Investigation of pajama properties on skin under mild cold conditions: the interaction between skin and clothing.

PubMed

Yao, Lei; Gohel, Mayur D I; Li, Yi; Chung, Waiyee J

2011-07-01

Clothing is considered the second skin of the human body. The aim of this study was to determine clothing-wearer interaction on skin physiology under mild cold conditions. Skin physiological parameters, subjective sensory response, stress level, and physical properties of clothing fabric from two longitude parallel-designed wear trials were studied. The wear trials involved four kinds of pajamas made from cotton or polyester material that had hydrophilic or hydrophobic treatment, conducted for three weeks under mild cold conditions. Statistical tools, factor analysis, hierarchical linear regression, and logistic regression were applied to analyze the strong predictors of skin physiological parameters, stress level, and sensory response. A framework was established to illustrate clothing-wearer interactions with clothing fabric properties, skin physiology, stress level, and sensory response under mild cold conditions. Fabric has various effects on the human body under mild cold conditions. A fabric's properties influence skin physiology, sensation, and psychological response. © 2011 The International Society of Dermatology.

Manipulating neural activity in physiologically classified neurons: triumphs and challenges

PubMed Central

Gore, Felicity; Schwartz, Edmund C.; Salzman, C. Daniel

2015-01-01

Understanding brain function requires knowing both how neural activity encodes information and how this activity generates appropriate responses. Electrophysiological, imaging and immediate early gene immunostaining studies have been instrumental in identifying and characterizing neurons that respond to different sensory stimuli, events and motor actions. Here we highlight approaches that have manipulated the activity of physiologically classified neurons to determine their role in the generation of behavioural responses. Previous experiments have often exploited the functional architecture observed in many cortical areas, where clusters of neurons share response properties. However, many brain structures do not exhibit such functional architecture. Instead, neurons with different response properties are anatomically intermingled. Emerging genetic approaches have enabled the identification and manipulation of neurons that respond to specific stimuli despite the lack of discernable anatomical organization. These approaches have advanced understanding of the circuits mediating sensory perception, learning and memory, and the generation of behavioural responses by providing causal evidence linking neural response properties to appropriate behavioural output. However, significant challenges remain for understanding cognitive processes that are probably mediated by neurons with more complex physiological response properties. Currently available strategies may prove inadequate for determining how activity in these neurons is causally related to cognitive behaviour. PMID:26240431

Physiological response of pilots to the LBNP-, flight-, and centrifuge load.

PubMed

Dosel, P; Hanousek, J; Cmiral, J; Petricek, J

1998-07-01

The possibility of the LBNP method's utilization at persons with low resistance of the cardiovascular system to the orthostatic load is a matter one of the research projects of IAM. We concentrated in previous stages our effort on an evaluation of basic physiological responses of the organism to this type of a load and on determination of reliable markers of the precollapse state. After analysis of results of examinations of 64 probands' set we defined qualifying criteria to the prediction for selection of individuals with the insufficient orthostatic resistance. Verification of experimental results by the comparison with well-established examination methods, during a real flight load and at the examination in a human centrifuge, is a goal of the following research activity. In current period of the task's solution the physiological response to an LBNP load has been compared with the physiological response to the load during real flight in an aircraft.

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...

Biorhythms and space experiments with nonhuman primates

NASA Technical Reports Server (NTRS)

Winget, C. M.

1977-01-01

Man's response to exposure to spaceflight and weightlessness is expressed in physiological adjustments which involve his health and ability to function. The amplitude and periodicity of fluctuations in biological processes affect various functions and responses to provocative stimuli. Primates and other species are subjected to tests to determine the consequences of an altered biorhythm on work and performance, emotional stability, biomedical evaluation in space, the ability to cope with the unexpected, and susceptibility to infection, toxicity, radiation, drugs, and stress. Factors in the environment or operational setup which can change the physiological baseline must be determined and controlled.

Aging obviates sex-specific physiological responses to exercise.

PubMed

Deschenes, Michael R; Taylor, Jessica L; Mangis, Katherine A

2013-01-01

Both sex and aging have been shown to affect physiological responses to exercise. The aim of the present investigation was to determine whether aging impacted the sex-specific nature of physiological responses to exercise commonly noted among young adults. Ten aged men (69.0 ± 1.7 years; mean ± SE) and 10 aged women (71.6 ± 1.3 years) reporting similar levels of habitual physical activity performed a 30-min exercise session at 60-65% of their predetermined peak oxygen uptake. Cardiovascular, thermoregulatory, and metabolic variables were assessed before exercise, at the 15th and 30th min of exercise, and at 5 and 15 min into a passive postexercise recovery period. Variables of interest were statistically analyzed via two-way analysis of variance with repeated measures; significance was set at P < 0.05. Significant effects of time (i.e., exercise) for each physiological variable of interest were identified, but not once was a significant effect of group (i.e., sex) detected. Exercise-induced physiological responses to prolonged, moderate intensity exercise were similar among aged men and aged women. This evidence that the sexually dimorphic nature of physiological responses to exercise is obviated with age should be taken into account when prescribing health-related exercise training programs for older individuals. Copyright © 2013 Wiley Periodicals, Inc.

Evolutionary History Underlies Plant Physiological Responses to Global Change Since the Last Glacial Maximum

NASA Astrophysics Data System (ADS)

Becklin, K. M.; Medeiros, J. S.; Sale, K. R.; Ward, J. K.

2014-12-01

Assessing family and species-level variation in physiological responses to global change across geologic time is critical for understanding factors that underlie changes in species distributions and community composition. Ancient plant specimens preserved within packrat middens are invaluable in this context since they allow for comparisons between co-occurring plant lineages. Here we used modern and ancient plant specimens preserved within packrat middens from the Snake Range, NV to investigate the physiological responses of a mixed montane conifer community to global change since the last glacial maximum. We used a conceptual model to infer relative changes in stomatal conductance and maximum photosynthetic capacity from measures of leaf carbon isotopes, stomatal characteristics, and leaf nitrogen content. Our results indicate that most of the sampled taxa decreased stomatal conductance and/or photosynthetic capacity from glacial to modern times. However, plant families differed in the timing and magnitude of these physiological responses. Additionally, leaf-level responses were more similar within plant families than within co-occurring species assemblages. This suggests that adaptation at the level of leaf physiology may not be the main determinant of shifts in community composition, and that plant evolutionary history may drive physiological adaptation to global change over recent geologic time.

Determinants of physiological and perceived physiological stress reactivity in children and adolescents.

PubMed

Evans, Brittany E; Greaves-Lord, Kirstin; Euser, Anja S; Tulen, Joke H M; Franken, Ingmar H A; Huizink, Anja C

2013-01-01

Abnormal physiological stress reactivity is increasingly investigated as a vulnerability marker for various physical and psychological health problems. However, studies are inconsistent in taking into account potential covariates that may influence the developing stress system. We systematically tested determinants (individual, developmental, environmental and substance use-related) of physiological and perceived physiological stress reactivity. We also examined the relation between physiological and perceived physiological stress reactivity. In a stratified sample of 363 children (7-12 years) and 344 adolescents (13-20 years) from the general population, we examined cortisol, heart rate, respiratory sinus arrhythmia and perceived physiological stress reactivity to a psychosocial stress procedure. Using multivariate linear regression models, we found that individual, developmental, environmental and substance use-related factors were related to each of the stress response indices. These determinant factors were different for each of the stress reactivity indices, and different in children versus adolescents. Perceived physiological stress reactivity predicted cortisol reactivity in adolescents only. All other relations between perceived physiological and physiological stress reactivity were not significant. As physiological stress variables are often examined as vulnerability markers for the development of health problems, we maintain that it is essential that future studies take into consideration factors that may account for found relations. Our study provides an overview and indication of which variables should be considered in the investigation of the relation between physiological stress indices and illness.

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

Acute Physiological Responses to Strongman Training Compared to Traditional Strength Training.

PubMed

Harris, Nigel K; Woulfe, Colm J; Wood, Matthew R; Dulson, Deborah K; Gluchowski, Ashley K; Keogh, Justin B

2016-05-01

Strongman training (ST) has become an increasingly popular modality, but data on physiological responses are limited. This study sought to determine physiological responses to an ST session compared to a traditional strength exercise training (RST) session. Ten healthy men (23.6 ± 27.5 years, 85.8 ± 10.3 kg) volunteered in a crossover design, where all participants performed an ST session, an RST session, and a resting session within 7 days apart. The ST consisted of sled drag, farmer's walk, 1 arm dumbbell clean and press, and tire flip at loads eliciting approximately 30 seconds of near maximal effort per set. The RST consisted of squat, deadlift, bench press, and power clean, progressing to 75% of 1 repetition maximum. Sessions were equated for approximate total set duration. Blood lactate and salivary testosterone were recorded immediately before and after training sessions. Heart rate, caloric expenditure, and substrate utilization were measured throughout the resting session, both training protocols and for 80 minutes after training sessions. Analyses were conducted to determine differences in physiological responses within and between protocols. No significant changes in testosterone occurred at any time point for either session. Lactate increased significantly immediately after both sessions. Heart rate, caloric expenditure, and substrate utilization were all elevated significantly during ST and RST. Heart rate and fat expenditure were significantly elevated compared to resting in both sessions' recovery periods; calorie and carbohydrate expenditures were not. Compared to RST, ST represents an equivalent physiological stimulus on key parameters indicative of potential training-induced adaptive responses. Such adaptations could conceivably include cardiovascular conditioning.

Lack of physiological responses to hydrocarbon accumulation by Mytilus trossulus after 3-4 years chronic exposure to spilled Exxon Valdez crude oil in Prince William Sound.

PubMed

Thomas, R E; Brodersen, C; Carls, M G; Babcock, M; Rice, S D

1999-01-01

Mussels, Mytilus trossulus, were sampled in 1992 and 1993 from beaches in Prince William Sound that had been oiled by the Exxon Valdez spill of March, 1989. At some of the oiled beaches, mussels were collected from beds overlying oiled sediments, and from bedrock adjacent to these beds. Mussels were also collected from beaches within the Sound that had not been impacted by the spill. Polynuclear aromatic hydrocarbon (PAH) concentrations in mussel tissue, physiological responses (byssal thread production, condition index, clearance rate, and glycogen content), were determined for each group of mussels. Total PAH concentrations in mussel tissue ranged from 0 to 6 micrograms g-1, and were significantly greater in mussels from oiled beds than those from reference beds. No significant differences were noted in byssal thread production, condition index, clearance rate, or glycogen content between oiled sample sites and reference sites. The lack of physiological response was surprising because mussels in this study were chronically exposed to PAH for 3-4 years, and none of the physiological responses measured appeared to be affected by that exposure. The lack of a physiological response suggests that chronically exposed mussels may develop a physiological tolerance to PAH, but we recognize that these measures may not have been sensitive enough to discriminate response from background noise.

Physiological and behavioural assessment of pain in ruminants: principles and caveats.

PubMed

Mellor, David J; Stafford, Kevin J

2004-06-01

Pain elicits a range of physiological and behavioural responses. These are commonly used to assess the impact of pain-inducing stimuli on animals, to determine whether or not significant pain is experienced and to devise strategies for alleviating pain. This paper outlines a range of principles and caveats to guide the evaluation of physiological and behavioural responses to painful stimuli, so that they can be better used to minimise pain in the experimental context. Although this advice is based on studies of farm animals responding to painful husbandry practices, it is more generally applicable.

Acute Physiological and Thermoregulatory Responses to Extended Interval Training in Endurance Runners: Influence of Athletic Performance and Age

PubMed Central

García-Pinillos, Felipe; Soto-Hermoso, Víctor Manuel; Latorre-Román, Pedro Ángel

2015-01-01

This study aimed to describe the acute impact of extended interval training (EIT) on physiological and thermoregulatory levels, as well as to determine the influence of athletic performance and age effect on the aforementioned response in endurance runners. Thirty-one experienced recreational male endurance runners voluntarily participated in this study. Subjects performed EIT on an outdoor running track, which consisted of 12 runs of 400 m. The rate of perceived exertion, physiological response through the peak and recovery heart rate, blood lactate, and thermoregulatory response through tympanic temperature, were controlled. A repeated measures analysis revealed significant differences throughout EIT in examined variables. Cluster analysis grouped according to the average performance in 400 m runs led to distinguish between athletes with a higher and lower sports level. Cluster analysis was also performed according to age, obtaining an older group and a younger group. The one-way analysis of variance between groups revealed no significant differences (p≥0.05) in the response to EIT. The results provide a detailed description of physiological and thermoregulatory responses to EIT in experienced endurance runners. This allows a better understanding of the impact of a common training stimulus on the physiological level inducing greater accuracy in the training prescription. Moreover, despite the differences in athletic performance or age, the acute physiological and thermoregulatory responses in endurance runners were similar, as long as EIT was performed at similar relative intensity. PMID:26839621

Population dynamics can be more important than physiological limits for determining range shifts under climate change.

PubMed

Fordham, Damien A; Mellin, Camille; Russell, Bayden D; Akçakaya, Reşit H; Bradshaw, Corey J A; Aiello-Lammens, Matthew E; Caley, Julian M; Connell, Sean D; Mayfield, Stephen; Shepherd, Scoresby A; Brook, Barry W

2013-10-01

Evidence is accumulating that species' responses to climate changes are best predicted by modelling the interaction of physiological limits, biotic processes and the effects of dispersal-limitation. Using commercially harvested blacklip (Haliotis rubra) and greenlip abalone (Haliotis laevigata) as case studies, we determine the relative importance of accounting for interactions among physiology, metapopulation dynamics and exploitation in predictions of range (geographical occupancy) and abundance (spatially explicit density) under various climate change scenarios. Traditional correlative ecological niche models (ENM) predict that climate change will benefit the commercial exploitation of abalone by promoting increased abundances without any reduction in range size. However, models that account simultaneously for demographic processes and physiological responses to climate-related factors result in future (and present) estimates of area of occupancy (AOO) and abundance that differ from those generated by ENMs alone. Range expansion and population growth are unlikely for blacklip abalone because of important interactions between climate-dependent mortality and metapopulation processes; in contrast, greenlip abalone should increase in abundance despite a contraction in AOO. The strongly non-linear relationship between abalone population size and AOO has important ramifications for the use of ENM predictions that rely on metrics describing change in habitat area as proxies for extinction risk. These results show that predicting species' responses to climate change often require physiological information to understand climatic range determinants, and a metapopulation model that can make full use of this data to more realistically account for processes such as local extirpation, demographic rescue, source-sink dynamics and dispersal-limitation. © 2013 John Wiley & Sons Ltd.

Environmental and biological context modulates the physiological stress response of bats to human disturbance.

PubMed

Phelps, Kendra L; Kingston, Tigga

2018-06-01

Environmental and biological context play significant roles in modulating physiological stress responses of individuals in wildlife populations yet are often overlooked when evaluating consequences of human disturbance on individual health and fitness. Furthermore, most studies gauge individual stress responses based on a single physiological biomarker, typically circulating glucocorticoid concentrations, which limits interpretation of the complex, multifaceted responses of individuals to stressors. We selected four physiological biomarkers to capture short-term and prolonged stress responses in a widespread cave-roosting bat, Hipposideros diadema, across multiple gradients of human disturbance in and around caves in the Philippines. We used conditional inference trees and random forest analysis to determine the role of environmental quality (cave complexity, available roosting area), assemblage composition (intra- and interspecific associations and species richness), and intrinsic characteristics of individuals (sex and reproductive status) in modulating responses to disturbance. Direct cave disturbance (hunting pressure and human visitation) was the primary driver of neutrophil-to-lymphocyte ratios, with lower ratios associated with increased disturbance, while context-specific factors were more important in explaining total leukocyte count, body condition, and ectoparasite load. Moreover, conditional inference trees revealed complex interactions among human disturbance and modulating factors. Cave complexity often ameliorated individual responses to human disturbance, whereas conspecific abundance often compounded responses. Our study demonstrates the importance of an integrated approach that incorporates environmental and biological context when identifying drivers of physiological responses, and that assesses responses to gradients of direct and indirect disturbance using multiple complementary biomarkers.

Determinants of Physiological and Perceived Physiological Stress Reactivity in Children and Adolescents

PubMed Central

Evans, Brittany E.; Greaves-Lord, Kirstin; Euser, Anja S.; Tulen, Joke H. M.; Franken, Ingmar H. A.; Huizink, Anja C.

2013-01-01

Aims Abnormal physiological stress reactivity is increasingly investigated as a vulnerability marker for various physical and psychological health problems. However, studies are inconsistent in taking into account potential covariates that may influence the developing stress system. We systematically tested determinants (individual, developmental, environmental and substance use-related) of physiological and perceived physiological stress reactivity. We also examined the relation between physiological and perceived physiological stress reactivity. Method In a stratified sample of 363 children (7–12 years) and 344 adolescents (13–20 years) from the general population, we examined cortisol, heart rate, respiratory sinus arrhythmia and perceived physiological stress reactivity to a psychosocial stress procedure. Results Using multivariate linear regression models, we found that individual, developmental, environmental and substance use-related factors were related to each of the stress response indices. These determinant factors were different for each of the stress reactivity indices, and different in children versus adolescents. Perceived physiological stress reactivity predicted cortisol reactivity in adolescents only. All other relations between perceived physiological and physiological stress reactivity were not significant. Conclusions As physiological stress variables are often examined as vulnerability markers for the development of health problems, we maintain that it is essential that future studies take into consideration factors that may account for found relations. Our study provides an overview and indication of which variables should be considered in the investigation of the relation between physiological stress indices and illness. PMID:23620785

Depression of Photosynthesis, Growth, and Yield in Field-Grown Green Pepper (Capsicum annuum L.) Exposed to Acidic Fog and Ambient Ozone 1

PubMed Central

Takemoto, Brent K.; Bytnerowicz, Andrzej; Olszyk, David M.

1988-01-01

The relationship among physiological, injury, growth, and yield responses was examined in field-grown green pepper (Capsicum annuum L. `California Wonder') subjected to two airborne environmental stresses. The primary objectives were to determine if the stresses could cause alterations in the plant responses, and to determine if any stress induced alterations in physiological or injury responses were correlated with effects on growth or yield. Responses were monitored in green pepper exposed to simulated acidic fog alone, or in combination with ambient concentrations of ozone in open-top field chambers. Both highly acidic fog and ambient ozone depressed green pepper growth and yield responses via the inhibition of photosynthesis. Applications of highly acidic fog (i.e. two exposures of pH 1.68 fog per week for 11 weeks) caused a significant depression of net photosynthesis, reduction in leaf buffering capacity, and an extensive amount of leaf injury. These alterations closely paralleled decreases in growth and yield on a percentage basis. In contrast, ambient ozone had similar impacts on net photosynthesis, growth and yield, but enhanced leaf buffering capacity, and caused no visible injury. The pollutant-specific differences in plant response are discussed with respect to whole-plant carbon metabolism and physiological compensation. PMID:16666330

Relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress.

PubMed

Kebede, Hirut; Abbas, Hamed K; Fisher, Daniel K; Bellaloui, Nacer

2012-11-20

Increased aflatoxin contamination in corn by the fungus Aspergillus flavus is associated with frequent periods of drought and heat stress during the reproductive stages of the plants. The objective of this study was to evaluate the relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress. The study was conducted in Stoneville, MS, USA under irrigated and non-irrigated conditions. Five commercial hybrids, P31G70, P33F87, P32B34, P31B13 and DKC63-42 and two inbred germplasm lines, PI 639055 and PI 489361, were evaluated. The plants were inoculated with Aspergillus flavus (K-54) at mid-silk stage, and aflatoxin contamination was determined on the kernels at harvest. Several physiological measurements which are indicators of stress response were determined. The results suggested that PI 639055, PI 489361 and hybrid DKC63-42 were more sensitive to drought and high temperature stress in the non-irrigated plots and P31G70 was the most tolerant among all the genotypes. Aflatoxin contamination was the highest in DKC63-42 and PI 489361 but significantly lower in P31G70. However, PI 639055, which is an aflatoxin resistant germplasm, had the lowest aflatoxin contamination, even though it was one of the most stressed genotypes. Possible reasons for these differences are discussed. These results suggested that the physiological responses were associated with the level of aflatoxin contamination in all the genotypes, except PI 639055. These and other physiological responses related to stress may help examine differences among corn genotypes in aflatoxin contamination.

Functional Groups Based on Leaf Physiology: Are they Spatially and Temporally Robust?

NASA Technical Reports Server (NTRS)

Foster, Tammy E.; Brooks, J. Renee; Quincy, Charles (Technical Monitor)

2002-01-01

The functional grouping hypothesis, which suggests that complexity in function can be simplified by grouping species with similar responses, was tested in the Florida scrub habitat. Functional groups were identified based on how species in fire maintained FL scrub function in terms of carbon, water and nitrogen dynamics. The suite of physiologic parameters measured to determine function included both instantaneous gas exchange measurements obtained from photosynthetic light response curves and integrated measures of function. Using cluster analysis, five distinct physiologically-based functional groups were identified. Using non-parametric multivariate analyses, it was determined that these five groupings were not altered by plot differences or by the three different management regimes; prescribed burn, mechanically treated and burn, and fire-suppressed. The physiological groupings also remained robust between the two years 1999 and 2000. In order for these groupings to be of use for scaling ecosystem processes, there needs to be an easy-to-measure morphological indicator of function. Life form classifications were able to depict the physiological groupings more adequately than either specific leaf area or leaf thickness. THe ability of life forms to depict the groupings was improved by separating the parasitic Ximenia americana from the shrub category.

Does corticosterone mediate predator-induced responses of larval Hylarana indica?

PubMed

Joshi, A M; Wadekar, N V; Gramapurohit, N P

2017-09-15

Prey-predator interactions have been studied extensively in terms of morphological and behavioural responses of prey to predation risk using diverse model systems. However, the underlying physiological changes associated with morphological, behavioural or life historical responses have been rarely investigated. Herein, we studied the effect of chronic predation risk on larval growth and metamorphosis of Hylarana indica and the underlying physiological changes in prey tadpoles. In the first experiment, tadpoles were exposed to a caged predator from Gosner stage 25-42 to record growth and metamorphosis. Further, whole body corticosterone (CORT) was measured to determine the physiological changes underlying morphological and life historical responses of these prey tadpoles. Surprisingly, tadpoles experiencing continuous predation risk grew and developed faster and metamorphosed at a larger size. Interestingly, these tadpoles had significantly lower CORT levels. In the second experiment, tadpoles were exposed to predation risk (PR) or PR+CORT from stage 25-42 to determine the role of CORT in mediating predator-induced responses of H. indica. Tadpoles facing continuous predation risk grew and developed faster and metamorphosed at a larger size reinforcing the results of the first experiment. However, when CORT was administered along with predation risk, tadpoles grew and developed slowly leading to delayed metamorphosis. Interestingly, growth and metamorphic traits of tadpoles exposed to PR+CORT were comparable to those of the control group indicating that exogenous CORT nullified the positive effect of predation risk. Apparently, CORT mediates predator-induced morphological responses of H. indica tadpoles by regulating their physiology. Copyright © 2016 Elsevier Inc. All rights reserved.

An Escherichia coli nitrogen starvation response is important for mutualistic coexistence with Rhodopseudomonas palustris.

PubMed

McCully, Alexandra L; Behringer, Megan G; Gliessman, Jennifer R; Pilipenko, Evgeny V; Mazny, Jeffrey L; Lynch, Michael; Drummond, D Allan; McKinlay, James B

2018-05-04

Microbial mutualistic cross-feeding interactions are ubiquitous and can drive important community functions. Engaging in cross-feeding undoubtedly affects the physiology and metabolism of individual species involved. However, the nature in which an individual's physiology is influenced by cross-feeding and the importance of those physiological changes for the mutualism have received little attention. We previously developed a genetically tractable coculture to study bacterial mutualisms. The coculture consists of fermentative Escherichia coli and phototrophic Rhodopseudomonas palustris In this coculture, E. coli anaerobically ferments sugars into excreted organic acids as a carbon source for R. palustris In return, a genetically-engineered R. palustris constitutively converts N 2 into NH 4 + , providing E. coli with essential nitrogen. Using RNA-seq and proteomics, we identified transcript and protein levels that differ in each partner when grown in coculture versus monoculture. When in coculture with R. palustris , E. coli gene-expression changes resembled a nitrogen starvation response under the control of the transcriptional regulator NtrC. By genetically disrupting E. coli NtrC, we determined that a nitrogen starvation response is important for a stable coexistence, especially at low R. palustris NH 4 + excretion levels. Destabilization of the nitrogen starvation regulatory network resulted in variable growth trends and in some cases, extinction. Our results highlight that alternative physiological states can be important for survival within cooperative cross-feeding relationships. Importance Mutualistic cross-feeding between microbes within multispecies communities is widespread. Studying how mutualistic interactions influence the physiology of each species involved is important for understanding how mutualisms function and persist in both natural and applied settings. Using a bacterial mutualism consisting of Rhodopseudomonas palustris and Escherichia coli growing cooperatively through bidirectional nutrient exchange, we determined that an E. coli nitrogen starvation response is important for maintaining a stable coexistence. The lack of an E. coli nitrogen starvation response ultimately destabilized the mutualism and, in some cases, led to community collapse after serial transfers. Our findings thus inform on the potential necessity of an alternative physiological state for mutualistic coexistence with another species compared to the physiology of species grown in isolation. Copyright © 2018 American Society for Microbiology.

Growth, shoot phenology and physiology of diverse seed sources of black spruce: I Seedling responses to varied atmospheric CO2 concentrations and photoperiods

Treesearch

Kurt H. Johnsen; John R. Seiler

1996-01-01

We conducted a greenhouse experiment to determine: (1) if diverse provenances of black spruce (Picea mariana (Mill.) B.S.P.) respond similarly in growth, phenology and physiology to an approximately 300 ppm increase in atmospheric CO2...

Comparative proteomic analysis reveals the positive effect of exogenous spermidine on photosynthesis and salinity tolerance in cucumber seedlings.

PubMed

Sang, Ting; Shan, Xi; Li, Bin; Shu, Sheng; Sun, Jin; Guo, Shirong

2016-08-01

Our results based on proteomics data and physiological alterations proposed the putative mechanism of exogenous Spd enhanced salinity tolerance in cucumber seedlings. Current studies showed that exogenous spermidine (Spd) could alleviate harmful effects of salinity. It is important to increase our understanding of the beneficial physiological responses of exogenous Spd treatment, and to determine the molecular responses underlying these responses. Here, we combined a physiological analysis with iTRAQ-based comparative proteomics of cucumber (Cucumis sativus L.) leaves, treated with 0.1 mM exogenous Spd, 75 mM NaCl and/or exogenous Spd. A total of 221 differentially expressed proteins were found and involved in 30 metabolic pathways, such as photosynthesis, carbohydrate metabolism, amino acid metabolism, stress response, signal transduction and antioxidant. Based on functional classification of the differentially expressed proteins and the physiological responses, we found cucumber seedlings treated with Spd under salt stress had higher photosynthesis efficiency, upregulated tetrapyrrole synthesis, stronger ROS scavenging ability and more protein biosynthesis activity than NaCl treatment, suggesting that these pathways may promote salt tolerance under high salinity. This study provided insights into how exogenous Spd protects photosynthesis and enhances salt tolerance in cucumber seedlings.

Adaptation of exercise-induced stress in well-trained healthy young men.

PubMed

JanssenDuijghuijsen, Lonneke M; Keijer, Jaap; Mensink, Marco; Lenaerts, Kaatje; Ridder, Lars; Nierkens, Stefan; Kartaram, Shirley W; Verschuren, Martie C M; Pieters, Raymond H H; Bas, Richard; Witkamp, Renger F; Wichers, Harry J; van Norren, Klaske

2017-01-01

What is the central question of this study? Exercise is known to induce stress-related physiological responses, such as changes in intestinal barrier function. Our aim was to determine the test-retest repeatability of these responses in well-trained individuals. What is the main finding and its importance? Responses to strenuous exercise, as indicated by stress-related markers such as intestinal integrity markers and myokines, showed high test-retest variation. Even in well-trained young men an adapted response is seen after a single repetition after 1 week. This finding has implications for the design of studies aimed at evaluating physiological responses to exercise. Strenuous exercise induces different stress-related physiological changes, potentially including changes in intestinal barrier function. In the Protégé Study (ISRCTN14236739; www.isrctn.com), we determined the test-retest repeatability in responses to exercise in well-trained individuals. Eleven well-trained men (27 ± 4 years old) completed an exercise protocol that consisted of intensive cycling intervals, followed by an overnight fast and an additional 90 min cycling phase at 50% of maximal workload the next morning. The day before (rest), and immediately after the exercise protocol (exercise) a lactulose and rhamnose solution was ingested. Markers of energy metabolism, lactulose-to-rhamnose ratio, several cytokines and potential stress-related markers were measured at rest and during exercise. In addition, untargeted urine metabolite profiles were obtained. The complete procedure (Test) was repeated 1 week later (Retest) to assess repeatability. Metabolic effect parameters with regard to energy metabolism and urine metabolomics were similar for both the Test and Retest period, underlining comparable exercise load. Following exercise, intestinal permeability (1 h plasma lactulose-to-rhamnose ratio) and the serum interleukin-6, interleukin-10, fibroblast growth factor-21 and muscle creatine kinase concentrations were significantly increased compared with rest only during the first test and not when the test was repeated. Responses to strenuous exercise in well-trained young men, as indicated by intestinal markers and myokines, show adaptation in Test-Retest outcome. This might be attributable to a carry-over effect of the defense mechanisms triggered during the Test. This finding has implications for the design of studies aimed at evaluating physiological responses to exercise. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.

Connecting genes, coexpression modules, and molecular signatures to environmental stress phenotypes in plants

PubMed Central

Weston, David J; Gunter, Lee E; Rogers, Alistair; Wullschleger, Stan D

2008-01-01

Background One of the eminent opportunities afforded by modern genomic technologies is the potential to provide a mechanistic understanding of the processes by which genetic change translates to phenotypic variation and the resultant appearance of distinct physiological traits. Indeed much progress has been made in this area, particularly in biomedicine where functional genomic information can be used to determine the physiological state (e.g., diagnosis) and predict phenotypic outcome (e.g., patient survival). Ecology currently lacks an analogous approach where genomic information can be used to diagnose the presence of a given physiological state (e.g., stress response) and then predict likely phenotypic outcomes (e.g., stress duration and tolerance, fitness). Results Here, we demonstrate that a compendium of genomic signatures can be used to classify the plant abiotic stress phenotype in Arabidopsis according to the architecture of the transcriptome, and then be linked with gene coexpression network analysis to determine the underlying genes governing the phenotypic response. Using this approach, we confirm the existence of known stress responsive pathways and marker genes, report a common abiotic stress responsive transcriptome and relate phenotypic classification to stress duration. Conclusion Linking genomic signatures to gene coexpression analysis provides a unique method of relating an observed plant phenotype to changes in gene expression that underlie that phenotype. Such information is critical to current and future investigations in plant biology and, in particular, to evolutionary ecology, where a mechanistic understanding of adaptive physiological responses to abiotic stress can provide researchers with a tool of great predictive value in understanding species and population level adaptation to climate change. PMID:18248680

An Exploration of the Factors That Contribute to Learning Satisfaction of First-Year Anatomy and Physiology Students

ERIC Educational Resources Information Center

Eagleton, Saramarie

2015-01-01

Lecturers have reverted to using a "blended" approach when teaching anatomy and physiology. Student responses as to how this contributes to their learning satisfaction were investigated using a self-administered questionnaire. The questionnaire consisted of closed- and open-ended questions that were based on three determinants of…

Stress Hormones and Their Regulation in a Captive Dolphin Population

DTIC Science & Technology

2014-09-30

environmental stressors, many of which are anthropogenic. The resulting stress response provides for immediate physiological needs and manages recovery...of two broad components: 1) assessing baseline variability in stress hormones and 2) evaluating physiological and metabolic alterations that occur...cortisol and aldosterone ) frequenctly observed in cetaceans; (2) determine the regulatory role of corticosteroid binding globulin (CBG) in

Effect of aerobic fitness on the physiological stress responses at work.

PubMed

Ritvanen, Tiina; Louhevaara, Veikko; Helin, Pertti; Halonen, Toivo; Hänninen, Osmo

2007-01-01

The aim of the present study was to examine the effects of aerobic fitness on physiological stress responses experienced by teachers during working hours. Twenty-six healthy female and male teachers aged 33-62 years participated in the study. The ratings of perceived stress visual analogue scale (VAS), and the measurement of physiological responses (norepinephrine, epinephrine, cortisol, diastolic and systolic blood pressure, heart rate (HR), and trapezius muscle activity by electromyography (EMG), were determined. Predicted maximal oxygen uptake (VO(2)max) was measured using the submaximal bicycle ergometer test. The predicted VO(2)max was standardized for age using residuals of linear regression analyses. Static EMG activity, HR and VAS were associated with aerobic fitness in teachers. The results suggest that a higher level of aerobic fitness may reduce muscle tension, HR and perceived work stress in teachers.

Impact of hand forces and start/stop frequency on physiological responses to three forms of pushing and pulling: a South African perspective.

PubMed

Ai, Todd

2012-01-01

There has been limited attention given to the physiological demands of pushing and pulling, especially in industrially developing countries such as South Africa. Two key factors affecting the physiological demands of these tasks are the hand forces exerted and the start/stop frequency. The purpose of the current study was therefore to investigate the physiological responses to pushing and pulling at various loads and start/stop frequencies. 36 male subjects participated in the study and were required to complete a total of 18 conditions (three techniques: pushing, two- and one-handed pulling; three loads: 200, 350 and 500 kg; and two frequencies: 2 and 4 stops per minute). During each condition the heart rate, oxygen uptake and energy expenditure were measured. Pushing was found to elicit significantly lower responses for all three dependent variables than either form of pulling. The start/stop frequency was also found to have a significant impact on subject responses. The findings of this study indicate that the technique adopted to maneuver loads is critical in determining the physical demands placed on the human operator. Furthermore increasing the frequency of start/stops plays an important role, thus the forces exerted during these two phases are important from a physiological perspective.

Local air gap thickness and contact area models for realistic simulation of human thermo-physiological response

NASA Astrophysics Data System (ADS)

Psikuta, Agnes; Mert, Emel; Annaheim, Simon; Rossi, René M.

2018-02-01

To evaluate the quality of new energy-saving and performance-supporting building and urban settings, the thermal sensation and comfort models are often used. The accuracy of these models is related to accurate prediction of the human thermo-physiological response that, in turn, is highly sensitive to the local effect of clothing. This study aimed at the development of an empirical regression model of the air gap thickness and the contact area in clothing to accurately simulate human thermal and perceptual response. The statistical model predicted reliably both parameters for 14 body regions based on the clothing ease allowances. The effect of the standard error in air gap prediction on the thermo-physiological response was lower than the differences between healthy humans. It was demonstrated that currently used assumptions and methods for determination of the air gap thickness can produce a substantial error for all global, mean, and local physiological parameters, and hence, lead to false estimation of the resultant physiological state of the human body, thermal sensation, and comfort. Thus, this model may help researchers to strive for improvement of human thermal comfort, health, productivity, safety, and overall sense of well-being with simultaneous reduction of energy consumption and costs in built environment.

Observation of arterial blood pressure of the primate

NASA Technical Reports Server (NTRS)

Meehan, J. P.; Henry, J. P.

1973-01-01

The developments are reported in physiological instrumentation, surgical procedures, measurement and data analysis techniques, and the definition of flight experiments to determine the effects of prolonged weightlessness on the cardiovascular system of subhuman primates. The development of an implantable telemetric data acquisition system is discussed along with cardiovascular research applications in renal hemodynamics. It is concluded that the implant technique permits a valid interpretation, free of emotional response, for the manipulated variable on physiological functions. It also allows a better definition of normal physiological baseline conditions.

Physiology response of the indigenous cattle breeds to the environment in West Sumbawa, Indonesia

NASA Astrophysics Data System (ADS)

Aritonang, S. B.; Yuniati, R.; Abinawanto, Imron, M.; Bowolaksono, A.

2017-07-01

Heat stress in cattle welfare is a growing concern because of increase in ambient temperature due to global warming. Physiological adaptation is as a way to survive and reproduce by regulation internal body temperature. West Sumbawa is a dry tropic area in eastern Indonesia where its temperature range is 24-38 °C and relative humidity is 50-90 %. This study aimed to determine the physiological response of indigenous cattle i.e. Bali cattle and Sumbawa Ongole cattle to the environment in West Sumbawa. Skin and rectal temperature and respiration rate within one minute were measured as physiology profiles from seven Bali cattle and two Sumbawa Ongole cattle. They were measured every 7.00 am and 15.00 pm for five consecutive days in August 2016. The results of measurements physiology profiles differ significantly between morning and afternoon among cattle breeds. Body temperature and respiration rate were significantly different among breeds (p < 0.05). Body temperature was lower but respiration rate of Sumbawa Ongole was higher than Bali cattle. Increased respiration rate of breeds was positively correlated with Temperature and Humidity Index (THI) value (p < 0.05), but neither was body temperature. Physiological response of Bali cattle to environmental West Sumbawa through the increase in body temperature, whereas Sumbawa Ongole cattle through increasing in respiration rate.

Order of exposure to pleasant and unpleasant odors affects autonomic nervous system response.

PubMed

Horii, Yuko; Nagai, Katsuya; Nakashima, Toshihiro

2013-04-15

When mammals are exposed to an odor, that odor is expected to elicit a physiological response in the autonomic nervous system. An unpleasant aversive odor causes non-invasive stress, while a pleasant odor promotes healing and relaxation in mammals. We hypothesized that pleasant odors might reduce a stress response previously induced by an aversive predator odor. Rats were thus exposed to pleasant and unpleasant odors in different orders to determine whether the order of odor exposure had an effect on the physiological response in the autonomic nervous system. The first trial examined autonomic nerve activity via sympathetic and parasympathetic nerve response while the second trial examined body temperature response. Initial exposure to a pleasant odor elicited a positive response and secondary exposure to an unpleasant odor elicited a negative response, as expected. However, we found that while initial exposure to an unpleasant odor elicited a negative stress response, subsequent secondary exposure to a pleasant odor not only did not alleviate that negative response, but actually amplified it. These findings were consistent for both the autonomic nerve activity response trial and the body temperature response trial. The trial results suggest that exposure to specific odors does not necessarily result in the expected physiological response and that the specific order of exposure plays an important role. Our study should provide new insights into our understanding of the physiological response in the autonomic nervous system related to odor memory and discrimination and point to areas that require further research. Copyright © 2013 Elsevier B.V. All rights reserved.

What can an ecophysiological approach tell us about the physiological responses of marine invertebrates to hypoxia?

PubMed

Spicer, John I

2014-01-01

Hypoxia (low O2) is a common and natural feature of many marine environments. However, human-induced hypoxia has been on the rise over the past half century and is now recognised as a major problem in the world's seas and oceans. Whilst we have information on how marine invertebrates respond physiologically to hypoxia in the laboratory, we still lack understanding of how they respond to such stress in the wild (now and in the future). Consequently, here the question 'what can an ecophysiological approach tell us about physiological responses of marine invertebrates to hypoxia' is addressed. How marine invertebrates work in the wild when challenged with hypoxia is explored using four case studies centred on different hypoxic environments. The recent integration of the various -omics into ecophysiology is discussed, and a number of advantages of, and challenges to, successful integration are suggested. The case studies and -omic/physiology integration data are used to inform the concluding part of the review, where it is suggested that physiological responses to hypoxia in the wild are not always the same as those predicted from laboratory experiments. This is due to behaviour in the wild modifying responses, and therefore more than one type of 'experimental' approach is essential to reliably determine the actual response. It is also suggested that assuming it is known what a measured response is 'for' can be misleading and that taking parodies of ecophysiology seriously may impede research progress. This review finishes with the suggestion that an -omics approach is, and is becoming, a powerful method of understanding the response of marine invertebrates to environmental hypoxia and may be an ideal way of studying hypoxic responses in the wild. Despite centring on physiological responses to hypoxia, the review hopefully serves as a contribution to the discussion of what (animal) ecophysiology looks like (or should look like) in the 21st century.

Physiological and genetic correlates of boldness: characterising the mechanisms of behavioural variation in rainbow trout, Oncorhynchus mykiss.

PubMed

Thomson, Jack S; Watts, Phillip C; Pottinger, Tom G; Sneddon, Lynne U

2011-01-01

Bold, risk-taking animals have previously been putatively linked with a proactive stress coping style whereas it is suggested shyer, risk-averse animals exhibit a reactive coping style. The aim of this study was to investigate whether differences in the expression of bold-type behaviour were evident within and between two lines of rainbow trout, Oncorhynchus mykiss, selectively bred for a low (LR) or high (HR) endocrine response to stress, and to link boldness and stress responsiveness with the expression of related candidate genes. Boldness was determined in individual fish over two trials by measuring the latency to approach a novel object. Differences in plasma cortisol concentrations and the expression of eight novel candidate genes previously identified as being linked with divergent behaviours or stress were determined. Bold and shy individuals, approaching the object within 180 s or not approaching within 300 s respectively, were evident within each line, and this was linked with activity levels in the HR line. Post-stress plasma cortisol concentrations were significantly greater in the HR line compared with the LR line, and six of the eight tested genes were upregulated in the brains of LR fish compared with HR fish. However, no direct relationship between boldness and either stress responsiveness or gene expression was found, although clear differences in stress physiology and, for the first time, gene expression could be identified between the lines. This lack of correlation between physiological and molecular responses and behavioural variation within both lines highlights the complexity of the behavioural-physiological complex. Copyright © 2010 Elsevier Inc. All rights reserved.

To study the effect of Kangaroo Mother Care on pain response in preterm neonates and to determine the behavioral and physiological responses to painful stimuli in preterm neonates: a study from western Rajasthan.

PubMed

Choudhary, Mukesh; Dogiyal, Hemaram; Sharma, Deepak; Datt Gupta, Brahma; Madabhavi, Irappa; Choudhary, Jagveer Singh; Choudhary, Sushil Kumar

2016-03-01

To study the effect of Kangaroo Mother Care (KMC) on pain response in preterm neonates and to determine the behavioral and physiological responses to painful stimuli in preterm neonates. This was a single-blind cross over study in which total 140 neonates were enrolled. Pain stimulus was given in the form of heel-lance before and after giving KMC and data were recorded. The effect of KMC on heart rate variability was statistically significant in preterm (30-34 wks) and very low birth weight (1.0-1.5 kg) neonates. The mean fall in SpO2 from base line was less in KMC group as compared to without KMC group at 60 s (1.63% versus 2.22%) and 120 s (0.45% versus 2.22%). The mean duration of cry was less in the KMC group (15.05 s) as compared to without KMC group (24.82 s) and the difference was statistically significant (p < 0.05). The mean duration of cry was reduced by 36% in KMC group as compared to the without KMC group. The effect of KMC on pain scores (premature infant pain profile (PIPP)) were significantly lower after heel-lance in KMC at 60 s (p < 0.01). KMC is a most physiological, non-pharmacological and easy intervention that involves parents: to manage procedural pain that can be implemented for physiological or behavioral stability in their premature infants.

Biological satellite Kosmos-936

NASA Technical Reports Server (NTRS)

Vedeshin, L. A.

1978-01-01

A description is given of physiological experiments performed on the biological satellite Kosmos-936. Other experiments to determine the electrostatic and dielectric responses to the effects of cosmic radiation are discussed.

Does smooth muscle in an intact airway undergo length adaptation during a sustained change in transmural pressure?

PubMed

Ansell, Thomas K; McFawn, Peter K; McLaughlin, Robert A; Sampson, David D; Eastwood, Peter R; Hillman, David R; Mitchell, Howard W; Noble, Peter B

2015-03-01

In isolated airway smooth muscle (ASM) strips, an increase or decrease in ASM length away from its current optimum length causes an immediate reduction in force production followed by a gradual time-dependent recovery in force, a phenomenon termed length adaptation. In situ, length adaptation may be initiated by a change in transmural pressure (Ptm), which is a primary physiological determinant of ASM length. The present study sought to determine the effect of sustained changes in Ptm and therefore, ASM perimeter, on airway function. We measured contractile responses in whole porcine bronchial segments in vitro before and after a sustained inflation from a baseline Ptm of 5 cmH2O to 25 cmH2O, or deflation to -5 cmH2O, for ∼50 min in each case. In one group of airways, lumen narrowing and stiffening in response to electrical field stimulation (EFS) were assessed from volume and pressure signals using a servo-controlled syringe pump with pressure feedback. In a second group of airways, lumen narrowing and the perimeter of the ASM in situ were determined by anatomical optical coherence tomography. In a third group of airways, active tension was determined under isovolumic conditions. Both inflation and deflation reduced the contractile response to EFS. Sustained Ptm change resulted in a further decrease in contractile response, which returned to baseline levels upon return to the baseline Ptm. These findings reaffirm the importance of Ptm in regulating airway narrowing. However, they do not support a role for ASM length adaptation in situ under physiological levels of ASM lengthening and shortening. Copyright © 2015 the American Physiological Society.

Orphan Toxin OrtT (YdcX) of Escherichia coli Reduces Growth during the Stringent Response

DTIC Science & Technology

2015-01-29

antimicrobials trimethoprim and sulfamethoxazole; these antimicrobials induce the stringent response by inhibiting tetrahydrofolate synthesis...in the presence of both antimicrobials trimethoprim and sulfamethoxazole; these antimicrobials induce the stringent response by inhibiting...level [20]. Toxins 2015, 7 301 Despite these difficulties in determining physiological roles, TA systems are clearly phage inhibition systems

Morphological and Biological alteration of maize root architectures on drought stress

USDA-ARS?s Scientific Manuscript database

Drought tolerance is a complex agronomic trait and root characteristics logically play an important role in determining the response of plants to drought stress. Studies were conducted to investigate genotypic variations in morphological and physiological responses of roots to drought stress in corn...

Morphological and biological alteration of maize root architectures on drought stress

USDA-ARS?s Scientific Manuscript database

Drought tolerance is a complex agronomic trait and root characteristics logically play an important role in determining the response of plants to drought stress. Studies were conducted to investigate genotypic variations in morphological and physiological responses of roots to drought stress in corn...

Physiological responses of wild type and putrescine-overproducing transgenic cells of poplar to variations in the form and concentration of nitrogen in the medium

Treesearch

Rakesh Minocha; Jae Soon Lee; Stephanie Long; Pratiksha Bhatnagar; Subhash C. Minocha

2004-01-01

We determined: (a) the physiological consequences of overproduction of putrescine in transgenic poplar (Populus nigra x mnrimoviczir) cells expressing an omithine decarboxylase transgene; and (b) effects of variation in nitrogen (N) concentration of the medium on cellular polyamine concentration in transgenic and non-transgenic cells. Cells grown in...

The development of a whole-body algorithm

NASA Technical Reports Server (NTRS)

Kay, F. J.

1973-01-01

The whole-body algorithm is envisioned as a mathematical model that utilizes human physiology to simulate the behavior of vital body systems. The objective of this model is to determine the response of selected body parameters within these systems to various input perturbations, or stresses. Perturbations of interest are exercise, chemical unbalances, gravitational changes and other abnormal environmental conditions. This model provides for a study of man's physiological response in various space applications, underwater applications, normal and abnormal workloads and environments, and the functioning of the system with physical impairments or decay of functioning components. Many methods or approaches to the development of a whole-body algorithm are considered. Of foremost concern is the determination of the subsystems to be included, the detail of the subsystems and the interaction between the subsystems.

The stress response and exploratory behaviour in Yucatan minipigs (Sus scrofa): Relations to sex and social rank.

PubMed

Adcock, Sarah J J; Martin, Gerard M; Walsh, Carolyn J

2015-12-01

According to the coping styles hypothesis, an individual demonstrates an integrated behavioural and physiological response to environmental challenge that is consistent over time and across situations. Individual consistency in behavioural responses to challenge has been documented across the animal kingdom. Comparatively few studies, however, have examined inter-individual variation in the physiological response, namely glucocorticoid and catecholamine levels, the stress hormones secreted by the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, respectively. Variation in coping styles between individuals may be explained in part by differences in social rank and sex. Using 20 Yucatan minipigs (Sus scrofa) we: (1) investigated the existence of consistent inter-individual variation in exploratory behaviour and the hormonal stress response, and tested for correlations as predicted by the coping styles hypothesis; and (2) evaluated whether inter-individual behavioural and hormonal variation is related to social rank and sex. Salivary stress biomarkers (cortisol, alpha-amylase, chromogranin A) were assessed in the presence and absence of a stressor consisting of social isolation in a crate for 10 min. Principal components analysis on a set of behavioural variables revealed two traits, which we labelled exploratory tendency and neophobia. Neither exploratory tendency nor neophobia predicted the physiological stress response. Subordinate pigs exhibited higher catecholamine levels compared to dominant conspecifics. We observed sex differences in the repeatability of salivary stress markers and reactivity of the stress systems. The results do not provide support for the existence of behavioural-physiological coping styles in pigs. Sex is an important determinant of the physiological stress response and warrants consideration in research addressing behavioural and hormonal variation. Copyright © 2015 Elsevier Inc. All rights reserved.

Elite Youth Soccer Players' Physiological Responses, Time-Motion Characteristics, and Game Performance in 4 vs. 4 Small-Sided Games: The Influence of Coach Feedback.

PubMed

Brandes, Mirko; Elvers, Sebastian

2017-10-01

The purpose of this study was to determine the impact of mild vs. strongly pushed coach feedback on the physiological response, ratio of perceived exertion (RPE), and time-motion characteristics in soccer training with small-sided games (SSGs). Sixteen elite youth soccer players (aged 17.2 ± 0.7 years, V[Combining Dot Above]O2max 62.1 ± 3.8 ml·kg·min) played two 4 vs. 4 small-sided games each. In random order, the coach provided a mild, unobtrusive, or a strongly pushed feedback throughout the game. Physiological measurements included heart rate expressed in mean values and intensity zones, blood lactate concentration, and RPE. The distance traveled, number of sprints, and work:rest ratio were captured by global positioning systems at 5 Hz. Game performance, such as volume of play and efficacy index, was estimated using the Team Sports Assessment Procedure. No differences were found for the physiological response and time-motion characteristics, but effect sizes demonstrated an increase in RPE (+0.4, p = 0.27) and a decrease in game performance (e.g., volume of play, -2.5, p = 0.08) under pushed feedback. Although a pushed feedback raises RPE, it negatively affected the players' game performance, without necessarily provoking higher physiological responses. These results should help coaches to understand that modifying the type of feedback provided during SSG does not impact the physiological response if SSG are already played with high intensity but that the feedback affects RPE and game performance. To keep a better game performance, soccer coaches are encouraged to provide smooth feedback during SSG.

Calmodulin gene expression in response to mechanical wounding and Botrytis cinerea infection in tomato fruit

USDA-ARS?s Scientific Manuscript database

Calmodulin, a ubiquitous calcium sensor, plays an important role in decoding the stress-triggered intracellular calcium changes and regulates the functions of numerous target proteins involved in various physiological responses in plants. To determine the functional significance of calmodulin in fl...

Impact of arbuscular mycorrhizal fungi on maize physiology and biochemical response under variable nitrogen levels

USDA-ARS?s Scientific Manuscript database

Arbuscular mycorrhizal (AM) fungi are known for colonizing plant roots, transporting water and nutrients from the soil to the plant. Therefore, environmental conditions set mainly by soil water and nutrient levels are important determinants of AM function and host plant response. Mechanisms of nitro...

Gender differences in hypoxic acclimatization in cyclooxygenase-2-deficient mice.

PubMed

Xu, Kui; Sun, Xiaoyan; Benderro, Girriso F; Tsipis, Constantinos P; LaManna, Joseph C

2017-02-01

The aim of this study was to determine the effect of cyclooxygenase-2 (COX-2) gene deletion on the adaptive responses during prolonged moderate hypobaric hypoxia. Wild-type (WT) and COX-2 knockout (KO) mice of both genders (3 months old) were exposed to hypobaric hypoxia (~0.4 ATM) or normoxia for 21 days and brain capillary densities were determined. Hematocrit was measured at different time intervals; brain hypoxia-inducible factor -1 α (HIF-1 α ), angiopoietin 2 (Ang-2), brain erythropoietin (EPO), and kidney EPO were measured under normoxic and hypoxic conditions. There were no gender differences in hypoxic acclimatization in the WT mice and similar adaptive responses were observed in the female KO mice. However, the male KO mice exhibited progressive vulnerability to prolonged hypoxia. Compared to the WT and female KO mice, the male COX-2 KO mice had significantly lower survival rate and decreased erythropoietic and polycythemic responses, diminished cerebral angiogenesis, decreased brain accumulation of HIF-1 α , and attenuated upregulation of VEGF, EPO, and Ang-2 during hypoxia. Our data suggest that there are physiologically important gender differences in hypoxic acclimatization in COX-2-deficient mice. The COX-2 signaling pathway appears to be required for acclimatization in oxygen-limiting environments only in males, whereas female COX-2-deficient mice may be able to access COX-2-independent mechanisms to achieve hypoxic acclimatization. © 2017 Case Western Reserve University. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Androgen replacement for women.

PubMed Central

Basson, R.

1999-01-01

OBJECTIVES: To determine whether a postmenopausal syndrome comprising specific changes in sexual desire and response associated with low free testosterone exists. To determine whether this syndrome is ameliorated by testosterone replacement. QUALITY OF EVIDENCE: Literature documenting that replacement of physiological levels of testosterone is beneficial and safe is scant. Only one randomized prospective blinded study examines sexual outcome in detail. MAIN MESSAGE: Testosterone is an important metabolic and sex hormone produced by the ovary throughout life. The variable reduction in ovarian testosterone production coincident with menopause is sometimes associated with a syndrome of specific changes in sexual desire and sexual response. Estrogen deficiency also impairs sexual response, but its replacement will not improve and might exacerbate sexual symptoms from androgen loss. Diagnosis of androgen deficiency is clinical, based on accurate assessment of a woman's sexual status before and after menopause and only confirmed (rather than diagnosed) by a low level of free testosterone. Partial androgen replacement restores much of the sexual response and facilitates sexual desire that is triggered by external cues. Avoiding supraphysiological levels of testosterone lessens risk of masculinization. Avoiding alkylated testosterone lessens hepatic or lipid impairment. CONCLUSION: Further prospective randomized studies of replacement of physiological levels of testosterone in women with androgen deficiency syndrome are needed, using formulations of testosterone available in Canada. The consistency of sexual changes, the associated personal and relationship distress, together with our clinical experience of the gratifying response to physiological replacement, make further studies urgently needed. PMID:10509222

Effect of Wearing a Telemetry Jacket on Behavioral and Physiologic Parameters of Dogs in the Open‑Field Test

PubMed Central

Fish, Richard E; Foster, Melanie L; Gruen, Margaret E; Sherman, Barbara L; Dorman, David C

2017-01-01

Safety pharmacology studies in dogs often integrate behavioral assessments made using video recording with physiologic measurements collected by telemetry. However, whether merely wearing the telemetry vest affects canine behavior and other parameters has not been evaluated. This pilot study assessed the effect of a telemetry vest on behavioral and physiologic responses to an environmental stressor, the sounds of a thunderstorm, in Labrador retrievers. Dogs were assigned to one of 2 experimental groups (Vest and No-Vest, n = 8 dogs per group) by using a matched pairs design, with a previously determined, sound-associated anxiety score as the blocking variable. Dogs were individually retested with the same standardized sound stimulus (thunderstorm) in an open-field arena, and their behavioral responses were video recorded. Video analysis of locomotor activity and anxiety-related behavior and manual determination of heart rate and body temperature were performed; results were compared between groups. Vest wearing did not affect total locomotor activity or rectal body temperature but significantly decreased heart rate by 8% and overall mean anxiety score by 34% during open-field test sessions. Our results suggest that the use of telemetry vests in dogs influences the measurement of physiologic parameters and behaviors that are assessed in safety pharmacology studies. PMID:28724487

Effect of Wearing a Telemetry Jacket on Behavioral and Physiologic Parameters of Dogs in the Open-Field Test.

PubMed

Fish, Richard E; Foster, Melanie L; Gruen, Margaret E; Sherman, Barbara L; Dorman, Davidc C

2017-07-01

Safety pharmacology studies in dogs often integrate behavioral assessments made using video recording with physiologic measurements collected by telemetry. However, whether merely wearing the telemetry vest affects canine behavior and other parameters has not been evaluated. This pilot study assessed the effect of a telemetry vest on behavioral and physiologic responses to an environmental stressor, the sounds of a thunderstorm, in Labrador retrievers. Dogs were assigned to one of 2 experimental groups (Vest and No-Vest, n = 8 dogs per group) by using a matched pairs design, with a previously determined, sound-associated anxiety score as the blocking variable. Dogs were individually retested with the same standardized sound stimulus (thunderstorm) in an open-field arena, and their behavioral responses were video recorded. Video analysis of locomotor activity and anxiety-related behavior and manual determination of heart rate and body temperature were performed; results were compared between groups. Vest wearing did not affect total locomotor activity or rectal body temperature but significantly decreased heart rate by 8% and overall mean anxiety score by 34% during open-field test sessions. Our results suggest that the use of telemetry vests in dogs influences the measurement of physiologic parameters and behaviors that are assessed in safety pharmacology studies.

Effect of sildenafil on subjective and physiologic parameters of the female sexual response in women with sexual arousal disorder.

PubMed

Berman, J R; Berman, L A; Lin, H; Flaherty, E; Lahey, N; Goldstein, I; Cantey-Kiser, J

2001-01-01

Sexual dysfunction is a complaint of 30-50% of American women. Aside from hormone replacement therapy, there are no current FDA-approved medical treatments for female sexual complaints. The goal of this pilot study was to determine safety and efficacy of sildenafil for use in women with sexual arousal disorder (SAD). Evaluations were completed on 48 women with complaints of SAD. Physiologic measurements, including genital blood flow, vaginal lubrication, intravaginal pressure-volume changes, and genital sensation were recorded pre- and postsexual stimulation at baseline and following 100 mg sildenafil. Subjective sexual function was assessed using a validated sexual function inventory at baseline and following 6 weeks of home use of sildenafil. At termination of the study patients also completed an intervention efficacy index (FIEI). Following sildenafil, poststimulation physiologic measurements improved significantly compared to baseline. Baseline subjective sexual function complaints, including low arousal, low desire, low sexual satisfaction, difficulty achieving orgasm, decreased vaginal lubrication, and dyspareunia also improved significantly following 6 weeks home use of sildenafil. Sildenafil appears to significantly improve both subjective and physiologic parameters of the female sexual response. Double-blind, placebo-controlled studies are currently in progress to further determine efficacy of this medication for treatment of female sexual dysfunction complaints in different populations of women.

Rain influences the physiological and metabolic responses to exercise in hot conditions.

PubMed

Ito, Ryo; Yamashita, Naoyuki; Suzuki, Eiko; Matsumoto, Takaaki

2015-01-01

Outdoor exercise often proceeds in rainy conditions. However, the cooling effects of rain on human physiological responses have not been systematically studied in hot conditions. The present study determined physiological and metabolic responses using a climatic chamber that can precisely simulate hot, rainy conditions. Eleven healthy men ran on a treadmill at an intensity of 70% VO2max for 30 min in the climatic chamber at an ambient temperature of 33°C in the presence (RAIN) or absence (CON) of 30 mm · h(-1) of precipitation and a headwind equal to the running velocity of 3.15 ± 0.19 m · s(-1). Oesophageal temperature, mean skin temperature, heart rate, rating of perceived exertion, blood parameters, volume of expired air and sweat loss were measured. Oesophageal and mean skin temperatures were significantly lower from 5 to 30 min, and heart rate was significantly lower from 20 to 30 min in RAIN than in CON (P < 0.05 for all). Plasma lactate and epinephrine concentrations (30 min) and sweat loss were significantly lower (P < 0.05) in RAIN compared with CON. Rain appears to influence physiological and metabolic responses to exercise in heat such that heat-induced strain might be reduced.

Vulnerability to predation and physiological stress responses of experimentally descaled juvenile Chinook salmon, Oncorhynchus tshawytscha

USGS Publications Warehouse

Gadomski, Dena M.; Mesa, Matthew G.; Olson, Todd M.

1994-01-01

Juvenile salmonids,Oncorhynchus spp., commonly encounter conditions (e.g., during hatchery release and dam passage) that result in damage to the skin, scale, and slime complex. We conducted laboratory experiments to determine if descaling of juvenile chinook salmon,O. tshawytscha, increased their vulnerability to predation, and to assess the physiological stress responses elicited by descaling. Salmon were experimentally descaled on either 10% or 20% of their total body area. When offered equal numbers of control and descaled juvenile chinook salmon, northern squawfish,Ptychocheilus oregonensis, did not consume significantly more of either prey type (48–60% of consumed prey were descaled). Juvenile chinook salmon descaled on 10% of their body area did show significant physiological stress responses, however. Mean concentrations of plasma cortisol peaked 1 h after descaling, and returned to control levels by 12 h. Plasma glucose peaked 3 h post-treatment and remained elevated for 24 h. Plasma lactate increased immediately following treatment and returned to undisturbed control levels by 3 h. The osmoregulatory response of plasma potassium was highly variable, but plasma sodium decreased immediately and remained low for 24 h. The observed physiological responses suggest that descaling of juvenile chinook salmon could result in decreased resistance to disease and other stressors encountered in the field, possibly leading to reduced performance capacity and lowered survival.

Transcriptomic response of sea urchin larvae Strongylocentrotus purpuratus to CO2-driven seawater acidification.

PubMed

Todgham, Anne E; Hofmann, Gretchen E

2009-08-01

Ocean acidification from the uptake of anthropogenic CO(2) is expected to have deleterious consequences for many calcifying marine animals. Forecasting the vulnerability of these marine organisms to climate change is linked to an understanding of whether species possess the physiological capacity to compensate for the potentially adverse effects of ocean acidification. We carried out a microarray-based transcriptomic analysis of the physiological response of larvae of a calcifying marine invertebrate, the purple sea urchin, Strongylocentrotus purpuratus, to CO(2)-driven seawater acidification. In lab-based cultures, larvae were raised under conditions approximating current ocean pH conditions (pH 8.01) and at projected, more acidic pH conditions (pH 7.96 and 7.88) in seawater aerated with CO(2) gas. Targeting expression of approximately 1000 genes involved in several biological processes, this study captured changes in gene expression patterns that characterize the transcriptomic response to CO(2)-driven seawater acidification of developing sea urchin larvae. In response to both elevated CO(2) scenarios, larvae underwent broad scale decreases in gene expression in four major cellular processes: biomineralization, cellular stress response, metabolism and apoptosis. This study underscores that physiological processes beyond calcification are impacted greatly, suggesting that overall physiological capacity and not just a singular focus on biomineralization processes is essential for forecasting the impact of future CO(2) conditions on marine organisms. Conducted on targeted and vulnerable species, genomics-based studies, such as the one highlighted here, have the potential to identify potential ;weak links' in physiological function that may ultimately determine an organism's capacity to tolerate future ocean conditions.

The use of multiple indices of physiological activity to access viability in chlorine disinfected Escherichia coli O157:H7

NASA Technical Reports Server (NTRS)

Lisle, J. T.; Pyle, B. H.; McFeters, G. A.

1999-01-01

A suite of fluorescent intracellular stains and probes was used, in conjunction with viable plate counts, to assess the effect of chlorine disinfection on membrane potential (rhodamine 123; Rh123 and bis-(1,3-dibutylbarbituric acid) trimethine oxonol; DiBAC4(3)), membrane integrity (LIVE/DEAD BacLight kit), respiratory activity (5-cyano-2,3-ditolyl tetrazolium chloride; CTC) and substrate responsiveness (direct viable counts; DVC) in the commensal pathogen Escherichia coli O157:H7. After a 5 min exposure to the disinfectant, physiological indices were affected in the following order: viable plate counts > substrate responsiveness > membrane potential > respiratory activity > membrane integrity. In situ assessment of physiological activity by examining multiple targets, as demonstrated in this study, permits a more comprehensive determination of the site and extent of injury in bacterial cells following sublethal disinfection with chlorine. This approach to assessing altered bacterial physiology has application in various fields where detection of stressed bacteria is of interest.

Magnetic resonance imaging and computerized tomography in malignant external otitis

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

Gherini, S.G.; Brackmann, D.E.; Bradley, W.G.

1986-05-01

In malignant external otitis (MEO), determining the anatomic extent of disease and evaluating the physiologic response to therapy remain a problem. Magnetic resonance imaging (MRI) has recently become available in limited clinical settings. Four patients with MEO were evaluated using MRI, computerized tomography (CT), technetium-99 (Tc-99) bone scanning, and gallium-67 citrate (Ga-67 citrate) scanning. MRI is superior to CT, Tc-99 bone scanning, and Ga-67 citrate scanning in evaluating the anatomic extent of soft tissue changes in MEO. MRI alone cannot be relied upon to determine the physiologic response to therapy. MRI can, however, serve as a valuable guide to themore » interpretation of Tc-99 bone and Ga-67 citrate scans, and in this respect, MRI is extremely useful in the treatment of MEO.« less

Cytokinin induces genome-wide binding of the type-B response regulator ARR10 to regulate growth and development in Arabidopsis

PubMed Central

Zubo, Yan O.; Blakley, Ivory Clabaugh; Yamburenko, Maria V.; Worthen, Jennifer M.; Street, Ian H.; Franco-Zorrilla, José M.; Zhang, Wenjing; Raines, Tracy; Kieber, Joseph J.; Loraine, Ann E.

2017-01-01

The plant hormone cytokinin affects a diverse array of growth and development processes and responses to the environment. How a signaling molecule mediates such a diverse array of outputs and how these response pathways are integrated with other inputs remain fundamental questions in plant biology. To this end, we characterized the transcriptional network initiated by the type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs) that mediate the cytokinin primary response, making use of chromatin immunoprecipitation sequencing (ChIP-seq), protein-binding microarrays, and transcriptomic approaches. By ectopic overexpression of ARR10, Arabidopsis lines hypersensitive to cytokinin were generated and used to clarify the role of cytokinin in regulation of various physiological responses. ChIP-seq was used to identify the cytokinin-dependent targets for ARR10, thereby defining a crucial link between the cytokinin primary-response pathway and the transcriptional changes that mediate physiological responses to this phytohormone. Binding of ARR10 was induced by cytokinin with binding sites enriched toward the transcriptional start sites for both induced and repressed genes. Three type-B ARR DNA-binding motifs, determined by use of protein-binding microarrays, were enriched at ARR10 binding sites, confirming their physiological relevance. WUSCHEL was identified as a direct target of ARR10, with its cytokinin-enhanced expression resulting in enhanced shooting in tissue culture. Results from our analyses shed light on the physiological role of the type-B ARRs in regulating the cytokinin response, mechanism of type-B ARR activation, and basis by which cytokinin regulates diverse aspects of growth and development as well as responses to biotic and abiotic factors. PMID:28673986

The Role Played by the Interaction between Genetic Factors and Attachment in the Stress Response in Infancy

ERIC Educational Resources Information Center

Frigerio, Alessandra; Ceppi, Elisa; Rusconi, Marianna; Giorda, Roberto; Raggi, Maria Elisabetta; Fearon, Pasco

2009-01-01

Background: The importance of understanding which environmental and biological factors are involved in determining individual differences in physiological response to stress is widely recognized, given the impact that stress has on physical and mental health. Methods: The child-mother attachment relationship and some genetic polymorphisms…

Yeast cell wall supplementation alters the performance and physiological response of beef heifers following an immune challenge

USDA-ARS?s Scientific Manuscript database

A study was designed to determine the effect of feeding yeast cell wall (YCW) products on the performance response and vaginal temperature of crossbred heifers following a subcutaneous endotoxin (lipopolysaccharide; LPS) challenge. Heifers (n=83; 225±9.4 kg) were obtained from commercial sale barns ...

A general enhancement of autonomic and cortisol responses during social evaluative threat.

PubMed

Bosch, Jos A; de Geus, Eco J C; Carroll, Douglas; Goedhart, Annebet D; Anane, Leila A; van Zanten, Jet J Veldhuizen; Helmerhorst, Eva J; Edwards, Kate M

2009-10-01

To examine the Social Self Preservation Theory, which predicts that stressors involving social evaluative threat (SET) characteristically activate the hypothalamic-pituitary-adrenal (HPA) axis. The idea that distinct psychosocial factors may underlie specific patterns of neuroendocrine stress responses has been a topic of recurrent debate. Sixty-one healthy university students (n = 31 females) performed a challenging speech task in one of three conditions that aimed to impose increasing levels of SET: performing the task alone (no social evaluation), with one evaluating observer, or with four evaluating observers. Indices of sympathetic (preejection period) and parasympathetic (heart rate variability) cardiac drive were obtained by impedance- and electrocardiography. Salivary cortisol was used to index HPA activity. Questionnaires assessed affective responses. Affective responses (shame/embarrassment, anxiety, negative affect, and self-esteem), cortisol, heart rate, sympathetic and parasympathetic activation all differentiated evaluative from nonevaluative task conditions (p < .001). The largest effect sizes were observed for cardiac autonomic responses. Physiological reactivity increased in parallel with increasing audience size (p < .001). An increase in cortisol was predicted by sympathetic activation during the task (p < .001), but not by affective responses. It would seem that SET determines the magnitude, rather than the pattern, of physiological activation. This potential to perturb broadly multiple physiological systems may help explain why social stress has been associated with a range of health outcomes. We propose a threshold-activation model as a physiological explanation for why engaging stressors, such as those involving social evaluation or uncontrollability, may seem to induce selectively cortisol release.

Physiologically grounded metrics of model skill: a case study estimating heat stress in intertidal populations

PubMed Central

Kish, Nicole E.; Helmuth, Brian; Wethey, David S.

