[Physiological characteristics and the level of risk factors for ischemic heart disease in marathon runners between 30 and 59 years of age].

PubMed

Kostka, T; Drygas, W; Mrozek, P

1989-02-06

The results of anthropometric, biochemical, cardiological and performance capacity studies in the 37 marathon runners, 113 men systematically practising recreational training programme with a domination of endurance exercises and 44 healthy men with little leisure time physical activity have been compared. In comparison with a group of physically non-active persons, the marathon runners are characterized by considerably higher physical working capacity, slimmer figure, lower resting heart rate, lower diastolic blood pressure, high concentration of HDL cholesterol and lower cholesterol: HDL cholesterol index. However, these differences are minimal in comparison with other systematically training persons, and with regard to the majority of factors statistically insignificant. It seems that for reaching the physiological effects desired from the point of view of ischemic heart disease prevention the endurance training of lower capacity and intensity would be sufficient.

Use of a physiological profile to document motor impairment in ageing and in clinical groups.

PubMed

Lord, S R; Delbaere, K; Gandevia, S C

2016-08-15

Ageing decreases exercise performance and is frequently accompanied by reductions in cognitive performance. Deterioration in the physiological capacity to stand, locomote and exercise can manifest itself as falling over and represents a significant deterioration in sensorimotor control. In the elderly, falling leads to serious morbidity and mortality with major societal costs. Measurement of a suite of physiological capacities that are required for successful motor performance (including vision, muscle strength, proprioception and balance) has been used to produce a physiological profile assessment (PPA) which has been tracked over the age spectrum and in different diseases (e.g. multiple sclerosis, Parkinson's disease). As well as measures of specific physiological capacities, the PPA generates an overall 'score' which quantitatively measures an individual's cumulative risk of falling. The present review collates data from the PPA (and the physiological capacities it measures) as well as its use in strategies to reduce falls in the elderly and those with different diseases. We emphasise that (i) motor impairment arises via reductions in a wide range of sensorimotor abilities; (ii) the PPA approach not only gives a snapshot of the physiological capacity of an individual, but it also gives insight into the deficits among groups of individuals with particular diseases; and (iii) deficits in seemingly restricted and disparate physiological domains (e.g. vision, strength, cognition) are funnelled into impairments in tasks requiring upright balance. Motor impairments become more prevalent with ageing but careful physiological measurement and appropriate interventions offer a way to maximise health across the lifespan. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

A comparison of the physiological profiles of elite Gaelic footballers, hurlers, and soccer players

PubMed Central

McIntyre, M

2005-01-01

Background: Gaelic football, soccer, and hurling are prominent field games in Ireland and involve participants undertaking a variety of playing tasks and skills which place various physiological demands on the participants. The aim of this study was to evaluate and compare the mid-season physiological profiles of elite players. Methods: Physiological assessment was carried out on 29 inter-county Gaelic footballers, 30 inter-county hurlers, and 21 League of Ireland soccer players. Results: Significant differences were reported for % body fat (p<0.05), aerobic capacity (p<0.05), flexibility (p<0.05), upper body strength (p<0.05), upper body strength endurance (p<0.05), abdominal endurance (p<0.05), and speed endurance (p<0.05), while there were no differences recorded for height, weight, or speed levels. A relatively heterogeneous body size is evident for all three sports. Soccer players had lower body fat levels, greater aerobic capacity, greater strength endurance, and greater flexibility compared to both Gaelic footballers and hurlers, possibly due to specific training and conditioning programmes or physical adaptation to match play The greater strength of both Gaelic footballers and hurlers and the superior speed endurance levels of Gaelic footballers also reflect the physical nature of the sports. Similar speed levels amongst all three sports reflect the importance of speed for performance. Conclusions: The various physiological attributes for Gaelic football, soccer, and hurling reflect the physical requirements for success and participation in each of these field games. PMID:15976166

Stress, Workload and Physiology Demand During Extravehicular Activity: A Pilot Study

PubMed Central

Rai, Balwant; Kaur, Jasdeep; Foing, Bernard H

2012-01-01

Background: Extravehicular activity (EVA), such as exercise performed under unique environmental conditions, is essential for supporting daily living in weightlessness and for further space exploration like long Mars mission. Aim: The study was planned stress, workload, and physiological demands of simulated Mars exploration. Materials and Methods: In this study, the six-person crew lived (24 hours) for 14 days during a short-term stay at the Mars Desert Research Station. The heart rates, salivary cortisol, workload, peak oxygen uptake or maximal aerobic capacity of the crew are measured before, during and after an EVA. Results: Data for heart rate showed the same trend as peak oxygen uptake or maximal aerobic capacity, with a maximal increase to 85% of peak. The rating of subscale showed a significant increase in EVA as compared to run. Salivary cortisol levels and heart rates were increased in both groups, although significant increased of cortisol levels and heart rates more in EVA as compared to hill running crew members. Conclusion: Further study is required on large scale taken into account of limitations of this study and including other physiological and psychological parameters in Mars analog environment. PMID:22754877

Functional and physiological properties of total, soluble, and insoluble dietary fibres derived from defatted rice bran.

PubMed

Daou, Cheickna; Zhang, Hui

2014-12-01

Enzymatic- gravimetric method was used to obtain three fractions of dietary from defatted rice bran. The functional and physiological properties such as viscosity, cation exchange capacity (CEC), and glucose dialysis retardation index (GDRI), cholesterol and bile salt adsorption capacity of the resultant fractions were evaluated. Insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) when compared showed that SDF exhibited significantly (p < 0.05) higher viscosity (2.35 mPa.s), greater GDRI value (17.65 %) at 60 min and significantly lowered concentration of cholesterol at pH 7 (29.90 %, p < 0.05). However IDF showed the highest CEC and its adsorption capacity of bile salt was higher than SDF (18.20 % vs. 13.76 %; p < 0.05), while CEC and cholesterol absorption capacity of TDF were similar to SDF. These properties indicate that rice bran soluble, insoluble and total fibres are functional ingredients which can be added to various food products and dietetic, low-calorie high-fiber foods to enhance their nutraceutical properties and health benefits.

Reference database of lung volumes and capacities in wistar rats from 2 to 24 months.

PubMed

Filho, Wilson Jacob; Fontinele, Renata Gabriel; de Souza, Romeu Rodrigues

2014-01-01

This study determines the effects of growing and aging on lung physiological volumes and capacities and the incidence of inflammation in the small airways with age in rats. A reference database comprising of body weight gain, lung physiological volumes and capacities and an anatomopathological study of lung lesions over 240 Wistar rats from two to 24 -mo, is described. Tidal volume (TV), minute respiratory volume (MRV), and forced vital capacity (FVC) decreased during the first six months of life and then remain constant until 24 -mo of age. The respiratory frequency (Rf) and dynamical compliance (Cdyn) maintain at constant values from 2 to 24- mo of age; the functional residual capacity (FRC) increases in the first 6 -mo and then remains constant up to 24 -mo. It was verified a less intensive inflammation in the small airways with age, when compared with the median and large airways. This study showed the normal parameters for lung volumes and capacities and the incidence of infections for growing and aging male and female rats. The age-related data on these main respiratory parameters in rats would be useful in studies of aging-related disorders using this model and for safety pharmacology studies necessary for the development of drugs.

Abnormal pulmonary function in adults with sickle cell anemia.

PubMed

Klings, Elizabeth S; Wyszynski, Diego F; Nolan, Vikki G; Steinberg, Martin H

2006-06-01

Pulmonary complications of sickle cell anemia (Hb-SS) commonly cause morbidity, yet few large studies of pulmonary function tests (PFTs) in this population have been reported. PFTs (spirometry, lung volumes, and diffusion capacity for carbon monoxide [DLCO]) from 310 adults with Hb-SS were analyzed to determine the pattern of pulmonary dysfunction and their association with other systemic complications of sickle cell disease. Raw PFT data were compared with predicted values. Each subject was subclassified into one of five groups: obstructive physiology, restrictive physiology, mixed obstructive/restrictive physiology, isolated low DLCO, or normal. The association between laboratory data of patients with decreased DLCO or restrictive physiology and those of normal subjects was assessed by multivariate linear regression. Normal PFTs were present in only 31 of 310 (10%) patients. Overall, adults with Hb-SS were characterized by decreased total lung capacities (70.2 +/- 14.7% predicted) and DLCO (64.5 +/- 19.9%). The most common PFT patterns were restrictive physiology (74%) and isolated low DLCO (13%). Decreased DLCO was associated with thrombocytosis (p = 0.05), with hepatic dysfunction (elevated alanine aminotransferase; p = 0.07), and a trend toward renal dysfunction (elevated blood urea nitrogen and creatinine; p = 0.05 and 0.07, respectively). Pulmonary function is abnormal in 90% of adult patients with Hb-SS. Common abnormalities include restrictive physiology and decreased DLCO. Decreased DLCO may indicate more severe sickle vasculopathy characterized by impaired hepatic and renal function.

Physiological regulation of evaporative water loss in endotherms: is the little red kaluta (Dasykaluta rosamondae) an exception or the rule?

PubMed Central

Withers, Philip C.; Cooper, Christine E.

2014-01-01

It is a central paradigm of comparative physiology that the effect of humidity on evaporative water loss (EWL) is determined for most mammals and birds, in and below thermoneutrality, essentially by physics and is not under physiological regulation. Fick's law predicts that EWL should be inversely proportional to ambient relative humidity (RH) and linearly proportional to the water vapour pressure deficit (Δwvp) between animal and air. However, we show here for a small dasyurid marsupial, the little kaluta (Dasykaluta rosamondae), that EWL is essentially independent of RH (and Δwvp) at low RH (as are metabolic rate and thermal conductance). These results suggest regulation of a constant EWL independent of RH, a hitherto unappreciated capacity of endothermic vertebrates. Independence of EWL from RH conserves water and heat at low RH, and avoids physiological adjustments to changes in evaporative heat loss such as thermoregulation. Re-evaluation of previously published data for mammals and birds suggests that a lesser dependence of EWL on RH is observed more commonly than previously thought, suggesting that physiological independence of EWL of RH is not just an unusual capacity of a few species, such as the little kaluta, but a more general capability of many mammals and birds. PMID:24741015

Comparability and repeatability of three commonly used methods for measuring endurance capacity.

PubMed

Baxter-Gilbert, James; Mühlenhaupt, Max; Whiting, Martin J

2017-12-01

Measures of endurance (time to exhaustion) have been used to address a wide range of questions in ecomorphological and physiological research, as well as being used as a proxy for survival and fitness. Swimming, stationary (circular) track running, and treadmill running are all commonly used methods for measuring endurance. Despite the use of these methods across a broad range of taxa, how comparable these methods are to one another, and whether they are biologically relevant, is rarely examined. We used Australian water dragons (Intellagama lesueurii), a species that is morphologically adept at climbing, swimming, and running, to compare these three methods of endurance and examined if there is repeatability within and between trial methods. We found that time to exhaustion was not highly repeatable within a method, suggesting that single measures or a mean time to exhaustion across trials are not appropriate. Furthermore, we compared mean maximal endurance times among the three methods, and found that the two running methods (i.e., stationary track and treadmill) were similar, but swimming was distinctly different, resulting in lower mean maximal endurance times. Finally, an individual's endurance rank was not repeatable across methods, suggesting that the three endurance trial methods are not providing similar information about an individual's performance capacity. Overall, these results highlight the need to carefully match a measure of performance capacity with the study species and the research questions being asked so that the methods being used are behaviorally, ecologically, and physiologically relevant. © 2018 Wiley Periodicals, Inc.

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

Jensen, Anna M.; Warren, Jeffrey; Hanson, Paul J.

Using seasonal- and cohort-specific photosynthetic temperature response functions, we quantified the physiological significance of maintaining multiple foliar cohorts in mature (~40-45 year old) Picea mariana trees in an ombrotrophic Sphagnum-bog, northern Minnesota, USA. We measured photosynthetic capacity, foliar respiration (Rd), biochemistry and morphology to estimate annual carbon (C) uptake by cohort, season and canopy position. Temperature response of key photosynthetic parameters at 25 C (i.e., light-saturated rate of CO 2 assimilation (Asat), light-saturated rate of Rubisco carboxylation (Vcmax), light-saturated electron transport rate (Jmax)) were clearly dependent on season and were generally less responsive in younger needles. Temperature optimums range betweenmore » 18.7-23.7, 31.3-38.3 and 28.7-36.7 C for Asat, Vcmax and Jmax respectively. Current-year (Y0) foliage had lower photosynthetic capacities compared to one-year-old (Y1) and two-year-old (Y2) foliage. As Y0 needles matured, values of Asat, Vcmax, Jmax, foliar LMA and nitrogen increased. Values of Vcmax, Jmax and Rd were related to foliar nitrogen but only in the youngest (Y0) cohort. Foliar ontogeny affected photosynthetic capacity more than growth temperature. Morphological and physiological cohort differences were reflected by their annual contribution to modeled C uptake, with a ~36% lower estimated annual C uptake by Y0 needles (LAI 0.52 m 2m -2) compared to Y1&2 cohorts (LAI 0.67 m 2m -2). Collectively, these results illustrate the physiological and ecological significance of characterizing multiple foliar cohorts during bud break and throughout the growth season, and for cumulative C uptake model estimates.« less

The physiological basis and clinical significance of lung volume measurements.

PubMed

Lutfi, Mohamed Faisal

2017-01-01

From a physiological standpoint, the lung volumes are either dynamic or static. Both subclasses are measured at different degrees of inspiration or expiration; however, dynamic lung volumes are characteristically dependent on the rate of air flow. The static lung volumes/capacities are further subdivided into four standard volumes (tidal, inspiratory reserve, expiratory reserve, and residual volumes) and four standard capacities (inspiratory, functional residual, vital and total lung capacities). The dynamic lung volumes are mostly derived from vital capacity. While dynamic lung volumes are essential for diagnosis and follow up of obstructive lung diseases, static lung volumes are equally important for evaluation of obstructive as well as restrictive ventilatory defects. This review intends to update the reader with the physiological basis, clinical significance and interpretative approaches of the standard static lung volumes and capacities.

Abnormal Pulmonary Function in Adults with Sickle Cell Anemia

PubMed Central

Klings, Elizabeth S.; Wyszynski, Diego F.; Nolan, Vikki G.; Steinberg, Martin H.

2006-01-01

Rationale: Pulmonary complications of sickle cell anemia (Hb-SS) commonly cause morbidity, yet few large studies of pulmonary function tests (PFTs) in this population have been reported. Objectives: PFTs (spirometry, lung volumes, and diffusion capacity for carbon monoxide [DLCO]) from 310 adults with Hb-SS were analyzed to determine the pattern of pulmonary dysfunction and their association with other systemic complications of sickle cell disease. Methods: Raw PFT data were compared with predicted values. Each subject was subclassified into one of five groups: obstructive physiology, restrictive physiology, mixed obstructive/restrictive physiology, isolated low DLCO, or normal. The association between laboratory data of patients with decreased DLCO or restrictive physiology and those of normal subjects was assessed by multivariate linear regression. Measurements and Main Results: Normal PFTs were present in only 31 of 310 (10%) patients. Overall, adults with Hb-SS were characterized by decreased total lung capacities (70.2 ± 14.7% predicted) and DlCO (64.5 ± 19.9%). The most common PFT patterns were restrictive physiology (74%) and isolated low DlCO (13%). Decreased DLCO was associated with thrombocytosis (p = 0.05), with hepatic dysfunction (elevated alanine aminotransferase; p = 0.07), and a trend toward renal dysfunction (elevated blood urea nitrogen and creatinine; p = 0.05 and 0.07, respectively). Conclusions: Pulmonary function is abnormal in 90% of adult patients with Hb-SS. Common abnormalities include restrictive physiology and decreased DLCO. Decreased DLCO may indicate more severe sickle vasculopathy characterized by impaired hepatic and renal function. PMID:16556694

A Physiological Signature of the Cost of Reproduction Associated with Parental Care.

PubMed

Fowler, Melinda A; Williams, Tony D

2017-12-01

Costs of reproduction are an integral and long-standing component of life-history theory, but we still know relatively little about the specific physiological mechanisms underlying these trade-offs. We experimentally manipulated workload during parental care in female European starlings (Sturnus vulgaris) using attachment of radios and/or wing clipping and assessed measures of workload, current breeding productivity, future fecundity, and survival (local return rate) in relation to treatment. Females with wing clipping and radio attachment paid a clear cost of reproduction compared with all other treatment groups: they had lower future fecundity and lower return rates despite having lower current breeding productivity. We then measured 13 physiological traits, including measures of aerobic/metabolic capacity, oxidative stress and muscle damage, intermediary metabolism and energy supply, and immune function. Our results show that the cost of reproduction in females with wing clipping and radio attachment was associated with lower oxygen-carrying capacity (lower hematocrit and hemoglobin levels), lower energy reserves (plasma nonesterified fatty acid and triglyceride levels), decreased immune function (lower haptoglobin levels), and elevated levels of oxidative stress (higher levels of dROMs [reactive oxygen metabolites] and lower levels of the endogenous antioxidant uric acid). Our study provides evidence that costs of reproduction involve a widespread decline in physiological function across multiple physiological systems consistent with long-standing ideas of cumulative "wear and tear" and allostatic load.

Physiological and Medical Aspects That Put Women Soldiers at Increased Risk for Overuse Injuries.

PubMed

Epstein, Yoram; Fleischmann, Chen; Yanovich, Ran; Heled, Yuval

2015-11-01

Anthropometric and physiological factors place female soldiers at a disadvantage relative to male soldiers in most aspects of physical performance. Average aerobic and anaerobic fitness levels are lower in women than in men. Thus, women have a lower overall work capacity and must exert themselves more than men to achieve the same output. The lower weight and fat-free mass and the higher body fat of women are associated with lower muscle strength and endurance, placing them at a disadvantage compared with men in performing military tasks such as lifting and carrying weights, or marching with a load. Working at a higher percentage of their maximal capacity to achieve the same performance levels as men, women tire earlier. Their smaller size, skeletal anatomy, and different bone geometry also predispose women to a higher incidence of exercise-related injuries. Consequently, the attrition rate of female soldiers in combat units is higher than that of their male counterparts. This review summarizes the literature on gender-related physiological and anatomical differences that put female soldiers at an increased risk of exercise-related injuries.

Physiological plasticity increases resilience of ectothermic animals to climate change

NASA Astrophysics Data System (ADS)

Seebacher, Frank; White, Craig R.; Franklin, Craig E.

2015-01-01

Understanding how climate change affects natural populations remains one of the greatest challenges for ecology and management of natural resources. Animals can remodel their physiology to compensate for the effects of temperature variation, and this physiological plasticity, or acclimation, can confer resilience to climate change. The current lack of a comprehensive analysis of the capacity for physiological plasticity across taxonomic groups and geographic regions, however, constrains predictions of the impacts of climate change. Here, we assembled the largest database to date to establish the current state of knowledge of physiological plasticity in ectothermic animals. We show that acclimation decreases the sensitivity to temperature and climate change of freshwater and marine animals, but less so in terrestrial animals. Animals from more stable environments have greater capacity for acclimation, and there is a significant trend showing that the capacity for thermal acclimation increases with decreasing latitude. Despite the capacity for acclimation, climate change over the past 20 years has already resulted in increased physiological rates of up to 20%, and we predict further future increases under climate change. The generality of these predictions is limited, however, because much of the world is drastically undersampled in the literature, and these undersampled regions are the areas of greatest need for future research efforts.

Physiological employment standards IV: integration of women in combat units physiological and medical considerations.

PubMed

Epstein, Yoram; Yanovich, Ran; Moran, Daniel S; Heled, Yuval

2013-11-01

Anthropometric and physiological factors place the average female soldier at a disadvantage relative to male soldiers in most aspects of physical performance. Aerobic and anaerobic fitness levels are lower in women than in men. Thus, women have a lower overall work capacity and must therefore exert themselves more than men to achieve the same output. The lower weight and fat-free mass and the higher body fat of women are associated with lower muscle strength and endurance, placing them at disadvantage compared with men in carrying out military tasks such as lifting and carrying weights or marching with a load. Working at a higher percentage of their maximal capacity to achieve the same performance levels as men, women tire earlier and are at increased risk of overuse injuries. Their smaller size, different bone geometry and lower bone strength also predispose women to a higher incidence of stress fractures. Although training in gender-integrated groups narrows the gaps in fitness, significant differences between the genders after basic training still remain. Nevertheless, integration of women into military combat professions is feasible in many cases. Some 'close combat roles' will still be an exception, mainly because of the extreme physical demands that are required in those units that are beyond the physiological adaptability capacities of an average female. There is no direct evidence that women have a negative impact on combat effectiveness. Once the gender differences are acknowledged and operational doctrines adjusted accordingly, female soldiers in mixed-gender units can meet the physical standards for the assigned missions.

Excess digestive capacity in predators reflects a life of feast and famine.

PubMed

Armstrong, Jonathan B; Schindler, Daniel E

2011-07-06

A central challenge for predators is achieving positive energy balance when prey are spatially and temporally heterogeneous. Ecological heterogeneity produces evolutionary trade-offs in the physiological design of predators; this is because the ability to capitalize on pulses of food abundance requires high capacity for food-processing, yet maintaining such capacity imposes energetic costs that are taxing during periods of food scarcity. Recent advances in physiology show that when variation in foraging opportunities is predictable, animals may adjust energetic trade-offs by rapidly modulating their digestive system to track variation in foraging opportunities. However, it is increasingly recognized that foraging opportunities for animals are unpredictable, which should favour animals that maintain a capacity for food-processing that exceeds average levels of consumption (loads). Despite this basic principle of quantitative evolutionary design, estimates of digestive load:capacity ratios in wild animals are virtually non-existent. Here we provide an extensive assessment of load:capacity ratios for the digestive systems of predators in the wild, compiling 639 estimates across 38 species of fish. We found that piscine predators typically maintain the physiological capacity to feed at daily rates 2-3 times higher than what they experience on average. A numerical simulation of the trade-off between food-processing capacity and metabolic cost suggests that the observed level of physiological opportunism is profitable only if predator-prey encounters, and thus predator energy budgets, are far more variable in nature than currently assumed.

Water consumption and water-saving characteristics of a ground cover rice production system

NASA Astrophysics Data System (ADS)

Jin, Xinxin; Zuo, Qiang; Ma, Wenwen; Li, Sen; Shi, Jianchu; Tao, Yueyue; Zhang, Yanan; Liu, Yang; Liu, Xiaofei; Lin, Shan; Ben-Gal, Alon

2016-09-01

The ground cover rice production system (GCRPS) offers a potentially water-saving alternative to the traditional paddy rice production system (TPRPS) by furrow irrigating mulched soil beds and maintaining soils under predominately unsaturated conditions. The guiding hypothesis of this study was that a GCRPS would decrease both physiological and non-physiological water consumption of rice compared to a TPRPS while either maintaining or enhancing production. This was tested in a two-year field experiment with three treatments (TPRPS, GCRPSsat keeping root zone average soil water content near saturated, and GCRPS80% keeping root zone average soil water content as 80-100% of field water capacity) and a greenhouse experiment with four treatments (TPRPS, GCRPSsat, GCRPSfwc keeping root zone average soil water content close to field water capacity, and GCRPS80%). The water-saving characteristics of GCRPS were analyzed as a function of the measured soil water conditions, plant parameters regarding growth and production, and water input and consumption. In the field experiment, significant reduction in both physiological and non-physiological water consumption under GCRPS lead to savings in irrigation water of ∼61-84% and reduction in total input water of ∼35-47%. Compared to TPRPS, deep drainage was reduced ∼72-88%, evaporation was lessened ∼83-89% and transpiration was limited ∼6-10% under GCRPS. In addition to saving water, plant growth and grain yield were enhanced under GCRPS due to increased soil temperature in the root zone. Therefore, water use efficiencies (WUEs), based on transpiration, irrigation and total input water, were respectively improved as much as 27%, 609% and 110% under GCRPS. Increased yield attributed to up to ∼19%, decreased deep drainage accounted for ∼75%, decreased evaporation accounted for ∼14% and reduced transpiration for ∼5% of the enhancement in WUE of input water under GCRPS, while increased runoff and water storage had negative influence on WUE (-7.5 and -3.7%, respectively) for GCRPS compared to TPRPS. The greenhouse experiment validated the results obtained in the field by simplifying the non-physiological water consumption processes, and thus confirming the relative importance of physiological processes and increased WUE under GCRPS.

Needle age and season influence photosynthetic temperature response and total annual carbon uptake in mature Picea mariana trees

DOE PAGES

Jensen, Anna M.; Warren, Jeffrey; Hanson, Paul J.; ...

2015-01-01

Using seasonal- and cohort-specific photosynthetic temperature response functions, we quantified the physiological significance of maintaining multiple foliar cohorts in mature (~40-45 year old) Picea mariana trees in an ombrotrophic Sphagnum-bog, northern Minnesota, USA. We measured photosynthetic capacity, foliar respiration (Rd), biochemistry and morphology to estimate annual carbon (C) uptake by cohort, season and canopy position. Temperature response of key photosynthetic parameters at 25 C (i.e., light-saturated rate of CO 2 assimilation (Asat), light-saturated rate of Rubisco carboxylation (Vcmax), light-saturated electron transport rate (Jmax)) were clearly dependent on season and were generally less responsive in younger needles. Temperature optimums range betweenmore » 18.7-23.7, 31.3-38.3 and 28.7-36.7 C for Asat, Vcmax and Jmax respectively. Current-year (Y0) foliage had lower photosynthetic capacities compared to one-year-old (Y1) and two-year-old (Y2) foliage. As Y0 needles matured, values of Asat, Vcmax, Jmax, foliar LMA and nitrogen increased. Values of Vcmax, Jmax and Rd were related to foliar nitrogen but only in the youngest (Y0) cohort. Foliar ontogeny affected photosynthetic capacity more than growth temperature. Morphological and physiological cohort differences were reflected by their annual contribution to modeled C uptake, with a ~36% lower estimated annual C uptake by Y0 needles (LAI 0.52 m 2m -2) compared to Y1&2 cohorts (LAI 0.67 m 2m -2). Collectively, these results illustrate the physiological and ecological significance of characterizing multiple foliar cohorts during bud break and throughout the growth season, and for cumulative C uptake model estimates.« less

Cenozoic climate change shaped the evolutionary ecophysiology of the Cupressaceae conifers

PubMed Central

Pittermann, Jarmila; Stuart, Stephanie A.; Dawson, Todd E.; Moreau, Astrid

2012-01-01

The Cupressaceae clade has the broadest diversity in habitat and morphology of any conifer family. This clade is characterized by highly divergent physiological strategies, with deciduous swamp-adapted genera-like Taxodium at one extreme, and evergreen desert genera-like Cupressus at the other. The size disparity within the Cupressaceae is equally impressive, with members ranging from 5-m-tall juniper shrubs to 100-m-tall redwood trees. Phylogenetic studies demonstrate that despite this variation, these taxa all share a single common ancestor; by extension, they also share a common ancestral habitat. Here, we use a common-garden approach to compare xylem and leaf-level physiology in this family. We then apply comparative phylogenetic methods to infer how Cenozoic climatic change shaped the morphological and physiological differences between modern-day members of the Cupressaceae. Our data show that drought-resistant crown clades (the Cupressoid and Callitroid clades) most likely evolved from drought-intolerant Mesozoic ancestors, and that this pattern is consistent with proposed shifts in post-Eocene paleoclimates. We also provide evidence that within the Cupressaceae, the evolution of drought-resistant xylem is coupled to increased carbon investment in xylem tissue, reduced xylem transport efficiency, and at the leaf level, reduced photosynthetic capacity. Phylogenetically based analyses suggest that the ancestors of the Cupressaceae were dependent upon moist habitats, and that drought-resistant physiology developed along with increasing habitat aridity from the Oligocene onward. We conclude that the modern biogeography of the Cupressaceae conifers was shaped in large part by their capacity to adapt to drought. PMID:22628565

Cenozoic climate change shaped the evolutionary ecophysiology of the Cupressaceae conifers.

PubMed

Pittermann, Jarmila; Stuart, Stephanie A; Dawson, Todd E; Moreau, Astrid

2012-06-12

The Cupressaceae clade has the broadest diversity in habitat and morphology of any conifer family. This clade is characterized by highly divergent physiological strategies, with deciduous swamp-adapted genera-like Taxodium at one extreme, and evergreen desert genera-like Cupressus at the other. The size disparity within the Cupressaceae is equally impressive, with members ranging from 5-m-tall juniper shrubs to 100-m-tall redwood trees. Phylogenetic studies demonstrate that despite this variation, these taxa all share a single common ancestor; by extension, they also share a common ancestral habitat. Here, we use a common-garden approach to compare xylem and leaf-level physiology in this family. We then apply comparative phylogenetic methods to infer how Cenozoic climatic change shaped the morphological and physiological differences between modern-day members of the Cupressaceae. Our data show that drought-resistant crown clades (the Cupressoid and Callitroid clades) most likely evolved from drought-intolerant Mesozoic ancestors, and that this pattern is consistent with proposed shifts in post-Eocene paleoclimates. We also provide evidence that within the Cupressaceae, the evolution of drought-resistant xylem is coupled to increased carbon investment in xylem tissue, reduced xylem transport efficiency, and at the leaf level, reduced photosynthetic capacity. Phylogenetically based analyses suggest that the ancestors of the Cupressaceae were dependent upon moist habitats, and that drought-resistant physiology developed along with increasing habitat aridity from the Oligocene onward. We conclude that the modern biogeography of the Cupressaceae conifers was shaped in large part by their capacity to adapt to drought.

Anthropometric and physiological predispositions for elite soccer.

PubMed

Reilly, T; Bangsbo, J; Franks, A

2000-09-01

This review is focused on anthropometric and physiological characteristics of soccer players with a view to establishing their roles within talent detection, identification and development programmes. Top-class soccer players have to adapt to the physical demands of the game, which are multifactorial. Players may not need to have an extraordinary capacity within any of the areas of physical performance but must possess a reasonably high level within all areas. This explains why there are marked individual differences in anthropometric and physiological characteristics among top players. Various measurements have been used to evaluate specific aspects of the physical performance of both youth and adult soccer players. The positional role of a player is related to his or her physiological capacity. Thus, midfield players and full-backs have the highest maximal oxygen intakes ( > 60 ml x kg(-1) x min(-1)) and perform best in intermittent exercise tests. On the other hand, midfield players tend to have the lowest muscle strength. Although these distinctions are evident in adult and elite youth players, their existence must be interpreted circumspectly in talent identification and development programmes. A range of relevant anthropometric and physiological factors can be considered which are subject to strong genetic influences (e.g. stature and maximal oxygen intake) or are largely environmentally determined and susceptible to training effects. Consequently, fitness profiling can generate a useful database against which talented groups may be compared. No single method allows for a representative assessment of a player's physical capabilities for soccer. We conclude that anthropometric and physiological criteria do have a role as part of a holistic monitoring of talented young players.

p53 improves aerobic exercise capacity and augments skeletal muscle mitochondrial DNA content.

PubMed

Park, Joon-Young; Wang, Ping-Yuan; Matsumoto, Takumi; Sung, Ho Joong; Ma, Wenzhe; Choi, Jeong W; Anderson, Stasia A; Leary, Scot C; Balaban, Robert S; Kang, Ju-Gyeong; Hwang, Paul M

2009-09-25

Exercise capacity is a physiological characteristic associated with protection from both cardiovascular and all-cause mortality. p53 regulates mitochondrial function and its deletion markedly diminishes exercise capacity, but the underlying genetic mechanism orchestrating this is unclear. Understanding the biology of how p53 improves exercise capacity may provide useful insights for improving both cardiovascular as well as general health. The purpose of this study was to understand the genetic mechanism by which p53 regulates aerobic exercise capacity. Using a variety of physiological, metabolic, and molecular techniques, we further characterized maximum exercise capacity and the effects of training, measured various nonmitochondrial and mitochondrial determinants of exercise capacity, and examined putative regulators of mitochondrial biogenesis. As p53 did not affect baseline cardiac function or inotropic reserve, we focused on the involvement of skeletal muscle and now report a wider role for p53 in modulating skeletal muscle mitochondrial function. p53 interacts with Mitochondrial Transcription Factor A (TFAM), a nuclear-encoded gene important for mitochondrial DNA (mtDNA) transcription and maintenance, and regulates mtDNA content. The increased mtDNA in p53(+/+) compared to p53(-/-) mice was more marked in aerobic versus glycolytic skeletal muscle groups with no significant changes in cardiac tissue. These in vivo observations were further supported by in vitro studies showing overexpression of p53 in mouse myoblasts increases both TFAM and mtDNA levels whereas depletion of TFAM by shRNA decreases mtDNA content. Our current findings indicate that p53 promotes aerobic metabolism and exercise capacity by using different mitochondrial genes and mechanisms in a tissue-specific manner.

Comparative genomic analysis as a tool for biologicaldiscovery

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

Nobrega, Marcelo A.; Pennacchio, Len A.

2003-03-30

Biology is a discipline rooted in comparisons. Comparative physiology has assembled a detailed catalogue of the biological similarities and differences between species, revealing insights into how life has adapted to fill a wide-range of environmental niches. For example, the oxygen and carbon dioxide carrying capacity of vertebrate has evolved to provide strong advantages for species respiring at sea level, at high elevation or within water. Comparative- anatomy, -biochemistry, -pharmacology, -immunology and -cell biology have provided the fundamental paradigms from which each discipline has grown.

The energy expenditure of normal and pathologic gait.

PubMed

Waters, R L; Mulroy, S

1999-07-01

Physiological energy expenditure measurement has proven to be a reliable method of quantitatively assessing the penalties imposed by gait disability. The purpose of this review is to outline the basic principles of exercise physiology relevant to human locomotion; detail the energy expenditure of normal walking; and summarize the results of energy expenditure studies performed in patients with specific neurologic and orthopedic disabilities. The magnitude of the disabilities and the patients' capacity to tolerate the increased energy requirements are compared. This paper also will examine the effectiveness of rehabilitation interventions at mitigating the energetic penalties of disability during ambulation.

Artificial light pollution: Shifting spectral wavelengths to mitigate physiological and health consequences in a nocturnal marsupial mammal.

PubMed

Dimovski, Alicia M; Robert, Kylie A

2018-05-02

The focus of sustainable lighting tends to be on reduced CO 2 emissions and cost savings, but not on the wider environmental effects. Ironically, the introduction of energy-efficient lighting, such as light emitting diodes (LEDs), may be having a great impact on the health of wildlife. These white LEDs are generated with a high content of short-wavelength 'blue' light. While light of any kind can suppress melatonin and the physiological processes it regulates, these short wavelengths are potent suppressors of melatonin. Here, we manipulated the spectral composition of LED lights and tested their capacity to mitigate the physiological and health consequences associated with their use. We experimentally investigated the impact of white LEDs (peak wavelength 448 nm; mean irradiance 2.87 W/m 2 ), long-wavelength shifted amber LEDs (peak wavelength 605 nm; mean irradiance 2.00 W/m 2 ), and no lighting (irradiance from sky glow < 0.37 × 10 -3 W/m 2 ), on melatonin production, lipid peroxidation, and circulating antioxidant capacity in the tammar wallaby (Macropus eugenii). Night-time melatonin and oxidative status were determined at baseline and again following 10 weeks exposure to light treatments. White LED exposed wallabies had significantly suppressed nocturnal melatonin compared to no light and amber LED exposed wallabies, while there was no difference in lipid peroxidation. Antioxidant capacity declined from baseline to week 10 under all treatments. These results provide further evidence that short-wavelength light at night is a potent suppressor of nocturnal melatonin. Importantly, we also illustrate that shifting the spectral output to longer wavelengths could mitigate these negative physiological impacts. © 2018 Wiley Periodicals, Inc.

Physiological response during activity programs using Wii-based video games in patients with cystic fibrosis (CF).

PubMed

del Corral, Tamara; Percegona, Janaína; Seborga, Melisa; Rabinovich, Roberto A; Vilaró, Jordi

2014-12-01

Patients with cystic fibrosis (CF) are characterized by an abnormal ventilation response that limits the exercise capacity. Exercise training increases exercise capacity, decreases dyspnea and improves health-related quality of life in CF. Adherence to pulmonary rehabilitation programs is a key factor to guarantee optimal benefits and a difficult goal in this population. The aim of this study was to determine the physiological response during three Nintendo Wii™ video game activities (VGA) candidates to be used as training modalities in patients with CF. 24 CF patients (age 12.6±3.7 years; BMI 18.8±2.9kgm(-2); FEV1 93.8±18.8%pred) were included. All participants performed, on two separate days, 3 different VGA: 1) Wii Fit Plus (Wii-Fit); 2) Wii Active (Wii-Acti), and 3) Wii Family Trainer (Wii-Train), in random order during 5min. The obtained results were compared with the 6-min walk test (6MWT). The physiological variables [oxygen uptake (VO2), minute ventilation (VE), and heart rate (HR)] were recorded using a portable metabolic analyzer. During all VGA and 6MWT, VO2 reached a plateau from the 3rd min. Compared with the 6MWT (1024.2±282.2mLm(-1)), Wii-Acti (1232.2±427.2mLm(-1)) and Wii-Train (1252.6±360.2mLm(-1)) reached higher VO2 levels during the last 3min (p<0.0001 in both cases), while Wii-Fit (553.8±113.2mLm(-1)) reached significantly lower levels of VO2 (p<0.001). Similar effects were seen for the ventilatory volume (VE). No differences in dyspnea and oxygen saturation were seen between the different modalities. All patients were compliant with all three Wii™ modalities. Active video game are well tolerated by patients with CF. All the modalities evaluated imposed a constant load but were associated with different physiological responses reflecting the different intensities imposed. Wii-Acti and Wii-Train impose a significantly high metabolic demand comparable to the 6MWT. Further research is needed to evaluate the effects of VGA as a training program to increase exercise capacity for CF patients. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Metabolic scope and interspecific competition in sculpins of Greenland are influenced by increased temperatures due to climate change.

