Numerical simulation of gender differences in a long-term microgravity exposure

NASA Astrophysics Data System (ADS)

Perez-Poch, Antoni

The objective of this work is to analyse and simulate gender differences when individuals are exposed to long-term microgravity. Risk probability of a health impairment which may put in jeopardy a long-term mission is also evaluated. Computer simulations are becoming a promising research line of work, as physiological models become more and more sophisticated and reliable. Technological advances in state-of-the-art hardware technology and software allow nowadays for better and more accurate simulations of complex phenomena, such as the response of the human cardiovascular system to long-term exposure to microgravity. Experimental data for long-term missions are difficult to achieve and reproduce, therefore the predictions of computer simulations are of a major importance in this field. Our approach is based on a previous model developed and implemented in our laboratory (NELME: Numerical Evaluation of Long-term Microgravity Effects). The software simulates the behaviour of the cardiovascular system and different human organs, has a modular architecture, and allows to introduce perturbations such as physical exercise or countermeasures. The implementation is based on a complex electricallike model of this control system, using inexpensive software development frameworks, and has been tested and validated with the available experimental data. Gender differences have been implemented for this specific work, as an adjustment of a number of parameters that are included in the model. Women versus men physiological differences have been therefore taken into account, based upon estimations from the physiology bibliography. A number of simulations have been carried out for long-term exposure to microgravity. Gravity varying from Earth-based to zero, and time exposure are the two main variables involved in the construction of results, including responses to patterns of physical aerobical exercise, and also thermal stress simulating an extra-vehicular activity. Results show that significant differences appear between men and women physiological response after long-term exposure (more than three months) to microgravity. Risk evaluation for every gender, and specific risk thresholds are provided. Initial results are compatible with the existing data, and provide unique information regarding different patterns of microgravity exposure. We conclude that computer-based models such us NELME are a promising line of work to predict health risks in long-term missions. More experimental work is needed to adjust some parameters of the model. This work may be seen as another contribution to a better understanding of the underlying processes involved for both women in man adaptation to long-term microgravity.

A long term model of circulation. [human body

NASA Technical Reports Server (NTRS)

White, R. J.

1974-01-01

A quantitative approach to modeling human physiological function, with a view toward ultimate application to long duration space flight experiments, was undertaken. Data was obtained on the effect of weightlessness on certain aspects of human physiological function during 1-3 month periods. Modifications in the Guyton model are reviewed. Design considerations for bilateral interface models are discussed. Construction of a functioning whole body model was studied, as well as the testing of the model versus available data.

Long term stability of nanowire nanoelectronics in physiological environments.

PubMed

Zhou, Wei; Dai, Xiaochuan; Fu, Tian-Ming; Xie, Chong; Liu, Jia; Lieber, Charles M

2014-03-12

Nanowire nanoelectronic devices have been exploited as highly sensitive subcellular resolution detectors for recording extracellular and intracellular signals from cells, as well as from natural and engineered/cyborg tissues, and in this capacity open many opportunities for fundamental biological research and biomedical applications. Here we demonstrate the capability to take full advantage of the attractive capabilities of nanowire nanoelectronic devices for long term physiological studies by passivating the nanowire elements with ultrathin metal oxide shells. Studies of Si and Si/aluminum oxide (Al2O3) core/shell nanowires in physiological solutions at 37 °C demonstrate long-term stability extending for at least 100 days in samples coated with 10 nm thick Al2O3 shells. In addition, investigations of nanowires configured as field-effect transistors (FETs) demonstrate that the Si/Al2O3 core/shell nanowire FETs exhibit good device performance for at least 4 months in physiological model solutions at 37 °C. The generality of this approach was also tested with in studies of Ge/Si and InAs nanowires, where Ge/Si/Al2O3 and InAs/Al2O3 core/shell materials exhibited stability for at least 100 days in physiological model solutions at 37 °C. In addition, investigations of hafnium oxide-Al2O3 nanolaminated shells indicate the potential to extend nanowire stability well beyond 1 year time scale in vivo. These studies demonstrate that straightforward core/shell nanowire nanoelectronic devices can exhibit the long term stability needed for a range of chronic in vivo studies in animals as well as powerful biomedical implants that could improve monitoring and treatment of disease.

Long Term Stability of Nanowire Nanoelectronics in Physiological Environments

PubMed Central

2015-01-01

Nanowire nanoelectronic devices have been exploited as highly sensitive subcellular resolution detectors for recording extracellular and intracellular signals from cells, as well as from natural and engineered/cyborg tissues, and in this capacity open many opportunities for fundamental biological research and biomedical applications. Here we demonstrate the capability to take full advantage of the attractive capabilities of nanowire nanoelectronic devices for long term physiological studies by passivating the nanowire elements with ultrathin metal oxide shells. Studies of Si and Si/aluminum oxide (Al2O3) core/shell nanowires in physiological solutions at 37 °C demonstrate long-term stability extending for at least 100 days in samples coated with 10 nm thick Al2O3 shells. In addition, investigations of nanowires configured as field-effect transistors (FETs) demonstrate that the Si/Al2O3 core/shell nanowire FETs exhibit good device performance for at least 4 months in physiological model solutions at 37 °C. The generality of this approach was also tested with in studies of Ge/Si and InAs nanowires, where Ge/Si/Al2O3 and InAs/Al2O3 core/shell materials exhibited stability for at least 100 days in physiological model solutions at 37 °C. In addition, investigations of hafnium oxide-Al2O3 nanolaminated shells indicate the potential to extend nanowire stability well beyond 1 year time scale in vivo. These studies demonstrate that straightforward core/shell nanowire nanoelectronic devices can exhibit the long term stability needed for a range of chronic in vivo studies in animals as well as powerful biomedical implants that could improve monitoring and treatment of disease. PMID:24479700

Pain physiology education improves health status and endogenous pain inhibition in fibromyalgia: a double-blind randomized controlled trial.

PubMed

Van Oosterwijck, Jessica; Meeus, Mira; Paul, Lorna; De Schryver, Mieke; Pascal, Aurelie; Lambrecht, Luc; Nijs, Jo

2013-10-01

There is evidence that education on pain physiology can have positive effects on pain, disability, and catastrophization in patients with chronic musculoskeletal pain disorders. A double-blind randomized controlled trial (RCT) was performed to examine whether intensive pain physiology education is also effective in fibromyalgia (FM) patients, and whether it is able to influence the impaired endogenous pain inhibition of these patients. Thirty FM patients were randomly allocated to either the experimental (receiving pain physiology education) or the control group (receiving pacing self-management education). The primary outcome was the efficacy of the pain inhibitory mechanisms, which was evaluated by spatially accumulating thermal nociceptive stimuli. Secondary outcome measures included pressure pain threshold measurements and questionnaires assessing pain cognitions, behavior, and health status. Assessments were performed at baseline, 2 weeks, and 3 months follow-up. Repeated measures ANOVAS were used to reveal possible therapy effects and effect sizes were calculated. After the intervention the experimental group had improved knowledge of pain neurophysiology (P<0.001). Patients from this group worried less about their pain in the short term (P=0.004). Long-term improvements in physical functioning (P=0.046), vitality (P=0.047), mental health (P<0.001), and general health perceptions (P<0.001) were observed. In addition, the intervention group reported lower pain scores and showed improved endogenous pain inhibition (P=0.041) compared with the control group. These results suggest that FM patients are able to understand and remember the complex material about pain physiology. Pain physiology education seems to be a useful component in the treatment of FM patients as it improves health status and endogenous pain inhibition in the long term.

Physiological studies of the brain: Implications for science teaching

NASA Astrophysics Data System (ADS)

Esler, William K.

Physiological changes resulting from repeated, long-term stimulation have been observed in the brains of both humans and laboratory animals. It may be speculated that these changes are related to short-term and long-term memory processes. A physiologically based model for memory processing (PBMMP) can serve to explain the interrelations of various areas of the brain as they process new stimuli and recall past events. The model can also serve to explain many current principles of learning theory and serve as a foundation for developing new theories of learning based upon the physiology of the brain.

Physiology of Developing Gravity Receptors and Otolith-Ocular Reflexes in Rat

NASA Technical Reports Server (NTRS)

Blanks, Robert H.

1997-01-01

This proposal had the long-term objective of examining the effects of microgravity on the physiology of the adult and developing mammalian gravity receptors. The grant outlined three-years of ground-based studies to examine. 1) the physiologic responses or otolith afferents in the adult rat and during postnatal development, and 2) the otolith organ contributions to the vertical vestibulo-ocular (VOR) and postural reflexes.

Highly Stable Graphene-Based Nanocomposite (GO-PEI-Ag) with Broad-Spectrum, Long-Term Antimicrobial Activity and Antibiofilm Effects.

PubMed

Zhao, Rongtao; Kong, Wen; Sun, Mingxuan; Yang, Yi; Liu, Wanying; Lv, Min; Song, Shiping; Wang, Lihua; Song, Hongbin; Hao, Rongzhang

2018-05-30

Various silver nanoparticle (AgNP)-decorated graphene oxide (GO) nanocomposites (GO-Ag) have received increasing attention owing to their antimicrobial activity and biocompatibility; however, their aggregation in physiological solutions and the generally complex synthesis methods warrant improvement. This study aimed to synthesize a polyethyleneimine (PEI)-modified and AgNP-decorated GO nanocomposite (GO-PEI-Ag) through a facile approach through microwave irradiation without any extra reductants and surfactants; its antimicrobial activity was investigated on Gram-negative/-positive bacteria (including drug-resistant bacteria) and fungi. Compared with GO-Ag, GO-PEI-Ag acquired excellent stability in physiological solutions and electropositivity, showing substantially higher antimicrobial efficacy. Moreover, GO-PEI-Ag exhibited particularly excellent long-term effects, presenting no obvious decline in antimicrobial activity after 1 week storage in physiological saline and repeated use for three times and the lasting inhibition of bacterial growth in nutrient-rich culture medium. In contrast, GO-Ag exhibited a >60% decline in antimicrobial activity after storage. Importantly, GO-PEI-Ag effectively eliminated adhered bacteria, thereby preventing biofilm formation. The primary antimicrobial mechanisms of GO-PEI-Ag were evidenced as physical damage to the pathogen structure, causing cytoplasmic leakage. Hence, stable GO-PEI-Ag with robust, long-term antimicrobial activity holds promise in combating public-health threats posed by drug-resistant bacteria and biofilms.

Transcriptional and Physiological Characterizations of Escherichia coli MG1655 that have been grown under Low Shear Stress Environment for 1000 Generations

NASA Astrophysics Data System (ADS)

Karouia, Fathi; Tirumalai, Madhan R.; Nelman-Gonzalez, Mayra A.; Sams, Clarence F.; Ott, Mark C.; Pierson, Duane L.; Fofanov, Yuriy; Willson, Richard C.; Fox, George E.

Human space travelers experience a unique environment that affects homeostasis and physio-logic adaptation. One of the important regulatory biology interactions affected by space flight is the alteration of the immune response. As such, the impairment of the immune system may lead to higher risk of bacterial and/or viral infection during human space flight missions. Mi-crobiological contaminants have been a source of concern over the years for NASA and there is evidence to suggest that microbes in space do not behave like they do on Earth. Previ-ous studies have examined the physiological response of bacteria when exposed to short-term microgravity either during spaceflight or in a Low Shear Modeled Microgravity (LSMMG) en-vironment. Exposure to these environments has been found to induce increased resistance to stresses and antibiotics, and in one case increase of virulence. As NASA increases the duration of space flight missions and is starting to envision human presence on the lunar surface and Mars, it becomes legitimate to question the long-term effects of microgravity on bacteria. The effect of long-term exposure to LSMMG on microbial gene expression and physiology in Escherichia coli (E. coli) is being examined using functional genomics, and molecular tech-niques. In previous E. coli short term studies, reproducible changes in transcription were seen but no direct responses to changes in the gravity vector were identified. Instead, absence of shear and a randomized gravity vector appeared to cause local extra-cellular environmental changes, which elicited cellular responses. In order to evaluate the long-term effects of micro-gravity on bacteria, E. coli was grown under simulated microgravity for 1000 generations and gene expression patterns and cellular physiology were analyzed in comparison with short-term exposure. The analysis revealed that the long-term response differed significantly from the short-term exposure and 357 genes were expressed significantly differently. Fimbriae encoding genes were significantly up-regulated whereas genes encoding the flagellar motor complex were down-regulated. Additionally, 81 significantly expressed genes have been implicated in and/or associated with biofilm formation. The remaining up-regulated genes seemed to be involved in a response that triggered expression of genes associated with the type II secretion complex. This complex has been involved in virulence factors and members of the multidrug efflux system which confer resistance to a multitude of antimicrobial agents and antibiotics. Biofilm formation and the aggregation of cells were evaluated by scanning electron microscopy (SEM). The analysis revealed that extracellular matrix and complex cellular networking were present among cells that were exposed to the long-term LSMMG environment. In addition the response to a variety of stresses and antibiotics were examined. Significant differences were seen between long-term exposure to LSMMG and the short-term control. Changes in expression may predispose the cells to more efficiently attach to surfaces and/or other cells and thereby confer resistance to antibiotics. Future studies will seek to determine the extent to which the long-term adaptation is influenced by genomic changes. These studies will contribute to the knowledge base needed to develop countermeasures that will decrease the risks associated with astronaut health and mission integrity that are presented by microorganisms.

Low-carbohydrate diet induces metabolic depression: a possible mechanism to conserve glycogen.

PubMed

Winwood-Smith, Hugh S; Franklin, Craig E; White, Craig R

2017-10-01

Long-term studies have found that low-carbohydrate diets are more effective for weight loss than calorie-restricted diets in the short term but equally or only marginally more effective in the long term. Low-carbohydrate diets have been linked to reduced glycogen stores and increased feelings of fatigue. We propose that reduced physical activity in response to lowered glycogen explains the diminishing weight loss advantage of low-carbohydrate compared with low-calorie diets over longer time periods. We explored this possibility by feeding adult Drosophila melanogaster a standard or a low-carbohydrate diet for 9 days and measured changes in metabolic rate, glycogen stores, activity, and body mass. We hypothesized that a low-carbohydrate diet would cause a reduction in glycogen stores, which recover over time, a reduction in physical activity, and an increase in resting metabolic rate. The low-carbohydrate diet reduced glycogen stores, which recovered over time. Activity was unaffected by diet, but metabolic rate was reduced, in the low-carbohydrate group. We conclude that metabolic depression could explain the decreased effectiveness of low-carbohydrate diets over time and recommend further investigation of long-term metabolic effects of dietary interventions and a greater focus on physiological plasticity within the study of human nutrition. Copyright © 2017 the American Physiological Society.

Proportional Feedback Control of Energy Intake During Obesity Pharmacotherapy.

PubMed

Hall, Kevin D; Sanghvi, Arjun; Göbel, Britta

2017-12-01

Obesity pharmacotherapies result in an exponential time course for energy intake whereby large early decreases dissipate over time. This pattern of declining drug efficacy to decrease energy intake results in a weight loss plateau within approximately 1 year. This study aimed to elucidate the physiology underlying the exponential decay of drug effects on energy intake. Placebo-subtracted energy intake time courses were examined during long-term obesity pharmacotherapy trials for 14 different drugs or drug combinations within the theoretical framework of a proportional feedback control system regulating human body weight. Assuming each obesity drug had a relatively constant effect on average energy intake and did not affect other model parameters, our model correctly predicted that long-term placebo-subtracted energy intake was linearly related to early reductions in energy intake according to a prespecified equation with no free parameters. The simple model explained about 70% of the variance between drug studies with respect to the long-term effects on energy intake, although a significant proportional bias was evident. The exponential decay over time of obesity pharmacotherapies to suppress energy intake can be interpreted as a relatively constant effect of each drug superimposed on a physiological feedback control system regulating body weight. © 2017 The Obesity Society.

Changes in heart rate variability are associated with expression of short-term and long-term contextual and cued fear memories.

PubMed

Liu, Jun; Wei, Wei; Kuang, Hui; Zhao, Fang; Tsien, Joe Z

2013-01-01

Heart physiology is a highly useful indicator for measuring not only physical states, but also emotional changes in animals. Yet changes of heart rate variability during fear conditioning have not been systematically studied in mice. Here, we investigated changes in heart rate and heart rate variability in both short-term and long-term contextual and cued fear conditioning. We found that while fear conditioning could increase heart rate, the most significant change was the reduction in heart rate variability which could be further divided into two distinct stages: a highly rhythmic phase (stage-I) and a more variable phase (stage-II). We showed that the time duration of the stage-I rhythmic phase were sensitive enough to reflect the transition from short-term to long-term fear memories. Moreover, it could also detect fear extinction effect during the repeated tone recall. These results suggest that heart rate variability is a valuable physiological indicator for sensitively measuring the consolidation and expression of fear memories in mice.

The modelling and assessment of whale-watching impacts

USGS Publications Warehouse

New, Leslie; Hall, Ailsa J.; Harcourt, Robert; Kaufman, Greg; Parsons, E.C.M.; Pearson, Heidi C.; Cosentino, A. Mel; Schick, Robert S

2015-01-01

In recent years there has been significant interest in modelling cumulative effects and the population consequences of individual changes in cetacean behaviour and physiology due to disturbance. One potential source of disturbance that has garnered particular interest is whale-watching. Though perceived as ‘green’ or eco-friendly tourism, there is evidence that whale-watching can result in statistically significant and biologically meaningful changes in cetacean behaviour, raising the question whether whale-watching is in fact a long term sustainable activity. However, an assessment of the impacts of whale-watching on cetaceans requires an understanding of the potential behavioural and physiological effects, data to effectively address the question and suitable modelling techniques. Here, we review the current state of knowledge on the viability of long-term whale-watching, as well as logistical limitations and potential opportunities. We conclude that an integrated, coordinated approach will be needed to further understanding of the possible effects of whale-watching on cetaceans.

Respiratory, cardiovascular and other physiological consequences of smoking cessation.

PubMed

Gratziou, Christina

2009-02-01

Smoking cessation is associated with substantial reductions in tobacco-related morbidity and mortality. Based on the current literature, the beneficial effects of quitting are particularly evident on pulmonary and cardiovascular function, but the negative physiological effects of cessation are less well documented. The objective of this article was to review systematically data on the physiological effects of smoking cessation. Articles based upon clinical trials, randomised controlled trials and meta-analyses were selected from titles and abstracts obtained via a MEDLINE search (May 2003-May 2008). Additional studies were identified from the bibliographies of reviewed literature. Smoking cessation is associated with improved lung function and a reduction in the presence and severity of respiratory symptoms. These changes, apparent within months of quitting, are sustained with long-term abstinence. The underlying pathophysiologies of smoking-induced airway inflammation and endothelial dysfunction are partially reversed following cessation in healthy ex-smokers, but not in those with chronic obstructive pulmonary disease. Smoking cessation is also associated with substantially improved cardiovascular function and reduced risk of primary and secondary cardiovascular morbidity and mortality. Although the overall long-term health benefits are unquestionable, smoking cessation is also associated with other possible undesirable short-term physiological effects such as weight gain, hypertension, constipation and mouth ulcers; and altered activity of the enzyme cytochrome P450 1A2 (CYP1A2), which metabolises many commonly used drugs. The negative physiological effects of smoking cessation may adversely affect a smoker's attempt to quit, and physicians should provide their smoking patients with motivation and regular encouragement and support when attempting to quit, whilst educating them on the health benefits of abstinence. Additionally, since cigarette smoke is a potent inducer of CYP1A2, patients attempting to quit smoking should have their dosages of drugs metabolised by this enzyme closely monitored.

Impacts of dwarf mistletoe on the physiology of host Tsuga heterophylla trees as recorded in tree-ring C and O stable isotopes

Treesearch

D. E. Marias; F. C. Meinzer; D. R. Woodruff; D. C. Shaw; S. L. Voelker; Steven W. Oak; William J. Otrosina; William D. Smith; Kamal J.K. Gandhi

2014-01-01

Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture and photosynthetic gas exchange and can eventually induce tree death. To investigate the long-term (1886–2010) impacts of dwarf mistletoe on the growth and gas exchange characteristics of host western hemlock, we...

Physiological responses to fertilization recorded in tree rings: isotopic lessons from a long-term fertilization trial - 2008

EPA Science Inventory

Nitrogen fertilizer applications are common land-use management tools, but details on physiological responses to these applications are often lacking, particularly for long-term responses over decades of forest management. We used tree-ring growth patterns and stable isotopes to...

Physiological responses to fertilization recorded in tree rings: Isotopic lessons from a long-term fertilization trial

EPA Science Inventory

Nitrogen fertilizer applications are common land use management tools, but details on physiological responses to these applications are often lacking, particularly for long-term responses over decades of forest management. We used tree ring growth patterns and stable isotopes to ...

Long-term experiment on physiological responses to synergetic effects of ocean acidification and photoperiod in the Antarctic sea ice algae Chlamydomonas sp. ICE-L.

PubMed

Xu, Dong; Wang, Yitao; Fan, Xiao; Wang, Dongsheng; Ye, Naihao; Zhang, Xiaowen; Mou, Shanli; Guan, Zheng; Zhuang, Zhimeng

2014-07-15

Studies on ocean acidification have mostly been based on short-term experiments of low latitude with few investigations of the long-term influence on sea ice communities. Here, the combined effects of ocean acidification and photoperiod on the physiological response of the Antarctic sea ice microalgae Chlamydomonas sp. ICE-L were examined. There was a general increase in growth, PSII photosynthetic parameters, and N and P uptake in continuous light, compared to those exposed to regular dark and light cycles. Elevated pCO2 showed no consistent effect on growth rate (p=0.8) and N uptake (p=0.38) during exponential phrase, depending on the photoperiod but had a positive effect on PSII photosynthetic capacity and P uptake. Continuous dark reduced growth, photosynthesis, and nutrient uptake. Moreover, intracellular lipid, mainly in the form of PUFA, was consumed at 80% and 63% in low and high pCO2 in darkness. However, long-term culture under high pCO2 gave a more significant inhibition of growth and Fv/Fm to high light stress. In summary, ocean acidification may have significant effects on Chlamydomonas sp. ICE-L survival in polar winter. The current study contributes to an understanding of how a sea ice algae-based community may respond to global climate change at high latitudes.

Short-term and long-term effects of violent media on aggression in children and adults.

PubMed

Bushman, Brad J; Huesmann, L Rowell

2006-04-01

To test whether the results of the accumulated studies on media violence and aggressive behavior are consistent with the theories that have evolved to explain the effects. We tested for the existence of both short-term and long-term effects for aggressive behavior. We also tested the theory-driven hypothesis that short-term effects should be greater for adults and long-term effects should be greater for children. Meta-analysis. Children younger than 18 years and adults. Violent media, including TV, movies, video games, music, and comic books. Measures of aggressive behavior, aggressive thoughts, angry feelings, physiological arousal (eg, heart rate, blood pressure), and helping behavior. Effect size estimates were combined using meta-analytic procedures. As expected, the short-term effects of violent media were greater for adults than for children whereas the long-term effects were greater for children than for adults. The results also showed that there were overall modest but significant effect sizes for exposure to media violence on aggressive behaviors, aggressive thoughts, angry feelings, arousal levels, and helping behavior. The results are consistent with the theory that short-term effects are mostly due to the priming of existing well-encoded scripts, schemas, or beliefs, which adults have had more time to encode. In contrast, long-term effects require the learning (encoding) of scripts, schemas, or beliefs. Children can encode new scripts, schemas, and beliefs via observational learning with less interference and effort than adults.

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 mutations that confer resistance and subsequent selection of these mutants. Finally, it is certain that further mutations and selection will ultimately determine adaptation of microalgae to the environmental forcing. Copyright © 2012 Elsevier B.V. All rights reserved.

Pleasure to play, arousal to stay: the effect of player emotions on digital game preferences and playing time.

PubMed

Poels, Karolien; van den Hoogen, Wouter; Ijsselsteijn, Wijnand; de Kort, Yvonne

2012-01-01

This study investigated how player emotions during game-play, measured through self-report and physiological recordings, predict playing time and game preferences. We distinguished between short-term (immediately after game-play) and long-term (after 3 weeks) playing time and game preferences. While pleasure was most predictive for short-term playing time and game preferences, arousal, particularly for game preferences, was most predictive on the longer term. This result was found through both self-report and physiological emotion measures. This study initiates theorizing about digital gaming as a hedonic consumer product and sketches future research endeavors of this topic.

Short-term and long-term effects of transient exogenous cortisol manipulation on oxidative stress in juvenile brown trout.

PubMed

Birnie-Gauvin, Kim; Peiman, Kathryn S; Larsen, Martin H; Aarestrup, Kim; Willmore, William G; Cooke, Steven J

2017-05-01

In the wild, animals are exposed to a growing number of stressors with increasing frequency and intensity, as a result of human activities and human-induced environmental change. To fully understand how wild organisms are affected by stressors, it is crucial to understand the physiology that underlies an organism's response to a stressor. Prolonged levels of elevated glucocorticoids are associated with a state of chronic stress and decreased fitness. Exogenous glucocorticoid manipulation reduces an individual's ability to forage, avoid predators and grow, thereby limiting the resources available for physiological functions like defence against oxidative stress. Using brown trout ( Salmo trutta ), we evaluated the short-term (2 weeks) and long-term (4 months over winter) effects of exogenous cortisol manipulations (versus relevant shams and controls) on the oxidative status of wild juveniles. Cortisol caused an increase in glutathione over a 2 week period and appeared to reduce glutathione over winter. Cortisol treatment did not affect oxidative stress levels or low molecular weight antioxidants. Cortisol caused a significant decrease in growth rates but did not affect predation risk. Over-winter survival in the stream was associated with low levels of oxidative stress and glutathione. Thus, oxidative stress may be a mechanism by which elevated cortisol causes negative physiological effects. © 2017. Published by The Company of Biologists Ltd.

Cardiorespiratory interaction with continuous positive airway pressure

PubMed Central

Bonafini, Sara; Fava, Cristiano; Steier, Joerg

2018-01-01

The treatment of choice for obstructive sleep apnoea (OSA) is continuous positive airway pressure therapy (CPAP). Since its introduction in clinical practice, CPAP has been used in various clinical conditions with variable and heterogeneous outcomes. In addition to the well-known effects on the upper airway CPAP impacts on intrathoracic pressures, haemodynamics and blood pressure (BP) control. However, short- and long-term effects of CPAP therapy depend on multiple variables which include symptoms, underlying condition, pressure used, treatment acceptance, compliance and usage. CPAP can alter long-term cardiovascular risk in patients with cardiorespiratory conditions. Furthermore, the effect of CPAP on the awake patient differs from the effect on the patients while asleep, and this might contribute to discomfort and removal of the use interface. The purpose of this review is to highlight the physiological impact of CPAP on the cardiorespiratory system, including short-term benefits and long-term outcomes. PMID:29445529

Nicotine Uses Neuron-Glia Communication to Enhance Hippocampal Synaptic Transmission and Long-term Memory

PubMed Central

López-Hidalgo, Mónica; Salgado-Puga, Karla; Alvarado-Martínez, Reynaldo; Medina, Andrea Cristina; Prado-Alcalá, Roberto A.; García-Colunga, Jesús

2012-01-01

Nicotine enhances synaptic transmission and facilitates long-term memory. Now it is known that bi-directional glia-neuron interactions play important roles in the physiology of the brain. However, the involvement of glial cells in the effects of nicotine has not been considered until now. In particular, the gliotransmitter D-serine, an endogenous co-agonist of NMDA receptors, enables different types of synaptic plasticity and memory in the hippocampus. Here, we report that hippocampal long-term synaptic plasticity induced by nicotine was annulled by an enzyme that degrades endogenous D-serine, or by an NMDA receptor antagonist that acts at the D-serine binding site. Accordingly, both effects of nicotine: the enhancement of synaptic transmission and facilitation of long-term memory were eliminated by impairing glial cells with fluoroacetate, and were restored with exogenous D-serine. Together, these results show that glial D-serine is essential for the long-term effects of nicotine on synaptic plasticity and memory, and they highlight the roles of glial cells as key participants in brain functions. PMID:23185511

Essential tremor.

PubMed Central

Murray, T. J.

1981-01-01

Essential tremor, including the juvenile and senile variations, may be a result of a disorder of the servomechanism that controls physiologic tremor. Hands and arms are affected most commonly, and the tremor can vary in amplitude as well as frequency. Long-term treatment with propranolol has been helpful for some patients, although older patients are less likely to benefit. Other drugs and behaviour modification therapy have been less successful. Surgical treatment is effective but should probably be reserved for severe cases. An effective instrument for measuring the subjective and objective aspects of the tremor is still needed, as is an effective long-term method of treatment. PMID:7018658

Long-term consequences of pain in human neonates.

PubMed

Grunau, Ruth E; Holsti, Liisa; Peters, Jeroen W B

2006-08-01

The low tactile threshold in preterm infants when they are in the neonatal intensive care unit (NICU), while their physiological systems are unstable and immature, potentially renders them more vulnerable to the effects of repeated invasive procedures. There is a small but growing literature on pain and tactile responsivity following procedural pain in the NICU, or early surgery. Long-term effects of repeated pain in the neonatal period on neurodevelopment await further research. However, there are multiple sources of stress in the NICU, which contribute to inducing high overall 'allostatic load', therefore determining specific effects of neonatal pain in human infants is challenging.

Probe pressure effects on human skin diffuse reflectance and fluorescence spectroscopy measurements

PubMed Central

Lim, Liang; Nichols, Brandon; Rajaram, Narasimhan; Tunnell, James W.

2011-01-01

Diffuse reflectance and fluorescence spectroscopy are popular research techniques for noninvasive disease diagnostics. Most systems include an optical fiber probe that transmits and collects optical spectra in contact with the suspected lesion. The purpose of this study is to investigate probe pressure effects on human skin spectroscopic measurements. We conduct an in-vivo experiment on human skin tissue to study the short-term (<2 s) and long-term (>30 s) effects of probe pressure on diffuse reflectance and fluorescence measurements. Short-term light probe pressure (P0 < 9 mN∕mm2) effects are within 0 ± 10% on all physiological properties extracted from diffuse reflectance and fluorescence measurements, and less than 0 ± 5% for diagnostically significant physiological properties. Absorption decreases with site-specific variations due to blood being compressed out of the sampled volume. Reduced scattering coefficient variation is site specific. Intrinsic fluorescence shows a large standard error, although no specific pressure-related trend is observed. Differences in tissue structure and morphology contribute to site-specific probe pressure effects. Therefore, the effects of pressure can be minimized when the pressure is small and applied for a short amount of time; however, long-term and large pressures induce significant distortions in measured spectra. PMID:21280899

Insulin treatment augments KCNQ1/KCNE1 currents but not KCNQ1 currents, which is associated with an increase in KCNE1 expression.

PubMed

Wu, Minghua; Obara, Yutaro; Ohshima, Shingo; Nagasawa, Yoshinobu; Ishii, Kuniaki

2017-11-04

Diabetes mellitus affects ion channel physiology. We have previously reported that acute application of insulin suppresses the KCNQ1/KCNE1 currents that play an important role in terminating ventricular action potential. In this study, we investigated the effect of long-term insulin treatment on KCNQ1/KCNE1 currents using the Xenopus oocyte expression system. Insulin treatment with a duration longer than 6 h had an opposite effect to acute insulin application, that is, it augmented the KCNQ1/KCNE1 currents. Inhibitors of PI3K, wortmannin and LY294002, and a MEK inhibitor, U0126, abolished the potentiating effect of long-term insulin treatment. The long-term treatment with insulin had no effect on KCNQ1 currents indicating an essential role of KCNE1 in the insulin effect, which is similar to the acute insulin effect. Cycloheximide, an inhibitor of protein synthesis, and brefeldin A, an inhibitor of protein transport from endoplasmic reticulum, suppressed the long-term insulin effect. Western blotting analysis combined with these pharmacological data suggest that long-term insulin treatment augments KCNQ1/KCNE1 currents by increasing KCNE1 protein expression. Copyright © 2017 Elsevier Inc. All rights reserved.

Long term retention, survival, growth, and physiological indicators of salmonids marked with passive integrated transponder tags

USGS Publications Warehouse

Ostrand, Kenneth G.; Zydlewski, Gayle B.; Gale, William L.; Zydlewski, Joseph D.

2011-01-01

To track individuals in situ, over 12 million salmon and trout have been marked with passive integrated transponder (PIT) tags in the Columbia River Basin, USA. However, few studies have examined long term tag retention as well as tag effects on juvenile salmon and trout. We marked juvenile coho salmon Oncorhynchus kisutch (N = 207), steelhead (anadromous rainbow trout) O. mykiss (N = 221), cutthroat trout O. clarkii (N = 202) and bull trout Salvelinus confluentus (N = 180) with 12, 19, or 23 mm PIT tags and examined tag retention, survival, growth, and physiological performance over a six month period in a laboratory environment. PIT tag retention rates were high for coho salmon (100%), steelhead (95%), cutthroat trout (97%), and bull trout (99%), regardless of tag size. Survival was also high for coho (99%), steelhead (99%), cutthroat trout (97%), and bull trout (88%) and did not vary among tag sizes. Short term individual growth rates for coho salmon marked with 12 mm tags were significantly higher than those marked with 19 mm and 23 mm PIT tags. Likewise, steelhead trout individual growth rates were lower for fish marked with 23 mm PIT tags followed by 19 and 12 mm tags. Conversely, long-term growth rates were positive and not affected by tag size. There were no significant effects of tag size or marking on coho gill Na+, K+, -ATPase activity (µmol ADP x mg protein–1 h–1) and plasma osmolality (µmol kg–1) or bull trout hepatosomatic indices. Our study suggests that marking juvenile salmonids with PIT tags results in high retention with little effect upon their survival, growth, and important physiological indicators regardless of tag size in a laboratory environment.

Update: Non-Invasive Positive Pressure Ventilation in Chronic Respiratory Failure Due to COPD.

PubMed

Altintas, Nejat

2016-01-01

Long-term non-invasive positive pressure ventilation (NPPV) has widely been accepted to treat chronic hypercapnic respiratory failure arising from different etiologies. Although the survival benefits provided by long-term NPPV in individuals with restrictive thoracic disorders or stable, slowly-progressing neuromuscular disorders are overwhelming, the benefits provided by long-term NPPV in patients with chronic obstructive pulmonary disease (COPD) remain under question, due to a lack of convincing evidence in the literature. In addition, long-term NPPV reportedly failed in the classic trials to improve important physiological parameters such as arterial blood gases, which might serve as an explanation as to why long-term NPPV has not been shown to substantially impact on survival. However, high intensity NPPV (HI-NPPV) using controlled NPPV with the highest possible inspiratory pressures tolerated by the patient has recently been described as a new and promising approach that is well-tolerated and is also capable of improving important physiological parameters such as arterial blood gases and lung function. This clearly contrasts with the conventional approach of low-intensity NPPV (LI-NPPV) that uses considerably lower inspiratory pressures with assisted forms of NPPV. Importantly, HI-NPPV was very recently shown to be superior to LI-NPPV in terms of improved overnight blood gases, and was also better tolerated than LI-NPPV. Furthermore, HI-NPPV, but not LI-NPPV, improved dyspnea, lung function and disease-specific aspects of health-related quality of life. A recent study showed that long-term treatment with NPPV with increased ventilatory pressures that reduced hypercapnia was associated with significant and sustained improvements in overall mortality. Thus, long-term NPPV seems to offer important benefits in this patient group, but the treatment success might be dependent on effective ventilatory strategies.

Perioperative abstinence from cigarettes: physiologic and clinical consequences.

PubMed

Warner, David O

2006-02-01

Chronic exposure to cigarette smoke produces profound changes in physiology that may alter responses to perioperative interventions and contribute to perioperative morbidity. Because of smoke-free policies in healthcare facilities, all smokers undergoing surgery are abstinent from cigarettes for at least some period of time so that all are in various stages of recovery from the effects of smoke. Understanding this recovery process will help perioperative physicians better treat these patients. This review examines current knowledge regarding how both short-term (duration ranging from hours to weeks) and long-term smoking cessation affects selected physiology and pathophysiology of particular relevance to perioperative outcomes and how these changes affect perioperative risk. It will also consider current evidence regarding how nicotine replacement therapy, a valuable adjunct to help patients maintain abstinence, may affect perioperative physiology.

Long-Term Provision of Environmental Resources Alters Behavior but not Physiology or Neuroanatomy of Male and Female BALB/c and C57BL/6 Mice

PubMed Central

Clipperton-Allen, Amy E; Ingrao, Joelle C; Ruggiero, Laura; Batista, Lucas; Ovari, Jelena; Hammermueller, Jutta; Armstrong, John N; Bienzle, Dorothee; Choleris, Elena; Turner, Patricia V

2015-01-01

Few studies have evaluated the long-term effects of providing environmental resources to mice. This consideration is important given that mice are often maintained in vivaria for months. We evaluated the effects of providing simple cage resources (wood wool, cotton nesting material, a plastic tunnel, and oat cereal) compared with standard housing (solid-bottom cage with hardwood chips) to group-housed adult male and female C57BL/6 and BALB/c mice (n = 20/sex/strain/group) over 6 mo to determine whether these resources had a lasting effect on animal physiology, anatomy, and behavior. Body weights increased in all groups over time but were proportionately higher in male and female BALB/c mice housed in resource-supplemented environments. Throughout the study, adding environmental resources had no effect on hematology and lymphocyte subsets, fecal corticoid metabolite levels, response to LPS injection, or dendritic spine length or density. Strain- or sex×environment-specific changes occurred in dark–light activity and thermal nociceptive responses. Dominant agonistic behaviors, abnormal conspecific sexual behaviors, and social nonagonistic behaviors demonstrated sex and strain×environment interactions such that fewer maladaptive social behaviors were noted in mice that were provided with environmental resources. This association was particularly evident in male mice of both strains in resource-supplemented environments. A small but significant increase in brain weight:body weight ratios occurred in mice in resource-supplemented environments. Under the conditions evaluated here, consistent use of simple environmental resources had a positive long-term effect on the behavioral wellbeing of male and female BALB/c and C57BL/6 mice yet minimally affected other aspects of murine physiology and neuroanatomy. PMID:26632781

Comparing the long-term retention of a physiology course for medical students with the traditional and problem-based learning.

PubMed

Pourshanazari, A A; Roohbakhsh, A; Khazaei, M; Tajadini, H

2013-03-01

The rapid improvements in medical sciences and the ever-increasing related data, however, require novel methods of instruction. One such method, which has been given less than due attention in Iran, is problem-based learning (PBL). In this study, we aimed to evaluate the impact of study skills and the PBL methods on short and long-term retention of information provided for medical students in the course of respiratory physiology and compare it with traditional learning method. In this study, 39 medical students from Medical School of Kerman University of Medical Sciences, Kerman, Iran (2006-2010) were enrolled in the study and allocated randomly in three equal groups (13 in each group). All groups underwent a pre-test to be assessed for their basic information regarding respiratory physiology. Two groups were instructed using the traditional method, and one group used PBL. Among the two groups of the traditional method, one was instructed about study skills and the other was not. Once the PBL group took the study skill workshop, they were aided by tutors for their education. In the final term test, those students who had learned study skills and were instructed with the traditional method scored higher compared to other groups (p < 0.05). However, in the 1 year (p < 0.05) and 4 year (p < 0.01) interval examinations, the PBL group achieved significantly higher scores. Despite the fact that PBL had no positive effect on the final term exam of our students, it yielded a more profound and retained understanding of the subject course. Moreover, considering the positive effect of study skills on long-term student scores, we recommend students to receive instructions regarding the appropriate study skills when initiated into universities.

Organ-specific physiological responses to acute physical exercise and long-term training in humans.

PubMed

Heinonen, Ilkka; Kalliokoski, Kari K; Hannukainen, Jarna C; Duncker, Dirk J; Nuutila, Pirjo; Knuuti, Juhani

2014-11-01

Virtually all tissues in the human body rely on aerobic metabolism for energy production and are therefore critically dependent on continuous supply of oxygen. Oxygen is provided by blood flow, and, in essence, changes in organ perfusion are also closely associated with alterations in tissue metabolism. In response to acute exercise, blood flow is markedly increased in contracting skeletal muscles and myocardium, but perfusion in other organs (brain and bone) is only slightly enhanced or is even reduced (visceral organs). Despite largely unchanged metabolism and perfusion, repeated exposures to altered hemodynamics and hormonal milieu produced by acute exercise, long-term exercise training appears to be capable of inducing effects also in tissues other than muscles that may yield health benefits. However, the physiological adaptations and driving-force mechanisms in organs such as brain, liver, pancreas, gut, bone, and adipose tissue, remain largely obscure in humans. Along these lines, this review integrates current information on physiological responses to acute exercise and to long-term physical training in major metabolically active human organs. Knowledge is mostly provided based on the state-of-the-art, noninvasive human imaging studies, and directions for future novel research are proposed throughout the review. ©2014 Int. Union Physiol. Sci./Am. Physiol. Soc.

Preterm Birth and Its Long-Term Effects: Methylation to Mechanisms

PubMed Central

Parets, Sasha E.; Bedient, Carrie E.; Menon, Ramkumar; Smith, Alicia K.

2014-01-01

The epigenetic patterns established during development may influence gene expression over a lifetime and increase susceptibility to chronic disease. Being born preterm (<37 weeks of gestation) is associated with increased risk mortality and morbidity from birth until adulthood. This brief review explores the potential role of DNA methylation in preterm birth (PTB) and its possible long-term consequences and provides an overview of the physiological processes central to PTB and recent DNA methylation studies of PTB. PMID:25256426

Motivation and placebos: do different mechanisms occur in different contexts?

PubMed

Hyland, Michael E

2011-06-27

This paper challenges the common assumption that the mechanisms underlying short-term placebo paradigms (where there is no motivation for health improvement) and long-term placebo paradigms (where patients value improvement in their health) are the same. Three types of motivational theory are reviewed: (i) classical placebo motivation theory that the placebo response results from the desire for therapeutic improvement; (ii) goal activation model that expectancy-driven placebo responses are enhanced when the placebo response satisfies an activated goal; and (iii) motivational concordance model that the placebo response is the consequence of concordance between the placebo ritual and significant intrinsic motives. It is suggested that current data are consistent with the following theory: response expectancy, conditioning and goal activation are responsible for short-term placebo effects but long-term therapeutic change is achieved through the effects of goal satisfaction and affect on the inflammatory response system and hypothalamic-pituitary-adrenal axis. Empirical predictions of this new theory are outlined, including ways in which placebo effects can be combined with other psychologically mediated effects on short-term and long-term psychological and physiological state.

Motivation and placebos: do different mechanisms occur in different contexts?

PubMed Central

Hyland, Michael E.

2011-01-01

This paper challenges the common assumption that the mechanisms underlying short-term placebo paradigms (where there is no motivation for health improvement) and long-term placebo paradigms (where patients value improvement in their health) are the same. Three types of motivational theory are reviewed: (i) classical placebo motivation theory that the placebo response results from the desire for therapeutic improvement; (ii) goal activation model that expectancy-driven placebo responses are enhanced when the placebo response satisfies an activated goal; and (iii) motivational concordance model that the placebo response is the consequence of concordance between the placebo ritual and significant intrinsic motives. It is suggested that current data are consistent with the following theory: response expectancy, conditioning and goal activation are responsible for short-term placebo effects but long-term therapeutic change is achieved through the effects of goal satisfaction and affect on the inflammatory response system and hypothalamic–pituitary–adrenal axis. Empirical predictions of this new theory are outlined, including ways in which placebo effects can be combined with other psychologically mediated effects on short-term and long-term psychological and physiological state. PMID:21576140

Mechanisms of weight loss, diabetes control and changes in food choices after gastrointestinal surgery.

PubMed

Papamargaritis, Dimitrios; Panteliou, Eleftheria; Miras, Alexander D; le Roux, Carel W

2012-12-01

The long-term effects of lifestyle changes, diet and medical therapy on obesity are limited. Bariatric surgery is the most effective long-term treatment with the greatest chances for amelioration of obesity-associated complications, including type 2 diabetes mellitus (T2DM). There is increasing evidence in the literature that bariatric operations have a profound effect on human physiology, by reducing hunger, increasing satiety, paradoxically increasing energy expenditure, and even promoting healthy food preferences. Some of these operations improve glucose homeostasis in patients with T2DM independently of weight loss. Changes in the gut hormone levels of glucagon-like peptide 1, peptide YY and ghrelin have been proposed as some of the mediators implicated in changing physiology. The aim of this review is to critically explore the current knowledge on the putative mechanisms of the change in weight and improvement in T2DM glycaemic control after the most commonly performed bariatric operations.

[Effects of long term mental arithmetic on physiological parameters, subjective indices and task performances].

PubMed

Yamada, Shimpei; Miyake, Shinji

2007-03-01

This study examined the effects of long term mental arithmetic on physiological parameters, subjective indices and task performances to investigate the psychophysiological changes induced by mental tasks. Fifteen male university students performed six successive trials of a ten-minute mental arithmetic task. They took a five-minute resting period before and after the tasks. CFF (Critical Flicker Fusion frequency) and subjective fatigue scores using a visual analog scale, POMS (Profiles of Mood States) and SFF (Subjective Feelings of Fatigue) were obtained after each task and resting period. The voices of participants who were instructed to speak five Japanese vowels ('a', 'i', 'u', 'e', 'o') were recorded after each block to investigate a chaotic property of vocal signals that is reported to be changed by fatigue. Subjective workload ratings were also obtained by the NASA-TLX (National Aeronautics and Space Administration-Task Load Index) after the task. Physiological signals of ECG (Electrocardiogram), PTG (Photoelectric Plethysmogram), SCL (Skin Conductance Level), TBV (Tissue Blood Volume) and Respiration were recorded for all experimental blocks. The number of answers, correct rates and average levels of task difficulty for each ten-minute task were used as task performance indices. In this experiment, the task performance did not decrease, whereas subjective fatigue increased. Activation of the sympathetic nervous system was suggested by physiological parameters.

A single exposure to severe stressors causes long-term desensitisation of the physiological response to the homotypic stressor.

PubMed

Armario, Antonio; Vallès, Astrid; Dal-Zotto, Silvina; Márquez, Cristina; Belda, Xavier

2004-09-01

Although some laboratories have reported that a single session of stress is able to induce a long-lasting sensitisation of the hypothalamic-pituitary-adrenal (HPA) response to further exposures to stress, we have found that a single exposure to severe emotional (immobilisation, restraint or shock) or systemic (endotoxin) stressors reduces the responsiveness of the HPA to the same, but not to a novel (heterotypic), stressor, in which case a slight sensitisation was observed. Long-term desensitisation has been found to reduce not only secretion of peripheral HPA hormones (ACTH and corticosterone), but also to reduce responses of central components of the HPA axis (c-fos and CRF gene expression at the level of the paraventricular nucleus of the hypothalamus, PVN). In addition, desensitisation also applies to the impact of the stressor on food intake and, probably, to stress-induced hyperglycaemia. The development of long-term desensitisation of the HPA axis does not appear to be a universal consequence of exposure to severe stressors as it was not observed in response to insulin-induced hypoglycaemia. Whether or not the development of long-term effects of stress depend on the specific pathways activated by particular stressors remains to be tested. The observed desensitisation of the HPA axis in response to the homotypic stressor shows two special features which makes it difficult to be interpreted in terms of an habituation-like process: (a) the effect increased with time (days to weeks) elapsed between the first and second exposure to the stressor, suggesting a progressive maturational process; and (b) the stronger the stressor the greater the long-term desensitisation. Therefore, it is possible that desensitisation of the HPA axis is the sum of two different phenomena: long-term effects and habituation-like processes. The contribution of the former may be more relevant with severe stressors and longer inter-stress intervals, and that of the latter with mild stressors and repeated exposures. Long-term stress-induced changes may not take place at the level of the PVN itself, but in brain nuclei showing synaptic plasticity and putatively involved in the control of the HPA axis and other physiological responses. As for the precise areas involved, these remain to be characterized.

Long-term iron deficiency: Tracing changes in the proteome of different pea (Pisum sativum L.) cultivars.

PubMed

Meisrimler, Claudia-Nicole; Wienkoop, Stefanie; Lyon, David; Geilfus, Christoph-Martin; Lüthje, Sabine

2016-05-17

Iron deficiency (-Fe) is one of the major problems in crop production. Dicots, like pea (Pisum sativum L.), are Strategy I plants, which induce a group of specific enzymes such as Fe(III)-chelate reductase (FRO), Fe responsive transporter (IRT) and H(+)-ATPase (HA) at the root plasma membrane under -Fe. Different species and cultivars have been shown to react diversely to -Fe. Furthermore, different kinds of experimental set-ups for -Fe have to be distinguished: i) short-term vs. long-term, ii) constant vs. acute alteration and iii) buffered vs. unbuffered systems. The presented work compares the effects of constant long-term -Fe in an unbuffered system on roots of four different pea cultivars in a timely manner (12, 19 and 25days). To differentiate the effects of -Fe and plant development, control plants (+Fe) were analyzed in comparison to -Fe plants. Besides physiological measurements, an integrative study was conducted using a comprehensive proteome analysis. Proteins, related to stress adaptation (e.g. HSP), reactive oxygen species related proteins and proteins of the mitochondrial electron transport were identified to be changed in their abundance. Regulations and possible functions of identified proteins are discussed. Pea (Pisum sativum L.) belongs to the legume family (Fabaceae) and is an important crop plant due to high Fe, starch and protein contents. According to FAOSTAT data (September 2015), world production of the garden pea quadrupled from 1970 to 2012. Since the initial studies by Gregor Mendel, the garden pea became the most-characterized legume and has been used in numerous investigations in plant biochemistry and physiology, but is not well represented in the "omics"-related fields. A major limitation in pea production is the Fe availability from soils. Adaption mechanisms to Fe deficiency vary between species, and even cultivars have been shown to react diversely. A label-free proteomic approach, in combination with physiological measurements, was chosen to observe four different pea cultivars for 5 to 25days. Physiological and proteome data showed that cultivar Blauwschokker and Vroege were more susceptible to -Fe than cultivar Kelvedon (highly efficient) and GftR (semi-efficient). Proteomic data hint that the adaptation process to long-term -Fe takes place between days 19 and 25. Results show that adaptation processes of efficient cultivars are able to postpone secondary negative effects of long-term -Fe, possibly by stabilizing the protein metabolic processing and the mitochondrial electron transport components. This maintains the cellular energy proliferation, keeps ROS production low and postpones the mitochondrial cell death signal. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of Transport at Weaning on the Behavior, Physiology and Performance of Pigs

PubMed Central

Sutherland, Mhairi A.; Backus, Brittany L.; McGlone, John J.

2014-01-01

Simple Summary Pigs are commonly transported to separate production facilities at weaning to reduce disease transfer, enhance productivity and to improve overall operational efficiency. A review of the scientific literature suggests that these animals experience stress due to concurrent weaning and transport; however, gaps in the knowledge include the short and long term health and welfare implications of transporting pigs at weaning. Pig welfare and the efficiency of the swine industry may improve if science-based recommendations were in place. Abstract Transport of pigs to separate production facilities at the time of weaning is a common practice, primarily performed to reduce vertical transfer of disease and enhance production and overall farm efficiency. During transport, pigs are exposed to numerous stressors in conjunction with the stress experienced as a result of weaning. In this review, the behavioral and physiological response of pigs experiencing weaning and transport simultaneously will be described, including the effects of space allowance, season and transport duration. Based on the scientific literature, the gaps in the knowledge regarding potential welfare issues are discussed. Changes in behavior and physiology suggest that weaned pigs may experience stress due to transport. Space allowance, season and duration are aspects of transport that can have a marked impact on these responses. To date, the literature regarding the effects of transport on weaned pigs has primarily focused on the short term stress response and little is known about the effects of concurrent weaning and transport on other aspects of pig welfare including morbidity and mortality rates. Greater understanding of the short and long term consequences of transport on weaned pig welfare particularly in relation to factors such as trip duration, provision of feed and water, and best handling practices would benefit the swine industry. Furthermore, the development of guidelines and recommendations to enhance the short and long term welfare of weaned pigs in relation to transport are needed. PMID:26479005

Variability of Hormonal Stress Markers Collected from a Managed Dolphin Population

DTIC Science & Technology

2012-09-30

production and subsequent cortisol and aldosterone release, a condition that is physiologically similar to Addison’s disease. The long-term impact of this...phone: (858) 546-7090 Award Number: N000141110436 http://www.nmmf.org/ LONG-TERM GOALS Quantifying physiological indicators of stress in...cortisol and aldosterone in this species (Houser et al., 2011). Parallel processing of serum catecholamines will be performed via high-performance

Chronic Exposure to Tributyltin Induces Brain Functional Damage in Juvenile Common Carp (Cyprinus carpio)

PubMed Central

Li, Zhi-Hua; Li, Ping; Shi, Ze-Chao

2015-01-01

The aim of the present study was to investigate the effect of Tributyltin (TBT) on brain function and neurotoxicity of freshwater teleost. The effects of long-term exposure to TBT on antioxidant related indices (MDA, malondialdehyde; SOD, superoxide dismutase; CAT, catalase; GR, glutathione reductase; GPx, glutathione peroxidase), Na+-K+-ATPase and neurological parameters (AChE, acetylcholinesterase; MAO, monoamine oxidase; NO, nitric oxide) in the brain of common carp were evaluated. Fish were exposed to sublethal concentrations of TBT (75 ng/L, 0.75 μg/L and 7.5 μg/L) for 15, 30, and 60 days. Based on the results, a low level and short-term TBT-induced stress could not induce the notable responses of the fish brain, but long-term exposure (more than 15 days) to TBT could lead to obvious physiological-biochemical responses (based on the measured parameters). The results also strongly indicated that neurotoxicity of TBT to fish. Thus, the measured physiological responses in fish brain could provide useful information to better understand the mechanisms of TBT-induced bio-toxicity. PMID:25879203

Chronic exposure to Tributyltin induces brain functional damage in juvenile common carp (Cyprinus carpio).

PubMed

Li, Zhi-Hua; Li, Ping; Shi, Ze-Chao

2015-01-01

The aim of the present study was to investigate the effect of Tributyltin (TBT) on brain function and neurotoxicity of freshwater teleost. The effects of long-term exposure to TBT on antioxidant related indices (MDA, malondialdehyde; SOD, superoxide dismutase; CAT, catalase; GR, glutathione reductase; GPx, glutathione peroxidase), Na+-K+-ATPase and neurological parameters (AChE, acetylcholinesterase; MAO, monoamine oxidase; NO, nitric oxide) in the brain of common carp were evaluated. Fish were exposed to sublethal concentrations of TBT (75 ng/L, 0.75 μg/L and 7.5 μg/L) for 15, 30, and 60 days. Based on the results, a low level and short-term TBT-induced stress could not induce the notable responses of the fish brain, but long-term exposure (more than 15 days) to TBT could lead to obvious physiological-biochemical responses (based on the measured parameters). The results also strongly indicated that neurotoxicity of TBT to fish. Thus, the measured physiological responses in fish brain could provide useful information to better understand the mechanisms of TBT-induced bio-toxicity.

The effects of volume versus intensity of long-term voluntary exercise on physiology and behavior in C57/Bl6 mice.

PubMed

Robison, Lisa S; Popescu, Dominique L; Anderson, Maria E; Beigelman, Steven I; Fitzgerald, Shannon M; Kuzmina, Antonina E; Lituma, David A; Subzwari, Sarima; Michaelos, Michalis; Anderson, Brenda J; Van Nostrand, William E; Robinson, John K

2018-06-04

Cardiovascular exercise (CVE) is associated with healthy aging and reduced risk of disease in humans, with similar benefits seen in animals. Most rodent studies, however, have used shorter intervention periods of a few weeks to a few months, begging questions as to the effects of longer-term, or even life-long, exercise. Additionally, most animal studies have utilized a single exercise treatment group - usually unlimited running wheel access - resulting in large volumes of exercise that are not clinically relevant. It is therefore incumbent to determine the physiological and cognitive/behavioral effects of a range of exercise intensities and volumes over a long-term period that model a lifelong commitment to CVE. In the current study, C57/Bl6 mice remained sedentary or were allowed either 1, 3, or 12 h of access to a running wheel per day, 5 days/weeks, beginning at 3.5-4 months of age. Following an eight-month intervention period, animals underwent a battery of behavioral testing, then euthanized and blood and tissue were collected. Longer access to a running wheel resulted in greater volume and higher running speed, but more breaks in running. All exercise groups showed similarly reduced body weight, increased muscle mass, improved motor function on the rotarod, and reduced anxiety in the open field. While all exercise groups showed increased food intake, this was greatest in the 12 h group but did not differ between 1 h and 3 h mice. While exercise dose-dependently increased working memory performance in the y-maze, the 1 h and 12 h groups showed the largest changes in the mass of many organs, as well as alterations in several behaviors including social interaction, novel object recognition, and Barnes maze performance. These findings suggest that long-term exercise has widespread effects on physiology, behavior, and cognition, which vary by "dose" and measure, and that even relatively small amounts of daily exercise can provide benefits. Copyright © 2018. Published by Elsevier Inc.

Rotation history effects on soybean plants and rhizosphere microbiome

USDA-ARS?s Scientific Manuscript database

Benefits of diversified cropping systems stem from the interactions between soil characteristics, crop growth patterns and physiology, and other organisms. In order to assist in the understanding and implementation of diversified rotation sequences, a long-term experiment was established to evaluate...

Laboratory simulation of the action of weightlessness on the human organism

NASA Technical Reports Server (NTRS)

Genin, A. M.

1977-01-01

A brief history of attemps by the U.S. and the U.S.S.R. to simulate weightlessness in the laboratory is presented. Model for laboratory modeling of weightlessness included the bed regimen, the clinostat, and water immersion. An outline of immediate physiological effects of weightlessness and long term effects is offered.

Resilience of SAR11 bacteria to rapid acidification in the high-latitude open ocean.

PubMed

Hartmann, Manuela; Hill, Polly G; Tynan, Eithne; Achterberg, Eric P; Leakey, Raymond J G; Zubkov, Mikhail V

2016-02-01

Ubiquitous SAR11 Alphaproteobacteria numerically dominate marine planktonic communities. Because they are excruciatingly difficult to cultivate, there is comparatively little known about their physiology and metabolic responses to long- and short-term environmental changes. As surface oceans take up anthropogenic, atmospheric CO2, the consequential process of ocean acidification could affect the global biogeochemical significance of SAR11. Shipping accidents or inadvertent release of chemicals from industrial plants can have strong short-term local effects on oceanic SAR11. This study investigated the effect of 2.5-fold acidification of seawater on the metabolism of SAR11 and other heterotrophic bacterioplankton along a natural temperature gradient crossing the North Atlantic Ocean, Norwegian and Greenland Seas. Uptake rates of the amino acid leucine by SAR11 cells as well as other bacterioplankton remained similar to controls despite an instant ∼50% increase in leucine bioavailability upon acidification. This high physiological resilience to acidification even without acclimation, suggests that open ocean dominant bacterioplankton are able to cope even with sudden and therefore more likely with long-term acidification effects. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Long-term urethral catheterisation.

PubMed

Turner, Bruce; Dickens, Nicola

This article discusses long-term urethral catheterisation, focusing on the relevant anatomy and physiology, indications for the procedure, catheter selection and catheter care. It is important that nurses have a good working knowledge of long-term catheterisation as the need for this intervention will increase with the rise in chronic health conditions and the ageing population.

Physiological and Biochemical Responses of Saltmarsh Plant Spartina alterniflora to Long-term Wave Exposure

NASA Astrophysics Data System (ADS)

Zhou, W.

2017-12-01

In recent years, ecosystem-based flood defence, i.e., eco-shoreline or living shoreline, that is more sustainable and cost-effective than conventional coastal engineering structures has been brought into large-scale practice. Numerous laboratory experiments have been performed to explore the wave-attenuation effects of saltmarsh plants that are widely used in eco-shoreline, and yet no study has ever been conducted on the physiological and biochemical responses of saltmarsh plants to long-term wave exposure, presumably due to the constraint that traditional wave generator fails to provide long-term stable wave conditions necessary for physiological experiments. In this study, a long-term shallow water wave environment simulator using crank-yoke mechanism was built in the laboratory to address this gap. Experiments using the wave simulator were conducted for 8 weeks in a greenhouse and the temperature was maintained at 24-30°C. 5‰ artificial sea water was filled in the test tank, and the water was changed every week. After being acclimatized, nine S. alterniflora individual plants (initial height 30 cm) were planted in each of the three streamlined cuboid containers (12cm×12cm×20cm), which were partially submerged in a test tank, and undertook horizontal sinusoidal motion imposed by the crank-yoke mechanism to mimic plants exposed to shallow water waves. The substrate filled in the containers were soils collected from the Yellow River Delta, so were the S. alterniflora plants. A realistic stem density of 400 stems/m2 was tested, which corresponded to a grid spacing of 5.0 cm. Shallow water waves with six wave heights (H: 0.041, 0.055, 0.069, 0.033, 0.044 and 0.056m), one plants submerged depth (0.1m) and two wave periods (2s and 3s) were simulated in the experiments. A no wave condition was also tested as control. Key physiological and biochemical parameters, such as stem length, peroxidase activity, catalase, superoxide dismutase, ascorbate peroxidase, etc. were measured on a weekly basis to monitor the plant response. Differences among the various groups were analyzed using repeated measures ANOVA to check for significance (P < 0.05). The results can help inform eco-shoreline projects in terms of plant selection and transplantation timing optimization, etc.

The effects of prolonged weightlessness and reduced gravity environments on human survival.

PubMed

Taylor, R L

1993-03-01

The manned exploration of the solar system and the surfaces of some of the smaller planets and larger satellites requires that we are able to keep the adverse human physiological response to long term exposure to near zero and greatly reduced gravity environments within acceptable limits consistent with metabolic function. This paper examines the physiological changes associated with microgravity conditions with particular reference to the weightless demineralizatoin of bone (WDB). It is suggested that many of these changes are the result of physical/mechanical processes and are not primarily a medical problem. There are thus two immediately obvious and workable, if relatively costly, solutions to the problem of weightlessness. The provision of a near 1 g field during prolonged space flights, and/or the development of rapid transit spacecraft capable of significant acceleration and short flight times. Although these developments could remove or greatly ameliorate the effects of weightlessness during long-distance space flights there remains a problem relating to the long term colonization of the surfaces of Mars, the Moon, and other small solar system bodies. It is not yet known whether or not there is a critical threshold value of 'g' below which viable human physiological function cannot be sustained. If such a threshold exists permanent colonization may only be possible if the threshold value of 'g' is less than that at the surface of the planet on which we wish to settle.

Physiological effects of weightlessness: countermeasure system development for a long-term Chinese manned spaceflight.

PubMed

Wang, Linjie; Li, Zhili; Tan, Cheng; Liu, Shujuan; Zhang, Jianfeng; He, Siyang; Zou, Peng; Liu, Weibo; Li, Yinghui

2018-04-25

The Chinese space station will be built around 2020. As a national space laboratory, it will offer unique opportunities for studying the physiological effects of weightlessness and the efficacy of the countermeasures against such effects. In this paper, we described the development of countermeasure systems in the Chinese space program. To emphasize the need of the Chinese space program to implement its own program for developing countermeasures, we reviewed the literature on the negative physiological effects of weightlessness, the challenges of completing missions, the development of countermeasure devices, the establishment of countermeasure programs, and the efficacy of the countermeasure techniques in American and Russian manned spaceflights. In addition, a brief overview was provided on the Chinese research and development on countermeasures to discuss the current status and goals of the development of countermeasures against physiological problems associated with weightlessness.

Food Shortage Causes Differential Effects on Body Composition and Tissue-Specific Gene Expression in Salmon Modified for Increased Growth Hormone Production.

PubMed

Abernathy, Jason; Panserat, Stéphane; Welker, Thomas; Plagne-Juan, Elisabeth; Sakhrani, Dionne; Higgs, David A; Audouin, Florence; Devlin, Robert H; Overturf, Ken

2015-12-01

Growth hormone (GH) transgenic salmon possesses markedly increased metabolic rate, appetite, and feed conversion efficiency, as well as an increased ability to compete for food resources. Thus, the ability of GH-transgenic fish to withstand periods of food deprivation as occurs in nature is potentially different than that of nontransgenic fish. However, the physiological and genetic effects of transgenic GH production over long periods of food deprivation remain largely unknown. Here, GH-transgenic coho salmon (Oncorhynchus kisutch) and nontransgenic, wild-type coho salmon were subjected to a 3-month food deprivation trial, during which time performance characteristics related to growth were measured along with proximate compositions. To examine potential genetic effects of GH-transgenesis on long-term food deprivation, a group of genes related to muscle development and liver metabolism was selected for quantitative PCR analysis. Results showed that GH-transgenic fish lose weight at an increased rate compared to wild-type even though proximate compositions remained relatively similar between the groups. A total of nine genes related to muscle physiology (cathepsin, cee, insulin-like growth factor, myostatin, murf-1, myosin, myogenin, proteasome delta, tumor necrosis factor) and five genes related to liver metabolism (carnitine palmitoyltransferase, fatty acid synthase, glucose-6-phosphatase, glucose-6-phosphate dehydrogenase, glucokinase) were shown to be differentially regulated between GH-transgenic and wild-type coho salmon over time. These genetic and physiological responses assist in identifying differences between GH-transgenic and wild-type salmon in relation to fitness effects arising from elevated growth hormone during periods of long-term food shortage.

Music and Well-Being in Long-Term Hospitalized Children

ERIC Educational Resources Information Center

Longhi, Elena; Pickett, Nick

2008-01-01

The aim of this study was to investigate the physiological responses of long-term hospitalized children when exposed to live music. Twenty-one paediatric patients at Great Ormond Street Children's Hospital, London, between 3 months and 14 years of age, took part in the study. They were all long-term patients with cardiac and/or respiratory…

Proteomic Analysis of Hair Follicles

NASA Astrophysics Data System (ADS)

Ishioka, Noriaki; Terada, Masahiro; Yamada, Shin; Seki, Masaya; Takahashi, Rika; Majima, Hideyuki J.; Higashibata, Akira; Mukai, Chiaki

2013-02-01

Hair root cells actively divide in a hair follicle, and they sensitively reflect physical conditions. By analyzing the human hair, we can know stress levels on the human body and metabolic conditions caused by microgravity environment and cosmic radiation. The Japan Aerospace Exploration Agency (JAXA) has initiated a human research study to investigate the effects of long-term space flight on gene expression and mineral metabolism by analyzing hair samples of astronauts who stayed in the International Space Station (ISS) for 6 months. During long-term flights, the physiological effects on astronauts include muscle atrophy and bone calcium loss. Furthermore, radiation and psychological effects are important issue to consider. Therefore, an understanding of the effects of the space environment is important for developing countermeasures against the effects experienced by astronauts. In this experiment, we identify functionally important target proteins that integrate transcriptome, mineral metabolism and proteome profiles from human hair. To compare the protein expression data with the gene expression data from hair roots, we developed the protein processing method. We extracted the protein from five strands of hair using ISOGEN reagents. Then, these extracted proteins were analyzed by LC-MS/MS. These collected profiles will give us useful physiological information to examine the effect of space flight.

Long-term regulation in the cardiovascular system - Cornerstone in the development of a composite physiological model

NASA Technical Reports Server (NTRS)

White, R. J.

1974-01-01

The present work discusses a model of the cardiovascular system and related subsystems capable of long-term simulations of the type desired for in-space hypogravic human physiological performance prediction. The discussion centers around the model of Guyton and modifications of it. In order to draw attention to the fluid handling capabilities of the model, one of several transfusion simulations performed is presented, namely, the isotonic saline transfusion simulation.

Influence of fungicides on gas exchange of pecan foliage

USDA-ARS?s Scientific Manuscript database

There are several fungicide chemistries used for disease control on pecan (Carya illinoinensis), but there is little or no knowledge of subtle short- or long-term side-effects of these chemistries on host physiological processes, including photosynthesis (Pn). This study quantifies the impact of se...

Long-term effects of prenatal atrazine exposure on physiology, body composition, and stress reactivity in rats

EPA Science Inventory

Low birth weight in humans is associated with increased risk of coronary heart disease, hypertension, and diabetes in adulthood. Experimental studies have also reported that undernutrition, stress or exposure to glucocorticoids during pregnancy is associated with hypertension, gl...

Short-Term and Long-Term Biological Effects of Chronic Chemical Contamination on Natural Populations of a Marine Bivalve.

PubMed

Breitwieser, Marine; Viricel, Amélia; Graber, Marianne; Murillo, Laurence; Becquet, Vanessa; Churlaud, Carine; Fruitier-Arnaudin, Ingrid; Huet, Valérie; Lacroix, Camille; Pante, Eric; Le Floch, Stéphane; Thomas-Guyon, Hélène

2016-01-01

Understanding the effects of chronic chemical contamination on natural populations of marine organisms is complex due to the combined effects of different types of pollutants and environmental parameters that can modulate the physiological responses to stress. Here, we present the effects of a chronic contamination in a marine bivalve by combining multiple approaches that provide information on individual and population health. We sampled variegated scallops (Mimachlamys varia) at sites characterized by different contaminants and contamination levels to study the short and long-term (intergenerational) responses of this species to physiological stress. We used biomarkers (SOD, MDA, GST, laccase, citrate synthase and phosphatases) as indicators of oxidative stress, immune system alteration, mitochondrial respiration and general metabolism, and measured population genetic diversity at each site. In parallel, concentration of 14 trace metals and 45 organic contaminants (PAHs, PCBs, pesticides) in tissues were measured. Scallops were collected outside and during their reproductive season to investigate temporal variability in contaminant and biomarker levels. Our analyses revealed that the levels of two biomarkers (Laccase-type phenoloxidase and malondialdehyde) were significantly correlated with Cd concentration. Additionally, we observed significant seasonal differences for four of the five biomarkers, which is likely due to the scallop reproductive status at time of sampling. As a source of concern, a location that was identified as a reference site on the basis of inorganic contaminant levels presented the same level of some persistent organic pollutants (DDT and its metabolites) than more impacted sites. Finally, potential long-term effects of heavy metal contamination were observed for variegated scallops as genetic diversity was depressed in the most polluted sites.

Short-Term and Long-Term Biological Effects of Chronic Chemical Contamination on Natural Populations of a Marine Bivalve

PubMed Central

Graber, Marianne; Murillo, Laurence; Becquet, Vanessa; Churlaud, Carine; Fruitier-Arnaudin, Ingrid; Huet, Valérie; Lacroix, Camille; Pante, Eric; Le Floch, Stéphane; Thomas-Guyon, Hélène

2016-01-01

Understanding the effects of chronic chemical contamination on natural populations of marine organisms is complex due to the combined effects of different types of pollutants and environmental parameters that can modulate the physiological responses to stress. Here, we present the effects of a chronic contamination in a marine bivalve by combining multiple approaches that provide information on individual and population health. We sampled variegated scallops (Mimachlamys varia) at sites characterized by different contaminants and contamination levels to study the short and long-term (intergenerational) responses of this species to physiological stress. We used biomarkers (SOD, MDA, GST, laccase, citrate synthase and phosphatases) as indicators of oxidative stress, immune system alteration, mitochondrial respiration and general metabolism, and measured population genetic diversity at each site. In parallel, concentration of 14 trace metals and 45 organic contaminants (PAHs, PCBs, pesticides) in tissues were measured. Scallops were collected outside and during their reproductive season to investigate temporal variability in contaminant and biomarker levels. Our analyses revealed that the levels of two biomarkers (Laccase-type phenoloxidase and malondialdehyde) were significantly correlated with Cd concentration. Additionally, we observed significant seasonal differences for four of the five biomarkers, which is likely due to the scallop reproductive status at time of sampling. As a source of concern, a location that was identified as a reference site on the basis of inorganic contaminant levels presented the same level of some persistent organic pollutants (DDT and its metabolites) than more impacted sites. Finally, potential long-term effects of heavy metal contamination were observed for variegated scallops as genetic diversity was depressed in the most polluted sites. PMID:26938082

Long-term fitness consequences of early environment in a long-lived ungulate

PubMed Central

Festa-Bianchet, Marco; Pelletier, Fanie

2017-01-01

Cohort effects can be a major source of heterogeneity and play an important role in population dynamics. Silver-spoon effects, when environmental quality at birth improves future performance regardless of the adult environment, can induce strong lagged responses on population growth. Alternatively, the external predictive adaptive response (PAR) hypothesis predicts that organisms will adjust their developmental trajectory and physiology during early life in anticipation of expected adult conditions but has rarely been assessed in wild species. We used over 40 years of detailed individual monitoring of bighorn ewes (Ovis canadensis) to quantify long-term cohort effects on survival and reproduction. We then tested both the silver-spoon and the PAR hypotheses. Cohort effects involved a strong interaction between birth and current environments: reproduction and survival were lowest for ewes that were born and lived at high population densities. This interaction, however, does not support the PAR hypothesis because individuals with matching high-density birth and adult environments had reduced fitness. Instead, individuals born at high density had overall lower lifetime fitness suggesting a silver-spoon effect. Early-life conditions can induce long-term changes in fitness components, and their effects on cohort fitness vary according to adult environment. PMID:28424347

Space colonization - Some physiological perspectives

NASA Technical Reports Server (NTRS)

Winkler, L. H.

1978-01-01

Physiological criteria determining the design of the habitat for a space colony with 10,000 people are discussed. Centrifugally generated earth-normal gravity, maximum ionizing radiation dose standards less than or equal to 0.5 rem/year (obtained with passive shielding), and an atmosphere with reduced nitrogen partial pressures were established as design requirements for the habitat. However, further research is needed to determine whether humans experience complete adaptation to weightlessness and whether there are long-term effects of breathing various atmospheric mixtures and pressures.

Modification of cytogenetic and physiological effects of space flight factors by biologically active compounds

NASA Technical Reports Server (NTRS)

Aliyev, A. A.; Mekhti-Zade, E. R.; Mashinskiy, A. L.; Alekperov, U. K.

1986-01-01

Physiological and cytogenetic changes in the Welsh onion plants induced by a short (82 days) and long term (522 days) space flight are expressed in decrease of seed germination, inhibition of stem growth, depression of cell division in root meristem, and increase in the number of structural chromosome rearrangements. The treatment of such plants with solutions of a-tocopherol, auxin, and kinetin decreased the level of chromosome aberrations to the control one and normalized cell divisions and growth partly or completely.

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 efforts to achieve and maintain weight loss. PMID:25896063

Computer game-based and traditional learning method: a comparison regarding students' knowledge retention.

PubMed

Rondon, Silmara; Sassi, Fernanda Chiarion; Furquim de Andrade, Claudia Regina

2013-02-25

Educational computer games are examples of computer-assisted learning objects, representing an educational strategy of growing interest. Given the changes in the digital world over the last decades, students of the current generation expect technology to be used in advancing their learning requiring a need to change traditional passive learning methodologies to an active multisensory experimental learning methodology. The objective of this study was to compare a computer game-based learning method with a traditional learning method, regarding learning gains and knowledge retention, as means of teaching head and neck Anatomy and Physiology to Speech-Language and Hearing pathology undergraduate students. Students were randomized to participate to one of the learning methods and the data analyst was blinded to which method of learning the students had received. Students' prior knowledge (i.e. before undergoing the learning method), short-term knowledge retention and long-term knowledge retention (i.e. six months after undergoing the learning method) were assessed with a multiple choice questionnaire. Students' performance was compared considering the three moments of assessment for both for the mean total score and for separated mean scores for Anatomy questions and for Physiology questions. Students that received the game-based method performed better in the pos-test assessment only when considering the Anatomy questions section. Students that received the traditional lecture performed better in both post-test and long-term post-test when considering the Anatomy and Physiology questions. The game-based learning method is comparable to the traditional learning method in general and in short-term gains, while the traditional lecture still seems to be more effective to improve students' short and long-term knowledge retention.

Computer game-based and traditional learning method: a comparison regarding students’ knowledge retention

PubMed Central

2013-01-01

Background Educational computer games are examples of computer-assisted learning objects, representing an educational strategy of growing interest. Given the changes in the digital world over the last decades, students of the current generation expect technology to be used in advancing their learning requiring a need to change traditional passive learning methodologies to an active multisensory experimental learning methodology. The objective of this study was to compare a computer game-based learning method with a traditional learning method, regarding learning gains and knowledge retention, as means of teaching head and neck Anatomy and Physiology to Speech-Language and Hearing pathology undergraduate students. Methods Students were randomized to participate to one of the learning methods and the data analyst was blinded to which method of learning the students had received. Students’ prior knowledge (i.e. before undergoing the learning method), short-term knowledge retention and long-term knowledge retention (i.e. six months after undergoing the learning method) were assessed with a multiple choice questionnaire. Students’ performance was compared considering the three moments of assessment for both for the mean total score and for separated mean scores for Anatomy questions and for Physiology questions. Results Students that received the game-based method performed better in the pos-test assessment only when considering the Anatomy questions section. Students that received the traditional lecture performed better in both post-test and long-term post-test when considering the Anatomy and Physiology questions. Conclusions The game-based learning method is comparable to the traditional learning method in general and in short-term gains, while the traditional lecture still seems to be more effective to improve students’ short and long-term knowledge retention. PMID:23442203

[Effect of a synthetic detergent (Syndet) on the pH of the skin of infants].