2016-01-01

Models of ecological responses to climate change fundamentally assume that predictor variables, which are often measured at large scales, are to some degree diagnostic of the smaller-scale biological processes that ultimately drive patterns of abundance and distribution. Given that organisms respond physiologically to stressors, such as temperature, in highly non-linear ways, small modelling errors in predictor variables can potentially result in failures to predict mortality or severe stress, especially if an organism exists near its physiological limits. As a result, a central challenge facing ecologists, particularly those attempting to forecast future responses to environmental change, is how to develop metrics of forecast model skill (the ability of a model to predict defined events) that are biologically meaningful and reflective of underlying processes. We quantified the skill of four simple models of body temperature (a primary determinant of physiological stress) of an intertidal mussel, Mytilus californianus, using common metrics of model performance, such as root mean square error, as well as forecast verification skill scores developed by the meteorological community. We used a physiologically grounded framework to assess each model's ability to predict optimal, sub-optimal, sub-lethal and lethal physiological responses. Models diverged in their ability to predict different levels of physiological stress when evaluated using skill scores, even though common metrics, such as root mean square error, indicated similar accuracy overall. Results from this study emphasize the importance of grounding assessments of model skill in the context of an organism's physiology and, especially, of considering the implications of false-positive and false-negative errors when forecasting the ecological effects of environmental change. PMID:27729979

Sex differences in associations between insulin resistance, heart rate variability, and arterial stiffness in healthy women and men: a physiology study.

PubMed

Rannelli, Luke Anthony; MacRae, Jennifer M; Mann, Michelle C; Ramesh, Sharanya; Hemmelgarn, Brenda R; Rabi, Doreen; Sola, Darlene Y; Ahmed, Sofia B

2017-04-01

Diabetes confers greater cardiovascular risk to women than to men. Whether insulin-resistance-mediated risk extends to the healthy population is unknown. Measures of insulin resistance (fasting insulin, homeostatic model assessment, hemoglobin A1c, quantitative insulin sensitivity check index, glucose) were determined in 48 (56% female) healthy subjects. Heart rate variability (HRV) was calculated by spectral power analysis and arterial stiffness was determined using noninvasive applanation tonometry. Both were measured at baseline and in response to angiotensin II infusion. In women, there was a non-statistically significant trend towards increasing insulin resistance being associated with an overall unfavourable HRV response and increased arterial stiffness to the stressor, while men demonstrated the opposite response. Significant differences in the associations between insulin resistance and cardiovascular physiological profile exist between healthy women and men. Further studies investigating the sex differences in the pathophysiology of insulin resistance in cardiovascular disease are warranted.

A Multilevel Prediction of Physiological Response to Challenge: Interactions among Child Maltreatment, Neighborhood Crime, eNOS and GABRA6

PubMed Central

Lynch, Michael; Manly, Jody Todd; Cicchetti, Dante

2015-01-01

Physiological response to stress has been linked to variety of healthy and pathological conditions. The current study conducted a multilevel examination of interactions among environmental toxins – i.e., neighborhood crime and child maltreatment – and specific genetic polymorphisms of eNOS and GABRA6. A total of 186 children were recruited at age 4. At this time, the presence or absence of child maltreatment was determined, as was the amount of crime that occurred in their neighborhood during the previous year. At age 9, the children were brought to the lab where their physiological response to a cognitive challenge – i.e., change in the amplitude of RSA – was assessed and DNA samples were collected for subsequent genotyping. Results confirmed that complex G x G, E x E, and G x E interactions were associated with different patterns of RSA reactivity. The implications for future research and evidence-based intervention are discussed. PMID:26535938

The effects of autonomy support on salivary alpha-amylase: The role of individual differences.

PubMed

Sieber, Vanda; Schüler, Julia; Wegner, Mirko

2016-12-01

The empirical evidence for the relationship between autonomy-supportive environments and physiological stress is inconsistent. Whereas some studies report a decrease in stress in autonomy-supportive environments, other studies show a negative effect of autonomy on physiological stress. As previous research has not considered individual differences within this relationship, the present research aims to close this empirical gap by proposing that an implicit autonomy disposition, which is defined as a dispositional preference for self-determination, serves as a moderator. In an experiment, we tested whether the autonomy disposition moderates the effect of different teaching styles (controlling, autonomy-supportive, and neutral) on the acute physiological stress response (salivary alpha-amylase) in adolescents (N=69). The study revealed that participants with a high implicit autonomy disposition displayed lower salivary alpha-amylase responses when exposed to autonomy-supportive vignettes compared to when they were exposed to controlling or neutral teaching styles. The opposite pattern was found in students with a low implicit autonomy disposition. The results illustrate that experimentally induced variations in autonomy support lead to different physiological stress responses, depending on individual differences in the implicit autonomy disposition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Growth and physiological responses of some Capsicum frutescens varieties to copper stress

NASA Astrophysics Data System (ADS)

Jadid, Nurul; Maziyah, Rizka; Nurcahyani, Desy Dwi; Mubarokah, Nilna Rizqiyah

2017-06-01

Copper (Cu) is an essential micronutrient participating in various physiological processes. However, excessive uptake of this micronutrient could potentially affect plant growth and development as well as plant productivity. In this present work, growth and physiological responses of some Capsicum frustescens varieties to Cu stress were determined. Three C. frutescens varieties used in this work were var. Bara, CF 291, and Genie. In addition, these varieties were treated with different concentration of Cu (0, 30, 70, and 120 ppm). The growth and physiological responses measured in this work included plant height, root length, malondialdehyde (MDA), and chlorophyll. The result showed that all varieties tested relatively displayed plant growth reduction including plant height and root length. Likewise, an increase of MDA level, a major bioindicator for oxidative damage was also found in all varieties following exposure to elevated Cu concentration. Finally, the chlorophyll content was also affected indicated by a decreased amount of chlorophyll, especially in var. CF291. The overall results demonstrated that elevated Cu concentration might decrease C. frutescens productivity where among the three varieties tested, var CF 291 seemed to be the most sensitive varieties to Cu stress.

Physiological genomics of response to soil drying in diverse Arabidopsis accessions.

PubMed

Des Marais, David L; McKay, John K; Richards, James H; Sen, Saunak; Wayne, Tierney; Juenger, Thomas E

2012-03-01

Arabidopsis thaliana, like many species, is characterized by abundant genetic variation. This variation is rapidly being cataloged at the sequence level, but careful dissection of genetic variation in whole-organism responses to stresses encountered in the natural environment are lacking; this functional variation can be exploited as a natural mutant screen to determine gene function. Here, we document physiological and transcriptomic response to soil drying in 17 natural accessions of Arabidopsis. By imposing ecologically realistic stress conditions, we found that acclimation in Arabidopsis involved a strong signature of increased investment in photosynthesis, carbohydrate turnover, and root growth. Our results extend previous work in the Columbia accession suggesting that abscisic acid signaling pathways play an important role in drought stress response. We also identified several mechanisms, including an increase in leaf nitrogen concentration and upregulation of two-component signaling relays, that were common to most natural accessions but had not been identified in studies using only the Columbia accession. Principal component analysis reveals strong correlations between suites of genes and specific physiological responses to stress. The functional variants we identified may represent adaptive mutations in natural habitats and useful variants for agronomic improvement of crop species.

Physiological Genomics of Response to Soil Drying in Diverse Arabidopsis Accessions[W][OA

PubMed Central

Des Marais, David L.; McKay, John K.; Richards, James H.; Sen, Saunak; Wayne, Tierney; Juenger, Thomas E.

2012-01-01

Arabidopsis thaliana, like many species, is characterized by abundant genetic variation. This variation is rapidly being cataloged at the sequence level, but careful dissection of genetic variation in whole-organism responses to stresses encountered in the natural environment are lacking; this functional variation can be exploited as a natural mutant screen to determine gene function. Here, we document physiological and transcriptomic response to soil drying in 17 natural accessions of Arabidopsis. By imposing ecologically realistic stress conditions, we found that acclimation in Arabidopsis involved a strong signature of increased investment in photosynthesis, carbohydrate turnover, and root growth. Our results extend previous work in the Columbia accession suggesting that abscisic acid signaling pathways play an important role in drought stress response. We also identified several mechanisms, including an increase in leaf nitrogen concentration and upregulation of two-component signaling relays, that were common to most natural accessions but had not been identified in studies using only the Columbia accession. Principal component analysis reveals strong correlations between suites of genes and specific physiological responses to stress. The functional variants we identified may represent adaptive mutations in natural habitats and useful variants for agronomic improvement of crop species. PMID:22408074

Why do genotypes of Picea glauca differ in their growth response to elevated CO₂?

PubMed

Zhang, Junyan; Mycroft, Erin E; Adams, Greg; Reekie, Ed

2011-01-01

Meta-analyses reveal that fast-growing species have a greater growth response to elevated CO(2) than slow-growing species. It is unknown whether this is a direct response or whether inter-specific differences in growth are simply correlated with other physiological or morphological differences among species that affect the growth response to CO(2). Here we use intra-specific variation in Picea glauca to examine the mechanistic basis for this relationship. Relative growth rate (RGR) of 29 genotypes grown at ambient (370 µl l(-1)) or elevated (740 µl 1(-1)) CO(2) was measured. Physiological and morphological traits describing differences in allocation, canopy structure, stomatal function and photosynthesis were determined. Most variation in RGR (74%) was explained by traits associated with canopy structure. Although there was a strong correlation between RGR(740) and RGR(370), we found no evidence that genotypes that grew fast at ambient CO(2) had a greater relative growth response to CO(2). Given that the pattern found at the intra-specific level differed from that reported at the inter-specific level, our results suggest that RGR per se does not affect the growth response to CO(2). Rather, the CO(2) growth response is determined by traits that may or may not be correlated with RGR.

Light, time, and the physiology of biotic response to rapid climate change in animals.

PubMed

Bradshaw, William E; Holzapfel, Christina M

2010-01-01

Examination of temperate and polar regions of Earth shows that the nonbiological world is exquisitely sensitive to the direct effects of temperature, whereas the biological world is largely organized by light. Herein, we discuss the use of day length by animals at physiological and genetic levels, beginning with a comparative experimental study that shows the preeminent role of light in determining fitness in seasonal environments. Typically, at seasonally appropriate times, light initiates a cascade of physiological events mediating the input and interpretation of day length to the output of specific hormones that ultimately determine whether animals prepare to develop, reproduce, hibernate, enter dormancy, or migrate. The mechanisms that form the basis of seasonal time keeping and their adjustment during climate change are reviewed at the physiological and genetic levels. Future avenues for research are proposed that span basic questions from how animals transition from dependency on tropical cues to temperate cues during range expansions, to more applied questions of species survival and conservation biology during periods of climatic stress.

Delayed system response times affect immediate physiology and the dynamics of subsequent button press behavior.

PubMed

Kohrs, Christin; Hrabal, David; Angenstein, Nicole; Brechmann, André

2014-11-01

System response time research is an important issue in human-computer interactions. Experience with technical devices and general rules of human-human interactions determine the user's expectation, and any delay in system response time may lead to immediate physiological, emotional, and behavioral consequences. We investigated such effects on a trial-by-trial basis during a human-computer interaction by measuring changes in skin conductance (SC), heart rate (HR), and the dynamics of button press responses. We found an increase in SC and a deceleration of HR for all three delayed system response times (0.5, 1, 2 s). Moreover, the data on button press dynamics was highly informative since subjects repeated a button press with more force in response to delayed system response times. Furthermore, the button press dynamics could distinguish between correct and incorrect decisions and may thus even be used to infer the uncertainty of a user's decision. Copyright © 2014 Society for Psychophysiological Research.

Physiological parameter values in greyhounds before and after high-intensity exercise.

PubMed

Pellegrino, Francisco Javier; Risso, Analía; Vaquero, Pablo G; Corrada, Yanina A

2018-01-01

Dog sports competitions have greatly expanded. The availability of reference values for each type of activity could help assess fitness accurately. Heart rate (HR), blood lactate (BL) and rectal temperature (RT) are relevant physiological parameters to determine the dogs response to effort. Previous studies in greyhounds have reported the effect of high-intensity exercise on many physiological parameters immediately after completing different racing distances and recovery times. However, there are no studies concerning physiological changes over shorter racing distances. We therefore assessed the effect of sprint exercise on HR, BL and RT in nine greyhounds performing sprint exercise over a 100-m distance chasing a lure. After the exercise, dogs underwent a passive 10-min recovery phase. Before the exercise, immediately after it and at 5 and 10 min during recovery, HR and RT were assessed and blood samples were collected for BL determination. HR, BL and RT values increased significantly after the exercise (P<0.01). Whereas HR returned to pre-exercise values at 10 min during the recovery phase (P>0.1), BL concentration and RT remained increased (P<0.01). The abrupt increase in HR, BL and RT values observed immediately after the exercise indicates the high intensity of the effort performed. Similarly, BL concentration after the exercise exceeded the 4 mmol/L lactate threshold, suggesting a predominant anaerobic metabolism during effort. Although HR returned to pre-exercise values 10 min after the exercise, a more extensive recovery phase would be necessary for a total return to resting values, particularly for BL and RT. In greyhounds subjected to high-intensity exercise, HR, BL and RT were reliable physiological parameters to accurately assess the physiological response to effort. The use of sprint exercises over short racing distances could be useful for appropriately monitoring fitness in sporting dogs.

Isometric quadriceps strength determines sailing performance and neuromuscular fatigue during an upwind sailing emulation.

PubMed

Bourgois, Jan G; Callewaert, Margot; Celie, Bert; De Clercq, Dirk; Boone, Jan

2016-01-01

This study investigates the physiological responses to upwind sailing on a laser emulation ergometer and analyses the components of the physical profile that determine the physiological responses related to sailing level. Ten male high-level laser sailors performed an upwind sailing test, incremental cycling test and quadriceps strength test. During the upwind sailing test, heart rate (HR), oxygen uptake, ventilation, respiratory exchange ratio, rating of perceived exertion (RPE) and lactate concentration were measured, combined with near-infrared spectroscopy (NIRS) and electromyography (EMG) registration of the M. Vastus lateralis. Repeated measures ANOVA showed for the cardio-respiratory, metabolic and muscles responses (mean power frequency [MPF], root mean square [RMS], deoxy[Hb+Mb]) during the upwind sailing test an initial significant increase followed by a stabilisation, despite a constant increase in RPE. Stepwise regression analysis showed that better sailing level was for 46.5% predicted by lower MPF decrease. Lower MPF decrease was for 57.8% predicted by a higher maximal isometric quadriceps strength. In conclusion, this study indicates that higher sailing level was mainly determined by a lower rate of neuromuscular fatigue during the upwind sailing test (as indicated by MPF decrease). Additionally, the level of neuromuscular fatigue was mainly determined by higher maximal isometric quadriceps strength stressing the importance of resistance training in the planning of training.

Morphological and physiological responses of seagrasses (Alismatales) to grazers (Testudines: Cheloniidae) and the role of these responses as grazing patch abandonment cues.

PubMed

Lacey, Elizabeth A; Collado-Vides, Ligia; Fourqurean, James W

2014-12-01

Green sea turtles, Chelonia mydas, are grazers influencing the distribution of seagrass within shallow coastal ecosystems, yet the drivers behind C. mydas patch use within seagrass beds are largely unknown. Current theories center on food quality (nutrient content) as the plant responds to grazing disturbances; however, no study has monitored these parameters in a natural setting without grazer manipulation. To determine the morphological and physiological responses potentially influencing seagrass recovery from grazing disturbances, seagrasses were monitored for one year under three different grazing scenarios (turtle grazed, fish grazed and ungrazed) in a tropical ecosystem in Akumal Bay, Quintana Roo, Mexico. Significantly less soluble carbohydrates and increased nitrogen and phosphorus content in Thalassia testudinum were indicative of the stresses placed on seagrasses during herbivory. To determine if these physiological responses were the drivers of the heterogeneous grazing behavior by C. mydas recorded in Akumal Bay, patches were mapped and monitored over a six-month interval. The abandoned patches had the lowest standing crop rather than leaf nutrient or rhi- zome soluble carbohydrate content. This suggests a modified Giving Up Density (GUD) behavior: the critical threshold where cost of continued grazing does not provide minimum nutrients, therefore, new patches must be utilized, explains resource abandonment and mechanism behind C. mydas grazing. This study is the first to apply GUD theory, often applied in terrestrial literature, to explain marine herbivore grazing behavior.

Interspecies physiological variation as a tool for cross-species assessments of global warming-induced endangerment: validation of an intrinsic determinant of macroecological and phylogeographic structure.

PubMed

Bernardo, Joseph; Ossola, Ryan J; Spotila, James; Crandall, Keith A

2007-12-22

Global warming is now recognized as the dominant threat to biodiversity because even protected populations and habitats are susceptible. Nonetheless, current criteria for evaluating species' relative endangerment remain purely ecological, and the accepted conservation strategies of habitat preservation and population management assume that species can mount ecological responses if afforded protection. The insidious threat from climate change is that it will attenuate or preclude ecological responses by species that are physiologically constrained; yet, quantitative, objective criteria for assessing relative susceptibility of diverse taxa to warming-induced stress are wanting. We explored the utility of using interspecies physiological variation for this purpose by relating species' physiological phenotypes to landscape patterns of ecological and genetic exchange. Using a salamander model system in which ecological, genetic and physiological diversity are well characterized, we found strong quantitative relationships of basal metabolic rates (BMRs) to both macroecological and phylogeographic patterns, with decreasing BMR leading to dispersal limitation (small contemporary ranges with marked phylogeographic structure). Measures of intrinsic physiological tolerance, which vary systematically with macroecological and phylogeographic patterns, afford objective criteria for assessing endangerment across a wide range of species and should be incorporated into conservation assessment criteria that currently rely exclusively upon ecological predictors.

Rapid cooling after acute hyperthermia alters intestinal tissue morphology and increases the systemic inflammatory response in pigs

USDA-ARS?s Scientific Manuscript database

Acute hyperthermia can result in mortality if recovery is not appropriately managed. The study objective was to determine the effects of heatstroke recovery methods on the physiological response in pigs. In four repetitions, 36 male pigs (88.7 ± 1.6 kg BW) were exposed to thermoneutral conditions (T...

Habitat associations of the sagebrush lizard (Sceloporus graciosus): Potential responses of an ectotherm to ponderosa pine forest restoration treatments

Treesearch

Shawn C. Knox; Carol Chambers; Stephen S. Germaine

2001-01-01

Little is known about the response of ectotherms to ponderosa pine (Pinus ponderosa) restoration treatments. The ambient body temperature of an ectotherm affects its physiology, development, and behavior. Microhabitat availability and heterogeneity are critical factors in determining which thermoregulation choices are available to a terrestrial ectotherm (Stevenson...

Zinc source and concentration altered physiological responses of beef heifers during a combined viral-bacterial respiratory challenge

USDA-ARS?s Scientific Manuscript database

Three treatments were evaluated in feedlot heifers to determine the effects of zinc supplementation on the immune response to a combined viral-bacterial respiratory disease challenge. Thirty-two beef heifers (255+/-15 kg) were subjected to a 30d period of Zn depletion, then randomly assigned to one ...

Immediate effects of transcutaneous electrical stimulation on physiological swallowing effort in older versus young adults.

PubMed

Berretin-Felix, Giédre; Sia, Isaac; Barikroo, Ali; Carnaby, Giselle D; Crary, Michael A

2016-09-01

This study compared the immediate impact of different transcutaneous electrical stimulation (TES) amplitudes on physiological swallowing effort in healthy older adults versus young adults. Swallowing physiology changes with age. Reduced physiological swallowing effort in older adults including lower lingua-palatal and pharyngeal pressures may increase risk for swallowing dysfunction (i.e. dysphagia). Transcutaneous electrical stimulation (TES) has been advocated as an adjunctive modality to enhance outcomes in exercise-based therapy for individuals with dysphagia. However, significant variation in how TES is applied during therapy remains and the physiological swallowing response to TES is poorly studied, especially in older adults. Physiological change in swallowing associated with no stimulation, sensory stimulation and motor stimulation was compared in 20 young adults versus 14 older adults. Lingua-palatal and pharyngeal manometric pressures assessed physiological swallowing effort. Multivariate analyses identified interactions between age and stimulation amplitude on lingual and pharyngeal functions. Motor stimulation reduced anterior tongue pressure in both age groups but selectively reduced posterior lingua-palatal pressures in young adults only. Sensory stimulation increased base of tongue (BOT) pressures in older adults but decreased BOT pressures in young adults. Motor stimulation increased hypopharyngeal pressures in both groups. Age and TES level interact in determining immediate physiological responses on swallow performance. A one-size-fit-all approach to TES in dysphagia rehabilitation may be misdirected. © 2014 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

Mitigating Physiological Responses to Layoff Threat: An Experimental Test of the Efficacy of Two Coping Interventions

PubMed Central

Probst, Tahira M.; Jiang, Lixin

2016-01-01

The purpose of the current study was to assess real-time physiological reactions to the threat of layoffs and to determine whether the use of an emotion-focused vs. problem-focused coping intervention would be more efficacious in attenuating these physiological reactions. A 2 (coping intervention) × 4 (within-subjects time points) mixed experimental design was used to test the hypotheses. Eighty-four undergraduates participated in this laboratory experiment during which their galvanic skin response (GSR) and heart rate (HR) were continuously monitored. Analyses indicate that individuals instructed to utilize an emotion-focused coping strategy experienced a significantly greater decline in their GSR compared to those utilizing the problem-focused coping method. Results suggest organizations conducting layoffs might focus first on dealing with the emotional aftermath of downsizing before focusing on problem-solving tasks, such as resume writing and other traditional outplacement activities. PMID:26999186

Differential Activation of Pontomedullary Nuclei by Acid Perfusion of Different Regions of the Esophagus

PubMed Central

Lang, Ivan M.; Medda, Bidyut K.; Shaker, Reza

2010-01-01

The objective of this study was to determine the brain stem nuclei and physiological responses activated by esophageal acidification. The effects of perfusion of the cervical (ESOc), or thoracic (ESOt) esophagus with PBS or HCl on c-fos immunoreactivity of the brain stem or on physiological variables, and the effects of vagotomy were examined in anesthetized cats. We found that acidification of the ESOc increased the number of c-fos positive neurons in the area postrema (AP), vestibular nucleus (VN), parabrachial nucleus (PBN), nucleus ambiguus (NA), dorsal motor nucleus (DMN), and all subnuclei of the nucleus tractus solitarius (NTS), but one. Acidification of the ESOt activated neurons in the central (CE), caudal (CD), dorsomedial (DM), dorsolateral (DL), ventromedial (VM) subnuclei of NTS, and the DMN. Vagotomy blocked all c-fos responses to acid perfusion of the whole esophagus (ESOw). Perfusion of the ESOc or ESOt with PBS activated secondary peristalsis (2P), but had no effect on blood pressure, heart rate, or respiratory rate. Perfusion of the ESOc, but not ESOt, with HCL activated pharyngeal swallowing (PS), profuse salivation, or physiological correlates of emesis. Vagotomy blocked all physiological effects of ESOw perfusion. We conclude that acidification of the ESOc and ESOt activate different sets of pontomedullary nuclei and different physiological responses. The NTSce, NTScom, NTSdm, and DMN are associated with activation of 2P, the NTSim and NTSis, are associated with activation of PS, and the AP, VN, and PBN are associated with activation of emesis and perhaps nausea. All responses to esophageal fluid perfusion or acidification are mediated by the vagus nerves. PMID:20655885

A general enhancement of autonomic and cortisol responses during social evaluative threat

PubMed Central

Bosch, Jos A.; de Geus, Eco J.C.; Carroll, Douglas; Goedhart, Annebet D.; Anane, Leila A.; van Zanten, Jet J Veldhuizen; Helmerhorst, Eva J.; Edwards, Kate M.

2013-01-01

Objective The idea that distinct psychosocial factors may underlie specific patterns of neuroendocrine stress responses has been a topic of recurrent debate. We examined a recent contribution to this debate, the Social Self Preservation Theory, which predicts that stressors involving social evaluative threat (SET) characteristically activate the hypothalamic-pituitary-adrenal (HPA) axis. Methods Sixty-one healthy university students (31 females) performed a challenging speech task in one of three conditions that aimed to impose increasing levels of SET: performing the task alone (no social evaluation), with 1 evaluating observer, or with 4 evaluating observers. Indices of sympathetic (pre-ejection period) and parasympathetic (heart rate variability) cardiac drive were obtained by impedance- and electrocardiography. Salivary cortisol was used to index HPA activity. Questionnaires assessed affective responses. Results Affective responses (shame/embarrassment, anxiety, negative affect, and self-esteem), cortisol, heart rate, sympathetic, and parasympathetic activation all differentiated evaluative from non-evaluative task conditions (p<.001). The largest effect-sizes were observed for cardiac autonomic responses. Physiological reactivity increased in parallel with increasing audience size (p<.001). A rise in cortisol was predicted by sympathetic activation during the task (p<.001), but not by affective responses. Conclusion It would appear that SET determines the magnitude, rather than the pattern, of physiological activation. This potential to broadly perturb multiple physiological systems may help explain why social stress has been associated with a range of health outcomes. We propose a threshold-activation model as a physiological explanation for why engaging stressors, such as those involving social evaluation or uncontrollability, may appear to selectively induce cortisol release. PMID:19779143

Growth responses and ion accumulation in the halophytic legume Prosopis strombulifera are determined by Na2SO4 and NaCl.

PubMed

Reginato, M; Sosa, L; Llanes, A; Hampp, E; Vettorazzi, N; Reinoso, H; Luna, V

2014-01-01

Halophytes are potential gene sources for genetic manipulation of economically important crop species. This study addresses the physiological responses of a widespread halophyte, Prosopis strombulifera (Lam.) Benth to salinity. We hypothesised that increasing concentrations of the two major salts present in soils of central Argentina (Na2SO4, NaCl, or their iso-osmotic mixture) would produce distinct physiological responses. We used hydroponically grown P. strombulifera to test this hypothesis, analysing growth parameters, water relations, photosynthetic pigments, cations and anions. These plants showed a halophytic response to NaCl, but strong general inhibition of growth in response to iso-osmotic solutions containing Na2SO4. The explanation for the adaptive success of P. strombulifera in high NaCl conditions seems to be related to a delicate balance between Na(+) accumulation (and its use for osmotic adjustment) and efficient compartmentalisation in vacuoles, the ability of the whole plant to ensure sufficient K(+) supply by maintaining high K(+)/Na(+) discrimination, and maintenance of normal Ca(2+) levels in leaves. The three salt treatments had different effects on the accumulation of ions. Findings in bi-saline-treated plants were of particular interest, where most of the physiological parameters studied showed partial alleviation of SO4(2-)-induced toxicity by Cl(-). Thus, discussions on physiological responses to salinity could be further expanded in a way that more closely mimics natural salt environments. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Genetic and physiological bases for phenological responses to current and predicted climates

PubMed Central

Wilczek, A. M.; Burghardt, L. T.; Cobb, A. R.; Cooper, M. D.; Welch, S. M.; Schmitt, J.

2010-01-01

We are now reaching the stage at which specific genetic factors with known physiological effects can be tied directly and quantitatively to variation in phenology. With such a mechanistic understanding, scientists can better predict phenological responses to novel seasonal climates. Using the widespread model species Arabidopsis thaliana, we explore how variation in different genetic pathways can be linked to phenology and life-history variation across geographical regions and seasons. We show that the expression of phenological traits including flowering depends critically on the growth season, and we outline an integrated life-history approach to phenology in which the timing of later life-history events can be contingent on the environmental cues regulating earlier life stages. As flowering time in many plants is determined by the integration of multiple environmentally sensitive gene pathways, the novel combinations of important seasonal cues in projected future climates will alter how phenology responds to variation in the flowering time gene network with important consequences for plant life history. We discuss how phenology models in other systems—both natural and agricultural—could employ a similar framework to explore the potential contribution of genetic variation to the physiological integration of cues determining phenology. PMID:20819808

High temperature and performance in a flight task simulator.

DOT National Transportation Integrated Search

1972-05-01

The effects of high cockpit temperature on physiological responses and performance were determined on pilots in a general aviation simulator. The pilots (all instrument rated) 'flew' an instrument flight while exposed to each of three cockpit tempera...

Competitive active video games: Physiological and psychological responses in children and adolescents.

PubMed

Lisón, Juan F; Cebolla, Ausias; Guixeres, Jaime; Álvarez-Pitti, Julio; Escobar, Patricia; Bruñó, Alejandro; Lurbe, Empar; Alcañiz, Mariano; Baños, Rosa

2015-10-01

Recent strategies to reduce sedentary behaviour in children include replacing sedentary screen time for active video games. Active video game studies have focused principally on the metabolic consumption of a single player, with physiological and psychological responses of opponent-based multiplayer games to be further evaluated. To determine whether adding a competitive component to playing active video games impacts physiological and psychological responses in players. Sixty-two healthy Caucasian children and adolescents, nine to 14 years years of age, completed three conditions (8 min each) in random order: treadmill walking, and single and opponent-based Kinect active video games. Affect, arousal, rate of perceived exertion, heart rate and percentage of heart rate reserve were measured for each participant and condition. Kinect conditions revealed significantly higher heart rate, percentage of heart rate reserve, rate of perceived exertion and arousal when compared with treadmill walking (P<0.001). Opponent-based condition revealed lower values for the rate of perceived exertion (P=0.02) and higher affect (P=0.022) when compared with single play. Competitive active video games improved children's psychological responses (affect and rate of perceived exertion) compared with single play, providing a solution that may contribute toward improved adherence to physical activity.

Physiological and behavioural responses of young horses to hot iron branding and microchip implantation.

PubMed

Erber, R; Wulf, M; Becker-Birck, M; Kaps, S; Aurich, J E; Möstl, E; Aurich, C

2012-02-01

Branding is the traditional and well-established method used to mark horses, but recently microchip transponders for implantation have become available. In this study, behaviour, physiological stress variables and skin temperature in foals were determined in response to hot-iron branding (n=7) and microchip implantation (n=7). Salivary cortisol concentrations increased in response to branding (1.8 ± 0.2 ng/mL) and microchip implantation (1.4 ± 0.1ng/mL), but cortisol release over time did not differ. In response to both manipulations there was a transient increase in heart rate (P<0.001) and heart rate variability (P<0.01). Branding and microchip implantation induced a comparable aversive behaviour (branding, score 3.86 ± 0.85; microchip, score 4.00 ± 0.82). Both techniques thus caused similar physiological and behavioural changes indicative of stress. Acutely, implantation of a microchip was as stressful as branding in foals. Branding caused a necrotising skin burn lasting at least 7 days. Moreover branding, but not microchip implantation (P<0.001), was accompanied by a generalized increase in skin temperature which was comparable to low degree post-burn hypermetabolism in humans. Copyright © 2011 Elsevier Ltd. All rights reserved.

A comparison of physiological indicators of sublethal cadmium stress in wetland plants

USGS Publications Warehouse

Mendelssohn, I.A.; McKee, K.L.; Kong, T.

2001-01-01

Physiological indices, including photosynthesis, chlorophyll fluorescence, adenylate energy charge (AEC) ratio, and leaf reflectance, were determined for Typha domingensis and Spartina alterniflora in response to increasing concentrations of Cd and compared with the growth responses of these species. Leaf expansion, the live/total ratio of plant aboveground biomass, and the aboveground regrowth rate after the initial harvests were significantly reduced with increasing Cd concentration in the growth medium. Of the four physiological responses measured, only photosynthesis and AEC responded to the Cd treatment before damage was visually apparent. Also, these indices were significantly correlated with leaf expansion rate and live/total ratio in most instances. Except at the end of the experiment, when the most stressed plants began to die, the Fv/Fm ratio was not significantly affected by the Cd treatment. The leaf spectral reflectance parameters showed no significant change during the entire treatment period. The significant correlation between the stress indicators and plant growth supported the findings that photosynthesis and AEC were the most responsive of the indicators tested, however, further research investigating other chlorophyll fluorescence and leaf reflectance parameters may demonstrate as well the value of these indicators in quantifying sublethal stress. ?? 2001 Elsevier Science B.V. All rights reserved.

The evolution of water balance in Glossina (Diptera: Glossinidae): correlations with climate.

PubMed

Kleynhans, Elsje; Terblanche, John S

2009-02-23

The water balance of tsetse flies (Diptera: Glossinidae) has significant implications for understanding biogeography and climate change responses in these African disease vectors. Although moisture is important for tsetse population dynamics, evolutionary responses of Glossina water balance to climate have been relatively poorly explored and earlier studies may have been confounded by several factors. Here, using a physiological and GIS climate database, we investigate potential interspecific relationships between traits of water balance and climate. We do so in conventional and phylogenetically independent approaches for both adults and pupae. Results showed that water loss rates (WLR) were significantly positively related to precipitation in pupae even after phylogenetic adjustment. Adults showed no physiology-climate correlations. Ancestral trait reconstruction suggests that a reduction in WLR and increased size probably evolved from an intermediate ancestral state and may have facilitated survival in xeric environments. The results of this study therefore suggest an important role for water balance physiology of pupae in determining interspecific variation and lend support to conclusions reached by early studies of tsetse physiology.

Physiological response to water immersion: a method for sport recovery?

PubMed

Wilcock, Ian M; Cronin, John B; Hing, Wayne A

2006-01-01

Recovery from exercise can be an important factor in performance during repeated bouts of exercise. In a tournament situation, where athletes may compete numerous times over a few days, enhancing recovery may provide a competitive advantage. One method that is gaining popularity as a means to enhance post-game or post-training recovery is immersion in water. Much of the literature on the ability of water immersion as a means to improve athletic recovery appears to be based on anecdotal information, with limited research on actual performance change. Water immersion may cause physiological changes within the body that could improve recovery from exercise. These physiological changes include intracellular-intravascular fluid shifts, reduction of muscle oedema and increased cardiac output (without increasing energy expenditure), which increases blood flow and possible nutrient and waste transportation through the body. Also, there may be a psychological benefit to athletes with a reduced cessation of fatigue during immersion. Water temperature alters the physiological response to immersion and cool to thermoneutral temperatures may provide the best range for recovery. Further performance-orientated research is required to determine whether water immersion is beneficial to athletes.

A systematic review of physiological reactivity to stimuli in autism.

PubMed

Lydon, Sinéad; Healy, Olive; Reed, Phil; Mulhern, Teresa; Hughes, Brian M; Goodwin, Matthew S

2016-12-01

The prevalence of abnormal behavioural responses to a variety of stimuli among individuals with autism has led researchers to examine whether physiological reactivity (PR) is typical in this population. This article reviewed studies assessing PR to sensory, social and emotional, and stressor stimuli in individuals with autism. Systematic searches of electronic databases identified 57 studies that met our inclusion criteria. Studies were analysed to determine: (a) participant characteristics; (b) physiological measures used; (c) PR to sensory, social and emotional or stressor stimuli; (d) the relation between PR and behavioural or psychological variables and (e) baseline physiological activity. A novel measure of methodological quality suitable for use with non-randomized, non-interventional, psychophysiological studies was also developed and applied. Individuals with autism were found to respond differently than typically developing controls in 78.6%, 66.7% and 71.4% of sensory, social and emotional, and stressor stimulus classes, respectively. However, this extant literature is characterized by variable and inconsistent findings, which do not appear to be accounted for by varying methodological quality, making it difficult to determine what specific factors differentiate individuals with autism who present with atypical PR from those who do not. Despite this uncertainty, individual differences in PR are clearly present in autism, suggesting additional research is needed to determine the variables relating to PR among those with ASD and to examine the possible existence of physiological subtype responders in the population.

The Impact of Heat Exposure and Sleep Restriction on Firefighters' Work Performance and Physiology during Simulated Wildfire Suppression.

PubMed

Vincent, Grace E; Aisbett, Brad; Larsen, Brianna; Ridgers, Nicola D; Snow, Rod; Ferguson, Sally A

2017-02-12

This study was designed to examine the effects of ambient heat on firefighters' physical task performance, and physiological and perceptual responses when sleep restricted during simulated wildfire conditions. Thirty firefighters were randomly allocated to the sleep restricted ( n = 17, SR; 19 °C, 4-h sleep opportunity) or hot and sleep restricted ( n = 13, HOT + SR; 33 °C, 4-h sleep opportunity) condition. Firefighters performed two days of simulated, intermittent, self-paced work circuits comprising six firefighting tasks. Heart rate, and core temperature were measured continuously. After each task, firefighters reported their rating of perceived exertion and thermal sensation. Effort sensation was also reported after each work circuit. Fluids were consumed ad libitum. Urine volume and urine specific gravity were analysed. Sleep was monitored using polysomnography. There were no differences between the SR and HOT + SR groups in firefighters' physiological responses, hydration status, ratings of perceived exertion, motivation, and four of the six firefighting tasks (charged hose advance, rake, hose rolling, static hose hold). Black out hose and lateral repositioning were adversely affected in the HOT + SR group. Working in hot conditions did not appear to consistently impair firefighters work performance, physiology, and perceptual responses. Future research should determine whether such findings remain true when individual tasks are performed over longer durations.

Differences in Perceived and Physiologic Genital Arousal Between Women With and Without Sexual Dysfunction.

PubMed

Handy, Ariel B; Stanton, Amelia M; Pulverman, Carey S; Meston, Cindy M

2018-01-01

Many sexual psychophysiologic studies have failed to find differences in physiologic genital arousal between women with and those without sexual dysfunction. However, differences in self-reported (ie, perceived) measures of genital responses between these 2 groups of women have been noted. To determine whether women with and without sexual dysfunction differ on measures of physiologic and perceived genital arousal based on type of analytic technique used, to explore differences in perceived genital arousal, and to assess the relation between physiologic and perceived genital arousal. Data from 5 studies (N = 214) were used in this analysis. Women were categorized into 3 groups: women with arousal-specific sexual dysfunction (n = 40), women with decreased sexual function (n = 72), and women who were sexually functional (n = 102). Women viewed an erotic film while their physiologic genital arousal was measured using a vaginal photoplethysmograph. After watching the film, women completed a self-report measure of perceived genital arousal. There were differences in vaginal pulse amplitude (VPA) levels and association of VPA with perceived genital sensations based on level of sexual function. Commonly used methods of analysis failed to identify significant differences in VPA among these groups of women. When VPA data were analyzed with hierarchical linear modeling, significant differences emerged. Notably, women with arousal-specific dysfunction exhibited lower VPA than sexually functional women at the beginning of the assessment. As the erotic film progressed, women with arousal-specific dysfunction became aroused at a faster rate than sexually functional women, and these 2 groups ultimately reached a similar level of VPA. Sexually functional women reported the highest levels of perceived genital responses among the 3 groups of women. No significant relation between VPA and perceived genital arousal emerged. Women's perception of their genital responses could play a role in women's experience of sexual dysfunction and might be more clinically relevant for women with sexual dysfunction than genital blood flow. This study's large sample is unique in sexual psychophysiology, and it strengthens the credibility of the findings. However, this study is limited in that arousal-specific dysfunction was determined with self-report measures, not by a clinician-administered assessment. These findings suggest distinct response trajectories in women with and without sexual dysfunction, and although perceived genital responses are important for women who are experiencing problems with arousal, they do not seem to be related to objective measures of physiologic arousal. Handy AB, Stanton AM, Pulverman CS, Meston CM. Differences in Perceived and Physiologic Genital Arousal Between Women With and Without Sexual Dysfunction. J Sex Med 2018;15:52-63. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

[Clinical exercise testing and the Fick equation: strategic thinking for optimizing diagnosis].

PubMed

Perrault, H; Richard, R

2012-04-01

This article examines the expected exercise-induced changes in the components of the oxygen transport system as described by the Fick equation with a view to enable a critical analysis of a standard incremental exercise test to identify normal and abnormal patterns of responses and generate hypotheses as to potential physiological and/or pathophysiological causes. The text reviews basic physiological principals and provides useful reminders of standard equations that serve to integrate circulatory, respiratory and skeletal muscle functions. More specifically, the article provides a conceptual and quantitative framework linking the exercise-induced increase in whole body oxygen uptake to central circulatory and peripheral circulatory factors with the view to establish the normalcy of response. Thus, the article reviews the exercise response to cardiac output determinants and provides qualitative and quantitative perspective bases for making assumptions on the peripheral circulatory factors and oxygen use. Finally, the article demonstrates the usefulness of exercise testing as an effective integrative physiological approach to develop clinical reasoning or verify pathophysiological outcomes. Copyright © 2012 SPLF. Published by Elsevier Masson SAS. All rights reserved.

The Act of Answering Questions Elicited Differentiated Responses in a Concealed Information Test.

PubMed

Otsuka, Takuro; Mizutani, Mitsuyoshi; Yagi, Akihiro; Katayama, Jun'ichi

2018-04-17

The concealed information test (CIT), a psychophysiological detection of deception test, compares physiological responses between crime-related and crime-unrelated items. In previous studies, whether the act of answering questions affected physiological responses was unclear. This study examined effects of both question-related and answer-related processes on physiological responses. Twenty participants received a modified CIT, in which the interval between presentation of questions and answering them was 27 s. Differentiated respiratory movements and cardiovascular responses between items were observed for both questions (items) and answers, while differentiated skin conductance response was observed only for questions. These results suggest that physiological responses to questions reflected orientation to a crime-related item, while physiological responses during answering reflected inhibition of psychological arousal caused by orienting. Regarding the CIT's accuracy, participants' perception of the questions themselves more strongly influenced physiological responses than answering them. © 2018 American Academy of Forensic Sciences.

Human physiological responses to cold exposure: Acute responses and acclimatization to prolonged exposure.

PubMed

Castellani, John W; Young, Andrew J

2016-04-01

Cold exposure in humans causes specific acute and chronic physiological responses. This paper will review both the acute and long-term physiological responses and external factors that impact these physiological responses. Acute physiological responses to cold exposure include cutaneous vasoconstriction and shivering thermogenesis which, respectively, decrease heat loss and increase metabolic heat production. Vasoconstriction is elicited through reflex and local cooling. In combination, vasoconstriction and shivering operate to maintain thermal balance when the body is losing heat. Factors (anthropometry, sex, race, fitness, thermoregulatory fatigue) that influence the acute physiological responses to cold exposure are also reviewed. The physiological responses to chronic cold exposure, also known as cold acclimation/acclimatization, are also presented. Three primary patterns of cold acclimatization have been observed, a) habituation, b) metabolic adjustment, and c) insulative adjustment. Habituation is characterized by physiological adjustments in which the response is attenuated compared to an unacclimatized state. Metabolic acclimatization is characterized by an increased thermogenesis, whereas insulative acclimatization is characterized by enhancing the mechanisms that conserve body heat. The pattern of acclimatization is dependent on changes in skin and core temperature and the exposure duration. Published by Elsevier B.V.

Psychological and physiological responses during an exam and their relation to personality characteristics.

PubMed

Spangler, G

1997-08-01

The aim of the study was to compare emotional and physiological responses to real and control examinations and to assess their relation to personality characteristics. Emotional responses were assessed by state anxiety and perceived stress. The assessment of physiological responses included the activity of the cardiac system (heart periods, vagal tone), the adrenocortical system (cortisol) and the immune system (immune globulin A, sIgA). Emotional and physiological responses of 23 students (12 males, 11 females) were assessed during an oral exam at the end of a basic course in psychology which was a prerequisite for the students' final exams. For the control condition physiological responses were assessed one week before the examination during a memory test. The findings of the study demonstrate different emotional and physiological response patterns to examinations as compared to the control condition. Heightened anxiety was observed only before the exam. Whereas within-situation physiological responses (higher heart periods, cortisol, and sIgA; lower vagal tone) were observed both under the exam and control condition, responses to exam condition indicated pre-exam anticipatory activation and post-exam restricted recovery responses. With regard to personality characteristics subjects with high ego-resiliency showed more flexible adaptation than subjects with low ego-resiliency both on the emotional level (anxiety down-regulation after exam) and on the physiological level (situation-specific responses, quick recovery). Subjects with high ego-control exhibited a lower physiological reactivity under both conditions, i.e. they seemed to maintain longer their control also on a physiological level independent of the type of situation.

Response of vegetation to carbon dioxide. Field studies of plant responses to elevated carbon dioxide levels 1984

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

NONE

1998-08-01

In the present study, CO{sub 2} enrichment has been applied to sweet potatoes and cowpeas in order to investigate its effect on their growth, physiology, and yield under field condition. Objectives were: (1) to establish at Tuskegee Institute the facilities for growing crops in the field under enriched CO{sub 2} atmospheric conditions; (2) to obtain field data on the morphological, physiological, biochemical, growth and yield responses of sweet potatoes and cowpeas to elevated levels of CO{sub 2}; (3) to determine the effects of elevated CO{sub 2} in the rate of nitrogen fixation of cowpeas; (4) to provide data for amore » generalized crop growth model for predicting yield of both sweet potatoes and cowpeas as a function of atmospheric CO{sub 2} enrichment.« less

Role of Coronary Myogenic Response in Pressure-Flow Autoregulation in Swine: A Meta-Analysis With Coronary Flow Modeling

PubMed Central

Dick, Gregory M.; Namani, Ravi; Patel, Bhavesh; Kassab, Ghassan S.

2018-01-01

Myogenic responses (pressure-dependent contractions) of coronary arterioles play a role in autoregulation (relatively constant flow vs. pressure). Publications on myogenic reactivity in swine coronaries vary in caliber, analysis, and degree of responsiveness. Further, data on myogenic responses and autoregulation in swine have not been completely compiled, compared, and modeled. Thus, it has been difficult to understand these physiological phenomena. Our purpose was to: (a) analyze myogenic data with standard criteria; (b) assign results to diameter categories defined by morphometry; and (c) use our novel multiscale flow model to determine the extent to which ex vivo myogenic reactivity can explain autoregulation in vivo. When myogenic responses from the literature are an input for our model, the predicted coronary autoregulation approaches in vivo observations. More complete and appropriate data are now available to investigate the regulation of coronary blood flow in swine, a highly relevant model for human physiology and disease. PMID:29875686

Clinically Relevant Levels of 4-Aminopyridine Strengthen Physiological Responses in Intact Motor Circuits in Rats, Especially After Pyramidal Tract Injury.

PubMed

Sindhurakar, Anil; Mishra, Asht M; Gupta, Disha; Iaci, Jennifer F; Parry, Tom J; Carmel, Jason B

2017-04-01

4-Aminopyridine (4-AP) is a Food and Drug Administration-approved drug to improve motor function in people with multiple sclerosis. Preliminary results suggest the drug may act on intact neural circuits and not just on demyelinated ones. To determine if 4-AP at clinically relevant levels alters the excitability of intact motor circuits. In anesthetized rats, electrodes were placed over motor cortex and the dorsal cervical spinal cord for electrical stimulation, and electromyogram electrodes were inserted into biceps muscle to measure responses. The motor responses to brain and spinal cord stimulation were measured before and for 5 hours after 4-AP administration both in uninjured rats and rats with a cut lesion of the pyramidal tract. Blood was collected at the same time as electrophysiology to determine drug plasma concentration with a goal of 20 to 100 ng/mL. We first determined that a bolus infusion of 0.32 mg/kg 4-AP was optimal: it produced on average 61.5 ± 1.8 ng/mL over the 5 hours after infusion. This dose of 4-AP increased responses to spinal cord stimulation by 1.3-fold in uninjured rats and 3-fold in rats with pyramidal tract lesion. Responses to cortical stimulation also increased by 2-fold in uninjured rats and up to 4-fold in the injured. Clinically relevant levels of 4-AP strongly augment physiological responses in intact circuits, an effect that was more robust after partial injury, demonstrating its broad potential in treating central nervous system injuries.

Biomarkers and Environmental Stress: Relevance of Cellular Responses in Determining Adverse Outcomes

EPA Science Inventory

Biomarkers are measurable changes in a biological system indicative of an interaction with a chemical, physical, or biological agent. Such changes can be molecular, biochemical, physiological, or histological and can be reflective of either xenobiotic exposures or effects. Molecu...

Anthocyanins are bioavailable in humans following an acute dose of cranberry juice

USDA-ARS?s Scientific Manuscript database

Research suggests that anthocyanins from berry fruit may affect a variety of physiological responses, including endothelial function, but little information is available regarding the pharmacokinetics of these flavonoids in humans. To determine the pharmacokinetics of cranberry anthocyanins a study ...

Oscillators entrained by food and the emergence of anticipatory timing behaviors

PubMed Central

SILVER, Rae; BALSAM, Peter

2011-01-01

Circadian rhythms are adjusted to the external environment by the light–dark cycle via the suprachiasmatic nucleus, and to the internal environment of the body by multiple cues that derive from feeding/fasting. These cues determine the timing of sleep/wake cycles and all the activities associated with these states. We suggest that numerous sources of temporal information, including hormonal cues such as corticoids, insulin, and ghrelin, as well as conditioned learned responses determined by the temporal relationships between photic and feeding/fasting signals, can determine the timing of regularly recurring circadian responses. We further propose that these temporal signals can act additively to modulate the pattern of daily activity. Based on such reasoning, we describe the rationale and methodology for separating the influences of these diverse sources of temporal information. The evidence indicates that there are individual differences in sensitivity to internal and external signals that vary over circadian time, time since the previous meal, time until the next meal, or with duration of food deprivation. All of these cues are integrated in sites and circuits modulating physiology and behavior. Individuals detect changes in internal and external signals, interpret those changes as “hunger,” and adjust their physiological responses and activity levels accordingly. PMID:21544255

Bed Rest and Orthostatic-Hypotensive Intolerance

NASA Technical Reports Server (NTRS)

Schneider, Suzanne M.

2000-01-01

Orthostatic tolerance may be defined as the ability of humans to maintain cerebral perfusion and consciousness upon movement from a supine or sitting position to the upright posture; for example, subjects can stand suddenly or be tilted to the head-up body position. Similar but not identical physiological responses can be induced by positive G(sub Z) (head to foot) acceleration or exposure to lower body negative pressure (LBNP). The objective is to suddenly shift blood to the lower body to determine how effectively cardiovascular and neural-hormonal compensatory responses react to maintain blood pressure. In the most precise method for measuring tolerance, individuals would be stressed until they faint (syncope). However, the potential consequences and discomforts of such a test usually prohibit such a procedure so that few investigators actually induce syncope. In a more common approach, subjects are exposed to a given level of stress, for example, head-up tilt for 15 min, and any increases in heart rate or decreases in blood pressure are interpreted as indicators of progress toward syncope. Presumably, the greater the perturbation of heart rate and blood pressure, the closer to "tolerance," i.e., point of unconsciousness. Another more appropriate approach is to induce a progressively increasing hypotensive stress until pre-determined physiological responses or pre-syncopal symptoms appear. The physiological criteria may include a sudden drop in systolic blood pressure (greater than 25 mm/min), a sudden drop in heart rate (greater than 15 beats/min), or a systolic blood pressure less than 70 mmHg. The most common pre-syncopal symptoms include lightheadedness, stomach awareness or distress, feelings of warmth, tingly skin, and light to profuse sweating. Usually a combination of physiological responses and symptoms occurs such that, on different days, the tolerance time to the same orthostatic protocol is reproducible for a given individual. The assumption is that by taking subjects to near fainting, one can determine their tolerance. This latter pre-syncopal approach is better for estimating orthostatic or hypotensive tolerance than the former measurement of heart rate and blood pressure responses to a given stress. There is considerable variability in individual responses to orthostasis. For example, some subjects are "heart-rate responders" and have a pronounced cardiovascular response similar to that when performing moderately hard aerobic exercise, whereas others may experience pre-syncopal symptoms with very little increase in heart rate. Some individuals have a slow, gradual fall in blood pressure to orthostasis, and others have little change in blood pressure until a sudden precipitous fall in pressure occurs just prior to fainting. With both tilt and LBNP tests there is a low correlation between heart-rate or blood-pressure responses to a sub-tolerance stress as a measure of pre-syncopal limited orthostatic-hypotensive tolerance.

Sexually different morphological, physiological and molecular responses of Fraxinus mandshurica flowers to floral development and chilling stress.

PubMed

Zhu, Zhu; Qi, Fenghui; Yan, Chaofu; Zhan, Yaguang

2016-02-01

Fraxinus mandshurica is considered a dioecious hardwood, and the temporal separation of the maturation of the male and female flowers is one reason that F. mandshurica has become an endangered species in China. Rainfall and low temperature influence pollen formation and dispersal and the blooming of female flowers. Therefore, low fertilization efficiency strongly influences the population of F. mandshurica. Nevertheless, few studies have investigated the sex-specific morphological, physiological and molecular differentiation of F. mandshurica during flowering and its responses to low temperature. In this study, we investigated the sexual differences in the morphological, physiological, and biochemical parameters of F. mandshurica during flowering and determined the physiological and biochemical parameters and expression levels of related genes in response to low-temperature stress induced by exposure to 4 °C (chilling stress) during pollen dispersal and fertilization. Our study supports the hypothesis that male flowers suffer more severe injuries while female flowers are more adaptable to environmental stress during flower development in F. mandshurica. The results showed higher physiological and biochemical levels of malondialdehyde, proline, and soluble sugar, as well as the expression of genes involved in calcium signaling, cold shock and DNA methylation in male flowers compared with female flowers, which suggested that male flowers suffer from more serious peroxidation than female flowers. In contrast, higher antioxidant capacity and FmaCAT expression were detected in female flowers, providing preliminary evidence that male flowers rapidly fade after pollination and further demonstrating that female flowers need a much stronger antioxidant enzyme system to maintain embryonic growth. Most peaks related to physiological and molecular responses were observed at 2-4 h and 8-10 h of exposure to chilling stress in the female and male flowers, respectively. This trend implies that female flowers have higher adaptability to low temperature during fertilization. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Estrogen receptors in neuropeptide Y neurons: at the crossroads of feeding and reproduction.

PubMed

Acosta-Martinez, Maricedes; Horton, Teresa; Levine, Jon E

2007-03-01

Hypothalamic neuropeptide Y (NPY) neurons function as physiological integrators in at least two different neuroendocrine systems - one governing feeding and the other controlling reproduction. Estrogen might modulate both systems by regulating NPY gene expression; it might reduce food intake by suppressing NPY expression, and evoke reproductive hormone surges by stimulating it. How can estrogen exert opposing effects in an ostensibly homogeneous NPY neuronal population? Recent work with immortalized NPY-producing cells suggests that the ratio of estrogen receptor alpha:estrogen receptor beta can determine the direction and temporal pattern of transcriptional responses to estrogen. Because this ratio might itself be physiologically regulated, these findings provide one explanation for multiple neuropeptidergic responses to a single steroid hormone.

Sex differences in physiological reactivity to acute psychosocial stress in adolescence.

PubMed

Ordaz, Sarah; Luna, Beatriz

2012-08-01

Females begin to demonstrate greater negative affective responses to stress than males in adolescence. This may reflect the concurrent emergence of underlying differences in physiological response systems, including corticolimbic circuitries, the hypothalamic-pituitary-adrenal axis (HPAA), and the autonomic nervous system (ANS). This review examines when sex differences in physiological reactivity to acute psychosocial stress emerge and the directionality of these differences over development. Indeed, the literature indicates that sex differences emerge during adolescence and persist into adulthood for all three physiological response systems. However, the directionality of the differences varies by system. The emerging corticolimbic reactivity literature suggests greater female reactivity, particularly in limbic regions densely innervated by gonadal hormone receptors. In contrast, males generally show higher levels of HPAA and ANS reactivity. We argue that the contrasting directionality of corticolimbic and peripheral physiological responses may reflect specific effects of gonadal hormones on distinct systems and also sex differences in evolved behavioral responses that demand different levels of peripheral physiological activation. Studies that examine both subjective reports of negative affect and physiological responses indicate that beginning in adolescence, females respond to acute stressors with more intense negative affect than males despite their comparatively lower peripheral physiological responses. This dissociation is not clearly explained by sex differences in the strength of the relationship between physiological and subjective responses. We suggest that females' greater subjective responsivity may instead arise from a greater activity in brain regions that translate stress responses to subjective awareness in adolescence. Future research directions include investigations of the role of pubertal hormones in physiological reactivity across all systems, examining the relationship of corticolimbic reactivity and negative affect, and sex differences in emotion regulation processes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sex differences in physiological reactivity to acute psychosocial stress in adolescence

PubMed Central

Ordaz, Sarah; Luna, Beatriz

2012-01-01

Summary Females begin to demonstrate greater negative affective responses to stress than males in adolescence. This may reflect the concurrent emergence of underlying differences in physiological response systems, including corticolimbic circuitries, the hypothalamic—pituitary— adrenal axis (HPAA), and the autonomic nervous system (ANS). This review examines when sex differences in physiological reactivity to acute psychosocial stress emerge and the directionality of these differences over development. Indeed, the literature indicates that sex differences emerge during adolescence and persist into adulthood for all three physiological response systems. However, the directionality of the differences varies by system. The emerging corti-colimbic reactivity literature suggests greater female reactivity, particularly in limbic regions densely innervated by gonadal hormone receptors. In contrast, males generally show higher levels of HPAA and ANS reactivity. We argue that the contrasting directionality of corticolimbic and peripheral physiological responses may reflect specific effects of gonadal hormones on distinct systems and also sex differences in evolved behavioral responses that demand different levels of peripheral physiological activation. Studies that examine both subjective reports of negative affect and physiological responses indicate that beginning in adolescence, females respond to acute stressors with more intense negative affect than males despite their comparatively lower peripheral physiological responses. This dissociation is not clearly explained by sex differences in the strength of the relationship between physiological and subjective responses. We suggest that females' greater subjective responsivity may instead arise from a greater activity in brain regions that translate stress responses to subjective awareness in adolescence. Future research directions include investigations of the role of pubertal hormones in physiological reactivity across all systems, examining the relationship of corticolimbic reactivity and negative affect, and sex differences in emotion regulation processes. PMID:22281210

Predictions of the Contribution of HCN Half-Maximal Activation Potential Heterogeneity to Variability in Intrinsic Adaptation of Spiral Ganglion Neurons.

PubMed

Boulet, Jason; Bruce, Ian C

2017-04-01

Spiral ganglion neurons (SGNs) exhibit a wide range in their strength of intrinsic adaptation on a timescale of 10s to 100s of milliseconds in response to electrical stimulation from a cochlear implant (CI). The purpose of this study was to determine how much of that variability could be caused by the heterogeneity in half-maximal activation potentials of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels, which are known to produce intrinsic adaptation. In this study, a computational membrane model of cat type I SGN was developed based on the Hodgkin-Huxley model plus HCN and low-threshold potassium (KLT) conductances in which the half-maximal activation potential of the HCN channel was varied and the response of the SGN to pulse train and paired-pulse stimulation was simulated. Physiologically plausible variation of HCN half-maximal activation potentials could indeed determine the range of adaptation on the timescale of 10s to 100s of milliseconds and recovery from adaptation seen in the physiological data while maintaining refractoriness within physiological bounds. This computational model demonstrates that HCN channels may play an important role in regulating the degree of adaptation in response to pulse train stimulation and therefore contribute to variable constraints on acoustic information coding by CIs. This finding has broad implications for CI stimulation paradigms in that cell-to-cell variation of HCN channel properties are likely to significantly alter SGN excitability and therefore auditory perception.

THE 1999 FRESNO PARTICULATE MATTER EXPOSURE STUDIES: COMPARISON OF COMMUNITY, OUTDOOR, AND RESIDENTIAL PM MASS MEASUREMENTS

EPA Science Inventory

Two collaborative studies have been conducted by the USEPA National Exposure Research Laboratory (NERL) and the National Health Effects and Ecological Research Laboratory (NHEERL) to determine personal exposures and physiological responses to particulate matter (PM) and gaseous...

A circuit for detection of interaural time differences in the nucleus laminaris of turtles.

PubMed

Willis, Katie L; Carr, Catherine E

2017-11-15

The physiological hearing range of turtles is approximately 50-1000 Hz, as determined by cochlear microphonics ( Wever and Vernon, 1956a). These low frequencies can constrain sound localization, particularly in red-eared slider turtles, which are freshwater turtles with small heads and isolated middle ears. To determine if these turtles were sensitive to interaural time differences (ITDs), we investigated the connections and physiology of their auditory brainstem nuclei. Tract tracing experiments showed that cranial nerve VIII bifurcated to terminate in the first-order nucleus magnocellularis (NM) and nucleus angularis (NA), and the NM projected bilaterally to the nucleus laminaris (NL). As the NL received inputs from each side, we developed an isolated head preparation to examine responses to binaural auditory stimulation. Magnocellularis and laminaris units responded to frequencies from 100 to 600 Hz, and phase-locked reliably to the auditory stimulus. Responses from the NL were binaural, and sensitive to ITD. Measures of characteristic delay revealed best ITDs around ±200 μs, and NL neurons typically had characteristic phases close to 0, consistent with binaural excitation. Thus, turtles encode ITDs within their physiological range, and their auditory brainstem nuclei have similar connections and cell types to other reptiles. © 2017. Published by The Company of Biologists Ltd.

Antimicrobial growth promoters modulate host responses in mice with a defined intestinal microbiota

PubMed Central

Brown, Kirsty; Zaytsoff, Sarah J. M.; Uwiera, Richard R. E.; Inglis, G. Douglas

2016-01-01

Antibiotics can promote growth in livestock (antimicrobial growth promoters, AGPs), however lack of knowledge regarding mechanisms has hampered the development of effective non-antibiotic alternatives. Antibiotics affect eukaryotic cells at therapeutic concentrations, yet effects of AGPs on host physiology are relatively understudied, partially due to the complexity of host-microorganism interactions within the gastrointestinal tract. To determine the direct effects of AGPs on the host, we generated Altered Schaedler Flora (ASF) mice, and administered chlortetracycline (CTC) and tylosin phosphate (TYL) in feed. Mice were challenged with Citrobacter rodentium to determine how AGPs alter host responses to physiological stress. Although CTC and TYL had inconsistent effects on the ASF taxa, AGPs protected mice from weight loss following C. rodentium inoculation. Mice treated with either CTC or TYL had lower expression of βd1 and Il17a in the intestine and had a robust induction of Il17a and Il10. Furthermore, AGP administration resulted in a lower hepatic expression of acute phase proteins (Saa1, Hp, and Cp) in liver tissue, and ameliorated C. rodentium-induced reductions in the expression of genes involved in lipogenesis (Hmgcl and Fabp1). Collectively, this indicates that AGPs directly affect host physiology, and highlights important considerations in the development of non-antibiotic alternatives. PMID:27929072

Mandibuloacral dysplasia: A premature ageing disease with aspects of physiological ageing.

PubMed

Cenni, Vittoria; D'Apice, Maria Rosaria; Garagnani, Paolo; Columbaro, Marta; Novelli, Giuseppe; Franceschi, Claudio; Lattanzi, Giovanna

2018-03-01

Mandibuloacral dysplasia (MAD) is a rare genetic condition characterized by bone abnormalities including localized osteolysis and generalized osteoporosis, skin pigmentation, lipodystrophic signs and mildly accelerated ageing. The molecular defects associated with MAD are mutations in LMNA or ZMPSTE24 (FACE1) gene, causing type A or type B MAD, respectively. Downstream of LMNA or ZMPSTE24 mutations, the lamin A precursor, prelamin A, is accumulated in cells and affects chromatin dynamics and stress response. A new form of mandibuloacral dysplasia has been recently associated with mutations in POLD1 gene, encoding DNA polymerase delta, a major player in DNA replication. Of note, involvement of prelamin A in chromatin dynamics and recruitment of DNA repair factors has been also determined under physiological conditions, at the border between stress response and cellular senescence. Here, we review current knowledge on MAD clinical and pathogenetic aspects and highlight aspects typical of physiological ageing. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Comparison of the physiological characteristics of transgenic insect-resistant cotton and conventional lines.

PubMed

Li, Xiaogang; Ding, Changfeng; Wang, Xingxiang; Liu, Biao

2015-03-04

The introduction of transgenic insect-resistant cotton into agricultural ecosystems has raised concerns regarding its ecological effects. Many studies have been conducted to compare the differences in characteristics between transgenic cotton and conventional counterparts. However, few studies have focused on the different responses of transgenic cotton to stress conditions, especially to the challenges of pathogens. The aim of this work is to determine the extent of variation in physiological characteristics between transgenic insect-resistant cotton and the conventional counterpart infected by cotton soil-borne pathogens. The results showed that the difference in genetic backgrounds is the main factor responsible for the effects on biochemical characteristics of transgenic cotton when incubating with cotton Fusarium oxysporum. However, genetic modification had a significantly greater influence on the stomatal structure of transgenic cotton than the effects of cotton genotypes. Our results highlight that the differences in genetic background and/or genetic modifications may introduce variations in physiological characteristics and should be considered to explore the potential unexpected ecological effects of transgenic cotton.

Simultaneous determination of shikimic acid, salicylic acid and jasmonic acid in wild and transgenic Nicotiana langsdorffii plants exposed to abiotic stresses.

PubMed

Scalabrin, Elisa; Radaelli, Marta; Capodaglio, Gabriele

2016-06-01

The presence and relative concentration of phytohormones may be regarded as a good indicator of an organism's physiological state. The integration of the rolC gene from Agrobacterium rhizogenes and of the rat glucocorticoid receptor (gr) in Nicotiana langsdorffii Weinmann plants has shown to determine various physiological and metabolic effects. The analysis of wild and transgenic N. langsdorffii plants, exposed to different abiotic stresses (high temperature, water deficit, and high chromium concentrations) was conducted, in order to investigate the metabolic effects of the inserted genes in response to the applied stresses. The development of a new analytical procedure was necessary, in order to assure the simultaneous determination of analytes and to obtain an adequately low limit of quantification. For the first time, a sensitive HPLC-HRMS quantitative method for the simultaneous determination of salicylic acid, jasmonic acid and shikimic acid was developed and validated. The method was applied to 80 plant samples, permitting the evaluation of plant stress responses and highlighting some metabolic mechanisms. Salicylic, jasmonic and shikimic acids proved to be suitable for the comprehension of plant stress responses. Chemical and heat stresses showed to induce the highest changes in plant hormonal status, differently affecting plant response. The potential of each genetic modification toward the applied stresses was marked and particularly the resistance of the gr modified plants was evidenced. This work provides new information in the study of N. langsdorffii and transgenic organisms, which could be useful for the further application of these transgenes. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Physiological falls risk assessment in older people with Alzheimer's disease.

PubMed

Lorbach, Edwina R; Webster, Kate E; Menz, Hylton B; Wittwer, Joanne E; Merory, John R

2007-01-01

Falls are common in people with Alzheimer's disease (AD). There is some evidence that deficits in vision, peripheral sensation, strength, reaction time and balance may be partly responsible for this increased risk. To determine the feasibility and test-retest reliability of a physiological test battery designed to assess falls risk [the Physiological Profile Assessment (PPA)] in people with AD, and to compare their PPA scores to age- and sex-matched controls. Twenty-one community-dwelling people with probable, mild to moderate AD aged 63-91 years, and 21 age- and sex-matched controls underwent the PPA tests and the Mini-Mental State Examination. All tests were then repeated in the AD group to determine test-retest reliability. Most of the PPA tests could be successfully administered to participants with AD. The AD group had a significantly higher overall falls risk score (t(40) = -2.41, p < 0.02), slower hand (t(40) = -4.86, p < 0.01) and foot reaction time (t(40) = -2.26, p < 0.05) and worse coordinated stability (t(40) = -2.40, p < 0.05) than the controls. Physiological falls risk assessment is feasible in older people with mild to moderate AD. Older people with AD demonstrate significant impairments in several physiological domains, particularly reaction time, compared to controls.

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.

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.

Characterization and Reduction of Cardiac- and Respiratory-Induced Noise as a Function of the Sampling Rate (TR) in fMRI

PubMed Central

Cordes, Dietmar; Nandy, Rajesh R.; Schafer, Scott; Wager, Tor D.

2014-01-01

It has recently been shown that both high-frequency and low-frequency cardiac and respiratory noise sources exist throughout the entire brain and can cause significant signal changes in fMRI data. It is also known that the brainstem, basal forebrain and spinal cord area are problematic for fMRI because of the magnitude of cardiac-induced pulsations at these locations. In this study, the physiological noise contributions in the lower brain areas (covering the brainstem and adjacent regions) are investigated and a novel method is presented for computing both low-frequency and high-frequency physiological regressors accurately for each subject. In particular, using a novel optimization algorithm that penalizes curvature (i.e. the second derivative) of the physiological hemodynamic response functions, the cardiac -and respiratory-related response functions are computed. The physiological noise variance is determined for each voxel and the frequency-aliasing property of the high-frequency cardiac waveform as a function of the repetition time (TR) is investigated. It is shown that for the brainstem and other brain areas associated with large pulsations of the cardiac rate, the temporal SNR associated with the low-frequency range of the BOLD response has maxima at subject-specific TRs. At these values, the high-frequency aliased cardiac rate can be eliminated by digital filtering without affecting the BOLD-related signal. PMID:24355483

The Impact of Heat Exposure and Sleep Restriction on Firefighters’ Work Performance and Physiology during Simulated Wildfire Suppression

PubMed Central

Vincent, Grace E.; Aisbett, Brad; Larsen, Brianna; Ridgers, Nicola D.; Snow, Rod; Ferguson, Sally A.

2017-01-01

This study was designed to examine the effects of ambient heat on firefighters’ physical task performance, and physiological and perceptual responses when sleep restricted during simulated wildfire conditions. Thirty firefighters were randomly allocated to the sleep restricted (n = 17, SR; 19 °C, 4-h sleep opportunity) or hot and sleep restricted (n = 13, HOT + SR; 33 °C, 4-h sleep opportunity) condition. Firefighters performed two days of simulated, intermittent, self-paced work circuits comprising six firefighting tasks. Heart rate, and core temperature were measured continuously. After each task, firefighters reported their rating of perceived exertion and thermal sensation. Effort sensation was also reported after each work circuit. Fluids were consumed ad libitum. Urine volume and urine specific gravity were analysed. Sleep was monitored using polysomnography. There were no differences between the SR and HOT + SR groups in firefighters’ physiological responses, hydration status, ratings of perceived exertion, motivation, and four of the six firefighting tasks (charged hose advance, rake, hose rolling, static hose hold). Black out hose and lateral repositioning were adversely affected in the HOT + SR group. Working in hot conditions did not appear to consistently impair firefighters work performance, physiology, and perceptual responses. Future research should determine whether such findings remain true when individual tasks are performed over longer durations. PMID:28208688

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure

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

Young, Philip R.; Eyeghe-Bickong, Hans A.; du Plessis, Kari

In this paper, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berrymore » stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Finally, taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries.« less

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure

DOE PAGES

Young, Philip R.; Eyeghe-Bickong, Hans A.; du Plessis, Kari; ...