PubMed

Seth, Henrik; Gräns, Albin; Sandblom, Erik; Olsson, Catharina; Wiklander, Kerstin; Johnsson, Jörgen I; Axelsson, Michael

2013-01-01

Ongoing climate change has led to an increase in sea surface temperatures of 2-4°C on the west coast of Greenland. Since fish are ectothermic, metabolic rate increases with ambient temperature. This makes these animals particularly sensitive to changes in temperature; subsequently any change may influence their metabolic scope, i.e. the physiological capacity to undertake aerobically challenging activities. Any temperature increase may thus disrupt species-specific temperature adaptations, at both the molecular level as well as in behavior, and concomitant species differences in the temperature sensitivity may shift the competitive balance among coexisting species. We investigated the influence of temperature on metabolic scope and competitive ability in three species of marine sculpin that coexist in Greenland coastal waters. Since these species have different distribution ranges, we hypothesized that there should be a difference in their physiological response to temperature; hence we compared their metabolic scope at three temperatures (4, 9 and 14°C). Their competitive ability at the ambient temperature of 9°C was also tested in an attempt to link physiological capacity with behaviour. The Arctic staghorn sculpin, the species with the northernmost distribution range, had a lower metabolic scope in the higher temperature range compared to the other two species, which had similar metabolic scope at the three temperatures. The Arctic staghorn sculpin also had reduced competitive ability at 9°C and may thus already be negatively affected by the current ocean warming. Our results suggest that climate change can have effects on fish physiology and interspecific competition, which may alter the species composition of the Arctic fish fauna.

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

PubMed

Calfapietra, Carlo; Peñuelas, Josep; Niinemets, Ülo

2015-02-01

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

Reduced swimming performance repeatedly evolves upon loss of migration in landlocked populations of Alewife

USGS Publications Warehouse

Velotta, Jonathan P.; McCormick, Stephen; Jones, Andrew W.; Schultz, Eric T.

2018-01-01

Whole-organism performance tasks are accomplished by the integration of morphological traits and physiological functions. Understanding how evolutionary change in morphology and physiology influences whole-organism performance will yield insight into the factors that shape its own evolution. We demonstrate that nonmigratory populations of alewife (Alosa pseudoharengus) have evolved reduced swimming performance in parallel, compared with their migratory ancestor. In contrast to theoretically and empirically based predictions, poor swimming among nonmigratory populations is unrelated to the evolution of osmoregulation and occurs despite the fact that nonmigratory alewives have a more fusiform (torpedo-like) body shape than their ancestor. Our results suggest that elimination of long-distance migration from the life cycle has shaped performance more than changes in body shape and physiological regulatory capacity.

Interannual physiological and growth responses of glacial Juniperus to changes in atmospheric [CO2] since the Last Glacial Maximum

NASA Astrophysics Data System (ADS)

Gerhart, L. M.; Harris, J. M.; Ward, J. K.

2011-12-01

During the Last Glacial Maximum, atmospheric [CO2] was as low as 180 ppm and has currently risen to a modern value of 393 ppm as a result of fossil fuel combustion and deforestation. In order to understand how changing [CO2] influenced trees over the last 50,000 years, we analyzed carbon isotope ratios and width of individual tree rings from glacial Juniperus specimens preserved in the Rancho La Brea tar pits in southern California (aged 14-49 kyr BP). Modern trees were also analyzed to compare effects of changing precipitation, temperature and atmospheric [CO2] on physiology and growth. To assess physiological responses, we calculated ci/ca (intercellular [CO2]/atmospheric [CO2]) for each annual ring of each tree. This ratio incorporates numerous aspects of plant physiology, including stomatal conductance and photosynthetic capacity. In addition, we measured ring widths for each sample, and standardized these measurements into indices in order to compare across individuals. Mean ci/ca values remained constant throughout 50,000 years despite major environmental changes, indicating a long-term physiological set point for ci/ca in this group. Constant ci/ca ratios would be maintained through offsetting changes in stomatal conductance and photosynthetic capacity. Glacial Juniperus never experienced ci values below 90 ppm, suggesting a survival compensation point for Juniperus. In addition, glacial trees showed significantly reduced interannual variation in ci/ca, even though interannual climatic variability was as high during the LGM in this region as it is today. A lack of variability in ci/ca of glacial trees suggests that tree physiology was dominated by low [CO2], which shows low interannual variation. Modern trees showed high interannual variation in ci/ca, since water availability dominates current physiological responses and varies greatly from year to year. Interestingly, interannual variation in ring width index did not show significant differences between glacial and modern trees, suggesting these trees were adapted to maintain growth under low [CO2]. These adaptations may constrain the ability of modern trees to fully utilize increases in atmospheric [CO2]. These results have significant implications for our understanding of the adaptations of trees to changing [CO2] and indicate that the environmental factors that most strongly influence plant physiology may have changed over geologic time scales.

Comparative physiology and relative swimming performance of three redhorse (Moxostoma spp.) species: associations with fishway passage success.

PubMed

Hatry, Charles; Thiem, Jason D; Binder, Thomas R; Hatin, Daniel; Dumont, Pierre; Stamplecoskie, Keith M; Molina, Juan M; Smokorowski, Karen E; Cooke, Steven J

2014-01-01

Our understanding of biological criteria to inform fish passage design is limited, partially due to the lack of understanding of biological motivators, cues, and constraints, as well as a lack of biological performance evaluations of structures once they are built. The Vianney-Legendre vertical slot fishway on the Richelieu River, Quebec, Canada, passes large numbers of migrating redhorse (Moxostoma spp.) upriver to spawning grounds each year. We evaluated the physiological capacity and relative swimming ability of three redhorse species (Moxostoma anisurum, Moxostoma carinatum, Moxostoma macrolepidotum; silver, river, and shorthead redhorse, respectively) to determine how these biotic factors relate to variation in fishway passage success and duration. Shorthead redhorse had higher maximum metabolic rates and were faster swimmers than silver and river redhorse at their species-specific peak migration temperatures. Blood lactate and glucose concentrations recovered more quickly for river redhorse than for silver and shorthead redhorse, and river redhorse placed second in terms of metabolic recovery and swim speed. Interestingly, fish sampled from the top of the fishway had nearly identical lactate, glucose, and pH values compared to control fish. Using passive integrated transponders in 2010 and 2012, we observed that passage success and duration were highly variable among redhorse species and were not consistent among years, suggesting that other factors such as water temperature and river flows may modulate passage success. Clearly, additional research is needed to understand how organismal performance, environmental conditions, and other factors (including abundance of conspecifics and other comigrants) interact with fishway features to dictate which fish will be successful and to inform research of future fishways. Our research suggests that there may be an opportunity for a rapid assessment approach where fish chased to exhaustion to determine maximal values of physiological disturbance are compared to fish sampled from the top of the fishway, which could reveal which species (or sizes of fish) are approaching or exceeding their physiological capacity during passage.

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

PubMed

MacInnis, Martin J; Gibala, Martin J

2017-05-01

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

Web-Based Mindfulness Intervention in Heart Disease: A Randomized Controlled Trial

PubMed Central

Younge, John O.; Wery, Machteld F.; Gotink, Rinske A.; Utens, Elisabeth M. W. J.; Michels, Michelle; Rizopoulos, Dimitris; van Rossum, Elisabeth F. C.

2015-01-01

Background Evidence is accumulating that mindfulness training has favorable effects on psychological outcomes, but studies on physiological outcomes are limited. Patients with heart disease have a high incidence of physiological and psychological problems and may benefit from mindfulness training. Our aim was to determine the beneficial physiological and psychological effects of online mindfulness training in patients with heart disease. Methods The study was a pragmatic randomized controlled single-blind trial. Between June 2012 and April 2014 we randomized 324 patients (mean age 43.2 years, 53.7% male) with heart disease in a 2:1 ratio (n = 215 versus n = 109) to a 12-week online mindfulness training in addition to usual care (UC) compared to UC alone. The primary outcome was exercise capacity measured with the 6 minute walk test (6MWT). Secondary outcomes were other physiological parameters (heart rate, blood pressure, respiratory rate, and NT-proBNP), subjective health status (SF-36), perceived stress (PSS), psychological well-being (HADS), social support (PSSS12) and a composite endpoint (all-cause mortality, heart failure, symptomatic arrhythmia, cardiac surgery, and percutaneous cardiac intervention). Linear mixed models were used to evaluate differences between groups on the repeated outcome measures. Results Compared to UC, mindfulness showed a borderline significant improved 6MWT (effect size, meters: 13.2, 95%CI: -0.02; 26.4, p = 0.050). There was also a significant lower heart rate in favor of the mindfulness group (effect size, beats per minute: -2.8, 95%CI: -5.4;-0.2, p = 0.033). No significant differences were seen on other outcomes. Conclusions Mindfulness training showed positive effects on the physiological parameters exercise capacity and heart rate and it might therefore be a useful adjunct to current clinical therapy in patients with heart disease. Trial Registration Dutch Trial Register 3453 PMID:26641099

Student Responses to a Hands-On Kinesthetic Lecture Activity for Learning about the Oxygen Carrying Capacity of Blood

ERIC Educational Resources Information Center

Breckler, Jennifer; Yu, Justin R.

2011-01-01

This article describes a new hands-on, or "kinesthetic," activity for use in a physiology lecture hall to help students comprehend an important concept in cardiopulmonary physiology known as oxygen carrying capacity. One impetus for designing this activity was to address the needs of students who have a preference for kinesthetic…

The Mask of Sanity: Facial Expressive, Self-Reported, and Physiological Consequences of Emotion Regulation in Psychopathic Offenders.

PubMed

Nentjes, Lieke; Bernstein, David P; Meijer, Ewout; Arntz, Arnoud; Wiers, Reinout W

2016-12-01

This study investigated the physiological, self-reported, and facial correlates of emotion regulation in psychopathy. Specifically, we compared psychopathic offenders (n = 42), nonpsychopathic offenders (n = 42), and nonoffender controls (n = 26) in their ability to inhibit and express emotion while watching affective films (fear, happy, and sad). Results showed that all participants were capable of drastically diminishing facial emotions under inhibition instructions. Contrary to expectation, psychopaths were not superior in adopting such a "poker face." Further, the inhibition of emotion was associated with cardiovascular changes, an effect that was also not dependent on psychopathy (or its factors), suggesting emotion inhibition to be an effortful process in psychopaths as well. Interestingly, psychopathic offenders did not differ from nonpsychopaths in the capacity to show content-appropriate facial emotions during the expression condition. Taken together, these data challenge the view that psychopathy is associated with either superior emotional inhibitory capacities or a generalized impairment in showing facial affect.

Learning by heart-the relationship between resting vagal tone and metacognitive judgments: a pilot study.

PubMed

Meessen, Judith; Sütterlin, Stefan; Gauggel, Siegfried; Forkmann, Thomas

2018-05-23

Metacognitive awareness and resting vagally mediated heart rate variability (HRV) as a physiological trait marker of cognitive inhibitory control capacities are both associated with better well-being and seem to share a common neural basis. Executive functioning which is considered a prerequisite for delivering prospective metacognitive judgments has been found to be correlated with HRV. This pilot study addresses the question, whether metacognitive awareness and resting vagally mediated HRV are positively associated. A sample of 20 healthy participants was analyzed that completed a typical Judgment of Learning task after an electrocardiogram had been recorded. The root-mean-squares of successive differences were used to calculate vagally mediated HRV. Metacognitive awareness was measured by comparing the judgments of learning with the actual memory performance, yielding a deviation score. HRV was found to be positively correlated with metacognitive awareness. Results suggest that metacognitive abilities might relate to physiological trait markers of cognitive inhibitory control capacities. Further experimental studies are needed to investigate causal relations.

An assessment of anti-schistosomal treatment on physical work capacity.

PubMed

Awad El Karim, M A; Collins, K J; Sukkar, M Y; Omer, A H; Amin, M A; Doré, C

1981-04-01

Acting as their own controls, village subjects from the Gezira are of the Sudan with relatively high levels of schistosomiasis infection were first tested in an exercise laboratory in Khartoum and the tests were then repeated after a period of about 1 yr during which time the subjects were treated with hycanthone and periodically monitored to ensure that they had remained free of the disease. In the meantime they were also given anti-malarial prophylaxis. Laboratory tests showed a significant improvement in physiological work capacity of up to 20% after treatment compared with untreated controls. An overall improvement in pulmonary function, particularly forced vital capacity, was observed as well as a significant increase in mean haemoglobin concentration by 1.1 g/100 ml of blood in the treated group. Apart from these improvements in physical working capacity, the treated subjects subjectively felt better after the exercise tests, as expressed by the disappearance of fatiguability.

[Individual physical performance capacity with physiological and biochemical indicators of stress].

PubMed

Bergert, K D; Nestler, K; Böttger, H; Schettler, R

1989-09-01

22 health male subjects were exposed by a combination of physical exercises and heat. Strain related physiological and biochemical parameters were measured. Different individual reactions were obtained under controlled conditions. In dependence on the individual performance an increased mobilisation of lactat, free fatty acids and catecholamines were found. The determination of aerob physical performance can be applied for the evaluation of working capacity.

Comparative nutrient digestibility of arctic foxes (Alopex lagopus) on Svalbard and farm-raised blue foxes (Alopex lagopus).

PubMed

Ahlstrøm, Øystein; Fuglei, Eva; Mydland, Liv Torunn

2003-01-01

Arctic foxes from Svalbard (n=4) and farmed blue foxes (n=4) was used in a digestibility experiment with a high-carbohydrate feed to add more information to the nutritional physiology of the arctic fox, and to compare its digestive capacity with that of the farmed blue fox. The arctic fox has a diet containing mainly protein and fat from mammals and birds, while farmed blue foxes have been exposed to an omnivorous dietary regime for more than 80 generations. The experiment showed in general no difference in digestive capacity for protein and fat between the foxes (P>0.05), but for carbohydrates, including starch and glucose, the blue fox revealed higher digestibility values. The superior digestive capacity for carbohydrates in blue fox might be a result of a long-term selection of animals digesting dietary carbohydrates more efficiently, or that an early age exposition to dietary carbohydrates has given permanent improvement of the carbohydrate digestion in the gut.

Physiological constraints to climate warming in fish follow principles of plastic floors and concrete ceilings.

PubMed

Sandblom, Erik; Clark, Timothy D; Gräns, Albin; Ekström, Andreas; Brijs, Jeroen; Sundström, L Fredrik; Odelström, Anne; Adill, Anders; Aho, Teija; Jutfelt, Fredrik

2016-05-17

Understanding the resilience of aquatic ectothermic animals to climate warming has been hindered by the absence of experimental systems experiencing warming across relevant timescales (for example, decades). Here, we examine European perch (Perca fluviatilis, L.) from the Biotest enclosure, a unique coastal ecosystem that maintains natural thermal fluctuations but has been warmed by 5-10 °C by a nuclear power plant for over three decades. We show that Biotest perch grow faster and display thermally compensated resting cardiorespiratory functions compared with reference perch living at natural temperatures in adjacent waters. However, maximum cardiorespiratory capacities and heat tolerance limits exhibit limited or no thermal compensation when compared with acutely heated reference perch. We propose that while basal energy requirements and resting cardiorespiratory functions (floors) are thermally plastic, maximum capacities and upper critical heat limits (ceilings) are much less flexible and thus will limit the adaptive capacity of fishes in a warming climate.

Oxidative Stress Induces Mitochondrial Dysfunction in a Subset of Autism Lymphoblastoid Cell Lines in a Well-Matched Case Control Cohort

PubMed Central

Rose, Shannon; Frye, Richard E.; Slattery, John; Wynne, Rebecca; Tippett, Marie; Pavliv, Oleksandra; Melnyk, Stepan; James, S. Jill

2014-01-01

There is increasing recognition that mitochondrial dysfunction is associated with the autism spectrum disorders. However, little attention has been given to the etiology of mitochondrial dysfunction or how mitochondrial abnormalities might interact with other physiological disturbances associated with autism, such as oxidative stress. In the current study we used respirometry to examine reserve capacity, a measure of the mitochondrial ability to respond to physiological stress, in lymphoblastoid cell lines (LCLs) derived from children with autistic disorder (AD) as well as age and gender-matched control LCLs. We demonstrate, for the first time, that LCLs derived from children with AD have an abnormal mitochondrial reserve capacity before and after exposure to increasingly higher concentrations of 2,3-dimethoxy-1,4-napthoquinone (DMNQ), an agent that increases intracellular reactive oxygen species (ROS). Specifically, the AD LCLs exhibit a higher reserve capacity at baseline and a sharper depletion of reserve capacity when ROS exposure is increased, as compared to control LCLs. Detailed investigation indicated that reserve capacity abnormalities seen in AD LCLs were the result of higher ATP-linked respiration and maximal respiratory capacity at baseline combined with a marked increase in proton leak respiration as ROS was increased. We further demonstrate that these reserve capacity abnormalities are driven by a subgroup of eight (32%) of 25 AD LCLs. Additional investigation of this subgroup of AD LCLs with reserve capacity abnormalities revealed that it demonstrated a greater reliance on glycolysis and on uncoupling protein 2 to regulate oxidative stress at the inner mitochondria membrane. This study suggests that a significant subgroup of AD children may have alterations in mitochondrial function which could render them more vulnerable to a pro-oxidant microenvironment derived from intrinsic and extrinsic sources of ROS such as immune activation and pro-oxidant environmental toxicants. These findings are consistent with the notion that AD is caused by a combination of genetic and environmental factors. PMID:24416410

Micro-reaction chamber electrodes for neural stimulation and recording.

PubMed

Shanmugasundaram, Balaji; Gluckman, Bruce J

2011-01-01

Biocompatible electrodes with smaller geometric area are preferred to improve the selectivity of the neural recording and stimulation applications. We introduce the concept of a micro-reaction chamber (μRC) in which a volume within the electrode back plane is used to confine and sequester the electrochemical reactions used for charge passage. The URC electrode design helps decrease impedance and improves the charge storage capacity without altering the geometry of the active site. Here we demonstrate that μRC electrodes fabricated from 50 μm diameter microwire have significantly improved charge storage capacity and lowered impedance at physiologically relevant frequencies in phosphate buffered saline solution compared with other designs.

High but not dry: diverse epiphytic bromeliad adaptations to exposure within a seasonally dry tropical forest community.

PubMed

Reyes-García, C; Mejia-Chang, M; Griffiths, H

2012-02-01

• Vascular epiphytes have developed distinct lifeforms to maximize water uptake and storage, particularly when delivered as pulses of precipitation, dewfall or fog. The seasonally dry forest of Chamela, Mexico, has a community of epiphytic bromeliads with Crassulacean acid metabolism showing diverse morphologies and stratification within the canopy. We hypothesize that niche differentiation may be related to the capacity to use fog and dew effectively to perform photosynthesis and to maintain water status. • Four Tillandsia species with either 'tank' or 'atmospheric' lifeforms were studied using seasonal field data and glasshouse experimentation, and compared on the basis of water use, leaf water δ(18) O, photosynthetic and morphological traits. • The atmospheric species, Tillandsia eistetteri, with narrow leaves and the lowest succulence, was restricted to the upper canopy, but displayed the widest range of physiological responses to pulses of precipitation and fog, and was a fog-catching 'nebulophyte'. The other atmospheric species, Tillandsia intermedia, was highly succulent, restricted to the lower canopy and with a narrower range of physiological responses. Both upper canopy tank species relied on tank water and stomatal closure to avoid desiccation. • Niche differentiation was related to capacity for water storage, dependence on fog or dewfall and physiological plasticity. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

Applied physiology of triathlon.

PubMed

O'Toole, M L; Douglas, P S

1995-04-01

The triathlon is a 3-event endurance sport in which athletes compete sequentially in swimming, cycling and running. The primary determinant of success is the ability to sustain a high rate of energy expenditure for prolonged periods of time. Exercise training-induced physiological adaptations in virtually all systems of the body allow the athlete to accomplish this. Aerobic capacity (measured as maximal oxygen uptake, VO2max), economy of motion (submaximal VO2) and fractional utilisation of maximal capacity (%VO2max) reflect the integrated responses of these physiological adaptations. Numerous studies have reported relatively high mean VO2max values for various groups of triathletes that are comparable to those reported for athletes in single-event endurance sports and clearly above those reported for untrained individuals. In shorter distance triathlons and in studies using recreational (rather than elite) triathletes, VO2max is related to performance in the corresponding event of the triathlon (e.g. tethered swimming VO2max with swim time). In longer events and with more elite triathletes, VO2max correlates less well with performance. The physiological adaptations that correspond to and facilitate improved VO2max occur centrally in the cardiovascular system, centred on increased maximal cardiac output, and peripherally in the metabolic systems, centred around increased arterio-venous O2 (a-v O2) difference. While a high VO2max in individuals is clearly of importance to triathlon performance, energy output must be sustained for long periods of time, making economy of motion also very important. Studies suggests that competitive swimmers have better swimming economy than triathletes. However, since many triathletes have previously been competitive swimmers this finding is questionable. The finding suggests that triathletes from nonswimming backgrounds would benefit from improving swimming technique rather than concentrating training workouts solely on distance. In cycling and running, comparison studies have not been done. Economy of motion in swimming, cycling and running have all been found to be correlated with comparable event performance. Training to improve swimming economy can be done without prior exercise, but training to improve swimming economy can be done without prior exercise, but training to improve cycling and running economy should take the multimode nature of a triathlon into consideration. That is, swimming should precede cycling economy training, and cycling should precede running economy training. Cardiovascular, metabolic and neuromuscular adaptations are the main physiological correlates of improved movement economy. Since exercise-induced stress on most physiological systems is based on relative, rather than absolute, exercise intensity, training and racing intensities are frequently quantified as a percentage of maximal capacity of %VO2max.(ABSTRACT TRUNCATED AT 400 WORDS)

The western painted turtle genome, a model for the evolution of extreme physiological adaptations in a slowly evolving lineage

PubMed Central

2013-01-01

Background We describe the genome of the western painted turtle, Chrysemys picta bellii, one of the most widespread, abundant, and well-studied turtles. We place the genome into a comparative evolutionary context, and focus on genomic features associated with tooth loss, immune function, longevity, sex differentiation and determination, and the species' physiological capacities to withstand extreme anoxia and tissue freezing. Results Our phylogenetic analyses confirm that turtles are the sister group to living archosaurs, and demonstrate an extraordinarily slow rate of sequence evolution in the painted turtle. The ability of the painted turtle to withstand complete anoxia and partial freezing appears to be associated with common vertebrate gene networks, and we identify candidate genes for future functional analyses. Tooth loss shares a common pattern of pseudogenization and degradation of tooth-specific genes with birds, although the rate of accumulation of mutations is much slower in the painted turtle. Genes associated with sex differentiation generally reflect phylogeny rather than convergence in sex determination functionality. Among gene families that demonstrate exceptional expansions or show signatures of strong natural selection, immune function and musculoskeletal patterning genes are consistently over-represented. Conclusions Our comparative genomic analyses indicate that common vertebrate regulatory networks, some of which have analogs in human diseases, are often involved in the western painted turtle's extraordinary physiological capacities. As these regulatory pathways are analyzed at the functional level, the painted turtle may offer important insights into the management of a number of human health disorders. PMID:23537068

Physiological and Biomechanical Mechanisms of Distance Specific Human Running Performance.

PubMed

Thompson, M A

2017-08-01

Running events range from 60-m sprints to ultra-marathons covering 100 miles or more, which presents an interesting diversity in terms of the parameters for successful performance. Here, we review the physiological and biomechanical variations underlying elite human running performance in sprint to ultramarathon distances. Maximal running speeds observed in sprint disciplines are achieved by high vertical ground reaction forces applied over short contact times. To create this high force output, sprint events rely heavily on anaerobic metabolism, as well as a high number and large cross-sectional area of type II fibers in the leg muscles. Middle distance running performance is characterized by intermediates of biomechanical and physiological parameters, with the possibility of unique combinations of each leading to high-level performance. The relatively fast velocities in mid-distance events require a high mechanical power output, though ground reaction forces are less than in sprinting. Elite mid-distance runners exhibit local muscle adaptations that, along with a large anaerobic capacity, provide the ability to generate a high power output. Aerobic capacity starts to become an important aspect of performance in middle distance events, especially as distance increases. In distance running events, V˙O2max is an important determinant of performance, but is relatively homogeneous in elite runners. V˙O2 and velocity at lactate threshold have been shown to be superior predictors of elite distance running performance. Ultramarathons are relatively new running events, as such, less is known about physiological and biomechanical parameters that underlie ultra-marathon performance. However, it is clear that performance in these events is related to aerobic capacity, fuel utilization, and fatigue resistance. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology 2017. This work is written by US Government employees and is in the public domain in the US.

Hepatic transcriptome profiles differ among maturing beef heifers supplemented with inorganic, organic, or mixed (50% inorganic:50% organic) forms of dietary selenium.

PubMed

Matthews, James C; Zhang, Zhi; Patterson, Jennifer D; Bridges, Phillip J; Stromberg, Arnold J; Boling, J A

2014-09-01

Selenium (Se) is an important trace mineral that, due to deficiencies in the soil in many parts of the USA, must be supplemented directly to the diet of foraging cattle. Both organic and inorganic forms of dietary Se supplements are available and commonly used, and it is known that Se form affects tissue assimilation, bioavailability, and physiological responses. However, little is known about the effects of form of dietary Se supplements on gene expression profiles, which ostensibly account for Se form-dependent physiological processes. To determine if hepatic transcriptomes of growing beef (Angus-cross) heifers (0.5 kg gain/day) was altered by form of dietary supplemental Se, none (Control), or 3 mg Se/day as inorganic Se (ISe, sodium selenite), organic (OSe, Sel-Plex®), or a blend of ISe and OSe (1.5 mg:1.5 mg, Mix) Se was fed for 168 days, and the RNA expression profiles from biopsied liver tissues was compared by microarray analysis. The relative abundance of 139 RNA transcripts was affected by Se treatment, with 86 of these with complete gene annotations. Statistical and bioinformatic analysis of the annotated RNA transcripts revealed clear differences among the four Se treatment groups in their hepatic expression profiles, including (1) solely and commonly affected transcripts; (2) Control and OSe profiles being more similar than Mix and ISe treatments; (3) distinct OSe-, Mix-, and ISe-Se treatment-induced "phenotypes" that possessed both common and unique predicted physiological capacities; and (4) expression of three microRNAs were uniquely sensitive to OSe, ISe, or Mix treatments, including increased capacity for redox potential induced by OSe and Mix Se treatments resulting from decreased expression of MiR2300b messenger RNA. These findings indicate that the form of supplemental dietary Se consumed by cattle will affect the composition of liver transcriptomes resulting, presumably, in different physiological capacities.

Ecophysiological adaptations to variable salinity environments in the crab Hemigrapsus crenulatus from the Southeastern Pacific coast: Sodium regulation, respiration and excretion.

PubMed

Urzúa, Ángel; Urbina, Mauricio A

2017-08-01

The estuarine crab Hemigrapsus crenulatus is a key benthic species of estuarine and intertidal ecosystems of the South Pacific, habitats that experience wide fluctuations in salinity. The physiological strategies that allow this crab to thrive under variable salinities, and how they change during the benthic stages of their life cycle, were evaluated under laboratory conditions. Oxygen consumption, ammonia excretion and the regulatory capacity of Na + through the normal range of environmental salinities (i.e. 5, 10, 15, 20, 25, 30) were evaluated in three size classes, ranging from juveniles to adults. In all sizes, the oxygen consumption, ammonia excretion and regulatory capacity of Na + decreased as salinity increased, with the highest values at 5 and the lowest values at 30 salinity. Bigger crabs showed a higher capacity to regulate Na + , as well as higher respiration and excretion rates compared to smaller crabs, suggesting that they are better equipped to exploit areas of the estuary with low salinity. Regardless of its size, H. crenulatus is a strong hyper regulator in diluted media (i.e. 5-20) while a conformer at salinities higher than 20. The regulatory capacity of Na + was positively related with oxygen consumption and ammonia excretion rates. These relationships between sodium regulation, respiration and excretion are interpreted as adaptive physiological mechanisms that allow H. crenulatus to maintain the osmotic and bioenergetic balance over a wide range of environmental salinities. Copyright © 2017 Elsevier Inc. All rights reserved.

The Physiological Profile of Junior Soccer Players at SSBB Surabaya Bhakti

NASA Astrophysics Data System (ADS)

Nashirudin, M.; Kusnanik, N. W.

2018-01-01

Soccer players are required to have good physical fitness in order to achieve optimum accomplishment; physical fitness stands as the foundation of technical and tactical proficiency as well as the mental maturity during the matches. The purpose of this study was to identify the physiological profile of junior soccer players of SSB Surabaya Bhakti age 16-17. The research was conducted at 20 junior soccer players. This research was quantitative with descriptive analysis. Data were collected by testing of physiological (anaerobic power and capacity including explosive leg power, speed, agility; aerobic capacity: cardiovascular endurance). Data was analyzed using percentage. The result showed that the percentage of explosive leg power of junior soccer players were 30% (good category), speed was 85% (average category), right agility was 90% (average category), left agility was 75% (average category). On the other hand, the aerobic power and capacity of the junior soccer players in this study was 50% (average category). The conclusion of this research is that the physiological profile of junior soccer players at SSB Surabaya Bhakti age 16-17 was majority in average category.

Physiological performance and work capacity of Sudanese cane cutters with Schistosoma mansoni infection.

PubMed

Collins, K J; Brotherhood, R J; Davies, C T; Doré, C; Hackett, A J; Imms, F J; Musgrove, J; Weiner, J S; Amin, M A; El Karim, M; Ismail, H M; Omer, A H; Sukkar, M Y

1976-05-01

Physiological tests of work performance and measurement of field productivity were made in 194 Sudanese cane cutters in order to study the effect of Schistosoma mansoni infection. The cane cutters were selected from two age ranges (16-24 and 25-45 years) and subdivided into three clinical groups: not infected, infected with, and infected without clinical signs of hepatosplenomegaly. Men infected with Schistosoma haemotobium, malaria (blood film), or with hemoglobin levels less than 10 g/100 ml were excluded. There was a statistically significant (P less than 0.002) higher mean hemoglobin concentration in those not infected but the mean difference was less than 1 g/100 ml. Submaximal responses to exercise on a stationary bicycle ergometer, oxygen intake, ventilation, tidal volume, cardiac frequency and estimated maximal aerobic power output calculated both in absolute terms and relative to lean body mass and leg volume were similar in the six groups of cane cutters. No significant differences were found in physique, body composition or in thermoregulatory function tests. The cane cutters were found to have little natural acclimatization to heat in terms of sweating capacity when compared with a group of fully acclimatized Sudanese soldiers. The mean productivity (mean daily weight of cane cut per man) was significantly correlated with the individual's estimated maximum aerobic capacity determined in the laboratory, but not with the degree of S. mansoni infection. The noninfected group was less "efficient" (mean productivity:oxygen intake) during cutting than the infected groups but a larger proportion of the noninfected were in their first season of cutting. There was a positive correlation between the number of seasons' cutting experience and the individual's age, degree of infection and mean productivity. Cane cutters studied in this investigation were a relatively fit, active population from whom the more seriously ill were excluded. These results do not, therefore necessarily reflect the effects of S. mansoni on physiological work capacity and productivity of more static populations in areas of high endemicity.

Anthropometric and physiological profiles of active blind Malaysian males.

PubMed

Singh, R; Singh, H J

1993-12-01

Cardiopulmonary capacities of twelve adults (aged between 14 to 44 years) with varying degrees of blindness engaged in regular recreational activities were compared with twelve age-matched normal sighted healthy males (control group) who were also involved in regular recreational activities. Maximum oxygen consumption (VO2max) was measured directly during exhaustive exercise test on a cycle ergometer. Forced vital capacity, leg strength and power were determined by spirometry, standing long jump and vertical jump respectively. No significant differences in VO2max, forced vital capacity and leg strength and power were observed between the blind and the control groups. No anthropometric differences were evident between the two groups. The results show therefore that the visually handicapped who are active can have a similar level of physical fitness, lung function and explosive leg strength as those of their active sighted counterparts.

Micro-Reaction Chamber Electrodes for Neural Stimulation and Recording

PubMed Central

Shanmugasundaram, Balaji; Gluckman, Bruce J.

2012-01-01

Biocompatible electrodes with smaller geometric area are preferred to improve the selectivity of the neural recording and stimulation applications. We introduce the concept of a micro-reaction chamber (µRC) in which a volume within the electrode back plane is used to confine and sequester the electrochemical reactions used for charge passage. The µRC electrode design helps decrease impedance and improves the charge storage capacity without altering the geometry of the active site. Here we demonstrate that µRC electrodes fabricated from 50 µm diameter microwire have significantly improved charge storage capacity and lowered impedance at physiologically relevant frequencies in phosphate buffered saline solution compared with other designs. PMID:22254394

Chronic exposure to soil salinity in terrestrial species: Does plasticity and underlying physiology differ among specialized ground-dwelling spiders?

PubMed

Renault, D; Puzin, C; Foucreau, N; Bouchereau, A; Pétillon, J

2016-07-01

In salt marshes, the alternation of low and high tides entails rapid shifts of submersion and aerial exposure for terrestrial communities. In these intertidal environments, terrestrial species have to deal with an osmotic loss in body water content and an increase in sodium chloride concentration when salt load increases. In salt marshes, spiders represent an abundant arthropod group, whose physiological ecology in response to variations of soil salinity must be further investigated. In this study, we compared the effect of salinity on the survival and physiology of three species of Lycosidae; two salt marsh species (Arctosa fulvolineata and Pardosa purbeckensis) and one forest species (P. saltans). Spiders were individually exposed at three salinity conditions (0‰, 35‰ and 70‰) and survival, changes in body water content, hemolymph ions (Na(+), Ca(2+), Mg(2+), K(+); ICP-MS technique) and metabolites (mainly amino acids, polyols, sugars; LC and GC techniques) were assessed. The survival of the forest species P. saltans was very quickly hampered at moderate and high salinities. In this spider, variations of hemolymph ions and metabolites revealed a quick loss of physiological homeostasis and a rapid salt-induced dehydration of the specimens. Conversely, high survival durations were measured in the two salt-marsh spiders, and more particularly in A. fulvolineata. In both P. purbeckensis and A. fulvolineata, the proportion of Na(+), Ca(2+), Mg(2+), K(+) remained constant at the three experimental conditions. Accumulation of hemolymph Na(+) and amino acids (mainly glutamine and proline) demonstrated stronger osmoregulatory capacities in these salt-marsh resident spiders. To conclude, even if phylogenetically close (belonging to the same, monophyletic, family), we found different physiological capacities to cope with salt load among the three tested spider species. Nevertheless, physiological responses to salinity were highly consistent with the realized ecological niches of the spiders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Auditory post-processing in a passive listening task is deficient in Alzheimer's disease.

PubMed

Bender, Stephan; Bluschke, Annet; Dippel, Gabriel; Rupp, André; Weisbrod, Matthias; Thomas, Christine

2014-01-01

To investigate whether automatic auditory post-processing is deficient in patients with Alzheimer's disease and is related to sensory gating. Event-related potentials were recorded during a passive listening task to examine the automatic transient storage of auditory information (short click pairs). Patients with Alzheimer's disease were compared to a healthy age-matched control group. A young healthy control group was included to assess effects of physiological aging. A bilateral frontal negativity in combination with deep temporal positivity occurring 500 ms after stimulus offset was reduced in patients with Alzheimer's disease, but was unaffected by physiological aging. Its amplitude correlated with short-term memory capacity, but was independent of sensory gating in healthy elderly controls. Source analysis revealed a dipole pair in the anterior temporal lobes. Results suggest that auditory post-processing is deficient in Alzheimer's disease, but is not typically related to sensory gating. The deficit could neither be explained by physiological aging nor by problems in earlier stages of auditory perception. Correlations with short-term memory capacity and executive control tasks suggested an association with memory encoding and/or overall cognitive control deficits. An auditory late negative wave could represent a marker of auditory working memory encoding deficits in Alzheimer's disease. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Increasing atmospheric CO2 reduces metabolic and physiological differences between isoprene- and non-isoprene-emitting poplars.

