones, proteases, cell envelope biosynthetic enzymes, and DNA repair and replication enzymes, and down-regulation of 35 genes, including genes concerned with competence, ribosomal proteins, and enzymes involved in amino acid and protein biosynthesis. Quantitative real-time reverse transcription-PCR analysis of eight selected genes confirmed the microarray data. Consistent with a demonstrated defect in competence and the suggested impairment of LuxS-dependent quorum sensing, biofilm formation was significantly decreased in each SRP mutant. PMID:17085548

  19. [Left ventricular hypertrophy of athletes: adaptative physiologic response of the heart].

    PubMed

    Ghorayeb, Nabil; Batlouni, Michel; Pinto, Ibraim M F; Dioguardi, Giuseppe S

    2005-09-01

    To verify whether left ventricular hypertrophy (LVH) of elite competition athletes (marathoners) represents a purely physiological, adaptative process, or it may involve pathological aspects in its anatomical and functional characteristics. From November 1999 to December 2000, consecutive samples from 30 under 50-year-old marathoners in full sportive activity, with previously documented LVH and absence of cardiopathy were selected. They were submitted to clinical exams, electrocardiogram, color Doppler echocardiogram and exercise treadmill test (ETT). Fifteen were assorted to be also submitted to ergoespirometric test and heart magnetic resonance imaging (MRI). In ETT, all of them showed good physical pulmonary capacity, with no evidences of ischemic response to exercise, symptoms or arrhythmias. In Doppler echocardiogram, values of diameter and diastolic thickness of LV posterior wall, interventricular septum, LV mass and left atrium diameter, were significantly higher when compared to non-athlete control group, with similar ages and anthropometric measurements. The mean of LV mass of athletes indexed to body surface (126 g/m2) was significantly greater than the one in control group (70 g/m2) (p < 0.001). Magnetic resonance imaging (MRI) showed there was not impairment of contractile strength or LV performance, and values of end diastolic volume, end systolic volume and EF within limits of normality. On the other hand, average ventricular parietal mass, 162.93 +/- 17.90 g, and LV parietal thickness, 13.67 +/- 2.13 mm, at the end of diastole in athlete group, differed significantly from control group: 110 +/- 14.2 g (p = 0.0001) and 8 +/- 0.9 mm, respectively (p = 0.0001). The same happened to the thickness at the end of systole, which was 18.87 +/- 3.40 mm (control group: 10 +/- 1.80 mm, p = 0.0001). Results allowed for concluding that LVH in marathoners in full sportive activity period, assessed by non-invasive methods, represents an adaptative response to

  20. Can supplementation with vitamin C and E alter physiological adaptations to strength training?

    PubMed Central

    2014-01-01

    Background Antioxidant supplementation has recently been demonstrated to be a double-edged sword, because small to moderate doses of exogenous antioxidants are essential or beneficial, while high doses may have adverse effects. The adverse effects can be manifested in attenuated effects of exercise and training, as the antioxidants may shut down some redox-sensitive signaling in the exercised muscle fibers. However, conditions such as age may potentially modulate the need for antioxidant intake. Therefore, this paper describes experiments for testing the hypothesis that high dosages of vitamin C (1000 mg/day) and E (235 mg/day) have negative effects on adaptation to resistance exercise and training in young volunteers, but positive effects in older men. Methods/design We recruited a total of 73 volunteers. The participants were randomly assigned to receiving either vitamin C and E supplementation or a placebo. The study design was double-blinded, and the participants followed an intensive training program for 10–12 weeks. Tests and measurements aimed at assessing changes in physical performance (maximal strength) and physiological characteristics (muscle mass), as well as biochemical and cellular systems and structures (e.g., cell signaling and morphology). Discussion Dietary supplements, such as vitamin C and E, are used by many people, especially athletes. The users often believe that high dosages of supplements improve health (resistance to illness and disease) and physical performance. These assumptions are, however, generally not supported in the scientific literature. On the contrary, some studies have indicated that high dosages of antioxidant supplements have negative effects on exercise-induced adaptation processes. Since this issue concerns many people and few randomized controlled trials have been conducted in humans, further studies are highly warranted. Trial registration ACTRN12614000065695 PMID:25075311

  1. Adaptive radiation of photosynthetic physiology in the Hawaiian lobeliads: dynamic photosynthetic responses.

    PubMed

    Montgomery, Rebecca A; Givnish, Thomas J

    2008-03-01

    Hawaiian lobeliads have radiated into habitats from open alpine bogs to densely shaded rainforest interiors, and show corresponding adaptations in steady-state photosynthetic light responses and associated leaf traits. Shaded environments are not uniformly dark, however, but punctuated by sunflecks that carry most of the photosynthetically active light that strikes plants. We asked whether lobeliads have diversified in their dynamic photosynthetic light responses and how dynamic responses influence daily leaf carbon gain. We quantified gas exchange and dynamic light regimes under field conditions for ten species representing each major Hawaiian sublineage. Species in shadier habitats experienced shorter and less numerous sunflecks: average sunfleck length varied from 1.4 +/- 1.7 min for Cyanea floribunda in shaded forest understories to 31.2 +/- 2.1 min for Trematolobelia kauaiensis on open ridges. As expected, the rate of photosynthetic induction increased significantly toward shadier sites, with assimilation after 60 s rising from ca. 30% of fully induced rates in species from open environments to 60% in those from densely shaded habitats. Uninduced light use efficiency-actual photosynthesis versus that expected under steady-state conditions-increased from 10 to 70% across the same gradient. In silico transplants-modeling daily carbon gain using one species' photosynthetic light response in its own and other species' dynamic light regimes-demonstrated the potential adaptive nature of species differences: understory Cyanea pilosa in its light regimes outperformed gap-dwelling Clermontia parviflora, while Clermontia in its light regimes outperformed Cyanea. The apparent crossover in daily photosynthesis occurred at about the same photon flux density where dominance shifts from Cyanea to Clermontia in the field. Our results further support our hypothesis that the lobeliads have diversified physiologically across light environments in Hawaiian ecosystems and that

  2. Contrasting plant physiological adaptation to climate in the native and introduced range of Hypericum perforatum.

    PubMed

    Maron, John L; Elmendorf, Sarah C; Vilà, Montserrat

    2007-08-01

    How introduced plants, which may be locally adapted to specific climatic conditions in their native range, cope with the new abiotic conditions that they encounter as exotics is not well understood. In particular, it is unclear what role plasticity versus adaptive evolution plays in enabling exotics to persist under new environmental circumstances in the introduced range. We determined the extent to which native and introduced populations of St. John's Wort (Hypericum perforatum) are genetically differentiated with respect to leaf-level morphological and physiological traits that allow plants to tolerate different climatic conditions. In common gardens in Washington and Spain, and in a greenhouse, we examined clinal variation in percent leaf nitrogen and carbon, leaf delta(13)C values (as an integrative measure of water use efficiency), specific leaf area (SLA), root and shoot biomass, root/shoot ratio, total leaf area, and leaf area ratio (LAR). As well, we determined whether native European H. perforatum experienced directional selection on leaf-level traits in the introduced range and we compared, across gardens, levels of plasticity in these traits. In field gardens in both Washington and Spain, native populations formed latitudinal clines in percent leaf N. In the greenhouse, native populations formed latitudinal clines in root and shoot biomass and total leaf area, and in the Washington garden only, native populations also exhibited latitudinal clines in percent leaf C and leaf delta(13)C. Traits that failed to show consistent latitudinal clines instead exhibited significant phenotypic plasticity. Introduced St. John's Wort populations also formed significant or marginally significant latitudinal clines in percent leaf N in Washington and Spain, percent leaf C in Washington, and in root biomass and total leaf area in the greenhouse. In the Washington common garden, there was strong directional selection among European populations for higher percent leaf N and

  3. Susceptibility and Adaptive Response to Bile Salts in Propionibacterium freudenreichii: Physiological and Proteomic Analysis

    PubMed Central

    Leverrier, Pauline; Dimova, Diliana; Pichereau, Vianney; Auffray, Yanick; Boyaval, Patrick; Jan, Gwénaël

    2003-01-01

    Tolerance to digestive stresses is one of the main factors limiting the use of microorganisms as live probiotic agents. Susceptibility to bile salts and tolerance acquisition in the probiotic strain Propionibacterium freudenreichii SI41 were characterized. We showed that pretreatment with a moderate concentration of bile salts (0.2 g/liter) greatly increased its survival during a subsequent lethal challenge (1.0 g/liter, 60 s). Bile salts challenge led to drastic morphological changes, consistent with intracellular material leakage, for nonadapted cells but not for preexposed ones. Moreover, the physiological state of the cells during lethal treatment played an important role in the response to bile salts, as stationary-phase bacteria appeared much less sensitive than exponentially growing cells. Either thermal or detergent pretreatment conferred significantly increased protection toward bile salts challenge. In contrast, some other heterologous pretreatments (hypothermic and hyperosmotic) had no effect on tolerance to bile salts, while acid pretreatment even might have sensitized the cells. Two-dimensional electrophoresis experiments revealed that at least 24 proteins were induced during bile salts adaptation. Identification of these polypeptides suggested that the bile salts stress response involves signal sensing and transduction, a general stress response (also triggered by thermal denaturation, oxidative toxicity, and DNA damage), and an alternative sigma factor. Taken together, our results provide new insights into the tolerance of P. freudenreichii to bile salts, which must be taken into consideration for the use of probiotic strains and the improvement of technological processes. PMID:12839748

  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. Physiological and Proteomic Adaptation of the Alpine Grass Stipa purpurea to a Drought Gradient

    PubMed Central

    Yang, Yunqiang; Dong, Chao; Yang, Shihai; Li, Xiong; Sun, Xudong; Yang, Yongping

    2015-01-01

    Stipa purpurea, an endemic forage species on the Tibetan Plateau, is highly resistant to cold and drought, but the mechanisms underlying its responses to drought stress remain elusive. An understanding of such mechanisms may be useful for developing cultivars that are adaptable to water deficit. In this study, we analyzed the physiological and proteomic responses of S. purpurea under increasing drought stress. Seedlings of S. purpurea were subjected to a drought gradient in a controlled experiment, and proteins showing changes in abundance under these conditions were identified by two-dimensional electrophoresis followed by mass spectrometry analysis. A western blotting analysis was conducted to confirm the increased abundance of a heat-shock protein, NCED2, and a dehydrin in S. purpurea seedlings under drought conditions. We detected carbonylated proteins to identify oxidation-sensitive proteins in S. purpurea seedlings, and found that ribulose-1, 5-bisphosphate carboxylase oxygenase (RuBisCO) was one of the oxidation-sensitive proteins under drought. Together, these results indicated drought stress might inhibit photosynthesis in S. purpurea by oxidizing RuBisCO, but the plants were able to maintain photosynthetic efficiency by a compensatory upregulation of unoxidized RuBisCO and other photosynthesis-related proteins. Further analyses confirmed that increased abundance of antioxidant enzymes could balance the redox status of the plants to mitigate drought-induced oxidative damage. PMID:25646623

  6. Physiological and proteomic adaptation of the alpine grass Stipa purpurea to a drought gradient.

    PubMed

    Yang, Yunqiang; Dong, Chao; Yang, Shihai; Li, Xiong; Sun, Xudong; Yang, Yongping

    2015-01-01

    Stipa purpurea, an endemic forage species on the Tibetan Plateau, is highly resistant to cold and drought, but the mechanisms underlying its responses to drought stress remain elusive. An understanding of such mechanisms may be useful for developing cultivars that are adaptable to water deficit. In this study, we analyzed the physiological and proteomic responses of S. purpurea under increasing drought stress. Seedlings of S. purpurea were subjected to a drought gradient in a controlled experiment, and proteins showing changes in abundance under these conditions were identified by two-dimensional electrophoresis followed by mass spectrometry analysis. A western blotting analysis was conducted to confirm the increased abundance of a heat-shock protein, NCED2, and a dehydrin in S. purpurea seedlings under drought conditions. We detected carbonylated proteins to identify oxidation-sensitive proteins in S. purpurea seedlings, and found that ribulose-1, 5-bisphosphate carboxylase oxygenase (RuBisCO) was one of the oxidation-sensitive proteins under drought. Together, these results indicated drought stress might inhibit photosynthesis in S. purpurea by oxidizing RuBisCO, but the plants were able to maintain photosynthetic efficiency by a compensatory upregulation of unoxidized RuBisCO and other photosynthesis-related proteins. Further analyses confirmed that increased abundance of antioxidant enzymes could balance the redox status of the plants to mitigate drought-induced oxidative damage.

  7. Compensation of the metabolic costs of antibiotic resistance by physiological adaptation in Escherichia coli.

    PubMed

    Händel, Nadine; Schuurmans, J Merijn; Brul, Stanley; ter Kuile, Benno H

    2013-08-01

    Antibiotic resistance is often associated with metabolic costs. To investigate the metabolic consequences of antibiotic resistance, the genomic and transcriptomic profiles of an amoxicillin-resistant Escherichia coli strain and the wild type it was derived from were compared. A total of 125 amino acid substitutions and 7 mutations that were located <1,000 bp upstream of differentially expressed genes were found in resistant cells. However, broad induction and suppression of genes were observed when comparing the expression profiles of resistant and wild-type cells. Expression of genes involved in cell wall maintenance, DNA metabolic processes, cellular stress response, and respiration was most affected in resistant cells regardless of the absence or presence of amoxicillin. The SOS response was downregulated in resistant cells. The physiological effect of the acquisition of amoxicillin resistance in cells grown in chemostat cultures consisted of an initial increase in glucose consumption that was followed by an adaptation process. Furthermore, no difference in maintenance energy was observed between resistant and sensitive cells. In accordance with the transcriptomic profile, exposure of resistant cells to amoxicillin resulted in reduced salt and pH tolerance. Taken together, the results demonstrate that the acquisition of antibiotic resistance in E. coli is accompanied by specifically reorganized metabolic networks in order to circumvent metabolic costs. The overall effect of the acquisition of resistance consists not so much of an extra energy requirement, but more a reduced ecological range.

  8. Phytoplankton production and physiological adaptation on the southeastern shelf of the Agulhas ecosystem

    NASA Astrophysics Data System (ADS)

    Barlow, R.; Lamont, T.; Kyewalyanga, M.; Sessions, H.; Morris, T.

    2010-07-01

    An investigation of phytoplankton production and physiology was undertaken during two research cruises on the southeastern shelf of southern Africa. The data set included photosynthesis-irradiance and active fluorescence parameters, phytoplankton absorption coefficients and HPLC pigment concentrations. Primary production was estimated to vary over a similar range for both cruises within 0.27-3.69 g C m -2 d -1. Pigment indices indicated that diatoms were dominant on the first cruise and the communities were subject to conditions where the mixed layer was deeper than the euphotic zone and they optimized their photosynthesis to very low light intensities at the bottom and below the euphotic zone. Mixed diatom-flagellate populations were observed during the second cruise where the euphotic zone was deeper than the mixed layer and the populations adapted to irradiances higher in the euphotic zone. In response to a mean lower water column PAR, it was found that these mixed communities increased the proportion of chlorophyll a in the pigment pool and had a higher quantum yield of photochemistry and higher light-limited photosynthetic efficiency.

  9. Physiological adaptations to fasting in an actively wintering canid, the Arctic blue fox (Alopex lagopus).

    PubMed

    Mustonen, Anne-Mari; Pyykönen, Teija; Puukka, Matti; Asikainen, Juha; Hänninen, Sari; Mononen, Jaakko; Nieminen, Petteri

    2006-01-01

    This study investigated the physiological adaptations to fasting using the farmed blue fox (Alopex lagopus) as a model for the endangered wild arctic fox. Sixteen blue foxes were fed throughout the winter and 32 blue foxes were fasted for 22 d in Nov-Dec 2002. Half of the fasted blue foxes were food-deprived again for 22 d in Jan-Feb 2003. The farmed blue fox lost weight at a slower rate (0.97-1.02% body mass d(-1)) than observed previously in the arctic fox, possibly due to its higher initial body fat content. The animals experienced occasional fasting-induced hypoglycaemia, but their locomotor activity was not affected. The plasma triacylglycerol and glycerol concentrations were elevated during phase II of fasting indicating stimulated lipolysis, probably induced by the high growth hormone concentrations. The total cholesterol, HDL- and LDL-cholesterol, urea, uric acid and total protein levels and the urea:creatinine ratio decreased during fasting. Although the plasma levels of some essential amino acids increased, the blue foxes did not enter phase III of starvation characterized by stimulated proteolysis during either of the 22-d fasting procedures. Instead of excessive protein catabolism, it is liver dysfunction, indicated by the increased plasma bilirubin levels and alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase activities, that may limit the duration of fasting in the species.

  10. Life After Being a Pathology Department Chair

    PubMed Central

    Lipscomb, Mary F.; Gorstein, Fred; Wilkinson, David; Sanfilippo, Fred

    2016-01-01

    Although there is a considerable literature on transition of faculty members to the position of department chair, there is a dearth of publications about transitioning from the chair to other activities including retirement. The Association of Pathology Chairs senior fellows (all of whom are former chairs of academic departments of pathology) made this topic a focus of discussion at the Association of Pathology Chairs 2016 Annual Meeting. Of the 33 senior fellows engaged in this discussion, following their time as chairs, a small majority (18) transitioned to other administrative posts within or outside the university, while the others either returned to the active faculty (7) or retired (8). The motivating factors and influences for transitioning from the chair were probed along with the processes used in executing the transition, such as the development of transition plans. The reasons for selecting the specific type of postchair activity were also investigated. There was extraordinary diversity in the type of post-chair activities pursued. To our knowledge, no other medical specialty has examined these issues, which may be potentially relevant for the career planning of active chairs. PMID:28725780

  11. The effect of detraining and reduced training on the physiological adaptations to aerobic exercise training.

    PubMed

    Neufer, P D

    1989-11-01

    In previously sedentary individuals, regularly performed aerobic exercise results in significant improvements in exercise capacity. The development of peak exercise performance, as typified by competitive endurance athletes, is dependent upon several months to years of aerobic training. The physiological adaptations associated with these improvements in both maximal exercise performance, as reflected by increases in maximal oxygen uptake (VO2max), and submaximal exercise endurance include increases in both cardiovascular function and skeletal muscle oxidative capacity. Despite prolonged periods of aerobic training, reductions in maximal and submaximal exercise performance occur within weeks after the cessation of training. These losses in exercise performance coincide with declines in cardiovascular function and muscle metabolic potential. Significant reductions in VO2max have been reported to occur within 2 to 4 weeks of detraining. This initial rapid decline in VO2max is likely related to a corresponding fall in maximal cardiac output which, in turn, appears to be mediated by a reduced stroke volume with little or no change in maximal heart rate. A loss in blood volume appears to, at least partially, account for the decline in stroke volume and VO2max during the initial weeks of detraining, although changes in cardiac hypertrophy, total haemoglobin content, skeletal muscle capillarisation and temperature regulation have been suggested as possible mediating factors. When detraining continues beyond 2 to 4 weeks, further declines in VO2max appear to be a function of corresponding reductions in maximal arterial-venous (mixed) oxygen difference. Whether reductions in oxygen delivery to and/or extraction by working muscle regulates this progressive decline is not readily apparent. Changes in maximal oxygen delivery may result from decreases in total haemoglobin content and/or maximal muscle blood flow and vascular conductance. The declines in skeletal muscle oxidative

  12. Hematological and physiological adaptations following 46 weeks of moderate altitude residence.

    PubMed

    Brothers, Michael D; Doan, Brandon K; Zupan, Michael F; Wile, Al L; Wilber, Randall L; Byrnes, William C

    2010-01-01

    physiological adaptations, as both hematological and physical performance differences persisted between groups. Further research at this uniquely well controlled MA setting is warranted.

  13. Correlative physiological and morphological studies of rapidly adapting mechanoreceptors in cat's glabrous skin.

    PubMed Central

    Iggo, A; Ogawa, H

    1977-01-01

    1. A total of fifty-four mechanoreceptor afferent units with fast conducting axons in the tibial nerve innervating the glabrous skin of the hind leg were isolated in anaesthetized cats. 2. Twenty-six rapidly adapting units (RA), eighteen slowly adapting units (SA) and ten Pacinian corpuscle units (PC) were differentiated from each other mainly on the presence of the off response in RA and PC units to a ramp stimulation, the persistence of discharges of the SA units during steady pressure on the receptive field and the classical tuning curve seen in the PC units. A few PC units in the hairy skin were also studied for comparison. 3. Lamellated corpuscles were found histologically in the skin of the receptive field of RA units and identified as Krause's corpuscle of cylindrical type by their superficial location in the cutaneous tissue and their structure revealed by electron microscopy. 4. Physiological characteristics of RA units to various forms of mechanical stimulation were studied and compared with those of the other two kinds of units. SA units had the lowest critical slope among three groups and PC units the highest. 5. The discharge pattern of RA and PC units to a ramp stimulation was found to be time-locked, whereas with SA unites only the first spike appeared at a fixed latency from the start of stimulation. 6. Some RA units showed a tuning curve which was flat from 10 to 200 Hz. Those with narrowly tuned curves had a best turning frequency at around 20 Hz. They were easily differentiated from the SA and PC units. SA units were tuned best at 5 HZ or less, and PC units at around 200 HZ. 7. The relation between the indentation velocity and amplitude of the ramp and the spike discharges was analysed in eleven RA units. In most cases the relation between identation velocity and maximum instataneous frequency was found to be best fit with a power function although other kinds of functions (linear, logarithmic, and logarithmic hyperbolic tangent) could also fit

  14. Adaptation.

    PubMed

    Broom, Donald M

    2006-01-01

    welfare can be very good when it is occurring. Other adaptation is difficult and may involve lower or higher level emergency physiological responses or abnormal behaviour, often with bad feelings such as pain or fear. In that case, welfare is poor or very poor even if complete adaptation eventually occurs and there is no long-term threat to the life of the individual. In some circumstances, adaptation may be unsuccessful, the individual is not able to cope, stress occurs and welfare is ultimately very poor.

  15. Autophagy: an adaptive physiological countermeasure to cellular senescence and ischaemia/reperfusion-associated cardiac arrhythmias.

    PubMed

    Lekli, Istvan; Haines, David Donald; Balla, Gyorgy; Tosaki, Arpad

    2017-06-01

    Oxidative stress placed on tissues that involved in pathogenesis of a disease activates compensatory metabolic changes, such as DNA damage repair that in turn causes intracellular accumulation of detritus and 'proteotoxic stress', leading to emergence of 'senescent' cellular phenotypes, which express high levels of inflammatory mediators, resulting in degradation of tissue function. Proteotoxic stress resulting from hyperactive inflammation following reperfusion of ischaemic tissue causes accumulation of proteinaceous debris in cells of the heart in ways that cause potentially fatal arrhythmias, in particular ventricular fibrillation (VF). An adaptive response to VF is occurrence of autophagy, an intracellular bulk degradation of damaged macromolecules and organelles that may restore cellular and tissue homoeostasis, improving chances for recovery. Nevertheless, depending on the type and intensity of stressors and inflammatory responses, autophagy may become pathological, resulting in excessive cell death. The present review examines the multilayered defences that cells have evolved to reduce proteotoxic stress by degradation of potentially toxic material beginning with endoplasmic reticulum-associated degradation, and the unfolded protein response, which are mechanisms for removal from the endoplasmic reticulum of misfolded proteins, and then progressing through the stages of autophagy, including descriptions of autophagosomes and related vesicular structures which process material for degradation and autophagy-associated proteins including Beclin-1 and regulatory complexes. The physiological roles of each mode of proteotoxic defence will be examined along with consideration of how emerging understanding of autophagy, along with a newly discovered regulatory cell type called telocytes, may be used to augment existing strategies for the prevention and management of cardiovascular disease. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by

  16. Hibernation physiology, freezing adaptation and extreme freeze tolerance in a northern population of the wood frog.

    PubMed

    Costanzo, Jon P; do Amaral, M Clara F; Rosendale, Andrew J; Lee, Richard E

    2013-09-15

    We investigated hibernation physiology and freeze tolerance in a population of the wood frog, Rana sylvatica, indigenous to Interior Alaska, USA, near the northernmost limit of the species' range. Winter acclimatization responses included a 233% increase in the hepatic glycogen depot that was subsidized by fat body and skeletal muscle catabolism, and a rise in plasma osmolality that reflected accrual of urea (to 106±10 μmol ml(-1)) and an unidentified solute (to ~73 μmol ml(-1)). In contrast, frogs from a cool-temperate population (southern Ohio, USA) amassed much less glycogen, had a lower uremia (28±5 μmol ml(-1)) and apparently lacked the unidentified solute. Alaskan frogs survived freezing at temperatures as low as -16°C, some 10-13°C below those tolerated by southern conspecifics, and endured a 2-month bout of freezing at -4°C. The profound freeze tolerance is presumably due to their high levels of organic osmolytes and bound water, which limits ice formation. Adaptive responses to freezing (-2.5°C for 48 h) and subsequent thawing (4°C) included synthesis of the cryoprotectants urea and glucose, and dehydration of certain tissues. Alaskan frogs differed from Ohioan frogs in retaining a substantial reserve capacity for glucose synthesis, accumulating high levels of cryoprotectants in brain tissue, and remaining hyperglycemic long after thawing. The northern phenotype also incurred less stress during freezing/thawing, as indicated by limited cryohemolysis and lactate accumulation. Post-glacial colonization of high latitudes by R. sylvatica required a substantial increase in freeze tolerance that was at least partly achieved by enhancing their cryoprotectant system.

  17. The physiology of climate change: how potentials for acclimatization and genetic adaptation will determine 'winners' and 'losers'.

    PubMed

    Somero, G N

    2010-03-15

    Physiological studies can help predict effects of climate change through determining which species currently live closest to their upper thermal tolerance limits, which physiological systems set these limits, and how species differ in acclimatization capacities for modifying their thermal tolerances. Reductionist studies at the molecular level can contribute to this analysis by revealing how much change in sequence is needed to adapt proteins to warmer temperatures--thus providing insights into potential rates of adaptive evolution--and determining how the contents of genomes--protein-coding genes and gene regulatory mechanisms--influence capacities for adapting to acute and long-term increases in temperature. Studies of congeneric invertebrates from thermally stressful rocky intertidal habitats have shown that warm-adapted congeners are most susceptible to local extinctions because their acute upper thermal limits (LT(50) values) lie near current thermal maxima and their abilities to increase thermal tolerance through acclimation are limited. Collapse of cardiac function may underlie acute and longer-term thermal limits. Local extinctions from heat death may be offset by in-migration of genetically warm-adapted conspecifics from mid-latitude 'hot spots', where midday low tides in summer select for heat tolerance. A single amino acid replacement is sufficient to adapt a protein to a new thermal range. More challenging to adaptive evolution are lesions in genomes of stenotherms like Antarctic marine ectotherms, which have lost protein-coding genes and gene regulatory mechanisms needed for coping with rising temperature. These extreme stenotherms, along with warm-adapted eurytherms living near their thermal limits, may be the major 'losers' from climate change.

  18. Interactive resistance chair to promote strengthening exercise in older adults.

    PubMed

    Jeong, In Cheol; Finkelstein, Joseph

    2015-01-01

    We developed a strengthening exercise support system which can be remotely managed and clinically supervised via internet. Older adults may potentially benefit from such an exercise system however functionality of this system requires validation before commencement of field studies in older adults. The aim of this study was to introduce and assess validity of a prototype telerehabilitation system supporting computer-assisted home-based strengthening exercise. The system included a resistance chair with a set of movement and physiologic sensors. Real-time feedback on exercise performance was displayed on a touch screen dashboard. Personalized exercise parameters were managed by a rehabilitation team via a designated telerehabilitation site. Assessment of the system demonstrated sufficient validity in real-time identification of exercise performance and cardiovascular parameters. We concluded that the interactive resistance chair has a potential in promoting strengthening exercise and it is warranted for further evaluation in community dwelling older adults.

  19. Chair-based fidgeting and energy expenditure

    PubMed Central

    Koepp, Gabriel A; Moore, Graham K; Levine, James A

    2016-01-01

    Introduction Sedentariness is associated with chronic health conditions, impaired cognitive function and obesity. Work contributes significantly to sedentariness because many work tasks necessitate sitting. Few sustained solutions exist to reverse workplace sedentariness. Here, we evaluated a chair and an under-table device that were designed to promote fidgeting while seated. Our hypothesis was that an under-table leg-fidget bar and/or a fidget-promoting chair significantly increased energy expenditure. We compared these devices with chair-based exercise and walking. Materials and methods We measured energy expenditure and heart rate in 16 people while they sat and worked using a standard chair, an under-desk device that encourages leg fidgeting and a fidget-promoting chair. We compared outcomes with chair-based exercise and walking. Results Energy expenditure increased significantly while using either an under-table leg-fidget bar or a fidget-promoting chair, when compared to the standard office chair (standard chair, 76±31 kcal/hour; leg-fidget bar, 98±42 kcal/hour (p<0.001); fidget chair, 89±40 kcal/hour (p=0.03)). However, heart rate did not increase significantly in either case. Bouts of exercise performed while seated provided energetic and heart rate equivalency to walking at 2 mph. Conclusions Chairs and devices that promote fidgeting can increase energy expenditure by ∼20–30% but not increase heart rate. Dynamic sitting may be among a lexicon of options to help people move more while at work. PMID:27900194

  20. Automated chair-training of rhesus macaques.

    PubMed

    Ponce, C R; Genecin, M P; Perez-Melara, G; Livingstone, M S

    2016-04-01

    Neuroscience research on non-human primates usually requires the animals to sit in a chair. To do this, typically monkeys are fitted with collars and trained to enter the chairs using either a pole, leash and jump cage. Animals may initially show resistance and risk injury. We have developed an automated chair-training method that minimizes restraints to ease the animals into their chairs. We developed a method to automatically train animals to enter a primate chair and stick out their heads for neckplate placement. To do this, we fitted the chairs with Arduino microcontrollers coupled to a water-reward system and touch- and proximity sensors. We found that the animals responded well to the chair, partially entering the chair within hours, sitting inside the chair within days and allowing us to manually introduce a door and neck plate, all within 14-21 sessions. Although each session could last many hours, automation meant that actual training person-hours could be as little as half an hour per day. The biggest advantage was that animals showed little resistance to entering the chair, compared to monkeys trained by leash pulling. This automated chair-training method can take longer than the standard collar-and-leash approach, but multiple macaques can be trained in parallel with fewer person-hours. It is also a promising method for animal-use refinement and in our case, it was the only effective training approach for an animal suffering from a behavioral pathology. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Chair-based fidgeting and energy expenditure.

    PubMed

    Koepp, Gabriel A; Moore, Graham K; Levine, James A

    2016-01-01

    Sedentariness is associated with chronic health conditions, impaired cognitive function and obesity. Work contributes significantly to sedentariness because many work tasks necessitate sitting. Few sustained solutions exist to reverse workplace sedentariness. Here, we evaluated a chair and an under-table device that were designed to promote fidgeting while seated. Our hypothesis was that an under-table leg-fidget bar and/or a fidget-promoting chair significantly increased energy expenditure. We compared these devices with chair-based exercise and walking. We measured energy expenditure and heart rate in 16 people while they sat and worked using a standard chair, an under-desk device that encourages leg fidgeting and a fidget-promoting chair. We compared outcomes with chair-based exercise and walking. Energy expenditure increased significantly while using either an under-table leg-fidget bar or a fidget-promoting chair, when compared to the standard office chair (standard chair, 76±31 kcal/hour; leg-fidget bar, 98±42 kcal/hour (p<0.001); fidget chair, 89±40 kcal/hour (p=0.03)). However, heart rate did not increase significantly in either case. Bouts of exercise performed while seated provided energetic and heart rate equivalency to walking at 2 mph. Chairs and devices that promote fidgeting can increase energy expenditure by ∼20-30% but not increase heart rate. Dynamic sitting may be among a lexicon of options to help people move more while at work.

  2. Synthetic physiology strategies for adapting tools from nature for genetically targeted control of fast biological processes.

    PubMed

    Chow, Brian Y; Chuong, Amy S; Klapoetke, Nathan C; Boyden, Edward S

    2011-01-01

    The life and operation of cells involve many physiological processes that take place over fast timescales of milliseconds to minutes. Genetically encoded technologies for driving or suppressing specific fast physiological processes in intact cells, perhaps embedded within intact tissues in living organisms, are critical for the ability to understand how these physiological processes contribute to emergent cellular and organismal functions and behaviors. Such "synthetic physiology" tools are often incredibly complex molecular machines, in part because they must operate at high speeds, without causing side effects. We here explore how synthetic physiology molecules can be identified and deployed in cells, and how the physiology of these molecules in cellular contexts can be assessed and optimized. For concreteness, we discuss these methods in the context of the "optogenetic" light-gated ion channels and pumps that we have developed over the past few years as synthetic physiology tools and widely disseminated for use in neuroscience for probing the role of specific brain cell types in neural computations, behaviors, and pathologies. We anticipate that some of the insights revealed here may be of general value for the field of synthetic physiology, as they raise issues that will be of importance for the development and use of high-performance, high-speed, side-effect free physiological control tools in heterologous expression systems.

  3. Use of physiological constraints to identify quantitative design principles for gene expression in yeast adaptation to heat shock

    PubMed Central

    Vilaprinyo, Ester; Alves, Rui; Sorribas, Albert

    2006-01-01

    Background Understanding the relationship between gene expression changes, enzyme activity shifts, and the corresponding physiological adaptive response of organisms to environmental cues is crucial in explaining how cells cope with stress. For example, adaptation of yeast to heat shock involves a characteristic profile of changes to the expression levels of genes coding for enzymes of the glycolytic pathway and some of its branches. The experimental determination of changes in gene expression profiles provides a descriptive picture of the adaptive response to stress. However, it does not explain why a particular profile is selected for any given response. Results We used mathematical models and analysis of in silico gene expression profiles (GEPs) to understand how changes in gene expression correlate to an efficient response of yeast cells to heat shock. An exhaustive set of GEPs, matched with the corresponding set of enzyme activities, was simulated and analyzed. The effectiveness of each profile in the response to heat shock was evaluated according to relevant physiological and functional criteria. The small subset of GEPs that lead to effective physiological responses after heat shock was identified as the result of the tuning of several evolutionary criteria. The experimentally observed transcriptional changes in response to heat shock belong to this set and can be explained by quantitative design principles at the physiological level that ultimately constrain changes in gene expression. Conclusion Our theoretical approach suggests a method for understanding the combined effect of changes in the expression of multiple genes on the activity of metabolic pathways, and consequently on the adaptation of cellular metabolism to heat shock. This method identifies quantitative design principles that facilitate understating the response of the cell to stress. PMID:16584550

  4. Annual Research Review: The Neurobiology and Physiology of Resilience and Adaptation across the Life Course

    ERIC Educational Resources Information Center

    Karatoreos, Ilia N.; McEwen, Bruce S.

    2013-01-01

    Background: Adaptation is key to survival. An organism must adapt to environmental challenges in order to be able to thrive in the environment in which they find themselves. Resilience can be thought of as a measure of the ability of an organism to adapt, and to withstand challenges to its stability. In higher animals, the brain is a key player in…

  5. Annual Research Review: The Neurobiology and Physiology of Resilience and Adaptation across the Life Course

    ERIC Educational Resources Information Center

    Karatoreos, Ilia N.; McEwen, Bruce S.

    2013-01-01

    Background: Adaptation is key to survival. An organism must adapt to environmental challenges in order to be able to thrive in the environment in which they find themselves. Resilience can be thought of as a measure of the ability of an organism to adapt, and to withstand challenges to its stability. In higher animals, the brain is a key player in…

  6. Leading Learning: Science Departments and the Chair

    ERIC Educational Resources Information Center

    Melville, Wayne; Campbell, Todd; Jones, Doug

    2016-01-01

    In this article, we have considered the role of the chair in leading the learning necessary for a department to become effective in the teaching and learning of science from a reformed perspective. We conceptualize the phrase "leading learning" to mean the chair's constitution of influence, power, and authority to intentionally impact…

  7. 21 CFR 890.3100 - Mechanical chair.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Mechanical chair. 890.3100 Section 890.3100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3100 Mechanical chair....

  8. 21 CFR 890.3100 - Mechanical chair.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mechanical chair. 890.3100 Section 890.3100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3100 Mechanical chair....

  9. Secondary School Department Chair Roles: Principal Expectations

    ERIC Educational Resources Information Center

    Brent, Brian O.; Deangelis, Karen J.; Surash, Barbara M.

    2014-01-01

    The literature on the principalship is extensive, revealing ways in which principals can foster or impede school success. At the same time, another formal secondary school-level position, the department chair, has garnered little scholarly attention. Thus far, the literature offers a limited account of the roles that chairs should or do perform in…

  10. Axiology, the Subject and the Chair

    NASA Astrophysics Data System (ADS)

    Melville, Wayne; Campbell, Todd; Jones, Doug

    2017-08-01

    This article addresses two gaps in the literature related to science department chairs: the axiological relationship between the chair and science, the subject, and the perceptions of the chair with respect to teaching and learning within their departments. In this work, axiology is used to understand how the chair's values toward the subject influenced his own perceived capacity to lead learning within his department in a reformed discourse. A narrative inquiry methodology was used to consider the chair's experiences in the development of his identify over his life span in the form of two stories: (1) the relationship between the chair and science, the subject, and (2) the perceptions of the chair with regards to teacher learning within the department. The findings revealed that the work and career of the chair in this study were authored by strong elements of personal continuity and points of stability around the valuing of science, the subject, even as this valuing evolved from being more focused on epistemic values early in his career, to being more concerned with universal values connected to his legacy and his department later in his career.

  11. Secondary School Science Department Chairs Leading Change

    ERIC Educational Resources Information Center

    Gaubatz, Julie A.

    2012-01-01

    Secondary school department chairs are content area specialists in their schools and are responsible for providing students with the most appropriate curricula. However, most secondary school department chairs have limited authority to institute change unilaterally (Gmelch, 1993; Hannay & Erb, 1999). To explore how these educational leaders…

  12. Secondary School Science Department Chairs Leading Change

    ERIC Educational Resources Information Center

    Gaubatz, Julie A.

    2012-01-01

    Secondary school department chairs are content area specialists in their schools and are responsible for providing students with the most appropriate curricula. However, most secondary school department chairs have limited authority to institute change unilaterally (Gmelch, 1993; Hannay & Erb, 1999). To explore how these educational leaders…

  13. 21 CFR 890.3100 - Mechanical chair.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Mechanical chair. 890.3100 Section 890.3100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3100 Mechanical chair....

  14. 21 CFR 890.3100 - Mechanical chair.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Mechanical chair. 890.3100 Section 890.3100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3100 Mechanical chair....

  15. 21 CFR 890.3100 - Mechanical chair.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Mechanical chair. 890.3100 Section 890.3100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3100 Mechanical chair....

  16. Leading Learning: Science Departments and the Chair

    ERIC Educational Resources Information Center

    Melville, Wayne; Campbell, Todd; Jones, Doug

    2016-01-01

    In this article, we have considered the role of the chair in leading the learning necessary for a department to become effective in the teaching and learning of science from a reformed perspective. We conceptualize the phrase "leading learning" to mean the chair's constitution of influence, power, and authority to intentionally impact…

  17. Understanding the Training Needs of Department Chairs

    ERIC Educational Resources Information Center

    Aziz, Shahnaz; Mullins, Morell E.; Balzer, William K.; Grauer, Eyal; Burnfield, Jennifer L.; Lodato, Michael A.; Cohen-Powless, Melissa A.

    2005-01-01

    Little empirical research has focused specifically on the process of identifying comprehensive training needs for department chairs and school directors in public universities. A case study is presented to demonstrate the systematic design and implementation of a program to comprehensively assess the training needs of department chairs and school…

  18. Who Will Be Your Next Board Chair?

    ERIC Educational Resources Information Center

    Wilson, E. B.

    2004-01-01

    This article suggests that trustees give the same high level of thoughtful consideration to selecting the board chair as they give to filling the presidency. More than the routine filling of a vacancy, the process for naming the board's next chair amounts to the selection of a governance team. The board's most important responsibility is not only…

  19. Enhancing the Effectiveness of Department Chairs

    ERIC Educational Resources Information Center

    Lumpkin, Angela

    2004-01-01

    The department chair is one of the most challenging positions in higher education. Advancing one's department can occur by attending to the parameters that highly successful organizations have implemented. In addition to outlining the challenges of serving as a department chair, this article describes four requirements for dealing with, and…

  20. Role of thermal physiology and bioenergetics on adaptation in tree shrew (Tupaia belangeri): the experiment test

    PubMed Central

    Zhang, Lin; Yang, Fang; Wang, Zheng-kun; Zhu, Wan-long

    2017-01-01

    Ambient conditions, as temperature and photoperiod, play a key role in animals’ physiology and behaviors. To test the hypothesis that the maximum thermal physiological and bioenergetics tolerances are induced by extreme environments in Tupaia belangeri. We integrated the acclimatized and acclimated data in several physiological, hormonal, and biochemical markers of thermogenic capacity and bioenergetics in T. belangeri. Results showed that T. belangeri increased body mass, thermogenesis capacity, protein contents and cytochrome c oxidase (COX) activity of liver and brown adipose tissue in winter-like environments, which indicated that temperature was the primary signal for T. belangeri to regulate several physiological capacities. The associated photoperiod signal also elevated the physiological capacities. The regulations of critical physiological traits play a primary role in meeting the survival challenges of winter-like condition in T. belangeri. Together, to cope with cold, leptin may play a potential role in thermogenesis and body mass regulation, as this hormonal signal is associated with other hormones. The strategies of thermal physiology and bioenergetics differs between typical Palearctic species and the local species. However, the maximum thermal physiology and bioenergetic tolerance maybe is an important strategy to cope with winter-like condition of T. belangeri. PMID:28145515

  1. A Chemosensory Adaptation Module for the Physiology Laboratory from Student-Directed "C. elegans" Research

    ERIC Educational Resources Information Center

    Lindblom, Tim

    2006-01-01

    The model organism, "Caenorhabditis elegans," in addition to being well suited to genetics and cell biology teaching applications, can also be useful in the physiology laboratory. In this article, the author describes how students in a junior level college Comparative Physiology course have made use of "C. elegans" in semester-long,…

  2. A Chemosensory Adaptation Module for the Physiology Laboratory from Student-Directed "C. elegans" Research

    ERIC Educational Resources Information Center

    Lindblom, Tim

    2006-01-01

    The model organism, "Caenorhabditis elegans," in addition to being well suited to genetics and cell biology teaching applications, can also be useful in the physiology laboratory. In this article, the author describes how students in a junior level college Comparative Physiology course have made use of "C. elegans" in semester-long,…

  3. SIRT1 is a Highly Networked Protein That Mediates the Adaptation to Chronic Physiological Stress

    PubMed Central

    Clark-Knowles, Katherine V.; Caron, Annabelle Z.; Gray, Douglas A.

    2013-01-01

    SIRT1 is a NAD+-dependent protein deacetylase that has a very large number of established protein substrates and an equally impressive list of biological functions thought to be regulated by its activity. Perhaps as notable is the remarkable number of points of conflict concerning the role of SIRT1 in biological processes. For example, evidence exists suggesting that SIRT1 is a tumor suppressor, is an oncogene, or has no effect on oncogenesis. Similarly, SIRT1 is variably reported to induce, inhibit, or have no effect on autophagy. We believe that the resolution of many conflicting results is possible by considering recent reports indicating that SIRT1 is an important hub interacting with a complex network of proteins that collectively regulate a wide variety of biological processes including cancer and autophagy. A number of the interacting proteins are themselves hubs that, like SIRT1, utilize intrinsically disordered regions for their promiscuous interactions. Many studies investigating SIRT1 function have been carried out on cell lines carrying undetermined numbers of alterations to the proteins comprising the SIRT1 network or on inbred mouse strains carrying fixed mutations affecting some of these proteins. Thus, the effects of modulating SIRT1 amount and/or activity are importantly determined by the genetic background of the cell (or the inbred strain of mice), and the effects attributed to SIRT1 are synthetic with the background of mutations and epigenetic differences between cells and organisms. Work on mice carrying alterations to the Sirt1 gene suggests that the network in which SIRT1 functions plays an important role in mediating physiological adaptation to various sources of chronic stress such as calorie restriction and calorie overload. Whether the catalytic activity of SIRT1 and the nuclear concentration of the co-factor, NAD+, are responsible for modulating this activity remains to be determined. However, the effect of modulating SIRT1 activity must

  4. Changing chairs: anticipating problems in prescribing wheelchairs.

    PubMed

    Batavia, M; Batavia, A I; Friedman, R

    2001-08-15

    This article presents a framework for prescribing, ordering, and adapting a new wheelchair, focusing on individual, environmental and wheelchair factors that must be taken into consideration to ensure optimal function. A review and analysis was conducted of all factors relevant to the transition to a new wheelchair. Without appropriate planning and implementation, this transition can result in unnecessary expenses, duplication of effort, and possibly even injury to the user and abandonment of the wheelchair. Recommendations are provided to manufacturers, therapists, technicians, users, insurers and physicians, who must work together throughout this process. To the extent feasible, the authors suggest that major changes from the previous wheelchair should be avoided, particularly for people with substantial functional limitations. Therapists and technicians must measure the user accurately, and anticipate those factors that can impede a smooth transition. Insurers and other payors must recognize that changing wheelchairs will often require substantial professional assistance, including several fittings to adjust the new chair to the needs of the user. Additional research and case reporting on outcomes of adjusting to a new wheelchair appear warranted.