2015-12-01

In this paper, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berrymore » stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Finally, taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries.« less

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure.

PubMed

Young, Philip R; Eyeghe-Bickong, Hans A; du Plessis, Kari; Alexandersson, Erik; Jacobson, Dan A; Coetzee, Zelmari; Deloire, Alain; Vivier, Melané A

2016-03-01

In this study, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) 'Sauvignon Blanc' berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berry stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries. © 2016 American Society of Plant Biologists. All Rights Reserved.

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure1

PubMed Central

du Plessis, Kari; Jacobson, Dan A.

2016-01-01

In this study, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berry stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries. PMID:26628747

Experiments and appropriate facilities for plant physiology research in space

NASA Astrophysics Data System (ADS)

Lork, W.

Light is a very essential parameter in a plant's life. Changing the quality and/or quantity of illumination will not only determine the further development (photomorphogenesis), but also effect spontaneous responses like curvatures (phototropism). But there are several still unknown links in the signal transduction chain from the perception of the light signals to the terminal response. It is known from ground-based experiments, that part of this signal transduction path is congruous with that of gravitational signals. Biosample is a technology development programme, which enables sophisticated experiments with whole plants in a microgravity environment. It allows complex sequences of gravitational- and light-stimuli with simultaneous recording of the plant's response (e.g. curvature of the stem) by video. This facility in union with new genetic mutants, which are less- or insensitive to light, gravity or both, are convenient tools for progress in plant physiology research.

Experimental lead poisoning in Turkey Vultures, Cathartes aura

USGS Publications Warehouse

Carpenter, J.W.; Pattee, O.H.; Fritts, S.H.; Rattner, B.A.; Wiemeyer, Stanley N.; Royle, J. Andrew; Smith, M.R.

2003-01-01

Lead-induced mortality appears to have been a major factor in the decline of the California condor, Gymnogyps californianus. We orally dosed turkey vultures (Cathartes aura) with BB-sized lead shot from January 1988 through July 1988 to determine physiological response (delta-aminolevulinic acid dehydratase inhibition, erythrocyte protoporphyrin levels, anemia), diagnostic tissue lead concentrations (blood, liver, and kidney), and comparative sensitivity of this species. Two turkey vultures died and two became so intoxicated they were euthanized. Overall, responses of measured parameters were comparable to other species exposed to lead although there was considerable individual variation. Survival time (143-211 days), even with the large number of shot and constant redosing, was much longer than reported for other species of birds, suggesting considerable tolerance by turkey vultures to the deleterious effects of lead ingestion. Based on these observations, turkey vultures appear to be poor models for assessing the risk of lead poisoning to California condors or predicting their physiological response.

[Human orgasm from the physiological perspective--part I].

PubMed

Gałecki, Piotr; Depko, Andrzej; Jedrzejewska, Sylwia; Talarowska, Monika

2012-07-01

Physiological phenomenon of sexuality occurring in both sexes that brings physical and mental satisfaction, and often affects the quality of life is an orgasm. The ability to experience regular orgasms affects relationship with partner. The definition of orgasm is not an easy task. The way of experiencing it is subjective, and the possibility of observing significantly reduced. Contemporary works on the phenomenon of orgasm are concentrated on several aspects: biological perspective (neurophysiological and biochemical determinants of orgasm), psychological perspective and on the differences in its course in both sexes. In sexology are two models of sexual response: a linear model of sexual response (by W. Masters and V. Johnson, and H. S. Kaplan) and the circular model of sexual response (created by R. Basson). The ability to experiencing an orgasm is inherent in men. In women, that phenomenon is acquired, is the consequence of further experience.

SNP analyses of postprandial responses in (an)orexigenic hormones and feelings of hunger reveal long-term physiological adaptations to facilitate homeostasis.

PubMed

den Hoed, M; Smeets, A J P G; Veldhorst, M A B; Nieuwenhuizen, A G; Bouwman, F G; Heidema, A G; Mariman, E C M; Westerterp-Plantenga, M S; Westerterp, K R

2008-12-01

The postprandial responses in (an)orexigenic hormones and feelings of hunger are characterized by large inter-individual differences. Food intake regulation was shown earlier to be partly under genetic control. This study aimed to determine whether the postprandial responses in (an)orexigenic hormones and parameters of food intake regulation are associated with single nucleotide polymorphisms (SNPs) in genes encoding for satiety hormones and their receptors. Peptide YY (PYY), glucagon-like peptide 1 and ghrelin levels, as well as feelings of hunger and satiety, were determined pre- and postprandially in 62 women and 41 men (age 31+/-14 years; body mass index 25.0+/-3.1 kg/m(2)). Dietary restraint, disinhibition and perceived hunger were determined using the three-factor eating questionnaire. SNPs were determined in the GHRL, GHSR, LEP, LEPR, PYY, NPY, NPY2R and CART genes. The postprandial response in plasma ghrelin levels was associated with SNPs in PYY (215G>C, P<0.01) and LEPR (326A>G and 688A>G, P<0.01), and in plasma PYY levels with SNPs in GHRL (-501A>C, P<0.05) and GHSR (477G>A, P<0.05). The postprandial response in feelings of hunger was characterized by an SNP-SNP interaction involving SNPs in LEPR and NPY2R (668A>G and 585T>C, P<0.05). Dietary restraint and disinhibition were associated with an SNP in GHSR (477G>A, P<0.05), and perceived hunger with SNPs in GHSR and NPY (477G>A and 204T>C, P<0.05). Part of the inter-individual variability in postprandial responses in (an)orexigenic hormones can be explained by genetic variation. These postprandial responses represent either long-term physiological adaptations to facilitate homeostasis or reinforce direct genetic effects.

Eccentric and concentric cardiac hypertrophy induced by exercise training: microRNAs and molecular determinants.

PubMed

Fernandes, T; Soci, U P R; Oliveira, E M

2011-09-01

Among the molecular, biochemical and cellular processes that orchestrate the development of the different phenotypes of cardiac hypertrophy in response to physiological stimuli or pathological insults, the specific contribution of exercise training has recently become appreciated. Physiological cardiac hypertrophy involves complex cardiac remodeling that occurs as an adaptive response to static or dynamic chronic exercise, but the stimuli and molecular mechanisms underlying transduction of the hemodynamic overload into myocardial growth are poorly understood. This review summarizes the physiological stimuli that induce concentric and eccentric physiological hypertrophy, and discusses the molecular mechanisms, sarcomeric organization, and signaling pathway involved, also showing that the cardiac markers of pathological hypertrophy (atrial natriuretic factor, β-myosin heavy chain and α-skeletal actin) are not increased. There is no fibrosis and no cardiac dysfunction in eccentric or concentric hypertrophy induced by exercise training. Therefore, the renin-angiotensin system has been implicated as one of the regulatory mechanisms for the control of cardiac function and structure. Here, we show that the angiotensin II type 1 (AT1) receptor is locally activated in pathological and physiological cardiac hypertrophy, although with exercise training it can be stimulated independently of the involvement of angiotensin II. Recently, microRNAs (miRs) have been investigated as a possible therapeutic approach since they regulate the translation of the target mRNAs involved in cardiac hypertrophy; however, miRs in relation to physiological hypertrophy have not been extensively investigated. We summarize here profiling studies that have examined miRs in pathological and physiological cardiac hypertrophy. An understanding of physiological cardiac remodeling may provide a strategy to improve ventricular function in cardiac dysfunction.

The Effects of Training on the Time Components of the Left Ventricle, and Cardiac Time Components: Sedentary versus Active Individuals.

ERIC Educational Resources Information Center

Plowman, Sharon Ann

A review of previous research was completed to determine (a) the response of the cardiac time components of the left ventricle to varying types and intensities of training programs, (b) the probable physiological explanations for these responses, and (c) the significance of the changes which did or did not occur. It was found that, at rest,…

Evidence for a novel functional role of astrocytes in the acute homeostatic response to high-fat diet intake in mice

PubMed Central

Buckman, Laura B.; Thompson, Misty M.; Lippert, Rachel N.; Blackwell, Timothy S.; Yull, Fiona E.; Ellacott, Kate L.J.

2014-01-01

Objective Introduction of a high-fat diet to mice results in a period of voracious feeding, known as hyperphagia, before homeostatic mechanisms prevail to restore energy intake to an isocaloric level. Acute high-fat diet hyperphagia induces astrocyte activation in the rodent hypothalamus, suggesting a potential role of these cells in the homeostatic response to the diet. The objective of this study was to determine physiologic role of astrocytes in the acute homeostatic response to high-fat feeding. Methods We bred a transgenic mouse model with doxycycline-inducible inhibition of NFkappaB (NFκB) signaling in astrocytes to determine the effect of loss of NFκB-mediated astrocyte activation on acute high-fat hyperphagia. ELISA was used to measure the levels of markers of astrocyte activation, glial-fibrillary acidic protein (GFAP) and S100B, in the medial basal hypothalamus. Results Inhibition of NFκB signaling in astrocytes prevented acute high-fat diet-induced astrocyte activation and resulted in a 15% increase in caloric intake (P < 0.01) in the first 24 h after introduction of the diet. Conclusions These data reveal a novel homeostatic role for astrocytes in the acute physiologic regulation of food intake in response to high-fat feeding. PMID:25685690

Evidence for a novel functional role of astrocytes in the acute homeostatic response to high-fat diet intake in mice.

PubMed

Buckman, Laura B; Thompson, Misty M; Lippert, Rachel N; Blackwell, Timothy S; Yull, Fiona E; Ellacott, Kate L J

2015-01-01

Introduction of a high-fat diet to mice results in a period of voracious feeding, known as hyperphagia, before homeostatic mechanisms prevail to restore energy intake to an isocaloric level. Acute high-fat diet hyperphagia induces astrocyte activation in the rodent hypothalamus, suggesting a potential role of these cells in the homeostatic response to the diet. The objective of this study was to determine physiologic role of astrocytes in the acute homeostatic response to high-fat feeding. We bred a transgenic mouse model with doxycycline-inducible inhibition of NFkappaB (NFκB) signaling in astrocytes to determine the effect of loss of NFκB-mediated astrocyte activation on acute high-fat hyperphagia. ELISA was used to measure the levels of markers of astrocyte activation, glial-fibrillary acidic protein (GFAP) and S100B, in the medial basal hypothalamus. Inhibition of NFκB signaling in astrocytes prevented acute high-fat diet-induced astrocyte activation and resulted in a 15% increase in caloric intake (P < 0.01) in the first 24 h after introduction of the diet. These data reveal a novel homeostatic role for astrocytes in the acute physiologic regulation of food intake in response to high-fat feeding.

Molecular, physiological and morphological analysis of waterlogging tolerance in clonal genotypes of Theobroma cacao L.

PubMed

Bertolde, Fabiana Zanelato; De Almeida, Alex-Alan Furtado; Corrêa, Ronan Xavier; Gomes, Fábio Pinto; Gaiotto, Fernanda Amato; Baligar, Virupax C; Loguercio, Leandro Lopes

2010-01-01

In soil, anoxia conditions generated by waterlogging induce changes in genetic, morphological and physiological processes, altering the growth and development of plants. Mass propagation of cacao (Theobroma cacao L.) plantlets (clones) is affected by waterlogging caused by heavy rains and irrigation methods used to induce rooting. An experiment was undertaken to assess the effects of a 45-day flooding (anoxia) on physiological and morphological traits of 35 elite cacao genotypes, aiming at potentially identifying those with greater tolerance to flooding of the growth substrate. Eighteen fluorochrome-labeled microsatellite (SSR) primer pairs were used to assess genetic variability among clones, with 248 alleles being amplified and used to calculate similarity coefficients. The resulting dendrogram indicated the presence of four major groups, in which two represented 60% and 31% of the genotypes tested. A general trend toward high levels of heterozygosity was also found for physiological and morphological traits. The survival index (IS) for flood tolerance observed varied from 30 to 96%. Clones TSA-654, TSA-656, TSA-792, CA-1.4, CEPEC-2009 and PH-17 showed an IS value above 94%, whereas CEPEC-2010, CEPEC-2002, CA-7.1 and VB-903 clones were those mostly affected by waterlogging, with IS value below 56%. All genotypes displayed lenticel and adventitious root formation in response to waterlogging, although with different intensities. To determine whether patterns of physiological response could be associated with tolerance to anoxia, a similarity-grouping analysis was performed using the ratio between waterlogged and control values obtained for a series of physiological variables assessed. No specific pattern of physiological and morphological responses to waterlogging was strictly associated with survival of plantlets. However, results revealed by the dendrogram suggest that absence of leaf chlorosis may be a proper trait to indicate cacao clones with higher survival rates under flooding conditions. Consequences of these findings are discussed in the context of developing improved strategies for mass production of clones from elite cacao genotypes.

Physiological responses to unvarying (steady) and 2-2-1 shifts : Miami International Flight Service Station.

DOT National Transportation Integrated Search

1985-02-01

Two types of shift rotation in the same air traffic facility were investigated in order to determine the relative advantages and disadvantages of nonrotating shift work (steady shift) and rotating shift work. The rotating shift work chosen for compar...

15 CFR 990.51 - Injury assessment-injury determination.

Code of Federal Regulations, 2011 CFR

2011-01-01

... natural resource service has occurred as a result of response actions or a substantial threat of a..., identify the nature of the injury. Potential categories of injury include, but are not limited to, adverse changes in: survival, growth, and reproduction; health, physiology and biological condition; behavior...

15 CFR 990.51 - Injury assessment-injury determination.

Code of Federal Regulations, 2010 CFR

2010-01-01

... natural resource service has occurred as a result of response actions or a substantial threat of a..., identify the nature of the injury. Potential categories of injury include, but are not limited to, adverse changes in: survival, growth, and reproduction; health, physiology and biological condition; behavior...

15 CFR 990.51 - Injury assessment-injury determination.

Code of Federal Regulations, 2013 CFR

2013-01-01

... natural resource service has occurred as a result of response actions or a substantial threat of a..., identify the nature of the injury. Potential categories of injury include, but are not limited to, adverse changes in: survival, growth, and reproduction; health, physiology and biological condition; behavior...

15 CFR 990.51 - Injury assessment-injury determination.

Code of Federal Regulations, 2014 CFR

2014-01-01

... natural resource service has occurred as a result of response actions or a substantial threat of a..., identify the nature of the injury. Potential categories of injury include, but are not limited to, adverse changes in: survival, growth, and reproduction; health, physiology and biological condition; behavior...

15 CFR 990.51 - Injury assessment-injury determination.

Code of Federal Regulations, 2012 CFR

2012-01-01

... natural resource service has occurred as a result of response actions or a substantial threat of a..., identify the nature of the injury. Potential categories of injury include, but are not limited to, adverse changes in: survival, growth, and reproduction; health, physiology and biological condition; behavior...

Behavioral, psycho-physiological and salivary cortisol modifications after short-term alprazolam treatment in patients with recent myocardial infarction.

PubMed

Pruneti, Carlo; Giusti, Mariarosa; Boem, Adriano; Luisi, Michele

2002-01-01

The aim of this study was to determine the behavioral and physiological effects of the central nervous system depressant alprazolam on a group of cardiac patients. Immediately after hospital discharge, the Crown and Crisp Experiential Index (CCEI) was administered, the salivary cortisol was detected and a psycho-physiological profile was recorded in 52 subjects who had suffered from myocardial infarction. Half of the subjects represented the experimental group and the remaining 26 individuals acted as a control group not undergoing treatment. The benzodiazepine alprazolam (0.25 mg) was administered twice daily to the treated group only. With the exception of the administration of the drug, all recruited subjects underwent the same clinical evaluation. The CCEI data of the treated group showed significant decreases for the following scales: free floating anxiety (p < 0.001), phobic anxiety (p < 0.01), somatic complaints (p < 0.05), and depression (p < 0.01). In the same group, with regard to the physiological parameters, the skin conductance response significantly decreased during the baseline phase (p < 0.01), and almost all parameters showed decreased values during mental stress test administration. Cortisol levels also decreased during the recovery phase of the psycho-physiological profile assessment. Alprazolam seems to be able to reduce sympathetic discharge and some stress-related behavioral and physiological responses. This could be of benefit for selected cardiac patients for whom increases in sympathetic tone may constitute a risk factor.

A multilevel prediction of physiological response to challenge: Interactions among child maltreatment, neighborhood crime, endothelial nitric oxide synthase gene (eNOS), and GABA(A) receptor subunit alpha-6 gene (GABRA6).

PubMed

Lynch, Michael; Manly, Jody Todd; Cicchetti, Dante

2015-11-01

Physiological response to stress has been linked to a variety of healthy and pathological conditions. The current study conducted a multilevel examination of interactions among environmental toxins (i.e., neighborhood crime and child maltreatment) and specific genetic polymorphisms of the endothelial nitric oxide synthase gene (eNOS) and GABA(A) receptor subunit alpha-6 gene (GABRA6). One hundred eighty-six children were recruited at age 4. The presence or absence of child maltreatment as well as the amount of crime that occurred in their neighborhood during the previous year were determined at that time. At age 9, the children were brought to the lab, where their physiological response to a cognitive challenge (i.e., change in the amplitude of the respiratory sinus arrhythmia) was assessed and DNA samples were collected for subsequent genotyping. The results confirmed that complex Gene × Gene, Environment × Environment, and Gene × Environment interactions were associated with different patterns of respiratory sinus arrhythmia reactivity. The implications for future research and evidence-based intervention are discussed.

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.

Physiological responses to an acute bout of sprint interval cycling.

PubMed

Freese, Eric C; Gist, Nicholas H; Cureton, Kirk J

2013-10-01

Sprint interval training has been shown to improve skeletal muscle oxidative capacity, V[Combining Dot Above]O2max, and health outcomes. However, the acute physiological responses to 4-7 maximal effort intervals have not been determined. To determine the V[Combining Dot Above]O2, cardiorespiratory responses, and energy expenditure during an acute bout of sprint interval cycling (SIC), health, college-aged subjects, 6 men and 6 women, completed 2 SIC sessions with at least 7 days between trials. Sprint interval cycling was performed on a cycle ergometer and involved a 5-minute warm-up followed by four 30-second all-out sprints with 4-minute active recovery. Peak oxygen uptake (ml·kg·min) during the 4 sprints were 35.3 ± 8.2, 38.8 ± 10.1, 38.8 ± 10.6, and 36.8 ± 9.3, and peak heart rate (b·min) were 164 ± 17, 172 ± 10, 177 ± 12, and 175 ± 22. We conclude that an acute bout of SIC elicits submaximal V[Combining Dot Above]O2 and cardiorespiratory responses during each interval that are above 80% of estimated maximal values. Although the duration of exercise in SIC is very short, the high level of V[Combining Dot Above]O2 and cardiorespiratory responses are sufficient to potentially elicit adaptations to training associated with elevated aerobic energy demand.

Physiological responses to dyadic interactions are influenced by neurotypical adults' levels of autistic and empathy traits.

PubMed

Truzzi, Anna; Setoh, Peipei; Shinohara, Kazuyuki; Esposito, Gianluca

2016-10-15

Autistic traits are distributed on a continuum that ranges from non-clinical to clinical condition. Atypical responses to social situations represent a core feature of the Autism Spectrum Disorders phenotype. Here, we hypothesize that atypical physiological responses to social stimuli may predict non-clinical autistic and empathy traits levels. We measured physiological responses (heart rate, facial temperature) of 40 adults (20F) while showing them 24 movies representing dyadic interactions. Autistic traits were assessed through Autism Quotient questionnaire (AQ), while empathy traits were measured using the Empathy Quotient questionnaire (EQ). Opposite correlations between AQ and EQ scores and physiological responses were found. Analysis of physiological responses revealed that individuals with better social abilities, low AQ and high EQ, show opposite activation patterns compared to people with high AQ and low EQ. Findings show that physiological responses could be biomarkers for people's autistic traits and social abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

Opportunities and constraints of presently used thermal manikins for thermo-physiological simulation of the human body.

PubMed

Psikuta, Agnes; Kuklane, Kalev; Bogdan, Anna; Havenith, George; Annaheim, Simon; Rossi, René M

2016-03-01

Combining the strengths of an advanced mathematical model of human physiology and a thermal manikin is a new paradigm for simulating thermal behaviour of humans. However, the forerunners of such adaptive manikins showed some substantial limitations. This project aimed to determine the opportunities and constraints of the existing thermal manikins when dynamically controlled by a mathematical model of human thermal physiology. Four thermal manikins were selected and evaluated for their heat flux measurement uncertainty including lateral heat flows between manikin body parts and the response of each sector to the frequent change of the set-point temperature typical when using a physiological model for control. In general, all evaluated manikins are suitable for coupling with a physiological model with some recommendations for further improvement of manikin dynamic performance. The proposed methodology is useful to improve the performance of the adaptive manikins and help to provide a reliable and versatile tool for the broad research and development domain of clothing, automotive and building engineering.

System and method for leveraging human physiological traits to control microprocessor frequency

DOEpatents

Shye, Alex; Pan, Yan; Scholbrock, Benjamin; Miller, J. Scott; Memik, Gokhan; Dinda, Peter A; Dick, Robert P

2014-03-25

A system and method for leveraging physiological traits to control microprocessor frequency are disclosed. In some embodiments, the system and method may optimize, for example, a particular processor-based architecture based on, for example, end user satisfaction. In some embodiments, the system and method may determine, for example, whether their users are satisfied to provide higher efficiency, improved reliability, reduced power consumption, increased security, and a better user experience. The system and method may use, for example, biometric input devices to provide information about a user's physiological traits to a computer system. Biometric input devices may include, for example, one or more of the following: an eye tracker, a galvanic skin response sensor, and/or a force sensor.

Repeated thermal stressor causes chronic elevation of baseline corticosterone and suppresses the physiological endocrine sensitivity to acute stressor in the cane toad (Rhinella marina).

PubMed

Narayan, Edward J; Hero, Jean-Marc

2014-04-01

Extreme environmental temperature could impact the physiology and ecology of animals. The stress endocrine axis provides necessary physiological stress response to acute (day-day) stressors. Presently, there are no empirical evidences showing that exposure to extreme thermal stressor could cause chronic stress in amphibians. This could also modulate the physiological endocrine sensitivity to acute stressors and have serious implications for stress coping in amphibians, particularly those living in fragmented and disease prone environments. We addressed this important question using the cane toad (Rhinella marina) model from its introduced range in Queensland, Australia. We quantified their physiological endocrine sensitivity to a standard acute (capture and handling) stressor after exposing the cane toads to thermal shock at 35°C for 30min daily for 34 days. Corticosterone (CORT) responses to the capture and handling protocol were measured on three sampling intervals (days 14, 24, and 34) to determine whether the physiological endocrine sensitivity was maintained or modulated over-time. Two control groups (C1 for baseline CORT measurement only and C2 acute handled only) and two temperature treatment groups (T1 received daily thermal shock up to day 14 only and a recovery phase of 20 days and T2 received thermal shock daily for 34 days). Results showed that baseline CORT levels remained high on day 14 (combined effect of capture, captivity and thermal stress) for both T1 and T2. Furthermore, baseline CORT levels decreased for T1 once the thermal shock was removed after day 14 and returned to baseline by day 29. On the contrary, baseline CORT levels kept on increasing for T2 over the 34 days of daily thermal shocks. Furthermore, the magnitudes of the acute CORT responses or physiological endocrine sensitivity were consistently high for both C1 and T1. However, acute CORT responses for T2 toads were dramatically reduced between days 24 and 34. These novel findings suggest that repeated exposure to extreme thermal stressor could cause chronic stress and consequently suppress the physiological endocrine sensitivity to acute stressors (e.g. pathogenic diseases) in amphibians. Copyright © 2014 Elsevier Ltd. All rights reserved.

An Integrative Model of Physiological Traits Can be Used to Predict Obstructive Sleep Apnea and Response to Non Positive Airway Pressure Therapy.

PubMed

Owens, Robert L; Edwards, Bradley A; Eckert, Danny J; Jordan, Amy S; Sands, Scott A; Malhotra, Atul; White, David P; Loring, Stephen H; Butler, James P; Wellman, Andrew

2015-06-01

Both anatomical and nonanatomical traits are important in obstructive sleep apnea (OSA) pathogenesis. We have previously described a model combining these traits, but have not determined its diagnostic accuracy to predict OSA. A valid model, and knowledge of the published effect sizes of trait manipulation, would also allow us to predict the number of patients with OSA who might be effectively treated without using positive airway pressure (PAP). Fifty-seven subjects with and without OSA underwent standard clinical and research sleep studies to measure OSA severity and the physiological traits important for OSA pathogenesis, respectively. The traits were incorporated into a physiological model to predict OSA. The model validity was determined by comparing the model prediction of OSA to the clinical diagnosis of OSA. The effect of various trait manipulations was then simulated to predict the proportion of patients treated by each intervention. The model had good sensitivity (80%) and specificity (100%) for predicting OSA. A single intervention on one trait would be predicted to treat OSA in approximately one quarter of all patients. Combination therapy with two interventions was predicted to treat OSA in ∼50% of patients. An integrative model of physiological traits can be used to predict population-wide and individual responses to non-PAP therapy. Many patients with OSA would be expected to be treated based on known trait manipulations, making a strong case for the importance of non-anatomical traits in OSA pathogenesis and the effectiveness of non-PAP therapies. © 2015 Associated Professional Sleep Societies, LLC.

Effects of work-related sleep restriction on acute physiological and psychological stress responses and their interactions: A review among emergency service personnel.

PubMed

Wolkow, Alexander; Ferguson, Sally; Aisbett, Brad; Main, Luana

2015-01-01

Emergency work can expose personnel to sleep restriction. Inadequate amounts of sleep can negatively affect physiological and psychological stress responses. This review critiqued the emergency service literature (e.g., firefighting, police/law enforcement, defense forces, ambulance/paramedic personnel) that has investigated the effect of sleep restriction on hormonal, inflammatory and psychological responses. Furthermore, it investigated if a psycho-physiological approach can help contextualize the significance of such responses to assist emergency service agencies monitor the health of their personnel. The available literature suggests that sleep restriction across multiple work days can disrupt cytokine and cortisol levels, deteriorate mood and elicit simultaneous physiological and psychological responses. However, research concerning the interaction between such responses is limited and inconclusive. Therefore, it is unknown if a psycho-physiological relationship exists and as a result, it is currently not feasible for agencies to monitor sleep restriction related stress based on psycho- physiological interactions. Sleep restriction does however, appear to be a major stressor contributing to physiological and psychological responses and thus, warrants further investigation. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Both Predator and Prey

PubMed Central

Löw, Andreas; Lang, Peter J.; Smith, J. Carson; Bradley, Margaret M.

2013-01-01

This research examined the psychophysiology of emotional arousal anticipatory to potentially aversive and highly pleasant outcomes. Human brain reactions (event-related potentials) and body reactions (heart rate, skin conductance, the probe startle reflex) were assessed along motivational gradients determined by apparent distance from sites of potential punishment or reward. A predator-prey survival context was simulated using cues that signaled possible money rewards or possible losses; the cues appeared to loom progressively closer to the viewer, until a final step when a rapid key response could ensure reward or avoid a punishing loss. The observed anticipatory response patterns of heightened vigilance and physiological mobilization are consistent with the view that the physiology of emotion is founded on action dispositions that evolved in mammals to facilitate survival by dealing with threats or capturing life-sustaining rewards. PMID:18947351

The ABA receptors -- we report you decide.

PubMed

McCourt, Peter; Creelman, Robert

2008-10-01

The plant hormone abscisic acid (ABA) has been implicated in a variety of physiological responses ranging from seed dormancy to stomatal conductance. Recently, three groups have reported the molecular identification of three disparate ABA receptors. Unlike the identification of other hormone receptors, in these three cases high affinity binding to ABA rather than the isolation of ABA insensitive mutants led to these receptor genes. Interestingly, two of the receptors encode genes involved in floral timing and chlorophyll biosynthesis, which are not considered traditional ABA responses. And the third receptor has been clouded in issues of its molecular identity. To clearly determine the roles of these genes in ABA perception it will require placing of these ABA-binding proteins into the rich ABA physiological context that has built up over the years.

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.

Enhancement of phytochemical using next generation technologies for the production of high quality fruits and vegetables

USDA-ARS?s Scientific Manuscript database

Tomato (Solanum lycopersicum L.) is an excellent plant model for unraveling physiological processes, fruit quality and fruit shelf determinants, stress responsive signaling, pathogenicity, and ripening development in climacteric fruits. Tomato is a popular vegetable, and along with potato, it is cla...

Sex Differences in Autonomic Correlates of Conduct Problems and Aggression

ERIC Educational Resources Information Center

Beauchaine, Theodore P.; Hong, James; Marsh, Penny

2008-01-01

The study aims to evaluate group differences in autonomic nervous system (ANS) responding between males and females with conduct problems and determine whether aggression accounts for variance in ANS responding over the effects of conduct problems. The results indicated marked differences in psycho-physiological responses between males and females.

Heat Stress in Feedlot Cattle.

USDA-ARS?s Scientific Manuscript database

The objective of this study was to determine if supplementing the diet of near-finished beef cattle with a yeast product would mitigate the negative impact of a controlled HS on the physiological and endocrine responses. Crossbred beef heifers (n=111; BW=281.07 kg) were divided into 2 pens in a comm...

Genetic Variations of Physiological Responses Following Heat Stress in Laying Hens

USDA-ARS?s Scientific Manuscript database

Heat stress (HS), also known as hyperthermia, is a major problem experienced by poultry during high-temperature conditions. The ability to manage the detrimental effects of HS can be attributed to many factors, including genetics. The objective of the present study was to determine the variation of ...

Interactive effects of dietary restraint and adiposity on stress-induced eating and the food choice of children

USDA-ARS?s Scientific Manuscript database

The Individual Differences Model posits that individual differences in physiological and psychological factors explain eating behaviors in response to stress. The purpose was to determine the effects of individual differences in adiposity, dietary restraint and stress reactivity on children's energy...

DCE-MRI defined subvolumes of a brain metastatic lesion by principle component analysis and fuzzy-c-means clustering for response assessment of radiation therapy

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

Farjam, Reza; Tsien, Christina I.; Lawrence, Theodore S.

Purpose: To develop a pharmacokinetic modelfree framework to analyze the dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) data for assessment of response of brain metastases to radiation therapy. Methods: Twenty patients with 45 analyzable brain metastases had MRI scans prior to whole brain radiation therapy (WBRT) and at the end of the 2-week therapy. The volumetric DCE images covering the whole brain were acquired on a 3T scanner with approximately 5 s temporal resolution and a total scan time of about 3 min. DCE curves from all voxels of the 45 brain metastases were normalized and then temporally aligned. Amore » DCE matrix that is constructed from the aligned DCE curves of all voxels of the 45 lesions obtained prior to WBRT is processed by principal component analysis to generate the principal components (PCs). Then, the projection coefficient maps prior to and at the end of WBRT are created for each lesion. Next, a pattern recognition technique, based upon fuzzy-c-means clustering, is used to delineate the tumor subvolumes relating to the value of the significant projection coefficients. The relationship between changes in different tumor subvolumes and treatment response was evaluated to differentiate responsive from stable and progressive tumors. Performance of the PC-defined tumor subvolume was also evaluated by receiver operating characteristic (ROC) analysis in prediction of nonresponsive lesions and compared with physiological-defined tumor subvolumes. Results: The projection coefficient maps of the first three PCs contain almost all response-related information in DCE curves of brain metastases. The first projection coefficient, related to the area under DCE curves, is the major component to determine response while the third one has a complimentary role. In ROC analysis, the area under curve of 0.88 ± 0.05 and 0.86 ± 0.06 were achieved for the PC-defined and physiological-defined tumor subvolume in response assessment. Conclusions: The PC-defined subvolume of a brain metastasis could predict tumor response to therapy similar to the physiological-defined one, while the former is determined more rapidly for clinical decision-making support.« less

DCE-MRI defined subvolumes of a brain metastatic lesion by principle component analysis and fuzzy-c-means clustering for response assessment of radiation therapy

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

Farjam, Reza; Tsien, Christina I.; Lawrence, Theodore S.

2014-01-15

Purpose: To develop a pharmacokinetic modelfree framework to analyze the dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) data for assessment of response of brain metastases to radiation therapy. Methods: Twenty patients with 45 analyzable brain metastases had MRI scans prior to whole brain radiation therapy (WBRT) and at the end of the 2-week therapy. The volumetric DCE images covering the whole brain were acquired on a 3T scanner with approximately 5 s temporal resolution and a total scan time of about 3 min. DCE curves from all voxels of the 45 brain metastases were normalized and then temporally aligned. Amore » DCE matrix that is constructed from the aligned DCE curves of all voxels of the 45 lesions obtained prior to WBRT is processed by principal component analysis to generate the principal components (PCs). Then, the projection coefficient maps prior to and at the end of WBRT are created for each lesion. Next, a pattern recognition technique, based upon fuzzy-c-means clustering, is used to delineate the tumor subvolumes relating to the value of the significant projection coefficients. The relationship between changes in different tumor subvolumes and treatment response was evaluated to differentiate responsive from stable and progressive tumors. Performance of the PC-defined tumor subvolume was also evaluated by receiver operating characteristic (ROC) analysis in prediction of nonresponsive lesions and compared with physiological-defined tumor subvolumes. Results: The projection coefficient maps of the first three PCs contain almost all response-related information in DCE curves of brain metastases. The first projection coefficient, related to the area under DCE curves, is the major component to determine response while the third one has a complimentary role. In ROC analysis, the area under curve of 0.88 ± 0.05 and 0.86 ± 0.06 were achieved for the PC-defined and physiological-defined tumor subvolume in response assessment. Conclusions: The PC-defined subvolume of a brain metastasis could predict tumor response to therapy similar to the physiological-defined one, while the former is determined more rapidly for clinical decision-making support.« less

Blood lactate thresholds and walking/running economy are determinants of backpack-running performance in trained soldiers.

PubMed

Simpson, Richard J; Graham, Scott M; Connaboy, Christopher; Clement, Richard; Pollonini, Luca; Florida-James, Geraint D

2017-01-01

We developed a standardized laboratory treadmill protocol for assessing physiological responses to a simulated backpack load-carriage task in trained soldiers, and assessed the efficacy of blood lactate thresholds (LTs) and economy in predicting future backpack running success over an 8-mile course in field conditions. LTs and corresponding physiological responses were determined in 17 elite British soldiers who completed an incremental treadmill walk/run protocol to exhaustion carrying 20 kg backpack load. Treadmill velocity at the breakpoint (r = -0.85) and Δ 1 mmol l(-1) (r = -0.80) LTs, and relative V˙O2 at 4 mmol l(-1) (r = 0.76) and treadmill walk/run velocities of 6.4 (r = 0.76), 7.4 (r = 0.80), 11.4 (r = 0.66) and 12.4 (r = 0.65) km h(-1) were significantly associated with field test completion time. We report for the first time that LTs and backpack walk/run economy are major determinants of backpack load-carriage performance in trained soldiers. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

2013-12-19

Physiological Responses of Belugas to "Stressors" to Aid in Assessing the Impact of Environmental and Anthropogenic Challenges on Health 5a. CONTRACT...ANSI Std.Z39.18 " DISTRIBUTION STATEMENT A. Approved for public release: distribution is unlimited. Investigation of the Physiological Responses... physiological i.e. neuroimmunoendocrino logical responses of beluga whales to "Stressors". "Stressor events" will allow for a better understanding and

Physiological Responses to Arm Activity in Individuals With Chronic Obstructive Pulmonary Disease Compared With Healthy Controls: A SYSTEMATIC REVIEW.

PubMed

Lima, Vanessa Pereira; Iamonti, Vinicius C; Velloso, Marcelo; Janaudis-Ferreira, Tania

The mechanisms underlying physiological limitations during arm activity in individuals with chronic obstructive pulmonary disease (COPD) are unknown. The objective of this systematic review was to describe cardiorespiratory responses, symptoms, chest wall kinematics, muscle activity, and lung volumes during arm activity in individuals with COPD relative to the responses of healthy controls. Original research articles that compared cardiorespiratory responses, symptoms, muscle activity, chest wall kinematics, and lung function during arm activity between individuals with COPD and healthy controls were identified after searches of 5 electronic databases and reference lists of pertinent articles. Two reviewers performed the electronic and manual searches with 1 screening title and abstracts. Two investigators screened the full texts to determine eligibility for inclusion. One reviewer performed the data extraction and tabulation using a standardized form with a second reviewer double-checking the data extracted. Of the 54 full-text articles assessed for eligibility, 6 met the inclusion criteria. Reduced cardiorespiratory responses during peak arm exercise in individuals with COPD compared with healthy controls were evident. Compared with healthy controls, individuals with COPD had increased dyspnea and hyperinflation during peak arm exercise. Increased effort of the trapezius muscle during arm activities was also found in persons with COPD compared with healthy controls. There is limited evidence describing physiological responses during arm activity in individuals with COPD. Findings of this systematic review suggest that individuals with COPD have decreased cardiorespiratory responses during peak arm exercise compared with controls but increased dyspnea, hyperinflation, and arm muscle effort.

The adenylate energy charge as a new and useful indicator of capture stress in chondrichthyans.

PubMed

Guida, Leonardo; Walker, Terence I; Reina, Richard D

2016-02-01

Quantifying the physiological stress response of chondrichthyans to capture has assisted the development of fishing practices conducive to their survival. However, currently used indicators of stress show significant interspecific and intraspecific variation in species' physiological responses and tolerances to capture. To improve our understanding of chondrichthyan stress physiology and potentially reduce variation when quantifying the stress response, we investigated the use of the adenylate energy charge (AEC); a measure of available metabolic energy. To determine tissues sensitive to metabolic stress, we extracted samples of the brain, heart, liver, white muscle and blood from gummy sharks (Mustelus antarcticus) immediately following gillnet capture and after 3 h recovery under laboratory conditions. Capture caused significant declines in liver, white muscle and blood AEC, whereas no decline was detected in the heart and brain AEC. Following 3 h of recovery from capture, the AEC of the liver and blood returned to "unstressed" levels (control values) whereas white muscle AEC was not significantly different to that immediately after capture. Our results show that the liver is most sensitive to metabolic stress and white muscle offers a practical method to sample animals non-lethally for determination of the AEC. The AEC is a highly informative indicator of stress and unlike current indicators, it can directly measure the change in available energy and thus the metabolic stress experienced by a given tissue. Cellular metabolism is highly conserved across organisms and, therefore, we think the AEC can also provide a standardised form of measuring capture stress in many chondrichthyan species.

Determination of torque-limits for human and cat lumbar spine specimens during displacement-controlled physiological motions.

PubMed

Ianuzzi, Allyson; Pickar, Joel G; Khalsa, Partap S

2009-01-01

Quadruped animal models have been validated and used as biomechanical models for the lumbar spine. The biomechanics of the cat lumbar spine has not been well characterized, even though it is a common model used in neuromechanical studies. Compare the physiological ranges of motion and determine torque-limits for cat and human lumbar spine specimens during physiological motions. Biomechanics study. Cat and human lumbar spine specimens. Intervertebral angle (IVA), joint moment, yield point, torque-limit, and correlation coefficients. Cat (L2-sacrum) and human (T12-sacrum) lumbar spine specimens were mechanically tested to failure during displacement-controlled extension (E), lateral bending (LB), and axial rotation (AR). Single trials consisted of 10 cycles (10mm/s or 5 degrees /s) to a target displacement where the magnitude of the target displacement was increased for subsequent trials until failure occurred. Whole-lumbar stiffness, torque at yield point, and joint stiffness were determined. Scaling relationships were established using equations analogous to those that describe the load response of elliptically shaped beams. IVA magnitudes for cat and human lumbar spines were similar during physiological motions. Human whole-lumbar and joint stiffness magnitudes were significantly greater than those for cat spine specimens (p<.05). Torque-limits were also greater for humans compared with cats. Scaling relationships with high correlation (R(2) greater than 0.77) were established during later LB and AR. The current study defined "physiological ranges of movement" for human and cat lumbar spine specimens during displacement-controlled testing, and should be observed in future biomechanical studies conducted under displacement control.

Physiological reactivity to phobic stimuli in people with fear of flying.

PubMed

Busscher, Bert; van Gerwen, Lucas J; Spinhoven, Philip; de Geus, Eco J C

2010-09-01

The nature of the relationship between physiological and subjective responses in phobic subjects remains unclear. Phobics have been thought to be characterized by a heightened physiological response (physiological perspective) or by a heightened perception of a normal physiological response (psychological perspective). In this study, we examined subjective measures of anxiety, heart rate (HR), and cardiac autonomic responses to flight-related stimuli in 127 people who applied for fear-of-flying therapy at a specialized treatment center and in 36 controls without aviophobia. In keeping with the psychological perspective, we found a large increase in subjective distress (eta(2)=.43) during exposure to flight-related stimuli in the phobics and no change in subjective distress in the controls, whereas the physiological responses of both groups were indiscriminate. However, in keeping with the physiological perspective, we found that, within the group of phobics, increases in subjective fear during exposure were moderately strong coupled to HR (r =.208, P=.022) and cardiac vagal (r =.199, P=.028) reactivity. In contrast to predictions by the psychological perspective, anxiety sensitivity did not modulate this coupling. We conclude that subjective fear responses and autonomic responses are only loosely coupled during mildly threatening exposure to flight-related stimuli. More ecologically valid exposure to phobic stimuli may be needed to test the predictions from the physiological and psychological perspectives. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Enhanced maximal exercise capacity, vasodilation to electrical muscle contraction, and hind limb vascular density in ASIC1a null mice.

PubMed

Drummond, Heather A; Xiang, Lusha; Chade, Alejandro R; Hester, Robert

2017-08-01

Acid-sensing ion channel (ASIC) proteins form extracellular proton-gated, cation-selective channels in neurons and vascular smooth muscle cells and are proposed to act as extracellular proton sensors. However, their importance to vascular responses under conditions associated with extracellular acidosis, such as strenuous exercise, is unclear. Therefore, the purpose of this study was to determine if one ASIC protein, ASIC1a, contributes to extracellular proton-gated vascular responses and exercise tolerance. To determine if ASIC1a contributes to exercise tolerance, we determined peak oxygen (O 2 ) uptake in conscious ASIC1a -/- mice during exhaustive treadmill running. Loss of ASIC1a was associated with a greater peak running speed (60 ± 2 vs. 53 ± 3 m·min -1 , P  = 0.049) and peak oxygen (O 2 ) uptake during exhaustive treadmill running (9563 ± 120 vs. 8836 ± 276 mL·kg -1 ·h -1 , n  = 6-7, P  = 0.0082). There were no differences in absolute or relative lean body mass, as determined by EchoMRI. To determine if ASIC1a contributes to vascular responses during muscle contraction, we measured femoral vascular conductance (FVC) during a stepwise electrical stimulation (0.5-5.0 Hz at 3 V for 60 sec) of the left major hind limb muscles. FVC increased to a greater extent in ASIC1a -/- versus ASIC1a +/+ mice (0.44 ± 0.03 vs. 0.30 ± 0.04 mL·min -1 ·100 g hind limb mass -1 · mmHg -1 , n  = 5 each, P  = 0.0009). Vasodilation following local application of external protons in the spinotrapezius muscle increased the duration, but not the magnitude, of the vasodilatory response in ASIC1a -/- mice. Finally, we examined hind limb vascular density using micro-CT and found increased density of 0-80  μ m vessels ( P  <   0.05). Our findings suggest an increased vascular density and an enhanced vasodilatory response to local protons, to a lesser degree, may contribute to the enhanced vascular conductance and increased peak exercise capacity in ASIC1a -/- mice. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Co-bedding as a Comfort measure For Twins undergoing painful procedures (CComForT Trial)

PubMed Central

2009-01-01

Background Co-bedding, a developmental care strategy, is the practice of caring for diaper clad twins in one incubator (versus separating and caring for each infant in separate incubators), thus creating the opportunity for skin-to-skin contact and touch between the twins. In studies of mothers and their infants, maternal skin-to-skin contact has been shown to decrease procedural pain response according to both behavioral and physiological indicators in very preterm neonates. It is uncertain if this comfort is derived solely from maternal presence or from stabilization of regulatory processes from direct skin contact. The intent of this study is to compare the comfort effect of co-bedding (between twin infants who are co-bedding and those who are not) on infant pain response and physiologic stability during a tissue breaking procedure (heelstick). Methods/Design Medically stable preterm twin infants admitted to the Neonatal Intensive Care Unit will be randomly assigned to a co-bedding group or a standard care group. Pain response will be measured by physiological and videotaped facial reaction using the Premature Infant Pain Profile scale (PIPP). Recovery from the tissue breaking procedure will be determined by the length of time for heart rate and oxygen saturation to return to baseline. Sixty four sets of twins (n = 128) will be recruited into the study. Analysis and inference will be based on the intention-to-treat principle. Discussion If twin contact while co-bedding is determined to have a comforting effect for painful procedures, then changes in current neonatal care practices to include co-bedding may be an inexpensive, non invasive method to help maintain physiologic stability and decrease the long term psychological impact of procedural pain in this high risk population. Knowledge obtained from this study will also add to existing theoretical models with respect to the exact mechanism of comfort through touch. Trial registration NCT00917631 PMID:20003351

Reactivity to low-flow as a potential determinant for brachial artery flow-mediated vasodilatation.

PubMed

Aizawa, Kunihiko; Elyas, Salim; Adingupu, Damilola D; Casanova, Francesco; Gooding, Kim M; Strain, W David; Shore, Angela C; Gates, Phillip E

2016-06-01

Previous studies have reported a vasoconstrictor response in the radial artery during a cuff-induced low-flow condition, but a similar low-flow condition in the brachial artery results in nonuniform reactivity. This variable reactivity to low-flow influences the subsequent flow-mediated dilatation (FMD) response following cuff-release. However, it is uncertain whether reactivity to low-flow is important in data interpretation in clinical populations and older adults. This study aimed to determine the influence of reactivity to low-flow on the magnitude of brachial artery FMD response in middle-aged and older individuals with diverse cardiovascular risk profiles. Data were analyzed from 165 individuals, divided into increased cardiovascular risk (CVR: n = 115, 85M, 67.0 ± 8.8 years) and healthy control (CTRL: n = 50, 30M, 63.2 ± 7.2 years) groups. Brachial artery diameter and blood velocity data obtained from Doppler ultrasound were used to calculate FMD, reactivity to low-flow and estimated shear rate (SR) using semiautomated edge-detection software. There was a significant association between reactivity to low-flow and FMD in overall (r = 0.261), CTRL (r = 0.410) and CVR (r = 0.189, all P < 0.05) groups. Multivariate regression analysis found that reactivity to low-flow, peak SR, and baseline diameter independently contributed to FMD along with sex, the presence of diabetes, and smoking (total R(2) = 0.450). There was a significant association between reactivity to low-flow and the subsequent FMD response in the overall dataset, and reactivity to low-flow independently contributed to FMD These findings suggest that reactivity to low-flow plays a key role in the subsequent brachial artery FMD response and is important in the interpretation of FMD data. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Physiological and behavioral responses to an exposure of pitch illusion in the simulator.

PubMed

Cheung, Bob; Hofer, Kevin; Heskin, Raquel; Smith, Andrew

2004-08-01

It has been suggested that a pilot's physiological and behavioral responses during disorientation can provide a real-time model of pilot state in order to optimize performance. We investigated whether there were consistent behavioral or physiological "markers" that can be monitored during a single episode of disorientation. An Integrated Physiological Trainer with a closed loop interactive aircraft control and point of gaze/eye-tracking device was employed. There were 16 subjects proficient in maintaining straight and level flight and with procedures in changing attitude who were exposed to yaw rotation and a brief head roll to 35 +/- 2 degrees. On return to upright head position, subjects were required to initiate either an ascent or descent to a prescribed attitude. BP, HR, skin conductance, eye movements, and point of gaze were monitored throughout the onset, duration, and immediately after the disorientation insult. Simultaneously, airspeed and power settings were recorded. Compared with the control condition, a significant increase (p < 0.01) in HR, HR variability, and mean arterial BP was observed during the disorientation. Flight performance decrement was reflected by a significant delay in setting power for attitude change and deviation in maintaining airspeed (p < 0.01). Changes in cardiovascular responses appear to be correlated with the onset of disorientation. The correlation of changing eye-tracking behavior and flight performance decrement is consistent with our previous findings. Further study is required to determine whether these findings can be extrapolated to repeated exposures and to other disorientation scenarios.

Effects of opioid- and non-opioid analgesics on responses to psychosocial stress in humans.

PubMed

Bershad, Anya K; Miller, Melissa A; Norman, Greg J; de Wit, Harriet

2018-06-01

Both preclinical and clinical evidence suggests that the endogenous opioid system is involved in responses to stress. For example, in animal models opioid agonists reduce isolation distress whereas opioid antagonists increase isolation distress. We recently reported that the mixed mu agonist and kappa antagonist buprenorphine dampened responses to acute psychosocial stress in humans. Now we extend this to study the effects of a pure mu-opioid agonist, hydromorphone, and a non-opioid analgesic, acetaminophen, on response to social stress. We compared the effect of hydromorphone (2 and 4 mg), acetaminophen (1000 mg) to a placebo using a between subject design. Healthy adult volunteers were randomly assigned to receive placebo (N = 13), 2 mg hydromorphone (N = 12), 4 mg hydromorphone (N = 12), or 1000 mg acetaminophen (paracetamol; N = 13) under double-blind conditions before undergoing a stress task or a control task on two separate sessions. The stress task, consisting of a standardized speaking task and the non-stressful control task were presented in counterbalanced order. Dependent measures included mood ratings, subjective appraisal of the stress (or no-stress) task, salivary cortisol, pupil diameter, heart rate, and blood pressure. The stress task produced its expected increase in heart rate, blood pressure, salivary cortisol, pupil diameter, and subjective ratings of anxiety and negative mood. Hydromorphone dose-dependently dampened cortisol responses to stress, and decreased ratings of how "challenging" participants found the task. Acetaminophen did not affect physiological responses, but, like hydromorphone, decreased ratings of how "challenging" the task was. The hydromorphone results support the idea that the mu-opioid system is involved in physiological responses to acute stress in humans, in line with results from preclinical studies. The non-opioid analgesic acetaminophen did not dampen physiological responses, but did reduce some components of psychological stress. It remains to be determined how both opioid and non-opioid systems mediate the complex physiological and psychological responses to social stress. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of copper on Mytilus californianus and Mytilus edulis. Annual report

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

Not Available

1980-06-06

Mytilus edulis and Mytilus californianus have come into widespread use as valuable test animals in estimating the effects and extent of copper pollution, both naturally as indicators and under simulated conditions as bioassays. These mussels are known bioaccumulators of heavy metals. They have a broad distribution, and mutually exclusive habitats. How the mussel reacts to copper is directly related to how copper affects the physiology of the mussel. The filtration rate and oxygen consumption of Mytilus are known to decline by more than 50% under exposure to as low as 200 ppB Cu in the water. Decline in heart ratemore » (bradycardia) also occurs under exposure to copper. Byssus thread production suffers in copper concentrations of 500 ppB and higher. The ability of M. edulis to close its valves in the presence of copper has been documented by several researchers. Of all the physiological parameters, oxygen consumption, heart rate, and valve closure are basic physiological functions which are easily measured. Mortality of Mytilus edulis is known to occur at concentrations of copper 330 ppB and higher within four to five days. It would be advantageous to have a continuous monitoring of the heart, oxygen consumption, and valve gape during this period to determine the state of each and the contribution of each to the possible death of the mussel. This study involves monitoring the three above physiological functions under varying concentrations of copper. In both species, M. edulis and M. californianus, detailed toxicological response records were obtained for each function. These records were then used to compare the physiological responses of each species to different levels of ambient copper in order to explain the possibility of repeatable, species-specific, response patterns to copper. (ERB)« less

Physiological, Behavioral, and Histological Responses of Male C57BL/6N Mice to Different CO2 Chamber Replacement Rates

PubMed Central

Boivin, Gregory P; Bottomley, Michael A; Dudley, Emily S; Schiml, Patricia A; Wyatt, Christopher N; Grobe, Nadja

2016-01-01

Rodent euthanasia with CO2 by using gradual displacement of 10% to 30% of the chamber volume per minute is considered acceptable by the AVMA Panel on Euthanasia. However, whether a 50% to 100% chamber replacement rate (CRR) of CO2 is more painful or distressful than 10% to 30% CRR is unclear. Therefore, we examined physiological and behavioral parameters, corticosterone and ACTH levels, and lung histology of mice euthanized at CRR of 15%, 30%, 50%, or 100%. Adult male C57BL/6N mice were euthanized at different CO2 CRR as physiological parameters were recorded telemetrically. Video recordings were reviewed to determine when the mouse first became ataxic, when it was fully recumbent (characterized by the mouse's nose resting on the cage floor), and when breathing stopped. Overall, CO2 euthanasia increased cardiovascular parameters and activity. Specific significant differences that were associated with 50% to 100% compared with 15% to 30% CO2 CRR included an increase in systolic blood pressure per second from initiation of CO2 until ataxia, a decrease in total diastolic blood pressure until ataxia, and a decrease in total heart rate until ataxia, immobility, and death. All physiological responses occurred more rapidly with higher CRR. Activity levels, behavioral responses, plasma adrenocorticotropic hormone and corticosterone levels, and lung pathology were not different between groups. We found no physiological, behavioral, or histologic evidence that 15% or 30% CO2 CRR is less painful or distressful than is 50% or 100% CO2 CRR. We conclude that 50% to 100% CO2 CRR is acceptable for euthanizing adult male C57BL/6N mice. PMID:27423153

Assessing the impact of thermal acclimation on physiological condition in the zebrafish model.

PubMed

Vergauwen, Lucia; Knapen, Dries; Hagenaars, An; De Boeck, Gudrun; Blust, Ronny

2013-01-01

The zebrafish has become a valuable vertebrate model organism in a wide range of scientific disciplines, but current information concerning the physiological temperature response of adult zebrafish is rather scarce. In this study, zebrafish were experimentally acclimated for 28 days to 18, 26 or 34 °C and a suite of non-invasive and invasive methods was applied to determine the thermal dependence of zebrafish physiological condition. With decreasing temperature, the metabolic rate of zebrafish decreased, as shown by the decreasing oxygen uptake and ammonia excretion rates, limiting the critical swimming speed, probably due to a decreased muscle fibre power output. In response to exercise, fuel stores were mobilized to the liver as shown by the increased hepatosomatic index, liver total absolute energetic value and liver carbohydrate concentration but due to the low metabolic rate they could not be adequately addressed to power swimming activity at 18 °C. Conversely, the increased metabolic performance at high temperature came with an increased metabolic cost resulting in decreased energy status reflected particularly well by the non-invasive condition factor and invasive measures of carcass protein concentration, carcass total absolute energetic value and liver carbohydrate concentration. We showed that the combined measurement of the relative condition factor and critical swimming speed is a powerful non-invasive tool for long-term follow-up studies. Invasive methods were redundant for measuring general energy status but they provided detailed information concerning metabolic reorganization. With this study we proved that the usefulness of the zebrafish as a model organism can easily be expanded to include physiological studies and we provided a reference dataset for the selection of measures of physiological responses for future studies using the zebrafish.

Examining the Attitudes and Physiological Responses Preservice Learners Have towards Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Gouvousis, Aphroditi; Heilmann, John; Golden, Jeanne; Kalinowski, Joseph; Hudson, Suzanne; Hough, Monica Strauss

2010-01-01

This study investigated attitudes and physiological responses demonstrated by preservice learners towards young children with autism spectrum disorders (ASD). The Self-Assessment Manikin (SAM) and two physiological measures (skin conductance and heart rate responses) were obtained. Four behaviors (two control and two problematic) depicting…

Interaction between intra-oral cinnamaldehyde and nicotine assessed by psychophysical and physiological responses.

PubMed

Jensen, Tanja K; Andersen, Michelle V; Nielsen, Kent A; Arendt-Nielsen, Lars; Boudreau, Shellie A

2016-08-01

Cinnamaldehyde and nicotine activate the transient receptor potential subtype A1 (TRPA1) channel, which may cause burning sensations. This study investigated whether cinnamaldehyde modulates nicotine-induced psychophysical and physiological responses in oral tissues. Healthy non-smokers (n = 22) received, in a randomized, double-blind, crossover design, three different gums containing 4 mg of nicotine, 20 mg of cinnamaldehyde, or a combination thereof. Assessments of orofacial temperature and blood flow, blood pressure, heart rate, taste experience, and intra-oral pain/irritation area and intensity were performed before, during, and after a 10-min chewing regime. Cinnamaldehyde increased the temperature of the tongue and blood flow of the lip, and was associated with pain/irritation, especially in the mouth. Nicotine increased the temperature of the tongue and blood flow of the cheek, and produced pain/irritation in the mouth and throat. The combination of cinnamaldehyde and nicotine did not overtly change the psychophysical or physiological responses. Interestingly, half of the subjects responded to cinnamaldehyde as an irritant, and these cinnamaldehyde responders reported greater nicotine-induced pain/irritation areas in the throat. Whether sensitivity to cinnamaldehyde can predict the response to nicotine-induced oral irritation remains to be determined. A better understanding of the sensory properties of nicotine in the oral mucosa has important therapeutic implications because pain and irritation represent compliance issues for nicotine replacement products. © 2016 Eur J Oral Sci.

Response of predatory mites to a herbivore-induced plant volatile: genetic variation for context-dependent behaviour.

PubMed

Sznajder, Beata; Sabelis, Maurice W; Egas, Martijn

2010-07-01

Plants infested with herbivores release specific volatile compounds that are known to recruit natural enemies. The response of natural enemies to these volatiles may be either learned or genetically determined. We asked whether there is genetic variation in the response of the predatory mite Phytoseiulus persimilis to methyl salicylate (MeSa). MeSa is a volatile compound consistently produced by plants being attacked by the two-spotted spider mite, the prey of P. persimilis. We predicted that predators express genetically determined responses during long-distance migration where previously learned associations may have less value. Additionally, we asked whether these responses depend on odors from uninfested plants as a background to MeSa. To infer a genetic basis, we analyzed the variation in response to MeSa among iso-female lines of P. persimilis by using choice-tests that involved either (1) MeSa presented as a single compound or (2) MeSa with background-odor from uninfested lima bean plants. These tests were conducted for starved and satiated predators, i.e., two physiological states, one that approximates migration and another that mimics local patch exploration. We found variation among iso-female lines in the responses to MeSa, thus showing genetic variation for this behavior. The variation was more pronounced in the starved predators, thus indicating that P. persimilis relies on innate preferences when migrating. Background volatiles of uninfested plants changed the predators' responses to MeSa in a manner that depended on physiological state and iso-female line. Thus, it is possible to select for context-dependent behavioral responses of natural enemies to plant volatiles.

Response of Predatory Mites to a Herbivore-Induced Plant Volatile: Genetic Variation for Context-Dependent Behaviour

PubMed Central

Sabelis, Maurice W.; Egas, Martijn

2010-01-01

Plants infested with herbivores release specific volatile compounds that are known to recruit natural enemies. The response of natural enemies to these volatiles may be either learned or genetically determined. We asked whether there is genetic variation in the response of the predatory mite Phytoseiulus persimilis to methyl salicylate (MeSa). MeSa is a volatile compound consistently produced by plants being attacked by the two-spotted spider mite, the prey of P. persimilis. We predicted that predators express genetically determined responses during long-distance migration where previously learned associations may have less value. Additionally, we asked whether these responses depend on odors from uninfested plants as a background to MeSa. To infer a genetic basis, we analyzed the variation in response to MeSa among iso-female lines of P. persimilis by using choice-tests that involved either (1) MeSa presented as a single compound or (2) MeSa with background-odor from uninfested lima bean plants. These tests were conducted for starved and satiated predators, i.e., two physiological states, one that approximates migration and another that mimics local patch exploration. We found variation among iso-female lines in the responses to MeSa, thus showing genetic variation for this behavior. The variation was more pronounced in the starved predators, thus indicating that P. persimilis relies on innate preferences when migrating. Background volatiles of uninfested plants changed the predators’ responses to MeSa in a manner that depended on physiological state and iso-female line. Thus, it is possible to select for context-dependent behavioral responses of natural enemies to plant volatiles. PMID:20574785

A wearable device for emotional recognition using facial expression and physiological response.

PubMed

Jangho Kwon; Da-Hye Kim; Wanjoo Park; Laehyun Kim

2016-08-01

This paper introduces a glasses-typed wearable system to detect user's emotions using facial expression and physiological responses. The system is designed to acquire facial expression through a built-in camera and physiological responses such as photoplethysmogram (PPG) and electrodermal activity (EDA) in unobtrusive way. We used video clips for induced emotions to test the system suitability in the experiment. The results showed a few meaningful properties that associate emotions with facial expressions and physiological responses captured by the developed wearable device. We expect that this wearable system with a built-in camera and physiological sensors may be a good solution to monitor user's emotional state in daily life.

The Systemic Control of Growth

PubMed Central

Boulan, Laura; Milán, Marco; Léopold, Pierre

2015-01-01

Growth is a complex process that is intimately linked to the developmental program to form adults with proper size and proportions. Genetics is an important determinant of growth, as exemplified by the role of local diffusible molecules setting up organ proportions. In addition, organisms use adaptive responses allowing modulating the size of individuals according to environmental cues, for example, nutrition. Here, we describe some of the physiological principles participating in the determination of final individual size. PMID:26261282

Physiological stress response, reflex impairment and delayed mortality of white sturgeon Acipenser transmontanus exposed to simulated fisheries stressors

PubMed Central

McLean, Montana F.; Hanson, Kyle C.; Cooke, Steven J.; Hinch, Scott G.; Patterson, David A.; Nettles, Taylor L.; Litvak, Matt K.; Crossin, Glenn T.

2016-01-01

White sturgeon (Acipenser transmontanus) are the largest freshwater fish in North America and a species exposed to widespread fishing pressure. Despite the growing interest in recreational fishing for white sturgeon, little is known about the sublethal and lethal impacts of angling on released sturgeon. In summer (July 2014, mean water temperature 15.3°C) and winter (February 2015, mean water temperature 6.6°C), captive white sturgeon (n = 48) were exposed to a combination of exercise and air exposure as a method of simulating an angling event. After the stressor, sturgeon were assessed for a physiological stress response, and reflex impairments were quantified to determine overall fish vitality (i.e. capacity for survival). A physiological stress response occurred in all sturgeon exposed to a fishing-related stressor, with the magnitude of the response correlated with the duration of the stressor. Moreover, the stress from exercise was more pronounced in summer, leading to higher reflex impairment scores (mean ± SEM, 0.44 ± 0.07 and 0.25 ± 0.05 in summer and winter, respectively). Reflex impairment was also correlated with lactate concentrations (e.g. physiological stress measures related to exhaustive exercise; r = 0.53) and recovery time (r = 0.76). Two mortalities occurred >24 h after the cessation of treatment in the summer. Given that natural habitats for white sturgeon can reach much higher temperatures than those presented in our study, we caution the use of this mortality estimate for a summer season, because latent mortality could be much higher when temperatures exceed 16°C. This is the first experiment investigating the physiological disturbance and reflex impairment of capture and release at two temperatures on subadult/adult white sturgeon, and the results suggest that future research needs to examine the longer term and fitness consequences of extended play and air exposure times, because these are largely unknown for wild populations. PMID:27766153

Repeated Exposure to Taekwondo Combat Modulates the Physiological and Hormonal Responses to Subsequent Bouts and Recovery Periods.

PubMed

Bridge, Craig A; Sparks, Andy S; McNaughton, Lars R; Close, Graeme L; Hausen, Matheus; Gurgel, Jonas; Drust, Barry

2018-05-17

Bridge, CA, Sparks, SA, McNaughton, LR, Close, GL, Hausen, M, Gurgel, J, and Drust, B. Repeated exposure to taekwondo combat modulates the physiological and hormonal responses to subsequent bouts and recovery periods. J Strength Cond Res XX(X): 000-000, 2018-This study examined the physiological and hormonal responses to successive taekwondo combats using an ecologically valid competition time structure. Ten elite male international taekwondo competitors (age 19 ± 3 years) took part in a simulated championship event. The competitors performed 4 combats that were interspersed with different recovery intervals (63 ± 4, 31 ± 3 and 156 ± 5 minutes, respectively). Heart rate (HR) was measured during the combats and venous blood samples were obtained both before and after each combat to determine the plasma metabolite and hormone concentrations. The plasma noradrenaline (21.8 ± 12.8 vs. 15.0 ± 7.0 nmol·l) and lactate (13.9 ± 4.2 vs. 10.5 ± 3.2 mmol·l) responses were attenuated (p < 0.05) between combat 1 and 4. Higher (p < 0.05) HR responses were evident in the final combat when compared with the earlier combats. Higher (p < 0.05) resting HR (139 ± 10 vs. 127 ± 12 b·min), plasma lactate (3.1 ± 1.2 vs. 2.0 ± 0.7 mmol·l), glycerol (131 ± 83 vs. 56 ± 38 μmol·l) and nonesterified free fatty acid (0.95 ± 0.29 vs. 0.71 ± 0.28 mmol·l) concentrations were measured before combat 3 compared with combat 1. Repeated exposure to taekwondo combat using an ecologically valid time structure modulates the physiological and hormonal responses to subsequent bouts and recovery periods. Strategies designed to assist competitors to effectively manage the metabolic changes associated with the fight schedule and promote recovery between the bouts may be important during championship events.

Non-invasive cortisol measurements as indicators of physiological stress responses in guinea pigs

PubMed Central

Pschernig, Elisabeth; Wallner, Bernard; Millesi, Eva

2016-01-01

Non-invasive measurements of glucocorticoid (GC) concentrations, including cortisol and corticosterone, serve as reliable indicators of adrenocortical activities and physiological stress loads in a variety of species. As an alternative to invasive analyses based on plasma, GC concentrations in saliva still represent single-point-of-time measurements, suitable for studying short-term or acute stress responses, whereas fecal GC metabolites (FGMs) reflect overall stress loads and stress responses after a species-specific time frame in the long-term. In our study species, the domestic guinea pig, GC measurements are commonly used to indicate stress responses to different environmental conditions, but the biological relevance of non-invasive measurements is widely unknown. We therefore established an experimental protocol based on the animals’ natural stress responses to different environmental conditions and compared GC levels in plasma, saliva, and fecal samples during non-stressful social isolations and stressful two-hour social confrontations with unfamiliar individuals. Plasma and saliva cortisol concentrations were significantly increased directly after the social confrontations, and plasma and saliva cortisol levels were strongly correlated. This demonstrates a high biological relevance of GC measurements in saliva. FGM levels measured 20 h afterwards, representing the reported mean gut passage time based on physiological validations, revealed that the overall stress load was not affected by the confrontations, but also no relations to plasma cortisol levels were detected. We therefore measured FGMs in two-hour intervals for 24 h after another social confrontation and detected significantly increased levels after four to twelve hours, reaching peak concentrations already after six hours. Our findings confirm that non-invasive GC measurements in guinea pigs are highly biologically relevant in indicating physiological stress responses compared to circulating levels in plasma in the short- and long-term. Our approach also underlines the importance of detailed investigations on how to use and interpret non-invasive measurements, including the determination of appropriate time points for sample collections. PMID:26839750

Cancer Surgery in the Elderly

PubMed Central

Kowdley, Gopal C.; Merchant, Nishant; Richardson, James P.; Somerville, Justin; Gorospe, Myriam; Cunningham, Steven C.

2012-01-01

The proportions both of elderly patients in the world and of elderly patients with cancer are both increasing. In the evaluation of these patients, physiologic age, and not chronologic age, should be carefully considered in the decision-making process prior to both cancer screening and cancer treatment in an effort to avoid ageism. Many tools exist to help the practitioner determine the physiologic age of the patient, which allows for more appropriate and more individualized risk stratification, both in the pre- and postoperative periods as patients are evaluated for surgical treatments and monitored for surgical complications, respectively. During and after operations in the oncogeriatric populations, physiologic changes occuring that accompany aging include impaired stress response, increased senescence, and decreased immunity, all three of which impact the risk/benefit ratio associated with cancer surgery in the elderly. PMID:22272172

Infant Regulatory Disorders: Temperamental, Physiological, and Behavioral Features

PubMed Central

Dale, Lourdes P.; O‘Hara, Emily A.; Keen, Julie; Porges, Stephen W.

2010-01-01

Successful development during the first year of life is dependent on the infant’s ability to regulate behavioral and physiological state in response to unpredictable environmental challenges. While most infants develop skills to self-soothe and regulate behavior, a subset lacks these skills and develops regulatory disorders (RD). Objectives To evaluate the component features of RD by determining if infants with RD differ from typically developing infants on measures of temperament, respiratory sinus arrhythmia, heart rate, and mother-infant interactions. Methods Parents of 50 9-month old infants completed behavioral questionnaires that provided information necessary to complete the Regulatory Disorders Checklist, which evaluates for difficulties in self-regulation and hypersensitivities. Infants with difficulties in both domains were assigned to the RD group. Mothers and their infants were videotaped interacting for 10 minutes. Infant heart rate was monitored before and during the mental development test. Results The RD group (n=10) was more temperamentally difficult and exhibited atypical physiological regulation relative to infants with difficulties in either self-regulation or hypersensitivity (n=25) or infants with no difficulties (n=15). During the mother-infant interactions, the RD group exhibited more high-level withdrawal behaviors, including verbal and physical protests, although there were no differences in the quantity and quality of the maternal approaches. Conclusion Infants with RD have both temperamental and physiological regulation difficulties, and may be in a physiologically state that makes it difficult to moderate behavior in response to social demands. Mothers of RD infants might be taught to modify their behavior to help their infants regulate behavioral and physiological state. PMID:21057324

The Relationship between Rumination and Affective, Cognitive, and Physiological Responses to Stress in Adolescents.