PubMed

Way, Danielle A; Ghirardo, Andrea; Kanawati, Basem; Esperschütz, Jürgen; Monson, Russell K; Jackson, Robert B; Schmitt-Kopplin, Philippe; Schnitzler, Jörg-Peter

2013-10-01

Isoprene, a volatile organic compound produced by some plant species, enhances abiotic stress tolerance under current atmospheric CO2 concentrations, but its biosynthesis is negatively correlated with CO2 concentrations. We hypothesized that losing the capacity to produce isoprene would require stronger up-regulation of other stress tolerance mechanisms at low CO2 than at higher CO2 concentrations. We compared metabolite profiles and physiological performance in poplars (Populus × canescens) with either wild-type or RNAi-suppressed isoprene emission capacity grown at pre-industrial low, current atmospheric, and future high CO2 concentrations (190, 390 and 590 ppm CO2 , respectively). Suppression of isoprene biosynthesis led to significant rearrangement of the leaf metabolome, increasing stress tolerance responses such as xanthophyll cycle pigment de-epoxidation and antioxidant levels, as well as altering lipid, carbon and nitrogen metabolism. Metabolic and physiological differences between isoprene-emitting and suppressed lines diminished as growth CO2 concentrations rose. The CO2 dependence of our results indicates that the effects of isoprene biosynthesis are strongest at pre-industrial CO2 concentrations. Rising CO2 may reduce the beneficial effects of biogenic isoprene emission, with implications for species competition. This has potential consequences for future climate warming, as isoprene emitted from vegetation has strong effects on global atmospheric chemistry. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Cardiorespiratory responses in an Antarctic fish suggest limited capacity for thermal acclimation.

PubMed

Egginton, Stuart; Campbell, Hamish A

2016-05-01

Polar fishes are at high risk from increasing seawater temperatures. Characterising the physiological responses to such changes may both clarify mechanisms that permit life under extreme conditions and identify limitations in the response to continued global warming. We hypothesised that Notothenia coriiceps would show physiological compensation after an acute exposure to 5°C, and following 6 weeks warm acclimation, compared with ambient temperature (0°C). However, initial tachycardia (22.4±2.8 versus 12.8±1.1 min(-1); P<0.01) was not reversed by acclimation (21.0±1.9 min(-1)). Hyperventilation (45.5±3.1 versus 21.4±2.4 breaths min(-1); P<0.001) showed a modest reduction following acclimation (38.0±2.9 min(-1); P<0.05), while resting oxygen consumption (0.52±0.08 mmol kg(-1) h(-1)) was acutely increased at 5°C (1.07±0.10 mmol kg(-1) h(-1); P<0.001) but unchanged with acclimation. Autonomic blockade showed initial responses were mainly of vagal origin, with little subsequent withdrawal or recovery in long-term heart rate variability after 6 weeks. Given the limited cardiorespiratory capacity to withstand sustained warming, effective physiological compensation probably requires a more prolonged acclimation period. © 2016. Published by The Company of Biologists Ltd.

Musculoskeletal, biomechanical, and physiological gender differences in the US military.

PubMed

Allison, Katelyn F; Keenan, Karen A; Sell, Timothy C; Abt, John P; Nagai, Takashi; Deluzio, Jennifer; McGrail, Mark; Lephart, Scott M

2015-01-01

The repeal of the Direct Ground Combat Assignment Rule has renewed focus on examining performance capabilities of female military personnel and their ability to occupy previously restricted military occupational specialties. Previous research has revealed female Soldiers suffer a greater proportion of musculoskeletal injuries compared to males, including a significantly higher proportion of lower extremity, knee, and overuse injuries. Potential differences may also exist in musculoskeletal, biomechanical, and physiological characteristics between male and female Soldiers requiring implementation of gender-specific training in order to mitigate injury risk and enhance performance. To examine differences in musculoskeletal, biomechanical, and physiological characteristics in male and female Soldiers. A total of 406 101st Airborne Division (Air Assault) Soldiers (348 male; 58 female) participated. Subjects underwent testing for flexibility, isokinetic and isometric strength (percent body weight), single-leg balance, lower body biomechanics during a stop jump and drop landing, body composition, anaerobic power/capacity, and aerobic capacity. Independent t tests assessed between-group comparisons. Women demonstrated significantly greater flexibility (P<.01-P<.001) and better balance (P≤.001) than men. Men demonstrated significantly greater strength (P≤.001), aerobic capacity (47.5±7.6 vs 40.3±5.4 ml/kg/min, P<.001), anaerobic power (13.3±2.1 vs 9.5±1.7 W/kg, P<.001), and anaerobic capacity (7.8±1.0 vs 6.1±0.8 W/kg, P<.001) and lower body fat (20.1±7.5 vs 26.7±5.7 (%BF), P<.001). Women demonstrated significantly greater hip flexion and knee valgus at initial contact during both the stop jump and drop landing tasks and greater knee flexion at initial contact during the drop landing task (P<.05-P<.001). Gender differences exist in biomechanical, musculoskeletal, and physiological characteristics. Sex-specific interventions may aid in improving such characteristics to optimize physical readiness and decrease the injury risk during gender-neutral training, and decreasing between-sex variability in performance characteristics may result in enhanced overall unit readiness. Identification of sex-specific differences in injury patterns and characteristics should facilitate adjustments in training in order for both sexes to meet the gender-neutral occupational demands for physically demanding military occupational specialties.

Species-Specific Responses of Juvenile Rockfish to Elevated pCO2: From Behavior to Genomics

PubMed Central

Hamilton, Scott L.; Logan, Cheryl A.; Fennie, Hamilton W.; Sogard, Susan M.; Barry, James P.; Makukhov, April D.; Tobosa, Lauren R.; Boyer, Kirsten; Lovera, Christopher F.; Bernardi, Giacomo

2017-01-01

In the California Current ecosystem, global climate change is predicted to trigger large-scale changes in ocean chemistry within this century. Ocean acidification—which occurs when increased levels of atmospheric CO2 dissolve into the ocean—is one of the biggest potential threats to marine life. In a coastal upwelling system, we compared the effects of chronic exposure to low pH (elevated pCO2) at four treatment levels (i.e., pCO2 = ambient [500], moderate [750], high [1900], and extreme [2800 μatm]) on behavior, physiology, and patterns of gene expression in white muscle tissue of juvenile rockfish (genus Sebastes), integrating responses from the transcriptome to the whole organism level. Experiments were conducted simultaneously on two closely related species that both inhabit kelp forests, yet differ in early life history traits, to compare high-CO2 tolerance among species. Our findings indicate that these congeners express different sensitivities to elevated CO2 levels. Copper rockfish (S. caurinus) exhibited changes in behavioral lateralization, reduced critical swimming speed, depressed aerobic scope, changes in metabolic enzyme activity, and increases in the expression of transcription factors and regulatory genes at high pCO2 exposure. Blue rockfish (S. mystinus), in contrast, showed no significant changes in behavior, swimming physiology, or aerobic capacity, but did exhibit significant changes in the expression of muscle structural genes as a function of pCO2, indicating acclimatization potential. The capacity of long-lived, late to mature, commercially important fish to acclimatize and adapt to changing ocean chemistry over the next 50–100 years is likely dependent on species-specific physiological tolerances. PMID:28056071

Histamine-binding capacities of different natural zeolites: a comparative study.

PubMed

Selvam, Thangaraj; Schwieger, Wilhelm; Dathe, Wilfried

2018-06-07

Two different natural zeolites from Cuba and Mexico, which are already being used as contemporaneous drugs or dietary supplements in Germany and Mexico, respectively, are applied in a comparative study of their histamine-binding capacities as a function of their particle sizes. The zeolites are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and N 2 -sorption measurements (BET surface areas). The Cuban zeolite contains clinoptilolite and mordenite as major phases (78% zeolite), whereas the Mexican one contains only clinoptilolite (65% zeolite). Both zeolites are apparently free from fibrous materials according to SEM. Both zeolites adsorb significant amount of histamine under the experimental conditions. Nevertheless, the results showed that the histamine-binding capacity of the Cuban zeolite is higher than the Mexican one and the smaller the particle size of zeolite, the higher the histamine-binding capacity. This difference could be due to the variation in their mineralogical compositions resulting in varied BET surface areas. Thus, the high histamine-binding capacities of Cuban zeolites seem to be due at least partly to the presence of the large-pore zeolite mordenite, providing high total pore volumes, which will be discussed in detail. For the first time, we have shown that the mineralogical compositions of natural zeolites and their particle sizes play a key role in binding histamine, which is one of the most important regulators in human physiology.

Development of techniques for measuring pilot workload

NASA Technical Reports Server (NTRS)

Spyker, D. A.; Stackhouse, S. P.; Khalafalla, A. S.; Mclane, R. C.

1971-01-01

An objective method of assessing information workload based on physiological measurements was developed. Information workload, or reserve capacity, was measured using a visual discrimination secondary task and subjective rating of task difficulty. The primary task was two axis (pitch and roll) tracking, and the independent variables in this study were aircraft pitch dynamics and wind gust disturbances. The study was structured to provide: (1) a sensitive, nonloading measure of reserve capacity, and (2) an unencumbering reliable measurement of the psychophysiological state. From these, a measured workload index (MWI) and physiological workload index (PWI) were extracted. An important measure of the success of this study was the degree to which the MWI and PWI agreed across the 243 randomly-presented, four-minute trials (9 subjects X 9 tasks X 3 replications). The electrophysiological data collected included vectorcardiogaram, respiration, electromyogram, skin impedance, and electroencephalogram. Special computer programs were created for the analysis of each physiological variable. The digital data base then consisted of 82 physiological features for each of the 243 trials. A prediction of workload based on physiological observations was formulated as a simultaneous least-squares prediction problem. A best subset of 10 features was chosen to predict the three measures of reserve capacity. The cannonical correlation coefficient was .754 with a chi squared value of 91.3 which allows rejection of the null hypothesis with p of .995.

Low haemoglobin concentration in Tibetan males is associated with greater high-altitude exercise capacity.

PubMed

Simonson, T S; Wei, G; Wagner, H E; Wuren, T; Qin, G; Yan, M; Wagner, P D; Ge, R L

2015-07-15

Tibetans living at high altitude have adapted genetically such that many display a low erythropoietic response, resulting in near sea-level haemoglobin (Hb) concentration. We hypothesized that absence of the erythropoietic response would be associated with greater exercise capacity compared to those with high [Hb] as a result of beneficial changes in oxygen transport. We measured, in 21 Tibetan males with [Hb] ranging from 15.2 g dl(-1) to 22.9 g dl(-1) (9.4 mmol l(-1) to 14.2 mmol l(-1) ), [Hb], ventilation, volumes of O2 and CO2 utilized at peak exercise (V̇O2 and V̇CO2), heart rate, cardiac output and arterial blood gas variables at peak exercise on a cycle ergometer at ∼4200 m. Lung and muscle O2 diffusional conductances were computed from these measurements. [Hb] was related (negatively) to V̇O2 kg(-1) (r = -0.45, P< 0.05), cardiac output kg(-1) (QT kg(-1) , r = -0.54, P < 0.02), and O2 diffusion capacity in muscle (DM kg(-1) , r = -0.44, P<0.05), but was unrelated to ventilation, arterial partial pressure of O2 (PaO2) or pulmonary diffusing capacity. Using multiple linear regression, variance in peak V̇O2 kg(-1) was primarily attributed to QT, DM, and PCO2 (R(2) = 0.88). However, variance in pulmonary gas exchange played essentially no role in determining peak V̇O2. These results (1) show higher exercise capacity in Tibetans without the erythropoietic response, supported mostly by cardiac and muscle O2 transport capacity and ventilation rather than pulmonary adaptations, and (2) support the emerging hypothesis that the polycythaemia of altitude, normally a beneficial response to low cellular PO2, may become maladaptive if excessively elevated under chronic hypoxia. The cause and effect relationships among [Hb], QT, DM, and PCO2 remain to be elucidated. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

A Physiological Case Study of a Paralympic Wheelchair Tennis Player: Reflective Practise

PubMed Central

Diaper, Nicholas J.; Goosey-Tolfrey, Victoria L.

2009-01-01

This study was designed to examine the physiological changes caused by long-term training in a world class female tennis player in preparation for a major championship. Additionally, we aim to describe the training interventions and determine a suitable cooling strategy that was to be used at the 2004 Paralympic Games. The athlete underwent regular physiological assessment during 2003-2004. Physiological measures involved body composition, submaximal and peak oxygen uptake and key variables associated with maximal sprinting. In addition, a suitable match-play cooling intervention and hydration strategy was also explored. Body composition improved over the course of the study. Aerobic capacity fell by 21%, yet the submaximal physiological variables such as lactate profile and pushing economy improved. The trade off of aerobic capacity was perhaps noticeably counter-balanced with the maintenance of the peak sprinting speed and improvement found in the fatigue profile across ten repeated sprints. The extensive training programme was responsible for these changes and these adaptations resulted in a more confident athlete, in peak physical condition leading into the Paralympic Games. It is difficult to appreciate the extent to which this work had an impact on tennis performance given the skill requirements of wheelchair tennis and this warrants future attention. Key points Physiological adaptations were apparent over the two-year training period. The training emphasis resulted in a reduction in aerobic capacity, yet an improvement in repetitive sprint performance was seen leading into the Major competition. An effective cooling technique was identified that could be used during wheelchair tennis performance. The athlete and coaches were complimentary to the physiological support provided, which resulted in a more confident athlete at the Paralympic Games. PMID:24149542

Genetic approaches in comparative and evolutionary physiology.

PubMed

Storz, Jay F; Bridgham, Jamie T; Kelly, Scott A; Garland, Theodore

2015-08-01

Whole animal physiological performance is highly polygenic and highly plastic, and the same is generally true for the many subordinate traits that underlie performance capacities. Quantitative genetics, therefore, provides an appropriate framework for the analysis of physiological phenotypes and can be used to infer the microevolutionary processes that have shaped patterns of trait variation within and among species. In cases where specific genes are known to contribute to variation in physiological traits, analyses of intraspecific polymorphism and interspecific divergence can reveal molecular mechanisms of functional evolution and can provide insights into the possible adaptive significance of observed sequence changes. In this review, we explain how the tools and theory of quantitative genetics, population genetics, and molecular evolution can inform our understanding of mechanism and process in physiological evolution. For example, lab-based studies of polygenic inheritance can be integrated with field-based studies of trait variation and survivorship to measure selection in the wild, thereby providing direct insights into the adaptive significance of physiological variation. Analyses of quantitative genetic variation in selection experiments can be used to probe interrelationships among traits and the genetic basis of physiological trade-offs and constraints. We review approaches for characterizing the genetic architecture of physiological traits, including linkage mapping and association mapping, and systems approaches for dissecting intermediary steps in the chain of causation between genotype and phenotype. We also discuss the promise and limitations of population genomic approaches for inferring adaptation at specific loci. We end by highlighting the role of organismal physiology in the functional synthesis of evolutionary biology. Copyright © 2015 the American Physiological Society.

The Effects of Heat Adaptation on Physiology, Perception and Exercise Performance in the Heat: A Meta-Analysis.

PubMed

Tyler, Christopher J; Reeve, Tom; Hodges, Gary J; Cheung, Stephen S

2016-11-01

Exercise performance and capacity are impaired in hot, compared to temperate, conditions. Heat adaptation (HA) is one intervention commonly adopted to reduce this impairment because it may induce beneficial exercise performance and physiological and perceptual adaptations. A number of investigations have been conducted on HA but, due to large methodological differences, the effectiveness of different HA regimens remain unclear. (1) To quantify the effect of different HA regimens on exercise performance and the physiological and perceptual responses to subsequent heat exposure. (2) To offer practical HA recommendations and suggestions for future HA research based upon a systematic and quantitative synthesis of the literature. PubMed was searched for original research articles published up to, and including, 16 February 2016 using appropriate first- and second-order search terms. English-language, peer-reviewed, full-text original articles using human participants were reviewed using the four-stage process identified in the PRISMA statement. Data for the following variables were obtained from the manuscripts by at least two of the authors: participant sex, maximal oxygen consumption and age; HA duration, frequency, modality, temperature and humidity; exercise performance and capacity; core and skin temperature; heart rate, stroke volume, cardiac output, skin blood flow, sweat onset temperature, body mass loss, sweat rate, perception of thirst, volitional fluid consumption, plasma volume changes; sweat concentrations of sodium, chloride and potassium; aldosterone, arginine vasopressin, heat shock proteins (Hsp), ratings of perceived exertion (RPE) and thermal sensation. Data were divided into three groups based upon the frequency of the HA regimen. Performance and capacity data were also divided into groups based upon the type of HA used. Hedges' g effect sizes and 95 % confidence intervals were calculated. Correlations were run where appropriate. Ninety-six articles were reviewed. The most common duration was 7-14 days and the most common method of HA was the controlled work-rate approach. HA had a moderately beneficial effect on exercise capacity and performance in the heat irrespective of regimen; however, longer regimens were more effective than shorter approaches. HA had a moderate-to-large beneficial effect on lowering core body temperature before and during exercise, maintaining cardiovascular stability, and improving heat-loss pathways. Data are limited but HA may reduce oxygen consumption during subsequent exercise, improve glycogen sparing, increase the power output at lactate threshold, reduce lactate concentrations during exercise, have a trivial effect on increasing extracellular concentrations of Hsp, and improve perceived ratings of exertion and thermal sensation. HA regimens lasting <14 days induce many beneficial physiological and perceptual adaptations to high ambient temperatures, and improve subsequent exercise performance and capacity in the heat; however, the extent of the adaptations is greatest when HA regimens lasting longer than 14 days are adopted. Large methodological differences in the HA literature mean that there is still uncertainty regarding the magnitude and time course of potential adaptation for a number of physiological and perceptual variables.

Exercise Responses after Inactivity

NASA Technical Reports Server (NTRS)

Convertino, Victor A.

1986-01-01

The exercise response after bed rest inactivity is a reduction in the physical work capacity and is manifested by significant decreases in oxygen uptake. The magnitude of decrease in maximal oxygen intake V(dot)O2max is related to the duration of confinement and the pre-bed-rest level of aerobic fitness; these relationships are relatively independent of age and gender. The reduced exercise performance and V(dot)O2max following bed rest are associated with various physiological adaptations including reductions in blood volume, submaximal and maximal stroke volume, maximal cardiac output, sceletal muscle tone and strength, and aerobic enzyme capacities, as well as increases in venous compliance and submaximal and maximal heart rate. This reduction in physiological capacity can be partially restored by specific countermeasures that provide regular muscular activity or orhtostatic stress or both during the bed rest exposure. The understanding of these physiological and physical responses to exercise following bed rest inactivity has important implications for the solution to safety and health problems that arise in clinical medicine, aerospace medicine, sedentary living, and aging.

Physiological and computed tomographic predictors of outcome from lung volume reduction surgery.

PubMed

Washko, George R; Martinez, Fernando J; Hoffman, Eric A; Loring, Stephen H; Estépar, Raúl San José; Diaz, Alejandro A; Sciurba, Frank C; Silverman, Edwin K; Han, MeiLan K; Decamp, Malcolm; Reilly, John J

2010-03-01

Previous investigations have identified several potential predictors of outcomes from lung volume reduction surgery (LVRS). A concern regarding these studies has been their small sample size, which may limit generalizability. We therefore sought to examine radiographic and physiologic predictors of surgical outcomes in a large, multicenter clinical investigation, the National Emphysema Treatment Trial. To identify objective radiographic and physiological indices of lung disease that have prognostic value in subjects with chronic obstructive pulmonary disease being evaluated for LVRS. A subset of the subjects undergoing LVRS in the National Emphysema Treatment Trial underwent preoperative high-resolution computed tomographic (CT) scanning of the chest and measures of static lung recoil at total lung capacity (SRtlc) and inspiratory resistance (Ri). The relationship between CT measures of emphysema, the ratio of upper to lower zone emphysema, CT measures of airway disease, SRtlc, Ri, the ratio of residual volume to total lung capacity (RV/TLC), and both 6-month postoperative changes in FEV(1) and maximal exercise capacity were assessed. Physiological measures of lung elastic recoil and inspiratory resistance were not correlated with improvement in either the FEV(1) (R = -0.03, P = 0.78 and R = -0.17, P = 0.16, respectively) or maximal exercise capacity (R = -0.02, P = 0.83 and R = 0.08, P = 0.53, respectively). The RV/TLC ratio and CT measures of emphysema and its upper to lower zone ratio were only weakly predictive of postoperative changes in both the FEV(1) (R = 0.11, P = 0.01; R = 0.2, P < 0.0001; and R = 0.23, P < 0.0001, respectively) and maximal exercise capacity (R = 0.17, P = 0.0001; R = 0.15, P = 0.002; and R = 0.15, P = 0.002, respectively). CT assessments of airway disease were not predictive of change in FEV(1) or exercise capacity in this cohort. The RV/TLC ratio and CT measures of emphysema and its distribution are weak but statistically significant predictors of outcome after LVRS.

Physiological responses to heat of resting man with impaired sweating capacity

NASA Technical Reports Server (NTRS)

Totel, G. L.

1974-01-01

The effects of total-body heat exposure were studied in three groups of subjects with varied degrees of impaired sweating capacity. The responses of two ectodermal dysplasic men, six quadriplegic men, and a man with widespread burned scar tissue were compared with the responses of three able-bodied men resting in the heat. It was found that the able-bodied and burned subjects competed successfully with a controlled environment of 38 C and 20% relative humidity for up to 150 min, whereas the quadriplegic and ectodermal dysplasic men developed hyperthermia, hyperventilation, and distress after only 120 and 75 min of heat exposure, respectively. The intolerance to heat is thus ascribed directly to the inability to produce and evaporate sweat.

Effects of shading on plant growth, flower quality and photosynthetic capacity of Rosa hybrida

NASA Astrophysics Data System (ADS)

Hou, Wei; Luo, Ya; Wang, Xiaorong; Chen, Qing; Sun, Bo; Wang, Yan; Liu, Zejing; Tang, Haoru; Zhang, Yong

2018-04-01

With the acceleration of the urbanization process, numbers of garden plants are grown in shaded environment. Rose (Rosa hybrida) is one of the most important ornamental plants used in urban green spaces. In the present study, effects of shading on plant growth, flower quality and photosynthetic capacity of R. hybrida were investigated. The results showed that shade not only delayed the initial flowering date, but also prolonged the flowering time. The physiological indices, including flower fresh weight, total anthocyanins and flavonoids contents, were lower in plants grown with shade compared with those grown in sun exposure. Overall, R. hybrida seemed to be a shade adapted plant which could be successfully grown in urban green spaces or understory with slight shade.

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

Lung Vital Capacity of Choir Singers and Nonsingers: A Comparative Study.

PubMed

Irzaldy, Abyan; Wiyasihati, Sundari Indah; Purwanto, Bambang

2016-11-01

The popularity of choir singing among Indonesian university students as an extracurricular activity has increased in the last few years. Choir singers use physiology principles especially respiration roles in the voice production process. This research aims to determine the lung vital capacity difference between singers and nonsingers. This is a cross-sectional study which uses primary data collected from spirograms of 20 university students. Half of the students were Airlangga University choir singers, and the other half were students who are not members of the choir. The spirometry tests were performed to obtain inspiratory capacity, vital capacity, and forced vital capacity of both groups. The average lung vital capacity of choir singers was higher (3.12 L) than that of the nonsingers (2.73 L). The average inspiratory capacity of the singer group was 1.79 L, and the average inspiratory capacity of the nonsinger group was 1.71 L. The lung vital capacity difference between singers and nonsingers group was statistically significant (P = 0.02). There was no significant inspiratory capacity difference between singers and nonsingers group in this study (P = 0.611). The forced vital capacity measurement showed a significant difference (P = 0.01) between singers (75.28%) and nonsingers (68.14%). It can be understood that the increasing vital capacity in choir singers is most likely from the expiration phase of the respiration. Further studies need to be conducted to confirm the causes of the increasing vital capacity in singers. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Discrete physiological effects of beetroot juice and potassium nitrate supplementation following 4-wk sprint interval training.

PubMed

Thompson, Christopher; Vanhatalo, Anni; Kadach, Stefan; Wylie, Lee J; Fulford, Jonathan; Ferguson, Scott K; Blackwell, Jamie R; Bailey, Stephen J; Jones, Andrew M

2018-06-01

The physiological and exercise performance adaptations to sprint interval training (SIT) may be modified by dietary nitrate ([Formula: see text]) supplementation. However, it is possible that different types of [Formula: see text] supplementation evoke divergent physiological and performance adaptations to SIT. The purpose of this study was to compare the effects of 4-wk SIT with and without concurrent dietary [Formula: see text] supplementation administered as either [Formula: see text]-rich beetroot juice (BR) or potassium [Formula: see text] (KNO 3 ). Thirty recreationally active subjects completed a battery of exercise tests before and after a 4-wk intervention in which they were allocated to one of three groups: 1) SIT undertaken without dietary [Formula: see text] supplementation (SIT); 2) SIT accompanied by concurrent BR supplementation (SIT + BR); or 3) SIT accompanied by concurrent KNO 3 supplementation (SIT + KNO 3 ). During severe-intensity exercise, V̇o 2peak and time to task failure were improved to a greater extent with SIT + BR than SIT and SIT + KNO 3 ( P < 0.05). There was also a greater reduction in the accumulation of muscle lactate at 3 min of severe-intensity exercise in SIT + BR compared with SIT + KNO 3 ( P < 0.05). Plasma [Formula: see text] concentration fell to a greater extent during severe-intensity exercise in SIT + BR compared with SIT and SIT + KNO 3 ( P < 0.05). There were no differences between groups in the reduction in the muscle phosphocreatine recovery time constant from pre- to postintervention ( P > 0.05). These findings indicate that 4-wk SIT with concurrent BR supplementation results in greater exercise capacity adaptations compared with SIT alone and SIT with concurrent KNO 3 supplementation. This may be the result of greater NO-mediated signaling in SIT + BR compared with SIT + KNO 3 . NEW & NOTEWORTHY We compared the influence of different forms of dietary nitrate supplementation on the physiological and performance adaptations to sprint interval training (SIT). Compared with SIT alone, supplementation with nitrate-rich beetroot juice, but not potassium [Formula: see text], enhanced some physiological adaptations to training.

Physiological adaptations to interval training and the role of exercise intensity

PubMed Central

MacInnis, Martin J.

2016-01-01

Abstract Interval exercise typically involves repeated bouts of relatively intense exercise interspersed by short periods of recovery. A common classification scheme subdivides this method into high‐intensity interval training (HIIT; ‘near maximal’ efforts) and sprint interval training (SIT; ‘supramaximal’ efforts). Both forms of interval training induce the classic physiological adaptations characteristic of moderate‐intensity continuous training (MICT) such as increased aerobic capacity (V˙O2 max ) and mitochondrial content. This brief review considers the role of exercise intensity in mediating physiological adaptations to training, with a focus on the capacity for aerobic energy metabolism. With respect to skeletal muscle adaptations, cellular stress and the resultant metabolic signals for mitochondrial biogenesis depend largely on exercise intensity, with limited work suggesting that increases in mitochondrial content are superior after HIIT compared to MICT, at least when matched‐work comparisons are made within the same individual. It is well established that SIT increases mitochondrial content to a similar extent to MICT despite a reduced exercise volume. At the whole‐body level, V˙O2 max is generally increased more by HIIT than MICT for a given training volume, whereas SIT and MICT similarly improve V˙O2 max despite differences in training volume. There is less evidence available regarding the role of exercise intensity in mediating changes in skeletal muscle capillary density, maximum stroke volume and cardiac output, and blood volume. Furthermore, the interactions between intensity and duration and frequency have not been thoroughly explored. While interval training is clearly a potent stimulus for physiological remodelling in humans, the integrative response to this type of exercise warrants further attention, especially in comparison to traditional endurance training. PMID:27748956

Age-related changes in the thermoregulatory capacity of tryptophan-deficient rats.

PubMed

Segall, P E; Timiras, P S

1975-01-01

From a larger study seeking to develop indexes of physiological aging, the present experiment was designed 1) to test thermoregulatory capacity in the aging and old rat subjected to 3 minutes of whole-body ice water immersion, and 2) using this index of physiological age, to determine whether tryptophan deficiency from time of weaning can retard the onset of senescence. Results indicate a progressive prolongation of temperature recovery time from young to middle age to old, and tryptophan-deficient animals restored to commercial diet at middle age show the thermoregulatory capacity of young adults. The implications of tryptophan deficiency with respect to brain development, serotonin metabolism, and temperature regulation are also discussed in terms of the possibility of intervening with the aging process.

Genetic approaches in comparative and evolutionary physiology

PubMed Central

Bridgham, Jamie T.; Kelly, Scott A.; Garland, Theodore

2015-01-01

Whole animal physiological performance is highly polygenic and highly plastic, and the same is generally true for the many subordinate traits that underlie performance capacities. Quantitative genetics, therefore, provides an appropriate framework for the analysis of physiological phenotypes and can be used to infer the microevolutionary processes that have shaped patterns of trait variation within and among species. In cases where specific genes are known to contribute to variation in physiological traits, analyses of intraspecific polymorphism and interspecific divergence can reveal molecular mechanisms of functional evolution and can provide insights into the possible adaptive significance of observed sequence changes. In this review, we explain how the tools and theory of quantitative genetics, population genetics, and molecular evolution can inform our understanding of mechanism and process in physiological evolution. For example, lab-based studies of polygenic inheritance can be integrated with field-based studies of trait variation and survivorship to measure selection in the wild, thereby providing direct insights into the adaptive significance of physiological variation. Analyses of quantitative genetic variation in selection experiments can be used to probe interrelationships among traits and the genetic basis of physiological trade-offs and constraints. We review approaches for characterizing the genetic architecture of physiological traits, including linkage mapping and association mapping, and systems approaches for dissecting intermediary steps in the chain of causation between genotype and phenotype. We also discuss the promise and limitations of population genomic approaches for inferring adaptation at specific loci. We end by highlighting the role of organismal physiology in the functional synthesis of evolutionary biology. PMID:26041111

Physiological effects of intermittent hypoxia.

PubMed

Powell, F L; Garcia, N

2000-01-01

Intermittent hypoxia (IH), or periodic exposure to hypoxia interrupted by return to normoxia or less hypoxic conditions, occurs in many circumstances. In high altitude mountaineering, IH is used to optimize acclimatization although laboratory studies have not generally revealed physiologically significant benefits. IH enhances athletic performance at sea level if blood oxygen capacity increases and the usual level of training is not decreased significantly. IH for high altitude workers who commute from low altitude homes is of considerable practical interest and the ideal commuting schedule for physical and mental performance is being studied. The effect of oxygen enrichment at altitude (i.e., intermittent normoxia on a background of chronic hypoxia) on human performance is under study also. Physiological mechanisms of IH, and specifically the differences between effects of IH and acute or chronic continuous hypoxia remains to be determined. Biomedical researchers are defining the molecular and cellular mechanisms for effects of hypoxia on the body in health and disease. A comparative approach may provide additional insight about the biological significance of these effects.

Effectiveness of inquiry-based learning in an undergraduate exercise physiology course.

PubMed

Nybo, Lars; May, Michael

2015-06-01

The present study was conducted to investigate the effects of changing a laboratory physiology course for undergraduate students from a traditional step-by-step guided structure to an inquiry-based approach. With this aim in mind, quantitative and qualitative evaluations of learning outcomes (individual subject-specific tests and group interviews) were performed for a laboratory course in cardiorespiratory exercise physiology that was conducted in one year with a traditional step-by-step guided manual (traditional course) and the next year completed with an inquiry-based structure (I-based course). The I-based course was a guided inquiry course where students had to design the experimental protocol and conduct their own study on the basis of certain predefined criteria (i.e., they should evaluate respiratory responses to submaximal and maximal exercise and provide indirect and direct measures of aerobic exercise capacity). The results indicated that the overall time spent on the experimental course as well as self-evaluated learning outcomes were similar across groups. However, students in the I-based course used more time in preparation (102 ± 5 min) than students in the traditional course (42 ± 3 min, P < 0.05), and 65 ± 5% students in the I-based course searched for additional literature before experimentation compared with only 2 ± 1% students in the traditional course. Furthermore, students in the I-based course achieved a higher (P < 0.05) average score on the quantitative test (45 ± 3%) compared with students in the traditional course (31 ± 4%). Although students were unfamiliar with cardiorespiratory exercise physiology and the experimental methods before the course, it appears that an inquiry-based approach rather than one that provides students with step-by-step instructions may benefit learning outcomes in a laboratory physiology course. Copyright © 2015 The American Physiological Society.

Regulatory mechanisms of metabolic flexibility in the dark-eyed junco (Junco hyemalis).

PubMed

Stager, Maria; Swanson, David L; Cheviron, Zachary A

2015-03-01

Small temperate birds reversibly modify their aerobic performance to maintain thermoregulatory homeostasis under seasonally changing environmental conditions and these physiological adjustments may be attributable to changes in the expression of genes in the underlying regulatory networks. Here, we report the results of an experimental procedure designed to gain insight into the fundamental mechanisms of metabolic flexibility in the dark-eyed junco (Junco hyemalis). We combined genomic transcriptional profiles with measures of metabolic enzyme activities and whole-animal thermogenic performance from juncos exposed to four 6-week acclimation treatments that varied in temperature (cold, 3°C; warm, 24°C) and photoperiod (short day, 8 h light:16 h dark; long day, 16 h light:8 h dark). Cold-acclimated birds increased thermogenic capacity compared with warm-acclimated birds, and this enhanced performance was associated with upregulation of genes involved in muscle hypertrophy, angiogenesis, and lipid transport and oxidation, as well as with catabolic enzyme activities. These physiological changes occurred over ecologically relevant timescales, suggesting that birds make regulatory adjustments to interacting, hierarchical pathways in order to seasonally enhance thermogenic capacity. © 2015. Published by The Company of Biologists Ltd.

Arousal, working memory capacity, and sexual decision-making in men.

PubMed

Spokes, Tara; Hine, Donald W; Marks, Anthony D G; Quain, Peter; Lykins, Amy D

2014-08-01

This study investigated whether working memory capacity (WMC) moderated the relationship between physiological arousal and sexual decision making. A total of 59 men viewed 20 consensual and 20 non-consensual images of heterosexual interaction while their physiological arousal levels were recorded using skin conductance response. Participants also completed an assessment of WMC and a date-rape analogue task for which they had to identify the point at which an average Australian male would cease all sexual advances in response to verbal and/or physical resistance from a female partner. Participants who were more physiologically aroused by and spent more time viewing the non-consensual sexual imagery nominated significantly later stopping points on the date-rape analogue task. Consistent with our predictions, the relationship between physiological arousal and nominated stopping point was strongest for participants with lower levels of WMC. For participants with high WMC, physiological arousal was unrelated to nominated stopping point. Thus, executive functioning ability (and WMC in particular) appears to play an important role in moderating men's decision making with regard to sexually aggressive behavior.

Ecophysiological and foliar nitrogen concentration responses of understorey Acacia spp. and Eucalyptus sp. to prescribed burning.

PubMed

Ma, Ling; Rao, Xingquan; Lu, Ping; Bai, Shahla Hosseini; Xu, Zhihong; Chen, Xiaoyang; Blumfield, Timothy; Xie, Jun

2015-07-01

Eucalyptus spp. is a dominant tree genus in Australia and most Eucalyptus spp. are canopy dominant species. In Australian natural forests, Eucalyptus spp. commonly are associated with understorey legumes which play a crucial role for ecological restoration owing to their nitrogen (N) fixing ability for replenishing the soil N lost after frequent prescribed burning. This study aimed to explore to what extent physiological responses of these species differ 7 and 12 years after last fire. Two most common understorey Acacia spp., Acacia leiocalyx and A. disparrima, as well as one non-leguminous Eucalyptus resinifera, were studied due to their dominance in the forest. Both A. leiocalyx and A. disparrima showed higher carbon (C) assimilation capacity, maximum photosynthetic capacity, and moderate foliar C/N ratio compared with E. resinifera. A. leiocalyx showed various advantages compared to A. disparrima such as higher photosynthetic capacity, adaptation to wider light range and higher foliar total N (TNmass). A. leiocalyx also relied on N2-fixing ability for longer time compared to A. disparrima. The results suggested that the two Acacia spp. were more beneficial to C and N cycles for the post burning ecosystem than the non-N2-fixing species E. resinifera. A. leiocalyx had greater contribution to complementing soil N cycle long after burning compared to A. disparrima.

Statins Affect Skeletal Muscle Performance: Evidence for Disturbances in Energy Metabolism.

PubMed

Allard, Neeltje A E; Schirris, Tom J J; Verheggen, Rebecca J; Russel, Frans G M; Rodenburg, Richard J; Smeitink, Jan A M; Thompson, Paul D; Hopman, Maria T E; Timmers, Silvie

2018-01-01

Statin myopathy is linked to disturbances in mitochondrial function and exercise intolerance. To determine whether differences exist in exercise performance, muscle function, and muscle mitochondrial oxidative capacity and content between symptomatic and asymptomatic statin users, and control subjects. Cross-sectional study. Department of Physiology, Radboud University Medical Center. Long-term symptomatic and asymptomatic statin users, and control subjects (n = 10 per group). Maximal incremental cycling tests, involuntary electrically stimulated isometric quadriceps-muscle contractions, and biopsy of vastus lateralis muscle. Maximal exercise capacity, substrate use during exercise, muscle function, and mitochondrial energy metabolism. Peak oxygen uptake, maximal work load, and ventilatory efficiency were comparable between groups, but both statin groups had a depressed anaerobic threshold compared with the control group (P = 0.01). Muscle relaxation time was prolonged in both statin groups compared with the control group and rate of maximal force rise was decreased (Ptime×group < 0.001 for both measures). Mitochondrial activity of complexes II and IV was lower in symptomatic statin users than control subjects and tended to be lower for complex (C) III (CII: P = 0.03; CIII: P = 0.05; CIV: P = 0.04). Mitochondrial content tended to be lower in both statin groups than in control subjects. Statin use attenuated substrate use during maximal exercise performance, induced muscle fatigue during repeated muscle contractions, and decreased muscle mitochondrial oxidative capacity. This suggests disturbances in mitochondrial oxidative capacity occur with statin use even in patients without statin-induced muscle complaints. Copyright © 2017 Endocrine Society

Contrasting phenotypic plasticity in the photoprotective strategies of the invasive species Carpobrotus edulis and the coexisting native species Crithmum maritimum.