  5. Boerhaave: Three Chairs to Oblivion

    ERIC Educational Resources Information Center

    Novak, Alfred

    1971-01-01

    Describes Boerhaave's contributions to botany, physiology, medical education, and chemistry from the late 17th to the early 18th centuries; his influence on other academics in Europe and North America is also discussed. (AL)

  6. Boerhaave: Three Chairs to Oblivion

    ERIC Educational Resources Information Center

    Novak, Alfred

    1971-01-01

    Describes Boerhaave's contributions to botany, physiology, medical education, and chemistry from the late 17th to the early 18th centuries; his influence on other academics in Europe and North America is also discussed. (AL)

  7. Global Transcriptional, Physiological, and Metabolite Analyses of the Responses of Desulfovibrio vulgaris Hildenborough to Salt Adaptation ▿ †

    PubMed Central

    He, Zhili; Zhou, Aifen; Baidoo, Edward; He, Qiang; Joachimiak, Marcin P.; Benke, Peter; Phan, Richard; Mukhopadhyay, Aindrila; Hemme, Christopher L.; Huang, Katherine; Alm, Eric J.; Fields, Matthew W.; Wall, Judy; Stahl, David; Hazen, Terry C.; Keasling, Jay D.; Arkin, Adam P.; Zhou, Jizhong

    2010-01-01

    The response of Desulfovibrio vulgaris Hildenborough to salt adaptation (long-term NaCl exposure) was examined by performing physiological, global transcriptional, and metabolite analyses. Salt adaptation was reflected by increased expression of genes involved in amino acid biosynthesis and transport, electron transfer, hydrogen oxidation, and general stress responses (e.g., heat shock proteins, phage shock proteins, and oxidative stress response proteins). The expression of genes involved in carbon metabolism, cell growth, and phage structures was decreased. Transcriptome profiles of D. vulgaris responses to salt adaptation were compared with transcriptome profiles of D. vulgaris responses to salt shock (short-term NaCl exposure). Metabolite assays showed that glutamate and alanine accumulated under salt adaptation conditions, suggesting that these amino acids may be used as osmoprotectants in D. vulgaris. Addition of amino acids (glutamate, alanine, and tryptophan) or yeast extract to the growth medium relieved salt-related growth inhibition. A conceptual model that links the observed results to currently available knowledge is proposed to increase our understanding of the mechanisms of D. vulgaris adaptation to elevated NaCl levels. PMID:20038696

  8. 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. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Physiological responses to error amplification in a robotic reaching adaptation task.

    PubMed

    Shirzad, Navid; Van der Loos, H F Machiel

    2014-01-01

    Analysis of physiological responses provides an objective measure of a person's affective state and has been proposed as a way to evaluate motivation and engagement of therapy clients during robot-assisted therapy regimens. This paper presents the analysis of three physiological responses to different levels of error amplification in a robotic reaching task to understand the feasibility of using physiological signals in order to modify therapy exercises to achieve higher participant attentiveness. In a pilot study with 22 healthy participants, we analyzed skin conductance, skin temperature, and respiration signals, with two main goals: 1) to compare physiological parameters between baseline (rest) and error-amplified reaching motion periods; and 2) to compare physiological parameters between reaching motion periods with different levels of error amplification. Results show that features extracted from skin conductance and respiration signals show significant differences between different error amplification levels. Features extracted from the skin temperature signal are not as reliable as measures of skin conductance and respiration, however they can provide supplementary information.

  10. [Physiological adaptations of sichuan golden monkeys (Rhinopithecus roxellana) to high altitude habitat in the Qinling Mountains].

    PubMed

    Gao, Yunfang

    2004-02-01

    The golden monkey (Rhinopithecus roxellana) is a special species in China, and possesses the highest altitude habitat (4,167 m) in all kinds of primates. So it is very important to study this monkey how to adapt to such a high and severe habitat. According to our research results in recent years and relative publications, this paper, from digestive, respiratory, blood, circulative and reproductive systems, inquired into the Sichuan golden monkey (Rhinopithecus roxellana), a named species for golden monkey, how to adapt to the high altitude habitat in the Qinling Mountains and what was the mechanism of these adaptations.

  11. Chair Talk: Resources to Maximize Administrative Efforts

    NASA Astrophysics Data System (ADS)

    MacDonald, H.; Chan, M. A.; Bierly, E. W.; Manduca, C. A.; Ormand, C. J.

    2009-12-01

    Earth science department chairs are generally scientists who have little/no formal administrative training. The common rotation of faculty members in three-six year cycles distributes the heavy leadership responsibilities but involves little preparation beforehand to deal with budgets, fundraising, personnel issues, confrontations, and crises. The amount of information exchange and support upon exit and handoff to the next chair is variable. Resources for chairs include workshops, meetings (ranging from annual meetings of geoscience chairs to monthly meetings of small groups of chairs from various disciplines on a campus), discussions, and online resources. These resources, some of which we designed in the past several years, provide information and support for chairs, help them share best practices, and reduce time spent “reinventing the wheel”. Most of these resources involve groups of chairs in our discipline who meet together. The AGU Board of Heads and Chairs of Earth and Space Science Departments offers annual one-day workshops at the Fall AGU meeting. The specific topics vary from year to year; they have included goals and roles of heads and chairs, fundraising and Advisory Boards, student recruitment, interdisciplinarity, dual-career couples, and undergraduate research. The workshop provides ample opportunities for open discussion. Annual one-two day meetings of groups of geoscience department chairs (e.g., research universities in a particular region) provide an opportunity for chairs to share specific data about their departments (e.g., salaries, graduate student stipends, information about facilities) and discuss strategies. At the College of William and Mary, a small group of chairs meets monthly throughout the year; each session includes time for open discussion as well as a more structured discussion on a particular topic (e.g., merit review, development and fundraising, mentoring early career faculty and the tenure process, leadership styles

  12. Radiation Pattern of Chair Armed Microstrip Antenna

    NASA Astrophysics Data System (ADS)

    Mishra, Rabindra Kishore; Sahu, Kumar Satyabrat

    2016-12-01

    This work analyzes planar antenna conformable to chair arm shaped surfaces for WLAN application. Closed form expressions for its radiation pattern are developed and validated using measurements on prototype and commercial EM code at 2.4 GHz.

  13. The Disintegrating Chair: Professors in Britain Today.

    ERIC Educational Resources Information Center

    Moodie, Graeme

    1986-01-01

    Changes in the status of the British "chair" or professorship in the twentieth century are examined, with focus on the types of changes, the reasons for them, and the administrative, educational, and intellectual results. (MSE)

  14. Estimating the capability of microalgae to physiological acclimatization and genetic adaptation to petroleum and diesel oil contamination.

    PubMed

    Romero-Lopez, Julia; Lopez-Rodas, Victoria; Costas, Eduardo

    2012-11-15

    There is increasing scientific interest in how phytoplankton reacts to petroleum contamination, since crude oil and its derivatives are generating extensive contamination of aquatic environments. However, toxic effects of short-term petroleum exposure are more widely known than the adaptation of phytoplankton to long-term petroleum exposure. An analysis of short-term and long-term effects of petroleum exposure was done using experimental populations of freshwater (Scenedesmus intermedius and Microcystis aeruginosa) and marine (Dunaliella tertiolecta) microalgae isolated from pristine sites without crude oil product contamination. These strains were exposed to increased levels of petroleum and diesel oil. Short-term exposure to petroleum or diesel oil revealed a rapid inhibition of photosynthetic performance and cell proliferation in freshwater and marine phytoplankton species. A broad degree of inter-specific variation in lethal contamination level was observed. When different strains were exposed to petroleum or diesel oil over the long-term, the cultures showed massive destruction of the sensitive cells. Nonetheless, after further incubation, some cultures were able to grow again due to cells that were resistant to the toxins. By means of a fluctuation analysis, discrimination between cells that had become resistant due to physiological acclimatization and resistant cells arising from rare spontaneous mutations was accomplished. In addition, an analysis was done as to the maximum capacity of adaptation to a gradual contamination process. An experimental ratchet protocol was used, which maintains a strong selection pressure in a temporal scale up to several months over very large experimental populations of microalgae. Microalgae are able to survive to petroleum contamination as a result of physiological acclimatization without genetic changes. However, when petroleum concentration exceeds the physiological limits, survival depends exclusively on the occurrence on

  15. An Approximation to the Adaptive Exponential Integrate-and-Fire Neuron Model Allows Fast and Predictive Fitting to Physiological Data

    PubMed Central

    Hertäg, Loreen; Hass, Joachim; Golovko, Tatiana; Durstewitz, Daniel

    2012-01-01

    For large-scale network simulations, it is often desirable to have computationally tractable, yet in a defined sense still physiologically valid neuron models. In particular, these models should be able to reproduce physiological measurements, ideally in a predictive sense, and under different input regimes in which neurons may operate in vivo. Here we present an approach to parameter estimation for a simple spiking neuron model mainly based on standard f–I curves obtained from in vitro recordings. Such recordings are routinely obtained in standard protocols and assess a neuron’s response under a wide range of mean-input currents. Our fitting procedure makes use of closed-form expressions for the firing rate derived from an approximation to the adaptive exponential integrate-and-fire (AdEx) model. The resulting fitting process is simple and about two orders of magnitude faster compared to methods based on numerical integration of the differential equations. We probe this method on different cell types recorded from rodent prefrontal cortex. After fitting to the f–I current-clamp data, the model cells are tested on completely different sets of recordings obtained by fluctuating (“in vivo-like”) input currents. For a wide range of different input regimes, cell types, and cortical layers, the model could predict spike times on these test traces quite accurately within the bounds of physiological reliability, although no information from these distinct test sets was used for model fitting. Further analyses delineated some of the empirical factors constraining model fitting and the model’s generalization performance. An even simpler adaptive LIF neuron was also examined in this context. Hence, we have developed a “high-throughput” model fitting procedure which is simple and fast, with good prediction performance, and which relies only on firing rate information and standard physiological data widely and easily available. PMID:22973220

  16. Adjustable Cardboard Dental Chair and Stool,

    DTIC Science & Technology

    1983-02-01

    tape and a water resistant sealant spray around the exposed edges, especially on the lower portions of the chair "* and stool. Assembly Because of design...securing the chair in the reclining position. The stool used for sit-down dentistry , when the patient is in the reclining position, is fabricated from...accommodate an adult patient, is sturdy, and includes a reclining and an upright position. A stool has been added to the design for sit-down dentistry , and

  17. Secondary school science department chairs leading change

    NASA Astrophysics Data System (ADS)

    Gaubatz, Julie A.

    Secondary school department chairs are content area specialists in their schools and are responsible for providing students with the most appropriate curricula. However, most secondary school department chairs have limited authority to institute change unilaterally (Gmelch, 1993; Hannay & Erb, 1999). To explore how these educational leaders navigate the change process within their departments, this study examined the change stories of six secondary school science department chairs who had led change attempts. In total, these department chairs shared six stories of successful change attempts and four unsuccessful change attempts. The topics of leadership and change were accessed through department chair interviews, document analysis, and a leadership inventory. Department chair leadership was analyzed with Blake and McCanse's (1991) Leadership Grid, and further explored using Yukl, Gordon, and Taber's (2002) detailed characterization of this grid. The change processes described in these department chair stories were analyzed using the frameworks provided by Ely's (1990) conditions of change, and Havelock and Zlotolow (1995) CREATER change stages model. In general, the findings of this study support Havelock and Zlotolow's CREATER model, as well as Ely's conditions of change, with dissatisfaction with the status quo emerging as the essential condition for successful change. This study connects these change process frameworks to specific leadership strategies and behaviors, and uses these connections to illuminate differences between successful and unsuccessful instances of change. These findings, along with other unanticipated findings emerging from department chair stories of change, such as the adverse influence of contentious resistors and the importance of team construction, add both to the literature on change and leadership and to the crucial point where these concepts intersect.

  18. ONR Chair in Arctic Marine Science

    DTIC Science & Technology

    2016-06-07

    SEP 1999 2. REPORT TYPE 3. DATES COVERED 00-00-1999 to 00-00-1999 4. TITLE AND SUBTITLE ONR Chair in Arctic Marine Science 5a. CONTRACT...Arctic Marine Science Robert H. Bourke Department of Oceanography Naval Postgraduate School 833 Dyer Road, Bldg. 232, Rm. 328 Monterey, CA 93943...onrpgahl.htm LONG-TERM GOAL A research Chair in Arctic Marine Science was established in 1976 by the Chief of Naval Research to increase the awareness

  19. Copepods Oithona similis and Oithona davisae: Two strategies of ecological-physiological adaptation in the Black Sea

    NASA Astrophysics Data System (ADS)

    Hubareva, E. S.; Svetlichny, L. S.

    2016-03-01

    Salinity tolerance, energy metabolism, buoyancy, and passive sinking and swimming speeds have been studied for comparative assessment of the adaptive potential of two species of cyclopoid copepods in the Black Sea, the native Oithona similis and new invader Oithona davisae. Both species were considered marine euryhaline copepods, but the range of salinity tolerance of O. davisae was much broader (5-55‰). The energy metabolism, locomotor activity, mean body mass density, and speed of passive sinking at the same temperature were significantly higher in O. davisae than in O. similis. The relationship between the physiological and behavioral parameters and ecological characteristics of the species are discussed.

  20. Functional Validation of Hydrophobic Adaptation to Physiological Temperature in the Small Heat Shock Protein αA-crystallin

    PubMed Central

    Posner, Mason; Kiss, Andor J.; Skiba, Jackie; Drossman, Amy; Dolinska, Monika B.; Hejtmancik, J. Fielding; Sergeev, Yuri V.

    2012-01-01

    Small heat shock proteins (sHsps) maintain cellular homeostasis by preventing stress and disease-induced protein aggregation. While it is known that hydrophobicity impacts the ability of sHsps to bind aggregation-prone denaturing proteins, the complex quaternary structure of globular sHsps has made understanding the significance of specific changes in hydrophobicity difficult. Here we used recombinant protein of the lenticular sHsp α A-crystallin from six teleost fishes environmentally adapted to temperatures ranging from -2°C to 40°C to identify correlations between physiological temperature, protein stability and chaperone-like activity. Using sequence and structural modeling analysis we identified specific amino acid differences between the warm adapted zebrafish and cold adapted Antarctic toothfish that could contribute to these correlations and validated the functional consequences of three specific hydrophobicity-altering amino acid substitutions in αA-crystallin. Site directed mutagenesis of three residues in the zebrafish (V62T, C143S, T147V) confirmed that each impacts either protein stability or chaperone-like activity or both, with the V62T substitution having the greatest impact. Our results indicate a role for changing hydrophobicity in the thermal adaptation of α A-crystallin and suggest ways to produce sHsp variants with altered chaperone-like activity. These data also demonstrate that a comparative approach can provide new information about sHsp function and evolution. PMID:22479631

  1. 32 CFR 202.6 - Selecting co-chairs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Selecting co-chairs. 202.6 Section 202.6...) MISCELLANEOUS RESTORATION ADVISORY BOARDS Operating Requirements § 202.6 Selecting co-chairs. (a) DoD installation co-chair. The DoD installation co-chair shall be selected by the Installation Commander...

  2. 32 CFR 202.6 - Selecting co-chairs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Selecting co-chairs. 202.6 Section 202.6...) MISCELLANEOUS RESTORATION ADVISORY BOARDS Operating Requirements § 202.6 Selecting co-chairs. (a) DoD installation co-chair. The DoD installation co-chair shall be selected by the Installation Commander...

  3. 32 CFR 202.6 - Selecting co-chairs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Selecting co-chairs. 202.6 Section 202.6...) MISCELLANEOUS RESTORATION ADVISORY BOARDS Operating Requirements § 202.6 Selecting co-chairs. (a) DoD installation co-chair. The DoD installation co-chair shall be selected by the Installation Commander...

  4. 32 CFR 202.6 - Selecting co-chairs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Selecting co-chairs. 202.6 Section 202.6...) MISCELLANEOUS RESTORATION ADVISORY BOARDS Operating Requirements § 202.6 Selecting co-chairs. (a) DoD installation co-chair. The DoD installation co-chair shall be selected by the Installation Commander...

  5. 32 CFR 202.6 - Selecting co-chairs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Selecting co-chairs. 202.6 Section 202.6...) MISCELLANEOUS RESTORATION ADVISORY BOARDS Operating Requirements § 202.6 Selecting co-chairs. (a) DoD installation co-chair. The DoD installation co-chair shall be selected by the Installation Commander...

  6. 21 CFR 880.6140 - Medical chair and table.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Medical chair and table. 880.6140 Section 880.6140... Devices § 880.6140 Medical chair and table. (a) Identification. A medical chair or table is a device intended for medical purposes that consists of a chair or table without wheels and not electrically powered...

  7. 21 CFR 880.6140 - Medical chair and table.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Medical chair and table. 880.6140 Section 880.6140... Devices § 880.6140 Medical chair and table. (a) Identification. A medical chair or table is a device intended for medical purposes that consists of a chair or table without wheels and not electrically powered...

  8. Integrated Physiological Mechanisms of Exercise Performance, Adaptation, and Maladaptation to Heat Stress

    DTIC Science & Technology

    2011-10-01

    number of heat exposures (359, 424). Heat acclimatization is specific to the environment (hot/dry vs. hot/ wet ) and physical activity level, however...Comprehensive Physiology Table 1 Risk of Hyperthermia (and Possible Exertional Heat Illness) for a Typical Marathon Racer Based on Wet Bulb Globe...clothing during activities in hot weather, and performing firefighting near the active fire. Environmental heat stress and exchange Wet Bulb Globe

  9. Comparison of novel physiological load-adaptive control strategies for ventricular assist devices.

    PubMed

    Habigt, Moriz; Ketelhut, Maike; Gesenhues, Jonas; Schrödel, Frank; Hein, Marc; Mechelinck, Mare; Schmitz-Rode, Thomas; Abel, Dirk; Rossaint, Rolf

    2016-11-17

    Terminal heart failure (HF) is the most prevalent cause of death in the Western world and the implantation of a left ventricular assist device (LVAD) has become the gold standard therapy today. Most of the actually implanted devices are driven at a constant speed (CS) regardless of the patient's physiological demand. A new physiological controller [power ratio (PR) controller], which keeps a constant ratio between LVAD power and left ventricular power, a previous concept [preload responsive speed (PRS) controller], which adds a variable LVAD power to reach a defined stroke work, and a CS controller were compared with an unimpaired ventricle in a full heart computer simulation model. The effects of changes in preload, afterload and left ventricular contractility are displayed by global hemodynamics and ventricular pressure-volume loops. Both physiological controllers demonstrated the desired load dependency, whereas the PR controller exceeded the PRS controller in response to an increased load and contractility. Response was inferior when preload or contractility was decreased. Thus, the PR controller might lead to an increased exercise tolerance of the patient. Additional studies are required to evaluate the controllers in vivo.

  10. Behaviorally Mediated, Warm Adaptation: A Physiological Strategy When Mice Are Allowed to Behaviorally Thermoregulate

    EPA Science Inventory

    Laboratory mice housed under standard vivarium conditions with an ambient temperature (Ta) of -22°C are likely to be cold stressed because this Ta is below their thermoneutral zone (TNZ). Mice raised at Tas within the TNZ adapt to the warmer temperatures, developing smaller int...

  11. Physiological and comparative evidence fails to confirm an adaptive role for aging in evolution.

    PubMed

    Cohen, Alan A

    2015-01-01

    The longstanding debate about whether aging may have evolved for some adaptive reason is generally considered to pit evolutionary theory against empirical observations consistent with aging as a programmed aspect of organismal biology, in particular conserved aging genes. Here I argue that the empirical evidence on aging mechanisms does not support a view of aging as a programmed phenomenon, but rather supports a view of aging as the dysregulation of complex networks that maintain organismal homeostasis. The appearance of programming is due largely to the inadvertent activation of existing pathways during the process of dysregulation. It is argued that aging differs markedly from known programmed biological phenomena such as apoptosis in that it is (a) very heterogeneous in how it proceeds, and (b) much slower than it would need to be. Furthermore, the taxonomic distribution of aging across species does not support any proposed adaptive theories of aging, which would predict that aging rate would vary on a finer taxonomic scale depending on factors such as population density. Thus, while there are problems with the longstanding non-adaptive paradigm, current evidence does not support the notion that aging is programmed or that it may have evolved for adaptive reasons.

  12. Histologic changes in the respiratory tract induced by inhalation of xenobiotics: physiologic adaptation or toxicity?

    PubMed

    Burger, G T; Renne, R A; Sagartz, J W; Ayres, P H; Coggins, C R; Mosberg, A T; Hayes, A W

    1989-12-01

    Toxicologists and pathologists are often faced with the dilemma of categorizing changes observed in the respiratory tract of laboratory animals as either "adaptive" or "toxic." However, it is often difficult to interpret the nature of a given change as either "adaptive" or "toxic." Certain lesions or changes in the respiratory tract are to be expected from the concentration of materials given or the experimental design of a study. Careful analysis suggests that some of these changes may be more properly described as adaptive rather than toxic within the context of a given study or situation. Tissue changes discussed in this paper include squamous metaplasia of laryngeal epithelium, goblet cell change in respiratory epithelium, macrophage accumulation within alveoli, and bronchiolization of alveolar epithelium. Examples provided show that some of these changes observed in inhalation studies are similar in severity but slightly increased in frequency over sham control animals. The introduction of exogenous material into the respiratory tract of laboratory animals in an experimental setting should be expected to result in certain changes. The challenge scientists must accept is to interpret these changes so that toxic events may be separated from adaptive changes. In order to meet this challenge, studies incorporating several species and novel technologies may have to be utilized.

  13. Behaviorally Mediated, Warm Adaptation: A Physiological Strategy When Mice Are Allowed to Behaviorally Thermoregulate

    EPA Science Inventory

    Laboratory mice housed under standard vivarium conditions with an ambient temperature (Ta) of -22°C are likely to be cold stressed because this Ta is below their thermoneutral zone (TNZ). Mice raised at Tas within the TNZ adapt to the warmer temperatures, developing smaller int...

  14. Developing a Job Description for a Vice Chair of Education in Radiology: The ADVICER Template.

    PubMed

    Lewis, Petra J; Probyn, Linda; McGuinness, Georgeann; Nguyen, Jeremy; Mullins, Mark E; Resnik, Charles; Oldham, Sandra

    2015-07-01

    The newly formed Alliance of Directors and Vice Chairs of Education in Radiology (ADVICER), a group within the Alliance for Clinician Educators in Radiology, identified an acute need for a generic job description template for Vice Chairs of Education in Radiology, a role that is being developed in many academic Departments of Radiology. Eighty-three percent of current members who responded to a survey had no detailed job description, and over half had no job description at all. Having a comprehensive and detailed job description is vital to developing this key position. Using the results of a survey sent to ADVICER members and seven Education Vice Chair job descriptions provided by members, the authors developed a detailed job description encompassing all potential elements of this position. Only 17% of survey respondents had a detailed job description. The role of an Education Vice Chair varies significantly between institutions in its scope and level of responsibilities. The resultant generic job description that was devised is intended to provide a template that would be modified by the candidate or the Department Chair. It is unlikely that any one individual would perform all the described activities. ADVICER has developed a comprehensive, flexible job description for Vice Chair of Education in Radiology that can be adapted by institutions as appropriate. It can be downloaded from http://aur.org/ADVICER/. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  15. Treadmill running and swimming imposes distinct cardiovascular physiological adaptations in the rat: focus on serotonergic and sympathetic nervous systems modulation.

    PubMed

    Baptista, S; Piloto, N; Reis, F; Teixeira-de-Lemos, E; Garrido, A P; Dias, A; Lourenço, M; Palmeiro, A; Ferrer-Antunes, C; Teixeira, F

    2008-12-01

    Physical exercise may improve the metabolic and haemodynamic responses, but the beneficial effects seem to depend on intensity, duration and muscular mass recruitment, which may vary between different types of protocols. This study was performed to evaluate the effects of two distinct moderate/long-term aerobic training protocols in the normal Wistar rat, the treadmill running and the swimming, on several important parameters related to cardiovascular (CV) physiological adaptations, namely: lipid profile, haemorheological measures, lipid peroxidation, peripheral serotonergic system (SS) modulation and sympathetic nervous system (SNS) activation. In both groups under training an HDL-c increment versus the sedentary control was demonstrated. There was a noticeable increase in ADP-induced platelet aggregation in the exercised rats, together with higher PDW and MPV values. The RBC patterns were altered in both groups under training; in the swimming one, however, significantly higher RBC and HCT and lower MCH and MCHC values were found, suggesting renovation of the RBCs. Plasma and platelet SS measures were generally higher in both groups under training, being noticeably relevant the 5-HT and 5-HIAA increment in the treadmill. In opposition, concerning the plasma and platelet NE and E concentrations, the rise was remarkably higher in the rats under a swimming protocol. In conclusion, this study demonstrates that, despite the similar beneficial effects on lipid profile, different aerobic exercise protocols may produce distinct CV physiological adaptations. Therefore, treadmill running was more influent than swimming concerning peripheral SS modulation while swimming was more important on SNS activation, thus recommending a judicious choice of the protocol to be tested in works which make use of rat models of exercise to study physiological or pathophysiological conditions.

  16. Pediatric dental chair vs. traditional dental chair: a pediatric dentist's poll.

    PubMed

    Barjatya, Khushboo; Vatsal, Ankur; Kambalimath, Halaswamy V; Kulkarni, Vinay Kumar; Reddy, Naveen Banda

    2015-01-01

    Proper positioning of the child patient, can not only have positive ramifications for the operator's posture, comfort, and career longevity - it can also lead to better treatment and increased productivity. The aim of the survey questionnaire was to assess the utilization, need, and attitude concerning dental chairs among pediatric dentist while working on and managing the child patient. The questions were structured using adobe forms central online software, regarding the user-friendliness of pediatric dental chair vs. traditional adult dental chair available in the market. Our result shows that out of 337 respondents, 79% worked on pediatric dental chair, whereas 21% had no experience of it. Of these 79% pediatric dentist, 48% preferred pediatric dental chair. But pediatric dental problem still has certain disadvantages like higher cost, leg space problem, lower availability, etc. During the research it was found that ergonomics and usability issues were the main problems. Thus, pediatric dental chair is not so popular in the current scenario. This study allowed for general ideas for the improvement of dental chairs and thus improved dental chair would fill the gap in the current scenario.

  17. Adaptation of Maternal-Fetal Physiology to Exercise in Pregnancy: The Basis of Guidelines for Physical Activity in Pregnancy

    PubMed Central

    Newton, Edward R; May, Linda

    2017-01-01

    Only 50 years ago obstetric care providers and women had many concerns regarding whether exercise during pregnancy created a harmful competition for substrate resources between the fetus and the mother. Animal and human research in the past 50 years, which includes acute and chronic aerobic exercise during pregnancy, has a reassuring margin of safety throughout gestation in women. Maternal physiology adapts to pregnancy changes involving the cardiorespiratory and glucometabolic alterations. Due to these changes, pregnant women have slight differences in response to acute exercise sessions. Chronic exposure to aerobic exercise before and during pregnancy is associated with numerous maternal and neonatal adaptations which may have short- and long-term benefits to maternal and child health. On the basis of the consistent evidence of safety of exercise during pregnancy, multiple nations and health care organizations, including the American College of Obstetrics and Gynecology, recommend moderate exercise for 20 to 30 minutes most days of the week. Despite the 15 to 20 years since the first recommendations were made, only 10% to 15% of pregnant women meet this recommendation. It seems there may be 2 foci for failure to achieve these exercise recommendations: patient specific and culturally driven and/or obstetric provider not recommending regular exercise due to lack of knowledge or motivation. This article addresses the provider knowledge by a review of the normal (at rest) physiologic adaptation to pregnancy. Then, we provide a detailed description of the type and intensity of controlled experiments that document the safety of exercise during pregnancy. The short- and long-term benefits are reviewed, including the safety in moderate-risk women. PMID:28579865

  18. Physiological responses to food deprivation in the house sparrow, a species not adapted to prolonged fasting.

    PubMed

    Khalilieh, Anton; McCue, Marshall D; Pinshow, Berry

    2012-09-01

    Many wild birds fast during reproduction, molting, migration, or because of limited food availability. Species that are adapted to fasting sequentially oxidize endogenous fuels in three discrete phases. We hypothesized that species not adapted to long fasts have truncated, but otherwise similar, phases of fasting, sequential changes in fuel oxidization, and similar changes in blood metabolites to fasting-adapted species. We tested salient predictions in house sparrows (Passer domesticus biblicus), a subspecies that is unable to tolerate more than ~32 h of fasting. Our main hypothesis was that fasting sparrows sequentially oxidize substrates in the order carbohydrates, lipids, and protein. We dosed 24 house sparrows with [(13)C]glucose, palmitic acid, or glycine and measured (13)CO(2) in their breath while they fasted for 24 h. To ascertain whether blood metabolite levels reflect fasting-induced changes in metabolic fuels, we also measured glucose, triacylglycerides, and β-hydroxybutyrate in the birds' blood. The results of both breath (13)CO(2) and plasma metabolite analyses did not support our hypothesis; i.e., that sparrows have the same metabolic responses characteristic of fasting-adapted species, but on a shorter time scale. Contrary to our main prediction, we found that recently assimilated (13)C-tracers were oxidized continuously in different patterns with no definite peaks corresponding to the three phases of fasting and also that changes in plasma metabolite levels accurately tracked the changes found by breath analysis. Notably, the rate of recently assimilated [(13)C]glycine oxidization was significantly higher (P < 0.001) than that of the other metabolic tracers at all postdosing intervals. We conclude that the inability of house sparrows to fast for longer than 32 h is likely related to their inability to accrue large lipid stores, separately oxidize different fuels, and/or spare protein during fasting.

  19. The Role of Efflux and Physiological Adaptation in Biofilm Tolerance and Resistance.

    PubMed

    Van Acker, Heleen; Coenye, Tom

    2016-06-10

    Microbial biofilms demonstrate a decreased susceptibility to antimicrobial agents. Various mechanisms have been proposed to be involved in this recalcitrance. We focus on two of these factors. Firstly, the ability of sessile cells to actively mediate efflux of antimicrobial compounds has a profound impact on resistance and tolerance, and several studies point to the existence of biofilm-specific efflux systems. Secondly, biofilm-specific stress responses have a marked influence on cellular physiology, and contribute to the occurrence of persister cells. We provide an overview of the data that demonstrate that both processes are important for survival following exposure to antimicrobial agents.

  20. Mechanism of Action of ABC Importers: Conservation, Divergence, and Physiological Adaptations.

    PubMed

    Lewinson, Oded; Livnat-Levanon, Nurit

    2017-03-10

    The past decade has seen a remarkable surge in structural characterization of ATP binding cassette (ABC) transporters, which have spurred a more focused functional analysis of these elaborate molecular machines. As a result, it has become increasingly apparent that there is a substantial degree of mechanistic variation between ABC transporters that function as importers, which correlates with their physiological roles. Here, we summarize recent advances in ABC importers' structure-function studies and provide an explanation as to the origin of the different mechanisms of action. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Noise analysis in professional office chairs.

    PubMed

    Alves, E J W; Filho, J N; Silva, S J; Câmara, J J D

    2012-01-01

    The noise caused by the movement of users on their chairs in the work environment may indicate structural weaknesses and risk, and still significantly reduce productivity by increasing employees stress level. By understanding the activities to be developed in a work place one may understand what should be necessary to a good development, thereafter a search for improvement of labor activity with the aim of better use of resources in the operation of product use may be done. The analysis of the incremental variation of noise in professional chairs aims to identify its origin and the time the emission of noise starts during the period of use, its development and the major causative agents. Determining the characteristics of the sound of different materials and adjustments mechanisms of the chair can determine how different materials interact with each other. The measurement of these noises in an acoustic isolated room using directional microphones, if recorded and analyzed properly makes it possible to investigate and orientate to suspect elements in order to propose solutions and identify the quality of other similar chairs. Based on the results recommendations can be established for the orientation of users, managers and people responsible for the acquisition of the products, inducing them to review the employment of materials and the choice of the processes of production. These aspects are not covered in the Brazilian ergonomics norms and standards in the use of chairs.

  2. Physiological and transcriptomic analyses reveal mechanistic insight into the adaption of marine Bacillus subtilis C01 to alumina nanoparticles

    PubMed Central

    Mu, Dashuai; Yu, Xiuxia; Xu, Zhenxing; Du, Zongjun; Chen, Guanjun

    2016-01-01

    An increasing number of studies have investigated the effects of nanoparticles (NPs) on microbial systems; however, few existing reports have focused on the defense mechanisms of bacteria against NPs. Whether secondary metabolism biosynthesis is a response to NP stress and contributes to the adaption of bacteria to NPs is unclear. Here, a significant induction in the surfactin production and biofilm formation were detected by adding Al2O3 NPs to the B. subtilis fermentation broth. Physiological analysis showed that Al2O3 NP stress could also affect the cell and colony morphogenesis and inhibit the motility and sporulation. Exogenously adding commercial surfactin restored the swarming motility. Additionally, a suite of toxicity assays analyzing membrane damage, cellular ROS generation, electron transport activity and membrane potential was used to determine the molecular mechanisms of toxicity of Al2O3 NPs. Furthermore, whole transcriptomic analysis was used to elucidate the mechanisms of B. subtilis adaption to Al2O3 NPs. These results revealed several mechanisms by which marine B. subtilis C01 adapt to Al2O3 NPs. Additionally, this study broadens the applications of nanomaterials and describes the important effects on secondary metabolism and multicellularity regulation by using Al2O3 NPs or other nano-products. PMID:27440502

  3. Physiological and transcriptomic analyses reveal mechanistic insight into the adaption of marine Bacillus subtilis C01 to alumina nanoparticles.

    PubMed

    Mu, Dashuai; Yu, Xiuxia; Xu, Zhenxing; Du, Zongjun; Chen, Guanjun

    2016-07-21

    An increasing number of studies have investigated the effects of nanoparticles (NPs) on microbial systems; however, few existing reports have focused on the defense mechanisms of bacteria against NPs. Whether secondary metabolism biosynthesis is a response to NP stress and contributes to the adaption of bacteria to NPs is unclear. Here, a significant induction in the surfactin production and biofilm formation were detected by adding Al2O3 NPs to the B. subtilis fermentation broth. Physiological analysis showed that Al2O3 NP stress could also affect the cell and colony morphogenesis and inhibit the motility and sporulation. Exogenously adding commercial surfactin restored the swarming motility. Additionally, a suite of toxicity assays analyzing membrane damage, cellular ROS generation, electron transport activity and membrane potential was used to determine the molecular mechanisms of toxicity of Al2O3 NPs. Furthermore, whole transcriptomic analysis was used to elucidate the mechanisms of B. subtilis adaption to Al2O3 NPs. These results revealed several mechanisms by which marine B. subtilis C01 adapt to Al2O3 NPs. Additionally, this study broadens the applications of nanomaterials and describes the important effects on secondary metabolism and multicellularity regulation by using Al2O3 NPs or other nano-products.

  4. p21Cip1 plays a critical role in the physiological adaptation to fasting through activation of PPARα

    PubMed Central

    Lopez-Guadamillas, Elena; Fernandez-Marcos, Pablo J.; Pantoja, Cristina; Muñoz-Martin, Maribel; Martínez, Dolores; Gómez-López, Gonzalo; Campos-Olivas, Ramón; Valverde, Angela M.; Serrano, Manuel

    2016-01-01

    Fasting is a physiological stress that elicits well-known metabolic adaptations, however, little is known about the role of stress-responsive tumor suppressors in fasting. Here, we have examined the expression of several tumor suppressors upon fasting in mice. Interestingly, p21 mRNA is uniquely induced in all the tissues tested, particularly in liver and muscle (>10 fold), and this upregulation is independent of p53. Remarkably, in contrast to wild-type mice, p21-null mice become severely morbid after prolonged fasting. The defective adaptation to fasting of p21-null mice is associated to elevated energy expenditure, accelerated depletion of fat stores, and premature activation of protein catabolism in the muscle. Analysis of the liver transcriptome and cell-based assays revealed that the absence of p21 partially impairs the transcriptional program of PPARα, a key regulator of fasting metabolism. Finally, treatment of p21-null mice with a PPARα agonist substantially protects them from their accelerated loss of fat upon fasting. We conclude that p21 plays a relevant role in fasting adaptation through the positive regulation of PPARα. PMID:27721423

  5. Physiological monitoring of cardiorespiratory adaptations during rehearsal and performance of contemporary dance.

    PubMed

    Wyon, Matthew A; Redding, Emma

    2005-08-01

    Previous research has shown that dance class and rehearsal stress different cardiorespiratory energy systems than dance performance. The aim of the present study was to monitor the physiological parameters of a number of dancers during a 12-week rehearsal period and an 8-week performance schedule. Seventeen dancers (8 men and 9 women) from 2 companies undertook the multistage dance specific aerobic fitness test before the rehearsal period, before the performance period, and after the performance period. Heart rate data were collected throughout the test; the mean heart rate during stage 5 and blood lactate levels were measured at the end of the test. No significant changes in heart rate or lactate parameters were noted between the prerehearsal and preperformance tests, but significant decreases during the preperformance and postperformance tests were shown in both parameters (p < 0.01 and p < 0.01, respectively), which suggests an increase in the subjects' aerobic capacities during the performance period. Implications from the present study suggest that dancers are not adequately physiologically prepared to perform to the same degree to which their skills are honed. The study suggests that supplemental training is required to bridge this physical gap and better prepare the dancer for performance.

  6. Leadership Considerations for Executive Vice Chairs, New Chairs, and Chairs in the 21st Century

    ERIC Educational Resources Information Center

    Kunkel, Elisabeth J. S.; Lehrmann, Jon A.; Vergare, Michael J.; Roberts, Laura Weiss

    2013-01-01

    The need to fulfill academic goals in the context of significant economic challenges, new regulatory requirements, and ever-changing expectations for leadership requires continuous adaptation. This paper serves as an educational resource for emerging leaders from the literature, national leaders, and other "best practices" in the…

  7. Leadership Considerations for Executive Vice Chairs, New Chairs, and Chairs in the 21st Century

    ERIC Educational Resources Information Center

    Kunkel, Elisabeth J. S.; Lehrmann, Jon A.; Vergare, Michael J.; Roberts, Laura Weiss

    2013-01-01

    The need to fulfill academic goals in the context of significant economic challenges, new regulatory requirements, and ever-changing expectations for leadership requires continuous adaptation. This paper serves as an educational resource for emerging leaders from the literature, national leaders, and other "best practices" in the…

  8. Physiological elevation of endogenous hormones results in superior strength training adaptation.

    PubMed

    Rønnestad, Bent R; Nygaard, Håvard; Raastad, Truls

    2011-09-01

    The purpose of this study was to determine the influence of transiently elevated endogenous hormone concentrations during exercise on strength training adaptations. Nine subjects performed four unilateral strength training session per week on the elbow flexors for 11 weeks. During two of the weekly sessions, leg exercises were performed to acutely increase the systemic anabolic hormone concentration immediately before the exercises for one of the elbow flexors (L + A). On the two other weekly training sessions, the contralateral elbow flexors were trained without prior leg exercises (A). By randomizing one arm of the subjects to serve as a control and the other as experimental, both conditions have the same nutritional and genetic environment. Serum testosterone and growth hormone was significantly increased during the L - A training session, while no hormonal changes occurred in the A session. Both A and L + A increased 1RM in biceps curl, peak power in elbow flexors at 30 and 60% of 1RM, and muscle volume of the elbow flexors (p < 0.05). However, only L + A achieved increase in CSA at the part of the arm flexors with largest cross sectional area (p < 0.001), while no changes occurred in A. L + A had superior relative improvement in 1RM biceps curl and favorable muscle adaptations in elbow flexors compared to A (p < 0.05). In conclusion, performing leg exercises prior to arm exercises, and thereby increasing the levels of serum testosterone and growth hormone, induced superior strength training adaptations compared to arm training without acute elevation of hormones.

  9. Great auricular neuropraxia with beach chair position.

    PubMed

    Joshi, Minal; Cheng, Ruth; Kamath, Hattiyangadi; Yarmush, Joel

    2017-01-01

    Shoulder arthroscopy has been shown to be the procedure of choice for many diagnostic and therapeutic interventions. Neuropraxia of the great auricular nerve (GAN) is an uncommon complication of shoulder surgery, with the patient in the beach chair position. We report a case of great auricular neuropraxia associated with direct compression by a horseshoe headrest, used in routine positioning for uncomplicated shoulder surgery. In this case, an arthroscopic approach was taken, under regional anesthesia with sedation in the beach chair position. The GAN, a superficial branch of the cervical plexus, is vulnerable to neuropraxia due to its superficial anatomical location. We recommend that for the procedures of the beach chair position, the auricle be protected and covered with cotton and gauze to avoid direct compression and the position of the head and neck be checked and corrected frequently.

  10. Great auricular neuropraxia with beach chair position

    PubMed Central

    Joshi, Minal; Cheng, Ruth; Kamath, Hattiyangadi; Yarmush, Joel

    2017-01-01

    Shoulder arthroscopy has been shown to be the procedure of choice for many diagnostic and therapeutic interventions. Neuropraxia of the great auricular nerve (GAN) is an uncommon complication of shoulder surgery, with the patient in the beach chair position. We report a case of great auricular neuropraxia associated with direct compression by a horseshoe headrest, used in routine positioning for uncomplicated shoulder surgery. In this case, an arthroscopic approach was taken, under regional anesthesia with sedation in the beach chair position. The GAN, a superficial branch of the cervical plexus, is vulnerable to neuropraxia due to its superficial anatomical location. We recommend that for the procedures of the beach chair position, the auricle be protected and covered with cotton and gauze to avoid direct compression and the position of the head and neck be checked and corrected frequently. PMID:28790863

  11. Adaptation of the human endocrine system to microgravity in the context of integrative physiology and ageing.

    PubMed

    Strollo, F

    2000-01-01

    This review deals with changes occurring in space in different endocrine systems. Sections are dedicated to hormones involved in bone remodelling, the hypothalamic-pituitary-adrenal axis, the hypothalamic-pituitary-thyroid axis, pancreatic hormones, the hypothalamic-pituitary-gonadal axis and the hypothalamic-pituitary-somato-mammotropic system. In space, most systems - especially those regulating bone/muscle metabolism and reproduction - undergo changes resembling those observed during senescence, but recover within weeks or months after return. This suggests space as a possible experimental model for the study of "reversible ageing processes". Studying ageing through space technology might give us the opportunity to combine the holistic view of integrative physiology with the most ambitious goal of the present scientific community, i.e. to yield successful ageing by promoting chronic disease prevention studies and by optimizing safe, anti-ageing therapeutic protocols.

  12. Attitudes toward retirement of ophthalmology department chairs.

    PubMed

    Dodds, David W; Cruz, Oscar A; Israel, Heidi

    2013-07-01

    To identify common perceptions and ideas about preparation and planning for retirement of chairs of academic departments of ophthalmology, determining areas of particular stress and proposing ways to better prepare for retirement. Cross-sectional study. One-hundred sixteen chairs of academic departments of ophthalmology in the United States. A confidential online survey emailed to ophthalmology chairs. Surveys assessed demographics; current work schedule; perceptions, preparation, and planning for retirement; and retirement training for faculty and residents. Ninety-six department chairs responded to the survey (82% response rate). Most chairs anticipate retiring around age 70. Significantly, only 9% are looking forward to retirement. Reasons for delaying retirement include keeping active (37%), income/insurance/benefits (20%), and maintaining lifestyle (17%). The most common concern is financing retirement (46%). Forty percent anticipate their reason for retirement will be because of age or health, whereas 20% anticipate fatigue or burnout. Nearly half of the respondents have no specific plan upon retirement. Most respondents anticipate pursuing other interests (43%); 32% intend to spend time with family, vacationing, and travelling. Younger respondents are more concerned with the financial aspects of retirement while more senior respondents appear to delay retirement to keep active or because they enjoy their work. Retirement is a source of stress for many ophthalmology department chairs and many indicate financial preparation is their major concern. Despite this, the major reason for putting off retirement is a desire to keep active. Developing a retirement plan eases stress and engenders a feeling of confidence about the future. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  13. Inhibition of MCU forces extramitochondrial adaptations governing physiological and pathological stress responses in heart

    PubMed Central

    Rasmussen, Tyler P.; Wu, Yuejin; Joiner, Mei-ling A.; Koval, Olha M.; Wilson, Nicholas R.; Luczak, Elizabeth D.; Wang, Qinchuan; Chen, Biyi; Gao, Zhan; Zhu, Zhiyong; Wagner, Brett A.; Soto, Jamie; McCormick, Michael L.; Kutschke, William; Weiss, Robert M.; Yu, Liping; Boudreau, Ryan L.; Abel, E. Dale; Zhan, Fenghuang; Spitz, Douglas R.; Buettner, Garry R.; Song, Long-Sheng; Zingman, Leonid V.; Anderson, Mark E.