PubMed

Aldao, Amelia; McLaughlin, Katie A; Hatzenbuehler, Mark L; Sheridan, Margaret A

Although previous studies have established that rumination influences responses to stressful life events, the mechanisms underlying this relationship remain inadequately understood. The current study examines the relationship between trait rumination and affective, cognitive, and physiological responses to a standardized laboratory-based stressor in adolescents. A community-based sample of adolescents (N = 157) aged 13-17 completed the Trier Social Stress Test (TSST). Affective, cognitive, and physiological responses were obtained before, during, and after the TSST. Adolescents who engaged in habitual rumination experienced greater negative affect and more negative cognitive appraisals in response to the TSST than adolescents with lower levels of rumination. Rumination was unrelated to heart rate reactivity, but predicted slower heart rate recovery from the TSST, indicating that rumination might be specifically associated with physiological recovery from stress. Rumination is associated with negative affective, cognitive, and physiological responses following stressors, suggesting potential mechanisms through which it might increase risk for psychopathology.

Thermal tolerance breadths among groundwater crustaceans living in a thermally constant environment.

PubMed

Mermillod-Blondin, F; Lefour, C; Lalouette, L; Renault, D; Malard, F; Simon, L; Douady, C J

2013-05-01

The climate variability hypothesis assumes that the thermal tolerance breadth of a species is primarily determined by temperature variations experienced in its environment. If so, aquatic invertebrates living in thermally buffered environments would be expected to exhibit narrow thermal tolerance breadths (stenothermy). We tested this prediction by studying the thermal physiology of three isopods (Asellidae, Proasellus) colonizing groundwater habitats characterized by an annual temperature amplitude of less than 1°C. The species responses to temperature variation were assessed in the laboratory using five physiological variables: survival, locomotor activity, aerobic respiration, immune defense and concentrations of total free amino acids and sugars. The three species exhibited contrasted thermal physiologies, although all variables were not equally informative. In accordance with the climate variability hypothesis, two species were extremely sensitive even to moderate changes in temperature (2°C) below and above their habitat temperature. In contrast, the third species exhibited a surprisingly high thermal tolerance breadth (11°C). Differences in response to temperature variation among Proasellus species indicated that their thermal physiology was not solely shaped by the current temperature seasonality in their natural habitats. More particularly, recent gene flow among populations living in thermally constant yet contrasted habitats might explain the occurrence of eurytherm species in thermally buffered environments.

Use of automated monitoring to assess behavioral toxicology in fish: Linking behavior and physiology

USGS Publications Warehouse

Brewer, S.K.; DeLonay, A.J.; Beauvais, S.L.; Little, E.E.; Jones, S.B.

1999-01-01

We measured locomotory behaviors (distance traveled, speed, tortuosity of path, and rate of change in direction) with computer-assisted analysis in 30 day posthatch rainbow trout (Oncorhynchus mykiss) exposed to pesticides. We also examined cholinesterase inhibition as a potential endpoint linking physiology and behavior. Sublethal exposure to chemicals often causes changes in swimming behavior, reflecting alterations in sensory and motor systems. Swimming behavior also integrates functions of the nervous system. Rarely are the connections between physiology and behavior made. Although behavior is often suggested as a sensitive, early indicator of toxicity, behavioral toxicology has not been used to its full potential because conventional methods of behavioral assessment have relied on manual techniques, which are often time-consuming and difficult to quantify. This has severely limited the application and utility of behavioral procedures. Swimming behavior is particularly amenable to computerized assessment and automated monitoring. Locomotory responses are sensitive to toxicants and can be easily measured. We briefly discuss the use of behavior in toxicology and automated techniques used in behavioral toxicology. We also describe the system we used to determine locomotory behaviors of fish, and present data demonstrating the system's effectiveness in measuring alterations in response to chemical challenges. Lastly, we correlate behavioral and physiological endpoints.

The Epiphytic Fern Elaphoglossum luridum (Fée) Christ. (Dryopteridaceae) from Central and South America: Morphological and Physiological Responses to Water Stress

PubMed Central

Minardi, Bruno Degaspari; Voytena, Ana Paula Lorenzen; Randi, Áurea Maria

2014-01-01

Elaphoglossum luridum (Fée) Christ. (Dryopteridaceae) is an epiphytic fern of the Atlantic Forest (Brazil). Anatomical and physiological studies were conducted to understand how this plant responds to water stress. The E. luridum frond is coriaceus and succulent, presenting trichomes, relatively thick cuticle, and sinuous cell walls in both abaxial and adaxial epidermis. Three treatments were analyzed: control, water deficit, and abscisic acid (ABA). Physiological studies were conducted through analysis of relative water content (RWC), photosynthetic pigments, chlorophyll a fluorescence, and malate content. No changes in RWC were observed among treatments; however, significant decreases in chlorophyll a content and photosynthetic parameters, including optimal irradiance (I opt) and maximum electron transport rate (ETRmax), were determined by rapid light curves (RLC). No evidence of crassulacean acid metabolism (CAM) pathway was observed in E. luridum in response to either water deficit or exogenous application of ABA. On the other hand, malate content decreased in the E. luridum frond after ABA treatment, seeming to downregulate malate metabolism at night, possibly through tricarboxylic acid (TCA) cycle regulation. PMID:25386618

Circulating microRNA are predictive of aging and acute adaptive response to resistance exercise in men

USDA-ARS?s Scientific Manuscript database

Circulating microRNA (c-miRNA) have the potential to function as novel noninvasive markers of the underlying physiological state of skeletal muscle. This investigation sought to determine the influence of aging on c-miRNA expression at rest and following resistance exercise in male volunteers (Young...

Delayed response to cold stress is characterized by successive metabolic shifts culminating in apple fruit peel necrosis

USDA-ARS?s Scientific Manuscript database

Superficial scald is a physiological disorder of apple fruit characterized by sunken, necrotic lesions appearing after prolonged cold storage, although initial injury occurs much earlier in the storage period. To determine the degree to which the transition to cell death is an active process and sp...

Verbal Ability, Social Stress, and Anxiety in Children with Autistic Disorder

ERIC Educational Resources Information Center

Lanni, Kimberly E.; Schupp, Clayton W.; Simon, David; Corbett, Blythe A.

2012-01-01

The aims of this study were to evaluate the physiological stress and anxiety responses in children with autism following completion of a standardized, social-evaluative stressor (Trier Social Stress Test-Child version), document the relationship between verbal ability, stress, and anxiety, and determine the association between stress and anxiety…

Human thermal comfort in urban outdoor spaces

Treesearch

Lee P. Herrington; J. S. Vittum

1977-01-01

Measurements of the physical environment of urban open spaces in Syracuse, New York, were used to compute the physiological responses of human users of the spaces. These calculations were then used to determine what environmental variables were both important to human comfort and susceptible to control by site design. Although air temperature and humidity are important...

Climate and the northern distribution limits of Dendroctonus frontalis Zimmerman (Coleoptera: Scolytidae)

Treesearch

M.J. Ungerer; M.P. Ayres; M.J. Lombardero

1999-01-01

The southern pine beetle, Dendroctonus frontalis is among the most important agents of ecological disturbance and economic loss in forests of the southeastern United States. We combined physiological measurements of insect temperature responses with climatic analyses to test the role of temperature in determining the northern distribution limits...

Habituation as a Determinant of Human Food Intake

ERIC Educational Resources Information Center

Epstein, Leonard H.; Temple, Jennifer L.; Roemmich, James N.; Bouton, Mark E.

2009-01-01

Research has shown that animals and humans habituate on a variety of behavioral and physiological responses to repeated presentations of food cues, and habituation is related to amount of food consumed and cessation of eating. The purpose of this article is to provide an overview of experimental paradigms used to study habituation, integrate a…

Development and Testing of a Datalogging Device for Physiological Measurements of Deep-diving Odontocetes

DTIC Science & Technology

2013-09-30

target species (such as melon-headed whales and false killer whales ) for some of these other projects were unusually low in 2013, so that there were...Science Center is supporting research on false killer whale movements in Hawaiian waters, and the Naval Postgraduate School (with funding from N45) is...determine the normal cardiovascular dive response of deep-diving odontocetes like beaked whales , and to examine how that response might be altered

Plant roots use a patterning mechanism to position lateral root branches toward available water.

PubMed

Bao, Yun; Aggarwal, Pooja; Robbins, Neil E; Sturrock, Craig J; Thompson, Mark C; Tan, Han Qi; Tham, Cliff; Duan, Lina; Rodriguez, Pedro L; Vernoux, Teva; Mooney, Sacha J; Bennett, Malcolm J; Dinneny, José R

2014-06-24

The architecture of the branched root system of plants is a major determinant of vigor. Water availability is known to impact root physiology and growth; however, the spatial scale at which this stimulus influences root architecture is poorly understood. Here we reveal that differences in the availability of water across the circumferential axis of the root create spatial cues that determine the position of lateral root branches. We show that roots of several plant species can distinguish between a wet surface and air environments and that this also impacts the patterning of root hairs, anthocyanins, and aerenchyma in a phenomenon we describe as hydropatterning. This environmental response is distinct from a touch response and requires available water to induce lateral roots along a contacted surface. X-ray microscale computed tomography and 3D reconstruction of soil-grown root systems demonstrate that such responses also occur under physiologically relevant conditions. Using early-stage lateral root markers, we show that hydropatterning acts before the initiation stage and likely determines the circumferential position at which lateral root founder cells are specified. Hydropatterning is independent of endogenous abscisic acid signaling, distinguishing it from a classic water-stress response. Higher water availability induces the biosynthesis and transport of the lateral root-inductive signal auxin through local regulation of tryptophan aminotransferase of Arabidopsis 1 and PIN-formed 3, both of which are necessary for normal hydropatterning. Our work suggests that water availability is sensed and interpreted at the suborgan level and locally patterns a wide variety of developmental processes in the root.

Targeted ablation of cardiac sympathetic neurons reduces resting, reflex and exercise-induced sympathetic activation in conscious rats.

PubMed

Lujan, Heidi L; Palani, Gurunanthan; Chen, Ying; Peduzzi, Jean D; Dicarlo, Stephen E

2009-05-01

Cholera toxin B subunit conjugated to saporin (SAP, a ribosomal inactivating protein that binds to and inactivates ribosomes) was injected in both stellate ganglia to evaluate the physiological response to targeted ablation of cardiac sympathetic neurons. Resting cardiac sympathetic activity (cardiac sympathetic tonus), exercise-induced sympathetic activity (heart rate responses to graded exercise), and reflex sympathetic activity (heart rate responses to graded doses of sodium nitroprusside, SNP) were determined in 18 adult conscious Sprague-Dawley male rats. Rats were randomly divided into the following three groups (n = 6/group): 1) control (no injection), 2) bilateral stellate ganglia injection of unconjugated cholera toxin B (CTB), and 3) bilateral stellate ganglia injection of cholera toxin B conjugated to SAP (CTB-SAP). CTB-SAP rats, compared with control and CTB rats, had reduced cardiac sympathetic tonus and reduced heart rate responses to graded exercise and graded doses of SNP. Furthermore, the number of stained neurons in the stellate ganglia and spinal cord (segments T(1)-T(4)) was reduced in CTB-SAP rats. Thus CTB-SAP retrogradely transported from the stellate ganglia is effective at ablating cardiac sympathetic neurons and reducing resting, exercise, and reflex sympathetic activity. Additional studies are required to further characterize the physiological responses to this procedure as well as determine if this new approach is safe and efficacious for the treatment of conditions associated with excess sympathetic activity (e.g., autonomic dysreflexia, hypertension, heart failure, and ventricular arrhythmias).

Gender- and hydration- associated differences in the physiological response to spinning.

PubMed

Ramos-Jiménez, Arnulfo; Hernández-Torres, Rosa Patricia; Wall-Medrano, Abraham; Torres-Durán, Patricia Victoria; Juárez-Oropeza, Marco Antonio; Viloria, María; Villalobos-Molina, Rafael

2014-03-01

There is scarce and inconsistent information about gender-related differences in the hydration of sports persons, as well as about the effects of hydration on performance, especially during indoor sports. To determine the physiological differences between genders during in indoor physical exercise, with and without hydration. 21 spinning sportspeople (12 men and 9 women) participated in three controlled, randomly assigned and non-sequential hydration protocols, including no fluid intake and hydration with plain water or a sports drink (volume adjusted to each individual every 15 min), during 90 min of spinning exercise. The response variables included body mass, body temperature, heart rate and blood pressure. During exercise without hydration, men and women lost ~2% of body mass, and showed higher body temperature (~0.2°C), blood pressure (~4 mmHg) and heart rate (~7 beats/min) compared to exercises with hydration. Body temperature and blood pressure were higher for men than for women during exercise without hydration, differences not observed during exercise with hydration. Between 42-99% of variance in body temperature, blood pressure and heart rate could be explained by the physical characteristics of subjects and the work done. During exercise with hydration (either with water or sport drink), the physiological response was similar for both genders. Exercise without hydration produced physical stress, which could be prevented with either of the fluids (plain water was sufficient). Gender differences in the physiological response to spinning (body temperature, mean blood pressure and heart rate) can be explained in part by the distinct physical characteristics of each individual. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Behavioral and Physiological Responses of Horses to Simulated Aircraft Noise

DTIC Science & Technology

1991-01-01

AL-TR-1991-0123 A R M BEHAVIORAL AND PHYSIOLOGICAL S RESPONSES OF HORSES TO SIMULATED T AIRCRAFT NOISE R 0 N G Michelle M. LeBlanc Christoph Lombard...COVERED • 10 January 1991 IFinal Report Dec 89 to Jan 91 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Behavioral and Physiological Responses of Horses to...NUMBER OF PAGES Aircraft, Noise, Domestic Animals, Horses , 70 Disturbance, Physiological Effects 16. PRICE CODE 17. SECURITY CLASSIFICATION 18. SECURITY

Physiological responses to environmental factors related to space flight. [hemodynamic and metabolic responses to weightlessness

NASA Technical Reports Server (NTRS)

Pace, N.

1973-01-01

Physiological base line data are established, and physiological procedures and instrumentation necessary for the automatic measurement of hemodynamic and metabolic parameters during prolonged periods of weightlessness are developed.

Physiological Response to Reward and Extinction Predicts Alcohol, Marijuana, and Cigarette Use Two Years Later

PubMed Central

Derefinko, Karen J.; Eisenlohr-Moul, Tory A.; Peters, Jessica R.; Roberts, Walter; Walsh, Erin C.; Milich, Richard; Lynam, Donald R.

2017-01-01

Background Physiological responses to reward and extinction are believed to represent the Behavioral Activation System (BAS) and Behavioral Inhibition System (BIS) constructs of Reinforcement Sensitivity Theory and underlie externalizing behaviors, including substance use. However, little research has examined these relations directly. Methods We assessed individuals’ cardiac pre-ejection periods (PEP) and electrodermal responses (EDR) during reward and extinction trials through the “Number Elimination Game” paradigm. Responses represented BAS and BIS, respectively. We then examined whether these responses provided incremental utility in the prediction of future alcohol, marijuana, and cigarette use. Results Zero-inflated Poisson (ZIP) regression models were used to examine the predictive utility of physiological BAS and BIS responses above and beyond previous substance use. Physiological responses accounted for incremental variance over previous use. Low BAS responses during reward predicted frequency of alcohol use at year 3. Low BAS responses during reward and extinction and high BIS responses during extinction predicted frequency of marijuana use at year 3. For cigarette use, low BAS response during extinction predicted use at year 3. Conclusions These findings suggest that the constructs of Reinforcement Sensitivity Theory, as assessed through physiology, contribute to the longitudinal maintenance of substance use. PMID:27306728

Physiological Response of Orchids to Mealybugs (Hemiptera: Pseudococcidae) Infestation.

PubMed

Kmiec, K; Kot, I; Golan, K; Górska-Drabik, E; Lagowska, B; Rubinowska, K; Michalek, W

2016-12-01

The harmfulness of mealybugs resulting from sucking plant sap, secreting honeydew, and transmitting plant viruses can give them the status of serious pests. This study documents the influence of Pseudococcus maritimus (Ehrhorn) and Pseudococcus longispinus (Targioni Tozzetti) infestation on alterations in selected physiological parameters of Phalaenopsis x hybridum 'Innocence'. The condition of the cytoplasmic membranes was expressed as the value of thiobarbituric acid reactive substances. We have determined changes in the activities of catalase and guaiacol peroxidase and measured the following chlorophyll fluorescence parameters: maximum quantum yield of photosystem II (Fv/Fm), effective quantum yield (Y), photochemical quenching (qP), and nonphotochemical quenching (qN). The strongest physiological response of orchids was recorded in the initial period of mealybugs infestation. Prolonged insect feeding suppressed lipid peroxidation, peroxidase and catalase activity, as well as photosynthesis photochemistry. The pattern of changes was dependent on mealybug species. This indicated the complexity of the processes responsible for plant tolerance. Data generated in this study have provided a better understanding of the impact of two mealybug species infestation on Phalaenopsis and should be useful in developing pest management strategies. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of suspension on tissue levels of glucocorticoid receptors

NASA Technical Reports Server (NTRS)

Steffen, J. M.

1984-01-01

Differential muscle responses can be simulated by hypokinetic/hypodynamic (H/H) suspension of rats with complete unloading of the hindlimb muscles. Since mechanism(s) underlying these atrophic effects were not clearly elucidated, experiments were initiated to investigate a possible role for glucocorticoids in the physiological and biochemical responses to H/H. The principal objective was to assess the potential for alterations in peripheral responsiveness to glucocorticoids in response to H/H. Studies have initially focused on the determination of tissue levels of glucocorticoid receptors as one index of hormonal sensitivity at the cellular level. Four hindlimb muscles (soleus, gastrocnemius, plantaris and EDL), previously demonstrated to exhibit differential responses to H/H, were investigated. Receptor levels in other glucocorticoid sensitive tissues (heart, liver, and kidney) were determined. Male rats (180-200g) were suspended for 7 or 14 days, sacrificed by cervical dislocation, and the tissues excised.

Ventilatory and Physiological Responses in Swimmers Below and Above Their Maximal Lactate Steady State.

PubMed

Espada, Mario C; Reis, Joana F; Almeida, Tiago F; Bruno, Paula M; Vleck, Veronica E; Alves, Francisco B

2015-10-01

The purpose of this study was to understand the ventilatory and physiological responses immediately below and above the maximal lactate steady-state (MLSS) velocity and to determine the relationship of oxygen uptake (VO2) kinetics parameters with performance, in swimmers. Competitive athletes (N = 12) completed in random order and on different days a 400-m all-out test, an incremental step test comprising 5 × 250- and 1 × 200-m stages and 30 minutes at a constant swimming velocity (SV) at 87.5, 90, and 92.5% of the maximal aerobic velocity for MLSS velocity (MLSSv) determination. Two square-wave transitions of 500 m, 2.5% above and below the MLSSv were completed to determine VO2 on-kinetics. End-exercise VO2 at 97.5 and 102.5% of MLSSv represented, respectively, 81 and 97% of VO2max; the latter was not significantly different from maximal VO2 (VO2max). The VO2 at MLSSv (49.3 ± 9.2 ml·kg(-1)·min(-1)) was not significantly different from the second ventilatory threshold (VT2) (51.3 ± 7.6 ml·kg(-1)·min(-1)). The velocity associated with MLSS seems to be accurately estimated by the SV at VT2 (vVT2), and vVO2max also seems to be estimated with accuracy from the central 300-m mean velocity of a 400-m trial, indicators that represent a helpful tool for coaches. The 400-m swimming performance (T400) was correlated with the time constant of the primary phase VO2 kinetics (τp) at 97.5% MLSSv, and T800 was correlated with τp in both 97.5 and 102.5% of MLSSv. The assessment of the VO2 kinetics in swimming can help coaches to build training sets according to a swimmer's individual physiological response.

The role of growth hormone in lines of mice divergently selected on body weight.

PubMed

Hastings, I M; Bootland, L H; Hill, W G

1993-04-01

An understanding of the physiological and genetic changes which determine the response to selection is critical for both evolutionary theory and to assess the application of new molecular techniques to commercial animal breeding. We investigated an aspect of physiology, growth hormone (GH) metabolism, which might a priori have been expected to play a large part in the response of mouse lines selected for high or low body weight. Disruption of endogenous GH or addition of exogenous GH had similar proportionate effects on body weight in both lines of mice (although differences in body composition arose) suggesting that neither the production of GH nor receptor sensitivity to GH had been altered as a result of selection. This supports a 'pleiotropic model' of the response to selection: that many genes with diverse metabolic roles all contribute to the divergent phenotype. This result has significant commercial implications as it suggests that artificial selection, transgenic technology and environmental manipulation may be synergistic rather than antagonistic strategies.

Behavioral and Metabolic Phenotype Indicate Personality in Zebrafish (Danio rerio).

PubMed

Yuan, Mingzhe; Chen, Yan; Huang, Yingying; Lu, Weiqun

2018-01-01

Consistency of individual differences of animal behavior and personality in reactions to various environmental stresses among their life stages could reflect basic divergences in coping style which may affect survival, social rank, and reproductive success in the wild. However, the physiological mechanisms determining personality remain poorly understood. In order to study whether behavior, metabolism and physiological stress responses relate to the personality, we employed post-stress recovery assays to separate zebrafish into two behavioral types (proactive and reactive). The results demonstrated consistent difference among personality, behavior and metabolism in which proactive individuals were more aggressive, had higher standard metabolic rates and showed lower shuttled frequencies between dark and light compartments than the reactive ones. The behavioral variations were also linked to divergent acute salinity stress responses: proactive individuals adopted a swift locomotion behavior in response to acute salinity challenge while reactive individuals remain unchanged. Our results provide useful insight into how personality acts on correlated traits and the importance of a holistic approach to understanding the mechanisms driving persistent inter-individual differences.

Suppression of bovine lymphocyte function by treatment with physiologic concentrations of cortisone

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

Ojo-Amaize, E.A.; Paape, M.J.; Guidry, A.J.

1986-03-01

The blastogenic response of peripheral blood lymphocytes (PBL) (8 cows) to capsular antigen extract of Staphylococcus aureus, PHA and LPS was measured in vitro using /sup 5/H-thymidine pulse labelling. isolated PBL were treated in vitro for 6-8 days with 10, 25 and 45 ng/ml cortisone. These concentrations simulate serum corticosteroid levels during environmental stress, acute clinical mastitis and ACTH therapy, respectively. To determine the minimal concentration of cortisone that would induce suppression, PBL were also incubated with increasing concentrations of cortisone starting at 10 pg/ml. All concentrations of cortisone caused a significant (P<0.01) depression of lymphocyte blastogenic response to S.more » aureus, PHA and LPS. Macrophage depletion experiments showed no macrophage suppressor effects. Both the blastogenic response of untreated peripheral blood lymphocytes to S. aureus, PHA and LPS and the degree to which that response was suppressed by cortisone differed significantly among cows. Results indicate that cortisone levels found during physiological stress and after therapeutic administration of ACTH can suppress lymphocyte function.« less

Vaccination prepartum enhances the beneficial effects of melatonin on the immune response and reduces platelet responsiveness in sheep

PubMed Central

2012-01-01

Background Melatonin regulates several physiological processes and its powerful action as antioxidant has been widely reported. Melatonin acts modulating the immune system, showing a protective effect on the cardiovascular system and improving vaccine administration as an adjuvant-like agent. Here, we have investigated the role of melatonin as an adjuvant of the Clostridium perfringens vaccine in prepartum sheep and whether melatonin modulates platelet physiology during peripartum. Results The experiments were carried out in peripartum sheep from a farm located in an area of Mediterranean-type ecosystem. Plasma melatonin levels were determined by ELISA and sheep platelet aggregation was monitored using an aggregometer. Here we demonstrated for the first time that plasma melatonin concentration were higher in pregnant (125 pg/mL) than in non-pregnant sheep (15 pg/mL; P < 0.05). Administration of melatonin prepartum did not significantly modify platelet function but significantly improved the immune response to vaccination against C. perfringens. Conclusion Administration of melatonin as an adjuvant provides a significant improvement in the immune response to vaccine administration prepartum against C. perfringens. PMID:22716226

Physiological response of wild rainbow trout to angling: Impact of angling duration, fish size, body condition, and temperature

USGS Publications Warehouse

Meka, Julie M.; McCormick, S.D.

2005-01-01

This study evaluated the immediate physiological response of wild rainbow trout to catch-and-release angling in the Alagnak River, southwest Alaska. Information was recorded on individual rainbow trout (n = 415) captured by angling including landing time and the time required to remove hooks (angling duration), the time to anesthetize fish in clove oil and withdraw blood, fish length and weight, and water temperature at capture locations. Plasma cortisol, glucose, ions (sodium, potassium, chloride), and lactate were analyzed to determine the effects of angling duration, fish size, body condition, and temperature. Levels of plasma ions did not change significantly during the observed physiological response and levels of plasma glucose were sometimes influenced by length (2000, 2001), body condition (2001), or temperature (2001). Levels of plasma cortisol and lactate in extended capture fish (angling duration greater than 2 min) were significantly higher than levels in rapid capture fish (angling duration less than 2 min). Rapid capture fish were significantly smaller than extended capture fish, reflecting that fish size influenced landing and handling times. Fish size was related to cortisol and lactate in 2002, which corresponded to the year when larger fish were captured and there were longer landing times. Body condition (i.e., weight/length regression residuals index), was significantly related to lactate in 2000 and 2001. Water temperatures were higher in 2001 (mean temperature ± S.E., 13 ± 2oC) than in 2002 (10 ± 2oC), and fish captured in 2001 had significantly higher cortisol and lactate concentrations than fish captured in 2002. The pattern of increase in plasma cortisol and lactate was due to the amount of time fish were angled, and the upper limit of the response was due to water temperature. The results of this study indicate the importance of minimizing the duration of angling in order to reduce the sublethal physiological disturbances in wild fish subjected to catch-and-release angling, particularly during warmer water temperatures. It is also important to note that factors such as fish size may influence both the duration of angling and subsequent physiological response. 

Physiologically-based pharmacokinetic models: approaches for enabling personalized medicine.

PubMed

Hartmanshenn, Clara; Scherholz, Megerle; Androulakis, Ioannis P

2016-10-01

Personalized medicine strives to deliver the 'right drug at the right dose' by considering inter-person variability, one of the causes for therapeutic failure in specialized populations of patients. Physiologically-based pharmacokinetic (PBPK) modeling is a key tool in the advancement of personalized medicine to evaluate complex clinical scenarios, making use of physiological information as well as physicochemical data to simulate various physiological states to predict the distribution of pharmacokinetic responses. The increased dependency on PBPK models to address regulatory questions is aligned with the ability of PBPK models to minimize ethical and technical difficulties associated with pharmacokinetic and toxicology experiments for special patient populations. Subpopulation modeling can be achieved through an iterative and integrative approach using an adopt, adapt, develop, assess, amend, and deliver methodology. PBPK modeling has two valuable applications in personalized medicine: (1) determining the importance of certain subpopulations within a distribution of pharmacokinetic responses for a given drug formulation and (2) establishing the formulation design space needed to attain a targeted drug plasma concentration profile. This review article focuses on model development for physiological differences associated with sex (male vs. female), age (pediatric vs. young adults vs. elderly), disease state (healthy vs. unhealthy), and temporal variation (influence of biological rhythms), connecting them to drug product formulation development within the quality by design framework. Although PBPK modeling has come a long way, there is still a lengthy road before it can be fully accepted by pharmacologists, clinicians, and the broader industry.

Cycle training modulates satellite cell and transcriptional responses to a bout of resistance exercise.

PubMed

Murach, Kevin A; Walton, R Grace; Fry, Christopher S; Michaelis, Sami L; Groshong, Jason S; Finlin, Brian S; Kern, Philip A; Peterson, Charlotte A

2016-09-01

This investigation evaluated whether moderate-intensity cycle ergometer training affects satellite cell and molecular responses to acute maximal concentric/eccentric resistance exercise in middle-aged women. Baseline and 72 h postresistance exercise vastus lateralis biopsies were obtained from seven healthy middle-aged women (56 ± 5 years, BMI 26 ± 1, VO2max 27 ± 4) before and after 12 weeks of cycle training. Myosin heavy chain (MyHC) I- and II-associated satellite cell density and cross-sectional area was determined via immunohistochemistry. Expression of 93 genes representative of the muscle-remodeling environment was also measured via NanoString. Overall fiber size increased ~20% with cycle training (P = 0.052). MyHC I satellite cell density increased 29% in response to acute resistance exercise before endurance training and 50% with endurance training (P < 0.05). Following endurance training, MyHC I satellite cell density decreased by 13% in response to acute resistance exercise (acute resistance × training interaction, P < 0.05). Genes with an interaction effect tracked with satellite cell behavior, increasing in the untrained state and decreasing in the endurance trained state in response to resistance exercise. Similar satellite cell and gene expression response patterns indicate coordinated regulation of the muscle environment to promote adaptation. Moderate-intensity endurance cycle training modulates the response to acute resistance exercise, potentially conditioning the muscle for more intense concentric/eccentric activity. These results suggest that cycle training is an effective endurance exercise modality for promoting growth in middle-aged women, who are susceptible to muscle mass loss with progressing age. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Exposure history determines pteropod vulnerability to ocean acidification along the US West Coast.

PubMed

Bednaršek, N; Feely, R A; Tolimieri, N; Hermann, A J; Siedlecki, S A; Waldbusser, G G; McElhany, P; Alin, S R; Klinger, T; Moore-Maley, B; Pörtner, H O

2017-07-03

The pteropod Limacina helicina frequently experiences seasonal exposure to corrosive conditions (Ω ar   < 1) along the US West Coast and is recognized as one of the species most susceptible to ocean acidification (OA). Yet, little is known about their capacity to acclimatize to such conditions. We collected pteropods in the California Current Ecosystem (CCE) that differed in the severity of exposure to Ω ar conditions in the natural environment. Combining field observations, high-CO 2 perturbation experiment results, and retrospective ocean transport simulations, we investigated biological responses based on histories of magnitude and duration of exposure to Ω ar  < 1. Our results suggest that both exposure magnitude and duration affect pteropod responses in the natural environment. However, observed declines in calcification performance and survival probability under high CO 2 experimental conditions do not show acclimatization capacity or physiological tolerance related to history of exposure to corrosive conditions. Pteropods from the coastal CCE appear to be at or near the limit of their physiological capacity, and consequently, are already at extinction risk under projected acceleration of OA over the next 30 years. Our results demonstrate that Ω ar exposure history largely determines pteropod response to experimental conditions and is essential to the interpretation of biological observations and experimental results.

Physiological mechanisms underlying animal social behaviour.

PubMed

Seebacher, Frank; Krause, Jens

2017-08-19

Many species of animal live in groups, and the group represents the organizational level within which ecological and evolutionary processes occur. Understanding these processes, therefore, relies on knowledge of the mechanisms that permit or constrain group formation. We suggest that physiological capacities and differences in physiology between individuals modify fission-fusion dynamics. Differences between individuals in locomotor capacity and metabolism may lead to fission of groups and sorting of individuals into groups with similar physiological phenotypes. Environmental impacts such as hypoxia can influence maximum group sizes and structure in fish schools by altering access to oxygenated water. The nutritional environment determines group cohesion, and the increase in information collected by the group means that individuals should rely more on social information and form more cohesive groups in uncertain environments. Changing environmental contexts require rapid responses by individuals to maintain group coordination, which are mediated by neuroendocrine signalling systems such as nonapeptides and steroid hormones. Brain processing capacity may constrain social complexity by limiting information processing. Failure to evaluate socially relevant information correctly limits social interactions, which is seen, for example, in autism. Hence, functioning of a group relies to a large extent on the perception and appropriate processing of signals from conspecifics. Many if not all physiological systems are mechanistically linked, and therefore have synergistic effects on social behaviour. A challenge for the future lies in understanding these interactive effects, which will improve understanding of group dynamics, particularly in changing environments.This article is part of the themed issue 'Physiological determinants of social behaviour in animals'. © 2017 The Author(s).

Physiological mechanisms underlying animal social behaviour

PubMed Central

2017-01-01

Many species of animal live in groups, and the group represents the organizational level within which ecological and evolutionary processes occur. Understanding these processes, therefore, relies on knowledge of the mechanisms that permit or constrain group formation. We suggest that physiological capacities and differences in physiology between individuals modify fission–fusion dynamics. Differences between individuals in locomotor capacity and metabolism may lead to fission of groups and sorting of individuals into groups with similar physiological phenotypes. Environmental impacts such as hypoxia can influence maximum group sizes and structure in fish schools by altering access to oxygenated water. The nutritional environment determines group cohesion, and the increase in information collected by the group means that individuals should rely more on social information and form more cohesive groups in uncertain environments. Changing environmental contexts require rapid responses by individuals to maintain group coordination, which are mediated by neuroendocrine signalling systems such as nonapeptides and steroid hormones. Brain processing capacity may constrain social complexity by limiting information processing. Failure to evaluate socially relevant information correctly limits social interactions, which is seen, for example, in autism. Hence, functioning of a group relies to a large extent on the perception and appropriate processing of signals from conspecifics. Many if not all physiological systems are mechanistically linked, and therefore have synergistic effects on social behaviour. A challenge for the future lies in understanding these interactive effects, which will improve understanding of group dynamics, particularly in changing environments. This article is part of the themed issue ‘Physiological determinants of social behaviour in animals’. PMID:28673909

Bleaching response of Symbiodinium (zooxanthellae): determination by flow cytometry.

PubMed

Lee, Co Sin; Yeo, Yin Sheng Wilson; Sin, Tsai Min

2012-10-01

Coral bleaching is of increasing concern to reef management and stakeholders. Thus far, quantification of coral bleaching tends to be heavily reliant on the enumeration of zooxanthellae, with less emphasis on assessment of photosynthetic or physiological condition, these being often assessed separately by techniques such as liquid chromatography. Traditional methods of enumeration using microscopy are time consuming, subjected to low precision and great observer error. In this study, we presented a method for the distinction of physoiological condition and rapid enumeration of zooxanthellae using flow cytometry (FCM). Microscopy verified that healthy looking/live versus damaged/dead zooxanthellae could be reliably and objectively distinguished and counted by FCM on the basis of red and green fluorescence and light scatter. Excellent correlations were also determined between FCM and microscopy estimates of cell concentrations of fresh zooxanthellae isolates from Pocillopora damicornis. The relative intensities of chlorophyll and β-carotene fluorescences were shown to be important in understanding the results of increased cell counts in freshly isolated zooxanthellae experimentally exposed to high temperatures (34, 36, and 38°C) over 24 h, with ambient temperature (29°C) used as controls. The ability to simultaneously identify and enumerate subpopulations of different physiological states in the same sample provides an enormous advantage in not just determining bleaching responses, but elucidating adaptive response and mechanisms for tolerance. Therefore, this approach might provide a rapid, convenient, and reproducible methodology for climate change studies and reef management programs. Copyright © 2012 International Society for Advancement of Cytometry.

Predicting musically induced emotions from physiological inputs: linear and neural network models.

PubMed

Russo, Frank A; Vempala, Naresh N; Sandstrom, Gillian M

2013-01-01

Listening to music often leads to physiological responses. Do these physiological responses contain sufficient information to infer emotion induced in the listener? The current study explores this question by attempting to predict judgments of "felt" emotion from physiological responses alone using linear and neural network models. We measured five channels of peripheral physiology from 20 participants-heart rate (HR), respiration, galvanic skin response, and activity in corrugator supercilii and zygomaticus major facial muscles. Using valence and arousal (VA) dimensions, participants rated their felt emotion after listening to each of 12 classical music excerpts. After extracting features from the five channels, we examined their correlation with VA ratings, and then performed multiple linear regression to see if a linear relationship between the physiological responses could account for the ratings. Although linear models predicted a significant amount of variance in arousal ratings, they were unable to do so with valence ratings. We then used a neural network to provide a non-linear account of the ratings. The network was trained on the mean ratings of eight of the 12 excerpts and tested on the remainder. Performance of the neural network confirms that physiological responses alone can be used to predict musically induced emotion. The non-linear model derived from the neural network was more accurate than linear models derived from multiple linear regression, particularly along the valence dimension. A secondary analysis allowed us to quantify the relative contributions of inputs to the non-linear model. The study represents a novel approach to understanding the complex relationship between physiological responses and musically induced emotion.

Puffed and bothered: Personality, performance, and the effects of stress on checkered pufferfish.

PubMed

Pleizier, Naomi; Wilson, Alexander D M; Shultz, Aaron D; Cooke, Steven J

2015-12-01

Although consistent individual-level differences in behaviour are widespread and potentially important in evolutionary and ecological processes, relatively few studies focus on the physiological mechanisms that might underlie and regulate these individual-level differences in wild populations. We conducted experiments to determine whether checkered pufferfish (Sphoeroides testudineus), which were collected from a dynamic (in terms of depth and water temperature) tidal mangrove creek environment in The Bahamas, have consistent individual-level differences in locomotor activity and the response to a simulated predator threat, as well as swimming performance and puffing in response to stressors. The relationships between personality and performance traits were evaluated to determine whether they represented stress-coping styles or syndromes. Subsequently, a displacement study was conducted to determine how personality and performance in the laboratory compared to movements in the field. In addition, we tested whether a physiological dose of the stress hormone cortisol would alter individual consistency in behavioural and performance traits. We found that pufferfish exhibited consistent individual differences in personality traits over time (e.g., activity and the duration of a response to a threat) and that performance was consistent between the lab and the natural enclosure. Locomotor activity and the duration of startled behaviour were not associated with swimming and puffing performance. Locomotor activity, puffing performance, and swimming performance were not related to whether fish returned to the tidal creek of capture after displacement. Similarly, a cortisol treatment did not modify behaviour or performance in the laboratory. The results reveal that consistent individual-level differences in behaviour and performance were present in a population from a fluctuating and physiologically challenging environment but that such traits are not necessarily correlated. We also determined that certain individual performance traits were repeatable between the lab and a natural enclosure. However, we found no evidence of a relationship between exogenous cortisol levels and behavioural traits or performance in these fish, which suggests that other internal and external mechanisms may underlie the behaviours and performance tested. Copyright © 2015 Elsevier Inc. All rights reserved.

A creatinine biosensor based on admittance measurement

NASA Astrophysics Data System (ADS)

Ching, Congo Tak-Shing; Sun, Tai-Ping; Jheng, Deng-Yun; Tsai, Hou-Wei; Shieh, Hsiu-Li

2015-08-01

Regular check of blood creatinine level is very important as it is a measurement of renal function. Therefore, the objective of this study is to develop a simple and reliable creatinine biosensor based on admittance measurement for precise determination of creatinine. The creatinine biosensor was fabricated with creatinine deiminase immobilized on screen-printed carbon electrodes. Admittance measurement at a specific frequency ranges (22.80 - 84.71 Hz) showed that the biosensor has an excellent linear (r2 > 0.95) response range (50 - 250 uM), which covers the normal physiological and pathological ranges of blood creatinine levels. Intraclass correlation coefficient (ICC) showed that the biosensor has excellent reliability and validity (ICC = 0.98). In conclusion, a simple and reliable creatinine biosensor was developed and it is capable of precisely determining blood creatinine levels in both the normal physiological and pathological ranges.

Genetic and phenotypic characteristics of baker's yeast: relevance to baking.

PubMed

Randez-Gil, Francisca; Córcoles-Sáez, Isaac; Prieto, José A

2013-01-01

Yeasts rarely encounter ideal physiological conditions during their industrial life span; therefore, their ability to adapt to changing conditions determines their usefulness and applicability. This is especially true for baking strains of Saccharomyces cerevisiae. The success of this yeast in the ancient art of bread making is based on its capacity to rapidly transform carbohydrates into CO2 rather than its unusual resistance to environmental stresses. Moreover, baker's yeast must exhibit efficient respiratory metabolism during yeast manufacturing, which determines biomass yield. However, optimal growth conditions often have negative consequences in other commercially important aspects, such as fermentative power or stress tolerance. This article reviews the genetic and physiological characteristics of baking yeast strains, emphasizing the activation of regulatory mechanisms in response to carbon source and stress signaling and their importance in defining targets for strain selection and improvement.

Using odor cues to elicit a behavioral and hormonal response in zoo-housed African wild dogs.

PubMed

Rafacz, Michelle L; Santymire, Rachel M

2014-01-01

Olfactory enrichment, like odor cues, can positively affect behavior, reproductive success, and stress physiology in zoo-housed species. Our goal was to determine if odor cues were enriching to the African wild dog (AWD; Lycaon pictus), a species with a complex social structure and a highly developed sense of smell. Our objectives were to: (1) examine changes in activity levels and stress hormone physiology in response to fecal odor cues from natural competitor and natural/unnatural prey species; and (2) determine whether these odor cues could function as effective enrichment for zoo-housed AWDs. Over a 6-month period, fecal samples were collected from two males (AWD 1: dominant, AWD 2: subordinate), fecal glucocorticoid metabolites (FGMs) were validated using an ACTH-challenge, and hormones were analyzed for FGMs by enzyme immunoassay. Behavioral observations were conducted using scan-sampling, and contact and proximity were recorded. AWDs were presented with three fecal odor cues: LION (competitor), CATTLE (unnatural prey), and GAZELLE (natural prey). Only the GAZELLE cue elicited an increase in activity (10.6%) in both individuals and increased positive social behaviors with higher frequencies of affiliative, submissive, and dominant behavior. AWD 1 demonstrated lower (P < 0.05) FGMs than AWD 2 both before and after all odor cues, and FGMs decreased (P = 0.08) in AWD 2 after all cues. We conclude that exposure to natural prey odor cues may be used as effective enrichment for AWDs, and that changes in stress hormone physiology in response to odor cues may be dependent on social rank in this species. © 2013 Wiley Periodicals, Inc.

Does oxygen delivery explain interindividual variation in forearm critical impulse?

PubMed

Kellawan, J Mikhail; Bentley, Robert F; Bravo, Michael F; Moynes, Jackie S; Tschakovsky, Michael E

2014-11-01

Within individuals, critical power appears sensitive to manipulations in O2 delivery. We asked whether interindividual differences in forearm O2 delivery might account for a majority of the interindividual differences in forearm critical force impulse (critical impulse), the force analog of critical power. Ten healthy men (24.6 ± 7.10 years) completed a maximal effort rhythmic handgrip exercise test (1 sec contraction-2 sec relaxation) for 10 min. The average of contraction impulses over the last 30 sec quantified critical impulse. Forearm brachial artery blood flow (FBF; echo and Doppler ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured continuously. O2 delivery (FBF arterial oxygen content (venous blood [hemoglobin] and oxygen saturation from pulse oximetry)) and forearm vascular conductance (FVC; FBF·MAP(-1)) were calculated. There was a wide range in O2 delivery (59.98-121.15 O2 mL·min(-1)) and critical impulse (381.5-584.8 N) across subjects. During maximal effort exercise, O2 delivery increased rapidly, plateauing well before the declining forearm impulse and explained most of the interindividual differences in critical impulse (r(2) = 0.85, P < 0.01). Both vasodilation (r(2) = 0.64, P < 0.001) and the exercise pressor response (r(2) = 0.33, P < 0.001) independently contributed to interindividual differences in FBF. In conclusion, interindividual differences in forearm O2 delivery account for most of the interindividual variation in critical impulse. Furthermore, individual differences in pressor response play an important role in determining differences in O2 delivery in addition to vasodilation. The mechanistic origins of this vasodilatory and pressor response heterogeneity across individuals remain to be determined. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Hormonal and metabolic responses of hypophysectomized rats with head-down suspension

NASA Technical Reports Server (NTRS)

Tipton, C. M.; Grindeland, R. E.; Woodman, C. R.; Gosselink, K.; Linderman, J. K.; Mukku, V. R.; Gooselink, K.

1994-01-01

The primary purpose of this investigation was to secure select anatomical and physiological measurements from hypophysectomized rats and their sham-operated control to determine how various endocrine influences could be modified by conditions of simulated microgravity. The focal point of the study was the exercise responses after head-down suspension; however, we were also interested in obtaining insights on nonexercise-related mechanisms. Since more details and information concerning this study will be published elsewhere, we will highlight those findings which warrant further research.

Human cardiovascular response to sympathomimetic agents during head-down bed rest: the effect of dietary sodium

NASA Technical Reports Server (NTRS)

Williams, W. J.; Stuart, C. A.; Fortney, S. M.; Pietrzyk, R. A.; Chen, Y. M.; Whitson, P. A.

1994-01-01

Changes in sympathoadrenal function and cardiovascular deconditioning have long been recognized as a feature of the physiological adaptation to microgravity. The deconditioning process, coupled with altered hydration status, is thought to significantly contribute to orthostatic intolerance upon return to Earth gravity. The cardiovascular response to stimulation by sympathomimetic agents before, during, and after exposure to simulated microgravity was determined in healthy volunteers equilibrated on normal or high sodium diets in order to further the understanding of the deconditioning process.

Effect of noisy stimulation on neurobiological sensitization systems and its role for normal and pathological physiology

NASA Astrophysics Data System (ADS)

Huber, Martin; Braun, Hans; Krieg, J.\\:Urgen-Christian

2004-03-01

Sensitization is discussed as an important phenomenon playing a role in normal physiology but also with respect to the initiation and progression of a variety of neuropsychiatric disorders such as epilepsia, substance-related disorders or recurrent affective disorders. The relevance to understand the dynamics of sensitization phenomena is emphasized by recent findings that even single stimulations can induce longlasting changes in biological systems. To address specific questions associated with the sensitization dynamics, we use a computational approach and develop simple but physiologically-plausible models. In the present study we examine the effect of noisy stimulation on sensitization development in the model. We consider sub- and suprathresold stimulations with varying noise intensities and determine as response measures the (i) absolute number of stimulus-induced sensitzations and (ii) the temporal relsation of stimulus-sensitization coupling. The findings indicate that stochastic effects including stochastic resonance might well contribute to the physiology of sensitization mechanisms under both nomal and pathological conditions.

Wearable Environmental and Physiological Sensing Unit

NASA Technical Reports Server (NTRS)

Spremo, Stevan; Ahlman, Jim; Stricker, Ed; Santos, Elmer

2007-01-01

The wearable environmental and physiological sensing unit (WEPS) is a prototype of systems to be worn by emergency workers (e.g., firefighters and members of hazardous-material response teams) to increase their level of safety. The WEPS includes sensors that measure a few key physiological and environmental parameters, a microcontroller unit that processes the digitized outputs of the sensors, and a radio transmitter that sends the processed sensor signals to a computer in a mobile command center for monitoring by a supervisor. The monitored parameters serve as real-time indications of the wearer s physical condition and level of activity, and of the degree and type of danger posed by the wearer s environment. The supervisor could use these indications to determine, for example, whether the wearer should withdraw in the face of an increasing hazard or whether the wearer should be rescued.

Interaction of Salinity and CaCO3 Affects the Physiology and Fatty Acid Metabolism in Portulaca oleracea.

PubMed

Bessrour, Mouna; Chelbi, Najla; Moreno, Diego A; Chibani, Farhat; Abdelly, Chedly; Carvajal, Micaela

2018-06-25

As a result of the extreme conditions that usually occur in Mediterranean climates, the objective of this work is to study the combined and/or separate effects of saline and alkaline stresses in Portulaca oleracea. The study was carried out to determine the nutritional food potential in relation to plant physiological parameters. The results show that alkaline media in which CaCO 3 was present did not affect growth but exposure to 100 mM NaCl decreased it greatly. Fatty acid content increased under all stress conditions but to a higher extent with salinity; however, the protein content was increased only by alkaline media. The beneficial effect of each stress on P. oleracea is discussed in light of the physiological response, pointing out the suitability of this plant for human nutrition.

N95 respirator use during advanced pregnancy.

PubMed

Roberge, Raymond J; Kim, Jung-Hyun; Powell, Jeffrey B

2014-10-01

To determine the physiological and subjective effects of wearing an N95 filtering facepiece respirator (N95 FFR) in advanced stages of pregnancy. Healthy pregnant women (n = 22) and nonpregnant women (n = 22) had physiological and subjective measurements taken with and without wearing an N95 FFR during exercise and postural sedentary activities over a 1-hour period. There were no differences between the pregnant and nonpregnant women with respect to heart rate, respiratory rate, oxygen saturation, transcutaneous carbon dioxide level, chest wall temperature, aural temperature, and subjective perceptions of exertion and thermal comfort. No significant effect on fetal heart rate was noted. Healthy pregnant women wearing an N95 FFR for 1 hour during exercise and sedentary activities did not exhibit any significant differences in measured physiological and subjective responses compared with nonpregnant women. Published by Elsevier Inc.

Distance Education Teaching Methods and Student Responses in the Animal Sciences

ERIC Educational Resources Information Center

Bing, Jada Quinome

2012-01-01

The overall objective of this dissertation is to observe whether or not an Anatomy & Physiology Distance Education (DistEd) course offered in the Animal Science Department will prove to be valuable in the learning process for students. Study 1 was conducted to determine whether gross anatomy of animals could be taught effectively at the…

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...

Physiological, biochemical, and psychological responses in air traffic control personnel : comparison of the 5-day and 2-2-1 shift rotation patterns.

DOT National Transportation Integrated Search

1973-12-01

Stress in controllers on the straight five-day shift was determined at Houston Intercontinental Tower in 1970. In 1971 controllers on the 2-2-1 rotation were studied at the same tower. Controllers generally prefer the 2-2-1 to the straight five-day s...

Species Extrapolation of Life-Stage Physiologically-Based Pharmacokinetic (PBPK) Models to Investigate the Developmental Toxicology of Ethanol Using In vitro to In vivo (IVIVE) Methods

EPA Science Inventory

To provide useful alternatives to in vivo animal studies, in vitro assays for dose-response assessments of xenobiotic chemicals must use concentrations in media and target tissues that are within biologically-plausible limits. Determining these concentrations is a complex matter,...

Effects of climate on growth traits of river red gum are determined by respiration parameters

Treesearch

Richard S. Criddle; Thimmappa S. Anekonda; Sharon Tong; John N. Church; F. Thomas Ledig; Lee D. Hansen

2000-01-01

Temperature is the major uncontrollable climate variable in plantation forestry. Matching plants to climate is essential for optimizing growth. Matching is usually done with field trials because of the lack of a predictive relation between laboratory measurements of physiological responses and climatic factors affecting growth. This paper evaluates the potential of...

The Influence of a High Intensity Physical Activity Intervention on a Selection of Health Related Outcomes: An Ecological Approach

ClinicalTrials.gov

2009-12-04

To Assess the Impact of the HIT Intervention on Physiological Responses; To Assess the Role of a Secondary High School as a Setting for Promoting Healthy Eating and PA Behaviours; To Determine the Associations Between CVD Risk Factors at Baseline in 15 - 18 Year Old Youth

Effects of steering demand on lane keeping behaviour, self-reports, and physiology. A simulator study.

PubMed

Dijksterhuis, Chris; Brookhuis, Karel A; De Waard, Dick

2011-05-01

In this study a driving simulator was used to determine changes in mental effort in response to manipulations of steering demand. Changes in mental effort were assessed by using subjective effort ratings, physiology, and the standard deviation of the lateral position. Steering demand was increased by exposure to narrow lane widths and high density oncoming traffic while speed was fixed in all conditions to prevent a compensatory reaction. Results indicated that both steering demand factors influence mental effort expenditure and using multiple measures contributes to effort assessment. Application of these outcomes for adaptive automation is envisaged. Copyright © 2010 Elsevier Ltd. All rights reserved.

Clinical use of virtual reality distraction system to reduce anxiety and pain in dental procedures.

PubMed

Wiederhold, Mark D; Gao, Kenneth; Wiederhold, Brenda K

2014-06-01

Virtual reality (VR) has been used by clinicians to manage pain in clinical populations. This study examines the use of VR as a form of distraction for dental patients using both subjective and objective measures to determine how a VR system affects patients' reported anxiety level, pain level, and physiological factors. As predicted, results of self-evaluation questionnaires showed that patients experienced less anxiety and pain after undergoing VR treatment. Physiological data reported similar trends in decreased anxiety. Overall, the favorable subjective and objective responses suggest that VR distraction systems can reduce discomfort and pain for patients with mild to moderate fear and anxiety.

Hemodynamic and Thermal Responses to Head and Neck Cooling in Men and Women

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Montgomery, Leslie D.; Carbo, Jorge E.; Webbon, Bruce W.

1995-01-01

Personal cooling systems are used to alleviate symptoms of multiple sclerosis and to prevent increased core temperature during daily activities. Configurations of these systems include passive ice vests and circulating liquid cooling garments (LCGs) in the forms of vests, cooling caps and combined head and neck cooling systems. However, little information is available oil the amount or heat that can be extracted from the body with these systems or the physiologic changes produced by routine operation of these systems. The objective of this study was to determine the operating characteristics and the physiologic change, produced by short term use of one commercially available thermal control system.

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

PubMed

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

2015-04-01

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

Intense flight and endotoxin injection elicit similar effects on leukocyte distributions but dissimilar effects on plasma-based immunological indices in pigeons.

PubMed

Matson, Kevin D; Horrocks, Nicholas P C; Tieleman, B Irene; Haase, Eberhard

2012-11-01

Most birds rely on flight for survival. Yet as an energetically taxing and physiologically integrative process, flight has many repercussions. Studying pigeons (Columba livia) and employing physiological and immunological indices that are relevant to ecologists working with wild birds, we determined what, if any, acute immune-like responses result from bouts of intense, non-migratory flight. We compared the effects of flight with the effects of a simulated bacterial infection. We also investigated indices in terms of their post-flight changes within individuals and their relationship with flight speed among individuals. Compared to un-flown controls, flown birds exhibited significant elevations in numbers of heterophils relative to numbers of lymphocytes and significant reductions in numbers of eosinophils and monocytes. Furthermore, within-individual changes in concentrations of an acute phase protein were greater in flown birds than in controls. However, none of the flight-affected indices showed any evidence of being related to flight speed. While some of the effects of flight were comparable to the effects of the simulated bacterial infection, other effects were observed only after one of these two physiological challenges. Our study suggests that flight by pigeons yields immune-like responses, and these responses have the potential to complicate the conclusions drawn by ecologists regarding immune function in free-living birds. Still, a better understanding of the repercussions of flight can help clarify the ties between the physiology of exercise and the disease ecology of migration and will ultimately assist in the broader goal of accounting for immunological variation within and among species.

Sensing of triacylglycerol in the gut: different mechanisms for fatty acids and 2-monoacylglycerol.

PubMed

Kleberg, Karen; Jacobsen, Anne Katrine; Ferreira, Jozelia G; Windeløv, Johanne Agerlin; Rehfeld, Jens F; Holst, Jens Juul; de Araujo, Ivan E; Hansen, Harald S

2015-04-15

Sensing of dietary triacylglycerol in the proximal small intestine results in physiological, hormonal and behavioural responses. However, the exact physiological pathways linking intestinal fat sensing to food intake and the activation of brain circuits remain to be identified. In this study we examined the role of triacylglycerol digestion for intestinal fat sensing, and compared the effects of the triacylglycerol digestion products, fatty acids and 2-monoacylglycerol, on behavioural, hormonal and dopaminergic responses in behaving mice. Using an operant task in which mice are trained to self-administer lipid emulsions directly into the stomach, we show that inhibiting triacylglycerol digestion disrupts normal behaviour of self-administration in mice, indicating that fat sensing is conditional to digestion. When administered separately, both digestion products, 2-monoacylglycerol and fatty acids, were sensed by the mice, and self-administration patterns of fatty acids were affected by the fatty acid chain length. Peripheral plasma concentrations of the gut hormones GLP-1, GIP, PYY, CCK and insulin did not offer an explanation of the differing behavioural effects produced by 2-monoacylglycerol and fatty acids. However, combined with behavioural responses, striatal dopamine effluxes induced by gut infusions of oleic acid were significantly greater than those produced by equivalent infusions of 2-oleoylglycerol. Our data demonstrate recruitment of different signalling pathways by fatty acids and 2-monoacylglycerol, and suggest that the structural properties of fat rather than total caloric value determine intestinal sensing and the assignment of reward value to lipids. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Breath-Hold Diving.

PubMed

Fitz-Clarke, John R

2018-03-25

Breath-hold diving is practiced by recreational divers, seafood divers, military divers, and competitive athletes. It involves highly integrated physiology and extreme responses. This article reviews human breath-hold diving physiology beginning with an historical overview followed by a summary of foundational research and a survey of some contemporary issues. Immersion and cardiovascular adjustments promote a blood shift into the heart and chest vasculature. Autonomic responses include diving bradycardia, peripheral vasoconstriction, and splenic contraction, which help conserve oxygen. Competitive divers use a technique of lung hyperinflation that raises initial volume and airway pressure to facilitate longer apnea times and greater depths. Gas compression at depth leads to sequential alveolar collapse. Airway pressure decreases with depth and becomes negative relative to ambient due to limited chest compliance at low lung volumes, raising the risk of pulmonary injury called "squeeze," characterized by postdive coughing, wheezing, and hemoptysis. Hypoxia and hypercapnia influence the terminal breakpoint beyond which voluntary apnea cannot be sustained. Ascent blackout due to hypoxia is a danger during long breath-holds, and has become common amongst high-level competitors who can suppress their urge to breathe. Decompression sickness due to nitrogen accumulation causing bubble formation can occur after multiple repetitive dives, or after single deep dives during depth record attempts. Humans experience responses similar to those seen in diving mammals, but to a lesser degree. The deepest sled-assisted breath-hold dive was to 214 m. Factors that might determine ultimate human depth capabilities are discussed. © 2018 American Physiological Society. Compr Physiol 8:585-630, 2018. Copyright © 2018 American Physiological Society. All rights reserved.

Methyl farnesoate synthesis is necessary for the environmental sex determination in the water flea Daphnia pulex.

PubMed

Toyota, Kenji; Miyakawa, Hitoshi; Hiruta, Chizue; Furuta, Kenjiro; Ogino, Yukiko; Shinoda, Tetsuro; Tatarazako, Norihisa; Miyagawa, Shinichi; Shaw, Joseph R; Iguchi, Taisen

2015-09-01

Sex-determination systems can be divided into two groups: genotypic sex determination (GSD) and environmental sex determination (ESD). ESD is an adaptive life-history strategy that allows control of sex in response to environmental cues in order to optimize fitness. However, the molecular basis of ESD remains largely unknown. The micro crustacean Daphnia pulex exhibits ESD in response to various external stimuli. Although methyl farnesoate (MF: putative juvenile hormone, JH, in daphnids) has been reported to induce male production in daphnids, the role of MF as a sex-determining factor remains elusive due to the lack of a suitable model system for its study. Here, we establish such a system for ESD studies in D. pulex. The WTN6 strain switches from producing females to producing males in response to the shortened day condition, while the MFP strain only produces females, irrespective of day-length. To clarify whether MF has a novel physiological role as a sex-determining factor in D. pulex, we demonstrate that a MF/JH biosynthesis inhibitor suppressed male production in WTN6 strain reared under the male-inducible condition, shortened day-length. Moreover, we show that juvenile hormone acid O-methyltransferase (JHAMT), a critical enzyme of MF/JH biosynthesis, displays MF-generating activity by catalyzing farnesoic acid. Expression of the JHAMT gene increased significantly just before the MF-sensitive period for male production in the WTN6 strain, but not in the MFP strain, when maintained under male-inducible conditions. These results suggest that MF synthesis regulated by JHAMT is necessary for male offspring production in D. pulex. Our findings provide novel insights into the genetic underpinnings of ESD and they begin to shed light on the physiological function of MF as a male-fate determiner in D. pulex. Copyright © 2015 Elsevier Ltd. All rights reserved.

Plant growth enhancement and associated physiological responses are coregulated by ethylene and gibberellin in response to harpin protein Hpa1.

PubMed

Li, Xiaojie; Han, Bing; Xu, Manyu; Han, Liping; Zhao, Yanying; Liu, Zhilan; Dong, Hansong; Zhang, Chunling

2014-04-01

The harpin protein Hpa1 produced by the bacterial blight pathogen of rice induces several growth-promoting responses in plants, activating the ethylene signaling pathway, increasing photosynthesis rates and EXPANSIN (EXP) gene expression levels, and thereby enhancing the vegetative growth. This study was attempted to analyze any mechanistic connections among the above and the role of gibberellin in these responses. Hpa1-induced growth enhancement was evaluated in Arabidopsis, tomato, and rice. And growth-promoting responses were determined mainly as an increase of chlorophyll a/b ratio, which indicates a potential elevation of photosynthesis rates, and enhancements of photosynthesis and EXP expression in the three plant species. In Arabidopsis, Hpa1-induced growth-promoting responses were partially compromised by a defect in ethylene perception or gibberellin biosynthesis. In tomato and rice, compromises of Hpa1-induced growth-promoting responses were caused by a pharmacological treatment with an ethylene perception inhibitor or a gibberellin biosynthesis inhibitor. In the three plant species, moreover, Hpa1-induced growth-promoting responses were significantly impaired, but not totally eliminated, by abolishing ethylene perception or gibberellin synthesis. However, simultaneous nullifications in both ethylene perception and gibberellin biosynthesis almost canceled the full effects of Hpa1 on plant growth, photosynthesis, and EXP2 expression. Theses results suggest that ethylene and gibberellin coregulate Hpa1-induced plant growth enhancement and associated physiological and molecular responses.

Effects of diet and exposure to hindlimb suspension on estrous cycling in Sprague-Dawley rats

NASA Technical Reports Server (NTRS)

Tou, Janet C L.; Grindeland, Richard E.; Wade, Charles E.

2004-01-01

Various factors can disrupt the female reproductive cycle resulting in subfertility. The primary objective of this study was to determine whether physiological changes associated with exposure to hypogravity disrupt reproductive cycles. The hindlimb suspension (HLS) model was used to simulate the major physiological effects of hypogravity in female Sprague-Dawley rats. Also, to determine whether diet may influence reproductive results, rats were fed purified American Institute of Nutrition (AIN)-93G or chow diet. Rats (n = 9-11/group) subjected to HLS had lengthened estrous cycles due to prolonged diestrus, indicating hypoestrogenism. Interestingly, HLS rats fed AIN-93G but not chow diet had significantly reduced time spent in estrus and decreased plasma estradiol. Attenuation of hypoestrogenism in the chow-fed rats suggested that diet provided an exogenous source of estrogen. The mechanism involved in the disruption of estrous cycling remains to be determined. HLS increased urinary corticosterone (CORT) levels during the initial 4 days of HLS, suggesting that physiological responses to acute stress may be a potential mechanism in the disruption of estrous cycles. Higher basal urinary CORT was observed in rats fed chow vs. AIN-93G diet. HLS resulted in increased urinary CORT. However, two-way ANOVA indicated a significant HLS effect (P < 0.001) but no effect of HLS x diet effect on urinary CORT levels, suggesting that estrogenic activity associated with the chow diet did not enhance the stress response. The results of this study indicate that HLS, diet, and the combination of HLS and diet influence estrous cycling. This has important implications for future reproductive success in the hypogravity environment of space.

Assessment of Psychophysiological Responses During Motion Sickness Testing

NASA Technical Reports Server (NTRS)

Stoud, Cynthia S.; Toscano, William B.; Cowings, Patricia; Freidman, Gary

1994-01-01

The purpose of this investigation is to evaluate a methodology designed to accurately trace the temporal progression of motion sickness and space motion sickness symptoms. With this method, subjects continuously monitor their own motion sickness symptoms during exposure to a provocative stimulus as symptoms occur, in contrast to previous methods during which subjects report symptoms verbally at discrete time intervals. This method not only is comparable to previous methods in the type of symptoms that subjects report, but subjects report symptoms more frequently. Frequent reporting of motion sickness symptoms allows researchers to detail the waxing and waning of motion sickness symptoms for each individual. Previous research has shown that physiological responses to motion sickness stimuli are characterized by unique individual differences in response patterns. By improving our assessment of motion sickness symptoms with continuous monitoring of symptoms, the relationship between specific physiological responses and sickness levels can be more accurately determined for each individual. Results from this study show significant positive relationships between skin conductance levels and symptom levels for ten individuals; a significant positive relationship between temperature and symptom levels for 5 of 10 individuals; and both positive and negative relationships between respiration, heart rate, blood volume pulse and symptom levels. Continuous monitoring of motion sickness symptoms can be used to more accurately assess motion sickness to aid in the evaluation of countermeasures. In addition, recognition of the onset of symptoms that are strongly related to specific physiological responses could be used as cues to initiate procedures (e.g., Autogenic Feedback Training) to prevent the development of severe motion sickness symptoms.

Physiological responsiveness of motor vehicle accident survivors with chronic posttraumatic stress disorder.

PubMed

Veazey, Connie H; Blanchard, Edward B; Hickling, Edward J; Buckley, Todd C

2004-03-01

This study sought to replicate past research that has shown differences in physiological responsiveness among survivors of motor vehicle accidents (MVAs) with posttraumatic stress disorder (PTSD) and those survivors who do not develop this disorder. Such physiological differences have been found specifically with heart rate (HR) reactivity. This study also attempts to account for differences among those survivors with PTSD who do respond physiologically in laboratory situations and those who do not show a physiological response when presented with audiotaped descriptions of their accidents. Results replicated the significant differences in HR reactivity between diagnostic groups with chronic PTSD versus those with subsyndromal PTSD and non-PTSD. Variables related to the severity of the diagnosis and trauma were found to discriminate between physiological responders and nonresponders with chronic PTSD.

Manipulating glucocorticoids in wild animals: basic and applied perspectives

PubMed Central

Sopinka, Natalie M.; Patterson, Lucy D.; Redfern, Julia C.; Pleizier, Naomi K.; Belanger, Cassia B.; Midwood, Jon D.; Crossin, Glenn T.; Cooke, Steven J.

2015-01-01

One of the most comprehensively studied responses to stressors in vertebrates is the endogenous production and regulation of glucocorticoids (GCs). Extensive laboratory research using experimental elevation of GCs in model species is instrumental in learning about stressor-induced physiological and behavioural mechanisms; however, such studies fail to inform our understanding of ecological and evolutionary processes in the wild. We reviewed emerging research that has used GC manipulations in wild vertebrates to assess GC-mediated effects on survival, physiology, behaviour, reproduction and offspring quality. Within and across taxa, exogenous manipulation of GCs increased, decreased or had no effect on traits examined in the reviewed studies. The notable diversity in responses to GC manipulation could be associated with variation in experimental methods, inherent differences among species, morphs, sexes and age classes, and the ecological conditions in which responses were measured. In their current form, results from experimental studies may be applied to animal conservation on a case-by-case basis in contexts such as threshold-based management. We discuss ways to integrate mechanistic explanations for changes in animal abundance in altered environments with functional applications that inform conservation practitioners of which species and traits may be most responsive to environmental change or human disturbance. Experimental GC manipulation holds promise for determining mechanisms underlying fitness impairment and population declines. Future work in this area should examine multiple life-history traits, with consideration of individual variation and, most importantly, validation of GC manipulations within naturally occurring and physiologically relevant ranges. PMID:27293716

Patterning of physiological and affective responses in older active adults during a maximal graded exercise test and self-selected exercise.

PubMed

Smith, Ashleigh E; Eston, Roger; Tempest, Gavin D; Norton, Belinda; Parfitt, Gaynor

2015-09-01

The American College of Sports Medicine has highlighted the importance of considering the physiological and affective responses to exercise when setting exercise intensity. Here, we examined the relationship between exercise intensity and physiological and affective responses in active older adults. Eighteen participants (60-74 years; 64.4 ± 3.9; 8 women) completed a maximal graded exercise test (GXT) on a treadmill. Since time to exhaustion in the GXT differed between participants, heart rate (HR), oxygen consumption (VO2), affective valence (affect) and rating of perceived exertion (RPE) were expressed relative to the individually determined ventilatory threshold (%atVT). During the GXT, VO2, HR and RPE increased linearly (all P < 0.01). Affect declined initially (but remained positive) (P = 0.03), stabilised around VT (still positive) (P > 0.05) and became negative towards the end of the test (P < 0.01). In a subsequent session, participants completed a 20-min bout of self-selected exercise (at a preferred intensity). Initially, participants chose to exercise below VT (88.2 ± 17.4 %VO2atVT); however, the intensity was adjusted to work at, or above VT (107.7 ± 19.9 %VO2atVT) after 10 min (P < 0.001), whilst affect remained positive. Together, these findings indicate that exercise around VT, whether administered during an exercise test, or self-selected by the participant, is likely to result in positive affective responses in older adults.

Magnitude and duration of cue-induced craving for marijuana in volunteers with cannabis use disorder

PubMed Central

Lundahl, Leslie H.; Greenwald, Mark K.

2016-01-01

Aims Evaluate magnitude and duration of subjective and physiologic responses to neutral and marijuana (MJ)–related cues in cannabis dependent volunteers. Methods 33 volunteers (17 male) who met DSM-IV criteria for Cannabis Abuse or Dependence were exposed to neutral (first) then MJ-related visual, auditory, olfactory and tactile cues. Mood, drug craving and physiology were assessed at baseline, post-neutral, post-MJ and 15-min post MJ cue exposure to determine magnitude of cue- responses. For a subset of participants (n=15; 9 male), measures of craving and physiology were collected also at 30-, 90-, and 150-min post-MJ cue to examine duration of cue-effects. Results In cue-response magnitude analyses, visual analog scale (VAS) items craving for, urge to use, and desire to smoke MJ, Total and Compulsivity subscale scores of the Marijuana Craving Questionnaire, anxiety ratings, and diastolic blood pressure (BP) were significantly elevated following MJ vs. neutral cue exposure. In cue-response duration analyses, desire and urge to use MJ remained significantly elevated at 30-, 90- and 150-min post MJ-cue exposure, relative to baseline and neutral cues. Conclusions Presentation of polysensory MJ cues increased MJ craving, anxiety and diastolic BP relative to baseline and neutral cues. MJ craving remained elevated up to 150-min after MJ cue presentation. This finding confirms that carry-over effects from drug cue presentation must be considered in cue reactivity studies. PMID:27436749

Magnitude and duration of cue-induced craving for marijuana in volunteers with cannabis use disorder.