PubMed

Fenollosa, Erola; Munné-Bosch, Sergi; Pintó-Marijuan, Marta

2017-06-01

Photoprotective strategies vary greatly within the plant kingdom and reflect a plant's physiological status and capacity to cope with environment variations. The plasticity and intensity of these responses may determine plant success. Invasive species are reported to show increased vigor to displace native species. Describing the mechanisms that confer such vigor is essential to understanding the success of invasive species. We performed an experiment whereby two species were monitored: Carpobrotus edulis, an aggressive invasive species in the Mediterranean basin, and Crithmum maritimum, a coexisting native species in the Cap de Creus Natural Park (NE Spain). We analyzed their photoprotective responses to seasonal environmental dynamics by comparing the capacity of the invader to respond to the local environmental stresses throughout the year. Our study analyses ecophysiological markers and photoprotective strategies to gain an insight into the success of invaders. We found that both species showed completely different but effective photoprotective strategies: in summer, C. edulis took special advantage of the xanthophyll cycle, whereas the success of C. maritimum in summer stemmed from morphological changes and alterations on β-carotene content. Winter also presented differences between the species, as the native showed reduced F v /F m ratios. Our experimental design allowed us to introduce a new approach to compare phenotypic plasticity: the integrated phenotypic plasticity index (PP int ), defined as the maximum Euclidian distance between phenotypes, using a combination of different variables to describe them. This index revealed significantly greater phenotypic plasticity in the invasive species compared to the native species. © 2017 Scandinavian Plant Physiology Society.

Digestive capacity predicts diet diversity in Neotropical frugivorous bats.

PubMed

Saldaña-Vázquez, Romeo A; Ruiz-Sanchez, Eduardo; Herrera-Alsina, Leonel; Schondube, Jorge E

2015-09-01

1. Predicting the diet diversity of animals is important to basic and applied ecology. Knowledge of diet diversity in animals helps us understand niche partitioning, functional diversity and ecosystem services such as pollination, pest control and seed dispersal. 2. There is a negative relationship between the length of the digestive tract and diet diversity in animals; however, the role of digestive physiology in determining diet diversity has been ignored. This is especially important in vertebrates with powered flight because, unlike non-flying vertebrates, they have limitations that may constrain gut size. 3. Here, we evaluate the relationship between digestive capacity and diet diversity in Carollinae and Stenodermatinae frugivorous bats. These bats disperse the seeds of plants that are key to Neotropical forest regeneration. 4. Our results show that digestive capacity is a good predictor of diet diversity in Carollinae and Stenodermatinae frugivorous bats (R(2) = 0·77). 5. Surprisingly, the most phylogenetically closely related species were not similar in their digestive capacity or diet diversity. The lack of a phylogenetic signal for the traits evaluated implies differences in digestive physiology and diet in closely related species. 6. Our results highlight the predictive usefulness of digestive physiology for understanding the feeding ecology of animals. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Assessment of energy balance of Indian farm women in relation to their nutritional profile in lean and peak agricultural seasons.

PubMed

Singh, Suman; Sinwal, Sushma; Rathore, Hemu

2012-01-01

In India, the farm women are not only involved in household activities but also contribute in various farm operations, animal husbandry. The objective was to assess nutritional profile of the farmwomen and their occupational health problems, to compare the physiological workload in lean and peak seasons and to find out relationship between physiological workload and nutritional intake. The study was conducted on a sample of 90 farmwomen. Energy Intake was calculated using physiological fuel values of carbohydrate, fat and protein. Energy Expenditure Rate (EER), Total Energy Expenditure (TEE) and Energy Balance were calculated. The physiological workload was assessed using sub-maximal workload technique. The results revealed that all the respondents of all categories were, more or less, performing all the agriculture, allied and household activities. In all the agriculture activities physiological hazards such as body pain and fatigue were dominant. Dietary, nutritional and energy intake was lower for heavy workers, from all landholding and BMI categories. HR and OCR were in linear relationship in all BMI categories. Physical work capacity increased with good nutritional status and decreased with age. Regression equations were suggested for calculating oxygen consumption (y) at their known heart rate (x) during various agriculture operations.

[Individual typological peculiarities of system blood flow, physical capacity for work and cardiac activity regulation in patients with different resistance to periodontal diseases].

PubMed

Bragin, A V

2008-01-01

From position of typological variability of physiological individuality concept-functional constitution types - the principle of organism integrity was substantiated for stomatological pathology. There were isolated typical and specific reactions of cardiac-vessel system in patients with different resistance to periodontal diseases. Each functional type - patients with different levels of usual motion activity - had their own physiological peculiarities of parameters of system blood flow, physical capacity for work and cardiac activity regulation, that determined individual typological organism reaction in cases of maxillo-facial system pathology. The received data gives the objective base for physiological approach to single out the extreme variants of norm for forming risk contingent and groups of resistant people to periodontal diseases.

Visuospatial Working Memory Capacity Predicts Physiological Arousal in a Narrative Task.

PubMed

Smithson, Lisa; Nicoladis, Elena

2016-06-01

Physiological arousal that occurs during narrative production is thought to reflect emotional processing and cognitive effort (Bar-Haim et al. in Dev Psychobiol 44:238-249, 2004). The purpose of this study was to determine whether individual differences in visuospatial working memory and/or verbal working memory capacity predict physiological arousal in a narrative task. Visuospatial working memory was a significant predictor of skin conductance level (SCL); verbal working memory was not. When visuospatial working memory interference was imposed, visuospatial working memory was no longer a significant predictor of SCL. Visuospatial interference also resulted in a significant reduction in SCL. Furthermore, listener ratings of narrative quality were contingent upon the visuospatial working memory resources of the narrator. Potential implications for educators and clinical practitioners are discussed.

The gradational step test for assessing cardiorespiratory capacity : an experimental evaluation of treadmill and step test procedures.

DOT National Transportation Integrated Search

1964-01-01

"Physical fitness" - the potential capacity for making adequate functional adjustments to increased metabolic demands - is most meaningful and accurately assessed in the laboratory by making physiological measurements on the experimental subject whil...

Variation in lung volumes and capacities among young males in relation to height.

PubMed

Bhatti, Urooj; Rani, Keenjher; Memon, Muhammad Qasim

2014-01-01

Vital Capacity (VC) is defined as a change in volume of lung after maximal inspiration followed by maximal expiration is called Vital Capacity of lungs. It is the sum of tidal volume, inspiratory reserve volume .and expiratory reserve volume. Vital capacity of normal adults ranges between 3 to 5 litres. A number of physiological factors like age, gender, height and ethnicity effect lung volumes. The reference values of lung volume and capacities were calculated previously and those studies played pivotal role in establishing the fact that air volume capacities measured in an individual fall within a wide range among healthy persons of same age, gender and height buit with different ethnicity. The objective of this study was to evaluate the changes in vital capacity in with height and gender. This cross-sectional study included 74 male students in the Department of Physiology, Liaquat University of Medical and Health Sciences, Jamshoro during January-March, 2014. The volunteers were divided into 2 groups of height ≤ 167.4 cm and > 167.4 cm. The volunteers' height was measured in cm. Vital capacity of the subjects was measured using standard protocol. Mean ± SD of age, height and vital capacity were calculated. Mean vital capacity in students with height > 167.4 cm was higher than average vital capacity of students with height ≤ 167.4 cm. It might be due to the increased surface area of the lungs in relation with increasing height. There are variations in vital capacity of individuals in relation to their heights, within the same ethnic and age groups.

Abstracts of Research Papers 1977 AAHPER Convention.

ERIC Educational Resources Information Center

Sage, George H., Ed.

This volume of abstracts describes papers written on the following topics: (1) Strength Physiology; (2) Learning Disabilities (motor); (3) Physiology - General; (4) Work Capacity; (5) Measurement and Recreation; (6) Biomechanics; (7) Professional Preparation (physical education); (8) Muscle Performance; (9) Sociology of Sport; (10) History of…

Exercise science: research to sustain and enhance performance

NASA Astrophysics Data System (ADS)

Wingo, Jonathan E.

2013-05-01

Cardiovascular adjustments accompanying exercise in high ambient temperatures are likely responsible for diminished aerobic capacity and performance in such conditions. These adjustments include a phenomenon known as cardiovascular drift in which heart rate rises and stroke volume declines progressively over time during constant-rate exercise. A variety of factors modulate the magnitude of cardiovascular drift, e.g., elevated core and skin temperatures, dehydration, and exercise intensity. Regardless of the mode of manipulation, decreases in stroke volume associated with cardiovascular drift result in directionally and proportionally similar decreases in maximal aerobic capacity. Maximal aerobic capacity is determined by maximal heart rate, maximal tissue oxygen extraction, and maximal stroke volume. Because maximal heart rate and maximal tissue oxygen extraction are unaffected during exercise in the heat, decreased stroke volume associated with cardiovascular drift likely persists during maximal efforts and explains the decrease in maximal aerobic capacity. Decreased maximal aerobic capacity results in a greater perceptual and physiological strain accompanying any given level of work. Therefore, sustaining and enhancing performance involves sophisticated monitoring of physiological strain combined with development of countermeasures that mitigate the magnitude of deleterious phenomena like cardiovascular drift.

Impaired Right Ventricular-Pulmonary Arterial Coupling and Effect of Sildenafil in Heart Failure With Preserved Ejection Fraction: An Ancillary Analysis From the Phosphodiesterase-5 Inhibition to Improve Clinical Status And Exercise Capacity in Diastolic Heart Failure (RELAX) Trial.

PubMed

Hussain, Imad; Mohammed, Selma F; Forfia, Paul R; Lewis, Gregory D; Borlaug, Barry A; Gallup, Dianne S; Redfield, Margaret M

2016-04-01

Right ventricular (RV) dysfunction (RVD) is a poor prognostic factor in heart failure with preserved ejection fraction (HFpEF). The physiological perturbations associated with RVD or RV function indexed to load (RV-pulmonary arterial [PA] coupling) in HFpEF have not been defined. HFpEF patients with marked impairment in RV-PA coupling may be uniquely sensitive to sildenafil. In a subset of HFpEF patients enrolled in the Phosphodiesteas-5 Inhibition to Improve Clinical Status And Exercise Capacity in Diastolic Heart Failure (RELAX) trial, physiological variables and therapeutic effect of sildenafil were examined relative to the severity of RVD (tricuspid annular plane systolic excursion [TAPSE]) and according to impairment in RV-PA coupling (TAPSE/pulmonary artery systolic pressure) ratio. The prevalence of atrial fibrillation and diuretic use, n-terminal probrain natriuretic peptide levels, renal dysfunction, neurohumoral activation, myocardial necrosis and fibrosis biomarkers, and the severity of diastolic dysfunction all increased with severity of RVD. Peak oxygen consumption decreased and ventilatory inefficiency (VE/VCO2 slope) increased with increasing severity of RVD. Many but not all physiological derangements were more closely associated with the TAPSE/pulmonary artery systolic pressure ratio. Compared with placebo, at 24 weeks, TAPSE decreased, and peak oxygen consumption and VE/CO2 slope were unchanged with sildenafil. There was no interaction between RV-PA coupling and treatment effect, and sildenafil did not improve TAPSE, peak oxygen consumption, or VE/VCO2 in patients with pulmonary hypertension and RVD. HFpEF patients with RVD and impaired RV-PA coupling have more advanced heart failure. In RELAX patients with RVD and impaired RV-PA coupling, sildenafil did not improve RV function, exercise capacity, or ventilatory efficiency. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00763867. © 2016 American Heart Association, Inc.

Leaf Photosynthetic Rate of Tropical Ferns Is Evolutionarily Linked to Water Transport Capacity

PubMed Central

Cao, Kun-Fang; Hu, Hong; Zhang, Jiao-Lin

2014-01-01

Ferns usually have relatively lower photosynthetic potential than angiosperms. However, it is unclear whether low photosynthetic potential of ferns is linked to leaf water supply. We hypothesized that there is an evolutionary association of leaf water transport capacity with photosynthesis and stomatal density in ferns. In the present study, a series of functional traits relating to leaf anatomy, hydraulics and physiology were assessed in 19 terrestrial and 11 epiphytic ferns in a common garden, and analyzed by a comparative phylogenetics method. Compared with epiphytic ferns, terrestrial ferns had higher vein density (Dvein), stomatal density (SD), stomatal conductance (gs), and photosynthetic capacity (Amax), but lower values for lower epidermal thickness (LET) and leaf thickness (LT). Across species, all traits varied significantly, but only stomatal length (SL) showed strong phylogenetic conservatism. Amax was positively correlated with Dvein and gs with and without phylogenetic corrections. SD correlated positively with Amax, Dvein and gs, with the correlation between SD and Dvein being significant after phylogenetic correction. Leaf water content showed significant correlations with LET, LT, and mesophyll thickness. Our results provide evidence that Amax of the studied ferns is linked to leaf water transport capacity, and there was an evolutionary association between water supply and demand in ferns. These findings add new insights into the evolutionary correlations among traits involving carbon and water economy in ferns. PMID:24416265

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.

Mitochondrial Physiology in the Major Arbovirus Vector Aedes aegypti: Substrate Preferences and Sexual Differences Define Respiratory Capacity and Superoxide Production

PubMed Central

Soares, Juliana B. R. Correa; Gaviraghi, Alessandro; Oliveira, Marcus F.

2015-01-01

Adult females of Aedes aegypti are facultative blood sucking insects and vectors of Dengue and yellow fever viruses. Insect dispersal plays a central role in disease transmission and the extremely high energy demand posed by flight is accomplished by a very efficient oxidative phosphorylation process, which take place within flight muscle mitochondria. These organelles play a central role in energy metabolism, interconnecting nutrient oxidation to ATP synthesis, but also represent an important site of cellular superoxide production. Given the importance of mitochondria to cell physiology, and the potential contributions of this organelle for A. aegypti biology and vectorial capacity, here, we conducted a systematic assessment of mitochondrial physiology in flight muscle of young adult A. aegypti fed exclusively with sugar. This was carried out by determining the activities of mitochondrial enzymes, the substrate preferences to sustain respiration, the mitochondrial bioenergetic efficiency and capacity, in both mitochondria-enriched preparations and mechanically permeabilized flight muscle in both sexes. We also determined the substrates preferences to promote mitochondrial superoxide generation and the main sites where it is produced within this organelle. We observed that respiration in A. aegypti mitochondria was essentially driven by complex I and glycerol 3 phosphate dehydrogenase substrates, which promoted distinct mitochondrial bioenergetic capacities, but with preserved efficiencies. Respiration mediated by proline oxidation in female mitochondria was strikingly higher than in males. Mitochondrial superoxide production was essentially mediated through proline and glycerol 3 phosphate oxidation, which took place at sites other than complex I. Finally, differences in mitochondrial superoxide production among sexes were only observed in male oxidizing glycerol 3 phosphate, exhibiting higher rates than in female. Together, these data represent a significant step towards the understanding of fundamental mitochondrial processes in A. aegypti, with potential implications for its physiology and vectorial capacity. PMID:25803027

Physiological and Computed Tomographic Predictors of Outcome from Lung Volume Reduction Surgery

PubMed Central

Washko, George R.; Martinez, Fernando J.; Hoffman, Eric A.; Loring, Stephen H.; Estépar, Raúl San José; Diaz, Alejandro A.; Sciurba, Frank C.; Silverman, Edwin K.; Han, MeiLan K.; DeCamp, Malcolm; Reilly, John J.

2010-01-01

Rationale: Previous investigations have identified several potential predictors of outcomes from lung volume reduction surgery (LVRS). A concern regarding these studies has been their small sample size, which may limit generalizability. We therefore sought to examine radiographic and physiologic predictors of surgical outcomes in a large, multicenter clinical investigation, the National Emphysema Treatment Trial. Objectives: To identify objective radiographic and physiological indices of lung disease that have prognostic value in subjects with chronic obstructive pulmonary disease being evaluated for LVRS. Methods: A subset of the subjects undergoing LVRS in the National Emphysema Treatment Trial underwent preoperative high-resolution computed tomographic (CT) scanning of the chest and measures of static lung recoil at total lung capacity (SRtlc) and inspiratory resistance (Ri). The relationship between CT measures of emphysema, the ratio of upper to lower zone emphysema, CT measures of airway disease, SRtlc, Ri, the ratio of residual volume to total lung capacity (RV/TLC), and both 6-month postoperative changes in FEV1 and maximal exercise capacity were assessed. Measurements and Main Results: Physiological measures of lung elastic recoil and inspiratory resistance were not correlated with improvement in either the FEV1 (R = −0.03, P = 0.78 and R = –0.17, P = 0.16, respectively) or maximal exercise capacity (R = –0.02, P = 0.83 and R = 0.08, P = 0.53, respectively). The RV/TLC ratio and CT measures of emphysema and its upper to lower zone ratio were only weakly predictive of postoperative changes in both the FEV1 (R = 0.11, P = 0.01; R = 0.2, P < 0.0001; and R = 0.23, P < 0.0001, respectively) and maximal exercise capacity (R = 0.17, P = 0.0001; R = 0.15, P = 0.002; and R = 0.15, P = 0.002, respectively). CT assessments of airway disease were not predictive of change in FEV1 or exercise capacity in this cohort. Conclusions: The RV/TLC ratio and CT measures of emphysema and its distribution are weak but statistically significant predictors of outcome after LVRS. PMID:19965810

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.

Reproductive investment is connected to innate immunity in a long-lived animal.

PubMed

Neggazi, Sara A; Noreikiene, Kristina; Öst, Markus; Jaatinen, Kim

2016-10-01

Life-history theory predicts that organisms optimize their resource allocation strategy to maximize lifetime reproductive success. Individuals can flexibly reallocate resources depending on their life-history stage, and environmental and physiological factors, which lead to variable life-history strategies even within species. Physiological trade-offs between immunity and reproduction are particularly relevant for long-lived species that need to balance current reproduction against future survival and reproduction, but their underlying mechanisms are poorly understood. A major unresolved issue is whether the first-line innate immune function is suppressed by reproductive investment. In this paper, we tested if reproductive investment is associated with the suppression of innate immunity, and how this potential trade-off is resolved depending on physiological state and residual reproductive value. We used long-lived capital-breeding female eiders (Somateria mollissima) as a model. We showed that the innate immune response, measured by plasma bacteria-killing capacity (BKC), was negatively associated with increasing reproductive investment, i.e., with increasing clutch size and advancing incubation stage. Females in a better physiological state, as indexed by low heterophil-to-lymphocyte (H/L) ratios, showed higher BKC during early incubation, but this capacity decreased as incubation progressed, whereas females in poorer state showed low BKC capacity throughout incubation. Although plasma BKC generally declined with increasing H/L ratios, this decrease was most pronounced in young females. Our results demonstrate that reproductive investment can suppress constitutive first-line immune defence in a long-lived bird, but the degree of immunosuppression depends on physiological state and age.

Experimental evaluation of work capacity as related to chronological and physiological aging.

DOT National Transportation Integrated Search

1963-09-01

Research statistics has establish the fact that physical work capacity declines as a consequence of aging. The question has been raised, however, if this decline is the inevitable result of senescence or merely due to change in living habits. Great n...

Neonatal stomach volume and physiology suggest feeding at 1-h intervals.

PubMed

Bergman, Nils J

2013-08-01

There is insufficient evidence on optimal neonatal feeding intervals, with a wide range of practices. The stomach capacity could determine feeding frequency. A literature search was conducted for studies reporting volumes or dimensions of stomach capacity before or after birth. Six articles were found, suggesting a stomach capacity of 20 mL at birth. A stomach capacity of 20 mL translates to a feeding interval of approximately 1 h for a term neonate. This corresponds to the gastric emptying time for human milk, as well as the normal neonatal sleep cycle. Larger feeding volumes at longer intervals may therefore be stressful and the cause of spitting up, reflux and hypoglycaemia. Outcomes for low birthweight infants could possibly be improved if stress from overfeeding was avoided while supporting the development of normal gastrointestinal physiology. Cycles between feeding and sleeping at 1-h intervals likely meet the evolutionary expectations of human neonates. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Adjusting to climate: acclimation, adaptation, and developmental plasticity in physiological traits of a tropical rainforest lizard.

PubMed

Llewelyn, John; Macdonald, Stewart L; Moritz, Craig; Martins, Felipe; Hatcher, Amberlee; Phillips, Ben L

2018-01-09

The impact of climate change may be felt most keenly by tropical ectotherms. In these taxa, it is argued, thermal specialisation means a given shift in temperature will have a larger effect on fitness. For species with limited dispersal ability, the impact of climate change depends on the capacity for their climate-relevant traits to shift. Such shifts can occur through genetic adaptation, various forms of plasticity, or a combination of these processes. Here we assess the extent and causes of shifts in seven physiological traits in a tropical lizard, the rainforest sunskink (Lampropholis coggeri). Two populations were sampled that differ from each other in both climate and physiological traits. We compared trait values in each animal soon after field collection versus following acclimation to laboratory conditions. We also compared trait values between populations in: (1) recently field-collected animals, (2) the same animals following laboratory acclimation, and (3) the laboratory-reared offspring of these animals. Our results reveal high trait lability, driven primarily by acclimation and local adaptation. By contrast, developmental plasticity, resulting from incubation temperature, had little-to-no effect on most traits. These results suggest that, while specialised, tropical ectotherms may be capable of rapid shifts in climate-relevant traits. This article is protected by copyright. All rights reserved.

Stomatal structure and physiology do not explain differences in water use among montane eucalypts.

PubMed

Gharun, Mana; Turnbull, Tarryn L; Pfautsch, Sebastian; Adams, Mark A

2015-04-01

Understanding the regulation of water use at the whole-tree scale is critical to advancing the utility of physiological ecology, for example in its role in predictive hydrology of forested catchments. For three eucalypt species that dominate high-elevation catchments in south-eastern Australia, we examined if whole-tree water use could be related to three widely discussed regulators of water use: stomatal anatomy, sensitivity of stomata [i.e. stomatal conductance (g(s))] to environmental influences, and sapwood area. While daily tree water use varied sixfold among species, sap velocity and sapwood area varied in parallel. Combined, stomatal structure and physiology could not explain differences in species-specific water use. Species which exhibited the fastest (Eucalyptus delegatensis) and slowest (Eucalyptus pauciflora) rates of water use both exhibited greater capacity for physiological control of g(s) [indicated by sensitivity to vapour pressure deficit (VPD)] and a reduced capacity to limit g(s) anatomically [indicated by greater potential g(s) (g(max))]. Conversely, g(s) was insensitive to VPD and g(max) was lowest for Eucalyptus radiata, the species showing intermediate rates of water use. Improved knowledge of stomatal anatomy will help us to understand the capacity of species to regulate leaf-level water loss, but seems likely to remain of limited use for explaining rates of whole-tree water use in montane eucalypts at the catchment scale.

Relationship of Physiological Parameters and Achievement in Wheelchair Athletics.

ERIC Educational Resources Information Center

Hurst, Judith A.

The relationship between achievement in track and field events (60, 100, 200, 400 meter runs and shotput, discus, and javelin throws) and selected physiological parameters (grip strength, body fat, vital lung capacity, and cardiovascular efficiency) of 20 wheelchair athletes was investigated. Results of track and field events were obtained from…

Ex ante economic evaluation of technologies for managing postharvest physiological disorders

USDA-ARS?s Scientific Manuscript database

Recently there has been much progress in the development of technologies that use bio-markers to detect and manage post-harvest physiological disorders for apples in long-tern storage. Such technologies have the capacity to alleviate fruit loss by allowing storage operators to more effectively mark...

Photosynthetic capacity and leaf nitrogen decline along a controlled climate gradient in provenances of two widely distributed Eucalyptus species.

PubMed

Crous, Kristine Y; Drake, John E; Aspinwall, Michael J; Sharwood, Robert E; Tjoelker, Mark G; Ghannoum, Oula

2018-05-27

Climate is an important factor limiting tree distributions and adaptation to different thermal environments may influence how tree populations respond to climate warming. Given the current rate of warming, it has been hypothesized that tree populations in warmer, more thermally stable climates may have limited capacity to respond physiologically to warming compared to populations from cooler, more seasonal climates. We determined in a controlled environment how several provenances of widely distributed Eucalyptus tereticornis and E. grandis adjusted their photosynthetic capacity to +3.5°C warming along their native distribution range (~16-38°S) and whether climate of seed origin of the provenances influenced their response to different growth temperatures. We also tested how temperature optima (T opt ) of photosynthesis and J max responded to higher growth temperatures. Our results showed increased photosynthesis rates at a standardized temperature with warming in temperate provenances, while rates in tropical provenances were reduced by about 40% compared to their temperate counterparts. Temperature optima of photosynthesis increased as provenances were exposed to warmer growth temperatures. Both species had ~30% reduced photosynthetic capacity in tropical and subtropical provenances related to reduced leaf nitrogen and leaf Rubisco content compared to temperate provenances. Tropical provenances operated closer to their thermal optimum and came within 3% of the T opt of J max during the daily temperature maxima. Hence, further warming may negatively affect C uptake and tree growth in warmer climates, whereas eucalypts in cooler climates may benefit from moderate warming. © 2018 John Wiley & Sons Ltd.

Winter photosynthesis in red spruce (Picea rubens Sarg.): limitations, potential benefits, and risks

Treesearch

P.G. Schaberg

2000-01-01

Numerous cold-induced changes in physiology limit the capacity of northern conifers to photosynthesize during winter. Studies of red spruce (Picea rubens Sarg.) have shown that rates of field photosynthesis (Pfield) and laboratory measurements of photosynthetic capacity (Pmax) generally parallel seasonal...

Identification of Water Use Strategies at Early Growth Stages in Durum Wheat from Shoot Phenotyping and Physiological Measurements

PubMed Central

Nakhforoosh, Alireza; Bodewein, Thomas; Fiorani, Fabio; Bodner, Gernot

2016-01-01

Modern imaging technology provides new approaches to plant phenotyping for traits relevant to crop yield and resource efficiency. Our objective was to investigate water use strategies at early growth stages in durum wheat genetic resources using shoot imaging at the ScreenHouse phenotyping facility combined with physiological measurements. Twelve durum landraces from different pedoclimatic backgrounds were compared to three modern check cultivars in a greenhouse pot experiment under well-watered (75% plant available water, PAW) and drought (25% PAW) conditions. Transpiration rate was analyzed for the underlying main morphological (leaf area duration) and physiological (stomata conductance) factors. Combining both morphological and physiological regulation of transpiration, four distinct water use types were identified. Most landraces had high transpiration rates either due to extensive leaf area (area types) or both large leaf areas together with high stomata conductance (spender types). All modern cultivars were distinguished by high stomata conductance with comparatively compact canopies (conductance types). Only few landraces were water saver types with both small canopy and low stomata conductance. During early growth, genotypes with large leaf area had high dry-matter accumulation under both well-watered and drought conditions compared to genotypes with compact stature. However, high stomata conductance was the basis to achieve high dry matter per unit leaf area, indicating high assimilation capacity as a key for productivity in modern cultivars. We conclude that the identified water use strategies based on early growth shoot phenotyping combined with stomata conductance provide an appropriate framework for targeted selection of distinct pre-breeding material adapted to different types of water limited environments. PMID:27547208

Comparison of heat strain recovery in different anti-heat stress clothing ensembles after work to exhaustion.

PubMed

Zhao, Yijie; Yi, Wen; Chan, Albert P C; Chan, Daniel W M

2017-10-01

A hot environment combined with physically demanding tasks can subject workers to a higher risk of heat stress. A series of regulations and guidelines have been proposed to design appropriate anti-heat stress work uniform to reduce body heat strain. The present study aimed to examine heat strain recovery in different anti-heat stress clothing ensembles after work to exhaustion in the heat. 10 healthy males performed intermittent treadmill running/walking to exhaustion, followed by 30min passive recovery sitting in a climatic chamber, which simulated the hot and humid outdoor environment (34°C temperature, 60% relative humidity, 0.3m/s air velocity, and 450W/m 2 solar radiation). The participants took part in five wear trials in counter-balanced order, including Sportswear, CIC Uniform, NEW Uniform, ICEBANK Cooling Vest, and NEW Cooling Vest, which have different levels of cooling capacity. Core temperature, skin temperature, heart rate, sweat loss, ratings of perceived exertion, and thermal sensations were measured throughout the entire heat exposure period. Physiological heat strain indices, including the physiological strain index (PhSI) and the perceptual strain index (PeSI), were used as a yardstick to quantify and compare the rate of recovery. Significantly lower physiological strain was observed in the newly developed NEW Uniform and NEW Cooling Vest groups compared with the commonly worn CIC Uniform group during recovery. At the end of the recovery period, participants in NEW Cooling Vest achieved the highest recovery (42.18% in PhSI and 81.08% in PeSI), followed by ICEBANK Cooling Vest, Sportswear, NEW Uniform, and CIC Uniform. The cooling capacity of anti-heat stress clothing ensembles and the recovery time significantly affect the rate of recovery in PhSI and PeSI, which may benefit the industry by formulating the appropriate work-rest schedule by considering the clothing effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ethephon induced abscission in mango: physiological fruitlet responses

PubMed Central

Hagemann, Michael H.; Winterhagen, Patrick; Hegele, Martin; Wünsche, Jens N.

2015-01-01

Fruitlet abscission of mango is typically very severe, causing considerable production losses worldwide. Consequently, a detailed physiological and molecular characterization of fruitlet abscission in mango is required to describe the onset and time-dependent course of this process. To identify the underlying key mechanisms of abscission, ethephon, an ethylene releasing substance, was applied at two concentrations (600 and 7200 ppm) during the midseason drop stage of mango. The abscission process is triggered by ethylene diffusing to the abscission zone where it binds to specific receptors and thereby activating several key physiological responses at the cellular level. The treatments reduced significantly the capacity of polar auxin transport through the pedicel at 1 day after treatment and thereafter when compared to untreated pedicels. The transcript levels of the ethylene receptor genes MiETR1 and MiERS1 were significantly upregulated in the pedicel and pericarp at 1, 2, and 3 days after the ethephon application with 7200 ppm, except for MiETR1 in the pedicel, when compared to untreated fruitlet. In contrast, ethephon applications with 600 ppm did not affect expression levels of MiETR1 in the pedicel and of MiERS1 in the pericarp; however, MiETR1 in the pericarp at day 2 and MiERS1 in the pedicel at days 2 and 3 were significantly upregulated over the controls. Moreover, two novel short versions of the MiERS1 were identified and detected more often in the pedicel of treated than untreated fruitlets at all sampling times. Sucrose concentration in the fruitlet pericarp was significantly reduced to the control at 2 days after both ethephon treatments. In conclusion, it is postulated that the ethephon-induced abscission process commences with a reduction of the polar auxin transport capacity in the pedicel, followed by an upregulation of ethylene receptors and finally a decrease of the sucrose concentration in the fruitlets. PMID:26442021

Pirfenidone treatment in idiopathic pulmonary fibrosis: A Saudi experience.

PubMed

Alhamad, Esam H

2015-01-01

Recent trials involving pirfenidone suggest a beneficial effect in the treatment of idiopathic pulmonary fibrosis (IPF). To report on the efficacy and safety of pirfenidone in the treatment of patients with IPF, at a tertiary care hospital in Saudi Arabia. The study included 58 patients with IPF who were evaluated from March 2012 to March 2013. During the study period, 33 patients received pirfenidone, and the remaining patients (n = 25) served as a control group. Baseline clinical characteristics, physiological parameters and the results of a 36-Item Short Form Health Survey (SF-36) were compared between the groups. Furthermore, we compared changes in forced vital capacity (FVC), diffusion capacity of the lung for carbon monoxide (DLco), six-minute walk distance (6MWD) and SF-36 for both groups during follow-up. The last follow-up period ended in January 2014. There were no significant differences in baseline clinical characteristics between the groups. Furthermore, we found no differences in FVC, DLco and SF-36 during follow-up (median, 12 months). However, patients receiving pirfenidone treatment were less likely to experience reductions in 6MWD compared with the control group (13% vs. 52%, respectively; P = 0.001). Although adverse events were more frequently reported by the pirfenidone group compared with the control group (85 vs. 56%, respectively; P = 0.015), these patients did not require discontinuation of treatment. Pirfenidone treatment preserves functional capacity, as reflected by the 6MWD. Adverse events associated with pirfenidone treatment were generally well tolerated by the patients.

Mitochondrial acclimation capacities to ocean warming and acidification are limited in the antarctic Nototheniid Fish, Notothenia rossii and Lepidonotothen squamifrons.

PubMed

Strobel, Anneli; Graeve, Martin; Poertner, Hans O; Mark, Felix C

2013-01-01

Antarctic notothenioid fish are characterized by their evolutionary adaptation to the cold, thermostable Southern Ocean, which is associated with unique physiological adaptations to withstand the cold and reduce energetic requirements but also entails limited compensation capacities to environmental change. This study compares the capacities of mitochondrial acclimation to ocean warming and acidification between the Antarctic nototheniid Notothenia rossii and the sub-Antarctic Lepidonotothen squamifrons, which share a similar ecology, but different habitat temperatures. After acclimation of L. squamifrons to 9°C and N. rossii to 7°C (normocapnic/hypercapnic, 0.2 kPa CO2/2000 ppm CO2) for 4-6 weeks, we compared the capacities of their mitochondrial respiratory complexes I (CI) and II (CII), their P/O ratios (phosphorylation efficiency), proton leak capacities and mitochondrial membrane fatty acid compositions. Our results reveal reduced CII respiration rates in warm-acclimated L. squamifrons and cold hypercapnia-acclimated N. rossii. Generally, L. squamifrons displayed a greater ability to increase CI contribution during acute warming and after warm-acclimation than N. rossii. Membrane unsaturation was not altered by warm or hypercapnia-acclimation in both species, but membrane fatty acids of warm-acclimated L. squamifrons were less saturated than in warm normocapnia-/hypercapnia-acclimated N. rossii. Proton leak capacities were not affected by warm or hypercapnia-acclimation of N. rossii. We conclude that an acclimatory response of mitochondrial capacities may include higher thermal plasticity of CI supported by enhanced utilization of anaplerotic substrates (via oxidative decarboxylation reactions) feeding into the citrate cycle. L. squamifrons possesses higher relative CI plasticities than N. rossii, which may facilitate the usage of energy efficient NADH-related substrates under conditions of elevated energy demand, possibly induced by ocean warming and acidification. The observed adjustments of electron transport system complexes with a higher flux through CI under warming and acidification suggest a metabolic acclimation potential of the sub-Antarctic L. squamifrons, but only limited acclimation capacities for N. rossii.

Cold acclimation induces distinctive changes in the chromatin state and transcript levels of COR genes in Cannabis sativa varieties with contrasting cold acclimation capacities.

PubMed

Mayer, Boris F; Ali-Benali, Mohamed Ali; Demone, Jordan; Bertrand, Annick; Charron, Jean-Benoit

2015-11-01

Little is known about the capacity of Cannabis sativa to cold-acclimate and develop freezing tolerance. This study investigates the cold acclimation (CA) capacity of nine C. sativa varieties and the underlying genetic and epigenetic responses. The varieties were divided into three groups based on their contrasting CA capacities by comparing the survival of non-acclimated and cold-acclimated plants in whole-plant freeze tests. In response to the CA treatment, all varieties accumulated soluble sugars but only the varieties with superior capacity for CA could maintain higher levels throughout the treatment. In addition, the varieties that acclimated most efficiently accumulated higher transcript levels of cold-regulated (COR) genes and genes involved in de novo DNA methylation while displaying locus- and variety-specific changes in the levels of H3K9ac, H3K27me3 and methylcytosine (MeC) during CA. Furthermore, these hardy C. sativa varieties displayed significant increases in MeC levels at COR gene loci when deacclimated, suggesting a role for locus-specific DNA methylation in deacclimation. This study uncovers the molecular mechanisms underlying CA in C. sativa and reveals higher levels of complexity regarding how genetic, epigenetic and environmental factors intertwine. © 2014 Scandinavian Plant Physiology Society.

Preserving privacy of online digital physiological signals using blind and reversible steganography.