    2015-01-01

    Myocardial mitochondrial Ca2+ entry enables physiological stress responses but in excess promotes injury and death. However, tissue-specific in vivo systems for testing the role of mitochondrial Ca2+ are lacking. We developed a mouse model with myocardial delimited transgenic expression of a dominant negative (DN) form of the mitochondrial Ca2+ uniporter (MCU). DN-MCU mice lack MCU-mediated mitochondrial Ca2+ entry in myocardium, but, surprisingly, isolated perfused hearts exhibited higher O2 consumption rates (OCR) and impaired pacing induced mechanical performance compared with wild-type (WT) littermate controls. In contrast, OCR in DN-MCU–permeabilized myocardial fibers or isolated mitochondria in low Ca2+ were not increased compared with WT, suggesting that DN-MCU expression increased OCR by enhanced energetic demands related to extramitochondrial Ca2+ homeostasis. Consistent with this, we found that DN-MCU ventricular cardiomyocytes exhibited elevated cytoplasmic [Ca2+] that was partially reversed by ATP dialysis, suggesting that metabolic defects arising from loss of MCU function impaired physiological intracellular Ca2+ homeostasis. Mitochondrial Ca2+ overload is thought to dissipate the inner mitochondrial membrane potential (ΔΨm) and enhance formation of reactive oxygen species (ROS) as a consequence of ischemia-reperfusion injury. Our data show that DN-MCU hearts had preserved ΔΨm and reduced ROS during ischemia reperfusion but were not protected from myocardial death compared with WT. Taken together, our findings show that chronic myocardial MCU inhibition leads to previously unanticipated compensatory changes that affect cytoplasmic Ca2+ homeostasis, reprogram transcription, increase OCR, reduce performance, and prevent anticipated therapeutic responses to ischemia-reperfusion injury. PMID:26153425

  14. Inhibition of MCU forces extramitochondrial adaptations governing physiological and pathological stress responses in heart.

    PubMed

    Rasmussen, Tyler P; Wu, Yuejin; Joiner, Mei-ling A; Koval, Olha M; Wilson, Nicholas R; Luczak, Elizabeth D; Wang, Qinchuan; Chen, Biyi; Gao, Zhan; Zhu, Zhiyong; Wagner, Brett A; Soto, Jamie; McCormick, Michael L; Kutschke, William; Weiss, Robert M; Yu, Liping; Boudreau, Ryan L; Abel, E Dale; Zhan, Fenghuang; Spitz, Douglas R; Buettner, Garry R; Song, Long-Sheng; Zingman, Leonid V; Anderson, Mark E

    2015-07-21

    Myocardial mitochondrial Ca(2+) entry enables physiological stress responses but in excess promotes injury and death. However, tissue-specific in vivo systems for testing the role of mitochondrial Ca(2+) are lacking. We developed a mouse model with myocardial delimited transgenic expression of a dominant negative (DN) form of the mitochondrial Ca(2+) uniporter (MCU). DN-MCU mice lack MCU-mediated mitochondrial Ca(2+) entry in myocardium, but, surprisingly, isolated perfused hearts exhibited higher O2 consumption rates (OCR) and impaired pacing induced mechanical performance compared with wild-type (WT) littermate controls. In contrast, OCR in DN-MCU-permeabilized myocardial fibers or isolated mitochondria in low Ca(2+) were not increased compared with WT, suggesting that DN-MCU expression increased OCR by enhanced energetic demands related to extramitochondrial Ca(2+) homeostasis. Consistent with this, we found that DN-MCU ventricular cardiomyocytes exhibited elevated cytoplasmic [Ca(2+)] that was partially reversed by ATP dialysis, suggesting that metabolic defects arising from loss of MCU function impaired physiological intracellular Ca(2+) homeostasis. Mitochondrial Ca(2+) overload is thought to dissipate the inner mitochondrial membrane potential (ΔΨm) and enhance formation of reactive oxygen species (ROS) as a consequence of ischemia-reperfusion injury. Our data show that DN-MCU hearts had preserved ΔΨm and reduced ROS during ischemia reperfusion but were not protected from myocardial death compared with WT. Taken together, our findings show that chronic myocardial MCU inhibition leads to previously unanticipated compensatory changes that affect cytoplasmic Ca(2+) homeostasis, reprogram transcription, increase OCR, reduce performance, and prevent anticipated therapeutic responses to ischemia-reperfusion injury.

  15. Age-related changes in intraventricular kinetic energy: a physiological or pathological adaptation?

    PubMed

    Wong, James; Chabiniok, Radomir; deVecchi, Adelaide; Dedieu, Nathalie; Sammut, Eva; Schaeffter, Tobias; Razavi, Reza

    2016-03-15

    Aging has important deleterious effects on the cardiovascular system. We sought to compare intraventricular kinetic energy (KE) in healthy subjects of varying ages with subjects with ventricular dysfunction to understand if changes in energetic momentum may predispose individuals to heart failure. Four-dimensional flow MRI was acquired in 35 healthy subjects (age: 1-67 yr) and 10 patients with left ventricular (LV) dysfunction (age: 28-79 yr). Healthy subjects were divided into age quartiles (1st quartile: <16 yr, 2nd quartile: 17-32 yr, 3rd quartile: 33-48 yr, and 4th quartile: 49-64 yr). KE was measured in the LV throughout the cardiac cycle and indexed to ventricular volume. In healthy subjects, two large peaks corresponding to systole and early diastole occurred during the cardiac cycle. A third smaller peak was seen during late diastole in eight adults. Systolic KE (P = 0.182) and ejection fraction (P = 0.921) were preserved through all age groups. Older adults showed a lower early peak diastolic KE compared with children (P < 0.0001) and young adults (P = 0.025). Subjects with LV dysfunction had reduced ejection fraction (P < 0.001) and compared with older healthy adults exhibited a similar early peak diastolic KE (P = 0.142) but with the addition of an elevated KE in diastasis (P = 0.029). In healthy individuals, peak diastolic KE progressively decreases with age, whereas systolic peaks remain constant. Peak diastolic KE in the oldest subjects is comparable to those with LV dysfunction. Unique age-related changes in ventricular diastolic energetics might be physiological or herald subclinical pathology. Copyright © 2016 the American Physiological Society.

  16. Physiological and morphological adaptations of the fruit tree Ziziphus rotundifolia in response to progressive drought stress.

    PubMed

    Arndt, S K; Clifford, S C; Wanek, W; Jones, H G; Popp, M

    2001-07-01

    The physiological basis of drought resistance in Ziziphus rotundifolia Lamk., which is an important, multipurpose fruit tree of the northwest Indian arid zone, was investigated in a greenhouse experiment. Three irrigation regimes were imposed over a 34-day period: an irrigation treatment, a gradual drought stress treatment (50% of water supplied in the irrigation treatment) and a rapid drought stress treatment (no irrigation). Changes in gas exchange, water relations, carbon isotope composition and solute concentrations of leaves, stems and roots were determined. The differential rate of stress development in the two drought treatments did not result in markedly different physiological responses, but merely affected the time at which they were expressed. The initial response to decreasing soil water content was reduced stomatal conductance, effectively maintaining predawn leaf water potential (Psi(leaf)), controlling water loss and increasing intrinsic water-use efficiency, while optimizing carbon gain during drought. Carbon isotope composition (delta13C) of leaf tissue sap provided a more sensitive indicator of changes in short-term water-use efficiency than delta13C of bulk leaf tissue. As drought developed, osmotic potential at full turgor decreased and total solute concentrations increased in leaves, indicating osmotic adjustment. Decreases in leaf starch concentrations and concomitant increases in hexose sugars and sucrose suggested a shift in carbon partitioning in favor of soluble carbohydrates. In severely drought-stressed leaves, high leaf nitrate reductase activities were paralleled by increases in proline concentration, suggesting an osmoprotective role for proline. As water deficit increased, carbon was remobilized from leaves and preferentially redistributed to stems and roots, and leaves were shed, resulting in reduced whole-plant transpiration and enforced dormancy. Thus, Z. rotundifolia showed a range of responses to different drought intensities

  17. Physiological framework for adaptation of stomata to CO2 from glacial to future concentrations

    PubMed Central

    Franks, Peter J.; Leitch, Ilia J.; Ruszala, Elizabeth M.; Hetherington, Alistair M.; Beerling, David J.

    2012-01-01

    In response to short-term fluctuations in atmospheric CO2 concentration, ca, plants adjust leaf diffusive conductance to CO2, gc, via feedback regulation of stomatal aperture as part of a mechanism for optimizing CO2 uptake with respect to water loss. The operational range of this elaborate control mechanism is determined by the maximum diffusive conductance to CO2, gc(max), which is set by the size (S) and density (number per unit area, D) of stomata on the leaf surface. Here, we show that, in response to long-term exposure to elevated or subambient ca, plants alter gc(max) in the direction of the short-term feedback response of gc to ca via adjustment of S and D. This adaptive feedback response to ca, consistent with long-term optimization of leaf gas exchange, was observed in four species spanning a diverse taxonomic range (the lycophyte Selaginella uncinata, the fern Osmunda regalis and the angiosperms Commelina communis and Vicia faba). Furthermore, using direct observation as well as flow cytometry, we observed correlated increases in S, guard cell nucleus size and average apparent 1C DNA amount in epidermal cell nuclei with increasing ca, suggesting that stomatal and leaf adaptation to ca is linked to genome scaling. PMID:22232765

  18. 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.

  19. Peripheral blood lymphocytes: a model for monitoring physiological adaptation to high altitude.

    PubMed

    Mariggiò, Maria A; Falone, Stefano; Morabito, Caterina; Guarnieri, Simone; Mirabilio, Alessandro; Pilla, Raffaele; Bucciarelli, Tonino; Verratti, Vittore; Amicarelli, Fernanda

    2010-01-01

    Depending on the absolute altitude and the duration of exposure, a high altitude environment induces various cellular effects that are strictly related to changes in oxidative balance. In this study, we used in vitro isolated peripheral blood lymphocytes as biosensors to test the effect of hypobaric hypoxia on seven climbers by measuring the functional activity of these cells. Our data revealed that a 21-day exposure to high altitude (5000 m) (1) increased intracellular Ca(2+) concentration, (2) caused a significant decrease in mitochondrial membrane potential, and (3) despite possible transient increases in intracellular levels of reactive oxygen species, did not significantly change the antioxidant and/or oxidative damage-related status in lymphocytes and serum, assessed by measuring Trolox-equivalent antioxidant capacity, glutathione peroxidase activity, vitamin levels, and oxidatively modified proteins and lipids. Overall, these results suggest that high altitude might cause an impairment in adaptive antioxidant responses. This, in turn, could increase the risk of oxidative-stress-induced cellular damage. In addition, this study corroborates the use of peripheral blood lymphocytes as an easily handled model for monitoring adaptive response to environmental challenge.

  20. Physiological framework for adaptation of stomata to CO2 from glacial to future concentrations.

    PubMed

    Franks, Peter J; Leitch, Ilia J; Ruszala, Elizabeth M; Hetherington, Alistair M; Beerling, David J

    2012-02-19

    In response to short-term fluctuations in atmospheric CO(2) concentration, c(a), plants adjust leaf diffusive conductance to CO(2), g(c), via feedback regulation of stomatal aperture as part of a mechanism for optimizing CO(2) uptake with respect to water loss. The operational range of this elaborate control mechanism is determined by the maximum diffusive conductance to CO(2), g(c(max)), which is set by the size (S) and density (number per unit area, D) of stomata on the leaf surface. Here, we show that, in response to long-term exposure to elevated or subambient c(a), plants alter g(c(max)) in the direction of the short-term feedback response of g(c) to c(a) via adjustment of S and D. This adaptive feedback response to c(a), consistent with long-term optimization of leaf gas exchange, was observed in four species spanning a diverse taxonomic range (the lycophyte Selaginella uncinata, the fern Osmunda regalis and the angiosperms Commelina communis and Vicia faba). Furthermore, using direct observation as well as flow cytometry, we observed correlated increases in S, guard cell nucleus size and average apparent 1C DNA amount in epidermal cell nuclei with increasing c(a), suggesting that stomatal and leaf adaptation to c(a) is linked to genome scaling.

  1. Physiology driven adaptivity for the numerical solution of the bidomain equations.

    PubMed

    Whiteley, Jonathan P

    2007-09-01

    Previous work [Whiteley, J. P. IEEE Trans. Biomed. Eng. 53:2139-2147, 2006] derived a stable, semi-implicit numerical scheme for solving the bidomain equations. This scheme allows the timestep used when solving the bidomain equations numerically to be chosen by accuracy considerations rather than stability considerations. In this study we modify this scheme to allow an adaptive numerical solution in both time and space. The spatial mesh size is determined by the gradient of the transmembrane and extracellular potentials while the timestep is determined by the values of: (i) the fast sodium current; and (ii) the calcium release from junctional sarcoplasmic reticulum to myoplasm current. For two-dimensional simulations presented here, combining the numerical algorithm in the paper cited above with the adaptive algorithm presented here leads to an increase in computational efficiency by a factor of around 250 over previous work, together with significantly less computational memory being required. The speedup for three-dimensional simulations is likely to be more impressive.

  2. Adaptive radiation of photosynthetic physiology in the Hawaiian lobeliads: light regimes, static light responses, and whole-plant compensation points.

    PubMed

    Givnish, Thomas J; Montgomery, Rebecca A; Goldstein, Guillermo

    2004-02-01

    Six endemic genera/sections of lobeliads (Campanulaceae) occupy nearly the full range of light regimes on moist sites in the Hawaiian Islands, from open alpine bogs and seacliffs to densely shaded rainforest interiors. To determine whether this clade has undergone a corresponding adaptive radiation in photosynthetic adaptations, we studied the natural light habitats and physiological characteristics of 11 species representing each sublineage. Across species in the field, average photon flux density (PFD) varies from 2.3 to 30.0 mol · m(-2) · d(-1), and maximum assimilation rate (A(max)) ranges from 0.17 to 0.35 μmol CO(2) · g(-1) · s(-1). Across species, A(max), dark respiration rate (R), Michaelis-Menten constant (k), light compensation point, specific leaf area (SLA), maximum carboxylation rate (V(cmax)), maximum rate of electron transport (J(max)), photosynthesis at saturating CO(2) (A(satCO(2))), and carboxylation efficiency (α) all increase significantly and in tightly coupled fashion with PFD, in accord with classical economic theory. Area-based rates have a higher degree of physiological integration with each other and tighter coupling to PFD than the corresponding mass-based rates, despite the energetic importance of the latter. Area-based rates frequently show adaptive cross-over: high-light species outperform low-light species at high PFD and vice versa at low PFD. A(max)-mass has little relationship to leaf mass per unit area (LMA), leaf N content, or leaf lifespan individually, but a multiple regression explains 96% of the variance in A(max)-mass across species in terms of SLA, leaf N content, and average PFD. Instantaneous leaf compensation points range from 0.1 to 1.2% full sunlight, far lower than the ecological (whole-plant) compensation points (ECPs) of 1.1 to 29.0% sunlight calculated based on photosynthetic parameters, leaf longevity, and allocation to leaf vs. nonleaf tissue. The ECPs are much closer to the lower limits of PFD actually

  3. Physiological adaptation of maternal plasma volume during pregnancy: a systematic review and meta-analysis.

    PubMed

    de Haas, S; Ghossein-Doha, C; van Kuijk, S M J; van Drongelen, J; Spaanderman, M E A

    2017-02-01

    To describe the physiological pattern of gestational plasma volume adjustments in normal singleton pregnancy and compare this with the pattern in pregnancies complicated by pregnancy-induced hypertension, pre-eclampsia or fetal growth restriction. We performed a meta-analysis of the current literature on plasma volume adjustments during physiological and complicated pregnancies. Literature was retrieved from PubMed (NCBI) and EMBASE (Ovid) databases. Included studies reported both reference plasma volume measurements (non-pregnant, prepregnancy or postpartum) and measurements obtained during predetermined gestational ages. Mean differences bet ween the reference and pregnancy plasma volume measurements were calculated for predefined intervals of gestational age using a random-effects model described by DerSimonian and Laird. Thirty studies were included in the meta-analysis with publication dates ranging from 1934 to 2007. Plasma volume increased in the first weeks of pregnancy, with the steepest increase occurring during the second trimester. Plasma volume continued to increase in the third trimester with a pooled maximum increase of 1.13 L (95% CI, 1.07-1.19 L), an increase of 45.6% (95% CI, 43.0-48.1%) in physiological pregnancies compared with the reference value. The plasma volume expansion in gestational hypertensive and growth-restricted pregnancies was 0.80 L (95% CI, 0.59-1.02 L), an increase of 32.3% (95% CI, 23.6-41.1%) in the third trimester, a smaller increase than in physiological pregnancies (P < 0.0001). During physiological pregnancy, plasma volume increases by, on average, more than 1 L as compared with non-pregnant conditions. In pregnancies complicated by pregnancy-induced hypertension, pre-eclampsia or fetal growth restriction, plasma volume increase in the third trimester is 13.3% lower than in normal pregnancy. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Adaptación fisiológica del volumen del plasma

  4. Space physiology II: adaptation of the central nervous system to space flight--past, current, and future studies.

    PubMed

    Clément, Gilles; Ngo-Anh, Jennifer Thu

    2013-07-01

    Experiments performed in orbit on the central nervous system have focused on the control of posture, eye movements, spatial orientation, as well as cognitive processes, such as three-dimensional visual perception and mental representation of space. Brain activity has also been recorded during and immediately after space flight for evaluating the changes in brain structure activation during tasks involving perception, attention, memory, decision, and action. Recent ground-based studies brought evidence that the inputs from the neurovestibular system also participate in orthostatic intolerance. It is, therefore, important to revisit the flight data of neuroscience studies in the light of new models of integrative physiology. The outcomes of this exercise will increase our knowledge on the adaptation of body functions to changing gravitational environment, vestibular disorders, aging, and our approach towards more effective countermeasures during human space flight and planetary exploration.

  5. Behaviorally mediated, warm adaptation: a physiological strategy when mice behaviorally thermoregulate.

    PubMed

    Gordon, Christopher J; Aydin, Cenk; Repasky, Elizabeth A; Kokolus, Kathleen M; Dheyongera, Geoffrey; Johnstone, Andrew F M

    2014-08-01

    Laboratory mice housed under standard vivarium conditions with an ambient temperature (Ta) of ~22°C are likely to be cold stressed because this Ta is below their thermoneutral zone (TNZ). Mice raised at Tas within the TNZ adapt to the warmer temperatures, developing smaller internal organs and longer tails compared to mice raised at 22°C. Since mice prefer Tas equal to their TNZ when housed in a thermocline, we hypothesized that mice reared for long periods (e.g., months) in a thermocline would undergo significant changes in organ development and tail length as a result of their thermoregulatory behavior. Groups of three female BALB/c mice at an age of 37 days were housed together in a thermocline consisting of a 90cm long aluminum runway with a floor temperature ranging from 23 to 39°C. Two side-by-side thermoclines allowed for a total of 6 mice to be tested simultaneously. Control mice were tested in isothermal runways maintained at a Ta of 22°C. All groups were given cotton pads for bedding/nest building. Mass of heart, lung, liver, kidney, brain, and tail length were assessed after 73 days of treatment. Mice in the thermocline and control (isothermal) runways were compared to cage control mice housed 3/cage with bedding under standard vivarium conditions. Mice in the thermocline generally remained in the warm end throughout the daytime with little evidence of nest building, suggesting a state of thermal comfort. Mice in the isothermal runway built elaborate nests and huddled together in the daytime. Mice housed in the thermocline had significantly smaller livers and kidneys and an increase in tail length compared to mice in the isothermal runway as well as when compared to the cage controls. These patterns of organ growth and tail length of mice in the thermocline are akin to warm adaptation. Thus, thermoregulatory behavior altered organ development, a process we term behaviorally mediated, warm adaptation. Moreover, the data suggest that the standard

  6. Evaluating adaptation options of microcirculatory-tissue systems based on the physiological link of nutritive blood flow and redox ratio

    NASA Astrophysics Data System (ADS)

    Krupatkin, Alexander I.; Sidorov, Victor V.; Dremin, Victor V.; Dunaev, Andrey V.; Novikova, Irina N.; Zhu, Simian; Nabi, Ghulam; Litvinova, Karina S.; Baklanova, Anastasia P.; Bakshaliev, Ruslan M.; Ravcheev, Sergey A.

    2015-03-01

    Fluorescent spectroscopy (FS) is becoming more widely used in chemistry, biology, in various fields of medical technology and medicine in general. Many purulent wounds, burns and other destructive inflammatory processes are accompanied by changes in the fluorescent activity of the tissues, which occurs due to a misbalance in accumulation of natural fluorophores: FAD, NADH, lipofuscin, porphyrins, structural proteins, etc. The study of redox ratio (RR), characterizing the metabolic processes, is important in the assessment of the metabolic activity ofmicrocirculatory-tissue systems (MTS). However, one of the big problems of the FS method is still the correct interpretation of the data and the development of practical methods for its application in clinical medicine. To solve this problem and create new diagnostic criteria, we propose to evaluate the adaptive capacity of MTS using indicators of links between nutritive blood flow and redox ratio during a physiological rest and functional load (occlusion test). As is known, these parameters (RR and nutritive blood flow) characterize the metabolic activity of tissues.We have performedan experimental study of the relationship between the RR, defined by FS, and nutritive blood flow, defined by the methods of laser Doppler flowmetry. Preliminary results in the study of a complex approach to diagnosis of the state of biological tissue were obtained. A positive relationship between the nutritive blood flow in the microcirculatory channel and RR of skin tissue is observed.The speed of change of metabolism in the phase of occlusion and reperfusion and duration of phase of recovery may be the criteria for adaptive capabilities of MTS, which has practical significance for physiology and medicine.

  7. Physiological complexity and system adaptability: evidence from postural control dynamics of older adults.

    PubMed

    Manor, Brad; Costa, Madalena D; Hu, Kun; Newton, Elizabeth; Starobinets, Olga; Kang, Hyun Gu; Peng, C K; Novak, Vera; Lipsitz, Lewis A

    2010-12-01

    The degree of multiscale complexity in human behavioral regulation, such as that required for postural control, appears to decrease with advanced aging or disease. To help delineate causes and functional consequences of complexity loss, we examined the effects of visual and somatosensory impairment on the complexity of postural sway during quiet standing and its relationship to postural adaptation to cognitive dual tasking. Participants of the MOBILIZE Boston Study were classified into mutually exclusive groups: controls [intact vision and foot somatosensation, n = 299, 76 ± 5 (SD) yr old], visual impairment only (<20/40 vision, n = 81, 77 ± 4 yr old), somatosensory impairment only (inability to perceive 5.07 monofilament on plantar halluxes, n = 48, 80 ± 5 yr old), and combined impairments (n = 25, 80 ± 4 yr old). Postural sway (i.e., center-of-pressure) dynamics were assessed during quiet standing and cognitive dual tasking, and a complexity index was quantified using multiscale entropy analysis. Postural sway speed and area, which did not correlate with complexity, were also computed. During quiet standing, the complexity index (mean ± SD) was highest in controls (9.5 ± 1.2) and successively lower in the visual (9.1 ± 1.1), somatosensory (8.6 ± 1.6), and combined (7.8 ± 1.3) impairment groups (P = 0.001). Dual tasking resulted in increased sway speed and area but reduced complexity (P < 0.01). Lower complexity during quiet standing correlated with greater absolute (R = -0.34, P = 0.002) and percent (R = -0.45, P < 0.001) increases in postural sway speed from quiet standing to dual-tasking conditions. Sensory impairments contributed to decreased postural sway complexity, which reflected reduced adaptive capacity of the postural control system. Relatively low baseline complexity may, therefore, indicate control systems that are more vulnerable to cognitive and other stressors.

  8. On the salty side of life: molecular, physiological and anatomical adaptation and acclimation of trees to extreme habitats.

    PubMed

    Polle, Andrea; Chen, Shaoliang

    2015-09-01

    Saline and sodic soils that cannot be used for agriculture occur worldwide. Cultivating stress-tolerant trees to obtain biomass from salinized areas has been suggested. Various tree species of economic importance for fruit, fibre and timber production exhibit high salinity tolerance. Little is known about the mechanisms enabling tree crops to cope with high salinity for extended periods. Here, the molecular, physiological and anatomical adjustments underlying salt tolerance in glycophytic and halophytic model tree species, such as Populus euphratica in terrestrial habitats, and mangrove species along coastlines are reviewed. Key mechanisms that have been identified as mediating salt tolerance are discussed at scales from the genetic to the morphological level, including leaf succulence and structural adjustments of wood anatomy. The genetic and transcriptomic bases for physiological salt acclimation are salt sensing and signalling networks that activate target genes; the target genes keep reactive oxygen species under control, maintain the ion balance and restore water status. Evolutionary adaptation includes gene duplication in these pathways. Strategies for and limitations to tree improvement, particularly transgenic approaches for increasing salt tolerance by transforming trees with single and multiple candidate genes, are discussed.

  9. Physiological Adaptations in Response to Environmental Stress During an N2-Fixing Anabaena Bloom

    PubMed Central

    Kellar, Penelope E.; Paerl, Hans W.

    1980-01-01

    Anabaena spiroides has the ability to maintain intense biomass production for extensive periods in the epilimnion of a small eutrophic lake characterized by conditions shown to cause photooxidative death in a number of other phytoplankton. By the enhancement of carotenoid synthesis chlorophyll a was protected from photooxidation and prevented from catalyzing other photooxidative reactions within the cells. By temporally separating CO2 and N2 fixation, maximum utilization of photosynthetically active radiation was achieved. Because CO2 fixation was more sensitive than N2 fixation to a high oxygen concentration, the former was maximized during morning hours, before the afternoon buildup of dissolved oxygen. The diurnal partitioning of carbon and N2 fixation has two additional advantages; possible competition for reductant-generating compounds is minimized, and adequate endogenous pools of carbon skeletons are assured to accept newly fixed ammonia. Hence, Anabaena, far from undergoing photooxidative death, appears to utilize a physiological strategy which allows optimization of radiant energy use for reductive processes and dominance of surface waters and shading of deeper phytoplankton during summer blooms. PMID:16345637

  10. Physiological and morphological adaptations in relation to water use efficiency in Mediterranean accessions of Solanum lycopersicum.

    PubMed

    Galmés, Jeroni; Conesa, Miquel Àngel; Ochogavía, Joan Manuel; Perdomo, Juan Alejandro; Francis, David M; Ribas-Carbó, Miquel; Savé, Robert; Flexas, Jaume; Medrano, Hipólito; Cifre, Josep

    2011-02-01

    The physiological traits underlying the apparent drought resistance of 'Tomàtiga de Ramellet' (TR) cultivars, a population of Mediterranean tomato cultivars with delayed fruit deterioration (DFD) phenotype and typically grown under non-irrigation conditions, are evaluated. Eight different tomato accessions were selected and included six TR accessions, one Mediterranean non-TR accession (NTR(M)) and a processing cultivar (NTR(O)). Among the TR accessions two leaf morphology types, normal divided leaves and potato-leaf, were selected. Plants were field grown under well-watered (WW) and water-stressed (WS) treatments, with 30 and 10% of soil water capacity, respectively. Accessions were clustered according to the leaf type and TR phenotype under WW and WS, respectively. Correlation among parameters under the different water treatments suggested that potential improvements in the intrinsic water-use efficiency (A(N)/g(s)) are possible without negative impacts on yield. Under WS TR accessions displayed higher A(N)/g(s), which was not due to differences in Rubisco-related parameters, but correlated with the ratio between the leaf mesophyll and stomatal conductances (g(m)/g(s)). The results confirm the existence of differential traits in the response to drought stress in Mediterranean accessions of tomato, and demonstrate that increases in the g(m)/g(s) ratio would allow improvements in A(N)/g(s) in horticultural crops.

  11. The high cost of reproduction in sea otters necessitates unique physiological adaptations.

    PubMed

    Thometz, Nicole M; Kendall, Traci L; Richter, Beau P; Williams, Terrie M

    2016-08-01

    Superimposed on inherently high basal metabolic demands, the additional energetic requirements of reproduction can push female sea otters beyond physiological limits. Indeed, the resulting energy imbalance contributes to disproportionately high rates of mortality at the end of lactation in this species. To examine and quantify metabolic changes associated with reproduction, we measured the resting metabolic rate (RMR) of a female sea otter across gestation, lactation and non-reproductive periods. Concurrently, measurements were made on a non-breeding control female. Our results suggest that RMR declines during gestation. Conversely, RMR increases during lactation, reaches a peak at 3-4 months postpartum, and remains elevated until weaning. Combining these direct measurements with published data, we found the cost of pup rearing to be significantly higher than previously estimated. High baseline energy demands and limited energy reserves, combined with significant lactation and pup rearing costs, appear to necessitate metabolic and thermal lability during key reproductive stages. © 2016. Published by The Company of Biologists Ltd.

  12. Adaptation of task difficulty in rehabilitation exercises based on the user's motor performance and physiological responses.

    PubMed

    Shirzad, Navid; Van der Loos, H F Machiel

    2013-06-01

    Although robot-assisted rehabilitation regimens are as effective, functionally, as conventional therapies, they still lack features to increase patients' engagement in the regimen. Providing rehabilitation tasks at a "desirable difficulty" is one of the ways to address this issue and increase the motivation of a patient to continue with the therapy program. Then the problem is to design a system that is capable of estimating the user's desirable difficulty, and ultimately, modifying the task based on this prediction. In this paper we compared the performance of three machine learning algorithms in predicting a user's desirable difficulty during a typical reaching motion rehabilitation task. Different levels of error amplification were used as different levels of task difficulty. We explored the usefulness of using participants' motor performance and physiological signals during the reaching task in prediction of their desirable difficulties. Results showed that a Neural Network approach gives higher prediction accuracy in comparison with models based on k-Nearest Neighbor and Discriminant Analysis methods.

  13. Morphological and physiological determinants of local adaptation to climate in Rocky Mountain butterflies

    PubMed Central

    MacLean, Heidi J.; Higgins, Jessica K.; Buckley, Lauren B.; Kingsolver, Joel G.

    2016-01-01

    Flight is a central determinant of fitness in butterflies and other insects, but it is restricted to a limited range of body temperatures. To achieve these body temperatures, butterflies use a combination of morphological, behavioural and physiological mechanisms. Here, we used common garden (without direct solar radiation) and reciprocal transplant (full solar radiation) experiments in the field to determine the thermal sensitivity of flight initiation for two species of Colias butterflies along an elevation gradient in the southwestern Rocky Mountains. The mean body temperature for flight initiation in the field was lower (24–26°C) than indicated by previous studies (28–30°C) in these species. There were small but significant differences in thermal sensitivity of flight initiation between species; high-elevation Colias meadii initiated flight at a lower mean body temperature than lower-elevation Colias eriphyle. Morphological differences (in wing melanin and thoracic setae) drive body temperature differences between species and contributed strongly to differences in the time and probability of flight and air temperatures at flight initiation. Our results suggest that differences both in thermal sensitivity (15% contribution) and in morphology (85% contribution) contribute to the differences in flight initiation between the two species in the field. Understanding these differences, which influence flight performance and fitness, aids in forecasting responses to climate change. PMID:27668080

  14. Physiological adaptations of microorganisms to high oxygen in two oligotrophic lakes

    SciTech Connect

    Mikell, A.T. Jr.

    1985-01-01

    Dissolved oxygen at four times normal saturation inhibited growth and metabolism of summer planktobacteria in surface waters of alpine oligotrophic Mountain Lake (Giles County, Virginia). Data included viable colony counts, D-(U-/sup 14/C)glucose incorporation into extractable lipid of colonies, and respiration-assimilation of D-(U-/sup 14/C)glucose by lake water samples. Significant differences were not detected in either colony counts or /sup 14/C-lipid when superoxide dismutase or catalase were added to the medium. The upper waters of Lake Hoare, Antarctica, contain dissolved oxygen at greater than or equal to42 mg liter/sup -1/ (=HDO). HDO did inhibit D-(U-/sup 14/C)glucoses assimilation-respiration compared with normal atmospheric dissolved oxygen (=ADO) in Lake Hoare water. D-(U-/sup 14/C)glucose was assimilated and respired optimally at 12/sup 0/C in Lake Hoare. Colony formation was inhibited in both lakes. Five microbial isolated were selected from Lake Hoare by growth under very high oxygen. Isolates were examined for physiological characteristics which might enhance their survival in the HDO environment. Bacterial isolates were motile Gram negative rods, catalase and oxidase positive, differing in their growth response to temperature and nutrient concentration. Four of five bacterial isolates demonstrated HDO inducible superoxide dismutase (SOD). Microorganisms in the high oxygen Lake Hoare waters may be protected from oxygen toxicity by the lake's oligotrophic nature as well as a combination of cellular defenses.

  15. Cell adaptation to a physiologically relevant ECM mimic with different viscoelastic properties

    PubMed Central

    Ghosh, Kaustabh; Pan, Zhi; Guan, E; Ge, Shouren; Liu, Yajie; Nakamura, Toshio; Ren, Xiang-Dong; Rafailovich, Miriam; Clark, Richard A.F.

    2009-01-01

    To successfully induce tissue repair or regeneration in vivo, bioengineered constructs must possess both optimal bioactivity and mechanical strength. This is because cell interaction with the extracellular matrix (ECM) produces two different but concurrent signaling mechanisms: ligation-induced signaling, which depends on ECM biological stimuli, and traction-induced signaling, which depends on ECM mechanical stimuli. In this report, we provide a fundamental understanding of how alterations in mechanical stimuli alone, produced by varying the viscoelastic properties of our bioengineered construct, modulate phenotypic behavior at the whole-cell level. Using a physiologically-relevant ECM mimic composed of hyaluronan and fibronectin, we found that adult human dermal fibroblasts modify their mechanical response in order to match substrate stiffness. More specifically, the cells on stiffer substrates had higher modulus and a more stretched and organized actin cytoskeleton (and vice versa), which translated into larger traction forces exerted on the substrate. This modulation of cellular mechanics had contrasting effects on migration and proliferation, where cells migrated faster on softer substrates while proliferating preferentially on the stiffer ones. These findings implicate substrate rigidity as a critical design parameter in the development of bioengineered constructs aimed at eliciting maximal cell and tissue function. PMID:17049594

  16. Physiological adaptations to prolonged fasting in the overwintering striped skunk (Mephitis mephitis).

    PubMed

    Mustonen, Anne-Mari; Bowman, Jeff; Sadowski, Carrie; Nituch, Larissa A; Bruce, Laura; Halonen, Toivo; Puukka, Katri; Rouvinen-Watt, Kirsti; Aho, Jari; Nieminen, Petteri

    2013-12-01

    Wintertime physiology of captive striped skunks (Mephitis mephitis) in response to cold ambient temperature (Ta) and fasting was investigated with body temperature (Tb) and activity recordings and analyses of hematology, plasma biochemistry and tissue fatty acids (FA). After 105 days of food deprivation, the skunks were in phase II of fasting indicated by the elevated plasma nonesterified FA and glycerol but no accumulation of nitrogen end products. Shorter-chain saturated and monounsaturated FA together with C18-20 n-3 polyunsaturated FA were preferentially mobilized. Individual amino acids responded to fasting in a complex manner, while essential and nonessential amino acid sums remained stable. Increases in hemoglobin and hematocrit suggested dehydration. The activity levels were lower in mid-January-early March, and the activity bouts were mostly displayed between 17:00-23:00 h. Daily torpor was observed in two females with 29 and 46 bouts. The deepest torpor (Tb<31 °C) occurred between dawn and early afternoon and lasted for 3.3 ± 0.18 h. The average minimum Tb was 29.2 ± 0.15 °C and the lowest recorded Tb was 25.8 °C. There was significant relation between the average 24-h Tb and Ta. Increases in wintertime Ta, as predicted by climate change scenarios, could influence torpor patterns in the species.

  17. Physiological adaptations to reproduction. II. Mitochondrial adjustments in livers of lactating mice.

    PubMed

    Pichaud, Nicolas; Garratt, Michael; Ballard, J William O; Brooks, Robert C

    2013-08-01

    Reproduction imposes significant costs and is characterized by an increased energy demand. As a consequence, individuals adjust their cellular structure and function in response to this physiological constraint. Because mitochondria are central to energy production, changes in their functional properties are likely to occur during reproduction. Such changes could cause adjustments in reactive oxygen species (ROS) production and consequently in oxidative stress levels. In this study, we investigated several mechanisms involved in energy production, including mitochondrial respiration at different steps of the electron transport system (ETS) and related the results to citrate synthase activity in the liver of non-reproductive and reproductive (two and eight pups) female house mice at peak lactation. Whereas we did not find differences between females having different litter sizes, liver mitochondria of reproductive females showed lower ETS activity and an increase in mitochondrial density when compared with the non-reproductive females. Although it is possible that these changes were due to combined processes involved in reproduction and not to the relative investment in lactation, we propose that the mitochondrial adjustment in liver might help to spare substrates and therefore energy for milk production in the mammary gland. Moreover, our results suggest that these changes lead to an increase in ROS production that subsequently upregulates antioxidant defence activity and decreases oxidative stress.

  18. Physiological tremor reveals how thixotropy adapts skeletal muscle for posture and movement.

    PubMed

    Vernooij, Carlijn A; Reynolds, Raymond F; Lakie, Martin

    2016-05-01

    People and animals can move freely, but they must also be able to stay still. How do skeletal muscles economically produce both movement and posture? Humans are well known to have motor units with relatively homogeneous mechanical properties. Thixotropic muscle properties can provide a solution by providing a temporary stiffening of all skeletal muscles in postural conditions. This stiffening is alleviated almost instantly when muscles start to move. In this paper, we probe this behaviour. We monitor both the neural input to a muscle, measured here as extensor muscle electromyography (EMG), and its output, measured as tremor (finger acceleration). Both signals were analysed continuously as the subject made smooth transitions between posture and movement. The results showed that there were marked changes in tremor which systematically increased in size and decreased in frequency as the subject moved faster. By contrast, the EMG changed little and reflected muscle force requirement rather than movement speed. The altered tremor reflects naturally occurring thixotropic changes in muscle behaviour. Our results suggest that physiological tremor provides useful and hitherto unrecognized insights into skeletal muscle's role in posture and movement.

  19. Physiological tremor reveals how thixotropy adapts skeletal muscle for posture and movement

    PubMed Central

    Vernooij, Carlijn A.; Reynolds, Raymond F.; Lakie, Martin

    2016-01-01

    People and animals can move freely, but they must also be able to stay still. How do skeletal muscles economically produce both movement and posture? Humans are well known to have motor units with relatively homogeneous mechanical properties. Thixotropic muscle properties can provide a solution by providing a temporary stiffening of all skeletal muscles in postural conditions. This stiffening is alleviated almost instantly when muscles start to move. In this paper, we probe this behaviour. We monitor both the neural input to a muscle, measured here as extensor muscle electromyography (EMG), and its output, measured as tremor (finger acceleration). Both signals were analysed continuously as the subject made smooth transitions between posture and movement. The results showed that there were marked changes in tremor which systematically increased in size and decreased in frequency as the subject moved faster. By contrast, the EMG changed little and reflected muscle force requirement rather than movement speed. The altered tremor reflects naturally occurring thixotropic changes in muscle behaviour. Our results suggest that physiological tremor provides useful and hitherto unrecognized insights into skeletal muscle's role in posture and movement. PMID:27293785

  20. Physiological adaptations in response to environmental stress during an n(2)-fixing anabaena bloom.

    PubMed

    Kellar, P E; Paerl, H W

    1980-09-01

    Anabaena spiroides has the ability to maintain intense biomass production for extensive periods in the epilimnion of a small eutrophic lake characterized by conditions shown to cause photooxidative death in a number of other phytoplankton. By the enhancement of carotenoid synthesis chlorophyll a was protected from photooxidation and prevented from catalyzing other photooxidative reactions within the cells. By temporally separating CO(2) and N(2) fixation, maximum utilization of photosynthetically active radiation was achieved. Because CO(2) fixation was more sensitive than N(2) fixation to a high oxygen concentration, the former was maximized during morning hours, before the afternoon buildup of dissolved oxygen. The diurnal partitioning of carbon and N(2) fixation has two additional advantages; possible competition for reductant-generating compounds is minimized, and adequate endogenous pools of carbon skeletons are assured to accept newly fixed ammonia. Hence, Anabaena, far from undergoing photooxidative death, appears to utilize a physiological strategy which allows optimization of radiant energy use for reductive processes and dominance of surface waters and shading of deeper phytoplankton during summer blooms.

  1. Cellular, physiological, and molecular adaptive responses of Erwinia amylovora to starvation.

    PubMed

    Santander, Ricardo D; Oliver, James D; Biosca, Elena G

    2014-05-01

    Erwinia amylovora causes fire blight, a destructive disease of rosaceous plants distributed worldwide. This bacterium is a nonobligate pathogen able to survive outside the host under starvation conditions, allowing its spread by various means such as rainwater. We studied E. amylovora responses to starvation using water microcosms to mimic natural oligotrophy. Initially, survivability under optimal (28 °C) and suboptimal (20 °C) growth temperatures was compared. Starvation induced a loss of culturability much more pronounced at 28 °C than at 20 °C. Natural water microcosms at 20 °C were then used to characterize cellular, physiological, and molecular starvation responses of E. amylovora. Challenged cells developed starvation-survival and viable but nonculturable responses, reduced their size, acquired rounded shapes and developed surface vesicles. Starved cells lost motility in a few days, but a fraction retained flagella. The expression of genes related to starvation, oxidative stress, motility, pathogenicity, and virulence was detected during the entire experimental period with different regulation patterns observed during the first 24 h. Further, starved cells remained as virulent as nonstressed cells. Overall, these results provide new knowledge on the biology of E. amylovora under conditions prevailing in nature, which could contribute to a better understanding of the life cycle of this pathogen.

  2. Morphological and physiological determinants of local adaptation to climate in Rocky Mountain butterflies.

    PubMed

    MacLean, Heidi J; Higgins, Jessica K; Buckley, Lauren B; Kingsolver, Joel G

    2016-01-01

    Flight is a central determinant of fitness in butterflies and other insects, but it is restricted to a limited range of body temperatures. To achieve these body temperatures, butterflies use a combination of morphological, behavioural and physiological mechanisms. Here, we used common garden (without direct solar radiation) and reciprocal transplant (full solar radiation) experiments in the field to determine the thermal sensitivity of flight initiation for two species of Colias butterflies along an elevation gradient in the southwestern Rocky Mountains. The mean body temperature for flight initiation in the field was lower (24-26°C) than indicated by previous studies (28-30°C) in these species. There were small but significant differences in thermal sensitivity of flight initiation between species; high-elevation Colias meadii initiated flight at a lower mean body temperature than lower-elevation Colias eriphyle. Morphological differences (in wing melanin and thoracic setae) drive body temperature differences between species and contributed strongly to differences in the time and probability of flight and air temperatures at flight initiation. Our results suggest that differences both in thermal sensitivity (15% contribution) and in morphology (85% contribution) contribute to the differences in flight initiation between the two species in the field. Understanding these differences, which influence flight performance and fitness, aids in forecasting responses to climate change.

  3. Development of the Digital Astronaut Project for the analysis of the mechanisms of physiologic adaptation to microgravity: Validation of the cardiovascular system module

    NASA Astrophysics Data System (ADS)

    Summers, Richard; Coleman, Thomas; Meck, Janice

    The physiologic adaptation of humans to the microgravity environment is complex and requires an integrative perspective to fully understand the mechanisms involved. A large computer model of human systems physiology provides the framework for the development of the Digital Astronaut to be used by NASA in the analysis of adaptive mechanisms. While project expansion is ongoing to include all relevant systems, we describe the validation results of the cardiovascular phase of model development. The cardiovascular aspects of the model were validated by benchmark comparisons to published literature findings of changes in left ventricular mass, right atrial pressure and plasma volumes. Computer simulations using the model predicted microgravity induced changes in the target endpoints within statistical validity of experimental findings. Therefore, the current cardiovascular portion of the Digital Astronaut Project computer model appears to accurately predict observed microgravity induced physiologic adaptations. The ongoing process of model development to include all spaceflight relevant systems will require similar validations.