PubMed

Braun, F; Lachmann, D; Zweymüller, E

1986-06-01

The long- and short-term effects on the skin of infants of a synthetic detergent (syndet) with an acid pH were investigated and compared to ordinary soap. The short-term effect was determined by measuring the skin pH on different parts of the body before and 20 min after washing with syndet. The long-term effect was tested in a second group, in which the infants were washed either with ordinary soap or with syndet for 3 days. The skin pH was measured 4-5 h after washing. The results were evaluated statistically. The results show that for a short time syndet displaces the skin pH towards acid pH in younger infants; however, the skin pH is not influenced in older infants. Syndet keeps the skin pH in the physiological range for a longer time after washing than ordinary soap.

A DEVELOPMENTAL COMPARISON OF THE NEUROBEHAVIORAL EFFECTS OF ECSTASY (MDMA)

PubMed Central

Piper, Brian J.

2007-01-01

The entactogen ±3,4-methylenedioxymethamphetamine (MDMA or ecstasy) is a popular recreational drug among college, high school, and, occasionally, middle school students. Preclinical research examining the acute and long-term effects of MDMA has predominately been conducted in reproductively mature subjects but there has been increasing interest in adolescent and in utero exposure. This review examines the acute and long-term responses to MDMA during perinatal, adolescent, and adult periods. The ability of MDMA to alter core body temperature emerges gradually during ontogeny while a reduction in body weight is evident at all ages. Learning and working-memory are also altered independent of the developmental stage of exposure. Current evidence suggests adults are more sensitive to the long-term serotonin depletions following MDMA but younger ages also exhibit substantial and rapid neuroplasticity. Sexually dimorphic MDMA responses have been identified for the acute hyperthermic and motoric effects of MDMA with pubescent males being especially susceptible. Several physiological, behavioral, and neurochemical MDMA issues requiring further study are also outlined. PMID:17174068

Long-term effects of UV light on contractility of rat arteries in vivo.

PubMed

Morimoto, Yuji; Kohyama, Shinya; Nakai, Kanji; Matsuo, Hirotaka; Karasawa, Fujio; Kikuchi, Makoto

2003-10-01

Several studies have shown that UV irradiation may be effective for preventing vascular restenosis or vasopasm. However, the long-term effects of UV light on the physiological properties of vessels such as arterial tension have not been elucidated. We therefore studied the long-term effects of UV using rat carotid arteries treated with UV-B light (wavelength = 313 nm, total energy = 14 mJ/mm2). The animals were sacrificed at 1, 7 and 14 days after UV light exposure, and the carotid arteries were studied by light microscopy and the contractile responses of isolated arterial rings were recorded under isometric tension. UV treatment had induced a substantial loss of smooth muscle cells (SMC) along the entire circumference of the media on days 7 and 14, whereas loss of SMC on day 1 was negligible. Contractile responses of arteries that had been exposed to UV light were significantly reduced on days, 1, 7 and 14. The susceptibility of UV-treated arteries to phenylephrine and prostaglandin F2 alpha was significantly decreased on days 1 and 7, but decreased susceptibility was not seen on day 14. Acetylcholine-induced relaxations were not altered by UV treatment. These results suggest that the long-term effect of UV light is an attenuation of smooth muscle contractility without impairment of endothelial function.

Advanced research to qualify man for long term weightlessness.

NASA Technical Reports Server (NTRS)

Jones, W. L.

1972-01-01

NASA is in the process of conducting a broad program of research and development of technology to qualify, support, and permit the successful use of man in long-term space flight. The technological tasks include human engineering, extravehicular engineering, life support, and human research to assess the effect of space stresses on human physiology and psychology. Various testing techniques that are being used may have future relevance to world health. These include a biocybernetic approach to the study of cardiovascular stresses, measurement of blood flow by means of the Doppler effect, and a device for simulating radiation dosages similar to those produced in solar flares. The planned program includes a study of both humans and animals.

Photosynthetic acclimation: state transitions and adjustment of photosystem stoichiometry--functional relationships between short-term and long-term light quality acclimation in plants.

PubMed

Dietzel, Lars; Bräutigam, Katharina; Pfannschmidt, Thomas

2008-03-01

In dense plant populations, individuals shade each other resulting in a low-light habitat that is enriched in far-red light. This light quality gradient decreases the efficiency of the photosynthetic light reaction as a result of imbalanced excitation of the two photosystems. Plants counteract such conditions by performing acclimation reactions. Two major mechanisms are known to assure efficient photosynthesis: state transitions, which act on a short-term timescale; and a long-term response, which enables the plant to re-adjust photosystem stoichiometry in favour of the rate-limiting photosystem. Both processes start with the perception of the imbalanced photosystem excitation via reduction/oxidation (redox) signals from the photosynthetic electron transport chain. Recent data in Arabidopsis indicate that initialization of the molecular processes in both cases involve the activity of the thylakoid membrane-associated kinase, STN7. Thus, redox-controlled phosphorylation events may not only adjust photosystem antenna structure but may also affect plastid, as well as nuclear, gene expression. Both state transitions and the long-term response have been described mainly in molecular terms, while the physiological relevance concerning plant survival and reproduction has been poorly investigated. Recent studies have shed more light on this topic. Here, we give an overview on the long-term response, its physiological effects, possible mechanisms and its relationship to state transitions as well as to nonphotochemical quenching, another important short-term mechanism that mediates high-light acclimation. Special emphasis is given to the functional roles and potential interactions between the different light acclimation strategies. A working model displays the various responses as an integrated molecular system that helps plants to acclimate to the changing light environment.

Numerical Simulation of cardiovascular deconditioning in different reduced gravity exposure scenarios. Parabolic flight validation.

NASA Astrophysics Data System (ADS)

Perez-Poch, Antoni; Gonzalez, Daniel

Numerical models and simulations are an emerging area of research in human physiology. As complex numerical models are available, along with high-speed computing technologies, it is possible to produce more accurate predictions of the long-term effects of reduced gravity on the human body. NELME (Numerical Emulation of Long-Term Microgravity Effects) has been developed as an electrical-like control system model of the pysiological changes that may arise when gravity changes are applied to the cardiovascular system. Validation of the model has been carried out in parabolic flights at UPC BarcelonaTech Platform. A number of parabolas of up to 8 seconds were performed at Sabadell Airport with an aerobatic single-engine CAP10B plane capable of performing such maneuvres. Heart rate, arterial pressure, and gravity data was collected and compared to the output obtained from the model in order to optimize its parameters. The model is then able to perform simulations for long-term periods of exposure to microgravity, and then the risk for a major malfunction is evaluated. Vascular resistance is known to be impaired during a long-term mission. This effects are not fully understood, and the model is capable of providing a continuous thread of simulated scenarios, while varying gravity in a nearly-continuous way. Aerobic exercise as countermeasure has been simulated as a periodic perturbation into the simulated physiological system. Results are discussed in terms of the validaty and reliability of the outcomes from the model, that have been found compatible with the available data in the literature. Different gender sensitivities to microgravity exposure are discussed. Also thermal stress along with exercise, as it happens in the case of Extravehicular activity is smulated. Results show that vascular resistance is significantly impared (p<0,05) at gravity levels less than 0,4g, when exposed for a period of time longer than 16 days. This degree of impairement is comparable with that resulting from a microgravity exposure. These results suggest that long-term activities on the surface of Mars may have a greater impact on the cardiovascular health than previously thought.

Short-term effects of cardiac steroids on intracellular membrane traffic in neuronal NT2 cells.

PubMed

Rosen, H; Glukmann, V; Feldmann, T; Fridman, E; Lichtstein, D

2006-12-30

Cardiac steroids (CS) are specific inhibitors of Na+, K+-ATPase activity. Although the presence of CS-like compounds in animal tissues has been established, their physiological role is not clear. In a previous study we showed that in pulse-chase membrane-labeling experiments, long term (hours) interaction of CS at physiological concentrations (nM) with Na+, K+-ATPase, caused changes in endocytosed membrane traffic in human NT2 cells. This was associated with the accumulation of large vesicles adjacent to the nucleus. For this sequence of events to function in the physiological setting, however, CS would be expected to modify membrane traffic upon short term (min) exposure and membrane labeling. We now demonstrate that CS affects membrane traffic also following a short exposure. This was reflected by the CS-induced accumulation of FM1-43 and transferrin in the cells, as well as by changes in their colocalization with Na+, K+-ATPase. We also show that the CS-induced changes in membrane traffic following up to 2 hrs exposure are reversible, whereas longer treatment induces irreversible effects. Based on these observations, we propose that endogenous CS-like compounds are physiological regulators of the recycling of endocytosed membrane proteins and cargo in neuronal cells, and may affect basic mechanisms such as neurotransmitter release and reuptake.

Stress-induced sensitization: the hypothalamic-pituitary-adrenal axis and beyond.

PubMed

Belda, Xavier; Fuentes, Silvia; Daviu, Nuria; Nadal, Roser; Armario, Antonio

2015-01-01

Exposure to certain acute and chronic stressors results in an immediate behavioral and physiological response to the situation followed by a period of days when cross-sensitization to further novel stressors is observed. Cross-sensitization affects to different behavioral and physiological systems, more particularly to the hypothalamus-pituitary-adrenal (HPA) axis. It appears that the nature of the initial (triggering) stressor plays a major role, HPA cross-sensitization being more widely observed with systemic or high-intensity emotional stressors. Less important appears to be the nature of the novel (challenging) stressor, although HPA cross-sensitization is better observed with short duration (5-15 min) challenging stressors. In some studies with acute immune stressors, HPA sensitization appears to develop over time (incubation), but most results indicate a strong initial sensitization that progressively declines over the days. Sensitization can affect other physiological system (i.e. plasma catecholamines, brain monoamines), but it is not a general phenomenon. When studied concurrently, behavioral sensitization appears to persist longer than that of the HPA axis, a finding of interest regarding long-term consequences of traumatic stress. In many cases, behavioral and physiological consequences of prior stress can only be observed following imposition of a new stressor, suggesting long-term latent effects of the initial exposure.

Long-Term Exposure to Oral Methylphenidate or dl-Amphetamine Mixture in Peri-Adolescent Rhesus Monkeys: Effects on Physiology, Behavior, and Dopamine System Development

PubMed Central

Soto, Paul L; Wilcox, Kristin M; Zhou, Yun; Ator, Nancy A; Riddle, Mark A; Wong, Dean F; Weed, Michael R

2012-01-01

The stimulants methylphenidate and amphetamine are used to treat children with attention deficit/hyperactivity disorder over important developmental periods, prompting concerns regarding possible long-term health impact. This study assessed the effects of such a regimen in male, peri-adolescent rhesus monkeys on a variety of cognitive/behavioral, physiological, and in vivo neurochemical imaging parameters. Twice daily (0900 and 1200 hours), for a total of 18 months, juvenile male monkeys (8 per group) consumed either an unadulterated orange-flavored solution, a methylphenidate solution, or a dl-amphetamine mixture. Doses were titrated to reach blood/plasma levels comparable to therapeutic levels in children. [11C]MPH and [11C]raclopride dynamic PET scans were performed to image dopamine transporter and D2-like receptors, respectively. Binding potential (BPND), an index of tracer-specific binding, and amphetamine-induced changes in BPND of [11C]raclopride were estimated by kinetic modeling. There were no consistent differences among groups on the vast majority of measures, including cognitive (psychomotor speed, timing, inhibitory control, cognitive flexibility), general activity, physiological (body weight, head circumference, crown-to-rump length), and neurochemical (ie, developmental changes in dopamine transporter, dopamine D2 receptor density, and amphetamine-stimulated dopamine release were as expected). Cytogenetic studies indicated that neither drug was a clastogen in rhesus monkeys. Thus, methylphenidate and amphetamine at therapeutic blood/plasma levels during peri-adolescence in non-human primates have little effect on physiological or behavioral/cognitive development. PMID:22805599

Long-term exposure to oral methylphenidate or dl-amphetamine mixture in peri-adolescent rhesus monkeys: effects on physiology, behavior, and dopamine system development.

PubMed

Soto, Paul L; Wilcox, Kristin M; Zhou, Yun; Kumar, Anil; Ator, Nancy A; Riddle, Mark A; Wong, Dean F; Weed, Michael R

2012-11-01

The stimulants methylphenidate and amphetamine are used to treat children with attention deficit/hyperactivity disorder over important developmental periods, prompting concerns regarding possible long-term health impact. This study assessed the effects of such a regimen in male, peri-adolescent rhesus monkeys on a variety of cognitive/behavioral, physiological, and in vivo neurochemical imaging parameters. Twice daily (0900 and 1200 hours), for a total of 18 months, juvenile male monkeys (8 per group) consumed either an unadulterated orange-flavored solution, a methylphenidate solution, or a dl-amphetamine mixture. Doses were titrated to reach blood/plasma levels comparable to therapeutic levels in children. [¹¹C]MPH and [¹¹C]raclopride dynamic PET scans were performed to image dopamine transporter and D₂-like receptors, respectively. Binding potential (BP(ND)), an index of tracer-specific binding, and amphetamine-induced changes in BP(ND) of [¹¹C]raclopride were estimated by kinetic modeling. There were no consistent differences among groups on the vast majority of measures, including cognitive (psychomotor speed, timing, inhibitory control, cognitive flexibility), general activity, physiological (body weight, head circumference, crown-to-rump length), and neurochemical (ie, developmental changes in dopamine transporter, dopamine D₂ receptor density, and amphetamine-stimulated dopamine release were as expected). Cytogenetic studies indicated that neither drug was a clastogen in rhesus monkeys. Thus, methylphenidate and amphetamine at therapeutic blood/plasma levels during peri-adolescence in non-human primates have little effect on physiological or behavioral/cognitive development.

Physiological responses and match characteristics in professional tennis players during a one-hour simulated tennis match

PubMed Central

Şenel, Ömer; Arslan, Erşan; Can, Sema

2016-01-01

Abstract The purpose of this study was to investigate the effects of serve and return game situations on physiological responses and match characteristics in professional male tennis players during one hour-long simulated singles tennis matches. Ten internationally ranked tennis players (age 22.2 ± 2.8 years; body height 180.7 ± 4.4 cm; body mass 75.9 ± 8.9 kg) participated in this study. Their physiological responses were measured using two portable analyzers during indoor hard court matches. Ratings of perceived exertion were also determined at the end of the game. The variables describing the characteristics of the matches determined from video recordings were: (a) duration of rallies; (b) rest time; (c) work-to-rest ratio; (d) effective playing time; and (d) strokes per rally. Significant differences (p<0.05) were found between serving and returning conditions in an hour-long simulated singles tennis match in terms of oxygen uptake, a heart rate, ratings of perceived exertion, pulmonary ventilation, respiration frequency and a respiratory gas exchange ratio. In addition, both the heart rate and ratings of perceived exertion responses were moderately correlated with the duration of rallies and strokes per rally (r = 0.60 to 0.26; p<0.05). Taken together, these results indicate that the serve game situation has a significant effect on the physiological response in an hour-long simulated tennis match between professional male tennis players. These findings might be used for the physiological adaptations required for tennis-specific aerobic endurance. PMID:28149371

Long-term soluble Abeta1-40 activates CaM kinase II in organotypic hippocampal cultures.

PubMed

Tardito, Daniela; Gennarelli, Massimo; Musazzi, Laura; Gesuete, Raffaella; Chiarini, Stefania; Barbiero, Valentina Sara; Rydel, Russell E; Racagni, Giorgio; Popoli, Maurizio

2007-09-01

Recent findings suggested a role for soluble amyloid-beta (Abeta) peptides in Alzheimer's disease associated cognitive decline. We investigated the action of soluble, monomeric Abeta(1-40) on CaM kinase II, a kinase involved in neuroplasticity and cognition. We treated organotypic hippocampal cultures short-term (up to 4h) and long-term (5 days) with Abeta(1-40) (1nM-5microM). Abeta did not induce cell damage, apoptosis or synaptic loss. Short-term treatment down-regulated enzymatic activity of the kinase, by reducing its Thr(286) phosphorylation. In contrast, long-term treatment (1nM-microM) markedly and significantly up-regulated enzymatic activity, with peak stimulation at 10nM (three-fold). Up-regulation of activity was associated with increased expression of the alpha-isoform of CaM kinase II, increased phosphorylation at Thr(286) (activator residue) and decreased phosphorylation at Thr(305-306) (inhibitory residues). We investigated the effect of glutamate on CaM kinase II following exposure to 1 or 10nM Abeta(1-40). As previously reported, glutamate increased CaM kinase II activity. However, the glutamate effect was not altered by pretreatment of slices with Abeta. Short- and long-term Abeta treatment showed opposite effects on CaM kinase II, suggesting that long-term changes are an adaptation to the kinase early down-regulation. The marked effect of Abeta(1-40) on the kinase suggests that semi-physiological and slowly raising peptide concentrations may have a significant impact on synaptic plasticity in the absence of synaptic loss or neuronal cell death.

Effects of long-acting beta adrenergic agonists on vocal fold ion transport.

PubMed

Sivasankar, Mahalakshmi; Blazer-Yost, Bonnie

2009-03-01

Inhaled medications prescribed for the hypersensitive airway typically combine corticosteroids and long-acting beta2 adrenergic agonists (LABAs). The phonatory side effects of these combination treatments are widely recognized. However, there is limited understanding of the physiological changes induced by these medications that underlie the phonatory side effects. The objective of this study was to investigate the distinct effects of corticosteroids and LABAs on vocal fold mucosal physiology. Understanding the physiological changes to the vocal folds after corticosteroid and LABA treatments is necessary to prevent the prevalent vocal decrement associated with these medications. Experimental in vitro design with treatment and control groups. Native porcine vocal fold mucosae (N = 38) were exposed to corticosteroid or LABA treatments. Ion transport was measured continuously at baseline and after treatment. To quantify the nature of ion transport, vocal folds were also treated with chloride and sodium channel inhibitors. Corticosteroid treatment did not alter ion transport. Conversely, exposure to LABAs significantly increased ion transport. This increase in ion transport was transient, observed immediately after treatment in all tissue and associated with increased chloride secretion. The distinct effects of corticosteroids and LABAs on vocal fold physiology have not been examined to date. This study demonstrates that short-term treatment with LABAs, but not corticosteroids, significantly increases ion transport. These findings suggest that one underlying physiological mechanism for phonatory changes associated with inhaled treatments may be related to acute alterations in vocal fold ion transport and surface hydration.

Cardiovascular and other dynamic systems in long-term space flight

NASA Technical Reports Server (NTRS)

Tipton, David A.

1987-01-01

The paper examines the physiology of the cardiovascular system, and to a lesser extent the endocrine, renal, and hematopoietic systems. The paper highlights the aspects of these areas that are most pertinent to space manufacturing, i.e., working in space. Areas covered include the physiological costs of working in microgravity and partial gravity (e.g., the moon or Mars), countermeasures to potentially adverse physiological adaptations, and problems associated with return to earth after long periods of weightlessness.

Alternative right ventricular pacing sites.

PubMed

Łuciuk, Dariusz; Łuciuk, Marek; Gajek, Jacek

2015-01-01

The main adverse effect of chronic stimulation is stimulation-induced heart failure in case of ventricular contraction dyssynchrony. Because of this fact, new techniques of stimulation should be considered to optimize electrotherapy. One of these methods is pacing from alternative right ventricular sites. The purpose of this article is to review currently accumulated data about alternative sites of cardiac pacing. Medline and PubMed bases were used to search English and Polish reports published recently. Recent studies report a deleterious effect of long term apical pacing. It is suggested that permanent apical stimulation, by omitting physiological conduction pattern with His-Purkinie network, may lead to electrical and mechanical dyssynchrony of heart muscle contraction. In the long term this pathological situation can lead to severe heart failure and death. Because of this, scientists began to search for some alternative sites of cardiac pacing to reduce the deleterious effect of stimulation. Based on current accumulated data, it is suggested that the right ventricular outflow tract, right ventricular septum, direct His-bundle or biventricular pacing are better alternatives due to more physiological electrical impulse propagation within the heart and the reduction of the dyssynchrony effect. These methods should preserve a better left ventricular function and prevent the development of heart failure in permanent paced patients. As there is still not enough, long-term, randomized, prospective, cross-over and multicenter studies, further research is required to validate the benefits of using this kind of therapy. The article should pay attention to new sites of cardiac stimulation as a better and safer method of treatment.

Dietary fiber type reflects physiological functionality: comparison of grain fiber, inulin, and polydextrose.

PubMed

Raninen, Kaisa; Lappi, Jenni; Mykkänen, Hannu; Poutanen, Kaisa

2011-01-01

Dietary fiber is a nutritional concept based not on physiological functions but on defined chemical and physical properties. Recent definitions of dietary fiber differentiate inherent plant cell wall-associated fiber from isolated or synthetic fiber. For the latter to be defined as fiber, beneficial physiological effects should be demonstrated, such as laxative effects, fermentability, attenuation of blood cholesterol levels, or postprandial glucose response. Grain fibers are a major natural source of dietary fiber worldwide, while inulin, a soluble indigestible fructose polymer isolated from chicory, and polydextrose, a synthetic indigestible glucose polymer, have more simple structures. Inulin and polydextrose show many of the same functionalities of grain fiber in the large intestine, in that they are fermentable, bifidogenic, and laxative. The reported effects on postprandial blood glucose and fasting cholesterol levels have been modest, but grain fibers also show variable effects. New biomarkers are needed to link the physiological functions of specific fibers with long-term health benefits. © 2011 International Life Sciences Institute.

Competitive fitness during feast and famine: how SOS DNA polymerases influence physiology and evolution in Escherichia coli.

PubMed

Corzett, Christopher H; Goodman, Myron F; Finkel, Steven E

2013-06-01

Escherichia coli DNA polymerases (Pol) II, IV, and V serve dual roles by facilitating efficient translesion DNA synthesis while simultaneously introducing genetic variation that can promote adaptive evolution. Here we show that these alternative polymerases are induced as cells transition from exponential to long-term stationary-phase growth in the absence of induction of the SOS regulon by external agents that damage DNA. By monitoring the relative fitness of isogenic mutant strains expressing only one alternative polymerase over time, spanning hours to weeks, we establish distinct growth phase-dependent hierarchies of polymerase mutant strain competitiveness. Pol II confers a significant physiological advantage by facilitating efficient replication and creating genetic diversity during periods of rapid growth. Pol IV and Pol V make the largest contributions to evolutionary fitness during long-term stationary phase. Consistent with their roles providing both a physiological and an adaptive advantage during stationary phase, the expression patterns of all three SOS polymerases change during the transition from log phase to long-term stationary phase. Compared to the alternative polymerases, Pol III transcription dominates during mid-exponential phase; however, its abundance decreases to <20% during long-term stationary phase. Pol IV transcription dominates as cells transition out of exponential phase into stationary phase and a burst of Pol V transcription is observed as cells transition from death phase to long-term stationary phase. These changes in alternative DNA polymerase transcription occur in the absence of SOS induction by exogenous agents and indicate that cell populations require appropriate expression of all three alternative DNA polymerases during exponential, stationary, and long-term stationary phases to attain optimal fitness and undergo adaptive evolution.

Setting the Stage for Physical Activity for Secondary Students

ERIC Educational Resources Information Center

Ciccomascolo, Lori; Riebe, Deborah

2006-01-01

Despite the positive long-term physiological and psychological effects of exercise, many young adults between the ages of 12 and 21 years do not participate in regular physical activity. With the time constraints and other challenges in teaching and assessing students, physical educators need realistic strategies that will help in their efforts to…

A nervous tumor microenvironment: the impact of adrenergic stress on cancer cells, immunosuppression, and immunotherapeutic response.

PubMed

Eng, Jason W-L; Kokolus, Kathleen M; Reed, Chelsey B; Hylander, Bonnie L; Ma, Wen W; Repasky, Elizabeth A

2014-11-01

Long conserved mechanisms maintain homeostasis in living creatures in response to a variety of stresses. However, continuous exposure to stress can result in unabated production of stress hormones, especially catecholamines, which can have detrimental health effects. While the long-term effects of chronic stress have well-known physiological consequences, recent discoveries have revealed that stress may affect therapeutic efficacy in cancer. Growing epidemiological evidence reveals strong correlations between progression-free and long-term survival and β-blocker usage in cancer patients. In this review, we summarize the current understanding of how the catecholamines, epinephrine and norepinephrine, affect cancer cell survival and tumor progression. We also highlight new data exploring the potential contributions of stress to immunosuppression in the tumor microenvironment and the implications of these findings for the efficacy of immunotherapies.

Responses of Nannochloropsis oceanica IMET1 to Long-Term Nitrogen Starvation and Recovery1[C][W][OA

PubMed Central

Dong, Hong-Po; Williams, Ernest; Wang, Da-zhi; Xie, Zhang-Xian; Hsia, Ru-ching; Jenck, Alizée; Halden, Rolf; Li, Jing; Chen, Feng; Place, Allen R.

2013-01-01

The Nannochloropsis genus contains oleaginous microalgae that have served as model systems for developing renewable biodiesel. Recent genomic and transcriptomic studies on Nannochloropsis species have provided insights into the regulation of lipid production in response to nitrogen stress. Previous studies have focused on the responses of Nannochloropsis species to short-term nitrogen stress, but the effect of long-term nitrogen deprivation remains largely unknown. In this study, physiological and proteomic approaches were combined to understand the mechanisms by which Nannochloropsis oceanica IMET1 is able to endure long-term nitrate deprivation and its ability to recover homeostasis when nitrogen is amended. Changes of the proteome during chronic nitrogen starvation espoused the physiological changes observed, and there was a general trend toward recycling nitrogen and storage of lipids. This was evidenced by a global down-regulation of protein expression, a retained expression of proteins involved in glycolysis and the synthesis of fatty acids, as well as an up-regulation of enzymes used in nitrogen scavenging and protein turnover. Also, lipid accumulation and autophagy of plastids may play a key role in maintaining cell vitality. Following the addition of nitrogen, there were proteomic changes and metabolic changes observed within 24 h, which resulted in a return of the culture to steady state within 4 d. These results demonstrate the ability of N. oceanica IMET1 to recover from long periods of nitrate deprivation without apparent detriment to the culture and provide proteomic markers for genetic modification. PMID:23637339

A Review of the Cognitive Effects Observed in Humans Following Acute Supplementation with Flavonoids, and Their Associated Mechanisms of Action.

PubMed

Bell, Lynne; Lamport, Daniel J; Butler, Laurie T; Williams, Claire M

2015-12-09

Flavonoids are polyphenolic compounds found in varying concentrations in many plant-based foods. Recent studies suggest that flavonoids can be beneficial to both cognitive and physiological health. Long term flavonoid supplementation over a period of weeks or months has been extensively investigated and reviewed, particularly with respect to cognitive ageing and neurodegenerative disease. Significantly less focus has been directed towards the short term effects of single doses of flavonoids on cognition. Here, we review 21 such studies with particular emphasis on the subclass and dose of flavonoids administered, the cognitive domains affected by flavonoid supplementation, and the effect size of the response. The emerging evidence suggests that flavonoids may be beneficial to attention, working memory, and psychomotor processing speed in a general population. Episodic memory effects are less well defined and may be restricted to child or older adult populations. The evidence also points towards a dose-dependent effect of flavonoids, but the physiological mechanisms of action remain unclear. Overall, there is encouraging evidence that flavonoid supplementation can benefit cognitive outcomes within an acute time frame of 0-6 h. But larger studies, combining cognitive and physiological measures, are needed to strengthen the evidence base.

ALTERED PHOSPHORYLATION OF MAP KINASE AFTER ACUTE EXPOSURE TO PCB153.

EPA Science Inventory

Long-term potentiation (LTP) is a model of synaptic plasticity believed to encompass the physiological substrate of memory. The mitogen-activated protein kinase (ERK1/2) signalling cascade contributes to synaptic plasticity and to long-term memory formation. Learning and LTP st...

Adrenal, metabolic and cardio-renal dysfunction develops after pregnancy in rats born small or stressed by physiological measurements during pregnancy.

PubMed

Cheong, Jean N; Cuffe, James S M; Jefferies, Andrew J; Moritz, Karen M; Wlodek, Mary E

2016-10-15

Women born small are at an increased risk of developing pregnancy complications. Stress may further increase a woman's likelihood for an adverse pregnancy. Adverse pregnancy adaptations can lead to long-term diseases even after her pregnancy. The current study investigated the effects of stress during pregnancy on the long-term adrenal, metabolic and cardio-renal health of female rats that were born small. Stress programmed increased adrenal Mc2r gene expression, a higher insulin secretory response to glucose during intraperitoneal glucose tolerance test (+36%) and elevated renal creatinine clearance after pregnancy. Females that were born small had increased homeostatic model assessment-insulin resistance and elevated systolic blood pressure after pregnancy, regardless of stress exposure. These findings suggest that being born small or being stressed during pregnancy programs long-term adverse health outcomes after pregnancy. However, stress in pregnancy does not exacerbate the long-term adverse health outcomes for females that were born small. Females born small are more likely to experience complications during their pregnancy, including pregnancy-induced hypertension, pre-eclampsia and gestational diabetes. The risk of developing complications is increased by stress exposure during pregnancy. In addition, pregnancy complications may predispose the mother to diseases after pregnancy. We determined whether stress during pregnancy would exacerbate the adrenal, metabolic and cardio-renal dysfunction of growth-restricted females in later life. Late gestation bilateral uterine vessel ligation was performed in Wistar Kyoto rats to induce growth restriction. At 4 months, growth-restricted and control female offspring were mated with normal males. Those allocated to the stressed group had physiological measurements [metabolic cage, tail cuff blood pressure, intraperitoneal glucose tolerance test (IPGTT)] conducted during pregnancy whilst the unstressed groups were unhandled. After the completion of pregnancy, dams were aged to 12 months and blood pressure, and metabolic and renal function were assessed. At 13 months, adrenal glands, pancreases and plasma were collected at post-mortem. Females stressed during pregnancy had increased adrenal Mc2r gene expression (+22%), higher insulin secretory response to glucose during IPGTT (+36%) and higher creatinine clearance (+29%, indicating increased estimated glomerular filtration rate). In contrast, females that were born small had increased homeostatic model assessment-insulin resistance (+54%), increased water intake (+23%), urine output (+44%) and elevated systolic blood pressure (+7%) regardless of exposure to stress. Our findings suggest that low maternal birth weight and maternal stress exposure during pregnancy are both independently detrimental for long-term adrenal, metabolic and cardio-renal health of the mother, although their effects were not exacerbated. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Lung dosimetry for inhaled radon progeny in smokers.

PubMed

Baias, Paul F; Hofmann, Werner; Winkler-Heil, Renate; Cosma, Constantin; Duliu, Octavian G

2010-02-01

Cigarette smoking may change the morphological and physiological parameters of the lung. Thus the primary objective of the present study was to investigate to what extent these smoke-induced changes can modify deposition, clearance and resulting doses of inhaled radon progeny relative to healthy non-smokers (NSs). Doses to sensitive bronchial target cells were computed for four categories of smokers: (1) Light, short-term (LST) smokers, (2) light, long-term (LLT) smokers, (3) heavy, short-term (HST) smokers and (4) heavy, long-term (HLT) smokers. Because of only small changes of morphological and physiological parameters, doses for the LST smokers hardly differed from those for NSs. For LLT and HST smokers, even a protective effect could be observed, caused by a thicker mucus layer and increased mucus velocities. Only in the case of HLT smokers were doses higher by about a factor of 2 than those for NSs, caused primarily by impaired mucociliary clearance, higher breathing frequency, reduced lung volume and airway obstructions. These higher doses suggest that the contribution of inhaled radon progeny to the risk of lung cancer in smokers may be higher than currently assumed on the basis of NS doses.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and long term immunologic memory.

PubMed

Sherr, David H

2004-06-01

The highlighted article by B. Paige Lawrence and Beth Vorderstrasse addresses an oft forgotten aspect of immunotoxicity, the effects of environmental toxins on immunologic memory. Here, the authors take a step towards filling that information gap by evaluating the effects of a prototypic environmental toxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on memory responses to a real-world pathogen, influenza A virus, presented to an animal model in a physiologically relevant manner. Multiple outcomes are evaluated, the vast majority of which suggest important and long-term TCDD-induced changes in the immune system after both primary and secondary exposure to this pathogen. The implications of these studies with regard to the immuno-competence of TCDD-exposed individuals are far reaching.

State of the body in disorders of diurnal physiological rhythms and long-term hypokinesia

NASA Technical Reports Server (NTRS)

Razin, S. N.; Rychko, A. V.

1980-01-01

In order to study the effects of hypokinesia and circadian rhythm restructuring on the morphological and functional status of the hypothalamo-hypophysic-adrenal system, young male Wistar rats were placed in small cages for varying periods. The animals were decapitated and preparations were made from sections of the brain and adrenals and numerous destructive changes were noted in the investigated regions of the brain, indicating that the condition of these areas is directly affected by disruption of established rhythms in physiological processes.

Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calin-Jageman, Robert J

Work funded on this grant has explored the mechanisms of long-term habituation, a ubiquitous form of learning that plays a key role in basic cognitive functioning. Specifically, behavioral, physiological, and molecular mechanisms of habituation have been explored using a simple model system, the tail-elicited siphon-withdrawal reflex (T-SWR) in the marine mollusk Aplysia californica. Substantial progress has been made on the first and third aims, providing some fundamental insights into the mechanisms by which memories are stored. We have characterized the physiological correlates of short- and long-term habituation. We found that short-term habituation is accompanied by a robust sensory adaptation, whereasmore » long-term habituation is accompanied by alterations in sensory and interneuron synaptic efficacy. Thus, our data indicates memories can be shifted between different sites in a neural network as they are consolidated from short to long term. At the molecular level, we have accomplished microarray analysis comparing gene expression in both habituated and control ganglia. We have identified a network of putatively regulated transcripts that seems particularly targeted towards synaptic changes (e.g. SNAP25, calmodulin) . We are now beginning additional work to confirm regulation of these transcripts and build a more detailed understanding of the cascade of molecular events leading to the permanent storage of long-term memories. On the third aim, we have fostered a nascent neuroscience program via a variety of successful initiatives. We have funded over 11 undergraduate neuroscience scholars, several of whom have been recognized at national and regional levels for their research. We have also conducted a pioneering summer research program for community college students which is helping enhance access of underrepresented groups to life science careers. Despite minimal progress on the second aim, this project has provided a) novel insight into the network mechanisms by which short-term memories are permanently stored, and b) a strong foundation for continued growth of an excellent undergraduate neuroscience program.« less

Effects of Social Isolation on Glucocorticoid Regulation in Social Mammals

PubMed Central

Hawkley, Louise C.; Cole, Steve W.; Capitanio, John P.; Norman, Greg J.; Cacioppo, John T.

2012-01-01

The regulation and function of the hypothalamic-pituitary-adrenocortical (HPA) axis and glucocorticoids have been well conserved across vertebrate species. Glucocorticoids influence a wide range of physiological functions that include glucose regulation, metabolism, inflammatory control, as well as cardiovascular, reproductive, and neuronal effects. Some of these are relatively quick-acting non-genomic effects, but most are slower-acting genomic effects. Thus, any stimulus that affects HPA function has the potential to exert wide-ranging short-term and long-term effects on much of vertebrate physiology. Here, we review the effects of social isolation on the functioning of the HPA axis in social species, and on glucocorticoid physiology in social mammals in particular. Evidence indicates that objective and perceived social isolation alter HPA regulation, although the nature and direction of the HPA response differs among species and across age. The inconsistencies in the direction and nature of HPA effects have implications for drawing cross-species conclusions about the effects of social isolation, and are particularly problematic for understanding HPA-related physiological processes in humans. The animal and human data are incommensurate because, for example, animal studies of objective isolation have typically not been modeled on, or for comparability with, the subjective experience of isolation in humans. An animal model of human isolation must be taken more seriously if we want to advance our understanding of the mechanisms for the effects of objective and perceived isolation in humans. PMID:22663934

Human Behaviour in Long-Term Missions

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Session WP1, the discussion focuses on the following topics: Psychological Support for International Space Station Mission; Psycho-social Training for Man in Space; Study of the Physiological Adaptation of the Crew During A 135-Day Space Simulation; Interpersonal Relationships in Space Simulation, The Long-Term Bed Rest in Head-Down Tilt Position; Psychological Adaptation in Groups of Varying Sizes and Environments; Deviance Among Expeditioners, Defining the Off-Nominal Act in Space and Polar Field Analogs; Getting Effective Sleep in the Space-Station Environment; Human Sleep and Circadian Rhythms are Altered During Spaceflight; and Methodological Approach to Study of Cosmonauts Errors and Its Instrumental Support.

Ageing and moisture uptake in polymethyl methacrylate (PMMA) bone cements☆

PubMed Central

Ayre, Wayne Nishio; Denyer, Stephen P.; Evans, Samuel L.

2014-01-01

Bone cements are extensively employed in orthopaedics for joint arthroplasty, however implant failure in the form of aseptic loosening is known to occur after long-term use. The exact mechanism causing this is not well understood, however it is thought to arise from a combination of fatigue and chemical degradation resulting from the hostile in vivo environment. In this study, two commercial bone cements were aged in an isotonic fluid at physiological temperatures and changes in moisture uptake, microstructure and mechanical and fatigue properties were studied. Initial penetration of water into the cement followed Fickian diffusion and was thought to be caused by vacancies created by leaching monomer. An increase in weight of approximately 2% was experienced after 30 days ageing and was accompanied by hydrolysis of poly(methyl methacrylate) (PMMA) in the outermost layers of the cement. This molecular change and the plasticising effect of water resulted in reduced mechanical and fatigue properties over time. Cement ageing is therefore thought to be a key contributor in the long-term failure of cemented joint replacements. The results from this study have highlighted the need to develop cements capable of withstanding long-term degradation and for more accurate test methods, which fully account for physiological ageing. PMID:24445003

Ageing and moisture uptake in polymethyl methacrylate (PMMA) bone cements.

PubMed

Ayre, Wayne Nishio; Denyer, Stephen P; Evans, Samuel L

2014-04-01

Bone cements are extensively employed in orthopaedics for joint arthroplasty, however implant failure in the form of aseptic loosening is known to occur after long-term use. The exact mechanism causing this is not well understood, however it is thought to arise from a combination of fatigue and chemical degradation resulting from the hostile in vivo environment. In this study, two commercial bone cements were aged in an isotonic fluid at physiological temperatures and changes in moisture uptake, microstructure and mechanical and fatigue properties were studied. Initial penetration of water into the cement followed Fickian diffusion and was thought to be caused by vacancies created by leaching monomer. An increase in weight of approximately 2% was experienced after 30 days ageing and was accompanied by hydrolysis of poly(methyl methacrylate) (PMMA) in the outermost layers of the cement. This molecular change and the plasticising effect of water resulted in reduced mechanical and fatigue properties over time. Cement ageing is therefore thought to be a key contributor in the long-term failure of cemented joint replacements. The results from this study have highlighted the need to develop cements capable of withstanding long-term degradation and for more accurate test methods, which fully account for physiological ageing. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Human Health Countermeasures - Partial-Gravity Analogs Workshop

NASA Technical Reports Server (NTRS)

Barr, Yael; Clement, Gilles; Norsk, Peter

2016-01-01

The experimental conditions that were deemed the most interesting by the HHC Element lead scientists are those permitting studies of the long-term effects of exposure to (a) chronic rotation when supine or in head down tilt (ground-based); and (b) long-radius centrifugation (space based). It is interesting to note that chronic ground based slow rotation room studies have not been performed since the 1960's, when the USA and USSR were investigating the potential use of AG for long-duration space missions. On the other hand, the other partial gravity analogs, i.e., parabolic flight, HUT, suspension, and short-radius centrifugation, have been regularly used in the last three decades (see review in Clément et al. 2015). Based on the workshop evaluations and the scores by the HHC scientific disciplines indicated in tables 3 and 4, simulation of partial G between 0 and 1 should be prioritized as follows: Priority 1. Chronic space-based partial-G analogs: a. Chronic space-based long-radius centrifugation. The ideal scenario would be chronic long-radius centrifugation of cells, animals and humans in a translational research approach - ideally beyond low earth orbit under deep space environmental effects and at various rotations - to obtain different G-effects. In this scenario, all physiological systems could be evaluated and the relationship between physiological response and G level established. This would be the most integrative way of defining, for the first time ever, G-thresholds for each physiological system. b. Chronic space-based centrifugation of animals. Chronic centrifugation of rodents at various G levels in space would allow for determination of AG thresholds of protection for each physiological system. In this case, all physiological systems will be of interest. Intermittent centrifugation will be of secondary interest. c. Chronic space-based centrifugation of cell cultures (RWV). Bioreactor studies of cells and cell cultures of various tissues at various G levels would allow for intracellular investigations of the effects of partial-G. Priority 2. Acute, intermittent space based partial-G analogs: a. Acute, intermittent space-based short radius human centrifugation. Intermittent centrifugation of humans would allow determination of thresholds of AG for protection of astronaut health in space. Priority 3. Chronic ground-based partial-G analogs: a. Chronic centrifugation of supine or head-down tilted humans. b. Chronic head-up tilt in humans. c. Chronic head-out graded dry immersion in humans. d. Chronic partial suspension of rodents e. Chronic rotating bioreactor cell culture studies (RWV) Priority 4. Acute ground based partial-G analogs. a. Parabolic flights. Very acute and short term effects of G levels between 0 and 1 in humans for fast responding systems like cardiovascular and sensorimotor as well as for acute responses in cell cultures and animals. b. Other acute models as indicated in table 3.

Long-term biological investigations in space.

PubMed

Lotz, R G; Fuchs, H; Bertsche, U

1975-01-01

Missions in space within the next two decades will be of longer duration than those carried out up to the present time, and the effects of such long-term flights on biological organisms are unknown. Results of biological experiments that have been performed to date cannot be extrapolated to results in future flights because of the unknown influence of adaptation over a long period of time. Prior experiments with Axolotl, fishes, and vertebrates by our research team (in part with sounding rockets) showed that these specimens did not appear to be suitable for long-term missions on which minimization of expense, technique, and energy is required. Subsequent investigations have shown the suitability of the leech (Hirudo medicinalis), which consumes blood of mammals up to ten times its own weight (1 g) and can live more than 2 years without further food supply. Emphasis in the experiments with Hirudo medicinalis is placed on metabolic rhythm and motility. Resorption and diffusion in tissue, development, and growth under long-term effects of cosmic proton radiation and zero-gravity are other focal points. The constancy of cellular life in the mature animals is a point in favor of these specimens. We have also taken into account the synergistic effects of the space environment on the problems just mentioned. The life-support system constructed for the leech has been tested successfully in four sounding rocket flights and, on that basis, has been prepared for a long-term mission. Long-term investigations out of the terrestrial biosphere will provide us with information concerning the degree of adaptation of certain physiological and biochemical functions and as to what extent biological readjustment or repair processes can occur under the specific stress conditions of space flight.

Hormones and the hippocampus.

PubMed

Lathe, R

2001-05-01

Hippocampal lesions produce memory deficits, but the exact function of the hippocampus remains obscure. Evidence is presented that its role in memory may be ancillary to physiological regulation. Molecular studies demonstrate that the hippocampus is a primary target for ligands that reflect body physiology, including ion balance and blood pressure, immunity, pain, reproductive status, satiety and stress. Hippocampal receptors are functional, probably accessible to their ligands, and mediate physiological and cognitive changes. This argues that an early role of the hippocampus may have been in sensing soluble molecules (termed here 'enteroception') in blood and cerebrospinal fluid, perhaps reflecting a common evolutionary origin with the olfactory system ('exteroception'). Functionally, hippocampal enteroception may reflect feedback control; evidence is reviewed that the hippocampus modulates body physiology, including the activity of the hypothalamus-pituitary-adrenal axis, blood pressure, immunity, and reproductive function. It is suggested that the hippocampus operates, in parallel with the amygdala, to modulate body physiology in response to cognitive stimuli. Hippocampal outputs are predominantly inhibitory on downstream neuroendocrine activity; increased synaptic efficacy in the hippocampus (e.g. long-term potentiation) could facilitate throughput inhibition. This may have implications for the role of the hippocampus and long-term potentiation in memory.

Long-Duration Space Flight

NASA Technical Reports Server (NTRS)

1997-01-01

Session WA1 includes short reports concerning: (1) Medical and Physiological Studies During 438-Day Space Flights: (2) Human Performance During a 14 Month Space Mission: (3) Homeostasis in Long-Term Microgravity Conditions; (4) Strategy of Preservation of Health of Cosmonauts in Prolonged and Superprolonged Space Flights; (5) Rehabilitation of Cosmonauts Health Following Long-Term Space Missions; and (6) Perfect Cosmonauts: Some Features of Bio-Portrait.

Effect of silver-loaded PMMA on Streptococcus mutans in a drip flow reactor.

PubMed

Williams, Dustin L; Epperson, Richard Tyler; DeGrauw, Jeffery P; Nielsen, Mattias B; Taylor, Nicholas B; Jolley, Ryan D

2017-09-01

Orthodontic retention has been proposed as a life-long commitment for patients who desire to maintain straight teeth. However, the presence of foreign material increases risk of bacterial colonization and caries formation, of which Streptococcus mutans is a key contributor. Multiple studies have assessed the ability of silver to be added to base plate material and resist attachment of S. mutans. However, it does not appear that long-term washout in connection with biofilm growth under physiologically relevant conditions has been taken into consideration. In this study, silver was added to base plate material and exposed to short- or long-term washout periods. Materials were then assessed for their ability to resist biofilm formation of S. mutans using a drip flow reactor that modeled the human oral environment. Data indicated that silver was able to resist biofilm formation following short-term washout, but long-term washout periods resulted in a lack of ability to resist biofilm formation. These data will be important for future development of base plate materials to achieve long-term antimicrobial efficacy to reduce risk of caries formation and benefit patients in the long term. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2632-2639, 2017. © 2017 Wiley Periodicals, Inc.

The chronic response of yellow-poplar and eastern white pine to ozone and elevated carbon dioxide: three-year summary

Treesearch

Joanne Rebbeck

1996-01-01

The objective of this study was to determine the long-term effects of ozone (O3) and carbon dioxide (CO2) on the growth and physiology of eastern white pine (Pinus strobus) and yellow-poplar (Liriodendron tulipifera) under plantation conditions. Two separate plantations of each species...

Do GSM 900MHz signals affect cerebral blood circulation? A near-infrared spectrophotometry study

NASA Astrophysics Data System (ADS)

Wolf, Martin; Haensse, Daniel; Morren, Geert; Froehlich, Juerg

2006-06-01

Effects of GSM 900MHz signals (EMF) typical for a handheld mobile phone on the cerebral blood circulation were investigated using near-infrared spectrophotometry (NIRS) in a three armed (12W/kg, 1.2W/kg, sham), double blind, randomized crossover trial in 16 healthy volunteers. During exposure we observed borderline significant short term responses of oxyhemoglobin and deoxyhemoglobin concentration, which correspond to a decrease of cerebral blood flow and volume and were smaller than regular physiological changes. Due to the relatively high number of statistical tests, these responses may be spurious and require further studies. There was no detectable dose-response relation or long term response within 20min. The detection limit was a fraction of the regular physiological changes elicited by functional activation. Compared to previous studies using PET, NIRS provides a much higher time resolution, which allowed investigating the short term effects efficiently, noninvasively, without the use of radioactive tracers and with high sensitivity.

Does reactivation trigger episodic memory change? A meta-analysis.

PubMed

Scully, Iiona D; Napper, Lucy E; Hupbach, Almut

2017-07-01

According to the reconsolidation hypothesis, long-term memories return to a plastic state upon their reactivation, leaving them vulnerable to interference effects and requiring re-storage processes or else these memories might be permanently lost. The present study used a meta-analytic approach to critically evaluate the evidence for reactivation-induced changes in human episodic memory. Results indicated that reactivation makes episodic memories susceptible to physiological and behavioral interference. When applied shortly after reactivation, interference manipulations altered the amount of information that could be retrieved from the original learning event. This effect was more pronounced for remote memories and memories of narrative structure. Additionally, new learning following reactivation reliably increased the number of intrusions from new information into the original memory. These findings support a dynamic view of long-term memory by showing that memories can be changed long after they were acquired. Copyright © 2016 Elsevier Inc. All rights reserved.

Lacosamide protects striatal and hippocampal neurons from in vitro ischemia without altering physiological synaptic plasticity.

PubMed

Mazzocchetti, Petra; Tantucci, Michela; Bastioli, Guendalina; Calabrese, Valeria; Di Filippo, Massimiliano; Tozzi, Alessandro; Calabresi, Paolo; Costa, Cinzia

2018-06-01

Lacosamide ([(R)-2-acetamido-N-benzyl-3-methoxypropanamide], LCM), is an antiepileptic that exerts anticonvulsant activity by selectively enhancing slow sodium channel inactivation. By inhibiting seizures and neuronal excitability it might therefore be a good candidate to stabilize neurons and protect them from energetic insults. Using electrophysiological analyses, we have investigated in mice the possible neuroprotective effect of LCM against in vitro ischemia obtained by oxygen and glucose deprivation (ODG), in striatal and hippocampal tissues, two brain structures particularly susceptible to ischemic injury and of pivotal importance for different form of learning and memory. We also explored in these regions the influence of LCM on firing discharge and on long-term synaptic plasticity. We found that in both areas LCM reduced the neuronal firing activity in a use-dependent manner without influencing the physiological synaptic transmission, confirming its anticonvulsant effects. Moreover, we found that this AED is able to protect, in a dose dependent manner, striatal and hippocampal neurons from energy metabolism failure produced by OGD. This neuroprotective effect does not imply impairment of long-term potentiation of striatal and hippocampal synapses and suggests that LCM might exert additional beneficial therapeutic effects beyond its use as antiepileptic. Copyright © 2018 Elsevier Ltd. All rights reserved.

Phenotypic plasticity in the common snapping turtle (Chelydra serpentina): long-term physiological effects of chronic hypoxia during embryonic development.

PubMed

Wearing, Oliver H; Eme, John; Rhen, Turk; Crossley, Dane A

2016-01-15

Studies of embryonic and hatchling reptiles have revealed marked plasticity in morphology, metabolism, and cardiovascular function following chronic hypoxic incubation. However, the long-term effects of chronic hypoxia have not yet been investigated in these animals. The aim of this study was to determine growth and postprandial O2 consumption (V̇o2), heart rate (fH), and mean arterial pressure (Pm, in kPa) of common snapping turtles (Chelydra serpentina) that were incubated as embryos in chronic hypoxia (10% O2, H10) or normoxia (21% O2, N21). We hypothesized that hypoxic development would modify posthatching body mass, metabolic rate, and cardiovascular physiology in juvenile snapping turtles. Yearling H10 turtles were significantly smaller than yearling N21 turtles, both of which were raised posthatching in normoxic, common garden conditions. Measurement of postprandial cardiovascular parameters and O2 consumption were conducted in size-matched three-year-old H10 and N21 turtles. Both before and 12 h after feeding, H10 turtles had a significantly lower fH compared with N21 turtles. In addition, V̇o2 was significantly elevated in H10 animals compared with N21 animals 12 h after feeding, and peak postprandial V̇o2 occurred earlier in H10 animals. Pm of three-year-old turtles was not affected by feeding or hypoxic embryonic incubation. Our findings demonstrate that physiological impacts of developmental hypoxia on embryonic reptiles continue into juvenile life. Copyright © 2016 the American Physiological Society.

Long-term and acute effects of temperature and oxygen on metabolism, food intake, growth and heat tolerance in a freshwater gastropod.

PubMed

Hoefnagel, K Natan; Verberk, Wilco C E P

2017-08-01

Temperature affects the physiology and life-history of ectothermic animals, often increasing metabolic rate and decreasing body size. Oxygen limitation has been put forward as a mechanism to explain thermal responses of body size and the ability to survive stress. However the time-scales involved in growth performance and heat tolerance differ radically. In order to increase our understanding of oxygen and temperature effects on body size and heat tolerance and the time scale involved, we reared Lymnaea stagnalis under six combinations of temperature and oxygen tension from hatching up to an age of 300 days and recorded shell length during this whole period. At the end of this period, we determined scope for growth by measuring food intake rate, assimilation efficiency, respiration rate and ammonium excretion rate at two different temperatures. We also measured the snails' ability to survive heat stress (CTmax), both at normoxia and hypoxia. We found that scope for growth and long term growth performance were much more affected by interactions of chronic oxygen and temperature conditions during rearing than by acute conditions during testing. Furthermore, our study shows that individual variation in growth performance can be traced back to individual differences in rates of food and oxygen consumption. Developmental acclimation also gave rise to differences in CTmax, but these were relatively small and were only expressed when CTmax was tested under hypoxia. The large effects of rearing oxygen conditions on growth and other physiological rates compared to modest effects of test oxygen conditions on CTmax suggest that small effects of hypoxia on the short term (e.g. heat tolerance) may nevertheless have large repercussions on the long term (e.g. growth and reproduction), even in a pulmonate snail that can compensate for hypoxia to some extent by aerial respiration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estradiol increases urethral tone through the local inhibition of neuronal nitric oxide synthase expression.

PubMed

Gamé, Xavier; Allard, Julien; Escourrou, Ghislaine; Gourdy, Pierre; Tack, Ivan; Rischmann, Pascal; Arnal, Jean-François; Malavaud, Bernard

2008-03-01

Estrogens are known to modulate lower urinary tract (LUT) trophicity and neuronal nitric oxide synthase (nNOS) expression in several organs. The aim of this study was to explore the effects of endogenous and supraestrus levels of 17beta-estradiol (E2) on LUT and urethral nNOS expression and function. LUT function and histology and urethral nNOS expression were studied in adult female mice subjected either to sham surgery, surgical castration, or castration plus chronic E2 supplementation (80 microg.kg(-1).day(-1), i.e., pregnancy level). The micturition pattern was profoundly altered by long-term supraestrus levels of E2 with decreased frequency paralleled by increased residual volumes higher than those of ovariectomized mice. Urethral resistance was increased twofold in E2-treated mice, with no structural changes in urethra, supporting a pure tonic mechanism. Acute nNOS inhibition by 7-nitroindazole decreased frequency and increased residual volumes in ovariectomized mice but had no additive effect on the micturition pattern of long-term supraestrus mice, showing that long-term supraestrus E2 levels and acute inhibition of nNOS activity had similar functional effects. Finally, E2 decreased urethral nNOS expression in ovariectomized mice. Long-term supraestrus levels of E2 increased urethral tone through inhibition of nNOS expression, whereas physiological levels of E2 had no effect.

Effects of episodic low aragonite saturation and elevated temperature on the physiology of Stylophora pistillata

NASA Astrophysics Data System (ADS)

Lürig, M.; Kunzmann, A.

2015-05-01

As global climate change is predicted to gradually alter the oceans' carbonate system and water temperature, knowledge about the effects an altered marine environment has on the physiology of reef building (hermatypic) coral species is more widely established. However, although it is recognized that seawater temperature and the carbonate system of a coral reef can change rapidly and with great amplitude, little is known about how the interaction of these natural fluctuations with long term effects of climate change may affect the metabolism and productivity of hermatypic corals. To investigate this, we acclimated the hermatypic coral Stylophora pistillata to a "worst case" scenario for carbon dioxide emissions (aragonite saturation state [ΩARAG] = 1.6), and tested how exposure to short term (24 h) elevated temperature (+ 3 °C) and further lowered ΩARAG (-1 unit) affected its photosynthesis and respiration. While episodic exposure to very low ΩARAG had only little effect on S. pistillata's physiology, short term heat stress caused a shift from net oxygen production to consumption and partial coral bleaching. Higher gross coral respiration, and lowered photosynthetic activity under episodically elevated temperature may have been the result of photoinhibition and partial coral bleaching. These findings suggest that fluctuating environmental conditions in combination with a low ΩARAG background signal may impair basic metabolic processes in calcifying corals. In a future high-CO2 world short term stress could be relevant for reef ecosystem processes, and may affect the resilience of coral reefs to other external influences and effects of climate change.

Research on Life Science and Life Support Engineering Problems of Manned Deep Space Exploration Mission

NASA Astrophysics Data System (ADS)

Qi, Bin; Guo, Linli; Zhang, Zhixian

2016-07-01

Space life science and life support engineering are prominent problems in manned deep space exploration mission. Some typical problems are discussed in this paper, including long-term life support problem, physiological effect and defense of varying extraterrestrial environment. The causes of these problems are developed for these problems. To solve these problems, research on space life science and space medical-engineering should be conducted. In the aspect of space life science, the study of space gravity biology should focus on character of physiological effect in long term zero gravity, co-regulation of physiological systems, impact on stem cells in space, etc. The study of space radiation biology should focus on target effect and non-target effect of radiation, carcinogenicity of radiation, spread of radiation damage in life system, etc. The study of basic biology of space life support system should focus on theoretical basis and simulating mode of constructing the life support system, filtration and combination of species, regulation and optimization method of life support system, etc. In the aspect of space medical-engineering, the study of bio-regenerative life support technology should focus on plants cultivation technology, animal-protein production technology, waste treatment technology, etc. The study of varying gravity defense technology should focus on biological and medical measures to defend varying gravity effect, generation and evaluation of artificial gravity, etc. The study of extraterrestrial environment defense technology should focus on risk evaluation of radiation, monitoring and defending of radiation, compound prevention and removal technology of dust, etc. At last, a case of manned lunar base is analyzed, in which the effective schemes of life support system, defense of varying gravity, defense of extraterrestrial environment are advanced respectively. The points in this paper can be used as references for intensive study on key technologies.

Food intake in the real world: implications for nutrition and aging.

PubMed

de Castro, John M; Stroebele, Nanette

2002-11-01

Nutrient intakes are affected by two classes of factors, physiological and environmental. In the real world, environmental variables such as social factors, palatability, and the time of eating appear to have large influences on amounts ingested in the short-term. Physiological control mechanisms also operate to regulate intake, and they induce compensatory responses to deviations from the norm. These physiological influences only appear to have weak influences on short-term intake unless there are large deviations from the normal state, but over the long-term they act patiently and persistently to rectify the excesses produced by environmental fluctuations and thereby tend to maintain a relative balance between energy intake and expenditure. As individuals age there is a progressive decline in physiological function including the mechanisms that act to control intake in the young. This should not produce a problem in a healthy individual in a stable environment: however, if that situation should change due to illness or an environmental change such as the death of a spouse, which produces decline in intake, elderly individuals would not have the physiological mechanisms present to compensate. Thus, the deficit in energy intake would not be replaced, and the lower level of intake would be maintained as long as the new health condition or environment remains stable. Hence, the decline in the effectiveness of the physiological systems with age makes the elderly particularly vulnerable and unable to rebound from deficits. Although the elderly have difficulty compensating for deficits automatically by physiologically-induced adjustments, the studies of real world intake reviewed in this article suggest that compensation can be produced by adjustments to the environment. The elderly appear to be as responsive to environmental factors as younger individuals. In particular, they appear to increase intake in response to social facilitation, diurnal rhythms, the eating environment, and palatability to the same extent as their juniors. These data suggest that alterations in the social, temporal, environmental, or hedonic conditions of eating could induce desired alterations in the nutrient intakes of the elderly. The study of real world eating behavior has produced evidence that suggests that this strategy can work. It remains for future applied investigations to ascertain whether or not this strategy is effective in treating undernutrition in the elderly.

The future implications and indications of anti-vascular endothelial growth factor therapy in ophthalmic practice

PubMed Central

Ghanekar, Yashoda; Kaur, Inderjeet

2007-01-01

In the last few years anti-vascular endothelial growth factor (VEGF) therapy has changed the paradigm in the treatment of neovascular age-related macular degeneration (ARMD). Besides, its potential use in the treatment of diabetic retinopathy and other possible proliferative vascular disorders has also shown promise. Clinical trial results have shown tremendous beneficial effect of ranibizumab in ARMD. Off-label use of bevacizumab has also shown similar benefit but long-term and clinical trial results do not exist. Some of the potential questions in the use of anti-VEGF are recurring cost, possible long-term effect on physiological function of VEGF and determination of endpoint of treatment. Overall, the use of anti-VEGF therapy in ocular angiogenesis has proven to be beneficial at least now. PMID:17951902

Establishment of a Long-Term Chick Forebrain Neuronal Culture on a Microelectrode Array Platform

PubMed Central

Kuang, Serena Y.; Huang, Ting; Wang, Zhonghai; Lin, Yongliang; Kindy, Mark; Xi, Tingfei; Gao, Bruce Z.

2016-01-01

The biosensor system formed by culturing primary animal neurons on a microelectrode array (MEA) platform is drawing an increasing research interest for its power as a rapid, sensitive, functional neurotoxicity assessment, as well as for many other electrophysiological related research purposes. In this paper, we established a long-term chick forebrain neuron culture (C-FBN-C) on MEAs with a more than 5 month long lifespan and up to 5 month long stability in morphology and physiological function; characterized the C-FBN-C morphologically, functionally, and developmentally; partially compared its functional features with rodent counterpart; and discussed its pros and cons as a novel biosensor system in comparison to rodent counterpart and human induced pluripotent stem cells (hiPSCs). Our results show that C-FBN-C on MEA platform 1) can be used as a biosensor of its own type in a wide spectrum of basic biomedical research; 2) is of value in comparative physiology in cross-species studies; and 3) may have potential to be used as an alternative, cost-effective approach to rodent counterpart within shared common functional domains (such as specific types of ligand-gated ion channel receptors and subtypes expressed in the cortical tissues of both species) in large-scale environmental neurotoxicant screening that would otherwise require millions of animals. PMID:26989485

Long-term changes in cognitive bias and coping response as a result of chronic unpredictable stress during adolescence.

PubMed

Chaby, Lauren E; Cavigelli, Sonia A; White, Amanda; Wang, Kayllie; Braithwaite, Victoria A

2013-01-01

Animals that experience adverse events in early life often have life-long changes to their physiology and behavior. Long-term effects of stress during early life have been studied extensively, but less attention has been given to the consequences of negative experiences solely during the adolescent phase. Adolescence is a particularly sensitive period of life when regulation of the glucocorticoid "stress" hormone response matures and specific regions in the brain undergo considerable change. Aversive experiences during this time might, therefore, be expected to generate long-term consequences for the adult phenotype. Here we investigated the long-term effects of exposure to chronic unpredictable stress during adolescence on adult decision-making, coping response, cognitive bias, and exploratory behavior in rats. Rats exposed to chronic unpredictable stress (e.g., isolation, crowding, cage tilt) were compared to control animals that were maintained in standard, predictable conditions throughout development. Unpredictable stress during adolescence resulted in a suite of long-term behavioral and cognitive changes including a negative cognitive bias [F (1, 12) = 5.000, P < 0.05], altered coping response [T (1, 14) = 2.216, P = 0.04], and accelerated decision-making [T (1, 14) = 3.245, P = 0.01]. Exposure to chronic stress during adolescence also caused a short-term increase in boldness behaviors; in a novel object test 15 days after the last stressor, animals exposed to chronic unpredictable stress had decreased latencies to leave a familiar shelter and approach a novel object [T (1, 14) = 2.240, P = 0.04; T (1, 14) = 2.419, P = 0.03, respectively]. The results showed that stress during adolescence has long-term impacts on behavior and cognition that affect the interpretation of ambiguous stimuli, behavioral response to adverse events, and how animals make decisions.

Long-Term Effects of Dredging Operations Program. Biological Consequences of Bioaccumulation in Aquatic Animals: An Assessment of the Current Literature

DTIC Science & Technology

1984-06-01

at which an effect was first ob- served. The response parameters of growth, reproduction, and some measure of metabolism , such as scope for growth...Aspects of physiological condition in Mytilus edulis L., with special reference to the effects of oxygen tension and salinity . In: Proceed. 9th Europ. Mar...estuarine teleost fish, Gillichthgs mirabilis: Salinity and temperature effects . Arch. Environ. Contam. Toxicol. 6:337-348. Somero, G. N., P. H. Yancey, T

Sweet Taste and Nutrient Value Subdivide Rewarding Dopaminergic Neurons in Drosophila

PubMed Central

Huetteroth, Wolf; Perisse, Emmanuel; Lin, Suewei; Klappenbach, Martín; Burke, Christopher; Waddell, Scott

2015-01-01

Summary Dopaminergic neurons provide reward learning signals in mammals and insects [1–4]. Recent work in Drosophila has demonstrated that water-reinforcing dopaminergic neurons are different to those for nutritious sugars [5]. Here, we tested whether the sweet taste and nutrient properties of sugar reinforcement further subdivide the fly reward system. We found that dopaminergic neurons expressing the OAMB octopamine receptor [6] specifically convey the short-term reinforcing effects of sweet taste [4]. These dopaminergic neurons project to the β′2 and γ4 regions of the mushroom body lobes. In contrast, nutrient-dependent long-term memory requires different dopaminergic neurons that project to the γ5b regions, and it can be artificially reinforced by those projecting to the β lobe and adjacent α1 region. Surprisingly, whereas artificial implantation and expression of short-term memory occur in satiated flies, formation and expression of artificial long-term memory require flies to be hungry. These studies suggest that short-term and long-term sugar memories have different physiological constraints. They also demonstrate further functional heterogeneity within the rewarding dopaminergic neuron population. PMID:25728694

The Immune System’s Role in Sepsis Progression, Resolution and Long-Term Outcome

PubMed Central

Delano, Matthew J.; Ward, Peter A.

2016-01-01

SUMMARY Sepsis occurs when an infection exceeds local tissue containment and induces a series of dysregulated physiologic responses that result in organ dysfunction. A subset of patients with sepsis progress to septic shock, defined by profound circulatory, cellular, and metabolic abnormalities, and associated with a greater mortality. Historically, sepsis-induced organ dysfunction and lethality were attributed to the complex interplay between the initial inflammatory and later anti-inflammatory responses. With advances in intensive care medicine and goal-directed interventions, early 30-day sepsis mortality has diminished, only to steadily escalate long after “recovery” from acute events. Since so many sepsis survivors succumb later to persistent, recurrent, nosocomial and secondary infections, many investigators have turned their attention to the long-term sepsis-induced alterations in cellular immune function. Sepsis clearly alters the innate and adaptive immune responses for sustained periods of time after clinical recovery, with immune suppression, chronic inflammation, and persistence of bacterial representing such alterations. Understanding that sepsis-associated immune cell defects correlate with long-term mortality, more investigations have centered on the potential for immune modulatory therapy to improve long term patient outcomes. These efforts are focused on more clearly defining and effectively reversing the persistent immune cell dysfunction associated with long-term sepsis mortality. PMID:27782333

A Review of the Cognitive Effects Observed in Humans Following Acute Supplementation with Flavonoids, and Their Associated Mechanisms of Action

PubMed Central

Bell, Lynne; Lamport, Daniel J.; Butler, Laurie T.; Williams, Claire M.

2015-01-01

Flavonoids are polyphenolic compounds found in varying concentrations in many plant-based foods. Recent studies suggest that flavonoids can be beneficial to both cognitive and physiological health. Long term flavonoid supplementation over a period of weeks or months has been extensively investigated and reviewed, particularly with respect to cognitive ageing and neurodegenerative disease. Significantly less focus has been directed towards the short term effects of single doses of flavonoids on cognition. Here, we review 21 such studies with particular emphasis on the subclass and dose of flavonoids administered, the cognitive domains affected by flavonoid supplementation, and the effect size of the response. The emerging evidence suggests that flavonoids may be beneficial to attention, working memory, and psychomotor processing speed in a general population. Episodic memory effects are less well defined and may be restricted to child or older adult populations. The evidence also points towards a dose-dependent effect of flavonoids, but the physiological mechanisms of action remain unclear. Overall, there is encouraging evidence that flavonoid supplementation can benefit cognitive outcomes within an acute time frame of 0–6 h. But larger studies, combining cognitive and physiological measures, are needed to strengthen the evidence base. PMID:26690214

Legacy effects in linked ecological-soil-geomorphic systems of drylands

USGS Publications Warehouse

Monger, Curtis; Sala, Osvaldo E.; Duniway, Michael C.; Goldfus, Haim; Meir, Isaac A.; Poch, Rosa M.; Throop, Heather L.; Vivoni, Enrique R.

2015-01-01

A legacy effect refers to the impacts that previous conditions have on current processes or properties. Legacies have been recognized by many disciplines, from physiology and ecology to anthropology and geology. Within the context of climatic change, ecological legacies in drylands (eg vegetative patterns) result from feedbacks between biotic, soil, and geomorphic processes that operate at multiple spatial and temporal scales. Legacy effects depend on (1) the magnitude of the original phenomenon, (2) the time since the occurrence of the phenomenon, and (3) the sensitivity of the ecological–soil–geomorphic system to change. Here we present a conceptual framework for legacy effects at short-term (days to months), medium-term (years to decades), and long-term (centuries to millennia) timescales, which reveals the ubiquity of such effects in drylands across research disciplines.

Global forest sector modeling: application to some impacts of climate change

Treesearch

Joseph Buongiorno

2016-01-01

This paper explored the potential long-term effects of a warming climate on the global wood sector, based on Way and Oren's synthesis (Tree Physiology 30,669-688) indicating positive responses of tree growth to higher temperature in boreal and temperative climates, and negative responses in the topics. Changes in forest productivity were introduced in the Global...

Evaluation of the impacts of herbivory by lace bugs on Chinese privet (Ligustrum sinense) survival and physiology

Treesearch

Yanzhuo Zhang; James Hanula; Joseph O' Brien; Scott Horn; Braman Kris; Jianghua Sun

2013-01-01

Biological control of chinese privet, Ligustrum sinense, is the best long-term option for control of this widespread invasive plant in the southeastern USA. A pre-release efficacy assessment was conducted by testing the effects of damage caused by a lace bug, Leptoypha hospita, on potted privet plants in the laboratory. Inoculating...

Seasonal and long-term effects of CO2 and O3 and their interaction with climate and soil moisture on water loss in ponderosa pine

EPA Science Inventory

Evapotranspiration (ET) is driven by evaporative demand, available solar energy and soil moisture as well as by physiological plant activity which may be substantially affected by elevated CO2 and O3. A multi-year study was conducted in outdoor sun-lit controlled-environment cha...

Seasonal and long-term effects of CO2 and O3 on water loss in ponderosa pine and their interaction with climate and soil moisture

EPA Science Inventory

Evapotranspiration (ET) is driven by evaporative demand, available solar energy and soil moisture (SM) as well as by plant physiological activity which may be substantially affected by elevated CO2 and O3. A multi-year study was conducted in outdoor sunlit-controlled environment ...

Circulating endothelial and progenitor cells: Evidence from acute and long-term exercise effects

PubMed Central

Koutroumpi, Matina; Dimopoulos, Stavros; Psarra, Katherini; Kyprianou, Theodoros; Nanas, Serafim

2012-01-01

Circulating bone-marrow-derived cells, named endothelial progenitor cells (EPCs), are capable of maintaining, generating, and replacing terminally differentiated cells within their own specific tissue as a consequence of physiological cell turnover or tissue damage due to injury. Endothelium maintenance and restoration of normal endothelial cell function is guaranteed by a complex physiological procedure in which EPCs play a significant role. Decreased number of peripheral blood EPCs has been associated with endothelial dysfunction and high cardiovascular risk. In this review, we initially report current knowledge with regard to the role of EPCs in healthy subjects and the clinical value of EPCs in different disease populations such as arterial hypertension, obstructive sleep-apnea syndrome, obesity, diabetes mellitus, peripheral arterial disease, coronary artery disease, pulmonary hypertension, and heart failure. Recent studies have introduced the novel concept that physical activity, either performed as a single exercise session or performed as part of an exercise training program, results in a significant increase of circulating EPCs. In the second part of this review we provide preliminary evidence from recent studies investigating the effects of acute and long-term exercise in healthy subjects and athletes as well as in disease populations. PMID:23272272

How orchids concentrate? The relationship between physiological stress reactivity and cognitive performance during infancy and early childhood.

PubMed

Wass, Sam V

2018-03-30

The Autonomic Nervous System (ANS) is involved both in higher-order cognition such as attention and learning, and in responding to unexpected, threatening events. Increased ANS reactivity may confer both superior short-term cognitive performance, and heightened long-term susceptibility to adverse events. Here, we evaluate this hypothesis within the Differential Susceptibility Theory (DST) framework. We hypothesise that individuals with increased reactivity may show heightened biological sensitivity to context, conferring both positive (development-enhancing) effects (superior attention and learning) and negative (risk-promoting) effects (increased sensitivity to unsupportive environments). First, we examine how ANS reactivity relates to early cognitive performance. We hypothesise that increased phasic ANS reactivity, observed at lower tonic (pre-stimulus) ANS activity, is associated with better attention and learning. We conclude that the evidence is largely in support. Second we discuss whether ANS reactivity to 'positive', attention-eliciting and to 'negative', aversive stimuli is a one-dimensional construct; and evaluate evidence for how the real-world environment influences physiological stress over short and long time-frames. We identify three areas where the evidence is currently inconclusive. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of stress on immune function: the good, the bad, and the beautiful.

PubMed

Dhabhar, Firdaus S

2014-05-01

Although the concept of stress has earned a bad reputation, it is important to recognize that the adaptive purpose of a physiological stress response is to promote survival during fight or flight. While long-term stress is generally harmful, short-term stress can be protective as it prepares the organism to deal with challenges. This review discusses the immune effects of biological stress responses that can be induced by psychological, physiological, or physical (including exercise) stressors. We have proposed that short-term stress is one of the nature's fundamental but under-appreciated survival mechanisms that could be clinically harnessed to enhance immunoprotection. Short-term (i.e., lasting for minutes to hours) stress experienced during immune activation enhances innate/primary and adaptive/secondary immune responses. Mechanisms of immuno-enhancement include changes in dendritic cell, neutrophil, macrophage, and lymphocyte trafficking, maturation, and function as well as local and systemic production of cytokines. In contrast, long-term stress suppresses or dysregulates innate and adaptive immune responses by altering the Type 1-Type 2 cytokine balance, inducing low-grade chronic inflammation, and suppressing numbers, trafficking, and function of immunoprotective cells. Chronic stress may also increase susceptibility to some types of cancer by suppressing Type 1 cytokines and protective T cells and increasing regulatory/suppressor T cell function. Here, we classify immune responses as being protective, pathological, or regulatory, and discuss "good" versus "bad" effects of stress on health. Thus, short-term stress can enhance the acquisition and/or expression of immunoprotective (wound healing, vaccination, anti-infectious agent, anti-tumor) or immuno-pathological (pro-inflammatory, autoimmune) responses. In contrast, chronic stress can suppress protective immune responses and/or exacerbate pathological immune responses. Studies such as the ones discussed here could provide mechanistic targets and conceptual frameworks for pharmacological and/or biobehavioral interventions designed to enhance the effects of "good" stress, minimize the effects of "bad" stress, and maximally promote health and healing.

Physiological Response and Habituation of Endangered Species to Military Training Activities

DTIC Science & Technology

2009-11-01

Wasser. 2008. Long-term impacts of poaching on relatedness, stress physiology, and reproductive output of adult female African elephants . Conservation...Statistical analyses................................................................................................................ 19 Study 6: Impact of...Study 6: Impact of radio transmitters on northern cardinal parental investment and productivity

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.

Immediate and long-term effects of meditation on acute stress reactivity, cognitive functions, and intelligence.

PubMed

Singh, Yogesh; Sharma, Ratna; Talwar, Anjana

2012-01-01

With the current globalization of the world's economy and demands for enhanced performance, stress is present universally. Life's stressful events and daily stresses cause both deleterious and cumulative effects on the human body. The practice of meditation might offer a way to relieve that stress. The research team intended to study the effects of meditation on stress-induced changes in physiological parameters, cognitive functions, intelligence, and emotional quotients. The research team conducted the study in two phases, with a month between them. Each participant served as his own control, and the first phase served as the control for the second phase. In phase 1, the research team studied the effects of a stressor (10 minutes playing a computer game) on participants' stress levels. In phase 2, the research team examined the effects of meditation on stress levels. The research team conducted the study in a lab setting at the All India Institute of Medical Sciences (AIIMS), New Delhi, India. The participants were 34 healthy, male volunteers who were students. To study the effects of long-term meditation on stress levels, intelligence, emotional quotients, and cognitive functions participants meditated daily for 1 month, between phases 1 and 2. To study the immediate effects of meditation on stress levels, participants meditated for 15 minutes after playing a computer game to induce stress. The research team measured galvanic skin response (GSR), heart rate (HR), and salivary cortisol and administered tests for the intelligence and emotional quotients (IQ and EQ), acute and perceived stress (AS and PS), and cognitive functions (ie, the Sternberg memory test [short-term memory] and the Stroop test [cognitive flexibility]). Using a pre-post study design, the team performed this testing (1) prior to the start of the study (baseline); (2) in phase 1, after induced stress; (3) in part 1 of phase 2, after 1 month of daily meditation, and (4) in part 2 of phase 2, after induced stress, both before and after 15 minutes of meditation. Induced stress from the computer game resulted in a significant increase in physiological markers of stress such as GSR and HR. In the short term, meditation was associated with a physiological relaxation response (significant decrease in GSR) and an improvement in scores on the Stroop test of reaction times. In the long-term, meditation brought significant improvements in IQ and scores for cognitive functions, whereas participants' stress levels (GSR and AS) decreased. EQ, salivary cortisol, and HR showed no significant changes. The practice of meditation reduced psychological stress responses and improved cognitive functions, and the effects were pronounced with practice of meditation for a longer duration (1 month).