PubMed

Shiu, Hung-Jr; Lin, Bor-Sing; Huang, Chien-Hung; Chiang, Pei-Ying; Lei, Chin-Laung

2017-11-01

Physiological signals such as electrocardiograms (ECG) and electromyograms (EMG) are widely used to diagnose diseases. Presently, the Internet offers numerous cloud storage services which enable digital physiological signals to be uploaded for convenient access and use. Numerous online databases of medical signals have been built. The data in them must be processed in a manner that preserves patients' confidentiality. A reversible error-correcting-coding strategy will be adopted to transform digital physiological signals into a new bit-stream that uses a matrix in which is embedded the Hamming code to pass secret messages or private information. The shared keys are the matrix and the version of the Hamming code. An online open database, the MIT-BIH arrhythmia database, was used to test the proposed algorithms. The time-complexity, capacity and robustness are evaluated. Comparisons of several evaluations subject to related work are also proposed. This work proposes a reversible, low-payload steganographic scheme for preserving the privacy of physiological signals. An (n,  m)-hamming code is used to insert (n - m) secret bits into n bits of a cover signal. The number of embedded bits per modification is higher than in comparable methods, and the computational power is efficient and the scheme is secure. Unlike other Hamming-code based schemes, the proposed scheme is both reversible and blind. Copyright © 2017 Elsevier B.V. All rights reserved.

The Benefits of Exercise Training on Aerobic Capacity in Patients with Heart Failure and Preserved Ejection Fraction.

PubMed

do Prado, Danilo Marcelo Leite; Rocco, Enéas Antônio

2017-01-01

Heart failure with preserved ejection fraction (HFpEF) is defined as an inability of the ventricles to optimally accept blood from atria with blunted end- diastolic volume response by limiting the stroke volume and cardiac output. The HEpEF prevalence is higher in elderly and women and may be associated to hypertension, diabetes mellitus and atrial fibrillation. Severe exercise intolerance, manifested by dyspnea and fatigue during physical effort is the important chronic symptom in HFpEF patients, in which is the major determinant of their reduced quality of life. In this sense, several studies demonstrated reduced aerobic capacity in terms of lower peak oxygen consumption (peak VO 2 ) in patients with HFpEF. In addition, the lower aerobic capacity observed in HFpEF may be due to impaired both convective and diffusive O 2 transport (i.e. reduced cardiac output and arteriovenous oxygen difference, respectively).Exercise training program can help restore physiological function in order to increase aerobic capacity and improve the quality of life in HFpEF patients. Therefore, the primary purpose of this chapter was to clarify the physiological mechanisms associated with reduced aerobic capacity in HFpEF patients. Secondly, special focus was devoted to show how aerobic exercise training can improve aerobic capacity and quality of life in HFpEF patients.

Heart Rate Variability: New Perspectives on Physiological Mechanisms, Assessment of Self-regulatory Capacity, and Health risk

PubMed Central

Shaffer, Fred

2015-01-01

Heart rate variability, the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operates on different time scales to adapt to environmental and psychological challenges. This article briefly reviews neural regulation of the heart and offers some new perspectives on mechanisms underlying the very low frequency rhythm of heart rate variability. Interpretation of heart rate variability rhythms in the context of health risk and physiological and psychological self-regulatory capacity assessment is discussed. The cardiovascular regulatory centers in the spinal cord and medulla integrate inputs from higher brain centers with afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. We also discuss the intrinsic cardiac nervous system and the heart-brain connection pathways, through which afferent information can influence activity in the subcortical, frontocortical, and motor cortex areas. In addition, the use of real-time HRV feedback to increase self-regulatory capacity is reviewed. We conclude that the heart's rhythms are characterized by both complexity and stability over longer time scales that reflect both physiological and psychological functional status of these internal self-regulatory systems. PMID:25694852

Heart Rate Variability: New Perspectives on Physiological Mechanisms, Assessment of Self-regulatory Capacity, and Health risk.

PubMed

McCraty, Rollin; Shaffer, Fred

2015-01-01

Heart rate variability, the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operates on different time scales to adapt to environmental and psychological challenges. This article briefly reviews neural regulation of the heart and offers some new perspectives on mechanisms underlying the very low frequency rhythm of heart rate variability. Interpretation of heart rate variability rhythms in the context of health risk and physiological and psychological self-regulatory capacity assessment is discussed. The cardiovascular regulatory centers in the spinal cord and medulla integrate inputs from higher brain centers with afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. We also discuss the intrinsic cardiac nervous system and the heart-brain connection pathways, through which afferent information can influence activity in the subcortical, frontocortical, and motor cortex areas. In addition, the use of real-time HRV feedback to increase self-regulatory capacity is reviewed. We conclude that the heart's rhythms are characterized by both complexity and stability over longer time scales that reflect both physiological and psychological functional status of these internal self-regulatory systems.

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

Anaerobic Threshold: Its Concept and Role in Endurance Sport

PubMed Central

Ghosh, Asok Kumar

2004-01-01

aerobic to anaerobic transition intensity is one of the most significant physiological variable in endurance sports. Scientists have explained the term in various ways, like, Lactate Threshold, Ventilatory Anaerobic Threshold, Onset of Blood Lactate Accumulation, Onset of Plasma Lactate Accumulation, Heart Rate Deflection Point and Maximum Lactate Steady State. But all of these have great role both in monitoring training schedule and in determining sports performance. Individuals endowed with the possibility to obtain a high oxygen uptake need to complement with rigorous training program in order to achieve maximal performance. If they engage in endurance events, they must also develop the ability to sustain a high fractional utilization of their maximal oxygen uptake (%VO2 max) and become physiologically efficient in performing their activity. Anaerobic threshold is highly correlated to the distance running performance as compared to maximum aerobic capacity or VO2 max, because sustaining a high fractional utilization of the VO2 max for a long time delays the metabolic acidosis. Training at or little above the anaerobic threshold intensity improves both the aerobic capacity and anaerobic threshold level. Anaerobic Threshold can also be determined from the speed-heart rate relationship in the field situation, without undergoing sophisticated laboratory techniques. However, controversies also exist among scientists regarding its role in high performance sports. PMID:22977357

Anaerobic threshold: its concept and role in endurance sport.

PubMed

Ghosh, Asok Kumar

2004-01-01

aerobic to anaerobic transition intensity is one of the most significant physiological variable in endurance sports. Scientists have explained the term in various ways, like, Lactate Threshold, Ventilatory Anaerobic Threshold, Onset of Blood Lactate Accumulation, Onset of Plasma Lactate Accumulation, Heart Rate Deflection Point and Maximum Lactate Steady State. But all of these have great role both in monitoring training schedule and in determining sports performance. Individuals endowed with the possibility to obtain a high oxygen uptake need to complement with rigorous training program in order to achieve maximal performance. If they engage in endurance events, they must also develop the ability to sustain a high fractional utilization of their maximal oxygen uptake (%VO(2) max) and become physiologically efficient in performing their activity. Anaerobic threshold is highly correlated to the distance running performance as compared to maximum aerobic capacity or VO(2) max, because sustaining a high fractional utilization of the VO(2) max for a long time delays the metabolic acidosis. Training at or little above the anaerobic threshold intensity improves both the aerobic capacity and anaerobic threshold level. Anaerobic Threshold can also be determined from the speed-heart rate relationship in the field situation, without undergoing sophisticated laboratory techniques. However, controversies also exist among scientists regarding its role in high performance sports.

Biochemical responses and physiological status in the crab Hemigrapsus crenulatus (Crustacea, Varunidae) from high anthropogenically-impacted estuary (Lenga, south-central Chile).

PubMed

Díaz-Jaramillo, M; Socowsky, R; Pardo, L M; Monserrat, J M; Barra, R

2013-02-01

Estuarine environmental assessment by sub-individual responses is important in order to understand contaminant effects and to find suitable estuarine biomonitor species. Our study aimed to analyze oxidative stress responses, including glutathione-S-transferase (GST) activity, total antioxidant capacity (ACAP) and lipid peroxidation levels (TBARS) in estuarine crabs Hemigrapsus crenulatus from a high anthropogenically-impacted estuary (Lenga) compared to low and non-polluted estuaries (Tubul and Raqui), in a seasonal scale (winter-summer), tissue specific (hepatopancreas and gills) and sex related responses. Results showed that hepatopancreas in male crabs better reflected inter-estuary differences. Morpho-condition traits as Cephalothorax hepatopancreas index (CHI) could be used as an indicator of physiological status of estuarine crabs. Discriminant analysis also showed that GST and TBARS levels in summer are more suitable endpoints for establishing differences between polluted and non-polluted sites. These results suggest the importance of seasonality, target tissue, sex and physiological status of brachyuran crabs for estuarine biomonitoring assessment. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

PubMed

Rivera-Brown, Anita M; Frontera, Walter R

2012-11-01

Physical activity and fitness are associated with a lower prevalence of chronic diseases, such as heart disease, cancer, high blood pressure, and diabetes. This review discusses the body's response to an acute bout of exercise and long-term physiological adaptations to exercise training with an emphasis on endurance exercise. An overview is provided of skeletal muscle actions, muscle fiber types, and the major metabolic pathways involved in energy production. The importance of adequate fluid intake during exercise sessions to prevent impairments induced by dehydration on endurance exercise, muscular power, and strength is discussed. Physiological adaptations that result from regular exercise training such as increases in cardiorespiratory capacity and strength are mentioned. The review emphasizes the cardiovascular and metabolic adaptations that lead to improvements in maximal oxygen capacity. Copyright © 2012 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Strawberry Achenes Are an Important Source of Bioactive Compounds for Human Health

PubMed Central

Ariza, María Teresa; Reboredo-Rodríguez, Patricia; Mazzoni, Luca; Forbes-Hernández, Tamara Yuliett; Giampieri, Francesca; Afrin, Sadia; Gasparrini, Massimiliano; Soria, Carmen; Martínez-Ferri, Elsa; Battino, Maurizio; Mezzetti, Bruno

2016-01-01

Strawberries are highly appreciated for their taste, nutritional value and antioxidant compounds, mainly phenolics. Fruit antioxidants derive from achenes and flesh, but achene contribution to the total fruit antioxidant capacity and to the bioaccessibility after intake is still unknown. In this work, the content of total phenolic compounds, flavonoids, anthocyanins and antioxidant capacity (TEAC, FRAP and DPPH) of achenes and flesh were compared in non-digested as well as in gastric and intestinal extracts after in vitro digestion. Results showed that, despite strawberry achenes represent a small fraction of the fruit, their contribution to total fruit antioxidant content was more than 41% and accounted for 81% of antioxidant capacity (TEAC). Achenes have higher quantity and different quality of antioxidants in non-digested and digested extracts. Antioxidant release was higher in the in vitro gastric digested extracts, but digestion conditions did not only affect quantity but quality, resulting in differences in antioxidant capacity and highlighting the importance of simulating physiological-like extraction conditions for assessing fruit antioxidant properties on human health. These results give new insights into the use of strawberry achenes as a source of bioactive compounds to be considered in strawberry breeding programs for improving human health. PMID:27409612

Trade-off between aerobic capacity and locomotor capability in an Antarctic pteropod

PubMed Central

Rosenthal, Joshua J. C.; Seibel, Brad A.; Dymowska, Agnieszka; Bezanilla, Francisco

2009-01-01

At −1.8 °C, the waters of Antarctica pose a formidable physiological barrier for most ectotherms. The few taxa that inhabit this zone have presumably made specific adjustments to their neuromuscular function and have enhanced their metabolic capacity. However, support for this assertion is equivocal and the details of specific compensations are largely unknown. This can generally be attributed to the fact that most Antarctic organisms are either too distantly related to their temperate relatives to permit direct comparisons (e.g., notothenioid fishes) or because they are not amenable to neuromuscular recording. Here, as a comparative model, we take advantage of 2 pelagic molluscs in the genus Clione to conduct a broadly integrative investigation on neuromuscular adaptation to the extreme cold. We find that for the Antarctic congener aerobic capacity is enhanced, but at a cost. To support a striking proliferation of mitochondria, the Antarctic species has shed a 2-gear swim system and the associated specialized neuromuscular components, resulting in greatly reduced scope for locomotor activity. These results suggest that polar animals have undergone substantial tissue-level reorganizations to accommodate their environment, which may reduce their capacity to acclimate to a changing climate. PMID:19325127

Strawberry Achenes Are an Important Source of Bioactive Compounds for Human Health.

PubMed

Ariza, María Teresa; Reboredo-Rodríguez, Patricia; Mazzoni, Luca; Forbes-Hernández, Tamara Yuliett; Giampieri, Francesca; Afrin, Sadia; Gasparrini, Massimiliano; Soria, Carmen; Martínez-Ferri, Elsa; Battino, Maurizio; Mezzetti, Bruno

2016-07-11

Strawberries are highly appreciated for their taste, nutritional value and antioxidant compounds, mainly phenolics. Fruit antioxidants derive from achenes and flesh, but achene contribution to the total fruit antioxidant capacity and to the bioaccessibility after intake is still unknown. In this work, the content of total phenolic compounds, flavonoids, anthocyanins and antioxidant capacity (TEAC, FRAP and DPPH) of achenes and flesh were compared in non-digested as well as in gastric and intestinal extracts after in vitro digestion. Results showed that, despite strawberry achenes represent a small fraction of the fruit, their contribution to total fruit antioxidant content was more than 41% and accounted for 81% of antioxidant capacity (TEAC). Achenes have higher quantity and different quality of antioxidants in non-digested and digested extracts. Antioxidant release was higher in the in vitro gastric digested extracts, but digestion conditions did not only affect quantity but quality, resulting in differences in antioxidant capacity and highlighting the importance of simulating physiological-like extraction conditions for assessing fruit antioxidant properties on human health. These results give new insights into the use of strawberry achenes as a source of bioactive compounds to be considered in strawberry breeding programs for improving human health.

A Study of the Effectiveness of Sensory Integration Therapy on Neuro-Physiological Development

ERIC Educational Resources Information Center

Reynolds, Christopher; Reynolds, Kathleen Sheena

2010-01-01

Background: Sensory integration theory proposes that because there is plasticity within the central nervous system (the brain is moldable) and because the brain consists of systems that are hierarchically organised, it is possible to stimulate and improve neuro-physiological processing and integration and thereby increase learning capacity.…

Critical oxygen levels and metabolic suppression in oceanic oxygen minimum zones.

PubMed

Seibel, Brad A

2011-01-15

The survival of oceanic organisms in oxygen minimum zones (OMZs) depends on their total oxygen demand and the capacities for oxygen extraction and transport, anaerobic ATP production and metabolic suppression. Anaerobic metabolism and metabolic suppression are required for daytime forays into the most extreme OMZs. Critical oxygen partial pressures are, within a range, evolved to match the minimum oxygen level to which a species is exposed. This fact demands that low oxygen habitats be defined by the biological response to low oxygen rather than by some arbitrary oxygen concentration. A broad comparative analysis of oxygen tolerance facilitates the identification of two oxygen thresholds that may prove useful for policy makers as OMZs expand due to climate change. Between these thresholds, specific physiological adaptations to low oxygen are required of virtually all species. The lower threshold represents a limit to evolved oxygen extraction capacity. Climate change that pushes oxygen concentrations below the lower threshold (~0.8 kPa) will certainly result in a transition from an ecosystem dominated by a diverse midwater fauna to one dominated by diel migrant biota that must return to surface waters at night. Animal physiology and, in particular, the response of animals to expanding hypoxia, is a critical, but understudied, component of biogeochemical cycles and oceanic ecology. Here, I discuss the definition of hypoxia and critical oxygen levels, review adaptations of animals to OMZs and discuss the capacity for, and prevalence of, metabolic suppression as a response to temporary residence in OMZs and the possible consequences of climate change on OMZ ecology.

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

Analytical traceability of melon (Cucumis melo var reticulatus): proximate composition, bioactive compounds, and antioxidant capacity in relation to cultivar, plant physiology state, and seasonal variability.

PubMed

Maietti, Annalisa; Tedeschi, Paola; Stagno, Caterina; Bordiga, Matteo; Travaglia, Fabiano; Locatelli, Monica; Arlorio, Marco; Brandolini, Vincenzo

2012-06-01

Two morphologically different cultivars of Italian melons (Baggio and Giusto) were characterized considering samples harvested in different times, at the beginning (BPP) and at the end of the physiological plant production period (EPP). Proximate composition, protein, minerals, pH, phenolic content, antioxidant capacity, ascorbic acid, carotenoids, condensed tannins, and flavonoids were measured, showing a significant decrease in EPP samples (phenolics, antioxidant capacity, condensed tannins, and flavonoids); ascorbic acid decreased in Giusto cv, carotenoids in Baggio cv. Mineral content increased in either the cultivars (EPP samples). Year-to-year difference was significantly highlighted; the plant growing cycle significantly affected the chemotype. Despite these effects, the Principal Component Analysis (PCA) permitted the discrimination of Baggio from Giusto cv, and the discrimination of BPP from EPP samples as well. © 2012 Institute of Food Technologists®

[Stimulation of wound healing by tetrachlordecaoxide. Results of a randomized double-blind study].

PubMed

Hinz, J; Hautzinger, H; Helling, J; Schirren, G; Sell, G; Stahl, K W; Kühne, F W

1984-05-10

In 38 patients with chronic therapeutically resistant wounds, which, in 25 cases, had been existing for more than one year, Tetrachlorodecaoxide ( TCDO ) in a water solution containing glycerin was analyzed for its capacity to induce wound healing and compared in this respect to the standard in moist wound treatment, physiological sodium chloride. The results of the clinical trial demonstrate that the TCDO solution is significantly superior to physiological saline in local wound treatment regarding the degree of wound smear reduction, the formation of wound granulation tissue, the stimulation of epithelisation on the wound borders and the shrinking of the wound surface. The differences in therapeutic efficiency are so large that, in spite of the relatively small patient samples (21 + 17) it was possible to verify the superiority of a method for wound treatment in a randomized double blind clinical trial.

Advanced Techniques in Pulmonary Function Test Analysis Interpretation and Diagnosis

PubMed Central

Gildea, T.J.; Bell, C. William

1980-01-01

The Pulmonary Functions Analysis and Diagnostic System is an advanced clinical processing system developed for use at the Pulmonary Division, Department of Medicine at the University of Nebraska Medical Center. The system generates comparative results and diagnostic impressions for a variety of routine and specialized pulmonary functions test data. Routine evaluation deals with static lung volumes, breathing mechanics, diffusing capacity, and blood gases while specialized tests include lung compliance studies, small airways dysfunction studies and dead space to tidal volume ratios. Output includes tabular results of normal vs. observed values, clinical impressions and commentary and, where indicated, a diagnostic impression. A number of pulmonary physiological and state variables are entered or sampled (A to D) with periodic status reports generated for the test supervisor. Among the various physiological variables sampled are respiratory frequency, minute ventilation, oxygen consumption, carbon dioxide production, and arterial oxygen saturation.

Challenges and opportunities in developmental integrative physiology☆

PubMed Central

Mueller, C.A.; Eme, J.; Burggren, W.W.; Roghair, R.D.; Rundle, S.D.

2015-01-01

This review explores challenges and opportunities in developmental physiology outlined by a symposium at the 2014 American Physiological Society Intersociety Meeting: Comparative Approaches to Grand Challenges in Physiology. Across animal taxa, adverse embryonic/fetal environmental conditions can alter morphological and physiological phenotypes in juveniles or adults, and capacities for developmental plasticity are common phenomena. Human neonates with body sizes at the extremes of perinatal growth are at an increased risk of adult disease, particularly hypertension and cardiovascular disease. There are many rewarding areas of current and future research in comparative developmental physiology. We present key mechanisms, models, and experimental designs that can be used across taxa to investigate patterns in, and implications of, the development of animal phenotypes. Intraspecific variation in the timing of developmental events can be increased through developmental plasticity (heterokairy), and could provide the raw material for selection to produce heterochrony — an evolutionary change in the timing of developmental events. Epigenetics and critical windows research recognizes that in ovo or fetal development represent a vulnerable period in the life history of an animal, when the developing organism may be unable to actively mitigate environmental perturbations. ‘Critical windows’ are periods of susceptibility or vulnerability to environmental or maternal challenges, periods when recovery from challenge is possible, and periods when the phenotype or epigenome has been altered. Developmental plasticity may allow survival in an altered environment, but it also has possible long-term consequences for the animal. “Catch-up growth” in humans after the critical perinatal window has closed elicits adult obesity and exacerbates a programmed hypertensive phenotype (one of many examples of “fetal programing”). Grand challenges for developmental physiology include integrating variation in developmental timing within and across generations, applying multiple stressor dosages and stressor exposure at different developmental timepoints, assessment of epigenetic and parental influences, developing new animal models and techniques, and assessing and implementing these designs and models in human health and development. PMID:25711780

Physiological and transcriptional analyses of developmental stages along sugarcane leaf.

PubMed

Mattiello, Lucia; Riaño-Pachón, Diego Mauricio; Martins, Marina Camara Mattos; da Cruz, Larissa Prado; Bassi, Denis; Marchiori, Paulo Eduardo Ribeiro; Ribeiro, Rafael Vasconcelos; Labate, Mônica T Veneziano; Labate, Carlos Alberto; Menossi, Marcelo

2015-12-29

Sugarcane is one of the major crops worldwide. It is cultivated in over 100 countries on 22 million ha. The complex genetic architecture and the lack of a complete genomic sequence in sugarcane hamper the adoption of molecular approaches to study its physiology and to develop new varieties. Investments on the development of new sugarcane varieties have been made to maximize sucrose yield, a trait dependent on photosynthetic capacity. However, detailed studies on sugarcane leaves are scarce. In this work, we report the first molecular and physiological characterization of events taking place along a leaf developmental gradient in sugarcane. Photosynthetic response to CO2 indicated divergence in photosynthetic capacity based on PEPcase activity, corroborated by activity quantification (both in vivo and in vitro) and distinct levels of carbon discrimination on different segments along leaf length. Additionally, leaf segments had contrasting amount of chlorophyll, nitrogen and sugars. RNA-Seq data indicated a plethora of biochemical pathways differentially expressed along the leaf. Some transcription factors families were enriched on each segment and their putative functions corroborate with the distinct developmental stages. Several genes with higher expression in the middle segment, the one with the highest photosynthetic rates, were identified and their role in sugarcane productivity is discussed. Interestingly, sugarcane leaf segments had a different transcriptional behavior compared to previously published data from maize. This is the first report of leaf developmental analysis in sugarcane. Our data on sugarcane is another source of information for further studies aiming to understand and/or improve C4 photosynthesis. The segments used in this work were distinct in their physiological status allowing deeper molecular analysis. Although limited in some aspects, the comparison to maize indicates that all data acquired on one C4 species cannot always be easily extrapolated to other species. However, our data indicates that some transcriptional factors were segment-specific and the sugarcane leaf undergoes through the process of suberizarion, photosynthesis establishment and senescence.

Physiological Employment Standards III: physiological challenges and consequences encountered during international military deployments.

PubMed

Nindl, Bradley C; Castellani, John W; Warr, Bradley J; Sharp, Marilyn A; Henning, Paul C; Spiering, Barry A; Scofield, Dennis E

2013-11-01

Modern international military deployments in austere environments (i.e., Iraq and Afghanistan) place considerable physiological demands on soldiers. Significant physiological challenges exist: maintenance of physical fitness and body composition, rigors of external load carriage, environmental extremes (heat, cold, and altitude), medical illnesses, musculoskeletal injuries, traumatic brain injuries, post-traumatic stress disorder, and environmental exposure hazards (i.e., burn pits, vehicle exhaust, etc.). To date there is very little published research and no comprehensive reviews on the physiological effects of deployments. The purpose of this paper is to overview what is currently known from the literature related mainly to current military conflicts with regard to the challenges and consequences from deployments. Summary findings include: (1) aerobic capacity declines while muscle strength, power and muscular endurance appear to be maintained, (2) load carriage continues to tax the physical capacities of the Soldier, (3) musculoskeletal injuries comprise the highest proportion of all injury categories, (4) environmental insults occur from both terrestrial extremes and pollutant exposure, and (5) post-deployment concerns linger for traumatic brain injury and post-traumatic stress disorder. A full understanding of these responses will assist in identifying the most effective risk mitigation strategies to ensure deployment readiness and to assist in establishment of military employment standards.

Leptospira interrogans lpxD Homologue Is Required for Thermal Acclimatization and Virulence

PubMed Central

Eshghi, Azad; Henderson, Jeremy; Trent, M. Stephen

2015-01-01

Leptospirosis is an emerging disease with an annual occurrence of over 1 million human cases worldwide. Pathogenic Leptospira bacteria are maintained in zoonotic cycles involving a diverse array of mammals, with the capacity to survive outside the host in aquatic environments. Survival in the diverse environments encountered by Leptospira likely requires various adaptive mechanisms. Little is known about Leptospira outer membrane modification systems, which may contribute to the capacity of these bacteria to successfully inhabit and colonize diverse environments and animal hosts. Leptospira bacteria carry two genes annotated as UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferase genes (la0512 and la4326 [lpxD1 and lpxD2]) that in other bacteria are involved in the early steps of biosynthesis of lipid A, the membrane lipid anchor of lipopolysaccharide. Inactivation of only one of these genes, la0512/lpxD1, imparted sensitivity to the host physiological temperature (37°C) and rendered the bacteria avirulent in an animal infection model. Polymyxin B sensitivity assays revealed compromised outer membrane integrity in the lpxD1 mutant at host physiological temperature, but structural analysis of lipid A in the mutant revealed only minor changes in the lipid A moiety compared to that found in the wild-type strain. In accordance with this, an in trans complementation restored the phenotypes to a level comparable to that of the wild-type strain. These results suggest that the gene annotated as lpxD1 in Leptospira interrogans plays an important role in temperature adaptation and virulence in the animal infection model. PMID:26283339

Trade-offs between water transport capacity and drought resistance in neotropical canopy liana and tree species.

PubMed

De Guzman, Mark E; Santiago, Louis S; Schnitzer, Stefan A; Álvarez-Cansino, Leonor

2017-10-01

In tropical forest canopies, it is critical for upper shoots to efficiently provide water to leaves for physiological function while safely preventing loss of hydraulic conductivity due to cavitation during periods of soil water deficit or high evaporative demand. We compared hydraulic physiology of upper canopy trees and lianas in a seasonally dry tropical forest to test whether trade-offs between safety and efficiency of water transport shape differences in hydraulic function between these two major tropical woody growth forms. We found that lianas showed greater maximum stem-specific hydraulic conductivity than trees, but lost hydraulic conductivity at less negative water potentials than trees, resulting in a negative correlation and trade-off between safety and efficiency of water transport. Lianas also exhibited greater diurnal changes in leaf water potential than trees. The magnitude of diurnal water potential change was negatively correlated with sapwood capacitance, indicating that lianas are highly reliant on conducting capability to maintain leaf water status, whereas trees relied more on stored water in stems to maintain leaf water status. Leaf nitrogen concentration was related to maximum leaf-specific hydraulic conductivity only for lianas suggesting that greater water transport capacity is more tied to leaf processes in lianas compared to trees. Our results are consistent with a trade-off between safety and efficiency of water transport and may have implications for increasing liana abundance in neotropical forests. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Ice age fish in a warming world: minimal variation in thermal acclimation capacity among lake trout (Salvelinus namaycush) populations

PubMed Central

Kelly, Nicholas I.; Burness, Gary; McDermid, Jenni L.; Wilson, Chris C.

2014-01-01

In the face of climate change, the persistence of cold-adapted species will depend on their adaptive capacity for physiological traits within and among populations. The lake trout (Salvelinus namaycush) is a cold-adapted salmonid and a relict from the last ice age that is well suited as a model species for studying the predicted effects of climate change on coldwater fishes. We investigated the thermal acclimation capacity of upper temperature resistance and metabolism of lake trout from four populations across four acclimation temperatures. Individuals were reared from egg fertilization onward in a common environment and, at 2 years of age, were acclimated to 8, 11, 15 or 19°C. Although one population had a slightly higher maximal metabolic rate (MMR), higher metabolic scope for activity and faster metabolic recovery across all temperatures, there was no interpopulation variation for critical thermal maximum (CTM) or routine metabolic rate (RMR) or for the thermal acclimation capacity of CTM, RMR, MMR or metabolic scope. Across the four acclimation temperatures, there was a 3°C maximal increase in CTM and 3-fold increase in RMR for all populations. Above 15°C, a decline in MMR and increase in RMR resulted in sharply reduced metabolic scope for all populations acclimated at 19°C. Together, these data suggest there is limited variation among lake trout populations in thermal physiology or capacity for thermal acclimatization, and that climate change may impact lake trout populations in a similar manner across a wide geographical range. Understanding the effect of elevated temperatures on the thermal physiology of this economically and ecologically important cold-adapted species will help inform management and conservation strategies for the long-term sustainability of lake trout populations. PMID:27293646

The effect of pH, buffer capacity and ionic strength on quetiapine fumarate release from matrix tablets prepared using two different polymeric blends.

PubMed

Hamed, Rania; AlJanabi, Reem; Sunoqrot, Suhair; Abbas, Aiman

2017-08-01

The objective of this study was to investigate the effect of the different physiological parameters of the gastrointestinal (GI) fluid (pH, buffer capacity, and ionic strength) on the in vitro release of the weakly basic BCS class II drug quetiapine fumarate (QF) from two once-a-day matrix tablet formulations (F1 and F2) developed as potential generic equivalents to Seroquel ® XR. F1 tablets were prepared using blends of high and low viscosity grades of hydroxypropyl methylcellulose (HPMC K4M and K100LV, respectively), while F2 tablets were prepared from HPMC K4M and PEGylated glyceryl behenate (Compritol ® HD5 ATO). The two formulations attained release profiles of QF over 24 h similar to that of Seroquel ® XR using the dissolution medium published by the Food and Drug Administration (FDA). A series of solubility and in vitro dissolution studies was then carried out using media that simulate the gastric and intestinal fluids and cover the physiological pH, buffer capacity and ionic strength range of the GIT. Solubility studies revealed that QF exhibits a typical weak base pH-dependent solubility profile and that the solubility of QF increases with increasing the buffer capacity and ionic strength of the media. The release profiles of QF from F1, F2 and Seroquel ® XR tablets were found to be influenced by the pH, buffer capacity and ionic strength of the dissolution media to varying degrees. Results highlight the importance of studying the physiological variables along the GIT in designing controlled release formulations for more predictive in vitro-in vivo correlations.

Eight-Week Training Cessation Suppresses Physiological Stress but Rapidly Impairs Health Metabolic Profiles and Aerobic Capacity in Elite Taekwondo Athletes.

PubMed

Liao, Yi-Hung; Sung, Yu-Chi; Chou, Chun-Chung; Chen, Chung-Yu

2016-01-01

Changes in an athlete's physiological and health metabolic profiles after detraining have not been studied in elite Taekwondo (TKD) athletes. To enable a better understanding of these physiological changes to training cessation, this study examined the effects of 8-weeks detraining on the aerobic capacity, body composition, inflammatory status and health metabolic profile in elite TKD athletes. Sixteen elite TKD athletes (age: 21.0 ± 0.8 yrs, BMI: 22.4 ± 3.9 kg/m2; Mean ± SD; 11 males and 5 females) participated in this study. Physical activity level assessment using computerized physical activity logs was performed during the competitive preparation season (i.e. one-week before national competition) and at two week intervals throughout the detraining period. Participant aerobic capacity, body fat, and blood biomarkers were measured before and after detraining, and the blood biomarker analyses included leukocyte subpopulations, blood glucose, insulin, dehydroepiandrosterone-sulfate (DHEA-S), and cortisol. Eight-week detraining increased DHEA-S/cortisol ratio (+57.3%, p = 0.004), increased insulin/cortisol ratio (+59.9%, p = 0.004), reduced aerobic power (-2.43%, p = 0.043), increased body fat accumulation (body fat%: +21.3%, p < 0.001), decreased muscle mass (muscle mass%: -4.04%, p < 0.001), and elevated HOMA-IR (the biomarker of systemic insulin resistance; +34.2%, p = 0.006). The neutrophil-to-lymphocyte ratio (NLR), a systemic inflammatory index, increased by 48.2% (p = 0.005). The change in aerobic capacity was correlated with the increased fat mass (r = -0.429, p = 0.049) but not with muscle loss. An increase in the NLR was correlated to the changes in HOMA-IR (r = 0.44, p = 0.044) and aerobic capacity (r = -0.439, p = 0.045). We demonstrate that 8-week detraining suppresses physiological stress but rapidly results in declines in athletic performance and health metabolic profiles, including reduced aerobic capacity, increased body fat, muscle loss, insulin resistance development and elevated systemic inflammatory status in these young elite TKD athletes. The inflammation state was positively associated with insulin resistance development, fat mass, WHR (the index for central fat accumulation), and the decline in VO2max.

Activation of PPARδ signaling improves skeletal muscle oxidative metabolism and endurance function in an animal model of ischemic left ventricular dysfunction.

PubMed

Zizola, Cynthia; Kennel, Peter J; Akashi, Hirokazu; Ji, Ruiping; Castillero, Estibaliz; George, Isaac; Homma, Shunichi; Schulze, P Christian

2015-05-01

Exercise intolerance in heart failure has been linked to impaired skeletal muscle oxidative capacity. Oxidative metabolism and exercise capacity are regulated by PPARδ signaling. We hypothesized that PPARδ stimulation reverts skeletal muscle oxidative dysfunction. Myocardial infarction (MI) was induced in C57BL/6 mice and the development of ventricular dysfunction was monitored over 8 wk. Mice were randomized to the PPARδ agonist GW501516 (5 mg/kg body wt per day for 4 wk) or placebo 8 wk post-MI. Muscle function was assessed through running tests and grip strength measurements. In muscle, we analyzed muscle fiber cross-sectional area and fiber types, metabolic gene expression, fatty acid (FA) oxidation and ATP content. Signaling pathways were studied in C2C12 myotubes. FA oxidation and ATP levels decreased in muscle from MI mice compared with sham- operated mice. GW501516 administration increased oleic acid oxidation levels in skeletal muscle of the treated MI group compared with placebo treatment. This was accompanied by transcriptional changes including increased CPT1 expression. Further, the PPARδ-agonist improved running endurance compared with placebo. Cell culture experiments revealed protective effects of GW501516 against the cytokine-induced decrease of FA oxidation and changes in metabolic gene expression. Skeletal muscle dysfunction in HF is associated with impaired PPARδ signaling and treatment with the PPARδ agonist GW501516 corrects oxidative capacity and FA metabolism and improves exercise capacity in mice with LV dysfunction. Pharmacological activation of PPARδ signaling could be an attractive therapeutic intervention to counteract the progressive skeletal muscle dysfunction in HF. Copyright © 2015 the American Physiological Society.

A new principle photosynthesis capacity biosensor based on quantitative measurement of delayed fluorescence in vivo.

PubMed

Wang, Junsheng; Xing, Da; Zhang, Lingrui; Jia, Li

2007-06-15

Delayed fluorescence (DF) is an excellent marker for evaluating plant photosynthesis. Compared with common methods for measuring the photosynthesis rate based on consumption of CO(2), DF technique can quantify the plant photosynthesis capacity more accurately and faster under its physiological status with less interference from the environment. We previously reported a method for measuring photosynthesis using DF of chloroplast [Wang, C.L., Xing, D., Chen, Q., 2004. Biosens. Bioelectron. 20, 454-459]. In the study, a novel fast and portable photosynthesis capacity biosensor system was developed, which was composed of light-emitting diode lattice as excitation light source, Channel Photomultiplier DC-Module to achieve DF, single-chip microcomputer as control center, hermetic dark sample chamber, battery power supply and CO(2), humidity and temperature controller. Compared with our previous work, the system was portable and can directly measure plant photosynthesis capacity in vivo in less than 10s. A database in the software to carry out data acquisition and processing was developed to translate maximal DF intensity to net photosynthesis rate (Pn). In addition, local-control and remote-control mode can be chosen in the system. To demonstrate the utility of the system, it was applied to evaluate maximum Pn of four different plant species samples (Queen Rape Myrtle (var. rubra), soybean (Lu Hei No. 1), maize (Jin Dan No. 39) and rice (Jing Dao No. 21)) in field. The results were compared with that using commercial photosynthesis system LI-6400 and the uncertainty was less than +/-5%. The new principle of photosynthesis measurement is a challenge and breakthrough to conventional method of gas exchange and may be a potential technique of next generation photosynthesis measurement.

Speed and stamina trade-off in lacertid lizards.

PubMed

Vanhooydonck, B; Van Damme, R; Aerts, P

2001-05-01

Morphological and physiological considerations suggest that sprinting ability and endurance capacity put conflicting demands on the design of an animal's locomotor apparatus and therefore cannot be maximized simultaneously. To test this hypothesis, we correlated size-corrected maximal sprint speed and stamina of 12 species of lacertid lizards. Phylogenetically independent contrasts of sprint speed and stamina showed a significant negative relationship, giving support to the idea of an evolutionary trade-off between the two performance measures. To test the hypothesis that the trade-off is mediated by a conflict in morphological requirements, we correlated both performance traits with snout-vent length, size-corrected estimates of body mass and limb length, and relative hindlimb length (the residuals of the relationship between hind- and forelimb length). Fast-running species had hindlimbs that were long compared to their forelimbs. None of the other size or shape variables showed a significant relationship with speed or endurance. We conclude that the evolution of sprint capacity may be constrained by the need for endurance capacity and vice versa, but the design conflict underlying this trade-off has yet to be identified.

Inferring physiological energetics of loggerhead turtle (Caretta caretta) from existing data using a general metabolic theory.