  4. Physiological fitness and health adaptations from purposeful training using off-road vehicles.

    PubMed

    Burr, J F; Jamnik, V K; Gledhill, N

    2011-08-01

    The purpose of this study was to evaluate fitness and health adaptations from a training program riding all-terrain vehicles (ATV) and off-road motorcycles (ORM) as the exercise stimulus. Participants (n = 58) were randomized to a control group (n = 12) or one of four experimental groups; 2 days/week ATV (n = 11), 2 days/week ORM (n = 12), 4 days/week ATV (n = 11), or 4 days/week ORM (n = 12). Aerobic fitness, musculoskeletal fitness, body composition, clinical health, and quality of life (QOL) were compared at baseline and following 6 weeks of training. In all riding groups, there were improvements in blood pressure (SBP = 9.4 ± 10.1, DBP = 5.8 ± 6.2 mmHg), fasting glucose (0.5 ± 0.7 mmol/l), subcutaneous adiposity (0.9 ± 1.1%), body mass (0.7 ± 2.7 kg), waist circumference (1.3 ± 2.5 cm), and isometric leg endurance (26 ± 44 s). All changes were of moderate to large magnitude (Cohen's d 0.52-0.94) with the exception of a small loss of body mass (Cohen's d = 0.27). Although changes occurred in the riding groups for aerobic power (2.9 ± 4.6 ml kg(-1) min(-1)), leg power (172 ± 486 w), and curl-ups (13.2 ± 22.7), these changes were not significantly different from the control group. No significant alterations occurred in resting heart rate, trunk flexibility, back endurance, hand grip strength, long jump, pull/push strength, or push-up ability as a result of training. Physical domain QOL increased in all 2 days/week riders but mental domain QOL increased in all ORM, but not ATV riders regardless of volume. Ambient carbon monoxide levels while riding (<30 ppm) were within safe exposure guidelines. Positive adaptations can be gained from a training program using off-road vehicle riding as the exercise stimulus.

  5. Physiological adaptation of Corynebacterium glutamicum to benzoate as alternative carbon source - a membrane proteome-centric view.

    PubMed

    Haussmann, Ute; Qi, Su-Wei; Wolters, Dirk; Rögner, Matthias; Liu, Shuang-Jiang; Poetsch, Ansgar

    2009-07-01

    The ability of microorganisms to assimilate aromatic substances as alternative carbon sources is the basis of biodegradation of natural as well as industrial aromatic compounds. In this study, Corynebacterium glutamicum was grown on benzoate as sole carbon and energy source. To extend the scarce knowledge about physiological adaptation processes occurring in this cell compartment, the membrane proteome was investigated under quantitative and qualitative aspects by applying shotgun proteomics to reach a comprehensive survey. Membrane proteins were relatively quantified using an internal standard metabolically labeled with (15)N. Altogether, 40 proteins were found to change their abundance during growth on benzoate in comparison to glucose. A global adaptation was observed in the membrane of benzoate-grown cells, characterized by increased abundance of proteins of the respiratory chain, by a starvation response, and by changes in sulfur metabolism involving the regulator McbR. Additional to the relative quantification, stable isotope-labeled synthetic peptides were used for the absolute quantification of the two benzoate transporters of C. glutamicum, BenK and BenE. It was found that both transporters were expressed during growth on benzoate, suggesting that both contribute substantially to benzoate uptake.

  6. The c-ring stoichiometry of ATP synthase is adapted to cell physiological requirements of alkaliphilic Bacillus pseudofirmus OF4

    PubMed Central

    Preiss, Laura; Klyszejko, Adriana L.; Hicks, David B.; Liu, Jun; Fackelmayer, Oliver J.; Yildiz, Özkan; Krulwich, Terry A.; Meier, Thomas

    2013-01-01

    The c-rings of ATP synthases consist of individual c-subunits, all of which harbor a conserved motif of repetitive glycine residues (GxGxGxG) important for tight transmembrane α-helix packing. The c-ring stoichiometry determines the number of ions transferred during enzyme operation and has a direct impact on the ion-to-ATP ratio, a cornerstone parameter of cell bioenergetics. In the extreme alkaliphile Bacillus pseudofirmus OF4, the glycine motif is replaced by AxAxAxA. We performed a structural study on two mutants with alanine-to-glycine changes using atomic force microscopy and X-ray crystallography, and found that mutants form smaller c12 rings compared with the WT c13. The molar growth yields of B. pseudofirmus OF4 cells on malate further revealed that the c12 mutants have a considerably reduced capacity to grow on limiting malate at high pH. Our results demonstrate that the mutant ATP synthases with either c12 or c13 can support ATP synthesis, and also underscore the critical importance of an alanine motif with c13 ring stoichiometry for optimal growth at pH >10. The data indicate a direct connection between the precisely adapted ATP synthase c-ring stoichiometry and its ion-to-ATP ratio on cell physiology, and also demonstrate the bioenergetic challenges and evolutionary adaptation strategies of extremophiles. PMID:23613590

  7. Induction of Osmoadaptive Mechanisms and Modulation of Cellular Physiology Help Bacillus licheniformis Strain SSA 61 Adapt to Salt Stress

    SciTech Connect

    Paul, Sangeeta; Aggarwal, Chetana; Thakur, Jyoti Kumar; Bandeppa, G.S.; Khan, Md. Aslam; Pearson, Lauren M.; Babnigg, Gyorgy; Giometti, Carol S.; Joachimiak, Andrzej

    2015-01-06

    Bacillus licheniformis strain SSA 61, originally isolated from Sambhar salt lake, was observed to grow even in the presence of 25 % salt stress. Osmoadaptive mechanisms of this halotolerant B. licheniformis strain SSA 61, for long-term survival and growth under salt stress, were determined. Proline was the preferentially accumulated compatible osmolyte. There was also increased accumulation of antioxidants ascorbic acid and glutathione. Among the different antioxidative enzymes assayed, superoxide dismutase played the most crucial role in defense against salt-induced stress in the organism. Adaptation to stress by the organism involved modulation of cellular physiology at various levels. There was enhanced expression of known proteins playing essential roles in stress adaptation, such as chaperones DnaK and GroEL, and general stress protein YfkM and polynucleotide phosphorylase/polyadenylase. Proteins involved in amino acid biosynthetic pathway, ribosome structure, and peptide elongation were also overexpressed. Salt stress-induced modulation of expression of enzymes involved in carbon metabolism was observed. There was up-regulation of a number of enzymes involved in generation of NADH and NADPH, indicating increased cellular demand for both energy and reducing power.

  8. Induction of osmoadaptive mechanisms and modulation of cellular physiology help Bacillus licheniformis strain SSA 61 adapt to salt stress.

    PubMed

    Paul, Sangeeta; Aggarwal, Chetana; Thakur, Jyoti Kumar; Bandeppa, G S; Khan, Md Aslam; Pearson, Lauren M; Babnigg, Gyorgy; Giometti, Carol S; Joachimiak, Andrzej

    2015-04-01

    Bacillus licheniformis strain SSA 61, originally isolated from Sambhar salt lake, was observed to grow even in the presence of 25 % salt stress. Osmoadaptive mechanisms of this halotolerant B. licheniformis strain SSA 61, for long-term survival and growth under salt stress, were determined. Proline was the preferentially accumulated compatible osmolyte. There was also increased accumulation of antioxidants ascorbic acid and glutathione. Among the different antioxidative enzymes assayed, superoxide dismutase played the most crucial role in defense against salt-induced stress in the organism. Adaptation to stress by the organism involved modulation of cellular physiology at various levels. There was enhanced expression of known proteins playing essential roles in stress adaptation, such as chaperones DnaK and GroEL, and general stress protein YfkM and polynucleotide phosphorylase/polyadenylase. Proteins involved in amino acid biosynthetic pathway, ribosome structure, and peptide elongation were also overexpressed. Salt stress-induced modulation of expression of enzymes involved in carbon metabolism was observed. There was up-regulation of a number of enzymes involved in generation of NADH and NADPH, indicating increased cellular demand for both energy and reducing power.

  9. Effect of thermal exposure on physiological adaptability and seminal attributes of rams under semi-arid environment.

    PubMed

    De, Kalyan; Kumar, Davendra; Balaganur, Krishnappa; Kumar Saxena, Vijay; Thirumurugan, Palanisamy; Khursheed Naqvi, Syed Mohammed

    2017-04-01

    Thermal stress in hot semi-arid environment is a major limitation of sheep production in tropical and sub-tropical climatic condition. The animals tend to maintain homeostasis through physiological adjustments in a hot environment (maximum temperature reaches up to 47.5°C). Therefore, the present study was carried out to assess the effect of thermal exposure on physiological adaptability and seminal attributes of rams under semi-arid environment. The experiment was conducted for eight weeks involving sixteen Malpura crossbred rams (GMM: Garole X Malpura X Malpura). The rams were divided equally into two groups, designated as G1 and G2, respectively. The rams in G1 (Control) group were kept in a sheep shed under naturally prevailing environment without artificial manipulation of ambient temperature (Temperature 30.48±0.38°C; Relative Humidity 28.59±1.15%). The rams of G2 group were exposed to different temperature at different hours of the day (38°C at 1000-1100h; 40°C at 1100-1200h; 42°C at 12:00-1300h; 43°C at 1300-1400h; 44°C at 1400-1500h and 42°C at 1500-1600h) in a climatic chamber for thermal exposure. Physiological responses, blood biochemical profile, blood endocrine profile, sexual behavior and seminal attributes were measured for both the groups. Thermal exposure significantly (P<0.05) increased the water intake; respiration rate, rectal temperature and skin temperature at afternoon in rams. Exposure of rams to thermal stress (G2) significantly (P<0.05) increased cortisol level and decreased tri-ido-thyronine level. The latency period after the first ejaculation, decreased significantly (P<0.05) in G2. The percentage of rapid motile sperm, linearity and average path velocity of sperm were also altered significantly (P<0.05) in thermal exposed rams as compared to control. However, comparable feed intake, body weight, and major blood biochemical parameters, as well as acceptable semen quality attributes of all the rams indicated that the Fec B

  10. The physiological adaptations and toxin profiles of the toxic Alexandrium fundyense on the eastern Bering Sea and Chukchi Sea shelves.

    PubMed

    Natsuike, Masafumi; Oikawa, Hiroshi; Matsuno, Kohei; Yamaguchi, Atsushi; Imai, Ichiro

    2017-03-01

    Abundant cyst distributions of the toxic dinoflagellate Alexandrium fundyense (previous A. tamarense north American clade) were recently observed on the north Chukchi Sea shelf and on the eastern Bering Sea shelf, suggesting that A. fundyense is both highly adapted to the local environments in the high latitude areas and might cause toxin contamination of plankton feeders. However, little is known about the physiological characteristics and toxin profiles of A. fundyense in these areas, which are characterized by low water temperatures, weak sunlight, and more or less permanent ice cover during winter. To clarify the physiological characteristics of A. fundyense, the effects of water temperature and light intensity on the vegetative growth and toxin profiles of this species were examined using A. fundyense strains isolated from one sediment sample collected from each area. Using the same sediments samples, seasonal changes of the cyst germination in different water temperatures were investigated. Vegetative cells grew at temperatures as low as 5°C and survived at 1°C under relatively low light intensity. They also grew at moderate water temperatures (10-15°C). Their cysts could germinate at low temperatures (1°C) and have an endogenous dormancy period from late summer to early spring, and warmer water temperatures (5-15°C) increased germination success. These physiological characteristics suggest that A. fundyense in the Chukchi Sea and eastern Bering Sea is adapted to the environments of high latitude areas. In addition, the results suggest that in the study areas A. fundyense has the potential to germinate and grow when water temperatures increase. Cellular toxin amounts of A. fundyense strains from the eastern Bering Sea and Chukchi Sea were ranged from 7.2 to 38.2 fmol cell(-1). These toxin amounts are comparable with A. fundyense strains isolated from other areas where PSP toxin contamination of bivalves occurs. The dominant toxin of the strains isolated

  11. 21 CFR 892.1820 - Pneumoencephalographic chair.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pneumoencephalographic chair. 892.1820 Section 892.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... pneumoencephalography (x-ray imaging of the brain). (b) Classification. Class II. ...

  12. 21 CFR 892.1820 - Pneumoencephalographic chair.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pneumoencephalographic chair. 892.1820 Section 892.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... pneumoencephalography (x-ray imaging of the brain). (b) Classification. Class II. ...

  13. 21 CFR 892.1820 - Pneumoencephalographic chair.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pneumoencephalographic chair. 892.1820 Section 892.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... pneumoencephalography (x-ray imaging of the brain). (b) Classification. Class II. ...

  14. 21 CFR 892.1820 - Pneumoencephalographic chair.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pneumoencephalographic chair. 892.1820 Section 892.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... pneumoencephalography (x-ray imaging of the brain). (b) Classification. Class II. ...

  15. 21 CFR 892.1820 - Pneumoencephalographic chair.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pneumoencephalographic chair. 892.1820 Section 892.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... pneumoencephalography (x-ray imaging of the brain). (b) Classification. Class II. ...

  16. Perceptions of Leadership Styles of Department Chairs

    ERIC Educational Resources Information Center

    Whitsett, Glee

    2007-01-01

    Much has been written about leadership in business management, but very little research has been done on leadership in academic departments. Department chairs have the authority to make most departmental decisions, but rarely does formal training exist for this position. Therefore, there is a need to study how the leadership styles among…

  17. The future-oriented department chair.

    PubMed

    Grigsby, R Kevin; Hefner, David S; Souba, Wiley W; Kirch, Darrell G

    2004-06-01

    The authors describe the current dilemma facing academic health centers (AHCs) as they recruit department chairs. In the past, leaders at AHCs predominantly were concerned with fulfilling the esteemed tripartite missions of patient care, research, and education. Today, their time and energy are occupied by a different set of tasks that have a distinct business orientation, including winning contracts, enhancing revenue, reducing costs, recruiting and managing a diverse workforce, and dealing with consumer satisfaction and marketing. New visions and strategies must be developed--requiring different dimensions of leadership. The authors offer concrete recommendations for recruiting, retaining, and sustaining department chairs, and argue that a deliberative, thoughtful process of engaging chair candidates should begin by focusing on the candidates' values as a first priority. Candidates who most clearly share organizational values should then be engaged in an iterative process of developing a shared vision, resulting in a letter of agreement that explicitly states the mutual expectations and commitments of both the organization and the candidate. Once department chairs are in place, ongoing development through leadership training, mentoring, and other investments help to retain and sustain them.

  18. Jumping From a Chair is a More Sensitive Measure of Power Performance In Older Adults Than Chair Rising.

    PubMed

    Zemková, Erika; Jeleň, Michal; Schickhofer, Peter; Hamar, Dušan

    2016-01-01

    Background/Study Context: The study estimates the reliability of peak velocity and peak power during chair rising and chair jumping tests and their ability to discriminate between different age and physical activity level groups. Physically active and sedentary individuals (N = 262) of different ages (young: 22.9 ± 2.0 years, range: 21-25 years; older: 63.1 ± 1.8 years, range: 61-65 years) performed, in random order, chair rising and chair jumping tests on a force plate. Randomly selected young subjects performed both tests repeatedly on two different occasions separated by 1 week. From the sitting position with the arms crossed on the chest, they either stand up completely (chair rising test), or jump as high as possible (chair jumping test). The test-retest reliability of peak power and peak velocity during chair rising as well as chair jumping was excellent, with high intraclass correlation coefficients (ICCs; .90-.98) and low standard error of measurement (SEM; 7.0-9.1%). Post hoc analysis revealed significant differences in peak power and peak velocity between the sedentary and physically active young and older subjects. However, greater coefficients of variation for both parameters were found for chair jumping than chair rising (21.1-40.2% vs. 11.0-15.2%). Additionaly, there were moderate correlations of peak power and peak velocity between chair rising and chair jumping (r = .42-.49). There were greater within- and between-group differences in peak force and peak power and a steeper increase in their values during the initial phase of chair jumping than chair rising. Both chair rising and chair jumping tests provide reliable data and are valid indicators of lower body power in young and older adults. However, jumping from a chair is a more sensitive measure of strength and power performance than chair rising.

  19. Physiological and performance adaptations of elite Greco-Roman wrestlers during a one-day tournament.

    PubMed

    Barbas, Ioannis; Fatouros, Ioannis G; Douroudos, Ioannis I; Chatzinikolaou, Athanasios; Michailidis, Yiannis; Draganidis, Dimitrios; Jamurtas, Athanasios Z; Nikolaidis, Michalis G; Parotsidis, Charalabos; Theodorou, Anastasios A; Katrabasas, Ioannis; Margonis, Konstantinos; Papassotiriou, Ioannis; Taxildaris, Kyriakos

    2011-07-01

    The aim of this study was to determine the effects of a simulated one-day Greco-Roman wrestling tournament on selected performance and inflammatory status indices. Twelve competitive wrestlers (22.1 ± 1.3 years) completed five matches according to the official Olympic wrestling tournament regulations following a ~6% weight loss. Performance measurements, muscle damage assessment, and blood sampling were performed before and following each match. Performance and inflammatory markers were not affected by weight loss. Mean wrestling heart rate reached ~85% of maximal and lactate concentration exceeded 17 mM. Fatigue rating demonstrated a progressive rise (P < 0.05) throughout the tournament, peaking in match 4. Performance demonstrated a progressive deterioration (P < 0.05) throughout the tournament, especially in the last two matches (P < 0.05), with upper-body measures exhibiting a greater decline (P < 0.05) and remaining below baseline (P < 0.05) until the end of the tournament. Muscle damage markers increased during the course of the tournament with upper limbs affected more. Creatine kinase activity, CRP levels, IL-6 concentration, and leukocyte counts increased (P < 0.05) progressively throughout the tournament, peaking in the last two matches. Cortisol, epinephrine and norepinephrine increased (P < 0.05) after each match, but testosterone declined (P < 0.05) progressively, reaching a nadir before the last match. This inflammatory response was accompanied by a marked increase (p < 0.05) in lipid peroxidation, protein oxidation, and antioxidant status markers indicating the development of oxidative stress. These results suggest that a one-day wrestling tournament may induce significant physiological demands on wrestlers that may adversely affect their performance and inflammatory status especially during the later stages of the tournament.

  20. Age-related changes in intraventricular kinetic energy: a physiological or pathological adaptation?

    PubMed Central

    Wong, James; Chabiniok, Radomir; deVecchi, Adelaide; Dedieu, Nathalie; Sammut, Eva; Schaeffter, Tobias

    2016-01-01

    Aging has important deleterious effects on the cardiovascular system. We sought to compare intraventricular kinetic energy (KE) in healthy subjects of varying ages with subjects with ventricular dysfunction to understand if changes in energetic momentum may predispose individuals to heart failure. Four-dimensional flow MRI was acquired in 35 healthy subjects (age: 1–67 yr) and 10 patients with left ventricular (LV) dysfunction (age: 28–79 yr). Healthy subjects were divided into age quartiles (1st quartile: <16 yr, 2nd quartile: 17–32 yr, 3rd quartile: 33–48 yr, and 4th quartile: 49–64 yr). KE was measured in the LV throughout the cardiac cycle and indexed to ventricular volume. In healthy subjects, two large peaks corresponding to systole and early diastole occurred during the cardiac cycle. A third smaller peak was seen during late diastole in eight adults. Systolic KE (P = 0.182) and ejection fraction (P = 0.921) were preserved through all age groups. Older adults showed a lower early peak diastolic KE compared with children (P < 0.0001) and young adults (P = 0.025). Subjects with LV dysfunction had reduced ejection fraction (P < 0.001) and compared with older healthy adults exhibited a similar early peak diastolic KE (P = 0.142) but with the addition of an elevated KE in diastasis (P = 0.029). In healthy individuals, peak diastolic KE progressively decreases with age, whereas systolic peaks remain constant. Peak diastolic KE in the oldest subjects is comparable to those with LV dysfunction. Unique age-related changes in ventricular diastolic energetics might be physiological or herald subclinical pathology. PMID:26747496

  1. Physiological Adaptations and Countermeasures Associated with Long-Duration Space Flights

    NASA Technical Reports Server (NTRS)

    Tipton, C. M.; Hargens, A. R.; Baldwin, K. M.; Schneider, V.; Convertino, V. A.; Kozlovskaya, I.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    On earth, the presence of gravity imposes weight-bearing gradients on tissues which influence the functions of multiple integrative systems. On the other hand, conditions of actual or simulated microgravity can modify and/or nullify these gradients and subsequently alter structure and function. The purpose of this symposium is to discuss the results from short-term Shuttle flights, long term Skylab or Mir missions, or long-term ground based experiments which indicate or suggest that performance has been or could be compromised in space missions of long durations (>one year) or with space tasks (e.g. building space stations) with the goal of identifying countermeasures that could minimize or eliminate the expected anatomical and physiological consequences. After an overview by C. Tipton from the U. Arizona, the countermeasures necessary for the fluid shifts and select functions of the cardiovascular system will be discussed by A. Hargens from NASA Ames Research Center. He will be followed by K. Baldwin of the U. California at Irvine who will discuss the countermeasures needed to prevent the changes that alter the structure, function and control of skeletal muscles. Since changes in bone mass with microgravity are a major concern of NASA, V. Schneider from NASA Headquarters will present data and the countermeasures for bone. Although the results are limited, the changes in the endocrine and immune system deserve mentioning and C. Tipton will assume this responsibility. V. Convertino from the Air Force School of Aerospace Medicine has the challenge of discussing the role, importance, and the specificity of exercise as an effective countermeasure while I. Kozlovskaya from Moscow will elaborate on the Russian experiences with past countermeasures and provide a viewpoint on future ones. After the brief (25 min.) presentations, the speakers will assemble as a panel to discuss the issues raised and the concerns of the audience.

  2. Physiological performance of warm-adapted marine ectotherms: Thermal limits of mitochondrial energy transduction efficiency.

    PubMed

    Martinez, Eloy; Hendricks, Eric; Menze, Michael A; Torres, Joseph J

    2016-01-01

    Thermal regimes in aquatic systems have profound implications for the physiology of ectotherms. In particular, the effect of elevated temperatures on mitochondrial energy transduction in tropical and subtropical teleosts may have profound consequences on organismal performance and population viability. Upper and lower whole-organism critical temperatures for teleosts suggest that subtropical and tropical species are not susceptible to the warming trends associated with climate change, but sub-lethal effects on energy transduction efficiency and population dynamics remain unclear. The goal of the present study was to compare the thermal sensitivity of processes associated with mitochondrial energy transduction in liver mitochondria from the striped mojarra (Eugerres plumieri), the whitemouth croaker (Micropogonias furnieri) and the palometa (Trachinotus goodei), to those of the subtropical pinfish (Lagodon rhomboides) and the blue runner (Caranx crysos). Mitochondrial function was assayed at temperatures ranging from 10 to 40°C and results obtained for both tropical and subtropical species showed a reduction in the energy transduction efficiency of the oxidative phosphorylation (OXPHOS) system in most species studied at temperatures below whole-organism critical temperature thresholds. Our results show a loss of coupling between O2 consumption and ATP production before the onset of the critical thermal maxima, indicating that elevated temperature may severely impact the yield of ATP production per carbon unit oxidized. As warming trends are projected for tropical regions, increasing water temperatures in tropical estuaries and coral reefs could impact long-term growth and reproductive performance in tropical organisms, which are already close to their upper thermal limit. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. 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.

  4. Cortical response to psycho-physiological changes in auto-adaptive robot assisted gait training.

    PubMed

    Jelinek, Herbert F; August, Katherine G; Imam, Md Hasan; Khandoker, Ahsan H; Koenig, Alexander; Riener, Robert

    2011-01-01

    Robot-assisted treadmill training improves motor function and walking ability in neurologically impaired patients. However, despite attention having been shown to play a role in training success, psychological responsiveness to task difficulty and motivational levels at task onset have not been measured. Seven healthy subjects participated in a robot-assist treadmill training task. Subjects engaged in a virtual task with varying difficulty levels that was shown to induce a feeling of being bored, excited and over-stressed. The participants' mental engagement was measured using the ECG-based heart rate variability in real time, during gait training as a proxy for EEG and psychological test batteries. Heart rate variability (HRV), which has been shown to reflect cortical engagement for both cognitive and physical tasks, was measured using nonlinear measures obtained from the Poincaré plot. We show that the cortical response to the task measured with HRV varies in relation to the level of mental engagement in response to the difficulty level of the virtual task. From these results we propose that nonlinear measures quantify cortical response / motivational level to robot-assist motor learning tasks and that the adaptation to the task is dependent on the level of motivation.

  5. Genotypic Variation in Growth and Physiological Response to Drought Stress and Re-Watering Reveals the Critical Role of Recovery in Drought Adaptation in Maize Seedlings

    PubMed Central

    Chen, Daoqian; Wang, Shiwen; Cao, Beibei; Cao, Dan; Leng, Guohui; Li, Hongbing; Yin, Lina; Shan, Lun; Deng, Xiping

    2016-01-01

    Non-irrigated crops in temperate climates and irrigated crops in arid climates are subjected to continuous cycles of water stress and re-watering. Thus, fast and efficient recovery from water stress may be among the key determinants of plant drought adaptation. The present study was designed to comparatively analyze the roles of drought resistance and drought recovery in drought adaptation and to investigate the physiological basis of genotypic variation in drought adaptation in maize (Zea mays) seedlings. As the seedlings behavior in growth associate with yield under drought, it could partly reflect the potential of drought adaptability. Growth and physiological responses to progressive drought stress and recovery were observed in seedlings of 10 maize lines. The results showed that drought adaptability is closely related to drought recovery (r = 0.714**), but not to drought resistance (r = 0.332). Drought induced decreases in leaf water content, water potential, osmotic potential, gas exchange parameters, chlorophyll content, Fv/Fm and nitrogen content, and increased H2O2 accumulation and lipid peroxidation. After recovery, most of these physiological parameters rapidly returned to normal levels. The physiological responses varied between lines. Further correlation analysis indicated that the physiological bases of drought resistance and drought recovery are definitely different, and that maintaining higher chlorophyll content (r = 0.874***) and Fv/Fm (r = 0.626*) under drought stress contributes to drought recovery. Our results suggest that both drought resistance and recovery are key determinants of plant drought adaptation, and that drought recovery may play a more important role than previously thought. In addition, leaf water potential, chlorophyll content and Fv/Fm could be used as efficient reference indicators in the selection of drought-adaptive genotypes. PMID:26793218

  6. Genotypic Variation in Growth and Physiological Response to Drought Stress and Re-Watering Reveals the Critical Role of Recovery in Drought Adaptation in Maize Seedlings.

    PubMed

    Chen, Daoqian; Wang, Shiwen; Cao, Beibei; Cao, Dan; Leng, Guohui; Li, Hongbing; Yin, Lina; Shan, Lun; Deng, Xiping

    2015-01-01

    Non-irrigated crops in temperate climates and irrigated crops in arid climates are subjected to continuous cycles of water stress and re-watering. Thus, fast and efficient recovery from water stress may be among the key determinants of plant drought adaptation. The present study was designed to comparatively analyze the roles of drought resistance and drought recovery in drought adaptation and to investigate the physiological basis of genotypic variation in drought adaptation in maize (Zea mays) seedlings. As the seedlings behavior in growth associate with yield under drought, it could partly reflect the potential of drought adaptability. Growth and physiological responses to progressive drought stress and recovery were observed in seedlings of 10 maize lines. The results showed that drought adaptability is closely related to drought recovery (r = 0.714(**)), but not to drought resistance (r = 0.332). Drought induced decreases in leaf water content, water potential, osmotic potential, gas exchange parameters, chlorophyll content, Fv/Fm and nitrogen content, and increased H2O2 accumulation and lipid peroxidation. After recovery, most of these physiological parameters rapidly returned to normal levels. The physiological responses varied between lines. Further correlation analysis indicated that the physiological bases of drought resistance and drought recovery are definitely different, and that maintaining higher chlorophyll content (r = 0.874(***)) and Fv/Fm (r = 0.626(*)) under drought stress contributes to drought recovery. Our results suggest that both drought resistance and recovery are key determinants of plant drought adaptation, and that drought recovery may play a more important role than previously thought. In addition, leaf water potential, chlorophyll content and Fv/Fm could be used as efficient reference indicators in the selection of drought-adaptive genotypes.

  7. 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.

  8. Immuno-physiological adaptations confer wax moth Galleria mellonella resistance to Bacillus thuringiensis

    PubMed Central

    Dubovskiy, Ivan M.; Grizanova, Ekaterina V.; Whitten, Miranda M. A.; Mukherjee, Krishnendu; Greig, Carolyn; Alikina, Tatiana; Kabilov, Marsel; Vilcinskas, Andreas; Glupov, Viktor V.; Butt, Tariq M.

    2016-01-01

    ABSTRACT Microevolutionary mechanisms of resistance to a bacterial pathogen were explored in a population of the Greater wax moth, Galleria mellonella, selected for an 8.8-fold increased resistance against the entomopathogenic bacterium Bacillus thuringiensis (Bt) compared with a non-selected (suspectible) line. Defense strategies of the resistant and susceptible insect lines were compared to uncover mechanisms underpinning resistance, and the possible cost of those survival strategies. In the uninfected state, resistant insects exhibited enhanced basal expression of genes related to regeneration and amelioration of Bt toxin activity in the midgut. In addition, these insects also exhibited elevated activity of genes linked to inflammation/stress management and immune defense in the fat body. Following oral infection with Bt, the expression of these genes was further elevated in the fat body and midgut of both lines and to a greater extent some of them in resistant line than the susceptible line. This gene expression analysis reveals a pattern of resistance mechanisms targeted to sites damaged by Bt with the insect placing greater emphasis on tissue repair as revealed by elevated expression of these genes in both the fat body and midgut epithelium. Unlike the susceptible insects, Bt infection significantly reduced the diversity and richness (abundance) of the gut microbiota in the resistant insects. These observations suggest that the resistant line not only has a more intact midgut but is secreting antimicrobial factors into the gut lumen which not only mitigate Bt activity but also affects the viability of other gut bacteria. Remarkably the resistant line employs multifactorial adaptations for resistance to Bt without any detected negative trade off since the insects exhibited higher fecundity. PMID:27029421

  9. Reproductive impacts and physiological adaptations of zebrafish to elevated dietary nickel.

    PubMed

    Alsop, Derek; Lall, Santosh P; Wood, Chris M

    2014-09-01

    Nickel (Ni) concentrations in the environment can rise due to human industrial activities. The toxicity of waterborne Ni to aquatic animals has been examined in a number of previous studies; however, little is known about the impacts of elevated dietary Ni. In the present study, zebrafish were chronically fed diets containing two concentrations of Ni [3.7 (control) and 116 μg Ni/g diet]. Ni-exposed males, but not females, were significantly smaller (26%) compared to controls at 80 days. In addition, total egg production was decreased by 65% in the Ni treatment at 75-78 days of the experiment. Ni was ubiquitously distributed in control animals (similar to previous studies), and concentrations varied between tissues by 15-fold. Ni exposure resulted in modest but significant Ni accumulation in some tissues (increases were highest in brain, vertebrae and gut; 44%, 34% and 25%, respectively), an effect observed only at 80 days. The limited Ni accumulation may be due to (1) the lack of an acidified stomach in zebrafish and/or (2) the efficient upregulation of Ni transport and excretion mechanisms, as indicated by the 4.5-fold increase in waterborne (63)Ni uptake by Ni-exposed fish. Eggs from Ni-exposed adults had Ni concentrations that were 5.2-fold higher than controls. However, by 4 days post fertilization, larvae had similar Ni concentrations as controls, demonstrating a capacity for rapid Ni depuration. Larvae from Ni-exposed adults were also more resistant to waterborne Ni (35% increase in the 96-h LC50 over controls). In conclusion, elevated dietary Ni significantly affected zebrafish reproduction despite only modest tissue Ni accumulation. There were also indications of adaptation, including increased Ni uptake rates and increased Ni tolerance of offspring from Ni-exposed adults. Ni concentrations were particularly elevated in the brain with exposure; possible relations to growth and reproductive impacts require further study. Copyright © 2014 Elsevier Inc. All

  10. HIF-1-driven skeletal muscle adaptations to chronic hypoxia: molecular insights into muscle physiology.

    PubMed

    Favier, F B; Britto, F A; Freyssenet, D G; Bigard, X A; Benoit, H

    2015-12-01

    Skeletal muscle is a metabolically active tissue and the major body protein reservoir. Drop in ambient oxygen pressure likely results in a decrease in muscle cells oxygenation, reactive oxygen species (ROS) overproduction and stabilization of the oxygen-sensitive hypoxia-inducible factor (HIF)-1α. However, skeletal muscle seems to be quite resistant to hypoxia compared to other organs, probably because it is accustomed to hypoxic episodes during physical exercise. Few studies have observed HIF-1α accumulation in skeletal muscle during ambient hypoxia probably because of its transient stabilization. Nevertheless, skeletal muscle presents adaptations to hypoxia that fit with HIF-1 activation, although the exact contribution of HIF-2, I kappa B kinase and activating transcription factors, all potentially activated by hypoxia, needs to be determined. Metabolic alterations result in the inhibition of fatty acid oxidation, while activation of anaerobic glycolysis is less evident. Hypoxia causes mitochondrial remodeling and enhanced mitophagy that ultimately lead to a decrease in ROS production, and this acclimatization in turn contributes to HIF-1α destabilization. Likewise, hypoxia has structural consequences with muscle fiber atrophy due to mTOR-dependent inhibition of protein synthesis and transient activation of proteolysis. The decrease in muscle fiber area improves oxygen diffusion into muscle cells, while inhibition of protein synthesis, an ATP-consuming process, and reduction in muscle mass decreases energy demand. Amino acids released from muscle cells may also have protective and metabolic effects. Collectively, these results demonstrate that skeletal muscle copes with the energetic challenge imposed by O2 rarefaction via metabolic optimization.

  11. [Genetic burden of psychosomatic diseases and exogenous risk-factors of cardiovascular diseases in healthy students with different physiological and psychological adaptation abilities].

    PubMed

    Tsitsiashvili, Kh Sh; Kavtaradze, G V; Bakradze, N M; Gvenetadze, R N; Makharadze, T G

    2005-03-01

    Exogenous risk factors of cardiovascular diseases and genetic burden of psychosomatic pathologies have been studied in practically healthy students with various physiological and psychological adaptation abilities for differential analysis of the risk for development of cardiological diseases. The complex of genetic burden of psychosomatic pathologies and exogenous risk factors was significantly more frequent in practically healthy students with strong profile of adaptation mechanisms, increased circadian profile, zero type and weak persistence of fixated set.

  12. Rear of REPLACEMENT MODEL single chair from mid station. Tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Rear of REPLACEMENT MODEL single chair from mid station. Tower 13 in background, LOOKing northeast. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

  13. View uphill of single chair lift, tower 15 in foreground, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View uphill of single chair lift, tower 15 in foreground, TOWERS 16 and 17 in the distance, LOOKING SOUTH. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

  14. Experimental investigation of chair type, row spacing, occupants, and carpet on theatre chair absorption.

    PubMed

    Choi, Young-Ji; Bradley, John S; Jeong, Dae-Up

    2015-01-01

    This paper examines how the individual variations of chair type, row spacing, as well as the presence of occupants and carpet, combine to influence the absorption characteristics of theater chairs as a function of sample perimeter-to-area (P/A) ratios. Scale models were used to measure the interactive effects of the four test variables on the chair absorption characteristics, avoiding the practical difficulties of full scale measurements. All of the test variables led to effects that could lead to important changes to auditorium acoustics conditions. At mid and higher frequencies, the various effects can usually be explained as due to, more or less, porous absorbing material. In the 125 and 250 Hz octave bands, the major changes were attributed to resonant absorbing mechanisms. The results indicate that for accurate predictions of the effective absorption of the chairs in an auditorium, one should use the P/A method and reverberation chamber tests of the chair absorption coefficients to predict the absorption coefficients of each block of chairs and use these results as input in a room acoustics computer model of the auditorium. The application of these results to auditorium acoustics design is described, more approximate approaches are considered, and relations to existing methods are discussed.

  15. Explaining bathymetric diversity patterns in marine benthic invertebrates and demersal fishes: physiological contributions to adaptation of life at depth.

    PubMed

    Brown, Alastair; Thatje, Sven

    2014-05-01

    Bathymetric biodiversity patterns of marine benthic invertebrates and demersal fishes have been identified in the extant fauna of the deep continental margins. Depth zonation is widespread and evident through a transition between shelf and slope fauna from the shelf break to 1000 m, and a transition between slope and abyssal fauna from 2000 to 3000 m; these transitions are characterised by high species turnover. A unimodal pattern of diversity with depth peaks between 1000 and 3000 m, despite the relatively low area represented by these depths. Zonation is thought to result from the colonisation of the deep sea by shallow-water organisms following multiple mass extinction events throughout the Phanerozoic. The effects of low temperature and high pressure act across hierarchical levels of biological organisation and appear sufficient to limit the distributions of such shallow-water species. Hydrostatic pressures of bathyal depths have consistently been identified experimentally as the maximum tolerated by shallow-water and upper bathyal benthic invertebrates at in situ temperatures, and adaptation appears required for passage to deeper water in both benthic invertebrates and demersal fishes. Together, this suggests that a hyperbaric and thermal physiological bottleneck at bathyal depths contributes to bathymetric zonation. The peak of the unimodal diversity-depth pattern typically occurs at these depths even though the area represented by these depths is relatively low. Although it is recognised that, over long evolutionary time scales, shallow-water diversity patterns are driven by speciation, little consideration has been given to the potential implications for species distribution patterns with depth. Molecular and morphological evidence indicates that cool bathyal waters are the primary site of adaptive radiation in the deep sea, and we hypothesise that bathymetric variation in speciation rates could drive the unimodal diversity-depth pattern over time. Thermal

  16. Explaining bathymetric diversity patterns in marine benthic invertebrates and demersal fishes: physiological contributions to adaptation of life at depth

    PubMed Central

    Brown, Alastair; Thatje, Sven

    2014-01-01

    Bathymetric biodiversity patterns of marine benthic invertebrates and demersal fishes have been identified in the extant fauna of the deep continental margins. Depth zonation is widespread and evident through a transition between shelf and slope fauna from the shelf break to 1000 m, and a transition between slope and abyssal fauna from 2000 to 3000 m; these transitions are characterised by high species turnover. A unimodal pattern of diversity with depth peaks between 1000 and 3000 m, despite the relatively low area represented by these depths. Zonation is thought to result from the colonisation of the deep sea by shallow-water organisms following multiple mass extinction events throughout the Phanerozoic. The effects of low temperature and high pressure act across hierarchical levels of biological organisation and appear sufficient to limit the distributions of such shallow-water species. Hydrostatic pressures of bathyal depths have consistently been identified experimentally as the maximum tolerated by shallow-water and upper bathyal benthic invertebrates at in situ temperatures, and adaptation appears required for passage to deeper water in both benthic invertebrates and demersal fishes. Together, this suggests that a hyperbaric and thermal physiological bottleneck at bathyal depths contributes to bathymetric zonation. The peak of the unimodal diversity–depth pattern typically occurs at these depths even though the area represented by these depths is relatively low. Although it is recognised that, over long evolutionary time scales, shallow-water diversity patterns are driven by speciation, little consideration has been given to the potential implications for species distribution patterns with depth. Molecular and morphological evidence indicates that cool bathyal waters are the primary site of adaptive radiation in the deep sea, and we hypothesise that bathymetric variation in speciation rates could drive the unimodal diversity–depth pattern over time

  17. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental chair and accessories. 872.6250 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a) Identification. A dental chair and accessories is a device, usually AC-powered, in which a patient sits. The...

  18. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dental chair and accessories. 872.6250 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a) Identification. A dental chair and accessories is a device, usually AC-powered, in which a patient sits. The...

  19. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dental chair and accessories. 872.6250 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a) Identification. A dental chair and accessories is a device, usually AC-powered, in which a patient sits. The...

  20. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dental chair and accessories. 872.6250 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a) Identification. A dental chair and accessories is a device, usually AC-powered, in which a patient sits. The...

  1. Science Instructional Leadership: The Role of the Department Chair

    ERIC Educational Resources Information Center

    Peacock, Jeremy S.

    2014-01-01

    With science teachers facing comprehensive curriculum reform that will shape science education for decades to come, high school department chairs represent a critical resource for instructional leadership and teacher support. While the historical literature on the department chair indicates that chairs are in prime positions to provide…

  2. DRIVE TERMINAL WITH VAULT MOTOR ROOM IN BASEMENT. SINGLE CHAIR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DRIVE TERMINAL WITH VAULT MOTOR ROOM IN BASEMENT. SINGLE CHAIR SKI LIFT (1947) ON LEFT, DOUBLE CHAIR SKI LIFT (1962) ON RIGHT. LOOKING SOUTHWEST WITH GENERAL STARK MOUNTAIN IN THE BACKGROUND. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

  3. Science Instructional Leadership: The Role of the Department Chair

    ERIC Educational Resources Information Center

    Peacock, Jeremy S.

    2014-01-01

    With science teachers facing comprehensive curriculum reform that will shape science education for decades to come, high school department chairs represent a critical resource for instructional leadership and teacher support. While the historical literature on the department chair indicates that chairs are in prime positions to provide…

  4. The effect of a dynamic chair on seated energy expenditure.

    PubMed

    Synnott, Aoife; Dankaerts, Wim; Seghers, Jan; Purtill, Helen; O'Sullivan, Kieran

    2017-10-01

    Dynamic sitting approaches have been advocated to increase seated energy expenditure with the view of lessening the sedentary nature of the task. This study compared energy expenditure (EE) and overall body discomfort on a novel dynamic chair with a standard office chair. Fifteen pain-free participants completed a DVD viewing task on both chairs in a randomised order. Energy expenditure and discomfort were collected simultaneously. Linear mixed models were used to analyse steady-state EE recorded on each of the chairs. Differences in discomfort were analysed using Wilkoxon Signed Rank Tests. Sitting on the novel dynamic chair significantly (p = 0.005) increased energy expenditure compared to a standard office chair. The discomfort experienced was mild overall, but was significantly greater on the dynamic chair (p = 0.004). Whilst the EE was seen to be significantly higher on the dynamic chair, the MET values are still below 1.5 METS. Thus, the use of a dynamic chair does not seem to be the most effective measure to prevent sedentary behaviour. Practitioner Summary: Sitting on a dynamic chair increased energy expenditure compared to sitting on a standard office chair among pain-free participants. Whilst the EE was seen to be significantly higher on the dynamic chair, the MET values are still below 1.5 METS (low level EE).

  5. 21 CFR 872.6250 - Dental chair and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental chair and accessories. 872.6250 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6250 Dental chair and accessories. (a) Identification. A dental chair and accessories is a device, usually AC-powered, in which a patient sits. The...

  6. 7 CFR 1900.6 - Chair, Loan Resolution Task Force.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false Chair, Loan Resolution Task Force. 1900.6 Section... AGRICULTURE PROGRAM REGULATIONS GENERAL Delegations of Authority § 1900.6 Chair, Loan Resolution Task Force. The Chair, Loan Resolution Task Force is delegated the following authorities, to be exercised until...

  7. 21 CFR 880.6140 - Medical chair and table.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Medical chair and table. 880.6140 Section 880.6140...) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Miscellaneous Devices § 880.6140 Medical chair and table. (a) Identification. A medical chair or table is a device...

  8. Preliminary results from digestive adaptation: a new surgical proposal for treating obesity, based on physiology and evolution.

    PubMed

    Santoro, Sérgio; Velhote, Manoel Carlos Prieto; Malzoni, Carlos Eduardo; Milleo, Fábio Quirino; Klajner, Sidney; Campos, Fábio Guilherme

    2006-07-06

    Most bariatric surgical techniques include essentially non-physiological features like narrowing anastomoses or bands, or digestive segment exclusion, especially the duodenum. This potentially causes symptoms or complications. The aim here was to report on the preliminary results from a new surgical technique for treating morbid obesity that takes a physiological and evolutionary approach. Case series description, in Hospital Israelita Albert Einstein and Hospital da Polícia Militar, São Paulo, and Hospital Vicentino, Ponta Grossa, Paraná. The technique included vertical (sleeve) gastrectomy, omentectomy and enterectomy that retained three meters of small bowel (initial jejunum and most of the ileum), i.e. the lower limit for normal adults. The operations on 100 patients are described. The mean follow-up was nine months (range: one to 29 months). The mean reductions in body mass index were 4.3, 6.1, 8.1, 10.1 and 10.7 kg/m2, respectively at 1, 2, 4, 6 and 12 months. All patients reported early satiety. There was major improvement in comorbidities, especially diabetes. Operative complications occurred in 7% of patients, all of them resolved without sequelae. There was no mortality. This procedure creates a proportionally reduced gastrointestinal tract, leaving its basic functions unharmed and producing adaptation of the gastric chamber size to hypercaloric diet. It removes the sources of ghrelin, plasminogen activator inhibitor-1 (PAI-1) and resistin production and leads more nutrients to the distal bowel, with desirable metabolic consequences. Patients do not need nutritional support or drug medication. The procedure is straightforward and safe.