On the nature and consequences of early loss.

PubMed

Hofer, M A

1996-01-01

To describe how an animal model system can be used to explore basic questions about the nature of loss and the effects of early loss on later vulnerability to disease. The physiological and behavioral responses of infant rats to separation from their mothers are first described and then analyzed experimentally into component mechanisms. These studies have revealed an extensive layer of processes underlying the psychological constructs generally used to understand the response to loss. Hidden within the observable interactions of parent and offspring, we found a number of discrete sensorimotor, thermal, and nutrient-based events that have unexpected long-term regulatory effects on specific components of infant physiology and behavior. Release from all of these inhibitory and excitatory regulators together during maternal separation constitutes a novel mechanism by which the experience of loss can be translated into a complex patterned response. Evidence for early regulatory processes has also been found in monkey and human mother-infant interactions. Here they may well constitute the building blocks from which attachment and object representations develop. We and others have found long-term effects of loss, and of selective replacement of regulators, on behavioral development and on later vulnerability to disease. The results give us a new understanding of early attachment as a developmental force and of human grief as a risk to health.

Long-term effects of neonatal hypoxia-ischemia on structural and physiological integrity of the eye and visual pathway by multimodal MRI.

PubMed

Chan, Kevin C; Kancherla, Swarupa; Fan, Shu-Juan; Wu, Ed X

2014-12-09

Neonatal hypoxia-ischemia is a major cause of brain damage in infants and may frequently present visual impairments. Although advancements in perinatal care have increased survival, the pathogenesis of hypoxic-ischemic injury and the long-term consequences to the visual system remain unclear. We hypothesized that neonatal hypoxia-ischemia can lead to chronic, MRI-detectable structural and physiological alterations in both the eye and the brain's visual pathways. Eight Sprague-Dawley rats underwent ligation of the left common carotid artery followed by hypoxia for 2 hours at postnatal day 7. One year later, T2-weighted MRI, gadolinium-enhanced MRI, chromium-enhanced MRI, manganese-enhanced MRI, and diffusion tensor MRI (DTI) of the visual system were evaluated and compared between opposite hemispheres using a 7-Tesla scanner. Within the eyeball, systemic gadolinium administration revealed aqueous-vitreous or blood-ocular barrier leakage only in the ipsilesional left eye despite comparable aqueous humor dynamics in the anterior chamber of both eyes. Binocular intravitreal chromium injection showed compromised retinal integrity in the ipsilesional eye. Despite total loss of the ipsilesional visual cortex, both retinocollicular and retinogeniculate pathways projected from the contralesional eye toward ipsilesional visual cortex possessed stronger anterograde manganese transport and less disrupted structural integrity in DTI compared with the opposite hemispheres. High-field, multimodal MRI demonstrated in vivo the long-term structural and physiological deficits in the eye and brain's visual pathways after unilateral neonatal hypoxic-ischemic injury. The remaining retinocollicular and retinogeniculate pathways appeared to be more vulnerable to anterograde degeneration from eye injury than retrograde, transsynaptic degeneration from visual cortex injury. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

Long-Term Effects of Neonatal Hypoxia-Ischemia on Structural and Physiological Integrity of the Eye and Visual Pathway by Multimodal MRI

PubMed Central

Chan, Kevin C.; Kancherla, Swarupa; Fan, Shu-Juan; Wu, Ed X.

2015-01-01

Purpose. Neonatal hypoxia-ischemia is a major cause of brain damage in infants and may frequently present visual impairments. Although advancements in perinatal care have increased survival, the pathogenesis of hypoxic-ischemic injury and the long-term consequences to the visual system remain unclear. We hypothesized that neonatal hypoxia-ischemia can lead to chronic, MRI-detectable structural and physiological alterations in both the eye and the brain's visual pathways. Methods. Eight Sprague-Dawley rats underwent ligation of the left common carotid artery followed by hypoxia for 2 hours at postnatal day 7. One year later, T2-weighted MRI, gadolinium-enhanced MRI, chromium-enhanced MRI, manganese-enhanced MRI, and diffusion tensor MRI (DTI) of the visual system were evaluated and compared between opposite hemispheres using a 7-Tesla scanner. Results. Within the eyeball, systemic gadolinium administration revealed aqueous-vitreous or blood-ocular barrier leakage only in the ipsilesional left eye despite comparable aqueous humor dynamics in the anterior chamber of both eyes. Binocular intravitreal chromium injection showed compromised retinal integrity in the ipsilesional eye. Despite total loss of the ipsilesional visual cortex, both retinocollicular and retinogeniculate pathways projected from the contralesional eye toward ipsilesional visual cortex possessed stronger anterograde manganese transport and less disrupted structural integrity in DTI compared with the opposite hemispheres. Conclusions. High-field, multimodal MRI demonstrated in vivo the long-term structural and physiological deficits in the eye and brain's visual pathways after unilateral neonatal hypoxic-ischemic injury. The remaining retinocollicular and retinogeniculate pathways appeared to be more vulnerable to anterograde degeneration from eye injury than retrograde, transsynaptic degeneration from visual cortex injury. PMID:25491295

Long-term effects of good handling practices during the pre-weaning period of crossbred dairy heifer calves.

PubMed

Silva, Luciana Pontes; Sant'Anna, Aline Cristina; Silva, Lívia Carolina Magalhães; Paranhos da Costa, Mateus José Rodrigues

2017-01-01

The aim of this study was to determine whether applying good practices of handling during the pre-weaning period have long-term effects on behavioral and physiological indicators, health status, and average daily gain (ADG) of crossbred Bos taurus × Bos indicus heifer calves. During the pre-weaning period, 98 crossbred of Holstein × Gir heifer calves were allotted into three treatments: (1) good practices of handling + brushing (GPB; n = 25), (2) good practices of handling (GP; n = 25), and (3) control (n = 48). Every 2 months, four evaluation periods (EV 1 to EV 4 ) were conducted to record data. Behavioral indicators comprised time to drive (TD), flight speed (FS), flight distance (FD), and composite reactivity score (CRS). Physiological indicators of acute stress during handling comprised respiratory and heart rates. Health status comprised data regarding occurrence of most common diseases (i.e., pneumonia and anaplasmosis). Collected data were analyzed by using a linear mixed model for repeated measures, Tukey's test, and chi-squared procedures. Treatment influenced (P < 0.05) TD, FS, and FD but not CRS (P = 0.78). From EV 1 to EV 3 , the control calves had the lowest TD. The GPB group had lower FS than the control but did not differ from GP. The GPB group had lower FD means than the other two groups in EV 2 , EV 3 , and EV 4 . No differences (P > 0.05) due to treatment were observed on heart and respiratory rates, ADG, or occurrence of pneumonia and anaplasmosis. It was concluded that adoption of good practices of handling during pre-weaning period may lead to long-term positive effects.

Alteration of cytochrome P450 1 regulation and HSP 70 level in brain of juvenile common carp (Cyprinus carpio) after chronic exposure to tributyltin.

PubMed

Li, Zhi-Hua; Zhong, Li-Qiao; Wu, Yan-Hua; Mu, Wei-Na

2016-02-01

Tributyltin (TBT), a toxic contaminant in aquatic environments, has bio-accumulated in aquatic food webs throughout the world and can be found at toxic levels in some biota. However, the molecular mechanisms and effects of TBT are not fully understood. The aim of the present study was to investigate the effect of long-term exposure of TBT on cytochrome P450 (CYP450) 1 regulation and heat-shock proteins (HSPs) profiling in brain of freshwater teleost. The effects of long-term exposure to TBT on mRNA expression of cytochrome P450 (CYP450) 1 family genes and ethoxyresorufin O-deethylase (EROD) activity in the brain of common carp were evaluated, as well as HSP 70 level. Fish were exposed to sublethal concentrations of TBT (75 ng/L, 0.75 μg/L and 7.5 μg/L) for 15, 30, and 60 days. Based on the results, long-term exposure (more than 15 days) to TBT could lead to obvious physiological-biochemical responses (based on EROD activity, HSP 70 level and CYP450 1 family genes expression). The mRNA expression of CYP450 1 family genes (CYP1A, CYP1B, CYP1C1 and CYP1C2) suggested that CYP1A was to accommodate most EROD activity in fish, but other CYP450 forms also involved in this proceeding. Thus, the measured physiological responses in fish brain could provide useful information to better understand the mechanisms of TBT-induced bio-toxicity and could be used as potential biomarkers for monitoring the TBT pollution in the field.

Long-term effects of chronic light pollution on seasonal functions of European blackbirds (Turdus merula).

PubMed

Dominoni, Davide M; Quetting, Michael; Partecke, Jesko

2013-01-01

Light pollution is known to affect important biological functions of wild animals, including daily and annual cycles. However, knowledge about long-term effects of chronic exposure to artificial light at night is still very limited. Here we present data on reproductive physiology, molt and locomotor activity during two-year cycles of European blackbirds (Turdus merula) exposed to either dark nights or 0.3 lux at night. As expected, control birds kept under dark nights exhibited two regular testicular and testosterone cycles during the two-year experiment. Control urban birds developed testes faster than their control rural conspecifics. Conversely, while in the first year blackbirds exposed to light at night showed a normal but earlier gonadal cycle compared to control birds, during the second year the reproductive system did not develop at all: both testicular size and testosterone concentration were at baseline levels in all birds. In addition, molt sequence in light-treated birds was more irregular than in control birds in both years. Analysis of locomotor activity showed that birds were still synchronized to the underlying light-dark cycle. We suggest that the lack of reproductive activity and irregular molt progression were possibly the results of i) birds being stuck in a photorefractory state and/or ii) chronic stress. Our data show that chronic low intensities of light at night can dramatically affect the reproductive system. Future studies are needed in order to investigate if and how urban animals avoid such negative impact and to elucidate the physiological mechanisms behind these profound long-term effects of artificial light at night. Finally we call for collaboration between scientists and policy makers to limit the impact of light pollution on animals and ecosystems.

Beta-blockers influence the short-term and long-term prognostic information of natriuretic peptides and catecholamines in chronic heart failure independent from specific agents.

PubMed

Frankenstein, Lutz; Nelles, Manfred; Slavutsky, Maxim; Schellberg, Dieter; Doesch, Andreas; Katus, Hugo; Remppis, Andrew; Zugck, Christian

2007-10-01

In chronic heart failure (CHF), the physiologic effects of natriuretic peptides and catecholamines are interdependent. Furthermore, reports state an agent-dependent effect of individual beta-blockers on biomarkers. Data on the short-term and long-term predictive power comparing these biomarkers as well as accounting for the influence of beta-blocker treatment both on the marker or the resultant prognostic information are scarce. We included 513 consecutive patients with systolic CHF, measured atrial natriuretic peptide (ANP), N-terminal prohormone brain natriuretic peptide (NTproBNP), noradrenaline, and adrenaline, and monitored them for 90 +/- 25 months. Death or the combination of death and cardiac transplantation at 1 year, 5 years, and overall follow-up were considered end points. Compared with patients not taking beta-blockers, patients taking beta-blockers had significantly lower levels of catecholamines but not natriuretic peptides. Only for adrenaline was the amount of this effect related to the specific beta-blocker chosen. Receiver operating characteristic curves demonstrated superior prognostic accuracy for NTproBNP both at the 1- and 5-year follow-up compared with ANP, noradrenaline, and adrenaline. In multivariate analysis including established risk markers (New York Heart Association functional class, left ventricular ejection fraction, peak oxygen uptake, and 6-minute walk test), of all neurohumoral parameters, only NTproBNP remained an independent predictor for both end points. Long-term beta-blocker therapy is associated with decreased levels of plasma catecholamines but not natriuretic peptides. This effect is independent from the actual beta-blocker chosen for natriuretic peptides and noradrenaline. In multivariate analysis, both for short-term and long-term prediction of mortality or the combined end point of death and cardiac transplantation, only NTproBNP remained independent from established clinical risk markers.

Long-term neuroendocrine and behavioural effects of a single exposure to stress in adult animals.

PubMed

Armario, Antonio; Escorihuela, Rosa M; Nadal, Roser

2008-08-01

There is now considerable evidence for long-lasting sequels of stress. A single exposure to high intensity predominantly emotional stressors such as immobilisation in wooden-boards (IMO) induces long-term (days to weeks) desensitization of the hypothalamic-pituitary-adrenal (HPA) response to the same (homotypic) stressor, whereas the response to novel (heterotypic) stressors was enhanced. In addition, long-lasting changes in behaviour have been described after a single exposure to brief or more prolonged sessions of shocks, predator, predator odour, underwater stress or a combination of three stressors on 1 day. The most consistent changes are reduced entries into the open arms of the elevated plus-maze and enhanced acoustic startle response, both reflecting enhanced anxiety. However, it is unclear whether there is any relationship between the intensity of the stressors, as evaluated by the main physiological indexes of stress (e.g. HPA axis), the putative traumatic experience they represent and their long-term behavioural consequences. This is particularly critical when trying to model post-traumatic stress disorders (PTSD), which demands a great effort to validate such putative models.

High quality diet improves lipid metabolic profile and breeding performance in the blue-footed booby, a long-lived seabird.

PubMed

González-Medina, Erick; Castillo-Guerrero, José Alfredo; Herzka, Sharon Zinah; Fernández, Guillermo

2018-01-01

Understanding the role of diet in the physiological condition of adults during reproduction and hence its effect on reproductive performance is fundamental to understand reproductive strategies in long-lived animals. In birds, little is known about the influence of the quality of food consumed at the beginning of the reproductive period and its short-term effects on reproductive performance. To assess the role of diet in the physiological condition of female blue-footed booby, Sula nebouxii (BFBO), during reproduction we evaluated whether individual differences in diet (assessed by using δ13C and δ15N values of whole blood from female birds and muscle tissue of the principal prey species) prior to egg laying and during incubation influenced their lipid metabolic profile (measured as triglyceride levels and C:N ratio) and their reproductive performance (defined by laying date, clutch size and hatching success). Females with higher δ15N values in their blood during the courtship and incubation periods had a higher lipid metabolic profile, earlier laying date, greater clutch size (2-3 eggs) and higher hatching success. Females that laid earlier and more eggs (2-3 eggs) consumed more Pacific anchoveta (Cetengraulis mysticetus) and Pacific thread herring (Opisthonema libertate) than did other females. These two prey species also had high amounts of lipids (C:N ratio) and caloric content (Kcal/g fresh weight). The quality of food consumed by females at the beginning of reproduction affected their physiological condition, as well as their short-term reproductive performance. Our work emphasizes the importance of determining the influence of food quality during reproduction to understand the reproductive decisions and consequences in long-lived animals.

High quality diet improves lipid metabolic profile and breeding performance in the blue-footed booby, a long-lived seabird

PubMed Central

González-Medina, Erick; Castillo-Guerrero, José Alfredo; Herzka, Sharon Zinah

2018-01-01

Understanding the role of diet in the physiological condition of adults during reproduction and hence its effect on reproductive performance is fundamental to understand reproductive strategies in long-lived animals. In birds, little is known about the influence of the quality of food consumed at the beginning of the reproductive period and its short-term effects on reproductive performance. To assess the role of diet in the physiological condition of female blue-footed booby, Sula nebouxii (BFBO), during reproduction we evaluated whether individual differences in diet (assessed by using δ13C and δ15N values of whole blood from female birds and muscle tissue of the principal prey species) prior to egg laying and during incubation influenced their lipid metabolic profile (measured as triglyceride levels and C:N ratio) and their reproductive performance (defined by laying date, clutch size and hatching success). Females with higher δ15N values in their blood during the courtship and incubation periods had a higher lipid metabolic profile, earlier laying date, greater clutch size (2–3 eggs) and higher hatching success. Females that laid earlier and more eggs (2–3 eggs) consumed more Pacific anchoveta (Cetengraulis mysticetus) and Pacific thread herring (Opisthonema libertate) than did other females. These two prey species also had high amounts of lipids (C:N ratio) and caloric content (Kcal/g fresh weight). The quality of food consumed by females at the beginning of reproduction affected their physiological condition, as well as their short-term reproductive performance. Our work emphasizes the importance of determining the influence of food quality during reproduction to understand the reproductive decisions and consequences in long-lived animals. PMID:29462199

Repeated freezing induces a trade-off between cryoprotection and egg production in the goldenrod gall fly, Eurosta solidaginis.

PubMed

Marshall, Katie E; Sinclair, Brent J

2018-06-12

Internal ice formation leads to wholesale changes in ionic, osmotic and pH homeostasis, energy metabolism, and mechanical damage, across a small range of temperatures, and is thus an abiotic stressor that acts at a distinct, physiologically-relevant, threshold. Insects that experience repeated freeze-thaw cycles over winter will cross this stressor threshold many times over their lifespan. Here we examine the effect of repeatedly crossing the freezing threshold on short-term physiological parameters (metabolic reserves and cryoprotectant concentration) as well as long-term fitness-related performance (survival and egg production) in the freeze-tolerant goldenrod gall fly Eurosta solidaginis We exposed overwintering prepupae to a series of low temperatures (-10, -15, or -20 °C) with increasing numbers of freezing events (3, 6, or 10) with differing recovery periods between events (1, 5, or 10 days). Repeated freezing increased sorbitol concentration by about 50% relative to a single freezing episode, and prompted prepupae to modify long chain triacylglycerols to acetylated triacylglycerols. Long-term, repeated freezing did not significantly reduce survival, but did reduce egg production by 9.8% relative to a single freezing event. Exposure temperature did not affect any of these measures, suggesting that threshold crossing events may be more important to fitness than the intensity of stress in E. solidaginis overwintering. © 2018. Published by The Company of Biologists Ltd.

Effectiveness of Qigong in promoting the health of wheelchair-bound older adults in long-term care facilities.

PubMed

Kuan, Shu-Chien; Chen, Kuei-Min; Wang, Chi

2012-04-01

Institutional wheelchair-bound older adults often do not get regular exercise and are prone to health problems. The aim of this study was to test the effects of a 12-week qigong exercise program on the physiological and psychological health of wheelchair-bound older adults in long-term care facilities. Study design was quasi-experimental, pre-post test, nonequivalent control group. Participants comprised a convenience sample of 72 wheelchair-bound older adults (qigong = 34; control = 38). The qigong group exercised 35 min/day, 5 days/week for 12 weeks. Measures for physical health (blood pressure, heart rate variability, and distal skin temperature) and psychological health (Brief Symptom Rating Scale-5) were collected before and during study Weeks 4, 8, and 12. The qigong group participants' blood pressure, distal skin temperature, and psychological health were significantly improved (all p < .001). These findings suggest that qigong exercise is a suitable daily activity for elderly residents in long-term care facilities and may help in the control of blood pressure among older adults.

Maternal Antibiotic-Induced Early Changes in Microbial Colonization Selectively Modulate Colonic Permeability and Inducible Heat Shock Proteins, and Digesta Concentrations of Alkaline Phosphatase and TLR-Stimulants in Swine Offspring

PubMed Central

Arnal, Marie-Edith; Zhang, Jing; Erridge, Clett; Smidt, Hauke; Lallès, Jean-Paul

2015-01-01

Elevated intake of high energy diets is a risk factor for the development of metabolic diseases and obesity. High fat diets cause alterations in colonic microbiota composition and increase gut permeability to bacterial lipopolysaccharide, and subsequent low-grade chronic inflammation in mice. Chronic inflammatory bowel diseases are increasing worldwide and may involve alterations in microbiota-host dialog. Metabolic disorders appearing in later life are also suspected to reflect changes in early programming. However, how the latter affects the colon remains poorly studied. Here, we hypothesized that various components of colonic physiology, including permeability, ion exchange and protective inducible heat shock proteins (HSP) are influenced in the short- and long-terms by early disturbances in microbial colonization. The hypothesis was tested in a swine model. Offspring were born to control mothers (n = 12) or mothers treated with the antibiotic (ATB) amoxicillin around parturition (n = 11). Offspring were slaughtered between 14 and 42 days of age to study short-term effects. For long-term effects, young adult offspring from the same litters consumed a normal or a palm oil-enriched diet for 4 weeks between 140 and 169 days of age. ATB treatment transiently modified maternal fecal microbiota although the minor differences observed for offspring colonic microbiota were nonsignificant. In the short-term, consistently higher HSP27 and HSP70 levels and transiently increased horseradish peroxidase permeability in ATB offspring colon were observed. Importantly, long-term consequences included reduced colonic horseradish peroxidase permeability, and increased colonic digesta alkaline phosphatase (AP) and TLR2- and TLR4-stimulant concentrations in rectal digesta in adult ATB offspring. Inducible HSP27 and HSP70 did not change. Interactions between early ATB treatment and later diet were noted for paracellular permeability and concentrations of colonic digesta AP. In conclusion, our data suggest that early ATB-induced changes in bacterial colonization modulate important aspects of colonic physiology in the short- and long-terms. PMID:25689154

Maternal antibiotic-induced early changes in microbial colonization selectively modulate colonic permeability and inducible heat shock proteins, and digesta concentrations of alkaline phosphatase and TLR-stimulants in swine offspring.

PubMed

Arnal, Marie-Edith; Zhang, Jing; Erridge, Clett; Smidt, Hauke; Lallès, Jean-Paul

2015-01-01

Elevated intake of high energy diets is a risk factor for the development of metabolic diseases and obesity. High fat diets cause alterations in colonic microbiota composition and increase gut permeability to bacterial lipopolysaccharide, and subsequent low-grade chronic inflammation in mice. Chronic inflammatory bowel diseases are increasing worldwide and may involve alterations in microbiota-host dialog. Metabolic disorders appearing in later life are also suspected to reflect changes in early programming. However, how the latter affects the colon remains poorly studied. Here, we hypothesized that various components of colonic physiology, including permeability, ion exchange and protective inducible heat shock proteins (HSP) are influenced in the short- and long-terms by early disturbances in microbial colonization. The hypothesis was tested in a swine model. Offspring were born to control mothers (n = 12) or mothers treated with the antibiotic (ATB) amoxicillin around parturition (n = 11). Offspring were slaughtered between 14 and 42 days of age to study short-term effects. For long-term effects, young adult offspring from the same litters consumed a normal or a palm oil-enriched diet for 4 weeks between 140 and 169 days of age. ATB treatment transiently modified maternal fecal microbiota although the minor differences observed for offspring colonic microbiota were nonsignificant. In the short-term, consistently higher HSP27 and HSP70 levels and transiently increased horseradish peroxidase permeability in ATB offspring colon were observed. Importantly, long-term consequences included reduced colonic horseradish peroxidase permeability, and increased colonic digesta alkaline phosphatase (AP) and TLR2- and TLR4-stimulant concentrations in rectal digesta in adult ATB offspring. Inducible HSP27 and HSP70 did not change. Interactions between early ATB treatment and later diet were noted for paracellular permeability and concentrations of colonic digesta AP. In conclusion, our data suggest that early ATB-induced changes in bacterial colonization modulate important aspects of colonic physiology in the short- and long-terms.

Chronic disaster syndrome: Displacement, disaster capitalism, and the eviction of the poor from New Orleans

PubMed Central

ADAMS, VINCANNE; VAN HATTUM, TASLIM; ENGLISH, DIANA

2009-01-01

Many New Orleans residents who were displaced in 2005 by Hurricanes Katrina and Rita and the subsequent levee failures and floods are still displaced. Living with long-term stress related to loss of family, community, jobs, and social security as well as the continuous struggle for a decent life in unsettled life circumstances, they manifest what we are calling “chronic disaster syndrome.” The term refers not only to the physiological and psychological effects generated at the individual level by ongoing social disruption but also to the nexus of socioeconomic and political conditions that produce this situation as a long-term and intractable problem. Chronic disaster syndrome emerges from the convergence of three phenomena that create a nexus of displacement: long-term effects of personal trauma (including near loss of life and loss of family members, homes, jobs, community, financial security, and well-being); the social arrangements that enable the smooth functioning of what Naomi Klein calls “disaster capitalism,” in which “disaster” is prolonged as a way of life; and the permanent displacement of the most vulnerable populations from the social landscape as a perceived remedy that actually exacerbates the syndrome. PMID:20161644

Chronic disaster syndrome: Displacement, disaster capitalism, and the eviction of the poor from New Orleans.

PubMed

Adams, Vincanne; VAN Hattum, Taslim; English, Diana

2009-11-01

Many New Orleans residents who were displaced in 2005 by Hurricanes Katrina and Rita and the subsequent levee failures and floods are still displaced. Living with long-term stress related to loss of family, community, jobs, and social security as well as the continuous struggle for a decent life in unsettled life circumstances, they manifest what we are calling "chronic disaster syndrome." The term refers not only to the physiological and psychological effects generated at the individual level by ongoing social disruption but also to the nexus of socioeconomic and political conditions that produce this situation as a long-term and intractable problem. Chronic disaster syndrome emerges from the convergence of three phenomena that create a nexus of displacement: long-term effects of personal trauma (including near loss of life and loss of family members, homes, jobs, community, financial security, and well-being); the social arrangements that enable the smooth functioning of what Naomi Klein calls "disaster capitalism," in which "disaster" is prolonged as a way of life; and the permanent displacement of the most vulnerable populations from the social landscape as a perceived remedy that actually exacerbates the syndrome.

Short and Long-Term Physiological Responses of Male and Female Rats to Two Dietary Levels of Pre-Gelatinized Maca (Lepidium Peruvianum Chacon)

PubMed Central

Meissner, H. O.; Kedzia, B.; Mrozikiewicz, P. M.; Mscisz, A.

2006-01-01

Objective: The aim of this study is to identify physiological responses of male and female rats to either a short- or long-term administration of two doses of Maca (Lepidium peruvianum) and observe relationships which may exist between groups of hormones and effects mediated by them. Design: The effect of pre-gelatinized (extruded) organic Maca powder (Maca-GO) was studied on Sprague-Dowley male and female rats (1:1 ratio) receiving two dietary levels of Maca-GO (0.75 g/kg and 7.5 g/kg body weight) and assessed against control during 28 and 90 day laboratory trials on 30 and 60 rats respectively. Blood morphology, biochemistry (hormones, lipids and minerals) and histology of internal organs were determined. Homogenates of skeletal muscles and bones of rats were also analyzed. Results: Maca-GO has low toxicity (LD=7.5 g/kg) and appears to be safe for short-term and extended use as dietary supplement or as a component of functional dietary and therapeutic preparations. There were different responses of male and female rats to different levels of Maca-GO administered during a short- and a longer-term periodl. When administered at higher dose for extended period of time (90 days), Maca-GO acted as a toner of hormonal processes in adult female rats at increased progesterone and a steady estradiol level, without affecting levels of blood FSH, LH and TSH. Conclusions: Obtained results justify further clinical research on use of Maca-GO in sportsmen, physically-active people of both sexes and peri-menopausal women to clarify mechanisms underlaying physiological mode of action of Maca-GO validaet in clinical study on humans. Substantial decrease in blood cortisol levels in a short- and longer-term trial and simultaneous tendency to lower blood ACTH, may indicate antidepressive effect of Maca-GO, which together with reduction in body weight, lowering triglycerides in blood plasma and increasing calcium and phosphorus deposition in bone and muscle tissues is worthy consideration in potential application to women at both, pre- and postmenopausal stage. PMID:23674962

Short and long-term physiological responses of male and female rats to two dietary levels of pre-gelatinized maca (lepidium peruvianum chacon).

PubMed

Meissner, H O; Kedzia, B; Mrozikiewicz, P M; Mscisz, A

2006-02-01

The aim of this study is to identify physiological responses of male and female rats to either a short- or long-term administration of two doses of Maca (Lepidium peruvianum) and observe relationships which may exist between groups of hormones and effects mediated by them. The effect of pre-gelatinized (extruded) organic Maca powder (Maca-GO) was studied on Sprague-Dowley male and female rats (1:1 ratio) receiving two dietary levels of Maca-GO (0.75 g/kg and 7.5 g/kg body weight) and assessed against control during 28 and 90 day laboratory trials on 30 and 60 rats respectively. Blood morphology, biochemistry (hormones, lipids and minerals) and histology of internal organs were determined. Homogenates of skeletal muscles and bones of rats were also analyzed. Maca-GO has low toxicity (LD=7.5 g/kg) and appears to be safe for short-term and extended use as dietary supplement or as a component of functional dietary and therapeutic preparations. There were different responses of male and female rats to different levels of Maca-GO administered during a short- and a longer-term periodl. When administered at higher dose for extended period of time (90 days), Maca-GO acted as a toner of hormonal processes in adult female rats at increased progesterone and a steady estradiol level, without affecting levels of blood FSH, LH and TSH. Obtained results justify further clinical research on use of Maca-GO in sportsmen, physically-active people of both sexes and peri-menopausal women to clarify mechanisms underlaying physiological mode of action of Maca-GO validaet in clinical study on humans. Substantial decrease in blood cortisol levels in a short- and longer-term trial and simultaneous tendency to lower blood ACTH, may indicate antidepressive effect of Maca-GO, which together with reduction in body weight, lowering triglycerides in blood plasma and increasing calcium and phosphorus deposition in bone and muscle tissues is worthy consideration in potential application to women at both, pre- and postmenopausal stage.

Using the endocannabinoid system as a neuroprotective strategy in perinatal hypoxic-ischemic brain injury

PubMed Central

Lara-Celador, I.; Goñi-de-Cerio, F.; Alvarez, Antonia; Hilario, Enrique

2013-01-01

One of the most important causes of brain injury in the neonatal period is a perinatal hypoxic-ischemic event. This devastating condition can lead to long-term neurological deficits or even death. After hypoxic-ischemic brain injury, a variety of specific cellular mechanisms are set in motion, triggering cell damage and finally producing cell death. Effective therapeutic treatments against this phenomenon are still unavailable because of complex molecular mechanisms underlying hypoxic-ischemic brain injury. After a thorough understanding of the mechanism underlying neural plasticity following hypoxic-ischemic brain injury, various neuroprotective therapies have been developed for alleviating brain injury and improving long-term outcomes. Among them, the endocannabinoid system emerges as a natural system of neuroprotection. The endocannabinoid system modulates a wide range of physiological processes in mammals and has demonstrated neuroprotective effects in different paradigms of acute brain injury, acting as a natural neuroprotectant. The aim of this review is to study the use of different therapies to induce long-term therapeutic effects after hypoxic-ischemic brain injury, and analyze the important role of the endocannabinoid system as a new neuroprotective strategy against perinatal hypoxic-ischemic brain injury. PMID:25206720

DOE Office of Scientific and Technical Information (OSTI.GOV)

McAllister, R.S.

Contents: Visual Acquisition Functions in Operational Environments; Investigation of Causes of Military Aircraft Accidents Involving Pilot Vertigo/Disorientation; Long Term Pulmonary Effects of Repeated Use of 100% Oxygen; Effects of Microwave Radiation on Naval Personnel; Effects of Extremely Low Frequency Radiation on Man; Behavioral Characteristics of Monkeys and Rats Irradiated with Microwaves; Evaluation of the Squirrel Monkey (Saimiri sciureus) as an Experimental Animal Model for Dysbaric Osteonecrosis; Oculovestibular Effects on Visual Performance in Moving Military Systems; Chronic Exposure of Mammals to Non-ionizing Electric and Magnetic Fields--Physiological and Psychophysiological Effects; and Open Literature Publications by Staff Members.

How long do the short-term violent video game effects last?

PubMed

Barlett, Christopher; Branch, Omar; Rodeheffer, Christopher; Harris, Richard

2009-01-01

How long do the effects of the initial short-term increase in aggression and physiological arousal last after violent video game play? Study 1 (N=91) had participants complete pre- and postvideo game measures of aggressive thoughts, aggressive feelings, and heart rate. Then, participants completed Time 3 measures after 4 min or 9 min of delay. Study 2 employed a similar procedure, but had participants (N=91) complete the hot sauce paradigm to assess aggressive behavior after a 0, 5, or 10 min delay. First, results indicated that aggressive feelings, aggressive thoughts, aggressive behavior, and heart rate initially increased after violent video game play. Second, results of the delay condition revealed that the increase in aggressive feelings and aggressive thoughts lasted less than 4 min, whereas heart rate and aggressive behavior lasted 4-9 min. Copyright 2009 Wiley-Liss, Inc.

View of human problems to be addressed for long-duration space flights

NASA Technical Reports Server (NTRS)

Berry, C. A.

1973-01-01

Review of the principal physiological changes seen in space flight, and discussion of various countermeasures which may prove to be useful in combating these changes in long-term space flight. A number of transient changes seen in Apollo astronauts following space flights are discussed, including cardiovascular and hemodynamic responses to weightlessness, musculoskeletal changes, changes in fluid and electrolyte balance, microbiological changes, and vestibular effects. A number of countermeasures to the effects of space flight on man are cited, including exercise, medication, diet, lower-body negative pressure, gradient positive pressure, venous occlusion cuffs, and others. A detailed review is then made of a number of psychological factors bearing on the ability of the human organism to withstand the rigors of long space flights.

Countermeasures for Maintenance of Cardiovascular and Muscle Function in Space Flight

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Session FA2, the discussion focuses on the following topics: Effects of Repeated Long Duration +2Gz Load on Man's Cardiovascular Function; Certain Approaches to the Development of On-Board Automated Training System; Cardiac, Arterial, and Venous Adaptation to Og during 6 Month MIR-Spaceflights with and without "Thigh Cuffs" (93-95); Space Cycle(TM) Induced Physiologic Responses; Muscular Deconditioning During Long-term Spaceflight Exercise Recommendations to Optimize Crew Performance; Structure And Function of Knee Extensors After Long-Duration Spaceflight in Man, Effects of Countermeasure Exercise Training; Force and power characteristics of an exercise ergometer designed for use in space; and The simulating of overgravity conditions for astronauts' motor apparatus at the conditions of the training for orbital flights.

A Physiological and Biochemical Study of the Effects of Extremely Low Frequency Electromagnetic Fields

DTIC Science & Technology

1979-07-01

microplasmodial cultures continuously subjected to the particular field conditions being studied. The stages in ’ ,oitotic cycle ,re determined by observing...of the decrease in rate varies with exposure conditions . Mean values of the decreases computed from the raw data are given on the righthand side of...exposures we were concerned about was the effect of long-term, chronic exposure. Figure 2 presents data for field conditions that are the same as

Effects of logging, hunting, and forest fragment size on physiological stress levels of two sympatric ateline primates in Colombia

PubMed Central

Rimbach, Rebecca; Link, Andrés; Heistermann, Michael; Gómez-Posada, Carolina; Galvis, Nelson; Heymann, Eckhard W.

2013-01-01

Habitat fragmentation and anthropogenic disturbances are of major concern to the conservation of endangered species because of their potentially negative impact on animal populations. Both processes can impose physiological stress (i.e. increased glucocorticoid output) on animals, and chronically elevated stress levels can have detrimental effects on the long-term viability of animal populations. Here, we investigated the effect of fragment size and human impact (logging and hunting pressure) on glucocorticoid levels of two sympatric Neotropical primates, the red howler monkey (Alouatta seniculus) and the critically endangered brown spider monkey (Ateles hybridus). These two species have been reported to contrast strongly in their ability to cope with anthropogenic disturbances. We collected faecal samples from eight spider monkey groups and 31 howler monkey groups, living in seven and 10 different forest fragments in Colombia, respectively. We measured faecal glucocorticoid metabolite (FGCM) levels in both species using previously validated methods. Surprisingly, fragment size did not influence FGCM levels in either species. Spider monkeys showed elevated FGCMs in fragments with the highest level of human impact, whereas we did not find this effect in howler monkeys. This suggests that the two species differ in their physiological responsiveness to anthropogenic changes, further emphasizing why brown spider monkeys are at higher extinction risk than red howler monkeys. If these anthropogenic disturbances persist in the long term, elevated FGCM levels can potentially lead to a state of chronic stress, which might limit the future viability of populations. We propose that FGCM measurements should be used as a tool to monitor populations living in disturbed areas and to assess the success of conservation strategies, such as corridors connecting forest fragments. PMID:27293615

Senescence in the wild: Insights from a long-term study on Seychelles warblers.

PubMed

Hammers, Martijn; Kingma, Sjouke A; Bebbington, Kat; van de Crommenacker, Janske; Spurgin, Lewis G; Richardson, David S; Burke, Terry; Dugdale, Hannah L; Komdeur, Jan

2015-11-01

Senescence--the progressive age-dependent decline in performance--occurs in most organisms. There is considerable variation in the onset and rate of senescence between and within species. Yet the causes of this variation are still poorly understood, despite being central to understanding the evolution of senescence. Long-term longitudinal studies on wild animals are extremely well-suited to studying the impact of environmental and individual characteristics (and the interaction between the two) on senescence, and can help us to understand the mechanisms that shape the evolution of senescence. In this review, we summarize and discuss the insights gained from our comprehensive long-term individual-based study of the Seychelles warbler (Acrocephalus sechellensis). This species provides an excellent model system in which to investigate the evolution of senescence in the wild. We found that Seychelles warblers show senescent declines in survival and reproduction, and discuss how individual characteristics (body condition, body size) and environmental effects (low- versus high-quality environments) may affect the onset and rate of senescence. Further, we highlight the evidence for trade-offs between early-life investment and senescence. We describe how key cellular and physiological processes (oxidative stress and telomere shortening) underpinning senescence are affected by individual and environmental characteristics in the Seychelles warbler (e.g. food availability, reproductive investment, disease) and we discuss how such physiological variation may mediate the relationship between environmental characteristics and senescence. Based on our work using Seychelles warblers as a model system, we show how insights from long-term studies of wild animals may help unravel the causes of the remarkable variation in senescence observed in natural systems, and highlight areas for promising future research.

A maternal high-fat, high-sucrose diet has sex-specific effects on fetal glucocorticoids with little consequence for offspring metabolism and voluntary locomotor activity in mice.

PubMed

Chin, Eunice H; Schmidt, Kim L; Martel, Kaitlyn M; Wong, Chi Kin; Hamden, Jordan E; Gibson, William T; Soma, Kiran K; Christians, Julian K

2017-01-01

Maternal overnutrition and obesity during pregnancy can have long-term effects on offspring physiology and behaviour. These developmental programming effects may be mediated by fetal exposure to glucocorticoids, which is regulated in part by placental 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 and 2. We tested whether a maternal high-fat, high-sucrose diet would alter expression of placental 11β-HSD1 and 2, thereby increasing fetal exposure to maternal glucocorticoids, with downstream effects on offspring physiology and behaviour. C57BL/6J mice were fed a high-fat, high-sucrose (HFHS) diet or a nutrient-matched low-fat, no-sucrose control diet prior to and during pregnancy and lactation. At day 17 of gestation, HFHS dams had ~20% lower circulating corticosterone levels than controls. Furthermore, there was a significant interaction between maternal diet and fetal sex for circulating corticosterone levels in the fetuses, whereby HFHS males tended to have higher corticosterone than control males, with no effect in female fetuses. However, placental 11β-HSD1 or 11β-HSD2 expression did not differ between diets or show an interaction between diet and sex. To assess potential long-term consequences of this sex-specific effect on fetal corticosterone, we studied locomotor activity and metabolic traits in adult offspring. Despite a sex-specific effect of maternal diet on fetal glucocorticoids, there was little evidence of sex-specific effects on offspring physiology or behaviour, although HFHS offspring of both sexes had higher circulating corticosterone at 9 weeks of age. Our results suggest the existence of as yet unknown mechanisms that mitigate the effects of altered glucocorticoid exposure early in development, making offspring resilient to the potentially negative effects of a HFHS maternal diet.

Stress and cortisol in disaster evacuees: an exploratory study on associations with social protective factors.

PubMed

Thompson, David Javier; Weissbecker, Inka; Cash, Elizabeth; Simpson, David M; Daup, Meagan; Sephton, Sandra E

2015-03-01

Though cumulative emotional and physical effects of disasters may diminish evacuees' short and long-term mental and physical health, social factors may buffer such consequences. We approached survivors of the October 2007 San Diego, California firestorms. We gathered data during the evacuation and 3 months afterward. Questionnaires measured social support as well as PTSD, depression, and anxiety symptoms. Saliva samples were used to assess the stress hormone, cortisol. Analyses, adjusting for age, gender, and socioeconomic status, showed PTSD symptoms were associated with flattening of the diurnal cortisol rhythm during evacuation. Secondary analyses showed those reporting a family emphasis on moral and religious values had lower psychological distress. Though anxiety symptoms had significantly decreased in the overall sample at follow-up, blunted cortisol rhythms persisted among those individuals with continued high anxiety. Results highlight a possible psychological, and perhaps a physiological, benefit of social and existential factors in disaster situations. Future work should explore the role of psychosocial factors and stress physiology in the development of long-term health concerns among individuals exposed to disaster.

Five Conditions Commonly Used to Down-regulate Tor Complex 1 Generate Different Physiological Situations Exhibiting Distinct Requirements and Outcomes*

PubMed Central

Tate, Jennifer J.; Cooper, Terrance G.

2013-01-01

Five different physiological conditions have been used interchangeably to establish the sequence of molecular events needed to achieve nitrogen-responsive down-regulation of TorC1 and its subsequent regulation of downstream reporters: nitrogen starvation, methionine sulfoximine (Msx) addition, nitrogen limitation, rapamycin addition, and leucine starvation. Therefore, we tested a specific underlying assumption upon which the interpretation of data generated by these five experimental perturbations is premised. It is that they generate physiologically equivalent outcomes with respect to TorC1, i.e. its down-regulation as reflected by TorC1 reporter responses. We tested this assumption by performing head-to-head comparisons of the requirements for each condition to achieve a common outcome for a downstream proxy of TorC1 inactivation, nuclear Gln3 localization. We demonstrate that the five conditions for down-regulating TorC1 do not elicit physiologically equivalent outcomes. Four of the methods exhibit hierarchical Sit4 and PP2A phosphatase requirements to elicit nuclear Gln3-Myc13 localization. Rapamycin treatment required Sit4 and PP2A. Nitrogen limitation and short-term nitrogen starvation required only Sit4. G1 arrest-correlated, long-term nitrogen starvation and Msx treatment required neither PP2A nor Sit4. Starving cells of leucine or treating them with leucyl-tRNA synthetase inhibitors did not elicit nuclear Gln3-Myc13 localization. These data indicate that the five commonly used nitrogen-related conditions of down-regulating TorC1 are not physiologically equivalent and minimally involve partially differing regulatory mechanisms. Further, identical requirements for Msx treatment and long-term nitrogen starvation raise the possibility that their effects are achieved through a common regulatory pathway with glutamine, a glutamate or glutamine metabolite level as the sensed metabolic signal. PMID:23935103

Long-term treatment-related morbidity in differentiated thyroid cancer: a systematic review of the literature

PubMed Central

Parker, William AE; Edafe, Ovie; Balasubramanian, Sabapathy P

2017-01-01

Background Differentiated thyroid cancer (DTC) occurs in relatively young patients and is associated with a good prognosis and long survival. The management of this disease involves thyroidectomy, radioiodine therapy, and long-term thyroid-stimulating hormone suppression therapy (THST). The long-term effects of the treatment and the interaction between subclinical hyperthyroidism and long-term hypoparathyroidism are poorly understood. This review sought to examine the available evidence. Methods A PubMed search was carried out using the search terms “Thyroid Neoplasms” AND (“Thyroxine” OR “Hypocalcemia” OR “Thyrotropin”). Original English language articles published in the last 30 years studying the morbidity from thyroid-stimulating hormone (TSH) suppression and hypoparathyroidism following a surgery for DTC were retrieved and reviewed by 2 authors. Results Of the 3,000 results, 66 papers including 4,517 patients were selected for the present study. Studies reported on a range of skeletal (included in 34 studies, 1,647 patients), cardiovascular (17 studies, 957 patients), psychological (10 studies, 663 patients), and other outcomes (10 studies, 1,348 patients). Nine of 26 studies on patients who underwent THST showed a reduction in bone density, and 13 of 23 studies showed an increase in bone turnover markers. Skeletal effects were more marked in postmenopausal women. There was no evidence of increased fracture risk, and only little data were available on hypoparathyroidism. Four of five studies showed an increased left ventricular mass index on echocardiography, and one study showed a higher prevalence of atrial fibrillation (AF). There was little difference in basic physiological parameters and limited literature regarding symptoms or significant events. Six studies showed associations between long-term TSH suppression and impaired quality of life. Impaired glucose metabolism and prothrombotic states were also found in DTC patients. Conclusion There is limited literature regarding long-term DTC treatment-related morbidity, particularly regarding the effects of long-term hypocalcemia. Most studies have focused on surrogate markers and not on clinical outcomes. A large prospective study on defined clinical outcomes would help characterize the morbidity of treatment and stimulate research on tailoring treatment strategies. PMID:28553154

The Effects of Stress on Cognitive Aging, Physiology and Emotion (ESCAPE) Project.

PubMed

Scott, Stacey B; Graham-Engeland, Jennifer E; Engeland, Christopher G; Smyth, Joshua M; Almeida, David M; Katz, Mindy J; Lipton, Richard B; Mogle, Jacqueline A; Munoz, Elizabeth; Ram, Nilam; Sliwinski, Martin J

2015-07-03

Despite evidence that psychological stress is an important risk factor for age-related cognitive loss, little research has directly evaluated psychological and physiological mediators of the relationship between stressful experiences and cognitive function. A key objective of the ESCAPE (Effects of Stress on Cognitive Aging, Physiology, and Emotion) project is to evaluate whether engaging in stress-related unconstructive repetitive thought (URT) is a pathway through which stressful experiences negatively affect cognitive health over the short- and long-term. Over the short-term, we hypothesize that engaging in URT will deplete attentional resources and result in worse cognitive performance in daily life. Over the long-term, we expect that the effects of chronic stress, from repeated exposure to stressors and regular engagement in URT, will be apparent in dysregulated hypothalamic-pituitary-adrenal (HPA) axis function and inflammation. Over time, stress-related physiological dysregulation will result in accelerated cognitive decline. This study utilizes a prospective longitudinal measurement-burst design. A systematic probability sample of participants aged 25 to 65 is recruited from residents of the Bronx, NY. Consenting participants complete a baseline assessment and follow-up waves at 9, 18, and 27 months post-baseline. At each wave, participants complete a 14 day measurement burst of brief surveys and cognitive assessments delivered via study smartphones during daily life. Participants provide saliva samples four times each day for five days during the measurement burst and fasting blood samples at the end of each burst from which cortisol and dehydroepiandrosterone sulfate (DHEAS), circulating inflammatory markers, and stimulated inflammatory responses to lipopolysaccharide in whole blood are determined. This study takes a multi-pronged approach to assessing stress (i.e., early adversity, chronic strains, major events, daily hassles), psychological mediators (e.g., URT), biological mechanisms (i.e., HPA function, inflammation) and outcomes across different time-scales (i.e., momentary cognitive performance, cognitive decline across years). The systematic probability sample is locally representative and can be compared with national norms on key markers of health and well-being. The findings will improve our understanding of how environmental, psychological, and physiological stress-related influences accumulate to affect cognitive health and identify potential targets (e.g., URT, inflammation) for prevention and intervention promoting cognitive health.

Salt and essential hypertension: pathophysiology and implications for treatment.

PubMed

Garfinkle, Michael A

2017-06-01

Essential hypertension is common and is associated with significant morbidity and mortality. However, questions remain as to the exact physiological mechanisms underlying this disease. First, we discuss how essential hypertension may be largely a result of a maladaptation to a high-salt diet and that high blood pressure, rather than being an inactive side effect of high salt intake, may be an adaptive mechanism to improve salt secretion. Next, we explain how any physiological state that reduces urinary sodium concentrating ability may increase an individual's risk for salt-induced hypertension. Finally, we conclude that natriuresis is a crucial criterion for effective long-term pharmacologic treatment of essential hypertension. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Effect of macronutrient composition on short-term food intake and weight loss.

PubMed

Bellissimo, Nick; Akhavan, Tina

2015-05-01

The purpose of this review is to describe the role of macronutrient composition on the suppression of short-term food intake (FI) and weight loss. The effects of macronutrient composition on short-term FI will be reviewed first, followed by a brief examination of longer-term clinical trials that vary in effects of dietary macronutrient composition on weight loss. The objectives were: 1) to examine the effect of macronutrient composition on the suppression of short-term FI, 2) to determine whether some macronutrient sources suppress FI beyond their provision of energy, 3) to assess the combined effects of macronutrients on FI and glycemic response, and 4) to determine whether knowledge of the effect of macronutrients on short-term FI has led to greater success in spontaneous weight loss, adherence to energy-restricted diets, and better weight maintenance after weight loss. Although knowledge of macronutrient composition on short-term FI regulation has advanced our understanding of the role of diet composition on energy balance, it has yet to lead to greater success in long-term weight loss and weight maintenance. It is clear from this review that many approaches based on manipulating dietary macronutrient composition can help people lose weight as long as they follow the diets. However, only by evaluating the interaction between the physiologic systems that govern FI and body weight may the benefits of dietary macronutrient composition be fully realized. © 2015 American Society for Nutrition.

Subchronic MK-801 treatment and post-weaning social isolation in rats: differential effects on locomotor activity and hippocampal long-term potentiation.

PubMed

Ashby, Donovan M; Habib, Diala; Dringenberg, Hans C; Reynolds, James N; Beninger, Richard J

2010-09-01

Subchronic NMDA receptor antagonist treatment and post-weaning social isolation are two animal models of schizophrenia symptoms. However, behavioral and physiological changes following a combination of these two procedures have not been investigated. Thus, we examined effects of a novel, "double hit" model combining these two treatments, comparing them to standard models involving only NMDA antagonist treatment or social isolation. Male, Sprague-Dawley rats were either group-housed or maintained in social isolation (starting at postnatal day [PD] 21 and continuing throughout the study). Each housing condition was further subdivided into two groups, receiving either subchronic treatment with either saline or MK-801 (0.5mg/kg, i.p., 2xday for seven days starting at PD 56). Post-weaning social isolation increased locomotor activity (assessed at PD 70) in response to a novel environment and an acute amphetamine injection, while subchronic MK-801 increased only amphetamine induced locomotor activity. Subsequent electrophysiological experiments (under urethane anesthesia) assessing changes in plasticity of hippocampal synapses showed that subchronic MK-801 treatment resulted in an increase in long-term potentiation in area CA1 in response to high frequency stimulation of the contralateral CA3 area, while housing condition had no effect. No other changes in hippocampal electrophysiology (input-output curves, paired-pulse facilitation) were observed. These data are the first to demonstrate an enhancement in hippocampal long-term plasticity in vivo following subchronic MK-801 administration, an effect that may be related to the well-characterized changes in glutamatergic and GABAergic systems seen after subchronic NMDA receptor blockade. That lack of additive or synergistic effects in the "double hit model" suggests that combining isolation and subchronic MK-801 treatment does not necessarily produce greater behavioral or physiological dysfunction than that seen with either treatment alone. Copyright 2010 Elsevier B.V. All rights reserved.

Rhythmical massage improves autonomic nervous system function: a single-blind randomised controlled trial.

PubMed

Seifert, Georg; Kanitz, Jenny-Lena; Rihs, Carolina; Krause, Ingrid; Witt, Katharina; Voss, Andreas

2018-05-01

Rhythmical massage therapy (RMT) is a massage technique used in anthroposophic medicine. The authors aimed to investigate the physiological action of RMT on the cardiovascular system by analysing heart rate variability (HRV). This study was a randomised, controlled and single-blinded trial, involving 44 healthy women (mean age: (26.20 ± 4.71) years). The subjects were randomised to one of three arms: RMT with aromatic oil (RA), RMT without aromatic oil (RM) or standardised sham massage (SM). In the study the subjects were exposed to a standardised stress situation followed by one of the study techniques and Holter electrocardiograms (ECGs) were recorded for 24 h. HRV parameters were calculated from linear (time and frequency domain) and nonlinear dynamics (symbolic dynamics, Poincare plot analysis) of the 24-h Holter ECG records. Short- and long-term effects of massage on autonomic regulation differed significantly among the three groups. Immediately after an RMT session, stimulation of HRV was found in the groups RA and RM. The use of an aromatic oil produced greater short-term measurable changes in HRV compared with rhythmic massage alone, but after 24 h the effect was no longer distinguishable from the RM group. The lowest stimulation of HRV parameters was measured in the SM group. RMT causes specific and marked stimulation of the autonomic nervous system. Use of a medicinal aromatic oil had only a temporary effect on HRV, indicating that the RM causes the most relevant long-term effect. The effect is relatively specific, as the physiological effects seen in the group of subjects who received only SM were considerably less pronounced. Registration trial DRKS00004164 on DRKS. Copyright © 2018 Shanghai Changhai Hospital. Published by Elsevier B.V. All rights reserved.

Applying the dual-isotope conceptual model to interpret physiological trends under uncontrolled conditions

EPA Science Inventory

The inter-relationships among δ13C and δ18O in tree ring cellulose and ring width have the potential to illuminate long-term physiological and environmental information in forest stands that have not been monitored. We examine how within-stand competition and environmental gradie...

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. Copyright © 2012 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Preliminary studies of elevated atmospheric CO/sub 2/ on conifers, May 1-December 30, 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Helms, J.A.

1985-01-01

The original scope of work consisted of two parts: Intensive physiological studies of Pinus ponderosa seedlings and saplings that were continuously exposed to various levels of CO/sub 2/ and SO/sub 2/ in open-topped chambers. Site selection and preparation in anticipation of DOE approval of a proposed 5-year project on effects of long-term exposure of forest vegetation to enhanced CO/sub 2/. Establishment of 5 Nelder-type plots utilizing 5 western conifers to permit fundamental studies on the physiological bases of tree-to-tree competition. Because the DOE project was not funded, site selection was abandoned.

Spacelab Life Sciences 1 - The stepping stone

NASA Technical Reports Server (NTRS)

Dalton, B. P.; Leon, H.; Hogan, R.; Clarke, B.; Tollinger, D.

1988-01-01

The Spacelab Life Sciences (SLS-1) mission scheduled for launch in March 1990 will study the effects of microgravity on physiological parameters of humans and animals. The data obtained will guide equipment design, performance of activities involving the use of animals, and prediction of human physiological responses during long-term microgravity exposure. The experiments planned for the SLS-1 mission include a particulate-containment demonstration test, integrated rodent experiments, jellyfish experiments, and validation of the small-mass measuring instrument. The design and operation of the Research Animal Holding Facility, General-Purpose Work Station, General-Purpose Transfer Unit, and Animal Enclosure Module are discussed and illustrated with drawings and diagrams.

Human factors. [in space colony environments

NASA Technical Reports Server (NTRS)

Billingham, J.

1977-01-01

Life aboard space habitats is considered with reference to physiological factors and self-government. Physiological concerns include the loss of bone structural strength, the long-term effects of zero-gravity, the role of inert gases in breathing, and the danger of slow cosmic-ray particles. With reference to the administration of space habitats, it is suggested that initially Intelsat might serve as a model for supranational sponsorship. Later it is envisioned that space habitats will have some autonomy but will still be subject to earth control; habitats will not wage war on earth or on each other; and that the habitats will be protected from any adverse developments that might occur on earth.

Long-term high-intensity sound stimulation inhibits h current (Ih ) in CA1 pyramidal neurons.

PubMed

Cunha, A O S; Ceballos, C C; de Deus, J L; Leão, R M

2018-05-19

Afferent neurotransmission to hippocampal pyramidal cells can lead to long-term changes to their intrinsic membrane properties and affect many ion currents. One of the most plastic neuronal currents is the hyperpolarization activated cationic current (I h ), which changes in CA1 pyramidal cells in response to many types of physiological and pathological processes, including auditory stimulation. Recently we demonstrated that long-term potentiation (LTP) in rat hippocampal Schaffer-CA1 synapses is depressed by high-intensity sound stimulation. Here we investigated if a long-term high-intensity sound stimulation could affect intrinsic membrane properties of rat CA1 pyramidal neurons. Our results showed that I h is depressed by long-term high intensity sound exposure (1 minute of 110 dB sound, applied two times per day for 10 days). This resulted in a decreased resting membrane potential, increased membrane input resistance and time constant, and decreased action potential threshold. In addition, CA1 pyramidal neurons from sound-exposed animals fired more action potentials than neurons from control animals; However, this effect was not caused by a decreased I h . Interestingly, a single episode (1 minute) of 110 dB sound stimulation which also inhibits hippocampal LTP did not affect I h and firing in pyramidal neurons, suggesting that effects on I h are long-term responses to high intensity sound exposure. Our results show that prolonged exposure to high-intensity sound affects intrinsic membrane properties of hippocampal pyramidal neurons, mainly by decreasing the amplitude of I h . This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Ambulatory instrumentation suitable for long-term monitoring of cattle health.

PubMed

Schoenig, S A; Hildreth, T S; Nagl, L; Erickson, H; Spire, M; Andresen, D; Warren, S

2004-01-01

The benefits of real-time health diagnoses of cattle are potentially tremendous. Early detection of transmissible disease, whether from natural or terrorist events, could help to avoid huge financial losses in the agriculture industry while also improving meat quality. This work discusses physiological and behavioral parameters relevant to cattle state-of-health assessment. These parameters, along with a potentially harsh monitoring environment, drive a set of design considerations that must be addressed when building systems to acquire long-term, real-time measurements in the field. A prototype system is presented that supports the measurement of suitable physiologic parameters and begins to address the design constraints for continuous state-of-health determination in free-roaming cattle.

Long-term Behavioral Tracking of Freely Swimming Weakly Electric Fish

PubMed Central

Jun, James J.; Longtin, André; Maler, Leonard

2014-01-01

Long-term behavioral tracking can capture and quantify natural animal behaviors, including those occurring infrequently. Behaviors such as exploration and social interactions can be best studied by observing unrestrained, freely behaving animals. Weakly electric fish (WEF) display readily observable exploratory and social behaviors by emitting electric organ discharge (EOD). Here, we describe three effective techniques to synchronously measure the EOD, body position, and posture of a free-swimming WEF for an extended period of time. First, we describe the construction of an experimental tank inside of an isolation chamber designed to block external sources of sensory stimuli such as light, sound, and vibration. The aquarium was partitioned to accommodate four test specimens, and automated gates remotely control the animals' access to the central arena. Second, we describe a precise and reliable real-time EOD timing measurement method from freely swimming WEF. Signal distortions caused by the animal's body movements are corrected by spatial averaging and temporal processing stages. Third, we describe an underwater near-infrared imaging setup to observe unperturbed nocturnal animal behaviors. Infrared light pulses were used to synchronize the timing between the video and the physiological signal over a long recording duration. Our automated tracking software measures the animal's body position and posture reliably in an aquatic scene. In combination, these techniques enable long term observation of spontaneous behavior of freely swimming weakly electric fish in a reliable and precise manner. We believe our method can be similarly applied to the study of other aquatic animals by relating their physiological signals with exploratory or social behaviors. PMID:24637642

[Comparative efficacy of different regimens of locomotor training in long-term space flights by the data of biomechanical and electromyographic parametrs of walking].

PubMed

Shpakov, A V; Voronov, A V; Fomina, E V; Lysova, N Iu; Chernova, M V; Kozlovskaia, I B

2013-01-01

Biomechanical and electromyographic characteristics of locomotion were investigated before and after space flight on the 3rd, 7th and 10th day after landing in 18 cosmonauts--crewmembers of long-term ISS space flights. It was shown that microgravity causes the development of significant changes in biomechanical and electromyographic characteristics of walking. Decrease of the angular displacement amplitude in leg joints, reduction of the length of the double step, increase of the electromyographic cost of locomotion were recorded after flight. It was also shown that interval locomotor physical training in long-term space flights in the regimen of alternation running and walking prevents physiological cost of locomotor movements increase after space flight and provides more effective maintenance of the neuromuscular system functions after flight. After flight smaller changes of biomechanical and electromyographic characteristics of walking were observed in cosmonauts who used locomotor training in interval regimen.

Effects of long-term construction noise on health of adult female Wistar rats.

PubMed

Zymantiene, J; Zelvyte, R; Pampariene, I; Aniuliene, A; Juodziukyniene, N; Kantautaite, J; Oberauskas, V

2017-03-28

The aim of this study was to investigate the influence of long-term building construction noise from refurbishment, which including vibration, on some physiological parameters and histopathological changes of organs of Wistar rats. Twenty 12 month old female rats were divided into two groups: rats group I (n = 10) were exposed to long-term construction noise and rats group II (n = 10) were kept under normal noise level. Study results revealed that long-term construction noise from building refurbishment has an influence on body weight, haematological and some serum biochemical parameters affects caecal microbiota, and causes histopathological changes in the organs of adult female Wistar rats. It was noticed that rats in group I exihibited significantly higher mean values for total protein, albumin and lower values for glucose, AST, ALT, blood urea nitrogen, haematological and caecal microbiota parameters than rats in group II. The most common pathologies were determined in the kidney, liver and lungs. Other observed pathologies were lymphadenopathy, catarrhal inflammation of the intestines, spleen hyperplasia and mammary gland adenofibroma. Single cases were subcutaneous fibroma in the thoracic region, abortus with uterine inflammation and thymus hyperplasia with formation of cysts were found.

Short- and long-term salinity challenge, Osmoregulatory ability, and (Na+, K+)-ATPase KINETICS AND α-SUBUNIT mRNA expression in the gills of the thinstripe hermit CRAB Clibanarius symmetricus.

PubMed

Faleiros, Rogério O; Garçon, Daniela P; Lucena, Malson N; McNamara, John C; Leone, Francisco A

2018-06-19

The evolutionary history of the Crustacea reveals ample adaptive radiation and the subsequent occupation of many osmotic niches resulting from physiological plasticity in their osmoregulatory mechanisms. We evaluate osmoregulatory ability in the intertidal, thinstripe hermit crab Clibanarius symmetricus after short-term exposure (6 h) or long-term acclimation (10 days) to a wide salinity range, also analyzing kinetic behavior and α-subunit mRNA expression of the gill (Na + , K + )-ATPase. The crab strongly hyper-regulates its hemolymph at 5 and 15‰S (Salinity, g L -1 ) but weakly hyper-regulates up to ≈27‰S. After 6 h exposure to 35‰S and 45‰S, C. symmetricus slightly hypo-regulates its hemolymph, becoming isosmotic after 10 days acclimation to these salinities. (Na + , K + )-ATPase specific activity decreases with increasing salinity for both exposure periods, reflecting physiological adjustment to isosmoticity. At low salinities, the gill enzyme exhibits a single, low affinity ATP binding site. However, at elevated salinities, a second, high affinity, ATP binding site appears, independently of exposure time. (Na + , K + )-ATPase α-subunit mRNA expression increases only after 10 days acclimation to 5‰S. Our findings suggest that hemolymph hyper-regulation is effected by alterations in enzyme activity during short-term exposure, but is sustained by increased mRNA expression during long-term acclimation. The decrease in gill (Na + , K + )-ATPase activity seen as a consequence of increasing salinity appears to underlie biochemical adjustments to hemolymph isosmoticity as hypo-regulatory ability diminishes. Copyright © 2018. Published by Elsevier Inc.

Effects of long-term intake of a yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 on mice.

PubMed

Usui, Yuki; Kimura, Yasumasa; Satoh, Takeshi; Takemura, Naoki; Ouchi, Yasuo; Ohmiya, Hiroko; Kobayashi, Kyosuke; Suzuki, Hiromi; Koyama, Satomi; Hagiwara, Satoko; Tanaka, Hirotoshi; Imoto, Seiya; Eberl, Gérard; Asami, Yukio; Fujimoto, Kosuke; Uematsu, Satoshi

2018-05-15

The gut is an extremely complicated ecosystem where microorganisms, nutrients and host cells interact vigorously. Although the function of the intestine and its barrier system weakens with age, some probiotics can potentially prevent age-related intestinal dysfunction. Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131, which are the constituents of LB81 yogurt, are representative probiotics. However, it is unclear whether their long-term intake has a beneficial influence on systemic function. Here, we examined the gut microbiome, fecal metabolites and gene expression profiles of various organs in mice. Although age-related alterations were apparent in them, long-term LB81 yogurt intake led to an increased Bacteroidetes to Firmicutes ratio and elevated abundance of the bacterial family S24-7 (Bacteroidetes), which is known to be associated with butyrate and propanoate production. According to our fecal metabolite analysis to detect enrichment, long-term LB81 yogurt intake altered the intestinal metabolic pathways associated with propanoate and butanoate in the mice. Gene ontology analysis also revealed that long-term LB81 yogurt intake influenced many physiological functions related to the defense response. The profiles of various genes associated with antimicrobial peptides-, tight junctions-, adherens junctions- and mucus-associated intestinal barrier functions were also drastically altered in the LB81 yogurt-fed mice. Thus, long-term intake of LB81 yogurt has the potential to maintain systemic homeostasis, such as the gut barrier function, by controlling the intestinal microbiome and its metabolites.

Drought and tree mortality in tropical rainforest: understanding and differentiating functional responses

NASA Astrophysics Data System (ADS)

Meir, P.; Rowland, L.; da Costa, A. C. L.; Mencuccini, M.; Oliveira, A.; Binks, O.; Christoffersen, B. O.; Eliane, M.; Vasconcelos, S.; Kruijt, B.; Ferreira, L.

2014-12-01

Our understanding of how forests respond to drought is especially constrained with respect to widespread tree mortality events. This limitation is particularly clear for tropical forests, despite the risk of drought to these ecosystems during the coming decades. We present new findings from the only current long-term 'ecosystem-scale' (1 ha) rainfall manipulation experiment in tropical rainforest, the Esecaflor experiment at Caxiuana National Forest, Para State, Brazil. Throughfall has been partially excluded from experimental forest at the Esecaflor experiment for more than a decade. We have previously demonstrated a capacity to model short-term physiological responses well, but longer term physiology and ecological dynamics remain challenging to understand and represent. In particular, high mortality and increased autotrophic respiration following extended drought are poorly understood phenomena, and their interaction with hydraulic responses and limitations needs to be characterised. We present initial data that for the first time combine carbon use and hydraulic metrics, comparing drought-vulnerable and non-vulnerable species that have experienced extended soil moisture deficit, as imposed in the experiment, also considering the response in soil respiration. We also discuss how these findings can be used to develop future empirical and modelling studies aimed at improving our capacity to predict the effects of drought on tropical forest ecosystems in Amazonia and in other tropical forest regions where species characteristics and environmental constraints may influence both short and long-term responses to drought.

Long-term physiological effects of enhanced O/sub 2/ release by inositol hexaphosphate-loaded erythrocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teisseire, B.; Ropars, C.; Villereal, M.C.

1987-10-01

A continuous lysing and resealing procedure with erythrocytes permitted incorporation in these cells of inositol hexaphosphate (InsP/sub 6/), a strong allosteric effector of Hb. This leads to significant rightward shifts of the HbO/sub 2/ dissociation curves with in vitro P/sub 50/, values increasing from 32.2 +/- 1.8 torr for control erythrocytes to 86 +/- 60 torr. The shape of the dissociation curve was still sigmoidal, although the Hill coefficient was decreased. The life span of InsP/sub 6/-loaded erythrocytes equaled that of control erythrocytes. Erythrocyte-survival studies were done using /sub 51/Cr labeling of cells. The long-term physiological effects of the InsP/submore » 6/-loaded erythrocytes on piglets were increased O/sub 2/ release and reduced cardiac output. The reduced O/sub 2/ affinity of the InsP/sub 6/-loaded erythrocytes was still effective 20 days after transfusion in awake piglets. The electrolyte concentration appeared stable over the 5-day observation period except for a transient, but significant, hyperkalemia immediately after transfusion. The reductions in the O/sub 2/ affinity of Hb reported here are large compared with previously reported values. Introduction of InsP/sub 6/ into viable erythrocytes improves tissue oxygenation when, for any reason, normal blood flow is impaired.« less

Dampening effects of long-term experimental drought on growth and mortality rates of a Holm oak forest.

PubMed

Barbeta, Adrià; Ogaya, Romà; Peñuelas, Josep

2013-10-01

Forests respond to increasing intensities and frequencies of drought by reducing growth and with higher tree mortality rates. Little is known, however, about the long-term consequences of generally drier conditions and more frequent extreme droughts. A Holm oak forest was exposed to experimental rainfall manipulation for 13 years to study the effect of increasing drought on growth and mortality of the dominant species Quercus ilex, Phillyrea latifolia, and Arbutus unedo. The drought treatment reduced stem growth of A. unedo (-66.5%) and Q. ilex (-17.5%), whereas P. latifolia remained unaffected. Higher stem mortality rates were noticeable in Q. ilex (+42.3%), but not in the other two species. Stem growth was a function of the drought index of early spring in the three species. Stem mortality rates depended on the drought index of winter and spring for Q. ilex and in spring and summer for P. latifolia, but showed no relation to climate in A. unedo. Following a long and intense drought (2005-2006), stem growth of Q. ilex and P. latifolia increased, whereas it decreased in A. unedo. Q. ilex also enhanced its survival after this period. Furthermore, the effect of drought treatment on stem growth in Q. ilex and A. unedo was attenuated as the study progressed. These results highlight the different vulnerabilities of Mediterranean species to more frequent and intense droughts, which may lead to partial species substitution and changes in forest structure and thus in carbon uptake. The response to drought, however, changed over time. Decreased intra- and interspecific competition after extreme events with high mortality, together with probable morphological and physiological acclimation to drought during the study period, may, at least in the short term, buffer forests against drier conditions. The long-term effects of drought consequently deserve more attention, because the ecosystemic responses are unlikely to be stable over time.Nontechnical summaryIn this study, we evaluate the effect of long-term (13 years) experimental drought on growth and mortality rates of three forest Mediterranean species, and their response to the different intensities and durations of natural drought. We provide evidence for species-specific responses to drought, what may eventually lead to a partial community shift favoring the more drought-resistant species. However, we also report a dampening of the treatment effect on the two drought-sensitive species, which may indicate a potential adaptation to drier conditions at the ecosystem or population level. These results are thus relevant to account for the stabilizing processes that would alter the initial response of ecosystem to drought through changes in plant physiology, morphology, and demography compensation. © 2013 John Wiley & Sons Ltd.

Multiresolution wavelet analysis for efficient analysis, compression and remote display of long-term physiological signals.

PubMed

Khuan, L Y; Bister, M; Blanchfield, P; Salleh, Y M; Ali, R A; Chan, T H

2006-06-01

Increased inter-equipment connectivity coupled with advances in Web technology allows ever escalating amounts of physiological data to be produced, far too much to be displayed adequately on a single computer screen. The consequence is that large quantities of insignificant data will be transmitted and reviewed. This carries an increased risk of overlooking vitally important transients. This paper describes a technique to provide an integrated solution based on a single algorithm for the efficient analysis, compression and remote display of long-term physiological signals with infrequent short duration, yet vital events, to effect a reduction in data transmission and display cluttering and to facilitate reliable data interpretation. The algorithm analyses data at the server end and flags significant events. It produces a compressed version of the signal at a lower resolution that can be satisfactorily viewed in a single screen width. This reduced set of data is initially transmitted together with a set of 'flags' indicating where significant events occur. Subsequent transmissions need only involve transmission of flagged data segments of interest at the required resolution. Efficient processing and code protection with decomposition alone is novel. The fixed transmission length method ensures clutter-less display, irrespective of the data length. The flagging of annotated events in arterial oxygen saturation, electroencephalogram and electrocardiogram illustrates the generic property of the algorithm. Data reduction of 87% to 99% and improved displays are demonstrated.

The Plant Research Unit: Long-Term Plant Growth Support for Space Station

NASA Technical Reports Server (NTRS)

Heathcote, D. G.; Brown, C. S.; Goins, G. D.; Kliss, M.; Levine, H.; Lomax, P. A.; Porter, R. L.; Wheeler, R.

1996-01-01

The specifications of the plant research unit (PRU) plant habitat, designed for space station operations, are presented. A prototype brassboard model of the PRU is described, and the results of the subsystems tests are outlined. The effects of the long term red light emitting diode (LED) illumination as the sole source for plant development were compared with red LEDs supplemented with blue wavelengths, and white fluorescent sources. It was found that wheat and Arabidopsis were able to complete a life cycle under red LEDs alone, but with differences in physiology and morphology. The differences noted were greatest for the Arabidopsis, where the time to flowering was increased under red illumination. The addition of 10 percent of blue light was effective in eliminating the observed differences. The results of the comparative testing of three nutrient delivery systems for the PRU are discussed.

Effects of gender and game type on autonomic nervous system physiological parameters in long-hour online game players.

PubMed

Lin, Tung-Cheng

2013-11-01

Online game playing may induce physiological effects. However, the physical mechanisms that cause these effects remain unclear. The purpose of this study was to examine the physiological effects of long-hour online gaming from an autonomic nervous system (ANS) perspective. Heart rate variability (HRV), a valid and noninvasive electrocardiographic method widely used to investigate ANS balance, was used to measure physiological effect parameters. This study used a five-time, repeated measures, mixed factorial design. Results found that playing violent games causes significantly higher sympathetic activity and diastolic blood pressure than playing nonviolent games. Long-hour online game playing resulted in the gradual dominance of the parasympathetic nervous system due to physical exhaustion. Gaming workload was found to modulate the gender effects, with males registering significantly higher sympathetic activity and females significantly higher parasympathetic activity in the higher gaming workload group.

Foot massage and physiological stress in people with dementia: a randomized controlled trial.

PubMed

Moyle, Wendy; Cooke, Marie Louise; Beattie, Elizabeth; Shum, David H K; O'Dwyer, Siobhan T; Barrett, Sue; Sung, Billy

2014-04-01

The anxiety associated with unfamiliar surroundings, the disorientation and mental confusion, and the social isolation that accompanies dementia can often create increased stress for people living in long-term care settings. Such a response is thought to affect the autonomic nervous system and result in emotional and physical symptoms of distress that may be manifested as agitation. There is the potential for such distress to influence the physiological response and in particular Blood Pressure and Heart Rate. A relaxation intervention such as massage may influence the physiological stress response. This randomized controlled trial aimed to compare the effect of foot massage (FM) versus a control activity (quiet presence, QP) on physiological stress response (i.e., blood pressure [BP] and heart rate [HR]) in people living with moderate-to-severe dementia in long-term-care settings. Fifty-three residents were randomized to intervention (10-minute FM) or control group (QP). While the FM group experienced a greater reduction in HR than the control group, these reductions were not significantly different between groups (p=0.83; see Table 1 ), or across time (p=0.46). Both groups experienced a reduction in systolic BP and diastolic BP, while the mean reduction in systolic BP was greater for those in the FM group. While the findings do not provide strong support for FM, the finding that both conditions allowed the person with dementia to rest in the presence of another human being is of importance in the care of people with dementia. The close presence of another person may in fact promote relaxation and therefore improve BP and HR measures.

Assessment of the effects of the zero gravity environment on the health and safety of space workers

NASA Technical Reports Server (NTRS)

1980-01-01

A review was conducted of currently available information relating to adverse effects to the health and safety that space power system (SPS) space workers may experience. Currently available information on the responses of humans to space flight is somewhat limited and was obtained under conditions which are grossly different from conditions to be experienced by future space workers. The limitations in information and differences in conditions were considered in the assessment of potential health and safety hazards to the SPS space workers. The study did not disclose any adverse effects that would result in long term deviations to the medical physiological health of space workers so long as proper preventive or ameliorating action were taken.

Soviet space flight: the human element.

PubMed

Garshnek, V

1988-05-01

Building on past experience and knowledge, the Soviet manned space flight effort has become broad, comprehensive, and forward-looking. Their long-running space station program has provided the capabilities to investigate long-term effects of microgravity on human physiology and behavior and test various countermeasures against microgravity-induced physiological deconditioning. Since the beginning of Soviet manned space flight, the biomedical training and preparation of cosmonauts has evolved from a process that increased human tolerance to space flight factors, to a system of interrelated measures to prepare cosmonauts physically and psychologically to live and work in space. Currently, the Soviet Union is constructing a multimodular space station, the Mir. With the emergence of dedicated laboratory modules, the Soviets have begun the transition from small-scale experimental research to large-scale production activities and specialized scientific work in space. In the future, additional laboratory modules will be added, including one dedicated to biomedical research, called the "Medilab." The longest manned space flight to date (326 days) has been completed by the Soviets. The biomedical effects of previous long-duration flights, and perhaps those of still greater length, may contribute important insight ito the possibility of extended missions beyond Earth, such as a voyage to Mars.