PubMed

Marn, Nina; Kooijman, S A L M; Jusup, Marko; Legović, Tarzan; Klanjšček, Tin

2017-05-01

Loggerhead turtle is an endangered sea turtle species with a migratory lifestyle and worldwide distribution, experiencing markedly different habitats throughout its lifetime. Environmental conditions, especially food availability and temperature, constrain the acquisition and the use of available energy, thus affecting physiological processes such as growth, maturation, and reproduction. These physiological processes at the population level determine survival, fecundity, and ultimately the population growth rate-a key indicator of the success of conservation efforts. As a first step towards the comprehensive understanding of how environment shapes the physiology and the life cycle of a loggerhead turtle, we constructed a full life cycle model based on the principles of energy acquisition and utilization embedded in the Dynamic Energy Budget (DEB) theory. We adapted the standard DEB model using data from published and unpublished sources to obtain parameter estimates and model predictions that could be compared with data. The outcome was a successful mathematical description of ontogeny and life history traits of the loggerhead turtle. Some deviations between the model and the data existed (such as an earlier age at sexual maturity and faster growth of the post-hatchlings), yet probable causes for these deviations were found informative and discussed in great detail. Physiological traits such as the capacity to withstand starvation, trade-offs between reproduction and growth, and changes in the energy budget throughout the ontogeny were inferred from the model. The results offer new insights into physiology and ecology of loggerhead turtle with the potential to lead to novel approaches in conservation of this endangered species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of shading on ornamental and physiological characteristics during flower development of groundcover rose (Rosa hybrida L.)

NASA Astrophysics Data System (ADS)

Hou, Wei; Luo, Ya; Wang, Xiaorong; Chen, Qing; Sun, Bo; Wang, Yan; Liu, Zejing; Tang, Haoru; Zhang, Yong

2018-04-01

The objective of the present investigation was to study the effect of shading on flower quality during flower development and photosynthetic capacity of groundcover rose (Rosa hybrida L.). The results showed that shade significantly increased flower diameter, levels of soluble protein and soluble sugar, total carotenoids content and superoxide dismutase (SOD) activity, while contents of malondialdehyde (MDA) and total anthocyanins in shaded flowers were significantly decreased as compared to sun-exposed flowers. However, no significant changes were observed in petal color parameters L*, a*, b* and C* between sun exposure and shade treatment plants at each flower developmental stage. Therefore, groundcover rose seemed to have the capacity to shade condition through auto-regulation. These results could provide us with a theoretical basis for further application of groundcover rose in the greening of urban spaces and an understanding of the mechanisms behind the changes induced by shade.

The effect of atrial-based pacing on exercise capacity as measured by the 6-minute walk test: a substudy of the Canadian Trial of Physiological Pacing (CTOPP).

PubMed

Baranchuk, Adrian; Healey, Jeff S; Thorpe, Kevin E; Morillo, Carlos A; Nair, Girish; Crystal, Eugene; Kerr, Charles R; Connolly, Stuart J

2007-08-01

Although several randomized trials have detected no reduction in major cardiovascular events with the routine use of dual-chamber as opposed to ventricular pacemakers, many individuals continue to advocate their use as a means of improving exercise capacity. The Canadian Trial of Physiological Pacing (CTOPP) trial is the largest trial comparing ventricular pacing to atrial-based pacing (atrial or dual-chamber) in patients with bradycardia. All patients in this trial were asked to complete a 6-minute hall walk test (6MWT) at the time of their first study follow-up. The distance walked in 6 minutes and the patient's heart rate before and immediately after the walk were recorded. Of the 2568 patients in the CTOPP, 76% completed the 6MWT. The mean distance walked was 350 +/- 127 m in the ventricular pacing group and 356 +/- 127 m in the atrial-based group (P = NS). Similarly, there was no difference in the change in heart rate between the two groups (17 +/- 13 vs. 18 +/- 12 bpm: P = NS). However, among patients with an unpaced heart rate of

High-intensity interval training versus continuous training on physiological and metabolic variables in prediabetes and type 2 diabetes: A meta-analysis.

PubMed

De Nardi, Angélica Trevisan; Tolves, Tainara; Lenzi, Thatiane Larissa; Signori, Luis Ulisses; Silva, Antônio Marcos Vargas da

2018-03-01

To compare the effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on functional capacity and cardiometabolic markers in individuals prediabetes and type 2 diabetes (T2D). The search was performed in PubMed (MEDLINE), EMBASE, PEDro, CENTRAL, Scopus, LILACS database, and Clinical Trials from the inception to July 2017, included randomized clinical trials that compared the use of HIIT and MICT in prediabetes and T2D adults. The risk of bias was defined by Cochrane Handbook and quality of evidence by GRADE. From 818 relevant records, seven studies were included in systematic review (64 prediabetes and 120 T2D patients) and five with T2D were meta-analyzed. HIIT promoted significantly increased of 3.02 mL/kg/min (CI95% 1.42-4.61) of VO 2 max, measured for functional capacity, compared to MICT. No differences were found between two modalities of exercises considering the outcomes HbA1c, systolic and diastolic blood pressure, total cholesterol, HDL and LDL cholesterol, triglycerides, BMI, and waist-to-hip ratio. Most of the studies presented unclear risk of bias, and low and very low quality of evidence. HIIT induces cardiometabolic adaptations similar to those of MICT in prediabetes and T2D, and provides greater benefits to functional capacity in patients with T2D. CRD42016047151. Copyright © 2018 Elsevier B.V. All rights reserved.

Retained differentiation capacity of human skeletal muscle satellite cells from spinal cord-injured individuals.

PubMed

Savikj, Mladen; Ruby, Maxwell A; Kostovski, Emil; Iversen, Per O; Zierath, Juleen R; Krook, Anna; Widegren, Ulrika

2018-06-01

Despite the well-known role of satellite cells in skeletal muscle plasticity, the effect of spinal cord injury on their function in humans remains unknown. We determined whether spinal cord injury affects the intrinsic ability of satellite cells to differentiate and produce metabolically healthy myotubes. We obtained vastus lateralis biopsies from eight spinal cord-injured and six able-bodied individuals. Satellite cells were isolated, grown and differentiated in vitro. Gene expression was measured by quantitative PCR. Abundance of differentiation markers and regulatory proteins was determined by Western blotting. Protein synthesis and fatty acid oxidation were measured by radioactive tracer-based assays. Activated satellite cells (myoblasts) and differentiated myotubes derived from skeletal muscle of able-bodied and spinal cord-injured individuals expressed similar (P > 0.05) mRNA levels of myogenic regulatory factors. Myogenic differentiation factor 1 expression was higher in myoblasts from spinal cord-injured individuals. Desmin and myogenin protein content was increased upon differentiation in both groups, while myotubes from spinal cord-injured individuals contained more type I and II myosin heavy chain. Phosphorylated and total protein levels of Akt-mechanistic target of rapamycin and forkhead box protein O signalling axes and protein synthesis rate in myotubes were similar (P > 0.05) between groups. Additionally, fatty acid oxidation of myotubes from spinal cord-injured individuals was unchanged (P > 0.05) compared to able-bodied controls. Our results indicate that the intrinsic differentiation capacity of satellite cells and metabolic characteristics of myotubes are preserved following spinal cord injury. This may inform potential interventions targeting satellite cell activation to alleviate skeletal muscle atrophy. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Improvement of Fitness and Efficacy of a Fire Blight Biocontrol Agent via Nutritional Enhancement Combined with Osmoadaptation ▿

PubMed Central

Cabrefiga, J.; Francés, J.; Montesinos, E.; Bonaterra, A.

2011-01-01

The efficacy of Pseudomonas fluorescens EPS62e in the biocontrol of Erwinia amylovora was improved by a procedure of physiological adaptation to increase colonization and survival in the phytosphere of rosaceous plants. The procedure consisted of osmoadaptation (OA) and nutritional enhancement (NE). OA was based on saline stress and osmolyte amendment of the growth medium during inoculum preparation. NE consisted of addition of glycine and Tween 80 to the formulation. NE and OA increased the growth rate and carrying capacity of EPS62e under high-relative-humidity (RH) conditions and improved survival at low RH on flowers under controlled environmental conditions. NE did not promote growth or affect infection capacity of E. amylovora. The effect of both methods was tested in the field by following the population of EPS62e using quantitative PCR (Q-PCR) (total population) and CFU counting (culturable population) methods. Following field application, EPS62e colonized blossoms, but it was stressed, as indicated by a sharp decrease in culturable compared to total population levels. However, once established in flowers and at the end of bloom, almost all the total population was culturable. The physiological adaptation treatments increased population levels of EPS62e over those of nonadapted cells during the late stage of the flowering period. Control of fire blight infections in flowers and immature fruits was tested by field application of EPS62e and subsequent inoculation with E. amylovora under controlled-environment conditions. The efficacy of fire blight control increased significantly with the combination of nutritional enhancement and osmoadaptation, in comparison with the absence of physiological adaptation. PMID:21441337

Luminal glucose concentrations in the gut under normal conditions.

PubMed

Ferraris, R P; Yasharpour, S; Lloyd, K C; Mirzayan, R; Diamond, J M

1990-11-01

Luminal glucose (Glc) concentrations in the small intestine (SI) are widely assumed to be 50-500 mM. These values have posed problems for interpreting SI luminal osmolality and absorptive capacity, Glc transporter Michaelis-Menten constants (Km), and the physiological role of active Glc transport and its regulation. Hence we measured luminal contents, osmolality, and Glc, Na+, and K+ concentrations in normally feeding rats, rabbits, and dogs. Measured Glc concentrations were compatible with the portion of measured osmolality not accounted for by Na+ and K+ salts, amino acids, and peptides. Mean SI luminal osmolalities were less than or equal to 100 mosmol/kg hypertonic. For animals on the most nearly physiological diets, SI Glc concentrations averaged 0.4-24 mM and ranged with time and SI region from 0.2 to a maximum of 48 mM. The older published very high values are artifacts of direct infusion of concentrated Glc solutions into the gut, nonspecific Glc assays, and failure to test for quantitative recovery or to centrifuge samples in the cold. By storing food after meals and releasing it between meals, rat stomach greatly damps diurnal fluctuations in quantity and osmolality of food reaching the SI and hence also damps fluctuations in absorption rates. These new values for luminal Glc have five important physiological implications: the problem of accounting for apparently very hypertonic SI contents in the face of high osmotic water permeability disappears; the effective Km of the SI Glc transporter is now comparable to prevailing Glc concentrations; the SI no longer appears to have enormous excess absorptive capacity for Glc; regulation of Glc transport by dietary intake now makes functional sense; and the claim that high luminal Glc concentrations permit solvent drag to become the major mode of Glc absorption under normal conditions is undermined.

Differential behavioral and physiological effects of anodal transcranial direct current stimulation in healthy adults of younger and older age

PubMed Central

Heise, Kirstin-Friederike; Niehoff, Martina; Feldheim, J.-F.; Liuzzi, Gianpiero; Gerloff, Christian; Hummel, Friedhelm C.

2014-01-01

Changes in γ-aminobutyric acid (GABA) mediated synaptic transmission have been associated with age-related motor and cognitive functional decline. Since anodal transcranial direct current stimulation (atDCS) has been suggested to target cortical GABAergic inhibitory interneurons, its potential for the treatment of deficient inhibitory activity and functional decline is being increasingly discussed. Therefore, after-effects of a single session of atDCS on resting-state and event-related short-interval intracortical inhibition (SICI) as evaluated with double-pulse TMS and dexterous manual performance were examined using a sham-controlled cross-over design in a sample of older and younger participants. The atDCS effect on resting-state inhibition differed in direction, magnitude, and timing, i.e., late relative release of inhibition in the younger and early relative increase in inhibition in the older. More pronounced release of event-related inhibition after atDCS was exclusively seen in the older. Event-related modulation of inhibition prior to stimulation predicted the magnitude of atDCS-induced effects on resting-state inhibition. Specifically, older participants with high modulatory capacity showed a disinhibitory effect comparable to the younger. Beneficial effects on behavior were mainly seen in the older and in tasks requiring higher dexterity, no clear association with physiological changes was found. Differential effects of atDCS on SICI, discussed to reflect GABAergic inhibition at the level of the primary motor cortex, might be distinct in older and younger participants depending on the functional integrity of the underlying neural network. Older participants with preserved modulatory capacity, i.e., a physiologically “young” motor network, were more likely to show a disinhibitory effect of atDCS. These results favor individually tailored application of tDCS with respect to specific target groups. PMID:25071555

[Epidemiology of arbovirus diseases: use and value of physiologic age determination of female mosquito vectors].

PubMed

Mondet, B

1996-01-01

The physiological age of Yellow Fever Aedes females in Africa was studied during four years, from 1988 to 1992. We used a method, according to Polovodova's method, which looks for the "yellow body" under natural light. Those yellow bodies exist in the old females, the "parous" ones, and not in the young females, the "nulliparous" ones. We present some results to illustrate the interest of studying the physiological age of mosquitoes in the epidemiology of the arboviral diseases. The transmission risk, in relation with abundance and parity rate was illustrated, in particular for Aedes africanus and Aedes luteocephalus, which is useful to compare species, or with a given species, to compare periods. The parity rate of Aedes furcifer females was studied on 6 points along a transect between a forest and a village. The rate and the abundance of the females caught on human bates are inversely proportional. The parity rate is minimum in the canopy forest (about 50%) and maximum inside a house (100%). The rains have different consequences on the species, according to the period of fall. At the beginning of the dry season, they bring about hatching, but not at the end of the dry season. Massive hatching, will occur just at the beginning of the rainy season, some weeks later. Studying the physiological age of Ae. africanus females, the number of nulliparous is not related to the rain. That means a possibility of "natural" hatching for part of the eggs. Among the female of the dry season, young females are found, which is important for the transmission capacity. The method, described herein, to determine the physiological age is perfectly applicable to the Yellow Fever vector Haemagogus janthinomys in Southern America. But for the Dengue vectors Aedes aegypti and probably Aedes albopictus, the Detinova's method seems better. Actually, it seems important to study the physiological age of the vectors Ae. aegypti and Ae. albopictus, as well as the evolution of the physiological age in space and time, in order to better know the epidemiology of dengue in Southern America.

Conserved and narrow temperature limits in alpine insects: Thermal tolerance and supercooling points of the ice-crawlers, Grylloblatta (Insecta: Grylloblattodea: Grylloblattidae).

PubMed

Schoville, Sean D; Slatyer, Rachel A; Bergdahl, James C; Valdez, Glenda A

2015-07-01

For many terrestrial species, habitat associations and range size are dependent on physiological limits, which in turn may influence large-scale patterns of species diversity. The temperature range experienced by individuals is considered to shape the breadth of the thermal niche, with species occupying temporally and/or geographically stable climates tolerating a narrow temperature range. High-elevation environments experience large temperature fluctuations, with frequent periods below 0 °C, but Grylloblatta (Grylloblattodea: Grylloblattidae) occupy climatically stable microhabitats within this region. Here we test critical thermal limits and supercooling points for five Grylloblatta populations from across a large geographic area, to examine whether the stable microhabitats of this group are associated with a narrow thermal niche and assess their capacity to tolerate cold conditions. Thermal limits are highly conserved in Grylloblatta, despite substantial genetic divergence among populations spanning 1500 m elevation and being separated by over 500 km. Further, Grylloblatta show exceptionally narrow thermal limits compared to other insect taxa with little capacity to improve cold tolerance via plasticity. In contrast, upper thermal limits were significantly depressed by cold acclimation. Grylloblatta maintain coordinated movement until they freeze, and they die upon freezing. Convergence of the critical thermal minima, supercooling point and lower lethal limits point to adaptation to a cold but, importantly, constant thermal environment. These physiological data provide an explanation for the high endemism and patchy distribution of Grylloblatta, which relies on subterranean retreats to accommodate narrow thermal limits. These retreats are currently buffered from temperature fluctuations by snow cover, and a declining snowpack thus places Grylloblatta at risk of exposure to temperatures beyond its tolerance capacity. Copyright © 2015 Elsevier Ltd. All rights reserved.

High Oxygen Delivery to Preserve Exercise Capacity in Patients with Idiopathic Pulmonary Fibrosis Treated with Nintedanib. Methodology of the HOPE-IPF Study.

PubMed

Ryerson, Christopher J; Camp, Pat G; Eves, Neil D; Schaeffer, Michele; Syed, Nafeez; Dhillon, Satvir; Jensen, Dennis; Maltais, Francois; O'Donnell, Denis E; Raghavan, Natya; Roman, Michael; Stickland, Michael K; Assayag, Deborah; Bourbeau, Jean; Dion, Genevieve; Fell, Charlene D; Hambly, Nathan; Johannson, Kerri A; Kalluri, Meena; Khalil, Nasreen; Kolb, Martin; Manganas, Helene; Morán-Mendoza, Onofre; Provencher, Steve; Ramesh, Warren; Rolf, J Douglass; Wilcox, Pearce G; Guenette, Jordan A

2016-09-01

Pulmonary rehabilitation improves dyspnea and exercise capacity in idiopathic pulmonary fibrosis (IPF); however, it is unknown whether breathing high amounts of oxygen during exercise training leads to further benefits. Herein, we describe the design of the High Oxygen Delivery to Preserve Exercise Capacity in IPF Patients Treated with Nintedanib study (the HOPE-IPF study). The primary objective of this study is to determine the physiological and perceptual impact of breathing high levels of oxygen during exercise training in patients with IPF who are receiving antifibrotic therapy. HOPE-IPF is a two-arm double-blind multicenter randomized placebo-controlled trial of 88 patients with IPF treated with nintedanib. Patients will undergo 8 weeks of three times weekly aerobic cycle exercise training, breathing a hyperoxic gas mixture with a constant fraction of 60% inhaled oxygen, or breathing up to 40% oxygen as required to maintain an oxygen saturation level of at least 88%. End points will be assessed at baseline, postintervention (Week 8), and follow-up (Week 26). The primary analysis will compare the between-group baseline with post-training change in endurance time during constant work rate cycle exercise tests. Additional analyses will evaluate the impact of training with high oxygen delivery on 6-minute walk distance, dyspnea, physical activity, and quality of life. The HOPE-IPF study will lead to a comprehensive understanding of IPF exercise physiology, with the potential to change clinical practice by indicating the need for increased delivery of supplemental oxygen during pulmonary rehabilitation in patients with IPF. Clinical trial registered with www.clinicaltrials.gov (NCT02551068).

Melatonin protects against uric acid-induced mitochondrial dysfunction, oxidative stress, and triglyceride accumulation in C2C12 myotubes.

PubMed

Maarman, Gerald J; Andrew, Brittany M; Blackhurst, Dee M; Ojuka, Edward O

2017-04-01

Excess uric acid has been shown to induce oxidative stress, triglyceride accumulation, and mitochondrial dysfunction in the liver and is an independent predictor of type-2 diabetes. Skeletal muscle plays a dominant role in type 2 diabetes and presents a large surface area to plasma uric acid. However, the effects of uric acid on skeletal muscle are underinvestigated. Our aim was therefore to characterize the effects of excessive uric acid on oxidative stress, triglyceride content, and mitochondrial function in skeletal muscle C 2 C 12 myotubes and assess how these are modulated by the antioxidant molecule melatonin. Differentiated C 2 C 12 myotubes were exposed to 750 µM uric acid or uric acid + 10 nM melatonin for 72 h. Compared with control, uric acid increased triglyceride content by ~237%, oxidative stress by 32%, and antioxidant capacity by 135%. Uric acid also reduced endogenous ROUTINE respiration, complex II-linked oxidative phosphorylation, and electron transfer system capacities. Melatonin counteracted the effects of uric acid without further altering antioxidant capacity. Our data demonstrate that excess uric acid has adverse effects on skeletal muscle similar to those previously reported in hepatocytes and suggest that melatonin at a low physiological concentration of 10 nM may be a possible therapy against some adverse effects of excess uric acid. NEW & NOTEWORTHY Few studies have investigated the effects of uric acid on skeletal muscle. This study shows that hyperuricemia induces mitochondrial dysfunction and triglyceride accumulation in skeletal muscle. The findings may explain why hyperuricemia is an independent predictor of diabetes. Copyright © 2017 the American Physiological Society.

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

NASA Astrophysics Data System (ADS)

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

2014-12-01

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

Transgenic Rice Expressing Ictb and FBP/Sbpase Derived from Cyanobacteria Exhibits Enhanced Photosynthesis and Mesophyll Conductance to CO2.

PubMed

Gong, Han Yu; Li, Yang; Fang, Gen; Hu, Dao Heng; Jin, Wen Bin; Wang, Zhao Hai; Li, Yang Sheng

2015-01-01

To find a way to promote the rate of carbon flux and further improve the photosynthetic rate in rice, two CO2-transporting and fixing relevant genes, Ictb and FBP/Sbpase, which were derived from cyanobacteria with the 35SCaMV promotor in the respective constructs, were transformed into rice. Three homologous transgenic groups with Ictb, FBP/Sbpase and the two genes combined were constructed in parallel, and the functional effects of these two genes were investigated by physiological, biochemical and leaf anatomy analyses. The results indicated that the mesophyll conductance and net photosynthetic rate were higher at approximately 10.5-36.8% and 13.5-34.6%, respectively, in the three groups but without any changes in leaf anatomy structure compared with wild type. Other physiological and biochemical parameters increased with the same trend in the three groups, which showed that the effect of FBP/SBPase on improving photosynthetic capacity was better than that of ICTB and that there was an additive effect in ICTB+FBP/SBPase. ICTB localized in the cytoplasm, whereas FBP/SBPase was successfully transported to the chloroplast. The two genes might show a synergistic interaction to promote carbon flow and the assimilation rate as a whole. The multigene transformation engineering and its potential utility for improving the photosynthetic capacity and yield in rice were discussed.

Review: Analysis of the evolutionary convergence for high performance swimming in lamnid sharks and tunas.

PubMed

Bernal, D; Dickson, K A; Shadwick, R E; Graham, J B

2001-06-01

Elasmobranchs and bony fishes have evolved independently for more than 400 million years. However, two Recent groups, the lamnid sharks (Family Lamnidae) and tunas (Family Scombridae), display remarkable similarities in features related to swimming performance. Traits separating these two groups from other fishes include a higher degree of body streamlining, a shift in the position of the aerobic, red, locomotor muscle that powers sustained swimming to a more anterior location in the body and nearer to the vertebral column, the capacity to conserve metabolic heat (i.e. regional endothermy), an increased gill surface area with a decreased blood-water barrier thickness, a higher maximum blood oxygen carrying capacity, and greater muscle aerobic and anaerobic enzyme activities at in vivo temperatures. The suite of morphological, physiological, and biochemical specializations that define "high-performance fishes" have been extensively characterized in the tunas. This review examines the convergent features of lamnid sharks and tunas in order to gain insight into the extent that comparable environmental selection pressures have led to the independent origin of similar suites of functional characteristics in these two distinctly different taxa. We propose that, despite differences between teleost and elasmobranch fishes, lamnid sharks and tunas have evolved morphological and physiological specializations that enhance their swimming performance relative to other sharks and most other high performance pelagic fishes.

The effect of predator exposure and reproduction on oxidative stress parameters in the Catarina scallop Argopecten ventricosus.

PubMed

Guerra, C; Zenteno-Savín, T; Maeda-Martínez, A N; Abele, D; Philipp, E E R

2013-05-01

Predation is known to impact growth and reproduction, and the physiological state of the prey, including its susceptibility to oxidative stress. In this study, we investigated how prolonged exposure to predators modulates tissue specific antioxidant defense and oxidative damage in the short-lived epibenthic scallop Argopecten ventricosus (2years maximum lifespan). Scallops that were experimentally exposed to predators had not only lower antioxidant capacities (superoxide dismutase and catalase), but also lower oxidative damage (protein carbonyls and TBARS=thiobarbituric acid reactive substances including lipid peroxides) in gills and mantle compared to individuals not exposed to predators. In contrast, oxidative damage in the swimming muscle was higher in predator-exposed scallops. When predator-exposed scallops were on the verge of spawning, levels of oxidative damage increased in gills and mantle in spite of a parallel increase in antioxidant defense in both tissues. Levels of oxidative damage increased also in the swimming muscle whereas muscle antioxidant capacities decreased. Interestingly, post-spawned scallops restored antioxidant capacities and oxidative damage to immature levels, suggesting they can recover from spawning-related oxidative stress. Our results show that predator exposure and gametogenesis modulate oxidative damage in a tissue specific manner and that high antioxidant capacities do not necessarily coincide with low oxidative damage. Copyright © 2013 Elsevier Inc. All rights reserved.

Contrasting colonization and plant growth promoting capacity between wild type and gfp-derative of the endophyte Pseudomonas putida W619 in hybrid poplar

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

Weyens N.; van der Lelie D.; Boulet, J.

2011-06-09

This study aims to investigate the colonization of poplar by the endophyte Pseudomonas putida W619 and its capacity to promote plant growth. Poplar cuttings were inoculated with P. putida W619 (wild-type or gfp-labelled). The colonization of both strains was investigated and morphological, physiological and biochemical parameters were analyzed to evaluate plant growth promotion. Inoculation with P. putida W619 (wild-type) resulted in remarkable growth promotion, decreased activities of antioxidative defence related enzymes, and reduced stomatal resistance, all indicative of improved plant health and growth in comparison with the non-inoculated cuttings. In contrast, inoculation with gfp-labelled P. putida W619 did not promotemore » growth; it even had a negative effect on plant health and growth. Furthermore, compared to the wildtype strain, colonization by the gfp-labelled P. putida W619::gfp1 was much lower; it only colonized the rhizosphere and root cortex while the wild-type strain also colonized the root xylem vessels. Despite the strong plant growth promoting capacity of P. putida W619 (wild-type), after gfp labelling its growth promoting characteristics disappeared and its colonization capacity was strongly influenced; for these reasons gfp labelling should be applied with sufficient caution.« less

An overview of the issues: physiological effects of bed rest and restricted physical activity

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Bloomfield, S. A.; Greenleaf, J. E.

1997-01-01

Reduction of exercise capacity with confinement to bed rest is well recognized. Underlying physiological mechanisms include dramatic reductions in maximal stroke volume, cardiac output, and oxygen uptake. However, bed rest by itself does not appear to contribute to cardiac dysfunction. Increased muscle fatigue is associated with reduced muscle blood flow, red cell volume, capillarization and oxidative enzymes. Loss of muscle mass and bone density may be reflected by reduced muscle strength and higher risk for injury to bones and joints. The resultant deconditioning caused by bed rest can be independent of the primary disease and physically debilitating in patients who attempt to reambulate to normal active living and working. A challenge to clinicians and health care specialists has been the identification of appropriate and effective methods to restore physical capacity of patients during or after restricted physical activity associated with prolonged bed rest. The examination of physiological responses to bed rest deconditioning and exercise training in healthy subjects has provided significant information to develop effective rehabilitation treatments. The successful application of acute exercise to enhance orthostatic stability, daily endurance exercise to maintain aerobic capacity, or specific resistance exercises to maintain musculoskeletal integrity rather than the use of surgical, pharmacological, and other medical treatments for clinical conditions has been enhanced by investigation and understanding of underlying mechanisms that distinguish physical deconditioning from the disease. This symposium presents an overview of cardiovascular and musculoskeletal deconditioning associated with reduced physical work capacity following prolonged bed rest and exercise training regimens that have proven successful in ameliorating or reversing these adverse effects.

Evaluation of the photochemical reflectance index in AVIRIS imagery

NASA Technical Reports Server (NTRS)

Gamon, John A.; Roberts, Dar A.; Green, Robert O.

1995-01-01

In this paper, we evaluate the potential for extracting the 'photochemical reflectance index' (PRI; previously called the 'physiological reflectance index') from AVIRIS data. This index, which is derived from narrow-band reflectance at 531 and 570 nm, has proven to be a useful indicator of photosynthetic function at the leaf and canopy scales. At the leaf level, PRI varies with photosynthetic capacity, radiation-use efficiency, and vegetation type (unpublished data). This finding is consistent with the hypothesis that vegetation types exhibiting chronically reduced photosynthesis during periods of stress (e.g. drought-tolerant evergreens) invest proportionally more in photoprotective processes than vegetation with high photosynthetic capacity (e.g. crops or deciduous perennials). Vertical transects in tropical and boreal forest canopies have indicated declines in PRI associated with downregulation of photosynthesis at the canopy tops under sunny, dry midday conditions (unpublished data). This reduced PRI in upper canopy levels provides a further basis for examining this signal with the 'view from above' afforded by aircraft overflights. Although many factors could confound interpretation of a subtle physiological signal at the landscape scale, we conducted a preliminary examination of PRI extracted from existing, AVIRIS imagery of Stanford University's Jasper Ridge Biological Preserve obtained on the June 2nd, 1992, overflight. The goal was to use the hyperspectral capabilities of AVIRIS to evaluate the potential of this index for obtaining useful physiological data at the landscape scale. The expectation based on leaf- and canopy-level studies was that regions containing vegetation of reduced photosynthetic capacity (e.g. chaparral or evergreen woodland) would exhibit lower PRI values than regions of high capacity (e.g. deciduous woodland).

Linking transcriptional responses to organismal tolerance reveals mechanisms of thermal sensitivity in a mesothermal endangered fish.

PubMed

Komoroske, Lisa M; Connon, Richard E; Jeffries, Ken M; Fangue, Nann A

2015-10-01

Forecasting species' responses to climate change requires understanding the underlying mechanisms governing environmental stress tolerance, including acclimation capacity and acute stress responses. Current knowledge of these physiological processes in aquatic ectotherms is largely drawn from eurythermal or extreme stenothermal species. Yet many species of conservation concern exhibit tolerance windows and acclimation capacities in between these extremes. We linked transcriptome profiles to organismal tolerance in a mesothermal endangered fish, the delta smelt (Hypomesus transpacificus), to quantify the cellular processes, sublethal thresholds and effects of thermal acclimation on acute stress responses. Delta smelt initiated rapid molecular changes in line with expectations of theoretical thermal limitation models, but also exhibited diminished capacity to modify the expression of some genes and cellular mechanisms key to coping with acute thermal stress found in eurytherms. Sublethal critical thresholds occurred 4-6 °C below their upper tolerance limits, and thermal acclimation shifted the onset of acute thermal stress and tolerance as predicted. However, we found evidence that delta smelt's limited thermal plasticity may be partially due to an inability of individuals to effectively make physiological adjustments to truly achieve new homoeostasis under heightened temperatures, resulting in chronic thermal stress. These findings provide insight into the physiological basis of the diverse patterns of thermal tolerances observed in nature. Moreover, understanding how underlying molecular mechanisms shape thermal acclimation capacity, acute stress responses and ultimately differential phenotypes contributes to a predictive framework to deduce species' responses in situ to changes in selective pressures due to climate change. © 2015 John Wiley & Sons Ltd.

An intensive combined training program modulates physical, physiological, biomotoric, and technical parameters in women basketball players.

PubMed

Kilinç, Fatih

2008-11-01

The purpose of this study was the investigation of the effects of an intensive combined training program based on the pretest scores of a university women's basketball team on their physical, physiological, biomotoric, and technical features. Twenty-four university volunteers were equally divided into two groups: an experiment group (intensive combined training group) and a control (technical training) group. The 10-week intensive combined training program was performed on the experiment group according to their pretest outcomes. Before and at the end of each period of training, which was scheduled four times a week, the physical, physiological, biomotoric, and technical performance of each subject were determined. With respect to the pre- and posttest measurements, the basketball group showed significant differences (p < 0.05) in girth measurements (shoulder, waist, hip, arm, thigh, and calf), in skinfold measurements (percent body fat), in physiological measurements (vital capacity and forced vital capacity), in biomotoric tests (right-left hand grip, dynamic and countermovement jump, sit-up, push-up, 1500-m endurance), and in technique tests (free and inside shooting). It can be concluded that a 10-week intensive combined training program performed on university women basketball players had a significant effect on improving their physical, physiological, biomotoric, and technical features. It proved to be highly recommendable for female basketball players who are preparing for short-term tournaments; the basketball group in this study won a championship.

BATS RECOVERING FROM WHITE-NOSE SYNDROME ELEVATE METABOLIC RATE DURING WING HEALING IN SPRING.

PubMed

Meierhofer, Melissa B; Johnson, Joseph S; Field, Kenneth A; Lumadue, Shayne S; Kurta, Allen; Kath, Joseph A; Reeder, DeeAnn M

2018-04-04

  Host responses to infection with novel pathogens are costly and require trade-offs among physiologic systems. One such pathogen is the fungus Pseudogymnoascus destructans (Pd) that causes white-nose syndrome (WNS) and has led to mass mortality of hibernating bats in eastern North America. Although infection with Pd does not always result in death, we hypothesized that bats that survive infection suffer significant consequences that negatively impact the ability of females to reproduce. To understand the physiologic consequences of surviving infection with Pd, we assessed differences in wing damage, mass-specific resting metabolic rate, and reproductive rate between little brown myotis ( Myotis lucifugus) that survived a winter in captivity after inoculation with Pd (WNS survivors) and comparable, uninfected bats. Survivors of WNS had significantly more damaged wing tissue and displayed elevated mass-specific metabolic rates compared with Pd-uninfected bats after emergence from hibernation. The WNS survivors and Pd-uninfected bats did not significantly differ in their reproductive capacity, at least in captivity. However, our metabolic data demonstrated greater energetic costs during spring in WNS survivors compared with uninfected bats, which may have led to other consequences for postpartum fitness. We suggest that, after surviving the energetic constraints of winter, temperate hibernating bats infected with Pd faced a second energetic bottleneck after emerging from hibernation.

Anuran amphibians as comparative models for understanding extreme dehydration tolerance: a negative feedback lymphatic mechanism for blood volume regulation.

PubMed

Hillman, Stanley S

2018-06-06

Anurans are the most terrestrial order of amphibians. Couple the high driving forces for evaporative loss in terrestrial environments and their low resistance to evaporation, dehydration is an inevitable stress on their water balance. Anurans have the greatest tolerances for dehydration of any vertebrate group, some species can tolerate evaporative losses up to 45% of their standard body mass. Anurans have remarkable capacities to regulate blood volume with hemorrhage and dehydration compared to mammals. Stabilization of blood volume is central to extending dehydration tolerance, since it avoids both the hypovolemic and hyperviscosity stresses on cardiac output and its consequential effects on aerobic capacity. Anurans, in contrast to mammals, seem incapable of generating a sufficient pressure difference, either oncotically or via interstitial compliance, to move fluid from the interstitium into the capillaries. Couple this inability to generate a sufficient pressure difference for transvascular uptake to a circulatory system with high filtration coefficients and a high rate of plasma turnover is the consequence. The novel lymphatic system of anurans is critical to a remarkable capacity for blood volume regulation. This review summarizes what is known about the anatomical and physiological specializations which are involved in explaining differential blood volume regulation and dehydration tolerance involving a true centrally mediated negative feedback of lymphatic function involving baroreceptors as sensors and lymph hearts, AVT, pulmonary ventilation and specialized skeletal muscles as effectors.

Hyperinflation and intrinsic positive end-expiratory pressure: less room to breathe.

PubMed

Krieger, Bruce P

2009-01-01

Clinically, the symptoms and limited exercise capabilities of patients with chronic obstructive pulmonary disease (COPD) correlate better with changes in lung volumes than with airflow measurements. The realization of the clinical importance of hyperinflation has been overshadowed for decades by the use of forced expiratory volume during 1 s (FEV(1)) and the ratio of the FEV(1) to the forced expiratory vital capacity (FEV(1)/FVC) to categorize the severity and progression of COPD. Hyperinflation is defined as an elevation in the end-expiratory lung volume or functional residual capacity. When severe hyperinflation encroaches upon inspiratory capacity and limits vital capacity, it results in elevated intrinsic positive end-expiratory pressure (PEEPi) that places the diaphragm at a mechanical disadvantage and increases the work of breathing. Severe hyperinflation is the major physiologic cause of the resulting hypercarbic respiratory failure and patients' inability to transition (i.e. wean) from mechanical ventilatory support to spontaneous breathing. This paper reviews the basic physiologic principles of hyperinflation and its clinical manifestations as demonstrated by PEEPi. Also reviewed are the adverse effects of hyperinflation and PEEPi in critically ill patients with COPD, and methods for minimizing or counterbalancing these effects. Copyright 2009 S. Karger AG, Basel.

Physical work capacity in older adults: implications for the aging worker.

PubMed

Kenny, Glen P; Yardley, Jane E; Martineau, Lucie; Jay, Ollie

2008-08-01

In many developed countries, the workforce is rapidly aging. Occupational demands however, have not decreased despite the fact that workers see a decline in physical work capacity with age. The purpose of this review is to examine the physiological adaptations to aging, the impact of aging on performance and the benefits of physical fitness in improving functional work capacity in aging individuals. An extensive search of the scientific literature was performed, acquiring published articles which examined the physiological changes associated with age-related decrements in the physical work capacity of healthy aging adults. The databases accessed included AARP Ageline, AccessScience, Annual Reviews, CISTI, Cochrane Library, Clinical Evidence, Digital Dissertations (Proquest), Embase, HealthSTAR, Medline, PubMed, Scopus, and PASCAL and included relevant information sites obtained on the world wide web. While a great deal of variation exists, an average decline of 20% in physical work capacity has been reported between the ages of 40 and 60 years, due to decreases in aerobic and musculoskeletal capacity. These declines can contribute to decreased work capacity, and consequential increases in work-related injuries and illness. However, differences in habitual physical activity will greatly influence the variability seen in individual physical work capacity and its components. Well-organized, management-supported, work-site health interventions encouraging physical activity during work hours could potentially decrease the incidence of age-related injury and illness. Age-associated functional declines and the accompanying risk of work-related injury can be prevented or at least delayed by the practice of regular physical activity. Older workers could optimally pursue their careers until retirement if they continuously maintain their physical training.