  9. Simulating Physiological Response with a Passive Sensor Manikin and an Adaptive Thermal Manikin to Predict Thermal Sensation and Comfort

    SciTech Connect

    Rugh, John P; Chaney, Larry; Hepokoski, Mark; Curran, Allen; Burke, Richard; Maranville, Clay

    2015-04-14

    Reliable assessment of occupant thermal comfort can be difficult to obtain within automotive environments, especially under transient and asymmetric heating and cooling scenarios. Evaluation of HVAC system performance in terms of comfort commonly requires human subject testing, which may involve multiple repetitions, as well as multiple test subjects. Instrumentation (typically comprised of an array of temperature sensors) is usually only sparsely applied across the human body, significantly reducing the spatial resolution of available test data. Further, since comfort is highly subjective in nature, a single test protocol can yield a wide variation in results which can only be overcome by increasing the number of test replications and subjects. In light of these difficulties, various types of manikins are finding use in automotive testing scenarios. These manikins can act as human surrogates from which local skin and core temperatures can be obtained, which are necessary for accurately predicting local and whole body thermal sensation and comfort using a physiology-based comfort model (e.g., the Berkeley Comfort Model). This paper evaluates two different types of manikins, i) an adaptive sweating thermal manikin, which is coupled with a human thermoregulation model, running in real-time, to obtain realistic skin temperatures; and, ii) a passive sensor manikin, which is used to measure boundary conditions as they would act on a human, from which skin and core temperatures can be predicted using a thermophysiological model. The simulated physiological responses and comfort obtained from both of these manikin-model coupling schemes are compared to those of a human subject within a vehicle cabin compartment transient heat-up scenario.

  10. Physiological and health-related adaptations to low-volume interval training: influences of nutrition and sex.

    PubMed

    Gibala, Martin J; Gillen, Jenna B; Percival, Michael E

    2014-11-01

    Interval training refers to the basic concept of alternating periods of relatively intense exercise with periods of lower-intensity effort or complete rest for recovery. Low-volume interval training refers to sessions that involve a relatively small total amount of exercise (i.e. ≤10 min of intense exercise), compared with traditional moderate-intensity continuous training (MICT) protocols that are generally reflected in public health guidelines. In an effort to standardize terminology, a classification scheme was recently proposed in which the term 'high-intensity interval training' (HIIT) be used to describe protocols in which the training stimulus is 'near maximal' or the target intensity is between 80 and 100 % of maximal heart rate, and 'sprint interval training' (SIT) be used for protocols that involve 'all out' or 'supramaximal' efforts, in which target intensities correspond to workloads greater than what is required to elicit 100 % of maximal oxygen uptake (VO2max). Both low-volume SIT and HIIT constitute relatively time-efficient training strategies to rapidly enhance the capacity for aerobic energy metabolism and elicit physiological remodeling that resembles changes normally associated with high-volume MICT. Short-term SIT and HIIT protocols have also been shown to improve health-related indices, including cardiorespiratory fitness and markers of glycemic control in both healthy individuals and those at risk for, or afflicted by, cardiometabolic diseases. Recent evidence from a limited number of studies has highlighted potential sex-based differences in the adaptive response to SIT in particular. It has also been suggested that specific nutritional interventions, in particular those that can augment muscle buffering capacity, such as sodium bicarbonate, may enhance the adaptive response to low-volume interval training.

  11. Physiological Adaptations Involved in Alkane Assimilation at a Low Temperature by Rhodococcus sp. Strain Q15†

    PubMed Central

    Whyte, L. G.; Slagman, S. J.; Pietrantonio, F.; Bourbonnière, L.; Koval, S. F.; Lawrence, J. R.; Inniss, W. E.; Greer, C. W.

    1999-01-01

    We examined physiological adaptations which allow the psychrotroph Rhodococcus sp. strain Q15 to assimilate alkanes at a low temperature (alkanes are contaminants which are generally insoluble and/or solid at low temperatures). During growth at 5°C on hexadecane or diesel fuel, strain Q15 produced a cell surface-associated biosurfactant(s) and, compared to glucose-acetate-grown cells, exhibited increased cell surface hydrophobicity. A transmission electron microscopy examination of strain Q15 grown at 5°C revealed the presence of intracellular electron-transparent inclusions and flocs of cells connected by an extracellular polymeric substance (EPS) when cells were grown on a hydrocarbon and morphological differences between the EPS of glucose-acetate-grown and diesel fuel-grown cells. A lectin binding analysis performed by using confocal scanning laser microscopy (CSLM) showed that the EPS contained a complex mixture of glycoconjugates, depending on both the growth temperature and the carbon source. Two glycoconjugates [β-d-Gal-(1-3)-d-GlcNAc and α-l-fucose] were detected only on the surfaces of cells grown on diesel fuel at 5°C. Using scanning electron microscopy, we observed strain Q15 cells on the surfaces of octacosane crystals, and using CSLM, we observed strain Q15 cells covering the surfaces of diesel fuel microdroplets; these findings indicate that this organism assimilates both solid and liquid alkane substrates at a low temperature by adhering to the alkane phase. Membrane fatty acid analysis demonstrated that strain Q15 adapted to growth at a low temperature by decreasing the degree of saturation of membrane lipid fatty acids, but it did so to a lesser extent when it was grown on hydrocarbons at 5°C; these findings suggest that strain Q15 modulates membrane fluidity in response to the counteracting influences of low temperature and hydrocarbon toxicity. PMID:10388690

  12. Samuel P. Massie Chair of Excellence Program

    SciTech Connect

    Johnson, James H.

    2014-12-01

    Abstract In 1994 the Department of Energy established the DOE Chair of Excellence Professorship in Environmental Disciplines Program. In 2004, the Massie Chair of Excellence Professor at Howard University transitioned from Dr. Edward Martin to Dr. James H. Johnson, Jr. At the time of his appointment Dr. Johnson served as professor of civil engineering and Dean of the College of Engineering, Architecture and Computer Sciences. Program activities under Dr. Johnson were in the following areas: • Increase the institution’s capacity to conduct scientific research and technical investigations at the cutting-edge. • Promote interactions, collaborations and partnerships between the private sector, Federal agencies, majority research institutes and other HBCUs. • Assist other HBCUs in reaching parity in engineering and related fields. • Mentor young investigators and be a role model for students.

  13. Space Grant Research Launches Rehabilitation Chair

    NASA Technical Reports Server (NTRS)

    2015-01-01

    Working with funding from the National Space Grant College and Fellowship Program-which was implemented by NASA Headquarters to fund research, education, and public service projects-a biomedical engineering student created a vibration-based system that could combat bone loss from prolonged trips to space. A rehabilitation chair incorporating the technology is now sold by Sheboygan, Wisconsin-based VibeTech Inc. and is helping people recover more quickly from injuries and surgery.

  14. Bach1 differentially regulates distinct Nrf2-dependent genes in human venous and coronary artery endothelial cells adapted to physiological oxygen levels.

    PubMed

    Chapple, Sarah J; Keeley, Thomas P; Mastronicola, Daniela; Arno, Matthew; Vizcay-Barrena, Gema; Fleck, Roland; Siow, Richard C M; Mann, Giovanni E

    2016-03-01

    The effects of physiological oxygen tension on Nuclear Factor-E2-Related Factor 2 (Nrf2)-regulated redox signaling remain poorly understood. We report the first study of Nrf2-regulated signaling in human primary endothelial cells (EC) adapted long-term to physiological O2 (5%). Adaptation of EC to 5% O2 had minimal effects on cell ultrastructure, viability, basal redox status or HIF1-α expression. Affymetrix array profiling and subsequent qPCR/protein validation revealed that induction of select Nrf2 target genes, HO-1 and NQO1, was significantly attenuated in cells adapted to 5% O2, despite nuclear accumulation and DNA binding of Nrf2. Diminished HO-1 induction under 5% O2 was stimulus independent and reversible upon re-adaptation to air or silencing of the Nrf2 repressor Bach1, notably elevated under 5% O2. Induction of GSH-related genes xCT and GCLM were oxygen and Bach1-insensitive during long-term culture under 5% O2, providing the first evidence that genes related to GSH synthesis mediate protection afforded by Nrf2-Keap1 defense pathway in cells adapted to physiological O2 levels encountered in vivo. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. 77 FR 18242 - Environmental Management Site-Specific Advisory Board Chairs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ... Update Recognition of Departing Chairs EM SSAB Chairs' Round Robin: Chairs' Site Reports EM Headquarters Budget Update EM Headquarters Waste Disposition Update EM SSAB Chairs' Round Robin: Cross-Complex...

  16. "Rocking-Chair"-Type Metal Hybrid Supercapacitors.

    PubMed

    Yoo, Hyun Deog; Han, Sang-Don; Bayliss, Ryan D; Gewirth, Andrew A; Genorio, Bostjan; Rajput, Nav Nidhi; Persson, Kristin A; Burrell, Anthony K; Cabana, Jordi

    2016-11-16

    Hybrid supercapacitors that follow a "rocking-chair"-type mechanism were developed by coupling divalent metal and activated carbon electrodes in nonaqueous electrolytes. Conventional supercapacitors require a large amount of electrolyte to provide a sufficient quantity of ions to the electrodes, due to their Daniell-type mechanism that depletes the ions from the electrolyte while charging. The alternative "rocking-chair"-type mechanism effectively enhances the energy density of supercapacitors by minimizing the necessary amount of electrolyte, because the ion is replenished from the metal anode while it is adsorbed to the cathode. Newly developed nonaqueous electrolytes for Mg and Zn electrochemistry, based on bis(trifluoromethylsulfonyl)imide (TFSI) salts, made the metal hybrid supercapacitors possible by enabling reversible deposition on the metal anodes and reversible adsorption on an activated carbon cathode. Factoring in gains through the cell design, the energy density of the metal hybrid supercapacitors is projected to be a factor of 7 higher than conventional devices thanks to both the "rocking-chair"-type mechanism that minimizes total electrolyte volume and the use of metal anodes, which have substantial merits in capacity and voltage. Self-discharge was also substantially alleviated compared to conventional supercapacitors. This concept offers a route to build supercapacitors that meet dual criteria of power and energy densities with a simple cell design.

  17. Intraspecific variation in stomatal traits, leaf traits and physiology reflects adaptation along aridity gradients in a South African shrub

    PubMed Central

    Carlson, Jane E.; Adams, Christopher A.; Holsinger, Kent E.

    2016-01-01

    Background and Aims Trait–environment relationships are commonly interpreted as evidence for local adaptation in plants. However, even when selection analyses support this interpretation, the mechanisms underlying differential benefits are often unknown. This study addresses this gap in knowledge using the broadly distributed South African shrub Protea repens. Specifically, the study examines whether broad-scale patterns of trait variation are consistent with spatial differences in selection and ecophysiology in the wild. Methods In a common garden study of plants sourced from 19 populations, associations were measured between five morphological traits and three axes describing source climates. Trait–trait and trait–environment associations were analysed in a multi-response model. Within two focal populations in the wild, selection and path analyses were used to test associations between traits, fecundity and physiological performance. Key Results Across 19 populations in a common garden, stomatal density increased with the source population’s mean annual temperature and decreased with its average amount of rainfall in midsummer. Concordantly, selection analysis in two natural populations revealed positive selection on stomatal density at the hotter, drier site, while failing to detect selection at the cooler, moister site. Dry-site plants with high stomatal density also had higher stomatal conductances, cooler leaf temperatures and higher light-saturated photosynthetic rates than those with low stomatal density, but no such relationships were present among wet-site plants. Leaf area, stomatal pore index and specific leaf area in the garden also co-varied with climate, but within-population differences were not associated with fitness in either wild population. Conclusions The parallel patterns of broad-scale variation, differences in selection and differences in trait–ecophysiology relationships suggest a mechanism for adaptive differentiation in

  18. Intraspecific variation in stomatal traits, leaf traits and physiology reflects adaptation along aridity gradients in a South African shrub.

    PubMed

    Carlson, Jane E; Adams, Christopher A; Holsinger, Kent E

    2016-01-01

    Trait-environment relationships are commonly interpreted as evidence for local adaptation in plants. However, even when selection analyses support this interpretation, the mechanisms underlying differential benefits are often unknown. This study addresses this gap in knowledge using the broadly distributed South African shrub Protea repens. Specifically, the study examines whether broad-scale patterns of trait variation are consistent with spatial differences in selection and ecophysiology in the wild. In a common garden study of plants sourced from 19 populations, associations were measured between five morphological traits and three axes describing source climates. Trait-trait and trait-environment associations were analysed in a multi-response model. Within two focal populations in the wild, selection and path analyses were used to test associations between traits, fecundity and physiological performance. Across 19 populations in a common garden, stomatal density increased with the source population's mean annual temperature and decreased with its average amount of rainfall in midsummer. Concordantly, selection analysis in two natural populations revealed positive selection on stomatal density at the hotter, drier site, while failing to detect selection at the cooler, moister site. Dry-site plants with high stomatal density also had higher stomatal conductances, cooler leaf temperatures and higher light-saturated photosynthetic rates than those with low stomatal density, but no such relationships were present among wet-site plants. Leaf area, stomatal pore index and specific leaf area in the garden also co-varied with climate, but within-population differences were not associated with fitness in either wild population. The parallel patterns of broad-scale variation, differences in selection and differences in trait-ecophysiology relationships suggest a mechanism for adaptive differentiation in stomatal density. Densely packed stomata may improve performance by

  19. Rhodobacteraceae on the marine brown alga Fucus spiralis are abundant and show physiological adaptation to an epiphytic lifestyle.

    PubMed

    Dogs, Marco; Wemheuer, Bernd; Wolter, Laura; Bergen, Nils; Daniel, Rolf; Simon, Meinhard; Brinkhoff, Thorsten

    2017-09-01

    Macroalgae harbour specific microbial communities on their surface that have functions related to host health and defence. In this study, the bacterial biofilm of the marine brown alga Fucus spiralis was investigated using 16S rRNA gene amplicon-based analysis and isolation of bacteria. Rhodobacteraceae (Alphaproteobacteria) were the predominant family constituting 23% of the epibacterial community. At the genus level, Sulfitobacter, Loktanella, Octadecabacter and a previously undescribed cluster were most abundant, and together they comprised 89% of the Rhodobacteraceae. Supported by a specific PCR approach, 23 different Rhodobacteraceae-affiliated strains were isolated from the surface of F. spiralis, which belonged to 12 established and three new genera. For seven strains, closely related sequences were detected in the 16S rRNA gene dataset. Growth experiments with substrates known to be produced by Fucus spp. showed that all of them were consumed by at least three strains, and vitamin B12 was produced by 70% of the isolates. Since growth of F. spiralis depends on B12 supplementation, bacteria may provide the alga with this vitamin. Most strains produced siderophores, which can enhance algal growth under iron-deficient conditions. Inhibiting properties against other bacteria were only observed when F. spiralis material was present in the medium. Thus, the physiological properties of the isolates indicated adaption to an epiphytic lifestyle. Copyright © 2017 Elsevier GmbH. All rights reserved.

  20. Variations in the non-coding transcriptome as a driver of inter-strain divergence and physiological adaptation in bacteria

    PubMed Central

    Kopf, Matthias; Klähn, Stephan; Scholz, Ingeborg; Hess, Wolfgang R.; Voß, Björn

    2015-01-01

    In all studied organisms, a substantial portion of the transcriptome consists of non-coding RNAs that frequently execute regulatory functions. Here, we have compared the primary transcriptomes of the cyanobacteria Synechocystis sp. PCC 6714 and PCC 6803 under 10 different conditions. These strains share 2854 protein-coding genes and a 16S rRNA identity of 99.4%, indicating their close relatedness. Conserved major transcriptional start sites (TSSs) give rise to non-coding transcripts within the sigB gene, from the 5′UTRs of cmpA and isiA, and 168 loci in antisense orientation. Distinct differences include single nucleotide polymorphisms rendering promoters inactive in one of the strains, e.g., for cmpR and for the asRNA PsbA2R. Based on the genome-wide mapped location, regulation and classification of TSSs, non-coding transcripts were identified as the most dynamic component of the transcriptome. We identified a class of mRNAs that originate by read-through from an sRNA that accumulates as a discrete and abundant transcript while also serving as the 5′UTR. Such an sRNA/mRNA structure, which we name ‘actuaton’, represents another way for bacteria to remodel their transcriptional network. Our findings support the hypothesis that variations in the non-coding transcriptome constitute a major evolutionary element of inter-strain divergence and capability for physiological adaptation. PMID:25902393

  1. Mimicking exercise in three-dimensional bioengineered skeletal muscle to investigate cellular and molecular mechanisms of physiological adaptation.

    PubMed

    Kasper, Andreas M; Turner, Daniel C; Martin, Neil R W; Sharples, Adam P

    2017-02-03

    Bioengineering of skeletal muscle in vitro in order to produce highly aligned myofibres in relevant three dimensional (3D) matrices have allowed scientists to model the in vivo skeletal muscle niche. This review discusses essential experimental considerations for developing bioengineered muscle in order to investigate exercise mimicking stimuli. We identify current knowledge for the use of electrical stimulation and co-culture with motor neurons to enhance skeletal muscle maturation and contractile function in bioengineered systems in vitro. Importantly, we provide a current opinion on the use of acute and chronic exercise mimicking stimuli (electrical stimulation and mechanical overload) and the subsequent mechanisms underlying physiological adaptation in 3D bioengineered muscle. We also identify that future studies using the latest bioreactor technology, providing simultaneous electrical and mechanical loading and flow perfusion in vitro, may provide the basis for advancing knowledge in the future. We also envisage, that more studies using genetic, pharmacological, and hormonal modifications applied in human 3D bioengineered skeletal muscle may allow for an enhanced discovery of the in-depth mechanisms underlying the response to exercise in relevant human testing systems. Finally, 3D bioengineered skeletal muscle may provide an opportunity to be used as a pre-clinical in vitro test-bed to investigate the mechanisms underlying catabolic disease, while modelling disease itself via the use of cells derived from human patients without exposing animals or humans (in phase I trials) to the side effects of potential therapies. © 2017 Wiley Periodicals, Inc.

  2. The interruption of thyroid and interrenal and the inter-hormonal interference in fish: does it promote physiologic adaptation or maladaptation?

    PubMed

    Peter, Valsa S; Peter, M C Subhash

    2011-12-01

    Endocrines, the chief components of chemical centers which produce hormones in tune with intrinsic and extrinsic clues, create a chemical bridge between the organism and the environment. In fishes also hormones integrate and modulate many physiologic functions and its synthesis, release, biological actions and metabolic clearance are well regulated. Consequently, thyroid hormones (THs) and cortisol, the products of thyroid and interrenal axes, have been identified for their common integrative actions on metabolic and osmotic functions in fish. On the other hand, many anthropogenic chemical substances, popularly known as endocrine disrupting chemicals, have been shown to disrupt the hormone-receptor signaling pathways in a number fish species. These chemicals which are known for their ability to induce endocrine disruption particularly on thyroid and interrenals can cause malfunction or maladaptation of many vital processes which are involved in the development, growth and reproduction in fish. On the contrary, evidence is presented that the endocrine interrupting agents (EIAs) can cause interruption of thyroid and interrenals, resulting in physiologic compensatory mechanisms which can be adaptive, though such hormonal interactions are less recognized in fishes. The EIAs of physical, chemical and biological origins can specifically interrupt and modify the hormonal interactions between THs and cortisol, resulting in specific patterns of inter-hormonal interference. The physiologic analysis of these inter-hormonal interruptions during acclimation and post-acclimation to intrinsic or extrinsic EIAs reveals that combinations of anti-hormonal, pro-hormonal or stati-hormonal interference may help the fish to fine-tune their metabolic and osmotic performances as part of physiologic adaptation. This novel hypothesis on the phenomenon of inter-hormonal interference and its consequent physiologic interference during thyroid and interrenal interruption thus forms the basis of

  3. Multi-adjustable chairs for children with disabilities.

    PubMed

    Pain, H; Pascoe, J; Gore, S; McLellan, D L

    1996-01-01

    There is a growing demand that severely disabled children should be offered a normal-looking, comfortable alternative to highly supportive wheelchair seating to facilitate relaxation and social integration. An evaluation of five chairs, funded by Medical Devices Agency, an executive agency of the Department of Health, was undertaken with potential and actual users of these chairs to investigate the chairs' function with respect to the child's posture, and what features were effective. Twenty-nine children tried five chairs for up to 30 min in each; and a postal survey received 100 responses. The chairs seem to meet many users' postural needs (78% of postal survey; 31-72% of short-term evaluation depending on chair); the chairs' adjustability and availability of special features are important in meeting the needs of this user group; evidence of poor design and its implications are discussed.

  4. Space Physiology within an Exercise Physiology Curriculum

    ERIC Educational Resources Information Center

    Carter, Jason R.; West, John B.

    2013-01-01

    Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of…

  5. Space Physiology within an Exercise Physiology Curriculum

    ERIC Educational Resources Information Center

    Carter, Jason R.; West, John B.

    2013-01-01

    Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of…

  6. Leap of faith: voluntary emersion behaviour and physiological adaptations to aerial exposure in a non-aestivating freshwater fish in response to aquatic hypoxia.

    PubMed

    Urbina, Mauricio A; Forster, Malcolm E; Glover, Chris N

    2011-05-03

    Lowland stream fauna in areas of intensive agriculture are increasingly under threat from anthropogenic activities leading to eutrophication and subsequent hypoxia. Survival of hypoxic episodes depends upon a combination of behavioural and physiological adaptations. Responses of inanga (Galaxias maculatus: Galaxiidae) to aquatic hypoxia were investigated in the laboratory. Contrary to expectation inanga did not display behaviour that might reduce energy expenditure during oxygen limitation, with swimming activity slightly, but significantly elevated relative to normoxia. Instead, as dissolved oxygen concentrations decreased, the fish moved higher in the water column, increased their swimming speed and exhibited aquatic surface respiration. Physiological changes such as enhanced opercular frequency were also noted. As hypoxia deepened inanga started to leap out of the water, emersing themselves on a floating platform. Once emersed, fish exhibited an enhanced oxygen consumption rate compared to hypoxic fish. Thus inanga appear better adapted to escape hypoxia (a behavioural adaptation) rather than tolerate it (physiological adaptation). The emersion strategy used for inanga in response to severe hypoxia is in agreement with their ability to take up more oxygen from the air than from hypoxic water and therefore may justify the potentially increased risks of desiccation and predation associated with leaving the water. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Physiological adaptation after a 12-week physical activity program for patients with Prader-Willi syndrome: two case reports.

    PubMed

    Amaro, Alexandre Slowetzky; Teixeira, Maria Cristina Triguero Veloz; de Mesquita, Maria Luiza Guedes; Rodrigues, Graciele Massoli; Rubin, Daniela Andrea; Carreiro, Luiz Renato Rodrigues

    2016-06-23

    Physical activity programs are a powerful tool against several diseases including obesity and their comorbidities. Prader-Willi syndrome is the most common genetic disease associated with obesity, and brings with it behavioral and emotional problems that need complex management. Research into the effect of physical activity programs on Prader-Willi syndrome is limited and it is frequently argued that if a physical activity program is too complex, the participants are more likely to drop out. Therefore, in this study, we assessed the physiological adaptation effect of a physical activity program with increasing complexity and load, in a boy and a girl with Prader-Willi syndrome by assessing changes in lipid profile, body composition, and physical fitness parameters. Case 1 was an 11-year-old girl, mixed race (brown), with an intelligence quotient of 68, 52.0 % body fat, and a body mass index of 45.3 kg/m(2). The Prader-Willi syndrome diagnosis was made when she was 5-years old and was found to be due to an imprinting genomic defect. Case 2 was a 14-year-old boy, mixed race (brown), with an intelligence quotient of 74, 48.8 % body fat, and a body mass index of 37.3 kg/m(2). The diagnosis was made when he was 10-years old and was found to be caused by gene deletion. Both participants presented physical characteristics and behavior problems typical of Prader-Willi syndrome. Case 2 presented high blood pressure, high cholesterol and sleep apnea and had to use continuous positive airway pressure to sleep. Both participants were assessed for 12 weeks (three times a week) using a physical activity program designed to improve strength and muscle hypertrophy. The work load was progressively adjusted as necessary and new exercises were added to the program. Prior to the program, the participants' parents received instructions about managing problem behavior and advice about nutrition. After physical activity program several health markers assessed by biological tests and

  8. Evaluation of a prototype multi-posture office chair.

    PubMed

    Legg, S J; Mackie, H W; Milicich, W

    2002-02-10

    Office chairs have often been designed to promote a single 'correct' rather rigid and upright posture, yet it is acknowledged that allowing changes in posture is good ergonomics practice. The present study investigated office worker's preferences for a standard shaped typist's chair (ST) and a prototype multi-posture (PMP) office chair designed to allow its users a variety of sitting positions. Forty-two (22 male and 20 female) telesales personnel (12), clerical staff (12) and researchers (18) used ST or PMP in their workplace for the first week of a 2-week study (with an even number in each work area). The PMP chair was introduced to participants with a brief lecture on how to use it and with an information booklet. Following this, each participant completed a chair comfort questionnaire. In the second week, participants swapped chairs and again completed the chair comfort questionnaire. At the end of the second week participants were also asked to complete a separate questionnaire about the usability of the information booklet that accompanied the PMP chair. Statistically significant differences in subject's rating of the two chairs were observed in 7 out of 19 questions. On a 100 mm scale, the ST chair was rated as having a greater mean overall acceptability, desirability and suitability for body build than the PMP chair. Participants also claimed to achieve better posture in the ST chair, that they tipped forward less and were more satisfied with its width. Although the participants generally preferred the ST chair, the PMP chair received more favourable ratings among the researchers who were quite mobile in their work, and in whom there was a trend for less neck, shoulder and upper back discomfort. More participants reported an overall preference for the PMP chair. The findings suggest that a more aesthetically acceptable PMP chair should be developed, peoples' reasons for preferring a more traditionally designed chair should be explored, and that the effect

  9. Adaptation of the Hydrocarbonoclastic Bacterium Alcanivorax borkumensis SK2 to Alkanes and Toxic Organic Compounds: a Physiological and Transcriptomic Approach

    PubMed Central

    Naether, Daniela J.; Slawtschew, Slavtscho; Stasik, Sebastian; Engel, Maria; Olzog, Martin; Wick, Lukas Y.; Timmis, Kenneth N.

    2013-01-01

    The marine hydrocarbonoclastic bacterium Alcanivorax borkumensis is able to degrade mixtures of n-alkanes as they occur in marine oil spills. However, investigations of growth behavior and physiology of these bacteria when cultivated with n-alkanes of different chain lengths (C6 to C30) as the substrates are still lacking. Growth rates increased with increasing alkane chain length up to a maximum between C12 and C19, with no evident difference between even- and odd-numbered chain lengths, before decreasing with chain lengths greater than C19. Surface hydrophobicity of alkane-grown cells, assessed by determination of the water contact angles, showed a similar pattern, with maximum values associated with growth rates on alkanes with chain lengths between C11 and C19 and significantly lower values for cells grown on pyruvate. A. borkumensis was found to incorporate and modify the fatty acid intermediates generated by the corresponding n-alkane degradation pathway. Cells grown on distinct n-alkanes proved that A. borkumensis is able to not only incorporate but also modify fatty acid intermediates derived from the alkane degradation pathway. Comparing cells grown on pyruvate with those cultivated on hexadecane in terms of their tolerance toward two groups of toxic organic compounds, chlorophenols and alkanols, representing intensely studied organic compounds, revealed similar tolerances toward chlorophenols, whereas the toxicities of different n-alkanols were significantly reduced when hexadecane was used as a carbon source. As one adaptive mechanism of A. borkumensis to these toxic organic solvents, the activity of cis-trans isomerization of unsaturated fatty acids was proven. These findings could be verified by a detailed transcriptomic comparison between cultures grown on hexadecane and pyruvate and including solvent stress caused by the addition of 1-octanol as the most toxic intermediate of n-alkane degradation. PMID:23645199

  10. Adaptation of the hydrocarbonoclastic bacterium Alcanivorax borkumensis SK2 to alkanes and toxic organic compounds: a physiological and transcriptomic approach.

    PubMed

    Naether, Daniela J; Slawtschew, Slavtscho; Stasik, Sebastian; Engel, Maria; Olzog, Martin; Wick, Lukas Y; Timmis, Kenneth N; Heipieper, Hermann J

    2013-07-01

    The marine hydrocarbonoclastic bacterium Alcanivorax borkumensis is able to degrade mixtures of n-alkanes as they occur in marine oil spills. However, investigations of growth behavior and physiology of these bacteria when cultivated with n-alkanes of different chain lengths (C6 to C30) as the substrates are still lacking. Growth rates increased with increasing alkane chain length up to a maximum between C12 and C19, with no evident difference between even- and odd-numbered chain lengths, before decreasing with chain lengths greater than C19. Surface hydrophobicity of alkane-grown cells, assessed by determination of the water contact angles, showed a similar pattern, with maximum values associated with growth rates on alkanes with chain lengths between C11 and C19 and significantly lower values for cells grown on pyruvate. A. borkumensis was found to incorporate and modify the fatty acid intermediates generated by the corresponding n-alkane degradation pathway. Cells grown on distinct n-alkanes proved that A. borkumensis is able to not only incorporate but also modify fatty acid intermediates derived from the alkane degradation pathway. Comparing cells grown on pyruvate with those cultivated on hexadecane in terms of their tolerance toward two groups of toxic organic compounds, chlorophenols and alkanols, representing intensely studied organic compounds, revealed similar tolerances toward chlorophenols, whereas the toxicities of different n-alkanols were significantly reduced when hexadecane was used as a carbon source. As one adaptive mechanism of A. borkumensis to these toxic organic solvents, the activity of cis-trans isomerization of unsaturated fatty acids was proven. These findings could be verified by a detailed transcriptomic comparison between cultures grown on hexadecane and pyruvate and including solvent stress caused by the addition of 1-octanol as the most toxic intermediate of n-alkane degradation.

  11. Physiological basis for high CO2 tolerance in marine ectothermic animals: pre-adaptation through lifestyle and ontogeny?

    NASA Astrophysics Data System (ADS)

    Melzner, F.; Gutowska, M. A.; Langenbuch, M.; Dupont, S.; Lucassen, M.; Thorndyke, M. C.; Bleich, M.; Pörtner, H.-O.

    2009-10-01

    pH disturbances during exposure to elevated environmental pCO2. Compensation of extracellular acid-base status in turn may be important in avoiding metabolic depression. So far, maintained "performance" at higher seawater pCO2 (>0.3 to 0.6 kPa) has only been observed in adults/juveniles of active, high metabolic species with a powerful ion regulatory apparatus. However, while some of these taxa are adapted to cope with elevated pCO2 during their regular embryonic development, gametes, zygotes and early embryonic stages, which lack specialized ion-regulatory epithelia, may be the true bottleneck for ecological success - even of the more tolerant taxa. Our current understanding of which marine animal taxa will be affected adversely in their physiological and ecological fitness by projected scenarios of anthropogenic ocean acidification is quite incomplete. While a growing amount of empirical evidence from CO2 perturbation experiments suggests that several taxa might react quite sensitively to ocean acidification, others seem to be surprisingly tolerant. However, there is little mechanistic understanding on what physiological traits are responsible for the observed differential sensitivities (see reviews of Seibel and Walsh, 2003; Pörtner et al., 2004; Fabry et al., 2008; Pörtner, 2008). This leads us to the first very basic question of how to define general CO2 tolerance on the species level.

  12. Body Mass Measurement Chair - Experiment M172

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Skylab's Body Mass Measurement chair, the facility of the Body Mass Measurement experiment (M172), is shown here in this 1970 photograph. The M172 experiment determined the body mass of each crew member and observed changes in body masses during flight. Knowledge of exact body mass variations throughout the flight in significantly aided in the correlation of other medical data obtained during the flight. Mass measurements under zero-gravity conditions were achieved by the application of Newton's second law (force equals mass times acceleration). The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.

  13. Body Mass Measurement Chair - Experiment M172

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Skylab's Body Mass Measurement chair, the facility of the Body Mass Measurement experiment (M172), is shown here in this 1970 photograph. The M172 experiment determined the body mass of each crew member and observed changes in body masses during flight. Knowledge of exact body mass variations throughout the flight in significantly aided in the correlation of other medical data obtained during the flight. Mass measurements under zero-gravity conditions were achieved by the application of Newton's second law (force equals mass times acceleration). The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.

  14. Comparison of four specific dynamic office chairs with a conventional office chair: impact upon muscle activation, physical activity and posture.

    PubMed

    Ellegast, Rolf P; Kraft, Kathrin; Groenesteijn, Liesbeth; Krause, Frank; Berger, Helmut; Vink, Peter

    2012-03-01

    Prolonged and static sitting postures provoke physical inactivity at VDU workplaces and are therefore discussed as risk factors for the musculoskeletal system. Manufacturers have designed specific dynamic office chairs featuring structural elements which promote dynamic sitting and therefore physical activity. The aim of the present study was to evaluate the effects of four specific dynamic chairs on erector spinae and trapezius EMG, postures/joint angles and physical activity intensity (PAI) compared to those of a conventional standard office chair. All chairs were fitted with sensors for measurement of the chair parameters (backrest inclination, forward and sideward seat pan inclination), and tested in the laboratory by 10 subjects performing 7 standardized office tasks and by another 12 subjects in the field during their normal office work. Muscle activation revealed no significant differences between the specific dynamic chairs and the reference chair. Analysis of postures/joint angles and PAI revealed only a few differences between the chairs, whereas the tasks performed strongly affected the measured muscle activation, postures and kinematics. The characteristic dynamic elements of each specific chair yielded significant differences in the measured chair parameters, but these characteristics did not appear to affect the sitting dynamics of the subjects performing their office tasks.

  15. Physiologic adaptation of man in space; Proceedings of the Seventh International Man in Space Symposium, Houston, TX, Feb. 10-13, 1986

    NASA Technical Reports Server (NTRS)

    Holland, Albert W. (Editor)

    1987-01-01

    Topics discussed in this volume include space motion sickness, cardiovascular adaptation, fluid shifts, extravehicular activity, general physiology, perception, vestibular response modifications, vestibular physiology, and pharmacology. Papers are presented on the clinical characterization and etiology of space motion sickness, ultrasound techniques in space medicine, fluid shifts in weightlessness, Space Shuttle inflight and postflight fluid shifts measured by leg volume changes, and the probability of oxygen toxicity in an 8-psi space suit. Consideration is also given to the metabolic and hormonal status of crewmembers in short-term space flights, adaptive changes in perception of body orientation and mental image rotation in microgravity, the effects of a visual-vestibular stimulus on the vestibulo-ocular reflex, rotation tests in the weightless phase of parabolic flight, and the mechanisms of antimotion sickness drugs.

  16. Physiologic adaptation of man in space; Proceedings of the Seventh International Man in Space Symposium, Houston, TX, Feb. 10-13, 1986

    NASA Technical Reports Server (NTRS)

    Holland, Albert W. (Editor)

    1987-01-01

    Topics discussed in this volume include space motion sickness, cardiovascular adaptation, fluid shifts, extravehicular activity, general physiology, perception, vestibular response modifications, vestibular physiology, and pharmacology. Papers are presented on the clinical characterization and etiology of space motion sickness, ultrasound techniques in space medicine, fluid shifts in weightlessness, Space Shuttle inflight and postflight fluid shifts measured by leg volume changes, and the probability of oxygen toxicity in an 8-psi space suit. Consideration is also given to the metabolic and hormonal status of crewmembers in short-term space flights, adaptive changes in perception of body orientation and mental image rotation in microgravity, the effects of a visual-vestibular stimulus on the vestibulo-ocular reflex, rotation tests in the weightless phase of parabolic flight, and the mechanisms of antimotion sickness drugs.

  17. From Chair to "Chair": A Representational Shift Account of Object Labeling Effects on Memory

    ERIC Educational Resources Information Center

    Lupyan, Gary

    2008-01-01

    What are the consequences of calling things by their names? Six experiments investigated how classifying familiar objects with basic-level names (chairs, tables, and lamps) affected recognition memory. Memory was found to be worse for items that were overtly classified with the category name--as reflected by lower hit rates--compared with items…

  18. Influence of dental chair backrest inclination on the registration of the mandibular position.

    PubMed

    Coelho, Mariana Freire; Cavalcanti, Bruno das Neves; Claro Neves, Ana Christina; Jóias, Renata Pilli; Rode, Sigmar de Mello

    2015-11-01

    Varying the inclination of the dental chair backrest might alter the distribution of occlusal contact points. The purpose of this study was to identify the influence of backrest inclination on the registration of the mandibular position. Ten participants aged between 18 and 30 years with a complete permanent dentition, uncompromised motor function, no tooth mobility, and no temporomandibular disorders were selected. To register interocclusal contacts, an autopolymerizing methylmethacrylate device was adapted to the maxillary anterior teeth and a composite resin increment was added to the mandibular central incisors. Contacts were registered with the following variations in the inclination of the dental chair backrest: 90 degrees, 120 degrees, and 180 degrees. A standardized digital photograph was made of each mark in each backrest position, and the images were superimposed to measure the distances in registration from 90 to 120 and from 90 to 180 degrees. Data were analyzed with the Student paired t test (α=.05). When the chair was inclined from the 90-degree to the 120-degree position, the mandible was repositioned posteriorly by a mean of 0.67 mm, but the difference was not statistically significant. When the chair was inclined from the 90-degree to the 180-degree position, however, the mandible was repositioned posteriorly by a statistically significant mean of 1.41 mm. Mandibular position is influenced by increasing inclination, and this influence was statistically significant at a 180-degree incline. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  19. Vestibulo-cardiorespiratory responses at the onset of chair rotation in endurance runners.

    PubMed

    Sato, Kohei; Katayama, Keisho; Katayama, Naomi; Hotta, Norio; Ishida, Koji; Miyamura, Miharu

    2005-02-01

    Stimulation of the vestibular system has been reported to elicit ventilatory and circulatory changes in humans. The purpose of this study was to clarify the characteristics of vestibular-mediated ventilatory and circulatory responses in male endurance runners at the onset of passive chair rotation, which selectively stimulates the semicircular canals. Fourteen runners and 14 male untrained subjects participated. The vestibular stimulus test, which consists of 180 degrees chair rotations (left or right half-turns on an earth-vertical axis) for a duration of 2 s, was carried out on each subject. Inspiratory minute ventilation, tidal volume, respiratory frequency, heart rate, and blood pressure were measured by breath-by-breath and beat-to-beat techniques before, during, and after the chair rotation for a total of 60 s. It was found in this study that (i) the relative change of minute ventilation response in the endurance runners was significantly (P < 0.05) greater than in the untrained subjects during and after the rotation, and that (ii) no significant group differences were observed in heart rate and mean blood pressure responses during and after the rotation. In conclusion, vestibular-mediated ventilatory response, but not circulatory response, at the onset of the chair rotation in the endurance runners was significantly greater than that in the untrained subjects. The results from the present study suggest that an increase in vestibulo-ventilatory response would be attributed to an adaptation to long-term endurance training.

  20. Individual housing does not influence the adaptation of the pituitary-adrenal axis and other physiological variables to chronic stress in adult male rats.

    PubMed

    Giralt, M; Armario, A

    1989-03-01

    Although the influence of housing conditions on the physiological response to stress has been extensively studied for several years, no attempts have been made to investigate the effect of this variable on the capacity for adaptation to chronic stress. To this end, adult male rats were housed either individually or in groups of four per cage and subjected to 2 hr of daily immobilization stress for 14 days. Housing did not influence any of the physiological variables measured either in unstressed or in stressed rats except the corticosterone response to stress which was higher in individually housed rats. Of the behavioral measures, individual housing significantly decreased defecation rate in the novel environment. Other behavioral measures were not influenced by housing. Chronic stress significantly reduced ambulation but no significant interaction between housing and chronic stress was observed. Taken together, these data indicate that a short period of individual housing did not affect the physiological and behavioral consequences of repeated exposure to chronic stress.

  1. Is chair rise performance a useful measure of leg power?

    PubMed

    Hardy, Rebecca; Cooper, Rachel; Shah, Imran; Harridge, Stephen; Guralnik, Jack; Kuh, Diana

    2010-01-01

    Chair rise performance, which is simple to assess in a home or clinic setting, has been used as a method of predicting leg power deficit in older adults. More recently, chair rise performance has been assessed in younger populations as a baseline for assessment of subsequent age-related declines in function and power. However, as rising from a chair repeatedly not only requires lower limb strength and power but also good balance and coordination, it may not be purely a measure of leg power especially among these younger, well functioning groups who are yet to experience agerelated declines and deficits in function. The aim of this study was to assess whether chair rise performance can be considered as a predictor of leg power, and hence of deficits in this, in men and women in mid-life. We assessed the relationship of chair rise performance with leg extensor power (LEP), measured using the Nottingham Power Rig (NPR), and with standing balance performance. LEP was measured in a clinic setting in a sub-sample of 81 men and 93 women from the MRC National Survey of Health and Development, a nationally representative cohort born in Britain in 1946. The time taken to rise from a chair 10 times and standing balance time were assessed during home visits at the same age. Increasing LEP was associated with better chair rise performance among those who completed 10 chair rises in ≥15 seconds, after adjustment for body size (p=0.008). Better standing balance performance was associated with better chair rise performance in men, but not women. That LEP and standing balance are both related to chair rise time in men suggests that chair rise time should not be thought of purely as a proxy measure of leg power in middle-aged populations. This has implications for longitudinal studies which want to study age-related decline in chair rise performance.

  2. Is chair rise performance a useful measure of leg power?

    PubMed Central

    Hardy, Rebecca; Cooper, Rachel; Shah, Imran; Harridge, Stephen; Guralnik, Jack; Kuh, Diana

    2011-01-01

    Background and Aims Chair rise performance, which is simple to assess in a home or clinic setting, has been used as a method of predicting leg power deficit in older adults. More recently chair rise performance has been assessed in younger populations as a baseline for assessment of subsequent age-related declines in function and power. However, as rising from a chair repeatedly not only requires lower limb strength and power but also good balance and coordination, it may not be purely a measure of leg power especially among these younger, well functioning groups who are yet to experience age-related declines and deficits in function. The aim of this study was to assess whether chair rise performance can be considered as a predictor of leg power, and hence of deficits in this, in men and women in mid-life. We assessed the relationship of chair rise performance with leg extensor power (LEP) measured using the Nottingham Power Rig (NPR), and with standing balance performance. Methods LEP was measured in a clinic setting in a sub-sample of 81 men and 93 women from the MRC National Survey of Health and Development, a nationally representative cohort born in Britain in 1946. The time taken to rise from a chair 10 times and standing balance time were assessed during home visits at the same age. Results Increasing LEP was associated with better chair rise performance among those who completed 10 chair rises in ≥15 seconds, after adjustment for body size (p=0.008). Better standing balance performance was associated with better chair rise performance in men, but not women. Conclusions That LEP and standing balance are both related to chair rise time in men suggests that chair rise time should not be thought of purely as a proxy measure of leg power in middle-aged populations. This has implications for longitudinal studies which want to study age-related decline in chair rise performance. PMID:21422795

  3. The role of oxidative, inflammatory and neuroendocrinological systems during exercise stress in athletes: implications of antioxidant supplementation on physiological adaptation during intensified physical training.

    PubMed

    Slattery, Katie; Bentley, David; Coutts, Aaron J

    2015-04-01

    During periods of intensified physical training, reactive oxygen species (ROS) release may exceed the protective capacity of the antioxidant system and lead to dysregulation within the inflammatory and neuroendocrinological systems. Consequently, the efficacy of exogenous antioxidant supplementation to maintain the oxidative balance in states of exercise stress has been widely investigated. The aim of this review was to (1) collate the findings of prior research on the effect of intensive physical training on oxidant-antioxidant balance; (2) summarise the influence of antioxidant supplementation on the reduction-oxidation signalling pathways involved in physiological adaptation; and (3) provide a synopsis on the interactions between the oxidative, inflammatory and neuroendocrinological response to exercise stimuli. Based on prior research, it is evident that ROS are an underlying aetiology in the adaptive process; however, the impact of antioxidant supplementation on physiological adaptation remains unclear. Equivocal results have been reported on the impact of antioxidant supplementation on exercise-induced gene expression. Further research is required to establish whether the interference of antioxidant supplementation consistently observed in animal-based and in vivo research extends to a practical sports setting. Moreover, the varied results reported within the literature may be due to the hormetic response of oxidative, inflammatory and neuroendocrinological systems to an exercise stimulus. The collective findings suggest that intensified physical training places substantial stress on the body, which can manifest as an adaptive or maladaptive physiological response. Additional research is required to determine the efficacy of antioxidant supplementation to minimise exercise-stress during intensive training and promote an adaptive state.