PubMed

Lundahl, Leslie H; Greenwald, Mark K

2016-09-01

Evaluate magnitude and duration of subjective and physiologic responses to neutral and marijuana (MJ)-related cues in cannabis dependent volunteers. 33 volunteers (17 male) who met DSM-IV criteria for Cannabis Abuse or Dependence were exposed to neutral (first) then MJ-related visual, auditory, olfactory and tactile cues. Mood, drug craving and physiology were assessed at baseline, post-neutral, post-MJ and 15-min post MJ cue exposure to determine magnitude of cue- responses. For a subset of participants (n=15; 9 male), measures of craving and physiology were collected also at 30-, 90-, and 150-min post-MJ cue to examine duration of cue-effects. In cue-response magnitude analyses, visual analog scale (VAS) items craving for, urge to use, and desire to smoke MJ, Total and Compulsivity subscale scores of the Marijuana Craving Questionnaire, anxiety ratings, and diastolic blood pressure (BP) were significantly elevated following MJ vs. neutral cue exposure. In cue-response duration analyses, desire and urge to use MJ remained significantly elevated at 30-, 90- and 150-min post MJ-cue exposure, relative to baseline and neutral cues. Presentation of polysensory MJ cues increased MJ craving, anxiety and diastolic BP relative to baseline and neutral cues. MJ craving remained elevated up to 150-min after MJ cue presentation. This finding confirms that carry-over effects from drug cue presentation must be considered in cue reactivity studies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Contribution of elastin and collagen to the inflation response of the pig thoracic aorta: assessing elastin's role in mechanical homeostasis.

PubMed

Lillie, M A; Armstrong, T E; Gérard, S G; Shadwick, R E; Gosline, J M

2012-08-09

This study was undertaken to understand elastin's role in the mechanical homeostasis of the arterial wall. The mechanical properties of elastin vary along the aorta, and we hypothesized this maintained a uniform mechanical environment for the elastin, despite regional variation in loading. Elastin's physiological loading was determined by comparing the inflation response of intact and autoclave purified elastin aortas from the proximal and distal thoracic aorta. Elastin's stretch and stress depend on collagen recruitment. Collagen recruitment started in the proximal aorta at systolic pressures (13.3 to 14.6 kPa) and in the distal at sub-diastolic pressures (9.3 to 10.6 kPa). In the proximal aorta collagen did not contribute significantly to the stress or stiffness, indicating that elastin determined the vessel properties. In the distal aorta, the circumferential incremental modulus was 70% higher than in the proximal aorta, half of which (37%) was due to a stiffening of the elastin. Compared to the elastin tissue in the proximal aorta, the distal elastin suffered higher physiological circumferential stretch (29%, P=0.03), circumferential stress (39%, P=0.02), and circumferential stiffness (37%, P=0.006). Elastin's physiological axial stresses were also higher (67%, P=0.003). These findings do not support the hypothesis that the loading on elastin is constant along the aorta as we expected from homeostasis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dynamics of Lung Defense in Pneumonia: Resistance, Resilience, and Remodeling

PubMed Central

Quinton, Lee J.; Mizgerd, Joseph P.

2015-01-01

Pneumonia is initiated by microbes in the lung, but physiological processes integrating responses across diverse cell types and organ systems dictate the outcome of respiratory infection. Resistance, or actions of the host to eradicate living microbes, in the lungs involves a combination of innate and adaptive immune responses triggered by air-space infection. Resilience, or the ability of the host tissues to withstand the physiologically damaging effects of microbial and immune activities, is equally complex, precisely regulated, and determinative. Both immune resistance and tissue resilience are dynamic and change throughout the lifetime, but we are only beginning to understand such remodeling and how it contributes to the incidence of severe pneumonias, which diminishes as childhood progresses and then increases again among the elderly. Here, we review the concepts of resistance, resilience, and remodeling as they apply to pneumonia, highlighting recent advances and current significant knowledge gaps. PMID:25148693

[Physiological reactivity and interoceptive awareness in pediatric anxiety disorders: A conceptual and empirical review].

PubMed

Rossignol, Mandy; Philippot, Pierre; Vögele, Claus

Objectives This review aims to summarize the data relative to objective and subjective measures of body responses in children and adolescents with anxiety.Methods We reviewed 24 studies measuring (1) cardiac responses and (2) interoceptive processes in children and adolescents with anxiety.Results Anxious children and adolescents generally do not differ from their non-anxious peers on their cardiac parameters and objective physiological reactivity to stressful events but some results suggest a reduced autonomic flexibility in pediatric anxiety related to chronic anxiety. Moreover, anxiety does not alter the interoceptive accuracy, but youths with anxiety misinterpret the intensity and the visibility of their symptoms.Conclusion Interoception are biased in pediatric anxiety and further studies are needed to provide information about the role of perceptive, attentional, and interpretative processes in these biases, as well as determine the respective influence of anxiety type and symptoms intensity.

Differentiation of K562 cells under ELF-EMF applied at different time courses.

PubMed

Ayşe, Inhan-Garip; Zafer, Akan; Sule, Oncul; Işil, Işal-Turgut; Kalkan, Tunaya

2010-08-01

The time-course of ELF-EMF application to biological systems is thought to be an important parameter determining the physiological outcome. This study investigated the effect of ELF-EMF on the differentiation of K562 cells at different time courses. ELF-EMF (50 Hz, 5 mT, 1 h) was applied at two different time-courses; first at the onset of hemin induction for 1 h, and second, daily 1 h for four days. While single exposure to ELF-EMF resulted in a decrease in differentiation, ELF-EMF applied everyday for 1 h caused an increase in differentiation. The effect of co-stressors, magnesium, and heat-shock was also determined and similar results were obtained. ELF-EMF increased ROS levels in K562 cells not treated with hemin, however did not change ROS levels of hemin treated cells indicating that ROS was not the cause. Overall, these results imply that the time-course of application is an important parameter determining the physiological response of cells to ELF-EMF.

Theoretical analysis of insulin-dependent glucose uptake heterogeneity in 3D bioreactor cell culture.

PubMed

Magrofuoco, Enrico; Elvassore, Nicola; Doyle, Francis J

2012-01-01

Three-dimensional (3D) cell cultures in bioreactors are becoming relevant as models for biological and physiological in vitro studies. In such systems, mathematical models can assist the experiment design that links the macroscopic properties to single-cell responses. We investigated the relationship between biochemical stimuli and cell response within a 3D cell culture in scaffold with heterogeneous porosity. Specifically, we studied the effect of insulin on the local glucose metabolism as a function of 3D pore size distribution. The multiscale mathematical model combines the mass transport within a 3D scaffold and a signaling pathways model. It considers the scaffold heterogeneity, and it describes spatiotemporal concentration of metabolites, biochemical stimuli, and cell density. The signaling model was integrated into this model, linking the local insulin concentration at cell membrane to the glucose uptake rate through glucose transporter type 4 (GLUT4) translocation from the cytosol to the cell membrane. The integrated model determines the cell response heterogeneities in a single channel, hence the biological response distribution in a 3D system. It also provides macroscopic outcomes to evaluate the feasibility of an experimental measurement of the system response. From our analysis, it became apparent that the flow rate is the most important operative variable, and that an optimum value ensures a fast and detectable cell response. This model on insulin-dependent glucose consumption rate offers insight into the cell metabolism physiology, which is a fundamental requirement for the study metabolic disorder such as Type 2 diabetes mellitus, in which the physiological insulin-dependent glucose metabolism is impaired. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

Season-dependent and independent responses of Mediterranean scrub to light conditions.

PubMed

Zunzunegui, María; Díaz-Barradas, Mari Cruz; Jáuregui, Juan; Rodríguez, Herminia; Álvarez-Cansino, Leonor

2016-05-01

Semi-arid plant species cope with excess of solar radiation with morphological and physiological adaptations that assure their survival when other abiotic stressors interact. At the leaf level, sun and shade plants may differ in the set of traits that regulate environmental stressors. Here, we evaluated if leaf-level physiological seasonal response of Mediterranean scrub species (Myrtus communis, Halimium halimifolium, Rosmarinus officinalis, and Cistus salvifolius) depended on light availability conditions. We aimed to determine which of these responses prevailed independently of the marked seasonality of Mediterranean climate, to define a leaf-level strategy in the scrub community. Thirty six leaf response variables - involving gas exchange, water status, photosystem II photochemical efficiency, photosynthetic pigments and leaf structure - were seasonally measured in sun exposed and shaded plants under field conditions. Physiological responses showed a common pattern throughout the year, in spite of the marked seasonality of the Mediterranean climate and of species-specific differences in the response to light intensity. Variables related to light use, CO2 assimilation, leaf pigment content, and LMA (leaf mass area) presented differences that were consistent throughout the year, although autumn was the season with greater contrast between sun and shade plants. Our data suggest that in Mediterranean scrub shade plants the lutein pool could have an important role in the photoprotection of the photosynthetic tissues. There was a negative linear correlation between the ratio lutein/total chlorophylls and the majority of leaf level variables. The combined effect of abiotic stress factors (light and drought or light and cold) was variable-specific, in some cases enhancing differences between sun and shade plants, while in others leading to unified strategies in all scrub species. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Biaxial Mechanical Evaluation of Absorbable and Nonabsorbable Synthetic Surgical Meshes Used for Hernia Repair: Physiological Loads Modify Anisotropy Response.

PubMed

Cordero, A; Hernández-Gascón, B; Pascual, G; Bellón, J M; Calvo, B; Peña, E

2016-07-01

The aim of this study was to obtain information about the mechanical properties of six meshes commonly used for hernia repair (Surgipro(®), Optilene(®), Infinit(®), DynaMesh(®), Ultrapro™ and TIGR(®)) by planar biaxial tests. Stress-stretch behavior and equibiaxial stiffness were evaluated, and the anisotropy was determined by testing. In particular, equibiaxial test (equal simultaneous loading in both directions) and biaxial test (half of the load in one direction following the Laplace law) were selected as a representation of physiologically relevant loads. The majority of the meshes displayed values in the range of 8 and 18 (N/mm) in each direction for equibiaxial stiffness (tangent modulus under equibiaxial load state in both directions), while a few achieved 28 and 50 (N/mm) (Infinit (®) and TIGR (®)). Only the Surgipro (®) mesh exhibited planar isotropy, with similar mechanical properties regardless of the direction of loading, and an anisotropy ratio of 1.18. Optilene (®), DynaMesh (®), Ultrapro (®) and TIGR (®) exhibited moderate anisotropy with ratios of 1.82, 1.84, 2.17 and 1.47, respectively. The Infinit (®) scaffold exhibited very high anisotropy with a ratio of 3.37. These trends in material anisotropic response changed during the physiological state in the human abdominal wall, i.e. T:0.5T test, which the meshes were loaded in one direction with half the load used in the other direction. The Surgipro (®) mesh increased its anisotropic response (Anis[Formula: see text] = 0.478) and the materials that demonstrated moderate and high anisotropic responses during multiaxial testing presented a quasi-isotropic response, especially the Infinit(®) mesh that decreased its anisotropic response from 3.369 to 1.292.

The impact of cardiac perception on emotion experience and cognitive performance under mental stress.

PubMed

Kindermann, Nicole K; Werner, Natalie S

2014-12-01

Mental stress evokes several physiological responses such as the acceleration of heart rate, increase of electrodermal activity and the release of adrenaline. Moreover, physiological stress responses interact with emotional and behavioral stress responses. In the present study we provide evidence that viscero-sensory feedback from the heart (cardiac perception) is an important factor modulating emotional and cognitive stress responses. In our study, we compared participants with high versus low cardiac perception using a computerized mental stress task, in which they had to respond to rapidly presented visual and acoustic stimuli. Additionally, we assessed physiological responses (heart rate, skin conductance). Participants high in cardiac perception reported more negative emotions and showed worse task performance under the stressor than participants low in cardiac perception. These results were not moderated by physiological responses. We conclude that cardiac perception modulates stress responses by intensifying negative emotions and by impairing cognitive performance.

Cardiac iodine-123-metaiodobenzylguanidine scintigraphy may be useful to identify pathologic from physiologic sinus bradycardia.

PubMed

Sunaga, Akihiro; Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Kanda, Takashi; Matsuda, Yasuhiro; Morozumi, Takakazu; Mano, Toshiaki; Uematsu, Masaaki

2017-06-01

Sinus bradycardia includes pathologic sick sinus syndrome (SSS) and physiologic bradycardia such as athletes' heart. Pacemaker implantation is indicated for patients with symptomatic SSS; however, the indication remains difficult to determine in those with mild and/or unspecific symptoms. The sympathetic tone is increased in response to reduced cardiac output in SSS, whereas excessive vagal tone has been seen in physiological bradycardia. We sought to determine if cardiac iodine-123-metaiodobenzylguanidine scintigraphy ( 123 I-MIBG) was useful in differentiating pathologic from physiologic sinus bradycardia. Twenty consecutive patients presenting with continuous sinus bradycardia (heart rate of <50 beats/min) in our outpatient clinic (male, eight patients; age, 70 ± 12 years old) were enrolled. The indication for a pacemaker implantation was determined by an experienced electrophysiologist in compliance with the international guidelines. The sympathetic nervous tone was assessed by cardiac 123 I-MIBG. Eight patients (40%) were clinically diagnosed as SSS (type I) including four suffering from obvious symptoms (syncope or dizziness) and four suffering from mild symptoms (fatigue), and had an indication for a pacemaker implantation. The patients with SSS indicated for a pacemaker implantation had a lower early heart-to-mediastinum ratio (2.0 ± 0.6 vs 2.5 ± 0.2, P = 0.043), lower delayed heart to mediastinum ratio (2.0 ± 0.8 vs 2.8 ± 0.3, P = 0.026), and higher washout rate (34 ± 6.0 vs 26 ± 6.0, P = 0.008) than those without. Excessive sympathetic tone detected by 123 I-MIBG may serve as an adjunct to determine the indication for a pacemaker implantation in sinus bradycardia. © 2017 Wiley Periodicals, Inc.

Physiologic Waveform Analysis for Early Detection of Hemorrhage during Transport and Higher Echelon Medical Care of Combat Casualties

DTIC Science & Technology

2011-11-01

stimulation to HR fluctuations that were experi- mentally determined by Berger et al. (8) in dogs with typical ILV3HR and ABP3HR impulse responses that were...pure vagal and sympathetic stimulation to HR fluctuations that were experimentally determined in dogs (middle; reproduced from Ref. 8) with typical...repre- sents an extrapolation of the efferent autonomic nervous limbs in dogs to the afferent, central, and efferent autonomic nervous limbs in humans

Physiologic Waveform Analysis for Early Detection of Hemorrhage during Transport and Higher Echelon Medical Care of Combat Casualties

DTIC Science & Technology

2012-11-01

vagal and sympathetic stimulation to HR fluctuations that were experi- mentally determined by Berger et al. (8) in dogs with typical ILV3HR and ABP3HR...impulse responses relating pure vagal and sympathetic stimulation to HR fluctuations that were experimentally determined in dogs (middle; reproduced...shown in Fig. 1 effectively repre- sents an extrapolation of the efferent autonomic nervous limbs in dogs to the afferent, central, and efferent

Stress physiology as a predictor of survival in Galapagos marine iguanas

PubMed Central

Romero, L. Michael; Wikelski, Martin

2010-01-01

Although glucocorticoid hormones are considered important physiological regulators for surviving adverse environmental stimuli (stressors), evidence for such a role is sparse and usually extrapolated from glucocorticoid effects under laboratory, short-term and/or non-emergency conditions. Galápagos marine iguanas (Amblyrhynchus cristatus) provide an excellent model for determining the ultimate function of a glucocorticoid response because susceptibility to starvation induced by El Niño conditions is essentially their only major natural stressor. In a prospective study, we captured 98 adult male marine iguanas and assessed four major components of their glucocorticoid response: baseline corticosterone titres; corticosterone responses to acute stressors (capture and handling); the maximal capacity to secrete corticosterone (via adrenocorticotropin injection); and the ability to terminate corticosterone responses (negative feedback). Several months after collecting initial measurements, weak El Niño conditions affected the Galápagos and 23 iguanas died. The dead iguanas were typified by a reduced efficacy of negative feedback (i.e. poorer post-stress suppression of corticosterone release) compared with surviving iguanas. We found no prior differences between dead and alive iguanas in baseline corticosterone concentrations, responses to acute stressors, nor in capacity to respond. These data suggest that a greater ability to terminate a stress response conferred a survival advantage during starvation. PMID:20504812

The physiological effects of oil, dispersant and dispersed oil on the bay mussel, Mytilus trossulus, in Arctic/Subarctic conditions.

PubMed

Counihan, Katrina L

2018-06-01

Increasing oil development around Alaska and other Arctic regions elevates the risk for another oil spill. Dispersants are used to mitigate the impact of an oil spill by accelerating natural degradation processes, but the reduced hydrophobicity of dispersed oil may increase its bioavailability to marine organisms. There is limited research on the effect of dispersed oil on cold water species and ecosystems. Therefore, spiked exposure tests were conducted with bay mussels (Mytilus trossulus) in seawater with non-dispersed oil, Corexit 9500 and oil dispersed with different concentrations of Corexit 9500. After three weeks of exposure, acute and chronic physiological impacts were determined. The majority of physiological responses occurred during the first seven days of exposure, with mussels exhibiting significant cytochrome P450 activity, superoxide dismutase activity and heat shock protein levels. Mussels exposed to non-dispersed oil also experienced immune suppression, reduced transcription and higher levels of mortality. After 21 days, mussels in all treatments exhibited evidence of genetic damage, tissue loss and a continued stress response. Bay mussels are useful as indicators of ecosystem health and recovery, and this study was an important step in understanding how non-dispersed oil, dispersant and dispersed oil affect the physiology of this sentinel species in Arctic/subarctic conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

Coping with thermal challenges: physiological adaptations to environmental temperatures.

PubMed

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

2012-07-01

Temperature profoundly influences physiological responses in animals, primarily due to the effects on biochemical reaction rates. Since physiological responses are often exemplified by their rate dependency (e.g., rate of blood flow, rate of metabolism, rate of heat production, and rate of ion pumping), the study of temperature adaptations has a long history in comparative and evolutionary physiology. Animals may either defend a fairly constant temperature by recruiting biochemical mechanisms of heat production and utilizing physiological responses geared toward modifying heat loss and heat gain from the environment, or utilize biochemical modifications to allow for physiological adjustments to temperature. Biochemical adaptations to temperature involve alterations in protein structure that compromise the effects of increased temperatures on improving catalytic enzyme function with the detrimental influences of higher temperature on protein stability. Temperature has acted to shape the responses of animal proteins in manners that generally preserve turnover rates at animals' normal, or optimal, body temperatures. Physiological responses to cold and warmth differ depending on whether animals maintain elevated body temperatures (endothermic) or exhibit minimal internal heat production (ectothermic). In both cases, however, these mechanisms involve regulated neural and hormonal over heat flow to the body or heat flow within the body. Examples of biochemical responses to temperature in endotherms involve metabolic uncoupling mechanisms that decrease metabolic efficiency with the outcome of producing heat, whereas ectothermic adaptations to temperature are best exemplified by the numerous mechanisms that allow for the tolerance or avoidance of ice crystal formation at temperatures below 0°C. 2012 American Physiological Society. Compr Physiol 2:2037-2061, 2012.

Plasticity of boldness in rainbow trout, Oncorhynchus mykiss: do hunger and predation influence risk-taking behaviour?

PubMed

Thomson, Jack S; Watts, Phillip C; Pottinger, Tom G; Sneddon, Lynne U

2012-05-01

Boldness, a measure of an individual's propensity for taking risks, is an important determinant of fitness but is not necessarily a fixed trait. Dependent upon an individual's state, and given certain contexts or challenges, individuals may be able to alter their inclination to be bold or shy in response. Furthermore, the degree to which individuals can modulate their behaviour has been linked with physiological responses to stress. Here we attempted to determine whether bold and shy rainbow trout, Oncorhynchus mykiss, can exhibit behavioural plasticity in response to changes in state (nutritional availability) and context (predation threat). Individual trout were initially assessed for boldness using a standard novel object paradigm; subsequently, each day for one week fish experienced either predictable, unpredictable, or no simulated predator threat in combination with a high (2% body weight) or low (0.15%) food ration, before being reassessed for boldness. Bold trout were generally more plastic, altering levels of neophobia and activity relevant to the challenge, whereas shy trout were more fixed and remained shy. Increased predation risk generally resulted in an increase in the expression of three candidate genes linked to boldness, appetite regulation and physiological stress responses - ependymin, corticotrophin releasing factor and GABA(A) - but did not produce a significant increase in plasma cortisol. The results suggest a divergence in the ability of bold and shy trout to alter their behavioural profiles in response to internal and exogenous factors, and have important implications for our understanding of the maintenance of different behavioural phenotypes in natural populations. Copyright © 2012 Elsevier Inc. All rights reserved.

Evaluation of uptake kinetics during a wastewater diversion into nearshore coastal waters in southern California

NASA Astrophysics Data System (ADS)

Kudela, Raphael M.; Howard, Meredith D. A.; Hayashi, Kendra; Beck, Carly

2017-02-01

The global eutrophication of coastal ecosystems from anthropogenic nutrients is one of the most significant issues affecting changes to coastal oceans today. A three-week diversion of wastewater effluent from the normal offshore discharge pipe (7 km offshore, 56 m depth) to a shorter outfall located in 16 m water (2.2 km offshore) as part of the 2012 Orange County Sanitation District Diversion provided an opportunity to evaluate the impacts of anthropogenic nitrogen on phytoplankton community response. Nitrogen uptake kinetic parameters were used to evaluate the short-term physiological response of the phytoplankton community to the diverted wastewater and to determine if potential ammonium suppression of nitrate uptake was observed. Despite expectations, there was a muted response to the diversion in terms of biomass accumulation and ambient nutrients remained low. At ambient nitrogen concentrations, calculated uptake rates strongly favored ammonium. During the diversion based on the kinetic parameters determined during short-term experiments, the phytoplankton community was using all three N substrates at low concentrations, and had the capacity to use urea, then ammonium, and then nitrate at high concentrations. Ammonium suppression of nitrate uptake was evident throughout the experiment, with increasing suppression through time. Despite this interaction, there was evidence for simultaneous utilization of nitrate, ammonium, and urea during the experiment. The general lack of phytoplankton response as evidenced by low biomass during the diversion was therefore not obviously linked to changes in uptake rates, physiological capacity, or ammonium suppression of nitrate uptake.

Linking physics with physiology in TMS: a sphere field model to determine the cortical stimulation site in TMS.

PubMed

Thielscher, Axel; Kammer, Thomas

2002-11-01

A fundamental problem of transcranial magnetic stimulation (TMS) is determining the site and size of the stimulated cortical area. In the motor system, the most common procedure for this is motor mapping. The obtained two-dimensional distribution of coil positions with associated muscle responses is used to calculate a center of gravity on the skull. However, even in motor mapping the exact stimulation site on the cortex is not known and only rough estimates of its size are possible. We report a new method which combines physiological measurements with a physical model used to predict the electric field induced by the TMS coil. In four subjects motor responses in a small hand muscle were mapped with 9-13 stimulation sites at the head perpendicular to the central sulcus in order to keep the induced current direction constant in a given cortical region of interest. Input-output functions from these head locations were used to determine stimulator intensities that elicit half-maximal muscle responses. Based on these stimulator intensities the field distribution on the individual cortical surface was calculated as rendered from anatomical MR data. The region on the cortical surface in which the different stimulation sites produced the same electric field strength (minimal variance, 4.2 +/- 0.8%.) was determined as the most likely stimulation site on the cortex. In all subjects, it was located at the lateral part of the hand knob in the motor cortex. Comparisons of model calculations with the solutions obtained in this manner reveal that the stimulated cortex area innervating the target muscle is substantially smaller than the size of the electric field induced by the coil. Our results help to resolve fundamental questions raised by motor mapping studies as well as motor threshold measurements.

Conservation physiology for applied management of marine fish: an overview with perspectives on the role and value of telemetry

PubMed Central

Metcalfe, J. D.; Le Quesne, W. J. F.; Cheung, W. W. L.; Righton, D. A.

2012-01-01

Physiological studies focus on the responses of cells, tissues and individuals to stressors, usually in laboratory situations. Conservation and management, on the other hand, focus on populations. The field of conservation physiology addresses the question of how abiotic drivers of physiological responses at the level of the individual alter requirements for successful conservation and management of populations. To achieve this, impacts of physiological effects at the individual level need to be scaled to impacts on population dynamics, which requires consideration of ecology. Successfully realizing the potential of conservation physiology requires interdisciplinary studies incorporating physiology and ecology, and requires that a constructive dialogue develops between these traditionally disparate fields. To encourage this dialogue, we consider the increasingly explicit incorporation of physiology into ecological models applied to marine fish conservation and management. Conservation physiology is further challenged as the physiology of an individual revealed under laboratory conditions is unlikely to reflect realized responses to the complex variable stressors to which it is exposed in the wild. Telemetry technology offers the capability to record an animal's behaviour while simultaneously recording environmental variables to which it is exposed. We consider how the emerging insights from telemetry can strengthen the incorporation of physiology into ecology. PMID:22566680

Are plants sentient?

PubMed

Calvo, Paco; Sahi, Vaidurya Pratap; Trewavas, Anthony

2017-11-01

Feelings in humans are mental states representing groups of physiological functions that usually have defined behavioural purposes. Feelings, being evolutionarily ancient, are thought to be coordinated in the brain stem of animals. One function of the brain is to prioritise between competing mental states and, thus, groups of physiological functions and in turn behaviour. Plants use groups of coordinated physiological activities to deal with defined environmental situations but currently have no known mental state to prioritise any order of response. Plants do have a nervous system based on action potentials transmitted along phloem conduits but which in addition, through anastomoses and other cross-links, forms a complex network. The emergent potential for this excitable network to form a mental state is unknown, but it might be used to distinguish between different and even contradictory signals to the individual plant and thus determine a priority of response. This plant nervous system stretches throughout the whole plant providing the potential for assessment in all parts and commensurate with its self-organising, phenotypically plastic behaviour. Plasticity may, in turn, depend heavily on the instructive capabilities of local bioelectric fields enabling both a degree of behavioural independence but influenced by the condition of the whole plant. © 2017 John Wiley & Sons Ltd.

Hemodynamic Instability during Dialysis: The Potential Role of Intradialytic Exercise

PubMed Central

Horton, Elizabeth Jane; Renshaw, Derek; Jimenez, Alofonso; Krishnan, Nithya

2018-01-01

Acute haemodynamic instability is a natural consequence of disordered cardiovascular physiology during haemodialysis (HD). Prevalence of intradialytic hypotension (IDH) can be as high as 20–30%, contributing to subclinical, transient myocardial ischemia. In the long term, this results in progressive, maladaptive cardiac remodeling and impairment of left ventricular function. This is thought to be a major contributor to increased cardiovascular mortality in end stage renal disease (ESRD). Medical strategies to acutely attenuate haemodynamic instability during HD are suboptimal. Whilst a programme of intradialytic exercise training appears to facilitate numerous chronic adaptations, little is known of the acute physiological response to this type of exercise. In particular, the potential for intradialytic exercise to acutely stabilise cardiovascular hemodynamics, thus preventing IDH and myocardial ischemia, has not been explored. This narrative review aims to summarise the characteristics and causes of acute haemodynamic instability during HD, with an overview of current medical therapies to treat IDH. Moreover, we discuss the acute physiological response to intradialytic exercise with a view to determining the potential for this nonmedical intervention to stabilise cardiovascular haemodynamics during HD, improve coronary perfusion, and reduce cardiovascular morbidity and mortality in ESRD. PMID:29682559

Effects of salinity on baldcypress seedlings: Physiological responses and their relation to salinity tolerance

USGS Publications Warehouse

Allen, J.A.; Chambers, J.L.; Pezeshki, S.R.

1997-01-01

Growth and physiological responses of 15 open-pollinated families of baldcypress (Taxodium distichum var. distichum) subjected to flooding with saline water were evaluated in this study. Ten of the families were from coastal sites in Louisiana and Alabama, USA that have elevated levels of soil-water salinity. The other five families were from inland, freshwater sites in Louisiana. Seedlings from all families tolerated flooding with water of low (2 g l-1) salinity. Differences in biomass among families became most apparent at the highest salinity levels (6 and 8 g l-1). Overall, increasing salinity reduced leaf biomass more than root biomass, which in turn was reduced more than stem biomass. A subset of seedlings from the main greenhouse experiment was periodically placed indoors under artificial light, and measurements were made of gas exchange and leaf water potential. Also, tissue concentrations of Cl-, Na+, K+, and Ca2+ were determined at the end of the greenhouse experiment. Significant intraspecific variation was found for nearly all the physiological parameters evaluated, but only leaf concentrations of Na+ and Cl- were correlated with an index of family-level differences in salt tolerance.

Salubrious effects of oxytocin on social stress-induced deficits

PubMed Central

Smith, Adam S.; Wang, Zuoxin

2012-01-01

Social relationships are a fundamental aspect of life, affecting social, psychological, physiological, and behavioral functions. While social interactions can attenuate stress and promote health, disruption, confrontations, isolation, or neglect in the social environment can each be major stressors. Social stress can impair the basal function and stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis, impairing function of multiple biological systems and posing a risk to mental and physical health. In contrast, social support can ameliorate stress-induced physiological and immunological deficits, reducing the risk of subsequent psychological distress and improving an individual's overall well-being. For better clinical treatment of these physiological and mental pathologies, it is necessary to understand the regulatory mechanisms of stress-induced pathologies as well as determine the underlying biological mechanisms that regulate social buffering of the stress system. A number of ethologically relevant animal models of social stress and species that form strong adult social bonds have been utilized to study the etiology, treatment, and prevention of stress-related disorders. While undoubtedly a number of biological pathways contribute to the social buffering of the stress response, the convergence of evidence denotes the regulatory effects of oxytocin in facilitating social bond-promoting behaviors and their effect on the stress response. Thus, oxytocin may be perceived as a common regulatory element of the social environment, stress response, and stress-induced risks on mental and physical health. PMID:22178036

Seasonal variations of gene expression biomarkers in Mytilus galloprovincialis cultured populations: temperature, oxidative stress and reproductive cycle as major modulators.

PubMed

Jarque, Sergio; Prats, Eva; Olivares, Alba; Casado, Marta; Ramón, Montserrat; Piña, Benjamin

2014-11-15

The blue mussel Mytilus galloprovincialis has been used as monitoring organism in many biomonitoring programs because of its broad distribution in South European sea waters and its physiological characteristics. Different pollution-stress biomarkers, including gene expression biomarkers, have been developed to determine its physiological response to the presence of different pollutants. However, the existing information about basal expression profiles is very limited, as very few biomarker-based studies were designed to reflect the natural seasonal variations. In the present study, we analyzed the natural expression patterns of several genes commonly used in biomonitoring, namely ferritin, metallothionein, cytochrome P450, glutathione S-transferase, heat shock protein and the kinase responsive to stress KRS, during an annual life cycle. Analysis of mantle-gonad samples of cultured populations of M. galloprovincialis from the Delta del Ebro (North East Spain) showed natural seasonal variability of these biomarkers, pointing to temperature and oxidative stress as major abiotic modulators. In turn, the reproductive cycle, a process that can be tracked by VCLM7 expression, and known to be influenced by temperature, seems to be the major biotic factor involved in seasonality. Our results illustrate the influence of environmental factors in the physiology of mussels through their annual cycle, a crucial information for the correct interpretation of responses under stress conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

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

2013-09-30

1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. FINAL REPORT Investigation of the Physiological Responses...The overall top level goal of this effort is to investigate the physiological i.e. neuroimmunoendocrinological responses of beluga whales to...adrenocorticotropin hormone, aldosterone , catecholamines) in different matrices (blood, saliva, blow, feces) in conjunction with immune function

Promises and Challenges of Eco-Physiological Genomics in the Field: Tests of Drought Responses in Switchgrass1[OPEN

PubMed Central

Schwartz, Scott; Lowry, David B.; Aspinwall, Michael J.; Palacio-Mejia, Juan Diego; Hawkes, Christine V.; Fay, Philip A.

2016-01-01

Identifying the physiological and genetic basis of stress tolerance in plants has proven to be critical to understanding adaptation in both agricultural and natural systems. However, many discoveries were initially made in the controlled conditions of greenhouses or laboratories, not in the field. To test the comparability of drought responses across field and greenhouse environments, we undertook three independent experiments using the switchgrass reference genotype Alamo AP13. We analyzed physiological and gene expression variation across four locations, two sampling times, and three years. Relatively similar physiological responses and expression coefficients of variation across experiments masked highly dissimilar gene expression responses to drought. Critically, a drought experiment utilizing small pots in the greenhouse elicited nearly identical physiological changes as an experiment conducted in the field, but an order of magnitude more differentially expressed genes. However, we were able to define a suite of several hundred genes that were differentially expressed across all experiments. This list was strongly enriched in photosynthesis, water status, and reactive oxygen species responsive genes. The strong across-experiment correlations between physiological plasticity—but not differential gene expression—highlight the complex and diverse genetic mechanisms that can produce phenotypically similar responses to various soil water deficits. PMID:27246097

The mechanical response of talin

NASA Astrophysics Data System (ADS)

Yao, Mingxi; Goult, Benjamin T.; Klapholz, Benjamin; Hu, Xian; Toseland, Christopher P.; Guo, Yingjian; Cong, Peiwen; Sheetz, Michael P.; Yan, Jie

2016-07-01

Talin, a force-bearing cytoplasmic adapter essential for integrin-mediated cell adhesion, links the actin cytoskeleton to integrin-based cell-extracellular matrix adhesions at the plasma membrane. Its C-terminal rod domain, which contains 13 helical bundles, plays important roles in mechanosensing during cell adhesion and spreading. However, how the structural stability and transition kinetics of the 13 helical bundles of talin are utilized in the diverse talin-dependent mechanosensing processes remains poorly understood. Here we report the force-dependent unfolding and refolding kinetics of all talin rod domains. Using experimentally determined kinetics parameters, we determined the dynamics of force fluctuation during stretching of talin under physiologically relevant pulling speeds and experimentally measured extension fluctuation trajectories. Our results reveal that force-dependent stochastic unfolding and refolding of talin rod domains make talin a very effective force buffer that sets a physiological force range of only a few pNs in the talin-mediated force transmission pathway.

The NASA Ames Fatigue Countermeasures Program: The Next Generation

NASA Technical Reports Server (NTRS)

Rosekind, Mark R.; Neri, David F.; Miller, Donna L.; Gregory, Kevin B.; Webbon, Lissa L.; Oyung, Ray L.

1997-01-01

Twenty-four hour, global aviation operations pose unique challenges to humans. Physiological requirements related to sleep, the internal circadian clock, and human fatigue are critical factors that are known to affect safety, performance, and productivity. Understanding the human operators' physiological capabilities, and limitations, will be important to address these issues as global demand for aviation activities continues to increase. In 1980, in response to a Congressional request, the National Aeronautics and Space Administration (NASA) Ames Research Center initiated a Fatigue/Jet Lag Program to examine the role of fatigue in flight operations. Originally established by Dr. John K. Lauber and Dr. Charles E. Billings, the Program was designed to address three objectives: (1) determine the extent of fatigue, sleep loss, and circadian disruption in flight operations; (2) determine how fatigue affected flight crew performance; and (3) develop strategies to maximize performance and alertness during flight operations.

Regulation of Coronary Blood Flow

PubMed Central

Goodwill, Adam G.; Dick, Gregory M.; Kiel, Alexander M.; Tune, Johnathan D.

2018-01-01

The heart is uniquely responsible for providing its own blood supply through the coronary circulation. Regulation of coronary blood flow is quite complex and, after over 100 years of dedicated research, is understood to be dictated through multiple mechanisms that include extravascular compressive forces (tissue pressure), coronary perfusion pressure, myogenic, local metabolic, endothelial as well as neural and hormonal influences. While each of these determinants can have profound influence over myocardial perfusion, largely through effects on end-effector ion channels, these mechanisms collectively modulate coronary vascular resistance and act to ensure that the myocardial requirements for oxygen and substrates are adequately provided by the coronary circulation. The purpose of this series of Comprehensive Physiology is to highlight current knowledge regarding the physiologic regulation of coronary blood flow, with emphasis on functional anatomy and the interplay between the physical and biological determinants of myocardial oxygen delivery. PMID:28333376

The role of physiological traits in assortment among and within fish shoals

PubMed Central

Marras, Stefano

2017-01-01

Individuals of gregarious species often group with conspecifics to which they are phenotypically similar. This among-group assortment has been studied for body size, sex and relatedness. However, the role of physiological traits has been largely overlooked. Here, we discuss mechanisms by which physiological traits—particularly those related to metabolism and locomotor performance—may result in phenotypic assortment not only among but also within animal groups. At the among-group level, varying combinations of passive assortment, active assortment, phenotypic plasticity and selective mortality may generate phenotypic differences among groups. Even within groups, however, individual variation in energy requirements, aerobic and anaerobic capacity, neurological lateralization and tolerance to environmental stressors are likely to produce differences in the spatial location of individuals or associations between group-mates with specific physiological phenotypes. Owing to the greater availability of empirical research, we focus on groups of fishes (i.e. shoals and schools). Increased knowledge of physiological mechanisms influencing among- and within-group assortment will enhance our understanding of fundamental concepts regarding optimal group size, predator avoidance, group cohesion, information transfer, life-history strategies and the evolutionary effects of group membership. In a broader perspective, predicting animal responses to environmental change will be impossible without a comprehensive understanding of the physiological basis of the formation and functioning of animal social groups. This article is part of the themed issue ‘Physiological determinants of social behaviour in animals’. PMID:28673911

Effects of Exogenous Melatonin and Tryptophan on Fecal Shedding of E. Coli O157:H7 in Cattle

USDA-ARS?s Scientific Manuscript database

Fecal prevalence of Escherichia coli O157 in ruminants is highest in the summer decreasing to very low levels in the winter. We hypothesize that this seasonal variation is a result of physiological responses within the host animal to changing day-length. To determine the effects of melatonin (MEL) o...

3D highly heterogeneous thermal model of pineal gland in-vitro study for electromagnetic exposure using finite volume method

NASA Astrophysics Data System (ADS)

Cen, Wei; Hoppe, Ralph; Lu, Rongbo; Cai, Zhaoquan; Gu, Ning

2017-08-01

In this paper, the relationship between electromagnetic power absorption and temperature distributions inside highly heterogeneous biological samples was accurately determinated using finite volume method. An in-vitro study on pineal gland that is responsible for physiological activities was for the first time simulated to illustrate effectiveness of the proposed method.

Reliability and Validity of the Zephyr[TM] BioHarness[TM] to Measure Respiratory Responses to Exercise

ERIC Educational Resources Information Center

Hailstone, Jono; Kilding, Andrew E.

2011-01-01

The Zephyr[TM] BioHarness[TM] (Zephyr Technology, Auckland, New Zealand) is a wireless physiological monitoring system that has the ability to measure respiratory rate unobtrusively. However, the ability of the BioHarness[TM] to accurately and reproducibly determine respiratory rate across a range of intensities is currently unknown. The aim of…

Time series analysis of forest carbon dynamics: recovery of Pinus palustris physiology following a prescribed fire

Treesearch

G. Starr; C. L. Staudhammer; H. W. Loescher; R. Mitchell; A. Whelan; J. K. Hiers; J. J. O’Brien

2015-01-01

Frequency and intensity of fire determines the structure and regulates the function of savanna ecosystems worldwide, yet our understanding of prescribed fire impacts on carbon in these systems is rudimentary. We combined eddy covariance (EC) techniques and fuel consumption plots to examine the short-term response of longleaf pine forest carbon dynamics to one...

Stress physiology in marine mammals: how well do they fit the terrestrial model?

PubMed

Atkinson, Shannon; Crocker, Daniel; Houser, Dorian; Mashburn, Kendall

2015-07-01

Stressors are commonly accepted as the causal factors, either internal or external, that evoke physiological responses to mediate the impact of the stressor. The majority of research on the physiological stress response, and costs incurred to an animal, has focused on terrestrial species. This review presents current knowledge on the physiology of the stress response in a lesser studied group of mammals, the marine mammals. Marine mammals are an artificial or pseudo grouping from a taxonomical perspective, as this group represents several distinct and diverse orders of mammals. However, they all are fully or semi-aquatic animals and have experienced selective pressures that have shaped their physiology in a manner that differs from terrestrial relatives. What these differences are and how they relate to the stress response is an efflorescent topic of study. The identification of the many facets of the stress response is critical to marine mammal management and conservation efforts. Anthropogenic stressors in marine ecosystems, including ocean noise, pollution, and fisheries interactions, are increasing and the dramatic responses of some marine mammals to these stressors have elevated concerns over the impact of human-related activities on a diverse group of animals that are difficult to monitor. This review covers the physiology of the stress response in marine mammals and places it in context of what is known from research on terrestrial mammals, particularly with respect to mediator activity that diverges from generalized terrestrial models. Challenges in conducting research on stress physiology in marine mammals are discussed and ways to overcome these challenges in the future are suggested.

Physiological responses induced by pleasant stimuli.

PubMed

Watanuki, Shigeki; Kim, Yeon-Kyu

2005-01-01

The specific physiological responses induced by pleasant stimuli were investigated in this study. Various physiological responses of the brain (encephaloelectrogram; EEG), autonomic nervous system (ANS), immune system and endocrine system were monitored when pleasant stimuli such as odors, emotional pictures and rakugo, a typical Japanese comical story-telling, were presented to subjects. The results revealed that (i) EEG activities of the left frontal brain region were enhanced by a pleasant odor; (ii) emotional pictures related to primitive element such as nudes and erotic couples elevated vasomotor sympathetic nervous activity; and (iii) an increase in secretory immunoglobulin A (s-IgA) and a decrease in salivary cortisol (s-cortisol) were induced by rakugo-derived linguistic pleasant emotion. Pleasant emotion is complicated state. However, by considering the evolutionary history of human being, it is possible to assess and evaluate pleasant emotion from certain physiological responses by appropriately summating various physiological parameters.

Differences in autonomic physiological responses between good and poor inductive reasoners.

PubMed

Melis, C; van Boxtel, A

2001-11-01

We investigated individual- and task-related differences in autonomic physiological responses induced by time limited figural and verbal inductive reasoning tasks. In a group of 52 participants, the percentage of correctly responded task items was evaluated together with nine different autonomic physiological response measures and respiration rate (RR). Weighted multidimensional scaling analyses of the physiological responses revealed three underlying dimensions, primarily characterized by RR, parasympathetic, and sympathetic activity. RR and sympathetic activity appeared to be relatively more important response dimensions for poor reasoners, whereas parasympathetic responsivity was relatively more important for good reasoners. These results suggest that poor reasoners showed higher levels of cognitive processing intensity than good reasoners. Furthermore, for the good reasoners, the dimension of sympathetic activity was relatively more important during the figural than during the verbal reasoning task, which was explained in terms of hemispheric lateralization in autonomic function.

Regulation of Bim in Health and Disease

PubMed Central

Sionov, Ronit Vogt; Vlahopoulos, Spiros A.; Granot, Zvi

2015-01-01

The BH3-only Bim protein is a major determinant for initiating the intrinsic apoptotic pathway under both physiological and pathophysiological conditions. Tight regulation of its expression and activity at the transcriptional, translational and post-translational levels together with the induction of alternatively spliced isoforms with different pro-apoptotic potential, ensure timely activation of Bim. Under physiological conditions, Bim is essential for shaping immune responses where its absence promotes autoimmunity, while too early Bim induction eliminates cytotoxic T cells prematurely, resulting in chronic inflammation and tumor progression. Enhanced Bim induction in neurons causes neurodegenerative disorders including Alzheimer's, Parkinson's and Huntington's diseases. Moreover, type I diabetes is promoted by genetically predisposed elevation of Bim in β-cells. On the contrary, cancer cells have developed mechanisms that suppress Bim expression necessary for tumor progression and metastasis. This review focuses on the intricate network regulating Bim activity and its involvement in physiological and pathophysiological processes. PMID:26405162

Regulation of Bim in Health and Disease.

PubMed

Sionov, Ronit Vogt; Vlahopoulos, Spiros A; Granot, Zvi

2015-09-15

The BH3-only Bim protein is a major determinant for initiating the intrinsic apoptotic pathway under both physiological and pathophysiological conditions. Tight regulation of its expression and activity at the transcriptional, translational and post-translational levels together with the induction of alternatively spliced isoforms with different pro-apoptotic potential, ensure timely activation of Bim. Under physiological conditions, Bim is essential for shaping immune responses where its absence promotes autoimmunity, while too early Bim induction eliminates cytotoxic T cells prematurely, resulting in chronic inflammation and tumor progression. Enhanced Bim induction in neurons causes neurodegenerative disorders including Alzheimer's, Parkinson's and Huntington's diseases. Moreover, type I diabetes is promoted by genetically predisposed elevation of Bim in β-cells. On the contrary, cancer cells have developed mechanisms that suppress Bim expression necessary for tumor progression and metastasis. This review focuses on the intricate network regulating Bim activity and its involvement in physiological and pathophysiological processes.

SLS-1 flight experiments preliminary significant results

NASA Technical Reports Server (NTRS)

1992-01-01

Spacelab Life Sciences-1 (SLS-1) is the first of a series of dedicated life sciences Spacelab missions designed to investigate the mechanisms involved in the physiological adaptation to weightlessness and the subsequent readaptation to 1 gravity (1 G). Hypotheses generated from the physiological effects observed during earlier missions led to the formulation of several integrated experiments to determine the underlying mechanisms responsible for the observed phenomena. The 18 experiments selected for flight on SLS-1 investigated the cardiovascular, cardiopulmonary, regulatory physiology, musculoskeletal, and neuroscience disciplines in both human and rodent subjects. The SLS-1 preliminary results gave insight to the mechanisms involved in the adaptation to the microgravity environment and readaptation when returning to Earth. The experimental results will be used to promote health and safety for future long duration space flights and, as in the past, will be applied to many biomedical problems encountered here on Earth.

Behaviour during elevated water temperatures: can physiology explain movement of juvenile Atlantic salmon to cool water?

PubMed

Breau, Cindy; Cunjak, Richard A; Peake, Stephan J

2011-07-01

1. Temperature governs most physiological processes in animals. Ectotherms behaviourally thermoregulate by selecting habitats with temperatures regulating their body temperature for optimal physiological functioning. However, ectotherms can experience temperature extremes forcing the organisms to seek temperature refuge. 2. Fish actively avoid potentially lethal temperatures by moving to cool-water sites created by inflowing tributaries and groundwater seeps. Juvenile Atlantic salmon (Salmo salar) of different age classes exhibit different behavioural responses to elevated temperatures (>23 °C). Yearling (1+) and 2-year-old (2+) Atlantic salmon often cease feeding, abandon territorial behaviour and swim continuously in aggregations in cool-water sites; whereas young-of-the-year (0+) fish continue defending territories and foraging. 3. This study determined whether the behavioural shift in older individuals (2+) occurred when basal metabolic rate, driven by increasing water temperature, reached the maximum metabolic rate such that anaerobic pathways were recruited to provide energy to support vital processes. Behaviour (feeding and stress responses), oxygen consumption, muscle lactate and glycogen, and circulating blood lactate and glucose concentrations were measured in wild 0+ and 2+ Atlantic salmon acclimated to water temperatures between 16 and 28 °C. 4. Results indicate that oxygen consumption of the 2+ fish increased with temperature and reached a plateau at 24 °C, a temperature that corresponded to cessation of feeding and a significant increase in muscle and blood lactate levels. By contrast, oxygen consumption in 0+ fish did not reach a plateau, feeding continued and muscle lactate did not increase, even at the highest temperatures tested (28 °C). 5. To conclude, the experiment demonstrated that the 0+ and 2+ fish had different physiological responses to the elevated water temperatures. The results suggest that wild 2+ Atlantic salmon employ behavioural responses (e.g. movement to cool-water sites) at elevated temperatures in an effort to mitigate physiological imbalances associated with an inability to support basal metabolism through aerobic metabolic processes. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

Anatomy and physiology of genital organs - women.

PubMed

Graziottin, Alessandra; Gambini, Dania

2015-01-01

"Anatomy is destiny": Sigmund Freud viewed human anatomy as a necessary, although not a sufficient, condition for understanding the complexity of human sexual function with a solid biologic basis. The aim of the chapter is to describe women's genital anatomy and physiology, focusing on women's sexual function with a clinically oriented vision. Key points include: embryology, stressing that the "female" is the anatomic "default" program, differentiated into "male" only in the presence of androgens at physiologic levels for the gestational age; sex determination and sex differentiation, describing the interplay between anatomic and endocrine factors; the "clitoral-urethral-vaginal" complex, the most recent anatomy reading of the corpora cavernosa pattern in women; the controversial G spot; the role of the pelvic floor muscles in modulating vaginal receptivity and intercourse feelings, with hyperactivity leading to introital dyspareunia and contributing to provoked vestibulodynia and recurrent postcoital cystitis, whilst lesions during delivery reduce vaginal sensations, genital arousability, and orgasm; innervation, vessels, bones, ligaments; and the physiology of women's sexual response. Attention to physiologic aging focuses on "low-grade inflammation," genital and systemic, with its impact on women sexual function, especially after the menopause, if the woman does not or cannot use hormone replacement therapy. © 2015 Elsevier B.V. All rights reserved.

Water depth effects on impact loading, kinematic and physiological variables during water treadmill running.

PubMed

Macdermid, Paul W; Wharton, Josh; Schill, Carina; Fink, Philip W

2017-07-01

The purpose of this study was to compare impact loading, kinematic and physiological responses to three different immersion depths (mid-shin, mid-thigh, and xiphoid process) while running at the same speed on a water based treadmill. Participants (N=8) ran on a water treadmill at three depths for 3min. Tri-axial accelerometers were used to identify running dynamics plus measures associated with impact loading rates, while heart rate data were logged to indicate physiological demand. Participants had greater peak impact accelerations (p<0.01), greater impact loading rates (p<0.0001), greater stride frequency (p<0.05), shorter stride length (p<0.01), and greater rate of acceleration development at toe-off (p<0.0001) for the mid-shin and mid-thigh compared to running immersed to the xiphoid process. Physiological effort determined by heart rate was also significantly less (p<0.0001) when running immersed to the xiphoid process. Water immersed treadmill running above the waistline alters kinematics of gait, reduces variables associated with impact, while decreasing physiological demand compared to depths below the waistline. Copyright © 2017 Elsevier B.V. All rights reserved.

Tracing anti-cancer and cancer-promoting actions of all-trans retinoic acid in breast cancer to a RARα epigenetic mechanism of mammary epithelial cell fate.

PubMed

Rossetti, Stefano; Ren, MingQiang; Visconti, Nicolo; Corlazzoli, Francesca; Gagliostro, Vincenzo; Somenzi, Giulia; Yao, Jin; Sun, Yijun; Sacchi, Nicoletta

2016-12-27

A hallmark of cancer cells is the ability to evade the growth inhibitory/pro-apoptotic action of physiological all-trans retinoic acid (RA) signal, the bioactive derivative of Vitamin A. However, as we and others reported, RA can also promote cancer cell growth and invasion. Here we show that anticancer and cancer-promoting RA actions in breast cancer have roots in a mechanism of mammary epithelial cell morphogenesis that involves both transcriptional (epigenetic) and non-transcriptional RARα (RARA) functions. We found that the mammary epithelial cell-context specific degree of functionality of the RARA transcriptional (epigenetic) component of this mechanism, by tuning the effects of the non-transcriptional RARA component, determines different cell fate decisions during mammary morphogenesis. Indeed, factors that hamper the RARA epigenetic function make physiological RA drive aberrant morphogenesis via non-transcriptional RARA, thus leading to cell transformation. Remarkably, also the cell context-specific degree of functionality of the RARA epigenetic component retained by breast cancer cells is critical to determine cell fate decisions in response to physiological as well as supraphysiological RA variation. Overall this study supports the proof of principle that the epigenetic functional plasticity of the mammary epithelial cell RARA mechanism, which is essential for normal morphogenetic processes, is necessary to deter breast cancer onset/progression consequent to the insidious action of physiological RA.

Hormonal and transcriptional profiles highlight common and differential host responses to arbuscular mycorrhizal fungi and the regulation of the oxylipin pathway

PubMed Central

López-Ráez, Juan A.; Verhage, Adriaan; Fernández, Iván; García, Juan M.; Azcón-Aguilar, Concepción; Flors, Victor; Pozo, María J.

2010-01-01

Arbuscular mycorrhizal (AM) symbioses are mutualistic associations between soil fungi and most vascular plants. The symbiosis significantly affects the host physiology in terms of nutrition and stress resistance. Despite the lack of host range specificity of the interaction, functional diversity between AM fungal species exists. The interaction is finely regulated according to plant and fungal characters, and plant hormones are believed to orchestrate the modifications in the host plant. Using tomato as a model, an integrative analysis of the host response to different mycorrhizal fungi was performed combining multiple hormone determination and transcriptional profiling. Analysis of ethylene-, abscisic acid-, salicylic acid-, and jasmonate-related compounds evidenced common and divergent responses of tomato roots to Glomus mosseae and Glomus intraradices, two fungi differing in their colonization abilities and impact on the host. Both hormonal and transcriptional analyses revealed, among others, regulation of the oxylipin pathway during the AM symbiosis and point to a key regulatory role for jasmonates. In addition, the results suggest that specific responses to particular fungi underlie the differential impact of individual AM fungi on plant physiology, and particularly on its ability to cope with biotic stresses. PMID:20378666

Review of comparative responses of men and women to heat stress

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

Kenney, W.L.

Most of their present knowledge regarding human responses to thermal stress is primarily a result of research conducted on male subjects. Recently, as women have moved into the industrial workplace and forefront of athletic activity, attention has turned to comparative responses of men and women. Very limited research on preadolescent children suggests no physiological thermoregulatory sex differences except for a slightly higher sweat rate in lean boys as compared to lean girls of a similar age. Boys also tended to be more tolerant of higher temperatures. Current beliefs regarding men and women are: (1) women, as a population, are lessmore » tolerant to a given imposed heat stress however, if cardiovascular fitness level, body size, and acclimation state are standardized, the differences tend to disappear; (2) women have a lower sweat rate than men of equal fitness, size, and acclimation which is disadvantageous in hot-dry environments, but advantageous in hot-wet environments; and (3) menstrual cycle effects are minimal. It is concluded that aerobic capacity, surface area-to-mass ratio, and state of acclimation are more important than sex in determining physiological responses to heat stress.« less

Salicaceae Endophytes Modulate Stomatal Behavior and Increase Water Use Efficiency in Rice

PubMed Central

Rho, Hyungmin; Van Epps, Victor; Wegley, Nicholas; Doty, Sharon L.; Kim, Soo-Hyung

2018-01-01

Bacterial and yeast endophytes isolated from the Salicaceae family have been shown to promote growth and alleviate stress in plants from different taxa. To determine the physiological pathways through which endophytes affect plant water relations, we investigated leaf water potential, whole-plant water use, and stomatal responses of rice plants to Salicaceae endophyte inoculation under CO2 enrichment and water deficit. Daytime stomatal conductance and stomatal density were lower in inoculated plants compared to controls. Leaf ABA concentrations increased with endophyte inoculation. As a result, transpirational water use decreased significantly with endophyte inoculation while biomass did not change or slightly increased. This response led to a significant increase in cumulative water use efficiency at harvest. Different endophyte strains produced the same results in host plant water relations and stomatal responses. These stomatal responses were also observed under elevated CO2 conditions, and the increase in water use efficiency was more pronounced under water deficit conditions. The effect on water use efficiency was positively correlated with daily light integrals across different experiments. Our results provide insights on the physiological mechanisms of plant-endophyte interactions involving plant water relations and stomatal functions. PMID:29552021

Microgravity-associated Changes in Cellular Signal Processing

NASA Astrophysics Data System (ADS)

Mednieks, M. I.; Hand, Arthur

It has been an ongoing interest in the NASA Life Sciences Division to determine the physiologic effects of space travel and to devise countermeasures to those effects that can be detrimental to humans. In addition to study of animals flown on the US STS-131, 133 and 135 shuttle missions, participating in the Russian COSMOS and BION-M1 missions has provided important opportunities to study the effects of microgravity on hormonal regulation of cell and tissue responses and on a defined molecular basis. A mouse model was employed to study the effects of space flight on regulation of protein secretion in oral fluid. Using morphologic, and molecular methods it was determined that the expression of a number of proteins is altered after space flight when compared to that of controls. Shown by microarray analyses, some salivary gland genes are down regulated, others up-regulated, while the majority are unaffected. Electron microscopic examination of salivary glands showed no overall tissue damage, but specific morphologic effects were seen that are consistent with an increase in apoptosis and altered duct cell function. Immuno-cytochemical and biochemical methods were used to identify the specific proteins. Initial studies indicate that some of the effects appear transient and could be an adjustment or homeostatic response to microgravity conditions. Further studies will determine if a pharmacologic means can serve as a countermeasure to physiologic changes in humans in catecholamine hormone regulated responses due to travel in space. Support: CT Space Grant College Consortium, School of Dental Medicine Alumni Research Fellowship and the NASA Award Number, NNX09AP13G,

Functional Groups Based on Leaf Physiology: Are they Spatially and Temporally Robust?

NASA Technical Reports Server (NTRS)

Foster, Tammy E.; Brooks, J. Renee

2004-01-01

The functional grouping hypothesis, which suggests that complexity in ecosystem function can be simplified by grouping species with similar responses, was tested in the Florida scrub habitat. Functional groups were identified based on how species in fire maintained Florida scrub regulate exchange of carbon and water with the atmosphere as indicated by both instantaneous gas exchange measurements and integrated measures of function (%N, delta C-13, delta N-15, C-N ratio). Using cluster analysis, five distinct physiologically-based functional groups were identified in the fire maintained scrub. These functional groups were tested to determine if they were robust spatially, temporally, and with management regime. Analysis of Similarities (ANOSIM), a non-parametric multivariate analysis, indicated that these five physiologically-based groupings were not altered by plot differences (R = -0.115, p = 0.893) or by the three different management regimes; prescribed burn, mechanically treated and burn, and fire-suppressed (R = 0.018, p = 0.349). The physiological groupings also remained robust between the two climatically different years 1999 and 2000 (R = -0.027, p = 0.725). Easy-to-measure morphological characteristics indicating functional groups would be more practical for scaling and modeling ecosystem processes than detailed gas-exchange measurements, therefore we tested a variety of morphological characteristics as functional indicators. A combination of non-parametric multivariate techniques (Hierarchical cluster analysis, non-metric Multi-Dimensional Scaling, and ANOSIM) were used to compare the ability of life form, leaf thickness, and specific leaf area classifications to identify the physiologically-based functional groups. Life form classifications (ANOSIM; R = 0.629, p 0.001) were able to depict the physiological groupings more adequately than either specific leaf area (ANOSIM; R = 0.426, p = 0.001) or leaf thickness (ANOSIM; R 0.344, p 0.001). The ability of life forms to depict the physiological groupings was improved by separating the parasitic Ximenia americana from the shrub category (ANOSIM; R = 0.794, p = 0.001). Therefore, a life form classification including parasites was determined to be a good indicator of the physiological processes of scrub species, and would be a useful method of grouping for scaling physiological processes to the ecosystem level.

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

2012-09-30

1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Investigation of the Physiological Responses of Belugas...of this effort is to investigate the physiological i.e. neuroimmunoendocrinological responses of beluga whales to “stressors”. “Stressor events...hormone, aldosterone , catecholamines) in different matrices (blood, saliva, blow, feces) in conjunction with immune function. In addition, “stressor

RESPONSE OF THE THERMOREGULATORY SYSTEM TO TOXIC CHEMICALS

EPA Science Inventory

The thermoregulatory system plays a crucial role in the physiological response to pesticides, airborne pollutants, and other toxic agents. The exposure to toxicants via inhalation, cutaneous absorption, or ingestion, their clearance from the body, the physiological responses, del...

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

ERIC Educational Resources Information Center

Fleck, Steven J.; Kraemer, William J.

1988-01-01

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

Response of the Thermoregulatory System to Toxic Chemicals

EPA Science Inventory

The thermoregulatory system plays a crucial role in the physiological response to pesticides, airborne pollutants, and other toxic agents. The exposure to toxicants via inhalation, cutaneous absorption, or ingestion, their clearance from the body, the physiological responses, del...

Neural Correlates of Object-Associated Choice Behavior in the Perirhinal Cortex of Rats

PubMed Central

Ahn, Jae-Rong

2015-01-01

The perirhinal cortex (PRC) is reportedly important for object recognition memory, with supporting physiological evidence obtained largely from primate studies. Whether neurons in the rodent PRC also exhibit similar physiological correlates of object recognition, however, remains to be determined. We recorded single units from the PRC in a PRC-dependent, object-cued spatial choice task in which, when cued by an object image, the rat chose the associated spatial target from two identical discs appearing on a touchscreen monitor. The firing rates of PRC neurons were significantly modulated by critical events in the task, such as object sampling and choice response. Neuronal firing in the PRC was correlated primarily with the conjunctive relationships between an object and its associated choice response, although some neurons also responded to the choice response alone. However, we rarely observed a PRC neuron that represented a specific object exclusively regardless of spatial response in rats, although the neurons were influenced by the perceptual ambiguity of the object at the population level. Some PRC neurons fired maximally after a choice response, and this post-choice feedback signal significantly enhanced the neuronal specificity for the choice response in the subsequent trial. Our findings suggest that neurons in the rat PRC may not participate exclusively in object recognition memory but that their activity may be more dynamically modulated in conjunction with other variables, such as choice response and its outcomes. PMID:25632144

Subjective, behavioral, and physiological responses to the rubber hand illusion do not vary with age in the adult phase.

PubMed

Palomo, Priscila; Borrego, Adrián; Cebolla, Ausiàs; Llorens, Roberto; Demarzo, Marcelo; Baños, Rosa M

2018-02-01

The Rubber Hand Illusion (RHI) is a perceptual illusion that enables integration of artificial limbs into the body representation through combined multisensory integration. Most previous studies investigating the RHI have involved young healthy adults within a very narrow age range (typically 20-30 years old). The purpose of this paper was to determine the influence of age on the RHI. The RHI was performed on 93 healthy adults classified into three groups of age (20-35 years old, N = 41; 36-60 years old, N = 28; and 61-80 years old, N = 24), and its effects were measured with subjective (Embodiment of Rubber Hand Questionnaire), behavioral (proprioceptive drift), and physiological (changes in skin temperature and conductance) measures. There were neither significant differences among groups in any response, nor significant covariability or correlation between age and other measures (but for skin temperature), which suggests that the RHI elicits similar responses across different age groups in the adult phase. Copyright © 2017 Elsevier Inc. All rights reserved.

Behavioral and Metabolic Phenotype Indicate Personality in Zebrafish (Danio rerio)

PubMed Central

Yuan, Mingzhe; Chen, Yan; Huang, Yingying; Lu, Weiqun

2018-01-01

Consistency of individual differences of animal behavior and personality in reactions to various environmental stresses among their life stages could reflect basic divergences in coping style which may affect survival, social rank, and reproductive success in the wild. However, the physiological mechanisms determining personality remain poorly understood. In order to study whether behavior, metabolism and physiological stress responses relate to the personality, we employed post-stress recovery assays to separate zebrafish into two behavioral types (proactive and reactive). The results demonstrated consistent difference among personality, behavior and metabolism in which proactive individuals were more aggressive, had higher standard metabolic rates and showed lower shuttled frequencies between dark and light compartments than the reactive ones. The behavioral variations were also linked to divergent acute salinity stress responses: proactive individuals adopted a swift locomotion behavior in response to acute salinity challenge while reactive individuals remain unchanged. Our results provide useful insight into how personality acts on correlated traits and the importance of a holistic approach to understanding the mechanisms driving persistent inter-individual differences. PMID:29899710

Sexual response in patients treated with sacral neuromodulation for lower urinary tract symptoms or fecal incontinence.

PubMed

van Voskuilen, A C; Oerlemans, D J; Gielen, N; Lansen-Koch, S M P; Weil, E H J; van Lankveld, J J D M; van den Hombergh, U; Baeten, C G M I; van Kerrenbroeck, P E V

2012-01-01

To determine whether sacral neuromodulation (SNM) for urinary symptoms or fecal incontinence gives improvement of female sexual function and whether improvement is due to physiological or psychological factors. Between 2002 and 2008, 8 patients had an array of questionnaires before and after SNM implantation. The questionnaires were: the Questionnaire for Screening for Sexual Dysfunctions, the Golombok Rust Inventory of Sexual Satisfaction, the Symptom Checklist-90, the Maudsley Marital Questionnaire and the McGill-Mah Orgasm Questionnaire. Three of these 8 patients underwent vaginal plethysmography before and after implantation. No statistically significant changes were found, although there seems to be a trend toward improvement in orgasm scores. In plethysmography all 3 patients showed increased vaginal pulse amplitude with the stimulator turned on with both erotic and non-erotic stimuli. This study does not show a clear effect of SNM on sexual function, although there seems to be an improvement in orgasm scores. The lack of response on psychological questionnaires and the increase in vaginal pulse amplitude after SNM implantation indicate that there might be a physiological response. Copyright © 2012 S. Karger AG, Basel.

Individual differences in stress reactions during a peer entry episode: effects of age, temperament, approach behavior, and self-perceived peer competence.

PubMed

Stansbury, K; Harris, M L

2000-05-01

The purpose of the current study was to determine whether a standardized peer entry paradigm would produce stress responses in 3- and 4-year-olds and how such stress responses would relate to temperament, observed approach to peers, and self-perceived peer competence. Physiological stress reactions were measured by activity of the hypothalamic-pituitary-adrenal (HPA) system. The 4-year-old group showed significantly less avoidance of the new peers and was rated higher on approach temperament. This older group also showed larger HPA stress responses to the new peer situation. Finally, discrepancy between self-reported peer competence and behavior in the peer entry situation was associated with larger stress responses on average. These findings support the notion that investment in a salient episode plays a role in determining the magnitude of HPA stress responses. The importance of examining discrepancies between self-perception and action in research on stress is discussed. Copyright 2000 Academic Press.

Clinical Use of Virtual Reality Distraction System to Reduce Anxiety and Pain in Dental Procedures

PubMed Central

Gao, Kenneth; Wiederhold, Brenda K.

2014-01-01

Abstract Virtual reality (VR) has been used by clinicians to manage pain in clinical populations. This study examines the use of VR as a form of distraction for dental patients using both subjective and objective measures to determine how a VR system affects patients' reported anxiety level, pain level, and physiological factors. As predicted, results of self-evaluation questionnaires showed that patients experienced less anxiety and pain after undergoing VR treatment. Physiological data reported similar trends in decreased anxiety. Overall, the favorable subjective and objective responses suggest that VR distraction systems can reduce discomfort and pain for patients with mild to moderate fear and anxiety. PMID:24892198

A centre for accommodative vergence motor control

NASA Technical Reports Server (NTRS)

Wilson, D.

1973-01-01

Latencies in accommodation, accommodative-vergence, and pupil-diameter responses to changing accommodation stimuli, as well as latencies in pupil response to light-intensity changes were measured. From the information obtained, a block diagram has been derived that uses the least number of blocks for representing the accommodation, accommodative-vergence, and pupil systems. The signal transmission delays over the various circuits of the model have been determined and compared to known experimental physiological-delay data. The results suggest the existence of a motor center that controls the accommodative vergence and is completely independent of the accommodation system.

Assessment of autonomic response by broad-band respiration

NASA Technical Reports Server (NTRS)

Berger, R. D.; Saul, J. P.; Cohen, R. J.

1989-01-01

We present a technique for introducing broad-band respiratory perturbations so that the response characteristics of the autonomic nervous system can be determined noninvasively over a wide range of physiologically relevant frequencies. A subject's respiratory bandwidth was broadened by breathing on cue to a sequence of audible tones spaced by Poisson intervals. The transfer function between the respiratory input and the resulting instantaneous heart rate was then computed using spectral analysis techniques. Results using this method are comparable to those found using traditional techniques, but are obtained with an economy of data collection.

Subjective and physiological emotional response in euthymic bipolar patients: a pilot study.

PubMed

Lemaire, Mathieu; Aguillon-Hernandez, Nadia; Bonnet-Brilhault, Frédérique; Martineau, Joëlle; El-Hage, Wissam

2014-12-15

The euthymic phase of bipolar disorders may be associated with residual emotional and/or subsyndromal symptoms. The aim of this study was to compare subjective and physiologic emotional response to negative, neutral and positive emotion eliciting pictures between euthymic bipolar patients (n=26) and healthy controls (n=30). We evaluated emotional response using an emotional induction method with emotional pictures from the International Affective Picture System. We measured subjective emotional response with the Self-Assessment Manikin and physiological emotional response by measuring pupil size. No difference was found between euthymic bipolar patients and controls regarding subjective emotional response. However, upon viewing positive pictures, pupil dilation was significantly lower in euthymic bipolar patients compared to controls. This finding suggests that euthymic bipolar phase may be associated with reduced physiologic emotional response to positive valence, which is consistent with a more general negative emotional bias or can be understood as a residual emotional subsyndromal symptom. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Temporal changes in physiology and haematology in response to high- and micro-doses of recombinant human erythropoietin.