Preliminary evaluation of a novel smoking system: effects on subjective and physiological measures and on smoking behavior.

PubMed

Buchhalter, A R; Eissenberg, T

2000-02-01

Tobacco companies are responding to public pressure to market less dangerous and aversive products by developing novel smoking systems. The short- and long-term effects of these systems must be evaluated to determine the risks inherent in their use. One such system, the Accord, uses a hand-held device to heat tobacco electronically and is marketed as a means to reduce second-hand smoke. In this study 10 cigarette smokers (> or = 10 cigarettes per day) were recruited to evaluate the short-term effects produced when using this system. Subjects abstained from smoking for at least 8 h before participating in two experimental sessions where they smoked either their usual brand or used the Accord at 30-min intervals for 2 hours. Subject-rated measures of tobacco withdrawal and craving, physiological measures, and smoking behavior were assessed within each session. Results show that, when using the Accord, the magnitude of smoking-induced craving reductions and the physiological effects of smoking were less, and puff volume and frequency were greater than when subjects smoked their own brand of cigarettes. The expired air carbon monoxide increases observed after smoking own brand cigarettes did not occur after using the Accord. The novel system does not provide maximal withdrawal suppression and produces little increase in expired air carbon monoxide; physiological data suggest that the novel system may deliver nicotine less efficiently than normally marketed cigarettes. Smokers using the Accord system may smoke more often or more intensely to compensate for decreased withdrawal suppression and/or nicotine delivery.

Investigation of the Physiological Responses of Belugas to Stressors to Aid in Assessing the Impact of Environmental and Anthropogenic Challenges on Health

DTIC Science & Technology

2011-09-30

1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Investigation of the Physiological Responses of Belugas...N00014-11-1-0437 http://searesearch.org LONG-TERM GOALS The overall top level goal of this effort is to investigate the physiological i.e...the relationships among hormones (e.g. cortisol, corticosterone, adrenocorticotropin hormone, aldosterone , catecholamines) in different matrices

Chronic, long-term social stress can cause decreased microtubule protein network activity and dynamics in cerebral cortex of male Wistar rats.

PubMed

Eskandari Sedighi, Ghazaleh; Riazi, Gholam Hossein; Vaez Mahdavi, Mohammad Reza; Cheraghi, Tayebe; Atarod, Deyhim; Rafiei, Shahrbanoo

2015-03-01

Social stress is viewed as a factor in the etiology of a variety of psychopathologies such as depression and anxiety. Animal models of social stress are well developed and widely used in studying clinical and physiological effects of stress. Stress is known to significantly affect learning and memory, and this effect strongly depends on the type of stress, its intensity, and duration. It has been demonstrated that chronic and acute stress conditions can change neuronal plasticity, characterized by retraction of apical dendrites, reduction in axonogenesis, and decreased neurogenesis. Various behavioral studies have also confirmed a decrease in learning and memory upon exposure of animals to long-term chronic stress. On the other hand, the close relationship between microtubule (MT) protein network and neuroplasticity controlling system suggests the possibility of MT protein alterations in high stressful conditions. In this work, we have studied the kinetics, activity, and dynamicity changes of MT proteins in the cerebral cortex of male Wistar rats that were subjected to social instability for 35 and 100 days. Our results indicate that MT protein network dynamicity and polymerization ability is decreased under long-term (100 days) social stress conditions.

Long-term health consequences of premature or early menopause and considerations for management

PubMed Central

Faubion, Stephanie S.; Kuhle, Carol L.; Shuster, Lynne T.; Rocca, Walter A.

2015-01-01

Aim To review the current evidence concerning the long-term harmful effects of premature or early menopause, and to discuss some of the clinical implications. Material and methods Narrative review of the literature. Results Women undergoing premature or early menopause, either following bilateral salpingo-oophorectomy or because of primary ovarian insufficiency, experience the early loss of estrogen and other ovarian hormones. The long-term consequences of premature or early menopause include adverse effects on cognition, mood, cardiovascular, bone, and sexual health, as well as an increased risk of early mortality. The use of hormone therapy has been shown to lessen some, although not all of these risks. Therefore, multiple medical societies recommend providing hormone therapy at least until the natural age of menopause. It is important to individualize hormone therapy for women with early estrogen deficiency, and higher dosages may be needed to approximate physiological concentrations found in premenopausal women. It is also important to address the psychological impact of early menopause and to review the options for fertility and the potential need for contraception, if the ovaries are intact. Conclusions Women who undergo premature or early menopause should receive individualized hormone therapy and counseling. PMID:25845383

Physiological Responses of Two Epiphytic Bryophytes to Nitrogen, Phosphorus and Sulfur Addition in a Subtropical Montane Cloud Forest

PubMed Central

Chen, Xi; Liu, Wen-yao; Song, Liang; Li, Su; Wu, Yi; Shi, Xian-meng; Huang, Jun-biao; Wu, Chuan-sheng

2016-01-01

Atmospheric depositions pose significant threats to biodiversity and ecosystem function. However, the underlying physiological mechanisms are not well understood, and few studies have considered the combined effects and interactions of multiple pollutants. This in situ study explored the physiological responses of two epiphytic bryophytes to combined addition of nitrogen, phosphorus and sulfur. We investigated the electrical conductivity (EC), total chlorophyll concentration (Chl), nutrient stoichiometry and chlorophyll fluorescence signals in a subtropical montane cloud forest in south-west China. The results showed that enhanced fertilizer additions imposed detrimental effects on bryophytes, and the combined enrichment of simulated fertilization exerted limited synergistic effects in their natural environments. On the whole, EC, Chl, the effective quantum yield of photosystem II (ΦPSII) and photochemical quenching (qP) were the more reliable indicators of increased artificial fertilization. However, conclusions on nutrient stoichiometry should be drawn cautiously concerning the saturation uptake and nutrient interactions in bryophytes. Finally, we discuss the limitations of prevailing fertilization experiments and emphasize the importance of long-term data available for future investigations. PMID:27560190

Costs of living for juvenile Chinook salmon (Oncorhynchus tshawytscha) in an increasingly warming and invaded world

USGS Publications Warehouse

Kuehne, Lauren M.; Olden, Julian D.; Duda, Jeffrey J.

2012-01-01

Rapid environmental change in freshwater ecosystems has created a need to understand the interactive effects of multiple stressors, with temperature and invasive predators identified as key threats to imperiled fish species. We tested the separate and interactive effects of water temperature and predation by non-native smallmouth bass (Micropterus dolomieu) on the lethal (mortality) and sublethal (behavior, physiology, and growth) effects for juvenile Chinook salmon (Oncorhynchus tshawytscha) in seminatural stream channel experiments. Over 48 h trials, there was no difference in direct predation with warmer temperatures, but significant interactive effects on sublethal responses of juvenile salmon. Warmer temperatures resulted in significantly stronger and more variable antipredator responses (surface shoaling and swimming activity), while physiological indicators (plasma glucose, plasma cortisol) suggested suppression of physiological mechanisms in response to the combined stressors. These patterns corresponded with additive negative growth in predation, temperature, and combined treatments. Our results suggest that chronic increases in temperature may not increase direct predation over short periods, but can result in significant sublethal costs with negative implications for long-term development, disease resistance, and subsequent size-selective mortality of Pacific salmon.

Tolerance of Ruppia sinensis Seeds to Desiccation, Low Temperature, and High Salinity With Special Reference to Long-Term Seed Storage.

PubMed

Gu, Ruiting; Zhou, Yi; Song, Xiaoyue; Xu, Shaochun; Zhang, Xiaomei; Lin, Haiying; Xu, Shuai; Yue, Shidong; Zhu, Shuyu

2018-01-01

Seeds are important materials for the restoration of globally-threatened marine angiosperm (seagrass) populations. In this study, we investigated the differences between different Ruppia sinensis seed types and developed two feasible long-term R. sinensis seed storage methods. The ability of R. sinensis seeds to tolerate the short-term desiccation and extreme cold had been investigated. The tolerance of R. sinensis seeds to long-term exposure of high salinity, cold temperature, and desiccation had been considered as potential methods for long-term seed storage. Also, three morphological and nine physiological indices were measured and compared between two types of seeds: Shape L and Shape S. We found that: (1) wet storage at a salinity of 30-40 psu and 0°C were the optimal long-term storage conditions, and the proportion of viable seeds reached over 90% after a storage period of 11 months since the seeds were collected from the reproductive shoots; (2) dry condition was not the optimal choice for long-term storage of R. sinensis seeds; however, storing seeds in a dry condition at 5°C and 33 ± 10% relative humidity for 9 months had a relatively high percentage (74.44 ± 2.22%) of viable seeds, consequently desiccation exposure could also be an acceptable seed storage method; (3) R. sinensis seeds would lose vigor in the interaction of extreme cold (-27°C) and desiccation; (4) there were significant differences in seed weight, seed curvature, and endocarp thickness between the two types of seeds. These findings provided fundamental physiological information for R. sinensis seeds and supported the long-term storage of its seeds. Our results may also serve as useful reference for seed storage of other threatened seagrass species and facilitate their ex situ conservation and habitat restoration.

Retrieval practice in the form of online homework improved information retention more when spaced 5 days rather than 1 day after class in two physiology courses.

PubMed

Cadaret, Caitlin N; Yates, Dustin T

2018-06-01

Studies have shown that practicing temporally spaced retrieval of previously learned information via formal assessments increases student retention of the information. Our objective was to determine the impact of online homework administered as a first retrieval practice 1 or 5 days after introduction of physiology topics on long-term information retention. Students in two undergraduate courses, Anatomy and Physiology (ASCI 240) and Animal Physiological Systems (ASCI 340), were presented with information on a specific physiological system during each weekly laboratory and then completed an online homework assignment either 1 or 5 days later. Information retention was assessed via an in-class quiz the following week and by a comprehensive final exam at semester's end (4-13 wk later). Performance on homework assignments was generally similar between groups for both courses. Information retention at 1 wk did not differ due to timing of homework in either course. In both courses, however, students who received homework 5 days after class performed better on final exam questions relevant to that week's topic compared with their day 1 counterparts. These findings indicate that the longer period between introducing physiology information in class and assigning the first retrieval practice was more beneficial to long-term information retention than the shorter period, despite seemingly equivalent benefits in the shorter term. Since information is typically forgotten over time, we speculate that the longer interval necessitates greater retrieval effort in much the same way as built-in desirable difficulties, thus allowing for stronger conceptual connections and deeper comprehension.

Interaction of metal oxide nanoparticles with higher terrestrial plants: Physiological and biochemical aspects.

PubMed

Du, Wenchao; Tan, Wenjuan; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L; Ji, Rong; Yin, Ying; Guo, Hongyan

2017-01-01

Multiple applications of metal oxide nanoparticles (MONPs) could result in their accumulation in soil, threatening higher terrestrial plants. Several reports have shown the effects of MONPs on plants. In this review, we analyze the most recent reports about the physiological and biochemical responses of plants to stress imposed by MONPs. Findings demonstrate that MONPs may be taken up and accumulated in plant tissues causing adverse or beneficial effects on seed germination, seedling elongation, photosynthesis, antioxidative stress response, agronomic, and yield characteristics. Given the importance of determining the potential risks of MONPs on crops and other terrestrial higher plants, research questions about field long-term conditions, transgenernational phytotoxicity, genotype specific sensitivity, and combined pollution problems should be considered. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Glucocorticoid programming of neuroimmune function.

PubMed

Walker, David J; Spencer, Karen A

2018-01-15

Throughout life physiological systems strive to maintain homeostasis and these systems are susceptible to exposure to maternal or environmental perturbations, particularly during embryonic development. In some cases, these perturbations may influence genetic and physiological processes that permanently alter the functioning of these physiological systems; a process known as developmental programming. In recent years, the neuroimmune system has garnered attention for its fundamental interactions with key hormonal systems, such as the hypothalamic pituitary adrenal (HPA) axis. The ultimate product of this axis, the glucocorticoid hormones, play a key role in modulating immune responses within the periphery and the CNS as part of the physiological stress response. It is well-established that elevated glucocorticoids induced by developmental stress exert profound short and long-term physiological effects, yet there is relatively little information of how these effects are manifested within the neuroimmune system. Pre and post-natal periods are prime candidates for manipulation in order to uncover the physiological mechanisms that underlie glucocorticoid programming of neuroimmune responses. Understanding the potential programming role of glucocorticoids may be key in uncovering vulnerable windows of CNS susceptibility to stressful experiences during embryonic development and improve our use of glucocorticoids as therapeutics in the treatment of neurodegenerative diseases. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Multiple Functions of Endocannabinoid Signaling in the Brain

PubMed Central

Katona, István; Freund, Tamás F.

2014-01-01

Despite being regarded as a hippie science for decades, cannabinoid research has finally found its well-deserved position in mainstream neuroscience. A series of groundbreaking discoveries revealed that endocannabinoid molecules are as widespread and important as conventional neurotransmitters like glutamate or GABA, yet act in profoundly unconventional ways. We aim to illustrate how uncovering the molecular, anatomical and physiological characteristics of endocannabinoid signaling revealed new mechanistic insights into several fundamental phenomena in synaptic physiology. First, we summarize unexpected advances in the molecular complexity of biogenesis and inactivation of the two endocannabinoids, anandamide and 2-arachidonoylglycerol. Then we show how these new metabolic routes are integrated into well-known intracellular signaling pathways. These endocannabinoid-producing signalosomes operate in phasic and tonic modes thereby differentially governing homeostatic, short-term and long-term synaptic plasticity throughout the brain. Finally, we discuss how cell type- and synapse-specific refinement of endocannabinoid signaling may explain the characteristic behavioral effects of cannabinoids. PMID:22524785

Comparing the Long-Term Retention of a Physiology Course for Medical Students with the Traditional and Problem-Based Learning

ERIC Educational Resources Information Center

Pourshanazari, A. A.; Roohbakhsh, A.; Khazaei, M.; Tajadini, H.

2013-01-01

The rapid improvements in medical sciences and the ever-increasing related data, however, require novel methods of instruction. One such method, which has been given less than due attention in Iran, is problem-based learning (PBL). In this study, we aimed to evaluate the impact of study skills and the PBL methods on short and long-term retention…

Physiological performance of the intertidal Manila clam (Ruditapes philippinarum) to long-term daily rhythms of air exposure

PubMed Central

Yin, Xuwang; Chen, Peng; Chen, Hai; Jin, Wen; Yan, Xiwu

2017-01-01

Intertidal organisms, especially the sessile species, often experience long-term periodic air exposure during their lives. Learning the biochemical and physiological responses of intertidal organisms to long-term periodic air exposure and the relationship to duration of air exposure provides insight into adaptation to this variably stressful environment. We studied the Manila clam, Ruditapes philippinarum, an important species in world aquaculture, as a model to evaluate survival, growth, lipid composition, oxygen consumption, oxidative damage, and antioxidant enzyme activity in relation to the duration of air exposure in a long-term (60 days) laboratory study of varying durations of periodic emersion and re-immersion. Our results show: (1) clams undergoing a longer period of air exposure had lower survival and growth compared to those given a shorter exposure, (2) levels of oxidative damage and activities of antioxidant enzymes were higher in all air exposure treatments, but did not increase with duration of air exposure, and (3) the content of docosahexaenoic acid increased with duration of air exposure. Our results can largely be interpreted in the context of the energy expenditure by the clams caused by aerobic metabolism during the daily cycle of emersion and re-immersion and the roles of docosahexaenoic acid against oxidative stress. PMID:28128354

Restraint training for awake functional brain scanning of rodents can cause long-lasting changes in pain and stress responses

PubMed Central

Low, Lucie A.; Bauer, Lucy C.; Pitcher, Mark H.; Bushnell, M. Catherine

2016-01-01

Abstract With the increased interest in longitudinal brain imaging of awake rodents, it is important to understand both the short-term and long-term effects of restraint on sensory and emotional processing in the brain. To understand the effects of repeated restraint on pain behaviors and stress responses, we modeled a restraint protocol similar to those used to habituate rodents for magnetic resonance imaging scanning, and studied sensory sensitivity and stress hormone responses over 5 days. To uncover lasting effects of training, we also looked at responses to the formalin pain test 2 weeks later. We found that while restraint causes acute increases in the stress hormone corticosterone, it can also cause lasting reductions in nociceptive behavior in the formalin test, coupled with heightened corticosterone levels and increased activation of the “nociceptive” central nucleus of the amygdala, as seen by Fos protein expression. These results suggest that short-term repeated restraint, similar to that used to habituate rats for awake functional brain scanning, could potentially cause long-lasting changes in physiological and brain responses to pain stimuli that are stress-related, and therefore could potentially confound the functional activation patterns seen in awake rodents in response to pain stimuli. PMID:27058679

Restraint training for awake functional brain scanning of rodents can cause long-lasting changes in pain and stress responses.

PubMed

Low, Lucie A; Bauer, Lucy C; Pitcher, Mark H; Bushnell, M Catherine

2016-08-01

With the increased interest in longitudinal brain imaging of awake rodents, it is important to understand both the short-term and long-term effects of restraint on sensory and emotional processing in the brain. To understand the effects of repeated restraint on pain behaviors and stress responses, we modeled a restraint protocol similar to those used to habituate rodents for magnetic resonance imaging scanning, and studied sensory sensitivity and stress hormone responses over 5 days. To uncover lasting effects of training, we also looked at responses to the formalin pain test 2 weeks later. We found that while restraint causes acute increases in the stress hormone corticosterone, it can also cause lasting reductions in nociceptive behavior in the formalin test, coupled with heightened corticosterone levels and increased activation of the "nociceptive" central nucleus of the amygdala, as seen by Fos protein expression. These results suggest that short-term repeated restraint, similar to that used to habituate rats for awake functional brain scanning, could potentially cause long-lasting changes in physiological and brain responses to pain stimuli that are stress-related, and therefore could potentially confound the functional activation patterns seen in awake rodents in response to pain stimuli.

Consequences of long-term oral administration of the mitochondria-targeted antioxidant MitoQ to wild-type mice.

PubMed

Rodriguez-Cuenca, Sergio; Cochemé, Helena M; Logan, Angela; Abakumova, Irina; Prime, Tracy A; Rose, Claudia; Vidal-Puig, Antonio; Smith, Anthony C; Rubinsztein, David C; Fearnley, Ian M; Jones, Bruce A; Pope, Simon; Heales, Simon J R; Lam, Brian Y H; Neogi, Sudeshna Guha; McFarlane, Ian; James, Andrew M; Smith, Robin A J; Murphy, Michael P

2010-01-01

The mitochondria-targeted quinone MitoQ protects mitochondria in animal studies of pathologies in vivo and is being developed as a therapy for humans. However, it is unclear whether the protective action of MitoQ is entirely due to its antioxidant properties, because long-term MitoQ administration may alter whole-body metabolism and gene expression. To address this point, we administered high levels of MitoQ orally to wild-type C57BL/6 mice for up to 28 weeks and investigated the effects on whole-body physiology, metabolism, and gene expression, finding no measurable deleterious effects. In addition, because antioxidants can act as pro-oxidants under certain conditions in vitro, we examined the effects of MitoQ administration on markers of oxidative damage. There were no changes in the expression of mitochondrial or antioxidant genes as assessed by DNA microarray analysis. There were also no increases in oxidative damage to mitochondrial protein, DNA, or cardiolipin, and the activities of mitochondrial enzymes were unchanged. Therefore, MitoQ does not act as a pro-oxidant in vivo. These findings indicate that mitochondria-targeted antioxidants can be safely administered long-term to wild-type mice. Copyright 2009 Elsevier Inc. All rights reserved.

Short- and Long-Term Feedbacks on Vegetation Water Use: Unifying Evidence from Observations and Modeling

NASA Astrophysics Data System (ADS)

Mackay, D. S.

2001-05-01

Recent efforts to measure and model the interacting influences of climate, soil, and vegetation on soil water and nutrient dynamics have identified numerous important feedbacks that produce nonlinear responses. In particular, plant physiological factors that control rates of transpiration respond to soil water deficits and vapor pressure deficits (VPD) in the short-term, and to climate, nutrient cycling and disturbance in the long-term. The starting point of this presentation is the observation that in many systems, in particular forest ecosystems, conservative water use emerges as a result of short-term closure of stomata in response to high evaporative demand, and long-term vegetative canopy development under nutrient limiting conditions. Evidence for important short-term controls is presented from sap flux measurements of stand transpiration, remote sensing, and modeling of transpiration through a combination of physically-based modeling and Monte Carlo analysis. A common result is a strong association between stomatal conductance (gs) and the negative evaporative gain (∂ gs/∂ VPD) associated with the sensitivity of stomatal closure to rates of water loss. The importance of this association from the standpoint of modeling transpiration depends on the degree of canopy-atmosphere coupling. This suggests possible simplifications to future canopy component models for use in watershed and larger-scale hydrologic models for short-term processes. However, further results are presented from theoretical modeling, which suggest that feedbacks between hydrology and vegetation in current long-term (inter-annual to century) models may be too simple, as they do not capture the spatially variable nature of slow nutrient cycling in response to soil water dynamics and site history. Memory effects in the soil nutrient pools can leave lasting effects on more rapid processes associated with soil, vegetation, atmosphere coupling.

FKBP5 methylation as a possible marker for cortisol state and transient cortisol exposure in healthy human subjects.

PubMed

Winkler, Britta K; Lehnert, Hendrik; Oster, Henrik; Kirchner, Henriette; Harbeck, Birgit

2017-10-01

Current glucocorticoid replacement regimens, in adrenal insufficiency, fail to mimic the physiological cortisol secretion, thereby fostering serious side effects. To experimentally evaluate the impact of CpG methylation within the FKBP5 gene as a possible short- and long-term marker for cortisol exposure in humans. An ACTH-stimulation test was carried out and methylation status of the FKBP5 gene in leukocytes was determined. A negative correlation between basal levels of methylation and serum cortisol was observed. Individual changes in FKBP5 methylation after 24 h correlated with cortisol responses. Considering previous studies conducted with murine leucocytes, FKBP5 methylation may be suitable as a long-term biomarker, rather than acute glucocorticoid exposure, also in humans.

Late gestational intermittent hypoxia induces metabolic and epigenetic changes in male adult offspring mice.

PubMed

Khalyfa, Abdelnaby; Cortese, Rene; Qiao, Zhuanhong; Ye, Honggang; Bao, Riyue; Andrade, Jorge; Gozal, David

2017-04-15

Late gestation during pregnancy has been associated with a relatively high prevalence of obstructive sleep apnoea (OSA). Intermittent hypoxia, a hallmark of OSA, could impose significant long-term effects on somatic growth, energy homeostasis and metabolic function in offspring. Here we show that late gestation intermittent hypoxia induces metabolic dysfunction as reflected by increased body weight and adiposity index in adult male offspring that is paralleled by epigenomic alterations and inflammation in visceral white adipose tissue. Fetal perturbations by OSA during pregnancy impose long-term detrimental effects manifesting as metabolic dysfunction in adult male offspring. Pregnancy, particularly late gestation (LG), has been associated with a relatively high prevalence of obstructive sleep apnoea (OSA). Intermittent hypoxia (IH), a hallmark of OSA, could impose significant long-term effects on somatic growth, energy homeostasis, and metabolic function in offspring. We hypothesized that IH during late pregnancy (LG-IH) may increase the propensity for metabolic dysregulation and obesity in adult offspring via epigenetic modifications. Time-pregnant female C57BL/6 mice were exposed to LG-IH or room air (LG-RA) during days 13-18 of gestation. At 24 weeks, blood samples were collected from offspring mice for lipid profiles and insulin resistance, indirect calorimetry was performed and visceral white adipose tissues (VWAT) were assessed for inflammatory cells as well as for differentially methylated gene regions (DMRs) using a methylated DNA immunoprecipitation on chip (MeDIP-chip). Body weight, food intake, adiposity index, fasting insulin, triglycerides and cholesterol levels were all significantly higher in LG-IH male but not female offspring. LG-IH also altered metabolic expenditure and locomotor activities in male offspring, and increased number of pro-inflammatory macrophages emerged in VWAT along with 1520 DMRs (P < 0.0001), associated with 693 genes. Pathway analyses showed that genes affected by LG-IH were mainly associated with molecular processes related to metabolic regulation and inflammation. LG-IH induces metabolic dysfunction as reflected by increased body weight and adiposity index in adult male offspring that is paralleled by epigenomic alterations and inflammation in VWAT. Thus, perturbations to fetal environment by OSA during pregnancy can have long-term detrimental effects on the fetus, and lead to persistent metabolic dysfunction in adulthood. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Thermoregulation: long-term microwave effects. Final report 1 Feb 83-31 Jan 84

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adair, E.R.

1984-04-17

A pilot study investigated the consequences of chronic exposure to 2450-MHz CW microwaves, or sham exposure, in a cold (18 degC) environment on the thermoregulatory responses, both behavioral and physiological, of squirrel monkeys. Two animals exposed to microwaves exhibited responses that were little different from those measured in animals residing in thermoneutral environments while two sham-exposed animals sustained thermoregulatory deficits. These tentative findings require replication.

Physiological and molecular effects of interleukin-18 administration on the mouse kidney.

PubMed

Yamanishi, Kyosuke; Mukai, Keiichiro; Hashimoto, Takuya; Ikubo, Kaoru; Nakasho, Keiji; El-Darawish, Yosif; Li, Wen; Okuzaki, Daisuke; Watanabe, Yuko; Hayakawa, Tetsu; Nojima, Hiroshi; Yamanishi, Hiromichi; Okamura, Haruki; Matsunaga, Hisato

2018-03-07

The cytokine interleukin-18 was originally identified as an interferon-γ-inducing proinflammatory factor; however, there is increasing evidence to suggest that it has non-immunological effects on physiological functions. We previously investigated the potential pathophysiological relationship between interleukin-18 and dyslipidemia, non-alcoholic fatty liver disease, and non-alcoholic steatohepatitis, and suggested interleukin-18 as a possible novel treatment for not only these diseases but also for cancer immunotherapy. Before clinical application, the effects of interleukin-18 on the kidney need to be determined. In the current study, we examined the kidney of interleukin-18 knockout (Il18 -/- ) mice and the effects of interleukin-18 on the kidney following intravenous administration of recombinant interleukin-18. Il18 -/- male mice were generated on the C57Bl/6 background and littermate C57Bl/6 Il18 +/+ male mice were used as controls. To assess kidney damage, serum creatinine and blood urea nitrogen levels were measured and histopathological analysis was performed. For molecular analysis, microarray and quantitative reverse transcription PCR was performed using mice 6 and 12 weeks old. To evaluate the short- and long-term effects of interleukin-18 on the kidney, recombinant interleukin-18 was administered for 2 and 12 weeks, respectively. Compared with Il18 +/+ mice, Il18 -/- mice developed kidney failure in their youth-6 weeks of age, but the condition was observed to improve as the mice aged, even though dyslipidemia, arteriosclerosis, and higher insulin resistance occurred. Analyses of potential molecular mechanisms involved in the onset of early kidney failure in Il18 -/- mice identified a number of associated genes, such as Itgam, Nov, and Ppard. Intravenous administration of recombinant interleukin-18 over both the short and long term showed no effects on the kidney despite significant improvement in metabolic diseases. Short- and long-term administration of interleukin-18 appeared to have no adverse effects on the kidney in these mice, suggesting that administration may be a safe and novel treatment for metabolic diseases and cancer.

Long-Term Effects Produced by Small Doses of Radioactive Substances in Chronical Experiment); OTDALENNYE POSLEDSTVIYA PORAZHENIYA MALYMI DOZAMI RADIOAKTIVNYKH VESHCHESTV V KHRONICHESKOM EKSPERIMENTE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burykina, L.N.; Zakutinskii, D.I.; Kraevskii, N.A.

Data on the long-term effects produced by radioactive substances administered to dogs, rabbits, and rats in various ways, both in single and repeated doses, are reported. The animals were studied for three years or longer. Three successive phases were found in the chronic irradiation disease caused by the introduction of radioactive substances: the stimulation phase characterized by an instability and variability of clinical symptoms (blood picture, cardio- vascular system, and the physiological system); the phase of apparent compensation when all the symptoms are restored to normal, although changes are recorded in the reactivity of various systems of the organism whenmore » functional loads are applied; and the phase when symptoms, typical of the chronic stage of radiation disease, develop. The blastomogenous effects of radioactive substances was given special attention. Pre-tumor changes in the bone was also studied. (J.S.R.)« less

Adult acclimation to combined temperature and pH stressors significantly enhances reproductive outcomes compared to short-term exposures.

PubMed

Suckling, Coleen C; Clark, Melody S; Richard, Joelle; Morley, Simon A; Thorne, Michael A S; Harper, Elizabeth M; Peck, Lloyd S

2015-05-01

This study examined the effects of long-term culture under altered conditions on the Antarctic sea urchin, Sterechinus neumayeri. Sterechinus neumayeri was cultured under the combined environmental stressors of lowered pH (-0.3 and -0.5 pH units) and increased temperature (+2 °C) for 2 years. This time-scale covered two full reproductive cycles in this species and analyses included studies on both adult metabolism and larval development. Adults took at least 6-8 months to acclimate to the altered conditions, but beyond this, there was no detectable effect of temperature or pH. Animals were spawned after 6 and 17 months exposure to altered conditions, with markedly different outcomes. At 6 months, the percentage hatching and larval survival rates were greatest in the animals kept at 0 °C under current pH conditions, whilst those under lowered pH and +2 °C performed significantly less well. After 17 months, performance was not significantly different across treatments, including controls. However, under the altered conditions urchins produced larger eggs compared with control animals. These data show that under long-term culture adult S. neumayeri appear to acclimate their metabolic and reproductive physiology to the combined stressors of altered pH and increased temperature, with relatively little measureable effect. They also emphasize the importance of long-term studies in evaluating effects of altered pH, particularly in slow developing marine species with long gonad maturation times, as the effects of altered conditions cannot be accurately evaluated unless gonads have fully matured under the new conditions. © 2014 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

Artificial gravity for long duration spaceflight

NASA Technical Reports Server (NTRS)

Cohen, Malcolm M.

1989-01-01

This paper reviews the fundamental physical properties of gravitational and centrifugal forces, describes the physiological changes that result from long-term exposure to the nearly gravity-free environment of space, and explores the nature of these changes. The paper then cites currently employed and advanced techniques that can be used to prevent some of these changes. Following this review, the paper examines the potential use of artificial gravity as the ultimate technique to maintain terrestrial levels of physiological functioning in space, and indicates some of the critical studies that must be conducted and some of the trade-offs that must be made before artificial gravity can intelligently be used for long duration spaceflight.

Ionizing radiation-induced metabolic oxidative stress and prolonged cell injury

PubMed Central

Azzam, Edouard I.; Jay-Gerin, Jean-Paul; Pain, Debkumar

2013-01-01

Cellular exposure to ionizing radiation leads to oxidizing events that alter atomic structure through direct interactions of radiation with target macromolecules or via products of water radiolysis. Further, the oxidative damage may spread from the targeted to neighboring, non-targeted bystander cells through redox-modulated intercellular communication mechanisms. To cope with the induced stress and the changes in the redox environment, organisms elicit transient responses at the molecular, cellular and tissue levels to counteract toxic effects of radiation. Metabolic pathways are induced during and shortly after the exposure. Depending on radiation dose, dose-rate and quality, these protective mechanisms may or may not be sufficient to cope with the stress. When the harmful effects exceed those of homeostatic biochemical processes, induced biological changes persist and may be propagated to progeny cells. Physiological levels of reactive oxygen and nitrogen species play critical roles in many cellular functions. In irradiated cells, levels of these reactive species may be increased due to perturbations in oxidative metabolism and chronic inflammatory responses, thereby contributing to the long-term effects of exposure to ionizing radiation on genomic stability. Here, in addition to immediate biological effects of water radiolysis on DNA damage, we also discuss the role of mitochondria in the delayed outcomes of ionization radiation. Defects in mitochondrial functions lead to accelerated aging and numerous pathological conditions. Different types of radiation vary in their linear energy transfer (LET) properties, and we discuss their effects on various aspects of mitochondrial physiology. These include short and long-term in vitro and in vivo effects on mitochondrial DNA, mitochondrial protein import and metabolic and antioxidant enzymes. PMID:22182453

Critical impact of vegetation physiology on the continental hydrologic cycle in response to increasing CO2

NASA Astrophysics Data System (ADS)

Lemordant, Léo; Gentine, Pierre; Swann, Abigail S.; Cook, Benjamin I.; Scheff, Jacob

2018-04-01

Predicting how increasing atmospheric CO2 will affect the hydrologic cycle is of utmost importance for a range of applications ranging from ecological services to human life and activities. A typical perspective is that hydrologic change is driven by precipitation and radiation changes due to climate change, and that the land surface will adjust. Using Earth system models with decoupled surface (vegetation physiology) and atmospheric (radiative) CO2 responses, we here show that the CO2 physiological response has a dominant role in evapotranspiration and evaporative fraction changes and has a major effect on long-term runoff compared with radiative or precipitation changes due to increased atmospheric CO2. This major effect is true for most hydrological stress variables over the largest fraction of the globe, except for soil moisture, which exhibits a more nonlinear response. This highlights the key role of vegetation in controlling future terrestrial hydrologic response and emphasizes that the carbon and water cycles are intimately coupled over land.

Can maternal DHA supplementation offer long-term protection against neonatal hyperoxic lung injury?

PubMed

Lingappan, Krithika; Moorthy, Bhagavatula

2015-12-15

The effect of adverse perinatal environment (like maternal infection) has long-standing effects on many organ systems, including the respiratory system. Use of maternal nutritional supplements is an exciting therapeutic option that could be used to protect the developing fetus. In a recent issue of the journal, Ali and associates (Ali M, Heyob KM, Velten M, Tipple TE, Rogers LK. Am J Physiol Lung Cell Mol Physiol 309: L441-L448, 2015) specifically look at maternal docosahexaenoic acid (DHA) supplementation and its effect on chronic apoptosis in the lung in a mouse model of perinatal inflammation and postnatal hyperoxia. Strikingly, the authors show that pulmonary apoptosis was augmented even 8 wk after the hyperoxia-exposed mice had been returned to room air. This effect was significantly attenuated in mice that were subjected to maternal dietary DHA supplementation. These findings are novel, significantly advance our understanding of chronic effects of adverse perinatal and neonatal events on the developing lung, and thereby offer novel therapeutic options in the form of maternal dietary supplementation with DHA. This editorial reviews the long-term effects of adverse perinatal environment on postnatal lung development and the protective effects of dietary supplements such as DHA. Copyright © 2015 the American Physiological Society.

Screen Violence and Youth Behavior.

PubMed

Anderson, Craig A; Bushman, Brad J; Bartholow, Bruce D; Cantor, Joanne; Christakis, Dimitri; Coyne, Sarah M; Donnerstein, Edward; Brockmyer, Jeanne Funk; Gentile, Douglas A; Green, C Shawn; Huesmann, Rowell; Hummer, Tom; Krahé, Barbara; Strasburger, Victor C; Warburton, Wayne; Wilson, Barbara J; Ybarra, Michele

2017-11-01

Violence in screen entertainment media (ie, television, film, video games, and the Internet), defined as depictions of characters (or players) trying to physically harm other characters (or players), is ubiquitous. The Workgroup on Media Violence and Violent Video Games reviewed numerous meta-analyses and other relevant research from the past 60 years, with an emphasis on violent video game research. Consistent with every major science organization review, the Workgroup found compelling evidence of short-term harmful effects, as well as evidence of long-term harmful effects. The vast majority of laboratory-based experimental studies have revealed that violent media exposure causes increased aggressive thoughts, angry feelings, physiologic arousal, hostile appraisals, aggressive behavior, and desensitization to violence and decreases prosocial behavior (eg, helping others) and empathy. Still, to more fully understand the potential for long-term harm from media violence exposure, the field is greatly in need of additional large-sample, high-quality, longitudinal studies that include validated measures of media violence exposure and measures of other known violence risk factors. Also, although several high-quality media violence intervention studies have been conducted, larger-scale studies with more comprehensive and longer-term assessments are needed to fully understand long-term effects and to inform the development of tools that will help to reduce problems associated with aggression and violence. The evidence that violent screen media constitutes a causal risk factor for increased aggression is compelling. Modern social-cognitive theories of social behavior provide useful frameworks for understanding how and why these effects occur. Copyright © 2017 by the American Academy of Pediatrics.

Intestinal Serotonin Transporter Inhibition by Toll-Like Receptor 2 Activation. A Feedback Modulation.

PubMed

Latorre, Eva; Layunta, Elena; Grasa, Laura; Castro, Marta; Pardo, Julián; Gomollón, Fernando; Alcalde, Ana I; Mesonero, José E

2016-01-01

TLR2 is a microbiota recognition receptor that has been described to contribute to intestinal homeostasis and to ameliorate inflammatory intestinal injury. In this context, serotonin (5-HT) has shown to be an essential intestinal physiological neuromodulator that is also involved in intestinal inflammatory diseases. Since the interaction between TLR2 activation and the intestinal serotoninergic system remains non-investigated, our main aim was to analyze the effect of TLR2 on intestinal serotonin transporter (SERT) activity and expression and the intracellular pathways involved. Caco-2/TC7 cells were used to analyze SERT and TLR2 molecular expression and SERT activity by measuring 5-HT uptake. The results showed that apical TLR2 activation inhibits SERT activity in Caco-2/TC7 cells mainly by reducing SERT protein level either in the plasma membrane, after short-term TLR2 activation or in both the plasma membrane and cell lysate, after long-term activation. cAMP/PKA pathway appears to mediate short-term inhibitory effect of TLR2 on SERT; however, p38 MAPK pathway has been shown to be involved in both short- and long-term TLR2 effect. Reciprocally, 5-HT long-term treatment yielded TLR2 down regulation in Caco-2/TC7 cells. Finally, results from in vivo showed an augmented intestinal SERT expression in mice Tlr2-/-, thus confirming our inhibitory effect of TLR2 on intestinal SERT in vitro. The present work infers that TLR2 may act in intestinal pathophysiology, not only by its inherent innate immune role, but also by regulating the intestinal serotoninergic system.

Intestinal Serotonin Transporter Inhibition by Toll-Like Receptor 2 Activation. A Feedback Modulation

PubMed Central

Layunta, Elena; Grasa, Laura; Castro, Marta; Pardo, Julián; Gomollón, Fernando; Mesonero, José E.

2016-01-01

TLR2 is a microbiota recognition receptor that has been described to contribute to intestinal homeostasis and to ameliorate inflammatory intestinal injury. In this context, serotonin (5-HT) has shown to be an essential intestinal physiological neuromodulator that is also involved in intestinal inflammatory diseases. Since the interaction between TLR2 activation and the intestinal serotoninergic system remains non-investigated, our main aim was to analyze the effect of TLR2 on intestinal serotonin transporter (SERT) activity and expression and the intracellular pathways involved. Caco-2/TC7 cells were used to analyze SERT and TLR2 molecular expression and SERT activity by measuring 5-HT uptake. The results showed that apical TLR2 activation inhibits SERT activity in Caco-2/TC7 cells mainly by reducing SERT protein level either in the plasma membrane, after short-term TLR2 activation or in both the plasma membrane and cell lysate, after long-term activation. cAMP/PKA pathway appears to mediate short-term inhibitory effect of TLR2 on SERT; however, p38 MAPK pathway has been shown to be involved in both short- and long-term TLR2 effect. Reciprocally, 5-HT long-term treatment yielded TLR2 down regulation in Caco-2/TC7 cells. Finally, results from in vivo showed an augmented intestinal SERT expression in mice Tlr2-/-, thus confirming our inhibitory effect of TLR2 on intestinal SERT in vitro. The present work infers that TLR2 may act in intestinal pathophysiology, not only by its inherent innate immune role, but also by regulating the intestinal serotoninergic system. PMID:28033388

Long-term physiological alterations and recovery in a mouse model of separation associated with time-restricted feeding: a tool to study anorexia nervosa related consequences.

PubMed

Zgheib, Sara; Méquinion, Mathieu; Lucas, Stéphanie; Leterme, Damien; Ghali, Olfa; Tolle, Virginie; Zizzari, Philippe; Bellefontaine, Nicole; Legroux-Gérot, Isabelle; Hardouin, Pierre; Broux, Odile; Viltart, Odile; Chauveau, Christophe

2014-01-01

Anorexia nervosa is a primary psychiatric disorder, with non-negligible rates of mortality and morbidity. Some of the related alterations could participate in a vicious cycle limiting the recovery. Animal models mimicking various physiological alterations related to anorexia nervosa are necessary to provide better strategies of treatment. To explore physiological alterations and recovery in a long-term mouse model mimicking numerous consequences of severe anorexia nervosa. C57Bl/6 female mice were submitted to a separation-based anorexia protocol combining separation and time-restricted feeding for 10 weeks. Thereafter, mice were housed in standard conditions for 10 weeks. Body weight, food intake, body composition, plasma levels of leptin, adiponectin, IGF-1, blood levels of GH, reproductive function and glucose tolerance were followed. Gene expression of several markers of lipid and energy metabolism was assayed in adipose tissues. Mimicking what is observed in anorexia nervosa patients, and despite a food intake close to that of control mice, separation-based anorexia mice displayed marked alterations in body weight, fat mass, lean mass, bone mass acquisition, reproductive function, GH/IGF-1 axis, and leptinemia. mRNA levels of markers of lipogenesis, lipolysis, and the brown-like adipocyte lineage in subcutaneous adipose tissue were also changed. All these alterations were corrected during the recovery phase, except for the hypoleptinemia that persisted despite the full recovery of fat mass. This study strongly supports the separation-based anorexia protocol as a valuable model of long-term negative energy balance state that closely mimics various symptoms observed in anorexia nervosa, including metabolic adaptations. Interestingly, during a recovery phase, mice showed a high capacity to normalize these parameters with the exception of plasma leptin levels. It will be interesting therefore to explore further the central and peripheral effects of the uncorrected hypoleptinemia during recovery from separation-based anorexia.

Mechanical characterization and numerical simulation of a subcutaneous implantable 3D printed cell encapsulation system.

PubMed

Adamo, Federica; Farina, Marco; Thekkedath, Usha R; Grattoni, Alessandro; Sesana, Raffaella

2018-06-01

Cell transplantation in bioengineered scaffolds and encapsulation systems has shown great promise in regenerative medicine. Depending on the site of implantation, type of cells and their expected function, these systems are designed to provide cells with a physiological-like environment while providing mechanical support and promoting long-term viability and function of the graft. A minimally invasive 3D printed system termed neovascularized implantable cell homing and encapsulation (NICHE) was developed in polylactic acid for subcutaneous transplantation of endocrine cells, including pancreatic islets. The suitability of the NICHE for long term in vivo deployment is investigated by assessing mechanical behavior of both fresh devices under simulated subcutaneous conditions and NICHE retrieved from subcutaneous implantation in pigs. Both experimental and numerical studies were performed with a focus on validating the constitutive material model used in the numerical analysis for accuracy and reliability. Notably, homogeneous isotropic constitutive material model calibrated by means of uniaxial testing well suited experimental results. The results highlight the long term durability for in vivo applications and the potential applicability of the model to predict the mechanical behavior of similar devices in various physiological settings. Copyright © 2018 Elsevier Ltd. All rights reserved.

CB1 receptors in the formation of the different phases of memory-related processes in the inhibitory avoidance test in mice.

PubMed

Kruk-Slomka, Marta; Biala, Grażyna

2016-03-15

The endocannabinoid system, through the cannabinoid type 1 (CB1) and 2 (CB2) receptors modulates many physiological functions, including different aspects of memory-related processes. The aim of the present experiments was to explore the role of the endocannabinoid system, through CB1 receptors in the different stages of short-term (acquisition, retention and retrieval) and long-term (acquisition, consolidation and retrieval) memory-related responses, using the inhibitory avoidance (IA) test in mice. Our results revealed that an acute injection of oleamide (10 and 20mg/kg), a CB1 receptor agonist, impairs the short-term or/and long-term acquisition, retention/consolidation, retrieval memory and learning processes in the IA test in mice. In turn, in this test an acute injection of AM 251 (1 and 3mg/kg), a CB1 receptor antagonist, improves the short-term or/and long-term memory stages, described above. Moreover, this memory impairment induced by effective dose of oleamide (20mg/kg) is reversed by non-effective dose of AM 251 (0.25mg/kg) in the IA task, which proves the selectivity of oleamide to CB1 receptors and confirms that the CB1 receptor-related mechanism is one of the possible mechanisms, responsible for memory and learning responses. Obtained results provide clear evidence that the endocannabinoid system, through CB1 receptors, participates in the different stages of short- and long-term memory-related behavior. This knowledge may open in the future new possibilities for the development of CB-based therapies, especially for memory impairment human disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluating the Clinical and Physiological Effects of Long Term Ultraviolet B Radiation on Guinea Pigs (Cavia porcellus)

PubMed Central

Watson, Megan K.; Stern, Adam W.; Labelle, Amber L.; Joslyn, Stephen; Fan, Timothy M.; Leister, Katie; Kohles, Micah; Marshall, Kemba; Mitchell, Mark A.

2014-01-01

Vitamin D is an important hormone in vertebrates. Most animals acquire this hormone through their diet, secondary to exposure to ultraviolet B (UVB) radiation, or a combination thereof. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on guinea pigs (Cavia porcellus) and to evaluate the long-term safety of artificial UVB light supplementation over the course of six months. Twelve juvenile acromelanic Hartley guinea pigs were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received only ambient fluorescent light for 12 hours daily. Animals in both groups were offered the same diet and housed under the same conditions. Blood samples were collected every three weeks to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations, computed tomography scans, and dual energy x-ray absorptiometry scans were performed during the course of the study. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly in the guinea pigs (p<0.0001) between the UVB supplementation group (101.49±21.81 nmol/L) and the control group (36.33±24.42 nmol/L). An increased corneal thickness in both eyes was also found in the UVB supplementation compared to the control group (right eye [OD]: p<0.0001; left eye [OS]: p<0.0001). There were no apparent negative clinical or pathologic side effects noted between the groups. This study found that exposing guinea pigs to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, and that this increase was sustainable over time. Providing guinea pigs exposure to UVB may be an important husbandry consideration that is not currently recommended. PMID:25517408

Individual styles of professional operator's performance for the needs of interplanetary mission.

NASA Astrophysics Data System (ADS)

Boritko, Yaroslav; Gushin, Vadim; Zavalko, Irina; Smoleevskiy, Alexandr; Dudukin, Alexandr

Maintenance of the cosmonaut’s professional performance reliability is one of the priorities of long-term space flights safety. Cosmonaut’s performance during long-term space flight decreases due to combination of the microgravity effects and inevitable degradation of skills during prolonged breaks in training. Therefore, the objective of the elaboration of countermeasures against skill decrement is very relevant. During the experiment with prolonged isolation "Mars-500" in IMBP two virtual models of professional operator’s activities were used to investigate the influence of extended isolation, monotony and confinement on professional skills degradation. One is well-known “PILOT-1” (docking to the space station), another - "VIRTU" (manned operations of planet exploration). Individual resistance to the artificial sensory conflict was estimated using computerized version of “Mirror koordinograf” with GSR registration. Two different individual performance styles, referring to the different types of response to stress, have been identified. Individual performance style, called "conservative control", manifested in permanent control of parameters, conditions and results of the operator’s activity. Operators with this performance style demonstrate high reliability in performing tasks. The drawback of the style is intensive resource expenditure - both the operator (physiological "cost") and the technical system operated (fuel, time). This style is more efficient while executing tasks that require long work with high reliability required according to a detailed protocol, such as orbital flight. Individual style, called "exploratory ", manifested in the search of new ways of task fulfillment. This style is accompanied by partial, periodic lack of control of the conditions and result of operator’s activity due to flexible approach to the tasks perfect implementation. Operators spent less resource (fuel, time, lower physiological "cost") due to high self-regulation in tasks not requiring high reliability. "Exploratory" style is more effective when working in nonregulated and off-nominal situations, such as interplanetary mission, due to possibility to use nonstandard innovative solutions, save physiological resources and rapidly mobilize to demonstrate high reliability at key moments.

Awake, long-term intranasal insulin treatment does not affect object memory, odor discrimination, or reversal learning in mice

PubMed Central

Bell, Genevieve A.; Fadool, Debra Ann

2017-01-01

Intranasal insulin delivery is currently being used in clinical trials to test for improvement in human memory and cognition, and in particular, for lessening memory loss attributed to neurodegenerative diseases. Studies have reported the effects of short-term intranasal insulin treatment on various behaviors, but less have examined long-term effects. The olfactory bulb contains the highest density of insulin receptors in conjunction with the highest level of insulin transport within the brain. Previous research from our laboratory has demonstrated that acute insulin intranasal delivery (IND) enhanced both short- and long-term memory as well as increased two-odor discrimination in a two-choice paradigm. Herein, we investigated the behavioral and physiological effects of chronic insulin IND. Adult, male C57BL6/J mice were intranasally treated with 5 μg/μl of insulin twice daily for 30 and 60 days. Metabolic assessment indicated no change in body weight, caloric intake, or energy expenditure following chronic insulin IND, but an increase in the frequency of meal bouts selectively in the dark cycle. Unlike acute insulin IND, which has been shown to cause enhanced performance in odor habituation/dishabituation and two-odor discrimination tasks in mice, chronic insulin IND did not enhance olfactometry-based odorant discrimination or olfactory reversal learning. In an object memory recognition task, insulin IND-treated mice performed no different from controls regardless of task duration. Biochemical analyses of the olfactory bulb revealed a modest 1.3X increase in IR kinase phosphorylation but no significant increase in Kv1.3 phosphorylation. Substrate phosphorylation of IR Kinase downstream effectors (MAPK/ERK and Akt signaling) proved to be highly variable. These data indicate that chronic administration of insulin IND in mice fails to enhance olfactory ability, object memory recognition, or a majority of systems physiology metabolic factors – as reported to elicit a modulatory effect with acute administration. This leads to two alternative interpretations regarding long-term insulin IND in mice: 1) It causes an initial stage of insulin resistance to dampen the behaviors that would normally be modulated under acute insulin IND, but ability to clear a glucose challenge is still retained, or 2) There is a lack of behavioral modulation at high concentration of insulin attributed to the twice daily intervals of hyperinsulinemia caused by insulin IND administration without any insulin resistance, per se. PMID:28259806

Awake, long-term intranasal insulin treatment does not affect object memory, odor discrimination, or reversal learning in mice.

PubMed

Bell, Genevieve A; Fadool, Debra Ann

2017-05-15

Intranasal insulin delivery is currently being used in clinical trials to test for improvement in human memory and cognition, and in particular, for lessening memory loss attributed to neurodegenerative diseases. Studies have reported the effects of short-term intranasal insulin treatment on various behaviors, but less have examined long-term effects. The olfactory bulb contains the highest density of insulin receptors in conjunction with the highest level of insulin transport within the brain. Previous research from our laboratory has demonstrated that acute insulin intranasal delivery (IND) enhanced both short- and long-term memory as well as increased two-odor discrimination in a two-choice paradigm. Herein, we investigated the behavioral and physiological effects of chronic insulin IND. Adult, male C57BL6/J mice were intranasally treated with 5μg/μl of insulin twice daily for 30 and 60days. Metabolic assessment indicated no change in body weight, caloric intake, or energy expenditure following chronic insulin IND, but an increase in the frequency of meal bouts selectively in the dark cycle. Unlike acute insulin IND, which has been shown to cause enhanced performance in odor habituation/dishabituation and two-odor discrimination tasks in mice, chronic insulin IND did not enhance olfactometry-based odorant discrimination or olfactory reversal learning. In an object memory recognition task, insulin IND-treated mice did not perform differently than controls, regardless of task duration. Biochemical analyses of the olfactory bulb revealed a modest 1.3 fold increase in IR kinase phosphorylation but no significant increase in Kv1.3 phosphorylation. Substrate phosphorylation of IR kinase downstream effectors (MAPK/ERK and Akt signaling) proved to be highly variable. These data indicate that chronic administration of insulin IND in mice fails to enhance olfactory ability, object memory recognition, or a majority of systems physiology metabolic factors - as reported to elicit a modulatory effect with acute administration. This leads to two alternative interpretations regarding long-term insulin IND in mice: 1) It causes an initial stage of insulin resistance to dampen the behaviors that would normally be modulated under acute insulin IND, but ability to clear a glucose challenge is still retained, or 2) There is a lack of behavioral modulation at high concentration of insulin attributed to the twice daily intervals of hyperinsulinemia caused by insulin IND administration without any insulin resistance, per se. Copyright © 2017 Elsevier Inc. All rights reserved.

New reasons and new ways to study birth physiology.

PubMed

Odent, M

2001-11-01

The age of cesarean sections on request, epidurals and drips of oxytocin is a turning point in the history of childbirth. Until recently women could not give birth without releasing a complex cocktail of 'love hormones'. Today, in many countries, most women have babies without releasing these specific hormones. The questions must be raised in terms of civilization. This turning point occurs at the very time when several scientific disciplines suggest that the way human beings are born has long-term consequences, particularly in terms of sociability, aggressiveness or, in other words, 'capacity to love'. I find it relevant to combine data provided by perspectives as diverse as ethology, animal experiments, studies of the behavioral effects of hormones that fluctuate in the perinatal period, and a branch of epidemiology I call 'Primal Health Research'. This combination of data offers new reasons to disturb the physiological processes as little as possible. We are also at a time when a physiological approach can help to rediscover the basic needs of women in labor. These women firstly need to be protected against any sort of neocortical stimulation. We must keep in mind what the main stimuli of neocortical activity are: language, bright lights, the 'feeling of being observed' and situations associated with a release of catecholamines.

New reasons and new ways to study birth physiology.

PubMed

Odent, M

2001-11-01

The age of cesarean sections on request, epidurals and drips of oxytocin is a turning point in the history of childbirth. Until recently women could not give birth without releasing a complex cocktail of 'love hormones'. Today, in many countries, most women have babies without releasing these specific hormones. The questions must be raised in terms of civilization. This turning point occurs at the very time when several scientific disciplines suggest that the way human beings are born has long-term consequences, particularly in terms of sociability, aggressiveness or, in other words, 'capacity to love'. I find it relevant to combine data provided by perspectives as diverse as ethology, animal experiments, studies of the behavioral effects of hormones that fluctuate in the perinatal period, and a branch of epidemiology I call 'Primal Health Research'. This combination of data offers new reasons to disturb the physiological processes as little as possible. We are also at a time when a physiological approach can help to rediscover the basic needs of women in labor. These women firstly need to be protected against any sort of neocortical stimulation. We must keep in mind what the main stimuli of neocortical activity are: language, bright lights, the 'feeling of being observed' and situations associated with a release of catecholamines. © 2001 International Federation of Gynecology and Obstetrics.

Fostering improved anatomy and physiology instructor pedagogy.

PubMed

Mattheis, Allison; Jensen, Murray

2014-12-01

Despite widespread calls for reform in undergraduate science, technology, engineering, and mathematics education, effecting lasting change in instructor practice is challenging to achieve. This article describes the results of a 2-yr research study that involved efforts to develop the pedagogical expertise of a group of anatomy and physiology instructors at the college level. Data were collected through a series of individual interviews that included the use of the Teacher Beliefs Inventory questionnaire (23) along with observations onsite in participants' college classrooms and at process-oriented guided inquiry learning (POGIL) curriculum writing workshops. Findings indicated attitudinal shifts on the part of participants from teacher-centered to more student-centered pedagogy and supported the benefits of long-term professional development for instructors. Here, we documented the successful progress of these professors as they participated in a curriculum development process that emphasized student-centered teaching with the goal of promoting broader change efforts in introductory anatomy and physiology. Copyright © 2014 The American Physiological Society.

Remote sensing of fire severity: linking post-fire reflectance data with physiological responses in two western conifer species

NASA Astrophysics Data System (ADS)

Sparks, A. M.; Smith, A. M.; Kolden, C.; Apostol, K. G.; Boschetti, L.

2014-12-01

Fire is a common disturbance in forested ecosystems in the western U.S. and can be responsible for long-term impacts on vegetation and soil. An improved understanding of how ecosystems recover after fire is necessary so that land managers can plan for and mitigate the effects of these disturbances. Although several studies have attempted to link fire intensity with severity, direct links between spectral indices of severity and key physiological changes in vegetation are not well understood. We conducted an assessment of how two western conifer species respond to four fire radiative energy treatments, with spectra acquired pre- and up to a month post-burn. After transforming the spectral data into Landsat 8 equivalent reflectance, burn severity indices commonly used in the remote sensing community were compared to concurrent physiological measurements including gas exchange and photosynthetic rate. Preliminary results indicate significant relationships between several fire severity indices and physiological responses measured in the conifer seedlings.

Stability enhancement of an atomic force microscope for long-term force measurement including cantilever modification for whole cell deformation

NASA Astrophysics Data System (ADS)

Weafer, P. P.; McGarry, J. P.; van Es, M. H.; Kilpatrick, J. I.; Ronan, W.; Nolan, D. R.; Jarvis, S. P.

2012-09-01

Atomic force microscopy (AFM) is widely used in the study of both morphology and mechanical properties of living cells under physiologically relevant conditions. However, quantitative experiments on timescales of minutes to hours are generally limited by thermal drift in the instrument, particularly in the vertical (z) direction. In addition, we demonstrate the necessity to remove all air-liquid interfaces within the system for measurements in liquid environments, which may otherwise result in perturbations in the measured deflection. These effects severely limit the use of AFM as a practical tool for the study of long-term cell behavior, where precise knowledge of the tip-sample distance is a crucial requirement. Here we present a readily implementable, cost effective method of minimizing z-drift and liquid instabilities by utilizing active temperature control combined with a customized fluid cell system. Long-term whole cell mechanical measurements were performed using this stabilized AFM by attaching a large sphere to a cantilever in order to approximate a parallel plate system. An extensive examination of the effects of sphere attachment on AFM data is presented. Profiling of cantilever bending during substrate indentation revealed that the optical lever assumption of free ended cantilevering is inappropriate when sphere constraining occurs, which applies an additional torque to the cantilevers "free" end. Here we present the steps required to accurately determine force-indentation measurements for such a scenario. Combining these readily implementable modifications, we demonstrate the ability to investigate long-term whole cell mechanics by performing strain controlled cyclic deformation of single osteoblasts.

Exposure to buffer solution alters tendon hydration and mechanics.

PubMed

Safa, Babak N; Meadows, Kyle D; Szczesny, Spencer E; Elliott, Dawn M

2017-08-16

A buffer solution is often used to maintain tissue hydration during mechanical testing. The most commonly used buffer solution is a physiological concentration of phosphate buffered saline (PBS); however, PBS increases the tissue's water content and decreases its tensile stiffness. In addition, solutes from the buffer can diffuse into the tissue and interact with its structure and mechanics. These bathing solution effects can confound the outcome and interpretation of mechanical tests. Potential bathing solution artifacts, including solute diffusion, and their effect on mechanical properties, are not well understood. The objective of this study was to measure the effects of long-term exposure of rat tail tendon fascicles to several concentrations (0.9-25%) of NaCl, sucrose, polyethylene glycol (PEG), and SPEG (NaCl+PEG) solutions on water content, solute diffusion, and mechanical properties. We found that with an increase in solute concentration the apparent water content decreased for all solution types. Solutes diffused into the tissue for NaCl and sucrose, however, no solute diffusion was observed for PEG or SPEG. The mechanical properties changed for both NaCl solutions, in particular after long-term (8h) incubation the modulus and equilibrium stress decreased compared to short-term (15min) for 25% NaCl, and the cross sectional area increased for 0.9% NaCl. However, the mechanical properties were unchanged for both PEG and SPEG except for minor alterations in stress relaxation parameters. This study shows that NaCl and sucrose buffer solutions are not suitable for long-term mechanical tests. We therefore propose using PEG or SPEG as alternative buffer solutions that after long-term incubation can maintain tissue hydration without solute diffusion and produce a consistent mechanical response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physiological advantages of dwarfing in surviving extinctions in high-CO2 oceans

NASA Astrophysics Data System (ADS)

Garilli, Vittorio; Rodolfo-Metalpa, Riccardo; Scuderi, Danilo; Brusca, Lorenzo; Parrinello, Daniela; Rastrick, Samuel P. S.; Foggo, Andy; Twitchett, Richard J.; Hall-Spencer, Jason M.; Milazzo, Marco

2015-07-01

Excessive CO2 in the present-day ocean-atmosphere system is causing ocean acidification, and is likely to cause a severe biodiversity decline in the future, mirroring effects in many past mass extinctions. Fossil records demonstrate that organisms surviving such events were often smaller than those before, a phenomenon called the Lilliput effect. Here, we show that two gastropod species adapted to acidified seawater at shallow-water CO2 seeps were smaller than those found in normal pH conditions and had higher mass-specific energy consumption but significantly lower whole-animal metabolic energy demand. These physiological changes allowed the animals to maintain calcification and to partially repair shell dissolution. These observations of the long-term chronic effects of increased CO2 levels forewarn of changes we can expect in marine ecosystems as CO2 emissions continue to rise unchecked, and support the hypothesis that ocean acidification contributed to past extinction events. The ability to adapt through dwarfing can confer physiological advantages as the rate of CO2 emissions continues to increase.

Zinc induces long-term upregulation of T-type calcium current in hippocampal neurons in vivo.

PubMed

Ekstein, Dana; Benninger, Felix; Daninos, Moshe; Pitsch, Julika; van Loo, Karen M J; Becker, Albert J; Yaari, Yoel

2012-11-15

Extracellular zinc can induce numerous acute and persistent physiological and toxic effects in neurons by acting at their plasma membrane or intracellularly following permeation or uptake into them. Zinc acutely and reversibly blocks T-type voltage-gated calcium current (I(CaT)), but the long-term effect of zinc on this current has not been studied. Because chemically induced status epilepticus (SE) results in the release of zinc into the extracellular space, as well as in a long-lasting increase in I(CaT) in CA1 pyramidal cells, we hypothesized that zinc may play a causative role in I(CaT) upregulation. We tested this hypothesis by monitoring for 18 days the effects of zinc and ibotenic acid (a neurotoxic agent serving as control for zinc), injected into the right lateral ventricle, on I(CaT) in rat CA1 pyramidal cells. Both zinc and ibotenic acid caused marked hippocampal lesions on the side of injection, but only minor damage to contralateral hippocampi. Zinc, but not ibotenic acid, caused upregulation of a nickel-sensitive I(CaT) in a subset of contralateral CA1 pyramidal cells, appearing 2 days after injection and lasting for about 2 weeks thereafter. In contrast, acute application of zinc to CA1 pyramidal cells promptly blocked I(CaT). These data indicate that extracellular zinc has a dual effect on I(CaT), blocking it acutely while causing its long-term upregulation. Through the latter effect, zinc may regulate the intrinsic excitability of principal neurons, particularly in pathological conditions associated with enhanced release of zinc, such as SE.

Century long assessment of herbaceous plants' physiological responses to climate change in Switzerland

NASA Astrophysics Data System (ADS)

Moreno-Gutierrez, Cristina; Kahmen, Ansgar

2017-04-01

The isotopic analysis of archived plant material offers the exceptional opportunity to reconstruct the physiological activity of plants over long time periods and thus, to assess plant responses to environmental changes during the last centuries. In addition, the stable isotope analysis of herbarium samples offers the opportunity to reconstruct the physiological processes of a large range of different plant species and from different environments. Interestingly, only few studies have to date assessed these archives. We will present a novel analysis of leaf nitrogen, oxygen and carbon isotope ratios of more than a thousand herbarium specimens collected since 1800 until present from the unique herbaria hold at the University of Basel. The objective of our study was to assess century-long physiological responses of herbaceous plant species from different plant functional groups and along an altitudinal gradient in Switzerland. The goal of our study was to determine with our investigations the long-term responses of plants to climate change. Such investigations are important as they allow to assess long-term processes of acclimation and adaptation in plants to global enviromental change. In our study we found that herbaceous plants have increased their intrinsic water use efficiency in response to increasing atmospheric CO2 concentration but this increment was higher in plants from higher altitudes, due to the higher efficiency of CO2 assimilation of alpine plants compared to plants from lowlands. There were also differences among functional groups, with grasses and forbs showing the highest increments. In addition, herbaceous plants showed a decreasing trend with time in their N isotopic composition, which may indicate progressive N limitation due to higher biological activity with increasing atmospheric CO2 concentration.

Prior exposure to capture heightens the corticosterone and behavioural responses of little penguins (Eudyptula minor) to acute stress

PubMed Central

Carroll, Gemma; Turner, Emma; Dann, Peter; Harcourt, Rob

2016-01-01

Studies of physiology can provide important insight into how animals are coping with challenges in their environment and can signal the potential effects of exposure to human activity in both the short and long term. In this study, we measured the physiological and behavioural response of little penguins (Eudyptula minor) that were naïve to human activity over 30 min of capture and handling. We assessed relationships between corticosterone secretion, behaviour, sex and time of day in order to characterize the determinants of the natural stress response. We then compared the response of these naïve penguins with the responses of female little penguins that had been exposed to research activity (bimonthly nest check and weighing) and to both research activity (monthly nest check and weighing) and evening viewing by tourists. We found that corticosterone concentrations increased significantly over 30 min of capture, with naïve penguins demonstrating a more acute stress response during the day than at night. Penguins that had previously been exposed to handling at the research and research/visitor sites showed elevated corticosterone concentrations and consistently more aggressive behaviour after 30 min compared with naïve birds, although there were no significant differences in baseline corticosterone concentrations. Our findings demonstrate that these little penguins have not habituated to routine capture, but rather mount a heightened physiological and behavioural response to handling by humans. Less invasive research monitoring techniques, such as individual identification with PIT tags and automatic recording and weighing, and a reduction in handling during the day should be considered to mitigate some of the potentially negative effects of disturbance. Given the paucity of data on the long-term consequences of heightened stress on animal physiology, our study highlights the need for further investigation of the relationship between the corticosterone stress response and fitness outcomes, such as breeding success and survival. PMID:27293742

Prior exposure to capture heightens the corticosterone and behavioural responses of little penguins (Eudyptula minor) to acute stress.

PubMed

Carroll, Gemma; Turner, Emma; Dann, Peter; Harcourt, Rob

2016-01-01

Studies of physiology can provide important insight into how animals are coping with challenges in their environment and can signal the potential effects of exposure to human activity in both the short and long term. In this study, we measured the physiological and behavioural response of little penguins (Eudyptula minor) that were naïve to human activity over 30 min of capture and handling. We assessed relationships between corticosterone secretion, behaviour, sex and time of day in order to characterize the determinants of the natural stress response. We then compared the response of these naïve penguins with the responses of female little penguins that had been exposed to research activity (bimonthly nest check and weighing) and to both research activity (monthly nest check and weighing) and evening viewing by tourists. We found that corticosterone concentrations increased significantly over 30 min of capture, with naïve penguins demonstrating a more acute stress response during the day than at night. Penguins that had previously been exposed to handling at the research and research/visitor sites showed elevated corticosterone concentrations and consistently more aggressive behaviour after 30 min compared with naïve birds, although there were no significant differences in baseline corticosterone concentrations. Our findings demonstrate that these little penguins have not habituated to routine capture, but rather mount a heightened physiological and behavioural response to handling by humans. Less invasive research monitoring techniques, such as individual identification with PIT tags and automatic recording and weighing, and a reduction in handling during the day should be considered to mitigate some of the potentially negative effects of disturbance. Given the paucity of data on the long-term consequences of heightened stress on animal physiology, our study highlights the need for further investigation of the relationship between the corticosterone stress response and fitness outcomes, such as breeding success and survival.

In Situ Live-Cell Nucleus Fluorescence Labeling with Bioinspired Fluorescent Probes.

PubMed

Ding, Pan; Wang, Houyu; Song, Bin; Ji, Xiaoyuan; Su, Yuanyuan; He, Yao

2017-08-01

Fluorescent imaging techniques for visualization of nuclear structure and function in live cells are fundamentally important for exploring major cellular events. The ideal cellular labeling method is capable of realizing label-free, in situ, real-time, and long-term nucleus labeling in live cells, which can fully obtain the nucleus-relative information and effectively alleviate negative effects of alien probes on cellular metabolism. However, current established fluorescent probes-based strategies (e.g., fluorescent proteins-, organic dyes-, fluorescent organic/inorganic nanoparticles-based imaging techniques) are unable to simultaneously realize label-free, in situ, long-term, and real-time nucleus labeling, resulting in inevitable difficulties in fully visualizing nuclear structure and function in live cells. To this end, we present a type of bioinspired fluorescent probes, which are highly efficacious for in situ and label-free tracking of nucleus in long-term and real-time manners. Typically, the bioinspired polydopamine (PDA) nanoparticles, served as fluorescent probes, can be readily synthesized in situ within live cell nucleus without any further modifications under physiological conditions (37 °C, pH ∼7.4). Compared with other conventional nuclear dyes (e.g., propidium iodide (PI), Hoechst), superior spectroscopic properties (e.g., quantum yield of ∼35.8% and high photostability) and low cytotoxicity of PDA-based probes enable long-term (e.g., 3 h) fluorescence tracking of nucleus. We also demonstrate the generality of this type of bioinspired fluorescent probes in different cell lines and complex biological samples.

Endogenous 17β-estradiol is required for activity-dependent long-term potentiation in the striatum: interaction with the dopaminergic system

PubMed Central

Tozzi, Alessandro; de Iure, Antonio; Tantucci, Michela; Durante, Valentina; Quiroga-Varela, Ana; Giampà, Carmela; Di Mauro, Michela; Mazzocchetti, Petra; Costa, Cinzia; Di Filippo, Massimiliano; Grassi, Silvarosa; Pettorossi, Vito Enrico; Calabresi, Paolo

2015-01-01

17β-estradiol (E2), a neurosteroid synthesized by P450-aromatase (ARO), modulates various brain functions. We characterized the role of the locally synthesized E2 on striatal long-term synaptic plasticity and explored possible interactions between E2 receptors (ERs) and dopamine (DA) receptors in the dorsal striatum of adult male rats. Inhibition of E2 synthesis or antagonism of ERs prevented the induction of long-term potentiation (LTP) in both medium spiny neurons (MSNs) and cholinergic interneurons (ChIs). Activation of a D1-like DA receptor/cAMP/PKA-dependent pathway restored LTP. In MSNs exogenous E2 reversed the effect of ARO inhibition. Also antagonism of M1 muscarinic receptors prevented the D1-like receptor-mediated restoration of LTP confirming a role for ChIs in controlling the E2-mediated LTP of MSNs. A novel striatal interaction, occurring between ERs and D1-like receptors in both MSNs and ChIs, might be critical to regulate basal ganglia physiology and to compensate synaptic alterations in Parkinson’s disease. PMID:26074768

Endogenous 17β-estradiol is required for activity-dependent long-term potentiation in the striatum: interaction with the dopaminergic system.

PubMed

Tozzi, Alessandro; de Iure, Antonio; Tantucci, Michela; Durante, Valentina; Quiroga-Varela, Ana; Giampà, Carmela; Di Mauro, Michela; Mazzocchetti, Petra; Costa, Cinzia; Di Filippo, Massimiliano; Grassi, Silvarosa; Pettorossi, Vito Enrico; Calabresi, Paolo

2015-01-01

17β-estradiol (E2), a neurosteroid synthesized by P450-aromatase (ARO), modulates various brain functions. We characterized the role of the locally synthesized E2 on striatal long-term synaptic plasticity and explored possible interactions between E2 receptors (ERs) and dopamine (DA) receptors in the dorsal striatum of adult male rats. Inhibition of E2 synthesis or antagonism of ERs prevented the induction of long-term potentiation (LTP) in both medium spiny neurons (MSNs) and cholinergic interneurons (ChIs). Activation of a D1-like DA receptor/cAMP/PKA-dependent pathway restored LTP. In MSNs exogenous E2 reversed the effect of ARO inhibition. Also antagonism of M1 muscarinic receptors prevented the D1-like receptor-mediated restoration of LTP confirming a role for ChIs in controlling the E2-mediated LTP of MSNs. A novel striatal interaction, occurring between ERs and D1-like receptors in both MSNs and ChIs, might be critical to regulate basal ganglia physiology and to compensate synaptic alterations in Parkinson's disease.

Long-term nicotine exposure dampens LPS-induced nerve-mediated airway hyperreactivity in murine airways.

PubMed

Xu, Yuan; Cardell, Lars-Olaf

2017-09-01

Nicotine is a major component of cigarette smoke. It causes addiction and is used clinically to aid smoke cessation. The aim of the present study is to investigate the effect of nicotine on lipopolysaccharide (LPS)-induced airway hyperreactivity (AHR) and to explore the potential involvement of neuronal mechanisms behind nicotine's effects in murine models in vivo and in vitro. BALB/c mice were exposed to nicotine in vivo via subcutaneous Alzet osmotic minipumps containing nicotine tartate salt solution (24 mg·kg -1 ·day -1 ) for 28 days. LPS (0.1 mg/ml, 20 µl) was administered intranasally for 3 consecutive days during the end of this period. Lung functions were measured with flexiVent. For the in vitro experiments, mice tracheae were organcultured with either nicotine (10 μM) or vehicle (DMSO, 0.1%) for 4 days. Contractile responses of the tracheal segments were measured in myographs following electric field stimulation (EFS; increasing frequencies of 0.2 to 12.8 Hz) before and after incubation with 10 µg/ml LPS for 1 h. Results showed that LPS induced AHR to methacholine in vivo and increased contractile responses to EFS in vitro. Interestingly, long-term nicotine exposure markedly dampened this LPS-induced AHR both in vitro and in vivo. Tetrodotoxin (TTX) inhibited LPS-induced AHR but did not further inhibit nicotine-suppressed AHR in vivo. In conclusion, long-term nicotine exposure dampened LPS-induced AHR. The effect of nicotine was mimicked by TTX, suggesting the involvement of neuronal mechanisms. This information might be used for evaluating the long-term effects of nicotine and further exploring of how tobacco products interact with bacterial airway infections. Copyright © 2017 the American Physiological Society.

Early caregiving and physiological stress responses.

PubMed

Luecken, Linda J; Lemery, Kathryn S

2004-05-01

Inadequate early caregiving has been associated with risks of stress-related psychological and physical illness over the life span. Dysregulated physiological stress responses may represent a mechanism linking early caregiving to health outcomes. This paper reviews evidence linking early caregiving to physiological responses that can increase vulnerability to stress-related illness. A number of high-risk family characteristics, including high conflict, divorce, abuse, and parental psychopathology, are considered in the development of stress vulnerability. Three theoretical pathways linking caregiving to physiological stress responses are outlined: genetic, psychosocial, and cognitive-affective. Exciting preliminary evidence suggests that early caregiving can impact long-term physiological stress responses. Directions for future research in this area are suggested.

Salivary α-amylase and cortisol after exercise in menopause: influence of long-term HRT.

PubMed

Patacchioli, F R; Ghiciuc, C M; Bernardi, M; Dima-Cozma, L C; Fattorini, L; Squeo, M R; Galoppi, P; Brunelli, R; Ferrante, F; Pasquali, V; Perrone, G

2015-01-01

This observational prospective study analyzed the effect of an incremental cardiopulmonary exercise test (CPET) on the secretion of salivary biomarkers of the adrenergic nervous system and hypothalamus-pituitary-adrenal (HPA) axis activity by measuring salivary α-amylase and cortisol diurnal trajectories in the setting of long-term hormone replacement therapy (HRT). Fifteen healthy sedentary postmenopausal women who were current HRT users and 15 women who had never used HRT were consecutively recruited. α-Amylase and cortisol were measured in salivary samples collected on the CPET day and on a rest day. Cardiovascular and respiratory fitness parameters were recorded during the CPET challenge. The participants had very homogeneous somatic characteristics, and they were all in generally good health. The postmenopausal never-HRT users presented an abnormal diurnal pattern of α-amylase at baseline and a flattened response to CPET. In contrast, women on HRT had a physiological α-amylase diurnal pattern and increased salivary α-amylase production during the CPET-induced challenge. The CPET challenge physiologically activated the HPA axis activity, as shown by the increase in the concentration of salivary cortisol during the effort test. HPA axis activity was not affected by long-term HRT. Postmenopausal women using HRT exhibited a cardiorespiratory functional capacity that was significantly (p < 0.05) higher than that of non-users. Our findings show that healthy postmenopausal women present an asymmetry between adrenergic nervous system and HPA axis activities under both basal and stress conditions. HRT was able to modify the abnormal adrenergic nervous system activity, most likely by reducing the sympathetic hyperactivity that characterizes menopause.

Stress Hormones and their Regulation in a Captive Dolphin Population

DTIC Science & Technology

2015-09-30

dorian.houser@nmmf.org Award Number: N000141310770 http://www.nmmf.org/ physiology --ecology.html LONG-TERM GOALS The Navy requires an understanding...establish protocols for improved sensitivity of low-level corticosteroids (cortisol and aldosterone ) frequenctly observed in cetaceans; (2) determine the...assessing baseline variability in stress hormones and 2) evaluating physiological and metabolic alterations that occur during stress. This grant

Does tachyphylaxis occur in long-term management of scalp seborrheic dermatitis with pyrithione zinc-based treatments?