Drosophila development, physiology, behavior, and lifespan are influenced by altered dietary composition

PubMed Central

Ormerod, Kiel G.; LePine, Olivia K.; Abbineni, Prabhodh S.; Bridgeman, Justin M.; Mercier, A. Joffre; Tattersall, Glenn J.

2017-01-01

ABSTRACT Diet profoundly influences the behavior of animals across many phyla. Despite this, most laboratories using model organisms, such as Drosophila, use multiple, different, commercial or custom-made media for rearing their animals. In addition to measuring growth, fecundity and longevity, we used several behavioral and physiological assays to determine if and how altering food media influence wild-type (Canton S) Drosophila melanogaster, at larval, pupal, and adult stages. Comparing 2 commonly used commercial food media we observed several key developmental and morphological differences. Third-instar larvae and pupae developmental timing, body weight and size, and even lifespan significantly differed between the 2 diets, and some of these differences persisted into adulthood. Diet was also found to produce significantly different thermal preference, locomotory capacity for geotaxis, feeding rates, and lower muscle response to hormonal stimulation. There were no differences, however, in adult thermal preferences, in the number or viability of eggs laid, or in olfactory learning and memory between the diets. We characterized the composition of the 2 diets and found particularly significant differences in cholesterol and (phospho)lipids between them. Notably, diacylglycerol (DAG) concentrations vary substantially between the 2 diets, and may contribute to key phenotypic differences, including lifespan. Overall, the data confirm that 2 different diets can profoundly influence the behavior, physiology, morphology and development of wild-type Drosophila, with greater behavioral and physiologic differences occurring during the larval stages. PMID:28277941

How do cuticular hydrocarbons evolve? Physiological constraints and climatic and biotic selection pressures act on a complex functional trait

PubMed Central

Blaimer, Bonnie B.; Schmitt, Thomas

2017-01-01

Cuticular hydrocarbons (CHCs) cover the cuticles of virtually all insects, serving as a waterproofing agent and as a communication signal. The causes for the high CHC variation between species, and the factors influencing CHC profiles, are scarcely understood. Here, we compare CHC profiles of ant species from seven biogeographic regions, searching for physiological constraints and for climatic and biotic selection pressures. Molecule length constrained CHC composition: long-chain profiles contained fewer linear alkanes, but more hydrocarbons with disruptive features in the molecule. This is probably owing to selection on the physiology to build a semi-fluid cuticular layer, which is necessary for waterproofing and communication. CHC composition also depended on the precipitation in the ants' habitats. Species from wet climates had more alkenes and fewer dimethyl alkanes than those from drier habitats, which can be explained by different waterproofing capacities of these compounds. By contrast, temperature did not affect CHC composition. Mutualistically associated (parabiotic) species possessed profiles highly distinct from non-associated species. Our study is, to our knowledge, the first to show systematic impacts of physiological, climatic and biotic factors on quantitative CHC composition across a global, multi-species dataset. We demonstrate how they jointly shape CHC profiles, and advance our understanding of the evolution of this complex functional trait in insects. PMID:28298343

Soldier Performance as a Function of Stress and Load: A Review

DTIC Science & Technology

1990-01-01

1985) increasing load obstacle course decreased weight performance Ikai & Steinhaus shouting forearm flex strength increased (1961) gun shot increased...performance. Capacity represents relatively fil1 ed physiological limits of behavior, while performance is a function of psychological factors (Ikai & Steinhaus ...3), 513-524. Ikai, M., & Steinhaus , A. H. (1961). Some factors modifying the expression of human strength. Journal of ADnlied Physiology, 15, 157-163

[Heat and moisture exchangers for conditioning of inspired air of intubated patients in intensive care. The humidification properties of passive air exchangers under clinical conditions].

PubMed

Rathgeber, J; Züchner, K; Kietzmann, D; Weyland, W

1995-04-01

Heat and moisture exchangers (HME) are used as artificial noses for intubated patients to prevent tracheo-bronchial or pulmonary damage resulting from dry and cold inspired gases. HME are mounted directly on the tracheal tube, where they collect a large fraction of the heat and moisture of the expired air, adding this to the subsequent inspired breath. The effective performance depends on the water-retention capacity of the HME: the amount of water added to the inspired gas cannot exceed the stored water uptake of the previous breath. This study evaluates the efficiency of four different HME under laboratory and clinical conditions using a new moisture-measuring device. METHODS. In a first step, the absolute efficiency of four different HME (DAR Hygrobac, Gibeck Humid-Vent 2P, Pall BB 22-15 T, and Pall BB 100) was evaluated using a lung model simulating physiological heat and humidity conditions of the upper airways. The model was ventilated with tidal volumes of 500, 1,000, and 1,500 ml and different flow rates. The water content of the ventilated air was determined between tracheal tube and HME using a new high-resolution humidity meter and compared with the absolute water loss of the exhaled air at the gas outlet of a Siemens Servo C ventilator measured with a dew-point hygrometer. Secondly, the moisturizing efficiency was evaluated under clinical conditions in an intensive care unit with 25 intubated patients. Maintaining the ventilatory conditions for each patient, the HME were randomly changed. The humidity data were determined as described above and compared with the laboratory findings. RESULTS AND DISCUSSION. The water content at the respirator outlet is inversely equivalent to the humidity of the inspired gases and represents the water loss from the respiratory tract if the patient is ventilated with dry gases. Moisture retention and heating capacity decreased with higher volumes and higher flow rates. These data are simple to obtain without affecting the patient and can easily be interpreted. It was demonstrated that, compared to physiological conditions, the DAR Hygrobac and Gibeck Humid Vent 2P-HME coated with hygroscopic salts-were able to maintain sufficient inspiratory humidity and heat. The Pall-HME, solely a condensation humidifier, did not meet the physiological requirements.

Early Deficits in Glycolysis Are Specific to Striatal Neurons from a Rat Model of Huntington Disease

PubMed Central

Gouarné, Caroline; Tardif, Gwenaëlle; Tracz, Jennifer; Latyszenok, Virginie; Michaud, Magali; Clemens, Laura Emily; Yu-Taeger, Libo; Nguyen, Huu Phuc; Bordet, Thierry; Pruss, Rebecca M.

2013-01-01

In Huntington disease (HD), there is increasing evidence for a link between mutant huntingtin expression, mitochondrial dysfunction, energetic deficits and neurodegeneration but the precise nature, causes and order of these events remain to be determined. In this work, our objective was to evaluate mitochondrial respiratory function in intact, non-permeabilized, neurons derived from a transgenic rat model for HD compared to their wild type littermates by measuring oxygen consumption rates and extracellular acidification rates. Although HD striatal neurons had similar respiratory capacity as those from their wild-type littermates when they were incubated in rich medium containing a supra-physiological glucose concentration (25 mM), pyruvate and amino acids, respiratory defects emerged when cells were incubated in media containing only a physiological cerebral level of glucose (2.5 mM). According to the concept that glucose is not the sole substrate used by the brain for neuronal energy production, we provide evidence that primary neurons can use lactate as well as pyruvate to fuel the mitochondrial respiratory chain. In contrast to glucose, we found no major deficits in HD striatal neurons’ capacity to use pyruvate as a respiratory substrate compared to wild type littermates. Additionally, we used extracellular acidification rates to confirm a reduction in anaerobic glycolysis in the same cells. Interestingly, the metabolic disturbances observed in striatal neurons were not seen in primary cortical neurons, a brain region affected in later stages of HD. In conclusion, our results argue for a dysfunction in glycolysis, which might precede any defects in the respiratory chain itself, and these are early events in the onset of disease. PMID:24303051

Optimal Adenosine Stress for Maximum Stress Perfusion, Coronary Flow Reserve, and Pixel Distribution of Coronary Flow Capacity by Kolmogorov-Smirnov Analysis.

PubMed

Kitkungvan, Danai; Lai, Dejian; Zhu, Hongjian; Roby, Amanda E; Johnson, Nils P; Steptoe, Derek D; Patel, Monica B; Kirkeeide, Richard; Gould, K Lance

2017-02-01

Different adenosine stress imaging protocols have not been systemically validated for absolute myocardial perfusion and coronary flow reserve (CFR) by positron emission tomography, where submaximal stress precludes assessing physiological severity of coronary artery disease. In 127 volunteers, serial rest-stress positron emission tomography scans using rubidium-82 with various adenosine infusion protocols identified (1) the protocol with maximum stress perfusion and CFR, (2) test-retest precision in same subject, (3) stress perfusion and CFR after adenosine compared with dipyridamole, (4) heterogeneity of coronary flow capacity combining stress perfusion and CFR, and (5) potential relevance for patients with risk factors or coronary artery disease. The adenosine 6-minute infusion with rubidium-82 injection at 3 minutes caused CFR that was significantly 15.7% higher than the 4-minute adenosine infusion with rubidium-82 injection at 2 minutes and significantly more homogeneous by Kolmogorov-Smirnov analysis for histograms of 1344 pixel range of perfusion in paired positron emission tomographies. In a coronary artery disease cohort separate from volunteers of this study, compared with the 3/6-minute protocol, the 2/4-minute adenosine protocol would potentially have changed 332 of 1732 (19%) positron emission tomographies at low-risk physiological severity CFR ≥2.3 to CFR <2.0, thereby implying high-risk quantitative severity potentially appropriate for interventions but because of suboptimal stress of the 2/4 protocol in some patients. The 6-minute adenosine infusion with rubidium-82 activation at 3 minutes produced CFR that averaged 15.7% higher than that in the 2/4-minute protocol, thereby potentially providing essential information for personalized management in some patients. © 2017 American Heart Association, Inc.

Leptospira interrogans lpxD Homologue Is Required for Thermal Acclimatization and Virulence.

PubMed

Eshghi, Azad; Henderson, Jeremy; Trent, M Stephen; Picardeau, Mathieu

2015-11-01

Leptospirosis is an emerging disease with an annual occurrence of over 1 million human cases worldwide. Pathogenic Leptospira bacteria are maintained in zoonotic cycles involving a diverse array of mammals, with the capacity to survive outside the host in aquatic environments. Survival in the diverse environments encountered by Leptospira likely requires various adaptive mechanisms. Little is known about Leptospira outer membrane modification systems, which may contribute to the capacity of these bacteria to successfully inhabit and colonize diverse environments and animal hosts. Leptospira bacteria carry two genes annotated as UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferase genes (la0512 and la4326 [lpxD1 and lpxD2]) that in other bacteria are involved in the early steps of biosynthesis of lipid A, the membrane lipid anchor of lipopolysaccharide. Inactivation of only one of these genes, la0512/lpxD1, imparted sensitivity to the host physiological temperature (37°C) and rendered the bacteria avirulent in an animal infection model. Polymyxin B sensitivity assays revealed compromised outer membrane integrity in the lpxD1 mutant at host physiological temperature, but structural analysis of lipid A in the mutant revealed only minor changes in the lipid A moiety compared to that found in the wild-type strain. In accordance with this, an in trans complementation restored the phenotypes to a level comparable to that of the wild-type strain. These results suggest that the gene annotated as lpxD1 in Leptospira interrogans plays an important role in temperature adaptation and virulence in the animal infection model. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Characteristics explaining performance in downhill mountain biking.

PubMed

Chidley, Joel B; MacGregor, Alexandra L; Martin, Caoimhe; Arthur, Calum A; Macdonald, Jamie H

2015-03-01

To identify physiological, psychological, and skill characteristics that explain performance in downhill (DH) mountain-bike racing. Four studies were used to (1) identify factors potentially contributing to DH performance (using an expert focus group), (2) develop and validate a measure of rider skill (using video analysis and expert judge evaluation), (3) evaluate whether physiological, psychological, and skill variables contribute to performance at a DH competition, and (4) test the specific contribution of aerobic capacity to DH performance. STUDY 1 identified aerobic capacity, handgrip endurance, anaerobic power, rider skill, and self-confidence as potentially important for DH. In study 2 the rider-skill measure displayed good interrater reliability. Study 3 found that rider skill and handgrip endurance were significantly related to DH ride time (β=-0.76 and -0.14, respectively; R2=.73), with exploratory analyses suggesting that DH ride time may also be influenced by self-confidence and aerobic capacity. Study 4 confirmed aerobic capacity as an important variable influencing DH performance (for a DH ride, mean oxygen uptake was 49±5 mL·kg(-1)·min(-1), and 90% of the ride was completed above the 1st ventilatory threshold). In order of importance, rider skill, handgrip endurance, self-confidence, and aerobic capacity were identified as variables influencing DH performance. Practically, this study provides a novel assessment of rider skill that could be used by coaches to monitor training and identify talent. Novel intervention targets to enhance DH performance were also identified, including self-confidence and aerobic capacity.

Are there sex differences in the capillary blood volume and diffusing capacity response to exercise?

PubMed

Bouwsema, Melissa M; Tedjasaputra, Vincent; Stickland, Michael K

2017-03-01

Previous work suggests that women may exhibit a greater respiratory limitation in exercise compared with height-matched men. Diffusion capacity (Dl CO ) increases with incremental exercise, and the smaller lungs of women may limit membrane diffusing capacity (Dm) and pulmonary capillary blood volume (Vc) in response to the increased oxygen demand. We hypothesized that women would have lower Dl CO , Dl CO relative to cardiac output (Dl CO /Q̇), Dm, Vc, and pulmonary transit time, secondary to lower Vc at peak exercise. Sixteen women (112 ± 12% predicted relative V̇o 2peak ) and sixteen men (118 ± 22% predicted relative V̇o 2peak ) were matched for height and weight. Hemoglobin-corrected diffusing capacity (Dl CO ), Vc, and Dm were determined via the multiple-[Formula: see text] Dl CO technique at rest and during incremental exercise up to 90% of V̇o 2peak Both groups increased Dl CO , Vc, and Dm with exercise intensity, but women had 20% lower Dl CO ( P < 0.001), 18% lower Vc ( P = 0.002), and 22% lower Dm ( P < 0.001) compared with men across all workloads, and neither group exhibited a plateau in Vc. When expressed relative to alveolar volume (Va), the between-sex difference was eliminated. The drop in Dl CO /Q̇ was proportionally less in women than men, and mean pulmonary transit time did not drop below 0.3 s in either group. Women demonstrate consistently lower Dl CO , Vc, and Dm compared with height-matched men during exercise; however, these differences disappear with correction for lung size. These results suggest that after differences in lung volume are accounted for there is no intrinsic sex difference in the Dl CO , Vc, or Dm response to exercise. NEW & NOTEWORTHY Women demonstrate lower diffusing capacity-to-cardiac output ratio (Dl CO /Q̇), pulmonary capillary blood volume (Vc), and membrane diffusing capacity (Dm) compared with height-matched men during exercise. However, these differences disappear after correction for lung size. The drop in Dl CO /Q̇ was proportionally less in women, and pulmonary transit time did not drop below 0.3 s in either group. After differences in lung volume are accounted for, there is no intrinsic sex difference in Dl CO , Vc, or Dm response to exercise. Copyright © 2017 the American Physiological Society.

Science of rugby league football: a review.

PubMed

Gabbett, Tim J

2005-09-01

The purpose of this paper is to provide a comprehensive review of the science of rugby league football at all levels of competition (i.e. junior, amateur, semi-professional, professional), with special reference to all discipline-specific scientific research performed in rugby league (i.e. physiological, psychological, injury epidemiology, strength and conditioning, performance analysis). Rugby league football is played at junior and senior levels in several countries worldwide. A rugby league team consists of 13 players (6 forwards and 7 backs). The game is played over two 30 - 40 min halves (depending on the standard of competition) separated by a 10 min rest interval. Several studies have documented the physiological capacities and injury rates of rugby league players. More recently, studies have investigated the physiological demands of competition. Interestingly, the physiological capacities of players, the incidence of injury and the physiological demands of competition all increase as the playing standard is increased. Mean blood lactate concentrations of 5.2, 7.2 and 9.1 mmol . l(-1) have been reported during competition for amateur, semi-professional and professional rugby league players respectively. Mean heart rates of 152 beats . min(-1) (78% of maximal heart rate), 166 beats . min(-1) (84% of maximal heart rate) and 172 beats . min(-1) (93% of maximal heart rate) have been recorded for amateur, semi-professional and junior elite rugby league players respectively. Skill-based conditioning games have been used to develop the skill and fitness of rugby league players, with mean heart rate and blood lactate responses during these activities almost identical to those obtained during competition. In addition, recent studies have shown that most training injuries are sustained in traditional conditioning activities that involve no skill component (i.e. running without the ball), whereas the incidence of injuries while participating in skill-based conditioning games is low. Collaborative research among the various sport science disciplines is required to identify strategies to reduce the incidence of injury and enhance the performance of rugby league players. An understanding of the movement patterns and physiological demands of different positions at all standards of competition would allow the development of strength and conditioning programmes to meet the precise requirements of these positions. Finally, studies investigating the impact of improvements in physiological capacities (including the effect of different strength and conditioning programmes) on rugby league playing performance are warranted.

Age-dependent leaf physiology and consequences for crown-scale carbon uptake during the dry season in an Amazon evergreen forest.

PubMed

Albert, Loren P; Wu, Jin; Prohaska, Neill; de Camargo, Plinio Barbosa; Huxman, Travis E; Tribuzy, Edgard S; Ivanov, Valeriy Y; Oliveira, Rafael S; Garcia, Sabrina; Smith, Marielle N; Oliveira Junior, Raimundo Cosme; Restrepo-Coupe, Natalia; da Silva, Rodrigo; Stark, Scott C; Martins, Giordane A; Penha, Deliane V; Saleska, Scott R

2018-03-04

Satellite and tower-based metrics of forest-scale photosynthesis generally increase with dry season progression across central Amazônia, but the underlying mechanisms lack consensus. We conducted demographic surveys of leaf age composition, and measured the age dependence of leaf physiology in broadleaf canopy trees of abundant species at a central eastern Amazon site. Using a novel leaf-to-branch scaling approach, we used these data to independently test the much-debated hypothesis - arising from satellite and tower-based observations - that leaf phenology could explain the forest-scale pattern of dry season photosynthesis. Stomatal conductance and biochemical parameters of photosynthesis were higher for recently mature leaves than for old leaves. Most branches had multiple leaf age categories simultaneously present, and the number of recently mature leaves increased as the dry season progressed because old leaves were exchanged for new leaves. These findings provide the first direct field evidence that branch-scale photosynthetic capacity increases during the dry season, with a magnitude consistent with increases in ecosystem-scale photosynthetic capacity derived from flux towers. Interactions between leaf age-dependent physiology and shifting leaf age-demographic composition are sufficient to explain the dry season photosynthetic capacity pattern at this site, and should be considered in vegetation models of tropical evergreen forests. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Age-dependent leaf physiology and consequences for crown-scale carbon uptake during the dry season in an Amazon evergreen forest

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

Albert, Loren P.; Wu, Jin; Prohaska, Neill

Satellite and tower-based metrics of forest-scale photosynthesis generally increase with dry season progression across central Amazônia, but the underlying mechanisms lack consensus. We conducted demographic surveys of leaf age composition, and measured age-dependence of leaf physiology in broadleaf canopy trees of abundant species at a central eastern Amazon site. Using a novel leaf-to-branch scaling approach, we used this data to independently test the much-debated hypothesis—arising from satellite and tower-based observations—that leaf phenology could explain the forest-scale pattern of dry season photosynthesis. Stomatal conductance and biochemical parameters of photosynthesis were higher for recently mature leaves than for old leaves. Most branchesmore » had multiple leaf age categories simultaneously present, and the number of recently mature leaves increased as the dry season progressed because old leaves were exchanged for new leaves. These findings provide the first direct field evidence that branch-scale photosynthetic capacity increases during the dry season, with a magnitude consistent with increases in ecosystem-scale photosynthetic capacity derived from flux towers. In conclusion, interaction between leaf age-dependent physiology and shifting leaf age-demographic composition are sufficient to explain the dry season photosynthetic capacity pattern at this site, and should be considered in vegetation models of tropical evergreen forests.« less

Effects of Age and Military Service on Strength and Physiological Characteristics of U.S. Army Soldiers.

PubMed

Abt, John P; Perlsweig, Katherine; Nagai, Takashi; Sell, Timothy C; Wirt, Michael D; Lephart, Scott M

2016-02-01

Soldiers must maintain tactical performance capabilities over the course of their career. Loss in physical readiness may be a function of age and the operational demands associated with increasing years of service. The purpose of this study was to assess strength and physiological characteristics in different cohorts of U.S. Army Soldiers based on years of service and age. A total of 253 Soldiers (age: 28.1 ± 6.8 years; height: 1.76 ± 0.11 m; mass: 84.1 ± 12.2 kg) participated. Individual subject cohorts were created based on years of service (1-5 years, 6-10 years, 11-15 years) and age (20-24 years, 25-29 years, 30-34 years, 35-39 years, 40-44 years). Testing included shoulder, knee, ankle, and torso strength, aerobic capacity/lactate threshold, anaerobic power/capacity, and body composition/total mass. Those with 11 to 15 years of service and between ages 30 and 34 had a higher percentage of body fat, and lower aerobic capacity and lactate threshold than younger Soldiers with fewer years of service. Physical training interventions should focus on maintenance of physiological characteristics to offset the loss of readiness at the similar time point of 11 to 15 years of service and 30 to 34 years of age. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Age-dependent leaf physiology and consequences for crown-scale carbon uptake during the dry season in an Amazon evergreen forest

DOE PAGES

Albert, Loren P.; Wu, Jin; Prohaska, Neill; ...

2018-03-04

Satellite and tower-based metrics of forest-scale photosynthesis generally increase with dry season progression across central Amazônia, but the underlying mechanisms lack consensus. We conducted demographic surveys of leaf age composition, and measured age-dependence of leaf physiology in broadleaf canopy trees of abundant species at a central eastern Amazon site. Using a novel leaf-to-branch scaling approach, we used this data to independently test the much-debated hypothesis—arising from satellite and tower-based observations—that leaf phenology could explain the forest-scale pattern of dry season photosynthesis. Stomatal conductance and biochemical parameters of photosynthesis were higher for recently mature leaves than for old leaves. Most branchesmore » had multiple leaf age categories simultaneously present, and the number of recently mature leaves increased as the dry season progressed because old leaves were exchanged for new leaves. These findings provide the first direct field evidence that branch-scale photosynthetic capacity increases during the dry season, with a magnitude consistent with increases in ecosystem-scale photosynthetic capacity derived from flux towers. In conclusion, interaction between leaf age-dependent physiology and shifting leaf age-demographic composition are sufficient to explain the dry season photosynthetic capacity pattern at this site, and should be considered in vegetation models of tropical evergreen forests.« less

Physiological and anthropometric determinants of rhythmic gymnastics performance.

PubMed

Douda, Helen T; Toubekis, Argyris G; Avloniti, Alexandra A; Tokmakidis, Savvas P

2008-03-01

To identify the physiological and anthropometric predictors of rhythmic gymnastics performance, which was defined from the total ranking score of each athlete in a national competition. Thirty-four rhythmic gymnasts were divided into 2 groups, elite (n = 15) and nonelite (n = 19), and they underwent a battery of anthropometric, physical fitness, and physiological measurements. The principal-components analysis extracted 6 components: anthropometric, flexibility, explosive strength, aerobic capacity, body dimensions, and anaerobic metabolism. These were used in a simultaneous multiple-regression procedure to determine which best explain the variance in rhythmic gymnastics performance. Based on the principal-component analysis, the anthropometric component explained 45% of the total variance, flexibility 12.1%, explosive strength 9.2%, aerobic capacity 7.4%, body dimensions 6.8%, and anaerobic metabolism 4.6%. Components of anthropometric (r = .50) and aerobic capacity (r = .49) were significantly correlated with performance (P < .01). When the multiple-regression model-y = 10.708 + (0.0005121 x VO2max) + (0.157 x arm span) + (0.814 x midthigh circumference) - (0.293 x body mass)-was applied to elite gymnasts, 92.5% of the variation was explained by VO2max (58.9%), arm span (12%), midthigh circumference (13.1%), and body mass (8.5%). Selected anthropometric characteristics, aerobic power, flexibility, and explosive strength are important determinants of successful performance. These findings might have practical implications for both training and talent identification in rhythmic gymnastics.

Developing and evaluating effective bioscience learning activities for nursing students.

PubMed

Salvage-Jones, Judith; Hamill, Jessie; Todorovic, Michael; Barton, Matthew J; Johnston, Amy N B

2016-07-01

Effective engagement of nursing students in the study of biosciences remains a challenge for many tertiary institutes. In this study we attempted to implement and then evaluate a simple hands-on intervention, consisting of a series of hands-on games and puzzles, to increase nursing student engagement with core concepts and anatomical learning involved in clinical anatomy and physiology. The study used a quazi-experimental longitudinal before and after design, to explore the effect of a learning intervention on student performance. Set across three different campuses of the same University, it included 1320 first year undergraduate nursing students from 2013 to 2014 who were studying Anatomy and Physiology. Students were exposed to the interventions or not, and concomitant academic performance, weekly quiz scores, performance in fortnightly worksheets and, across the semester, exam performance were compared. The results show that while the intervention appeared to increase academic performance in students on one campus (2013) compared to the other two, this difference was not sustained into 2014 when a bigger cohort was examined. Despite significant subjective student satisfaction and enthusiasm about these learning and teaching interventions, the data does not support the capacity of these activities to enhance student academic performance. Tertiary entrance scores, being a non-native English speakers and socio-economic status all had a bigger impact on student performance than engagement with fun anatomy and physiology activities. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Treadmill Exercise Within LBNP as an Integrated Coutermeasure to Microgravity

NASA Technical Reports Server (NTRS)

Lee, Stuart; Hargens, A. R.; Schneider, S. M.; Watenpaugh, D. E.

2010-01-01

An integrated exercise countermeasure for microgravity is needed to protect multiple physiologic systems and save crew time. Such a countermeasure should protect orthostatic tolerance, upright ambulatory capability (including sprinting), aerobic capacity, muscle strength/endurance, and other physiologic parameters relevant to human performance. We developed a novel physiologic countermeasure, treadmill exercise within LBNP, for preventing cardiovascular and musculoskeletal deconditioning associated with prolonged bed rest and spaceflight. We evaluated 40 min of daily LBNP treadmill exercise by a battery of physiologic parameters relevant to maintaining exercise performance and health of both women and men during bed-rest (simulated microgravity) studies lasting from 5 to 60 days. For 30 day studies, we employed identical twins with one twin as the control and the other twin as the exerciser to improve comparative power. During the WISE 60-day HDT study, the treadmill exercise within LBNP was performed 3-4 days each week and resistive exercise was performed 2-3 days each week. Our treadmill within LBNP protocol maintained plasma volume and sprint speed (30 day HDT bed-rest studies of identical twins), orthostatic tolerance to a degree, upright exercise capacity, muscle strength and endurance, and some bone parameters during 30 day (twin studies) and 60 day (WISE-2005) bed-rest simulations of microgravity. When combining treadmill exercise within LBNP and resistive exercise (WISE), cardiac mass increased significantly in the exercise (EX) group during bed rest relative to controls (CON). Upright peak VO2, and knee extensor strength and endurance decreased significantly in CON subjects; but these parameters were preserved in the EX group. In the 60 day WISE study, each LBNP exercise session was followed immediately by 10 minutes of static LBNP, and the last such session occurred three days before the end of bed rest. Still, orthostatic tolerance was better maintained in the EX group than in the CON group. Therefore, these collective peer-reviewed results document that our treadmill exercise within LBNP countermeasure safely and efficiently protects multiple physiologic systems in women and men during bed-rest studies of up to 60 days. Supported by NASA grants NNJ04HF71G and NAG 9-1425, NIH grant GCRC M01 RR00827 and by WISE support from ESA, NASA, CSA, and CNES.

Large-Scale Bioinformatics Analysis of Bacillus Genomes Uncovers Conserved Roles of Natural Products in Bacterial Physiology.

PubMed

Grubbs, Kirk J; Bleich, Rachel M; Santa Maria, Kevin C; Allen, Scott E; Farag, Sherif; Shank, Elizabeth A; Bowers, Albert A

2017-01-01

Bacteria possess an amazing capacity to synthesize a diverse range of structurally complex, bioactive natural products known as specialized (or secondary) metabolites. Many of these specialized metabolites are used as clinical therapeutics, while others have important ecological roles in microbial communities. The biosynthetic gene clusters (BGCs) that generate these metabolites can be identified in bacterial genome sequences using their highly conserved genetic features. We analyzed an unprecedented 1,566 bacterial genomes from Bacillus species and identified nearly 20,000 BGCs. By comparing these BGCs to one another as well as a curated set of known specialized metabolite BGCs, we discovered that the majority of Bacillus natural products are comprised of a small set of highly conserved, well-distributed, known natural product compounds. Most of these metabolites have important roles influencing the physiology and development of Bacillus species. We identified, in addition to these characterized compounds, many unique, weakly conserved BGCs scattered across the genus that are predicted to encode unknown natural products. Many of these "singleton" BGCs appear to have been acquired via horizontal gene transfer. Based on this large-scale characterization of metabolite production in the Bacilli , we go on to connect the alkylpyrones, natural products that are highly conserved but previously biologically uncharacterized, to a role in Bacillus physiology: inhibiting spore development. IMPORTANCE Bacilli are capable of producing a diverse array of specialized metabolites, many of which have gained attention for their roles as signals that affect bacterial physiology and development. Up to this point, however, the Bacillus genus's metabolic capacity has been underexplored. We undertook a deep genomic analysis of 1,566 Bacillus genomes to understand the full spectrum of metabolites that this bacterial group can make. We discovered that the majority of the specialized metabolites produced by Bacillus species are highly conserved, known compounds with important signaling roles in the physiology and development of this bacterium. Additionally, there is significant unique biosynthetic machinery distributed across the genus that might lead to new, unknown metabolites with diverse biological functions. Inspired by the findings of our genomic analysis, we speculate that the highly conserved alkylpyrones might have an important biological activity within this genus. We go on to validate this prediction by demonstrating that these natural products are developmental signals in Bacillus and act by inhibiting sporulation.

A novel estimating method for steering efficiency of the driver with electromyography signals

NASA Astrophysics Data System (ADS)

Liu, Yahui; Ji, Xuewu; Hayama, Ryouhei; Mizuno, Takahiro

2014-05-01

The existing research of steering efficiency mainly focuses on the mechanism efficiency of steering system, aiming at designing and optimizing the mechanism of steering system. In the development of assist steering system especially the evaluation of its comfort, the steering efficiency of driver physiological output usually are not considered, because this physiological output is difficult to measure or to estimate, and the objective evaluation of steering comfort therefore cannot be conducted with movement efficiency perspective. In order to take a further step to the objective evaluation of steering comfort, an estimating method for the steering efficiency of the driver was developed based on the research of the relationship between the steering force and muscle activity. First, the steering forces in the steering wheel plane and the electromyography (EMG) signals of the primary muscles were measured. These primary muscles are the muscles in shoulder and upper arm which mainly produced the steering torque, and their functions in steering maneuver were identified previously. Next, based on the multiple regressions of the steering force and EMG signals, both the effective steering force and the total force capacity of driver in steering maneuver were calculated. Finally, the steering efficiency of driver was estimated by means of the estimated effective force and the total force capacity, which represented the information of driver physiological output of the primary muscles. This research develops a novel estimating method for driver steering efficiency of driver physiological output, including the estimation of both steering force and the force capacity of primary muscles with EMG signals, and will benefit to evaluate the steering comfort with an objective perspective.

Physiological differences between cycling and running: lessons from triathletes.

PubMed

Millet, Gregoire P; Vleck, V E; Bentley, D J

2009-01-01

The purpose of this review was to provide a synopsis of the literature concerning the physiological differences between cycling and running. By comparing physiological variables such as maximal oxygen consumption (V O(2max)), anaerobic threshold (AT), heart rate, economy or delta efficiency measured in cycling and running in triathletes, runners or cyclists, this review aims to identify the effects of exercise modality on the underlying mechanisms (ventilatory responses, blood flow, muscle oxidative capacity, peripheral innervation and neuromuscular fatigue) of adaptation. The majority of studies indicate that runners achieve a higher V O(2max) on treadmill whereas cyclists can achieve a V O(2max) value in cycle ergometry similar to that in treadmill running. Hence, V O(2max) is specific to the exercise modality. In addition, the muscles adapt specifically to a given exercise task over a period of time, resulting in an improvement in submaximal physiological variables such as the ventilatory threshold, in some cases without a change in V O(2max). However, this effect is probably larger in cycling than in running. At the same time, skill influencing motor unit recruitment patterns is an important influence on the anaerobic threshold in cycling. Furthermore, it is likely that there is more physiological training transfer from running to cycling than vice versa. In triathletes, there is generally no difference in V O(2max) measured in cycle ergometry and treadmill running. The data concerning the anaerobic threshold in cycling and running in triathletes are conflicting. This is likely to be due to a combination of actual training load and prior training history in each discipline. The mechanisms surrounding the differences in the AT together with V O(2max) in cycling and running are not largely understood but are probably due to the relative adaptation of cardiac output influencing V O(2max) and also the recruitment of muscle mass in combination with the oxidative capacity of this mass influencing the AT. Several other physiological differences between cycling and running are addressed: heart rate is different between the two activities both for maximal and submaximal intensities. The delta efficiency is higher in running. Ventilation is more impaired in cycling than in running. It has also been shown that pedalling cadence affects the metabolic responses during cycling but also during a subsequent running bout. However, the optimal cadence is still debated. Central fatigue and decrease in maximal strength are more important after prolonged exercise in running than in cycling.

Effects of sodium bicarbonate and albumin on the in vitro water-holding capacity and some physiological properties of Trigonella foenum graecum L. galactomannan in rats.

PubMed

Dakam, William; Shang, Judith; Agbor, Gabriel; Oben, Julius

2007-03-01

This study seeks to improve the beneficial effects of fenugreek (Trigonella foenum graecum L.) galactomannan (GM) in lowering the plasma lipid profile and weight. Three different combinations of diets were prepared with fenugreek GM--(a) fenugreek GM + water (GM); (b) fenugreek GM + sodium bicarbonate (GMB); and (c) fenugreek GM + bicarbonate + albumin (GMBA)--and their in vitro water retention capacity and in vivo lipid-lowering effect were studied. Distilled water and sodium bicarbonate were used as controls. The sodium bicarbonate significantly increased the in vitro water-holding capacity of fenugreek GM (49.1 +/- 8.7 vs. 21.6 +/- 0.9 g of water/g of dry weight, P < .01). Administration by oral intubation of the combination GMBA to male albino Wistar rats (250 mg/kg of body weight) over a 4-week period was the most effective in reducing body weight (-27.0 +/- 0.4%, P < .001). Within this period, the combinations GMBA and GMB brought about the most significant reduction in the levels of plasma total cholesterol (P < .005). The GMBA combination was also the most effective in reducing levels of plasma low-density lipoprotein cholesterol (P < .001) and the atherogenicity indices. GM, GMB, and GMBA brought about significant (P < .01, .001, and .001, respectively) increases in the plasma high-density lipoprotein cholesterol levels, with the highest increase coming with GMBA. A significant increase in plasma triglycerides (P < .05) was brought about by the GMBA combination, probably resulting from the rapid reduction of body weight observed. Food intake was reduced by GM, GMB, and GMBA, while water intake increased in that order. The GMB combination significantly reduced transit time (P < .01) compared to GM. On the other hand, GMB and GMBA improved glycemic control, compared to GM. We conclude that albumin and sodium bicarbonate have the ability to improve some beneficial physiological effects of fenugreek GM. This finding could have applications in the areas of human obesity, weight loss, and the control of blood lipids.

Data on how several physiological parameters of stored red blood cells are similar in glucose 6-phosphate dehydrogenase deficient and sufficient donors.

PubMed

Tzounakas, Vassilis L; Kriebardis, Anastasios G; Georgatzakou, Hara T; Foudoulaki-Paparizos, Leontini E; Dzieciatkowska, Monika; Wither, Matthew J; Nemkov, Travis; Hansen, Kirk C; Papassideri, Issidora S; D'Alessandro, Angelo; Antonelou, Marianna H

2016-09-01

This article contains data on the variation in several physiological parameters of red blood cells (RBCs) donated by eligible glucose-6-phosphate dehydrogenase (G6PD) deficient donors during storage in standard blood bank conditions compared to control, G6PD sufficient (G6PD(+)) cells. Intracellular reactive oxygen species (ROS) generation, cell fragility and membrane exovesiculation were measured in RBCs throughout the storage period, with or without stimulation by oxidants, supplementation of N-acetylcysteine and energy depletion, following incubation of stored cells for 24 h at 37 °C. Apart from cell characteristics, the total or uric acid-dependent antioxidant capacity of the supernatant in addition to extracellular potassium concentration was determined in RBC units. Finally, procoagulant activity and protein carbonylation levels were measured in the microparticles population. Further information can be found in "Glucose 6-phosphate dehydrogenase deficient subjects may be better "storers" than donors of red blood cells" [1].