  4. Life After Being a Pathology Department Chair: Issues and Opportunities.

    PubMed

    Bailey, David N; Lipscomb, Mary F; Gorstein, Fred; Wilkinson, David; Sanfilippo, Fred

    2016-01-01

    Although there is a considerable literature on transition of faculty members to the position of department chair, there is a dearth of publications about transitioning from the chair to other activities including retirement. The Association of Pathology Chairs senior fellows (all of whom are former chairs of academic departments of pathology) made this topic a focus of discussion at the Association of Pathology Chairs 2016 Annual Meeting. Of the 33 senior fellows engaged in this discussion, following their time as chairs, a small majority (18) transitioned to other administrative posts within or outside the university, while the others either returned to the active faculty (7) or retired (8). The motivating factors and influences for transitioning from the chair were probed along with the processes used in executing the transition, such as the development of transition plans. The reasons for selecting the specific type of postchair activity were also investigated. There was extraordinary diversity in the type of post-chair activities pursued. To our knowledge, no other medical specialty has examined these issues, which may be potentially relevant for the career planning of active chairs.

  5. Chair of a department of medicine: now a different job.

    PubMed

    Kastor, John A

    2013-07-01

    The job of chair of a department of medicine, once seen as the apex in the career of an academic internist, has lost much of its allure, in part because of increasing administrative and financial obligations that require more of the time and effort of chairs than formerly. This is the impression the author gathered from interviewing 44 current and former chairs, deans, division chiefs, and hospital directors.He was told that chairs have lost some of their independence as departments have become increasingly dependent on the support of the executives at their university hospitals who, as the source of funds and facilities, can even specify which clinical services the chairs may develop. Conflict over the assignment of resources between dean and hospital CEO, which one interviewee stated can produce "incredible tensions," can complicate efforts of chairs to build clinical and research strength within their departments according to their own preferences. The growing administrative and financial duties of the job have forced some chairs to decrease their dedication to the classic responsibilities of teaching medical students and house officers.Recruiting outstanding leaders for departments of medicine challenges search committees and deans more than in the past because many suitable candidates do not choose to be considered and prefer to lead institutes, centers, or specialty divisions. The author suggests, however, that schools-by providing chairs with adequate administrative support and authority-can structure the job to improve its attractiveness and allow chairs more time to engage in traditional academic pursuits.

  6. Details of Plan, Pier Base, Chair Rail, Alter Frame, and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Details of Plan, Pier Base, Chair Rail, Alter Frame, and Sanctuary - National Home for Disabled Volunteer Soldiers, Northwestern Branch, Chapel, 5000 West National Avenue, Milwaukee, Milwaukee County, WI

  7. Physiological and morphological adaptations of herbaceous perennial legumes allow differential access to sources of varyingly soluble phosphate.

    PubMed

    Pang, Jiayin; Yang, Jiyun; Lambers, Hans; Tibbett, Mark; Siddique, Kadambot H M; Ryan, Megan H

    2015-08-01

    The aim of this study was to investigate the capacity of three perennial legume species to access sources of varyingly soluble phosphorus (P) and their associated morphological and physiological adaptations. Two Australian native legumes with pasture potential (Cullen australasicum and Kennedia prostrata) and Medicago sativa cv. SARDI 10 were grown in sand under two P levels (6 and 40 µg P g(-1) ) supplied as Ca(H2 PO4 )2 ·H2 O (Ca-P, highly soluble, used in many fertilizers) or as one of three sparingly soluble forms: Ca10 (OH)2 (PO4 )6 (apatite-P, found in relatively young soils; major constituent of rock phosphate), C6 H6 O24 P6 Na12 (inositol-P, the most common form of organic P in soil) and FePO4 (Fe-P, a poorly-available inorganic source of P). All species grew well with soluble P. When 6 µg P g(-1) was supplied as sparingly soluble P, plant dry weight (DW) and P uptake were very low for C. australasicum and M. sativa (0.1-0.4 g DW) with the exception of M. sativa supplied with apatite-P (1.5 g). In contrast, K. prostrata grew well with inositol-P (1.0 g) and Fe-P (0.7 g), and even better with apatite-P (1.7 g), similar to that with Ca-P (1.9 g). Phosphorus uptake at 6 µg P g(-1) was highly correlated with total root length, total rhizosphere carboxylate content and total rhizosphere acid phosphatase (EC 3.1.3.2) activity. These findings provide strong indications that there are opportunities to utilize local Australian legumes in low P pasture systems to access sparingly soluble soil P and increase perennial legume productivity, diversity and sustainability.

  8. Physiological basis for high CO2 tolerance in marine ectothermic animals: pre-adaptation through lifestyle and ontogeny?

    NASA Astrophysics Data System (ADS)

    Melzner, F.; Gutowska, M. A.; Langenbuch, M.; Dupont, S.; Lucassen, M.; Thorndyke, M. C.; Bleich, M.; Pörtner, H.-O.

    2009-05-01

    Future ocean acidification has the potential to adversely affect many marine organisms. A growing body of evidence suggests that many species could suffer from reduced fertilization success, decreases in larval- and adult growth rates, reduced calcification rates, metabolic depression and even mortality when being exposed to near-future levels (year 2100 scenarios) of ocean acidification. Little research focus is currently placed on those organisms/taxa that might be less vulnerable to the anticipated changes in ocean chemistry; this is unfortunate, as the comparison of more vulnerable to more tolerant physiotypes could provide us with those physiological traits that are crucial for ecological success in a future ocean. Here, we attempt to summarize some ontogenetic and lifestyle traits that lead to an increased tolerance towards high environmental pCO2. In general, marine ectothermic metazoans with an extensive extracellular fluid volume may be less vulnerable to future acidification as their cells are already exposed to much higher pCO2 values (0.1 to 0.4 kPa, 1000 to 4000 μatm) than those of unicellular organisms and gametes, for which the ocean (0.04 kPa, 400 μatm) is the extracellular space. A doubling in environmental pCO2 therefore only represents a 10% change in extracellular CO2 in some marine teleosts. High extracellular pCO2 values are to some degree related to high metabolic rates, as diffusion gradients need to be high in order to excrete an amount of CO2 that is directly proportional to the amount of O2 consumed. In active metazoans, such as teleost fish, cephalopods and many brachyuran crustaceans, exercise induced increases in metabolic rate require an efficient ion-regulatory machinery for CO2 excretion and acid-base regulation, especially when anaerobic metabolism is involved and metabolic protons leak into the extracellular space. These ion-transport systems, which are located in highly developed gill epithelia, form the basis for efficient

  9. A Qualitative Study of Faculty Members' Views of Women Chairs

    PubMed Central

    Isaac, Carol; Griffin, Lindsay

    2010-01-01

    Abstract Background Concurrent with the evolving role of the department chair in academic medicine is the entry of women physicians into chair positions. Because implicit biases that stereotypically masculine behaviors are required for effective leadership remain strong, examining faculty members' perceptions of their chair's leadership in medical school departments with women chairs can provide insight into the views of women leaders in academic medicine and the complex ways in which gender may impact these chairs' leadership style and actions. Methods We conducted semistructured interviews with 13 male and 15 female faculty members representing all faculty tracks in three clinical departments chaired by women. Inductive, qualitative analysis of the subsequent text allowed themes to emerge across interviews. Results Four themes emerged regarding departmental leadership. One dealt with the leadership of the previous chair. The other three described the current chair's characteristics (tough, direct, and transparent), her use of communal actions to help support and mentor her faculty, and her ability to build power through consensus. Because all three chairs were early in their tenure, a wait and see attitude was frequently expressed. Faculty generally viewed having a woman chair as an indication of positive change, with potential individual and institutional advantages. Conclusions This exploratory study suggests that the culture of academic medicine has moved beyond questioning women physicians' competence to lead once they are in top organizational leadership positions. The findings are also consonant with experimental research indicating that women leaders are most successful when they pair stereotypic male (agentic) behaviors with stereotypic female (communal) behaviors. All three chairs exhibited features of a transformational leadership style and characteristics deemed essential for effective leadership in academic medicine. PMID:20156081

  10. The effects of nitrogen form on root morphological and physiological adaptations of maize, white lupin and faba bean under phosphorus deficiency

    PubMed Central

    Liu, Haitao; Tang, Caixian; Li, Chunjian

    2016-01-01

    Root morphological/physiological modifications are important for phosphorus (P) acquisition of plants under P deficiency, but strategies differ among plant species. Detailed studies on the response of maize roots to P deficiency are limited. Nitrogen (N) form influences root morphology/physiology, and thus may influence root responses to P deficiency. This work investigated adaptive mechanisms of maize roots to low P by comparison with white lupin and faba bean supplied with two N forms. Plants were grown for 7–16 days in hydroponics with sufficient (250 µmol L−1) and deficient P supply (1 µmol L−1) under supply of NH4NO3 or Ca(NO3)2. Plant growth and P uptake were measured, and release of protons and organic acid anions, and acid phosphatase activity in the root were monitored. The results showed that P deficiency significantly decreased shoot growth while increased root growth and total root length of maize and faba bean, but not white lupin. It enhanced the release of protons and organic acid anions, and acid phosphatase activity, from the roots of both legumes but not maize. Compared with Ca(NO3)2, NH4NO3 dramatically increased proton release by roots but did not alter root morphology or physiology of the three species in response to low P. It is concluded that the N form did not fundamentally change root morphological/physiological responses of the three species to P deficiency. Morphological variation in maize and morpho-physiological modifications in white lupin and faba bean were the main adaptive strategies to P deficiency. PMID:27519912

  11. Paying the Price for Academic Leadership: Department Chair Tradeoffs.

    ERIC Educational Resources Information Center

    Gmelch, Walter H.

    Nearly 80,000 scholars currently serve as department chairs, and almost one-quarter will need to be replaced each year. Such a high turnover rate is partly due to surprises and unexpected sacrifices embedded in the department chair position. In an effort to help professors prepare for and overcome unforseen tradeoffs, the University Council for…

  12. Department Chairs' Perceptions of the Importance of Business Communication Skills.

    ERIC Educational Resources Information Center

    Wardrope, William J.

    2002-01-01

    Determines business department chairs' ratings of topics typically covered in the business communication course. Indicates that department chairs perceive writing skills to be more important to business communication courses than other communication skills, such as speaking, technology-mediated communication, interpersonal communication,…

  13. Challenges and Opportunities in Chairing Multi-Disciplinary Departments.

    ERIC Educational Resources Information Center

    Kerwin-Vaca, MaryAnn

    Departmental chairs at community colleges must administer, coordinate, and direct all of the activities within a given department, a responsibility which becomes more difficult for chairs of multi-disciplinary departments (MDD's). To deal with these additional responsibilities, MDD administrators must have special leadership skills. They must be…

  14. The Hot Seat: Profiling the Marketing Department Chair

    ERIC Educational Resources Information Center

    Aggarwal, Praveen; Rochford, Linda; Vaidyanathan, Rajiv

    2009-01-01

    The chair of the marketing department serves a critical role in balancing the needs of the university with those of the faculty. Because most department chairs are drawn from the faculty in their departments, the administrative role they take on conflicts with their desire to maintain their academic roles as teacher and researcher. Although there…

  15. Reflections in the Rearview Mirror of a Departing Board Chair

    ERIC Educational Resources Information Center

    Di Prisco, Joseph

    2010-01-01

    This article shares reflections in the rearview mirror of a departing board chair. The author has served seven years as board chair of Redwood Day School (California). As he departs, he figures out a few things that might be worth sharing. The author shares his responses to some Frequently Unasked Questions.

  16. Turnover of First-Time Chairs in Departments of Psychiatry

    ERIC Educational Resources Information Center

    Buckley, Peter F.; Rayburn, William F.

    2011-01-01

    Objective: The authors examine the tenure of first-time Chairs in academic departments of psychiatry in order to stimulate discussion on extant workforce and leadership issues. Method: Data on tenure of Chairs in psychiatry and other nonsurgical specialties were derived from the longitudinal database of the Association of American Medical Colleges…

  17. The Future Competencies of Department Chairs: A Human Resources Perspective

    ERIC Educational Resources Information Center

    Jones, Faye R.

    2011-01-01

    This exploratory study of department chairs, deans, and faculty at extensive research public universities in Florida resulted in the identification of 85 future competencies of department chairs using a human resources perspective. Results include a discussion of the top 20 most important competencies and the top 20 competencies anticipated to be…

  18. The Future Competencies of Department Chairs: A Human Resources Perspective

    ERIC Educational Resources Information Center

    Jones, Faye R.

    2011-01-01

    This exploratory study of department chairs, deans, and faculty at extensive research public universities in Florida resulted in the identification of 85 future competencies of department chairs using a human resources perspective. Results include a discussion of the top 20 most important competencies and the top 20 competencies anticipated to be…

  19. Reflections in the Rearview Mirror of a Departing Board Chair

    ERIC Educational Resources Information Center

    Di Prisco, Joseph

    2010-01-01

    This article shares reflections in the rearview mirror of a departing board chair. The author has served seven years as board chair of Redwood Day School (California). As he departs, he figures out a few things that might be worth sharing. The author shares his responses to some Frequently Unasked Questions.

  20. Effective Communication for Academic Chairs. SUNY Series in Speech Communication.

    ERIC Educational Resources Information Center

    Hickson, Mark, III, Ed.; Stacks, Don W.

    This book presents 11 contributed papers which examine communication aspects of the department chair position in academia. It is noted that most academic department chairs are not trained in management skills, including communication strategies. After an introductory chapter by Christopher H. Spicer and Ann Q. Staton, the following papers are…

  1. FIRO B: Analyzing Community College Department Chairs' Effectiveness.

    ERIC Educational Resources Information Center

    Coats, Linda T.; And Others

    A study was conducted to explore the relationship between the interpersonal behavior of community college department chairs and the assessment of their leadership effectiveness by department faculty. The study population consisted of 30 humanities and social science chairs at 15 Mississippi community colleges, as well as 171 faculty members at the…

  2. Turnover of First-Time Chairs in Departments of Psychiatry

    ERIC Educational Resources Information Center

    Buckley, Peter F.; Rayburn, William F.

    2011-01-01

    Objective: The authors examine the tenure of first-time Chairs in academic departments of psychiatry in order to stimulate discussion on extant workforce and leadership issues. Method: Data on tenure of Chairs in psychiatry and other nonsurgical specialties were derived from the longitudinal database of the Association of American Medical Colleges…

  3. Exploring the Tensions and Ambiguities of University Department Chairs

    ERIC Educational Resources Information Center

    Armstrong, Denise E.; Woloshyn, Vera E.

    2017-01-01

    The department chair is a complex middle-management position located at the organizational fulcrum between faculty and senior administration. This qualitative study sought to develop a deeper understanding of chairs' experiences when enacting their dual roles as managers and scholars. Using a basic interpretative study design, we interviewed 10…

  4. Department Chairs' Perceptions of the Importance of Business Communication Skills.

    ERIC Educational Resources Information Center

    Wardrope, William J.

    2002-01-01

    Determines business department chairs' ratings of topics typically covered in the business communication course. Indicates that department chairs perceive writing skills to be more important to business communication courses than other communication skills, such as speaking, technology-mediated communication, interpersonal communication,…

  5. The Strategic Value of Succession Planning for Department Chairs.

    PubMed

    Rayburn, William; Grigsby, Kevin; Brubaker, Linda

    2016-04-01

    Most faculty who aspire to be department chairs are unaware of succession processes at their institution. This Commentary highlights the importance of succession planning, emphasizing the general need for transparency. Succession planning provides institutional leaders the opportunity to optimize, renew, and revitalize their organization by ensuring successful leadership transitions. In contrast to leadership pathways in the military, corporate business, and hospital administration, planned succession of medical school department chairs has received little attention. Different approaches to succession planning are essential for emergency and planned transitions. Emergency succession plans should be in place at all times, regularly revisited, and modified as needed. Department chairs should begin considering their planned succession between one and five years after their initial appointment. The succession discussion between a chair and medical school dean requires cautious, thoughtful, and open discussions. Intradepartmental annual faculty performance evaluations permit the chair to mentor potential successors in acquiring future-oriented, institution-based leadership qualities necessary to be considered for a future department chair position. If health and time permit, the successful chair should remain in his or her current position until a successor is named or, preferably, is in place. Appointment of an interim chair as part of succession planning can be useful for on-the-job training of an internal candidate, yet awkwardness might ensue if there is more than one internal candidate.Succession development offers the great advantage of maintaining smooth organizational performance while optimizing talent management and exploring opportunities for transitioning individuals into leadership roles.

  6. The Hot Seat: Profiling the Marketing Department Chair

    ERIC Educational Resources Information Center

    Aggarwal, Praveen; Rochford, Linda; Vaidyanathan, Rajiv

    2009-01-01

    The chair of the marketing department serves a critical role in balancing the needs of the university with those of the faculty. Because most department chairs are drawn from the faculty in their departments, the administrative role they take on conflicts with their desire to maintain their academic roles as teacher and researcher. Although there…

  7. Design of a practical dental chair made of corrugated cardboard.

    PubMed

    Goldstein, C M

    1978-12-01

    Directions for the construction of a corrugated cardboard dental chair, useful for mobile clinics and community dentistry programs, are presented. The designers of the cardboard dental chair and I hope that it will be as useful to other members of our profession as it has been to the USC Mobile Dental Clinic.

  8. Electromyography comparison of normal chair-desk system and assistant chair-desk system on fatigue

    PubMed Central

    Kwon, Moon-Seok; Lee, Sang-Ho; Cho, Ik-Rae; Won, Yu-Mi; Han, Mi-Kyung; Jung, Kon-Nym; Lee, Jae-Hee; Chin, Ji-Hyoung; Rho, Jae-Hun; Kim, Ju-Yeon; Yang, Jae-Bong; No, Jae-Kui; Park, Tae-Geun; Lee, Taek-Kyun; Park, Hyo-Joo; Lee, Sam-Jun; Yoo, Kyoung-Seok; Kang, Suh-Jung; Kwon, Se-Jeong; Shin, Mi-Ae; Kim, Hu-Nyun; Kahn, Hyung-Sik; Kim, Min-Jung; Kim, Tae-Young

    2015-01-01

    [Purpose] This study was designed to test the effects of the Assistant Chair-Desk System (ACDS), which can reduce the forward tilt of the neck and trunk and the level of fatigue during long lasting study in the sitting position. [Subjects] Fourteen middle school students and 14 college students of mixed gender participated in this study. [Methods] Fatigue level, the trapezius muscle, and the forward tilt angle of the head and trunk as well as distance factors were assessed before after using a normal chair-desk system (NCDS) and the ACDS for 120 minutes. [Results] There was an interaction effect in the angle and length of the neck from the sitting posture changes after 2 hours of studying using the NCDS and ACDS. There were also significant differences in the fatigue levels, hip joint angles and the lengths from the head according to the main effects of the chair-systems. [Conclusion] The studying position while using the ACDS was determined to prevent significant fatigue levels of the muscle and body, provide support to the head, by limiting the forward movement of the neck, and prevent forward tilt of the neck and trunk, by enabling the target point and gaze to be closer to the horizontal direction. PMID:26644668

  9. Electromyography comparison of normal chair-desk system and assistant chair-desk system on fatigue.

    PubMed

    Kwon, Moon-Seok; Lee, Sang-Ho; Cho, Ik-Rae; Won, Yu-Mi; Han, Mi-Kyung; Jung, Kon-Nym; Lee, Jae-Hee; Chin, Ji-Hyoung; Rho, Jae-Hun; Kim, Ju-Yeon; Yang, Jae-Bong; No, Jae-Kui; Park, Tae-Geun; Lee, Taek-Kyun; Park, Hyo-Joo; Lee, Sam-Jun; Yoo, Kyoung-Seok; Kang, Suh-Jung; Kwon, Se-Jeong; Shin, Mi-Ae; Kim, Hu-Nyun; Kahn, Hyung-Sik; Kim, Min-Jung; Kim, Tae-Young

    2015-10-01

    [Purpose] This study was designed to test the effects of the Assistant Chair-Desk System (ACDS), which can reduce the forward tilt of the neck and trunk and the level of fatigue during long lasting study in the sitting position. [Subjects] Fourteen middle school students and 14 college students of mixed gender participated in this study. [Methods] Fatigue level, the trapezius muscle, and the forward tilt angle of the head and trunk as well as distance factors were assessed before after using a normal chair-desk system (NCDS) and the ACDS for 120 minutes. [Results] There was an interaction effect in the angle and length of the neck from the sitting posture changes after 2 hours of studying using the NCDS and ACDS. There were also significant differences in the fatigue levels, hip joint angles and the lengths from the head according to the main effects of the chair-systems. [Conclusion] The studying position while using the ACDS was determined to prevent significant fatigue levels of the muscle and body, provide support to the head, by limiting the forward movement of the neck, and prevent forward tilt of the neck and trunk, by enabling the target point and gaze to be closer to the horizontal direction.

  10. Can multi-generational exposure to ocean warming and acidification lead to the adaptation of life history and physiology in a marine metazoan?

    PubMed

    Gibbin, Emma M; Chakravarti, Leela J; Jarrold, Michael D; Christen, Felix; Turpin, Vincent; Massamba N'Siala, Gloria; Blier, Pierre U; Calosi, Piero

    2017-02-15

    Ocean warming and acidification are concomitant global drivers that are currently threatening the survival of marine organisms. How species will respond to these changes depends on their capacity for plastic and adaptive responses. Little is known about the mechanisms that govern plasticity and adaptability or how global changes will influence these relationships across multiple generations. Here, we exposed the emerging model marine polychaete Ophryotrocha labronica to conditions simulating ocean warming and acidification, in isolation and in combination over five generations to identify: (i) how multiple versus single global change drivers alter both juvenile and adult life-history traits; (ii) the mechanistic link between adult physiological and fitness-related life-history traits; and (iii) whether the phenotypic changes observed over multiple generations are of plastic and/or adaptive origin. Two juvenile (developmental rate; survival to sexual maturity) and two adult (average reproductive body size; fecundity) life-history traits were measured in each generation, in addition to three physiological (cellular reactive oxygen species content, mitochondrial density, mitochondrial capacity) traits. We found that multi-generational exposure to warming alone caused an increase in juvenile developmental rate, reactive oxygen species production and mitochondrial density, decreases in average reproductive body size and fecundity, and fluctuations in mitochondrial capacity, relative to control conditions. Exposure to ocean acidification alone had only minor effects on juvenile developmental rate. Remarkably, when both drivers of global change were present, only mitochondrial capacity was significantly affected, suggesting that ocean warming and acidification act as opposing vectors of stress across multiple generations.

  11. Physiological Observations and Omics to Develop Personalized Sensormotor Adaptability Countermeasures Using Bed Rest and Space Flight Data

    NASA Technical Reports Server (NTRS)

    Mulavara, A. P.; Seidler, R. D.; Feiveson, A.; Oddsson, L.; Zanello, S.; Oman, C. M.; Ploutz-Snyder, L.; Peters, B.; Cohen, H. S.; Reschke, M.; hide

    2014-01-01

    Astronauts experience sensorimotor disturbances during the initial exposure to microgravity and during the re-adapation phase following a return to an earth-gravitational environment. These alterations may disrupt the ability to perform mission critical functional tasks requiring ambulation, manual control and gaze stability. Interestingly, astronauts who return from space flight show substantial differences in their abilities to readapt to a gravitational environment. The ability to predict the manner and degree to which individual astronauts would be affected would improve the effectiveness of countermeasure training programs designed to enhance sensorimotor adaptability. For such an approach to succeed, we must develop predictive measures of sensorimotor adaptability that will allow us to foresee, before actual space flight, which crewmembers are likely to experience the greatest challenges to their adaptive capacities. The goals of this project are to identify and characterize this set of predictive measures that include: 1) behavioral tests to assess sensory bias and adaptability quantified using both strategic and plastic-adaptive responses; 2) imaging to determine individual brain morphological and functional features using structural magnetic resonance imaging (MRI), diffusion tensor imaging, resting state functional connectivity MRI, and sensorimotor adaptation task-related functional brain activation; 3) genotype markers for genetic polymorphisms in Catechol-O-Methyl Transferase, Dopamine Receptor D2, Brain-derived neurotrophic factor and genetic polymorphism of alpha2-adrenergic receptor that play a role in the neural pathways underlying sensorimotor adaptation. We anticipate these predictive measures will be significantly correlated with individual differences in sensorimotor adaptability after long-duration space flight and an analog bed rest environment. We will be conducting a retrospective study leveraging data already collected from relevant

  12. Organizing awareness and increasing emotion regulation: revising chair work in emotion-focused therapy for borderline personality disorder.

    PubMed

    Pos, Alberta E; Greenberg, Leslie S

    2012-02-01

    Emotion-focused therapy (EFT) is an empirically supported treatment that may have potential as a stage-two treatment for borderline personality disorder (BPD). Specific aspects of BPD--the tendency to experience fluctuating self-states; weakness in meta-cognitive or reflective functioning; and the tendency for self-states to be organized by presently occurring interpersonal processes--present challenges to applying some EFT interventions with this population. In particular, even within a highly attuned, validating and accepting empathic relationship, clients with BPD may have difficulty with the usual manualizations of chair work interventions. This is because these interventions often employ polarization and intensification of experience in order to activate adaptive alternate emotional resources and self organizations. For the client with borderline personality disorder, these interventions may be counter-productive, emotionally dysregulating and disorganizing. EFT chair work, however, also has the potential to provide structure to the borderline clients experience of self, to stimulate metacognitive awareness, provide an alive experience of the process of polarization, attenuate emotional activation, and increase the experience of self-coherence. This article describes the development of stepwise approximations of EFT two-chair intervention for self-critical splits. It outlines potential stages of two-chair work as well as intervention principles important for productive chair work with this population. The EFT change principles of awareness, expression regulation, reflection, transformation, and corrective experience still centrally apply. However, several additional strategies are discussed to scaffold clients' capacity to both experience and regulate emotion.

  13. 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

  14. Adaptive Calibration of Children's Physiological Responses to Family Stress: The Utility of Evolutionary Developmental Theory--Comment on Del Giudice et al. (2012) and Sturge-Apple et al. (2012)

    ERIC Educational Resources Information Center

    Bugental, Daphne Blunt

    2012-01-01

    Children's physiological reactions to stress are presented from the broader theoretical perspective of adaptive calibration to the environment, as rooted in life history theory. Del Giudice, Hinnant, Ellis, and El-Sheikh (2012) focus on children's physiological responses to a stressful task as a consequence of their history of family stress.…

  15. Adaptive Calibration of Children's Physiological Responses to Family Stress: The Utility of Evolutionary Developmental Theory--Comment on Del Giudice et al. (2012) and Sturge-Apple et al. (2012)

    ERIC Educational Resources Information Center

    Bugental, Daphne Blunt

    2012-01-01

    Children's physiological reactions to stress are presented from the broader theoretical perspective of adaptive calibration to the environment, as rooted in life history theory. Del Giudice, Hinnant, Ellis, and El-Sheikh (2012) focus on children's physiological responses to a stressful task as a consequence of their history of family stress.…

  16. Physiology and the Biomedical Engineering Curriculum: Utilizing Emerging Instructional Technologies to Promote Development of Adaptive Expertise in Undergraduate Students

    ERIC Educational Resources Information Center

    Nelson, Regina K.

    2013-01-01

    A mixed-methods research study was designed to test whether undergraduate engineering students were better prepared to learn advanced topics in biomedical engineering if they learned physiology via a quantitative, concept-based approach rather than a qualitative, system-based approach. Experiments were conducted with undergraduate engineering…

  17. Physiology and the Biomedical Engineering Curriculum: Utilizing Emerging Instructional Technologies to Promote Development of Adaptive Expertise in Undergraduate Students

    ERIC Educational Resources Information Center

    Nelson, Regina K.

    2013-01-01

    A mixed-methods research study was designed to test whether undergraduate engineering students were better prepared to learn advanced topics in biomedical engineering if they learned physiology via a quantitative, concept-based approach rather than a qualitative, system-based approach. Experiments were conducted with undergraduate engineering…

  18. Burnout in United States academic chairs of radiation oncology programs.

    PubMed

    Kusano, Aaron S; Thomas, Charles R; Bonner, James A; DeWeese, Theodore L; Formenti, Silvia C; Hahn, Stephen M; Lawrence, Theodore S; Mittal, Bharat B

    2014-02-01

    The aims of this study were to determine the self-reported prevalence of burnout in chairs of academic radiation oncology departments, to identify factors contributing to burnout, and to compare the prevalence of burnout with that seen in other academic chair groups. An anonymous online survey was administered to the membership of the Society of Chairs of Academic Radiation Oncology Programs (SCAROP). Burnout was measured with the Maslach Burnout Inventory-Human Services Survey (MBI-HSS). Questionnaires were returned from 66 of 87 chairs (76% response rate). Seventy-nine percent of respondents reported satisfaction with their current positions. Common major stressors were budget deficits and human resource issues. One-quarter of chairs reported that it was at least moderately likely that they would step down in the next 1 to 2 years; these individuals demonstrated significantly higher emotional exhaustion. Twenty-five percent of respondents met the MBI-HSS criteria for low burnout, 75% for moderate burnout, and none for high burnout. Group MBI-HSS subscale scores demonstrated a pattern of moderate emotional exhaustion, low depersonalization, and moderate personal accomplishment, comparing favorably with other specialties. This is the first study of burnout in radiation oncology chairs with a high response rate and using a validated psychometric tool. Radiation oncology chairs share similar major stressors to other chair groups, but they demonstrate relatively high job satisfaction and lower burnout. Emotional exhaustion may contribute to the anticipated turnover in coming years. Further efforts addressing individual and institutional factors associated with burnout may improve the relationship with work of chairs and other department members. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Burnout in United States Academic Chairs of Radiation Oncology Programs

    SciTech Connect

    Kusano, Aaron S.; Thomas, Charles R.; DeWeese, Theodore L.; Formenti, Silvia C.; Hahn, Stephen M.; Lawrence, Theodore S.; Mittal, Bharat B.

    2014-02-01

    Purpose: The aims of this study were to determine the self-reported prevalence of burnout in chairs of academic radiation oncology departments, to identify factors contributing to burnout, and to compare the prevalence of burnout with that seen in other academic chair groups. Methods and Materials: An anonymous online survey was administered to the membership of the Society of Chairs of Academic Radiation Oncology Programs (SCAROP). Burnout was measured with the Maslach Burnout Inventory-Human Services Survey (MBI-HSS). Results: Questionnaires were returned from 66 of 87 chairs (76% response rate). Seventy-nine percent of respondents reported satisfaction with their current positions. Common major stressors were budget deficits and human resource issues. One-quarter of chairs reported that it was at least moderately likely that they would step down in the next 1 to 2 years; these individuals demonstrated significantly higher emotional exhaustion. Twenty-five percent of respondents met the MBI-HSS criteria for low burnout, 75% for moderate burnout, and none for high burnout. Group MBI-HSS subscale scores demonstrated a pattern of moderate emotional exhaustion, low depersonalization, and moderate personal accomplishment, comparing favorably with other specialties. Conclusions: This is the first study of burnout in radiation oncology chairs with a high response rate and using a validated psychometric tool. Radiation oncology chairs share similar major stressors to other chair groups, but they demonstrate relatively high job satisfaction and lower burnout. Emotional exhaustion may contribute to the anticipated turnover in coming years. Further efforts addressing individual and institutional factors associated with burnout may improve the relationship with work of chairs and other department members.

  20. Alkanols and chlorophenols cause different physiological adaptive responses on the level of cell surface properties and membrane vesicle formation in Pseudomonas putida DOT-T1E.

    PubMed

    Baumgarten, Thomas; Vazquez, José; Bastisch, Christian; Veron, Wilfried; Feuilloley, Marc G J; Nietzsche, Sandor; Wick, Lukas Y; Heipieper, Hermann J

    2012-01-01

    In order to cope with the toxicity imposed by the exposure to environmental hydrocarbons, many bacteria have developed specific adaptive responses such as modifications in the cell envelope. Here we compared the influence of n-alkanols and chlorophenols on the surface properties of the solvent-tolerant bacterium Pseudomonas putida DOT-T1E. In the presence of toxic concentrations of n-alkanols, this strain significantly increased its cell surface charge and hydrophobicity with changes depending on the chain length of the added n-alkanols. The adaptive response occurred within 10 min after the addition of the solvent and was demonstrated to be of physiological nature. Contrary to that, chlorophenols of similar hydrophobicity and potential toxicity as the corresponding alkanols caused only minor effects in the surface properties. To our knowledge, this is the first observation of differences in the cellular adaptive response of bacteria to compound classes of quasi equal hydrophobicity and toxicity. The observed adaptation of the physico-chemical surface properties of strain DOT-T1E to the presence of alkanols was reversible and correlated with changes in the composition of the lipopolysaccharide content of the cells. The reaction is explained by previously described reactions allowing the release of membrane vesicles that was demonstrated for cells affected by 1-octanol and heat shock, whereas no membrane vesicles were released after the addition of chlorophenols.

  1. Physiological adaptations and tolerance towards higher concentration of selenite (Se(+4)) in Enterobacter sp. AR-4, Bacillus sp. AR-6 and Delftia tsuruhatensis AR-7.

    PubMed

    Prakash, Dhan; Pandey, Janmejay; Tiwary, B N; Jain, Rakesh K

    2010-05-01

    Environmental contamination with selenium is a major health concern. A few bacterial strains have been isolated that can transform toxic selenite to non-toxic elemental selenium only at low concentrations (0.001-150 mM) in recent past. We have previously reported isolation and characterization of few selenite-tolerant bacterial strains. These strains were found to be resistant to selenite at (300-600 mM) concentrations. In the present study we have characterized some physiological adaptations of strains Enterobacter sp. AR-4, Bacillus sp. AR-6 and Delftia tsuruhatensis AR-7 during exposure to higher concentration of selenite under aerobic and anaerobic environments. Adaptive responses are largely associated with alteration of cell morphology and change in total cellular fatty acid composition. Interestingly, electron microscopy studies revealed substantial decrease in cell size and intracellular deposition of Se(0) crystals when reduction is carried out under aerobic conditions. On the other hand, cell size increased with adhesion of Se(0) on cell surface during anaerobic reduction. Fatty acid composition analysis demonstrated selective increase in saturated and cyclic fatty acids and decrease in unsaturated ones during aerobic transformation. Changes observed during anaerobic transformation were in surprising contrast as indicated by total absence of saturated and cyclic fatty acids. Results presented here provide evidences for putative occurrence of two distinct mechanisms involved in tolerance towards higher concentrations of selenite utilization under aerobic and anaerobic conditions. Further, prior exposure to higher concentration of Se(+4) enabled rapid adaptation indicating role of inducible system in adaptation.

  2. 77 FR 55813 - Environmental Management Site-Specific Advisory Board Chairs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ... Update EM SSAB Chairs' Round Robin: Topics, Achievements, and Accomplishments EM Headquarters Budget Update EM Headquarters Waste Disposition Strategies EM SSAB Chairs' Round Robin: Cross-Complex...

  3. Do we need a "Chair of alternative methods", and where?

    PubMed

    Wendel, Albrecht

    2002-01-01

    assurance. A successful initiative to establish a Good Cell Culture Practice (GCCP) in analogy to Good Laboratory Practice (GLP) has evolved out of the field of in vitro alternatives. The concept of validating the relevance of an in vitro test in comparison to the respective in vivo situation represents a consequent translation of evidence-based medicine into in vitro biomedicine. In other words: It does no longer suffice that an in vitro model is plausible - it has to prove its suitability and quality. (c) The broad implementation of advanced in vitro technology into curricula implies development of lectures, courses and other teaching materials including virtual education offers. Such a basis will allow efficient spreading of knowledge and ease transnational acceptance. Last but not least, taking over the leadership for erecting a chair for alternative methods represents a major political signal that demonstrates to the public the willingness to adapt academic education to modern social awareness. A location for such an initiative needs to be found that is in the centre of Europe, has the necessary infrastructure of surrounding biomedical research, international networks for the evaluation and validation of tests, technology transfer to industrial use and access to relevant publication organs. The unequivocal answer to the question in the heading is therefore: we need a chair for in vitro alternatives because (i) the patient is our primary concern but the animal is not just secondary (ii) man's responsibility for the integrity of all creatures including the own species makes it mandatory.

  4. Cranial nerves neuropraxia after shoulder arthroscopy in beach chair position.

    PubMed

    Cogan, A; Boyer, P; Soubeyrand, M; Hamida, F Ben; Vannier, J-L; Massin, P

    2011-05-01

    We report a case of neuropraxia of the 9th, 10th and 12th cranial nerve pairs after arthroscopic rotator cuff repair in the beach chair position. The elements in the medical file seem to exclude an intracranial cause of the lesions and support a mechanical, extracranial cause due to intubation and/or the beach chair position. This clinical case report shows the neurological risks of the beach chair position during arthroscopic shoulder surgery and presents the essential safety measures to prevent these risks. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  5. Temperature relations of aerial and aquatic physiological performance in a mid-intertidal limpet Cellana toreuma: adaptation to rapid changes in thermal stress during emersion.

    PubMed

    Huang, Xiongwei; Wang, Tifeng; Ye, Ziwen; Han, Guodong; Dong, Yunwei

    2015-01-01

    The physiological performance of a mid-intertidal limpet Cellana toreuma was determined to study the physiological adaptation of intertidal animals to rapid changes and extreme temperatures during emersion. The relationship between the Arrhenius breakpoint temperature (ABT) and in situ operative body temperature was studied to predict the possible impact of climate change on the species. The temperature coefficient (Q10) of emersed animals was higher than that of submersed animals and the ratio of aerial: aquatic heart rate rose with increasing temperature. The ABTs of submersed and emersed animals were 30.2 and 34.2°C, respectively. The heart rate and levels of molecular biomarkers (hsps, ampkα, ampkβ and sirt1 mRNA) were determined in 48 h simulated semi-diurnal tides. There were no obvious changes of heart rate and gene expression during the transition between emersion and submersion at room temperature, although expressions of hsp70 and hsp90 were induced significantly after thermal stress. These results indicate that C. toreuma can effectively utilize atmospheric oxygen, and the higher Q10 and ABT of emersed animals are adaptations to the rapid change and extreme thermal stress during emersion. However, the in situ operative body temperature frequently exceeds the aerial ABT of C. toreuma, indicating the occurrence of large-scale mortality of C. toreuma in summer, and this species should be sensitive to increasing temperature in the scenario of climate change.

  6. Does reduced precipitation trigger physiological and morphological drought adaptations in European beech (Fagus sylvatica L.)? Comparing provenances across a precipitation gradient.

    PubMed

    Knutzen, Florian; Meier, Ina Christin; Leuschner, Christoph

    2015-09-01

    Global warming and associated decreases in summer rainfall may threaten tree vitality and forest productivity in many regions of the temperate zone in the future. One option for forestry to reduce the risk of failure is to plant genotypes which combine high productivity with drought tolerance. Growth experiments with provenances from different climates indicate that drought exposure can trigger adaptive drought responses in temperate trees, but it is not well known whether and to what extent regional precipitation reduction can increase the drought resistance of a species. We conducted a common garden growth experiment with five European beech (Fagus sylvatica L.) populations from a limited region with pronounced precipitation heterogeneity (816-544 mm year(-1)), where phylogenetically related provenances grew under small to large water deficits. We grew saplings of the five provenances at four soil moisture levels (dry to moist) and measured ∼30 morphological (leaf and root properties, root : shoot ratio), physiological (leaf water status parameters, leaf conductance) and growth-related traits (above- and belowground productivity) with the aim to examine provenance differences in the drought response of morphological and physiological traits and to relate the responsiveness to precipitation at origin. Physiological traits were more strongly influenced by provenance (one-third of the studied traits), while structural traits were primarily affected by water availability in the experiment (two-thirds of the traits). The modulus of leaf tissue elasticity ϵ reached much higher values late in summer in plants from moist origins resulting in more rapid turgor loss and a higher risk of hydraulic failure upon drought. While experimental water shortage affected the majority of morphological and productivity-related traits in the five provenances, most parameters related to leaf water status were insensitive to water shortage. Thus, plant morphology, and root

  7. In vivo spinal posture during upright and reclined sitting in an office chair.

    PubMed

    Zemp, Roland; Taylor, William R; Lorenzetti, Silvio

    2013-01-01

    Increasing numbers of people spend the majority of their working lives seated in an office chair. Musculoskeletal disorders, in particular low back pain, resulting from prolonged static sitting are ubiquitous, but regularly changing sitting position throughout the day is thought to reduce back problems. Nearly all currently available office chairs offer the possibility to alter the backrest reclination angles, but the influence of changing seating positions on the spinal column remains unknown. In an attempt to better understand the potential to adjust or correct spine posture using adjustable seating, five healthy subjects were analysed in an upright and reclined sitting position conducted in an open, upright MRI scanner. The shape of the spine, as described using the vertebral bodies' coordinates, wedge angles, and curvature angles, showed high inter-subject variability between the two seating positions. The mean lumbar, thoracic, and cervical curvature angles were 29 ± 15°, -29 ± 4°, and 13 ± 8° for the upright and 33 ± 12°, -31 ± 7°, and 7 ± 7° for the reclined sitting positions. Thus, a wide range of seating adaptation is possible through modification of chair posture, and dynamic seating options may therefore provide a key feature in reducing or even preventing back pain caused by prolonged static sitting.

  8. Contrasting Physiological and Proteomic Adaptations to Iron and/or Copper Limitation in Two Strains of the Same Open Ocean Diatom Thalassiosira oceanica

    NASA Astrophysics Data System (ADS)

    Schuback, N.; Hippmann, A.; Maldonado, M. T.; Allen, A. E.; McCrow, J.; Foster, L. J.; Green, B. R.; Alami, M.

    2016-02-01

    Iron plays a significant role in controlling marine primary productivity. Despite that extremely low dissolved iron (Fe) concentrations are found in Fe-limited regions, some phytoplankton are able to survive and thrive. Two strains of the model oceanic diatom Thalassiosira oceanica, TO 1003 and TO 1005, have both been used in previous studies to characterize adaptations to iron limitation. These studies have shown that T. oceanica has lowered its Fe requirements and increased its Fe acquisition efficiency compared to coastal counterparts. Both strategies may impose a higher cellular copper (Cu) demand. However, the underlying biochemical adaptations in these oceanic diatoms remain unknown. Recently, the genome, as well as the first proteomic and transcriptomic analyses of T. oceanica 1005 grown under different Fe levels, were published. To further our understanding of the interplay between Fe- and Cu- physiology in open ocean diatoms, we examined an array of physiological responses to varying degrees of Fe-, Cu- and Fe/Cu co-limitation in both strains. We also determined the differential expression of proteins using stable isotope labeling and LC-MS/MS proteomic analysis. The two strains, TO 1003 and TO 1005, need markedly different metal concentrations in the media. TO1003 requires 30% less Cu to sustain its optimal growth and less than 1/10th of the minimum Cu that is needed by TO 1005 to survive. In contrast, TO 1005 is able to grow with less Fe available in the media. The physiological and proteomic responses of these two strains when acclimated to low Fe and/or Cu concentrations will be presented. The evolutionary implications will be discussed.

  9. 32. DETAIL OF BOARD ROOM CHAIR WITH SILVER PLATE LISTING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. DETAIL OF BOARD ROOM CHAIR WITH SILVER PLATE LISTING NAMES AND DATES OF PAST OCCUPANTS AND PLATE WITH NAME OF CURRENT OCCUPANT - Philadelphia Saving Fund Society, Twelfth & Market Streets, Philadelphia, Philadelphia County, PA

  10. 82. REGENTS' ROOM WEST WALL, WITH ORIGINAL CHAIRS BY JAMES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    82. REGENTS' ROOM WEST WALL, WITH ORIGINAL CHAIRS BY JAMES RENWICK, JR. MANTELPIECE AND MIRROR ARE NOT ORIGINAL TO THE ROOM. - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  11. "Piekara's Chair": Mechanical Model for Atomic Energy Levels.