PubMed

Schwartz, James R; Rocchetta, Heather; Asawanonda, Pravit; Luo, Fangyi; Thomas, Jennifer H

2009-01-01

Scalp seborrheic dermatitis and dandruff (SD/D) are chronic conditions requiring long-term treatment. There is a common belief that patients frequently experience decreasing benefits over time when using a single product. This physiologic accommodation is termed tachyphylaxis. To systematically investigate the anecdotal belief that tachyphylaxis occurs in long-term treatment of SD/D using quantitative clinical assessments. An international questionnaire completed by 722 dermatologists assessed the belief of tachyphylaxis incidence with pyrithione zinc (PTZ)-based shampoos, time course, occurrence relative to active ingredients, and effect of switching products. Two double-blind, randomized, clinical evaluations were conducted, 24- and 48-week studies, whereby a 1% PTZ shampoo, a 2% PTZ shampoo, or a matched placebo control shampoo was used by each subject for the duration of the study. Dermatologists assessed the adherent scalp flaking (scale of 0-10) at baseline and at specified intervals. Sixty-four per cent of responding dermatologists believed tachyphylaxis occurred with PTZ products, and most felt that tachyphylaxis occurred within 3 months of use. Evaluation of mean treatment responses vs. placebo and individual responses as a function of study duration showed a consistent benefit for all products at all time points; therefore, no evidence for tachyphylaxis was found (within 48 weeks of treatment). No evidence for tachyphylaxis in SD/D treatment by PTZ-based shampoos was found. Compliance could explain the decreasing response rate seen over time; the solution is to choose an affordable therapeutic product that is effective long term without cosmetic trade-offs.

Influence of sky view factor on outdoor thermal environment and physiological equivalent temperature

NASA Astrophysics Data System (ADS)

He, Xiaodong; Miao, Shiguang; Shen, Shuanghe; Li, Ju; Zhang, Benzhi; Zhang, Ziyue; Chen, Xiujie

2015-03-01

Sky view factor (SVF), which is an indicator of urban canyon geometry, affects the surface energy balance, local air circulation, and outdoor thermal comfort. This study focused on a continuous and long-term meteorological observation system to investigate the effects of SVF on outdoor thermal conditions and physiological equivalent temperature (PET) in the central business district (CBD) of Beijing (which is located within Chaoyang District), specifically addressed current knowledge gaps for SVF-PET relationships in cities with typical continental/microthermal climates. An urban sub-domain scale model and the RayMan model were used to diagnose wind fields and to calculate SVF and long-term PET, respectively. Analytical results show that the extent of shading contributes to variations in thermal perception distribution. Highly shaded areas (SVF <0.3) typically exhibit less frequent hot conditions during summer, while enduring longer periods of cold discomfort in winter than moderately shaded areas (0.3< SVF <0.5) and slightly shaded areas (SVF >0.5), and vice versa. Because Beijing has a monsoon-influenced humid continental climate with hot summers and long, cold, windy, and dry winters, a design project that ideally provides moderate shading should be planned to balance hot discomfort in summer and cold discomfort in winter, which effectively prolongs the comfort periods in outdoor spaces throughout the entire year. This research indicate that climate zone characteristics, urban environmental conditions, and thermal comfort requirements of residents must be accounted for in local-scale scientific planning and design, i.e., for urban canyon streets and residential estates.

In-car countermeasures open window and music revisited on the real road: popular but hardly effective against driver sleepiness.

PubMed

Schwarz, Johanna F A; Ingre, Michael; Fors, Carina; Anund, Anna; Kecklund, Göran; Taillard, Jacques; Philip, Pierre; Åkerstedt, Torbjörn

2012-10-01

This study investigated the effects of two very commonly used countermeasures against driver sleepiness, opening the window and listening to music, on subjective and physiological sleepiness measures during real road driving. In total, 24 individuals participated in the study. Sixteen participants received intermittent 10-min intervals of: (i) open window (2 cm opened); and (ii) listening to music, during both day and night driving on an open motorway. Both subjective sleepiness and physiological sleepiness (blink duration) was estimated to be significantly reduced when subjects listened to music, but the effect was only minor compared with the pronounced effects of night driving and driving duration. Open window had no attenuating effect on either sleepiness measure. No significant long-term effects beyond the actual countermeasure application intervals occurred, as shown by comparison to the control group (n = 8). Thus, despite their popularity, opening the window and listening to music cannot be recommended as sole countermeasures against driver sleepiness. © 2012 European Sleep Research Society.

Hypertension: physiology and pathophysiology.

PubMed

Hall, John E; Granger, Joey P; do Carmo, Jussara M; da Silva, Alexandre A; Dubinion, John; George, Eric; Hamza, Shereen; Speed, Joshua; Hall, Michael E

2012-10-01

Despite major advances in understanding the pathophysiology of hypertension and availability of effective and safe antihypertensive drugs, suboptimal blood pressure (BP) control is still the most important risk factor for cardiovascular mortality and is globally responsible for more than 7 million deaths annually. Short-term and long-term BP regulation involve the integrated actions of multiple cardiovascular, renal, neural, endocrine, and local tissue control systems. Clinical and experimental observations strongly support a central role for the kidneys in the long-term regulation of BP, and abnormal renal-pressure natriuresis is present in all forms of chronic hypertension. Impaired renal-pressure natriuresis and chronic hypertension can be caused by intrarenal or extrarenal factors that reduce glomerular filtration rate or increase renal tubular reabsorption of salt and water; these factors include excessive activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, increased formation of reactive oxygen species, endothelin, and inflammatory cytokines, or decreased synthesis of nitric oxide and various natriuretic factors. In human primary (essential) hypertension, the precise causes of impaired renal function are not completely understood, although excessive weight gain and dietary factors appear to play a major role since hypertension is rare in nonobese hunter-gathers living in nonindustrialized societies. Recent advances in genetics offer opportunities to discover gene-environment interactions that may also contribute to hypertension, although success thus far has been limited mainly to identification of rare monogenic forms of hypertension. © 2012 American Physiological Society

Long-term stabilization of place cell remapping produced by a fearful experience

PubMed Central

Wang, Melissa E.; Wann, Ellen G.; Yuan, Robin K.; Ramos Álvarez, Manuel M.; Stead, Squire M.; Muzzio, Isabel A.

2012-01-01

Fear is an emotional response to danger that is highly conserved throughout evolution because it is critical for survival. Accordingly, episodic memory for fearful locations is widely studied using contextual fear conditioning, a hippocampus-dependent task (Kim and Fanselow, 1992; Phillips and LeDoux, 1992). The hippocampus has been implicated in episodic emotional memory and is thought to integrate emotional stimuli within a spatial framework. Physiological evidence supporting the role of the hippocampus in contextual fear indicates that pyramidal cells in this region, which fire in specific locations as an animal moves through an environment, shift their preferred firing locations shortly after the presentation of an aversive stimulus (Moita et al., 2004). However, the long-term physiological mechanisms through which emotional memories are encoded by the hippocampus are unknown. Here we show that during and directly after a fearful experience, new hippocampal representations are established and persist in the long term. We recorded from the same place cells in mouse hippocampal area CA1 over several days during predator odor contextual fear conditioning and found that a subset of cells changed their preferred firing locations in response to the fearful stimulus. Furthermore, the newly formed representations of the fearful context stabilized in the long term. Our results demonstrate that place cells respond to the presence of an aversive stimulus, modify their firing patterns during emotional learning, and stabilize a long-term spatial representation in response to a fearful encounter. The persistent nature of these representations may contribute to the enduring quality of emotional memories. PMID:23136419

The effect of siblings on early development: a potential contributor to personality differences in mammals.

PubMed

Hudson, Robyn; Bautista, Amando; Reyes-Meza, Verónica; Montor, Jorge Morales; Rödel, Heiko G

2011-09-01

Although most mammals grow up in the company of same or different age sibs (or half sibs), surprisingly little attention has been given to how relations among them might influence the development of individual differences in morphology, physiology, and behavior. Here we review evidence from our work on domestic and wild European rabbits, and more recently on laboratory rats, mice, and domestic cats, supporting the proposition that in mammals early sibling relations contribute to the development of individual differences in these three domains and thereby to long-term behavioral differences of the kind we might consider part of an animal's behavioral style or personality. First we report a consistent and marked negative relation between litter size and individuals' body mass at birth and weaning, as well as marked within-litter differences in prenatal body mass and placental efficiency. We then report individual differences in preweaning behaviors associated with these morphological variables such as position occupied in the litter huddle and development of motor ability, as well as physiological differences in thermoregulation, immune parameters, and endocrine indicators of stress. Finally, we report first evidence from wild rabbits that early relations among littermates may have long-term consequences for individual differences in behavioral style. We conclude that in mammals, individual differences in early growth, physiology and behavior potentially important for the development of animal personality, are shaped to an appreciable extent by early sibling relations and that this little-researched field deserves closer attention. Copyright © 2011 Wiley Periodicals, Inc.

Hair cortisol and progesterone detection in dairy cattle: interrelation with physiological status and milk production.

PubMed

Tallo-Parra, O; Carbajal, A; Monclús, L; Manteca, X; Lopez-Bejar, M

2018-07-01

Hair cortisol concentrations (HCCs) and hair progesterone concentrations (HPCs) allow monitoring long-term retrospective steroid levels. However, there are still gaps in the knowledge of the mechanisms of steroid deposition in hair and its potential application in dairy cattle research. This study aimed to evaluate the potential uses of hair steroid determinations by studying the interrelations between HCC, HPC, physiological data from cows, and their milk production and quality. Cortisol and progesterone concentrations were analyzed in hair from 101 milking Holstein Friesian cows in a commercial farm. Physiological data were obtained from the 60 d prior to hair collection. Moreover, productive data from the month when hair was collected and the previous one were also obtained as well as at 124 d after hair sampling. Significant but weak correlations were found between HCC and HPC (r = 0.25, P < 0.0001) and between HPC and age (r = 0.06, P = 0.0133). High HCC were associated with low milk yields from the 2 previous months to hair sampling (P = 0.0396) and during the whole lactation (P < 0.0001). High HCC were also related to high somatic cell count (P = 0.0241). No effect of HCC on fat or protein content was detected. No significant correlations were detected between hair steroid concentrations and pregnancy status, days of gestation, parturition category (primiparous vs multiparous), number of lactations or days in milk. The relationship between physiological variables and HCC or HPC could depend on the duration of the time period over which hair accumulates hormones. Steroid concentrations in hair present high variability between individuals but are a potential tool for dairy cattle welfare and production research by providing a useful and practical tool for long-term steroid monitoring. Copyright © 2018 Elsevier Inc. All rights reserved.

Foot Massage and Physiological Stress in People with Dementia: A Randomized Controlled Trial

PubMed Central

Cooke, Marie Louise; Beattie, Elizabeth; Shum, David H.K.; O'Dwyer, Siobhan T.; Barrett, Sue; Sung, Billy

2014-01-01

Abstract Background: The anxiety associated with unfamiliar surroundings, the disorientation and mental confusion, and the social isolation that accompanies dementia can often create increased stress for people living in long-term care settings. Such a response is thought to affect the autonomic nervous system and result in emotional and physical symptoms of distress that may be manifested as agitation. There is the potential for such distress to influence the physiological response and in particular Blood Pressure and Heart Rate. A relaxation intervention such as massage may influence the physiological stress response. Methods: This randomized controlled trial aimed to compare the effect of foot massage (FM) versus a control activity (quiet presence, QP) on physiological stress response (i.e., blood pressure [BP] and heart rate [HR]) in people living with moderate-to-severe dementia in long-term-care settings. Results: Fifty-three residents were randomized to intervention (10-minute FM) or control group (QP). While the FM group experienced a greater reduction in HR than the control group, these reductions were not significantly different between groups (p=0.83; see Table 1), or across time (p=0.46). Both groups experienced a reduction in systolic BP and diastolic BP, while the mean reduction in systolic BP was greater for those in the FM group. Conclusions: While the findings do not provide strong support for FM, the finding that both conditions allowed the person with dementia to rest in the presence of another human being is of importance in the care of people with dementia. The close presence of another person may in fact promote relaxation and therefore improve BP and HR measures. PMID:24047244

Physiological proteins in resource-limited herbivores experiencing a population die-off

NASA Astrophysics Data System (ADS)

Garnier, R.; Bento, A. I.; Hansen, C.; Pilkington, J. G.; Pemberton, J. M.; Graham, A. L.

2017-08-01

Nutrient availability is predicted to interact with herbivore population densities. Competition for low quality food at high density may reduce summer food intake, and in turn winter survival. Conversely, low population density may favor physiological recovery through better access to better quality spring forage. Here, we take advantage of the long-term study of the Soay sheep population of St. Kilda (Scotland) to measure plasma protein markers and immunity in two consecutive summers with contrasting population densities. We show that, following a winter die-off resulting in a shift to low population density, albumin and total proteins increased, but only in adult sheep. The effect was not solely attributable to selective disappearance of malnourished sheep. Similarly, the concentration of antibodies was higher following the die-off, potentially indicating recovery of immune function. Overall, our results are consistent with the physiological recovery of surviving individuals after a harsh winter.

Homeostatic regulation of adult hippocampal neurogenesis in aging rats: long-term effects of early exercise

PubMed Central

Merkley, Christina M.; Jian, Charles; Mosa, Adam; Tan, Yao-Fang; Wojtowicz, J. Martin

2014-01-01

Adult neurogenesis is highly responsive to environmental and physiological factors. The majority of studies to date have examined short-term consequences of enhancing or blocking neurogenesis but long-term changes remain less well understood. Current evidence for age-related declines in neurogenesis warrant further investigation into these long-term changes. In this report we address the hypothesis that early life experience, such as a period of voluntary running in juvenile rats, can alter properties of adult neurogenesis for the remainder of the animal's life. The results indicate that the number of proliferating and differentiating neuronal precursors is not altered in runners beyond the initial weeks post-running, suggesting homeostatic regulation of these processes. However, the rate of neuronal maturation and survival during a 4 week period after cell division was enhanced up to 11 months of age (the end of the study period). This study is the first to show that a transient period of physical activity at a young age promotes changes in neurogenesis that persist over the long-term, which is important for our understanding of the modulation of neurogenesis by exercise with age. Functional integration of adult-born neurons within the hippocampus that resist homeostatic regulation with aging, rather than the absolute number of adult-born neurons, may be an essential feature of adult neurogenesis that promotes the maintenance of neural plasticity in old age. PMID:25071426

The brown seaweed Sargassum cymosum: changes in metabolism and cellular organization after long-term exposure to cadmium.

PubMed

Costa, Giulia B; Simioni, Carmen; Pereira, Débora T; Ramlov, Fernanda; Maraschin, Marcelo; Chow, Fungyi; Horta, Paulo A; Bouzon, Zenilda L; Schmidt, Éder C

2017-03-01

Sargassum cymosum was exposed to cadmium (Cd) to determine any physiological and ultrastructural effects. To accomplish this, S. cymosum samples were cultivated under photosynthetic active radiation (PAR) and Cd (0, 0.1, 0.2, 0.4 and 0.8 mg L -1 ) during 7 and 14 days in laboratory-controlled conditions (0 mg L -1 Cd at both exposure times as control). Seaweeds had high retention capacity (over 90 %) for both exposure times. Growth rates showed significant increases by 14 days, especially for 0.1 and 0.4 mg L -1 Cd. Photosynthetic parameters were unaffected by Cd treatments. Chlorophyll contents were present in higher concentrations for all Cd treatments compared to respective control. Carotenoid profile showed significant differences in total composition and proportion of fucoxanthin and β-carotene, and no lutein was detected at 14 days. Phenolic and flavonoid compounds showed major accumulation at 14 days. Transmission electron microscopy (TEM) analyses presented major alterations in Cd-treated samples, when compared with respective control, in particular disorganization of cell wall fibrils. When compared to respective control samples, multivariate analyses showed disparate and complex interactions among metabolites in Cd-exposed seaweeds, giving evidence of physiological defence response. Thus, it can be concluded that Cd is a stressor for S. cymosum, resulting in physiological and structural alterations related to defence mechanisms against oxidative stress and toxicological effects resulting from long-term metal exposure. However, in the present paper, some observed changes also appear to result from acclimation mechanisms under lower concentration of Cd relative to the tolerance of S. cymosum to experimental conditions.

Acute and chronic stress and the inflammatory response in hyperprolactinemic rats.

PubMed

Ochoa-Amaya, J E; Malucelli, B E; Cruz-Casallas, P E; Nasello, A G; Felicio, L F; Carvalho-Freitas, M I R

2010-01-01

Prolactin (PRL), a hormone produced by the pituitary gland, has multiple physiological functions, including immunoregulation. PRL can also be secreted in response to stressful stimuli. During stress, PRL has been suggested to oppose the immunosuppressive effects of inflammatory mediators. Therefore, the aim of the present study was to analyze the effects of short- and long-term hyperprolactinemia on the inflammatory response in rats subjected to acute or chronic cold stress. Inflammatory edema was induced by carrageenan in male rats, and hyperprolactinemia was induced by injections of the dopamine receptor antagonist domperidone. The volume of inflammatory edema was measured by plethysmography after carrageenan injection. Additionally, the effects of hyperprolactinemia on body weight and serum corticosterone levels were evaluated. Five days of domperidone-induced hyperprolactinemia increased the volume of inflammatory edema. No differences in serum corticosterone levels were observed between groups. No significant differences were found among 30 days domperidone-induced hyperprolactinemic animals subjected to acute stress and the inflammatory response observed in chronic hyperprolactinemic animals subjected to chronic stress. The results suggest that short-term hyperprolactinemia has pro-inflammatory effects. Because such an effect was not observed in long-term hyperprolactinemic animals, PRL-induced tolerance seems likely. We suggest that short-term hyperprolactinemia may act as a protective factor in rats subjected to acute stress. These data suggest that hyperprolactinemia and stress interact differentially according to the time period. Copyright 2010 S. Karger AG, Basel.

Life in the sea of plenty: Seasonal and regional comparison of physiological performance of Euphausia hanseni in the northern Benguela upwelling system

NASA Astrophysics Data System (ADS)

Werner, Thorsten; Buchholz, Cornelia; Buchholz, Friedrich

2015-09-01

Variability in upwelling events may lead to periods of constrained food availability in the northern Benguela upwelling system (NBUS), thereby affecting the physiological state and metabolic activity of euphausiids. Most attention has so far been paid to seasonal effects but little is known about regional variability. Metabolic activity (expressed by respiration and excretion rates) and physiological state (expressed by reproductive effort and moult activity) in Euphausia hanseni were examined at different stations during austral summer (minimum upwelling) and austral winter (maximum upwelling). Overall, regional differences in physiological state, influencing metabolic activity, were greater than seasonal ones, indicating favourable conditions for growth and reproduction year-round. Higher respiration rates were found for females in more advanced stages of sexual development. Moult stage did not affect oxygen consumption rates, however. The physiological state of E. hanseni at the time of capture may serve as a meaningful indicator of the associated hydrographic conditions in the NBUS, to be further used in eco-system analysis on seasonal or long-term time scales. A latitudinal comparison of species highlights the extraordinary physiological plasticity of euphausiids.

[Atmospheric air pollution: a risk factor for COPD?].

PubMed

Allain, Y-M; Roche, N; Huchon, G

2010-04-01

Tobacco smoking is the leading cause of COPD worldwide but other risk factors have been recognized. Air pollution is one of them, but its exact role in the development of COPD is hard to demonstrate. Its physiological effects on lung function have only been studied since the nineties by long and tedious cohort studies. Difficulties arise from the heterogeneity of air pollution (gas and particles); thus, its respiratory effects have to be examined for every component separately, and in different populations. It is also necessary to analyse the effects of atmospheric pollution in the short and the long term, considering both its physiological, clinical and toxicological effects, from childhood to adulthood. These factors make it difficult to obtain statistically significant results. Nevertheless, most studies seem to point to a role of air pollution in the development of COPD via oxydative stress but further studies are needed to confirm the exact effect of each component of air pollution on the respiratory tract. These studies could lead to improved public health policies and results are awaited that would identify at-risk populations, decide appropriate preventive measures and propose documented thresholds in pollution exposure... thereby limiting the spread of COPD. Copyright 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Short-term exposure to JP-8 jet fuel results in long-term immunotoxicity.

PubMed

Harris, D T; Sakiestewa, D; Robledo, R F; Witten, M

1997-01-01

Chronic exposure to jet fuel has been shown to have adverse effects on human liver function, to cause emotional dysfunction, to cause abnormal electroencephalograms, to cause shortened attention spans, and to decrease sensorimotor speed. Due to the decision by the United States Air Force to implement the widespread use of JP-8 jet fuel in its operations, a thorough understanding of its potential effects upon exposed personnel is both critical and necessary. Exposure to potential environmental toxicants such as JP-8 may have significant effects on host systems beyond those readily visible (i.e., physiology, cardiology, respiratory, etc.); e.g., the immune system. Previous studies have shown that short-term, low concentration JP-8 exposure had significant effects on the immune system, which should have serious consequences for the exposed host in terms of susceptibility to infectious agents. If these alterations in immune function were long-lasting, it might also result in an increased likelihood of development and/or progression of cancer, as well as autoimmune disease. In the current study, mice were exposed for 1 h/day for 7 days to a moderate (1000 mg/m3) and a high (2500 mg/m3) concentration of aerosolized JP-8 jet fuel to stimulate occupational exposures. One to 28 days after the last exposure the mice were analyzed for effects of the exposure on their immune systems. It was observed that decrease in viable immune cell numbers and immune organ weights found at 24 h after exposure persisted for extended periods of time. Further, JP-8 exposure resulted in significantly decreased immune infection, as analyzed by mitogenesis assays, which persisted for up to 4 weeks post-exposure. Thus, short-term exposure of mice to JP-8 jet fuel caused significant toxicological effects on the immune system, which were long-lasting and persistent. It appears that the immune system may be the most sensitive indicator of toxicological damage due to JP-8 exposure. Such long-term changes in immune status may have significant effects on the health of the exposed individual.

Behavioral and physiological consequences of enrichment loss in rats

PubMed Central

Smith, Brittany L.; Lyons, Carey E; Correa, Fernanda Guilhaume; Benoit, Stephen C.; Myers, Brent; Solomon, Matia B.; Herman, James P.

2017-01-01

Significant loss produces the highest degree of stress and compromised well-being in humans. Current rodent models of stress involve the application of physically or psychologically aversive stimuli, but do not address the concept of loss. We developed a rodent model for significant loss, involving removal of long-term access to a rewarding enriched environment. Our results indicate that removal from environmental enrichment produces a profound behavioral and physiological phenotype with depression-like qualities, including helplessness behavior, hypothalamo-pituitary-adrenocortical axis dysregulation and overeating. Importantly, this enrichment removal phenotype was prevented by antidepressant treatment. Furthermore, the effects of enrichment removal do not occur following relief from chronic stress and are not duplicated by loss of exercise or social contact. PMID:28012292

The role of physiology in the development of golf performance.

PubMed

Smith, Mark F

2010-08-01

The attainment of consistent high performance in golf requires effective physical conditioning that is carefully designed and monitored in accordance with the on-course demands the player will encounter. Appreciating the role that physiology plays in the attainment of consistent performance, and how a player's physicality can inhibit performance progression, supports the notion that the application of physiology is fundamental for any player wishing to excel in golf. With cardiorespiratory, metabolic, hormonal, musculoskeletal and nutritional demands acting on the golfer within and between rounds, effective physical screening of a player will ensure physiological and anatomical deficiencies that may influence performance are highlighted. The application of appropriate golf-specific assessment methods will ensure that physical attributes that have a direct effect on golf performance can be measured reliably and accurately. With the physical development of golf performance being achieved through a process of conditioning with the purpose of inducing changes in structural and metabolic functions, training must focus on foundation whole-body fitness and golf-specific functional strength and flexibility activities. For long-term player improvement to be effective, comprehensive monitoring will ensure the player reaches an optimal physical state at predetermined times in the competitive season. Through continual assessment of a player's physical attributes, training effectiveness and suitability, and the associated adaptive responses, key physical factors that may impact most on performance success can be determined.

Effect of cell phone exposure on physiologic and hematologic parameters of male medical students of Bijapur (Karnataka) with reference to serum lipid profile.

PubMed

Parkar, Matin A; Ahmed, Rishad; Abdullah, Bilal Bin; Patil, B S; Das, Kusal K

2010-01-01

The public awareness about cell phone safety increased greatly in the last few years as various reports of potential adverse health effects on humans exposed to radiations emitted from cellular phones were published. The aim of the study was to assess the effect of long term cell phone exposure on physiological and hematological parameters along with its impact on serum lipid profiles and a single call effect on heart rate, blood pressure and SpO2(%) of healthy male medical students. The students were divided into two groups, group I (n=22, age 20.63 +/- 1.17 yrs) comprising first year medical students who were never exposed to cell phones at the time of this study and group II (n=35, age 22.00 +/- 1.56 yrs) consists of final year (fourth year) male medical students who were using cell phone for more than four years before this study. The results showed no significant differences the groups in basal heart rate, systolic blood pressure, SpO2(%), or various hematologic parameters. Acute exposure (single call of cell phone with 900 MHz for 1 minute) in both groups showed a significant increase in peak heart rate in group II as compared with group I and a significant decrease in peak SpO2 (%) in group I as compared with group II. Serum total cholesterol, VLDL-cholesterol, and triglycerides concentration were significantly higher in group II (long term cell phone exposed) than in group I, suggesting a mild alteration of lipid profile among group II subjects.

The inhibitory effects of nicotine on physiological sexual arousal in nonsmoking women: results from a randomized, double-blind, placebo-controlled, cross-over trial.

PubMed

Harte, Christopher B; Meston, Cindy M

2008-05-01

Extensive research suggests that long-term cigarette smoking is an independent risk factor for the introduction of sexual dysfunction in men. However, results of limited data investigating this relationship in women are mixed. No studies have examined the acute effects of tobacco or nicotine on physiological sexual response in women. Controlled experimental studies examining acute effects of isolated nicotine intake on female physiological sexual responses are necessary in order to help elucidate tobacco's potential role in the development and/or maintenance of sexual impairment in women. To examine whether isolated nicotine intake acutely affects sexual arousal responses in nonsmoking women. Twenty-five sexually functional women (mean age = 20 years) each with less than 100 direct exposures to nicotine completed two counterbalanced conditions in which they were randomized to received either nicotine gum (6 mg) or placebo gum, both administered double-blind and matched for appearance, taste, and consistency, approximately 40 minutes prior to viewing an erotic film. Physiological (changes in vaginal pulse amplitude via vaginal photoplethysmography) and subjective (continuous self-report) sexual responses to erotic stimuli were examined, as well as changes in mood. Nicotine significantly reduced genital responses to the erotic films (P = 0.05), corresponding to a 30% attenuation in physiological sexual arousal. This occurred in 11 of 18 women with valid physiological assessments. Nicotine had no significant effect on continuous self-report ratings of sexual arousal (P = 0.45), or on mood (all Ps > 0.05). Acute nicotine intake significantly attenuates physiological sexual arousal in healthy nonsmoking women. Our findings provide support to the hypothesis that nicotine may be the primary pharmacological agent responsible for genital hemodynamic disruption, thereby facilitating a cascade of biochemical and vascular events which may impair normal sexual arousal responses.

Maternal Obesity and its Short- and Long-Term Maternal and Infantile Effects

PubMed Central

Korkmaz, Levent; Baştuğ, Osman; Kurtoğlu, Selim

2016-01-01

Obesity, in childhood or in adulthood, remains to be a global health problem. The worldwide prevalence of obesity has increased in the last few decades, and consequently, the women of our time suffer more gestational problems than women in the past. The prevalence of obesity is greater in older women than in younger ones and in women with low educational level than in their counterparts with a higher level of education. Maternal obesity during pregnancy may increase congenital malformations and neonatal morbidity and mortality. Maternal obesity is associated with a decreased intention to breastfeed, decreased initiation of breastfeeding, and decreased duration of breastfeeding. We discuss the current epidemiological evidence for the association of maternal obesity with congenital structural neural tube and cardiac defects, fetal macrosomia that predisposes infants to birth injuries and to problems with physiological and metabolic transition, as well as potential for long-term complications secondary to prenatal and neonatal programming effects compounded by a reduction in sustained breastfeeding. PMID:26758575

Effects of Neonatal Methamphetamine and Stress on Brain Monoamines and Corticosterone in Preweanling Rats

PubMed Central

Jablonski, Sarah A.; Graham, Devon L.; Vorhees, Charles V.; Williams, Michael T.

2017-01-01

Neonatal exposure to methamphetamine (MA) and developmental chronic stress significantly alter neurodevelopmental profiles that show a variety of long-term physiological and behavioral effects. In the current experiment, Sprague-Dawley rats were exposed to one of two housing conditions along with MA. Rats were given 0 (saline), 5, or 7.5 mg/kg MA, four times per day from postnatal day (P)11 to 15 or P11 to 20. Half of the litters were reared in cages with standard bedding and half with no bedding. Separate litters were assessed at P15 or P20 for organ weights (adrenals, spleen, thymus); corticosterone; and monoamine assessments (dopamine, serotonin, norepinephrine) and their metabolites within the neostriatum, hippocampus, and prefrontal cortex. Findings show neonatal MA altered mono-amines, corticosterone, and organ characteristics alone, and as a function of developmental age and stress compared with controls. These alterations may in part be responsible for MA and early life stress-induced long-term learning and memory deficits. PMID:27817108

Maternal Obesity and its Short- and Long-Term Maternal and Infantile Effects.

PubMed

Korkmaz, Levent; Baştuğ, Osman; Kurtoğlu, Selim

2016-06-05

Obesity, in childhood or in adulthood, remains to be a global health problem. The worldwide prevalence of obesity has increased in the last few decades, and consequently, the women of our time suffer more gestational problems than women in the past. The prevalence of obesity is greater in older women than in younger ones and in women with low educational level than in their counterparts with a higher level of education. Maternal obesity during pregnancy may increase congenital malformations and neonatal morbidity and mortality. Maternal obesity is associated with a decreased intention to breastfeed, decreased initiation of breastfeeding, and decreased duration of breastfeeding. We discuss the current epidemiological evidence for the association of maternal obesity with congenital structural neural tube and cardiac defects, fetal macrosomia that predisposes infants to birth injuries and to problems with physiological and metabolic transition, as well as potential for long-term complications secondary to prenatal and neonatal programming effects compounded by a reduction in sustained breastfeeding.

Hormone Treatment and Muscle Anabolism during Aging: Androgens

PubMed Central

Dillon, E. Lichar; Durham, William J.; Urban, Randall J.; Sheffield-Moore, Melinda

2010-01-01

Aging is associated with a gradual decline in circulating testosterone concentrations and decreased musculature in men. While testosterone administration is often considered when symptoms of hypogonadism are presented, the long-term effects of androgen use on muscle physiology are not yet fully understood. The definition of hypogonadism in men remains obscure but is generally indicated by total testosterone concentrations less than a threshold value of 300-500 ng/dL. Androgen replacement therapy is generally safe in men and women with low endogenous testosterone concentrations. The development of selective androgen receptor modulators (SARMs) may provide additional options in treatment of hypogonadism while lowering the potential of side effects often associated with long-term androgen use. Androgen administration, either alone or in combination with other treatments, can be successful in improving muscle mass by increasing protein anabolism and reducing protein catabolism in men and women. Further research is necessary to optimize the anabolic and anticatabolic properties of androgens for treatment and prevention of muscle loss in men and women. PMID:20452103

Insulin and insulin-like growth factor-1 induce pronounced hypertrophy of skeletal myofibers in tissue culture

NASA Technical Reports Server (NTRS)

Vandenburgh, Herman H.; Karlisch, Patricia; Shansky, Janet

1990-01-01

Skeletal myofibers differentiated from primary avian myoblasts in tissue culture can be maintained in positive nitrogen balance in a serum-free medium for at least 6 to 7 days when embedded in a three dimensional collagen gel matrix. The myofibers are metabolically sensitive to physiological concentrations of insulin but these concentrations do not stimulate cell growth. Higher insulin concentrations stimulate both cell hyperplasia and myofiber hypertrophy. Cell growth results from a long term 42 percent increase in total protein synthesis and a 38 percent increase in protein degradation. Myofiber diameters increase by 71 to 98 percent after 6 to 7 days in insulin-containing medium. Insulin-like growth factor-1 but not insulin-like growth factor-2, at 250 ng/ml, is as effective as insulin in stimulating cell hyperplasia and myofiber hypertrophy. This model system provides a new method for studying the long-term anabolic effects of insulin and insulin-like growth factors on myofiber hypertrophy under defined tissue culture conditions.

Nephrotoxicity in rabbits after long-term nandrolone decanoate administration.

PubMed

Tsitsimpikou, Christina; Vasilaki, Fotini; Tsarouhas, Konstantinos; Fragkiadaki, Persefoni; Tzardi, Maria; Goutzourelas, Nikolaos; Nepka, Charitini; Kalogeraki, Alexandra; Heretis, Ioannis; Epitropaki, Zoi; Kouretas, Dimitrios; Tsatsakis, Aristidis M

2016-09-30

Among the various side effects of supra-physiological dose of anabolic androgenic steroids that are described, renal toxicity remains the least evaluated. The present study provides evidence that long-term administration of nandrolone decanoate could lead to alterations of renal function and structure in the experimental rabbit model. A pronounced increase in serum urea, creatinine, SGOT and SGPT is observed in the treated animals, with intramuscular administration being more detrimental. Histopathological evaluation of kidneys indicated hyperaemia, fibrosis and focal inflammation. Furthermore, the significantly increased telomerase activity found in the kidneys of the intramuscularly treated animals could possibly represent a counteracting survival mechanism. Oxidative stress markers that were influenced the most were TBARS, indicating lipid peroxidation, and GSH. An interesting finding in our study though, was that while intramuscular administration showed the highest biochemical derangement, oxidative stress markers provided mixed results between intramuscularly and subcutaneously treated rabbits. In conclusion, nephrotoxicity of nandrolone decanoate remains a multi-factorial, partly irreversible effect that involves augmented tissue oxidative status. Copyright © 2016. Published by Elsevier Ireland Ltd.

Feasibility of future epidemiological studies on possible health effects of mobile phone base stations.

PubMed

Neubauer, Georg; Feychting, Maria; Hamnerius, Yngve; Kheifets, Leeka; Kuster, Niels; Ruiz, Ignacio; Schüz, Joachim; Uberbacher, Richard; Wiart, Joe; Röösli, Martin

2007-04-01

The increasing deployment of mobile communication base stations led to an increasing demand for epidemiological studies on possible health effects of radio frequency emissions. The methodological challenges of such studies have been critically evaluated by a panel of scientists in the fields of radiofrequency engineering/dosimetry and epidemiology. Strengths and weaknesses of previous studies have been identified. Dosimetric concepts and crucial aspects in exposure assessment were evaluated in terms of epidemiological studies on different types of outcomes. We conclude that in principle base station epidemiological studies are feasible. However, the exposure contributions from all relevant radio frequency sources have to be taken into account. The applied exposure assessment method should be piloted and validated. Short to medium term effects on physiology or health related quality of life are best investigated by cohort studies. For long term effects, groups with a potential for high exposure need to first be identified; for immediate effect, human laboratory studies are the preferred approach. (c) 2006 Wiley-Liss, Inc.

[Nintendo 3DS: technology, physiology and possible risks for children's eyes].

PubMed

Pallas, A; Meyer, C H; Mojon, D

2013-03-01

In March 2011 the new Nintendo 3DS went on sale in Switzerland and Germany. The game console features an attractive 3D display without the need of special glasses. By means of a so-called parallax barrier the depth perception can be increased or even turned off. In adults excessive use may cause symptoms such as headaches, dizziness or nausea. In children a visual impairment could be reinforced and an amblyopia could become manifest. Excessive, long hours of use especially in children could have its risks and the possible long-term effects remain unpredictable. On the other hand in the future it is likely that these kinds of 3D screens will be of considerable diagnostic value in orthoptics. The issue is likely to become a more important issue in everyday life in the future. As there is hardly any information available in the medical literature on this subject it is the aim of this article to provide an overview of the technology and physiology with the advantages and disadvantages.

The role of sympathetic and vagal cardiac control on complexity of heart rate dynamics.

PubMed

Silva, Luiz Eduardo Virgilio; Silva, Carlos Alberto Aguiar; Salgado, Helio Cesar; Fazan, Rubens

2017-03-01

Analysis of heart rate variability (HRV) by nonlinear approaches has been gaining interest due to their ability to extract additional information from heart rate (HR) dynamics that are not detectable by traditional approaches. Nevertheless, the physiological interpretation of nonlinear approaches remains unclear. Therefore, we propose long-term (60 min) protocols involving selective blockade of cardiac autonomic receptors to investigate the contribution of sympathetic and parasympathetic function upon nonlinear dynamics of HRV. Conscious male Wistar rats had their electrocardiogram (ECG) recorded under three distinct conditions: basal, selective (atenolol or atropine), or combined (atenolol plus atropine) pharmacological blockade of autonomic muscarinic or β 1 -adrenergic receptors. Time series of RR interval were assessed by multiscale entropy (MSE) and detrended fluctuation analysis (DFA). Entropy over short (1 to 5, MSE 1-5 ) and long (6 to 30, MSE 6-30 ) time scales was computed, as well as DFA scaling exponents at short (α short , 5 ≤ n ≤ 15), mid (α mid , 30 ≤ n ≤ 200), and long (α long , 200 ≤ n ≤ 1,700) window sizes. The results show that MSE 1-5 is reduced under atropine blockade and MSE 6-30 is reduced under atropine, atenolol, or combined blockade. In addition, while atropine expressed its maximal effect at scale six, the effect of atenolol on MSE increased with scale. For DFA, α short decreased during atenolol blockade, while the α mid increased under atropine blockade. Double blockade decreased α short and increased α long Results with surrogate data show that the dynamics during combined blockade is not random. In summary, sympathetic and vagal control differently affect entropy (MSE) and fractal properties (DFA) of HRV. These findings are important to guide future studies. NEW & NOTEWORTHY Although multiscale entropy (MSE) and detrended fluctuation analysis (DFA) are recognizably useful prognostic/diagnostic methods, their physiological interpretation remains unclear. The present study clarifies the effect of the cardiac autonomic control on MSE and DFA, assessed during long periods (1 h). These findings are important to help the interpretation of future studies. Copyright © 2017 the American Physiological Society.

Growth and physiology of loblolly pine in response to long-term resource management: defining growth potential in the southern United States

Treesearch

Lisa J. Samuelson; John Butnor; Chris Maier; Tom A. Stokes; Kurt Johnsen; Michael Kane

2008-01-01

Leaf physiology and stem growth were assessed in loblolly pine (Pinus taeda L.) in response to 10 to 11 years of treatment with weed control (W), weed control plus irrigation (WI), weed control plus irrigation and fertigation (WIF), or weed control plus irrigation, fertigation, and pest control (WIFP) to determine whether increased resource...

Repeating patterns of sleep restriction and recovery: Do we get used to it?

PubMed

Simpson, Norah S; Diolombi, Moussa; Scott-Sutherland, Jennifer; Yang, Huan; Bhatt, Vrushank; Gautam, Shiva; Mullington, Janet; Haack, Monika

2016-11-01

Despite its prevalence in modern society, little is known about the long-term impact of restricting sleep during the week and 'catching up' on weekends. This common sleep pattern was experimentally modeled with three weeks of 5 nights of sleep restricted to 4h followed by two nights of 8-h recovery sleep. In an intra-individual design, 14 healthy adults completed both the sleep restriction and an 8-h control condition, and the subjective impact and the effects on physiological markers of stress (cortisol, the inflammatory marker IL-6, glucocorticoid receptor sensitivity) were assessed. Sleep restriction was not perceived to be subjectively stressful and some degree of resilience or resistance to the effects of sleep restriction was observed in subjective domains. In contrast, physiological stress response systems remain activated with repeated exposures to sleep restriction and limited recovery opportunity. Morning IL-6 expression in monocytes was significantly increased during week 2 and 3 of sleep restriction, and remained increased after recovery sleep in week 2 (p<0.05) and week 3 (p<0.09). Serum cortisol showed a significantly dysregulated 24h-rhythm during weeks 1, 2, and 3 of sleep restriction, with elevated morning cortisol, and decreased cortisol in the second half of the night. Glucocorticoid sensitivity of monocytes was increased, rather than decreased, during the sleep restriction and sleep recovery portion of each week. These results suggest a disrupted interplay between the hypothalamic-pituitary-adrenal and inflammatory systems in the context of repeated exposure to sleep restriction and recovery. The observed dissociation between subjective and physiological responses may help explain why many individuals continue with the behavior pattern of restricting and recovering sleep over long time periods, despite a cumulative deleterious physiological effect. Copyright © 2016 Elsevier Inc. All rights reserved.

Cell response to long term mechanical interaction with nanopipettes

NASA Astrophysics Data System (ADS)

Orynbayeva, Zulfiya; Singhal, Riju; Vitol, Elina; Bouchard, Michael; Azizkhan-Clifford, Jane; Layton, Bradley; Friedman, Gary; Gogotsi, Yury

2009-03-01

Traditional microinjection into cells is performed over a relatively short term. Pipettes are typically withdrawn following any kind of injection. On the other hand, there is growing interest in using nanopipettes for cellular and subcellular probing. This interest is partly due to new developments in nanopipette technology which employ carbon nanotubes and provide robustness, flexibility, and biocompatibility. However, as far as we know, no systematic study of physiological, biochemical, and biophysical processes associated with cell response to lengthy mechanical stimulations by nanopipette probing have been performed so far. We present a detailed investigation of a wide range of effects of long term pipette insertion into a cell. Both traditional glass micropipettes and the novel carbon nanotube-tipped probes were involved in this study. The mechanism of Ca2+ response to the mechanical stimuli introduced by the nanopipette, and the role of different organelles in this mechanism were studied. We hypothesize that the calcium response is a function of cytoskeleton integrity and the mode of coupling between the cytoskeleton and the plasma membrane domains.

Process-Oriented Guided-Inquiry Learning Improves Long-Term Retention of Information

ERIC Educational Resources Information Center

Vanags, Thea; Pammer, Kristen; Brinker, Jay

2013-01-01

Many chemistry educators have adopted the process-oriented guided instructional learning (POGIL) pedagogy. However, it is not clear which aspects of POGIL are the most important in terms of actual learning. We compared 354 first-year undergraduate psychology students' learning in physiological psychology using four teaching methods: control,…

Our eclectic adventures in the slower eras of photosynthesis: from New England Down Under to biosphere 2 and beyond.

PubMed

Osmond, Barry

2014-01-01

This is a tale of a career in plant physiological ecology that enjoyed the freedom to address photosynthetic physiology and biochemistry in leaves of plants from diverse environments. It was supported by block funding (now sadly a thing of the past) for research at the Australian National University, by grants during appointments in the United States and in Germany, and by Columbia University. It became a "career experiment" in which long-term, high-trust support for curiosity-driven plant biology in Australia, and at times in the United States, led to surprisingly innovative results. Although the rich diversity of short-term competitive grant opportunities in the United States sustained ongoing research, it proved difficult to mobilize support for more risky long-term projects. A decade after the closure of the Biosphere 2 Laboratory, this article highlights the achievements of colleagues in experimental climate change research from 1998 to 2003.

Whey proteins in the regulation of food intake and satiety.

PubMed

Luhovyy, Bohdan L; Akhavan, Tina; Anderson, G Harvey

2007-12-01

Whey protein has potential as a functional food component to contribute to the regulation of body weight by providing satiety signals that affect both short-term and long-term food intake regulation. Because whey is an inexpensive source of high nutritional quality protein, the utilization of whey as a physiologically functional food ingredient for weight management is of current interest. At present, the role of individual whey proteins and peptides in contributing to food intake regulation has not been fully defined. However, Whey protein reduces short-term food intake relative to placebo, carbohydrate and other proteins. Whey protein affects satiation and satiety by the actions of: (1) whey protein fractions per se; (2) bioactive peptides; (3) amino-acids released after digestion; (4) combined action of whey protein and/or peptides and/or amino acids with other milk constituents. Whey ingestion activates many components of the food intake regulatory system. Whey protein is insulinotropic, and whey-born peptides affect the renin-angiotensin system. Therefore whey protein has potential as physiologically functional food component for persons with obesity and its co-morbidities (hypertension, type II diabetes, hyper- and dislipidemia). It remains unclear, however, if the favourable effects of whey on food intake, subjective satiety and intake regulatory mechanisms in humans are obtained from usual serving sizes of dairy products. The effects described have been observed in short-term experiments and when whey is consumed in much higher amounts.

Effect of long-term culture of mouse embryonic stem cells under low oxygen concentration as well as on glycosaminoglycan hyaluronan on cell proliferation and differentiation.

PubMed

Ramírez, M Á; Pericuesta, E; Yáñez-Mó, M; Palasz, A; Gutiérrez-Adán, A

2011-02-01

Maintaining undifferentiated stem cells in defined conditions is of critical importance to improve their in vitro culture. We have evaluated the effects of culturing mouse stem (mES) cells under physiological oxygen concentration as well as by replacing fibroblast feeder layer (mEF) with gelatin or glycosaminoglycan hyaluronan (HA), on cell proliferation and differentiation. After 3 days culture or after long-term cell culture under different conditions, levels of apoptotic cell death were determined by cell cycle and TUNEL (TdT-mediated dUTP nick end labelling) assays and levels of cell proliferation by CFSE (5-(and-6)-carboxyfluorescein diacetate succinimidyl ester) labelling. We assessed spontaneous differentiation into cardiomyocytes and mRNA expression of pluripotency and differentiation biomarkers. After 3 days culture under hypoxic conditions, levels of proliferation and apoptosis of mES cells were higher, in correlation with increase in intracellular reactive oxygen species. However, when cells were continuously grown for 1 month under those conditions, the level of apoptosis was, in all cases, under 4%. Hypoxia reduced spontaneous differentiation of mES into cardiomyocytes. Long-term culture on HA was more effective in maintaining the pluripotent state of the mES cells when compared to that on gelatin. Level of terminal differentiation was highest on mEF, intermediate on HA and lowest on gelatin. Our data suggest that hypoxia is not necessary for maintaining pluripotency of mES cells and appeared to be detrimental during ES differentiation. Moreover, HA may offer a valuable alternative for long-term culture of mES cells in vitro. © 2010 Blackwell Publishing Ltd.

Automated system for integration and display of physiological response data

NASA Technical Reports Server (NTRS)

1975-01-01

The system analysis approach was applied in a study of physiological systems in both 1-g and weightlessness, for short and long term experiments. A whole body, algorithm developed as the first step in the construction of a total body simulation system is described and an advanced biomedical computer system concept including interactive display/command consoles is discussed. The documentation of the design specifications, design and development studies, and user's instructions (which include program listings) for these delivered end-terms; the reports on the results of many research and feasibility studies; and many subcontract reports are cited in the bibliography.

Extra-Anatomic Jump Graft from the Right Colic Vein: A Novel Technique to Manage Portal Vein Thrombosis in Liver Transplantation

PubMed Central

Tarantino, Giuseppe; Olivieri, Tiziana; Pecchi, Annarita; Ballarin, Roberto; Di Benedetto, Fabrizio

2018-01-01

Background In the context of cirrhosis, portal vein thrombosis (PVT) is present in 2.1% to 26% of patients. PVT is no longer considered an absolute contraindication for liver transplantation, and nowadays, surgical strategies depend on the extent of PVT. Complete PVT is associated with higher morbidity rates and poor prognosis, while comparable long-term outcomes can be achieved as long as physiological portal inflow is restored. Materials and Methods We report our experience with a 45-year-old patient undergoing liver transplant with a PVT (stage III-b). To restore portal vein inflow to the liver, an extra-anatomic jump graft from the right colic vein with donor iliac vein interposition was constructed. Results The patient recovered well, with a progressive improvement of the general conditions, and was finally discharged on p.o.d. 14. No anastomotic defects were found at the postoperative CT scan 10 months after the surgery. Conclusion Our technical innovation represents a valid and safe alternative to the cavoportal hemitransposition, providing a proper flow restoration and reproducing a physiological setting, while avoiding the complications related to the cavoportal shunt. We believe that the reconstitution of liver portal inflow should be obtained with the most physiological approach possible and considering long-term liver function. PMID:29593928

Sensor Network Infrastructure for a Home Care Monitoring System

PubMed Central

Palumbo, Filippo; Ullberg, Jonas; Štimec, Ales; Furfari, Francesco; Karlsson, Lars; Coradeschi, Silvia

2014-01-01

This paper presents the sensor network infrastructure for a home care system that allows long-term monitoring of physiological data and everyday activities. The aim of the proposed system is to allow the elderly to live longer in their home without compromising safety and ensuring the detection of health problems. The system offers the possibility of a virtual visit via a teleoperated robot. During the visit, physiological data and activities occurring during a period of time can be discussed. These data are collected from physiological sensors (e.g., temperature, blood pressure, glucose) and environmental sensors (e.g., motion, bed/chair occupancy, electrical usage). The system can also give alarms if sudden problems occur, like a fall, and warnings based on more long-term trends, such as the deterioration of health being detected. It has been implemented and tested in a test environment and has been deployed in six real homes for a year-long evaluation. The key contribution of the paper is the presentation of an implemented system for ambient assisted living (AAL) tested in a real environment, combining the acquisition of sensor data, a flexible and adaptable middleware compliant with the OSGistandard and a context recognition application. The system has been developed in a European project called GiraffPlus. PMID:24573309

Sensor network infrastructure for a home care monitoring system.

PubMed

Palumbo, Filippo; Ullberg, Jonas; Stimec, Ales; Furfari, Francesco; Karlsson, Lars; Coradeschi, Silvia

2014-02-25

This paper presents the sensor network infrastructure for a home care system that allows long-term monitoring of physiological data and everyday activities. The aim of the proposed system is to allow the elderly to live longer in their home without compromising safety and ensuring the detection of health problems. The system offers the possibility of a virtual visit via a teleoperated robot. During the visit, physiological data and activities occurring during a period of time can be discussed. These data are collected from physiological sensors (e.g., temperature, blood pressure, glucose) and environmental sensors (e.g., motion, bed/chair occupancy, electrical usage). The system can also give alarms if sudden problems occur, like a fall, and warnings based on more long-term trends, such as the deterioration of health being detected. It has been implemented and tested in a test environment and has been deployed in six real homes for a year-long evaluation. The key contribution of the paper is the presentation of an implemented system for ambient assisted living (AAL) tested in a real environment, combining the acquisition of sensor data, a flexible and adaptable middleware compliant with the OSGistandard and a context recognition application. The system has been developed in a European project called GiraffPlus.

Double bypass for inoperable pancreatic malignancy at laparotomy: postoperative complications and long-term outcome

PubMed Central

Ausania, F; Vallance, AE; Manas, DM; Prentis, JM; Snowden, CP; White, SA; Charnley, RM; French, JJ; Jaques, BC

2012-01-01

INTRODUCTION Between 4% and 13% of patients with operable pancreatic malignancy are found unresectable at the time of surgery. Double bypass is a good option for fit patients but it is associated with high risk of postoperative complications. The aim of this study was to identify pre-operatively which patients undergoing double bypass are at high risk of complications and to assess their long-term outcome. METHODS Of the 576 patients undergoing pancreatic resections between 2006 and 2011, 50 patients who underwent a laparotomy for a planned pancreaticoduodenectomy had a double bypass procedure for inoperable disease. Demographic data, risk factors for postoperative complications and pre-operative anaesthetic assessment data including the Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (P-POSSUM) and cardiopulmonary exercise testing (CPET) were collected. RESULTS Fifty patients (33 men and 17 women) were included in the study. The median patient age was 64 years (range: 39–79 years). The complication rate was 50% and the in-hospital mortality rate was 4%. The P-POSSUM physiology subscore and low anaerobic threshold at CPET were significantly associated with postoperative complications (p=0.005 and p=0.016 respectively) but they were unable to predict them. Overall long-term survival was significantly shorter in patients with postoperative complications (9 vs 18 months). Postoperative complications were independently associated with poorer long-term survival (p=0.003, odds ratio: 3.261). CONCLUSIONS P-POSSUM and CPET are associated with postoperative complications but the possibility of using them for risk prediction requires further research. However, postoperative complications following double bypass have a significant impact on long-term survival and this type of surgery should therefore only be performed in specialised centres. PMID:23131226

Changes in Cortical Plasticity in Relation to a History of Concussion during Adolescence

PubMed Central

Meehan, Sean K.; Mirdamadi, Jasmine L.; Martini, Douglas N.; Broglio, Steven P.

2017-01-01

Adolescence and early adulthood is a critical period for neurophysiological development potentially characterized by an increased susceptibility to the long-term effects of traumatic brain injury. The current study investigated differences in motor cortical physiology and neuroplastic potential across a cohort of young adults with adolescent concussion history and those without. Transcranial magnetic stimulation (TMS) was used to assess motor evoked potential (MEP) amplitude, short-interval cortical inhibition (SICI) and intracortical facilitation (ICF) before and after intermittent theta burst stimulation (iTBS). Pre-iTBS, MEP amplitude, but not SICI or ICF, was greater in the concussion history group. Post-iTBS, the expected increase in MEP amplitude and ICF was tempered in the concussion history group. Change in SICI was variable within the concussion history group. Post hoc assessment revealed that SICI was significantly lower in individuals whose concussion was not diagnosed at the time of injury compared to both those without a concussion history or whose concussion was medically diagnosed. Concussive impacts during adolescence appear to result in a persistent reduction of the ability to modulate facilitatory motor networks. Failure to report/identify concussive impacts close to injury during adolescence also appears to produce persistent change in inhibitory networks. These findings highlight the potential long-term impact of adolescent concussion upon motor cortical physiology. PMID:28144218

The habitat disruption induces immune-suppression and oxidative stress in honey bees

PubMed Central

Morimoto, Tomomi; Kojima, Yuriko; Toki, Taku; Komeda, Yayoi; Yoshiyama, Mikio; Kimura, Kiyoshi; Nirasawa, Keijiro; Kadowaki, Tatsuhiko

2011-01-01

The honey bee is a major insect used for pollination of many commercial crops worldwide. Although the use of honey bees for pollination can disrupt the habitat, the effects on their physiology have never been determined. Recently, honey bee colonies have often collapsed when introduced in greenhouses for pollination in Japan. Thus, suppressing colony collapses and maintaining the number of worker bees in the colonies is essential for successful long-term pollination in greenhouses and recycling of honey bee colonies. To understand the physiological states of honey bees used for long-term pollination in greenhouses, we characterized their gene expression profiles by microarray. We found that the greenhouse environment changes the gene expression profiles and induces immune-suppression and oxidative stress in honey bees. In fact, the increase of the number of Nosema microsporidia and protein carbonyl content was observed in honey bees during pollination in greenhouses. Thus, honey bee colonies are likely to collapse during pollination in greenhouses when heavily infested with pathogens. Degradation of honey bee habitat by changing the outside environment of the colony, during pollination services for example, imposes negative impacts on honey bees. Thus, worldwide use of honey bees for crop pollination in general could be one of reasons for the decline of managed honey bee colonies. PMID:22393496

Compressive sensing scalp EEG signals: implementations and practical performance.

PubMed

Abdulghani, Amir M; Casson, Alexander J; Rodriguez-Villegas, Esther

2012-11-01

Highly miniaturised, wearable computing and communication systems allow unobtrusive, convenient and long term monitoring of a range of physiological parameters. For long term operation from the physically smallest batteries, the average power consumption of a wearable device must be very low. It is well known that the overall power consumption of these devices can be reduced by the inclusion of low power consumption, real-time compression of the raw physiological data in the wearable device itself. Compressive sensing is a new paradigm for providing data compression: it has shown significant promise in fields such as MRI; and is potentially suitable for use in wearable computing systems as the compression process required in the wearable device has a low computational complexity. However, the practical performance very much depends on the characteristics of the signal being sensed. As such the utility of the technique cannot be extrapolated from one application to another. Long term electroencephalography (EEG) is a fundamental tool for the investigation of neurological disorders and is increasingly used in many non-medical applications, such as brain-computer interfaces. This article investigates in detail the practical performance of different implementations of the compressive sensing theory when applied to scalp EEG signals.

Ocean acidification and rising temperatures may increase biofilm primary productivity but decrease grazer consumption

PubMed Central

Russell, Bayden D.; Connell, Sean D.; Findlay, Helen S.; Tait, Karen; Widdicombe, Stephen; Mieszkowska, Nova

2013-01-01

Climate change may cause ecosystems to become trophically restructured as a result of primary producers and consumers responding differently to increasing CO2 and temperature. This study used an integrative approach using a controlled microcosm experiment to investigate the combined effects of CO2 and temperature on key components of the intertidal system in the UK, biofilms and their consumers (Littorina littorea). In addition, to identify whether pre-exposure to experimental conditions can alter experimental outcomes we explicitly tested for differential effects on L. littorea pre-exposed to experimental conditions for two weeks and five months. In contrast to predictions based on metabolic theory, the combination of elevated temperature and CO2 over a five-week period caused a decrease in the amount of primary productivity consumed by grazers, while the abundance of biofilms increased. However, long-term pre-exposure to experimental conditions (five months) altered this effect, with grazing rates in these animals being greater than in animals exposed only for two weeks. We suggest that the structure of future ecosystems may not be predictable using short-term laboratory experiments alone owing to potentially confounding effects of exposure time and effects of being held in an artificial environment over prolonged time periods. A combination of laboratory (physiology responses) and large, long-term experiments (ecosystem responses) may therefore be necessary to adequately predict the complex and interactive effects of climate change as organisms may acclimate to conditions over the longer term. PMID:23980241

Ocean acidification and rising temperatures may increase biofilm primary productivity but decrease grazer consumption.

PubMed

Russell, Bayden D; Connell, Sean D; Findlay, Helen S; Tait, Karen; Widdicombe, Stephen; Mieszkowska, Nova

2013-01-01

Climate change may cause ecosystems to become trophically restructured as a result of primary producers and consumers responding differently to increasing CO2 and temperature. This study used an integrative approach using a controlled microcosm experiment to investigate the combined effects of CO2 and temperature on key components of the intertidal system in the UK, biofilms and their consumers (Littorina littorea). In addition, to identify whether pre-exposure to experimental conditions can alter experimental outcomes we explicitly tested for differential effects on L. littorea pre-exposed to experimental conditions for two weeks and five months. In contrast to predictions based on metabolic theory, the combination of elevated temperature and CO2 over a five-week period caused a decrease in the amount of primary productivity consumed by grazers, while the abundance of biofilms increased. However, long-term pre-exposure to experimental conditions (five months) altered this effect, with grazing rates in these animals being greater than in animals exposed only for two weeks. We suggest that the structure of future ecosystems may not be predictable using short-term laboratory experiments alone owing to potentially confounding effects of exposure time and effects of being held in an artificial environment over prolonged time periods. A combination of laboratory (physiology responses) and large, long-term experiments (ecosystem responses) may therefore be necessary to adequately predict the complex and interactive effects of climate change as organisms may acclimate to conditions over the longer term.

Uncoupling primer and releaser responses to pheromone in honey bees

NASA Astrophysics Data System (ADS)

Grozinger, Christina M.; Fischer, Patrick; Hampton, Jacob E.

2007-05-01

Pheromones produce dramatic behavioral and physiological responses in a wide variety of species. Releaser pheromones elicit rapid responses within seconds or minutes, while primer pheromones produce long-term changes which may take days to manifest. Honeybee queen mandibular pheromone (QMP) elicits multiple distinct behavioral and physiological responses in worker bees, as both a releaser and primer, and thus produces responses on vastly different time scales. In this study, we demonstrate that releaser and primer responses to QMP can be uncoupled. First, treatment with the juvenile hormone analog methoprene leaves a releaser response (attraction to QMP) intact, but modulates QMP’s primer effects on sucrose responsiveness. Secondly, two components of QMP (9-ODA and 9-HDA) do not elicit a releaser response (attraction) but are as effective as QMP at modulating a primer response, downregulation of foraging-related brain gene expression. These results suggest that different responses to a single pheromone may be produced via distinct pathways.

Iron-mediated redox modulation in neural plasticity

PubMed Central

Muñoz, Pablo

2012-01-01

The role of iron in brain physiology has focused on the neuropathological, effects due to iron-induced oxidative stress. However, our recent work has established a physiological relationship between the iron-mediated oxidative modification and normal neuronal function. Our results obtained from hippocampal neurons, suggest that iron-generated reactive species oxygen (ROS) are involved in calcium signaling initiated by stimulation of NMDA receptors. This signal is amplified by ryanodine receptors (RyR), a redox- sensitive calcium channel, allowing the phosphorylation and nuclear translocation of ERK1/2. Furthermore, using electrophysiological approaches, we showed that iron is required for basal synaptic transmission and full expression of long-term potentiation, a type of synaptic plasticity. Our data combined suggest that the oxidative effect of iron is critical to activate processes that are downstream of NMDAR activation. Finally, due to the high reactivity of DNA with iron-generated ROS, we hypothesize an additional function of iron in gene regulation. PMID:22808323

Near-Infrared Fluorescent Nanoprobes for Revealing the Role of Dopamine in Drug Addiction.

PubMed

Feng, Peijian; Chen, Yulei; Zhang, Lei; Qian, Cheng-Gen; Xiao, Xuanzhong; Han, Xu; Shen, Qun-Dong

2018-02-07

Brain imaging techniques enable visualizing the activity of central nervous system without invasive neurosurgery. Dopamine is an important neurotransmitter. Its fluctuation in brain leads to a wide range of diseases and disorders, like drug addiction, depression, and Parkinson's disease. We designed near-infrared fluorescence dopamine-responsive nanoprobes (DRNs) for brain activity imaging during drug abuse and addiction process. On the basis of light-induced electron transfer between DRNs and dopamine and molecular wire effect of the DRNs, we can track the dynamical change of the neurotransmitter level in the physiological environment and the releasing of the neurotransmitter in living dopaminergic neurons in response to nicotine stimulation. The functional near-infrared fluorescence imaging can dynamically track the dopamine level in the mice midbrain under normal or drug-activated condition and evaluate the long-term effect of addictive substances to the brain. This strategy has the potential for studying neural activity under physiological condition.

Performance factors in women's team handball: physical and physiological aspects--a review.

PubMed

Manchado, Carmen; Tortosa-Martínez, Juan; Vila, Helena; Ferragut, Carmen; Platen, Petra

2013-06-01

Team handball is an Olympic sport played professionally in many European countries. Nevertheless, a scientific knowledge regarding women's elite team handball demands is limited. Thus, the purpose of this article was to review a series of studies (n = 33) on physical characteristics, physiological attributes, physical attributes, throwing velocity, and on-court performances of women's team handball players. Such empirical and practical information is essential to design and implement successful short-term and long-term training programs for women's team handball players. Our review revealed that (a) players that have a higher skill level are taller and have a higher fat-free mass; (b) players who are more aerobically resistant are at an advantage in international level women team handball; (c) strength and power exercises should be emphasized in conditioning programs, because they are associated with both sprint performance and throwing velocity; (d) speed drills should also be implemented in conditioning programs but after a decrease in physical training volume; (e) a time-motion analysis is an effective method of quantifying the demands of team handball and provides a conceptual framework for the specific physical preparation of players. According to our results, there are only few studies on on-court performance and time-motion analysis for women's team handball players, especially concerning acceleration profiles. More studies are needed to examine the effectiveness of different training programs of women's team handball players' physiological and physical attributes.

Bullying in schoolchildren - its relationship to dental appearance and psychosocial implications: an update for GDPs.

PubMed

Seehra, J; Newton, J T; DiBiase, A T

2011-05-14

Bullying in school-aged children is a global phenomenon. The effects of bullying can be both short- and long-term, resulting in both physiological and psychological symptoms. It is likely that dental care professionals will encounter children who are subjected to bullying. The aim of this narrative review is to discuss the incidence of bullying, the types of bullying, the effects of bullying and the interventions aimed at combating bullying in schoolchildren. The role of dentofacial aesthetics and the relationship of bullying and the presence of a malocclusion are also discussed.

Mathematical modeling of acute and chronic cardiovascular changes during Extended Duration Orbiter (EDO) flights

NASA Technical Reports Server (NTRS)

White, Ronald J.; Leonard, Joel I.; Srinivasan, R. Srini; Charles, John B.

1991-01-01

The purpose of NASA's Extended Duration Orbiter program is a gradual extension of the capabilities of the Space Shuttle Orbiter beyond its current 7-10 day limit on mission duration, as warranted by deepening understanding of the long-term physiological effects of weightlessness. Attention is being given to the cardiovascular problem of orthostatic tolerance loss due to its adverse effects on crew performance and health during reentry and initial readaptation to earth gravity. An account is given of the results of the application of proven mathematical models of circulatory and cardiovascular systems under microgravity conditions.

LSG_Broll

NASA Image and Video Library

2018-05-15

NASA engineers discussed the Life Sciences Glovebox, the agency's newest research facility for the International Space Station today at Marshall Space Flight Center in Huntsville, Alabama. The Life Sciences Glovebox will be used to study the long-term impact of microgravity on human physiology, revealing new ways to improve life on Earth while protecting human explorers during long-duration deep space missions.

Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans.

PubMed

Makihara, Yukiko; Segal, Richard L; Wolpaw, Jonathan R; Thompson, Aiko K

2014-09-15

In normal animals, operant conditioning of the spinal stretch reflex or the H-reflex has lesser effects on synergist muscle reflexes. In rats and people with incomplete spinal cord injury (SCI), soleus H-reflex operant conditioning can improve locomotion. We studied in normal humans the impact of soleus H-reflex down-conditioning on medial (MG) and lateral gastrocnemius (LG) H-reflexes and on locomotion. Subjects completed 6 baseline and 30 conditioning sessions. During conditioning trials, the subject was encouraged to decrease soleus H-reflex size with the aid of visual feedback. Every sixth session, MG and LG H-reflexes were measured. Locomotion was assessed before and after conditioning. In successfully conditioned subjects, the soleus H-reflex decreased 27.2%. This was the sum of within-session (task dependent) adaptation (13.2%) and across-session (long term) change (14%). The MG H-reflex decreased 14.5%, due mainly to task-dependent adaptation (13.4%). The LG H-reflex showed no task-dependent adaptation or long-term change. No consistent changes were detected across subjects in locomotor H-reflexes, EMG activity, joint angles, or step symmetry. Thus, in normal humans, soleus H-reflex down-conditioning does not induce long-term changes in MG/LG H-reflexes and does not change locomotion. In these subjects, task-dependent adaptation of the soleus H-reflex is greater than it is in people with SCI, whereas long-term change is less. This difference from results in people with SCI is consistent with the fact that long-term change is beneficial in people with SCI, since it improves locomotion. In contrast, in normal subjects, long-term change is not beneficial and may necessitate compensatory plasticity to preserve satisfactory locomotion. Copyright © 2014 the American Physiological Society.

Variability of Hormonal Stress Markers and Stress Responses in a Large Cross-Sectional Sample of Elephant Seals

DTIC Science & Technology

2013-09-30

cortisol and aldosterone impacted glucose, lactate, NEFA , BUN and electrolyte levels. These data provide novel information on the physiological and...massey.ac.nz Award Number: N000141110434 LONG-TERM GOALS Physiological indicators of stress in wild marine mammals, the interrelationships...glucocorticoid hormones (GC), aldosterone (A), thyroid hormones (TH), and catecholamines within a free-ranging northern elephant seal population and its

Variability of Hormonal Stress Markers and Stress Responses in a Large Cross-Sectional Sample of Elephant Seals

DTIC Science & Technology

2014-09-30

cortisol and aldosterone impacted glucose, lactate, NEFA , BUN and electrolyte levels. These data provide novel information on the physiological and...massey.ac.nz Award Number: N000141110434 LONG-TERM GOALS Physiological indicators of stress in wild marine mammals, the interrelationships between...hormones (GC), aldosterone (A), thyroid hormones (TH), and catecholamines within a free-ranging northern elephant seal population and its dependence

Bryophyte physiological responses to, and recovery from, long-term nitrogen deposition and phosphorus fertilisation in acidic grassland.

PubMed

Arróniz-Crespo, María; Leake, Jonathan R; Horton, Peter; Phoenix, Gareth K

2008-01-01

Atmospheric nitrogen deposition can cause major declines in bryophyte abundance yet the physiological basis for such declines is not fully understood. Bryophyte physiological responses may also be sensitive bioindicators of both the impacts of, and recovery from, N deposition. Here, responses of tissue nutrients (nitrogen (N), phosphorus (P) and potassium (K): NPK), N and P metabolism enzymes (nitrate reductase and phosphomonoesterase), photosynthetic pigments, chlorophyll fluorescence, sclerophylly and percentage cover of two common bryophytes (Pseudoscleropodium purum and Rhytidiadelphus squarrosus) to long-term (11 yr) enhanced N deposition (+3.5 and +14 g N m(-2) yr(-1)) are reported in factorial combination with P addition. Recovery of responses 22 months after treatment cessation were also assessed. Enhanced N deposition caused up to 90% loss of bryophyte cover but no recovery was observed. Phosphomonoesterase activity and tissue N:P ratios increased up to threefold in response to N loading and showed clear recovery, particularly in P. purum. Smaller responses and recovery were also seen in all chlorophyll fluorescence measurements and altered photosynthetic pigment composition. The P limitation of growth appears to be a key mechanism driving bryophyte loss along with damage to photosystem II. Physiological measurements are more sensitive than measurements of abundance as bioindicators of N deposition impact and of recovery in particular.

New Pharmacology Studies on the ISS

NASA Technical Reports Server (NTRS)

Wotring, Virginia E.; Pour, S.

2015-01-01

It is known that medications degrade over time and that extreme storage conditions will hasten their degradation. This is the basis of the HRP Risk of Ineffective or Toxic Medications Due to Long Term Storage. Gaps include questions about the effects of the spaceflight environment and about the potential for safe use of medications beyond their expiration dates. There are also open questions regarding effects of the spaceflight environment on human physiology and subsequent changes in how medications act on the body; these unanswered questions gave rise to the HRP Concern of Clinically Relevant Unpredicted Effects of Medication. Studies designed to address this Risk and Concern are described below.

Amyloid-β Peptide Is Needed for cGMP-Induced Long-Term Potentiation and Memory.

PubMed

Palmeri, Agostino; Ricciarelli, Roberta; Gulisano, Walter; Rivera, Daniela; Rebosio, Claudia; Calcagno, Elisa; Tropea, Maria Rosaria; Conti, Silvia; Das, Utpal; Roy, Subhojit; Pronzato, Maria Adelaide; Arancio, Ottavio; Fedele, Ernesto; Puzzo, Daniela

2017-07-19

High levels of amyloid-β peptide (Aβ) have been related to Alzheimer's disease pathogenesis. However, in the healthy brain, low physiologically relevant concentrations of Aβ are necessary for long-term potentiation (LTP) and memory. Because cGMP plays a key role in these processes, here we investigated whether the cyclic nucleotide cGMP influences Aβ levels and function during LTP and memory. We demonstrate that the increase of cGMP levels by the phosphodiesterase-5 inhibitors sildenafil and vardenafil induces a parallel release of Aβ due to a change in the approximation of amyloid precursor protein (APP) and the β-site APP cleaving enzyme 1. Moreover, electrophysiological and behavioral studies performed on animals of both sexes showed that blocking Aβ function, by using anti-murine Aβ antibodies or APP knock-out mice, prevents the cGMP-dependent enhancement of LTP and memory. Our data suggest that cGMP positively regulates Aβ levels in the healthy brain which, in turn, boosts synaptic plasticity and memory. SIGNIFICANCE STATEMENT Amyloid-β (Aβ) is a key pathogenetic factor in Alzheimer's disease. However, low concentrations of endogenous Aβ, mimicking levels of the peptide in the healthy brain, enhance hippocampal long-term potentiation (LTP) and memory. Because the second messenger cGMP exerts a central role in LTP mechanisms, here we studied whether cGMP affects Aβ levels and function during LTP. We show that cGMP enhances Aβ production by increasing the APP/BACE-1 convergence in endolysosomal compartments. Moreover, the cGMP-induced enhancement of LTP and memory was disrupted by blockade of Aβ, suggesting that the physiological effect of the cyclic nucleotide on LTP and memory is dependent upon Aβ. Copyright © 2017 the authors 0270-6474/17/376926-12$15.00/0.

Dual effects of fluoxetine on mouse early embryonic development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Chang-Woon; Department of Obstetrics and Gynecology, Samsung Changwon Hospital, Sungkyunkwan University, Changwon 630-723; Choe, Changyong

2012-11-15

Fluoxetine, a selective serotonin reuptake inhibitor, regulates a variety of physiological processes, such as cell proliferation and apoptosis, in mammalian cells. Little is known about the role of fluoxetine in early embryonic development. This study was undertaken to investigate the effect of fluoxetine during mouse early embryonic development. Late two-cell stage embryos (2-cells) were cultured in the presence of various concentrations of fluoxetine (1 to 50 μM) for different durations. When late 2-cells were incubated with 5 μM fluoxetine for 6 h, the percentage that developed into blastocysts increased compared to the control value. However, late 2-cells exposed to fluoxetinemore » (5 μM) over 24 h showed a reduction in blastocyst formation. The addition of fluoxetine (5 μM) together with KN93 or KN62 (calcium/calmodulin-dependent protein kinase II (CaMKII) inhibitors) failed to increase blastocyst formation. Fluoxetine treatment inhibited TREK-1 and TREK-2, members of the two-pore domain K{sup +} channel family expressed in mouse embryos, activities, indicating that fluoxetine-induced membrane depolarization in late 2-cells might have resulted from TREK inhibition. In addition, long-term exposure to fluoxetine altered the TREK mRNA expression levels. Furthermore, injection of siRNA targeting TREKs significantly decreased blastocyst formation by ∼ 30% compared to injection of scrambled siRNA. Long-term exposure of fluoxetine had no effect on blastocyst formation of TREK deficient embryos. These results indicate that low-dose and short-term exposures of late 2-cells to fluoxetine probably increase blastocyst formation through activation of CaMKII-dependent signal transduction pathways, whereas long-term exposure decreases mouse early embryonic development through inhibition of TREK channel gating. Highlights: ► Short-term exposure of 2-cells to fluoxetine enhances mouse blastocyst formation. ► The enhancive effect of fluoxetine is resulted from CaMKII activation. ► Long-term exposure of 2-cells to fluoxetine decreases mouse blastocyst formation. ► The inhibitory effect of fluoxetine is mediated through TREK channel gating.« less

Prenatal stress effects in a wild, long-lived primate: predictive adaptive responses in an unpredictable environment.

PubMed

Berghänel, Andreas; Heistermann, Michael; Schülke, Oliver; Ostner, Julia

2016-09-28

Prenatal maternal stress affects offspring phenotype in numerous species including humans, but it is debated whether these effects are evolutionarily adaptive. Relating stress to adverse conditions, current explanations invoke either short-term developmental constraints on offspring phenotype resulting in decelerated growth to avoid starvation, or long-term predictive adaptive responses (PARs) resulting in accelerated growth and reproduction in response to reduced life expectancies. Two PAR subtypes were proposed, acting either on predicted internal somatic states or predicted external environmental conditions, but because both affect phenotypes similarly, they are largely indistinguishable. Only external (not internal) PARs rely on high environmental stability particularly in long-lived species. We report on a crucial test case in a wild long-lived mammal, the Assamese macaque (Macaca assamensis), which evolved and lives in an unpredictable environment where external PARs are probably not advantageous. We quantified food availability, growth, motor skills, maternal caretaking style and maternal physiological stress from faecal glucocorticoid measures. Prenatal maternal stress was negatively correlated to prenatal food availability and led to accelerated offspring growth accompanied by decelerated motor skill acquisition and reduced immune function. These results support the 'internal PAR' theory, which stresses the role of stable adverse internal somatic states rather than stable external environments. © 2016 The Author(s).

Long-term effects of early life exposure to environmental estrogens on ovarian function: Role of epigenetics

PubMed Central

Cruz, Gonzalo; Foster, Warren; Paredes, Alfonso; Yi, Kun Don; Uzumcu, Mehmet

2014-01-01

Estrogens play an important role in development and function of the brain and reproductive tract. Accordingly, it is thought that developmental exposure to environmental estrogens can disrupt neural and reproductive tract development potentially resulting in long-term alterations in neurobehavior and reproductive function. Many chemicals have been shown to have estrogenic activity whereas others affect estrogen production and turnover resulting in disruption of estrogen signaling pathways. However, these mechanisms and the concentrations required to induce these effects cannot account for the myriad adverse effects of environmental toxicants on estrogen sensitive target tissues. Hence, alternative mechanisms are thought to underlie the adverse effects documented in experimental animal models and thus could be important to human health. In this review, the epigenetic regulation of gene expression is explored as a potential target of environmental toxicants including estrogenic chemicals. We suggest that toxicant-induced changes in epigenetic signatures are important mechanisms underlying disruption of ovarian follicular development. In addition, we discuss how exposure to environmental estrogens during early life can alter gene expression through effects on epigenetic control potentially leading to permanent changes in ovarian physiology. PMID:25040227

Long-term effects of early-life exposure to environmental oestrogens on ovarian function: role of epigenetics.