PubMed

Clark, Brad; Woolford, Sarah M; Eastwood, Annette; Sharpe, Ken; Barnes, Peter G; Gore, Christopher J

2017-10-01

There is evidence to suggest athletes have adopted recombinant human erythropoietin (rHuEPO) dosing regimens that diminish the likelihood of being caught by direct detection techniques. However, the temporal response in physiology, performance, and Athlete Biological Passport (ABP) parameters to such regimens is not clearly understood. Participants were assigned to a high-dose only group (HIGH, n = 8, six rHuEPO doses of 250 IU/kg over two weeks), a combined high micro-dose group (COMB, n = 8, high-dose plus nine rHuEPO micro-doses over a further three weeks), or one of two placebo control groups who received saline in the same pattern as the HIGH (HIGH-PLACEBO, n = 4) or COMB (COMB-PLACEBO, n = 4) groups. Temporal changes in physiology and performance were tracked by graded exercise test (GXT) and haemoglobin mass assessment at baseline, after high dose, after micro-dose (COMB and COMB-PLACEBO only) and after a four-week washout. Venous blood samples were collected throughout the baseline, rHuEPO administration, and washout periods to determine the haematological and ABP response to each dosing regimen. Physiological adaptations induced by a two-week rHuEPO high-dose were maintained by rHuEPO micro-dosing for at least three weeks. However, all participants administered rHuEPO registered at least one suspicious ABP value during the administration or washout periods. These results indicate there is sufficient sensitivity in the ABP to detect use of high rHuEPO doping regimens in athletic populations and they provide important empirical examples for use by anti-doping experts. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Contrasting physiological responses of two co-occurring eucalypts to seasonal drought at restored bauxite mine sites.

PubMed

Szota, Christopher; Farrell, Claire; Koch, John M; Lambers, Hans; Veneklaas, Erik J

2011-10-01

This study describes the physiological response of two co-occurring tree species (Eucalyptus marginata and Corymbia calophylla) to seasonal drought at low- and high-quality restored bauxite mine sites in south-western Australia. Seasonal changes in photosynthesis (A), stomatal conductance (g(s)), leaf water potential (ψ), leaf osmotic potential (ψ), leaf relative water content (RWC) and pressure-volume analysis were captured over an 18-month field study to (i) determine the nature and severity of physiological stress in relation to site quality and (ii) identify any physiological differences between the two species. Root system restriction at the low-quality site reduced maximum rates of gas exchange (g(s) and A) and increased water stress (midday ψ and daily RWC) in both species during drought. Both species showed high stomatal sensitivity during drought; however, E. marginata demonstrated a higher dehydration tolerance where ψ and RWC fell to -3.2 MPa and 73% compared with -2.4 MPa and 80% for C. calophylla. Corymbia calophylla showed lower g(s) and higher ψ and RWC during drought, indicating higher drought tolerance. Pressure-volume curves showed that cell-wall elasticity of E. marginata leaves increased in response to drought, while C. calophylla leaves showed lower osmotic potential at zero turgor in summer than in winter, indicating osmotic adjustment. Both species are clearly able to tolerate seasonal drought at hostile sites; however, by C. calophylla closing stomata earlier in the drought cycle, maintaining a higher water status during drought and having the additional mechanism of osmotic adjustment, it may have a greater capacity to survive extended periods of drought.

Involuntary Attention and Physiological Arousal Evoked by Structural Features and Emotional Content in TV Commercials.

ERIC Educational Resources Information Center

Lang, Annie

1990-01-01

Examines how emotional content in televised messages intensifies physiological attentional responses. Explains that heart rate data indicating both shorter-term responses and longer-term arousal were collected from 10 female and 4 male advertising students. Finds that emotional content increases physiological arousal in viewers and that heart…

Physiological Responses to Salinity Vary with Proximity to the Ocean in a Coastal Amphibian.

PubMed

Hopkins, Gareth R; Brodie, Edmund D; Neuman-Lee, Lorin A; Mohammadi, Shabnam; Brusch, George A; Hopkins, Zoë M; French, Susannah S

2016-01-01

Freshwater organisms are increasingly exposed to elevated salinity in their habitats, presenting physiological challenges to homeostasis. Amphibians are particularly vulnerable to osmotic stress and yet are often subject to high salinity in a variety of inland and coastal environments around the world. Here, we examine the physiological responses to elevated salinity of rough-skinned newts (Taricha granulosa) inhabiting a coastal stream on the Pacific coast of North America and compare the physiological responses to salinity stress of newts living in close proximity to the ocean with those of newts living farther upstream. Although elevated salinity significantly affected the osmotic (body weight, plasma osmolality), stress (corticosterone), and immune (bactericidal ability) responses of newts, animals found closer to the ocean were generally less reactive to salt stress than those found farther upstream. Our results provide possible evidence for some physiological tolerance in this species to elevated salinity in coastal environments. As freshwater environments become increasingly saline and more stressful, understanding the physiological tolerances of vulnerable groups such as amphibians will become increasingly important to our understanding of their abilities to respond, to adapt, and, ultimately, to survive.

Impacts of environmental variability on desiccation rate, plastic responses and population dynamics of Glossina pallidipes.

PubMed

Kleynhans, E; Clusella-Trullas, S; Terblanche, J S

2014-02-01

Physiological responses to transient conditions may result in costly responses with little fitness benefits, and therefore, a trade-off must exist between the speed of response and the duration of exposure to new conditions. Here, using the puparia of an important insect disease vector, Glossina pallidipes, we examine this potential trade-off using a novel combination of an experimental approach and a population dynamics model. Specifically, we explore and dissect the interactions between plastic physiological responses, treatment-duration and -intensity using an experimental approach. We then integrate these experimental results from organismal water-balance data and their plastic responses into a population dynamics model to examine the potential relative fitness effects of simulated transient weather conditions on population growth rates. The results show evidence for the predicted trade-off for plasticity of water loss rate (WLR) and the duration of new environmental conditions. When altered environmental conditions lasted for longer durations, physiological responses could match the new environmental conditions, and this resulted in a lower WLR and lower rates of population decline. At shorter time-scales however, a mismatch between acclimation duration and physiological responses was reflected by reduced overall population growth rates. This may indicate a potential fitness cost due to insufficient time for physiological adjustments to take place. The outcomes of this work therefore suggest plastic water balance responses have both costs and benefits, and these depend on the time-scale and magnitude of variation in environmental conditions. These results are significant for understanding the evolution of plastic physiological responses and changes in population abundance in the context of environmental variability. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Controversial constitutive TSHR activity: patients, physiology, and in vitro characterization.

PubMed

Huth, S; Jaeschke, H; Schaarschmidt, J; Paschke, R

2014-06-01

G protein-coupled receptors constitute a large family of transmembrane receptors, which activate cellular responses by signal transmission and regulation of second messenger metabolism after ligand binding. For several of these receptors it is known that they also signal ligand-independently. The G protein-coupled thyroid stimulating hormone receptor (TSHR) is characterized by a high level of constitutive activity in the wild type state. However, little is known yet concerning the physiological relevance of the constitutive wild type TSHR activity. Certainly, knowledge of the physiological relevance of constitutive wild type receptor activity is necessary to better understand thyroid physiology and it is a prerequisite for the development of better therapies for nonautoimmune hyperthyroidism and thyroid cancer. Based on a literature search regarding all published TSHR mutations, this review covers several mutations which are clearly associated with a hyperthyroidism-phenotype, but interestingly show a lack of constitutive activity determined by in vitro characterization. Possible reasons for the observed discrepancies between clinical phenotypes and in vitro characterization results for constitutive TSHR activity are reviewed. All current in vitro characterization methods for constitutive TSHR mutations are "preliminary attempts" and may well be revised by more comprehensive and even better approaches. However, a standardized approach for the determination of constitutive activity can help to identify TSHR mutations for which the investigation of additional signaling mechanisms would be most interesting to find explanations for the current clinical phenotype/in vitro discrepancies and thereby also define suitable methods to explore the physiological relevance of constitutive wild type TSHR activity. © Georg Thieme Verlag KG Stuttgart · New York.

Use of technology to facilitate physical activity in children with autism spectrum disorders: A pilot study.

PubMed

Bittner, Melissa D; Rigby, B Rhett; Silliman-French, Lisa; Nichols, David L; Dillon, Suzanna R

2017-08-01

Deficits in social behavior and communication skills are correlated with reduced gross motor skills in children with autism spectrum disorders (ASD). The ExerciseBuddy application (EB app) was designed to communicate these motor skills to those with ASD and integrates evidence-based practices such as visual support and video modeling supported by The National Professional Development Center on Autism Spectrum Disorders. The purpose of this study was to determine the effectiveness of the EB app in facilitating increased physiologic responses to physical activity via a continuous measurement of energy expenditure and heart rate versus practice-style teaching methods in children with ASD. Six children, ages 5 to 10years, diagnosed with ASD were recruited. Each participant performed a variety of locomotor or object control skills as defined by the Test of Gross Motor Development-2 once per week for 4weeks. Motor skills were communicated and demonstrated using either practice-style teaching methods or the instructional section of the EB app. Energy expenditure and heart rate were measured continuously during each 12-minute session. A Wilcoxon signed-rank test was performed to assess any differences between the use of the app and practice-style teaching methods. The use of the EB app elicited greater values for peak energy expenditure (p=0.043) and peak heart rate response (p=0.028) while performing locomotor skills but no differences were observed while performing object control skills. Similarities were observed with average physiologic responses between the use of the EB app and practice-style teaching methods. The use of the EB app may allow for a greater peak physiologic response during more dynamic movements and a similar average cardiovascular and metabolic response when compared to practice-style teaching methods in children with ASD. Published by Elsevier Inc.

Cerebrovascular, cardiovascular and strength responses to acute ammonia inhalation.

PubMed

Perry, Blake G; Pritchard, Hayden J; Barnes, Matthew J

2016-03-01

Ammonia is used as a stimulant in strength based sports to increase arousal and offset fatigue however little is known about its physiological and performance effects. The purpose of this study was twofold (1) establish the physiological response to acute ammonia inhalation (2) determine whether the timing of the physiological response corresponds with a performance enhancement, if any. Fifteen healthy males completed two trials. Trial one investigated the beat-to-beat middle cerebral artery blood flow velocity (MCAv), heart rate (HR) and mean arterial pressure (MAP) response to ammonia inhalation. During trial two, participants performed a maximal single mid-thigh pull (MTP) at various time points following ammonia inhalation in a randomised order: MTPs were conducted immediately, 15, 30 and 60 s following ammonia inhalation. A MTP with no ammonia inhalation served as the control. During this trial maximal MTP force, rate of force development (RFD) and electromyography (EMG) activity were recorded. MCAvmean increased and peaked on average by 6 cm s(-1) (P < 0.001), 9.4 ± 5.5 s following ammonia inhalation. Similarly, HR was increased by 6 ± 11 beats per minute 15 s following ammonia inhalation (P < 0.001). MAP remained unchanged following inhalation (P = 0.51). The use and timing of ammonia inhalation had no effect on maximal force, RFD or EMG (all P > 0.2) compared to control. MCAv was elevated despite no increase in MAP occurring; this is indicative of a cerebrovascular vasodilation. Despite the marked cerebrovascular and cardiovascular response to ammonia inhalation no ergogenic effect was observed during the MTP, irrespective of the timing of administration.

Electric signalling in fruit trees in response to water applications and light-darkness conditions.

PubMed

Gurovich, Luis A; Hermosilla, Paulo

2009-02-15

A fundamental property of all living organisms is the generation and conduction of electrochemical impulses throughout their different tissues and organs, resulting from abiotic and biotic changes in environmental conditions. In plants and animals, signal transmission can occur over long and short distances, and it can correspond to intra- and inter-cellular communication mechanisms that determine the physiological behaviour of the organism. Rapid plant and animal responses to environmental changes are associated with electrical excitability and signalling. The same molecules and pathways are used to drive physiological responses, which are characterized by movement (physical displacement) in animals and by continuous growth in plants. In the field of environmental plant electrophysiology, automatic and continuous measurements of electrical potential differences (DeltaEP) between plant tissues can be effectively used to study information transport mechanisms and physiological responses that result from external stimuli on plants. A critical mass of data on electrical behaviour in higher plants has accumulated in the last 5 years, establishing plant neurobiology as the most recent discipline of plant science. In this work, electrical potential differences were monitored continuously using Ag/AgCl microelectrodes, which were inserted 15mm deep into sapwood at various positions in the trunks of several fruit-bearing trees. Electrodes were referenced to an unpolarisable Ag/AgCl microelectrode, which was installed 5cm deep in the soil. Systematic patterns of DeltaEP during day-night cycles and at different conditions of soil water availability are discussed as alternative tools to assess early plant stress conditions. This research relates to the adaptive response of trees to soil water availability and light-darkness cycles.

Alternative Reinforcer Response Cost Impacts Cocaine Choice in Humans

PubMed Central

Stoops, William W.; Lile, Joshua A.; Glaser, Paul E.A.; Hays, Lon R.; Rush, Craig R.

2011-01-01

Cocaine use disorders are an unrelenting public health concern. Behavioral treatments reduce cocaine use by providing non-drug alternative reinforcers. The purpose of this human laboratory experiment was to determine how response cost for non-drug alternative reinforcers influenced cocaine choice. Seven cocaine-using, non-treatment-seeking subjects completed a crossover, double-blind protocol in which they first sampled doses of intranasal cocaine (5, 10, 20 or 30 mg) and completed a battery of subject-rated and physiological measures. Subjects then made eight discrete choices between the sampled dose and an alternative reinforce (US$0.25). The response cost to earn a cocaine dose was always a fixed ratio (FR) of 100 responses. The response cost for the alternative reinforcer varied across sessions (FR1, FR10, FR100, FR1000). Dose-related increases were observed for cocaine choice. Subjects made fewer drug choices when the FR requirements for the alternative reinforcers were lower than that for drug relative to when the FR requirements were equal to or higher than that for drug. Intranasal cocaine also produced prototypical stimulant-like subject-rated and physiological effects (e.g., increased ratings of Like Drug; elevated blood pressure). These data demonstrate that making alternative reinforcers easier to earn reduces cocaine self-administration, which has implications for treatment efforts. PMID:22015480

Affective and cognitive determinants of women's sexual response to erotica.

PubMed

Vilarinho, Sandra; Laja, Pedro; Carvalho, Joana; Quinta-Gomes, Ana Luísa; Oliveira, Cátia; Janssen, Erick; Nobre, Pedro J

2014-11-01

The specific cognitive-affective mechanisms involved in the activation and regulation of the subjective and genital components of sexual arousal are not fully understood yet. The aim of the present study was to investigate the contribution of self-reported thoughts and affect to the prediction of women's subjective and genital responses to erotica. Twenty-eight sexually functional women (mean age = 32, SD = 6.29) were presented with sexually explicit and nonexplicit romantic films. Genital responses, subjective sexual arousal, state affect, and self-reported thoughts were assessed. Vaginal pulse amplitude was measured using a vaginal photoplethysmograph. Subjective sexual arousal, thoughts, and affective responses were assessed through self-report scales. Correlations between subjective and physiological sexual arousal were low (r = -0.05, P > 0.05). Self-reported thoughts and affect were significant predictors of subjective sexual arousal. The strongest single predictor of subjective arousal was sexual arousal thoughts (e.g., "I'm getting excited") (β = 0.63, P < 0.01). None of the cognitive or affective variables predicted women's genital responses. Overall, results support the role of cognitive (self-reported thoughts) and affective dimensions in women's subjective sexual arousal to erotica and, consistent with previous findings, suggest that subjective and physiological sexual arousal may be impacted by different processes. © 2014 International Society for Sexual Medicine.

The Bidirectional Relationship between Sleep and Immunity against Infections

PubMed Central

Ibarra-Coronado, Elizabeth G.; Pantaleón-Martínez, Ana Ma.; Velazquéz-Moctezuma, Javier; Prospéro-García, Oscar; Méndez-Díaz, Mónica; Pérez-Tapia, Mayra; Pavón, Lenin; Morales-Montor, Jorge

2015-01-01

Sleep is considered an important modulator of the immune response. Thus, a lack of sleep can weaken immunity, increasing organism susceptibility to infection. For instance, shorter sleep durations are associated with a rise in suffering from the common cold. The function of sleep in altering immune responses must be determined to understand how sleep deprivation increases the susceptibility to viral, bacterial, and parasitic infections. There are several explanations for greater susceptibility to infections after reduced sleep, such as impaired mitogenic proliferation of lymphocytes, decreased HLA-DR expression, the upregulation of CD14+, and variations in CD4+ and CD8+ T lymphocytes, which have been observed during partial sleep deprivation. Also, steroid hormones, in addition to regulating sexual behavior, influence sleep. Thus, we hypothesize that sleep and the immune-endocrine system have a bidirectional relationship in governing various physiological processes, including immunity to infections. This review discusses the evidence on the bidirectional effects of the immune response against viral, bacterial, and parasitic infections on sleep patterns and how the lack of sleep affects the immune response against such agents. Because sleep is essential in the maintenance of homeostasis, these situations must be adapted to elicit changes in sleep patterns and other physiological parameters during the immune response to infections to which the organism is continuously exposed. PMID:26417606

The Bidirectional Relationship between Sleep and Immunity against Infections.

PubMed

Ibarra-Coronado, Elizabeth G; Pantaleón-Martínez, Ana Ma; Velazquéz-Moctezuma, Javier; Prospéro-García, Oscar; Méndez-Díaz, Mónica; Pérez-Tapia, Mayra; Pavón, Lenin; Morales-Montor, Jorge

2015-01-01

Sleep is considered an important modulator of the immune response. Thus, a lack of sleep can weaken immunity, increasing organism susceptibility to infection. For instance, shorter sleep durations are associated with a rise in suffering from the common cold. The function of sleep in altering immune responses must be determined to understand how sleep deprivation increases the susceptibility to viral, bacterial, and parasitic infections. There are several explanations for greater susceptibility to infections after reduced sleep, such as impaired mitogenic proliferation of lymphocytes, decreased HLA-DR expression, the upregulation of CD14+, and variations in CD4+ and CD8+ T lymphocytes, which have been observed during partial sleep deprivation. Also, steroid hormones, in addition to regulating sexual behavior, influence sleep. Thus, we hypothesize that sleep and the immune-endocrine system have a bidirectional relationship in governing various physiological processes, including immunity to infections. This review discusses the evidence on the bidirectional effects of the immune response against viral, bacterial, and parasitic infections on sleep patterns and how the lack of sleep affects the immune response against such agents. Because sleep is essential in the maintenance of homeostasis, these situations must be adapted to elicit changes in sleep patterns and other physiological parameters during the immune response to infections to which the organism is continuously exposed.

Manipulation of heart rate variability can modify response to anger-inducing stimuli.

PubMed

Francis, Heather M; Penglis, Kathryn M; McDonald, Skye

2016-10-01

Research suggests that heart rate variability (HRV) is a physiological indicator of the flexibility of the autonomic nervous system and can provide an objective measure of an individual's ability to appropriately match emotional responses to environmental demands. The present study investigated whether angry response to emotional stimuli was related to HRV, and whether manipulation of HRV using biofeedback could change the anger response in a healthy adult population. Fifty-eight participants received HRV biofeedback (n = 29) or an active control condition (n = 29). HRV measures included standard deviation of normal-to-normal intervals (SDNN), low-frequency (LF) and high-frequency (HF) power, and was recorded across three sessions: baseline, training, and anger induction. The anger induction procedure resulted in increased subjective experience of anger, as well as physiological changes. The biofeedback group had higher HRV than active controls both during the training session (SDNN and LF HRV) and during anger induction (LF HRV). HRV during anger induction was significantly associated with self-reported emotional response for participants receiving biofeedback but not for active controls. Results provide support for HRV as an index of emotion regulation, specifically anger. Further research is needed to determine whether long-term HRV biofeedback can have a lasting effect on managing anger.

Abnormal expression and functional characteristics of cyclic adenosine monophosphate response element binding protein in postmortem brain of suicide subjects.

PubMed

Dwivedi, Yogesh; Rao, Jagadeesh Sridhara; Rizavi, Hooriyah S; Kotowski, Jacek; Conley, Robert R; Roberts, Rosalinda C; Tamminga, Carol A; Pandey, Ghanshyam N

2003-03-01

Cyclic adenosine monophosphate response element binding protein (CREB) is a transcription factor that, on phosphorylation by protein kinases, is activated, and in response, regulates the transcription of many neuronally expressed genes. In view of the recent observations that catalytic properties and/or expression of many kinases that mediate their physiological responses through the activation of CREB are altered in the postmortem brain of subjects who commit suicide (hereafter referred to as suicide subjects), we examined the status of CREB in suicidal behavior. These studies were performed in Brodmann area (BA) 9 and hippocampus obtained from 26 suicide subjects and 20 nonpsychiatric healthy control subjects. Messenger RNA levels of CREB and neuron-specific enolase were determined in total RNA by means of quantitative reverse transcriptase-polymerase chain reaction. Protein levels and the functional characteristics of CREB were determined in nuclear fractions by means of Western blot and cyclic adenosine monophosphate response element (CRE)-DNA binding activity, respectively. In the same nuclear fraction, we determined the catalytic activity of cyclic adenosine monophosphate-stimulated protein kinase A by means of enzymatic assay. We observed a significant reduction in messenger RNA and protein levels of CREB, CRE-DNA binding activity, and basal and cyclic adenosine monophosphate-stimulated protein kinase A activity in BA 9 and hippocampus of suicide subjects, without any change in messenger RNA levels of neuron-specific enolase in BA 9. Except for protein kinase A activity, changes in CREB expression and CRE-DNA binding activity were present in all suicide subjects, irrespective of diagnosis. These changes were unrelated to postmortem intervals, age, sex, or antidepressant treatment. Given the significance of CREB in mediating various physiological functions through gene transcription, our results of decreased expression and functional characteristics of CREB in postmortem brain of suicide subjects suggest that CREB may play an important role in suicidal behavior.

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.

Food availability is expressed through physiological stress indicators in nestling white ibis: A food supplementation experiment

USGS Publications Warehouse

Herring, G.; Cook, Mark I.; Gawlik, D.E.; Call, Erynn M.

2011-01-01

Physiological responses to environmental stress such as adrenocortical hormones and cellular stress proteins have recently emerged as potentially powerful tools for investigating physiological effects of avian food limitation. However, little is known about the physiological stress responses of free-living nestling birds to environmental variation in food availability. We experimentally tested how hydrologically mediated changes in food availability affect the physiological stress responses of juvenile white ibises Eudocimus albus in a fluctuating wetland. We provided supplementary food to free-living nestlings during 2years with contrasting hydrologic and food availability conditions, and used plasma (PCORT) and faecal (FCORT) corticosterone and heat shock proteins (HSP60 and HSP70) from first-hatched (A-nestlings) and second-hatched (B-nestlings) to detect relatively short- to long-term responses to food limitation. Nestling physiological stress responses were relatively low in all treatments during the year with optimal food availability, but PCORT, FCORT and HSP60 levels increased during the poor food year. FCORT and HSP60 responses were clearly due to nutritional condition as elevated concentrations were evident primarily in control nestlings. Significant year by hatch order interactions for both FCORT and HSP60 revealed that these increases were largely incurred by B-nestlings. FCORT and HSP60 responses were also well developed early in neonatal development and remained elevated for the duration of the experiment suggesting a chronic stress response. PCORT and HSP70 were less informative stress responses. The nutritionally mediated increases in FCORT and HSP60 provide compelling evidence that white ibis nestlings can be physiologically affected by environmental food levels. FCORT and HSP60 are effective indicators of nutritional mediated stress for nestling white ibises and potentially for other species prone to capture or handling stress. ?? 2010 The Authors. Functional Ecology ?? 2010 British Ecological Society.

Thermoregulatory responses in exercising rats: methodological aspects and relevance to human physiology.

PubMed

Wanner, Samuel Penna; Prímola-Gomes, Thales Nicolau; Pires, Washington; Guimarães, Juliana Bohnen; Hudson, Alexandre Sérvulo Ribeiro; Kunstetter, Ana Cançado; Fonseca, Cletiana Gonçalves; Drummond, Lucas Rios; Damasceno, William Coutinho; Teixeira-Coelho, Francisco

2015-01-01

Rats are used worldwide in experiments that aim to investigate the physiological responses induced by a physical exercise session. Changes in body temperature regulation, which may affect both the performance and the health of exercising rats, are evident among these physiological responses. Despite the universal use of rats in biomedical research involving exercise, investigators often overlook important methodological issues that hamper the accurate measurement of clear thermoregulatory responses. Moreover, much debate exists regarding whether the outcome of rat experiments can be extrapolated to human physiology, including thermal physiology. Herein, we described the impact of different exercise intensities, durations and protocols and environmental conditions on running-induced thermoregulatory changes. We focused on treadmill running because this type of exercise allows for precise control of the exercise intensity and the measurement of autonomic thermoeffectors associated with heat production and loss. Some methodological issues regarding rat experiments, such as the sites for body temperature measurements and the time of day at which experiments are performed, were also discussed. In addition, we analyzed the influence of a high body surface area-to-mass ratio and limited evaporative cooling on the exercise-induced thermoregulatory responses of running rats and then compared these responses in rats to those observed in humans. Collectively, the data presented in this review represent a reference source for investigators interested in studying exercise thermoregulation in rats. In addition, the present data indicate that the thermoregulatory responses of exercising rats can be extrapolated, with some important limitations, to human thermal physiology.

Thermoregulatory responses in exercising rats: methodological aspects and relevance to human physiology

PubMed Central

Wanner, Samuel Penna; Prímola-Gomes, Thales Nicolau; Pires, Washington; Guimarães, Juliana Bohnen; Hudson, Alexandre Sérvulo Ribeiro; Kunstetter, Ana Cançado; Fonseca, Cletiana Gonçalves; Drummond, Lucas Rios; Damasceno, William Coutinho; Teixeira-Coelho, Francisco

2015-01-01

Rats are used worldwide in experiments that aim to investigate the physiological responses induced by a physical exercise session. Changes in body temperature regulation, which may affect both the performance and the health of exercising rats, are evident among these physiological responses. Despite the universal use of rats in biomedical research involving exercise, investigators often overlook important methodological issues that hamper the accurate measurement of clear thermoregulatory responses. Moreover, much debate exists regarding whether the outcome of rat experiments can be extrapolated to human physiology, including thermal physiology. Herein, we described the impact of different exercise intensities, durations and protocols and environmental conditions on running-induced thermoregulatory changes. We focused on treadmill running because this type of exercise allows for precise control of the exercise intensity and the measurement of autonomic thermoeffectors associated with heat production and loss. Some methodological issues regarding rat experiments, such as the sites for body temperature measurements and the time of day at which experiments are performed, were also discussed. In addition, we analyzed the influence of a high body surface area-to-mass ratio and limited evaporative cooling on the exercise-induced thermoregulatory responses of running rats and then compared these responses in rats to those observed in humans. Collectively, the data presented in this review represent a reference source for investigators interested in studying exercise thermoregulation in rats. In addition, the present data indicate that the thermoregulatory responses of exercising rats can be extrapolated, with some important limitations, to human thermal physiology. PMID:27227066

CO2 and temperature effects on morphological and physiological traits affecting risk of drought-induced mortality.

PubMed

Duan, Honglang; Chaszar, Brian; Lewis, James D; Smith, Renee A; Huxman, Travis E; Tissue, David T

2018-04-26

Despite a wealth of eco-physiological assessments of plant response to extreme drought, few studies have addressed the interactive effects of global change factors on traits driving mortality. To understand the interaction between hydraulic and carbon metabolic traits influencing tree mortality, which may be independently influenced by atmospheric [CO2] and temperature, we grew Eucalyptus sideroxylon A. Cunn. ex Woolls from seed in a full-factorial [CO2] (280, 400 and 640 μmol mol-1, Cp, Ca and Ce, respectively) and temperature (ambient and ambient +4 °C, Ta and Te, respectively) experiment. Prior to drought, growth across treatment combinations resulted in significant variation in physiological and morphological traits, including photosynthesis (Asat), respiration (Rd), stomatal conductance, carbohydrate storage, biomass and leaf area (LA). Ce increased Asat, LA and leaf carbohydrate concentration compared with Ca, while Cp generated the opposite response; Te reduced Rd. However, upon imposition of drought, Te hastened mortality (9 days sooner compared with Ta), while Ce significantly exacerbated drought stress when combined with Te. Across treatments, earlier time-to-mortality was mainly associated with lower (more negative) leaf water potential (Ψl) during the initial drought phase, along with higher water loss across the first 3 weeks of water limitation. Among many variables, Ψl was more important than carbon status in predicting time-to-mortality across treatments, yet leaf starch was associated with residual variation within treatments. These results highlight the need to carefully consider the integration, interaction and hierarchy of traits contributing to mortality, along with their responses to environmental drivers. Both morphological traits, which influence soil resource extraction, and physiological traits, which affect water-for-carbon exchange to the atmosphere, must be considered to adequately predict plant response to drought. Researchers have struggled with assessing the relative importance of hydraulic and carbon metabolic traits in determining mortality, yet an integrated trait, time-dependent framework provides considerable insight into the risk of death from drought for trees.

Contact and nutrient caregiving effects on newborn infant pain responses.

PubMed

Gormally, S; Barr, R G; Wertheim, L; Alkawaf, R; Calinoiu, N; Young, S N

2001-01-01

To understand how the 'caregiving context' could affect responses to procedural pain, the authors sought to determine whether (1) the combined effects of sweet taste and holding (caregiving contact) were greater than the effects of either alone, (2) any combined effects were additive or interactive, and (3) the interventions had similar effects on behavioral (crying and facial activity) and physiological (heart rate, vagal tone) responses to the heel-stick procedure in newborn infants in a randomized two-factorial intervention trial. Eighty-five normally developing newborn infants were studied with a mean gestational age of 39.4 weeks on the 2nd or 3rd day of life. Infants were randomized in blocks of eight to receive (1) no holding and water taste (control participants), (2) no holding and sucrose taste (sucrose group), (3) holding and water taste (holding group), or (4) holding and sucrose taste (holding and sucrose group). Crying was reduced significantly by taste and holding, and the interventions combined additively. Facial activity was only significantly reduced by holding. For physiological measures, the interventions interacted with each other and preintervention levels to reduce heart rate and lower vagal tone more during the procedure in infants in whom heart rate and vagal tone were higher before intervention. Consequently, sweet taste and holding interventions combined in complex ways when acting on different behavioral and physiological response systems to modify stressful pain experiences. The results suggest that providing a caregiving context when painful procedures are performed may be a simple and practical method of reducing pain experience in infants, and that no one measure captures these effects.

Transcriptional and Physiological Responses to Nutrient Loading on Toxin Formation and Photosynthesis in Microcystis Aeruginosa FACHB-905

PubMed Central

Peng, Guotao; Lin, Sijie; Fan, Zhengqiu; Wang, Xiangrong

2017-01-01

An important goal of understanding harmful algae blooms is to determine how environmental factors affect the growth and toxin formation of toxin-producing species. In this study, we investigated the transcriptional responses of toxin formation gene (mcyB) and key photosynthesis genes (psaB, psbD and rbcL) of Microcystis aeruginosa FACHB-905 in different nutrient loading conditions using real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR). Three physio-biochemical parameters (malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH)) were also evaluated to provide insight into the physiological responses of Microcystis cells. We observed an upregulation of mcyB gene in nutrient-deficient conditions, especially in nitrogen (N) limitation condition, and the transcript abundance declined after the nutrient were resupplied. Differently, high transcription levels were seen in phosphorus (P) deficient treatments for key photosynthesis genes throughout the culture period, while those in N-deficient cells varied with time, suggesting an adaptive regulation of Microsystis cells to nutrient stress. Increased contents of antioxidant enzymes (SOD and GSH) were seen in both N and P-deficient conditions, suggesting the presence of excess amount of free radical generation caused by nutrient stress. The amount of SOD and GSH continued to increase even after the nutrient was reintroduced and a strong correlation was seen between the MDA and enzyme activities, indicating the robust effort of rebalancing the redox system in Microcystis cells. Based on these transcriptional and physiological responses of M. aeruginosa to nutrient loading, these results could provide more insight into Microcystis blooms management and toxin formation regulation. PMID:28513574

Investigation of Factors Affecting Body Temperature Changes During Routine Clinical Head Magnetic Resonance Imaging

PubMed Central

Kim, Myeong Seong

2016-01-01

Background Pulsed radiofrequency (RF) magnetic fields, required to produce magnetic resonance imaging (MRI) signals from tissue during the MRI procedure have been shown to heat tissues. Objectives To investigate the relationship between body temperature rise and the RF power deposited during routine clinical MRI procedures, and to determine the correlation between this effect and the body’s physiological response. Patients and Methods We investigated 69 patients from the Korean national cancer center to identify the main factors that contribute to an increase in body temperature (external factors and the body’s response) during a clinical brain MRI. A routine protocol sequence of MRI scans (1.5 T and 3.0 T) was performed. The patient’s tympanic temperature was recorded before and immediately after the MRI procedure and compared with changes in variables related to the body’s physiological response to heat. Results Our investigation of the physiological response to RF heating indicated a link between increasing age and body temperature. A higher increase in body temperature was observed in older patients after a 3.0-T MRI (r = 0.07, P = 0.29 for 1.5-T MRI; r = 0.45, P = 0.002 for 3.0-T MRI). The relationship between age and body heat was related to the heart rate (HR) and changes in HR during the MRI procedure; a higher RF power combined with a reduction in HR resulted in an increase in body temperature. Conclusion A higher magnetic field strength and a decrease in the HR resulted in an increase in body temperature during the MRI procedure. PMID:27895872

Animal models and their importance to human physiological responses in microgravity

NASA Technical Reports Server (NTRS)

Tipton, C. M.

1996-01-01

Two prominent theories to explain the physiological effects of microgravity relate to the cascade of changes associated with the cephalic shifts of fluids and the absence of tissue deformation forces. One-g experiments for humans used bed rest and the head-down tilt (HDT) method, while animal experiments have been conducted using the tail-suspended, head-down, and hindlimbs non-weightbearing model. Because of the success of the HDT approach with rats to simulate the gravitational effects on the musculoskeletal system exhibited by humans, the same model has been used to study the effects of gravity on the cardiopulmonary systems of humans and other vertebrates. Results to date indicate the model is effective in producing comparable changes associated with blood volume, erythropoiesis, cardiac mass, baroreceptor responsiveness, carbohydrate metabolism, post-flight VO2max, and post-flight cardiac output during exercise. Inherent with these results is the potential of the model to be useful in investigating responsible mechanisms. The suspension model has promise in understanding the capillary blood PO2 changes in space as well as the arterial PO2 changes in subjects participating in a HDT experiment. However, whether the model can provide insights on the up-or-down regulation of adrenoreceptors remains to be determined, and many investigators believe the HDT approach should not be followed to study gravitational influences on pulmonary function in either humans or animals. It was concluded that the tail-suspended animal model had sufficient merit to study in-flight and post-flight human physiological responses and mechanisms.

Transcriptional and Physiological Responses to Nutrient Loading on Toxin Formation and Photosynthesis in Microcystis Aeruginosa FACHB-905.

PubMed

Peng, Guotao; Lin, Sijie; Fan, Zhengqiu; Wang, Xiangrong

2017-05-17

An important goal of understanding harmful algae blooms is to determine how environmental factors affect the growth and toxin formation of toxin-producing species. In this study, we investigated the transcriptional responses of toxin formation gene ( mcyB ) and key photosynthesis genes ( psaB , psbD and rbcL) of Microcystis aeruginosa FACHB-905 in different nutrient loading conditions using real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR). Three physio-biochemical parameters (malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH)) were also evaluated to provide insight into the physiological responses of Microcystis cells. We observed an upregulation of mcyB gene in nutrient-deficient conditions, especially in nitrogen (N) limitation condition, and the transcript abundance declined after the nutrient were resupplied. Differently, high transcription levels were seen in phosphorus (P) deficient treatments for key photosynthesis genes throughout the culture period, while those in N-deficient cells varied with time, suggesting an adaptive regulation of Microsystis cells to nutrient stress. Increased contents of antioxidant enzymes (SOD and GSH) were seen in both N and P-deficient conditions, suggesting the presence of excess amount of free radical generation caused by nutrient stress. The amount of SOD and GSH continued to increase even after the nutrient was reintroduced and a strong correlation was seen between the MDA and enzyme activities, indicating the robust effort of rebalancing the redox system in Microcystis cells. Based on these transcriptional and physiological responses of M. aeruginosa to nutrient loading, these results could provide more insight into Microcystis blooms management and toxin formation regulation.

Melanin: the biophysiology of oral melanocytes and physiological oral pigmentation

PubMed Central

2014-01-01

The presence of melanocytes in the oral epithelium is a well-established fact, but their physiological functions are not well defined. Melanin provides protection from environmental stressors such as ultraviolet radiation and reactive oxygen species; and melanocytes function as stress-sensors having the capacity both to react to and to produce a variety of microenvironmental cytokines and growth factors, modulating immune, inflammatory and antibacterial responses. Melanocytes also act as neuroendocrine cells producing local neurotransmitters including acetylcholine, catecholamines and opioids, and hormones of the melanocortin system such as proopiomelanocortin, adrenocorticotropic hormone and α-melanocyte stimulating hormone, that participate in intracellular and in intercellular signalling pathways, thus contributing to tissue homeostasis. There is a wide range of normal variation in melanin pigmentation of the oral mucosa. In general, darker skinned persons more frequently have oral melanin pigmentation than light-skinned persons. Variations in oral physiological pigmentation are genetically determined unless associated with some underlying disease. In this article, we discuss some aspects of the biophysiology of oral melanocytes, of the functions of melanin, and of physiological oral pigmentation. PMID:24661309

Effect of early handling of turkey poults on later responses to a dexamethasone-Escherichia coli challenge. 1. Production values and physiological response.

PubMed

Huff, G R; Huff, W E; Balog, J M; Rath, N C

2001-09-01

The stress responses of mice and rats has been shown to be permanently altered by brief, gentle handling during the first 10 d of life, resulting in increased BW and resistance to stress-induced immunosuppression. The purpose of this study was to determine whether early handling of turkey poults could permanently affect production values and physiology of adult turkeys. Turkey poults were handled 0, 1 (1x), or 2 (2x) times daily for the first 10 d after hatch. Handling consisted of gently catching each poult and holding it for 10 s. On Day 11 after hatch, half of the birds from each handling treatment were treated with three injections of 2 mg dexamethasone (DEX)/kg BW on alternating days. On the day of the third DEX injection, duplicate pens of birds were also inoculated in the airsac with 0 or 50 cfu of Escherichia coli. The same birds were treated with a second series of DEX injections at 5 wk of age. Two weeks later, all birds were weighed, and 3 wk later four birds per pen were bled and 10 birds per pen were necropsied; relative organ weights were then determined. Surviving birds were treated with a third series of DEX injections at 10 wk of age; 2 wk later, all surviving turkeys were bled, weighed, and necropsied. Feed consumption was determined weekly. There were no differences due to handling treatment on the body weights or on the relative organ weights of birds that died after the first DEX treatment. Birds treated with a second DEX injection at 5 wk of age and handled 1x daily had decreased BW. Those handled 1x or 2x daily had higher feed conversion ratios. Surviving birds that were given a third DEX treatment had higher BW and no difference in feed conversion when handled 1x or 2x daily. Relative liver, heart, and spleen weights were affected by handling of DEX-E. coli-treated birds, as were serum chemistry values for calcium, iron, glucose, total protein, blood urea nitogen, uric acid, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and gamma-glutamyltransferase. Handling also affected the numbers of white blood cells of DEX-treated birds. These results indicate that brief and gentle handling of turkey poults during the first 10 d after hatch has lasting effects on production values and physiology of adult turkeys and that these effects can be positive or negative. These results suggest a genetic divergence in the response to stress and its effect on production values and physiology of commercial turkey populations.

Beyond the Mean: Biological Impacts of Cryptic Temperature Change.

PubMed

Sheldon, Kimberly S; Dillon, Michael E

2016-07-01

Studies have typically used shifts in mean temperatures to make predictions about the biotic impacts of climate change. Though shifts in mean temperatures correlate with changes in phenology and distributions, other hidden, or cryptic, changes in temperature, such as temperature variation and extreme temperatures, could pose greater risks to species and ecological communities. Yet, these cryptic temperature changes have received relatively little attention because mean temperatures are readily available and the organism-appropriate temperature response is often elusive. An alternative to using mean temperatures is to view organisms as physiological filters of hourly temperature data. We explored three classes of physiological filters: (1) nonlinear thermal responses using performance curves of insect fitness, (2) cumulative thermal effects using degree-day models for corn emergence, and (3) threshold temperature effects using critical thermal maxima and minima for diverse ectotherms. For all three physiological filters, we determined the change in biological impacts of hourly temperature data from a standard reference period (1961-90) to a current period (2005-10). We then examined how well mean temperature changes during the same time period predicted the biotic impacts we determined from hourly temperature data. In all cases, mean temperature alone provided poor predictions of the impacts of climate change. These results suggest that incorporating high frequency temperature data can provide better predictions for how species will respond to temperature change. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

A Riparian Vegetation Ecophysiological Response Model

Treesearch

Jeffrey P. Leighton; Roland J. Risser

1989-01-01

A mathematical model is described that relates mature riparian vegetation ecophysiological response to changes in stream level. This model was developed to estimate the physiological response of riparian vegetation to reductions in streamflow. Field data from two sites on the North Fork of the Kings River were used in the model development. The physiological response...

Stress, fighting and neuroendocrine function.

NASA Technical Reports Server (NTRS)

Conner, R. L.; Levine, S.; Vernikos-Danellis, J.

1971-01-01

Plasma concentrations of pituitary adrenocorticotrophic hormone (ACTH) and adrenocortical steroids in rats after testing in the shock-induced fighting paradigm were examined. The investigations provide data consistent with the view that psychological aspects of the stressful situation are important in determining the effects of shock on physiological function. The data indicate that the pituitary-adrenal response can be attenuated by the expression of an organized pattern of behavior.

Teenage Pregnancy and Drug Abuse: Sources of Problem Behaviors. ERIC/CUE Digest No. 58.

ERIC Educational Resources Information Center

Bempechat, Janine; And Others

Drug and alcohol abuse and teenage pregnancy are two behaviors manifested by at-risk children that are both a cause and a result of their lack of success in school and possible subsequent dropping out. The distinction between substance use and abuse may be determined using the following criteria: (1) age of onset; (2) physiological responses; (3)…

Height is more important than light in determining leaf morphology in a tropical forest

Treesearch

Molly A. Cavaleri; Steven F. Oberbauer; David B. Clark; Deborah A. Clark; Michael G. Ryan

2010-01-01

Both within and between species, leaf physiological parameters are strongly related to leaf dry mass per area (LMA, g/m2), which has been found to increase from forest floor to canopy top in every forest where it has been measured. Although vertical LMA gradients in forests have historically been attributed to a direct phenotypic response to light, an increasing number...

Emotion regulation and emotion coherence: evidence for strategy-specific effects.

PubMed

Dan-Glauser, Elise S; Gross, James J

2013-10-01

One of the central tenets of emotion theory is that emotions involve coordinated changes across experiential, behavioral, and physiological response domains. Surprisingly little is known, however, about how the strength of this emotion coherence is altered when people try to regulate their emotions. To address this issue, we recorded experiential, behavioral, and physiological responses while participants watched negative and positive pictures. Cross-correlations were used to quantify emotion coherence. Study 1 tested how two types of suppression (expressive and physiological) influence coherence. Results showed that both strategies decreased the response coherence measured in negative and positive contexts. Study 2 tested how multichannel suppression (simultaneously targeting expressive and physiological responses) and acceptance influence emotion coherence. Results again showed that suppression decreased coherence. By contrast, acceptance was not significantly different from the unregulated condition. These findings help to clarify the nature of emotion response coherence by showing how different forms of emotion regulation may differentially affect it.

Common bean varieties demonstrate differential physiological and metabolic responses to the pathogenic fungus Sclerotinia sclerotiorum.

PubMed

Robison, Faith M; Turner, Marie F; Jahn, Courtney E; Schwartz, Howard F; Prenni, Jessica E; Brick, Mark A; Heuberger, Adam L

2018-02-24

Plant physiology and metabolism are important components of a plant response to microbial pathogens. Physiological resistance of common bean (Phaseolus vulgaris L.) to the fungal pathogen Sclerotinia sclerotiorum has been established, but the mechanisms of resistance are largely unknown. Here, the physiological and metabolic responses of bean varieties that differ in physiological resistance to S. sclerotiorum are investigated. Upon infection, the resistant bean variety A195 had a unique physiological response that included reduced photosynthesis and maintaining a higher leaf surface pH during infection. Leaf metabolomics was performed on healthy tissue adjacent to the necrotic lesion at 16, 24, and 48 hr post inoculation, and 144 metabolites were detected that varied between A195 and Sacramento following infection. The metabolites that varied in leaves included amines/amino acids, organic acids, phytoalexins, and ureides. The metabolic pathways associated with resistance included amine metabolism, uriede-based nitrogen remobilization, antioxidant production, and bean-specific phytoalexin production. A second experiment was conducted in stems of 13 bean genotypes with varying resistance. Stem resistance was associated with phytoalexin production, but unlike leaf metabolism, lipid changes were associated with susceptibility. Taken together, the data supports a multifaceted, physiometabolic response of common bean to S. sclerotiorum that mediates resistance. © 2018 John Wiley & Sons Ltd.

Promises and challenges of eco-physiological genomics in the field: tests of drought responses in switchgrass

DOE PAGES

Lovell, John T.; Shakirov, Eugene V.; Schwartz, Scott; ...

2016-05-31

Identifying the physiological and genetic basis of stress tolerance in plants has proven to be critical to understanding adaptation in both agricultural and natural systems. However, many discoveries were initially made in the controlled conditions of greenhouses or laboratories, not in the field. To test the comparability of drought responses across field and greenhouse environments, we undertook three independent experiments using the switchgrass reference genotype Alamo AP13. We analyzed physiological and gene expression variation across four locations, two sampling times, and three years. Relatively similar physiological responses and expression coefficients of variation across experiments masked highly dissimilar gene expression responsesmore » to drought. Critically, a drought experiment utilizing small pots in the greenhouse elicited nearly identical physiological changes as an experiment conducted in the field, but an order of magnitude more differentially expressed genes. However, we were able to define a suite of several hundred genes that were differentially expressed across all experiments. This list was strongly enriched in photosynthesis, water status, and reactive oxygen species responsive genes. The strong across-experiment correlations between physiological plasticity—but not differential gene expression—highlight the complex and diverse genetic mechanisms that can produce phenotypically similar responses to various soil water deficits.« less

Physiological and Growth Responses of Midrotation Loblolly Pine to Treatments of Fire, Herbicide, and Fertilizer

Treesearch

Emily J. Goodwin; Lisa M. Marino McInnis; Hans M. Williams; Brian P. Oswald; Kenneth W. Farrish

2004-01-01

The objectives of this study were to examine the effects of fertilizer and understory vegetation control (herbicide and prescribed fire) on mature tree physiology and to link observed physiological responses with tree growth. Photosynthetic rate (photosynthesis), transpiration, stomatal conductance, stem diameter, and crown area were measured in two midrotation...

Capillary response to skeletal muscle contraction: evidence that redundancy between vasodilators is physiologically relevant during active hyperaemia.

PubMed

Lamb, Iain R; Novielli, Nicole M; Murrant, Coral L

2018-04-15

The current theory behind matching blood flow to metabolic demand of skeletal muscle suggests redundant interactions between metabolic vasodilators. Capillaries play an important role in blood flow control given their ability to respond to muscle contraction by causing conducted vasodilatation in upstream arterioles that control their perfusion. We sought to determine whether redundancies occur between vasodilators at the level of the capillary by stimulating the capillaries with muscle contraction and vasodilators relevant to muscle contraction. We identified redundancies between potassium and both adenosine and nitric oxide, between nitric oxide and potassium, and between adenosine and both potassium and nitric oxide. During muscle contraction, we demonstrate redundancies between potassium and nitric oxide as well as between potassium and adenosine. Our data show that redundancy is physiologically relevant and involved in the coordination of the vasodilator response during muscle contraction at the level of the capillaries. We sought to determine if redundancy between vasodilators is physiologically relevant during active hyperaemia. As inhibitory interactions between vasodilators are indicative of redundancy, we tested whether vasodilators implicated in mediating active hyperaemia (potassium (K + ), adenosine (ADO) and nitric oxide (NO)) inhibit one another's vasodilatory effects through direct application of pharmacological agents and during muscle contraction. Using the hamster cremaster muscle and intravital microscopy, we locally stimulated capillaries with one vasodilator in the absence and the presence of a second vasodilator (10 -7 m S-nitroso-N-acetylpenicillamine (SNAP), 10 -7 m ADO, 10 mm KCl) applied sequentially and simultaneously, and observed the response in the associated upstream 4A arteriole controlling the perfusion of the stimulated capillary. We found that KCl significantly attenuated SNAP- and ADO-induced vasodilatations by ∼49.7% and ∼128.0% respectively and ADO significantly attenuated KCl- and SNAP-induced vasodilatations by ∼94.7% and ∼59.6%, respectively. NO significantly attenuated KCl vasodilatation by 93.8%. Further, during muscle contraction we found that inhibition of NO production using l-N G -nitroarginine methyl ester and inhibition of ADO receptors using xanthine amine congener was effective at inhibiting contraction-induced vasodilatation but only in the presence of K + release channel inhibition. Thus, only when the inhibiting vasodilator K + was blocked was the second vasodilator, NO or ADO, able to produce effective vasodilatation. Therefore, we show that there are inhibitory interactions between specific vasodilators at the level of the capillary. Further, these inhibitions can be observed during muscle contraction indicating that redundancies between vasodilators are physiologically relevant and influence vasodilatation during active hyperaemia. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

Mechanosensation and the Primary Cilium

NASA Astrophysics Data System (ADS)

Glaser, Joseph; Resnick, Andrew

2010-10-01

The primary cilium has come under increased scrutiny as a site for mechano- and chemosensation by cells. We have undertaken a program of study using mouse renal cell lines from the cortical collecting duct to quantify how mechanical forces arising from fluid shear are transduced into cellular responses. Fluid flow through a model nephron has been analyzed to determine the in vivo forces. A novel tissue culture flow chamber permitting accurate reproduction of physiologically relevant conditions has been calibrated. We have determined that in vivo conditions can be accurately modeled in our flow chamber.

Physiological and molecular responses of Lactuca sativa to colonization by Salmonella enterica serovar Dublin.

PubMed

Klerks, M M; van Gent-Pelzer, M; Franz, E; Zijlstra, C; van Bruggen, A H C

2007-08-01

This paper describes the physiological and molecular interactions between the human-pathogenic organism Salmonella enterica serovar Dublin and the commercially available mini Roman lettuce cv. Tamburo. The association of S. enterica serovar Dublin with lettuce plants was first determined, which indicated the presence of significant populations outside and inside the plants. The latter was evidenced from significant residual concentrations after highly efficient surface disinfection (99.81%) and fluorescence microscopy of S. enterica serovar Dublin in cross sections of lettuce at the root-shoot transition region. The plant biomass was reduced significantly compared to that of noncolonized plants upon colonization with S. enterica serovar Dublin. In addition to the physiological response, transcriptome analysis by cDNA amplified fragment length polymorphism analysis also provided clear differential gene expression profiles between noncolonized and colonized lettuce plants. From these, generally and differentially expressed genes were selected and identified by sequence analysis, followed by reverse transcription-PCR displaying the specific gene expression profiles in time. Functional grouping of the expressed genes indicated a correlation between colonization of the plants and an increase in expressed pathogenicity-related genes. This study indicates that lettuce plants respond to the presence of S. enterica serovar Dublin at physiological and molecular levels, as shown by the reduction in growth and the concurrent expression of pathogenicity-related genes. In addition, it was confirmed that Salmonella spp. can colonize the interior of lettuce plants, thus potentially imposing a human health risk when processed and consumed.

Transforming Water: Social Influence Moderates Psychological, Physiological, and Functional Response to a Placebo Product

PubMed Central

Crum, Alia J.; Phillips, Damon J.; Goyer, J. Parker; Akinola, Modupe; Higgins, E. Tory

2016-01-01

This paper investigates how social influence can alter physiological, psychological, and functional responses to a placebo product and how such responses influence the ultimate endorsement of the product. Participants consumed a product, “AquaCharge Energy Water,” falsely-labeled as containing 200 mg of caffeine but which was actually plain spring water, in one of three conditions: a no social influence condition, a disconfirming social influence condition, and a confirming social influence condition. Results demonstrated that the effect of the product labeling on physiological alertness (systolic blood pressure), psychological alertness (self-reported alertness), functional alertness (cognitive interference), and product endorsement was moderated by social influence: participants experienced more subjective, physiological and functional alertness and stronger product endorsement when they consumed the product in the confirming social influence condition than when they consumed the product in the disconfirming social influence condition. These results suggest that social influence can alter subjective, physiological, and functional responses to a faux product, in this case transforming the effects of plain water. PMID:27875567

Transforming Water: Social Influence Moderates Psychological, Physiological, and Functional Response to a Placebo Product.

PubMed

Crum, Alia J; Phillips, Damon J; Goyer, J Parker; Akinola, Modupe; Higgins, E Tory

2016-01-01

This paper investigates how social influence can alter physiological, psychological, and functional responses to a placebo product and how such responses influence the ultimate endorsement of the product. Participants consumed a product, "AquaCharge Energy Water," falsely-labeled as containing 200 mg of caffeine but which was actually plain spring water, in one of three conditions: a no social influence condition, a disconfirming social influence condition, and a confirming social influence condition. Results demonstrated that the effect of the product labeling on physiological alertness (systolic blood pressure), psychological alertness (self-reported alertness), functional alertness (cognitive interference), and product endorsement was moderated by social influence: participants experienced more subjective, physiological and functional alertness and stronger product endorsement when they consumed the product in the confirming social influence condition than when they consumed the product in the disconfirming social influence condition. These results suggest that social influence can alter subjective, physiological, and functional responses to a faux product, in this case transforming the effects of plain water.

Cellulose conjugated FITC-labelled mesoporous silica nanoparticles: intracellular accumulation and stimuli responsive doxorubicin release

NASA Astrophysics Data System (ADS)

Hakeem, Abdul; Zahid, Fouzia; Duan, Ruixue; Asif, Muhammad; Zhang, Tianchi; Zhang, Zhenyu; Cheng, Yong; Lou, Xiaoding; Xia, Fan

2016-02-01

Herein, we design novel cellulose conjugated mesoporous silica nanoparticle (CLS-MSP) based nanotherapeutics for stimuli responsive intracellular doxorubicin (DOX) delivery. DOX molecules are entrapped in pores of the fabricated mesoporous silica nanoparticles (MSPs) while cellulose is used as an encapsulating material through esterification on the outlet of the pores of the MSPs to avoid premature DOX release under physiological conditions. In in vitro studies, stimuli responsive DOX release is successfully achieved from DOX loaded cellulose conjugated mesoporous silica nanoparticles (DOX/CLS-MSPs) by pH and cellulase triggers. Intracellular accumulation of DOX/CLS-MSPs in human liver cancer cells (HepG2 cells) is investigated through confocal microscope magnification. Cell viability of HepG2 cells is determined as the percentage of the cells incubated with DOX/CLS-MSPs compared with that of non-incubated cells through an MTT assay.Herein, we design novel cellulose conjugated mesoporous silica nanoparticle (CLS-MSP) based nanotherapeutics for stimuli responsive intracellular doxorubicin (DOX) delivery. DOX molecules are entrapped in pores of the fabricated mesoporous silica nanoparticles (MSPs) while cellulose is used as an encapsulating material through esterification on the outlet of the pores of the MSPs to avoid premature DOX release under physiological conditions. In in vitro studies, stimuli responsive DOX release is successfully achieved from DOX loaded cellulose conjugated mesoporous silica nanoparticles (DOX/CLS-MSPs) by pH and cellulase triggers. Intracellular accumulation of DOX/CLS-MSPs in human liver cancer cells (HepG2 cells) is investigated through confocal microscope magnification. Cell viability of HepG2 cells is determined as the percentage of the cells incubated with DOX/CLS-MSPs compared with that of non-incubated cells through an MTT assay. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr08753h

Effect of Compassion Meditation on Neuroendocrine, Innate Immune and Behavioral Responses to Psychosocial Stress

PubMed Central

Pace, Thaddeus W.W.; Negi, Lobsang Tenzin; Adame, Daniel D.; Cole, Steven P.; Sivilli, Teresa I.; Brown, Timothy D.; Issa, Michael J.; Raison, Charles L.

2009-01-01

Summary Meditation practices may impact physiological pathways that are modulated by stress and relevant to disease. While much attention has been paid to meditation practices that emphasize calming the mind, improving focused attention, or developing mindfulness, less is known about meditation practices that foster compassion. Accordingly, the current study examined the effect of compassion meditation on innate immune, neuroendocrine and behavioral responses to psychosocial stress and evaluated the degree to which engagement in meditation practice influenced stress-reactivity. Sixty-one healthy adults were randomized to 6 weeks of training in compassion meditation (n=33) or participation in a health discussion control group (n=28) followed by exposure to a standardized laboratory stressor (Trier Social Stress Test [TSST]). Physiologic and behavioral responses to the TSST were determined by repeated assessments of plasma concentrations of interleukin (IL)-6 and cortisol as well as total distress scores on the Profile of Mood States (POMS). No main effect of group assignment on TSST responses was found for IL-6, cortisol or POMS scores. However, within the meditation group, increased meditation practice was correlated with decreased TSST-induced IL-6 (rp =-0.46, p=0.008) and POMS distress scores (rp =-0.43, p=0.014). Moreover, individuals with meditation practice times above the median exhibited lower TSST-induced IL-6 and POMS distress scores compared to individuals below the median, who did not differ from controls. These data suggest that engagement in compassion meditation may reduce stress-induced immune and behavioral responses, although future studies are required to determine whether individuals who engage in compassion meditation techniques are more likely to exhibit reduced stress reactivity. PMID:18835662

Consistent individual differences in haemolymph density reflect risk propensity in a marine invertebrate

PubMed Central

Fürtbauer, Ines

2015-01-01

While the literature on consistent individual differences in correlated suites of physiological and behavioural traits is steadily growing for vertebrates, invertebrates have received less attention. The few studies that do exist have measured temporary physiological states (or responses), rather than consistent individual physiological traits. Here, I explore the consistency of individual differences in physiology and behaviour of n=53 shore crabs (Carcinus maenas) by repeatedly measuring haemolymph density (HD) and the crabs' responses to a novel environment. In crustaceans, HD is directly proportional to protein concentrations, and thus indicative of physiological condition. HD was highly repeatable, and crabs showed consistent individual differences in their behavioural responses to a novel environment, thus indicating individual consistency in both physiology and behaviour. Furthermore, HD was significantly correlated with the crabs' risk propensity, i.e. individuals with higher HD spent more time near shelter. Overall, this provides the first evidence for consistency in an endogenous physiological trait in an invertebrate. The link between consistent physiology and behaviour, i.e. coping styles, analogous to those found in vertebrates, suggests metabolic and/or immunological correlates of personality which offer great potential for future studies. PMID:26543575

Energy conserving thermoregulatory patterns and lower disease severity in a bat resistant to the impacts of white-nose syndrome.

PubMed

Moore, Marianne S; Field, Kenneth A; Behr, Melissa J; Turner, Gregory G; Furze, Morgan E; Stern, Daniel W F; Allegra, Paul R; Bouboulis, Sarah A; Musante, Chelsey D; Vodzak, Megan E; Biron, Matthew E; Meierhofer, Melissa B; Frick, Winifred F; Foster, Jeffrey T; Howell, Daryl; Kath, Joseph A; Kurta, Allen; Nordquist, Gerda; Johnson, Joseph S; Lilley, Thomas M; Barrett, Benjamin W; Reeder, DeeAnn M

2018-01-01

The devastating bat fungal disease, white-nose syndrome (WNS), does not appear to affect all species equally. To experimentally determine susceptibility differences between species, we exposed hibernating naïve little brown myotis (Myotis lucifugus) and big brown bats (Eptesicus fuscus) to the fungus that causes WNS, Pseudogymnoascus destructans (Pd). After hibernating under identical conditions, Pd lesions were significantly more prevalent and more severe in little brown myotis. This species difference in pathology correlates with susceptibility to WNS in the wild and suggests that survival is related to different host physiological responses. We observed another fungal infection, associated with neutrophilic inflammation, that was equally present in all bats. This suggests that both species are capable of generating a response to cold tolerant fungi and that Pd may have evolved mechanisms for evading host responses that are effective in at least some bat species. These host-pathogen interactions are likely mediated not just by host physiological responses, but also by host behavior. Pd-exposed big brown bats, the less affected species, spent more time in torpor than did control animals, while little brown myotis did not exhibit this change. This differential thermoregulatory response to Pd infection by big brown bat hosts may allow for a more effective (or less pathological) immune response to tissue invasion.

Physiological Responses to Microclimate Cooling Used By the Air Soldier Dressed at MOPP 4 in an Extreme Desert Condition: Effects of Six Configurations

DTIC Science & Technology

2012-12-01

USARIEM TECHNICAL REPORT PHYSIOLOGICAL RESPONSES TO MICROCLIMATE COOLING USED BY THE AIR SOLDIER DRESSED AT MOPP 4 IN AN...2012 2. REPORT TYPE 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Physiological Responses to Microclimate Cooling Used By the Air Soldier 5b. GRANT... Microclimate Cooling System MCG HI – Air Warrior Microclimate Cooling Garment Used in High Cooling Configuration MCG LO - Air Warrior Microclimate

Estimated Tissue and Blood N(2) Levels and Risk of Decompression Sickness in Deep-, Intermediate-, and Shallow-Diving Toothed Whales during Exposure to Naval Sonar.

PubMed

Kvadsheim, P H; Miller, P J O; Tyack, P L; Sivle, L D; Lam, F P A; Fahlman, A

2012-01-01

Naval sonar has been accused of causing whale stranding by a mechanism which increases formation of tissue N(2) gas bubbles. Increased tissue and blood N(2) levels, and thereby increased risk of decompression sickness (DCS), is thought to result from changes in behavior or physiological responses during diving. Previous theoretical studies have used hypothetical sonar-induced changes in both behavior and physiology to model blood and tissue N(2) tension [Formula: see text], but this is the first attempt to estimate the changes during actual behavioral responses to sonar. We used an existing mathematical model to estimate blood and tissue N(2) tension [Formula: see text] from dive data recorded from sperm, killer, long-finned pilot, Blainville's beaked, and Cuvier's beaked whales before and during exposure to Low- (1-2 kHz) and Mid- (2-7 kHz) frequency active sonar. Our objectives were: (1) to determine if differences in dive behavior affects risk of bubble formation, and if (2) behavioral- or (3) physiological responses to sonar are plausible risk factors. Our results suggest that all species have natural high N(2) levels, with deep diving generally resulting in higher end-dive [Formula: see text] as compared with shallow diving. Sonar exposure caused some changes in dive behavior in both killer whales, pilot whales and beaked whales, but this did not lead to any increased risk of DCS. However, in three of eight exposure session with sperm whales, the animal changed to shallower diving, and in all these cases this seem to result in an increased risk of DCS, although risk was still within the normal risk range of this species. When a hypothetical removal of the normal dive response (bradycardia and peripheral vasoconstriction), was added to the behavioral response during model simulations, this led to an increased variance in the estimated end-dive N(2) levels, but no consistent change of risk. In conclusion, we cannot rule out the possibility that a combination of behavioral and physiological responses to sonar have the potential to alter the blood and tissue end-dive N(2) tension to levels which could cause DCS and formation of in vivo bubbles, but the actually observed behavioral responses of cetaceans to sonar in our study, do not imply any significantly increased risk of DCS.

Physiological determinants of human acute hypoxia tolerance.

DOT National Transportation Integrated Search

2013-11-01

AbstractIntroduction. We investigated possible physiological determinants of variability in hypoxia tolerance in subjects given a 5-minute normobaric exposure to 25,000 ft equivalent. Physiological tolerance to hypoxia was defined as the magnitude of...

Behavioral and physiologic responses to environmental enrichment in the maned wolf (Chrysocyon brachyurus).

PubMed

Cummings, Dawn; Brown, Janine L; Rodden, Melissa D; Songsasen, Nucharin

2007-09-01

The ex situ population of maned wolves is not self-sustaining due to poor reproduction, caused primarily by parental incompetence. Studies have shown that environmental enrichment can promote natural parental behaviors in zoo animals. The objective of this study was to determine the effects of environmental enrichment on behavioral and physiological responses of maned wolves. During an 8-week experimental period, daily behavior observations and fecal sample collection were conducted on four adult wolves (2.2) individually housed in environments without enrichment. After 2 weeks, the wolves were chronologically provided with 2-week intervals of hiding dead mice around the exhibit, no enrichment, and introduction of boomer balls. Responses of the wolves to enrichment were assessed based on activity levels and exploratory rates, as well as the level of corticoid metabolites in fecal samples collected daily throughout the study period. Providing wolves with environmental enrichment significantly increased exploratory behaviors (P<0.05), especially when mice were hidden in the enclosure. Fecal corticoid concentrations were increased during periods of enrichment in males (P<0.05), but not in females. Overall, there were no correlations between behavioral responses to enrichment and fecal corticoid levels. Behavioral results suggest that environmental enrichment elicits positive effects on the behavior of captive maned wolves. There is evidence suggesting that providing animals with ability to forage for food is a more effective enrichment strategy than introducing objects. There is need for a longer term study to determine the impact of environmental enrichment in this species. Zoo Biol 26:331-343, 2007. (c) 2007 Wiley-Liss, Inc.

Does the vestibular system contribute to head direction cell activity in the rat?

NASA Technical Reports Server (NTRS)

Brown, J. E.; Yates, B. J.; Taube, J. S.; Oman, C. M. (Principal Investigator)

2002-01-01

Head direction cells (HDC) located in several regions of the brain, including the anterior dorsal nucleus of the thalamus (ADN), postsubiculum (PoS), and lateral mammillary nuclei (LMN), provide the neural substrate for the determination of head direction. Although activity of HDC is influenced by various sensory signals and internally generated cues, lesion studies and some anatomical and physiological evidence suggest that vestibular inputs are critical for the maintenance of directional sensitivity of these cells. However, vestibular inputs must be transformed considerably in order to signal head direction, and the neuronal circuitry that accomplishes this signal processing has not been fully established. Furthermore, it is unclear why the removal of vestibular inputs abolishes the directional sensitivity of HDC, as visual and other sensory inputs and motor feedback signals strongly affect the firing of these neurons and would be expected to maintain their directional-related activity. Further physiological studies will be required to establish the role of vestibular system in producing HDC responses, and anatomical studies are needed to determine the neural circuitry that mediates vestibular influences on determination of head direction.

A Review of Cardiac Autonomic Measures: Considerations for Examination of Physiological Response in Children with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Benevides, Teal W.; Lane, Shelly J.

2015-01-01

The autonomic nervous system (ANS) is responsible for multiple physiological responses, and dysfunction of this system is often hypothesized as contributing to cognitive, affective, and behavioral responses in children. Research suggests that examination of ANS activity may provide insight into behavioral dysregulation in children with autism…

Relationship between Physiological and Parent-Observed Auditory Over-Responsiveness in Children with Typical Development and Those with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Takahashi, Hidetoshi; Nakahachi, Takayuki; Stickley, Andrew; Ishitobi, Makoto; Kamio, Yoko

2018-01-01

The objective of this study was to investigate relationships between caregiver-reported sensory processing abnormalities, and the physiological index of auditory over-responsiveness evaluated using acoustic startle response measures, in children with autism spectrum disorders and typical development. Mean acoustic startle response magnitudes in…

Sex-specific ecophysiological responses to environmental fluctuations of free-ranging Hermann's tortoises: implication for conservation.

PubMed

Sibeaux, Adélaïde; Michel, Catherine Louise; Bonnet, Xavier; Caron, Sébastien; Fournière, Kévin; Gagno, Stephane; Ballouard, Jean-Marie

2016-01-01

Physiological parameters provide indicators to evaluate how organisms respond to conservation actions. For example, individuals translocated during reinforcement programmes may not adapt to their novel host environment and may exhibit elevated chronic levels of stress hormones and/or decreasing body condition. Conversely, successful conservation actions should be associated with a lack of detrimental physiological perturbation. However, physiological references fluctuate over time and are influenced by various factors (e.g. sex, age, reproductive status). It is therefore necessary to determine the range of natural variations of the selected physiological metrics to establish useful baselines. This study focuses on endangered free-ranging Hermann's tortoises ( Testudo hermanni hermanni ), where conservation actions have been preconized to prevent extinction of French mainland populations. The influence of sex and of environmental factors (site, year and season) on eight physiological parameters (e.g. body condition, corticosterone concentrations) was assessed in 82 individuals from two populations living in different habitats. Daily displacements were monitored by radio-tracking. Most parameters varied between years and seasons and exhibited contrasting sex patterns but with no or limited effect of site. By combining behavioural and physiological traits, this study provides sex-specific seasonal baselines that can be used to monitor the health status of Hermann's tortoises facing environmental threats (e.g. habitat changes) or during conservation actions (e.g. translocation). These results might also assist in selection of the appropriate season for translocation.

Physiological responses to environmental factors related to space flight

NASA Technical Reports Server (NTRS)

Pace, N.; Grunbaum, B. W.; Kodama, A. M.; Mains, R. C.; Rahlmann, D. F.

1975-01-01

Physiological procedures and instrumentation developed for the measurement of hemodynamic and metabolic parameters during prolonged periods of weightlessness are described along with the physiological response of monkeys to weightlessness. Specific areas examined include: cardiovascular studies; thyroid function; blood oxygen transport; growth and reproduction; excreta analysis for metabolic balance studies; and electrophoretic separation of creatine phosphokinase isoenzymes in human blood.

Development and application of an antibody-based protein microarray to assess physiological stress in grizzly bears (Ursus arctos).