    ERIC Educational Resources Information Center

    Golab-Meyer, Zofia

    1991-01-01

    Uses the teaching method of models or analogies, specifically the model called "Piekara's chair," to show how teaching classical mechanics can familiarize students with the notion of energy levels in atomic physics. (MDH)

  12. 10. Photocopy, VIEW OF INTERIOR STAGE WITH ORIGINAL CHAIRS IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Photocopy, VIEW OF INTERIOR STAGE WITH ORIGINAL CHAIRS IN FOREGROUND, circa. 1912. Original photograph at Nebraska State Historical Society. - Zapadni Cesko-Bratreske Jednoty Hall Number 53, Fifth Avenue, Niobrara, Knox County, NE

  13. 15. FIRST FLOOR, DETAIL VIEW, HISTORIC CHAIRS ORIGINAL TO THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. FIRST FLOOR, DETAIL VIEW, HISTORIC CHAIRS ORIGINAL TO THE HOUSE OF TOMORROW AT THE 1934 WORLD'S FAIR IN CHICAGO. - House of Tomorrow, 241 Lake Front Drive (moved from Chicago, IL), Beverly Shores, Porter County, IN

  14. 57. DETAIL OF EAST END OF CHANCEL SHOWING BISHOP'S CHAIR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    57. DETAIL OF EAST END OF CHANCEL SHOWING BISHOP'S CHAIR, ALTAR, AND STAINED GLASS WINDOWS; NOTE MINTON TILE MEDALLIONS ON FLOOR - Church of the Holy Cross, State Route 261, Stateburg, Sumter County, SC

  15. 16. Interior detail, window, wainscot and chair rail, original Office, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Interior detail, window, wainscot and chair rail, original Office, Engine Stores Building, Southern Pacific Railroad Carlin Shops, view to northwest (90mm lens). - Southern Pacific Railroad, Carlin Shops, Engine Stores Building, Foot of Sixth Street, Carlin, Elko County, NV

  16. Turnover of first-time Chairs in departments of psychiatry.

    PubMed

    Buckley, Peter F; Rayburn, William F

    2011-01-01

    The authors examine the tenure of first-time Chairs in academic departments of psychiatry in order to stimulate discussion on extant workforce and leadership issues. Data on tenure of Chairs in psychiatry and other nonsurgical specialties were derived from the longitudinal database of the Association of American Medical Colleges and evaluated for successive 4-year epochs between 1983 and 2002. The 5-year retention rate of Chairs of academic departments of psychiatry is 68%, and the 10-year retention rate drops sharply to 39%, similar to other specialties. Although most first-time Chairs of psychiatry last 5 years in their position, much fewer remain 10 years or longer. Therefore, efforts to promote succession planning for academic leadership in psychiatry are warranted. Copyright © 2011 Academic Psychiatry

  17. "Piekara's Chair": Mechanical Model for Atomic Energy Levels.

    ERIC Educational Resources Information Center

    Golab-Meyer, Zofia

    1991-01-01

    Uses the teaching method of models or analogies, specifically the model called "Piekara's chair," to show how teaching classical mechanics can familiarize students with the notion of energy levels in atomic physics. (MDH)

  18. 39. BUILTIN WALNUT DESK AND ANTIQUE TUSCAN CHAIR IN NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. BUILT-IN WALNUT DESK AND ANTIQUE TUSCAN CHAIR IN NORTHWEST CORNER OF ENTRANCE FOYER WITH SUPPLEMENTAL FLASH ILLUMINATION. - Fallingwater, State Route 381 (Stewart Township), Ohiopyle, Fayette County, PA

  19. Pediatric palliative care: using miniature chairs to facilitate communication.

    PubMed

    Chin, Loh Ee; Loong, Lam Chee; Ngen, Chin Cheuk; Beng, Tan Seng; Shireen, Chin; Kuan, Wong Sook; Shaw, Rosalie

    2014-12-01

    Good communication is essential but sometimes challenging in pediatric palliative care. We describe 3 cases whereby miniature chairs made of various materials and colors were used successfully to encourage communication among pediatric patients, family, and health care professionals. This chair-inspired model may serve as a simple tool to facilitate complex discussions and to enable self-expression by children in the pediatric palliative care setting. © The Author(s) 2013.

  20. Effects of body temperature on post-anoxic oxidative stress from the perspective of postnatal physiological adaptive processes in rats.

    PubMed

    Kletkiewicz, H; Rogalska, J; Nowakowska, A; Wozniak, A; Mila-Kierzenkowska, C; Caputa, M

    2016-04-01

    It is well known that decrease in body temperature provides protection to newborns subjected to anoxia/ischemia. We hypothesized that the normal body temperature of 33°C in neonatal rats (4°C below normal body temperature in adults) is in fact a preadaptation to protect CNS from anoxia and further reductions as well as elevations in temperature may be counterproductive. Our experiments aimed to examine the effect of changes in body temperature on oxidative stress development in newborn rats exposed to anoxia. Two-day-old Wistar rats were divided into 4 temperature groups: i. hypothermic at body temperature of 31°C, ii. maintaining physiological neonatal body temperature of 33°C, iii. forced to maintain hyperthermic temperature of 37°C, and i.v. forced to maintain hyperthermic temperature of 39°C. The temperature was controlled starting 15 minutes before and afterword during 10 minutes of anoxia as well as for 2 hours post-anoxia. Cerebral concentrations of lipid peroxidation products malondialdehyde (MDA) and conjugated dienes (CD) and the activities of antioxidant enzymes had been determined post mortem: immediately after anoxia was finished and 3, 7, and 14 days later. There were no post-anoxic changes in the concentration of MDA, CD and in antioxidant enzymes activity in newborn rats kept at their physiological body temperature of 33°C. In contrast, perinatal anoxia at body temperature elevated to 37°C or 39°C as well as under hypothermic conditions (31°C) intensified post-anoxic oxidative stress and depleted the antioxidant pool. Overall, these findings suggest that elevated body temperature (hyperthermia or fever), as well as exceeding cooling beyond the physiological level of body temperature of newborn rats, may extend perinatal anoxia-induced brain lesions. Our findings provide new insights into the role of body temperature in anoxic insult in vivo.

  1. Pressure Induced Changes in Adaptive Immune Function in Belugas (Delphinapterus leucas); Implications for Dive Physiology and Health

    PubMed Central

    Thompson, Laura A.; Romano, Tracy A.

    2016-01-01

    Increased pressure, associated with diving, can alter cell function through several mechanisms and has been shown to impact immune functions performed by peripheral blood mononuclear cells (PBMC) in humans. While marine mammals possess specific adaptations which protect them from dive related injury, it is unknown how their immune system is adapted to the challenges associated with diving. The purpose of this study was to measure PBMC activation (IL2R expression) and Concanavalin A induced lymphocyte proliferation (BrdU incorporation) in belugas following in vitro pressure exposures during baseline, Out of Water Examination (OWE) and capture/release conditions. Beluga blood samples (n = 4) were obtained from animals at the Mystic Aquarium and from free ranging animals in Alaska (n = 9). Human blood samples (n = 4) (Biological Specialty Corporation) were run for comparison. In vivo catecholamines and cortisol were measured in belugas to characterize the neuroendocrine response. Comparison of cellular responses between controls and pressure exposed cells, between conditions in belugas, between belugas and humans as well as between dive profiles, were run using mixed generalized linear models (α = 0.05). Cortisol was significantly higher in Bristol Bay belugas and OWE samples as compared with baseline for aquarium animals. Both IL2R expression and proliferation displayed significant pressure induced changes, and these responses varied between conditions in belugas. Both belugas and humans displayed increased IL2R expression, while lymphocyte proliferation decreased for aquarium animals and increased for humans and Bristol Bay belugas. Results suggest beluga PBMC function is altered during diving and changes may represent dive adaptation as the response differs from humans, a non-dive adapted mammal. In addition, characteristics of a dive (i.e., duration, depth) as well as neuroendocrine activity can alter the response of beluga cells, potentially impacting the

  2. Pressure Induced Changes in Adaptive Immune Function in Belugas (Delphinapterus leucas); Implications for Dive Physiology and Health.

    PubMed

    Thompson, Laura A; Romano, Tracy A

    2016-01-01

    Increased pressure, associated with diving, can alter cell function through several mechanisms and has been shown to impact immune functions performed by peripheral blood mononuclear cells (PBMC) in humans. While marine mammals possess specific adaptations which protect them from dive related injury, it is unknown how their immune system is adapted to the challenges associated with diving. The purpose of this study was to measure PBMC activation (IL2R expression) and Concanavalin A induced lymphocyte proliferation (BrdU incorporation) in belugas following in vitro pressure exposures during baseline, Out of Water Examination (OWE) and capture/release conditions. Beluga blood samples (n = 4) were obtained from animals at the Mystic Aquarium and from free ranging animals in Alaska (n = 9). Human blood samples (n = 4) (Biological Specialty Corporation) were run for comparison. In vivo catecholamines and cortisol were measured in belugas to characterize the neuroendocrine response. Comparison of cellular responses between controls and pressure exposed cells, between conditions in belugas, between belugas and humans as well as between dive profiles, were run using mixed generalized linear models (α = 0.05). Cortisol was significantly higher in Bristol Bay belugas and OWE samples as compared with baseline for aquarium animals. Both IL2R expression and proliferation displayed significant pressure induced changes, and these responses varied between conditions in belugas. Both belugas and humans displayed increased IL2R expression, while lymphocyte proliferation decreased for aquarium animals and increased for humans and Bristol Bay belugas. Results suggest beluga PBMC function is altered during diving and changes may represent dive adaptation as the response differs from humans, a non-dive adapted mammal. In addition, characteristics of a dive (i.e., duration, depth) as well as neuroendocrine activity can alter the response of beluga cells, potentially impacting the

  3. Application of Physiological Self-Regulation and Adaptive Task Allocation Techniques for Controlling Operator Hazardous States of Awareness

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III; Pope, Alan T.; Freeman, Frederick G.

    2001-01-01

    Prinzel, Hadley, Freeman, and Mikulka found that adaptive task allocation significantly enhanced performance only when used at the endpoints of the task workload continuum (i.e., very low or high workload), but that the technique degraded performance if invoked during other levels of task demand. These researchers suggested that other techniques should be used in conjunction with adaptive automation to help minimize the onset of hazardous states of awareness (HSA) and keep the operator 'in-the-loop.' The paper reports on such a technique that uses psychophysiological self-regulation to modulate the level of task engagement. Eighteen participants were assigned to three groups (self-regulation, false feedback, and control) and performed a compensatory tracking task that was cycled between three levels of task difficulty on the basis of the electroencephalogram (EEG) record. Those participants who had received self-regulation training performed significantly better and reported lower NASA-TLX scores than participants in the false feedback and control groups. Furthermore, the false feedback and control groups had significantly more task allocations resulting in return-to-manual performance decrements and higher EEG difference scores. Theoretical and practical implications of these results for adaptive automation are discussed.

  4. The western painted turtle genome, a model for the evolution of extreme physiological adaptations in a slowly evolving lineage

    PubMed Central

    2013-01-01

    Background We describe the genome of the western painted turtle, Chrysemys picta bellii, one of the most widespread, abundant, and well-studied turtles. We place the genome into a comparative evolutionary context, and focus on genomic features associated with tooth loss, immune function, longevity, sex differentiation and determination, and the species' physiological capacities to withstand extreme anoxia and tissue freezing. Results Our phylogenetic analyses confirm that turtles are the sister group to living archosaurs, and demonstrate an extraordinarily slow rate of sequence evolution in the painted turtle. The ability of the painted turtle to withstand complete anoxia and partial freezing appears to be associated with common vertebrate gene networks, and we identify candidate genes for future functional analyses. Tooth loss shares a common pattern of pseudogenization and degradation of tooth-specific genes with birds, although the rate of accumulation of mutations is much slower in the painted turtle. Genes associated with sex differentiation generally reflect phylogeny rather than convergence in sex determination functionality. Among gene families that demonstrate exceptional expansions or show signatures of strong natural selection, immune function and musculoskeletal patterning genes are consistently over-represented. Conclusions Our comparative genomic analyses indicate that common vertebrate regulatory networks, some of which have analogs in human diseases, are often involved in the western painted turtle's extraordinary physiological capacities. As these regulatory pathways are analyzed at the functional level, the painted turtle may offer important insights into the management of a number of human health disorders. PMID:23537068

  5. 10 CFR 1023.5 - Duties and responsibilities of the Chair.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Duties and responsibilities of the Chair. 1023.5 Section..., Functions and Authorities § 1023.5 Duties and responsibilities of the Chair. The Chair shall be responsible... a majority of the members of the Board shall establish; (g) Designating an acting chair during the...

  6. 10 CFR 1023.5 - Duties and responsibilities of the Chair.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Duties and responsibilities of the Chair. 1023.5 Section..., Functions and Authorities § 1023.5 Duties and responsibilities of the Chair. The Chair shall be responsible... a majority of the members of the Board shall establish; (g) Designating an acting chair during the...

  7. The Art and Ethos of Chairing: Unpacking the Toolbox of Governance.

    ERIC Educational Resources Information Center

    Trommler, Frank

    2000-01-01

    Discusses the art and ethos of chairing or governance and all of the duties and responsibilities in being a department chair. The chair develops multiple personalities as administrator, mediator, visionary, and entrepreneur. Eight important tools are identified that a chair has at hand to carry out the multifarious work and maintain an effective…

  8. Staphylococcal adaptation to diverse physiologic niches: an overview of transcriptomic and phenotypic changes in different biological environments

    PubMed Central

    Dastgheyb, Sana S; Otto, Michael

    2015-01-01

    Host niches can differ strongly regarding, for example, oxygen tension, pH or nutrient availability. Staphylococcus aureus and other staphylococci are common colonizers of human epithelia as well as important human pathogens. The phenotypes that they show in different host environments, and the corresponding bacterial transcriptomes and proteomes, are currently under intense investigation. In this review, we examine the available literature describing staphylococcal phenotypes, such as expression of virulence factors, gross morphologic characteristics and growth patterns, in various physiological environments. Going forward, these studies will help researchers and clinicians to form an enhanced and more detailed picture of the interactions existing between the host and staphylococci as some of its most frequent colonizers and invaders. PMID:26584249

  9. Physiological and biomechanical adaptations to the cycle to run transition in Olympic triathlon: review and practical recommendations for training.

    PubMed

    Millet, G P; Vleck, V E

    2000-10-01

    Current knowledge of the physiological, biomechanical, and sensory effects of the cycle to run transition in the Olympic triathlon (1.5 km, 10 km, 40 km) is reviewed and implications for the training of junior and elite triathletes are discussed. Triathlon running elicits hyperventilation, increased heart rate, decreased pulmonary compliance, and exercise induced hypoxaemia. This may be due to exercise intensity, ventilatory muscle fatigue, dehydration, muscle fibre damage, a shift in metabolism towards fat oxidation, and depleted glycogen stores after a 40 km cycle. The energy cost (CR) of running during the cycle to run transition is also increased over that of control running. The increase in CR varies from 1.6% to 11.6% and is a reflection of triathlete ability level. This increase may be partly related to kinematic alterations, but research suggests that most biomechanical parameters are unchanged. A more forward leaning trunk inclination is the most significant observation reported. Running pattern, and thus running economy, could also be influenced by sensorimotor perturbations related to the change in posture. Technical skill in the transition area is obviously very important. The conditions under which the preceding cycling section is performed-that is, steady state or stochastic power output, drafting or non-drafting-are likely to influence the speed of adjustment to transition. The extent to which a decrease in the average 10 km running speed occurs during competition must be investigated further. It is clear that the higher the athlete is placed in the field at the end of the bike section, the greater the importance to their finishing position of both a quick transition area time and optimal adjustment to the physiological demands of the cycle to run transition. The need for, and current methods of, training to prepare junior and elite triathletes for a better transition are critically reviewed in light of the effects of sequential cycle to run exercise.

  10. Physiological and biomechanical adaptations to the cycle to run transition in Olympic triathlon: review and practical recommendations for training

    PubMed Central

    Millet, G.; Vleck, V.

    2000-01-01

    Current knowledge of the physiological, biomechanical, and sensory effects of the cycle to run transition in the Olympic triathlon (1.5 km, 10 km, 40 km) is reviewed and implications for the training of junior and elite triathletes are discussed. Triathlon running elicits hyperventilation, increased heart rate, decreased pulmonary compliance, and exercise induced hypoxaemia. This may be due to exercise intensity, ventilatory muscle fatigue, dehydration, muscle fibre damage, a shift in metabolism towards fat oxidation, and depleted glycogen stores after a 40 km cycle. The energy cost (CR) of running during the cycle to run transition is also increased over that of control running. The increase in CR varies from 1.6% to 11.6% and is a reflection of triathlete ability level. This increase may be partly related to kinematic alterations, but research suggests that most biomechanical parameters are unchanged. A more forward leaning trunk inclination is the most significant observation reported. Running pattern, and thus running economy, could also be influenced by sensorimotor perturbations related to the change in posture. Technical skill in the transition area is obviously very important. The conditions under which the preceding cycling section is performed—that is, steady state or stochastic power output, drafting or non-drafting—are likely to influence the speed of adjustment to transition. The extent to which a decrease in the average 10 km running speed occurs during competition must be investigated further. It is clear that the higher the athlete is placed in the field at the end of the bike section, the greater the importance to their finishing position of both a quick transition area time and optimal adjustment to the physiological demands of the cycle to run transition. The need for, and current methods of, training to prepare junior and elite triathletes for a better transition are critically reviewed in light of the effects of sequential cycle to run

  11. Fasting in the American marten (Martes americana): a physiological model of the adaptations of a lean-bodied animal.

    PubMed

    Nieminen, Petteri; Rouvinen-Watt, Kirsti; Saarela, Seppo; Mustonen, Anne-Mari

    2007-10-01

    The American marten (Martes americana) is a boreal forest marten with low body adiposity throughout the year. The aim of this study was to investigate the adaptations of this lean-bodied species to fasting for an ecologically relevant duration (48 h) by exposing eight farm-bred animals to total food deprivation with seven control animals. Selected morphological and hematological parameters, plasma and serum biochemistry, endocrinological variables and liver and white adipose tissue (WAT) enzyme activities were determined. After 48 h without food, the marten were within phase II of fasting with depleted liver and muscle glycogen stores, but with active lipid mobilization indicated by the high lipase activities in several WAT depots. The plasma ghrelin concentrations were higher due to food deprivation, possibly increasing appetite and enhancing foraging behavior. The lower plasma insulin and higher cortisol concentrations could mediate augmented lipolysis and the lower triiodothyronine levels could suppress the metabolic rate. Fasting did not affect the plasma levels of stress-associated catecholamines or variables indicating tissue damage. In general, the adaptations to short-term fasting exhibited some differences compared to the related farm-bred American mink (Mustela vison), an example of which was the better ability of the marten to hydrolyze lipids despite its significantly lower initial fat mass.

  12. Physiological and cell morphology adaptation of Bacillus subtilis at near-zero specific growth rates: a transcriptome analysis.

    PubMed

    Overkamp, Wout; Ercan, Onur; Herber, Martijn; van Maris, Antonius J A; Kleerebezem, Michiel; Kuipers, Oscar P

    2015-02-01

    Nutrient scarcity is a common condition in nature, but the resulting extremely low growth rates (below 0.025 h(-1) ) are an unexplored research area in Bacillus subtilis. To understand microbial life in natural environments, studying the adaptation of B. subtilis to near-zero growth conditions is relevant. To this end, a chemostat modified for culturing an asporogenous B. subtilis sigF mutant strain at extremely low growth rates (also named a retentostat) was set up, and biomass accumulation, culture viability, metabolite production and cell morphology were analysed. During retentostat culturing, the specific growth rate decreased to a minimum of 0.00006 h(-1) , corresponding to a doubling time of 470 days. The energy distribution between growth and maintenance-related processes showed that a state of near-zero growth was reached. Remarkably, a filamentous cell morphology emerged, suggesting that cell separation is impaired under near-zero growth conditions. To evaluate the corresponding molecular adaptations to extremely low specific growth, transcriptome changes were analysed. These revealed that cellular responses to near-zero growth conditions share several similarities with those of cells during the stationary phase of batch growth. However, fundamental differences between these two non-growing states are apparent by their high viability and absence of stationary phase mutagenesis under near-zero growth conditions.

  13. Functional evidence for physiological mechanisms to circumvent neurotoxicity of cardenolides in an adapted and a non-adapted hawk-moth species

    PubMed Central

    Petschenka, Georg; Pick, Christian; Wagschal, Vera; Dobler, Susanne

    2013-01-01

    Because cardenolides specifically inhibit the Na+K+-ATPase, insects feeding on cardenolide-containing plants need to circumvent this toxic effect. Some insects such as the monarch butterfly rely on target site insensitivity, yet other cardenolide-adapted lepidopterans such as the oleander hawk-moth, Daphnis nerii, possess highly sensitive Na+K+-ATPases. Nevertheless, larvae of this species and the related Manduca sexta are insensitive to injected cardenolides. By radioactive-binding assays with nerve cords of both species, we demonstrate that the perineurium surrounding the nervous tissue functions as a diffusion barrier for a polar cardenolide (ouabain). By contrast, for non-polar cardenolides such as digoxin an active efflux carrier limits the access to the nerve cord. This barrier can be abolished by metabolic inhibitors and by verapamil, a specific inhibitor of P-glycoproteins (PGPs). This supports that a PGP-like transporter is involved in the active cardenolide-barrier of the perineurium. Tissue specific RT-PCR demonstrated expression of three PGP-like genes in hornworm nerve cords, and immunohistochemistry further corroborated PGP expression in the perineurium. Our results thus suggest that the lepidopteran perineurium serves as a diffusion barrier for polar cardenolides and provides an active barrier for non-polar cardenolides. This may explain the high in vivo resistance to cardenolides observed in some lepidopteran larvae, despite their highly sensitive Na+K+-ATPases. PMID:23516239

  14. The matricellular protein cysteine-rich protein 61 (CCN1/Cyr61) enhances physiological adaptation of retinal vessels and reduces pathological neovascularization associated with ischemic retinopathy.

    PubMed

    Hasan, Adeel; Pokeza, Nataliya; Shaw, Lynn; Lee, Hyun-Seung; Lazzaro, Douglas; Chintala, Hemabindu; Rosenbaum, Daniel; Grant, Maria B; Chaqour, Brahim

    2011-03-18

    Retinal vascular damages are the cardinal hallmarks of retinopathy of prematurity (ROP), a leading cause of vision impairment and blindness in childhood. Both angiogenesis and vasculogenesis are disrupted in the hyperoxia-induced vaso-obliteration phase, and recapitulated, although aberrantly, in the subsequent ischemia-induced neovessel formation phase of ROP. Yet, whereas the histopathological features of ROP are well characterized, many key modulators with a therapeutic potential remain unknown. The CCN1 protein also known as cysteine-rich protein 61 (Cyr61) is a dynamically expressed, matricellular protein required for proper angiogenesis and vasculogenesis during development. The expression of CCN1 becomes abnormally reduced during the hyperoxic and ischemic phases of ROP modeled in the mouse eye with oxygen-induced retinopathy (OIR). Lentivirus-mediated re-expression of CCN1 enhanced physiological adaptation of the retinal vasculature to hyperoxia and reduced pathological angiogenesis following ischemia. Remarkably, injection into the vitreous of OIR mice of hematopoietic stem cells (HSCs) engineered to express CCN1 harnessed ischemia-induced neovessel outgrowth without adversely affecting the physiological adaptation of retinal vessels to hyperoxia. In vitro exposure of HSCs to recombinant CCN1 induced integrin-dependent cell adhesion, migration, and expression of specific endothelial cell markers as well as many components of the Wnt signaling pathway including Wnt ligands, their receptors, inhibitors, and downstream targets. CCN1-induced Wnt signaling mediated, at least in part, adhesion and endothelial differentiation of cultured HSCs, and inhibition of Wnt signaling interfered with normalization of the retinal vasculature induced by CCN1-primed HSCs in OIR mice. These newly identified functions of CCN1 suggest its possible therapeutic utility in ischemic retinopathy.

  15. Physiological adaptations in the lichens Peltigera rufescens and Cladina arbuscula var. mitis, and the moss Racomitrium lanuginosum to copper-rich substrate.

    PubMed

    Backor, Martin; Klejdus, Borivoj; Vantová, Ivana; Kovácik, Jozef

    2009-09-01

    Two lichen species (Peltigera rufescens and Cladina arbuscula subsp. mitis) and one moss species (Racomitrium lanuginosum) growing on a copper mine heaps (probably 200-300yr old) in the village of Spania dolina (Slovak Republic) were assessed for selected physiological parameters, including composition of assimilation pigments, chlorophyll a fluorescence, soluble proteins and free amino acid content. The lichen C. arbuscula subsp. mitis was collected also at a control locality where total copper concentration in the soil was approximately 3% that of the waste heaps. Concentrations of Al, Co, Cu, Ni, Sb and Zn were highest in thalli of Peltigera, while the moss Racomitrium contained the highest content of Fe and Pb. Thalli of Cladina contained less metals than the cyanolichen Peltigera, and except for Zn metal concentrations in Cladina from the control locality were lower than in thalli of the same species from copper mine heaps. Regardless of the species or locality, the composition of assimilation pigments and chlorophyll a fluorescence showed that the tested lichens and moss were in good physiological condition and adapted to increased copper levels in the soil. There were significantly different amounts of total free amino acids in Peltigera, Cladina and Racomitrium from the Cu-polluted field. However, differences in amount of free amino acids in control, as well as Cu-polluted thalli of Cladina were less pronounced.

  16. Physiological and molecular characterization of atypical lipid-dependent Malassezia yeasts from a dog with skin lesions: adaptation to a new host?

    PubMed

    Cafarchia, C; Latrofa, M S; Figueredo, L A; da Silva Machado, M L; Ferreiro, L; Guillot, J; Boekhout, T; Otranto, D

    2011-05-01

    Three lipid-dependent Malassezia isolates (here named 114A, 114B and 114C) recovered from a dog with skin lesions were phenotypically and genotypically characterized. All presented ovoid cells and buds formed on a narrow base. Most of the results from physiological tests were consistent with those of Malassezia furfur. The phylogenetic analysis of ITS-1 and LSU nucleotide sequences was concordant in placing all three clinical Malassezia isolates close to M. furfur. However, the phylogenetic data on the chs-2 sequence revealed that clinical isolate 114A is distinct from M. furfur and was closely affiliated to the sequence of M. pachydermatis with high nodal support. In particular, lipid-dependent isolates 114A displayed chs-2 sequences similar (100%) to that of the non-lipid dependent species Malassezia pachydermatis. The presence of the genetic and physiological polymorphisms detected in these three isolates of M. furfur could have resulted from a process of adaptation of this anthropophilic species to a new host.

  17. Do Telomeres Adapt to Physiological Stress? Exploring the Effect of Exercise on Telomere Length and Telomere-Related Proteins

    PubMed Central

    Ludlow, Andrew T.; Ludlow, Lindsay W.; Roth, Stephen M.

    2013-01-01

    Aging is associated with a tissue degeneration phenotype marked by a loss of tissue regenerative capacity. Regenerative capacity is dictated by environmental and genetic factors that govern the balance between damage and repair. The age-associated changes in the ability of tissues to replace lost or damaged cells is partly the cause of many age-related diseases such as Alzheimer's disease, cardiovascular disease, type II diabetes, and sarcopenia. A well-established marker of the aging process is the length of the protective cap at the ends of chromosomes, called telomeres. Telomeres shorten with each cell division and with increasing chronological age and short telomeres have been associated with a range of age-related diseases. Several studies have shown that chronic exposure to exercise (i.e., exercise training) is associated with telomere length maintenance; however, recent evidence points out several controversial issues concerning tissue-specific telomere length responses. The goals of the review are to familiarize the reader with the current telomere dogma, review the literature exploring the interactions of exercise with telomere phenotypes, discuss the mechanistic research relating telomere dynamics to exercise stimuli, and finally propose future directions for work related to telomeres and physiological stress. PMID:24455708

  18. Whole transcriptome analysis of the fasting and fed Burmese python heart: insights into extreme physiological cardiac adaptation.

    PubMed

    Wall, Christopher E; Cozza, Steven; Riquelme, Cecilia A; McCombie, W Richard; Heimiller, Joseph K; Marr, Thomas G; Leinwand, Leslie A

    2011-01-01

    The infrequently feeding Burmese python (Python molurus) experiences significant and rapid postprandial cardiac hypertrophy followed by regression as digestion is completed. To begin to explore the molecular mechanisms of this response, we have sequenced and assembled the fasted and postfed Burmese python heart transcriptomes with Illumina technology using the chicken (Gallus gallus) genome as a reference. In addition, we have used RNA-seq analysis to identify differences in the expression of biological processes and signaling pathways between fasted, 1 day postfed (DPF), and 3 DPF hearts. Out of a combined transcriptome of ∼2,800 mRNAs, 464 genes were differentially expressed. Genes showing differential expression at 1 DPF compared with fasted were enriched for biological processes involved in metabolism and energetics, while genes showing differential expression at 3 DPF compared with fasted were enriched for processes involved in biogenesis, structural remodeling, and organization. Moreover, we present evidence for the activation of physiological and not pathological signaling pathways in this rapid, novel model of cardiac growth in pythons. Together, our data provide the first comprehensive gene expression profile for a reptile heart.

  19. Do telomeres adapt to physiological stress? Exploring the effect of exercise on telomere length and telomere-related proteins.

    PubMed

    Ludlow, Andrew T; Ludlow, Lindsay W; Roth, Stephen M

    2013-01-01

    Aging is associated with a tissue degeneration phenotype marked by a loss of tissue regenerative capacity. Regenerative capacity is dictated by environmental and genetic factors that govern the balance between damage and repair. The age-associated changes in the ability of tissues to replace lost or damaged cells is partly the cause of many age-related diseases such as Alzheimer's disease, cardiovascular disease, type II diabetes, and sarcopenia. A well-established marker of the aging process is the length of the protective cap at the ends of chromosomes, called telomeres. Telomeres shorten with each cell division and with increasing chronological age and short telomeres have been associated with a range of age-related diseases. Several studies have shown that chronic exposure to exercise (i.e., exercise training) is associated with telomere length maintenance; however, recent evidence points out several controversial issues concerning tissue-specific telomere length responses. The goals of the review are to familiarize the reader with the current telomere dogma, review the literature exploring the interactions of exercise with telomere phenotypes, discuss the mechanistic research relating telomere dynamics to exercise stimuli, and finally propose future directions for work related to telomeres and physiological stress.

  20. Influence of Chair Vibrations on Indoor Sonic Boom Annoyance

    NASA Technical Reports Server (NTRS)

    Rathsam, Jonathan; Klos, Jacob; Loubeau, Alexandra

    2015-01-01

    One goal of NASA’s Commercial Supersonic Technology Project is to identify candidate noise metrics suitable for regulating quiet sonic boom aircraft. A suitable metric must consider the short duration and pronounced low frequency content of sonic booms. For indoor listeners, rattle and creaking sounds and floor and chair vibrations may also be important. The current study examined the effect of such vibrations on the annoyance of test subjects seated indoors. The study involved two chairs exposed to nearly identical acoustic levels: one placed directly on the floor, and the other isolated from floor vibrations by pneumatic elastomeric mounts. All subjects experienced both chairs, sitting in one chair for the first half of the experiment and the other chair for the remaining half. Each half of the experiment consisted of 80 impulsive noises played at the exterior of the sonic boom simulator. When all annoyance ratings were analyzed together there appeared to be no difference in mean annoyance with isolation condition. When the apparent effect of transfer bias was removed, a subtle but measurable effect of vibration on annoyance was identified.

  1. The microbiological quality of water in dental chair units.

    PubMed

    Pankhurst, C L; Philpott-Howard, J N

    1993-03-01

    Infection control is an important issue in the dental surgery but the potential hazards associated with contaminated dental water have received relatively little attention in recent years. The complex design of the equipment results in stagnation of water within the dental chair and subsequent amplification of contaminating environmental organisms, including pseudomonads and legionellae, to potentially hazardous levels. Immunocompromised patients may be at particular risk of infection. Very poor water quality with total bacterial counts above 10(4) ml-1 is unpleasant for all patients, and the dental chair supply should be of drinking water quality. In addition to these problems, bacteria and viruses may be aspirated from the oral cavity and contaminate the handpiece. Measures to reduce microbial contamination of dental chairs and equipment include flushing water through the chair's equipment at the beginning of each day; continuous or pulsed water chlorination, or application of biocides other than chlorine; provision of sterile bottled water in the system; and autoclaving handpieces between patients. Future dental chair design must attempt to resolve the problems associated with microbial contamination of the water supply and aerosols generated during dental procedures.

  2. Influence of chair vibrations on indoor sonic boom annoyance

    NASA Astrophysics Data System (ADS)

    Rathsam, Jonathan; Klos, Jacob; Loubeau, Alexandra

    2015-10-01

    One goal of NASA's Commercial Supersonic Technology Project is to identify candidate noise metrics suitable for regulating quiet sonic boom aircraft. A suitable metric must consider the short duration and pronounced low frequency content of sonic booms. For indoor listeners, rattle and creaking sounds and floor and chair vibrations may also be important. The current study examined the effect of such vibrations on the annoyance of test subjects seated indoors. The study involved two chairs exposed to nearly identical acoustic levels: one placed directly on the floor, and the other isolated from floor vibrations by pneumatic elastomeric mounts. All subjects experienced both chairs, sitting in one chair for the first half of the experiment and the other chair for the remaining half. Each half of the experiment consisted of 80 impulsive noises played at the exterior of the sonic boom simulator. When all annoyance ratings were analyzed together there appeared to be no difference in mean annoyance with isolation condition. When the apparent effect of transfer bias was removed, a subtle but measurable effect of vibration on annoyance was identified.

  3. Classroom furniture design--correlation of pupil and chair dimensions.

    PubMed

    Domljan, Danijela; Grbac, Ivica; Hadina, Julijana

    2008-03-01

    The present study aimed at determining the relationship of anthropometric dimensions of pupils from grades 1 to 8 in primary school with the dimensions of school chairs. Two dimensions of the chairs in daily use were evaluated to ascertain whether the fit is sufficient and the effect on pupils' sitting posture. The work included a sample of 556 pupils from three primary schools in Zagreb, Croatia and two types of furniture. Dimensions of school chairs were compared with three anthropometric variables of the pupils. Descriptive statistics were analysed for all variables. These study results have shown that furniture of appropriate dimensions is not available to a large number of students in Croatia. Currently supplied classroom equipment is provided in only two sizes and does not fit the users. It is recommended that task chairs may be acceptable if they are issued in four heights or individually adjustable chairs be introduced in Croatian schools. Furthermore it is strongly recommended that schools actively promote appropriate active sitting behaviour.

  4. The influence of chair seat height on the performance of community-dwelling older adults' 30-second chair stand test.

    PubMed

    Kuo, Yi-Liang

    2013-06-01

    Although chair seat height affects the performance of sit-to-stand movement, no previous study has examined the influence of chair seat height on the 30-second chair stand test (CST). Fifty-five community-dwelling older adults (age 70.0 ± 6.3 years) performed the test from the standard height of 43 cm and then from five randomly ordered seat heights from 80 to 120 % of each participant's lower leg length. Chair seat height significantly influences the performance of community-dwelling older adults' 30-s CST (F = 57.50, p < 0.001). The mean score for standard conditions was significantly lower from those at 120, 110, and 100 % conditions (p < 0.05). No significant difference was observed between the standard and 80 % conditions (p > 0.95) and between the standard and 90 % conditions (p = 0.353). When comparing the scores between the randomly ordered chair seat heights, all comparisons were significantly different (p < 0.001) except for the difference between the 120 and 110 % conditions (p = 0.104). Chair seat height's relation to the lower leg length should be considered when interpreting 30-s CST scores. Additionally, it is necessary to optimize the chair seat height when using the 30-s CST as an outcome measure for exercise intervention or to screen for people with weaker lower extremities.

  5. Does a prototype 'Experimental' chair facilitate more postural changes in computing adolescents compared to a normal school chair?

    PubMed

    van Niekerk, Sjan-Mari; Louw, Quinette Abegail; Grimmer, Karen

    2016-09-27

    Prolonged sitting, such as when computing, has been linked to adolescent spinal pain. A chair should fit the user's body dimensions and aid the user in frequently changing sitting posture, rather than support one 'ideal' posture. Such a chair is not currently available to high school learners. To develop a novel experimental school chair. To determine whether the experimental chair encourages regular small range movement in all directions whilst students work at computers in class. To compare the number of postural changes between the normal static school chair and the experimental chair, whilst students do computing work. A development and validation study was conducted. Twelve high school students were randomly selected from a conveniently selected school. Fifteen minutes of 3D posture measurements were collected in both the prototype and school computer chair. The analysis focused on the frequency of postural movement. Data of eleven learners were analysed. There were statistically significant increases in the number of postural changes on the 'Experimental' chair compared to the school chair, for both pelvic side-flexion and pelvic rotation (ρ= 0.01). The experimental chair provided more postural movements when compared to the school computer chair. Future studies should use this experimental chair to determine the effect of increased postural movement, of especially the pelvis, on the prevalence and intensity of musculoskeletal symptoms of high school learners in the Cape Metropole area, Western Cape, South Africa.

  6. Genome-Guided Analysis of Physiological Capacities of Tepidanaerobacter acetatoxydans Provides Insights into Environmental Adaptations and Syntrophic Acetate Oxidation

    PubMed Central

    Niazi, Adnan; Bongcam-Rudloff, Erik; Schnürer, Anna

    2015-01-01

    This paper describes the genome-based analysis of Tepidanaerobacter acetatoxydans strain Re1, a syntrophic acetate-oxidising bacterium (SAOB). Principal issues such as environmental adaptations, metabolic capacities, and energy conserving systems have been investigated and the potential consequences for syntrophic acetate oxidation discussed. Briefly, in pure culture, T. acetatoxydans grows with different organic compounds and produces acetate as the main product. In a syntrophic consortium with a hydrogenotrophic methanogen, it can also reverse its metabolism and instead convert acetate to formate/H2 and CO2. It can only proceed if the product formed is continuously removed. This process generates a very small amount of energy that is scarcely enough for growth, which makes this particular syntrophy of special interest. As a crucial member of the biogas-producing community in ammonium-rich engineered AD processes, genomic features conferring ammonium resistance, bacterial defense, oxygen and temperature tolerance were found, as well as attributes related to biofilm formation and flocculation. It is likely that T. acetatoxydans can form an electrochemical gradient by putative electron-bifurcating Rnf complex and [Fe-Fe] hydrogenases, as observed in other acetogens. However, genomic deficiencies related to acetogenic metabolism and anaerobic respiration were discovered, such as the lack of formate dehydrogenase and F1F0 ATP synthase. This has potential consequences for the metabolic pathways used under SAO and non-SAO conditions. The two complete sets of bacteriophage genomes, which were found to be encoded in the genome, are also worthy of mention. PMID:25811859

  7. Proteomic analysis reveals oxidative stress response as the main adaptative physiological mechanism in cows under different production systems.

    PubMed

    Marco-Ramell, Anna; Arroyo, Laura; Saco, Yolanda; García-Heredia, Anabel; Camps, Jordi; Fina, Marta; Piedrafita, Jesús; Bassols, Anna

    2012-07-19

    Three groups of cows representing three ranges of welfare in the production system were included in the study: two groups of Bruna dels Pirineus beef cattle maintained under different management systems (good and semiferal conditions) and a group of Alberes cows, a breed that lives in the mountains (hardest conditions). In order to identify new stress/welfare biomarkers, serum from Bruna cows living in both environments was subjected to DIGE labelling, two-dimensional electrophoresis and MALDI-MS or ion trap MS. Identification was achieved for 15 proteins, which mainly belonged to three biological functions, the oxidative stress pathway (glutathione peroxidase (GPx) and paraoxonase (PON-1)), the acute phase protein family (Heremans Schmid glycoprotein alpha2 (α2-HSG)) and the complement system. Biological validation included the Alberes breed. GPx and PON-1 were validated by an enzymatic assay and found to be higher and lower, respectively, in cows living in hard conditions. α2-HSG was validated by ELISA and found to be reduced in hard conditions. Other biomarkers of the redox status were also altered by living conditions: protein carbonyl content, superoxide dismutase (SOD) and glutathione reductase (GR). Our results show that changes in the redox system are the main adaptation of cows living in challenging environmental conditions.

  8. Effect of walking stress on growth, physiological adaptability and endocrine responses in Malpura ewes in a semi-arid tropical environment

    NASA Astrophysics Data System (ADS)

    Sejian, Veerasamy; Maurya, Vijai P.; Naqvi, Syed M. K.

    2012-03-01

    Sheep in hot semi-arid environments are mostly reared using extensive systems. In addition to thermal stress and feed scarcity, the animals need to walk long distances for grazing in this ecological zone. A study was conducted to assess the effect of long-distance walking on adaptive capability in terms of physiological, biochemical and endocrine responses in Malpura ewes. Fourteen adult Malpura non-pregnant ewes weighing between 33 and 35 kg were used in the study. The ewes were randomly allocated into two groups of seven animals each: GI ( n = 7; Control), and GII ( n = 7; walking stress). The animals were stall-fed with a diet consisting of 70% roughage and 30% concentrate. Both GI and GII ewes had uniform access to feed and water. The walking stress group (GII) ewes were made to walk 14 km in two spans between 0900 and 1500 hours with 1 h 30 min for each span (7 km) of walking. The ewes subjected to walking stress (GII) were prevented from grazing by applying a face mask made of cotton thread. The study was conducted for a period of two estrous cycles (35 days) during the autumn season (October-November). Physiological responses were recorded twice daily at 0800 and 1400 hours at weekly intervals. Blood samples were collected from the jugular vein at weekly intervals to study the effects of walking stress on blood biochemical and endocrine parameters. The results indicate that walking stress had significant ( P < 0.05) influence on body weight, average daily gain, respiration rate (RR), rectal temperature (RT), haemoglobin (Hb), packed cell volume (PCV), plasma glucose, calcium, phosphorus, aspartate amino transferase (AST), alanine amino transferase (ALT), tri-iodo-thyronine (T3), thyroxin (T4), and cortisol. However, walking stress did not influence the reproductive hormone levels. The significant changes in RR, RT, plasma cortisol, T3 and T4 show that Malpura ewes have the capability to adapt to long-distance walking, and that adrenal and thyroid gland

  9. Effect of walking stress on growth, physiological adaptability and endocrine responses in Malpura ewes in a semi-arid tropical environment.

    PubMed

    Sejian, Veerasamy; Maurya, Vijai P; Naqvi, Syed M K

    2012-03-01

    Sheep in hot semi-arid environments are mostly reared using extensive systems. In addition to thermal stress and feed scarcity, the animals need to walk long distances for grazing in this ecological zone. A study was conducted to assess the effect of long-distance walking on adaptive capability in terms of physiological, biochemical and endocrine responses in Malpura ewes. Fourteen adult Malpura non-pregnant ewes weighing between 33 and 35 kg were used in the study. The ewes were randomly allocated into two groups of seven animals each: GI (n = 7; Control), and GII (n = 7; walking stress). The animals were stall-fed with a diet consisting of 70% roughage and 30% concentrate. Both GI and GII ewes had uniform access to feed and water. The walking stress group (GII) ewes were made to walk 14 km in two spans between 0900 and 1500 hours with 1 h 30 min for each span (7 km) of walking. The ewes subjected to walking stress (GII) were prevented from grazing by applying a face mask made of cotton thread. The study was conducted for a period of two estrous cycles (35 days) during the autumn season (October-November). Physiological responses were recorded twice daily at 0800 and 1400 hours at weekly intervals. Blood samples were collected from the jugular vein at weekly intervals to study the effects of walking stress on blood biochemical and endocrine parameters. The results indicate that walking stress had significant (P < 0.05) influence on body weight, average daily gain, respiration rate (RR), rectal temperature (RT), haemoglobin (Hb), packed cell volume (PCV), plasma glucose, calcium, phosphorus, aspartate amino transferase (AST), alanine amino transferase (ALT), tri-iodo-thyronine (T(3)), thyroxin (T(4)), and cortisol. However, walking stress did not influence the reproductive hormone levels. The significant changes in RR, RT, plasma cortisol, T(3) and T(4) show that Malpura ewes have the capability to adapt to long-distance walking, and that adrenal and

  10. A New Version of the Beuchet Chair Illusion.

    PubMed

    Wiseman, Richard

    2016-01-01

    The Beuchet Chair is a powerful and highly popular optical illusion. The illusion involves two reasonably large pieces of apparatus: an oversized chair seat and four normal-sized chair legs. When properly arranged and viewed from a precise location, a person standing on the seat appears to be much smaller than they actually are. Although compelling, the illusion is relatively challenging and expensive to construct, requires a large amount of space to stage, and is not especially portable. Here, I outline a new version of the illusion that just involves a small piece of cardboard, a cloth, and a tripod. This new version costs almost nothing to create, is highly portable, and requires far less space than the original.