PubMed

Cruz, G; Foster, W; Paredes, A; Yi, K D; Uzumcu, M

2014-09-01

Oestrogens play an important role in development and function of the brain and reproductive tract. Accordingly, it is considered that developmental exposure to environmental oestrogens can disrupt neural and reproductive tract development, potentially resulting in long-term alterations in neurobehaviour and reproductive function. Many chemicals have been shown to have oestrogenic activity, whereas others affect oestrogen production and turnover, resulting in the disruption of oestrogen signalling pathways. However, these mechanisms and the concentrations required to induce these effects cannot account for the myriad adverse effects of environmental toxicants on oestrogen-sensitive target tissues. Hence, alternative mechanisms are assumed to underlie the adverse effects documented in experimental animal models and thus could be important to human health. In this review, the epigenetic regulation of gene expression is explored as a potential target of environmental toxicants including oestrogenic chemicals. We suggest that toxicant-induced changes in epigenetic signatures are important mechanisms underlying the disruption of ovarian follicular development. In addition, we discuss how exposure to environmental oestrogens during early life can alter gene expression through effects on epigenetic control potentially leading to permanent changes in ovarian physiology. © 2014 British Society for Neuroendocrinology.

Molecular and physiological responses of trees to waterlogging stress.

PubMed

Kreuzwieser, Jürgen; Rennenberg, Heinz

2014-10-01

One major effect of global climate change will be altered precipitation patterns in many regions of the world. This will cause a higher probability of long-term waterlogging in winter/spring and flash floods in summer because of extreme rainfall events. Particularly, trees not adapted at their natural site to such waterlogging stress can be impaired. Despite the enormous economic, ecological and social importance of forest ecosystems, the effect of waterlogging on trees is far less understood than the effect on many crops or the model plant Arabidopsis. There is only a handful of studies available investigating the transcriptome and metabolome of waterlogged trees. Main physiological responses of trees to waterlogging include the stimulation of fermentative pathways and an accelerated glycolytic flux. Many energy-consuming, anabolic processes are slowed down to overcome the energy crisis mediated by waterlogging. A crucial feature of waterlogging tolerance is the steady supply of glycolysis with carbohydrates, particularly in the roots; stress-sensitive trees fail to maintain sufficient carbohydrate availability resulting in the dieback of the stressed tissues. The present review summarizes physiological and molecular features of waterlogging tolerance of trees; the focus is on carbon metabolism in both, leaves and roots of trees. © 2014 John Wiley & Sons Ltd.

Biomedical research on the International Space Station postural and manipulation problems of the human upper limb in weightlessness

NASA Astrophysics Data System (ADS)

Neri, Gianluca; Zolesi, Valfredo

2000-01-01

Accumulated evidence, based on information gathered on space flight missions and ground based models involving both humans and animals, clearly suggests that exposure to states of microgravity conditions for varying duration induces certain physiological changes; they involve cardiovascular deconditioning, balance disorders, bone weakening, muscle hypertrophy, disturbed sleep patterns and depressed immune responses. The effects of the microgravity on the astronauts' movement and attitude have been studied during different space missions, increasing the knowledge of the human physiology in weightlessness. The purpose of the research addressed in the present paper is to understand and to assess the performances of the upper limb, especially during grasp. Objects of the research are the physiological changes related to the long-term duration spaceflight environment. Specifically, the changes concerning the upper limb are investigated, with particular regard to the performances of the hand in zero-g environments. This research presents also effects on the Earth, improving the studies on a number of pathological states, on the health care and the rehabilitation. In this perspective, a set of experiments are proposed, aimed at the evaluation of the effects of the zero-g environments on neurophysiology of grasping movements, fatigue assessment, precision grip. .

Effects of long-term individual and combined water and temperature stress on the growth of rice, wheat and maize: relationship with morphological and physiological acclimation.

PubMed

Perdomo, Juan Alejandro; Conesa, Miquel À; Medrano, Hipólito; Ribas-Carbó, Miquel; Galmés, Jeroni

2015-10-01

This study evaluates the long-term individual and combined effects of high temperature (HT) and water deficit (WD) stress on plant growth, leaf gas-exchange and water use efficiency in cultivars of the three most important crops worldwide, rice, wheat and maize. Total plant biomass (B t ) accumulation decreased under all treatments, being the combined HT-WD treatment the most detrimental in all three species. Although decreases in B t correlated with adjustments in biomass allocation patterns (i.e. the leaf area ratio), most of the variation observed in B t was explained by changes in leaf gas exchange parameters. Thus, integrated values of leaf carbon balance obtained from daily course measurements of photosynthesis and respiration were better predictors of plant growth than the instantaneous measurements of leaf gas exchange. Leaf water use efficiency, assessed both by gas exchange and carbon isotope measurements, was negatively correlated with B t under WD, but not under the combined WD and HT treatment. A comparative analysis of the negative effects of single and combined stresses on the main parameters showed an additive component for WD and HT in rice and maize, in contrast to wheat. Overall, the results of the specific cultivars included in the study suggest that the species native climate plays a role shaping the species acclimation potential to the applied stresses. In this regard, wheat, originated in a cold climate, was the most affected species, which foretells a higher affectation of this crop due to climate change. © 2014 Scandinavian Plant Physiology Society.

First long-term evidence supporting endovascular repair of abdominal aortic aneurysms.

PubMed

Indes, Jeffrey E; Muhs, Bart E; Dardik, Alan

2013-04-01

The traditional method of treating abdominal aortic aneurysms with open surgical repair has been steadily replaced by endovascular repair, thought to be a more minimally invasive approach. It is not known, however, whether the endovascular approach is truly less invasive for operative physiology; in addition, this approach has a different spectrum of complications. As such, it is uncertain whether elective endovascular repair of nonruptured aortic aneurysms reduces long-term morbidity and mortality compared with traditional open approaches. In this article, the authors evaluate a recent publication investigating long-term outcomes of a prospective randomized multicenter trial evaluating patients with asymptomatic abdominal aortic aneurysms treated with either endovascular or open repair, and discuss the results in the context of current evidence.

Effects of Long-Term Starvation on a Host Bivalve (Codakia orbicularis, Lucinidae) and Its Symbiont Population▿

PubMed Central

Caro, Audrey; Got, Patrice; Bouvy, Marc; Troussellier, Marc; Gros, Olivier

2009-01-01

The bivalve Codakia orbicularis, hosting sulfur-oxidizing gill endosymbionts, was starved (in artificial seawater filtered through a 0.22-μm-pore-size membrane) for a long-term experiment (4 months). The effects of starvation were observed using transmission electron microscopy, fluorescence in situ hybridization and catalyzed reporter deposition (CARD-FISH), and flow cytometry to monitor the anatomical and physiological modifications in the gill organization of the host and in the symbiotic population housed in bacteriocytes. The abundance of the symbiotic population decreased through starvation, with a loss of one-third of the bacterial population each month, as shown by CARD-FISH. At the same time, flow cytometry revealed significant changes in the physiology of symbiotic cells, with a decrease in cell size and modifications to the nucleic acid content, while most of the symbionts maintained a high respiratory activity (measured using the 5-cyano-2,3-ditolyl tetrazolium chloride method). Progressively, the number of symbiont subpopulations was reduced, and the subsequent multigenomic state, characteristic of this symbiont in freshly collected clams, turned into one and five equivalent genome copies for the two remaining subpopulations after 3 months. Concomitant structural modifications appeared in the gill organization. Lysosymes became visible in the bacteriocytes, while large symbionts disappeared, and bacteriocytes were gradually replaced by granule cells throughout the entire lateral zone. Those data suggested that host survival under these starvation conditions was linked to symbiont digestion as the main nutritional source. PMID:19346359

Physiological condition of juvenile wading birds in relation to multiple landscape stressors in the Florida Everglades: effects of hydrology, prey availability, and mercury bioaccumulation

USGS Publications Warehouse

Herring, Garth; Eagles-Smith, Collin A.; Gawlik, Dale E.; Beerens, James M.; Ackerman, Joshua T.

2014-01-01

The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.

Physiological condition of juvenile wading birds in relation to multiple landscape stressors in the Florida Everglades: effects of hydrology, prey availability, and mercury bioaccumulation.

PubMed

Herring, Garth; Eagles-Smith, Collin A; Gawlik, Dale E; Beerens, James M; Ackerman, Joshua T

2014-01-01

The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.

Physiological Condition of Juvenile Wading Birds in Relation to Multiple Landscape Stressors in the Florida Everglades: Effects of Hydrology, Prey Availability, and Mercury Bioaccumulation

PubMed Central

Herring, Garth; Eagles-Smith, Collin A.; Gawlik, Dale E.; Beerens, James M.; Ackerman, Joshua T.

2014-01-01

The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks. PMID:25184221

Long-Term Effects of Environmental Endocrine Disruptors on Reproductive Physiology and Behavior

PubMed Central

Patisaul, Heather B.; Adewale, Heather B.

2009-01-01

It is well established that, over the course of development, hormones shape the vertebrate brain such that sex specific physiology and behaviors emerge. Much of this occurs in discrete developmental windows that span gestation through the prenatal period, although it is now becoming clear that at least some of this process continues through puberty. Perturbation of this developmental progression can permanently alter the capacity for reproductive success. Wildlife studies have revealed that exposure to endocrine disrupting compounds (EDCs), either naturally occurring or man made, can profoundly alter reproductive physiology and ultimately impact entire populations. Laboratory studies in rodents and other species have elucidated some of the mechanisms by which this occurs and strongly indicate that humans are also vulnerable to disruption. Use of hormonally active compounds in human medicine has also unfortunately revealed that the developing fetus can be exposed to and affected by endocrine disruptors, and that it might take decades for adverse effects to manifest. Research within the field of environmental endocrine disruption has also contributed to the general understanding of how early life experiences can alter reproductive physiology and behavior through non-genomic, epigenetic mechanisms such as DNA methylation and histone acetylation. These types of effects have the potential to impact future generations if the germ line is affected. This review provides an overview of how exposure to EDCs, particularly those that interfere with estrogen action, impacts reproductive physiology and behaviors in vertebrates. PMID:19587848

Sickness-induced changes in physiology do not affect fecundity or same-sex behavior.

PubMed

Sylvia, Kristyn E; Báez Ramos, Patricia; Demas, Gregory E

2018-02-01

Previous work in our lab has shown that early-life infection affects female reproductive physiology and function (i.e., smaller ovaries, abnormal estrous cycles) and alters investigation and aggression towards male conspecifics in a reproductive context. Although many studies have investigated the effects of postnatal immune challenge on physiological and behavioral development, fewer studies have examined whether these changes have ultimate effects on reproduction. In the current study, we paired Siberian hamsters (Phodopus sungorus) and simulated a bacterial infection in early life by administering lipopolysaccharide (LPS) to male and female pups on pnd3 and pnd5. In adulthood, hamsters were paired with novel individuals of the same sex, and we scored an array of social behaviors (e.g., investigation, aggression). We then paired animals with individuals of the opposite sex for 5 consecutive nights, providing them with the opportunity to mate. We found that females exhibited impaired reproductive physiology and function in adulthood (i.e., smaller ovaries and abnormal estrous cycles), similar to our previous work. However, both LPS-treated males and females exhibited similar same-sex social behavior when compared with saline-treated controls, they successfully mated, and there were no significant changes in fecundity. These data suggest that the physiological changes in response to neonatal immune challenge may not have long-term effects on reproductive success in a controlled environment. Collectively, the results of this study are particularly important when investigating the relationships between physiology and behavior within an ultimate context. Animals exposed to early-life stress may in fact be capable of compensating for changes in physiology in order to survive and reproduce in some contexts. Copyright © 2017 Elsevier Inc. All rights reserved.

Short- and long-term effects of carbohydrate limitation on sugar and organic acid accumulation during mandarin fruit growth.

PubMed

Antoine, Sandrine; Pailly, Olivier; Gibon, Yves; Luro, François; Santini, Jérémie; Giannettini, Jean; Berti, Liliane

2016-08-01

The physiological roles of organic acids in fruit cells are not fully understood, especially in citrus, whereas the decline in titratable acidity during ripening shown by many citrus fruits is due to the utilization of citric acid. We induced carbohydrate depletion by removing source leaves at two key periods in mandarin development (early and full citric acid accumulation). Then, we assessed the resulting changes in the short term (within 48 h) and long term (several weeks until ripening). Control mature fruits were characterized by elevated fresh weight, large diameters and high quantities of malic acid, citric acid and sucrose. At the same stage, fruits subjected to early or late defoliation had higher glucose, fructose, citric acid concentrations and lower sucrose concentrations. They differed only in their malic acid concentrations, which were higher in early defoliation fruits and similar in late defoliation fruits when compared to control fruits. Finally, fruits subjected to late defoliation were characterized by high proline and γ-aminobutyric acid concentrations, and low fructose and glucose concentrations. We have shown that short- and long-term carbohydrate limitation modifies sugar and organic acid metabolism during mandarin fruit growth. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Exercise following myocardial infarction. Current recommendations.

PubMed

Leon, A S

2000-05-01

Cardiac rehabilitation services are comprehensive long term programmes designed to limit the physiological and psychological effects of cardiovascular disease (CVD), control cardiac symptoms and reduce the risk of subsequent CVD events by stabilising or partially reversing the underlying atherosclerosis process through risk factor modification. Exercise training is the cornerstone of such programmes. Ideally, exercise conditioning or training for the stable cardiac patient should include a combination of cardiorespiratory endurance (aerobic) training, arm exercises and muscular conditioning resistance (strength) training. Flexibility exercises should also be performed, usually as part of the warm-up and cool-down routines preceding and following endurance and strength training. This review discusses the potential physiological, psychological and health benefits of regular exercise and provides guidelines for exercise training for the rehabilitation of post-myocardial infarction patients following hospitalisation.

Variable conductivity and embolism in roots and branches of four contrasting tree species and their impacts on whole-plant hydraulic performance under future atmospheric CO2 concentration

Treesearch

J.-C. Domec; K. Schafer; R. Oren; H. Kim; H. McCarthy

2010-01-01

Anatomical and physiological acclimation to water stress of the tree hydraulic system involves trade-offs between maintenance of stomatal conductance and loss of hydraulic conductivity, with short-term impacts on photosynthesis and long-term consequences to survival and growth.

Short- and long-term physiological responses of grapevine leaves to UV-B radiation.

PubMed

Martínez-Lüscher, J; Morales, F; Delrot, S; Sánchez-Díaz, M; Gomés, E; Aguirreolea, J; Pascual, I

2013-12-01

The present study aimed at evaluating the short- and long-term effects of UV-B radiation on leaves of grapevine Vitis vinifera (cv. Tempranillo). Grapevine fruit-bearing cuttings were exposed to two doses of supplemental biologically effective UV-B radiation (UV-BBE) under glasshouse-controlled conditions: 5.98 and 9.66kJm(-2)d(-1). The treatments were applied either for 20d (from mid-veraison to ripeness) or 75d (from fruit set to ripeness). A 0kJm(-2)d(-1) UV-B treatment was included as control. The main effects of UV-B were observed after the short-term exposure (20d) to 9.66kJm(-2)d(-1). Significant decreases in net photosynthesis, stomatal conductance, sub-stomatal CO2 concentration, the actual photosystem II (PSII) efficiency, total soluble proteins and de-epoxidation state of the VAZ cycle were observed, whereas the activities of several antioxidant enzymes increased significantly. UV-B did not markedly affect dark respiration, photorespiration, the maximum potential PSII efficiency (Fv/Fm), non-photochemical quenching (NPQ), as well as the intrinsic PSII efficiency. However, after 75d of exposure to 5.98and 9.66kJm(-2)d(-1) UV-B most photosynthetic and biochemical variables were unaffected and there were no sign of oxidative damage in leaves. The results suggest a high long-term acclimation capacity of grapevine to high UV-B levels, associated with a high accumulation of UV-B absorbing compounds in leaves, whereas plants seemed to be tolerant to moderate doses of UV-B. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Activation of the central melanocortin system chronically reduces body mass without the necessity of long-term caloric restriction.

PubMed

Côté, I; Sakarya, Y; Kirichenko, N; Morgan, D; Carter, C S; Tümer, N; Scarpace, P J

2017-02-01

Melanotan II (MTII) is a potent appetite suppressor that rapidly reduces body mass. Given the rapid loss of anorexic response upon chronic MTII treatment, most investigations have focused on the initial physiological adaptations. However, other evidence supports MTII as a long-term modulator of energy balance that remains to be established. Therefore, we examined the chronic effects of MTII on energy homeostasis. MTII (high or low dose) or artificial cerebrospinal fluid (aCSF) was infused into the lateral ventricle of the brain of 6-month-old F344BN rats (6-7/group) over 40 days. MTII suppressed appetite in a dose-dependent manner (P < 0.05). Although food intake promptly rose back to control level, body mass was persistently reduced in both MTII groups (P < 0.01). At day 40, both MTII groups displayed lower adiposity than the aCSF animals (P < 0.01). These results show that MTII chronically reduces body mass without the requirement of long-term caloric restriction. Our study proposes that food restriction helps initiate mass loss; however, combined with a secondary pharmacological approach preserving a negative energy balance state over time may help combat obesity.

Is warmer better? Decreased oxidative damage in notothenioid fish after long-term acclimation to multiple stressors.

PubMed

Enzor, Laura A; Place, Sean P

2014-09-15

Antarctic fish of the suborder Notothenioidei have evolved several unique adaptations to deal with subzero temperatures. However, these adaptations may come with physiological trade-offs, such as an increased susceptibility to oxidative damage. As such, the expected environmental perturbations brought on by global climate change have the potential to significantly increase the level of oxidative stress and cellular damage in these endemic fish. Previous single stressor studies of the notothenioids have shown they possess the capacity to acclimate to increased temperatures, but the cellular-level effects remain largely unknown. Additionally, there is little information on the ability of Antarctic fish to respond to ecologically relevant environmental changes where multiple variables change concomitantly. We have examined the potential synergistic effects that increased temperature and Ṗ(CO2) have on the level of protein damage in Trematomus bernacchii, Pagothenia borchgrevinki and Trematomus newnesi, and combined these measurements with changes in total enzymatic activity of catalase (CAT) and superoxide dismutase (SOD) in order to gauge tissue-specific changes in antioxidant capacity. Our findings indicate that total SOD and CAT activity levels displayed only small changes across treatments and tissues. Short-term acclimation to decreased seawater pH and increased temperature resulted in significant increases in oxidative damage. Surprisingly, despite no significant change in antioxidant capacity, cellular damage returned to near-basal levels, and significantly decreased in T. bernacchii, after long-term acclimation. Overall, these data suggest that notothenioid fish currently maintain the antioxidant capacity necessary to offset predicted future ocean conditions, but it remains unclear whether this capacity comes with physiological trade-offs. © 2014. Published by The Company of Biologists Ltd.

Effects of light on the largest extant benthic foraminifer, Cycloclypeus carpenteri

NASA Astrophysics Data System (ADS)

Fujita, Kazuhiko; Kanda, Yoji

2015-04-01

Cycloclypeus carpenteri is the largest extant benthic foraminifer. This species dwells in deep euphotic depths of warm oligotrophic waters, and is a host to diatom endosymbionts. Fossil Cycloclypeus has been found in tropical shelf carbonates since the Oligocene. Light is supposed to be the primary environmental factor controlling the depth distribution of this species. However, physiological responses of this foraminifer to light are not yet well understood. We investigated short-term and long-term effects of light on Cycloclypeus carpenteri collected from about 70 m depth, west of Okinawa Island (Japan). To determine short-term responses to light, net oxygen production was measured at different light levels and wavelengths using an oxygen microelectrode. Photosynthesis-irradiance curve of this species indicated that net oxygen production increased up to 50 µE m-2 s-1, was saturated until 100 µE m-2 s-1, then was photoinhibited over 100 µE m-2 s-1. Net production was higher when incubated on blue wavelength than on either red or green wavelengths. To determine long-term light effects, asexually reproduced clone individuals were incubated for about 4 months at different light levels ranging from 0 to 100 µE m-2 s-1. The long-term incubations indicated that growth rates measured by the surface area were optimal at light levels from 5 to 50 µE m-2 s-1, but were lowered at 0 and 100 µE m-2 s-1. These results suggest that Cycloclypeus carpenteri can be acclimatized at less than 100 µE m-2 s-1 of light by changing photopigment (chrolophyll) concentrations of algal symbionts, but this species cannot survive in dark and over 100 µE m-2 s-1 of light due to the breakdown of algal symbiosis.

Long-term CO2 rise has increased photosynthetic efficiency and water use efficiency but did not stimulate diameter growth of tropical trees

NASA Astrophysics Data System (ADS)

Groenendijk, P.; Zuidema, P.; Sleen, P. V. D.; Vlam, M.; Ehlers, I.; Schleucher, J.

2014-12-01

Tropical forests are a crucial component of the global carbon cycle, and their responses to atmospheric changes may shift carbon cycling and climate systems. Dynamic Global Vegetation Models (DGVMs) are the major tools to simulate tropical forest responses to climate change. One of the main determinants of these simulated responses is the effect of CO2 on tropical tree physiology and growth, the 'CO2 fertilization effect'. The paucity of CO2 enrichment experiments in the tropics importantly limits insights into the CO2 fertilization effect as well as the validation of DGVMs. However, use can be made of the 40% rise in atmospheric CO2 concentration since the onset of the Industrial Revolution. The effects of the historical CO2 rise on tree physiology and growth can be obtained from stable isotopes, isotopomers and tree diameter increments obtained in tree-ring studies. We studied the physiological and growth responses of 12 tree species in Bolivia, Cameroon and Thailand to 150 years of CO2 enrichment. Analyses of 13C of wood cellulose revealed strong, long-term increases in leaf intercellular CO2 concentrations for all study species and a marked improvement of intrinsic water use efficiency (iWUE). For a subset of one species per site, we studied the Deuterium isotopomers (isomers with isotopic atoms) of glucose in wood to obtain a direct estimate of the photorespiration-to-photosynthesis ratio. We found that this ratio consistently and strongly decreased over the past century, thus increasing the effeciency and rate of photosynthesis. In spite of these strong physiological responses to increased CO2levels, we did not find evidence for increased tree diameter growth for any of the sites, or for sites combined. Possible reasons for the lack of a growth stimulation include increased (leaf) temperature, insufficient availability of nutrients or a shift in biomass investment in trees. Our results suggest that the strong CO2 fertilization of tropical tree growth often assumed in DGVMs does not hold and that these models may overestimate future biomass production in tropical forests. Empirical information on responses of tropical trees to historical CO2rise as presented here can be used to validate and possibly adapt (components of) DGVMs and improve the projections of tropical forest structure under climate change.

User's instructions for the whole-body algorithms

NASA Technical Reports Server (NTRS)

Grounds, D. J.; Fitzjerrell, D. G.; Leonard, J. I.; Marks, V. J.

1975-01-01

The design of an algorithm that provides for the simulation of long and short term biological stresses is reported. The physiological responses of models representing circulatory, respiratory, cardiovascular, and thermoregulatory systems during space flight simulation are described.

Catecholaminergic consolidation of motor cortical neuroplasticity in humans.

PubMed

Nitsche, Michael A; Grundey, Jessica; Liebetanz, David; Lang, Nicolas; Tergau, Frithjof; Paulus, Walter

2004-11-01

Amphetamine, a catecholaminergic re-uptake-blocker, is able to improve neuroplastic mechanisms in humans. However, so far not much is known about the underlying physiological mechanisms. Here, we study the impact of amphetamine on NMDA receptor-dependent long-lasting excitability modifications in the human motor cortex elicited by weak transcranial direct current stimulation (tDCS). Amphetamine significantly enhanced and prolonged increases in anodal, tDCS-induced, long-lasting excitability. Under amphetamine premedication, anodal tDCS resulted in an enhancement of excitability which lasted until the morning after tDCS, compared to approximately 1 h in the placebo condition. Prolongation of the excitability enhancement was most pronounced for long-term effects; the duration of short-term excitability enhancement was only slightly increased. Since the additional application of the NMDA receptor antagonist dextromethorphane blocked any enhancement of tDCS-driven excitability under amphetamine, we conclude that amphetamine consolidates the tDCS-induced neuroplastic effects, but does not initiate them. The fact that propanolol, a beta-adrenergic antagonist, diminished the duration of the tDCS-generated after-effects suggests that adrenergic receptors play a certain role in the consolidation of NMDA receptor-dependent motor cortical excitability modifications in humans. This result may enable researchers to optimize neuroplastic processes in the human brain on the rational basis of purpose-designed pharmacological interventions.

Extra-auditory responses to long-term intermittent noise stimulation in humans.

PubMed

Fruhstorfer, B; Hensel, H

1980-12-01

Respiration, heart rate, cutaneous blood flow, and electroencephalogram (EEG) reactions to long-term intermittent noise exposure were recorded from 13 volunteers (20-29 yr) with normal hearing and vegetative reactivity. They received daily within 1 h 12 noise stimuli (16 s 100 dB (A) white noise) for 10 or 21 days, respectively. Most subjects reported partial subjective adaptation to the noise. Heart rate adapted within a session but did not change considerably during successive days. Vascular responses did not change during one session but diminished mainly during the first 10 days. Noise responses in the EEG remained constant, but a decrease in vigilance occurred during the whole experimental series. Respiration responses were unpredictable and showed no trend within the sessions. It was concluded that certain physiological responses adapt to loud noise but that the time course of adaptation is different. Therefore a general statement about physiological noise adaptation is not possible.

Fasting - the ultimate diet?

PubMed

Johnstone, A M

2007-05-01

Adult humans often undertake acute fasts for cosmetic, religious or medical reasons. For example, an estimated 14% of US adults have reported using fasting as a means to control body weight and this approach has long been advocated as an intermittent treatment for gross refractory obesity. There are unique historical data sets on extreme forms of food restriction that give insight into the consequences of starvation or semi-starvation in previously healthy, but usually non-obese subjects. These include documented medical reports on victims of hunger strike, famine and prisoners of war. Such data provide a detailed account on how the body adapts to prolonged starvation. It has previously been shown that fasting for the biblical period of 40 days and 40 nights is well within the overall physiological capabilities of a healthy adult. However, the specific effects on the human body and mind are less clearly documented, either in the short term (hours) or in the longer term (days). This review asks the following three questions, pertinent to any weight-loss therapy, (i) how effective is the regime in achieving weight loss, (ii) what impact does it have on psychology? and finally, (iii) does it work long-term?

Studies of physiology and the morphology of the cat LGN following proton irradiation.

PubMed

Reder, C S; Moyers, M F; Lau, D; Kirby, M A

2000-03-15

We have examined the effects of proton irradiation on the histologic and receptive field properties of thalamic relay cells in the cat visual system. The cat lateral geniculate nucleus (LGN) is a large structure with well-defined anatomical boundaries, and well-described afferent, efferent, and receptive field properties. A 1.0-mm proton microbeam was used on the cat LGN to determine short-term (3 months) and long-term (9 months) receptive field effects of irradiation on LGN relay cells. The doses used were 16-, 40-, and 60-gray (Gy). Following irradiation, abnormalities in receptive field organization were found in 40- and 60-Gy short-term animals, and in all of the long-term animals. The abnormalities included "silent" areas of the LGN where a visual response could not be evoked and other regions that had unusually large or small compound receptive fields. Histologic analysis failed to identify cellular necrosis or vascular damage in the irradiated LGN, but revealed a disruption in retinal afferents to areas of the LGN. These results indicate that microbeam proton irradiation can disrupt cellular function in the absence of obvious cellular necrosis. Moreover, the area and extent of this disruption increased with time, having larger affect with longer post-irradiation periods.

Long Term Consequences: Effects on Normal Development Profile after Concussion

PubMed Central

Daneshvar, Daniel H.; Riley, David O.; Nowinski, Christopher J.; McKee, Ann C.; Stern, Robert A.; Cantu, Robert C.

2011-01-01

Each year in the United States, approximately 1.7 million people are diagnosed with a traumatic brain injury (TBI); an estimated 75% of these injuries are classified as mild TBIs (mTBI) or concussions. The symptoms of such injuries include a variety of somatic, cognitive, and behavioral deficits. While these symptoms typically resolve in a matter of weeks, both children and adults may suffer from Post-Concussion Syndrome (PCS) for months or longer. Suffering from PCS-related symptoms for an extended time may delay an individual’s return to work, adversely affect one’s quality of life, and result in additional social and economic costs. Though a consensus has not been reached on the cause of long-term PCS, it is likely that biological, physiological, psychological, and social elements all play a role in symptom persistence. Additionally, persistent PCS may adversely affect one’s developmental trajectory. The enduring effects of head trauma are not limited to PCS-related effects, however. A progressive tauopathy, chronic traumatic encephalopathy (CTE) is believed to stem from repeated brain trauma. While CTE was originally associated with boxing, it has recently been found in other cases of repetitive head injury including former football and hockey players, and professional wrestlers. In addition to this observed pathology, repetitive brain trauma is also associated with Alzheimer’s-like dementia, Parkinsonism, and motor neuron disease including Amyotrophic Lateral Sclerosis (ALS). With these significant long-term effects of head injuries, there is a clear need to develop effective diagnoses, treatments, and education plans to reduce future burden and incidence. PMID:22050943

The influence of a tilt training programme on the renin-angiotensin-aldosterone system activity in patients with vasovagal syncope.

PubMed

Gajek, Jacek; Zyśko, Dorota; Krzemińska, Sylwia; Mazurek, Walentyna

2009-08-01

We assessed the influence of short-term and long-term tilt training on the activity of the renin-angiotensin-aldosterone system (RAAS) in vasovagal patients. Thirty-nine patients (28 F, 11 M) aged 39.7 +/- 11.2 years with a history of vasovagal syncope and a positive head-up tilt test (HUT) were studied. Blood samples for plasma renin activity (PRA) and aldosterone (ALDO) concentration were drawn at the baseline, immediately after HUT and 10 min after HUT, during the diagnostic, the negative short-term (2-5 days) follow-up HUT and long-term (1-3 months) follow-up HUT. Tilt training was started after diagnostic HUT. In diagnostic HUT, PRA increased significantly immediately after HUT comparing to the baseline, during recovery the values did not change. ALDO concentration increased after HUT comparing to baseline and further increased during recovery. After short-term tilt training, PRA and ALDO concentrations did not significantly change compared to their corresponding values in diagnostic HUT. After long-term tilt training, PRA did not significantly change compared to the values in the diagnostic and short-term follow-up HUT. ALDO concentration also did not change significantly at the baseline and immediately after HUT, and 10 min after HUT ALDO concentration was significantly lower than after diagnostic HUT. Tilt training changes the response of RAAS to the prolonged orthostasis in vasovagal patients. The coupling between PRA and ALDO after diagnostic HUT has been found to be altered and the physiological relationship was restored after long-term tilt training. The beneficial effect of tilt training depends partially on changed RAAS activation.

Transient and permanent effects of suboptimal incubation temperatures on growth, metabolic rate, immune function and adrenocortical responses in zebra finches.

PubMed

Wada, Haruka; Kriengwatana, Buddhamas; Allen, Natalie; Schmidt, Kimberly L; Soma, Kiran K; MacDougall-Shackleton, Scott A

2015-09-01

In birds, incubation temperature can vary by several degrees Celsius among nests of a given species. Parents may alter incubation temperature to cope with environmental conditions and/or to manipulate embryonic development, and such changes in incubation behavior could have long-lasting effects on offspring phenotype. To investigate short- and long-term effects of suboptimal incubation temperatures on survival and physiological functions in zebra finches, eggs were incubated at 36.2, 37.4 or 38.4 °C for the entire incubation period. The post-hatch environment was identical among the treatment groups. We found that hatching success was lowest in the 38.4 °C group, while post-hatch survival was lowest in the 36.2 °C group. Incubation temperature had sex-specific effects on offspring phenotype: incubation temperatures affected body mass (Mb) but not physiological parameters of males and conversely, the physiological parameters but not Mb of females. Specifically, males from the 38.4 °C group weighed significantly less than males from the 36.2 °C group from the nestling period to adulthood, whereas females from different incubation temperature groups did not differ in Mb. In contrast, females incubated at 36.2 °C had transient but significantly elevated basal metabolic rate and adrenocortical responses during the nestling and fledgling periods, whereas no treatment effect was observed in males. Innate immunity was not affected by incubation temperature in either sex. These results suggest that a 1 °C deviation from what is considered an optimal incubation temperature can lower offspring performance and offspring survival. © 2015. Published by The Company of Biologists Ltd.

Longitudinal studies of time-dependent changes in both bladder and erectile function after streptozotocin-induced diabetes in Fischer 344 male rats.

PubMed

Melman, Arnold; Zotova, Elena; Kim, Mimi; Arezzo, Joseph; Davies, Kelvin; DiSanto, Michael; Tar, Moses

2009-11-01

To provide sensitive physiological endpoints for the onset and long-term progression of deficits induced by diabetes mellitus (DM) in bladder and erectile function in male rats, and to evaluate parallel changes in urogenital and nerve function induced by hyperglycaemia over a protracted period as a model for chronic deficits in patients with diabetes. The study comprised in 877 male, 3-month-old, Fischer 344 rats; 666 were injected intraperitoneally with 35 mg/kg streptozotocin (STZ) and divided into insulin-treated and untreated diabetic groups. The rats were studied over 8 months and measurements made of both erectile and bladder function, as well as nerve conduction studies over the duration of the study. There was an early (first month) abnormality of both erectile and bladder function that persisted through the 8 months of the study. The erectile dysfunction was manifest as reduced intracavernous pressure/blood pressure ratio, and the bladder dysfunction as a persistent increase in detrusor overactivity with no detrusor decompensation. Insulin treatment prevented or modified the abnormality in each organ. Hyperglycaemia caused a progressive decrease in caudal nerve conduction velocity. The mean digital sensory and tibial motor nerve conduction velocity did not deteriorate over time. Correlation measurements of nerve and organ function were not consistent. The results of this extensive long-term study show early and profound effects of hyperglycaemia on the smooth muscle of the penis and bladder, that were persistent and stable in surviving rats over the 8 months. The physiological changes did not correlate well with neurological measurements of those organs. Significantly, diverse smooth-muscle cellular and subcellular events antedated the measured neurological manifestations of the hyperglycaemia by several months. Although autonomic diabetic neuropathy is a primary life-threatening complication of long-term diabetes in humans, this rat model of STZ-induced diabetes showed that the rapid onset of physiological manifestations was based on many molecular changes in the smooth muscle cells in this model of type 1 DM.

Effects of Caffeine on Olfactory Learning in Crickets.

PubMed

Sugimachi, Seigo; Matsumoto, Yukihisa; Mizunami, Makoto; Okada, Jiro

2016-10-01

Caffeine is a plant-derived alkaloid that is generally known as a central nervous system (CNS) stimulant. In order to examine the effects of caffeine on higher CNS functions in insects, we used an appetitive olfactory learning paradigm for the cricket Gryllus bimaculatus. Crickets can form significant long-term memories (LTMs) after repetitive training sessions, during which they associate a conditioned stimulus (CS: odor) with an unconditioned stimulus (US: reward). Administration of hemolymphal injections of caffeine established LTM after only single-trial conditioning over a wide range of caffeine dosages (1.6 µµg/kg to 39 mg/kg). We investigated the physiological mechanisms underlying this enhancement of olfactory learning performance pharmacologically, focusing on three major physiological roles of caffeine: 1) inhibition of phosphodiesterase (PDE), 2) agonism of ryanodine receptors, and 3) antagonism of adenosine receptors. Application of drugs relevant to these actions resulted in significant effects on LTM formation. These results suggest that externally applied caffeine enhances LTM formation in insect olfactory learning via multiple cellular mechanisms.

Long-term memory deficits in Pavlovian fear conditioning in Ca2+/calmodulin kinase kinase alpha-deficient mice.

PubMed

Blaeser, Frank; Sanders, Matthew J; Truong, Nga; Ko, Shanelle; Wu, Long Jun; Wozniak, David F; Fanselow, Michael S; Zhuo, Min; Chatila, Talal A

2006-12-01

Signaling by the Ca(2+)/calmodulin kinase (CaMK) cascade has been implicated in neuronal gene transcription, synaptic plasticity, and long-term memory consolidation. The CaM kinase kinase alpha (CaMKKalpha) isoform is an upstream component of the CaMK cascade whose function in different behavioral and learning and memory paradigms was analyzed by targeted gene disruption in mice. CaMKKalpha mutants exhibited normal long-term spatial memory formation and cued fear conditioning but showed deficits in context fear during both conditioning and long-term follow-up testing. They also exhibited impaired activation of the downstream kinase CaMKIV/Gr and its substrate, the transcription factor cyclic AMP-responsive element binding protein (CREB) upon fear conditioning. Unlike CaMKIV/Gr-deficient mice, the CaMKKalpha mutants exhibited normal long-term potentiation and normal levels of anxiety-like behavior. These results demonstrate a selective role for CaMKKalpha in contextual fear memory and suggest that different combinations of upstream and downstream components of the CaMK cascade may serve distinct physiological functions.

Meeting Report: The Role of Environmental Lighting and Circadian Disruption in Cancer and Other Diseases

PubMed Central

Stevens, Richard G.; Blask, David E.; Brainard, George C.; Hansen, Johnni; Lockley, Steven W.; Provencio, Ignacio; Rea, Mark S.; Reinlib, Leslie

2007-01-01

Light, including artificial light, has a range of effects on human physiology and behavior and can therefore alter human physiology when inappropriately timed. One example of potential light-induced disruption is the effect of light on circadian organization, including the production of several hormone rhythms. Changes in light–dark exposure (e.g., by nonday occupation or transmeridian travel) shift the timing of the circadian system such that internal rhythms can become desynchronized from both the external environment and internally with each other, impairing our ability to sleep and wake at the appropriate times and compromising physiologic and metabolic processes. Light can also have direct acute effects on neuroendocrine systems, for example, in suppressing melatonin synthesis or elevating cortisol production that may have untoward long-term consequences. For these reasons, the National Institute of Environmental Health Sciences convened a workshop of a diverse group of scientists to consider how best to conduct research on possible connections between lighting and health. According to the participants in the workshop, there are three broad areas of research effort that need to be addressed. First are the basic biophysical and molecular genetic mechanisms for phototransduction for circadian, neuroendocrine, and neurobehavioral regulation. Second are the possible physiologic consequences of disrupting these circadian regulatory processes such as on hormone production, particularly melatonin, and normal and neoplastic tissue growth dynamics. Third are effects of light-induced physiologic disruption on disease occurrence and prognosis, and how prevention and treatment could be improved by application of this knowledge. PMID:17805428

Short-term effects of fertilization on loblolly pine (Pinus taeda L.) physiology

Treesearch

C.M. Gough; J.R. Seiler; Chris A. Maier

2004-01-01

Fertilization commonly increases biomass production in loblolly pine (Pinus taeda L.). However, the sequence of short-term physiological adjustments allowing for the establishment of leaf area and enhanced growth is not well understood. The effects of fertilization on photosynthetic parameters, root respiration, and growth for over 200 d following...

Environment, behavior and physiology: do birds use barometric pressure to predict storms?

PubMed

Breuner, Creagh W; Sprague, Rachel S; Patterson, Stephen H; Woods, H Arthur

2013-06-01

Severe storms can pose a grave challenge to the temperature and energy homeostasis of small endothermic vertebrates. Storms are accompanied by lower temperatures and wind, increasing metabolic expenditure, and can inhibit foraging, thereby limiting energy intake. To avoid these potential problems, most endotherms have mechanisms for offsetting the energetic risks posed by storms. One possibility is to use cues to predict oncoming storms and to alter physiology and behavior in ways that make survival more likely. Barometric pressure declines predictably before inclement weather, and several lines of evidence indicate that animals alter behavior based on changes in ambient pressure. Here we examined the effects of declining barometric pressure on physiology and behavior in the white-crowned sparrow, Zonotrichia leucophrys. Using field data from a long-term study, we first evaluated the relationship between barometric pressure, storms and stress physiology in free-living white-crowned sparrows. We then manipulated barometric pressure experimentally in the laboratory and determined how it affects activity, food intake, metabolic rates and stress physiology. The field data showed declining barometric pressure in the 12-24 h preceding snowstorms, but we found no relationship between barometric pressure and stress physiology. The laboratory study showed that declining barometric pressure stimulated food intake, but had no effect on metabolic rate or stress physiology. These data suggest that white-crowned sparrows can sense and respond to declining barometric pressure, and we propose that such an ability may be common in wild vertebrates, especially small ones for whom individual storms can be life-threatening events.

[PSYCHO PHYSIOLOGICAL MARKERS OF ACCELERATED AGING AMONG THOSE WORKING WITH OCCUPATIONAL HAZARDS].

PubMed

Bashkireva, A S; Kachan, Ye Yu; Kulapina, M E

2015-01-01

Using comparative analysis of two occupational groups we assessed the significance of psycho physiological markers of short-term memory accelerated aging in order to reveal how the age-related changes and working process affect mental work capacity. We revealed peculiarities of systemic structure of functions which determine mental work capacity depending on the age and length of service in lorry drivers. It was proved that age and long driving experience affect mnestic functions which show up quantitative and qualitative changes such as reduced volume of memorized information, longer time needed to memorize it, and tendency to diminished accuracy of memorization. We also proved that premature age-related changes of psycho physiological indices in drivers are the "risk indicators", while long driving experience is a real risk factor contributing to the acceleration of aging.

Benefits of thermal acclimation in a tropical aquatic ectotherm, the Arafura filesnake, Acrochordus arafurae.

PubMed

Bruton, Melissa J; Cramp, Rebecca L; Franklin, Craig E

2012-05-01

The presumption that organisms benefit from thermal acclimation has been widely debated in the literature. The ability to thermally acclimate to offset temperature effects on physiological function is prevalent in ectotherms that are unable to thermoregulate year-round to maintain performance. In this study we examined the physiological and behavioural consequences of long-term exposure to different water temperatures in the aquatic snake Acrochordus arafurae. We hypothesised that long dives would benefit this species by reducing the likelihood of avian predation. To achieve longer dives at high temperatures, we predicted that thermal acclimation of A. arafurae would reduce metabolic rate and increase use of aquatic respiration. Acrochordus arafurae were held at 24 or 32°C for 3 months before dive duration and physiological factors were assessed (at both 24 and 32°C). Although filesnakes demonstrated thermal acclimation of metabolic rate, use of aquatic respiration was thermally independent and did not acclimate. Mean dive duration did not differ between the acclimation groups at either temperature; however, warm-acclimated animals increased maximum and modal dive duration, demonstrating a longer dive duration capacity. Our study established that A. arafurae is capable of thermal acclimation and this confers a benefit to the diving abilities of this snake.

Does Environmental Enrichment Reduce Stress? An Integrated Measure of Corticosterone from Feathers Provides a Novel Perspective

PubMed Central

Fairhurst, Graham D.; Frey, Matthew D.; Reichert, James F.; Szelest, Izabela; Kelly, Debbie M.; Bortolotti, Gary R.

2011-01-01

Enrichment is widely used as tool for managing fearfulness, undesirable behaviors, and stress in captive animals, and for studying exploration and personality. Inconsistencies in previous studies of physiological and behavioral responses to enrichment led us to hypothesize that enrichment and its removal are stressful environmental changes to which the hormone corticosterone and fearfulness, activity, and exploration behaviors ought to be sensitive. We conducted two experiments with a captive population of wild-caught Clark's nutcrackers (Nucifraga columbiana) to assess responses to short- (10-d) and long-term (3-mo) enrichment, their removal, and the influence of novelty, within the same animal. Variation in an integrated measure of corticosterone from feathers, combined with video recordings of behaviors, suggests that how individuals perceive enrichment and its removal depends on the duration of exposure. Short- and long-term enrichment elicited different physiological responses, with the former acting as a stressor and birds exhibiting acclimation to the latter. Non-novel enrichment evoked the strongest corticosterone responses of all the treatments, suggesting that the second exposure to the same objects acted as a physiological cue, and that acclimation was overridden by negative past experience. Birds showed weak behavioral responses that were not related to corticosterone. By demonstrating that an integrated measure of glucocorticoid physiology varies significantly with changes to enrichment in the absence of agonistic interactions, our study sheds light on potential mechanisms driving physiological and behavioral responses to environmental change. PMID:21412426

Chromium-induced kidney disease.

PubMed

Wedeen, R P; Qian, L F

1991-05-01

Kidney disease is often cited as one of the adverse effects of chromium, yet chronic renal disease due to occupational or environmental exposure to chromium has not yet been reported. Occasional cases of acute tubular necrosis (ATN) following massive absorption of chromate have been described. Chromate-induced ATN has been extensively studied in experimental animals following parenteral administration of large doses of potassium chromate (hexavalent) (15 mg/kg body weight). The chromate is selectively accumulated in the convoluted proximal tubule where necrosis occurs. An adverse long-term effect of low-dose chromium exposure on the kidneys is suggested by reports of low molecular weight (LMW) proteinuria in chromium workers. Excessive urinary excretion of beta 2-microglobulin, a specific proximal tubule brush border protein, and retinol-binding protein has been reported among chrome platers and welders. However, LMW proteinuria occurs after a variety of physiologic stresses, is usually reversible, and cannot by itself be considered evidence of chronic renal disease. Chromate-induced ATN and LMW proteinuria in chromium workers, nevertheless, raise the possibility that low-level, long-term exposure may produce persistent renal injury. The absence of evidence of chromate-induced exposure may produce persistent renal injury. The absence of evidence of chromate-induced chronic renal disease cannot be interpreted as evidence of the absence of such injury. Rather, it must be recognized that no prospective cohort or case-control study of the delayed renal effects of low-level, long-term exposure to chromium has been published.

The selective A-type K+ current blocker Tx3-1 isolated from the Phoneutria nigriventer venom enhances memory of naïve and Aβ(25-35)-treated mice.

PubMed

Gomes, Guilherme M; Dalmolin, Gerusa D; Cordeiro, Marta do Nascimento; Gomez, Marcus V; Ferreira, Juliano; Rubin, Maribel A

2013-12-15

Potassium channels regulate many neuronal functions, including neuronal excitability and synaptic plasticity, contributing, by these means, to mnemonic processes. In particular, A-type K(+) currents (IA) play a key role in hippocampal synaptic plasticity. Therefore, we evaluated the effect of the peptidic toxin Tx3-1, a selective blocker of IA currents, extracted from the venom of the spider Phoneutria nigriventer, on memory of mice. Administration of Tx3-1 (i.c.v., 300 pmol/site) enhanced both short- and long-term memory consolidation of mice tested in the novel object recognition task. In comparison, 4-aminopyridine (4-AP; i.c.v., 30-300 pmol/site), a non-selective K(+) channel blocker did not alter long-term memory and caused toxic side effects such as circling, freezing and tonic-clonic seizures. Moreover, Tx3-1 (i.c.v., 10-100 pmol/site) restored memory of Aβ25-35-injected mice, and exhibited a higher potency to improve memory of Aβ25-35-injected mice when compared to control group. These results show the effect of the selective blocker of IA currents Tx3-1 in both short- and long-term memory retention and in memory impairment caused by Aβ25-35, reinforcing the role of IA in physiological and pathological memory processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Organomatics and organometrics: Novel platforms for long-term whole-organ culture

PubMed Central

Bruinsma, Bote G.; Yarmush, Martin L.; Uygun, Korkut

2014-01-01

Organ culture systems are instrumental as experimental whole-organ models of physiology and disease, as well as preservation modalities facilitating organ replacement therapies such as transplantation. Nevertheless, a coordinated system of machine perfusion components and integrated regulatory control has yet to be fully developed to achieve long-term maintenance of organ function ex vivo. Here we outline current strategies for organ culture, or organomatics, and how these systems can be regulated by means of computational algorithms, or organometrics, to achieve the organ culture platforms anticipated in modern-day biomedicine. PMID:25035864

Feasibility assessment of Doppler radar long-term physiological measurements.

PubMed

Massagram, Wansuree; Lubecke, Victor M; Boric-Lubecke, Olga

2011-01-01

In this paper we examine the feasibility of applying doppler radar technique for a long-term health monitoring. Doppler radar was used to detect and eliminate periods of significant motion. This technique was verified using a human study on 17 subjects, and it was determined that for 15 out of 17 subjects there was no significant motion for over 85% of the measurement interval in supine positions. Majority of subjects exhibited significantly less motion in supine position, which is promising for sleep monitoring, and monitoring of hospitalized patients.

Intraspecific variation in social organization by genetic variation, developmental plasticity, social flexibility or entirely extrinsic factors.

PubMed

Schradin, Carsten

2013-05-19

Previously, it was widely believed that each species has a specific social organization, but we know now that many species show intraspecific variation in their social organization. Four different processes can lead to intraspecific variation in social organization: (i) genetic variation between individuals owing to local adaptation (between populations) or evolutionarily stable strategies within populations; (ii) developmental plasticity evolved in long-term (more than one generation) unpredictable and short-term (one generation) predictable environments, which is mediated by organizational physiological effects during early ontogeny; (iii) social flexibility evolved in highly unpredictable environments, which is mediated by activational physiological effects in adults; (iv) entirely extrinsic factors such as the death of a dominant breeder. Variation in social behaviour occurs between individuals in the case of genetic variation and developmental plasticity, but within individuals in the case of social flexibility. It is important to study intraspecific variation in social organization to understand the social systems of species because it reveals the mechanisms by which species can adapt to changing environments, offers a useful tool to study the ultimate and proximate causes of sociality, and is an interesting phenomenon by itself that needs scientific explanation.

Pregnant Women's Preferences for Men's Faces Differ Significantly from Nonpregnant Women.

PubMed

Limoncin, Erika; Ciocca, Giacomo; Gravina, Giovanni Luca; Carosa, Eleonora; Mollaioli, Daniele; Cellerino, Alessandro; Mennucci, Andrea; Di Sante, Stefania; Lenzi, Andrea; Jannini, Emmanuele A

2015-05-01

There is evidence that women's preferences for facial characteristics in men's faces change according to menstrual phase and sexual hormones. Literature indicates that the pregnancy is characterized by a specific sexual hormonal pattern with respect to all other physiological conditions concerning the sexual hormone status during the reproductive age, configuring this physiological condition as an excellent surrogate to study how the sexual hormones may affect many of the aspects concerning the sexual behavior. The aim of this study was to investigate pregnancy as a model of hormonal influence on women's facial preferences in short-term and long-term relationships and compare the choices of pregnant women with those of nonpregnant women. Measurement of women's preferences for synthetic men's faces, morphed from hyper-masculine to hypomasculine shape. Forty-six women in the third trimester of pregnancy, and 70 nonpregnant women took part in the study. All women were shown a composite male face. The sexual dimorphism of the images was enhanced or reduced in a continuous fashion using an open-source morphing program that produced a sequence of 21 pictures of the same face warped from a feminized to a masculinized shape. Pregnant women's choices differed significantly from those of nonpregnant women. In fact, in the context of both a hypothetical short- (M = -0.4 ± 0.11) and long-term relationship (M = -0.4 ± 0.07) pregnant women showed a clear preference for a less masculine man's face than the other group (short-term: M = 0.15 ± 0.13; long-term: M = -0.06 ± 0.15; P < 0.0001). Women in the third trimester of pregnancy clearly prefer more feminine men's faces, distancing themselves from the choices of women in other physiological conditions concerning the sexual hormonal status during the reproductive age. However, other psychosocial variables may explain this interesting finding. © 2015 International Society for Sexual Medicine.

Human Aging: Usual and Successful.

ERIC Educational Resources Information Center

Rowe, John W.; Kahn, Robert L.

1987-01-01

Offers perspectives on the role of extrinsic factors in the aging process, the long-term consequences of extrinsically initiated changes, and implications for gerontological research. Explains the distinction between usual and successful aging in light of physiologic and psychosocial characteristics. (ML)

Heart rate complexity in sinoaortic-denervated mice.

PubMed

Silva, Luiz Eduardo V; Rodrigues, Fernanda Luciano; de Oliveira, Mauro; Salgado, Hélio Cesar; Fazan, Rubens

2015-02-01

What is the central question of this study? New measurements for cardiovascular complexity, such as detrended fluctuation analysis (DFA) and multiscale entropy (MSE), have been shown to predict cardiovascular outcomes. Given that cardiovascular diseases are accompanied by autonomic imbalance and decreased baroreflex sensitivity, the central question is: do baroreceptors contribute to cardiovascular complexity? What is the main finding and its importance? Sinoaortic denervation altered both DFA scaling exponents and MSE, indicating that both short- and long-term mechanisms of complexity are altered in sinoaortic denervated mice, resulting in a loss of physiological complexity. These results suggest that the baroreflex is a key element in the complex structures involved in heart rate variability regulation. Recently, heart rate (HR) oscillations have been recognized as complex behaviours derived from non-linear processes. Physiological complexity theory is based on the idea that healthy systems present high complexity, i.e. non-linear, fractal variability at multiple scales, with long-range correlations. The loss of complexity in heart rate variability (HRV) has been shown to predict adverse cardiovascular outcomes. Based on the idea that most cardiovascular diseases are accompanied by autonomic imbalance and a decrease in baroreflex sensitivity, we hypothesize that the baroreflex plays an important role in complex cardiovascular behaviour. Mice that had been subjected to sinoaortic denervation (SAD) were implanted with catheters in the femoral artery and jugular vein 5 days prior to the experiment. After recording the baseline arterial pressure (AP), pulse interval time series were generated from the intervals between consecutive values of diastolic pressure. The complexity of the HRV was determined using detrended fluctuation analysis and multiscale entropy. The detrended fluctuation analysis α1 scaling exponent (a short-term index) was remarkably decreased in the SAD mice (0.79 ± 0.06 versus 1.13 ± 0.04 for the control mice), whereas SAD slightly increased the α2 scaling exponent (a long-term index; 1.12 ± 0.03 versus 1.04 ± 0.02 for control mice). In the SAD mice, the total multiscale entropy was decreased (13.2 ± 1.3) compared with the control mice (18.9 ± 1.4). In conclusion, fractal and regularity structures of HRV are altered in SAD mice, affecting both short- and long-term mechanisms of complexity, suggesting that the baroreceptors play a considerable role in the complex structure of HRV. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Physiological responses and evaluation of effects of BMI, smoking and drinking in high altitude acclimatization: a cohort study in Chinese Han young males.

PubMed

Peng, Qian-Qian; Basang, Zhuoma; Cui, Chao-Ying; Li, Lei; Qian, Ji; Gesang, Quzhen; Yang, La; La, Zong; De, Yang; Dawa, Puchi; Qu, Ni; Suo, Qu; Dan, Zhen; Xiao, Duoji; Wang, Xiao-Feng; Jin, Li

2013-01-01

High altitude acclimatization is a series of physiological responses taking places when subjects go to altitude. Many factors could influence these processes, such as altitude, ascending speed and individual characteristics. In this study, based on a repeated measurement design of three sequential measurements at baseline, acute phase and chronic phase, we evaluated the effect of BMI, smoking and drinking on a number of physiological responses in high altitude acclimatization by using mixed model and partial least square path model on a sample of 755 Han Chinese young males. We found that subjects with higher BMI responses were reluctant to hypoxia. The effect of smoking was not significant at acute phase. But at chronic phase, red blood cell volume increased less while respiratory function increased more for smoking subjects compared with nonsmokers. For drinking subjects, red blood cell volume increased less than nondrinkers at both acute and chronic phases, while blood pressures increased more than nondrinkers at acute phase and respiratory function, red blood cell volume and oxygen saturation increased more than nondrinkers at chronic phase. The heavy and long-term effect of smoking, drinking and other factors in high altitude acclimatization needed to be further studied.

Physiological Responses and Evaluation of Effects of BMI, Smoking and Drinking in High Altitude Acclimatization: A Cohort Study in Chinese Han Young Males

PubMed Central

Cui, Chao-ying; Li, Lei; Qian, Ji; Gesang, Quzhen; Yang, La; La, Zong; De, Yang; Dawa, Puchi; Qu, Ni; Suo, Qu; Dan, Zhen; Xiao, Duoji; Wang, Xiao-feng; Jin, Li

2013-01-01

High altitude acclimatization is a series of physiological responses taking places when subjects go to altitude. Many factors could influence these processes, such as altitude, ascending speed and individual characteristics. In this study, based on a repeated measurement design of three sequential measurements at baseline, acute phase and chronic phase, we evaluated the effect of BMI, smoking and drinking on a number of physiological responses in high altitude acclimatization by using mixed model and partial least square path model on a sample of 755 Han Chinese young males. We found that subjects with higher BMI responses were reluctant to hypoxia. The effect of smoking was not significant at acute phase. But at chronic phase, red blood cell volume increased less while respiratory function increased more for smoking subjects compared with nonsmokers. For drinking subjects, red blood cell volume increased less than nondrinkers at both acute and chronic phases, while blood pressures increased more than nondrinkers at acute phase and respiratory function, red blood cell volume and oxygen saturation increased more than nondrinkers at chronic phase. The heavy and long-term effect of smoking, drinking and other factors in high altitude acclimatization needed to be further studied. PMID:24260204

Physiological effects and therapeutic potential of proinsulin C-peptide

PubMed Central

Maric-Bilkan, Christine; Luppi, Patrizia; Wahren, John

2014-01-01

Connecting Peptide, or C-peptide, is a product of the insulin prohormone, and is released with and in amounts equimolar to those of insulin. While it was once thought that C-peptide was biologically inert and had little biological significance beyond its role in the proper folding of insulin, it is now known that C-peptide binds specifically to the cell membranes of a variety of tissues and initiates specific intracellular signaling cascades that are pertussis toxin sensitive. Although it is now clear that C-peptide is a biologically active molecule, controversy still remains as to the physiological significance of the peptide. Interestingly, C-peptide appears to reverse the deleterious effects of high glucose in some tissues, including the kidney, the peripheral nerves, and the vasculature. C-peptide is thus a potential therapeutic agent for the treatment of diabetes-associated long-term complications. This review addresses the possible physiologically relevant roles of C-peptide in both normal and disease states and discusses the effects of the peptide on sensory nerve, renal, and vascular function. Furthermore, we highlight the intracellular effects of the peptide and present novel strategies for the determination of the C-peptide receptor(s). Finally, a hypothesis is offered concerning the relationship between C-peptide and the development of microvascular complications of diabetes. PMID:25249503

Effect of 24-hour mandatory vs on-demand critical care specialist presence on long-term survival and quality of life of critically ill patients in the intensive care unit of a teaching hospital.

PubMed

Reriani, Martin; Biehl, Michelle; Sloan, Jeff A; Malinchoc, Michael; Gajic, Ognjen

2012-08-01

Mandatory compared with on-demand intensivist presence improves processes of care and decreases intensive care unit (ICU) complication rate and hospital length of stay. The effect of continuous mandatory intensivist coverage on long-term patient mortality and quality of life (QOL) is not known. We compared the long-term survival before (year 2005) and after (year 2006) the intervention when the staffing model changed from on-demand presence to mandatory 24-hour staff-critical care specialist presence in the medical ICU. Baseline and 6-month QOL surveys (SF-36 [short form 36 health survey]) were compared in subgroups of patients admitted before and after the staffing change. Cox proportional hazard and paired statistical analyses were used for survival and QOL comparisons. The baseline characteristics did not differ significantly between the 2 groups except for race and Acute Physiology and Chronic Health Evaluation III score (median, 30 vs 37; P < .001 before and after the staffing model change). Long-term survival was not significantly different before and after the staffing change-adjusted hazard ratio, 1.05; 95% confidence interval, 0.95 to 1.16; P = .3. In a subset of ICU survivors, SF-36 physical component score improved significantly at 6 months compared with baseline after the staffing model change-Δ mean (SD) 8 (14) vs 2 (11), P = .03. However, there was no difference in the Δ mean mental component score of the SF-36 between the 2 groups (P = .77). Introduction of an additional night shift to provide mandatory as opposed to on-demand 24-hour staff critical care specialist coverage did not affect long-term survival of medical ICU patients. Copyright © 2012 Elsevier Inc. All rights reserved.

Recreation Embedded State Tuning for Optimal Readiness and Effectiveness (RESTORE)

NASA Technical Reports Server (NTRS)

Pope, Alan T.; Prinzel, Lawrence J., III

2005-01-01

Physiological self-regulation training is a behavioral medicine intervention that has demonstrated capability to improve psychophysiological coping responses to stressful experiences and to foster optimal behavioral and cognitive performance. Once developed, these psychophysiological skills require regular practice for maintenance. A concomitant benefit of these physiologically monitored practice sessions is the opportunity to track crew psychophysiological responses to the challenges of the practice task in order to detect shifts in adaptability that may foretell performance degradation. Long-duration missions will include crew recreation periods that will afford physiological self-regulation training opportunities. However, to promote adherence to the regimen, the practice experience that occupies their recreation time must be perceived by the crew as engaging and entertaining throughout repeated reinforcement sessions on long-duration missions. NASA biocybernetic technologies and publications have developed a closed-loop concept that involves adjusting or modulating (cybernetic, for governing) a person's task environment based upon a comparison of that person's physiological responses (bio-) with a training or performance criterion. This approach affords the opportunity to deliver physiological self-regulation training in an entertaining and motivating fashion and can also be employed to create a conditioned association between effective performance state and task execution behaviors, while enabling tracking of individuals psychophysiological status over time in the context of an interactive task challenge. This paper describes the aerospace spin-off technologies in this training application area as well as the current spin-back application of the technologies to long-duration missions - the Recreation Embedded State Tuning for Optimal Readiness and Effectiveness (RESTORE) concept. The RESTORE technology is designed to provide a physiological self-regulation training countermeasure for maintaining and reinforcing cognitive readiness, resilience under psychological stress, and effective mood states in long-duration crews. The technology consists of a system for delivering physiological self-regulation training and for tracking crew central and autonomic nervous system function; the system interface is designed to be experienced as engaging and entertaining throughout repeated training sessions on long-duration missions. Consequently, this self-management technology has threefold capability for recreation, behavioral health problem prophylaxis and remediation, and psychophysiological assay. The RESTORE concept aims to reduce the risk of future manned exploration missions by enhancing the capability of individual crewmembers to self-regulate cognitive states through recreation-embedded training protocols to effectively deal with the psychological toll of long-duration space flight.

Melatonin: Pharmacology, Functions and Therapeutic Benefits

PubMed Central

Tordjman, Sylvie; Chokron, Sylvie; Delorme, Richard; Charrier, Annaëlle; Bellissant, Eric; Jaafari, Nemat; Fougerou, Claire

2017-01-01

Abstract: Background: Melatonin synchronizes central but also peripheral oscillators (fetal adrenal gland, pancreas, liver, kidney, heart, lung, fat, gut, etc.), allowing temporal organization of biological functions through circadian rhythms (24-hour cycles) in relation to periodic environmental changes and therefore adaptation of the individual to his/her internal and external environment. Measures of melatonin are considered the best peripheral indices of human circadian timing based on an internal 24-hour clock. Methods: First, the pharmacology of melatonin (biosynthesis and circadian rhythms, pharmacokinetics and mechanisms of action) is described, allowing a better understanding of the short and long term effects of melatonin following its immediate or prolonged release. Then, research related to the physiological effects of melatonin is reviewed. Results: The physiological effects of melatonin are various and include detoxification of free radicals and antioxidant actions, bone formation and protection, reproduction, and cardiovascular, immune or body mass regulation. Also, protective and therapeutic effects of melatonin are reported, especially with regard to brain or gastrointestinal protection, psychiatric disorders, cardiovascular diseases and oncostatic effects. Conclusion: This review highlights the high number and diversity of major melatonin effects and opens important perspectives for measuring melatonin as a biomarker (biomarker of early identification of certain disorders and also biomarker of their follow-up) and using melatonin with clinical preventive and therapeutic applications in newborns, children and adults based on its physiological regulatory effects. PMID:28503116

Clinical aspects of blood pressure autorhythmometry

NASA Technical Reports Server (NTRS)

Levine, H.; Halberg, F.

1974-01-01

Self-measurements made by a 55-year-old physician with mild to moderate hypertension of ten years' duration are considered. The physician had been in excellent health until age 45 when sustained elevation of blood pressure up to 180/100 mmHg and a slight aortic diastolic murmur were noted. On the basis of the investigation it is suggested that physical and mental performance measures provide an objective basis for assessing the desirability of a given physiological change. Such studies will have to be complemented by a search for long-term effects.

Conceptualization and design of a variable-gravity research facility

NASA Technical Reports Server (NTRS)

1987-01-01

The goal is to provide facilities for the study of the effects of variable-gravity levels in reducing the physiological stresses upon the humans of long-term stay time in zero-g. The designs studied include: twin-tethered two module system with a central despun module with docking port and winch gear; and rigid arm tube facility using shuttle external tanks. Topics examined included: despun central capsule configuration, docking clearances, EVA requirements, crew selection, crew scheduling, food supply and preparation, waste handling, leisure use, biomedical issues, and psycho-social issues.

Phytoestrogens and Their Metabolites in Bulk-Tank Milk: Effects of Farm Management and Season

PubMed Central

Adler, Steffen A.; Purup, Stig; Hansen-Møller, Jens; Thuen, Erling; Steinshamn, Håvard

2015-01-01

Phytoestrogens have structures similar to endogenous steroids and may induce or inhibit the response of hormone receptors. The objectives of the present study were to compare the effects of long-term vs. short-term grassland management in organic and conventional dairy production systems, compare organic and conventional production systems and assess seasonal variation on phytoestrogen concentrations in bulk-tank milk. The concentrations of phytoestrogens were analyzed in bulk-tank milk sampled three times in two subsequent years from 28 dairy farms: Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON) farms with respect to grassland management. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. The proportion of red clover (Trifolium pretense L.) in the herbage was positively correlated with milk concentrations of the mammalian isoflavone equol. Therefore, organically produced bulk-tank milk contained more equol than conventionally produced milk, and milk from ORG-SG farms had more equol than milk from ORG-LG farms. Milk produced during the indoor-feeding periods had more equol than milk produced during the outdoor feeding period, because pastures contained less red clover than fields intended for silage production. Organically produced milk had also higher concentrations of the mammalian lignan enterolactone, but in contrast to equol, concentrations increased in the outdoor-feeding periods compared to the indoor-feeding periods. There were no indications of fertility problems on ORG-SG farms who had the highest red clover proportions in the herbage. This study shows that production system, grassland management, and season affect milk concentrations of phytoestrogens. However, compared to soy products, milk concentrations of phytoestrogens are low and future studies are required to investigate if the intake of phytoestrogens from dairy products has physiological effects in humans. PMID:25996600

Behavioural and physiological responses of limpet prey to a seastar predator and their transmission to basal trophic levels.

PubMed

Manzur, Tatiana; Vidal, Francisco; Pantoja, José F; Fernández, Miriam; Navarrete, Sergio A

2014-07-01

Besides the well-documented behavioural changes induced by predators on prey, predator-induced stress can also include a suite of biochemical, neurological and metabolic changes that may represent important energetic costs and have long-lasting effects on individuals and on the demography of prey populations. The rapid transmission of prey behavioural changes to lower trophic levels, usually associated with alteration of feeding rates, can substantially change and even reverse direction over the long term as prey cope with the energetic costs associated with predation-induced stress. It is therefore critical to evaluate different aspects and assess the costs of non-consumptive predator effects on prey. We investigated the behavioural and physiological responses of an herbivorous limpet, Fissurella limbata, to the presence of chemical cues and direct non-lethal contact by the common seastar predator, Heliaster helianthus. We also evaluated whether the limpets feeding behaviour was modified by the predator and whether this translated into positive or negative effects on biomass of the green alga, Ulva sp. Our experimental results show the presence of Heliaster led to increased movement activity, increased distances travelled, changes in time budget over different environmental conditions and increased feeding rate in the keyhole limpets. Moreover, additional experiments showed that, beyond the increased metabolic rate associated with limpet increased activity, predator chemical cues heighten metabolic rate as part of the induced stress response. Changes in individual movement and displacement distances observed through the 9-day experiment can be interpreted as part of the escape response exhibited by limpets to reduce the risk of being captured by the predator. Increased limpet feeding rate on algae can be visualized as a way individuals compensate for the elevated energetic costs of movement and heightened metabolic rates produced by the predator-induced stress, which can lead to negative effects on abundance of the lower trophic level. We suggest that in order to understand the total non-consumptive effect of predators in natural communities, it is necessary to evaluate not only short-term behavioural responses, but also the costs associated with the multiple interdependent pathways triggered by predator-induced stress, and determine how individuals cope with these costs in the long term. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

High Dietary Protein Intake and Protein-Related Acid Load on Bone Health.

PubMed

Cao, Jay J

2017-12-01

Consumption of high-protein diets is increasingly popular due to the benefits of protein on preserving lean mass and controlling appetite and satiety. The paper is to review recent clinical research assessing dietary protein on calcium metabolism and bone health. Epidemiological studies show that long-term, high-protein intake is positively associated with bone mineral density and reduced risk of bone fracture incidence. Short-term interventional studies demonstrate that a high-protein diet does not negatively affect calcium homeostasis. Existing evidence supports that the negative effects of the acid load of protein on urinary calcium excretion are offset by the beneficial skeletal effects of high-protein intake. Future research should focus on the role and the degree of contribution of other dietary and physiological factors, such as intake of fruits and vegetables, in reducing the acid load and further enhancing the anabolic effects of protein on the musculoskeletal system.

Significance of microbial asynchronous anabolism to soil carbon dynamics driven by litter inputs

PubMed Central

Fan, Zhaosheng; Liang, Chao

2015-01-01

Soil organic carbon (SOC) plays an important role in the global carbon cycle. However, it remains largely unknown how plant litter inputs impact magnitude, composition and source configuration of the SOC stocks over long term through microbial catabolism and anabolism, mostly due to uncoupled research on litter decomposition and SOC formation. This limits our ability to predict soil system responses to changes in land-use and climate. Here, we examine how microbes act as a valve controlling carbon sequestrated from plant litters versus released to the atmosphere in natural ecosystems amended with plant litters varying in quantity and quality. We find that litter quality – not quantity – regulates long-term SOC dynamics under different plausible scenarios. Long-term changes in bulk SOC stock occur only when the quality of carbon inputs causes asynchronous change in a microbial physiological trait, defined as “microbial biosynthesis acceleration” (MBA). This is the first theoretical demonstration that the response of the SOC stocks to litter inputs is critically determined by the microbial physiology. Our work suggests that total SOC at an equilibrium state may be an intrinsic property of a given ecosystem, which ultimately is controlled by the asynchronous MBA between microbial functional groups. PMID:25849864

Significance of microbial asynchronous anabolism to soil carbon dynamics driven by litter inputs

DOE PAGES

Fan, Zhaosheng; Liang, Chao

2015-04-02

Soil organic carbon (SOC) plays an important role in the global carbon cycle. However, it remains largely unknown how plant litter inputs impact magnitude, composition and source configuration of the SOC stocks over long term through microbial catabolism and anabolism, mostly due to uncoupled research on litter decomposition and SOC formation. This limits our ability to predict soil system responses to changes in land-use and climate. Here, we examine how microbes act as a valve controlling carbon sequestrated from plant litters versus released to the atmosphere in natural ecosystems amended with plant litters varying in quantity and quality. We findmore » that litter quality – not quantity – regulates long-term SOC dynamics under different plausible scenarios. Long-term changes in bulk SOC stock occur only when the quality of carbon inputs causes asynchronous change in a microbial physiological trait, defined as ‘‘microbial biosynthesis acceleration’’ (MBA). This is the first theoretical demonstration that the response of the SOC stocks to litter inputs is critically determined by the microbial physiology. Our work suggests that total SOC at an equilibrium state may be an intrinsic property of a given ecosystem, which ultimately is controlled by the asynchronous MBA between microbial functional groups.« less

Short-term high-fat diet primes excitatory synapses for long-term depression in orexin neurons.

PubMed

Linehan, Victoria; Fang, Lisa Z; Hirasawa, Michiru

2018-01-15

High-fat diet consumption is a major cause of obesity. Orexin neurons are known to be activated by a high-fat diet and in turn promote further consumption of a high-fat diet. Our study shows that excitatory synapses to orexin neurons become amenable to long-term depression (LTD) after 1 week of high-fat diet feeding. However, this effect reverses after 4 weeks of a high-fat diet. This LTD may be a homeostatic response to a high-fat diet to curb the activity of orexin neurons and hence caloric consumption. Adaptation seen after prolonged high-fat diet intake may contribute to the development of obesity. Overconsumption of high-fat diets is one of the strongest contributing factors to the rise of obesity rates. Orexin neurons are known to be activated by a palatable high-fat diet and mediate the activation of the mesolimbic reward pathway, resulting in further food intake. While short-term exposure to a high-fat diet is known to induce synaptic plasticity within the mesolimbic pathway, it is unknown if such changes occur in orexin neurons. To investigate this, 3-week-old male rats were fed a palatable high-fat western diet (WD) or control chow for 1 week and then in vitro patch clamp recording was performed. In the WD condition, an activity-dependent long-term depression (LTD) of excitatory synapses was observed in orexin neurons, but not in chow controls. This LTD was presynaptic and depended on postsynaptic metabotropic glutamate receptor 5 (mGluR5) and retrograde endocannabinoid signalling. WD also increased extracellular glutamate levels, suggesting that glutamate spillover and subsequent activation of perisynaptic mGluR5 may occur more readily in the WD condition. In support of this, pharmacological inhibition of glutamate uptake was sufficient to prime chow control synapses to undergo a presynaptic LTD. Interestingly, these WD effects are transient, as extracellular glutamate levels were similar to controls and LTD was no longer observed in orexin neurons after 4 weeks of WD. In summary, excitatory synapses to orexin neurons become amenable to LTD under a palatable high-fat diet, which may represent a homeostatic mechanism to prevent overactivation of these neurons and to curtail high-fat diet consumption. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Limited capacity of working memory in unihemispheric random walks implies conceivable slow dispersal.

PubMed

Wei, Kun; Zhong, Suchuan

2017-08-01

Phenomenologically inspired by dolphins' unihemispheric sleep, we introduce a minimal model for random walks with physiological memory. The physiological memory consists of long-term memory which includes unconscious implicit memory and conscious explicit memory, and working memory which serves as a multi-component system for integrating, manipulating and managing short-term storage. The model assumes that the sleeping state allows retrievals of episodic objects merely from the episodic buffer where these memory objects are invoked corresponding to the ambient objects and are thus object-oriented, together with intermittent but increasing use of implicit memory in which decisions are unconsciously picked up from historical time series. The process of memory decay and forgetting is constructed in the episodic buffer. The walker's risk attitude, as a product of physiological heuristics according to the performance of objected-oriented decisions, is imposed on implicit memory. The analytical results of unihemispheric random walks with the mixture of object-oriented and time-oriented memory, as well as the long-time behavior which tends to the use of implicit memory, are provided, indicating the common sense that a conservative risk attitude is inclinable to slow movement.

Water and light improvement after thinning at a xeric site: Which weights the most? A dual isotope approach

NASA Astrophysics Data System (ADS)

Giuggiola, Arnaud; Ogée, Jérôme; Gessler, Arthur; Rigling, Andreas; Bugmann, Harald; Treydte, Kerstin

2015-04-01

Reductions in stand density foster individual tree growth due to increases of resources such as water, light and nutrients. Detailed knowledge of the short- to long-term physiological response underlying the growth response to thinning is crucial for the management of forests already suffering from recurrent drought-induced dieback. We applied a dual isotope approach together with mechanistic isotope models such as MuSICA to study the physiological processes underlying growth enhancement in a long-term thinning experiment in a xeric Pinus sylvestris forest in Switzerland. This approach allowed for identifying and disentangling changes in stomatal conductance and assimilation rate. Our results indicate that an increase in stomatal conductance outweighs an increase in assimilation, meaning that the observed growth releases in heavy thinned trees at our xeric site are primarily driven by enhanced water availability rather than by the increase in light availability. We conclude that in areas with isohydric species (drought avoiders) that tend to grow close to their physiological limits, thinning is highly recommended to maintain a less negative water balance and thus foster tree growth, and ultimately the survival rate of individual trees and forests.

Long-Term Evolution of the Sun and our Biosphere: Causes and Effects?

NASA Astrophysics Data System (ADS)

Des Marais, D. J.