PubMed

Carlson, Ruth I; Cattet, Marc R L; Sarauer, Bryan L; Nielsen, Scott E; Boulanger, John; Stenhouse, Gordon B; Janz, David M

2016-01-01

A novel antibody-based protein microarray was developed that simultaneously determines expression of 31 stress-associated proteins in skin samples collected from free-ranging grizzly bears (Ursus arctos) in Alberta, Canada. The microarray determines proteins belonging to four broad functional categories associated with stress physiology: hypothalamic-pituitary-adrenal axis proteins, apoptosis/cell cycle proteins, cellular stress/proteotoxicity proteins and oxidative stress/inflammation proteins. Small skin samples (50-100 mg) were collected from captured bears using biopsy punches. Proteins were isolated and labelled with fluorescent dyes, with labelled protein homogenates loaded onto microarrays to hybridize with antibodies. Relative protein expression was determined by comparison with a pooled standard skin sample. The assay was sensitive, requiring 80 µg of protein per sample to be run in triplicate on the microarray. Intra-array and inter-array coefficients of variation for individual proteins were generally <10 and <15%, respectively. With one exception, there were no significant differences in protein expression among skin samples collected from the neck, forelimb, hindlimb and ear in a subsample of n = 4 bears. This suggests that remotely delivered biopsy darts could be used in future sampling. Using generalized linear mixed models, certain proteins within each functional category demonstrated altered expression with respect to differences in year, season, geographical sampling location within Alberta and bear biological parameters, suggesting that these general variables may influence expression of specific proteins in the microarray. Our goal is to apply the protein microarray as a conservation physiology tool that can detect, evaluate and monitor physiological stress in grizzly bears and other species at risk over time in response to environmental change.

Surface sulfonamide modification of poly(N-isopropylacrylamide)-based block copolymer micelles to alter pH and temperature responsive properties for controlled intracellular uptake.

PubMed

Cyphert, Erika L; von Recum, Horst A; Yamato, Masayuki; Nakayama, Masamichi

2018-06-01

Two different surface sulfonamide-functionalized poly(N-isopropylacrylamide)-based polymeric micelles were designed as pH-/temperature-responsive vehicles. Both sulfadimethoxine- and sulfamethazine-surface functionalized micelles were characterized to determine physicochemical properties, hydrodynamic diameters, zeta potentials, temperature-dependent size changes, and lower critical solution temperatures (LCST) in both pH 7.4 and 6.8 solutions (simulating both physiological and mild low pH conditions), and tested in the incorporation of a proof-of-concept hydrophobic antiproliferative drug, paclitaxel. Cellular uptake studies were conducted using bovine carotid endothelial cells and fluorescently labeled micelles to evaluate if there was enhanced cellular uptake of the micelles in a low pH environment. Both variations of micelles showed enhanced intracellular uptake under mildly acidic (pH 6.8) conditions at temperatures slightly above their LCST and minimal uptake at physiological (pH 7.4) conditions. Due to the less negative zeta potential of the sulfamethazine-surface micelles compared to sulfadimethoxine-surface micelles, and the proximity of their LCST to physiological temperature (37°C), the sulfamethazine variation was deemed more amenable for clinically relevant temperature and pH-stimulated applications. Nevertheless, we believe both polymeric micelle variations have the capacity to be implemented as an intracellular drug or gene delivery system in response to mildly acidic conditions. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1552-1560, 2018. © 2018 Wiley Periodicals, Inc.

Effects of music on physiological and behavioral responses of premature infants: a randomized controlled trial.

PubMed

Alipour, Zahra; Eskandari, Narges; Ahmari Tehran, Hoda; Eshagh Hossaini, Seyed Kamal; Sangi, Sareh

2013-08-01

Despite persuasive theories about the beneficial effects of music and singing in developmental care for premature infants, few small studies are available in this regard. We conducted this study to investigate the physiological and behavioral responses of premature infants to recorded lullaby music and silence. In a randomized controlled trial, 90 premature infants in the neonatal care unit of a hospital in Qom (Iran) were randomly allocated to intervention (lullaby and silence) or control groups. Lullaby music was played via headphones at a volume of 50-60 dB. In the silence group, headphones were placed on the infants' ears while no music was played. The three groups were surveyed for physiological responses including oxygen saturation, respiratory and heart rates, and behavioral states every five minutes before, during, and after the intervention. The three groups were not significantly different in terms of mean values of respiratory and heart rates, oxygen saturation, and behavioral states of infants. Similarly, no significant within group differences in respiratory and heart rates, oxygen saturation, and behavioral states were observed at different times. Our findings did not support the beneficial effects of music for premature infants. However, music is a noninvasive, non-pharmaceutical, and relatively low-cost intervention that can be implemented at infants' bedside. Thus further research is warranted to determine whether the effects noted in previous studies can be consistently replicated in diverse settings and with diverse groups of preterm infants. Copyright © 2013 Elsevier Ltd. All rights reserved.

Major Crop Species Show Differential Balance between Root Morphological and Physiological Responses to Variable Phosphorus Supply

PubMed Central

Lyu, Yang; Tang, Hongliang; Li, Haigang; Zhang, Fusuo; Rengel, Zed; Whalley, William R.; Shen, Jianbo

2016-01-01

The relationship between root morphological and physiological responses to variable P supply in different plant species is poorly understood. We compared root morphological and physiological responses to P supply in seven crop species (Zea mays, Triticum aestivum, Brassica napus, Lupinus albus, Glycine max, Vicia faba, Cicer arietinum) treated with or without 100 mg P kg-1 in two soils (acidic and calcareous). Phosphorus deficiency decreased root length more in fibrous root species (Zea mays, Triticum aestivum, Brassica napus) than legumes. Zea mays and Triticum aestivum had higher root/shoot biomass ratio and Brassica napus had higher specific root length compared to legumes, whereas legumes (except soybean) had higher carboxylate exudation than fibrous root species. Lupinus albus exhibited the highest P-acquisition efficiency due to high exudation of carboxylates and acid phosphatases. Lupinus albus and Cicer arietinum depended mostly on root exudation (i.e., physiological response) to enhance P acquisition, whereas Zea mays, Triticum aestivum and Brassica napus had higher root morphology dependence, with Glycine max and Vicia faba in between. Principal component analysis using six morphological and six physiological responses identified root size and diameter as the most important morphological traits, whereas important physiological responses included carboxylate exudation, and P-acquisition and P-utilization efficiency followed by rhizosphere soil pH and acid phosphatase activity. In conclusion, plant species can be grouped on the basis of their response to soil P being primarily via root architectural or exudation plasticity, suggesting a potential benefit of crop-specific root-trait-based management to cope with variable soil P supply in sustainable grain production. PMID:28066491

Pituitary hyperplasia and gigantism in mice caused by a cholera toxin transgene.

PubMed

Burton, F H; Hasel, K W; Bloom, F E; Sutcliffe, J G

1991-03-07

Cyclic AMP is thought to act as an intracellular second messenger, mediating the physiological response of many cell types to extracellular signals. In the pituitary, growth hormone (GH)-producing cells (somatotrophs) proliferate and produce GH in response to hypothalamic GH-releasing factor, which binds a receptor that stimulates Gs protein activation of adenylyl cyclase. We have now determined whether somatotroph proliferation and GH production are stimulated by cAMP alone, or require concurrent, non-Gs-mediated induction of other regulatory molecules by designing a transgene to induce chronic supraphysiological concentrations of cAMP in somatotrophs. The rat GH promoter was used to express an intracellular form of cholera toxin, a non-cytotoxic and irreversible activator of Gs. Introduction of this transgene into mice caused gigantism, elevated serum GH levels, somatotroph proliferation and pituitary hyperplasia. These results support the direct triggering of these events by cAMP, and illustrate the utility of cholera toxin transgenes as a tool for physiological engineering.

VESsel GENeration Analysis (VESGEN): Innovative Vascular Mappings for Astronaut Exploration Health Risks and Human Terrestrial Medicine

NASA Technical Reports Server (NTRS)

Parsons-Wingerter, Patricia; Kao, David; Valizadegan, Hamed; Martin, Rodney; Murray, Matthew C.; Ramesh, Sneha; Sekaran, Srinivaas

2017-01-01

Currently, astronauts face significant health risks in future long-duration exploration missions such as colonizing the Moon and traveling to Mars. Numerous risks include greatly increased radiation exposures beyond the low earth orbit (LEO) of the ISS, and visual and ocular impairments in response to microgravity environments. The cardiovascular system is a key mediator in human physiological responses to radiation and microgravity. Moreover, blood vessels are necessarily involved in the progression and treatment of vascular-dependent terrestrial diseases such as cancer, coronary vessel disease, wound-healing, reproductive disorders, and diabetes. NASA developed an innovative, globally requested beta-level software, VESsel GENeration Analysis (VESGEN) to map and quantify vascular remodeling for application to astronaut and terrestrial health challenges. VESGEN mappings of branching vascular trees and networks are based on a weighted multi-parametric analysis derived from vascular physiological branching rules. Complex vascular branching patterns are determined by biological signaling mechanisms together with the fluid mechanics of multi-phase laminar blood flow.

A quinoline-based Cu2 + ion complex fluorescence probe for selective detection of inorganic phosphate anion in aqueous solution and its application to living cells

NASA Astrophysics Data System (ADS)

Dai, Yanpeng; Wang, Peng; Fu, Jiaxin; Yao, Kun; Xu, Kuoxi; Pang, Xiaobin

2017-08-01

A quinaldine functionalized probe QP has been designed and synthesized. It exhibited selective turn-off fluorescence response toward Cu2 + ion over most of the biologically important ions at physiological pH. The binding ratio of the probe QP and Cu2 + ion was determined to be 1:1 through fluorescence titration, Job's plot and ESI-MS. The binding constant (K) of Cu2 + to probe QP was found to be 2.12 × 104 M- 1. Further, the Cu2 + ensemble of probe QP was found to respond H2PO4- and HPO42 - among other important biological anions via fluorescence turn-on response at physiological pH. Fluorescence microscopy imaging using living Hela cells showed that probe QP could be used as an effective fluorescent probe for detecting Cu2 + cation and H2PO4- and HPO42 - anions in living cells.

A quinoline-based Cu2+ ion complex fluorescence probe for selective detection of inorganic phosphate anion in aqueous solution and its application to living cells.

PubMed

Dai, Yanpeng; Wang, Peng; Fu, Jiaxin; Yao, Kun; Xu, Kuoxi; Pang, Xiaobin

2017-08-05

A quinaldine functionalized probe QP has been designed and synthesized. It exhibited selective turn-off fluorescence response toward Cu 2+ ion over most of the biologically important ions at physiological pH. The binding ratio of the probe QP and Cu 2+ ion was determined to be 1:1 through fluorescence titration, Job's plot and ESI-MS. The binding constant (K) of Cu 2+ to probe QP was found to be 2.12×10 4 M -1 . Further, the Cu 2+ ensemble of probe QP was found to respond H 2 PO 4 - and HPO 4 2- among other important biological anions via fluorescence turn-on response at physiological pH. Fluorescence microscopy imaging using living Hela cells showed that probe QP could be used as an effective fluorescent probe for detecting Cu 2+ cation and H 2 PO 4 - and HPO 4 2- anions in living cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Hormone-mediated adjustment of sex ratio in vertebrates.

PubMed

Navara, Kristen J

2013-12-01

The ability to adjust sex ratios at the individual level exists among all vertebrate groups studied to date. In many cases, there is evidence for facultative adjustment of sex ratios in response to environmental and/or social cues. Because environmental and social information must be first transduced into a physiological signal to influence sex ratios, hormones likely play a role in the adjustment of sex ratio in vertebrates, because the endocrine system acts as a prime communicator that directs physiological activities in response to changing external conditions. This symposium was developed to bring together investigators whose work on adjustment of sex ratio represents a variety of vertebrate groups in an effort to draw comparisons between species in which the sex-determination process is well-established and those in which more work is needed to understand how adjustments in sex ratio are occurring. This review summarizes potential hormone targets that may underlie the mechanisms of adjustment of sex ratio in humans, non-human mammals, birds, reptiles, and fishes.

A critical review of 5-HT brain microdialysis and behavior.

PubMed

Rueter, L E; Fornal, C A; Jacobs, B L

1997-01-01

Serotonin (5-HT) has been implicated in many central nervous system-mediated functions including sleep, arousal, feeding, motor activity and the stress response. In order to help establish the precise role of 5-HT in physiology and behavior, in vivo microdialysis studies have sought to identify the conditions under which the release of 5-HT is altered. Extracellular 5-HT levels have been monitored in more than fifteen regions of the brain during a variety of spontaneous behaviors, and in response to several physiological, environmental, and behavioral manipulations. The vast majority of these studies found increases (30-100%) in 5-HT release in almost all brain regions studied. Since electrophysiological studies have shown that behavioral arousal is the primary determinant of brain serotonergic neuronal activity, we suggest that the increase in 5-HT release seen during a wide variety of experimental conditions is largely due to one factor, namely an increase in behavioral arousal/motor activity associated with the manipulation.

Contrasting stress responses of two co-occurring chipmunk species (Tamias alpinus and T. speciosus).

PubMed

Hammond, Talisin T; Palme, Rupert; Lacey, Eileen A

2015-01-15

Glucocorticoid (GC) hormones are important mediators of responses to environmental conditions. Accordingly, differences in GC physiology may contribute to interspecific variation in response to anthropogenically-induced patterns of climate change. To begin exploring this possibility, we validated the use of fecal cortisol/corticosterone metabolites (FCM) to measure baseline glucocorticoid levels in two species of co-occurring chipmunks that have exhibited markedly different patterns of response to environmental change. In Yosemite National Park, the alpine chipmunk (Tamias alpinus) has undergone a significant upward contraction of its elevational range over the past century; in contrast, the lodgepole chipmunk (Tamiasspeciosus) has experienced no significant change in elevational distribution over this period. To determine if GC levels in these species vary in response to external stimuli and to assess whether these responses differ between species, we compared FCM levels for the same individuals (1) at the time of capture in the field, (2) after a short period of captivity, and (3) after adrenocorticotropic hormone (ACTH), (4) handling, and (5) trapping challenges conducted while these animals were held in captivity. Our analyses indicate that T. alpinus was more responsive to several of these changes in external conditions. Although both species displayed a significant FCM response to ACTH challenge, only T. alpinus showed a significant response to our handling challenge and to captive housing conditions. These findings underscore the importance of species-specific validation studies and support the potential for studies of GC physiology to generate insights into interspecific differences in response to environmental change. Copyright © 2014 Elsevier Inc. All rights reserved.

Characteristics of hyperthermia-induced hyperventilation in humans

PubMed Central

Tsuji, Bun; Hayashi, Keiji; Kondo, Narihiko; Nishiyasu, Takeshi

2016-01-01

ABSTRACT In humans, hyperthermia leads to activation of a set of thermoregulatory responses that includes cutaneous vasodilation and sweating. Hyperthermia also increases ventilation in humans, as is observed in panting dogs, but the physiological significance and characteristics of the hyperventilatory response in humans remain unclear. The relative contribution of respiratory heat loss to total heat loss in a hot environment in humans is small, and this hyperventilation causes a concomitant reduction in arterial CO2 pressure (hypocapnia), which can cause cerebral hypoperfusion. Consequently, hyperventilation in humans may not contribute to the maintenance of physiological homeostasis (i.e., thermoregulation). To gain some insight into the physiological significance of hyperthermia-induced hyperventilation in humans, in this review, we discuss 1) the mechanisms underlying hyperthermia-induced hyperventilation, 2) the factors modulating this response, and 3) the physiological consequences of the response. PMID:27227102

Physiological responses to social and nonsocial stimuli in neurotypical adults with high and low levels of autistic traits: implications for understanding nonsocial drive in autism spectrum disorders.

PubMed

Singleton, Clarence J; Ashwin, Chris; Brosnan, Mark

2014-12-01

Researchers have suggested that the two primary cognitive features of autism spectrum disorder (ASD), a drive toward nonsocial processing and a reduced drive toward social processing, may be unrelated to each other in the neurotypical (NT) population and may therefore require separate explanations. Drive toward types of processing may be related to physiological arousal to categories of stimuli, such as social (e.g., faces) or nonsocial (e.g., trains). This study investigated how autistic traits in an NT population might relate to differences in physiological responses to nonsocial compared with social stimuli. NT participants were recruited to examine these differences in those with high vs. low degrees of ASD traits. Forty-six participants (21 male, 25 female) completed the Autism Spectrum Quotient (AQ) to measure ASD traits before viewing a series of 24 images while skin conductance response (SCR) was recorded. Images included six nonsocial, six social, six face-like cartoons, and six nonsocial (relating to participants' personal interests). Analysis revealed that those with a higher AQ had significantly greater SCR arousal to nonsocial stimuli than those with a low AQ, and the higher the AQ, the greater the difference between SCR arousal to nonsocial and social stimuli. This is the first study to identify the relationship between AQ and physiological response to nonsocial stimuli, and a relationship between physiological response to both social and nonsocial stimuli, suggesting that physiological response may underlie the atypical drive toward nonsocial processing seen in ASD, and that at the physiological level at least the social and nonsocial in ASD may be related to one another. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.

Physiological responses to incremental exercise in the heat following internal and external precooling.

PubMed

James, C A; Richardson, A J; Watt, P W; Gibson, O R; Maxwell, N S

2015-06-01

Twelve males completed three incremental, discontinuous treadmill tests in the heat [31.9(1.0) °C, 61.9(8.9)%] to determine speed at two fixed blood lactate concentrations (2 and 3.5 mmol/L), running economy (RE), and maximum oxygen uptake ( V ˙ O 2 m a x ). Trials involved 20 min of either internal cooling (ICE, 7.5 g/kg ice slurry ingestion) or mixed-methods external cooling (EXT, cold towels, forearm immersion, ice vest, and cooling shorts), alongside no intervention (CON). Following precooling, participants ran 0.3 km/h faster at 2 mmol/L and 0.2 km/h faster at 3.5 mmol/L (P = 0.04, partial η(2)  = 0.27). Statistical differences were observed vs CON for ICE (P = 0.03, d = 0.15), but not EXT (P = 0.12, d = 0.15). There was no effect of cooling on RE (P = 0.81, partial η(2)  = 0.02), nor on V ˙ O 2 m a x (P = 0.69, partial η(2)  = 0.04). An effect for cooling on physiological strain index was observed (P < 0.01, partial η(2)  = 0.41), with differences vs CON for EXT (P = 0.02, d = 0.36), but not ICE (P = 0.06, d = 0.36). Precooling reduced thermal sensation (P < 0.01, partial η(2)  = 0.66) in both cooling groups (P < 0.01). Results indicate ICE and EXT provide similar physiological responses for exercise up to 30 min duration in the heat. Differing thermoregulatory responses are suggestive of specific event characteristics determining the choice of cooling. Precooling appears to reduce blood lactate accumulation and reduce thermoregulatory and perceptual strain during incremental exercise. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Reduced labial temperature in response to sexual films with distractors among women with lower sexual desire.

PubMed

Prause, Nicole; Heiman, Julia

2010-02-01

Sexual desire variation traditionally has been treated as due to variance in affective response to sexual stimulation, but differences in attention to the stimuli may better account for differences in sexual desire. Determine whether sexual desire varies due to attention biases towards sexual stimuli. Sexual arousal was quantified by physiological (labia minus temperature) and experienced (continuously adjusting a potentiometer) indicators. Twenty-two women who varied in their level of sexual desire attended one laboratory session during which they viewed a neutral nature film, a sexual film, and a sexual film with distractors while their labial temperature and self-reported sexual arousal were recorded. Participants reported and displayed lower sexual arousal during the sexual stimulus with distractors as compared to the sexual film without distractors. While all women reported lower sexual arousal to the sexual film with distractors, women with relatively lower sexual desire also reported lower sexual arousal to the sexual film with no distractors than women with higher sexual desire. Physiologically, women with lower sexual desire exhibited lower labial temperature. Since the predicted lower self-reported and physiological sexual arousal to the sexual stimulus with distractors for the women with lower sexual desire did not emerge, this study does not support that sexual desire levels vary due to differential attention to sexual stimuli.

Effect of forest walking on autonomic nervous system activity in middle-aged hypertensive individuals: a pilot study.

PubMed

Song, Chorong; Ikei, Harumi; Kobayashi, Maiko; Miura, Takashi; Taue, Masao; Kagawa, Takahide; Li, Qing; Kumeda, Shigeyoshi; Imai, Michiko; Miyazaki, Yoshifumi

2015-03-02

There has been increasing attention on the therapeutic effects of the forest environment. However, evidence-based research that clarifies the physiological effects of the forest environment on hypertensive individuals is lacking. This study provides scientific evidence suggesting that a brief forest walk affects autonomic nervous system activity in middle-aged hypertensive individuals. Twenty participants (58.0±10.6 years) were instructed to walk predetermined courses in forest and urban environments (as control). Course length (17-min walk), walking speed, and energy expenditure were equal between the forest and urban environments to clarify the effects of each environment. Heart rate variability (HRV) and heart rate were used to quantify physiological responses. The modified semantic differential method and Profile of Mood States were used to determine psychological responses. The natural logarithm of the high-frequency component of HRV was significantly higher and heart rate was significantly lower when participants walked in the forest than when they walked in the urban environment. The questionnaire results indicated that, compared with the urban environment, walking in the forest increased "comfortable", "relaxed", "natural" and "vigorous" feelings and decreased "tension-anxiety," "depression," "anxiety-hostility," "fatigue" and "confusion". A brief walk in the forest elicited physiological and psychological relaxation effects on middle-aged hypertensive individuals.

Could beaked whales get the bends? Effect of diving behaviour and physiology on modelled gas exchange for three species: Ziphius cavirostris, Mesoplodon densirostris and Hyperoodon ampullatus.

PubMed

Hooker, Sascha K; Baird, Robin W; Fahlman, Andreas

2009-07-31

A mathematical model, based on current knowledge of gas exchange and physiology of marine mammals, was used to predict blood and tissue tension N2 (P(N2)) using field data from three beaked whale species: northern bottlenose whales, Cuvier's beaked whales, and Blainville's beaked whales. The objective was to determine if physiology (body mass, diving lung volume, dive response) or dive behaviour (dive depth and duration, changes in ascent rate, diel behaviour) would lead to differences in P(N2) levels and thereby decompression sickness (DCS) risk between species. Diving lung volume and extent of the dive response had a large effect on end-dive P(N2). The dive profile had a larger influence on end-dive P(N2) than body mass differences between species. Despite diel changes in dive behaviour, P(N2) levels showed no consistent trend. Model output suggested that all three species live with tissue P(N2) levels that would cause a significant proportion of DCS cases in terrestrial mammals. Cuvier's beaked whale diving behaviour appears to put them at higher risk than the other species, which may explain their prevalence in strandings after the use of mid-frequency sonar.

Sound the alarm: A meta-analysis on the effect of aquatic noise on fish behavior and physiology.

PubMed

Cox, Kieran; Brennan, Lawrence P; Gerwing, Travis G; Dudas, Sarah E; Juanes, Francis

2018-07-01

The aquatic environment is increasingly bombarded by a wide variety of noise pollutants whose range and intensity are increasing with each passing decade. Yet, little is known about how aquatic noise affects marine communities. To determine the implications that changes to the soundscape may have on fishes, a meta-analysis was conducted focusing on the ramifications of noise on fish behavior and physiology. Our meta-analysis identified 42 studies that produced 2,354 data points, which in turn indicated that anthropogenic noise negatively affects fish behavior and physiology. The most predominate responses occurred within foraging ability, predation risk, and reproductive success. Additionally, anthropogenic noise was shown to increase the hearing thresholds and cortisol levels of numerous species while tones, biological, and environmental noise were most likely to affect complex movements and swimming abilities. These findings suggest that the majority of fish species are sensitive to changes in the aquatic soundscape, and depending on the noise source, species responses may have extreme and negative fitness consequences. As such, this global synthesis should serve as a warning of the potentially dire consequences facing marine ecosystems if alterations to aquatic soundscapes continue on their current trajectory. © 2018 John Wiley & Sons Ltd.

Carbon and water flux responses to physiology by environment interactions: a sensitivity analysis of variation in climate on photosynthetic and stomatal parameters

NASA Astrophysics Data System (ADS)

Bauerle, William L.; Daniels, Alex B.; Barnard, David M.

2014-05-01

Sensitivity of carbon uptake and water use estimates to changes in physiology was determined with a coupled photosynthesis and stomatal conductance ( g s) model, linked to canopy microclimate with a spatially explicit scheme (MAESTRA). The sensitivity analyses were conducted over the range of intraspecific physiology parameter variation observed for Acer rubrum L. and temperate hardwood C3 (C3) vegetation across the following climate conditions: carbon dioxide concentration 200-700 ppm, photosynthetically active radiation 50-2,000 μmol m-2 s-1, air temperature 5-40 °C, relative humidity 5-95 %, and wind speed at the top of the canopy 1-10 m s-1. Five key physiological inputs [quantum yield of electron transport ( α), minimum stomatal conductance ( g 0), stomatal sensitivity to the marginal water cost of carbon gain ( g 1), maximum rate of electron transport ( J max), and maximum carboxylation rate of Rubisco ( V cmax)] changed carbon and water flux estimates ≥15 % in response to climate gradients; variation in α, J max, and V cmax input resulted in up to ~50 and 82 % intraspecific and C3 photosynthesis estimate output differences respectively. Transpiration estimates were affected up to ~46 and 147 % by differences in intraspecific and C3 g 1 and g 0 values—two parameters previously overlooked in modeling land-atmosphere carbon and water exchange. We show that a variable environment, within a canopy or along a climate gradient, changes the spatial parameter effects of g 0, g 1, α, J max, and V cmax in photosynthesis- g s models. Since variation in physiology parameter input effects are dependent on climate, this approach can be used to assess the geographical importance of key physiology model inputs when estimating large scale carbon and water exchange.

Evaluation of water-use efficiency in foxtail millet (Setaria italica) using visible-near infrared and thermal spectral sensing techniques.

PubMed

Wang, Meng; Ellsworth, Patrick Z; Zhou, Jianfeng; Cousins, Asaph B; Sankaran, Sindhuja

2016-05-15

Water limitations decrease stomatal conductance (g(s)) and, in turn, photosynthetic rate (A(net)), resulting in decreased crop productivity. The current techniques for evaluating these physiological responses are limited to leaf-level measures acquired by measuring leaf-level gas exchange. In this regard, proximal sensing techniques can be a useful tool in studying plant biology as they can be used to acquire plant-level measures in a high-throughput manner. However, to confidently utilize the proximal sensing technique for high-throughput physiological monitoring, it is important to assess the relationship between plant physiological parameters and the sensor data. Therefore, in this study, the application of rapid sensing techniques based on thermal imaging and visual-near infrared spectroscopy for assessing water-use efficiency (WUE) in foxtail millet (Setaria italica (L.) P. Beauv) was evaluated. The visible-near infrared spectral reflectance (350-2500 nm) and thermal (7.5-14 µm) data were collected at regular intervals from well-watered and drought-stressed plants in combination with other leaf physiological parameters (transpiration rate-E, A(net), g(s), leaf carbon isotopic signature-δ(13)C(leaf), WUE). Partial least squares regression (PLSR) analysis was used to predict leaf physiological measures based on the spectral data. The PLSR modeling on the hyperspectral data yielded accurate and precise estimates of leaf E, gs, δ(13)C(leaf), and WUE with coefficient of determination in a range of 0.85-0.91. Additionally, significant differences in average leaf temperatures (~1°C) measured with a thermal camera were observed between well-watered plants and drought-stressed plants. In summary, the visible-near infrared reflectance data, and thermal images can be used as a potential rapid technique for evaluating plant physiological responses such as WUE. Copyright © 2016 Elsevier B.V. All rights reserved.

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 ...

Autonomic Physiological Response Patterns Related to Intelligence

ERIC Educational Resources Information Center

Melis, Cor; van Boxtel, Anton

2007-01-01

We examined autonomic physiological responses induced by six different cognitive ability tasks, varying in complexity, that were selected on the basis of on Guilford's Structure of Intellect model. In a group of 52 participants, task performance was measured together with nine different autonomic response measures and respiration rate. Weighted…

The role thermal physiology plays in species invasion

PubMed Central

Kelley, Amanda L.

2014-01-01

The characterization of physiological phenotypes that may play a part in the establishment of non-native species can broaden our understanding about the ecology of species invasion. Here, an assessment was carried out by comparing the responses of invasive and native species to thermal stress. The goal was to identify physiological patterns that facilitate invasion success and to investigate whether these traits are widespread among invasive ectotherms. Four hypotheses were generated and tested using a review of the literature to determine whether they could be supported across taxonomically diverse invasive organisms. The four hypotheses are as follows: (i) broad geographical temperature tolerances (thermal width) confer a higher upper thermal tolerance threshold for invasive rather than native species; (ii) the upper thermal extreme experienced in nature is more highly correlated with upper thermal tolerance threshold for invasive vs. native animals; (iii) protein chaperone expression—a cellular mechanism that underlies an organism's thermal tolerance threshold—is greater in invasive organisms than in native ones; and (iv) acclimation to higher temperatures can promote a greater range of thermal tolerance for invasive compared with native species. Each hypothesis was supported by a meta-analysis of the invasive/thermal physiology literature, providing further evidence that physiology plays a substantial role in the establishment of invasive ectotherms. PMID:27293666

Bacterial diversity in Adélie penguin, Pygoscelis adeliae, guano: molecular and morpho-physiological approaches.

PubMed

Zdanowski, Marek K; Weglenski, Piotr; Golik, Pawel; Sasin, Joanna M; Borsuk, Piotr; Zmuda, Magdalena J; Stankovic, Anna

2004-11-01

The total number of bacteria and culturable bacteria in Adélie penguin (Pygoscelis adeliae) guano was determined during 42 days of decomposition in a location adjacent to the rookery in Admiralty Bay, King George Island, Antarctica. Of the culturable bacteria, 72 randomly selected colonies were described using 49 morpho-physiological tests, 27 of which were subsequently considered significant in characterizing and differentiating the isolates. On the basis of the nucleotide sequence of a fragment of the 16S rRNA gene in each of 72 pure isolates, three major phylogenetic groups were identified, namely the Moraxellaceae/Pseudomonadaceae (29 isolates), the Flavobacteriaceae (14), and the Micrococcaceae (29). Grouping of the isolates on the basis of morpho-physiological tests (whether 49 or 27 parameters) showed similar results to those based on 16S rRNA gene sequences. Clusters were characterized by considerable intra-cluster variation in both 16S rRNA gene sequences and morpho-physiological responses. High diversity in abundance and morphometry of total bacterial communities during penguin guano decomposition was supported by image analysis of epifluorescence micrographs. The results indicate that the bacterial community in penguin guano is not only one of the richest in Antarctica, but is extremely diverse, both phylogenetically and morpho-physiologically.

Living and working in space; IAA Man in Space Symposium, 9th, Cologne, Federal Republic of Germany, June 17-21, 1991, Selection of Papers

NASA Technical Reports Server (NTRS)

Klein, Karl E. (Editor); Contant, Jean-Michel (Editor)

1992-01-01

The present symposium on living and working in space encompasses the physiological responses of humans in space and biomedical support for the conditions associated with space travel. Specific physiological issues addressed include cerebral and sensorimotor functions, effects on the cardiovascular and respiratory system, musculoskeletal system, body fluid, hormones and electrolytes, and some orthostatic hypotension mechanisms as countermeasures. The biomedical support techniques examined include selection training, and care, teleoperation and artificial intelligence, robotic automation, bioregenerative life support, and toxic hazard risks in space habitats. Also addressed are determinants of orientation in microgravity, the hormonal control of body fluid metabolism, integrated human-machine intelligence in space machines, and material flow estimation in CELSS.

Sex differences in cough reflex.

PubMed

Plevkova, J; Buday, T; Kavalcikova-Bogdanova, N; Ioan, I; Demoulin-Alexikova, S

2017-11-01

Majority of patients visiting cough clinics are postmenopausal women, who are affected by intractable cough for years. Why the cough reflex becomes exaggerated in women is not known. Basic research excludes females from the studies contributing to the sex bias which may be responsible for lack of understanding of "hypersensitive" cough in women. Biological and behavioural differences between women and men are the factors affecting cough physiology. Gender also shapes the patterns of behaviour and determines the character of environmental exposures which differs between sexes. The article offers an insight into the physiology of the cough, differences in the maturation of it and biological, social and behavioural factors contributing to the sex differences in cough. Copyright © 2016 Elsevier B.V. All rights reserved.

Hormonal regulation of fluid and electrolytes during prolonged bed rest - Implications for microgravity

NASA Technical Reports Server (NTRS)

Greenleaf, John E.

1989-01-01

The results of studies on the physiological changes of body fluids and electrolytes during bed rest with and without exercise training are overviewed to determine the effect of exercise and to assess the role of hormonal regulation in fluid-electrolyte responses to hypogravity. Special attention is given to fluid shifts observed in spacecraft personnel during space missions. It is concluded that, despite an apparent uncoupling of prominent hormonal interactions during bed-rest deconditioning (and, possibly, during microgravity), the exercise-training-induced hypervolemia helps to counter the hypohydrostatic-induced dehydration. Thus, it was found that, after nearly a year of spaceflight during which one cosmonaut exercised for about 4 hr per day, the water balance and physiological functioning were not disturbed significantly.

Maternal choline supplementation: a nutritional approach for improving offspring health?

PubMed

Jiang, Xinyin; West, Allyson A; Caudill, Marie A

2014-05-01

The modulatory role of choline on the fetal epigenome and the impact of in utero choline supply on fetal programming and health are of great interest. Studies in animals and/or humans suggest that maternal choline supplementation during pregnancy benefits important physiologic systems such as offspring cognitive function, response to stress, and cerebral inhibition. Because alterations in offspring phenotype frequently coincide with epigenetic modifications and changes in gene expression, maternal choline supplementation may be a nutritional strategy to improve lifelong health of the child. Future studies are warranted to elucidate further the effect of choline on the fetal epigenome and to determine the level of maternal choline intake required for optimal offspring physiologic function. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inflight Pharmacokinetic and Pharmacodynamic Responses to Medications Commonly Used in Spaceflight

NASA Technical Reports Server (NTRS)

Wotring, V. E.; Derendorf, H.; Kast, J.; Barger, L.; Basner, M.

2016-01-01

Researchers do not know if medications act the same in the spaceflight environment as they do on Earth. Aspects of the spaceflight environment (low gravity, radiation exposure, closed environment, stress) have been shown to alter human physiology. Some of these physiological changes could be expected to alter either pharmacokinetics (PK, how the body absorbs, distributes, metabolizes and excretes administered medications) or pharmacodynamics (PD, receptors or signaling systems that are the targets of medication action). Anecdotal data has suggested that, at least for certain medications or indications, inflight medication efficacy is poor. In order to prepare for exploration missions where speedy evacuation to Earth may not be a possibility, the likelihood of unexpected medication action must be determined.

Minimum-noise production of translation factor eIF4G maps to a mechanistically determined optimal rate control window for protein synthesis

PubMed Central

Meng, Xiang; Firczuk, Helena; Pietroni, Paola; Westbrook, Richard; Dacheux, Estelle; Mendes, Pedro; McCarthy, John E.G.

2017-01-01

Gene expression noise influences organism evolution and fitness. The mechanisms determining the relationship between stochasticity and the functional role of translation machinery components are critical to viability. eIF4G is an essential translation factor that exerts strong control over protein synthesis. We observe an asymmetric, approximately bell-shaped, relationship between the average intracellular abundance of eIF4G and rates of cell population growth and global mRNA translation, with peak rates occurring at normal physiological abundance. This relationship fits a computational model in which eIF4G is at the core of a multi-component–complex assembly pathway. This model also correctly predicts a plateau-like response of translation to super-physiological increases in abundance of the other cap-complex factors, eIF4E and eIF4A. Engineered changes in eIF4G abundance amplify noise, demonstrating that minimum stochasticity coincides with physiological abundance of this factor. Noise is not increased when eIF4E is overproduced. Plasmid-mediated synthesis of eIF4G imposes increased global gene expression stochasticity and reduced viability because the intrinsic noise for this factor influences total cellular gene noise. The naturally evolved eIF4G gene expression noise minimum maps within the optimal activity zone dictated by eIF4G's mechanistic role. Rate control and noise are therefore interdependent and have co-evolved to share an optimal physiological abundance point. PMID:27928055

Ecosystem CO2/H2O fluxes are explained by hydraulically limited gas exchange during tree mortality from spruce bark beetles

Treesearch

John M. Frank; William J. Massman; Brent E. Ewers; Laurie S. Huckaby; Jose F. Negron

2014-01-01

Disturbances are increasing globally due to anthropogenic changes in land use and climate. This study determines whether a disturbance that affects the physiology of individual trees can be used to predict the response of the ecosystem by weighing two competing hypothesis at annual time scales: (a) changes in ecosystem fluxes are proportional to observable patterns of...

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

DTIC Science & Technology

2012-09-30

Award Number: N000141110434 LONG-TERM GOALS Physiological indicators of stress in wild marine mammals, the interrelationships between...populations. OBJECTIVES The objectives of this effort are to: 1) determine the variation in glucocorticoid hormones (GC), aldosterone (A), thyroid...will be processed for ACTH, cortisol, aldosterone , catecholamines (epinephrine, norepinephrine), and TH (T3 and T4) via radioimmunoassay (RIA). All

The response of sap flow to pulses of rain in a temperate Australian woodland

Treesearch

Melanie Zeppel; Catrioina M.O. Macinnis-Ng; Chelcy R. Ford; Derek Eamus

2008-01-01

In water-limited systems, pulses of rainfall can trigger a cascade of plant physiological responses. However, the timing and size of the physiological response can vary depending on plant and environmental characteristics, such as rooting depth, plant size, rainfall amount, or antecedent soil moisture. We investigated the influence of pulses of rainfall on the response...

The role of thermal physiology in recent declines of birds in a biodiversity hotspot.

PubMed

Milne, Robyn; Cunningham, Susan J; Lee, Alan T K; Smit, Ben

2015-01-01

We investigated whether observed avian range contractions and population declines in the Fynbos biome of South Africa were mechanistically linked to recent climate warming. We aimed to determine whether there were correlations between preferred temperature envelope, or changes in temperature within species' ranges, and recent changes in range and population size, for 12 Fynbos-resident bird species, including six that are endemic to the biome. We then measured the physiological responses of each species at air temperatures ranging from 24 to 42°C to determine whether physiological thermal thresholds could provide a mechanistic explanation for observed population trends. Our data show that Fynbos-endemic species occupying the coolest regions experienced the greatest recent reductions in range and population size (>30% range reduction between 1991 and the present). In addition, species experiencing the largest increases in air temperature within their ranges showed the greatest declines. However, evidence for a physiological mechanistic link between warming and population declines was equivocal, with only the larger species showing low thermal thresholds for their body mass, compared with other birds globally. In addition, some species appear more vulnerable than others to air temperatures in their ranges above physiological thermal thresholds. Of these, the high-altitude specialist Cape rockjumper (Chaetops frenatus) seems most at risk from climate warming. This species showed: (i) the lowest threshold for increasing evaporative water loss at high temperatures; and (ii) population declines specifically in those regions of its range recording significant warming trends. Our findings suggest that caution must be taken when attributing causality explicitly to thermal stress, even when population trends are clearly correlated with rates of warming. Studies explicitly investigating the mechanisms underlying such correlations will be key to appropriate conservation planning.

The role of thermal physiology in recent declines of birds in a biodiversity hotspot

PubMed Central

Milne, Robyn; Cunningham, Susan J; Lee, Alan T K

2015-01-01

Abstract We investigated whether observed avian range contractions and population declines in the Fynbos biome of South Africa were mechanistically linked to recent climate warming. We aimed to determine whether there were correlations between preferred temperature envelope, or changes in temperature within species' ranges, and recent changes in range and population size, for 12 Fynbos-resident bird species, including six that are endemic to the biome. We then measured the physiological responses of each species at air temperatures ranging from 24 to 42°C to determine whether physiological thermal thresholds could provide a mechanistic explanation for observed population trends. Our data show that Fynbos-endemic species occupying the coolest regions experienced the greatest recent reductions in range and population size (>30% range reduction between 1991 and the present). In addition, species experiencing the largest increases in air temperature within their ranges showed the greatest declines. However, evidence for a physiological mechanistic link between warming and population declines was equivocal, with only the larger species showing low thermal thresholds for their body mass, compared with other birds globally. In addition, some species appear more vulnerable than others to air temperatures in their ranges above physiological thermal thresholds. Of these, the high-altitude specialist Cape rockjumper (Chaetops frenatus) seems most at risk from climate warming. This species showed: (i) the lowest threshold for increasing evaporative water loss at high temperatures; and (ii) population declines specifically in those regions of its range recording significant warming trends. Our findings suggest that caution must be taken when attributing causality explicitly to thermal stress, even when population trends are clearly correlated with rates of warming. Studies explicitly investigating the mechanisms underlying such correlations will be key to appropriate conservation planning. PMID:27293732

Contagious Anxiety: Anxious European Americans Can Transmit Their Physiological Reactivity to African Americans.

PubMed

West, Tessa V; Koslov, Katrina; Page-Gould, Elizabeth; Major, Brenda; Mendes, Wendy Berry

2017-12-01

During interracial encounters, well-intentioned European Americans sometimes engage in subtle displays of anxiety, which can be interpreted as signs of racial bias by African American partners. In the present research, same-race and cross-race stranger dyads ( N = 123) engaged in getting-acquainted tasks, during which measures of sympathetic nervous system responses (preejection period, PEP) and heart rate variability were continuously collected. PEP scores showed that African American partners had stronger physiological linkage to European American partners who evidenced greater anxiety-greater cortisol reactivity, behavioral tension, and self-reported discomfort-which suggests greater physiological responsiveness to momentary changes in partners' affective states when those partners were anxious. European Americans showed physiological linkage to African American and European American partners, but linkage did not vary as a function of their partner's anxiety. Using physiological linkage offers a novel approach to understanding how affective responses unfold during dynamic intergroup interactions.

Excluded and behaving unethically: social exclusion, physiological responses, and unethical behavior.

PubMed

Kouchaki, Maryam; Wareham, Justin

2015-03-01

Across 2 studies, we investigated the ethical consequences of physiological responses to social exclusion. In Study 1, participants who were socially excluded were more likely to engage in unethical behavior to make money and the level of physiological arousal experienced during exclusion--measured using galvanic skin response--mediated the effects of exclusion on unethical behavior. Likewise, in Study 2, results from a sample of supervisor-subordinate dyads revealed a positive relationship between experience of workplace ostracism and unethical behaviors as rated by the immediate supervisors. This relationship was mediated by employees' reports of experienced physiological arousal. Together, the results of these studies demonstrate that physiological arousal accompanies social exclusion and provides an explanatory mechanism for the increased unethical behavior in both samples. Theoretical implications of these findings for research on ethical behavior and social exclusion in the workplace are discussed. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Interactive effects of phosphorus deficiency and exogenous auxin on root morphological and physiological traits in white lupin (Lupinus albus L.).

PubMed

Tang, Hongliang; Shen, Jianbo; Zhang, Fusuo; Rengel, Zed

2013-04-01

White lupin (Lupinus albus) exhibits strong root morphological and physiological responses to phosphorus (P) deficiency and auxin treatments, but the interactive effects of P and auxin in regulating root morphological and physiological traits are not fully understood. This study aimed to assess white lupin root traits as influenced by P (0 or 250 μmol L(-1)) and auxin (10(-8) mol L(-1) NAA) in nutrient solution. Both P deficiency and auxin treatments significantly altered root morphological traits, as evidenced by reduced taproot length, increased number and density of first-order lateral roots, and enhanced cluster-root formation. Changes in root physiological traits were also observed, i.e., increased proton, citrate, and acid phosphatase exudation. Exogenous auxin enhanced root responses and sensitivity to P deficiency. A significant interplay exists between P and auxin in the regulation of root morphological and physiological traits. Principal component analysis showed that P availability explained 64.8% and auxin addition 21.3% of the total variation in root trait parameters, indicating that P availability is much more important than auxin in modifying root responses of white lupin. This suggests that white lupin can coordinate root morphological and physiological responses to enhance acquisition of P resources, with an optimal trade-off between root morphological and physiological traits regulated by external stimuli such as P availability and auxin.

Information analysis of posterior canal afferents in the turtle, Trachemys scripta elegans.

PubMed

Rowe, Michael H; Neiman, Alexander B

2012-01-24

We have used sinusoidal and band-limited Gaussian noise stimuli along with information measures to characterize the linear and non-linear responses of morpho-physiologically identified posterior canal (PC) afferents and to examine the relationship between mutual information rate and other physiological parameters. Our major findings are: 1) spike generation in most PC afferents is effectively a stochastic renewal process, and spontaneous discharges are fully characterized by their first order statistics; 2) a regular discharge, as measured by normalized coefficient of variation (cv*), reduces intrinsic noise in afferent discharges at frequencies below the mean firing rate; 3) coherence and mutual information rates, calculated from responses to band-limited Gaussian noise, are jointly determined by gain and intrinsic noise (discharge regularity), the two major determinants of signal to noise ratio in the afferent response; 4) measures of optimal non-linear encoding were only moderately greater than optimal linear encoding, indicating that linear stimulus encoding is limited primarily by internal noise rather than by non-linearities; and 5) a leaky integrate and fire model reproduces these results and supports the suggestion that the combination of high discharge regularity and high discharge rates serves to extend the linear encoding range of afferents to higher frequencies. These results provide a framework for future assessments of afferent encoding of signals generated during natural head movements and for comparison with coding strategies used by other sensory systems. This article is part of a Special Issue entitled: Neural Coding. Copyright © 2011 Elsevier B.V. All rights reserved.

Similar Metabolic, Innate Immunity, and Adipokine Profiles in Adult and Pediatric Sepsis Versus Systemic Inflammatory Response Syndrome-A Pilot Study.

PubMed

Tavladaki, Theonymfi; Spanaki, Anna Maria; Dimitriou, Helen; Kondili, Efmorfia; Choulaki, Christianna; Georgopoulos, Dimitris; Briassoulis, George

2017-11-01

To examine whether the septic profiles of heat shock protein 72, heat shock protein 90α, resistin, adiponectin, oxygen consumption, CO2 production, energy expenditure, and metabolic pattern, along with illness severity, nutritional, and inflammatory indices, differ between adult and pediatric patients compared with systemic inflammatory response syndrome and healthy controls. To evaluate whether these biomolecules may discriminate sepsis from systemic inflammatory response syndrome in adult and pediatric patients. Prospective cohort study. University ICU and PICU. Seventy-eight adults (sepsis/23; systemic inflammatory response syndrome/23; healthy controls/33), 67 children (sepsis/18; systemic inflammatory response syndrome/23; controls/27), mechanically ventilated. None. Flow cytometry determined mean fluorescence intensity for monocyte or neutrophil heat shock protein expression. Resistin, adiponectin, and extracellular heat shock proteins were measured using enzyme-linked immunosorbent assay; energy expenditure by E-COVX (GE Healthcare). Genomic DNA was extracted with PureLink Genomic DNA kit (Invitrogen, Carlsbad, CA) to detect heat shock protein 72 single nucleotide polymorphisms. Similarly, in adult and pediatric patients, Acute Physiology and Chronic Evaluation-II/Acute Physiology and Pediatric Risk of Mortality-III, Simplified Acute Physiology Score-III, C-reactive protein, lactate, and resistin were higher and myocardial contractility, monocyte heat shock protein 72, oxygen consumption, CO2 production, energy expenditure, metabolic pattern, glucose, and albumin lower in sepsis compared with systemic inflammatory response syndrome or controls (p < 0.05). For discriminating sepsis from systemic inflammatory response syndrome, resistin, extracellular heat shock protein 90α, and lactate achieved a receiver operating characteristic curve greater than 0.80 in children and greater than 0.75 in adults (p < 0.05). In both, adults and children, genotype heat shock protein 72 analysis did not disclose any diagnosis or mortality group differences regarding either rs6457452 or rs1061581 haplotypes. Sepsis presents with similar profiles in adult and pediatric patients, characterized by enhanced inflammatory hormonal response and by repressed innate immunity, metabolism, and myocardial contractility. These features early distinguish sepsis from systemic inflammatory response syndrome across all age groups.

Intrinsic optical signal imaging of glucose-stimulated physiological responses in the insulin secreting INS-1 β-cell line

NASA Astrophysics Data System (ADS)

Li, Yi-Chao; Cui, Wan-Xing; Wang, Xu-Jing; Amthor, Franklin; Yao, Xin-Cheng

2011-03-01

Intrinsic optical signal (IOS) imaging has been established for noninvasive monitoring of stimulus-evoked physiological responses in the retina and other neural tissues. Recently, we extended the IOS imaging technology for functional evaluation of insulin secreting INS-1 cells. INS-1 cells provide a popular model for investigating β-cell dysfunction and diabetes. Our experiments indicate that IOS imaging allows simultaneous monitoring of glucose-stimulated physiological responses in multiple cells with high spatial (sub-cellular) and temporal (sub-second) resolution. Rapid image sequences reveal transient optical responses that have time courses comparable to glucose-evoked β-cell electrical activities.

Ambulant Measurements of Physiological Status and Cognitive Performance during Sustained Operations

DTIC Science & Technology

2009-10-01

the target, reaction time, illegal responses, and missed responses were recorded. 2.4 Physiological measurements 2.4.1 Anthropometry ...system (SPi-Elite, GPsports Australia ) was mounted on the soldiers’ backpack. The system measured continuously during the training weeks. Walking or...the percentage missed stimuli were even more alike. 3.3 Physiological measurements 3.3.1 Anthropometry The soldiers who completed the training

Physiological responses to short-term thermal stress in mayfly (Neocloeon triangulifer) larvae in relation to upper thermal limits.

PubMed

Kim, Kyoung Sun; Chou, Hsuan; Funk, David H; Jackson, John K; Sweeney, Bernard W; Buchwalter, David B

2017-07-15

Understanding species' thermal limits and their physiological determinants is critical in light of climate change and other human activities that warm freshwater ecosystems. Here, we ask whether oxygen limitation determines the chronic upper thermal limits in larvae of the mayfly Neocloeon triangulifer , an emerging model for ecological and physiological studies. Our experiments are based on a robust understanding of the upper acute (∼40°C) and chronic thermal limits of this species (>28°C, ≤30°C) derived from full life cycle rearing experiments across temperatures. We tested two related predictions derived from the hypothesis that oxygen limitation sets the chronic upper thermal limits: (1) aerobic scope declines in mayfly larvae as they approach and exceed temperatures that are chronically lethal to larvae; and (2) genes indicative of hypoxia challenge are also responsive in larvae exposed to ecologically relevant thermal limits. Neither prediction held true. We estimated aerobic scope by subtracting measurements of standard oxygen consumption rates from measurements of maximum oxygen consumption rates, the latter of which was obtained by treating with the metabolic uncoupling agent carbonyl cyanide-4-(trifluoromethoxy) pheylhydrazone (FCCP). Aerobic scope was similar in larvae held below and above chronic thermal limits. Genes indicative of oxygen limitation (LDH, EGL-9) were only upregulated under hypoxia or during exposure to temperatures beyond the chronic (and more ecologically relevant) thermal limits of this species (LDH). Our results suggest that the chronic thermal limits of this species are likely not driven by oxygen limitation, but rather are determined by other factors, e.g. bioenergetics costs. We caution against the use of short-term thermal ramping approaches to estimate critical thermal limits (CT max ) in aquatic insects because those temperatures are typically higher than those that occur in nature. © 2017. Published by The Company of Biologists Ltd.

Human Physiology and the Environment in Health and Disease: Readings from Scientific American.

ERIC Educational Resources Information Center

1976

This anthology of articles is designed to supplement standard texts for courses in human physiology, environmental physiology, anatomy and physiology, pathobiology, general biology, and environmental medicine. It focuses on the influences of the external environment on the body, the physiological responses to environmental challenges, and the ways…

Cardiorespiratory response to exercise testing in individuals with Alzheimer’s disease

PubMed Central

Billinger, Sandra A.; Vidoni, Eric D.; Honea, Robyn A.; Burns, Jeffrey M.

2011-01-01

Objective To exercise testing in AD and possible disease-related change over time. Though physical activity and fitness are receiving increased attention as a possible adjunct treatment for Alzheimer’s disease (AD), relatively little work has been done characterizing their physiologic response to exercise Design Retrospective assessment of a 2-year, observational study Setting University medical center Participants 50 nondemented individuals and 31 with AD Interventions None Main Outcome Measures Participants underwent a clinical dementia evaluation and performed an incremental exercise test using a treadmill and the modified Bruce protocol at baseline and at a two year follow-up. We examined oxygen consumption, minute ventilation, heart rate and ventilatory equivalents for oxygen and carbon dioxide at submaximal and peak exercise intensities to determine if the measures were different between groups or over time. Results AD and nondemented participants performed similarly at submaximal effort and both groups showed similar change in exercise response over 2 years. However, nondemented individuals had consistently higher values of oxygen consumption (p≤0.02) and minute ventilation at peak effort at baseline (p=0.003). Conclusions Individuals with AD demonstrate physiologic responses to submaximal exercise effort that are not significantly different than individuals without dementia. However, differences are apparent at the extreme of effort. PMID:22133248

The developing framework of marine ecotoxicology: Pollutants as a variable in marine ecosystems?

USGS Publications Warehouse

Luoma, Samuel N.

1996-01-01

Marine ecosystems include a subset in which at least some interrelated geochemical, biochemical, physiological, population and community characteristics are changed by pollutants. Moderate contamination is relatively widespread in coastal and estuarine ecosystems, so the subset of ecosystems with at least some processes affected could be relatively large. Pollutant influences have changed and will probably continue to change on time scales of decades. Biological exposures and dose in such ecosystems are species-specific and determined by how the species is exposed to different environmental media and the geochemistry of individual pollutants within those media. Bioaccumulation models offer significant promise for interpreting such exposures. Biological responses to pollutants need to be more directly linked to exposure and dose. At the level of the individual this might be improved by better understanding relationships between tissue concentrations of pollutants and responses to pollutants. Multi-discipline field and laboratory studies combined with advanced understanding of some basic processes have reduced the ambiguities in interpreting a few physiological/organismic responses to pollutants in nature. Recognition of pollutant-induced patterns in population responses could lead to similar advances. A rational framework for ecotoxicology is developing, but its further advance is dependent upon better integration of ecotoxicology with basic marine ecology and biology.

Responses to increasing exercise upon reaching the anaerobic threshold, and their control by the central nervous system.

PubMed

Peinado, Ana B; Rojo, Jesús J; Calderón, Francisco J; Maffulli, Nicola

2014-01-01

The anaerobic threshold (AT) has been one of the most studied of all physiological variables. Many authors have proposed the use of several markers to determine the moment at with the AT is reached. The present work discusses the physiological responses made to exercise - the measurement of which indicates the point at which the AT is reached - and how these responses might be controlled by the central nervous system. The detection of the AT having been reached is a sign for the central nervous system (CNS) to respond via an increase in efferent activity via the peripheral nervous system (PNS). An increase in CNS and PNS activities are related to changes in ventilation, cardiovascular function, and gland and muscle function. The directing action of the central command (CC) allows for the coordination of the autonomous and motor systems, suggesting that the AT can be identified in the many ways: changes in lactate, ventilation, plasma catecholamines, heart rate (HR), salivary amylase and muscular electrical activity. This change in response could be indicative that the organism would face failure if the exercise load continued to increase. To avoid this, the CC manages the efferent signals that show the organism that it is running out of homeostatic potential.

Responses to increasing exercise upon reaching the anaerobic threshold, and their control by the central nervous system

PubMed Central

2014-01-01

The anaerobic threshold (AT) has been one of the most studied of all physiological variables. Many authors have proposed the use of several markers to determine the moment at with the AT is reached. The present work discusses the physiological responses made to exercise - the measurement of which indicates the point at which the AT is reached - and how these responses might be controlled by the central nervous system. The detection of the AT having been reached is a sign for the central nervous system (CNS) to respond via an increase in efferent activity via the peripheral nervous system (PNS). An increase in CNS and PNS activities are related to changes in ventilation, cardiovascular function, and gland and muscle function. The directing action of the central command (CC) allows for the coordination of the autonomous and motor systems, suggesting that the AT can be identified in the many ways: changes in lactate, ventilation, plasma catecholamines, heart rate (HR), salivary amylase and muscular electrical activity. This change in response could be indicative that the organism would face failure if the exercise load continued to increase. To avoid this, the CC manages the efferent signals that show the organism that it is running out of homeostatic potential. PMID:24818009

MDMA does not alter responses to the Trier Social Stress Test in humans.

PubMed

Bershad, Anya K; Miller, Melissa A; de Wit, Harriet

2017-07-01

±3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") is a stimulant-psychedelic drug with unique social effects. It may dampen reactivity to negative social stimuli such as social threat and rejection. Perhaps because of these effects, MDMA has shown promise as a treatment for post-traumatic stress disorder (PTSD). However, the effect of single doses of MDMA on responses to an acute psychosocial stressor has not been tested. In this study, we sought to test the effects of MDMA on responses to stress in healthy adults using a public speaking task. We hypothesized that the drug would reduce responses to the stressful task. Volunteers (N = 39) were randomly assigned to receive placebo (N = 13), 0.5 mg/kg MDMA (N = 13), or 1.0 mg/kg MDMA (N = 13) during a stress and a no-stress session. Dependent measures included subjective reports of drug effects and emotional responses to the task, as well as salivary cortisol, heart rate, and blood pressure. The stress task produced its expected increase in physiological responses (cortisol, heart rate) and subjective ratings of stress in all three groups, and MDMA produced its expected subjective and physiological effects. MDMA alone increased ratings of subjective stress, heart rate, and saliva cortisol concentrations, but contrary to our hypothesis, it did not moderate responses to the Trier Social Stress Test. Despite its efficacy in PTSD and anxiety, MDMA did not reduce either the subjective or objective responses to stress in this controlled study. The conditions under which MDMA relieves responses to negative events or memories remain to be determined.

MDMA does not alter responses to the Trier Social Stress Test in humans

PubMed Central

Bershad, Anya K.; Miller, Melissa A.; de Wit, Harriet

2018-01-01

Rationale ±3,4-Methylenedioxymethamphetamine (MDMA, “ecstasy”) is a stimulant-psychedelic drug with unique social effects. It may dampen reactivity to negative social stimuli such as social threat and rejection. Perhaps because of these effects, MDMA has shown promise as a treatment for post-traumatic stress disorder (PTSD). However, the effect of single doses of MDMA on responses to an acute psychosocial stressor has not been tested. Objectives In this study, we sought to test the effects of MDMA on responses to stress in healthy adults using a public speaking task. We hypothesized that the drug would reduce responses to the stressful task. Methods Volunteers (N = 39) were randomly assigned to receive placebo (N = 13), 0.5 mg/kg MDMA (N = 13), or 1.0 mg/kg MDMA (N = 13) during a stress and a no-stress session. Dependent measures included subjective reports of drug effects and emotional responses to the task, as well as salivary cortisol, heart rate, and blood pressure. Results The stress task produced its expected increase in physiological responses (cortisol, heart rate) and subjective ratings of stress in all three groups, and MDMA produced its expected subjective and physiological effects. MDMA alone increased ratings of subjective stress, heart rate, and saliva cortisol concentrations, but contrary to our hypothesis, it did not moderate responses to the Trier Social Stress Test. Conclusions Despite its efficacy in PTSD and anxiety, MDMA did not reduce either the subjective or objective responses to stress in this controlled study. The conditions under which MDMA relieves responses to negative events or memories remain to be determined. PMID:28432376

Emotion Regulation and Emotion Coherence: Evidence for Strategy-Specific Effects

PubMed Central

Dan-Glauser, Elise S.; Gross, James J.

2014-01-01

One of the central tenets of emotion theory is that emotions involve coordinated changes across experiential, behavioral, and physiological response domains. Surprisingly little is known, however, on how the strength of this emotion coherence is altered when people try to regulate their emotions. To address this issue, we recorded experiential, behavioral, and physiological responses while participants watched negative and positive pictures. Cross-correlations were used to quantify emotion coherence. Study 1 tested how two types of suppression (expressive and physiological) influence coherence. Results showed that both strategies decreased the response coherence measured in negative and positive contexts. Study 2 tested how multi-channel suppression (simultaneously targeting expressive and physiological responses) and acceptance influence emotion coherence. Results again showed that suppression decreased coherence. By contrast, acceptance was not significantly different from the unregulated condition. These findings help to clarify the nature of emotion response coherence by showing how different forms of emotion regulation may differentially affect it. PMID:23731438

Psychological and physiological human responses to simulated and real environments: A comparison between Photographs, 360° Panoramas, and Virtual Reality.

PubMed

Higuera-Trujillo, Juan Luis; López-Tarruella Maldonado, Juan; Llinares Millán, Carmen

2017-11-01

Psychological research into human factors frequently uses simulations to study the relationship between human behaviour and the environment. Their validity depends on their similarity with the physical environments. This paper aims to validate three environmental-simulation display formats: photographs, 360° panoramas, and virtual reality. To do this we compared the psychological and physiological responses evoked by simulated environments set-ups to those from a physical environment setup; we also assessed the users' sense of presence. Analysis show that 360° panoramas offer the closest to reality results according to the participants' psychological responses, and virtual reality according to the physiological responses. Correlations between the feeling of presence and physiological and other psychological responses were also observed. These results may be of interest to researchers using environmental-simulation technologies currently available in order to replicate the experience of physical environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gallbladder motility and the sex of the guinea pig.

PubMed

Kline, Loren; Karpinski, Edward

2016-06-01

Progesterone (P), 17β-estradiol (E2), and dihydrotestosterone (DHT) affect gallbladder motility. When gallbladders were taken from women and men, women had more estrogen and P receptors than men. Both P and E2 had an inhibitory effect upon gallbladder contractility in men and premenopausal and postmenopausal women. Similar findings have been reported in gallbladder strips from male and female guinea pigs. In the present study, there was no significant difference in the amount of E2-, P-, or DHT-induced relaxation of CCK-induced tension when the responses in gallbladder strips from male and female guinea pigs were compared. Three metabolites of P were used: 17-hydroxyprogesterone (17-P), 20α-hydroxyprogesterone (20-P), and 21-hydroxyprogesterone (21-P). There was no significant difference in the responses from strips from male and female guinea pigs. In order to determine if the effects of E2 and P were additive, strips from male animals were exposed to either E2 or P and the amount of relaxation recorded. After recovery, the strips were exposed to E2 or P in reverse order to ensure the order of treatment had no effect. Then, the strips were treated with both E2 and P simultaneously and the relaxation recorded. This procedure was repeated with strips from female guinea pigs. The effect of E2 and P was found to be additive; however, the response of the strips from each sex were not significantly different. It is concluded that the sex of the guinea pig has no significant effect on the response to the sex hormones used. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Inflammation-sensitive in situ smart scaffolding for regenerative medicine.

PubMed

Patra, Hirak K; Sharma, Yashpal; Islam, Mohammad Mirazul; Jafari, Mohammad Javad; Murugan, N Arul; Kobayashi, Hisatoshi; Turner, Anthony P F; Tiwari, Ashutosh

2016-10-06

To cope with the rapid evolution of the tissue engineering field, it is now essential to incorporate the use of on-site responsive scaffolds. Therefore, it is of utmost importance to find new 'Intelligent' biomaterials that can respond to the physicochemical changes in the microenvironment. In this present report, we have developed biocompatible stimuli responsive polyaniline-multiwalled carbon nanotube/poly(N-isopropylacrylamide), (PANI-MWCNT/PNIPAm) composite nanofiber networks and demonstrated the physiological temperature coordinated cell grafting phenomenon on its surface. The composite nanofibers were prepared by a two-step process initiated with an assisted in situ polymerization followed by electrospinning. To obtain a smooth surface in individual nanofibers with the thinnest diameter, the component ratios and electrospinning conditions were optimized. The temperature-gated rearrangements of the molecular structure are characterized by FTIR spectroscopy with simultaneous macromolecular architecture changes reflected on the surface morphology, average diameter and pore size as determined by scanning electron microscopy. The stimuli responsiveness of the nanofibers has first been optimized with computational modeling of temperature sensitive components (coil-like and globular conformations) to tune the mechanism for temperature dependent interaction during in situ scaffolding with the cell membrane. The nanofiber networks show excellent biocompatibility, tested with fibroblasts and also show excellent sensitivity to inflammation to combat loco-regional acidosis that delay the wound healing process by an in vitro model that has been developed for testing the proposed responsiveness of the composite nanofiber networks. Cellular adhesion and detachment are regulated through physiological temperature and show normal proliferation of the grafted cells on the composite nanofibers. Thus, we report for the first time, the development of physiological temperature gated inflammation-sensitive smart biomaterials for advanced tissue regeneration and regenerative medicine.

Plasticity and stress tolerance override local adaptation in the responses of Mediterranean holm oak seedlings to drought and cold.

PubMed

Gimeno, Teresa E; Pías, Beatriz; Lemos-Filho, José P; Valladares, Fernando

2009-01-01

Plant populations of widely distributed species experience a broad range of environmental conditions that can be faced by phenotypic plasticity or ecotypic differentiation and local adaptation. The strategy chosen will determine a population's ability to respond to climate change. To explore this, we grew Quercus ilex (L.) seedlings from acorns collected at six selected populations from climatically contrasting localities and evaluated their response to drought and late season cold events. Maximum photosynthetic rate (A(max)), instantaneous water use efficiency (iWUE), and thermal tolerance to freeze and heat (estimated from chlorophyll fluorescence versus temperature curves) were measured in 5-month-old seedlings in control (no stress), drought (water-stressed), and cold (low suboptimal temperature) conditions. The observed responses were similar for the six populations: drought decreased A(max) and increased iWUE, and cold reduced A(max) and iWUE. All the seedlings maintained photosynthetic activity under adverse conditions (drought and cold), and rapidly increased their iWUE by closing stomata when exposed to drought. Heat and freeze tolerances were similarly high for seedlings from all the populations, and they were significantly increased by drought and cold, respectively; and were positively related to each other. Differences in seedling performance across populations were primarily induced by maternal effects mediated by seed size and to a lesser extent by idiosyncratic physiologic responses to drought and low temperatures. Tolerance to multiple stresses together with the capacity to physiologically acclimate to heat waves and cold snaps may allow Q. ilex to cope with the increasingly stressful conditions imposed by climate change. Lack of evidence of physiologic seedling adaptation to local climate may reflect opposing selection pressures to complex, multidimensional environmental conditions operating within the distribution range of this species.

Barley responses to combined waterlogging and salinity stress: separating effects of oxygen deprivation and elemental toxicity

PubMed Central

Zeng, Fanrong; Shabala, Lana; Zhou, Meixue; Zhang, Guoping; Shabala, Sergey

2013-01-01

Salinity and waterlogging are two major factors affecting crop production around the world and often occur together (e.g., salt brought to the surface by rising water tables). While the physiological and molecular mechanisms of plant responses to each of these environmental constraints are studied in detail, the mechanisms underlying plant tolerance to their combined stress are much less understood. In this study, whole-plant physiological responses to individual/combined salinity and waterlogging stresses were studied using two barley varieties grown in either vermiculite (semi-hydroponics) or sandy loam. Two weeks of combined salinity and waterlogging treatment significantly decreased plant biomass, chlorophyll content, maximal quantum efficiency of PSII and water content (WC) in both varieties, while the percentage of chlorotic and necrotic leaves and leaf sap osmolality increased. The adverse effects of the combined stresses were much stronger in the waterlogging-sensitive variety Naso Nijo. Compared with salinity stress alone, the combined stress resulted in a 2-fold increase in leaf Na+, but a 40% decrease in leaf K+ content. Importantly, the effects of the combined stress were more pronounced in sandy loam compared with vermiculite and correlated with changes in the soil redox potential and accumulation of Mn and Fe in the waterlogged soils. It is concluded that hypoxia alone is not a major factor determining differential plant growth under adverse stress conditions, and that elemental toxicities resulting from changes in soil redox potential have a major impact on genotypic differences in plant physiological and agronomical responses. These results are further discussed in the context of plant breeding for waterlogging stress tolerance. PMID:23967003

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

Reduced G tolerance associated with supplement use.

PubMed

Barker, Patrick D

2011-02-01

High G forces encountered in tactical military aviation and aerobatic flight produce a host of physiologic responses aimed at preserving cerebral perfusion. The military has instituted measures to augment the physiologic response in order to avoid G-induced loss of consciousness (G-LOC) because of its potential to cause a catastrophic mishap. The case presented here details a Naval Aviator who experienced reduced G tolerance over two successive flights with a temporal relationship of starting a new supplement. Two components of the supplement, coenzyme Q10 and niacin, are highlighted here for their hemodynamic effects. After stopping the supplement the aviator regained his normal G tolerance and had no further issues in flight. There are several factors that can reduce G tolerance and supplement use has to be considered here because of the potential for altering the normal physiological response to increased G force. Our discussion reviews the physiological effects of increased G force, the spectrum of signs of decompensation under the stress of G force, and the potential effects this supplement had on the normal physiological response to increased G force, thus reducing the aviator's G tolerance.

Baby, you light-up my face: culture-general physiological responses to infants and culture-specific cognitive judgements of adults.

PubMed

Esposito, Gianluca; Nakazawa, Jun; Ogawa, Shota; Stival, Rita; Kawashima, Akiko; Putnick, Diane L; Bornstein, Marc H

2014-01-01

Infants universally elicit in adults a set of solicitous behaviors that are evolutionarily important for the survival of the species. However, exposure, experience, and prejudice appear to govern adults' social choice and ingroup attitudes towards other adults. In the current study, physiological arousal and behavioral judgments were assessed while adults processed unfamiliar infant and adult faces of ingroup vs. outgroup members in two contrasting cultures, Japan and Italy. Physiological arousal was investigated using the novel technique of infrared thermography and behavioral judgments using ratings. We uncovered a dissociation between physiological and behavioral responses. At the physiological level, both Japanese and Italian adults showed significant activation (increase of facial temperature) for both ingroup and outgroup infant faces. At the behavioral level, both Japanese and Italian adults showed significant preferences for ingroup adults. Arousal responses to infants appear to be mediated by the autonomic nervous system and are not dependent on direct caregiving exposure, but behavioral responses appear to be mediated by higher-order cognitive processing based on social acceptance and cultural exposure.

Relationships of the early insulin secretory response and oral disposition index with gastric emptying in subjects with normal glucose tolerance.