  11. A New Version of the Beuchet Chair Illusion

    PubMed Central

    2016-01-01

    The Beuchet Chair is a powerful and highly popular optical illusion. The illusion involves two reasonably large pieces of apparatus: an oversized chair seat and four normal-sized chair legs. When properly arranged and viewed from a precise location, a person standing on the seat appears to be much smaller than they actually are. Although compelling, the illusion is relatively challenging and expensive to construct, requires a large amount of space to stage, and is not especially portable. Here, I outline a new version of the illusion that just involves a small piece of cardboard, a cloth, and a tripod. This new version costs almost nothing to create, is highly portable, and requires far less space than the original. PMID:27928495

  12. The Difference of Physiological and Proteomic Changes in Maize Leaves Adaptation to Drought, Heat, and Combined Both Stresses

    PubMed Central

    Zhao, Feiyun; Zhang, Dayong; Zhao, Yulong; Wang, Wei; Yang, Hao; Tai, Fuju; Li, Chaohai; Hu, Xiuli

    2016-01-01

    At the eight-leaf stage, maize is highly sensitive to stresses such as drought, heat, and their combination, which greatly affect its yield. At present, few studies have analyzed maize response to combined drought and heat stress at the eight-leaf stage. In this study, we measured certain physical parameters of maize at the eight-leaf stage when it was exposed to drought, heat, and their combination. The results showed an increase in the content of H2O2 and malondialdehyde (MDA), and in the enzyme activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR), but a decrease in the quantum efficiency of photosystem II (ΦPSII). The most obvious increase or decrease in physical parameters was found under the combined stress condition. Moreover, to identify proteins differentially regulated by the three stress conditions at the eight-leaf stage, total proteins from the maize leaves were identified and quantified using multiplex iTRAQ-based quantitative proteomic and LC-MS/MS methods. In summary, the expression levels of 135, 65, and 201 proteins were significantly changed under the heat, drought and combined stress conditions, respectively. Of the 135, 65, and 201 differentially expressed proteins, 61, 28, and 16 responded exclusively to drought stress, heat stress, and combined stress, respectively. Bioinformatics analysis implied that chaperone proteins and proteases play important roles in the adaptive response of maize to heat stress and combined stress, and that the leaf senescence promoted by ethylene-responsive protein and ripening-related protein may play active roles in maize tolerance to combined drought and heat stress. The signaling pathways related to differentially expressed proteins were obviously different under all three stress conditions. Thus, the functional characterization of these differentially expressed proteins will be helpful for discovering new targets to enhance maize tolerance to stress. PMID:27833614

  13. Leaf Physiological and Proteomic Analysis to Elucidate Silicon Induced Adaptive Response under Salt Stress in Rosa hybrida 'Rock Fire'.

    PubMed

    Soundararajan, Prabhakaran; Manivannan, Abinaya; Ko, Chung Ho; Muneer, Sowbiya; Jeong, Byoung Ryong

    2017-08-14

    understanding on potential mechanism(s) adapted by rose due to the exogenous Si supplementation during the salinity stress.

  14. Genus-Wide Comparative Genomics of Malassezia Delineates Its Phylogeny, Physiology, and Niche Adaptation on Human Skin

    PubMed Central

    Wu, Guangxi; Zhao, He; Li, Chenhao; Rajapakse, Menaka Priyadarsani; Wong, Wing Cheong; Xu, Jun; Saunders, Charles W.; Reeder, Nancy L.; Reilman, Raymond A.; Scheynius, Annika; Sun, Sheng; Billmyre, Blake Robert; Li, Wenjun; Averette, Anna Floyd; Mieczkowski, Piotr; Heitman, Joseph; Theelen, Bart; Schröder, Markus S.; De Sessions, Paola Florez; Butler, Geraldine; Maurer-Stroh, Sebastian; Boekhout, Teun; Nagarajan, Niranjan; Dawson, Thomas L.

    2015-01-01

    Malassezia is a unique lipophilic genus in class Malasseziomycetes in Ustilaginomycotina, (Basidiomycota, fungi) that otherwise consists almost exclusively of plant pathogens. Malassezia are typically isolated from warm-blooded animals, are dominant members of the human skin mycobiome and are associated with common skin disorders. To characterize the genetic basis of the unique phenotypes of Malassezia spp., we sequenced the genomes of all 14 accepted species and used comparative genomics against a broad panel of fungal genomes to comprehensively identify distinct features that define the Malassezia gene repertoire: gene gain and loss; selection signatures; and lineage-specific gene family expansions. Our analysis revealed key gene gain events (64) with a single gene conserved across all Malassezia but absent in all other sequenced Basidiomycota. These likely horizontally transferred genes provide intriguing gain-of-function events and prime candidates to explain the emergence of Malassezia. A larger set of genes (741) were lost, with enrichment for glycosyl hydrolases and carbohydrate metabolism, concordant with adaptation to skin’s carbohydrate-deficient environment. Gene family analysis revealed extensive turnover and underlined the importance of secretory lipases, phospholipases, aspartyl proteases, and other peptidases. Combining genomic analysis with a re-evaluation of culture characteristics, we establish the likely lipid-dependence of all Malassezia. Our phylogenetic analysis sheds new light on the relationship between Malassezia and other members of Ustilaginomycotina, as well as phylogenetic lineages within the genus. Overall, our study provides a unique genomic resource for understanding Malassezia niche-specificity and potential virulence, as well as their abundance and distribution in the environment and on human skin. PMID:26539826

  15. Genus-Wide Comparative Genomics of Malassezia Delineates Its Phylogeny, Physiology, and Niche Adaptation on Human Skin.

    PubMed

    Wu, Guangxi; Zhao, He; Li, Chenhao; Rajapakse, Menaka Priyadarsani; Wong, Wing Cheong; Xu, Jun; Saunders, Charles W; Reeder, Nancy L; Reilman, Raymond A; Scheynius, Annika; Sun, Sheng; Billmyre, Blake Robert; Li, Wenjun; Averette, Anna Floyd; Mieczkowski, Piotr; Heitman, Joseph; Theelen, Bart; Schröder, Markus S; De Sessions, Paola Florez; Butler, Geraldine; Maurer-Stroh, Sebastian; Boekhout, Teun; Nagarajan, Niranjan; Dawson, Thomas L

    2015-11-01

    Malassezia is a unique lipophilic genus in class Malasseziomycetes in Ustilaginomycotina, (Basidiomycota, fungi) that otherwise consists almost exclusively of plant pathogens. Malassezia are typically isolated from warm-blooded animals, are dominant members of the human skin mycobiome and are associated with common skin disorders. To characterize the genetic basis of the unique phenotypes of Malassezia spp., we sequenced the genomes of all 14 accepted species and used comparative genomics against a broad panel of fungal genomes to comprehensively identify distinct features that define the Malassezia gene repertoire: gene gain and loss; selection signatures; and lineage-specific gene family expansions. Our analysis revealed key gene gain events (64) with a single gene conserved across all Malassezia but absent in all other sequenced Basidiomycota. These likely horizontally transferred genes provide intriguing gain-of-function events and prime candidates to explain the emergence of Malassezia. A larger set of genes (741) were lost, with enrichment for glycosyl hydrolases and carbohydrate metabolism, concordant with adaptation to skin's carbohydrate-deficient environment. Gene family analysis revealed extensive turnover and underlined the importance of secretory lipases, phospholipases, aspartyl proteases, and other peptidases. Combining genomic analysis with a re-evaluation of culture characteristics, we establish the likely lipid-dependence of all Malassezia. Our phylogenetic analysis sheds new light on the relationship between Malassezia and other members of Ustilaginomycotina, as well as phylogenetic lineages within the genus. Overall, our study provides a unique genomic resource for understanding Malassezia niche-specificity and potential virulence, as well as their abundance and distribution in the environment and on human skin.

  16. Physiological adaptations and ovarian cyclicity of Holstein and Montbéliarde cows under two low-input production systems.

    PubMed

    Pires, J A A; Chilliard, Y; Delavaud, C; Rouel, J; Pomiès, D; Blanc, F

    2015-12-01

    The objective was to study milk production, body reserve mobilization, metabolic and hormonal profiles, and ovarian cyclicity of Holstein-Friesian (HOLS) and Montbéliarde (MONT) cows under two low-input dairy production systems with seasonal spring calving: an extensive (EXT; 12 HOLS and 12 MONT) based on permanent diversified grasslands and zero concentrate, and a semi-extensive (SEMI; 12 HOLS and 10 MONT) based on established temporary grasslands and up to 4 kg/day of concentrate. Individual measurements were performed between -4 and 12 weeks of lactation. Cows in EXT secreted less milk (22.1 v. 24.4 kg/day), protein (660 v. 755 g/day) and energy (67.7 v. 74.4 MJ/day), had greater plasma β-hydroxybutyrate (BHBA) (0.97 v. 0.69 mM), lower glucose (59.0 v. 62.0 mg/dl) and IGF-1 (62 v. 71 ng/ml), lower milk fat concentration in fatty acids originating from de novo synthesis (e.g. ∑ 10:0 to 15:0) and greater concentration of those derived in part from mobilization of fat reserves (e.g. 18:0 and ∑>C16), and showed greater frequency of abnormal ovarian cycles compared with SEMI. Across production systems, HOLS produced more milk (24.7 v. 21.8 kg/day), protein (738 v. 674 g/day) and fat (939 v. 819 g/day), secreted more energy (75.1 v. 67.0 MJ/day), lost more body condition score (BCS) (1.41 v. 1.03) and reached a lower BCS nadir (1.12 v. 1.43), had greater plasma BHBA (0.91 v. 0.75 mM), lower insulin (15.9 v. 17.2 µIU/ml) and tended to have lower glucose (59.6 v. 61.4 mg/dl), had lower milk fat concentration in ∑ 10:0 to 15:0, tended to have higher ∑>C16 and tended to show more abnormal estrous cycles compared with MONT. Ultrasound measurements did not differentiate fat mobilization and were confounded by breed differences of skin thickness. The greater nutrient allowance in SEMI improved indicators of physiological status and ovarian function during early lactation compared with EXT, but did not attenuate body reserve mobilization because cows prioritized

  17. Physiological and behavioral basis for the successful adaptation of goats to severe water restriction under hot environmental conditions.

    PubMed

    Kaliber, M; Koluman, N; Silanikove, N

    2016-01-01

    Among domestic ruminants, goats are renowned for their ability to tolerate water deprivation, water restriction and energy restriction. However, some basic questions regarding their ability to endure water restriction under heat stress are still open. Three levels of water restriction (56%, 73% and 87% of the ad libitum) were imposed on 20 cross-bred 3-year-old female goats (75% German Fawn and 25% Hair Goat) distributed into four groups, with five animals per treatment. The experiment was conducted from the beginning of July to the end of August in a farm located in the Eastern Mediterranean region of Turkey (40 m in altitude; 36 59' N, 35 18'E), in which subtropical weather conditions prevail. The average daily temperature during the experiment was 34.2°C, whereas the highest and lowest temperatures were 42°C and 23.1°C, respectively. The average relative humidity was 68.2% and wind speed was 1.2 km/h. Weekly average thermal heat indexes during the experiment were 78.3 (week 1), 79.1 (week 2), 80.1 (weak 3), 79.8 (weak 4), 81.3 (weak 5) and on average 79.7. Feed intake, heart rate, thermoregulatory responses (rectal temperature, respiration rate), blood plasma concentrations of ions (Na, K), antidiuretic hormone (ADH), metabolites (glucose, cholesterol, creatinine and urea) and behavioral aspects (standing, walking, lying) were studied over 30 days. The responses to water restriction were proportional to the level of restriction. The reductions in feed intake (up to 13%), BW (up to 4.6%) and the increases in rectal temperature (0.5°C) and breath rate (10 respirations/min) were moderate and also were far from responses encountered under severe heat and water stresses. The increase in plasma Na (from 119 to 140 mM) and ADH concentrations (from 12.6 to 17.4 pg/ml) indicates that the physiological response to water restriction was in response to mild dehydration, which also explains the increase in blood plasma concentrations of glucose, cholesterol, creatinine

  18. Jaczko to resign as chair of Nuclear Regulatory Commission

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-05-01

    Gregory Jaczko, chair of the U.S. Nuclear Regulatory Commission (NRC), announced on 21 May that he will resign once his successor is appointed. His resignation will end a stormy 3-year chairmanship during which he was accused of bullying NRC staff, lying to Congress, and being too close to the political process. Jaczko formerly served as science advisor to Sen. Harry Reid (D-Nev.). As NRC chair, Jaczko halted the commission's license application review for storing nuclear waste at Nevada's Yucca Mountain. In addition, during his NRC tenure the commission focused on identifying and implementing lessons from Japan's Fukushima Daiichi reactors damaged by the 2011 tsunami.

  19. Space physiology within an exercise physiology curriculum.

    PubMed

    Carter, Jason R; West, John B

    2013-09-01

    Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of chronic terrestrial exercise (TEx) and microgravity (μG). We used a series of peer-reviewed publications to demonstrate that many of the physiological adaptations to TEx and μG are opposite. For example, TEx typically improves cardiovascular function and orthostatic tolerance, whereas μG can lead to declines in both. TEx leads to muscle hypertrophy, and μG elicits muscle atrophy. TEx increases bone mineral density and red blood cell mass, whereas μG decreases bone mineral density and red blood cell mass. Importantly, exercise during spaceflight remains a crucial countermeasure to limit some of these adverse physiological adaptations to μG. This curriculum develops critical thinking skills by dissecting peer-reviewed articles and discussing the strengths and weaknesses associated with simulated and actual μG studies. Moreover, the curriculum includes studies on both animals and humans, providing a strong translational component to the curriculum. In summary, we have developed a novel space physiology curriculum delivered during the final weeks of an exercise physiology course in which students gain critical new knowledge that reinforces key concepts presented throughout the semester.

  20. Patients' choice of portable folding chairs to reduce symptoms of orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Smit, A. A.; Wieling, W.; Opfer-Gehrking, T. L.; van Emmerik-Levelt, H. M.; Low, P. A.

    1999-01-01

    Patients with neurogenic orthostatic hypotension may use portable folding chairs to prevent or reduce symptoms of low blood pressure. However, a concomitant movement disorder may limit the use of these chairs in daily living. In this prospective study, 13 patients with orthostatic hypotension, balance disturbance associated with motor disability, or both examined three commercially available portable folding chairs. A questionnaire was used to document the characteristics in chair design that were relevant for satisfactory use to these patients. Armrests, seat width, and an adjustable sitting height were found to be important features of a portable folding chair. One chair was selected by 11 of 13 patients to fit most needs.

  1. Patients' choice of portable folding chairs to reduce symptoms of orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Smit, A. A.; Wieling, W.; Opfer-Gehrking, T. L.; van Emmerik-Levelt, H. M.; Low, P. A.

    1999-01-01

    Patients with neurogenic orthostatic hypotension may use portable folding chairs to prevent or reduce symptoms of low blood pressure. However, a concomitant movement disorder may limit the use of these chairs in daily living. In this prospective study, 13 patients with orthostatic hypotension, balance disturbance associated with motor disability, or both examined three commercially available portable folding chairs. A questionnaire was used to document the characteristics in chair design that were relevant for satisfactory use to these patients. Armrests, seat width, and an adjustable sitting height were found to be important features of a portable folding chair. One chair was selected by 11 of 13 patients to fit most needs.

  2. Using physiologically based pharmacokinetic modeling to address nonlinear kinetics and changes in rodent physiology and metabolism due to aging and adaptation in deriving reference values for propylene glycol methyl ether and propylene glycol methyl ether acetate.

    SciTech Connect

    Kirman, C R.; Sweeney, Lisa M.; Corley, Rick A.; Gargas, M L.

    2005-04-01

    Reference values, including an oral reference dose (RfD) and an inhalation reference concentration (RfC), were derived for propylene glycol methyl ether (PGME), and an oral RfD was derived for its acetate (PGMEA). These values were based upon transient sedation observed in F344 rats and B6C3F1 mice during a two-year inhalation study. The dose-response relationship for sedation was characterized using internal dose measures as predicted by a physiologically based pharmacokinetic (PBPK) model for PGME and its acetate. PBPK modeling was used to account for changes in rodent physiology and metabolism due to aging and adaptation, based on data collected during weeks 1, 2, 26, 52, and 78 of a chronic inhalation study. The peak concentration of PGME in richly perfused tissues was selected as the most appropriate internal dose measure based upon a consideration of the mode of action for sedation and similarities in tissue partitioning between brain and other richly perfused tissues. Internal doses (peak tissue concentrations of PGME) were designated as either no-observed-adverse-effect levels (NOAELs) or lowest-observed-adverse-effect levels (LOAELs) based upon the presence or absence of sedation at each time-point, species, and sex in the two year study. Distributions of the NOAEL and LOAEL values expressed in terms of internal dose were characterized using an arithmetic mean and standard deviation, with the mean internal NOAEL serving as the basis for the reference values, which was then divided by appropriate uncertainty factors. Where data were permitting, chemical-specific adjustment factors were derived to replace default uncertainty factor values of ten. Nonlinear kinetics are were predicted by the model in all species at PGME concentrations exceeding 100 ppm, which complicates interspecies and low-dose extrapolations. To address this complication, reference values were derived using two approaches which differ with respect to the order in which these extrapolations

  3. A smart health monitoring chair for nonintrusive measurement of biological signals.

    PubMed

    Baek, Hyun Jae; Chung, Gih Sung; Kim, Ko Keun; Park, Kwang Suk

    2012-01-01

    We developed nonintrusive methods for simultaneous electrocardiogram, photoplethysmogram, and ballistocardiogram measurements that do not require direct contact between instruments and bare skin. These methods were applied to the design of a diagnostic chair for unconstrained heart rate and blood pressure monitoring purposes. Our methods were operationalized through capacitively coupled electrodes installed in the chair back that include high-input impedance amplifiers, and conductive textiles installed in the seat for capacitive driven-right-leg circuit configuration that is capable of recording electrocardiogram information through clothing. Photoplethysmograms were measured through clothing using seat mounted sensors with specially designed amplifier circuits that vary in light intensity according to clothing type. Ballistocardiograms were recorded using a film type transducer material, polyvinylidenefluoride (PVDF), which was installed beneath the seat cover. By simultaneously measuring signals, beat-to-beat heart rates could be monitored even when electrocardiograms were not recorded due to movement artifacts. Beat-to-beat blood pressure was also monitored using unconstrained measurements of pulse arrival time and other physiological parameters, and our experimental results indicated that the estimated blood pressure tended to coincide with actual blood pressure measurements. This study demonstrates the feasibility of our method and device for biological signal monitoring through clothing for unconstrained long-term daily health monitoring that does not require user awareness and is not limited by physical activity.

  4. Design and experimental evaluation of yoked hand-clutching for a lever drive chair.

    PubMed

    Sarigul-Klijn, Yasemin; Smith, Brendan W; Reinkensmeyer, David J

    2017-05-16

    Lever-drive wheelchairs lower physical strain but are less maneuverable than push-rim wheelchairs. Here, we study a possible solution in which the user simultaneously actuates clutches mounted between the levers and wheels each stroke via a clutch handle attached to one lever; this solution is of particular interest for user groups with only one functional hand. First, to demonstrate maneuverability, we show how this "yoked clutch" allows an experienced user to maneuver a constrained space. Then, we compared the difficulty of learning a yoked clutch chair to a conventional lever-drive transmission (i.e. a one-way bearing). Twenty-two unimpaired novice adults navigated a figure-eight track during six training sessions over two weeks. Participant mean speed improved roughly 60% for both chairs, with similar exponential improvement time constants (3 days) and final speeds. However, speed improvement mostly took place overnight rather than within the session for hand-clutching, and the physiological cost index was also about 40% higher. These results indicate that while hand-clutching is no more difficult to learn than a lever-drive, it is reliant on overnight improvement. Also, its increased maneuverability comes with decreased efficiency. We discuss how the yoked clutch may be particularly well suited for individuals with stroke during inpatient rehabilitation.

  5. Managing People: A Guide for Department Chairs and Deans.

    ERIC Educational Resources Information Center

    Leaming, Deryl R., Ed.

    This book is a collection of essays by experienced department chairs, deans, and vice-presidents. Each essay discusses a different aspect of people management in higher education, explaining the issues and offering suggestions and resources. The chapters are: (1) "Understanding Yourself" (Deryl R. Leaming); (2) "Understanding and Communicating…

  6. Bourdieu, Department Chairs and the Reform of Science Education

    ERIC Educational Resources Information Center

    Melville, Wayne; Hardy, Ian; Bartley, Anthony

    2011-01-01

    Using the insights of the French sociologist, Pierre Bourdieu, this article considers the role of the science department chair in the reform of school science education. Using Bourdieu's "thinking tools" of "field", "habitus" and "capital", we case study the work of two teachers who both actively pursue the teaching and learning of science as…

  7. Strategies for establishing an endowed chair in a service setting.

    PubMed

    Randhawa, Simmy; Robinson, Nellie C; Feetham, Suzanne; Church, Tracy; Hinds, Pamela S; Talley, Linda B; Williams, Catherine

    2014-01-01

    To advance care for patients and families requires that providers and administrators in clinical settings place a high priority on the scientific domain of nursing. New knowledge intended to benefit nursing care is most effectively and efficiently achieved when a vibrant and well-supported nursing research program is embedded within a health care system. An endowed chair in nursing research is an esteemed strategy acknowledging the contributions of nursing science, providing credibility to a researcher and research programs, and demonstrating commitment to the infrastructure for nursing research. Organizational readiness through leadership; systems thinking; relationship development; and knowledge of the dynamics, process, and expectations of philanthropy are essential to establishing an endowed chair. Philanthropic endeavors can be used to strategically develop a high-impact campaign that resonates across public and private sectors to secure funding to solidify and advance nursing research. By actively engaging stakeholders including system leaders, frontline nurses, and other care providers and development leaders, a successful campaign can establish and sustain an endowed chair in nursing research. This article describes the stakeholders, processes, structure, and outcomes for the first endowed chair in nursing research at Children's National Health System in Washington, DC.

  8. Development of Leadership Skills in Community College Department Chairs

    ERIC Educational Resources Information Center

    Sirkis, Jocelyn Eager

    2011-01-01

    The role of a community college department chairperson is not well defined and the job is often perceived as more of a burden than an honor. Faculty come to the position frequently by "default" and without a ready set of management and leadership skills. The matter is of concern since chairs influence academic department strategy, culture, and…

  9. 21 CFR 890.3110 - Electric positioning chair.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electric positioning chair. 890.3110 Section 890.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3110...

  10. 21 CFR 890.3110 - Electric positioning chair.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electric positioning chair. 890.3110 Section 890.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3110...

  11. The analytic setting today: using the couch or the chair?

    PubMed

    Wiener, Jan

    2015-09-01

    This paper re-visits Murray Jackson's 1961 paper in the Journal of Analytical Psychology, 'Chair, couch and countertransference', with the aim of exploring the role of the couch for Jungian analysts in clinical practice today. Within the Society of Analytical Psychology (SAP) and some other London-based societies, there has been an evolution of practice from face-to-face sessions with the patient in the chair, as was Jung's preference, to a mode of practice where patients use the couch with the analyst sitting to the side rather than behind, as has been the tradition in psychoanalysis. Fordham was the founding member of the SAP and it was because of his liaison with psychoanalysis and psychoanalysts that this cultural shift came about. Using clinical examples, the author explores the couch/chair question in terms of her own practice and the internal setting as a structure in her mind. With reference to Bleger's (2013) paper 'Psychoanalysis of the psychoanalytic setting', the author discusses how the analytic setting, including use of the couch or the chair, can act as a silent container for the most primitive aspects of the patient's psyche which will only emerge in analysis when the setting changes or is breached. © 2015, The Society of Analytical Psychology.

  12. Moving up: successful negotiation for the position of academic chair.

    PubMed

    Braddom-Ritzler, Carolyn

    2005-09-01

    This article was written for the Academic Affairs Committee to help candidates for physical medicine and rehabilitation chair positions to effectively negotiate the new position. The article summarizes negotiation strategies provided from personal interviews and other communication via e-mail and phone with experienced physical medicine and rehabilitation chairpersons.

  13. Managing People: A Guide for Department Chairs and Deans.

    ERIC Educational Resources Information Center

    Leaming, Deryl R., Ed.

    This book is a collection of essays by experienced department chairs, deans, and vice-presidents. Each essay discusses a different aspect of people management in higher education, explaining the issues and offering suggestions and resources. The chapters are: (1) "Understanding Yourself" (Deryl R. Leaming); (2) "Understanding and Communicating…

  14. Chairing and Caring: Gendered Dimensions of Leadership in Academe

    ERIC Educational Resources Information Center

    Acker, Sandra

    2012-01-01

    This article uses three frames of analysis, each with gendered implications, to interpret the author's narrative of experience as a department chair (head of department) in a Canadian university from 1999 to 2002. The narrative is based not only on memory but on transcripts of interviews conducted with the author at various points during her term…

  15. CANADIAN UNIVERSITIES: Funding of 2000 Slots Sets Off Musical Chairs.

    PubMed

    Kondro, W

    2000-06-23

    Four months before it goes into effect, a $605 million program to help Canadian universities attract and retain the best scientific talent has ignited a furor within Canadian academe. Research-intensive universities have begun aggressively shopping for prospective candidates, using the new chairs as bait. Smaller universities say that has left them fending off talent raids.

  16. Chairs, Cars, and Bridges: Teaching Aesthetics from the Everyday

    ERIC Educational Resources Information Center

    Zande, Robin Vande

    2007-01-01

    It is very typical for students in K-12 art education to study aesthetics based on artistic objects. Artistic objects, however, need not be the sole source for aesthetic investigation. In this article, the author discusses the use of designed objects such as chairs, cars, and bridges in the discussion of aesthetic concepts. Students, as consumers…

  17. Presidents and Chairs on Common Ground: Handling Flashpoints Together

    ERIC Educational Resources Information Center

    Fletcher, Donald H.; Maxwell, David E.

    2011-01-01

    In the face of public controversies, presidents and board chairs are often called upon to resolve difficult and divisive issues. When they are faced with public controversies and other challenges, a strong working relationship grounded in mutual respect and trust can make the difference between meeting the challenge head on and falling behind.…

  18. Gender, Performativity, and Leadership: Department Chairs in Research Universities

    ERIC Educational Resources Information Center

    Lepkowski, Christine

    2014-01-01

    Women are significantly underrepresented as administrators in higher education leadership. This qualitative study examined the leadership of department chairs at public research universities to better understand how their gender and other identities affected their leadership. The following research questions shaped the study: (1) How do department…

  19. Leadership Role of the Department Chair in Private Colleges

    ERIC Educational Resources Information Center

    Morris, Adam; Miller, Michael

    2008-01-01

    The academic leader is among the most misunderstood management positions in the modern world. Little empirical research has been conducted on the academic leader, especially department chairpersons. With many decisions being made at the department level, many researchers reiterate the importance of department chairs in institutions of higher…

  20. The Characteristics of High School Department Chairs: A National Perspective

    ERIC Educational Resources Information Center

    DeAngelis, Karen J.

    2013-01-01

    Department chairs occupy a potentially important leadership position in high schools, yet little is known about them, particularly with regard to who they are and how they compare to other high school teachers. This is surprising given growing expectations for distributed leadership practice in schools. In this study, I utilize a national dataset…

  1. Bourdieu, Department Chairs and the Reform of Science Education

    ERIC Educational Resources Information Center

    Melville, Wayne; Hardy, Ian; Bartley, Anthony

    2011-01-01

    Using the insights of the French sociologist, Pierre Bourdieu, this article considers the role of the science department chair in the reform of school science education. Using Bourdieu's "thinking tools" of "field", "habitus" and "capital", we case study the work of two teachers who both actively pursue the teaching and learning of science as…

  2. An unusual presentation of nickel-associated "school chair sign".

    PubMed

    Hamann, Dathan J; Jacob, Sharon E

    2014-01-01

    Symmetric sources of exposure generally result in symmetric contact dermatitis, but patient habits may distort or modify exposures in ways that may obscure clinical relevance. We present a variant of "school chair sign" consistent with the child's usual habit of sitting obliquely with her right leg crossed over her left leg.

  3. 21 CFR 890.3110 - Electric positioning chair.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electric positioning chair. 890.3110 Section 890.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3110...

  4. 21 CFR 890.3110 - Electric positioning chair.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electric positioning chair. 890.3110 Section 890.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3110...

  5. 21 CFR 890.3110 - Electric positioning chair.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electric positioning chair. 890.3110 Section 890.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3110...

  6. Chairs, Cars, and Bridges: Teaching Aesthetics from the Everyday

    ERIC Educational Resources Information Center

    Zande, Robin Vande

    2007-01-01

    It is very typical for students in K-12 art education to study aesthetics based on artistic objects. Artistic objects, however, need not be the sole source for aesthetic investigation. In this article, the author discusses the use of designed objects such as chairs, cars, and bridges in the discussion of aesthetic concepts. Students, as consumers…

  7. 21 CFR 880.6140 - Medical chair and table.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical chair and table. 880.6140 Section 880.6140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Miscellaneous...

  8. Gender, Performativity, and Leadership: Department Chairs in Research Universities

    ERIC Educational Resources Information Center

    Lepkowski, Christine

    2014-01-01

    Women are significantly underrepresented as administrators in higher education leadership. This qualitative study examined the leadership of department chairs at public research universities to better understand how their gender and other identities affected their leadership. The following research questions shaped the study: (1) How do department…

  9. 30. LAUNCH CONTROL CAPSULE. ACOUSTICAL ENCLOSURE. OPERATORS' CHAIR AND COMMUNICATIONS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. LAUNCH CONTROL CAPSULE. ACOUSTICAL ENCLOSURE. OPERATORS' CHAIR AND COMMUNICATIONS CONSOLE IN FOREGROUND. ELECTRONIC EQUIPMENT RACK AT LEFT; LAUNCH CONTROL CONSOLE WITH CAPTAIN JAMES L. KING, JR. IN CENTER. LIEUTENANT KEVIN R. MCCLUNEY IN BACKGROUND. VIEW TO SOUTHEAST. - Minuteman III ICBM Launch Control Facility November-1, 1.5 miles North of New Raymer & State Highway 14, New Raymer, Weld County, CO

  10. Reshaping Foreign Language Programs: Implications for Department Chairs.

    ERIC Educational Resources Information Center

    Gay-Crosier, Raymond

    1987-01-01

    A chair of a university's department of Romance languages and literature addresses the status of two high priorities in the teaching of foreign languages: the integration of linguistics in the "new" curriculum; the continuing development of language teaching approaches in the classroom; and the commitment of foreign language programs in the…

  11. Wheel chair transfer techniques for the dental office.

    PubMed

    Posnick, W R; Martin, H H

    1977-04-01

    With the use of these three techniques and variations when necessary, the immobile or partially immobile patient may be moved relatively easily in the dental office. The dentist and his auxiliaries should be able to make the wheel chair transfer a routine and uneventful procedure that will increase the chances of the patient's return in the future.

  12. Cushions and specialist chairs for pressure sore management.

    PubMed

    Cooper, P

    Many patients spend more time sitting out of bed than being cared for in bed. Consequently, the demand for specialist support surfaces for chairs to reduce the risk of pressure damage while the patient is up sitting is rising. This product focus examines a number of seating support surfaces produced by Karomed.

  13. When Women Are Equal: The Canada Research Chair Experience

    ERIC Educational Resources Information Center

    Grant, Karen R.; Drakich, Janice

    2011-01-01

    This paper focuses on the gendered nature of elite academic careers. Of interest is how similar or different the experiences are of women and men who have been appointed to Canada Research Chairs (CRCs). In particular, we examine the impacts of holding a CRC position and consider the factors that shape that experience for women and men. Based on…

  14. Leaf morphological and physiological adaptations of a deciduous oak (Quercus faginea Lam.) to the Mediterranean climate: a comparison with a closely related temperate species (Quercus robur L.)

    PubMed Central

    Peguero-Pina, José Javier; Sisó, Sergio; Sancho-Knapik, Domingo; Díaz-Espejo, Antonio; Flexas, Jaume; Galmés, Jeroni; Gil-Pelegrín, Eustaquio

    2016-01-01

    ‘White oaks’—one of the main groups of the genus Quercus L.—are represented in western Eurasia by the ‘roburoid oaks’, a deciduous and closely related genetic group that should have an Arcto-Tertiary origin under temperate-nemoral climates. Nowadays, roburoid oak species such as Quercus robur L. are still present in these temperate climates in Europe, but others are also present in southern Europe under Mediterranean-type climates, such as Quercus faginea Lam. We hypothesize the existence of a coordinated functional response at the whole-shoot scale in Q. faginea under Mediterranean conditions to adapt to more xeric habitats. The results reveal a clear morphological and physiological segregation between Q. robur and Q. faginea, which constitute two very contrasting functional types in response to climate dryness. The most outstanding divergence between the two species is the reduction in transpiring area in Q. faginea, which is the main trait imposed by the water deficit in Mediterranean-type climates. The reduction in leaf area ratio in Q. faginea should have a negative effect on carbon gain that is partially counteracted by a higher inherent photosynthetic ability of Q. faginea when compared with Q. robur, as a consequence of higher mesophyll conductance, higher maximum velocity of carboxylation and much higher stomatal conductance (gs). The extremely high gs of Q. faginea counteracts the expected reduction in gs imposed by the stomatal sensitivity to vapor pressure deficit, allowing this species to diminish water losses maintaining high net CO2 assimilation values along the vegetative period under nonlimiting soil water potential values. In conclusion, the present study demonstrates that Q. faginea can be regarded as an example of adaptation of a deciduous oak to Mediterranean-type climates. PMID:26496958

  15. Lack of Physiological Depth Patterns in Conspecifics of Endemic Antarctic Brown Algae: A Trade-Off between UV Stress Tolerance and Shade Adaptation?

    PubMed Central

    Gómez, Iván; Huovinen, Pirjo

    2015-01-01

    A striking characteristic of endemic Antarctic brown algae is their broad vertical distribution. This feature is largely determined by the shade adaptation in order to cope with the seasonal variation in light availability. However, during spring-summer months, when light penetrates deep in the water column these organisms have to withstand high levels of solar radiation, including UV. In the present study we examine the light use characteristics in parallel to a potential for UV tolerance (measured as content of phenolic compounds, antioxidant activity and maximum quantum yield of fluorescence) in conspecific populations of four Antarctic brown algae (Ascoseira mirabilis, Desmarestia menziesii, D. anceps and Himantothallus grandifolius) distributed over a depth gradient between 5 and 30 m. The main results indicated that a) photosynthetic efficiency was uniform along the depth gradient in all the studied species, and b) short-term (6 h) exposure to UV radiation revealed a high tolerance measured as chlorophyll fluorescence, phlorotannin content and antioxidant capacity. Multivariate analysis of similarity indicated that light requirements for photosynthesis, soluble phlorotannins and antioxidant capacity are the variables determining the responses along the depth gradient in all the studied species. The suite of physiological responses of algae with a shallower distribution (A. mirabilis and D. menziesii) differed from those with deeper vertical range (D. anceps and H. grandifolius). These patterns are consistent with the underwater light penetration that defines two zones: 0–15 m, with influence of UV radiation (1% of UV-B and UV-A at 9 m and 15 m respectively) and a zone below 15 m marked by PAR incidence (1% up to 30 m). These results support the prediction that algae show a UV stress tolerance capacity along a broad depth range according to their marked shade adaptation. The high contents of phlorotannins and antioxidant potential appear to be strongly

  16. Leaf morphological and physiological adaptations of a deciduous oak (Quercus faginea Lam.) to the Mediterranean climate: a comparison with a closely related temperate species (Quercus robur L.).

    PubMed

    Peguero-Pina, José Javier; Sisó, Sergio; Sancho-Knapik, Domingo; Díaz-Espejo, Antonio; Flexas, Jaume; Galmés, Jeroni; Gil-Pelegrín, Eustaquio

    2016-03-01

    'White oaks'--one of the main groups of the genus Quercus L.--are represented in western Eurasia by the 'roburoid oaks', a deciduous and closely related genetic group that should have an Arcto-Tertiary origin under temperate-nemoral climates. Nowadays, roburoid oak species such as Quercus robur L. are still present in these temperate climates in Europe, but others are also present in southern Europe under Mediterranean-type climates, such as Quercus faginea Lam. We hypothesize the existence of a coordinated functional response at the whole-shoot scale in Q. faginea under Mediterranean conditions to adapt to more xeric habitats. The results reveal a clear morphological and physiological segregation between Q. robur and Q. faginea, which constitute two very contrasting functional types in response to climate dryness. The most outstanding divergence between the two species is the reduction in transpiring area in Q. faginea, which is the main trait imposed by the water deficit in Mediterranean-type climates. The reduction in leaf area ratio in Q. faginea should have a negative effect on carbon gain that is partially counteracted by a higher inherent photosynthetic ability of Q. faginea when compared with Q. robur, as a consequence of higher mesophyll conductance, higher maximum velocity of carboxylation and much higher stomatal conductance (gs). The extremely high gs of Q. faginea counteracts the expected reduction in gs imposed by the stomatal sensitivity to vapor pressure deficit, allowing this species to diminish water losses maintaining high net CO2 assimilation values along the vegetative period under nonlimiting soil water potential values. In conclusion, the present study demonstrates that Q. faginea can be regarded as an example of adaptation of a deciduous oak to Mediterranean-type climates.

  17. Lack of Physiological Depth Patterns in Conspecifics of Endemic Antarctic Brown Algae: A Trade-Off between UV Stress Tolerance and Shade Adaptation?

    PubMed

    Gómez, Iván; Huovinen, Pirjo

    2015-01-01

    A striking characteristic of endemic Antarctic brown algae is their broad vertical distribution. This feature is largely determined by the shade adaptation in order to cope with the seasonal variation in light availability. However, during spring-summer months, when light penetrates deep in the water column these organisms have to withstand high levels of solar radiation, including UV. In the present study we examine the light use characteristics in parallel to a potential for UV tolerance (measured as content of phenolic compounds, antioxidant activity and maximum quantum yield of fluorescence) in conspecific populations of four Antarctic brown algae (Ascoseira mirabilis, Desmarestia menziesii, D. anceps and Himantothallus grandifolius) distributed over a depth gradient between 5 and 30 m. The main results indicated that a) photosynthetic efficiency was uniform along the depth gradient in all the studied species, and b) short-term (6 h) exposure to UV radiation revealed a high tolerance measured as chlorophyll fluorescence, phlorotannin content and antioxidant capacity. Multivariate analysis of similarity indicated that light requirements for photosynthesis, soluble phlorotannins and antioxidant capacity are the variables determining the responses along the depth gradient in all the studied species. The suite of physiological responses of algae with a shallower distribution (A. mirabilis and D. menziesii) differed from those with deeper vertical range (D. anceps and H. grandifolius). These patterns are consistent with the underwater light penetration that defines two zones: 0-15 m, with influence of UV radiation (1% of UV-B and UV-A at 9 m and 15 m respectively) and a zone below 15 m marked by PAR incidence (1% up to 30 m). These results support the prediction that algae show a UV stress tolerance capacity along a broad depth range according to their marked shade adaptation. The high contents of phlorotannins and antioxidant potential appear to be strongly

  18. GnRH-Induced Ca(2+) Signaling Patterns and Gonadotropin Secretion in Pituitary Gonadotrophs. Functional Adaptations to Both Ordinary and Extraordinary Physiological Demands.

    PubMed

    Durán-Pastén, Maria Luisa; Fiordelisio, Tatiana

    2013-09-30

    PITUITARY GONADOTROPHS ARE A SMALL FRACTION OF THE ANTERIOR PITUITARY POPULATION, YET THEY SYNTHESIZE GONADOTROPINS: luteinizing (LH) and follicle-stimulating (FSH), essential for gametogenesis and steroidogenesis. LH is secreted via a regulated pathway while FSH release is mostly constitutive and controlled by synthesis. Although gonadotrophs fire action potentials spontaneously, the intracellular Ca(2+) rises produced do not influence secretion, which is mainly driven by Gonadotropin-Releasing Hormone (GnRH), a decapeptide synthesized in the hypothalamus and released in a pulsatile manner into the hypophyseal portal circulation. GnRH binding to G-protein-coupled receptors triggers Ca(2+) mobilization from InsP3-sensitive intracellular pools, generating the global Ca(2+) elevations necessary for secretion. Ca(2+) signaling responses to increasing (GnRH) vary in stereotyped fashion from subthreshold to baseline spiking (oscillatory), to biphasic (spike-oscillatory or spike-plateau). This progression varies somewhat in gonadotrophs from different species and biological preparations. Both baseline spiking and biphasic GnRH-induced Ca(2+) signals control LH/FSH synthesis and exocytosis. Estradiol and testosterone regulate gonadotropin secretion through feedback mechanisms, while FSH synthesis and release are influenced by activin, inhibin, and follistatin. Adaptation to physiological events like the estrous cycle, involves changes in GnRH sensitivity and LH/FSH synthesis: in proestrus, estradiol feedback regulation abruptly changes from negative to positive, causing the pre-ovulatory LH surge. Similarly, when testosterone levels drop after orquiectomy the lack of negative feedback on pituitary and hypothalamus boosts both GnRH and LH secretion, gonadotrophs GnRH sensitivity increases, and Ca(2+) signaling patterns change. In addition, gonadotrophs proliferate and grow. These plastic changes denote a more vigorous functional adaptation in response to an extraordinary

  19. GnRH-Induced Ca2+ Signaling Patterns and Gonadotropin Secretion in Pituitary Gonadotrophs. Functional Adaptations to Both Ordinary and Extraordinary Physiological Demands

    PubMed Central

    Durán-Pastén, Maria Luisa; Fiordelisio, Tatiana

    2013-01-01

    Pituitary gonadotrophs are a small fraction of the anterior pituitary population, yet they synthesize gonadotropins: luteinizing (LH) and follicle-stimulating (FSH), essential for gametogenesis and steroidogenesis. LH is secreted via a regulated pathway while FSH release is mostly constitutive and controlled by synthesis. Although gonadotrophs fire action potentials spontaneously, the intracellular Ca2+ rises produced do not influence secretion, which is mainly driven by Gonadotropin-Releasing Hormone (GnRH), a decapeptide synthesized in the hypothalamus and released in a pulsatile manner into the hypophyseal portal circulation. GnRH binding to G-protein-coupled receptors triggers Ca2+ mobilization from InsP3-sensitive intracellular pools, generating the global Ca2+ elevations necessary for secretion. Ca2+ signaling responses to increasing (GnRH) vary in stereotyped fashion from subthreshold to baseline spiking (oscillatory), to biphasic (spike-oscillatory or spike-plateau). This progression varies somewhat in gonadotrophs from different species and biological preparations. Both baseline spiking and biphasic GnRH-induced Ca2+ signals control LH/FSH synthesis and exocytosis. Estradiol and testosterone regulate gonadotropin secretion through feedback mechanisms, while FSH synthesis and release are influenced by activin, inhibin, and follistatin. Adaptation to physiological events like the estrous cycle, involves changes in GnRH sensitivity and LH/FSH synthesis: in proestrus, estradiol feedback regulation abruptly changes from negative to positive, causing the pre-ovulatory LH surge. Similarly, when testosterone levels drop after orquiectomy the lack of negative feedback on pituitary and hypothalamus boosts both GnRH and LH secretion, gonadotrophs GnRH sensitivity increases, and Ca2+ signaling patterns change. In addition, gonadotrophs proliferate and grow. These plastic changes denote a more vigorous functional adaptation in response to an extraordinary functional

  20. Human Research Program 2010 Chair Standing Review Panel Meeting

    NASA Technical Reports Server (NTRS)

    Steinberg, Susan

    2011-01-01

    The 13 Human Research Program (HRP) Standing Review Panel (SRP) Chairs, and in some cases one or two additional panel members (see section XIV, roster) referred to as the Chair (+1) SRP throughout this document, met at the NASA Johnson Space Center (JSC) on December 7, 2010 to allow the HRP Elements and Projects to report on their progress over the past year, their current status, and their plans for the upcoming year based on NASA's current goals and objectives for human space exploration. A large focus of the meeting was also used to discuss integration across the HRP scientific disciplines based on a recommendation from the 2009 HRP SRP review. During the one-day meeting, each of the HRP Elements and Projects presented the changes they made to the HRP Integrated Research Plan (IRP Rev. B) over the last year, and what their top three areas of integration are between other HRP Elements/Projects. The Chair (+1) SRP spent sufficient time addressing the panel charge, either as a group or in a separate closed session, and the Chair (+1) SRP and the HRP presenters and observers, in most cases, had sufficient time to discuss during and after the presentations. The SRP made a final debriefing to the HRP Program Scientist, Dr. John B. Charles, prior to the close of the meeting on December 7, 2010. Overall, the Chair (+1) SRP concluded that most of the HRP Elements/Projects did a commendable job during the past year in addressing integration across the HRP scientific disciplines with the available resources. The Chair (+1) SRP agreed that the idea of integration between HRP Elements/Projects is noble, but believes all parties involved should have the same definition of integration, in order to be successful. The Chair (+1) SRP also believes that a key to successful integration is communication among the HRP Elements/Projects which may present a challenge. The Chair (+1) SRP recommends that the HRP have a workshop on program integration (with HRP Element