2000-05-01

The course of early biological evolution felt the environmental consequences of changes in the solar output (discussed here), as well as long-term decreases in planetary heat flow and the flux of extraterrestrial impactors. A large, early UV flux fueled the photodissociation of atmospheric water vapor, sustaining a significant hydrogen flux to space. This flux caused Earth's crust to become oxidized, relative to its mantle. Accordingly, reduced gases and aqueous solutes that were erupted volcanically into the relatively more oxidized surface environment created sources of chemical redox energy for the origin and early evolution of life. Although the solar constant has increased some 30 percent over Earth's lifetime, oceans remained remarkably stable for more than 3.8 billion years. Thus a very effective climate regulation was probably achieved by decreasing over time the atmospheric inventories of greenhouse gases such as carbon dioxide and methane. Such decreases probably had major consequences for the biosphere. Substantial early marine bicarbonate and carbon dioxide inventories sustained abundant abiotic precipitation of carbonates, with consequences for the stability and habitability of key aqueous environments. A long-term decline in carbon dioxide levels increased the bioenergetic requirements for carbon dioxide as well as other aspects of the physiology of photosynthetic microorganisms. The long-term trend of global mean surface temperature is still debated, as is the role of the sun's evolution in that trend. Future increases in the solar constant will drive atmospheric carbon dioxide levels down further, challenging plants to cope with ever-dwindling concentrations of carbon substrates. Climate regulation will be achieved by modulating an increasing abundance of high-albedo water vapor clouds. Future biological evolution defies precise predictions, however it is certain that the sun's continuing evolution will play a key role.

Evaluation of long-term treatment effect in a type 1 diabetes intervention trial: differences after stimulation with glucagon or a mixed meal.

PubMed

Pozzilli, Paolo; Raz, Itamar; Peled, Dana; Elias, Dana; Avron, Ann; Tamir, Merana; Eren, Rachel; Dagan, Shlomo; Cohen, Irun R

2014-01-01

Endogenous insulin secretion, measured by C-peptide area under the curve (AUC), can be tested using both the glucagon stimulation test (GST) and the mixed-meal tolerance test (MMTT). This study compares these two stimulation methods using long-term data from patients newly diagnosed with type 1 diabetes or with latent autoimmune diabetes. A recently completed phase 3 intervention study with DiaPep277 demonstrated improved glycemic control and a significant treatment effect of glucagon-stimulated C-peptide secretion. Unexpectedly, MMTT failed to detect differences between the treated and control groups. Data from 343 patients in two balanced-randomized, double-blind, placebo-controlled, parallel-group trials of DiaPep277 were used to compare and correlate between GST- and MMTT-derived C-peptide AUC. Pearson's correlations were calculated for absolute C-peptide AUC at baseline and 12 and 24 months and for long-term changes in AUC (AUC). The absolute AUC values obtained at any single time point by the two tests were well correlated in both data sets (r = 0.74-0.9). However, the correlations between the AUC were much weaker (r = 0.39-0.58). GST-stimulated C-peptide secretion was stable over the fasting glucose range permitted for the test (4-11.1 mmol/L), but MMTT-stimulated C-peptide secretion decreased over the same range, implying differences in sensitivity to glucose. Measurement of long-term changes in stimulated C-peptide, reflecting endogenous insulin secretion, during the course of intervention trials may be affected by the method of stimulation, possibly reflecting different sensitivities to the physiological status of the tested subject.

Maintenance of long-term adaptation of synaptic transmission requires axonal transport following induction in an identified crayfish motoneuron.

PubMed

Nguyen, P V; Atwood, H L

1992-03-01

Motoneurons can adapt to altered levels of electrical activity by effecting semi-permanent changes in their neuromuscular synaptic physiology. In the present study, we tested the hypothesis that maintenance of activity-dependent long-term adaptation of synaptic transmission in a crayfish abdominal extensor motoneuron (phasic axon 3) required axonal transport following induction. Intact crayfish were chronically wired for periodic in vivo stimulation of axon 3. Periodic unilateral stimulation for 3-5 consecutive days (2 h/day) induced long-term adaptation (LTA) of neuromuscular synaptic transmission in axon 3. Initial EPSP amplitudes (measured at 0.1 Hz) were significantly reduced to approximately 40% of contralateral control amplitudes over a 7-day poststimulation period. Additionally, synaptic depression during 5 Hz test stimulation of axon 3 was significantly less in chronically stimulated neurons: excitatory postsynaptic potential (EPSP) amplitudes measured after 20 min of 5 Hz test stimulation (final EPSPs) were significantly larger in conditioned neurons than in unstimulated controls. The depression of initial EPSP amplitudes persisted for 7 days postinduction, while the increased synaptic stamina persisted for 4 days but was absent at 7 days postinduction. Axotomy of axon 3 following induction of LTA had no effect on long-term maintenance of the activity-induced reduction in initial EPSP amplitudes. Initial EPSP amplitudes in conditioned, axotomized neurons were still reduced to 42% of control amplitudes over the 7-day postinduction period. In contrast, postinduction axotomy of axon 3 elicited an accelerated decay of the enhanced synaptic stamina. Following axotomy, final EPSP amplitudes were significantly larger in conditioned neurons for only 1 day poststimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term culture of pluripotent stem-cell-derived human neurons on diamond--A substrate for neurodegeneration research and therapy.

PubMed

Nistor, Paul A; May, Paul W; Tamagnini, Francesco; Randall, Andrew D; Caldwell, Maeve A

2015-08-01

Brain Computer Interfaces (BCI) currently represent a field of intense research aimed both at understanding neural circuit physiology and at providing functional therapy for traumatic or degenerative neurological conditions. Due to its chemical inertness, biocompatibility and stability, diamond is currently being actively investigated as a potential substrate material for culturing cells and for use as the electrically active component of a neural sensor. Here we provide a protocol for the differentiation of mature, electrically active neurons on microcrystalline synthetic thin-film diamond substrates starting from undifferentiated pluripotent stem cells. Furthermore, we investigate the optimal characteristics of the diamond microstructure for long-term neuronal sustainability. We also analyze the effect of boron as a dopant for such a culture. We found that the diamond crystalline structure has a significant influence on the neuronal culture unlike the boron doping. Specifically, small diamond microcrystals promote higher neurite density formation. We find that boron incorporated into the diamond does not influence the neurite density and has no deleterious effect on cell survival. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Stress and the developing adolescent brain.

PubMed

Eiland, L; Romeo, R D

2013-09-26

Adolescence is a time of continued brain maturation, particularly in limbic and cortical regions, which undoubtedly plays a role in the physiological and emotional changes coincident with adolescence. An emerging line of research has indicated that stressors experienced during this crucial developmental stage may affect the trajectory of this neural maturation and contribute to the increase in psychological morbidities, such as anxiety and depression, often observed during adolescence. In this review, we discuss the short- and long-term effects of periadolescent stress exposure on the structure and function of the brain. More specifically, we examine how stress at prepubertal and early adolescent stages of development affects the morphological plasticity of limbic and cortical brain regions, as well as the enduring effects of adolescent stress exposure on these brain regions in adulthood. We suggest that, due to a number of converging factors during this period of maturation, the adolescent brain may be particularly sensitive to stress-induced neurobehavioral dysfunctions with important consequences on an individual's immediate and long-term health and well-being. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

A short pulse of mechanical force induces gene expression and growth in MC3T3-E1 osteoblasts via an ERK 1/2 pathway

NASA Technical Reports Server (NTRS)

Hatton, Jason P.; Pooran, Milad; Li, Chai-Fei; Luzzio, Chris; Hughes-Fulford, Millie

2003-01-01

Physiological mechanical loading is crucial for maintenance of bone integrity and architecture. We have calculated the strain caused by gravity stress on osteoblasts and found that 4-30g corresponds to physiological levels of 40-300 microstrain. Short-term gravity loading (15 minutes) induced a 15-fold increase in expression of growth-related immediate early gene c-fos, a 5-fold increase in egr-1, and a 3-fold increase in autocrine bFGF. The non-growth-related genes EP-1, TGF-beta, and 18s were unaffected by gravity loading. Short-term physiological loading induced extracellular signal-regulated kinase (ERK 1/2) phosphorylation in a dose-dependent manner with maximum phosphorylation saturating at mechanical loading levels of 12g (p < 0.001) with no effect on total ERK. The phosphorylation of focal adhesion kinase (FAK) was unaffected by mechanical force. g-Loading did not activate P38 MAPK or c-jun N-terminal kinase (JNK). Additionally, a gravity pulse resulted in the localization of phosphorylated ERK 1/2 to the nucleus; this did not occur in unloaded cells. The induction of c-fos was inhibited 74% by the MEK1/2 inhibitor U0126 (p < 0.001) but was not affected by MEK1 or p38 MAPK-specific inhibitors. The long-term consequence of a single 15-minute gravity pulse was a 64% increase in cell growth (p < 0.001). U0126 significantly inhibited gravity-induced growth by 50% (p < 0.001). These studies suggest that short periods of physiological mechanical stress induce immediate early gene expression and growth in MC3T3-E1 osteoblasts primarily through an ERK 1/2-mediated pathway.

Do 'mind over muscle' strategies work? Examining the effects of attentional association and dissociation on exertional, affective and physiological responses to exercise.

PubMed

Lind, Erik; Welch, Amy S; Ekkekakis, Panteleimon

2009-01-01

Despite the well established physical and psychological benefits derived from leading a physically active life, rates of sedentary behaviour remain high. Dropout and non-compliance are major contributors to the problem of physical inactivity. Perceptions of exertion, affective responses (e.g. displeasure or discomfort), and physiological stress could make the exercise experience aversive, particularly for beginners. Shifting one's attentional focus towards environmental stimuli (dissociation) instead of one's body (association) has been theorized to enhance psychological responses and attenuate physiological stress. Research evidence on the effectiveness of attentional focus strategies, however, has been perplexing, covering the entire gamut of possible outcomes (association and dissociation having been shown to be both effective and ineffective). This article examines the effects of manipulations of attentional focus on exertional and affective responses, as well as on exercise economy and tolerance. The possible roles of the characteristics of the exercise stimulus (intensity, duration) and the exercise participants, methodological issues, and limitations of experimental designs are discussed. In particular, the critical role of exercise intensity is emphasized. Dissociative strategies may be more effective in reducing perceptions of exertion and enhancing affective responses at low to moderate exercise intensities, but their effectiveness may be diminished at higher and near-maximal levels, at which physiological cues dominate. Conversely, associative strategies could enable the exerciser to regulate intensity to avoid injury or overexertion. Thus, depending on intensity, both strategies have a place in the 'toolbox' of the public health or exercise practitioner as methods of enhancing the exercise experience and promoting long-term compliance.

Implantable fiber-optic interface for parallel multisite long-term optical dynamic brain interrogation in freely moving mice

PubMed Central

Doronina-Amitonova, L. V.; Fedotov, I. V.; Ivashkina, O. I.; Zots, M. A.; Fedotov, A. B.; Anokhin, K. V.; Zheltikov, A. M.

2013-01-01

Seeing the big picture of functional responses within large neural networks in a freely functioning brain is crucial for understanding the cellular mechanisms behind the higher nervous activity, including the most complex brain functions, such as cognition and memory. As a breakthrough toward meeting this challenge, implantable fiber-optic interfaces integrating advanced optogenetic technologies and cutting-edge fiber-optic solutions have been demonstrated, enabling a long-term optogenetic manipulation of neural circuits in freely moving mice. Here, we show that a specifically designed implantable fiber-optic interface provides a powerful tool for parallel long-term optical interrogation of distinctly separate, functionally different sites in the brain of freely moving mice. This interface allows the same groups of neurons lying deeply in the brain of a freely behaving mouse to be reproducibly accessed and optically interrogated over many weeks, providing a long-term dynamic detection of genome activity in response to a broad variety of pharmacological and physiological stimuli. PMID:24253232

Implantable fiber-optic interface for parallel multisite long-term optical dynamic brain interrogation in freely moving mice

NASA Astrophysics Data System (ADS)

Doronina-Amitonova, L. V.; Fedotov, I. V.; Ivashkina, O. I.; Zots, M. A.; Fedotov, A. B.; Anokhin, K. V.; Zheltikov, A. M.

2013-11-01

Seeing the big picture of functional responses within large neural networks in a freely functioning brain is crucial for understanding the cellular mechanisms behind the higher nervous activity, including the most complex brain functions, such as cognition and memory. As a breakthrough toward meeting this challenge, implantable fiber-optic interfaces integrating advanced optogenetic technologies and cutting-edge fiber-optic solutions have been demonstrated, enabling a long-term optogenetic manipulation of neural circuits in freely moving mice. Here, we show that a specifically designed implantable fiber-optic interface provides a powerful tool for parallel long-term optical interrogation of distinctly separate, functionally different sites in the brain of freely moving mice. This interface allows the same groups of neurons lying deeply in the brain of a freely behaving mouse to be reproducibly accessed and optically interrogated over many weeks, providing a long-term dynamic detection of genome activity in response to a broad variety of pharmacological and physiological stimuli.

mTORC2 controls actin polymerization required for consolidation of long-term memory

PubMed Central

Huang, Wei; Zhu, Ping Jun; Zhang, Shixing; Zhou, Hongyi; Stoica, Loredana; Galiano, Mauricio; Krnjević, Krešimir; Roman, Gregg; Costa-Mattioli, Mauro

2013-01-01

A major goal of biomedical research has been the identification of molecular mechanisms that can enhance memory. Here we report a novel signaling pathway that regulates the conversion from short- to long-term memory. The mTOR complex 2 (mTORC2), which contains the key regulatory protein Rictor (Rapamycin-Insensitive Companion of mTOR), was discovered only recently, and little is known about its physiological role. We show that conditional deletion of rictor in the postnatal murine forebrain greatly reduces mTORC2 activity and selectively impairs both long-term memory (LTM) and the late (but not the early) phase of hippocampal long-term potentiation (LTP). Actin polymerization is reduced in the hippocampus of mTORC2-deficient mice and its restoration rescues both L-LTP and LTM. More importantly, a compound that selectively promotes mTORC2 activity converts early-LTP into late-LTP and enhances LTM. These findings indicate that mTORC2 could be a novel therapeutic target for the treatment of cognitive dysfunction. PMID:23455608

Long-term in vivo study of vertebrate embryonic development using noninvasive harmonics optical microscopy

NASA Astrophysics Data System (ADS)

Chen, Szu-Yu; Hsieh, C.-S.; Chu, S.-W.; Lin, Cheng-Yung; Ko, C.-Y.; Chen, Y.-C.; Tsai, Huai-Jen; Hu, C.-H.; Sun, Chi-Kuang

2005-03-01

Harmonics optical microscopy (HOM) provides a truly "noninvasive" tool for in vivo and long-term study of vertebrate embryonic development. Based on the nonlinear natures, it provides sub-micrometer 3D spatial resolution and high 3D optical-sectioning power (~1μm axial resolution) without using invasive and toxic fluorophores. Since only virtual-level-transition is involved, HOM is known to leave no energy deposition and no photodamages. Combined with second harmonic generation, which is sensitive to specific structure such as nerve and muscle fibers, HOM can be used to do functional studies of early developmental dynamics of many vertebrate physiological systems. Recently, zebrafish has become a standard model for many biological and medical studies of vertebrates, due to the similarity between embryonic development of zebrafish and human being. Zebrafish embryos now have been used to study many vertebrate physiological systems. We have demonstrated an in vivo HOM study of developmental dynamics of several embryonic physiological systems in live zebrafish embryos, with focuses on the developments of brains, eyes, ears, and hearts. Based on a femtosecond Cr:forsterite laser, which provides the deepest penetration (~1.5mm) and least photodamage in the zebrafish embryo, complete developing processes of different physiological systems within a period of time longer than 20 hours can be non-invasively observed inside the same embryo.

Density-dependent microbial turnover improves soil carbon model predictions of long-term litter manipulations

NASA Astrophysics Data System (ADS)

Georgiou, Katerina; Abramoff, Rose; Harte, John; Riley, William; Torn, Margaret

2017-04-01

Climatic, atmospheric, and land-use changes all have the potential to alter soil microbial activity via abiotic effects on soil or mediated by changes in plant inputs. Recently, many promising microbial models of soil organic carbon (SOC) decomposition have been proposed to advance understanding and prediction of climate and carbon (C) feedbacks. Most of these models, however, exhibit unrealistic oscillatory behavior and SOC insensitivity to long-term changes in C inputs. Here we diagnose the sources of instability in four models that span the range of complexity of these recent microbial models, by sequentially adding complexity to a simple model to include microbial physiology, a mineral sorption isotherm, and enzyme dynamics. We propose a formulation that introduces density-dependence of microbial turnover, which acts to limit population sizes and reduce oscillations. We compare these models to results from 24 long-term C-input field manipulations, including the Detritus Input and Removal Treatment (DIRT) experiments, to show that there are clear metrics that can be used to distinguish and validate the inherent dynamics of each model structure. We find that widely used first-order models and microbial models without density-dependence cannot readily capture the range of long-term responses observed across the DIRT experiments as a direct consequence of their model structures. The proposed formulation improves predictions of long-term C-input changes, and implies greater SOC storage associated with CO2-fertilization-driven increases in C inputs over the coming century compared to common microbial models. Finally, we discuss our findings in the context of improving microbial model behavior for inclusion in Earth System Models.

'Enzyme Test Bench': A biochemical application of the multi-rate modeling

NASA Astrophysics Data System (ADS)

Rachinskiy, K.; Schultze, H.; Boy, M.; Büchs, J.

2008-11-01

In the expanding field of 'white biotechnology' enzymes are frequently applied to catalyze the biochemical reaction from a resource material to a valuable product. Evolutionary designed to catalyze the metabolism in any life form, they selectively accelerate complex reactions under physiological conditions. Modern techniques, such as directed evolution, have been developed to satisfy the increasing demand on enzymes. Applying these techniques together with rational protein design, we aim at improving of enzymes' activity, selectivity and stability. To tap the full potential of these techniques, it is essential to combine them with adequate screening methods. Nowadays a great number of high throughput colorimetric and fluorescent enzyme assays are applied to measure the initial enzyme activity with high throughput. However, the prediction of enzyme long term stability within short experiments is still a challenge. A new high throughput technique for enzyme characterization with specific attention to the long term stability, called 'Enzyme Test Bench', is presented. The concept of the Enzyme Test Bench consists of short term enzyme tests conducted under partly extreme conditions to predict the enzyme long term stability under moderate conditions. The technique is based on the mathematical modeling of temperature dependent enzyme activation and deactivation. Adapting the temperature profiles in sequential experiments by optimum non-linear experimental design, the long term deactivation effects can be purposefully accelerated and detected within hours. During the experiment the enzyme activity is measured online to estimate the model parameters from the obtained data. Thus, the enzyme activity and long term stability can be calculated as a function of temperature. The results of the characterization, based on micro liter format experiments of hours, are in good agreement with the results of long term experiments in 1L format. Thus, the new technique allows for both: the enzyme screening with regard to the long term stability and the choice of the optimal process temperature. The presented article gives a successful example for the application of multi-rate modeling, experimental design and parameter estimation within biochemical engineering. At the same time, it shows the limitations of the methods at the state of the art and addresses the current problems to the applied mathematics community.

Long-term potentiation and long-term depression: a clinical perspective

PubMed Central

Bliss, Timothy V.P.; Cooke, Sam F

2011-01-01

Long-term potentiation and long-term depression are enduring changes in synaptic strength, induced by specific patterns of synaptic activity, that have received much attention as cellular models of information storage in the central nervous system. Work in a number of brain regions, from the spinal cord to the cerebral cortex, and in many animal species, ranging from invertebrates to humans, has demonstrated a reliable capacity for chemical synapses to undergo lasting changes in efficacy in response to a variety of induction protocols. In addition to their physiological relevance, long-term potentiation and depression may have important clinical applications. A growing insight into the molecular mechanisms underlying these processes, and technological advances in non-invasive manipulation of brain activity, now puts us at the threshold of harnessing long-term potentiation and depression and other forms of synaptic, cellular and circuit plasticity to manipulate synaptic strength in the human nervous system. Drugs may be used to erase or treat pathological synaptic states and non-invasive stimulation devices may be used to artificially induce synaptic plasticity to ameliorate conditions arising from disrupted synaptic drive. These approaches hold promise for the treatment of a variety of neurological conditions, including neuropathic pain, epilepsy, depression, amblyopia, tinnitus and stroke. PMID:21779718

Long- and short-term photoacclimation in epipsammon from non-tidal coastal shallows compared to epipelon from intertidal mudflat

NASA Astrophysics Data System (ADS)

Pniewski, Filip F.; Richard, Pierre; Latała, Adam; Blanchard, Gerard

2018-06-01

Long- and short-term photoacclimation and their interaction were determined in two types of microphytobenthos assemblages, i.e. epipelon from an intertidal mudflat and epipsammon from non-tidal sandy coastal shallows collected during summer and autumn months. Microphytobenthos photophysiology was assessed from steady-state light curve (SSLC) and rapid light-response curves (RLC) of variable chlorophyll fluorescence. The epipelon was low light acclimated, whereas in the epipsammon high light acclimation was observed. The epipelon turned out to be more susceptible to high light and in autumn a clear down turn in the relative electron transport rates was recorded. Long-term photoacclimation strongly affected both microphytobenthos types' short-term light responses. The epipelon acclimated to high ambient light intensities through the decreased light absorption and energy dissipation. The epipsammon, on the other hand, developed physiological flexibility allowing efficient use of the absorbed light and thus providing protection against higher irradiance.

Long-term use of neonatal helmet-CPAP: a case report.

PubMed

Doglioni, N; Micaglio, M; Zanardo, V; Trevisanuto, D

2009-12-01

In a recent short-term physiological study, we demonstrated a new continuous positive airway pressure (CPAP) system (neonatal helmet-CPAP) that could be a feasible device for managing preterm infants needing continuous distending pressure with better tolerability than nasal-CPAP. However, its application for a long-term period has never been reported in neonates. Here, we describe the use of neonatal helmet-CPAP in a neonate with persistent pulmonary hypertension of the newborn. Twenty minutes after neonatal helmet-CPAP placement, the baseline post-ductal tcSaO2 (66%) and alveolar-arterial gradient O2 improved from 66% and 648 mmHg to 100% and 465 mmHg, respectively. The neonatal helmet-CPAP was applied for 48 hours and was well-tolerated by the patient without complications. Long-term use of neonatal helmet-CPAP appears feasible and well-tolerated. Comparative trials are needed.

Not just sticks and stones: Indirect ethnic discrimination leads to greater physiological reactivity.

PubMed

Huynh, Virginia W; Huynh, Que-Lam; Stein, Mary-Patricia

2017-07-01

We examined the effect of indirect ethnic discrimination on physiological reactivity (i.e., cortisol, blood pressure, heart rate) in Latino emerging adults. Participants (N = 32) were randomly assigned to be exposed to indirect ethnic discrimination (experimental condition) or not (control condition) while undergoing a cognitive stress task. Greater total cortisol output was observed in participants in the experimental condition, relative to those in the control condition. No significant differences in heart rate or blood pressure were noted. Results suggest that witnessing ethnic discrimination affects cortisol recovery responses, but not cardiovascular reactivity. Words that are not intentionally hurtful or directed at a specific person may still "hurt"-affecting biological processes associated with hypothalamic-pituitary-adrenocortical (HPA) axis and potentially leading to long-term health consequences. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

INFLUENCE OF IRON CHELATION ON R1 AND R2 CALIBRATION CURVES IN GERBIL LIVER AND HEART

PubMed Central

Wood, John C.; Aguilar, Michelle; Otto-Duessel, Maya; Nick, Hanspeter; Nelson, Marvin D.; Moats, Rex

2008-01-01

MRI is gaining increasing importance for the noninvasive quantification of organ iron burden. Since transverse relaxation rates depend on iron distribution as well as iron concentration, physiologic and pharmacologic processes that alter iron distribution could change MRI calibration curves. This paper compares the effect of three iron chelators, deferoxamine, deferiprone, and deferasirox on R1 and R2 calibration curves according to two iron loading and chelation strategies. 33 Mongolian gerbils underwent iron loading (iron dextran 500 mg/kg/wk) for 3 weeks followed by 4 weeks of chelation. An additional 56 animals received less aggressive loading (200 mg/kg/week) for 10 weeks, followed by 12 weeks of chelation. R1 and R2 calibration curves were compared to results from 23 iron-loaded animals that had not received chelation. Acute iron loading and chelation biased R1 and R2 from the unchelated reference calibration curves but chelator-specific changes were not observed, suggesting physiologic rather than pharmacologic differences in iron distribution. Long term chelation deferiprone treatment increased liver R1 50% (p<0.01), while long term deferasirox lowered liver R2 30.9% (p<0.0001). The relationship between R1 and R2 and organ iron concentration may depend upon the acuity of iron loading and unloading as well as the iron chelator administered. PMID:18581418

Virally delivered Channelrhodopsin-2 Safely and Effectively Restores Visual Function in Multiple Mouse Models of Blindness

PubMed Central

Doroudchi, M Mehdi; Greenberg, Kenneth P; Liu, Jianwen; Silka, Kimberly A; Boyden, Edward S; Lockridge, Jennifer A; Arman, A Cyrus; Janani, Ramesh; Boye, Shannon E; Boye, Sanford L; Gordon, Gabriel M; Matteo, Benjamin C; Sampath, Alapakkam P; Hauswirth, William W; Horsager, Alan

2011-01-01

Previous work established retinal expression of channelrhodopsin-2 (ChR2), an algal cation channel gated by light, restored physiological and behavioral visual responses in otherwise blind rd1 mice. However, a viable ChR2-based human therapy must meet several key criteria: (i) ChR2 expression must be targeted, robust, and long-term, (ii) ChR2 must provide long-term and continuous therapeutic efficacy, and (iii) both viral vector delivery and ChR2 expression must be safe. Here, we demonstrate the development of a clinically relevant therapy for late stage retinal degeneration using ChR2. We achieved specific and stable expression of ChR2 in ON bipolar cells using a recombinant adeno-associated viral vector (rAAV) packaged in a tyrosine-mutated capsid. Targeted expression led to ChR2-driven electrophysiological ON responses in postsynaptic retinal ganglion cells and significant improvement in visually guided behavior for multiple models of blindness up to 10 months postinjection. Light levels to elicit visually guided behavioral responses were within the physiological range of cone photoreceptors. Finally, chronic ChR2 expression was nontoxic, with transgene biodistribution limited to the eye. No measurable immune or inflammatory response was observed following intraocular vector administration. Together, these data indicate that virally delivered ChR2 can provide a viable and efficacious clinical therapy for photoreceptor disease-related blindness. PMID:21505421

The emergence of Nervennahrung: Nerves, mind and metabolism in the long eighteenth century.

PubMed

Stahnisch, Frank W

2012-06-01

Morphological assumptions concerning the form, structure and internal life of the brain and nervous system profoundly influenced contemporary physiological concepts about nerve actions throughout the 'long eighteenth century'. This article investigates some early theories of mind and metabolism. In a bottom-up fashion, it asks how eighteenth-century theories regarding the physiological actions of the body organs shaped the conceptions of the structure of the brain and nervous tissue themselves. These proposed that a healthy Nervennahrung (the German word for 'nerve nutrition', which might be rendered as brain food in modern English), not only guaranteed the integrity and stability of neuronal structures in the body, but also explained the complex texture of the brain and spinal cord in physiological terms. Eighteenth-century nerve theories already embodied a Leitmotiv of neurology and brain psychiatry from the later nineteenth century: 'Without phosphorus there is no thought!' Copyright © 2011 Elsevier Ltd. All rights reserved.

Mitral valve replacement with preservation of the subvalvular apparatus.

PubMed

Reardon, M J; David, T E

1999-03-01

The introduction of the Starr-Edwards valve allowed complete replacement of diseased left-sided heart valves. With improved cardiopulmonary bypass, myocardial protection, and surgical techniques the mortality rate from aortic valve replacement decreased substantially, whereas the mortality rate from mitral valve replacement remained high, largely because of low cardiac output syndrome. Increasing use of mitral valve repair techniques resulted in a marked decrease in short-term and long-term morbidity and mortality when treating patients with mitral regurgitation. Some believed that this resulted from maintenance of the mitral annular papillary muscle continuity during mitral valve repair. Subsequent experimental and clinical studies have validated the positive short-term and long-term effects of maintaining the integrity of the mitral valve subvalvular apparatus. This article considers the history of the clinical use of preservation of the subvalvular apparatus, the physiologic studies examining this concept, and the clinical data available on its use. It also examines the following: 1) mitral stenosis versus mitral regurgitation and the preservation of the subvalvular apparatus; 2) whether the anterior, posterior, or both areas of the subvalvular apparatus should be preserved; and 3) the surgical techniques for the preservation of the subvalvular apparatus and valve implantation.

Omega 3 fatty acids on child growth, visual acuity and neurodevelopment.

PubMed

Campoy, Cristina; Escolano-Margarit, Ma Victoria; Anjos, Tania; Szajewska, Hania; Uauy, Ricardo

2012-06-01

The aim of this review is to evaluate the effects of omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation in pregnant and lactating women and infants during postnatal life, on the visual acuity, psychomotor development, mental performance and growth of infants and children. Eighteen publications (11 sets of randomized control clinical trial [RCTs]) assessed the effects of the n-3 LCPUFA supplementation during pregnancy on neurodevelopment and growth, in the same subjects at different time points; 4 publications (2 data sets from RCTs) addressed physiological responses to n-3 LCPUFA supplementation during pregnancy & lactation and 5 publications (3 data sets from RCTs) exclusively during lactation. Some of these studies showed beneficial effects of docosahexaenoic acid (DHA) supplementation during pregnancy and/or lactation especially on visual acuity outcomes and some on long-term neurodevelopment; a few, showed positive effects on growth. There were also 15 RCTs involving term infants who received infant formula supplemented with DHA, which met our selection criteria. Many of these studies claimed a beneficial effect of such supplementation on visual, neural, or developmental outcomes and no effects on growth. Although new well designed and conducted studies are being published, evidence from RCTs does not demonstrate still a clear and consistent benefit of n-3 LCPUFA supplementation during pregnancy and/or lactation on term infants growth, neurodevelopment and visual acuity. These results should be interpreted with caution due to methodological limitations of the included studies.

Substance use and its implications for the critical care nurses: a literature review.

PubMed

Brotto, Vanessa; Lee, Geraldine

2007-04-01

Illicit drug use in Australia has been increasing and studies indicate that illicit drug users have a higher risk of accidents which may result in the user needing critical care. However, there is a significant gap in the literature specifically pertaining to the implications of drug use in critical care. The primary objective was to examine the literature for the physiological effects of methylenedioxymethamphetamine (MDMA), cocaine and amphetamines in critically ill patients. A comprehensive literature review was undertaken and a body systems framework was used to categorise the effects of these illicit drugs. The illicit substances addressed have potentially fatal and long-term side effects. For those users involved in accidents or trauma requiring intensive or critical care nursing, the mortality and co-morbidity risks are increased significantly. It is, therefore, important that nurses are able to recognise the specific physiological effects and possible complications that can occur with the use of each illicit drug. Both nursing and medical staff need to have a thorough understanding of how illicit substances work and how they can affect the critical care patient and the care they are given.

The Nitrate-nitrite-NO pathway and its implications for Heart Failure and Preserved Ejection Fraction

PubMed Central

Chirinos, Julio A.; Zamani, Payman

2016-01-01

The pathogenesis of exercise intolerance in patients with heart failure and preserved ejection fraction (HFpEF) is likely multifactorial. In addition to cardiac abnormalities (diastolic dysfunction, abnormal contractile reserve, chronotropic incompetence), several peripheral abnormalities are likely to be involved. These include abnormal pulsatile hemodynamics, abnormal arterial vasodilatory responses to exercise, and abnormal peripheral O2 delivery, extraction and utilization. The nitrate-nitrite-NO pathway is emerging as a potential target to modify key physiologic abnormalities, including late systolic LV load from arterial wave reflections (which has deleterious short- and long-term consequences for the LV), arterial vasodilatory reserve, muscle O2 delivery, and skeletal muscle mitochondrial function. In a recently completed randomized trial, the administration of a single dose of exogenous inorganic nitrate has been shown exert various salutary arterial hemodynamic effects, ultimately leading to enhanced aerobic capacity in patients with HFpEF. These effects have the potential for both immediate improvements in exercise tolerance and for long-term “disease-modifying” effects. In this review, we provide an overview of key mechanistic contributors to exercise intolerance in HFpEF, and of the potential therapeutic role of drugs that target the nitrate-nitrite-NO pathway. PMID:26792295

A single high dose of dexamethasone affects the phosphorylation state of glutamate AMPA receptors in the human limbic system

PubMed Central

Lopes, M W; Leal, R B; Guarnieri, R; Schwarzbold, M L; Hoeller, A; Diaz, A P; Boos, G L; Lin, K; Linhares, M N; Nunes, J C; Quevedo, J; Bortolotto, Z A; Markowitsch, H J; Lightman, S L; Walz, R

2016-01-01

Glucocorticoids (GC) released during stress response exert feedforward effects in the whole brain, but particularly in the limbic circuits that modulates cognition, emotion and behavior. GC are the most commonly prescribed anti-inflammatory and immunosuppressant medication worldwide and pharmacological GC treatment has been paralleled by the high incidence of acute and chronic neuropsychiatric side effects, which reinforces the brain sensitivity for GC. Synapses can be bi-directionally modifiable via potentiation (long-term potentiation, LTP) or depotentiation (long-term depression, LTD) of synaptic transmission efficacy, and the phosphorylation state of Ser831 and Ser845 sites, in the GluA1 subunit of the glutamate AMPA receptors, are a critical event for these synaptic neuroplasticity events. Through a quasi-randomized controlled study, we show that a single high dexamethasone dose significantly reduces in a dose-dependent manner the levels of GluA1-Ser831 phosphorylation in the amygdala resected during surgery for temporal lobe epilepsy. This is the first report demonstrating GC effects on key markers of synaptic neuroplasticity in the human limbic system. The results contribute to understanding how GC affects the human brain under physiologic and pharmacologic conditions. PMID:27959333

Dual effects of fluoxetine on mouse early embryonic development.

PubMed

Kim, Chang-Woon; Choe, Changyong; Kim, Eun-Jin; Lee, Jae-Ik; Yoon, Sook-Young; Cho, Young-Woo; Han, Sunkyu; Tak, Hyun-Min; Han, Jaehee; Kang, Dawon

2012-11-15

Fluoxetine, a selective serotonin reuptake inhibitor, regulates a variety of physiological processes, such as cell proliferation and apoptosis, in mammalian cells. Little is known about the role of fluoxetine in early embryonic development. This study was undertaken to investigate the effect of fluoxetine during mouse early embryonic development. Late two-cell stage embryos (2-cells) were cultured in the presence of various concentrations of fluoxetine (1 to 50μM) for different durations. When late 2-cells were incubated with 5μM fluoxetine for 6h, the percentage that developed into blastocysts increased compared to the control value. However, late 2-cells exposed to fluoxetine (5μM) over 24h showed a reduction in blastocyst formation. The addition of fluoxetine (5μM) together with KN93 or KN62 (calcium/calmodulin-dependent protein kinase II (CaMKII) inhibitors) failed to increase blastocyst formation. Fluoxetine treatment inhibited TREK-1 and TREK-2, members of the two-pore domain K(+) channel family expressed in mouse embryos, activities, indicating that fluoxetine-induced membrane depolarization in late 2-cells might have resulted from TREK inhibition. In addition, long-term exposure to fluoxetine altered the TREK mRNA expression levels. Furthermore, injection of siRNA targeting TREKs significantly decreased blastocyst formation by ~30% compared to injection of scrambled siRNA. Long-term exposure of fluoxetine had no effect on blastocyst formation of TREK deficient embryos. These results indicate that low-dose and short-term exposures of late 2-cells to fluoxetine probably increase blastocyst formation through activation of CaMKII-dependent signal transduction pathways, whereas long-term exposure decreases mouse early embryonic development through inhibition of TREK channel gating. Copyright © 2012 Elsevier Inc. All rights reserved.

Omentin-1 levels are reduced by pharmacologic doses of leptin, but remain unaffected by energy deprivation and display no day-night variation.

PubMed

Hamnvik, Ole-Petter Riksfjord; Thakkar, Bindiya; Chamberland, John; Aronis, Konstantinos; Schneider, Benjamin; Mantzoros, Christos S

2015-02-01

To study the day-night variation of omentin-1 levels and assess whether leptin and/or short- and long-term energy deprivation alter circulating omentin-1 levels via cytokines. Omentin-1 levels were measured hourly in serum samples from six healthy men to evaluate for day-night variation. To study effects of acute energy deprivation and of leptin administration, eight healthy subjects were studied in the fasting state for 72 h with administration of either placebo or metreleptin (recombinant human leptin) in physiologic replacement doses. We evaluated the effect of leptin in pharmacologic doses on serum omentin-1 and cytokine levels, as well as on omentin-1 levels in ex vivo omental adipose tissue, in 15 healthy volunteers. To study the effect of chronic energy deprivation and weight loss on omentin-1 levels, we followed 18 obese subjects for 12 months who underwent bariatric surgery. There is no day-night variation in omentin-1 levels. Short-term and chronic energy deprivation, as well as ex vivo leptin administration and physiologic replacement doses of leptin, do not alter omentin-1 levels; pharmacologic doses of metreleptin reduce omentin-1 levels, whereas levels of tumor necrosis factor-α receptor II and interleukin-6 tend to increase. Omentin-1 levels are reduced by pharmacologic doses of metreleptin independent of effects on cytokine levels.

Dioxins: diagnostic and prognostic challenges arising from complex mechanisms

PubMed Central

Rysavy, Noel M.; Maaetoft-Udsen, Kristina; Turner, Helen

2013-01-01

Dioxins are ubiquitous environmental challenges to humans, with a pervasiveness that arises from two hundred years of rapid industrialization and mechanization of Western societies and which is now extending into the developing world. Despite their penetrance of the human biota, these compounds are poorly understood in terms of their true physiological potential for harm, and the mechanisms by which they impact cellular and organ level function are only recently becoming clear. Emerging awareness that chronic exposures to toxins may have generational and subtle effects on the outcomes of diseases such as cancer and diabetes, which are already multifactorial and highly complex, creates the context for the current review paper. Here, we summarize dioxin exposure paradigms and the resulting physiological effects that have been documented in animals and humans. Novel insights into potential endogenous end exogenous ligands, as well as the mechanisms by which these ligands impact acute and chronic cellular processes, are discussed. We develop the idea that the diagnosis of dioxin exposure, the subtleties of the cellular effects of the compounds and prognosis of the long term effects of exposure are problems requiring that researchers leverage the power of genomics and epigenetics. However, the continuation of longitudinal epidemiological studies and development of a firmer basis from which to extrapolate animal studies will be critical in ensuring optimal insight from these resource-intensive techniques. PMID:22610997

Interpreting tree responses to thinning and fertilization using tree-ring stable isotopes

EPA Science Inventory

Carbon sequestration has focused renewed interest in understanding how forest management affects forest carbon gain over timescales of decades, and yet details on physiological mechanisms over decades are often lacking for understanding long-term growth responses to management. ...

The long-term physical and psychological health impacts of flooding: A systematic mapping.

PubMed

Zhong, Shuang; Yang, Lianping; Toloo, Sam; Wang, Zhe; Tong, Shilu; Sun, Xiaojie; Crompton, David; FitzGerald, Gerard; Huang, Cunrui

2018-06-01

Flooding has caused significant and wide ranging long-term health impacts for affected populations. However, until now, the long-term health outcomes, epidemiological trends and specific impact factors of flooding had not been identified. In this study, the relevant literature was systematically mapped to create the first synthesis of the evidence of the long-term health impacts of flooding. The systematic mapping method was used to collect and categorize all the relevant literature. A study was included if it had a description or measurement of health impacts over six months after flooding. The search was limited to peer reviewed articles and grey literature written in English, published from 1996 to 2016. A total of 56 critical articles were extracted for the final map, including 5 qualitative and 51 quantitative studies. Most long-term studies investigated the psychological impacts of flooding, including PTSD, depression, anxiety, psychiatric disorders, sleep disorder and suicide. Others investigated the physiological impacts, including health-related quality of life, acute myocardial infarction, chronic diseases, and malnutrition. Social support was proved to be protective factors that can improve health outcomes in the long-term after flooding. To date, there have been relatively few reviews had focused on the long-term health impacts of flooding. This study coded and catalogued the existing evidence across a wide range of variables and described the long-term health consequences within a conceptual map. Although there was no boundary between the short-term and the long-term impacts of flooding, the identified health outcomes in this systematic mapping could be used to define long-term health impacts. The studies showed that the prevalence of psychological diseases had a reversed increasing trend occurred even in the long-term in relatively poor post-flooding environments. Further cohort or longitudinal research focused on disability, chronic diseases, relocation population, and social interventions after flooding, are urgently required. Copyright © 2018 Elsevier B.V. All rights reserved.

Immunological responses to semen in the female genital tract.

PubMed

Schuberth, H J; Taylor, U; Zerbe, H; Waberski, D; Hunter, R; Rath, D

2008-11-01

When spermatozoa, seminal plasma and semen extender reach the uterus and interact with local leukocytes and endometrial cells, several immune mechanisms are initiated which have immediate, mid-term and long-term effects on ovulation, sperm cell selection, fertilization and pregnancy success by assuring the acceptance of fetal tissues. This report gives an overview on relevant key immune mechanisms following roughly the time axis after insemination. Detailed knowledge regarding these mechanisms will aid maximizing reproductive efficiency in livestock production. In the future, the many species involved will require a more comparative approach, since evidence is growing that endometrial physiology and the response to varying amounts and compositions of seminal plasma, various semen extenders, and variable numbers of spermatozoa also provoke different immune responses.

Acclimatization and Adaptive Capacity of Marine Species in a Changing Ocean.

PubMed

Foo, S A; Byrne, M

To persist in an ocean changing in temperature, pH and other stressors related to climate change, many marine species will likely need to acclimatize or adapt to avoid extinction. If marine populations possess adequate genetic variation in tolerance to climate change stressors, species might be able to adapt to environmental change. Marine climate change research is moving away from single life stage studies where individuals are directly placed into projected scenarios ('future shock' approach), to focus on the adaptive potential of populations in an ocean that will gradually change over coming decades. This review summarizes studies that consider the adaptive potential of marine invertebrates to climate change stressors and the methods that have been applied to this research, including quantitative genetics, laboratory selection studies and trans- and multigenerational experiments. Phenotypic plasticity is likely to contribute to population persistence providing time for genetic adaptation to occur. Transgenerational and epigenetic effects indicate that the environmental and physiological history of the parents can affect offspring performance. There is a need for long-term, multigenerational experiments to determine the influence of phenotypic plasticity, genetic variation and transgenerational effects on species' capacity to persist in a changing ocean. However, multigenerational studies are only practicable for short generation species. Consideration of multiple morphological and physiological traits, including changes in molecular processes (eg, DNA methylation) and long-term studies that facilitate acclimatization will be essential in making informed predictions of how the seascape and marine communities will be altered by climate change. © 2016 Elsevier Ltd. All rights reserved.

Studying the Physiology of Tadpoles through their Naturally Transparent Abdomen Walls

NASA Astrophysics Data System (ADS)

Naitoh, T.; Yamashita, M.; Wassersug, R.

Because their development is external and they grow rapidly, anurans (frogs and toads) have been important model species in studies of how spaceflight affects vertebrate development. However the long term effects of spaceflight on post embryonic stages have barely been studied in these, or for that matter, any other vertebrate species. Tadpoles of certain species have naturally transparent skin covering a large portion of their ventral abdomen wall. Consequently viscera and visceral movements can be observed through this window without any invasive treatment to the animals. Respiration rate (as measured by buccal floor movements), heart rate, and gut motility are all indices of physiological state that can be observed in unconstrained larvae of these particular anuran species. We are using changes in these physiological variables to study the responses of tadpoles to changes in their external environment. Our study of the physiological responses of these tadpoles to microgravity has been selected as a candidate spaceflight experiment (to be housed in the Canadian Aquatic Research Facility). Ground-based studies with these same larvae are currently underway. Those experiments make use of stepwise changes in temperature as a stimulus to document the effect of temperature on intestinal motility in tadpoles. The scope of our studies on gravitational physiology and key issues in post- embryonic development of anurans are the focus of our presentation. This research is a prelude to raising a vertebrate through a complete life cycle in the space environment.

Emerging applications of nanotechnology for diagnosis and therapy of disease: a review.

PubMed

Bayford, Richard; Rademacher, Tom; Roitt, Ivan; Wang, Scarlet Xiaoyan

2017-07-24

Nanotechnology is of increasing interest in the fields of medicine and physiology over recent years. Its application could considerably improve disease detection and therapy, and although the potential is considerable, there are still many challenges that need to be addressed before it is accepted in routine clinical use. This review focuses on emerging applications that nanotechnology could enhance or provide new approaches in diagnoses and therapy. The main focus of recent research centres on targeted therapies and enhancing imaging; however, the introduction of nanomaterial into the human body must be controlled, as there are many issues with possible toxicity and long-term effects. Despite these issues, the potential for nanotechnology to provide new methods of combating cancer and other disease conditions is considerable. There are still key challenges for researchers in this field, including the means of delivery and targeting in the body to provide effective treatment for specific disease conditions. Nanoparticles are difficult to measure due to their size and physical properties; hence there is still a great need to improve physiological measurement methods in the field to ascertain how effective their use is in the human subject. This review is a brief snapshot into the fast changing research field of measurement and physiological links to nanoparticle use and its potential in the future.

Detachable glass microelectrodes for recording action potentials in active moving organs.

PubMed

Barbic, Mladen; Moreno, Angel; Harris, Tim D; Kay, Matthew W

2017-06-01

Here, we describe new detachable floating glass micropipette electrode devices that provide targeted action potential recordings in active moving organs without requiring constant mechanical constraint or pharmacological inhibition of tissue motion. The technology is based on the concept of a glass micropipette electrode that is held firmly during cell targeting and intracellular insertion, after which a 100-µg glass microelectrode, a "microdevice," is gently released to remain within the moving organ. The microdevices provide long-term recordings of action potentials, even during millimeter-scale movement of tissue in which the device is embedded. We demonstrate two different glass micropipette electrode holding and detachment designs appropriate for the heart (sharp glass microdevices for cardiac myocytes in rats, guinea pigs, and humans) and the brain (patch glass microdevices for neurons in rats). We explain how microdevices enable measurements of multiple cells within a moving organ that are typically difficult with other technologies. Using sharp microdevices, action potential duration was monitored continuously for 15 min in unconstrained perfused hearts during global ischemia-reperfusion, providing beat-to-beat measurements of changes in action potential duration. Action potentials from neurons in the hippocampus of anesthetized rats were measured with patch microdevices, which provided stable base potentials during long-term recordings. Our results demonstrate that detachable microdevices are an elegant and robust tool to record electrical activity with high temporal resolution and cellular level localization without disturbing the physiological working conditions of the organ. NEW & NOTEWORTHY Cellular action potential measurements within tissue using glass micropipette electrodes usually require tissue immobilization, potentially influencing the physiological relevance of the measurement. Here, we addressed this limitation with novel 100-µg detachable glass microelectrodes that can be precisely positioned to provide long-term measurements of action potential duration during unconstrained tissue movement. Copyright © 2017 the American Physiological Society.

Physiological characteristics of wild Atlantic salmon post-smolts during estuarine and coastal migration

USGS Publications Warehouse

Stefansson, S.O.; Bjornsson, B. Th; Sundell, K.; Nyhammer, G.; McCormick, S.D.

2003-01-01

Changes were measured in some of the major physiological variables associated with seawater adaptability, growth and energetics in wild Atlantic salmon Salmo salar smolts and post-smolts migrating from the river and through the estuary, fjord and coastal areas in the River Orkla and the Trondheimsfjord, Norway during late May to early June. Gill Na+,K+-ATPase activity increased to levels of 12-16 ??mol ADP mg protein-1 h -1 in post-smolts caught in higher salinity zones, probably representing long-term levels of Atlantic salmon post-smolts in oceanic conditions. Muscle moisture was regulated within narrow limits (77.7-78.7%) in fish from all zones during both years, suggesting that post-smolts adapt to marine conditions without any long-term disturbance of hydro-mineral balance. Lipid and glycogen content showed a general trend towards depletion from the river, through the fjord and into the ocean. There was, however, no significant change in protein content. The present results confirm that smolts are naturally 'energy deficient' during downstream migration, and suggest that post-smolts also mobilize energy reserves during their early marine phase, while protein is allocated for somatic growth. Plasma growth hormone (GH) levels increased transiently during passage through the estuary and fjord, with lower levels observed in post-smolts caught off-shore, i.e. in fish which were feeding on marine prey and had adapted to the marine environment. These physiological changes may confer substantial selective advantages during the critical early marine phase of anadromous salmonids, and hence are adaptive for long-term survival in sea water. ?? 2003 The Fisheries Society of the British Isles.

The use of touch to enhance nursing care of older person in long-term mental health care facilities.

PubMed

Gleeson, M; Timmins, F

2004-10-01

The self-care deficits experienced by older clients in long-term mental health settings, because of cognitive impairment, are likely to impact upon the clients' higher-order needs. The practice of nursing the elderly involves a lot of personal contact, during the delivery of fundamental physical care. While physiological and safety needs are crucial to clients in long-term settings, higher-order needs need also to be addressed. From the clients' perspective nurse's use of touch provides comfort, warmth and security, although there is a dearth of empirical evidence of these benefits. This paper explores the nurse's use of touch, the impact of touch and the experiences of touch on the older person in long-term settings. Because of the dearth of research in the use of touch with elderly clients in long-term care mental health facilities, a review of the literature was performed on the topic. This revealed that touch by nurses is frequently associated with routine tasks within nursing, and is less likely to be a caring touch intervention. Recommendations include further research on the topic and caution with widespread adoption of caring touch as an intervention.

Numerical simulation of aerobic exercise as a countermeasure in human spaceflight

NASA Astrophysics Data System (ADS)

Perez-Poch, Antoni

The objective of this work is to analyse the efficacy of long-term regular exercise on relevant cardiovascular parameters when the human body is also exposed to microgravity. Computer simulations are an important tool which may be used to predict and analyse these possible effects, and compare them with in-flight experiments. We based our study on a electrical-like computer model (NELME: Numerical Evaluation of Long-term Microgravity Effects) which was developed in our laboratory and validated with the available data, focusing on the cardiovascu-lar parameters affected by changes in gravity exposure. NELME is based on an electrical-like control system model of the physiological changes, that are known to take place when grav-ity changes are applied. The computer implementation has a modular architecture. Hence, different output parameters, potential effects, organs and countermeasures can be easily imple-mented and evaluated. We added to the previous cardiovascular system module a perturbation module to evaluate the effect of regular exercise on the output parameters previously studied. Therefore, we simulated a well-known countermeasure with different protocols of exercising, as a pattern of input electric-like perturbations on the basic module. Different scenarios have been numerically simulated for both men and women, in different patterns of microgravity, reduced gravity and time exposure. Also EVAs were simulated as perturbations to the system. Results show slight differences in gender, with more risk reduction for women than for men after following an aerobic exercise pattern during a simulated mission. Also, risk reduction of a cardiovascular malfunction is evaluated, with a ceiling effect found in all scenarios. A turning point in vascular resistance for a long-term exposure of microgravity below 0.4g has been found of particular interest. In conclusion, we show that computer simulations are a valuable tool to analyse different effects of long-term microgravity exposure on the human body. Potential countermeasures such as physical exercise can also be evaluated as an induced perturbation into the system. Relevant results are compatible with existing data, and are of valuable interest as an assessment of the efficacy of aerobic exercise as a countermeasure in future missions to Mars.

Differences in photosynthesis and isoprene emission in post oak (Quercus stellata) and sweetgum (Liquidambar styraciflua) trees along an urban-to-rural gradient in Texas

NASA Astrophysics Data System (ADS)

Crossett, C.; Lahr, E.; Haas, G.; Schade, G. W.

2014-12-01

Many plants produce isoprene, a volatile organic compound that can mitigate damage to photosynthetic systems during short- or long-term increases in leaf temperature. After its production within leaves, isoprene is emitted to the atmosphere and influences regional atmospheric chemistry. Here, we use an urban-to-rural gradient to explore future effects of climate change on tree eco-physiology and feedbacks to atmospheric chemistry. Urban areas mimic many of the conditions expected to occur in the future; in particular, cities have warmer temperatures due to the urban heat island (UHI) effect, and less water availability relative to rural areas. Along a 90 km urban-to-rural gradient, we measured photosynthesis and isoprene emission from trees at three sites in eastern Texas: Houston (urban), The Woodlands (suburban) and Sam Houston National Forest (rural). Isoprene emission from post oak (Quercus stellata) was higher in Houston than the other sites, and when leaf temperatures were increased above ambient conditions, trees produced more isoprene. Leaves produced more isoprene at high leaf temperatures in early summer than in late summer, suggesting gradual acclimation of photosynthetic processes over the course of the summer. We also found that sweetgum (Liquidambar styraciflua) emitted more isoprene than post oak, but when leaf temperatures were increased, isoprene emission was exhausted more quickly in sweetgum relative to post oak. At the same time, post oak maintained higher levels of photosynthesis seasonally and during short-term temperature increases. Both post oak and sweetgum are significant isoprene emitters and represent approximately two and four percent crown cover in the United States, respectively. Our results suggest that in a warming climate, we can expect trees to produce more isoprene seasonally and in response to short-term temperature extremes, and that species-specific differences in photosynthesis and isoprene emission may play an important role in forest dynamics, particularly in long-term forest growth and carbon storage. Further exploration of the interactive effect of increased CO2, temperature, and drought on tree physiology will improve our understanding of forest dynamics and forest-climate feedbacks.

Effects of 7.5% Carbon Dioxide Inhalation on Anxiety and Mood in Cigarette Smokers

PubMed Central

Attwood, Angela S.; Ataya, Alia F.; Bailey, Jayne E.; Lightman, Stafford L.; Munafò, Marcus R.

2016-01-01

Cigarette smoking is associated with elevated risk of anxiety and mood disorder. Using the 7.5% carbon dioxide (CO2) inhalation model of anxiety induction, we examined the effects of smoking status and abstinence from smoking on anxiety responses. Physiological and subjective responses to CO2 and medical air were compared in smokers and non-smokers (Experiment One) and in overnight abstinent and non-abstinent smokers (Experiment Two). CO2 induced greater increases in blood pressure in non-smokers compared with smokers (ps < 0.043), and greater increases in anxiety (p = 0.005) and negative affect (p = 0.054) in non-abstinent compared with abstinent smokers. CO2 increased physiological and subjective indices of anxiety. There were differences across smoking groups indicating that the CO2 inhalation model is a useful tool for examining the relationship between smoking and anxiety. The findings suggested that both acute smoking and acute abstinence may protect against anxious responding. Further investigation is needed in long-term heavy smokers. PMID:24763184

Effects of 7.5% carbon dioxide inhalation on anxiety and mood in cigarette smokers.

PubMed

Attwood, Angela S; Ataya, Alia F; Bailey, Jayne E; Lightman, Stafford L; Munafò, Marcus R

2014-08-01

Cigarette smoking is associated with elevated risk of anxiety and mood disorder. Using the 7.5% carbon dioxide (CO2) inhalation model of anxiety induction, we examined the effects of smoking status and abstinence from smoking on anxiety responses. Physiological and subjective responses to CO2 and medical air were compared in smokers and non-smokers (Experiment One) and in overnight abstinent and non-abstinent smokers (Experiment Two). CO2 induced greater increases in blood pressure in non-smokers compared with smokers (ps < 0.043), and greater increases in anxiety (p = 0.005) and negative affect (p = 0.054) in non-abstinent compared with abstinent smokers. CO2 increased physiological and subjective indices of anxiety. There were differences across smoking groups indicating that the CO2 inhalation model is a useful tool for examining the relationship between smoking and anxiety. The findings suggested that both acute smoking and acute abstinence may protect against anxious responding. Further investigation is needed in long-term heavy smokers. © The Author(s) 2014.

Does selection for short sleep duration explain human vulnerability to Alzheimer’s disease?

PubMed Central

Nesse, Randolph M; Finch, Caleb E; Nunn, Charles L

2017-01-01

Abstract Compared with other primates, humans sleep less and have a much higher prevalence of Alzheimer ’s disease (AD) pathology. This article reviews evidence relevant to the hypothesis that natural selection for shorter sleep time in humans has compromised the efficacy of physiological mechanisms that protect against AD during sleep. In particular, the glymphatic system drains interstitial fluid from the brain, removing extra-cellular amyloid beta (eAβ) twice as fast during sleep. In addition, melatonin—a peptide hormone that increases markedly during sleep—is an effective antioxidant that inhibits the polymerization of soluble eAβ into insoluble amyloid fibrils that are associated with AD. Sleep deprivation increases plaque formation and AD, which itself disrupts sleep, potentially creating a positive feedback cycle. These and other physiological benefits of sleep may be compromised by short sleep durations. Our hypothesis highlights possible long-term side effects of medications that reduce sleep, and may lead to potential new strategies for preventing and treating AD. PMID:28096295

Co-culture of Gastric Organoids and Immortalized Stomach Mesenchymal Cells.

PubMed

Bertaux-Skeirik, Nina; Centeno, Jomaris; Feng, Rui; Schumacher, Michael A; Shivdasani, Ramesh A; Zavros, Yana

2016-01-01

Three-dimensional primary epithelial-derived gastric organoids have recently been established as an important tool to study gastric development, physiology, and disease. Specifically, mouse-derived fundic gastric organoids (mFGOs) co-cultured with Immortalized Stomach Mesenchymal Cells (ISMCs) reflect expression patterns of mature fundic cell types seen in vivo, thus allowing for long-term in vitro studies of gastric epithelial cell physiology, regeneration, and bacterial-host interactions. Here, we describe the development and culture of mFGOs, co-cultured with ISMCs.

The associations between workplace bullying, salivary cortisol, and long-term sickness absence: a longitudinal study.

PubMed

Grynderup, Matias Brødsgaard; Nabe-Nielsen, Kirsten; Lange, Theis; Conway, Paul Maurice; Bonde, Jens Peter; Garde, Anne Helene; Gullander, Maria; Kaerlev, Linda; Persson, Roger; Rugulies, Reiner; Vammen, Marianne Agergaard; Høgh, Annie; Hansen, Åse Marie

2017-09-16

Workplace stressors, such as bullying, are strongly related to subsequent long-term sickness absence, but little is known of the possible physiological mechanisms linking workplace stressors and sickness absence. The primary aim of this study was to investigate to what extent cortisol levels were associated with subsequent sickness absence and if cortisol mediated the association between workplace bullying and sickness absence. We additionally investigated possible bidirectional associations between bullying, cortisol, and long-term sickness absence. Participants came from two Danish cohort studies, the "Psychosocial RIsk factors for Stress and MEntal disease" (PRISME) cohort and the "Workplace Bullying and Harassment" (WBH) cohort (n = 5418). Information about exposure to workplace bullying and morning and evening salivary cortisol was collected at three time points with approximately two years in between. After each data collection, all participants were followed for two years in registers, and cases with long-term sickness absence lasting 30 or more consecutive days were identified. The association between cortisol levels and subsequent sickness absence was assessed by logistic regression, while the extent to which the association between bullying and sickness absence was mediated by cortisol was quantified through natural direct and indirect effects. High evening cortisol was associated with a decreased risk of sickness absence (OR = 0.82, 95% CI = 0.68-0.99), but we did not find that high morning cortisol levels (OR = 0.98, 95% CI = 0.81-1.18) or high morning-to-evening slope (OR = 0.99, 95% CI = 0.82-1.18) were associated with subsequent sickness absence. We also tested for reverse causation and found that long-term sickness absence, but not salivary cortisol, was a strong risk factor for subsequent workplace bullying. There was no indication that cortisol mediated the association between workplace bullying and sickness absence. We found no straightforward and simple association between cortisol and long-term sickness absence. Furthermore, the association between workplace bullying and long-term sickness absence was not mediated by cortisol.

Resistance exercise reduces memory impairment induced by monosodium glutamate in male and female rats.

PubMed

Araujo, Paulo Cesar Oliveira; Quines, Caroline Brandão; Jardim, Natália Silva; Leite, Marlon Regis; Nogueira, Cristina Wayne

2017-07-01

What is the central question of this study? Monosodium glutamate causes cognitive impairment. Does resistance exercise improve the performance of rats treated with monosodium glutamate? What is the main finding and its importance? Resistance exercise is effective against monosodium glutamate-induced memory impairment in male and female rats. Monosodium glutamate (MSG), a flavour enhancer in diets, causes cognitive impairment in rodents. Exercise has been reported to protect against impairment of memory in humans. In this study, we investigated whether resistance exercise improves the performance of male and female rats treated with MSG in tests of memory and motor co-ordination. Wistar rats received MSG [4 g (kg body weight) -1  day -1 , s.c.] from postnatal day 1 to 10. At postnatal day 60, the animals started a resistance exercise protocol in an 80 deg inclined vertical ladder apparatus and performed it during 7 weeks. Rats performed object recognition and location memory tests. Resistance exercise reduced impairment in motor co-ordination of male and female rats treated with MSG. Resistance exercise was effective against the decrease in exploratory preference in the long-term recognition memory for novel objects of male rats treated with MSG. In MSG-treated female rats, resistance exercise was effective against the decrease in exploratory preference in the novel object location test. The exploratory preference of female rats in the long-term recognition memory test was similar in all groups. The short-term memory was not altered by MSG or resistance exercise in male and female rats. This study demonstrates that MSG affected the memory of male and female rats in different ways. Resistance exercise was effective against the decrease in recognition for male rats and in location memory for female rats treated with MSG. This report demonstrates the beneficial effects of resistance exercise against the prejudice of motor condition and impairment of memory induced by MSG in male and female rats. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

Long term flight electrodes

NASA Technical Reports Server (NTRS)

Mosier, B.

1975-01-01

The reproducibility, stability, and methods of preparation for the various types and forms of biomedical electrodes are discussed. A critical and selective compilation of information on biological and/or physiological electrodes is presented. A discussion of plant hydrocolloids, clays, hydrophyllic colloids, synthetic waxes, and acrylic polymers is included.

Juvenile stress potentiates aversive 22-kHz ultrasonic vocalizations and freezing during auditory fear conditioning in adult male rats.

PubMed

Yee, Nicole; Schwarting, Rainer K W; Fuchs, Eberhard; Wöhr, Markus

2012-09-01

Traumatic experiences that occur during adolescence can render individuals vulnerable to mood and anxiety disorders. A model in juvenile rats (age: 27-29 days) was developed previously to study the long-term effects of adolescent stress exposure on behaviour and physiology. This paradigm, termed juvenile stress, involves subjecting juvenile rats to different stressors on consecutive days over a 3-day period. Here, we investigated the effects of the juvenile stress paradigm on freezing behaviour and aversive 22-kHz ultrasonic vocalizations (USVs) during auditory fear conditioning in adult male rats (age: 68-90 days). We found that rats previously subjected to juvenile stress increased aversive 22-kHz USVs (total calls and time spent calling) compared with controls during fear-conditioning training. The acoustic USV parameters between control and juvenile stress rats were largely equivalent, including duration, peak frequency and amplitude. While rats did not differ in freezing behaviour during fear conditioning, juvenile stress rats exhibited greater cue-conditioned freezing upon testing 24 h later. Our results show that juvenile stress elicited different long-term changes in freezing and aversive USVs during fear conditioning. Furthermore, they highlight the importance of assessing USVs to detect experience-dependent differences between control and stress-exposed animals which are not detectable by measuring visible behaviour.

Glucose Homeostasis During Short-term and Prolonged Exposure to High Altitudes

PubMed Central

Ader, Marilyn; Bergman, Richard N.

2015-01-01

Most of the literature related to high altitude medicine is devoted to the short-term effects of high-altitude exposure on human physiology. However, long-term effects of living at high altitudes may be more important in relation to human disease because more than 400 million people worldwide reside above 1500 m. Interestingly, individuals living at higher altitudes have a lower fasting glycemia and better glucose tolerance compared with those who live near sea level. There is also emerging evidence of the lower prevalence of both obesity and diabetes at higher altitudes. The mechanisms underlying improved glucose control at higher altitudes remain unclear. In this review, we present the most current evidence about glucose homeostasis in residents living above 1500 m and discuss possible mechanisms that could explain the lower fasting glycemia and lower prevalence of obesity and diabetes in this population. Understanding the mechanisms that regulate and maintain the lower fasting glycemia in individuals who live at higher altitudes could lead to new therapeutics for impaired glucose homeostasis. PMID:25675133

The long-term effects of prenatal nicotine exposure on response inhibition: an fMRI study of young adults.

PubMed

Longo, Carmelinda A; Fried, Peter A; Cameron, Ian; Smith, Andra M

2013-01-01

The long-term effects of prenatal nicotine exposure on response inhibition were investigated in young adults using functional magnetic resonance imaging (fMRI). Participants were members of the Ottawa Prenatal Prospective Study, a longitudinal study that collected a unique body of information on participants from infancy to young adulthood, which allowed for the measurement of an unprecedented number of potentially confounding drug exposure variables including: prenatal marijuana and alcohol exposure and current marijuana, nicotine and alcohol use. Twelve young adults with prenatal nicotine exposure and 13 non-exposed controls performed a Go/No-Go task while fMRI blood oxygen level-dependent responses were examined. Despite similar task performance, participants prenatally exposed to nicotine demonstrated significantly greater activity in several regions of the brain that typically subserve response inhibition including the inferior frontal gyrus, the inferior parietal lobe, the thalamus and the basal ganglia. In addition, prenatally exposed participants showed greater activity in relatively large posterior regions of the cerebellum. These results suggest that prenatal nicotine exposure leads to altered neural functioning during response inhibition that continues into adulthood. This alteration is compensated for by recruitment of greater neural resources within regions of the brain that subserve response inhibition and the recruitment of additional brain regions to successfully perform the task. Response inhibition is an important executive functioning skill and impairments can impede functioning in much of everyday life. Thus, awareness of the continued long-term neural physiological effects of prenatal nicotine exposure is critical. Copyright © 2013 Elsevier Inc. All rights reserved.

Physiological responses and scope for growth upon medium-term exposure to the combined effects of ocean acidification and temperature in a subtidal scavenger Nassarius conoidalis.

PubMed

Zhang, Haoyu; Shin, Paul K S; Cheung, S G

2015-05-01

Physiological responses (ingestion rate, absorption rate and efficiency, respiration, rate, excretion rate) and scope for growth of a subtidal scavenging gastropod Nassarius conoidalis under the combined effects of ocean acidification (pCO2 levels: 380, 950, 1250 μatm) and temperature (15, 30 °C) were investigated for 31 days. There was a significant reduction in all the physiological rates and scope for growth following short-term exposure (1-3 days) to elevated pCO2 except absorption efficiency at 15 °C and 30 °C, and respiration rate and excretion rate at 15 °C. The percentage change in the physiological rates ranged from 0% to 90% at 15 °C and from 0% to 73% at 30 °C when pCO2 was increased from 380 μatm to 1250 μatm. The effect of pCO2 on the physiological rates was enhanced at high temperature for ingestion, absorption, respiration and excretion. When the exposure period was extended to 31 days, the effect of pCO2 was significant on the ingestion rate only. All the physiological rates remained unchanged when temperature increased from 24 °C to 30 °C but the rates at 15 °C were significantly lower, irrespective of the duration of exposure. Our data suggested that a medium-term exposure to ocean acidification has no effect on the energetics of N. conoidalis. Nevertheless, the situation may be complicated by a longer term of exposure and/or a reduction in salinity in a warming world. Copyright © 2015 Elsevier Ltd. All rights reserved.

Resistance to thermal stress in corals without changes in symbiont composition.

PubMed

Bellantuono, Anthony J; Hoegh-Guldberg, Ove; Rodriguez-Lanetty, Mauricio

2012-03-22

Discovering how corals can adjust their thermal sensitivity in the context of global climate change is important in understanding the long-term persistence of coral reefs. In this study, we showed that short-term preconditioning to higher temperatures, 3°C below the experimentally determined bleaching threshold, for a period of 10 days provides thermal tolerance for the symbiosis stability between the scleractinian coral, Acropora millepora and Symbiodinium. Based on genotypic analysis, our results indicate that the acclimatization of this coral species to thermal stress does not come down to simple changes in Symbiodinium and/or the bacterial communities that associate with reef-building corals. This suggests that the physiological plasticity of the host and/or symbiotic components appears to play an important role in responding to ocean warming. The further study of host and symbiont physiology, both of Symbiodinium and prokaryotes, is of paramount importance in the context of global climate change, as mechanisms for rapid holobiont acclimatization will become increasingly important to the long-standing persistence of coral reefs.

A wearable physiological sensor suite for unobtrusive monitoring of physiological and cognitive state.

PubMed

Matthews, Robert; McDonald, Neil J; Hervieux, Paul; Turner, Peter J; Steindorf, Martin A

2007-01-01

This paper describes an integrated Physiological Sensor Suite (PSS) based upon QUASAR's innovative non-invasive bioelectric sensor technologies that will provide, for the first time, a fully integrated, noninvasive methodology for physiological sensing. The PSS currently under development at QUASAR is a state-of-the-art multimodal array of sensors that, along with an ultra-low power personal area wireless network, form a comprehensive body-worn system for real-time monitoring of subject physiology and cognitive status. Applications of the PSS extend from monitoring of military personnel to long-term monitoring of patients diagnosed with cardiac or neurological conditions. Results for side-by-side comparisons between QUASAR's biosensor technology and conventional wet electrodes are presented. The signal fidelity for bioelectric measurements using QUASAR's biosensors is comparable to that for wet electrodes.

Learning, memory and long-term potentiation are altered in Nedd4 heterozygous mice.

PubMed

Camera, Daria; Coleman, Harold A; Parkington, Helena C; Jenkins, Trisha A; Pow, David V; Boase, Natasha; Kumar, Sharad; Poronnik, Philip

2016-04-15

The consolidation of short-term memory into long-term memory involves changing protein level and activity for the synaptic plasticity required for long-term potentiation (LTP). AMPA receptor trafficking is a key determinant of LTP and recently ubiquitination by Nedd4 has been shown to play an important role via direct action on the GluA1 subunit, although the physiological relevance of these findings are yet to be determined. We therefore investigated learning and memory in Nedd4(+/-) mice that have a 50% reduction in levels of Nedd4. These mice showed decreased long-term spatial memory as evidenced by significant increases in the time taken to learn the location of and subsequently find a platform in the Morris water maze. In contrast, there were no significant differences between Nedd4(+/+) and Nedd4(+/-) mice in terms of short-term spatial memory in a Y-maze test. Nedd4(+/-) mice also displayed a significant reduction in post-synaptic LTP measured in hippocampal brain slices. Immunofluorescence of Nedd4 in the hippocampus confirmed its expression in hippocampal neurons of the CA1 region. These findings indicate that reducing Nedd4 protein by 50% significantly impairs LTP and long-term memory thereby demonstrating an important role for Nedd4 in these processes. Copyright © 2016 Elsevier B.V. All rights reserved.

The perfused swine uterus model: long-term perfusion

PubMed Central

2012-01-01

Background It has previously been shown that the viability of swine uteri can be maintained within the physiological range in an open perfusion model for up to 8 hours. The aim of this study was to assess medium- to long-term perfusion of swine uteri using a modified Krebs–Ringer bicarbonate buffer solution (KRBB) in the established open perfusion model. Methods In an experimental study at an infertility institute, 30 swine uteri were perfused: group 1: n = 11, KRBB; group 2: n = 8, modified KRBB with drainage of perfusate supernatant; group 3: n = 11, modified KRBB with drainage of perfusate every 2 h and substitution with fresh medium. Modified and conventional KRBB were compared with regard to survival and contraction parameters: intrauterine pressure (IUP), area under the curve (AUC), and frequency of contractions (F). Results Modified KRBB showed significantly higher IUP, AUC, and F values than perfusion with conventional KRBB. In group 3, the organ survival time of up to 17 h, with a 98% rate of effective contraction time, differed significantly from group 1 (P < 0.001). Conclusions Using modified KRBB in combination with perfusate substitution improves the open model for perfusion of swine uteri with regard to survival time and quality of contraction parameters. This model can be used for medium- to long-term perfusion of swine uteri, allowing further metabolic ex vivo studies in a cost-effective way and with little logistic effort. PMID:23241226

Hair cortisol concentrations correlate negatively with survival in a wild primate population.

PubMed

Rakotoniaina, Josué H; Kappeler, Peter M; Kaesler, Eva; Hämäläinen, Anni M; Kirschbaum, Clemens; Kraus, Cornelia

2017-09-01

Glucocorticoid hormones are known to play a key role in mediating a cascade of physiological responses to social and ecological stressors and can therefore influence animals' behaviour and ultimately fitness. Yet, how glucocorticoid levels are associated with reproductive success or survival in a natural setting has received little empirical attention so far. Here, we examined links between survival and levels of glucocorticoid in a small, short-lived primate, the grey mouse lemur (Microcebus murinus), using for the first time an indicator of long-term stress load (hair cortisol concentration). Using a capture-mark-recapture modelling approach, we assessed the effect of stress on survival in a broad context (semi-annual rates), but also under a specific period of high energetic demands during the reproductive season. We further assessed the power of other commonly used health indicators (body condition and parasitism) in predicting survival outcomes relative to the effect of long-term stress. We found that high levels of hair cortisol were associated with reduced survival probabilities both at the semi-annual scale and over the reproductive season. Additionally, very good body condition (measured as scaled mass index) was related to increased survival at the semi-annual scale, but not during the breeding season. In contrast, variation in parasitism failed to predict survival. Altogether, our results indicate that long-term increased glucocorticoid levels can be related to survival and hence population dynamics, and suggest differential strength of selection acting on glucocorticoids, body condition, and parasite infection.

Marked dissociation between hypothalamic-pituitary-adrenal activation and long-term behavioral effects in rats exposed to immobilization or cat odor.

PubMed

Muñoz-Abellán, C; Andero, R; Nadal, R; Armario, A

2008-09-01

Exposure of rodents to cats or certain cat odors results in long-term behavioral effects reminiscent of enhanced anxiety that have been considered to model post-traumatic stress disorder. However, other severe stressors such as tail-shock or immobilization in wooden boards (IMO) appear to induce shorter lasting changes in anxiety. In addition, there are controversial results regarding the effects of urine/feces odors. In the present work, we studied in two experiments the relationship between the degree of stress experienced by the animals during exposure to IMO, urine odors or fur odors (as assessed by hypothalamic-pituitary-adrenal activation and plasma glucose) and the short- and long-term behavioral consequences. In the first experiment, rats were individually exposed for 15 min to a novel environment (white large cages) containing either clean cat litter (controls) or litter soiled by cats (urine odors). Half of the rats in each condition were left to freely explore the environment whereas the others were subjected to immobilization (IMO) within the cages. Although ACTH, corticosterone and glucose responses to IMO were much stronger than those to the white cages with clean litter or urine odors (which did not differ from each other), no effect of treatments on anxiety-like behavior in the elevated plus-maze (EPM) were found one week later. However, previous IMO exposure did cause sensitization of the ACTH response to the EPM. In the second experiment, the response to white large cages containing either no odor (controls), litter soiled by cats (urine odor) or a cloth impregnated with cat odor (fur odor) was compared. Urine and fur odors elicited similar ACTH and corticosterone responses that were higher than those of controls, but plasma glucose levels were slightly higher in rats exposed to fur odor. When compared to controls, activity was only diminished in the novel cages containing fur odor. Similarly, fur odor-exposed rats, but not those exposed to urine odor, showed signs of enhanced anxiety in the EPM seven days later, although the ACTH response to the EPM was similar in the three groups. The present data demonstrate: (a) a marked dissociation between the degree of ACTH, corticosterone and glucose responses to stressors and their long-term anxiety-like effects; (b) that the type of cat odor is critical in determining the short-term and long-term physiological and behavioral consequences of exposure; and (c) that plasma ACTH released during brief exposure to the EPM does not appear to reflect anxiety-like behavior.

Programming social, cognitive, and neuroendocrine development by early exposure to novelty.

PubMed

Tang, Akaysha C; Akers, Katherine G; Reeb, Bethany C; Romeo, Russell D; McEwen, Bruce S

2006-10-17

Mildly stressful early life experiences can potentially impact a broad range of social, cognitive, and physiological functions in humans, nonhuman primates, and rodents. Recent rodent studies favor a maternal-mediation hypothesis that considers maternal-care differences induced by neonatal stimulation as the cause of individual differences in offspring development. Using neonatal novelty exposure, a neonatal stimulation paradigm that dissociates maternal individual differences from a direct stimulation effect on the offspring, we investigated the effect of early exposures to novelty on a diverse range of psychological functions using several assessment paradigms. Pups that received brief neonatal novelty exposures away from the home environment showed enhancement in spatial working memory, social competition, and corticosterone response to surprise during adulthood compared with their home-staying siblings. These functional enhancements in novelty-exposed rats occurred despite evidence that maternal care was directed preferentially toward home-staying instead of novelty-exposed pups, indicating that greater maternal care is neither necessary nor sufficient for these early stimulation-induced functional enhancements. We suggest a unifying maternal-modulation hypothesis, which distinguishes itself from the maternal-mediation hypothesis in that (i) neonatal stimulation can have direct effects on pups, cumulatively leading to long-term improvement in adult offspring; and (ii) maternal behavior can attenuate or potentiate these effects, thereby decreasing or increasing this long-term functional improvement.