PubMed

Marathe, Chinmay S; Rayner, Christopher K; Lange, Kylie; Bound, Michelle; Wishart, Judith; Jones, Karen L; Kahn, Steven E; Horowitz, Michael

2017-02-01

The oral disposition index, the product of the early insulin secretory response during an oral glucose tolerance test and insulin sensitivity, is used widely for both the prediction of, and evaluation of the response to interventions, in type 2 diabetes. Gastric emptying, which determines small intestinal exposure of nutrients, modulates postprandial glycemia. The aim of this study was to determine whether the insulin secretory response and the disposition index (DI) related to gastric emptying in subjects with normal glucose tolerance. Thirty-nine subjects consumed a 350 mL drink containing 75 g glucose labeled with 99m Tc-sulfur colloid. Gastric emptying (by scintigraphy), blood glucose (G) and plasma insulin (I) were measured between t  = 0-120 min. The rate of gastric emptying was derived from the time taken for 50% emptying ( T 50 ) and expressed as kcal/min. The early insulin secretory response was estimated by the ratio of the change in insulin (∆I 0-30 ) to that of glucose at 30 min (∆G 0-30 ) represented as ∆I 0-30 /∆G 0-30 Insulin sensitivity was estimated as 1/fasting insulin and the DI was then calculated as ∆I 0-30 /∆G 0-30  × 1/fasting insulin. There was a direct relationship between ∆G 0-30 and gastric emptying ( r  = 0.47, P  = 0.003). While there was no association of either ∆I 0-30 ( r  = -0.16, P  = 0.34) or fasting insulin ( r  = 0.21, P  = 0.20), there were inverse relationships between the early insulin secretory response ( r  = -0.45, P  = 0.004) and the DI ( r  = -0.33, P  = 0.041), with gastric emptying. We conclude that gastric emptying is associated with both insulin secretion and the disposition index in subjects with normal glucose tolerance, such that when gastric emptying is relatively more rapid, both the early insulin secretory response and the disposition index are less. These findings should be interpreted as "hypothesis generating" and provide the rationale for longitudinal studies to examine the impact of baseline rate of gastric emptying on the prospective risk of type 2 diabetes. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Measuring Physiological Stress Responses in Children: Lessons from a Novice

ERIC Educational Resources Information Center

Quas, Jodi A.

2011-01-01

In this article the author describes challenges associated with integrating physiological measures of stress into developmental research, especially in the domains of memory and cognition. An initial critical challenge concerns how to define stress, which can refer to one or a series of events, a response, the consequence of that response, an…

Physiological-Cognitive-Emotional Responses to Defense-Arousing Communication: Overview and Sex Differences.

ERIC Educational Resources Information Center

Gordon, Ronald D.

A 328-item checklist, suitable for the self-reporting of responses to any stimulus event, was administered to 107 upper division college students in an attempt to investigate the physiological-cognitive-emotional responses to defense arousing communication and to discover a greater range of the key features of the phenomena of…

MEASUREMENT AND ANALYSIS OF PHYSIOLOGICAL RESPONSE TO FILM.

ERIC Educational Resources Information Center

CASE, HARRY W.; LEVONIAN, EDWARD

THE PRIMARY OBJECTIVE OF THIS STUDY WAS THE DEVELOPMENT OF A SYSTEM WHICH WOULD ALLOW THE MEASUREMENT AND ANALYSIS OF PHYSIOLOGICAL RESPONSE OF STUDENTS VIEWING FILM MATERIAL UNDER CONVENTIONAL CLASSROOM CONDITIONS. THE GALVANIC SKIN RESPONSE (GSR) WAS MEASURED BY SENSORS AND USED AS AN INDICATOR OF STUDENT INTERACTION WITH THE FILM MATERIAL. IN…

Student Response (Clicker) Systems: Preferences of Biomedical Physiology Students in Asian Classes

ERIC Educational Resources Information Center

Hwang, Isabel; Wong, Kevin; Lam, Shun Leung; Lam, Paul

2015-01-01

Student response systems (commonly called "clickers") are valuable tools for engaging students in classroom interactions. In this study, we investigated the use of two types of response systems (a traditional clicker and a mobile device) by students in human physiology courses. Our results showed high student satisfaction with the use of…

A comparative analysis of transcriptomic, biochemical and physiological responses to elevated ozone identifies species-specific mechanisms of resilience in legume crops

USDA-ARS?s Scientific Manuscript database

Current concentrations of tropospheric ozone (O3) pollution negatively impact plant metabolism, which can result in decreased crop yields. Interspecific variation in the physiological response of plants to elevated [O3] exists; however, the underlying cellular responses explaining species-specific d...

The Role of Emotional Responses and Physiological Reactivity in the Marital Conflict-Child Functioning Link

ERIC Educational Resources Information Center

El-Sheikh, Mona

2005-01-01

Background: Children's emotional responses and physiological reactivity to conflict were examined as mediators and moderators in the associations between exposure to parental marital conflict and child adjustment and cognitive problems. Method: One hundred and eighty elementary school children participated. In response to a simulated argument,…

Physiological responses induced by emotion-eliciting films.

PubMed

Fernández, Cristina; Pascual, Juan C; Soler, Joaquim; Elices, Matilde; Portella, Maria J; Fernández-Abascal, Enrique

2012-06-01

Emotion-eliciting films are commonly used to evoke subjective emotional responses in experimental settings. The main aim of the present study was to investigate whether a set of film clips with discrete emotions were capable to elicit measurable objective physiological responses. The convergence between subjective and objective measures was evaluated. Finally, the effect of gender on emotional responses was investigated. A sample of 123 subjects participated in the study. Individuals were asked to view a set of emotional film clips capable to induce seven emotions: anger, fear, sadness, disgust, amusement, tenderness and neutral state. Skin conductance level (SCL), heart rate (HR) and subjective emotional responses were measured for each film clip. In comparison with neutral films, SCL was significantly increased after viewing fear films, and HR was also significantly incremented for anger and fear films. Physiological variations were associated with arousal measures indicating a convergence between subjective and objective reactions. Women appeared to display significantly greater SCL and HR responses for films inducing sadness. The findings suggest that physiological activation would be more easily induced by emotion-eliciting films that tap into emotions with higher subjective arousal such as anger and fear.

Physiologic correlates to background noise acceptance

NASA Astrophysics Data System (ADS)

Tampas, Joanna; Harkrider, Ashley; Nabelek, Anna

2004-05-01

Acceptance of background noise can be evaluated by having listeners indicate the highest background noise level (BNL) they are willing to accept while following the words of a story presented at their most comfortable listening level (MCL). The difference between the selected MCL and BNL is termed the acceptable noise level (ANL). One of the consistent findings in previous studies of ANL is large intersubject variability in acceptance of background noise. This variability is not related to age, gender, hearing sensitivity, personality, type of background noise, or speech perception in noise performance. The purpose of the current experiment was to determine if individual differences in physiological activity measured from the peripheral and central auditory systems of young female adults with normal hearing can account for the variability observed in ANL. Correlations between ANL and various physiological responses, including spontaneous, click-evoked, and distortion-product otoacoustic emissions, auditory brainstem and middle latency evoked potentials, and electroencephalography will be presented. Results may increase understanding of the regions of the auditory system that contribute to individual noise acceptance.

Enhanced growth, yield and physiological characteristics of rice under elevated carbon dioxide

NASA Astrophysics Data System (ADS)

Abzar, A.; Ahmad, Wan Juliana Wan; Said, Mohd Nizam Mohd; Doni, Febri; Zaidan, Mohd Waznul Adly Mohd; Fathurahman, Zain, Che Radziah Che Mohd

2018-04-01

Carbon dioxide (CO2) is rapidly increasing in the atmosphere. It is an essential element for photosynthesis which attracts attention among scientists on how plants will perform in the rising CO2 level. Rice as one of the most important staple food in the world has been studied on the growth responses under elevated CO2. The present research was carried out to determine the growth and physiology of rice in elevated CO2 condition. This research was carried out using complete randomized design with elevated (800 ppm) and ambient CO2. Results showed that growth parameters such as plant height, tillers and number of leaves per plant were increased by elevated CO2. The positive changes in plant physiology when exposed to high CO2 concentration includes significant change (p<0.05) in yield parameters such as panicle number, grain number per panicle, biomass and 1000 grain weight under the elevated CO2 of 800 ppm.

The US Navy/Canadian DCIEM research initiative on pressure breathing physiology

NASA Technical Reports Server (NTRS)

Whitley, Phillip E.

1994-01-01

Development of improved positive pressure breathing garments for altitude and acceleration protection has occurred without collection of sufficient physiological data to understand the mechanisms of the improvement. Furthermore, modeling of the predicted response of future enhanced garments is greatly hampered by this lack of information. A joint, international effort is under way between Canada's Defense and Civil Institute for Environmental Medicine (DCIEM) and the US Navy's Naval Air Warfare Center Aircraft Division, Warminster (NAWCACDIVWAR). Using a Canadian subject pool, experiments at both the DCIEM altitude facility and the NAWCADIVWAR Dynamic Flight Simulator have been conducted to determine the cardiovascular and respiratory consequences of high levels of positive pressure breathing for altitude and positive pressure breathing for acceleration protection. Various improved pressure breathing garments were used to collect comparative physiological and performance data. New pressure breathing level and durahon capabilities have been encountered. Further studies will address further improvements in pressure suit design and correlation of altitude and acceleration data.

Peptidase modulation of the pulmonary effects of tachykinins.

PubMed

Martins, M A; Shore, S A; Drazen, J M

1991-01-01

The physiological effects of the tachykinin peptides substance P (SP) and neurokinin A (NKA) are limited by their microenvironmental degradation. We used the isolated tracheally superfused guinea pig lung to examine the importance of various degradative enzymes in limiting the physiological effects of exogenously administered and endogenously released tachykinins. When SP and NKA are administered via the airway epithelium, neutral endopeptidase (NEP; EC 3.4.24.11) is the major degradative enzyme as indicated by the effects of NEP inhibitors alone compared to the effects of a NEP inhibitor along with a cocktail of other peptidase inhibitors. The effects of enzyme inhibitors on physiological responses is mirrored in the amounts of peptide recovered from lung perfusates as determined using an enzyme-linked immunosorbent assay. We found similar effects when SP and NKA were released endogenously by the acute infusion of capsaicin. These data indicate that NEP is the predominant degradative enzyme modulating the effects of SP and NKA administered via the airways.

Physiological limits to endurance exercise performance: influence of sex

PubMed Central

2017-01-01

Abstract This brief review summarizes factors associated with elite endurance performance, trends in distance running training, and participation by men and more recently women. It is framed in the context of key ideas about the physiological determinants of endurance performance but also touches on some historical and sociological factors relevant to the overall topic. Historical trends that served to increase women's participation in elite endurance events are also discussed as is the role of increased volume and intensity of training. The rapid improvement in women's world record marathon times in the 1970s and 80s are emblematic of these trends and represent a combination of increased training volume and intensity and more competitive opportunities. This occurred as bans on participation by women in endurance events were lifted. For men these same trends evolved over a much longer time frame. The main physiological factor responsible for 10–12% slower times in women compared to men at the elite level are also considered and probably centre aroundV˙O2 max . PMID:28028816

The potential of a modified physiologically equivalent temperature (mPET) based on local thermal comfort perception in hot and humid regions

NASA Astrophysics Data System (ADS)

Lin, Tzu-Ping; Yang, Shing-Ru; Chen, Yung-Chang; Matzarakis, Andreas

2018-02-01

Physiologically equivalent temperature (PET) is a thermal index that is widely used in the field of human biometeorology and urban bioclimate. However, it has several limitations, including its poor ability to predict thermo-physiological parameters and its weak response to both clothing insulation and humid conditions. A modified PET (mPET) was therefore developed to address these shortcomings. To determine whether the application of mPET in hot-humid regions is more appropriate than the PET, an analysis of a thermal comfort survey database, containing 2071 questionnaires collected from participants in hot-humid Taiwan, was conducted. The results indicate that the thermal comfort range is similar (26-30 °C) when the mPET and PET are applied as thermal indices to the database. The sensitivity test for vapor pressure and clothing insulation also show that the mPET responds well to the behavior and perceptions of local people in a subtropical climate.

Cardiorespiratory physiological phenotypic plasticity in developing air-breathing anabantid fishes (Betta splendens and Trichopodus trichopterus).

PubMed

Mendez-Sanchez, Jose F; Burggren, Warren W

2017-08-01

Developmental plasticity of cardiorespiratory physiology in response to chronic hypoxia is poorly understood in larval fishes, especially larval air-breathing fishes, which eventually in their development can at least partially "escape" hypoxia through air breathing. Whether the development air breathing makes these larval fishes less or more developmentally plastic than strictly water breathing larval fishes remains unknown. Consequently, developmental plasticity of cardiorespiratory physiology was determined in two air-breathing anabantid fishes ( Betta splendens and Trichopodus trichopterus ). Larvae of both species experienced an hypoxic exposure that mimicked their natural environmental conditions, namely chronic nocturnal hypoxia (12 h at 17 kPa or 14 kPa), with a daily return to diurnal normoxia. Chronic hypoxic exposures were made from hatching through 35 days postfertilization, and opercular and heart rates measured as development progressed. Opercular and heart rates in normoxia were not affected by chronic nocturnal hypoxic. However, routine oxygen consumption M˙O2 (~4  μ mol·O 2 /g per hour in normoxia in larval Betta ) was significantly elevated by chronic nocturnal hypoxia at 17 kPa but not by more severe (14 kPa) nocturnal hypoxia. Routine M˙O2 in Trichopodus (6-7  μ mol·O 2 /g per hour), significantly higher than in Betta , was unaffected by either level of chronic hypoxia. P Crit , the PO 2 at which M˙O2 decreases as ambient PO 2 falls, was measured at 35 dpf, and decreased with increasing chronic hypoxia in Betta , indicating a large, relatively plastic hypoxic tolerance. However, in contrast, P Crit in Trichopodus increased as rearing conditions grew more hypoxic, suggesting that hypoxic acclimation led to lowered hypoxic resistance. Species-specific differences in larval physiological developmental plasticity thus emerge between the relatively closely related Betta and Trichopodus Hypoxic rearing increased hypoxic tolerance in Betta , which inhabits temporary ponds with nocturnal hypoxia. Trichopodus , inhabiting more permanent oxygenated bodies of water, showed few responses to hypoxia, reflecting a lower degree of developmental phenotypic plasticity. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Distinct right ventricle remodeling in response to pressure overload in the rat.

PubMed

Mendes-Ferreira, P; Santos-Ribeiro, D; Adão, R; Maia-Rocha, C; Mendes-Ferreira, M; Sousa-Mendes, C; Leite-Moreira, A F; Brás-Silva, C

2016-07-01

Pulmonary arterial hypertension (PAH), the most serious chronic disorder of the pulmonary circulation, is characterized by pulmonary vasoconstriction and remodeling, resulting in increased afterload on the right ventricle (RV). In fact, RV function is the main determinant of prognosis in PAH. The most frequently used experimental models of PAH include monocrotaline- and chronic hypoxia-induced PAH, which primarily affect the pulmonary circulation. Alternatively, pulmonary artery banding (PAB) can be performed to achieve RV overload without affecting the pulmonary vasculature, allowing researchers to determine the RV-specific effects of their drugs/interventions. In this work, using two different degrees of pulmonary artery constriction, we characterize, in full detail, PAB-induced adaptive and maladaptive remodeling of the RV at 3 wk after PAB surgery. Our results show that application of a mild constriction resulted in adaptive hypertrophy of the RV, with preserved systolic and diastolic function, while application of a severe constriction resulted in maladaptive hypertrophy, with chamber dilation and systolic and diastolic dysfunction up to the isolated cardiomyocyte level. By applying two different degrees of constriction, we describe, for the first time, a reliable and short-duration PAB model in which RV adaptation can be distinguished at 3 wk after surgery. We characterize, in full detail, structural and functional changes of the RV in its response to moderate and severe constriction, allowing researchers to better study RV physiology and transition to dysfunction and failure, as well as to determine the effects of new therapies. Copyright © 2016 the American Physiological Society.

Effects of Antecedent GABA A Receptor Activation on Counterregulatory Responses to Exercise in Healthy Man

PubMed Central

Hedrington, Maka S.; Tate, Donna B.; Younk, Lisa M.

2015-01-01

The aim of this study was to determine whether antecedent stimulation of γ-aminobutyric acid (GABA) A receptors with the benzodiazepine alprazolam can blunt physiologic responses during next-day moderate (90 min) exercise in healthy man. Thirty-one healthy individuals (16 male/15 female aged 28 ± 1 year, BMI 23 ± 3 kg/m2) were studied during separate, 2-day protocols. Day 1 consisted of morning and afternoon 2-h hyperinsulinemic-euglycemic or hypoglycemic clamps with or without 1 mg alprazolam given 30 min before a clamp. Day 2 consisted of 90-min euglycemic cycling exercise at 50% VO2max. Despite similar euglycemia (5.3 ± 0.1 mmol/L) and insulinemia (46 ± 6 pmol/L) during day 2 exercise studies, GABA A activation with alprazolam during day 1 euglycemia resulted in significant blunting of plasma epinephrine, norepinephrine, glucagon, cortisol, and growth hormone responses. Lipolysis (glycerol, nonesterified fatty acids) and endogenous glucose production during exercise were also reduced, and glucose infusion rates were increased following prior euglycemia with alprazolam. Prior hypoglycemia with alprazolam resulted in further reduction of glucagon and cortisol responses during exercise. We conclude that prior activation of GABA A pathways can play a significant role in blunting key autonomous nervous system, neuroendocrine, and metabolic physiologic responses during next-day exercise in healthy man. PMID:25901095

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.

Revisiting life strategy concepts in environmental microbial ecology.

PubMed

Ho, Adrian; Di Lonardo, D Paolo; Bodelier, Paul L E

2017-03-01

Microorganisms are physiologically diverse, possessing disparate genomic features and mechanisms for adaptation (functional traits), which reflect on their associated life strategies and determine at least to some extent their prevalence and distribution in the environment. Unlike animals and plants, there is an unprecedented diversity and intractable metabolic versatility among bacteria, making classification or grouping these microorganisms based on their functional traits as has been done in animal and plant ecology challenging. Nevertheless, based on representative pure cultures, microbial traits distinguishing different life strategies had been proposed, and had been the focus of previous reviews. In the environment, however, the vast majority of naturally occurring microorganisms have yet to be isolated, restricting the association of life strategies to broad phylogenetic groups and/or physiological characteristics. Here, we reviewed the literature to determine how microbial life strategy concepts (i.e. copio- and oligotrophic strategists, and competitor-stress tolerator-ruderals framework) are applied in complex microbial communities. Because of the scarcity of direct empirical evidence elucidating the associated life strategies in complex communities, we rely heavily on observational studies determining the response of microorganisms to (a)biotic cues (e.g. resource availability) to infer microbial life strategies. Although our focus is on the life strategies of bacteria, parallels were drawn from the fungal community. Our literature search showed inconsistency in the community response of proposed copiotrophic- and oligotrophic-associated microorganisms (phyla level) to changing environmental conditions. This suggests that tracking microorganisms at finer phylogenetic and taxonomic resolution (e.g. family level or lower) may be more effective to capture changes in community response and/or that edaphic factors exert a stronger effect in community response. We discuss the limitations and provide recommendations for future research applying microbial life strategies in environmental studies. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Determinants of ventilation and pulmonary artery pressure during early acclimatization to hypoxia in humans.

PubMed

Fatemian, Marzieh; Herigstad, Mari; Croft, Quentin P P; Formenti, Federico; Cardenas, Rosa; Wheeler, Carly; Smith, Thomas G; Friedmannova, Maria; Dorrington, Keith L; Robbins, Peter A

2016-03-01

Pulmonary ventilation and pulmonary arterial pressure both rise progressively during the first few hours of human acclimatization to hypoxia. These responses are highly variable between individuals, but the origin of this variability is unknown. Here, we sought to determine whether the variabilities between different measures of response to sustained hypoxia were related, which would suggest a common source of variability. Eighty volunteers individually underwent an 8-h isocapnic exposure to hypoxia (end-tidal P(O2)=55 Torr) in a purpose-built chamber. Measurements of ventilation and pulmonary artery systolic pressure (PASP) assessed by Doppler echocardiography were made during the exposure. Before and after the exposure, measurements were made of the ventilatory sensitivities to acute isocapnic hypoxia (G(pO2)) and hyperoxic hypercapnia, the latter divided into peripheral (G(pCO2)) and central (G(cCO2)) components. Substantial acclimatization was observed in both ventilation and PASP, the latter being 40% greater in women than men. No correlation was found between the magnitudes of pulmonary ventilatory and pulmonary vascular responses. For G(pO2), G(pCO2) and G(cC O2), but not the sensitivity of PASP to acute hypoxia, the magnitude of the increase during acclimatization was proportional to the pre-acclimatization value. Additionally, the change in G(pO2) during acclimatization to hypoxia correlated well with most other measures of ventilatory acclimatization. Of the initial measurements prior to sustained hypoxia, only G(pCO2) predicted the subsequent rise in ventilation and change in G(pO2) during acclimatization. We conclude that the magnitudes of the ventilatory and pulmonary vascular responses to sustained hypoxia are predominantly determined by different factors and that the initial G(pCO2) is a modest predictor of ventilatory acclimatization. © 2015 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Considerations on pharmacodynamics and pharmacokinetics: can everything be explained by the extent of drug binding to its receptor?

PubMed

Castañeda-Hernández, G; Granados-Soto, V

2000-03-01

It is frequently assumed that pharmacological responses depend solely on the extent of drug binding to its receptor according to the occupational theory. It is therefore presumed that the intensity of the effect is determined by drug concentration at its receptor site, yielding a unique concentration-effect relationship. However, when dependence, abstinence, and tolerance phenomena occur, as well as for pharmacological responses in vivo that are modulated by homeostatic mechanisms, the rate of drug input shifts the concentration-effect relationship. Hence, such responses cannot be explained on the sole basis of the extent of drug binding to its receptor. Information on the cellular and molecular processes involved in the generation of abstinence, dependence, and tolerance will undoubtedly result in the development of pharmacodynamic models allowing a satisfactory explanation of drug effects modulated by these phenomena. Notwithstanding, integrative physiology concepts are required to develop pharmacokinetic-pharmacodynamic models allowing the description of drug effects in an intact organism. It is therefore important to emphasize that integrative physiology cannot be neglected in pharmacology teaching and research, but should be considered as an equally valuable tool as molecular biology and other biomedical disciplines for the understanding of pharmacological effects.

Population-dependent effects of ocean acidification.

PubMed

Wood, Hannah L; Sundell, Kristina; Almroth, Bethanie Carney; Sköld, Helén Nilsson; Eriksson, Susanne P

2016-04-13

Elevated carbon dioxide levels and the resultant ocean acidification (OA) are changing the abiotic conditions of the oceans at a greater rate than ever before and placing pressure on marine species. Understanding the response of marine fauna to this change is critical for understanding the effects of OA. Population-level variation in OA tolerance is highly relevant and important in the determination of ecosystem resilience and persistence, but has received little focus to date. In this study, whether OA has the same biological consequences in high-salinity-acclimated population versus a low-salinity-acclimated population of the same species was investigated in the marine isopod Idotea balthica.The populations were found to have physiologically different responses to OA. While survival rate was similar between the two study populations at a future CO2 level of 1000 ppm, and both populations showed increased oxidative stress, the metabolic rate and osmoregulatory activity differed significantly between the two populations. The results of this study demonstrate that the physiological response to OA of populations from different salinities can vary. Population-level variation and the environment provenance of individuals used in OA experiments should be taken into account for the evaluation and prediction of climate change effects. © 2016 The Author(s).

Population-dependent effects of ocean acidification

PubMed Central

Wood, Hannah L.; Sundell, Kristina; Almroth, Bethanie Carney; Sköld, Helén Nilsson; Eriksson, Susanne P.

2016-01-01

Elevated carbon dioxide levels and the resultant ocean acidification (OA) are changing the abiotic conditions of the oceans at a greater rate than ever before and placing pressure on marine species. Understanding the response of marine fauna to this change is critical for understanding the effects of OA. Population-level variation in OA tolerance is highly relevant and important in the determination of ecosystem resilience and persistence, but has received little focus to date. In this study, whether OA has the same biological consequences in high-salinity-acclimated population versus a low-salinity-acclimated population of the same species was investigated in the marine isopod Idotea balthica. The populations were found to have physiologically different responses to OA. While survival rate was similar between the two study populations at a future CO2 level of 1000 ppm, and both populations showed increased oxidative stress, the metabolic rate and osmoregulatory activity differed significantly between the two populations. The results of this study demonstrate that the physiological response to OA of populations from different salinities can vary. Population-level variation and the environment provenance of individuals used in OA experiments should be taken into account for the evaluation and prediction of climate change effects. PMID:27053741

Women's self-rated attraction to male faces does not correspond with physiological arousal.

PubMed

Hagerman, S; Woolard, Z; Anderson, K; Tatler, B W; Moore, F R

2017-10-19

There has been little work to determine whether attractiveness ratings of faces correspond to sexual or more general attraction. We tested whether a measure of women's physiological arousal (pupil diameter change) was correlated with ratings of men's facial attractiveness. In Study 1, women rated the faces of men for whom we also measured salivary testosterone. They rated each face for attractiveness, and for desirability for friendship and long- and short-term romantic relationships. Pupil diameter change was not related to subjective ratings of attractiveness, but was positively correlated with the men's testosterone. In Study 2 we compared women's pupil diameter change in response to the faces of men with high versus low testosterone, as well as in response to non-facial images pre-rated as either sexually arousing or threatening. Pupil dilation was not affected by testosterone, and increased relatively more in response to sexually arousing than threatening images. We conclude that self-rated preferences may not provide a straightforward and direct assessment of sexual attraction. We argue that future work should identify the constructs that are tapped via attractiveness ratings of faces, and support the development of methodology which assesses objective sexual attraction.

Biogastronomy: Factors that determine the biological response to meal ingestion.

PubMed

Pribic, T; Azpiroz, F

2018-02-02

The biological response to a meal includes physiological changes, primarily related to the digestive process, and a sensory experience, involving sensations related to the homeostatic control of food consumption, eg, satiety and fullness, with a hedonic dimension, ie associated with changes in digestive well-being and mood. The responses to a meal include a series of events before, during and after ingestion. While much attention has been paid to the events before and during ingestion, relatively little is known about the postprandial sensations, which are key to the gastronomical experience. The aim of this narrative review is to provide a comprehensive overview and to define the framework to investigate the factors that determine the postprandial experience. Based on a series of proof-of-concept studies and related information, we propose that the biological responses to a meal depend on the characteristics of the meal, primarily its palatability and composition, and the responsiveness of the guest, which may be influenced by multiple previous and concurrent conditioning factors. This information provides the scientific backbone to the development of personalized gastronomy. © 2018 John Wiley & Sons Ltd.

Combinations of Physiologic Estrogens with Xenoestrogens Alter ERK Phosphorylation Profiles in Rat Pituitary Cells

PubMed Central

Jeng, Yow-Jiun; Watson, Cheryl S.

2011-01-01

Background Estrogens are potent nongenomic phospho-activators of extracellular-signal–regulated kinases (ERKs). A major concern about the toxicity of xenoestrogens (XEs) is potential alteration of responses to physiologic estrogens when XEs are present simultaneously. Objectives We examined estrogen-induced ERK activation, comparing the abilities of structurally related XEs (alkylphenols and bisphenol A) to alter ERK responses induced by physiologic concentrations (1 nM) of estradiol (E2), estrone (E1), and estriol (E3). Methods We quantified hormone/mimetic-induced ERK phosphorylations in the GH3/B6/F10 rat pituitary cell line using a plate immunoassay, comparing effects with those on cell proliferation and by estrogen receptor subtype-selective ligands. Results Alone, these structurally related XEs activate ERKs in an oscillating temporal pattern similar (but not identical) to that with physiologic estrogens. The potency of all estrogens was similar (active between femtomolar and nanomolar concentrations). XEs potently disrupted physiologic estrogen signaling at low, environmentally relevant concentrations. Generally, XEs potentiated (at the lowest, subpicomolar concentrations) and attenuated (at the highest, picomolar to 100 nM concentrations) the actions of the physiologic estrogens. Some XEs showed pronounced nonmonotonic responses/inhibitions. The phosphorylated ERK and proliferative responses to receptor-selective ligands were only partially correlated. Conclusions XEs are both imperfect potent estrogens and endocrine disruptors; the more efficacious an XE, the more it disrupts actions of physiologic estrogens. This ability to disrupt physiologic estrogen signaling suggests that XEs may disturb normal functioning at life stages where actions of particular estrogens are important (e.g., development, reproductive cycling, pregnancy, menopause). PMID:20870566

Emotional and physiological responses of fluent listeners while watching the speech of adults who stutter.

PubMed

Guntupalli, Vijaya K; Everhart, D Erik; Kalinowski, Joseph; Nanjundeswaran, Chayadevie; Saltuklaroglu, Tim

2007-01-01

People who stutter produce speech that is characterized by intermittent, involuntary part-word repetitions and prolongations. In addition to these signature acoustic manifestations, those who stutter often display repetitive and fixated behaviours outside the speech producing mechanism (e.g. in the head, arm, fingers, nares, etc.). Previous research has examined the attitudes and perceptions of those who stutter and people who frequently interact with them (e.g. relatives, parents, employers). Results have shown an unequivocal, powerful and robust negative stereotype despite a lack of defined differences in personality structure between people who stutter and normally fluent individuals. However, physiological investigations of listener responses during moments of stuttering are limited. There is a need for data that simultaneously examine physiological responses (e.g. heart rate and galvanic skin conductance) and subjective behavioural responses to stuttering. The pairing of these objective and subjective data may provide information that casts light on the genesis of negative stereotypes associated with stuttering, the development of compensatory mechanisms in those who stutter, and the true impact of stuttering on senders and receivers alike. To compare the emotional and physiological responses of fluent speakers while listening and observing fluent and severe stuttered speech samples. Twenty adult participants (mean age = 24.15 years, standard deviation = 3.40) observed speech samples of two fluent speakers and two speakers who stutter reading aloud. Participants' skin conductance and heart rate changes were measured as physiological responses to stuttered or fluent speech samples. Participants' subjective responses on arousal (excited-calm) and valence (happy-unhappy) dimensions were assessed via the Self-Assessment Manikin (SAM) rating scale with an additional questionnaire comprised of a set of nine bipolar adjectives. Results showed significantly increased skin conductance and lower mean heart rate during the presentation of stuttered speech relative to the presentation of fluent speech samples (p<0.05). Listeners also self-rated themselves as being more aroused, unhappy, nervous, uncomfortable, sad, tensed, unpleasant, avoiding, embarrassed, and annoyed while viewing stuttered speech relative to the fluent speech. These data support the notion that stutter-filled speech can elicit physiological and emotional responses in listeners. Clinicians who treat stuttering should be aware that listeners show involuntary physiological responses to moderate-severe stuttering that probably remain salient over time and contribute to the evolution of negative stereotypes of people who stutter. With this in mind, it is hoped that clinicians can work with people who stutter to develop appropriate coping strategies. The role of amygdala and mirror neural mechanism in physiological and subjective responses to stuttering is discussed.

Inhibition of anti-CD3 monoclonal antibody-induced T-cell proliferation and interleukin-2 secretion by physiologic combinations of dexamethasone and prostaglandin E2.

PubMed

Elliott, L; Brooks, W; Roszman, T

1993-12-01

1. The purpose of these studies was to characterize further previous observations from our laboratory indicating that physiologic concentrations of dexamethasone (DEX) and prostaglandin E2 (PGE2) added together result in synergistic inhibition of the proliferative response of T cells stimulated via the T-cell receptor CD3 signaling complex (TCR/CD3). 2. Various physiologic concentrations of DEX and PGE2 were added to T cells stimulated with immobilized anti-CD3 monoclonal antibody (mAb) and cultured at optimal and suboptimal cell densities. The results demonstrate that the proliferative response of anti-CD3 mAb-stimulated T cells cultured at a suboptimal cell density is more suppressed than that of T cells cultured at optimal concentrations. 3. The proliferative response of CD4+ T cells to immobilized anti-CD3 mAb was also determined in the presence of PGE2 and DEX. The data indicate that the CD4+ subset of T cells is more sensitive to the synergistic antiproliferative effects of DEX and PGE2 compared to whole T-cell populations. 4. Various concentrations of DEX and/or PGE2 were added to T cells stimulated with anti-CD3 mAb and the secretion of interleukin-2 (IL-2) was determined. The results demonstrate that concentrations of DEX and PGE2 which individually do not significantly suppress IL-2 synthesis act together to inhibit the synthesis of IL-2 synergistically. 5. The addition of an exogenous source of recombinant IL-2 (rIL-2) to T cells stimulated in the presence of DEX and PGE2 completely reversed the synergistic antiproliferative effect of these two compounds. This reversal was even more pronounced with T cells cultured at a suboptimal cell density. Additionally, PGE2 and DEX did not affect expression of the IL-2 receptor (IL-2R), as measured by upregulation of the alpha chain, on anti-CD3 mAb stimulated T cells. 6. Collectively these data indicate that physiologic concentrations of PGE2 and DEX, which alone have no effect on anti-CD3 mAb-induced T-cell proliferation, act synergistically to inhibit T-cell proliferation as well as IL-2 synthesis.

Thermal preference, thermal resistance, and metabolic rate of juvenile Chinese pond turtles Mauremys reevesii acclimated to different temperatures.

PubMed

Xu, Wei; Dang, Wei; Geng, Jun; Lu, Hong-Liang

2015-10-01

The thermal acclimatory capacity of a particular species may determine its resilience to environmental change. Evaluating the physiological acclimatory responses of economically important species is useful for determining their optimal culture conditions. Here, juvenile Chinese three-keeled pond turtles (Mauremys reevesii) were acclimated to one of three different temperatures (17, 25 or 33°C) for four weeks to assess the effects of thermal acclimation on some physiological traits. Thermal acclimation significantly affected thermal resistance, but not thermal preference, of juvenile M. reevesii. Turtles acclimated to 17°C were less resistant to high temperatures than those acclimated to 25°C and 33°C. However, turtles increased resistance to low temperatures with decreasing acclimation temperature. The acclimation response ratio of the critical thermal minimum (CTMin) was lower than that of the critical thermal maximum (CTMax) for acclimation temperatures between 17 and 25°C, but slightly higher between 25 and 33°C. The thermal resistance range (i.e., the difference between CTMax and CTMin) was widest in turtles acclimated to the intermediate temperature (25°C), and narrowest in those acclimated to low temperature (17°C). The standard metabolic rate increased as body temperature and acclimation temperature increased, and the temperature quotient (Q10) between acclimation temperatures 17 and 25°C was higher than the Q10 between 25 and 33°C. Our results suggest that juvenile M. reevesii may have a greater resistance under mild thermal conditions resembling natural environments, and better physiological performance at relatively warm temperatures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of Satellite Solar-Induced Chlorophyll Fluorescence to Understanding Large-Scale Variations in Vegetation Phenology and Function Over Northern High Latitude Forests

NASA Technical Reports Server (NTRS)

Jeong, Su-Jong; Schimel, David; Frankenberg, Christian; Drewry, Darren T.; Fisher, Joshua B.; Verma, Manish; Berry, Joseph A.; Lee, Jung-Eun; Joiner, Joanna

2016-01-01

This study evaluates the large-scale seasonal phenology and physiology of vegetation over northern high latitude forests (40 deg - 55 deg N) during spring and fall by using remote sensing of solar-induced chlorophyll fluorescence (SIF), normalized difference vegetation index (NDVI) and observation-based estimate of gross primary productivity (GPP) from 2009 to 2011. Based on GPP phenology estimation in GPP, the growing season determined by SIF time-series is shorter in length than the growing season length determined solely using NDVI. This is mainly due to the extended period of high NDVI values, as compared to SIF, by about 46 days (+/-11 days), indicating a large-scale seasonal decoupling of physiological activity and changes in greenness in the fall. In addition to phenological timing, mean seasonal NDVI and SIF have different responses to temperature changes throughout the growing season. We observed that both NDVI and SIF linearly increased with temperature increases throughout the spring. However, in the fall, although NDVI linearly responded to temperature increases, SIF and GPP did not linearly increase with temperature increases, implying a seasonal hysteresis of SIF and GPP in response to temperature changes across boreal ecosystems throughout their growing season. Seasonal hysteresis of vegetation at large-scales is consistent with the known phenomena that light limits boreal forest ecosystem productivity in the fall. Our results suggest that continuing measurements from satellite remote sensing of both SIF and NDVI can help to understand the differences between, and information carried by, seasonal variations vegetation structure and greenness and physiology at large-scales across the critical boreal regions.

A review of factors influencing the stress response in Australian marsupials

PubMed Central

Hing, Stephanie; Narayan, Edward; Thompson, R. C. Andrew; Godfrey, Stephanie

2014-01-01

Many Australian marsupials are threatened species. In order to manage in situ and ex situ populations effectively, it is important to understand how marsupials respond to threats. Stress physiology (the study of the response of animals to challenging stimuli), a key approach in conservation physiology, can be used to characterize the physiological response of wildlife to threats. We reviewed the literature on the measurement of glucocorticoids (GCs), endocrine indicators of stress, in order to understand the stress response to conservation-relevant stressors in Australian marsupials and identified 29 studies. These studies employed a range of methods to measure GCs, with faecal glucocorticoid metabolite enzyme immunoassay being the most common method. The main stressors considered in studies of marsupials were capture and handling. To date, the benefits of stress physiology have yet to be harnessed fully in marsupial conservation. Despite a theoretical base dating back to the 1960s, GCs have only been used to understand how 21 of the 142 extant species of Australian marsupial respond to stressors. These studies include merely six of the 60 marsupial species of conservation concern (IUCN Near Threatened to Critically Endangered). Furthermore, the fitness consequences of stress for Australian marsupials are rarely examined. Individual and species differences in the physiological stress response also require further investigation, because significant species-specific variations in GC levels in response to stressors can shed light on why some individuals or species are more vulnerable to stress factors while others appear more resilient. This review summarizes trends, knowledge gaps and future research directions for stress physiology research in Australian marsupial conservation. PMID:27293648

A single bout of resistance exercise can enhance episodic memory performance.

PubMed

Weinberg, Lisa; Hasni, Anita; Shinohara, Minoru; Duarte, Audrey

2014-11-01

Acute aerobic exercise can be beneficial to episodic memory. This benefit may occur because exercise produces a similar physiological response as physical stressors. When administered during consolidation, acute stress, both physical and psychological, consistently enhances episodic memory, particularly memory for emotional materials. Here we investigated whether a single bout of resistance exercise performed during consolidation can produce episodic memory benefits 48 h later. We used a one-leg knee extension/flexion task for the resistance exercise. To assess the physiological response to the exercise, we measured salivary alpha amylase (a biomarker of central norepinephrine), heart rate, and blood pressure. To test emotional episodic memory, we used a remember-know recognition memory paradigm with equal numbers of positive, negative, and neutral IAPS images as stimuli. The group that performed the exercise, the active group, had higher overall recognition accuracy than the group that did not exercise, the passive group. We found a robust effect of valence across groups, with better performance on emotional items as compared to neutral items and no difference between positive and negative items. This effect changed based on the physiological response to the exercise. Within the active group, participants with a high physiological response to the exercise were impaired for neutral items as compared to participants with a low physiological response to the exercise. Our results demonstrate that a single bout of resistance exercise performed during consolidation can enhance episodic memory and that the effect of valence on memory depends on the physiological response to the exercise. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessing Stress Responses in Beaked and Sperm Whales in the Bahamas

DTIC Science & Technology

2016-05-23

cetacean (beaked whales) and a co-occurring species (sperm whales) for comparison. The physiologic data generated by this project will provide baseline...sex and reproductive status (i.e. other physiologic influences) when interpreting levels of GCs as indicators of stress responses. 2.2 2.2 0 Adult...better understand the sub-lethal, physiologic consequences of underwater noise disturbance on species of concern, like beaked whales, is crucial to

Adaptive Calibration of Children's Physiological Responses to Family Stress: The Utility of Evolutionary Developmental Theory--Comment on Del Giudice et al. (2012) and Sturge-Apple et al. (2012)

ERIC Educational Resources Information Center

Bugental, Daphne Blunt

2012-01-01

Children's physiological reactions to stress are presented from the broader theoretical perspective of adaptive calibration to the environment, as rooted in life history theory. Del Giudice, Hinnant, Ellis, and El-Sheikh (2012) focus on children's physiological responses to a stressful task as a consequence of their history of family stress.…

Assessment of anxiety in open field and elevated plus maze using infrared thermography.

PubMed

Lecorps, Benjamin; Rödel, Heiko G; Féron, Christophe

2016-04-01

Due to their direct inaccessibility, affective states are classically assessed by gathering concomitant physiological and behavioral measures. Although such a dual approach to assess emotional states is frequently used in different species including humans, the invasiveness of procedures for physiological recordings particularly in smaller-sized animals strongly restricts their application. We used infrared thermography, a non-invasive method, to assess physiological arousal during open field and elevated plus maze tests in mice. By measuring changes in surface temperature indicative of the animals' emotional response, we aimed to improve the inherently limited and still controversial information provided by behavioral parameters commonly used in these tests. Our results showed significant and consistent thermal responses during both tests, in accordance with classical physiological responses occurring in stressful situations. Besides, we found correlations between these thermal responses and the occurrence of anxiety-related behaviors. Furthermore, initial temperatures measured at the start of each procedure (open field, elevated plus maze), which can be interpreted as a measure of the animals' initial physiological arousal, predicted the levels of activity and of anxiety-related behaviors displayed during the tests. Our results stress the strong link between physiological correlates of emotions and behaviors expressed during unconditioned fear tests. Copyright © 2016 Elsevier Inc. All rights reserved.

Understanding Evolutionary Impacts of Seasonality: An Introduction to the Symposium.

PubMed

Williams, Caroline M; Ragland, Gregory J; Betini, Gustavo; Buckley, Lauren B; Cheviron, Zachary A; Donohue, Kathleen; Hereford, Joe; Humphries, Murray M; Lisovski, Simeon; Marshall, Katie E; Schmidt, Paul S; Sheldon, Kimberly S; Varpe, Øystein; Visser, Marcel E

2017-11-01

Seasonality is a critically important aspect of environmental variability, and strongly shapes all aspects of life for organisms living in highly seasonal environments. Seasonality has played a key role in generating biodiversity, and has driven the evolution of extreme physiological adaptations and behaviors such as migration and hibernation. Fluctuating selection pressures on survival and fecundity between summer and winter provide a complex selective landscape, which can be met by a combination of three outcomes of adaptive evolution: genetic polymorphism, phenotypic plasticity, and bet-hedging. Here, we have identified four important research questions with the goal of advancing our understanding of evolutionary impacts of seasonality. First, we ask how characteristics of environments and species will determine which adaptive response occurs. Relevant characteristics include costs and limits of plasticity, predictability, and reliability of cues, and grain of environmental variation relative to generation time. A second important question is how phenological shifts will amplify or ameliorate selection on physiological hardiness. Shifts in phenology can preserve the thermal niche despite shifts in climate, but may fail to completely conserve the niche or may even expose life stages to conditions that cause mortality. Considering distinct environmental sensitivities of life history stages will be key to refining models that forecast susceptibility to climate change. Third, we must identify critical physiological phenotypes that underlie seasonal adaptation and work toward understanding the genetic architectures of these responses. These architectures are key for predicting evolutionary responses. Pleiotropic genes that regulate multiple responses to changing seasons may facilitate coordination among functionally related traits, or conversely may constrain the expression of optimal phenotypes. Finally, we must advance our understanding of how changes in seasonal fluctuations are impacting ecological interaction networks. We should move beyond simple dyadic interactions, such as predator prey dynamics, and understand how these interactions scale up to affect ecological interaction networks. As global climate change alters many aspects of seasonal variability, including extreme events and changes in mean conditions, organisms must respond appropriately or go extinct. The outcome of adaptation to seasonality will determine responses to climate change. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Arousal and hallucinatory activity under two isolation conditions

NASA Technical Reports Server (NTRS)

Levin, J.

1974-01-01

Experimental exploration of the hypothesis that soundproof-room and water-immersion isolation environments differ with respect to the variety of physiological responses and reported hallucinations they elicit. The results obtained support the hypothesis in regard to physiological responses only.

Costs of mounting an immune response during pregnancy in a lizard.

PubMed

Meylan, Sandrine; Richard, Murielle; Bauer, Sophie; Haussy, Claudy; Miles, Donald

2013-01-01

Immune defenses are of great benefit to hosts, but reducing the impact of infection by mounting an immune response also entails costs. However, the physiological mechanisms that generate the costs of an immune response remain poorly understood. Moreover, the majority of studies investigating the consequences of an immune challenge in vertebrates have been conducted on mammals and birds. The aim of this study is to investigate the physiological costs of mounting an immune response during gestation in an ectothermic species. Indeed, because ectothermic species are unable to internally regulate their body temperature, the apportionment of resources to homeostatic activities in ectothermic species can differ from that in endothermic species. We conducted this study on the common lizard Zootoca vivipara. We investigated the costs of mounting an immune response by injecting females with sheep red blood cells and quantified the consequences to reproductive performance (litter mass and success) and physiological performance (standard metabolic rate, endurance, and phytohemagglutinin response). In addition, we measured basking behavior. Our analyses revealed that mounting an immune response affected litter mass, physiological performance, and basking behavior. Moreover, we demonstrated that the modulation of an immune challenge is impacted by intrinsic factors, such as body size and condition.

Human Physiological Responses to Acute and Chronic Cold Exposure

NASA Technical Reports Server (NTRS)

Stocks, Jodie M.; Taylor, Nigel A. S.; Tipton, Michael J.; Greenleaf, John E.

2001-01-01

When inadequately protected humans are exposed to acute cold, excessive body heat is lost to the environment and unless heat production is increased and heat loss attenuated, body temperature will decrease. The primary physiological responses to counter the reduction in body temperature include marked cutaneous vasoconstriction and increased metabolism. These responses, and the hazards associated with such exposure, are mediated by a number of factors which contribute to heat production and loss. These include the severity and duration of the cold stimulus; exercise intensity; the magnitude of the metabolic response; and individual characteristics such as body composition, age, and gender. Chronic exposure to a cold environment, both natural and artificial, results in physiological alterations leading to adaptation. Three quite different, but not necessarily exclusive, patterns of human cold adaptation have been reported: metabolic, hypothermic, and insulative. Cold adaptation has also been associated with an habituation response, in which there is a desensitization, or damping, of the normal response to a cold stress. This review provides a comprehensive analysis of the human physiological and pathological responses to cold exposure. Particular attention is directed to the factors contributing to heat production and heat loss during acute cold stress, and the ability of humans to adapt to cold environments.

Human physiological responses to wooden indoor environment.

PubMed

Zhang, Xi; Lian, Zhiwei; Wu, Yong

2017-05-15

Previous studies are mainly focused on non-wooden environments, whereas few are concerned with wooden ones. How wooden indoor environments impact the physiology of the occupants is still unclear. The purpose of this study was to explore the distinct physiological responses to wooden and non-wooden indoor environments, assessed by physiological parameters tests including blood pressure, electrocardiogram measurements, electro-dermal activity, oxyhemoglobin saturation, skin temperature, and near distance vision. Twenty healthy adults participated in this experiment, and their physiological responses were evaluated in a 90minute investigation. The results illustrated that; less tension and fatigue were generated in the wooden rooms than in the non-wooden rooms when the participants did their work. In addition, the study also found that the wooden environments benefit the autonomic nervous system, respiratory system, and visual system. Moreover, wooden rooms play a valuable role in physiological regulation and ease function especially after a consecutive period of work. These results provide an experimental basis to support that wooden environment is beneficial to indoor occupants than the non-wooden indoor environment. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of antecedent moderate-intensity exercise on the glycemia-increasing effect of a 30-sec maximal sprint: a sex comparison.

PubMed

Justice, Tara D; Hammer, Greta L; Davey, Raymond J; Paramalingam, Nirubasini; Guelfi, Kym J; Lewis, Lynley; Davis, Elizabeth A; Jones, Timothy W; Fournier, Paul A

2015-05-01

This study investigated whether a prior bout of moderate-intensity exercise attenuates the glycemia-increasing effect of a maximal 30-sec sprint. A secondary aim was to determine whether the effect of antecedent exercise on the glucoregulatory response to sprinting is affected by sex. Participants (men n = 8; women n = 7) were tested on two occasions during which they either rested (CON) or cycled for 60-min at a moderate intensity of ~65% V ˙ O 2 peak (EX) before performing a 30-sec maximal cycling effort 195 min later. In response to the sprint, blood glucose increased to a similar extent between EX and CON trials, peaking at 10 min of recovery, with no difference between sexes (P > 0.05). Blood glucose then declined at a faster rate in EX, and this was associated with a glucose rate of disappearance (R d) that exceeded the glucose rate of appearance (R a) earlier in EX compared with CON, although the overall glucose R a and R d profile was higher in men compared with women (P < 0.05). The response of growth hormone was attenuated during recovery from EX compared with CON (P < 0.05), with a lower absolute response in women compared with men (P < 0.05). The response of epinephrine and norepinephrine was also lower in women compared with men (P < 0.05) but similar between trials. In summary, a prior bout of moderate-intensity exercise does not affect the magnitude of the glycemia-increasing response to a 30-sec sprint; however, the subsequent decline in blood glucose is more rapid. This blood glucose response is similar between men and women, despite less pronounced changes in glucose R a and R d, and a lower response of plasma catecholamines and growth hormone to sprinting in women. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Combined effects of mild-to-moderate obesity and asthma on physiological and sensory responses to exercise.

PubMed

Cortés-Télles, Arturo; Torre-Bouscoulet, Luis; Silva-Cerón, Monica; Mejía-Alfaro, Roberto; Syed, Nafeez; Zavorsky, Gerald S; Guenette, Jordan A

2015-11-01

Despite the close link between asthma and obesity, there are no studies that have evaluated the sensory and physiological responses to exercise in obese asthmatics. We recently demonstrated that normal weight asthmatics with well controlled disease have preserved cardiorespiratory and sensory responses to exercise relative to non-asthmatic controls. However, these similarities may not hold true in patients with combined obesity and asthma. Accordingly, we sought to determine if combined asthma and obesity was associated with deleterious effects on cardiorespiratory fitness, exercise performance, dyspnoea, and physiological responses to exercise. Fourteen well-controlled obese asthmatics and fourteen age-matched normal weight asthmatics performed routine spirometry and underwent an incremental cardiopulmonary cycle test to assess the ventilatory, pulmonary gas exchange, cardiovascular, and sensory responses to exercise. Groups were well matched for age, height, spirometry, and asthma control. Obese asthmatics had a significantly greater body mass index (33 ± 3 vs. 23 ± 1 kg/m(2), p < 0.001) and lower self-reported activity levels by 47 % relative to normal weight asthmatics (p < 0.05). Obese asthmatics had a significantly lower maximal oxygen uptake (VO(2)) (82 ± 14 vs. 92 ± 10 %predicted) and work rate (75 ± 8 vs. 89 ± 13 %predicted) relative to normal weight asthmatics (p < 0.05). The anaerobic threshold occurred at a lower VO(2) in obese asthmatics vs. normal weight asthmatics (54 ± 15 vs. 66 ± 16 %predicted, p < 0.05). Ventilatory responses were superimposed throughout exercise with no evidence of a ventilatory limitation in either group. Cardiovascular responses were normal in both groups. Dyspnoea responses were similar but the obese asthmatics experienced greater leg fatigue ratings at submaximal work rates. In conclusion, obese individuals with well controlled asthma have reduced cardiorespiratory fitness and greater leg fatigue ratings relative to normal weight asthmatics. The relatively reduced cardiorespiratory fitness and exercise performance in obese compared to normal weight asthmatics is most likely driven by their more sedentary lifestyle and resultant deconditioning rather than due to respiratory factors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Heat acclimation attenuates physiological strain and the HSP72, but not HSP90α, mRNA response to acute normobaric hypoxia.

PubMed

Gibson, Oliver R; Turner, Gareth; Tuttle, James A; Taylor, Lee; Watt, Peter W; Maxwell, Neil S

2015-10-15

Heat acclimation (HA) attenuates physiological strain in hot conditions via phenotypic and cellular adaptation. The aim of this study was to determine whether HA reduced physiological strain, and heat shock protein (HSP) 72 and HSP90α mRNA responses in acute normobaric hypoxia. Sixteen male participants completed ten 90-min sessions of isothermic HA (40°C/40% relative humidity) or exercise training [control (CON); 20°C/40% relative humidity]. HA or CON were preceded (HYP1) and proceeded (HYP2) by a 30-min normobaric hypoxic exposure [inspired O2 fraction = 0.12; 10-min rest, 10-min cycling at 40% peak O2 uptake (V̇O2 peak), 10-min cycling at 65% V̇O2 peak]. HA induced greater rectal temperatures, sweat rate, and heart rates (HR) than CON during the training sessions. HA, but not CON, reduced resting rectal temperatures and resting HR and increased sweat rate and plasma volume. Hemoglobin mass did not change following HA nor CON. HSP72 and HSP90α mRNA increased in response to each HA session, but did not change with CON. HR during HYP2 was lower and O2 saturation higher at 65% V̇O2 peak following HA, but not CON. O2 uptake/HR was greater at rest and 65% V̇O2 peak in HYP2 following HA, but was unchanged after CON. At rest, the respiratory exchange ratio was reduced during HYP2 following HA, but not CON. The increase in HSP72 mRNA during HYP1 did not occur in HYP2 following HA. In CON, HSP72 mRNA expression was unchanged during HYP1 and HYP2. In HA and CON, increases in HSP90α mRNA during HYP1 were maintained in HYP2. HA reduces physiological strain, and the transcription of HSP72, but not HSP90α mRNA in acute normobaric hypoxia. Copyright © 2015 the American Physiological Society.

Changes in intestinal microbiota composition and metabolism coincide with increased intestinal permeability in young adults under prolonged physiological stress.

PubMed

Karl, J Philip; Margolis, Lee M; Madslien, Elisabeth H; Murphy, Nancy E; Castellani, John W; Gundersen, Yngvar; Hoke, Allison V; Levangie, Michael W; Kumar, Raina; Chakraborty, Nabarun; Gautam, Aarti; Hammamieh, Rasha; Martini, Svein; Montain, Scott J; Pasiakos, Stefan M

2017-06-01

The magnitude, temporal dynamics, and physiological effects of intestinal microbiome responses to physiological stress are poorly characterized. This study used a systems biology approach and a multiple-stressor military training environment to determine the effects of physiological stress on intestinal microbiota composition and metabolic activity, as well as intestinal permeability (IP). Soldiers ( n = 73) were provided three rations per day with or without protein- or carbohydrate-based supplements during a 4-day cross-country ski-march (STRESS). IP was measured before and during STRESS. Blood and stool samples were collected before and after STRESS to measure inflammation, stool microbiota, and stool and plasma global metabolite profiles. IP increased 62 ± 57% (mean ± SD, P < 0.001) during STRESS independent of diet group and was associated with increased inflammation. Intestinal microbiota responses were characterized by increased α-diversity and changes in the relative abundance of >50% of identified genera, including increased abundance of less dominant taxa at the expense of more dominant taxa such as Bacteroides Changes in intestinal microbiota composition were linked to 23% of metabolites that were significantly altered in stool after STRESS. Together, pre-STRESS Actinobacteria relative abundance and changes in serum IL-6 and stool cysteine concentrations accounted for 84% of the variability in the change in IP. Findings demonstrate that a multiple-stressor military training environment induced increases in IP that were associated with alterations in markers of inflammation and with intestinal microbiota composition and metabolism. Associations between IP, the pre-STRESS microbiota, and microbiota metabolites suggest that targeting the intestinal microbiota could provide novel strategies for preserving IP during physiological stress. NEW & NOTEWORTHY Military training, a unique model for studying temporal dynamics of intestinal barrier and intestinal microbiota responses to stress, resulted in increased intestinal permeability concomitant with changes in intestinal microbiota composition and metabolism. Prestress intestinal microbiota composition and changes in fecal concentrations of metabolites linked to the microbiota were associated with increased intestinal permeability. Findings suggest that targeting the intestinal microbiota could provide novel strategies for mitigating increases in intestinal permeability during stress.

Ferrum nano particles and multiwall carbon nano tubes based electrode as FIA detector for determination of amino acids in hypothalamus microdialysis fluids

NASA Astrophysics Data System (ADS)

Sun, L.; Wang, J.; Wang, Y. T.; Yu, L.; Peng, H.; Zhu, J. Z.

2017-01-01

An amperometric electrode based on multiwall carbon nanotubes (MWCNTs) and Fe nanoparticles (NPs) has been successfully fabricated. Combined with Flow Injection Analysis (FIA) and chromatography separation column, the electrode exhibits linear response in the concentration range of 0.1 -12 μM and the sensitivity of 30.0 nA μM-1 for most of amino acids. The determination of 17 amino acids in the hypothalamus microdialysis fluids of guinea pigs, illustrates that the electrode is a powerful tool to investigate physiology and pathology mechanisms

Divergence in Eco-Physiological Responses to Drought Mirrors the Distinct Distribution of Chamerion angustifolium Cytotypes in the Himalaya–Hengduan Mountains Region

PubMed Central

Guo, Wen; Yang, Jie; Sun, Xu-Dong; Chen, Guang-Jie; Yang, Yong-Ping; Duan, Yuan-Wen

2016-01-01

Polyploid species generally occupy harsher habitats (characterized by cold, drought and/or high altitude) than diploids, but the converse was observed for Chamerion angustifolium, in which diploid plants generally inhabit higher altitudes than their polyploid derivatives. Plants at high altitudes may experience cold-induced water stress, and we therefore examined the physiological responses of diploid and hexaploid C. angustifolium to water stress to better understand the ecological differentiation of plants with different ploidy levels. We conducted a common garden experiment by subjecting seedlings of different ploidy levels to low, moderate, and severe water stress. Fourteen indicators of physiological fitness were measured, and the anatomical characteristics of the leaves of each cytotype were determined. Both cytotypes were influenced by drought, and diploids exhibited higher fitness in terms of constant root:shoot ratio (R:S ratio) and maximum quantum yield of PS II (Fv/Fm), less reduced maximal photosynthetic rate (Amax), transpiration rate (E), intercellular CO2 concentration (Ci) and stomatal conductance (gs), and higher long-term water use efficiency (WUEL) under severe water stress than did hexaploids. Analysis of leaf anatomy revealed morphological adjustments for tolerating water deficiency in diploids, in the form of closely packed mesophyll cells and small conduits in the midvein. Our results indicate that diploid C. angustifolium is more tolerant of drought than hexaploid plants, ensuring the successful survival of the diploid at high altitudes. This eco-physiological divergence may facilitate the species with different cytotypes to colonize new and large geographic ranges with heterogeneous environmental conditions. PMID:27630654

Gender-related traits in the dioecious shrub Empetrum rubrum in two plant communities in the Magellanic steppe

NASA Astrophysics Data System (ADS)

Díaz-Barradas, Mari Cruz; Zunzunegui, María; Collantes, Marta; Álvarez-Cansino, Leonor; García Novo, Francisco

2014-10-01

Following the theory on costs of reproduction, sexually dimorphic plants may exhibit several trade-offs in energy and resources that can determine gender dimorphism in morphological or physiological traits, especially during the reproductive period. In this study we assess whether the sexes of the dioecious species Empetrum rubrum differ in morphological and ecophysiological traits related to water economy and photochemical efficiency and whether these differences change in nearby populations with contrasting plant communities. We conducted physiological, morphological, sex ratio, and cover measurements in E. rubrum plants in the Magellanic steppe, North-Eastern part of Tierra del Fuego (Argentina), from two types of heathlands with differing community composition. We found differences between sites in soil pH and wind speed at the canopy level. E. rubrum plants exhibited lower photosynthetic height and higher LAI (leaf area index), lower RWC (relative water content) and higher water-use efficiency (lower Δ13C) in the heathland with harsher environmental conditions. Gender dimorphism in the physiological response was patent for photochemical efficiency and water use (RWC and Δ13C discrimination), with males showing a more conservative strategy in relation to females. Accordingly, male-biased sex ratio in the stress-prone community suggested a better performance of male plants under stressful environmental conditions. The integrated analysis of all variables (photochemical efficiency, RWC, leaf dry matter content (LDMC), pigments, and Δ13C) indicated an interaction between gender and heathland community effects in the physiological response. We suggest that female plants may exhibit compensatory mechanisms to face their higher reproductive costs.

Exposure to seismic air gun signals causes physiological harm and alters behavior in the scallop Pecten fumatus

PubMed Central

McCauley, Robert D.; Fitzgibbon, Quinn P.; Hartmann, Klaas; Semmens, Jayson M.

2017-01-01

Seismic surveys map the seabed using intense, low-frequency sound signals that penetrate kilometers into the Earth’s crust. Little is known regarding how invertebrates, including economically and ecologically important bivalves, are affected by exposure to seismic signals. In a series of field-based experiments, we investigate the impact of exposure to seismic surveys on scallops, using measurements of physiological and behavioral parameters to determine whether exposure may cause mass mortality or result in other sublethal effects. Exposure to seismic signals was found to significantly increase mortality, particularly over a chronic (months postexposure) time scale, though not beyond naturally occurring rates of mortality. Exposure did not elicit energetically expensive behaviors, but scallops showed significant changes in behavioral patterns during exposure, through a reduction in classic behaviors and demonstration of a nonclassic “flinch” response to air gun signals. Furthermore, scallops showed persistent alterations in recessing reflex behavior following exposure, with the rate of recessing increasing with repeated exposure. Hemolymph (blood analog) physiology showed a compromised capacity for homeostasis and potential immunodeficiency, as a range of hemolymph biochemistry parameters were altered and the density of circulating hemocytes (blood cell analog) was significantly reduced, with effects observed over acute (hours to days) and chronic (months) scales. The size of the air gun had no effect, but repeated exposure intensified responses. We postulate that the observed impacts resulted from high seabed ground accelerations driven by the air gun signal. Given the scope of physiological disruption, we conclude that seismic exposure can harm scallops. PMID:28923925

Parity modifies endocrine hormones in urine and problem-solving strategies of captive owl monkeys (Aotus spp.).

PubMed

Bardi, Massimo; Eckles, Meredith; Kirk, Emily; Landis, Timothy; Evans, Sian; Lambert, Kelly G

2014-12-01

Parental behavior modifies neural, physiologic, and behavioral characteristics of both maternal and paternal mammals. These parenting-induced modifications extend to brain regions not typically associated with parental responses themselves but that enhance ancillary responses, such as foraging efficiency and predator avoidance. Here we hypothesized that male and female owl monkeys (Aotus spp.) with reproductive experience (RE) would demonstrate more adaptive ancillary behavioral and neuroendocrine responses than those of their nonRE counterparts. To assess cognitive skills and coping flexibility, we introduced a foraging strategy task, including a set of novel objects (coin holders) marked with different symbols representing different food rewards, to the animals. To assess endocrine responses, urine samples were assayed for cortisol and dehydroepiandrosterone (DHEA) levels and their ratios to determine physiologic measures of emotional regulation in RE and nonRE owl monkeys. Compared with nonRE monkeys, experienced parents had higher DHEA:cortisol ratios after exposure to habituation training and on the first day of testing in the foraging task. Both hormones play critical roles in the stress response and coping mechanisms, and a high DHEA:cortisol ratio usually indicates increased coping skills. In addition, RE monkeys exhibited more efficient foraging responses (by 4-fold) than did the nonRE mating pairs. We conclude that RE modifies relevant behavioral and hormonal responses of both maternal and paternal owl monkeys exposed to a challenging cognitive paradigm. Corroborating previous research demonstrating adaptive modifications in foraging efficiency and emotional responses in reproductively experienced rodents, the current results extend these findings to a monogamous primate species.

Parity Modifies Endocrine Hormones in Urine and Problem-Solving Strategies of Captive Owl Monkeys (Aotus spp.)

PubMed Central

Eckles, Meredith; Kirk, Emily; Landis, Timothy; Evans, Sian; Lambert, Kelly G

2014-01-01

Parental behavior modifies neural, physiologic, and behavioral characteristics of both maternal and paternal mammals. These parenting-induced modifications extend to brain regions not typically associated with parental responses themselves but that enhance ancillary responses, such as foraging efficiency and predator avoidance. Here we hypothesized that male and female owl monkeys (Aotus spp.) with reproductive experience (RE) would demonstrate more adaptive ancillary behavioral and neuroendocrine responses than those of their nonRE counterparts. To assess cognitive skills and coping flexibility, we introduced a foraging strategy task, including a set of novel objects (coin holders) marked with different symbols representing different food rewards, to the animals. To assess endocrine responses, urine samples were assayed for cortisol and dehydroepiandrosterone (DHEA) levels and their ratios to determine physiologic measures of emotional regulation in RE and nonRE owl monkeys. Compared with nonRE monkeys, experienced parents had higher DHEA:cortisol ratios after exposure to habituation training and on the first day of testing in the foraging task. Both hormones play critical roles in the stress response and coping mechanisms, and a high DHEA:cortisol ratio usually indicates increased coping skills. In addition, RE monkeys exhibited more efficient foraging responses (by 4-fold) than did the nonRE mating pairs. We conclude that RE modifies relevant behavioral and hormonal responses of both maternal and paternal owl monkeys exposed to a challenging cognitive paradigm. Corroborating previous research demonstrating adaptive modifications in foraging efficiency and emotional responses in reproductively experienced rodents, the current results extend these findings to a monogamous primate species. PMID:25527030

Physiological constraints and energetic costs of diving behaviour in marine mammals: a review of studies using trained Steller sea lions diving in the open ocean.

PubMed

Rosen, David A S; Hindle, Allyson G; Gerlinsky, Carling D; Goundie, Elizabeth; Hastie, Gordon D; Volpov, Beth L; Trites, Andrew W

2017-01-01

Marine mammals are characterized as having physiological specializations that maximize the use of oxygen stores to prolong time spent under water. However, it has been difficult to undertake the requisite controlled studies to determine the physiological limitations and trade-offs that marine mammals face while diving in the wild under varying environmental and nutritional conditions. For the past decade, Steller sea lions (Eumetopias jubatus) trained to swim and dive in the open ocean away from the physical confines of pools participated in studies that investigated the interactions between diving behaviour, energetic costs, physiological constraints, and prey availability. Many of these studies measured the cost of diving to understand how it varies with behaviour and environmental and physiological conditions. Collectively, these studies show that the type of diving (dive bouts or single dives), the level of underwater activity, the depth and duration of dives, and the nutritional status and physical condition of the animal affect the cost of diving and foraging. They show that dive depth, dive and surface duration, and the type of dive result in physiological adjustments (heart rate, gas exchange) that may be independent of energy expenditure. They also demonstrate that changes in prey abundance and nutritional status cause sea lions to alter the balance between time spent at the surface acquiring oxygen (and offloading CO 2 and other metabolic by-products) and time spent at depth acquiring prey. These new insights into the physiological basis of diving behaviour further our understanding of the potential scope for behavioural responses of marine mammals to environmental changes, the energetic significance of these adjustments, and the consequences of approaching physiological limits.

A new way of thinking about complications of prematurity.

PubMed

Moore, Tiffany A; Berger, Ann M; Wilson, Margaret E

2014-01-01

The morbidity and mortality of preterm infants are impacted by their ability to maintain physiologic homeostasis using metabolic, endocrine, and immunologic mechanisms independent of the mother's placenta. Exploring McEwen's allostatic load model in preterm infants provides a new way to understand the altered physiologic processes associated with frequently occurring complications of prematurity such as bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and retinopathy of prematurity. The purpose of this article is to present a new model to enhance understanding of the altered physiologic processes associated with complications of prematurity. The model of allostatic load and complications of prematurity was derived to explore the relationship between general stress of prematurity and complications of prematurity. The proposed model uses the concepts of general stress of prematurity, allostasis, physiologic response patterns (adaptive-maladaptive), allostatic load, and complications of prematurity. These concepts are defined and theoretical relationships in the proposed model are interpreted using the four maladaptive response patterns of repeated hits, lack of adaptation, prolonged response, and inadequate response. Empirical evidence for cortisol, inflammation, and oxidative stress responses are used to support the theoretical relationships. The proposed model provides a new way of thinking about physiologic dysregulation in preterm infants. The ability to describe and understand complex physiologic mechanisms involved in complications of prematurity is essential for research. Advancing the knowledge of complications of prematurity will advance clinical practice and research and lead to testing of interventions to reduce negative outcomes in preterm infants.

The Power of Physiology in Changing Landscapes: Considerations for the Continued Integration of Conservation and Physiology.

PubMed

Madliger, Christine L; Love, Oliver P

2015-10-01

The growing field of conservation physiology applies a diversity of physiological traits (e.g., immunological, metabolic, endocrine, and nutritional traits) to understand and predict organismal, population, and ecosystem responses to environmental change and stressors. Although the discipline of conservation physiology is gaining momentum, there is still a pressing need to better translate knowledge from physiology into real-world tools. The goal of this symposium, ‘‘Physiology in Changing Landscapes: An Integrative Perspective for Conservation Biology’’, was to highlight that many current investigations in ecological, evolutionary, and comparative physiology are necessary for understanding the applicability of physiological measures for conservation goals, particularly in the context of monitoring and predicting the health, condition, persistence, and distribution of populations in the face of environmental change. Here, we outline five major investigations common to environmental and ecological physiology that can contribute directly to the progression of the field of conservation physiology: (1) combining multiple measures of physiology and behavior; (2) employing studies of dose–responses and gradients; (3) combining a within-individual and population-level approach; (4) taking into account the context-dependency of physiological traits; and (5) linking physiological variables with fitness metrics. Overall, integrative physiologists have detailed knowledge of the physiological systems that they study; however, communicating theoretical and empirical knowledge to conservation biologists and practitioners in an approachable and applicable way is paramount to the practical development of physiological tools that will have a tangible impact for conservation.