Practical guidelines for workload assessment

NASA Technical Reports Server (NTRS)

Tattersall, Andrew J.

1994-01-01

The practical problems that might be encountered in carrying out workload evaluations in work settings have been outlined. Different approaches have been distinguished that may determine the type of research design used and provide assistance in the difficult choice between workload assessment techniques. One approach to workload assessment is to examine the short-term consequences of combining various tasks. Theoretical models of attention allocation will underpin specific studies of interference and the consequences of task demand and task conflict for performance. A further approach with a different temporal orientation may lead us to a better understanding of the relationships between work demands and strain through the analysis of individual differences in cognitive control processes. The application of these processes may depend on individual differences in long term styles and short term strategies, but may be used to prevent decrements in work performance under difficult conditions. However, control may attract costs as well as benefits in terms of changes in effective state and physiological activity. Thus, strain associated with work demands may only be measurable in the form of tradeoffs between performance and other domains of individual activity. The methodological implications are to identify patterns of adjustment to workload variations using repeated measures and longitudinal sampling of performance as well as subjective and physiological measures. Possible enhancements to workplace design must take into account these human factors considerations of workload in order to avoid potential decrements in individual performance and associated organizational problems.

Enlarging effects of estradiol on the nuclear volume of neurons in the hypothalamus during aging.

PubMed

Hsu, C; Yang, S L; Hsieh, Y L; Lue, S I; Hsu, H K; Peng, M T

1998-01-01

Neuronal nuclear volumes (NNVs) were measured in the medial preoptic nucleus (MPN), anterior hypothalamic area (AHA) and arcuate nucleus (ARN) of young adult, middle-aged, and old rats of both sexes. The NNVs in the darkly stained sexual-dimorphic nucleus of the preoptic area (SDN-POA) and the lighter staining surrounding area (non-SDN-POA) within the MPN were measured separately. Intact young and middle-aged female rats had larger NNVs than those of the males in SDN-POA, non-SDN-POA and AHA but not in ARN. During aging, only intact old female rats manifested significant NNV shrinkage in all the measured areas. Long-term treatment with estradiol benzoate (EB) caused a significant enlargement of the NNVs in non-SDN-POA and ARN of middle-aged and old male rats as well as the NNVs in SDN-POA, non-SDN-POA and ARN of old female rats. The enlarging effect of EB on NNVs in both SDN-POA and non-SDN-POA of female rats could be prevented by ovariectomy. Furthermore, NNVs in SDN-POA and non-SDN-POA of ovariectomized female rats were even smaller than those of the age-matched intact female rats. These results indicate that: (1) the NNVs of MPN and ARN in male and female rats were enlarged after long-term exposure of physiological dose of estradiol; (2) the enlarging effects of EB on NNV in MPN can explain why the NNV of intact female rats is larger than that of males, and (3) during aging, the sex-specific shrinkage of NNVs in MPN, AHA and ARN of female rats may be due to an intrinsic aging process rather than long-term effects of EB.

Maternal stress does not exacerbate long-term bone deficits in female rats born growth restricted, with differential effects on offspring bone health.

PubMed

Anevska, Kristina; Cheong, Jean N; Wark, John D; Wlodek, Mary E; Romano, Tania

2018-02-01

Females born growth restricted have poor adult bone health. Stress exposure during pregnancy increases risk of pregnancy complications. We determined whether maternal stress exposure in growth-restricted females exacerbates long-term maternal and offspring bone phenotypes. On gestational day 18, bilateral uterine vessel ligation (restricted) or sham (control) surgery was performed on Wistar-Kyoto rats. At 4 mo, control and restricted females were mated and allocated to unstressed or stressed pregnancies. Stressed pregnancies had physiological measurements performed; unstressed females were not handled. After birth, mothers were aged to 13 mo. Second-generation (F2) offspring generated four experimental groups: control unstressed, restricted unstressed, control stressed and restricted stressed. F2 offspring were studied at postnatal day 35 (PN35), 6, 12, and 16 mo. Peripheral quantitative computed tomography was performed on maternal and F2 offspring femurs. Restricted females, irrespective of stress during pregnancy, had decreased endosteal circumference, bending strength, and increased osteocalcin concentrations after pregnancy at 13 mo. F2 offspring of stressed mothers were born lighter. F2 male offspring from stressed pregnancies had decreased trabecular content at 6 mo and decreased endosteal circumference at 16 mo. F2 female offspring from growth-restricted mothers had reduced cortical thickness at PN35 and reduced endosteal circumference at 6 mo. At 12 mo, females from unstressed restricted and stressed control mothers had decreased trabecular content. Low birth weight females had long-term bone changes, highlighting programming effects on bone health. Stress during pregnancy did not exacerbate these programmed effects. Male and female offspring responded differently to maternal growth restriction and stress, indicating gender-specific programming effects.

The role of long-term physical exercise on performance and brain activation during the Stroop colour word task in fibromyalgia patients.

PubMed

Martinsen, S; Flodin, P; Berrebi, J; Löfgren, M; Bileviciute-Ljungar, I; Mannerkorpi, K; Ingvar, M; Fransson, P; Kosek, E

2018-05-01

The Stroop colour word test (SCWT) has been widely used to assess changes in cognitive performance such as processing speed, selective attention and the degree of automaticity. Moreover, the SCWT has proven to be a valuable tool to assess neuronal plasticity that is coupled to improvement in performance in clinical populations. In a previous study, we showed impaired cognitive processing during SCWT along with reduced task-related activations in patients with fibromyalgia. In this study, we used SCWT and functional magnetic resonance imagingFMRI to investigate the effects of a 15-week physical exercise intervention on cognitive performance, task-related cortical activation and distraction-induced analgesia (DIA) in patients with fibromyalgia and healthy controls. The exercise intervention yielded reduced fibromyalgia symptoms, improved cognitive processing and increased task-related activation of amygdala, but no effect on DIA. Our results suggest beneficial effects of physical exercise on cognitive functioning in FM. © 2017 The Authors. Clinical Physiology and Functional Imaging published by John Wiley & Sons Ltd on behalf of Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Effects of Three Fire-Suppressant Foams on the Germination and Physiological Responses of Plants

NASA Astrophysics Data System (ADS)

Song, Uhram; Mun, Saeromi; Waldman, Bruce; Lee, Eun Ju

2014-10-01

Suppressant foams used to fight forest fires may leave residual effects on surviving biota that managers need to consider prior to using them. We examined how three fire-suppressant foams (FSFs) (Forexpan S, Phos-Chek-WD881, and Silv-ex) affected seed germination and physiological responses of three plant species. Exposure to FSFs, whether in diluted concentrations or those typical in the field, reduced final germination percentages of seeds grown in petri dishes and within growth chambers. However, the FSFs did not cause total germination failure in any treatment. Inhibition of germination increased with longer exposure times, but only to diluted FSF solutions. Unlike in the laboratory experiments, none of the three FSFs affected seedling emergence when tested in field conditions. Further, we found no evidence of long-term phytotoxic effects on antioxidant enzyme activity nor chlorophyll content of the plant saplings. Therefore, although the three FSFs showed evidence of phytotoxicity to plants in laboratory tests, their actual impact on terrestrial ecosystems may be minimal. We suggest that the benefits of using these FSFs to protect plants in threatened forest ecosystems outweigh their minor risks.

Radiative and Physiological Effects of Increased CO2: How Does This Interaction Affect Climate?

NASA Technical Reports Server (NTRS)

Bounoua, Lahouari

2011-01-01

Several climate models indicate that in a 2xCO2 environment, temperature and precipitation would increase and runoff would increase faster than precipitation. These models, however, did not allow the vegetation to increase its leaf density as a response to the physiological effects of increased CO2 and consequent changes in climate. Other assessments included these interactions but did not account for the vegetation downregulation to reduce plant's photosynthetic activity and as such resulted in a weak vegetation negative response. When we combine these interactions in climate simulations with 2xCO2, the associated increase in precipitation contributes primarily to increase evapotranspiration rather than surface runoff, consistent with observations, and results in an additional cooling effect not fully accounted for in previous 2xCO2 simulations. By accelerating the water cycle, this feedback slows but does not alleviate the projected warming, reducing the land surface warming by 0.6 C. Compared to previous studies, these results imply that long term negative feedback from CO2-induced increases in vegetation density could reduce temperature following a stabilization of CO2 concentration.

Effects of three fire-suppressant foams on the germination and physiological responses of plants.

PubMed

Song, Uhram; Mun, Saeromi; Waldman, Bruce; Lee, Eun Ju

2014-10-01

Suppressant foams used to fight forest fires may leave residual effects on surviving biota that managers need to consider prior to using them. We examined how three fire-suppressant foams (FSFs) (Forexpan S, Phos-Chek-WD881, and Silv-ex) affected seed germination and physiological responses of three plant species. Exposure to FSFs, whether in diluted concentrations or those typical in the field, reduced final germination percentages of seeds grown in petri dishes and within growth chambers. However, the FSFs did not cause total germination failure in any treatment. Inhibition of germination increased with longer exposure times, but only to diluted FSF solutions. Unlike in the laboratory experiments, none of the three FSFs affected seedling emergence when tested in field conditions. Further, we found no evidence of long-term phytotoxic effects on antioxidant enzyme activity nor chlorophyll content of the plant saplings. Therefore, although the three FSFs showed evidence of phytotoxicity to plants in laboratory tests, their actual impact on terrestrial ecosystems may be minimal. We suggest that the benefits of using these FSFs to protect plants in threatened forest ecosystems outweigh their minor risks.

Reconfiguration of the small intestine and diabetes remitting effects of Roux-en-Y gastric bypass surgery.

PubMed

Docherty, Neil G; le Roux, Carel W

2016-03-01

Alterations in small intestinal physiology are proposed to play a causative role in the beneficial impact of Roux-en-Y gastric bypass on type 2 diabetes mellitus. The present article describes the key proposed mechanisms implicated with an emphasis on some of the newer findings in the field. Augmented incretin and diminished anti-incretin effects postsurgery are explored and a model proposed that reconciles the hindgut and foregut hypotheses of improved glycaemic control as being complementary rather than mutually exclusive. Synthesis of recent findings on postbypass changes in intestinal glucose handling then follows. Finally an updated view of the role of distal bile diversion and changes in the microbiota on enteroendocrine signalling is presented. A series of nonmutually exclusive changes in small intestinal physiology likely make a significant contribution to improved glycaemic control postgastric bypass. Longitudinal data indicate that these effects do not translate into a long-term cure. A number of surgery-induced changes, however, are amenable to device-based and pharmacology-based mimicry, and this is an area for prioritization of future research focus.

Recent trends in the treatment of testosterone deficiency syndrome.

PubMed

Hong, Bum Sik; Ahn, Tai Young

2007-11-01

Testosterone deficiency syndrome (TDS) is defined as a clinical and biochemical syndrome associated with advancing age and is characterized by typical symptoms and deficiency in serum testosterone levels. TDS is a result of the interaction of hypothalamo-pituitary and testicular factors. Now, treatment of TDS with testosterone is still controversial due to a lack of large, controlled clinical trials on efficacy. The risks of treatment with testosterone appear to be minimal, although long-term studies on the safety of testosterone therapy are lacking. The aim of the therapy is to establish a physiological concentration of serum testosterone in order to correct the androgen deficiency, relieve its symptoms and prevent long-term sequelae. All of the available products, despite their varying pharmacodynamic and pharmacokinetic profiles, are able to reach this goal. Newer testosterone patches seem not to cause severe skin irritation. Testosterone gels minimize the skin irritation while providing flexibility in dosing and a low discontinuation rate. Oral testosterone undecanoate (TU) is free of liver toxicity. Recent formulation of oral TU markedly increased shelf-live, a major drawback in the older preparation. Producing swings in testosterone levels rising rapidly to the supraphysiological range is not the case with the new injectable long-acting preparation of TU. To be able to rapidly react and stop treatment in cases where side-effects and contraindications are detected, the short-acting transdermal and oral delivery modes have certain advantages. However, there is no evidence that the use of an injectable long-acting TU in men with TDS has limitations in clinical application for this reason. The use of dehydroepiandrosterone is still controversial because of a lack of well designed long-term trials, although some recent studies suggest positive effects on various body systems. Only a few studies have been carried out to investigate the effect of hCG (human chorionic gonadotropin) in TDS with some positive results on various body systems.

Elevated pCO2 affects tissue biomass composition, but not calcification, in a reef coral under two light regimes.

PubMed

Wall, C B; Mason, R A B; Ellis, W R; Cunning, R; Gates, R D

2017-11-01

Ocean acidification (OA) is predicted to reduce reef coral calcification rates and threaten the long-term growth of coral reefs under climate change. Reduced coral growth at elevated p CO 2 may be buffered by sufficiently high irradiances; however, the interactive effects of OA and irradiance on other fundamental aspects of coral physiology, such as the composition and energetics of coral biomass, remain largely unexplored. This study tested the effects of two light treatments (7.5 versus 15.7 mol photons m -2  d -1 ) at ambient or elevated p CO 2 (435 versus 957 µatm) on calcification, photopigment and symbiont densities, biomass reserves (lipids, carbohydrates, proteins), and biomass energy content (kJ) of the reef coral Pocillopora acuta from Kāne'ohe Bay, Hawai'i. While p CO 2 and light had no effect on either area- or biomass-normalized calcification, tissue lipids gdw -1 and kJ gdw -1 were reduced 15% and 14% at high p CO 2 , and carbohydrate content increased 15% under high light. The combination of high light and high p CO 2 reduced protein biomass (per unit area) by approximately 20%. Thus, under ecologically relevant irradiances, P. acuta in Kāne'ohe Bay does not exhibit OA-driven reductions in calcification reported for other corals; however, reductions in tissue lipids, energy content and protein biomass suggest OA induced an energetic deficit and compensatory catabolism of tissue biomass. The null effects of OA on calcification at two irradiances support a growing body of work concluding some reef corals may be able to employ compensatory physiological mechanisms that maintain present-day levels of calcification under OA. However, negative effects of OA on P. acuta biomass composition and energy content may impact the long-term performance and scope for growth of this species in a high p CO 2 world.

Elevated pCO2 affects tissue biomass composition, but not calcification, in a reef coral under two light regimes

PubMed Central

Mason, R. A. B.; Ellis, W. R.; Cunning, R.; Gates, R. D.

2017-01-01

Ocean acidification (OA) is predicted to reduce reef coral calcification rates and threaten the long-term growth of coral reefs under climate change. Reduced coral growth at elevated pCO2 may be buffered by sufficiently high irradiances; however, the interactive effects of OA and irradiance on other fundamental aspects of coral physiology, such as the composition and energetics of coral biomass, remain largely unexplored. This study tested the effects of two light treatments (7.5 versus 15.7 mol photons m−2 d−1) at ambient or elevated pCO2 (435 versus 957 µatm) on calcification, photopigment and symbiont densities, biomass reserves (lipids, carbohydrates, proteins), and biomass energy content (kJ) of the reef coral Pocillopora acuta from Kāne‘ohe Bay, Hawai‘i. While pCO2 and light had no effect on either area- or biomass-normalized calcification, tissue lipids gdw−1 and kJ gdw−1 were reduced 15% and 14% at high pCO2, and carbohydrate content increased 15% under high light. The combination of high light and high pCO2 reduced protein biomass (per unit area) by approximately 20%. Thus, under ecologically relevant irradiances, P. acuta in Kāne‘ohe Bay does not exhibit OA-driven reductions in calcification reported for other corals; however, reductions in tissue lipids, energy content and protein biomass suggest OA induced an energetic deficit and compensatory catabolism of tissue biomass. The null effects of OA on calcification at two irradiances support a growing body of work concluding some reef corals may be able to employ compensatory physiological mechanisms that maintain present-day levels of calcification under OA. However, negative effects of OA on P. acuta biomass composition and energy content may impact the long-term performance and scope for growth of this species in a high pCO2 world. PMID:29291059

Orchard establishment, precocity, and eco-physiological traits of several pomegranate cultivars

USDA-ARS?s Scientific Manuscript database

California faces many threats to food security, ranging from water limitations resulting from long-term drought to invasive pests and disease. Major tree crops, such as citrus and avocado, are threatened by Citrus Greening and Fusarium Dieback, respectively, posing significant economic threats to gr...

Study of toxicological evaluation of fire suppressants and extinguishers

NASA Technical Reports Server (NTRS)

1975-01-01

The application of fluorocarbons as possible candidates for fire extinguishers and/or suppressants in confined spaces (such as spacecraft, aircraft, or submarines) was investigated, with special emphasis on their safety to man since they would be inhaled on an almost continuous basis. Short-term exposure experiments, using various animal species, were devised to look at specific parameters in order to determine which of the candidate compounds were sufficiently non-toxic to warrant long-term investigations. The following physiologic criteria were examined; tissue distribution, fluoride concentration, effect on mitochondria, microsomes, liposomes, and liver cell nuclei, erythrocyte fragility, clinical chemistry values, hematology, pathology, cardiac sensitization, behavioral effects. Various rodent species were used for initial investigations, with non-human primate exposures for Freon 116 which was warranted for negative results on rodents. Various types of exposure chambers were used, including closed dynamic chambers allowing for a recirculating atmosphere.

Long-Term Durability Test for the Left Ventricular Assist System EVAHEART under the Physiologic Pulsatile Load.

PubMed

Kitano, Tomoya; Iwasaki, Kiyotaka

The EVAHEART Left Ventricular Assist System (LVAS) was designed for the long-term support of a patient with severe heart failure. It has an original water lubrication system for seal and bearing and wear on these parts was considered one of its critical failure modes. A durability test focusing on wear was designed herein. We developed a mock loop, which generates a physiologic pulsatile flow and is sufficiently durable for a long-term test. The pulsatile load and the low fluid viscosity enable the creation of a severe condition for the mechanical seal. A total of 18 EVAHEART blood pumps completed 2 years of operation under the pulsatile condition without any failure. It indicated the EVAHEART blood pump had a greater than 90% reliability with a 88% confidence level. The test was continued with six blood pumps and achieved an average of 8.6 years, which was longer than the longest clinical use in Japan. The test result showed that no catastrophic, critical, marginal, or minor failures of the blood pump or their symptoms were observed. The seal performance was maintained after the test. Moreover, the surface roughness did not change, which showed any burn or abnormal wear occurred. The original water lubrication system equipped in EVAHEART LVAS prevent severe wear on the seal and the bearing, and it can be used in the bridge to transplant and destination therapy.

Smolt physiology and endocrinology

USGS Publications Warehouse

McCormick, Stephen D.; McCormick, Stephen D.; Farrell, Anthony Peter; Brauner, Colin J.

2013-01-01

Hormones play a critical role in maintaining body fluid balance in euryhaline fishes during changes in environmental salinity. The neuroendocrine axis senses osmotic and ionic changes, then signals and coordinates tissue-specific responses to regulate water and ion fluxes. Rapid-acting hormones, e.g. angiotensins, cope with immediate challenges by controlling drinking rate and the activity of ion transporters in the gill, gut, and kidney. Slow-acting hormones, e.g. prolactin and growth hormone/insulin-like growth factor-1, reorganize the body for long-term acclimation by altering the abundance of ion transporters and through cell proliferation and differentiation of ionocytes and other osmoregulatory cells. Euryhaline species exist in all groups of fish, including cyclostomes, and cartilaginous and teleost fishes. The diverse strategies for responding to changes in salinity have led to differential regulation and tissue-specific effects of hormones. Combining traditional physiological approaches with genomic, transcriptomic, and proteomic analyses will elucidate the patterns and diversity of the endocrine control of euryhalinity.

THE HIGH-ALTITUDE RESEARCH OF MABEL PUREFOY FITZGERALD, 1911-13.

PubMed

Goodman, Martin

2015-03-20

Home schooled without a science education, Mabel Purefoy FitzGerald (1872-1973) attended physiology lectures at Oxford in 1897, even though the school was closed to women. She found work as a researcher, published early noted papers and earned the active respect and support of senior scientists of her day. Her laboratory work with the physiologist J. S. Haldane saw her invited to the join the Pikes Peak Expedition in 1911. While the male team members measured the physiological effects of long-term residency at 14101 feet, as the sole woman FitzGerald took measurements of haemoglobin and alveolar air from herself and from mining staff and families at altitudes from 6000 to 12500 feet, travelling to remote mining communities in the Colorado Rockies. A subsequent expedition collected data at lower altitudes. Recorded in two papers, the results presented pioneering evidence of the role of oxygen in breathing.

[Influence of environmental noise on sleep quality and sleeping disorders-implications for health].

PubMed

Kohlhuber, M; Bolte, G

2011-12-01

Environmental noise is a well-known risk factor influencing sleep-wake behavior and sleep quality. Epidemiologic studies have shown that environmental noise is regarded as the most annoying environmental factor. Noise causes modifications in physiologic and mental functions and may result in health outcomes like elevated blood pressure and ischemic heart disease. Reactions to high sound levels during sleep are decreased sleep intensity, arousals, and increased stress hormone secretion. Effects of poor sleep quality are reduced cognitive performance, tiredness, and psychosomatic symptoms. Long-term consequences of recurrent sleep loss due to environmental noise may be heart disease and increased medication intake. Arousals occur especially due to single noise events and intermittent noise. Laboratory and field studies showed no habituation of physiologic parameters to high sound levels. Sleep is especially sensitive to noise; therefore, sound levels during nighttime should be much lower than during daytime.

Acute and chronic effects of noradrenergic enhancement on transcranial direct current stimulation-induced neuroplasticity in humans.

PubMed

Kuo, Hsiao-I; Paulus, Walter; Batsikadze, Giorgi; Jamil, Asif; Kuo, Min-Fang; Nitsche, Michael A

2017-02-15

Chronic administration of the selective noradrenaline reuptake inhibitor (NRI) reboxetine (RBX) increased and prolonged the long-term potentiation-like plasticity induced by anodal transcranial direct current stimulation (tDCS) for over 24 h. Chronic administration of RBX converted cathodal tDCS-induced long-term depression-like plasticity into facilitation for 120 min. Chronic noradrenergic activity enhancement on plasticity of the human brain might partially explain the delayed therapeutic impact of selective NRIs in depression and other neuropsychiatric diseases. Noradrenaline affects cognition and motor learning processes via its impact on long-term potentiation (LTP) and depression (LTD). We aimed to explore the impact of single dose and chronic administration of the selective noradrenaline reuptake inhibitor (NRI) reboxetine (RBX) on plasticity induced by transcranial direct current stimulation (tDCS) in healthy humans via a double-blinded, placebo-controlled, randomized crossover study. Sixteen healthy volunteers received placebo or single dose RBX (8 mg) before anodal or cathodal tDCS of the primary motor cortex. Afterwards, the same subjects took RBX (8 mg day -1 ) consecutively for 21 days. During this period, two additional interventions were performed (RBX with anodal or cathodal tDCS), to explore the impact of chronic RBX treatment on plasticity. Plasticity was monitored by motor-evoked potential amplitudes elicited by transcranial magnetic stimulation. Chronic administration of RBX increased and prolonged the LTP-like plasticity induced by anodal tDCS for over 24 h. Chronic RBX significantly converted cathodal tDCS-induced LTD-like plasticity into facilitation, as compared to the single dose condition, for 120 min after stimulation. The results show a prominent impact of chronic noradrenergic enhancement on plasticity of the human brain that might partially explain the delayed therapeutic impact of selective NRIs in depression and other neuropsychiatric diseases. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Gene therapy-mediated delivery of targeted cytotoxins for glioma therapeutics

PubMed Central

Candolfi, Marianela; Xiong, Weidong; Yagiz, Kader; Liu, Chunyan; Muhammad, A. K. M. G.; Puntel, Mariana; Foulad, David; Zadmehr, Ali; Ahlzadeh, Gabrielle E.; Kroeger, Kurt M.; Tesarfreund, Matthew; Lee, Sharon; Debinski, Waldemar; Sareen, Dhruv; Svendsen, Clive N.; Rodriguez, Ron; Lowenstein, Pedro R.; Castro, Maria G.

2010-01-01

Restricting the cytotoxicity of anticancer agents by targeting receptors exclusively expressed on tumor cells is critical when treating infiltrative brain tumors such as glioblastoma multiforme (GBM). GBMs express an IL-13 receptor (IL13Rα2) that differs from the physiological IL4R/IL13R receptor. We developed a regulatable adenoviral vector (Ad.mhIL-4.TRE.mhIL-13-PE) encoding a mutated human IL-13 fused to Pseudomonas exotoxin (mhIL-13-PE) that specifically binds to IL13Rα2 to provide sustained expression, effective anti-GBM cytotoxicity, and minimal neurotoxicity. The therapeutic Ad also encodes mutated human IL-4 that binds to the physiological IL4R/IL13R without interacting with IL13Rα2, thus inhibiting potential binding of mhIL-13-PE to normal brain cells. Using intracranial GBM xenografts and syngeneic mouse models, we tested the Ad.mhIL-4.TRE.mhIL-13-PE and two protein formulations, hIL-13-PE used in clinical trials (Cintredekin Besudotox) and a second-generation mhIL-13-PE. Cintredekin Besudotox doubled median survival without eliciting long-term survival and caused severe neurotoxicity; mhIL-13-PE led to ∼40% long-term survival, eliciting severe neurological toxicity at the high dose tested. In contrast, Ad-mediated delivery of mhIL-13-PE led to tumor regression and long-term survival in over 70% of the animals, without causing apparent neurotoxicity. Although Cintredekin Besudotox was originally developed to target GBM, when tested in a phase III trial it failed to achieve clinical endpoints and revealed neurotoxicity. Limitations of Cintredekin Besudotox include its short half-life, which demanded frequent or continued administration, and binding to IL4R/IL13R, present in normal brain cells. These shortcomings were overcome by our therapeutic Ad, thus representing a significant advance in the development of targeted therapeutics for GBM. PMID:21030678

Improvement of water and light availability after thinning at a xeric site: which matters more? A dual isotope approach.

PubMed

Giuggiola, Arnaud; Ogée, Jérôme; Rigling, Andreas; Gessler, Arthur; Bugmann, Harald; Treydte, Kerstin

2016-04-01

Thinning fosters individual tree growth by increasing the availability of water, light and nutrients. At sites where water rather than light is limiting, thinning also enhances soil evaporation and might not be beneficial. Detailed knowledge of the short- to long-term physiological response underlying the growth responses to thinning is crucial for the management of forests already suffering from recurrent drought-induced dieback. We applied a dual isotope approach together with mechanistic isotope models to study the physiological processes underlying long-term growth enhancement of heavily thinned Pinus sylvestris in a xeric forest in Switzerland. This approach allowed us to identify and disentangle thinning-induced changes in stomatal conductance and assimilation rate. At our xeric study site, the increase in stomatal conductance far outweighed the increase in assimilation, implying that growth release in heavily thinned trees is primarily driven by enhanced water availability rather than increased light availability. We conclude that in forests with relatively isohydric species (drought avoiders) that are growing close to their physiological limits, thinning is recommended to maintain a less negative water balance and thus foster tree growth, and ultimately the survival of forest trees under drought. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Long-term in vivo harmonics imaging of zebrafish embryonic development based on a femtosecond Cr:forsterite laser

NASA Astrophysics Data System (ADS)

Chen, S.-Y.; Tsai, T.-H.; Hsieh, C.-S.; Tai, S.-P.; Lin, C.-Y.; Ko, C.-Y.; Chen, Y.-C.; Tsai, H.-J.; Hu, C.-H.; Sun, C.-K.

2005-03-01

Based on a femtosecond Cr:forsterite laser, harmonics optical microscopy (HOM) provides a truly "noninvasive" tool for in vivo and long-term study of vertebrate embryonic development. Based on optical nonlinearity, HOM provides sub-micrometer 3D spatial resolution and high 3D optical-sectioning power without using invasive and toxic fluorophores. Since only virtual-level-transition is involved, HOM is known to leave no energy deposition and no photodamage. Combined with second harmonic generation, which is sensitive to specific structure such as nerve and muscle fibers, HOM can perform functional studies of early developmental dynamics of many vertebrate physiological systems. Recently, zebrafish has become a standard model for many biological and medical studies of vertebrates, due to the similarity between embryonic development of zebrafish and human being. Here we demonstrate in vivo HOM studies of developmental dynamics of several important embryonic physiological systems in live zebrafish embryos, with focuses on the developments of brains, eyes, ears, and hearts. Based on a femtosecond Cr:forsterite laser, which provides the deepest penetration (~1.5mm) and least photodamage in the zebrafish embryo, complete developing processes of different physiological systems within a period of time longer than 20 hours can be non-invasively observed inside the same embryo.

Long-term high-soybean oil feeding alters regulation of body temperature in rats.

PubMed

Tsushima, Hiromi; Yamada, Kazuyo; Miyazawa, Daisuke; Mori, Mayumi; Hashimoto, Yoko; Ohkubo, Takeshi; Hibino, Hidehiko; Okuyama, Harumi

2014-01-01

We investigated whether body temperature (BT) regulatory mechanisms are influenced by dietary fatty acids (FA). Male Wistar rats were fed a high-fat diet containing fish oil (HFD), soybean oil (HSD) or lard (HLD). At the 20-week intervention, the BT of the HSD and HLD groups were lower than that of the normal diet (ND) group in the light and dark periods. The intracerebroventricular injections of interleukin-1β and bombesin in the HSD group induced greater hyperthermia and weaker hypothermia, respectively, than in the ND group. The HSD differentially affected BT under both physiological and pharmacological conditions. In the hypothalamus, the ratio of n-6/n-3 FAs was higher in the HSD group compared with the ND group. DNA microarrays revealed increased expression of thyroid-stimulating hormone β-subunit, and decreased expression of several genes in the hypothalamus of the HSD group compared with the ND group. The HSD feeding increased several adipokine concentrations in the plasma. However, there were no adipokines or gene expressions that changed in only the HSD and HLD groups showing significant hypothermia under the physiological condition. These findings suggested that long-term HSD intake produces abnormal BT regulation. It is less likely that adipokines or proteins/peptides are involved in abnormal BT regulation under the physiological conditions after HSD feeding.

Vaginal biological and sexual health--the unmet needs.

PubMed

Graziottin, A

2015-01-01

The vagina is a most neglected organ. It is usually clinically considered with a minimalistic view, as a 'connecting tube' for a number of physiologic functions: passage of menstrual blood, intercourse, natural conception and delivery. Unmet needs include, but are not limited to, respect of vaginal physiologic biofilms; diagnosis and care of the optimal tone of the levator ani, which surrounds and partly support it; care of its anatomic integrity at and after delivery and at pelvic/vaginal surgery; care of long-term consequences of pelvic radiotherapy; long-term care of the atrophic changes it will undergo after the menopause, unless appropriate, at least local, estrogen therapy is used; appreciation and respect of its erotic meaning, as a loving, receptive, 'bonding' organ for the couple. The vaginal erotic value is key as a non-visible powerful center of femininity and sexuality, deeply and secretly attractive in terms of taste, scent (together with the vulva), touch and proprioception. The most welcoming when lubrication, softness and vaginal orgasm award the woman and the partner with the best of pleasures. Prevention of sexual/vaginal abuse is a very neglected unmet need, as well. Who cares?

Ovarian Failure and the Menopause

PubMed Central

McEwen, Donald C.

1965-01-01

Long-term replacement therapy for ovarian deficiency or failure, including the menopause, has been widely debated. In the past, treatment, if indicated, was reassurance, sedation, and occasionally short-term estrogen therapy. Today, because of recent advances in steroid synthesis, the consequences of ovarian deficiency may be preventable. Ovarian function and failure are discussed, the apparent physiological renaissance of nine patients documented, and the methods of treatment detailed. Thirty-three patients, who took part in this program during the past two years, have continued treatment with enthusiasm, without major problems in management, and have shown evidence of improved physical and emotional well-being. Further unbiased long-term research, possibly using modern computer technique, is needed to decide between traditional and replacement therapy for the menopause. ImagesFig. 1 PMID:14289145

Electrical brain stimulation (tES) improves learning more than performance: A meta-analysis.

PubMed

Simonsmeier, Bianca A; Grabner, Roland H; Hein, Julia; Krenz, Ugne; Schneider, Michael

2018-01-01

Researchers have recently started evaluating whether stimulating the brain noninvasively with a weak and painless electrical current (transcranial Electrical Stimulation, tES) enhances physiological and cognitive processes. Some studies found that tES has weak but positive effects on brain physiology, cognition, or assessment performance, which has attracted massive public interest. We present the first meta-analytic test of the hypothesis that tES in a learning phase is more effective than tES in an assessment phase. The meta-analysis included 246 effect sizes from studies on language or mathematical competence. The effect of tES was stronger when stimulation was administered during a learning phase (d=0.712) as compared to stimulation administered during test performance (d=0.207). The overall effect was stimulation-dosage specific and, as found in a previous meta-analysis, significant only for anodal stimulation and not for cathodal. The results provide evidence for the modulation of long-term synaptic plasticity by tES in the context of practically relevant learning tasks and highlight the need for more systematic evaluations of tES in educational settings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Visual-motor recalibration in geographical slant perception

NASA Technical Reports Server (NTRS)

Bhalla, M.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

1999-01-01

In 4 experiments, it was shown that hills appear steeper to people who are encumbered by wearing a heavy backpack (Experiment 1), are fatigued (Experiment 2), are of low physical fitness (Experiment 3), or are elderly and/or in declining health (Experiment 4). Visually guided actions are unaffected by these manipulations of physiological potential. Although dissociable, the awareness and action systems were also shown to be interconnected. Recalibration of the transformation relating awareness and actions was found to occur over long-term changes in physiological potential (fitness level, age, and health) but not with transitory changes (fatigue and load). Findings are discussed in terms of a time-dependent coordination between the separate systems that control explicit visual awareness and visually guided action.

Artificial Gravity Research Project

NASA Technical Reports Server (NTRS)

Kamman, Michelle R.; Paloski, William H.

2005-01-01

Protecting the health, safety, and performance of exploration-class mission crews against the physiological deconditioning resulting from long-term weightlessness during transit and long-term hypogravity during surface operations will require effective, multi-system countermeasures. Artificial gravity (AG), which would replace terrestrial gravity with inertial forces generated by rotating the transit vehicle or by a human centrifuge device within the transit vehicle or surface habitat, has long been considered a potential solution. However, despite its attractiveness as an efficient, multi-system countermeasure and its potential for improving the environment and simplifying operational activities (e.g., WCS, galley, etc.), much still needs to be learned regarding the human response to rotating environments before AG can be successfully implemented. This paper will describe our approach for developing and implementing a rigorous AG Research Project to address the key biomedical research questions that must be answered before developing effective AG countermeasure implementation strategies for exploration-class missions. The AG Research Project will be performed at JSC, ARC, extramural academic and government research venues, and international partner facilities maintained by DLR and IMBP. The Project includes three major ground-based human research subprojects that will lead to flight testing of intermittent short-radius AG in ISS crewmembers after 201 0, continuous long-radius AG in CEV crews transiting to and from the Moon, and intermittent short-radius AG plus exercise in lunar habitats. These human ground-based subprojects include: 1) a directed, managed international short-radius project to investigate the multi-system effectiveness of intermittent AG in human subjects deconditioned by bed rest, 2) a directed, managed long-radius project to investigate the capacity of humans to live and work for extended periods in rotating environments, and 3) a focused, investigator-initiated project to investigate system-specific adaptation to and from rotating environments. The AG Research Project also includes two major animal research subprojects: 1) a directed, managed ground-based subproject using rodents and, possibly, sub-human primates, to address mechanistic issues that cannot be studied in humans, to rapidly develop higher sample numbers than can be achieved in the human subprojects, and to establish feasible parameter operating bands to reduce the breadth of the human subprojects, and 2) a flight subproject using rodents to estimate the physiological effects of long term exposure to hypogravity and to investigate the effects of contamination by terrestrial gravity in estimating AG effectiveness. The animal flight subproject would be performed aboard ISS using the CAM module in approximately the 2008-201 1 timeframe. The paper will first present an overview of the key biomedical research questions to be answered. It will then describe the overall approaches to be utilized in developing and implementing the AG Research Project, including definition of the intended scientific research, management and development approaches, identification of roles and responsibilities, risk management, and definition of project deliverables. The primary focus of the paper will be on the first of the three ground-based human research subprojects, since it is the only one currently in development and is scheduled to start active subject investigations in April of 2005.

Space Physiology and Operational Space Medicine

NASA Technical Reports Server (NTRS)

Scheuring, Richard A.

2009-01-01

The objectives of this slide presentation are to teach a level of familiarity with: the effects of short and long duration space flight on the human body, the major medical concerns regarding future long duration missions, the environmental issues that have potential medical impact on the crew, the role and capabilities of the Space Medicine Flight Surgeon and the environmental impacts experienced by the Apollo crews. The main physiological effects of space flight on the human body reviewed in this presentation are: space motion sickness (SMS), neurovestibular, cardiovascular, musculoskeletal, immune/hematopoietic system and behavioral/psycho-social. Some countermeasures are discussed to these effects.

Comparative In Vivo Effects of Hemoglobin-Based Oxygen Carriers (HBOC) with Varying Prooxidant and Physiological Reactivity.

PubMed

Toma, Vlad Al; Farcaș, Anca D; Roman, Ioana; Sevastre, Bogdan; Hathazi, Denisa; Scurtu, Florina; Damian, Grigore; Silaghi-Dumitrescu, Radu

2016-01-01

A series of hemoglobin-based oxygen carrier candidates (HBOC), previously noted for their differences in prooxidative and physiological reactivity, were compared in terms of the negative effects displayed upon injection in Wistar rats. At the concentrations tested, antioxidant strategies based on albumin as well as based on rubrerythrin appear to offer observable physiological advantages.

A metabolic profile for ‘Honeycrisp’ apple soggy breakdown, a chilling induced physiological disorder

USDA-ARS?s Scientific Manuscript database

‘Honeycrisp’ is an economically important apple cultivar increasing rapidly in planted acreage in many apple growing regions. Long-term cold storage can enhance value by enabling a longer window of availability, but the cultivar is highly susceptible to chilling induced disorders. Soggy breakdown ...

Female genital mutilation/cutting type IV in Cambodia: a case report.

PubMed

Abdulcadir, Jasmine; Irion, Olivier; de Tejada, Begoña Martinez

2015-12-01

Nontherapeutic female genital modifications can cause short- and long-term consequences. Caregivers should promote women's self knowledge on genitals' anatomy and physiology, and psychophysical and sexual health. They should also inform on possible negative consequences of vulvar nontherapeutic alterations requested and avoid the medicalization of female genital mutilation.

Long Term Synaptic Plasticity and Learning in Neuronal Networks

DTIC Science & Technology

1989-01-14

Videomicroscopy and synaptic physiology of cultured hippocampal slices. Soc, Neurosci. Abstr. 14:246, 1988. Griffith, W.H., Brown, T.H. and Johnston, D...Chapman, P.F., Chang, V., and Brown, T.H. . Videomicroscopy of acute brain slices from hippocampus and amygdala. Brain Res. Bull, 21: 373-383, 1988

Biofortification: How can we exploit plant science and biotechnology to reduce micronutrient deficiencies?

USDA-ARS?s Scientific Manuscript database

Throughout the developing world, the long-term consequences of insufficient amounts of essential micronutrients in the human diet can be more devastating than low energy intake. Micronutrients are involved in all aspects of development, growth, and physiology of the human body (including from early ...

Pelvic ring injuries: Surgical management and long-term outcomes

PubMed Central

Halawi, Mohamad J.

2016-01-01

Pelvic ring injuries present a therapeutic challenge to the orthopedic surgeon. Management is based on the patient's physiological status, fracture classification, and associated injuries. Surgical stabilization is indicated in unstable injury patterns and those that fail nonsurgical management. The optimal timing for definitive fixation is not clearly defined, but early stabilization is recommended. Surgical techniques include external fixation, open reduction and internal fixation, and minimally invasive percutaneous osteosynthesis. Special considerations are required for concomitant acetabular fractures, sacral fractures, and those occurring in skeletally immature patients. Long-term outcomes are limited by lack of pelvis-specific outcome measures and burden of associated injuries. PMID:26908968

Long-term exercise-specific neuroprotection in spinal muscular atrophy-like mice.

PubMed

Chali, Farah; Desseille, Céline; Houdebine, Léo; Benoit, Evelyne; Rouquet, Thaïs; Bariohay, Bruno; Lopes, Philippe; Branchu, Julien; Della Gaspera, Bruno; Pariset, Claude; Chanoine, Christophe; Charbonnier, Frédéric; Biondi, Olivier

2016-04-01

The real impact of physical exercise parameters, i.e. intensity, type of contraction and solicited energetic metabolism, on neuroprotection in the specific context of neurodegeneration remains poorly explored. In this study behavioural, biochemical and cellular analyses were conducted to compare the effects of two different long-term exercise protocols, high intensity swimming and low intensity running, on motor units of a type 3 spinal muscular atrophy (SMA)-like mouse model. Our data revealed a preferential SMA-induced death of intermediate and fast motor neurons which was limited by the swimming protocol only, suggesting a close relationship between neuron-specific protection and their activation levels by specific exercise. The exercise-induced neuroprotection was independent of SMN protein expression and associated with specific metabolic and behavioural adaptations with notably a swimming-induced reduction of muscle fatigability. Our results provide new insight into the motor units' adaptations to different physical exercise parameters and will contribute to the design of new active physiotherapy protocols for patient care. Spinal muscular atrophy (SMA) is a group of autosomal recessive neurodegenerative diseases differing in their clinical outcome, characterized by the specific loss of spinal motor neurons, caused by insufficient level of expression of the protein survival of motor neuron (SMN). No cure is at present available for SMA. While physical exercise might represent a promising approach for alleviating SMA symptoms, the lack of data dealing with the effects of different exercise types on diseased motor units still precludes the use of active physiotherapy in SMA patients. In the present study, we have evaluated the efficiency of two long-term physical exercise paradigms, based on either high intensity swimming or low intensity running, in alleviating SMA symptoms in a mild type 3 SMA-like mouse model. We found that 10 months' physical training induced significant benefits in terms of resistance to muscle damage, energetic metabolism, muscle fatigue and motor behaviour. Both exercise types significantly enhanced motor neuron survival, independently of SMN expression, leading to the maintenance of neuromuscular junctions and skeletal muscle phenotypes, particularly in the soleus, plantaris and tibialis of trained mice. Most importantly, both exercises significantly improved neuromuscular excitability properties. Further, all these training-induced benefits were quantitatively and qualitatively related to the specific characteristics of each exercise, suggesting that the related neuroprotection is strongly dependent on the specific activation of some motor neuron subpopulations. Taken together, the present data show significant long-term exercise benefits in type 3 SMA-like mice providing important clues for designing rehabilitation programmes in patients. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Humor theories and the physiological benefits of laughter.

PubMed

Wilkins, Julia; Eisenbraun, Amy Janel

2009-01-01

There are 3 main theories used to explain the functions of humor: (1) the relief theory, (2) the incongruity theory, and (3) the superiority theory. While these theories focus on the specific role that humor plays for people in situations such as dealing with misfortune, making sense of rule violations, and bonding with others, we propose that underlying each of these theories are the physiological benefits of laughter. We draw on findings from empirical studies on laughter to demonstrate that these physiological benefits occur regardless of the theory that is used to explain the humor function. Findings from these studies have important implications for nurse practitioners working in hospice settings, long-term care facilities, nursing homes, and hospitals.

Evaluation of exercise-respiratory system modifications and integration schemes for physiological systems

NASA Technical Reports Server (NTRS)

Gallagher, R. R.

1974-01-01

Exercise subroutine modifications are implemented in an exercise-respiratory system model yielding improvement of system response to exercise forcings. A more physiologically desirable respiratory ventilation rate in addition to an improved regulation of arterial gas tensions and cerebral blood flow is observed. A respiratory frequency expression is proposed which would be appropriate as an interfacing element of the respiratory-pulsatile cardiovascular system. Presentation of a circulatory-respiratory system integration scheme along with its computer program listing is given. The integrated system responds to exercise stimulation for both nonstressed and stressed physiological states. Other integration possibilities are discussed with respect to the respiratory, pulsatile cardiovascular, thermoregulatory, and the long-term circulatory systems.

Long-term effect of carbohydrate reserves on growth and reproduction of Prosopis denudans (Fabaceae): implications for conservation of woody perennials

PubMed Central

Vilela, Alejandra E.; Agüero, Paola R.; Ravetta, Damián; González-Paleo, Luciana

2016-01-01

Prosopis denudans, an extreme xerophyte shrub, is consumed by ungulates and threatened by firewood gathering, because it is one of the preferred species used by Mapuche indigenous people of Patagonia. In a scenario of uncontrolled use of vegetation, it is very difficult to develop a conservation plan that jointly protects natural resources and its users. We performed a field experiment to assess the impact of defoliation on growth, reproduction and stores of a wild population of P. denudans. We imposed four levels of defoliation (removal of 100, 66, 33 and 0% of leaves) and evaluated the short- and long-term (3 years) effects of this disturbance. Seasonal changes in shoot carbohydrates suggested that they support leaf-flush and blooming. Severely defoliated individuals also used root reserves to support growth and leaf-flush after clipping. Vegetative growth was not affected by defoliation history. Leaf mass area increased after the initial clipping, suggesting the development of structural defenses. The depletion of root reserves at the end of the first year affected inflorescence production the following spring. We conclude that P. denudans shrubs could lose up to one-third of their green tissues without affecting growth or inflorescence production. The removal of a higher proportion of leaves will diminish stores, which in turn, will reduce or completely prevent blooming and, therefore, fruit production the following seasons. Very few studies integrate conservation and plant physiology, and we are not aware, so far, of any work dealing with long-term plant carbon economy of a long-lived perennial shrub as an applied tool in conservation. These results might help the development of management strategies that consider both the use and the conservation of wild populations of P. denudans. PMID:27293747

[Adaptive adjustment of rhizome and root system on morphology, biomass and nutrient in Phyllostachys rivalis under long-term waterlogged condition].

PubMed

Liu, Yu-fang; Chen, Shuang-lin; Li Ying-chun; Guo, Zi-wu; Li, Ying-chun; Yang, Qing-ping

2015-12-01

The research was to approach the growth strategy of rhizome and roots based on the morphology, biomass and nutrient in Phyllostachys rivalis under long-term waterlogged conditions, and provided a theoretical basis for its application for vegetation restoration in wetland and water-level fluctuation belts. The morphological characteristics, physiological and biochemical indexes of annual bamboo rhizome and roots were investigated with an experiment using individually potted P. rivalis which was treated by artificial water-logging for 3, 6, and 12 months. Accordingly the morphological characteristics, biomass allocation, nutrient absorption and balance in rhizome and roots of P. rivalis were analyzed. The results showed that there was no obvious impact of long-term water-logging on the length and diameter of rhizomes, diameter of roots in P. rivalis. The morphological characteristics of rhizome had been less affected generally under water-logging for 3 months. And less rhizomes were submerged, while the growth of roots was inhibited to some extent. Furthermore, with waterlogging time extended, submerged roots and rhizomes grew abundantly, and the roots and rhizomes in soil were promoted. Moreover for ratios of rhizome biomass in soil and water, there were no obvious variations, the same for the root biomass in soil to total biomass. The ratio of root biomass in water to total biomass and the ratio of root biomass in water to root biomass in soil both increased significantly. The results indicated that P. rivalis could adapt to waterlogged conditions gradually through growth regulation and reasonable biomass distribution. However, the activity of rhizome roots in soil decreased and the nutrient absorption was inhibited by long-term water-logging, although it had no effect on stoichiometric ratios of root nutrient in soil. The activity of rhizome root in water increased and the stoichiometric ratios adjusted adaptively to waterlogged conditions, the ratio of N/P increased, while N/K and P/K decreased, which implied that roots in water absorbed oxygen and nutrients could help P. rivalis adapt to long-term waterlogged environment effectively.

Adiponectin and peptide YY in the fasting blue fox (Alopex lagopus).

PubMed

Mustonen, Anne-Mari; Pyykönen, Teija; Nieminen, Petteri

2005-02-01

Adiponectin (Acrp30) and peptide YY (PYY) are weight-regulatory hormones participating in the control of energy homeostasis. This study investigated the effects of long-term wintertime fasting on plasma Acrp30 and PYY levels in the carnivorous blue fox, a farm-bred variant of the arctic fox (Alopex lagopus). Plasma Acrp30 and PYY concentrations were determined with radioimmunoassays during a 22-day period of fasting, which led to a 20.3% reduction in body mass of the animals (n=32). Sixteen fed blue foxes served as the control group. Acrp30 and PYY were present in blue fox plasma at similar or lower levels as reported previously for other mammals. Fasting had no acute effects on Acrp30 or PYY concentrations of the blue foxes. However, the Acrp30 levels of the fasted blue foxes were 24%-48% higher than in the fed animals between days 8-22 of fasting. Fasted blue foxes also had 6.2-fold higher plasma PYY concentrations after 15 days of fasting. Acrp30 and PYY seem to play roles in the body weight-regulation of the blue fox during long-term fasting, but their specific functions and physiological significance remain to be determined.

The short and long term effects of docetaxel chemotherapy on rodent object recognition and spatial reference memory.

PubMed

Fardell, Joanna E; Vardy, Janette; Johnston, Ian N

2013-10-17

Previous animal studies have examined the potential for cytostatic drugs to induce learning and memory deficits in laboratory animals but, to date, there is no pre-clinical evidence that taxanes have the potential to cause cognitive impairment. Therefore our aim was to explore the short- and long-term cognitive effects of different dosing schedules of the taxane docetaxel (DTX) on laboratory rodents. Healthy male hooded Wistar rats were treated with DTX (6 mg/kg, 10mg/kg) or physiological saline (control), once a week for 3 weeks (Experiment 1) or once only (10mg/kg; Experiment 2). Cognitive function was assessed using the novel object recognition (NOR) task and spatial water maze (WM) task 1 to 3 weeks after treatment and again 4 months after treatment. Shortly after DTX treatment, rats perform poorly on NOR regardless of treatment regimen. Treatment with a single injection of 10mg/kg DTX does not appear to induce sustained deficits in object recognition or peripheral neuropathy. Overall these findings show that treatment with the taxane DTX in the absence of cancer and other anti-cancer treatments causes cognitive impairment in healthy rodents. Copyright © 2013 Elsevier Inc. All rights reserved.

Mathematical Modeling of Physical and Cognitive Performance Decrement from Mechanical and Inhalation Insults

DTIC Science & Technology

2006-12-01

on specific short term problems. 1.1.1 Dynamic Physiological Modeling The oxygenation of the blood by the lung through respiration is a critical...tests as apnea , reduced arterial saturation, and may even be linked to long term CNS deficits. Inhalation of toxic gases can dramatically affect the...of TGAS model the respiration , circulation, and metabolic processes and include models of the ventilation and cardiac output control due to 3

Changes in antioxidants are critical in determining cell responses to short- and long-term heat stress.

PubMed

Sgobba, Alessandra; Paradiso, Annalisa; Dipierro, Silvio; De Gara, Laura; de Pinto, Maria Concetta

2015-01-01

Heat stress can have deleterious effects on plant growth by impairing several physiological processes. Plants have several defense mechanisms that enable them to cope with high temperatures. The synthesis and accumulation of heat shock proteins (HSPs), as well as the maintenance of an opportune redox balance play key roles in conferring thermotolerance to plants. In this study changes in redox parameters, the activity and/or expression of reactive oxygen species (ROS) scavenging enzymes and the expression of two HSPs were studied in tobacco Bright Yellow-2 (TBY-2) cells subjected to moderate short-term heat stress (SHS) and long-term heat stress (LHS). The results indicate that TBY-2 cells subjected to SHS suddenly and transiently enhance antioxidant systems, thus maintaining redox homeostasis and avoiding oxidative damage. The simultaneous increase in HSPs overcomes the SHS and maintains the metabolic functionality of cells. In contrast the exposure of cells to LHS significantly reduces cell growth and increases cell death. In the first phase of LHS, cells enhance antioxidant systems to prevent the formation of an oxidizing environment. Under prolonged heat stress, the antioxidant systems, and particularly the enzymatic ones, are inactivated. As a consequence, an increase in H2 O2 , lipid peroxidation and protein oxidation occurs. This establishment of oxidative stress could be responsible for the increased cell death. The rescue of cell growth and cell viability, observed when TBY-2 cells were pretreated with galactone-γ-lactone, the last precursor of ascorbate, and glutathione before exposure to LHS, highlights the crucial role of antioxidants in the acquisition of basal thermotolerance. © 2014 Scandinavian Plant Physiology Society.

The first success of glass eel production in the world: basic biology on fish reproduction advances new applied technology in aquaculture.

PubMed

Kagawa, Hirohiko; Tanaka, Hideki; Ohta, Hiromi; Unuma, Tatsuya; Nomura, Kazuharu

2005-04-01

The eel has long been esteemed as an important food fish in the world, especially in Japan, and has been used as an experimental fish for many fields of fish physiology. However, the decreases in eel resources have been a serious concern in recent years. The catches of glass eels as seedlings for aquaculture have shown a long-term decrease in both Europe and East Asia. To increase eel resources, the development of techniques for artificial induction of maturation and spawning and rearing their larvae have been eagerly desired. Recent progress of reproductive physiology of fish, especially mechanisms of oocyte maturation and ovulation in female and of spermatozoa maturation in male, facilitate to establish techniques for hormonal induction of maturation and spawning in sexually immature eels. With persistent effort to development of rearing techniques of larvae, we have first succeeded to produce glass eel. These applied techniques are may contribute to understand the basic reproductive physiology of the eel.

Skylab

NASA Image and Video Library

1972-01-01

This chart details Skylab's Metabolic Activity experiment (M171), a medical evaluation facility designed to measure astronauts' metabolic changes while on long-term space missions. The experiment obtained information on astronauts' physiological capabilities and limitations and provided data useful in the design of future spacecraft and work programs. Physiological responses to physical activity was deduced by analyzing inhaled and exhaled air, pulse rate, blood pressure, and other selected variables of the crew while they performed controlled amounts of physical work with a bicycle ergometer. The Marshall Space Flight Center had program responsibility for the development of Skylab hardware and experiments.

Skylab

NASA Image and Video Library

1973-01-01

This Skylab-3 onboard photograph shows Astronaut Allen Bean on the ergometer, breathing into the metabolic analyzer. Skylab's Metabolic Activity experiment (M171), a medical evaluation facility, was designed to measure astronauts' metabolic changes while on long-term space missions. The experiment obtained information on astronauts' physiological capabilities and limitations and provided data useful in the design of future spacecraft and work programs. Physiological responses to physical activity was deduced by analyzing inhaled and exhaled air, pulse rate, blood pressure, and other selected variables of the crew while they performed controlled amounts of physical work with a bicycle ergometer.

Environmental Perturbations, Behavioral Change, and Population Response in a Long-Term Northern Elephant Seal Study

DTIC Science & Technology

2013-09-30

and Physiology a-Molecular & Integrative Physiology 161:388-394. Goldstein, T ., I . Mena, S. J. Anthony, R. Medina, P. W. Robinson, D. J. Greig, D. P...behaviour and foraging success in the northern elephant seal. Functional Ecology 27:1055-1063. Lyons, E. T ., T . A. Kuzmina , T . R. Spraker, N. Jaggi...Klanjšček, T ., Lusseau, D., Kraus, S., McMahon, C.R., Robinson, P. W., Schick, R., Schwarz, L.K., Simmons, S. E., Thomas, L., Tyack, P. and Harwood

PPG neurons of the lower brain stem and their role in brain GLP-1 receptor activation.

PubMed

Trapp, Stefan; Cork, Simon C

2015-10-15

Within the brain, glucagon-like peptide-1 (GLP-1) affects central autonomic neurons, including those controlling the cardiovascular system, thermogenesis, and energy balance. Additionally, GLP-1 influences the mesolimbic reward system to modulate the rewarding properties of palatable food. GLP-1 is produced in the gut and by hindbrain preproglucagon (PPG) neurons, located mainly in the nucleus tractus solitarii (NTS) and medullary intermediate reticular nucleus. Transgenic mice expressing glucagon promoter-driven yellow fluorescent protein revealed that PPG neurons not only project to central autonomic control regions and mesolimbic reward centers, but also strongly innervate spinal autonomic neurons. Therefore, these brain stem PPG neurons could directly modulate sympathetic outflow through their spinal inputs to sympathetic preganglionic neurons. Electrical recordings from PPG neurons in vitro have revealed that they receive synaptic inputs from vagal afferents entering via the solitary tract. Vagal afferents convey satiation to the brain from signals like postprandial gastric distention or activation of peripheral GLP-1 receptors. CCK and leptin, short- and long-term satiety peptides, respectively, increased the electrical activity of PPG neurons, while ghrelin, an orexigenic peptide, had no effect. These findings indicate that satiation is a main driver of PPG neuronal activation. They also show that PPG neurons are in a prime position to respond to both immediate and long-term indicators of energy and feeding status, enabling regulation of both energy balance and general autonomic homeostasis. This review discusses the question of whether PPG neurons, rather than gut-derived GLP-1, are providing the physiological substrate for the effects elicited by central nervous system GLP-1 receptor activation. Copyright © 2015 the American Physiological Society.

The Impact of Space Flight on Survival and Interaction of Cupriavidus metallidurans CH34 with Basalt, a Volcanic Moon Analog Rock

PubMed Central

Byloos, Bo; Coninx, Ilse; Van Hoey, Olivier; Cockell, Charles; Nicholson, Natasha; Ilyin, Vyacheslav; Van Houdt, Rob; Boon, Nico; Leys, Natalie

2017-01-01

Microbe-mineral interactions have become of interest for space exploration as microorganisms could be used to biomine from extra-terrestrial material and extract elements useful as micronutrients in life support systems. This research aimed to identify the impact of space flight on the long-term survival of Cupriavidus metallidurans CH34 in mineral water and the interaction with basalt, a lunar-type rock in preparation for the ESA spaceflight experiment, BIOROCK. Therefore, C. metallidurans CH34 cells were suspended in mineral water supplemented with or without crushed basalt and send for 3 months on board the Russian FOTON-M4 capsule. Long-term storage had a significant impact on cell physiology and energy status (by flow cytometry analysis, plate count and intracellular ATP measurements) as 60% of cells stored on ground lost their cell membrane potential, only 17% were still active, average ATP levels per cell were significantly lower and cultivability dropped to 1%. The cells stored in the presence of basalt and exposed to space flight conditions during storage however showed less dramatic changes in physiology, with only 16% of the cells lost their cell membrane potential and 24% were still active, leading to a higher cultivability (50%) and indicating a general positive effect of basalt and space flight on survival. Microbe-mineral interactions and biofilm formation was altered by spaceflight as less biofilm was formed on the basalt during flight conditions. Leaching from basalt also changed (measured with ICP-OES), showing that cells release more copper from basalt and the presence of cells also impacted iron and magnesium concentration irrespective of the presence of basalt. The flight conditions thus could counteract some of the detrimental effects observed after the 3 month storage conditions. PMID:28503167

Influence of chronic undernutrition and leptin on GOAT mRNA levels in rat stomach mucosa.

PubMed

González, C Ruth; Vázquez, María J; López, Miguel; Diéguez, Carlos

2008-12-01

The most unique feature of ghrelin is the acyl-modification of a hydroxyl group of the Ser3 in the N-terminus. The Ser3 is commonly modified by n-octanoic acid in vertebrates being needed for its biological effects, at least in terms of feeding. Therefore, a critical question regarding the role of ghrelin was to characterize the mechanism involved in its acylation. The acyltransferase that catalyzes ghrelin octanoylation has been recently identified and named ghrelin O-acyltransferase (GOAT). The aim of this study was to clarify the physiological implications of GOAT in the regulation of energy balance, by assessing the effect of undernutrition, as well as fasting in adult male rats. We have determined GOAT mRNA expression levels by real time-PCR in the stomach mucosa. Our results show that chronic food restriction led to an increase in GOAT mRNA, particularly following long-term chronic malnutrition (21 days). Furthermore, following 48 h complete fasting, a situation with high-circulating ghrelin levels, we found similar mRNA expression of GOAT in fed and fasted rats; exogenous leptin administration markedly increase GOAT mRNA levels in the stomach mucosa of fasted rats. These findings suggest that increased GOAT mRNA levels may have a role in mediating the physiological responses to chronic undernutrition and could represent an adaptive response to prevent long-lasting alterations in energy balance and body weight homeostasis. Furthermore, our data also offer mechanistic insights into the reason why during fasting acylated ghrelin levels are not increased at a time when a marked increase in an orexigenic signal as important as acylated ghrelin will be expected.

Induction of human breast cell carcinogenesis by triclocarban and intervention by curcumin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sood, Shilpa; Choudhary, Shambhunath; Wang, Hwa-Chain Robert, E-mail: hcrwang@utk.edu

Highlights: •Triclocarban exposure induces breast epithelial cell carcinogenesis. •Triclocarban induces the Erk–Nox pathway, ROS elevation, and DNA damage. •Physiological doses of triclocarban induce cellular carcinogenesis. •Non-cytotoxic curcumin blocks triclocarban-induced carcinogenesis and pathways. -- Abstract: More than 85% of breast cancers are sporadic and attributable to long-term exposure to environmental carcinogens and co-carcinogens. To identify co-carcinogens with abilities to induce cellular pre-malignancy, we studied the activity of triclocarban (TCC), an antimicrobial agent commonly used in household and personal care products. Here, we demonstrated, for the first time, that chronic exposure to TCC at physiologically-achievable nanomolar concentrations resulted in progressive carcinogenesis ofmore » human breast cells from non-cancerous to pre-malignant. Pre-malignant carcinogenesis was measured by increasingly-acquired cancer-associated properties of reduced dependence on growth factors, anchorage-independent growth and increased cell proliferation, without acquisition of cellular tumorigenicity. Long-term TCC exposure also induced constitutive activation of the Erk–Nox pathway and increases of reactive oxygen species (ROS) in cells. A single TCC exposure induced transient induction of the Erk–Nox pathway, ROS elevation, increased cell proliferation, and DNA damage in not only non-cancerous breast cells but also breast cancer cells. Using these constitutively- and transiently-induced changes as endpoints, we revealed that non-cytotoxic curcumin was effective in intervention of TCC-induced cellular pre-malignancy. Our results lead us to suggest that the co-carcinogenic potential of TCC should be seriously considered in epidemiological studies to reveal the significance of TCC in the development of sporadic breast cancer. Using TCC-induced transient and constitutive endpoints as targets will likely help identify non-cytotoxic preventive agents, such as curcumin, effective in suppressing TCC-induced cellular pre-malignancy.« less

The Impact of Space Flight on Survival and Interaction of Cupriavidus metallidurans CH34 with Basalt, a Volcanic Moon Analog Rock.

PubMed

Byloos, Bo; Coninx, Ilse; Van Hoey, Olivier; Cockell, Charles; Nicholson, Natasha; Ilyin, Vyacheslav; Van Houdt, Rob; Boon, Nico; Leys, Natalie

2017-01-01

Microbe-mineral interactions have become of interest for space exploration as microorganisms could be used to biomine from extra-terrestrial material and extract elements useful as micronutrients in life support systems. This research aimed to identify the impact of space flight on the long-term survival of Cupriavidus metallidurans CH34 in mineral water and the interaction with basalt, a lunar-type rock in preparation for the ESA spaceflight experiment, BIOROCK. Therefore, C. metallidurans CH34 cells were suspended in mineral water supplemented with or without crushed basalt and send for 3 months on board the Russian FOTON-M4 capsule. Long-term storage had a significant impact on cell physiology and energy status (by flow cytometry analysis, plate count and intracellular ATP measurements) as 60% of cells stored on ground lost their cell membrane potential, only 17% were still active, average ATP levels per cell were significantly lower and cultivability dropped to 1%. The cells stored in the presence of basalt and exposed to space flight conditions during storage however showed less dramatic changes in physiology, with only 16% of the cells lost their cell membrane potential and 24% were still active, leading to a higher cultivability (50%) and indicating a general positive effect of basalt and space flight on survival. Microbe-mineral interactions and biofilm formation was altered by spaceflight as less biofilm was formed on the basalt during flight conditions. Leaching from basalt also changed (measured with ICP-OES), showing that cells release more copper from basalt and the presence of cells also impacted iron and magnesium concentration irrespective of the presence of basalt. The flight conditions thus could counteract some of the detrimental effects observed after the 3 month storage conditions.

Enumeration, isolation and identification of diazotrophs from Korean wetland rice varieties grown with long-term application of N and compost and their short-term inoculation effect on rice plants.

PubMed

Muthukumarasamy, R; Kang, U G; Park, K D; Jeon, W-T; Park, C Y; Cho, Y S; Kwon, S-W; Song, J; Roh, D-H; Revathi, G

2007-04-01

This study has been aimed (i) to isolate and identify diazotrophs from Korean rice varieties; (ii) to examine the long-term effect of N and compost on the population dynamics of diazotrophs and (iii) to realize the shot-term inoculation effect of these diazotrophs on rice seedlings. Diazotrophic and heterotrophic bacterial numbers were enumerated by most probable number method and the isolates were identified based on morphological, physiological, biochemical and 16s rDNA sequence analysis. Long-term application of fertilizer N with compost enhanced both these numbers in rice plants and its environment. Bacteria were high in numbers when malate and azelaic acids were used as carbon source, but less when sucrose was used as a carbon substrate. The combined application promoted the association of diazotrophic bacteria like Azospirillum spp., Herbaspirillum spp., Burkholderia spp., Gluconacetobacter diazotrophicus and Pseudomonas spp. in wetland rice plants. Detection of nifD genes from different diazotrophic isolates indicated their nitrogen fixing ability. Inoculation of a representative isolate from each group onto rice seedlings of the variety IR 36 grown in test tubes indicated the positive effect of these diazotrophs on the growth of rice seedlings though the percentage of N present in the plants did not differ much. Application of compost with fertilizer N promoted the diazotrophic and heterotrophic bacterial numbers and their association with wetland rice and its environment. Compost application in high N fertilized fields would avert the reduction of N(2)-fixing bacterial numbers and their association was beneficial to the growth of rice plants. The inhibitory effect of high N fertilization on diazotrophic bacterial numbers could be reduced by the application of compost and this observation would encourage more usage of organic manure. This study has also thrown light on the wider geographic distribution of G. diazotrophicus with wetland rice in temperate region where sugarcane (from which this bacterium was first reported to be associating and thereon from other plant species) is not cultivated.

Short-term stress enhances cellular immunity and increases early resistance to squamous cell carcinoma.

PubMed

Dhabhar, Firdaus S; Saul, Alison N; Daugherty, Christine; Holmes, Tyson H; Bouley, Donna M; Oberyszyn, Tatiana M

2010-01-01

In contrast to chronic/long-term stress that suppresses/dysregulates immune function, an acute/short-term fight-or-flight stress response experienced during immune activation can enhance innate and adaptive immunity. Moderate ultraviolet-B (UV) exposure provides a non-invasive system for studying the naturalistic emergence, progression and regression of squamous cell carcinoma (SCC). Because SCC is an immunoresponsive cancer, we hypothesized that short-term stress experienced before UV exposure would enhance protective immunity and increase resistance to SCC. Control and short-term stress groups were treated identically except that the short-term stress group was restrained (2.5h) before each of nine UV-exposure sessions (minimum erythemal dose, 3-times/week) during weeks 4-6 of the 10-week UV exposure protocol. Tumors were measured weekly, and tissue collected at weeks 7, 20, and 32. Chemokine and cytokine gene expression was quantified by real-time PCR, and CD4+ and CD8+ T cells by flow cytometry and immunohistochemistry. Compared to controls, the short-term stress group showed greater cutaneous T-cell attracting chemokine (CTACK)/CCL27, RANTES, IL-12, and IFN-gamma gene expression at weeks 7, 20, and 32, higher skin infiltrating T cell numbers (weeks 7 and 20), lower tumor incidence (weeks 11-20) and fewer tumors (weeks 11-26). These results suggest that activation of short-term stress physiology increased chemokine expression and T cell trafficking and/or function during/following UV exposure, and enhanced Type 1 cytokine-driven cell-mediated immunity that is crucial for resistance to SCC. Therefore, the physiological fight-or-flight stress response and its adjuvant-like immuno-enhancing effects, may provide a novel and important mechanism for enhancing immune system mediated tumor-detection/elimination that merits further investigation.

Light exposure induces short- and long-term changes in the excitability of retinorecipient neurons in suprachiasmatic nucleus

PubMed Central

LeSauter, Joseph; Cloues, Robin; Witkovsky, Paul

2011-01-01

The suprachiasmatic nucleus (SCN) is the locus of a hypothalamic circadian clock that synchronizes physiological and behavioral responses to the daily light-dark cycle. The nucleus is composed of functionally and peptidergically diverse populations of cells for which distinct electrochemical properties are largely unstudied. SCN neurons containing gastrin-releasing peptide (GRP) receive direct retinal input via the retinohypothalamic tract. We targeted GRP neurons with a green fluorescent protein (GFP) marker for whole cell patch-clamping. In these neurons, we studied short (0.5–1.5 h)- and long-term (2–6 h) effects of a 1-h light pulse (LP) given 2 h after lights off [Zeitgeber time (ZT) 14:00–15:00] on membrane potential and spike firing. In brain slices taken from light-exposed animals, cells were depolarized, and spike firing rate increased between ZT 15:30 and 16:30. During a subsequent 4-h period beginning around ZT 17:00, GRP neurons from light-exposed animals were hyperpolarized by ∼15 mV. None of these effects was observed in GRP neurons from animals not exposed to light or in immediately adjacent non-GRP neurons whether or not exposed to light. Depolarization of GRP neurons was associated with a reduction in GABAA-dependent synaptic noise, whereas hyperpolarization was accompanied both by a loss of GABAA drive and suppression of a TTX-resistant leakage current carried primarily by Na. This suggests that, in the SCN, exposure to light may induce a short-term increase in GRP neuron excitability mediated by retinal neurotransmitters and neuropeptides, followed by long-term membrane hyperpolarization resulting from suppression of a leakage current, possibly resulting from genomic signals. PMID:21593396

Peroral Estradiol Is Sufficient to Induce Carcinogen-Induced Mammary Tumorigenesis in Ovariectomized Rats without Progesterone

PubMed Central

Stires, Hillary; Saboya, Mariana; Globerman, Samantha P.; Cohick, Wendie S.

2016-01-01

A role for estrogens in breast cancer is widely accepted, however, recent evidence highlights that timing and exposure levels are important in determining whether they elicit harmful versus beneficial effects. The rat chemical carcinogen model has been widely used to study the effects of estrogens but conclusions on the levels that lead to tumor development and an absolute requirement for progesterone (P4) are lacking. A newer method of hormone administration mixes hormones with nut butter for peroral consumption allowing for a less stressful method of long-term administration with lower spikes in serum estradiol (E2) levels. The present study was designed to determine if estrogens alone at a physiological dose can drive carcinogen-induced tumors in ovariectomized (OVX) rats or if P4 is also required using this method of hormone administration. Short-term studies were conducted to determine the dose of estrogen (E) that would lead to increased uterine weight following OVX. Subsequently, rats were OVX on postnatal day (PND) 40 then treated daily with E (600 μg/kg/day), P4 (15 mg/kg/day), or the combination. On PND 50, all rats were injected with nitrosomethylurea to induce mammary tumors. Uterine weights, body weights, and serum E2 levels were measured to demonstrate the efficacy of the method for increasing E2 levels during long-term treatment. After 26 weeks, tumor incidence was similar in Sham, E, and E + P4 animals indicating that E was sufficient to induce tumorigenesis when hormone levels were normalized by this method. This study demonstrates peroral administration can be used in long-term studies to elucidate relationships between different types and levels of steroid hormones. PMID:27611094

Integrating occupational therapy in treating combat stress reaction within a military unit: An intervention model.

PubMed

Gindi, Shahar; Galili, Giora; Volovic-Shushan, Shani; Adir-Pavis, Shirly

2016-01-01

Combat stress reaction (CR) is a syndrome with a wide range of symptoms including changes in soldiers' behaviors, emotional and physiological responses, avoidance and a decrease in both personal and military functioning. The short-term goal in treating CR is a speedy return to healthy functioning, whereas the long-term goal is to prevent the development of PTSD. Previous research has indicated that the achievement of this short-term goal affects the achievement of the long-term goal and vice versa. Effective treatment requires intervention by trained professionals proficient in reinforcing personal and functional identity without psychiatric labelling. The present paper presents a therapeutic model integrating OT in treating CR within a military setting. The model emphasizes the importance of preventing fixation to the role of 'patient' and a rapid return to maximal functioning. Based on Kielhofner's Model of Human Occupation, which aims to promote adaptive and efficient functioning by engaging soldiers in tasks supporting their military identity, empowering functionality, and increasing their perceived competency. The model emphasizes the therapeutic milieu within a military environment. Practical application of this model focuses on interdisciplinary aspects and client-focused application. The paper describes an assessment process for each soldier entering the CR unit and a treatment model integrating OT.

Risk formulation for the sonic effects of offshore wind farms on fish in the EU region.

PubMed

Kikuchi, Ryunosuke

2010-02-01

In 2007, European leaders agreed to source 20% of their energy needs from renewable energy; since that time, offshore wind farms have been receiving attention in the European Union (EU). In 2008, the European Community submitted a proposal to the United Nations Environment Program (UNEP) in order to combat marine noise pollution. In consideration of these facts, the present paper aims to deduce a preliminary hypothesis and its formulation for the effect of offshore wind farm noise on fish. The following general picture is drawn: the short-term potential impact during pre-construction; the short-term intensive impact during construction; and the physiological and/or masking effects that may occur over a long period while the wind farm is in operation. The EU's proposal to UNEP includes noise databases that list the origins of man-made sounds; it is advisable that offshore wind farms should be listed in the noise databases in order to promote rational environment management. Copyright 2009 Elsevier Ltd. All rights reserved.

Fast Learning with Weak Synaptic Plasticity.

PubMed

Yger, Pierre; Stimberg, Marcel; Brette, Romain

2015-09-30

New sensory stimuli can be learned with a single or a few presentations. Similarly, the responses of cortical neurons to a stimulus have been shown to increase reliably after just a few repetitions. Long-term memory is thought to be mediated by synaptic plasticity, but in vitro experiments in cortical cells typically show very small changes in synaptic strength after a pair of presynaptic and postsynaptic spikes. Thus, it is traditionally thought that fast learning requires stronger synaptic changes, possibly because of neuromodulation. Here we show theoretically that weak synaptic plasticity can, in fact, support fast learning, because of the large number of synapses N onto a cortical neuron. In the fluctuation-driven regime characteristic of cortical neurons in vivo, the size of membrane potential fluctuations grows only as √N, whereas a single output spike leads to potentiation of a number of synapses proportional to N. Therefore, the relative effect of a single spike on synaptic potentiation grows as √N. This leverage effect requires precise spike timing. Thus, the large number of synapses onto cortical neurons allows fast learning with very small synaptic changes. Significance statement: Long-term memory is thought to rely on the strengthening of coactive synapses. This physiological mechanism is generally considered to be very gradual, and yet new sensory stimuli can be learned with just a few presentations. Here we show theoretically that this apparent paradox can be solved when there is a tight balance between excitatory and inhibitory input. In this case, small synaptic modifications applied to the many synapses onto a given neuron disrupt that balance and produce a large effect even for modifications induced by a single stimulus. This effect makes fast learning possible with small synaptic changes and reconciles physiological and behavioral observations. Copyright © 2015 the authors 0270-6474/15/3513351-12$15.00/0.

Effects of experimental long-term CO2 exposure on Daphnia magna (Straus 1820): From physiological effects to ecological consequences.

PubMed

Parra, Gema; Galotti, Andréa; Jiménez-Melero, Raquel; Guerrero, Francisco; Sánchez-Moyano, Emilio; Jiménez-Gómez, Francisco; Conradi, Mercedes

2016-08-01

The carbon capture and storage (CCS) technologies that were proposed to mitigate environmental problems arising from anthropogenic CO2 emissions, also have potential environmental risks. An eventual CCS leak might induce very low pH values in the aquatic system. Due to the lack of knowledge of long-term CO2 exposures with very low pH values, this study aims to know the effects and consequences of such a situation for zooplankton, using the Daphnia magna experimental model. A CO2 injection system was used to provide the experimental condition. A twenty-one days experiment with control and low pH treatment (pH = 7) replicates was carried out under light and temperature-controlled conditions. Survival, individual growth, RNA:DNA ratio, and neonates production were analysed during the aforementioned period. No differences on survival (except last day), individual growth and RNA:DNA ratio were observed between both control and low pH treatments. However, clear differences were detected in neonates production and, consequently, in population growth rates and secondary production. The observed differences could be related with an energy allocation strategy to ensure individual survival but would have ecological consequences affecting higher trophic levels. Copyright © 2016 Elsevier Ltd. All rights reserved.