Direct measurement and characterization of active photosynthesis zones inside biofuel producing and wastewater remediating microalgal biofilms

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

Bernstein, Hans C.; Kesaano, Maureen; Moll, Karen

2014-03-01

Abstract: Microalgal biofilm based technologies are of keen interest due to their high biomass concentrations and ability to utilize renewable resources, such as light and CO2. While photoautotrophic biofilms have long been used for wastewater remediation applications, biofuel production represents a relatively new and under-represented focus area. However, the direct measurement and characterization of fundamental parameters required for physiological analyses are challenging due to biofilm heterogeneity. This study evaluated oxygenic photosynthesis and biofuel precursor molecule production using a novel rotating algal biofilm reactor (RABR) operated at field- and laboratory-scales for wastewater remediation and biofuel production, respectively. Clear differences in oxygenic-photosynthesis,more » respiration and biofuel-precursor capacities were observed between the two systems and different conditions based on light and nitrogen availability. Nitrogen depletion was not found to have the same effect on lipid accumulation compared to prior planktonic studies. Physiological characterizations of these microalgal biofilms identify potential areas for future process optimization.« less

Increased mannoprotein content in wines produced by Saccharomyces kudriavzevii×Saccharomyces cerevisiae hybrids.

PubMed

Pérez-Través, Laura; Querol, Amparo; Pérez-Torrado, Roberto

2016-11-21

Several wine quality aspects are influenced by yeast mannoproteins on account of aroma compounds retention, lactic-acid bacterial growth stimulation, protection against protein haze and astringency reduction. Thus selecting a yeast strain that produces high levels of mannoproteins is important for the winemaking industry. In this work, we observed increased levels of mannoproteins in S. cerevisiae×S. kudriavzevii hybrids, compared to the S. cerevisiae strain, in wine fermentations. Furthermore, the expression of a key gene related to mannoproteins biosynthesis, PMT1, increased in the S. cerevisiae×S. kudriavzevii hybrid. We showed that artificially constructed S. cerevisiae×S. kudriavzevii hybrids also increased the levels of mannoproteins. This work demonstrates that either natural or artificial S. cerevisiae×S. kudriavzevii hybrids present mannoprotein overproducing capacity under winemaking conditions, a desirable physiological feature for this industry. These results suggest that genome interaction in hybrids generates a physiological environment that enhances the release of mannoproteins. Copyright © 2016 Elsevier B.V. All rights reserved.

Comfort and microbial barrier properties of garments worn next to the skin

NASA Astrophysics Data System (ADS)

Kopitar, D.; Rogina-Car, B.; Skenderi, Z.

2017-10-01

Compared with viscose fibre, modal fibre is characterized by some advantageous properties such as higher dry and wet tenacities, higher wet modulus, lower water retention capacity and lower level of swelling. Impact of different knitted fabric structure made of cotton and 97 % CMD/3 % EL fibres on thermo-physiological comfort and microbial barrier properties were investigated. All knitted fabrics have very good physiological properties. The microbial barrier permeability of knitted fabric after extreme contamination with bacterial spores in dry state showed that double jersey offered more effective microbial barrier than the single jersey knitted fabrics respectively the greater thickness of double jersey knitted fabric provide more difficult barrier to bacterial spores to pass. In wet state all knitted fabrics have more effective microbial barrier which could be explained by cellulose fibres swelling. In wet state 97 % CMD/3 % EL single jersey knitted fabric have more effective microbial barrier then cotton double and single jersey knitted fabrics.

Perceptions of seniors with heart failure regarding autonomous zero-effort monitoring of physiological parameters in the smart-home environment.

PubMed

Grace, Sherry L; Taherzadeh, Golnoush; Jae Chang, Isaac Sung; Boger, Jennifer; Arcelus, Amaya; Mak, Susanna; Chessex, Caroline; Mihailidis, Alex

Technological advances are leading to the ability to autonomously monitor patient's health status in their own homes, to enable aging-in-place. To understand the perceptions of seniors with heart failure (HF) regarding smart-home systems to monitor their physiological parameters. In this qualitative study, HF outpatients were invited to a smart-home lab, where they completed a sequence of activities, during which the capacity of 5 autonomous sensing modalities was compared to gold standard measures. Afterwards, a semi-structured interview was undertaken. These were transcribed and analyzed using an interpretive-descriptive approach. Five themes emerged from the 26 interviews: (1) perceptions of technology, (2) perceived benefits of autonomous health monitoring, (3) disadvantages of autonomous monitoring, (4) lack of perceived need for continuous health monitoring, and (5) preferences for autonomous monitoring. Patient perception towards autonomous monitoring devices was positive, lending credence to zero-effort technology as a viable and promising approach. Copyright © 2017 Elsevier Inc. All rights reserved.

Water stress and recovery in the performance of two Eucalyptus globulus clones: physiological and biochemical profiles.

PubMed

Correia, Barbara; Pintó-Marijuan, Marta; Neves, Lucinda; Brossa, Ricard; Dias, Maria Celeste; Costa, Armando; Castro, Bruno B; Araújo, Clara; Santos, Conceição; Chaves, Maria Manuela; Pinto, Glória

2014-04-01

Eucalyptus plantations are among the most productive forest stands in Portugal and Spain, being mostly used for pulp production and, more recently, as an energy crop. However, the region's Mediterranean climate, with characteristic severe summer drought, negatively affects eucalypt growth and increases mortality. Although the physiological response to water shortage is well characterized for this species, evidence about the plants' recovery ability remains scarce. In order to assess the physiological and biochemical response of Eucalyptus globulus during the recovery phase, two genotypes (AL-18 and AL-10) were submitted to a 3-week water stress period at two different intensities (18 and 25% of field capacity), followed by 1 week of rewatering. Recovery was assessed 1 day and 1 week after rehydration. Drought reduced height, biomass, water potential, NPQ and gas exchange in both genotypes. Contrarily, the levels of pigments, chlorophyll fluorescence parameters (F(v) /F(m) and (φPSII)), MDA and ABA increased. During recovery, the physiological and biochemical profile of stressed plants showed a similar trend: they experienced reversion of altered traits (MDA, ABA, E, g(s), pigments), while other parameters did not recover ((φPSII), NPQ). Furthermore, an overcompensation of CO(2) assimilation was achieved 1 week after rehydration, which was accompanied by greater growth and re-establishment of oxidative balance. Both genotypes were tolerant to the tested conditions, although clonal differences were found. AL-10 was more productive and showed a more rapid and dynamic response to rehydration (namely in carotenoid content, (φPSII) and NPQ) compared to clone AL-18. © 2013 Scandinavian Plant Physiology Society.

Taurine Supplementation Improves Functional Capacity, Myocardial Oxygen Consumption, and Electrical Activity in Heart Failure.

PubMed

Ahmadian, Mehdi; Dabidi Roshan, Valiollah; Ashourpore, Eadeh

2017-07-04

Taurine is an amino acid found abundantly in the heart in very high concentrations. It is assumed that taurine contributes to several physiological functions of mammalian cells, such as osmoregulation, anti-inflammation, membrane stabilization, ion transport modulation, and regulation of oxidative stress and mitochondrial protein synthesis. The objective of the current study was to evaluate the effectiveness of taurine supplementation on functional capacity, myocardial oxygen consumption, and electrical activity in patients with heart failure. In a double-blind and randomly designed study, 16 patients with heart failure were assigned to two groups: taurine (TG, n = 8) and placebo (PG, n = 8). TG received 500-mg taurine supplementation three times per day for two weeks. Significant decrease in the values of Q-T segments (p < 0.01) and significant increase in the values of P-R segments (p < 0.01) were detected following exercise post-supplementation in TG rather than in PG. Significantly higher values of taurine concentration, T wave, Q-T segment, physical capacities, and lower values of cardiovascular capacities were detected post-supplementation in TG as compared with PG (all p values <0.01). Taurine significantly enhanced the physical function and significantly reduced the cardiovascular function parameters following exercise. Our results also suggest that the short-term taurine supplementation is an effective strategy for improving some selected hemodynamic parameters in heart failure patients. Together, these findings support the view that taurine improves cardiac function and functional capacity in patients with heart failure. This idea warrants further study.

Physiologic Levels of Endogenous Hydrogen Sulfide Maintain the Proliferation and Differentiation Capacity of Periodontal Ligament Stem Cells.

PubMed

Su, Yingying; Liu, Dayong; Liu, Yi; Zhang, Chunmei; Wang, Jinsong; Wang, Songlin

2015-11-01

Many invading oral bacteria are known to produce considerable amounts of hydrogen sulfide (H2S). The toxic activity of exogenous H2S in periodontal tissue has been demonstrated, but the role of endogenous H2S in the physiologic function of periodontal tissue remains poorly understood. The purpose of the present study is to investigate the biologic functions of H2S in the proliferation and differentiation of human periodontal ligament stem cells (PDLSCs). PDLSCs were isolated from periodontal ligament tissues of periodontally healthy volunteers or patients with periodontitis. Immunocytochemical staining, flow cytometry, and Western blot analysis were used to examine the expression of H2S-synthesizing enzymes cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE). The proliferation capacity of PDLSCs was determined by cell counting kit-8 assay, carboxyfluorescein succinimidyl ester analysis, and 5-ethynyl-2'-deoxyuridine assay. The osteogenic potential of PDLSCs was tested using alkaline phosphatase staining, Alizarin Red staining, and in vivo transplantation experiments. Oil Red O staining was used to analyze adipogenic ability. The results show that human PDLSCs express both CBS and CSE and produce H2S. Blocking the generation of endogenous H2S with CBS inhibitor hydroxylamine significantly attenuated PDLSC proliferation and reduced the osteogenic and adipogenic differentiation capacity of PDLSCs. In contrast, CSE inhibitor DL-propargylglycine had no effect on PDLSC function. Exogenous H2S could inhibit the production of endogenous H2S and impair PDLSC function in a dose-dependent manner. Physiologic levels of endogenous H2S maintain the proliferation and differentiation capacity of PDLSCs, and CBS may be the main source of endogenous H2S in PDLSCs.

Can multi-generational exposure to ocean warming and acidification lead to the adaptation of life history and physiology in a marine metazoan?

PubMed

Gibbin, Emma M; Chakravarti, Leela J; Jarrold, Michael D; Christen, Felix; Turpin, Vincent; Massamba N'Siala, Gloria; Blier, Pierre U; Calosi, Piero

2017-02-15

Ocean warming and acidification are concomitant global drivers that are currently threatening the survival of marine organisms. How species will respond to these changes depends on their capacity for plastic and adaptive responses. Little is known about the mechanisms that govern plasticity and adaptability or how global changes will influence these relationships across multiple generations. Here, we exposed the emerging model marine polychaete Ophryotrocha labronica to conditions simulating ocean warming and acidification, in isolation and in combination over five generations to identify: (i) how multiple versus single global change drivers alter both juvenile and adult life-history traits; (ii) the mechanistic link between adult physiological and fitness-related life-history traits; and (iii) whether the phenotypic changes observed over multiple generations are of plastic and/or adaptive origin. Two juvenile (developmental rate; survival to sexual maturity) and two adult (average reproductive body size; fecundity) life-history traits were measured in each generation, in addition to three physiological (cellular reactive oxygen species content, mitochondrial density, mitochondrial capacity) traits. We found that multi-generational exposure to warming alone caused an increase in juvenile developmental rate, reactive oxygen species production and mitochondrial density, decreases in average reproductive body size and fecundity, and fluctuations in mitochondrial capacity, relative to control conditions. Exposure to ocean acidification alone had only minor effects on juvenile developmental rate. Remarkably, when both drivers of global change were present, only mitochondrial capacity was significantly affected, suggesting that ocean warming and acidification act as opposing vectors of stress across multiple generations. © 2017. Published by The Company of Biologists Ltd.

Hip Strength Improves Novice Surface Combat Swimming Flutterkick Performance.

PubMed

Beethe, Anne Z; Nagle, Elizabeth F; Lovalekar, Mita; Nagai, Takashi; Nindl, Bradley C; Connaboy, Christopher

2018-05-29

The current study was designed to examine strength, range of motion (ROM), anthropometric, and physiological contributions to novice surface combat swimming (sCS) performance, and establish differences from freestyle swimming (FS) performance to further understand the transition of FS to sCS performance. Thirteen competitive swimmers (7 males, 6 females; 27.7±2.3 years; 176.2±2.6 cm; 75.4±3.9 kg) completed eight testing sessions consisting of the following: physiological land-based measurements for maximal anaerobic and aerobic capacity and upper and lower extremity strength and ROM, a sCS anaerobic capacity swim test measuring peak and mean force and fatigue index, two aerobic capacity tests measuring maximal aerobic capacity for both FS and sCS, and four 500m performance swims for time, one FS and three sCS. Separate multiple linear regression analysis was used to analyze predictors of both sCS and FS performance models. Freestyle swimming performance was predicted by the final FS VO 2max with a R 2 of 42.03% (F(1,10) = 7.25; p = 0.0226) whereas sCS performance was predicted by isometric hip extension peak strength with an R 2 of 41.46% (F(1,11) = 7.79; p = 0.0176). Results demonstrate different physiological characteristics predict performance, suggesting an altered strategy is utilized for novice sCS than FS. It is suggested this may be due to the added constraints as mandated by mission requirements including boots, weighted gear, and clandestine requirements with hips lowered beneath the surface. Further research should examine the kinematics of the sCS flutterkick to improve performance by developing training strategies specific for the task.

Bone Alkaline Phosphatase and Tartrate-Resistant Acid Phosphatase: Potential Co-regulators of Bone Mineralization.

PubMed

Halling Linder, Cecilia; Ek-Rylander, Barbro; Krumpel, Michael; Norgård, Maria; Narisawa, Sonoko; Millán, José Luis; Andersson, Göran; Magnusson, Per

2017-07-01

Phosphorylated osteopontin (OPN) inhibits hydroxyapatite crystal formation and growth, and bone alkaline phosphatase (BALP) promotes extracellular mineralization via the release of inorganic phosphate from the mineralization inhibitor inorganic pyrophosphate (PPi). Tartrate-resistant acid phosphatase (TRAP), produced by osteoclasts, osteoblasts, and osteocytes, exhibits potent phosphatase activity towards OPN; however, its potential capacity as a regulator of mineralization has not previously been addressed. We compared the efficiency of BALP and TRAP towards the endogenous substrates for BALP, i.e., PPi and pyridoxal 5'-phosphate (PLP), and their impact on mineralization in vitro via dephosphorylation of bovine milk OPN. TRAP showed higher phosphatase activity towards phosphorylated OPN and PPi compared to BALP, whereas the activity of TRAP and BALP towards PLP was comparable. Bovine milk OPN could be completely dephosphorylated by TRAP, liberating all its 28 phosphates, whereas BALP dephosphorylated at most 10 phosphates. OPN, dephosphorylated by either BALP or TRAP, showed a partially or completely attenuated phosphorylation-dependent inhibitory capacity, respectively, compared to native OPN on the formation of mineralized nodules. Thus, there are phosphorylations in OPN important for inhibition of mineralization that are removed by TRAP but not by BALP. In conclusion, our data indicate that both BALP and TRAP can alleviate the inhibitory effect of OPN on mineralization, suggesting a potential role for TRAP in skeletal mineralization. Further studies are warranted to explore the possible physiological relevance of TRAP in bone mineralization.

A geophysiologist's thoughts on geoengineering.

PubMed

Lovelock, James

2008-11-13

The Earth is now recognized as a self-regulating system that includes a reactive biosphere; the system maintains a long-term steady-state climate and surface chemical composition favourable for life. We are perturbing the steady state by changing the land surface from mainly forests to farm land and by adding greenhouse gases and aerosol pollutants to the air. We appear to have exceeded the natural capacity to counter our perturbation and consequently the system is changing to a new and as yet unknown but probably adverse state. I suggest here that we regard the Earth as a physiological system and consider amelioration techniques, geoengineering, as comparable to nineteenth century medicine.

Mercury in mercury(II)-spiked soils is highly susceptible to plant bioaccumulation.

PubMed

Hlodák, Michal; Urík, Martin; Matúš, Peter; Kořenková, Lucia

2016-01-01

Heavy metal phytotoxicity assessments usually use soluble metal compounds in spiked soils to evaluate metal bioaccumulation, growth inhibition and adverse effects on physiological parameters. However, exampling mercury phytotoxicity for barley (Hordeum vulgare) this paper highlights unsuitability of this experimental approach. Mercury(II) in spiked soils is extremely bioavailable, and there experimentally determined bioaccumulation is significantly higher compared to reported mercury bioaccumulation efficiency from soils collected from mercury-polluted areas. Our results indicate this is not affected by soil sorption capacity, thus soil ageing and formation of more stable mercuric complexes with soil fractions is necessary for reasonable metal phytotoxicity assessments.

All or nothing: Survival, reproduction and oxidative balance in Spotted Wing Drosophila (Drosophila suzukii) in response to cold.

PubMed

Plantamp, Christophe; Salort, Katleen; Gibert, Patricia; Dumet, Adeline; Mialdea, Gladys; Mondy, Nathalie; Voituron, Yann

2016-06-01

Winter severity and overwintering capacity are key ecological factors in successful invasions, especially in ectotherms. The integration of physiological approaches into the study of invasion processes is emerging and promising. Physiological information describes the mechanisms underlying observed survival and reproductive capacities, and it can be used to predict an organism's response to environmental perturbations such as cold temperatures. We investigated the effects of various cold treatments on life history and physiological traits of an invasive pest species, Drosophila suzukii, such as survival, fertility and oxidative balance. This species, a native of temperate Asian areas, is known to survive where cold temperatures are particularly harsh and has been recently introduced into Europe and North America. We found that cold treatments had a strong impact on adult survival but no effect on female's fertility. Although only minor changes were observed after cold treatment on studied physiological traits, a strong sex-based difference was observed in both survival and physiological markers (antioxidant defences and oxidative markers). Females exhibited higher survival, reduced oxidative defences, less damage to nucleic acids, and more damage to lipids. These results suggest that D. suzukii relies on a pathway other than oxidative balance to resist cold injury. Altogether, our results provide information concerning the mechanisms of successful invasion by D. suzukii. These findings may assist in the development of population models that predict the current and future geographic ranges of this species. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

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

2017-03-01

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

Competition for nitrogen between European beech and sycamore maple shifts in favour of beech with decreasing light availability.

PubMed

Simon, Judy; Li, Xiuyuan; Rennenberg, Heinz

2014-01-01

Plant species use different strategies for maximizing growth and fitness under changing environmental conditions. At the ecosystem level, seedlings in particular compete with other vegetation components for light and nitrogen (N), which often constitute growth-limiting resources. In this study, we investigated the effect of light availability on the competition for N between seedlings of European beech and sycamore maple and analysed the consequences of this competition for the composition of N metabolites in fine roots. Our results show different strategies in N acquisition between beech and sycamore maple. Both species responded to reduced light availability by adapting their morphological and physiological traits with a decrease in biomass and net assimilation rate and an increase in specific leaf area and leaf area ratio. For beech seedlings, competition with sycamore maple led to a reduction in organic N uptake capacity. Reduced light availability led to a decrease in ammonium, but an increase in glutamine-N uptake capacity in sycamore maple. However, this response was stronger compared with that of beech and was accompanied by reduced growth. Thus, our results suggest better adaptation of N acquisition to reduced light availability in beech compared with sycamore maple seedlings.

Total lung capacity, residual volume and predicted residual volume in a densitometric study of older men.

PubMed Central

Latin, R W; Ruhling, R O

1986-01-01

Results of investigations using various lung volumes for hydrostatic weighing determinations (HWD) appear to be inconclusive. Often, these lung volumes are predicted and not clinically determined. For this reason, total lung capacity (TLC), a measured residual volume (RV), and a predicted residual volume (PRV) were used during HWDs to compare the techniques. Twenty-five older men, 56 to 70 years (means +/- 62.1 + 4.2 years) performed HWDs at RV (10 trials) and at TLC (3-5 trials). Values for body density and fat free mass were not significantly different between RV and TLC; both values were, however, significantly different from those derived using PRV. There were statistically significant differences (p less than 0.05) between all 3 per cent body fat values but the 1.1 per cent difference between TLC and RV may not be physiologically important. It was concluded that TLC and RV may be used comparably during HWDs, but a PRV may produce significantly different values. Since HWD at TLC is easily performed and circumvents the difficulties associated with the RV technique, it may be the preferred method for older subjects. PMID:3730758

Pragmatic perspective on aerobic scope: peaking, plummeting, pejus and apportioning.

PubMed

Farrell, A P

2016-01-01

A major challenge for fish biologists in the 21st century is to predict the biotic effects of global climate change. With marked changes in biogeographic distribution already in evidence for a variety of aquatic animals, mechanistic explanations for these shifts are being sought, ones that then can be used as a foundation for predictive models of future climatic scenarios. One mechanistic explanation for the thermal performance of fishes that has gained some traction is the oxygen and capacity-limited thermal tolerance (OCLTT) hypothesis, which suggests that an aquatic organism's capacity to supply oxygen to tissues becomes limited when body temperature reaches extremes. Central to this hypothesis is an optimum temperature for absolute aerobic scope (AAS, loosely defined as the capacity to deliver oxygen to tissues beyond a basic need). On either side of this peak for AAS are pejus temperatures that define when AAS falls off and thereby reduces an animal's absolute capacity for activity. This article provides a brief perspective on the potential uses and limitations of some of the key physiological indicators related to aerobic scope in fishes. The intent is that practitioners who attempt predictive ecological applications can better recognize limitations and make better use of the OCLTT hypothesis and its underlying physiology. © 2015 The Fisheries Society of the British Isles.

Student responses to a hands-on kinesthetic lecture activity for learning about the oxygen carrying capacity of blood.

PubMed

Breckler, Jennifer; Yu, Justin R

2011-03-01

This article describes a new hands-on, or "kinesthetic," activity for use in a physiology lecture hall to help students comprehend an important concept in cardiopulmonary physiology known as oxygen carrying capacity. One impetus for designing this activity was to address the needs of students who have a preference for kinesthetic learning and to help increase their understanding and engagement during lecture. This activity uses simple inexpensive materials, provides an effective model for demonstrating related pathophysiology, and helps promote active learning. The activity protocol and its implementation are described here in detail. We also report data obtained from student surveys and assessment tools to determine the effectiveness of the activity on student conceptual learning and perceptions. A brief multiple-choice pretest showed that although students had already been introduced to the relevant concepts in lecture, they had not yet mastered these concepts before performing the activity. Two postactivity assessments showed that student performance was significantly improved on the posttest compared with the pretest and that information was largely retained at the end of the course. Survey data showed that one-half of the students stated kinesthetic learning as among their learning preferences, yet nearly all students enjoyed and were engaged in this hands-on kinesthetic activity regardless of their preferences. Most students would recommend it to their peers and expressed a desire for more kinesthetic learning opportunities in the lecture curriculum.

Effects of exercise on fatigue, sleep, and performance: a randomized trial.

PubMed

Coleman, Elizabeth Ann; Goodwin, Julia A; Kennedy, Robert; Coon, Sharon K; Richards, Kathy; Enderlin, Carol; Stewart, Carol B; McNatt, Paula; Lockhart, Kim; Anaissie, Elias J

2012-09-01

To compare usual care with a home-based individualized exercise program (HBIEP) in patients receiving intensive treatment for multiple myeloma (MM)and epoetin alfa therapy. Randomized trial with repeated measures of two groups (one experimental and one control) and an approximate 15-week experimental period. Outpatient setting of the Myeloma Institute for Research and Therapy at the Rockfellow Cancer Center at the University of Arkansas for Medical Sciences. 187 patients with newly diagnosed MM enrolled in a separate study evaluating effectiveness of the Total Therapy regimen, with or without thalidomide. Measurements included the Profile of Mood States fatigue scale, Functional Assessment of Cancer Therapy-Fatigue, ActiGraph® recordings, 6-Minute Walk Test, and hemoglobin levels at baseline and before and after stem cell collection. Descriptive statistics were used to compare demographics and treatment effects, and repeated measures analysis of variance was used to determine effects of HBIEP. Fatigue, nighttime sleep, performance (aerobic capacity) as dependent or outcome measures, and HBIEP combining strength building and aerobic exercise as the independent variable. Both groups were equivalent for age, gender, race, receipt of thalidomide, hemoglobin levels, and type of treatment regimen for MM. No statistically significant differences existed among the experimental and control groups for fatigue, sleep, or performance (aerobic capacity). Statistically significant differences (p < 0.05) were found in each of the study outcomes for all patients as treatment progressed and patients experienced more fatigue and poorer nighttime sleep and performance (aerobic capacity). The effect of exercise seemed to be minimal on decreasing fatigue, improving sleep, and improving performance (aerobic capacity). Exercise is safe and has physiologic benefits for patients undergoing MM treatment; exercise combined with epoetin alfa helped alleviate anemia.

The Comparative Osmoregulatory Ability of Two Water Beetle Genera Whose Species Span the Fresh-Hypersaline Gradient in Inland Waters (Coleoptera: Dytiscidae, Hydrophilidae)

PubMed Central

Pallarés, Susana; Arribas, Paula; Bilton, David T.; Millán, Andrés; Velasco, Josefa

2015-01-01

A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh—hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal’s haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg-1). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg-1) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm-1, respectively, and maintained osmotic gradients over 3500 mosmol kg-1, comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by individual species in nature. Therefore, osmoregulatory capacity may mediate habitat segregation amongst congeners across the salinity gradient. PMID:25886355

Extensive Acclimation in Ectotherms Conceals Interspecific Variation in Thermal Tolerance Limits

PubMed Central

Pintor, Anna F. V.; Schwarzkopf, Lin; Krockenberger, Andrew K.

2016-01-01

Species’ tolerance limits determine their capacity to tolerate climatic extremes and limit their potential distributions. Interspecific variation in thermal tolerances is often proposed to indicate climatic vulnerability and is, therefore, the subject of many recent meta-studies on differential capacities of species from climatically different habitats to deal with climate change. Most studies on thermal tolerances do not acclimate animals or use inconsistent, and insufficient, acclimation times, limiting our knowledge of the shape, duration and extent of acclimation responses. Consequently patterns in thermal tolerances observed in meta-analyses, based on data from the literature are based on inconsistent, partial acclimation and true trends may be obscured. In this study we describe time-course of complete acclimation of critical thermal minima in the tropical ectotherm Carlia longipes and compare it to the average acclimation response of other reptiles, estimated from published data, to assess how much acclimation time may contribute to observed differences in thermal limits. Carlia longipes decreased their lower critical thermal limits by 2.4°C and completed 95% of acclimation in 17 weeks. Wild populations did not mirror this acclimation process over the winter. Other reptiles appear to decrease cold tolerance more quickly (95% in 7 weeks) and to a greater extent, with an estimated average acclimation response of 6.1°C. However, without data on tolerances after longer acclimation times available, our capacity to estimate final acclimation state is very limited. Based on the subset of data available for meta-analysis, much of the variation in cold tolerance observed in the literature can be attributed to acclimation time. Our results indicate that (i) acclimation responses can be slow and substantial, even in tropical species, and (ii) interspecific differences in acclimation speed and extent may obscure trends assessed in some meta-studies. Cold tolerances of wild animals are representative of cumulative responses to recent environments, while lengthy acclimation is necessary for controlled comparisons of physiological tolerances. Measures of inconsistent, intermediate acclimation states, as reported by many studies, represent neither the realised nor the potential tolerance in that population, are very likely underestimates of species’ physiological capacities and may consequently be of limited value. PMID:26990769

Extensive Acclimation in Ectotherms Conceals Interspecific Variation in Thermal Tolerance Limits.

PubMed

Pintor, Anna F V; Schwarzkopf, Lin; Krockenberger, Andrew K

2016-01-01

Species' tolerance limits determine their capacity to tolerate climatic extremes and limit their potential distributions. Interspecific variation in thermal tolerances is often proposed to indicate climatic vulnerability and is, therefore, the subject of many recent meta-studies on differential capacities of species from climatically different habitats to deal with climate change. Most studies on thermal tolerances do not acclimate animals or use inconsistent, and insufficient, acclimation times, limiting our knowledge of the shape, duration and extent of acclimation responses. Consequently patterns in thermal tolerances observed in meta-analyses, based on data from the literature are based on inconsistent, partial acclimation and true trends may be obscured. In this study we describe time-course of complete acclimation of critical thermal minima in the tropical ectotherm Carlia longipes and compare it to the average acclimation response of other reptiles, estimated from published data, to assess how much acclimation time may contribute to observed differences in thermal limits. Carlia longipes decreased their lower critical thermal limits by 2.4°C and completed 95% of acclimation in 17 weeks. Wild populations did not mirror this acclimation process over the winter. Other reptiles appear to decrease cold tolerance more quickly (95% in 7 weeks) and to a greater extent, with an estimated average acclimation response of 6.1°C. However, without data on tolerances after longer acclimation times available, our capacity to estimate final acclimation state is very limited. Based on the subset of data available for meta-analysis, much of the variation in cold tolerance observed in the literature can be attributed to acclimation time. Our results indicate that (i) acclimation responses can be slow and substantial, even in tropical species, and (ii) interspecific differences in acclimation speed and extent may obscure trends assessed in some meta-studies. Cold tolerances of wild animals are representative of cumulative responses to recent environments, while lengthy acclimation is necessary for controlled comparisons of physiological tolerances. Measures of inconsistent, intermediate acclimation states, as reported by many studies, represent neither the realised nor the potential tolerance in that population, are very likely underestimates of species' physiological capacities and may consequently be of limited value.

Aerobic capacity and peak power output of elite quadriplegic games players

PubMed Central

Goosey‐Tolfrey, V; Castle, P; Webborn, N

2006-01-01

Background Participation in wheelchair sports such as tennis and rugby enables people with quadriplegia to compete both individually and as a team at the highest level. Both sports are dominated by frequent, intermittent, short term power demands superimposed on a background of aerobic activity. Objective To gain physiological profiles of highly trained British quadriplegic athletes, and to examine the relation between aerobic and sprint capacity. Methods Eight male quadriplegic athletes performed an arm crank exercise using an ergometer fitted with a Schoberer Rad Messtechnik (SRM) powermeter. The sprint test consisted of three maximum‐effort sprints of five seconds duration against a resistance of 2%, 3%, and 4% of body mass. The highest power output obtained was recorded (PPO). Peak oxygen consumption (V̇o2peak), peak heart rate (HRpeak), and maximal power output (POaer) were determined. Results Mean POaer was 67.7 (16.2) W, mean V̇o2peak was 0.96 (0.17) litres/min, and HRpeak was 134 (19) beats/min for the group. There was high variability among subjects. Peak power over the five second sprint for the group was 220 (62) W. There was a significant correlation between V̇o2peak (litres/min) and POaer (W) (r  =  0.74, p<0.05). Conclusions These British quadriplegic athletes have relatively high aerobic fitness when compared with the available literature. Moreover, the anaerobic capacity of these athletes appeared to be relatively high compared with paraplegic participants. PMID:16611721

Auxin physiology of the tomato mutant diageotropica

NASA Technical Reports Server (NTRS)

Daniel, S. G.; Rayle, D. L.; Cleland, R. E.

1989-01-01

The tomato (Lycopersicon esculentum, Mill.) mutant diageotropica (dgt) exhibits biochemical, physiological, and morphological abnormalities that suggest the mutation may have affected a primary site of auxin perception or action. We have compared two aspects of the auxin physiology of dgt and wild-type (VFN8) seedlings: auxin transport and cellular growth parameters. The rates of basipetal indole-3-acetic acid (IAA) polar transport are identical in hypocotyl sections of the two genotypes, but dgt sections have a slightly greater capacity for IAA transport. 2,3,5-Triiodobenzoic acid and ethylene reduce transport in both mutant and wild-type sections. The kinetics of auxin uptake into VFN8 and dgt sections are nearly identical. These results make it unlikely that an altered IAA efflux carrier or IAA uptake symport are responsible for the pleiotropic effects resulting from the dgt mutation. The lack of auxin-induced cell elongation in dgt plants is not due to insufficient turgor, as the osmotic potential of dgt cell sap is less (more negative) than that of VFN8. An auxin-induced increase in wall extensibility, as measured by the Instron technique, only occurs in the VFN8 plants. These data suggest dgt hypocotyls suffer a defect in the sequence of events culminating in auxin-induced cell wall loosening.

Linking physiological and cellular responses to thermal stress: β-adrenergic blockade reduces the heat shock response in fish.

PubMed

Templeman, Nicole M; LeBlanc, Sacha; Perry, Steve F; Currie, Suzanne

2014-08-01

When faced with stress, animals use physiological and cellular strategies to preserve homeostasis. We were interested in how these high-level stress responses are integrated at the level of the whole animal. Here, we investigated the capacity of the physiological stress response, and specifically the β-adrenergic response, to affect the induction of the cellular heat shock proteins, HSPs, following a thermal stress in vivo. We predicted that blocking β-adrenergic stimulation during an acute heat stress in the whole animal would result in reduced levels of HSPs in red blood cells (RBCs) of rainbow trout compared to animals where adrenergic signaling remained intact. We first determined that a 1 h heat shock at 25 °C in trout acclimated to 13 °C resulted in RBC adrenergic stimulation as determined by a significant increase in cell swelling, a hallmark of the β-adrenergic response. A whole animal injection with the β2-adrenergic antagonist, ICI-118,551, successfully reduced this heat-induced RBC swelling. The acute heat shock caused a significant induction of HSP70 in RBCs of 13 °C-acclimated trout as well as a significant increase in plasma catecholamines. When heat-shocked fish were treated with ICI-118,551, we observed a significant attenuation of the HSP70 response. We conclude that circulating catecholamines influence the cellular heat shock response in rainbow trout RBCs, demonstrating physiological/hormonal control of the cellular stress response.

Comparative analysis of the cold acclimation and freezing tolerance capacities of seven diploid Brachypodium distachyon accessions

PubMed Central

Colton-Gagnon, Katia; Ali-Benali, Mohamed Ali; Mayer, Boris F.; Dionne, Rachel; Bertrand, Annick; Do Carmo, Sonia; Charron, Jean-Benoit

2014-01-01

Background and Aims Cold is a major constraint for cereal cultivation under temperate climates. Winter-hardy plants interpret seasonal changes and can acquire the ability to resist sub-zero temperatures. This cold acclimation process is associated with physiological, biochemical and molecular alterations in cereals. Brachypodium distachyon is considered a powerful model system to study the response of temperate cereals to adverse environmental conditions. To date, little is known about the cold acclimation and freezing tolerance capacities of Brachypodium. The main objective of this study was to evaluate the cold hardiness of seven diploid Brachypodium accessions. Methods An integrated approach, involving monitoring of phenological indicators along with expression profiling of the major vernalization regulator VRN1 orthologue, was followed. In parallel, soluble sugars and proline contents were determined along with expression profiles of two COR genes in plants exposed to low temperatures. Finally, whole-plant freezing tests were performed to evaluate the freezing tolerance capacity of Brachypodium. Key Results Cold treatment accelerated the transition from the vegetative to the reproductive phase in all diploid Brachypodium accessions tested. In addition, low temperature exposure triggered the gradual accumulation of BradiVRN1 transcripts in all accessions tested. These accessions exhibited a clear cold acclimation response by progressively accumulating proline, sugars and COR gene transcripts. However, whole-plant freezing tests revealed that these seven diploid accessions only have a limited capacity to develop freezing tolerance when compared with winter varieties of temperate cereals such as wheat and barley. Furthermore, little difference in terms of survival was observed among the accessions tested despite their previous classification as either spring or winter genotypes. Conclusions This study is the first to characterize the freezing tolerance capacities of B. distachyon and provides strong evidence that some diploid accessions such as Bd21 have a facultative growth habit. PMID:24323247

Disparity between Physical Capacity and Participation in Seniors with Chronic Disease

PubMed Central

Ashe, Maureen C.; Eng, Janice J.; Miller, William C.; Soon, Judith A.

2011-01-01

Consistently low rates of physical activity are reported for older adults and there is even lower participation if a chronic disease is present. Purpose To explore the predictors of physical capacity and participation in older community-dwelling individuals living with multiple chronic diseases. Methods This was a descriptive cross-sectional investigation of physical capacity (physiological potential) and physical activity participation (recorded engagement in physical activity). Multiple regression and odds ratios were used to investigate determinants of physical capacity (6 Minute Walk Test) and physical activity participation (Physical Activity Scale for Individuals with Physical Disabilities Questionnaire; pedometer steps/day). Results 200 community dwelling ambulatory participants living with 2 or more chronic disease were assessed. Sixty-five percent (65%) were women and the mean age was 74 ± 6 years (range 65–90 years). Mobility (Timed Up and Go) was a consistent determinant across all 3 primary outcomes. For the Six Minute Walk Test, determinants included mobility, BMI, grip strength, number of medications, leg strength, balance and Chronic Disease Management Self Efficacy Scale (r2=0.58; P=.000). The determinants for the self-reported participation measure (Physical Activity Scale for Individuals with Physical Disabilities Questionnaire) was mobility (r2=0.04; P=.007). For the mean daily pedometer steps, the determinants included mobility, body mass index (BMI), age and Chronic Disease Management Self-Efficacy Scale (r2=0.27; P=.000). There were higher risks for inactivity associated with impairments compared with the presence of a chronic disease. In addition, over 1/3 of participants had sufficient physical capacity, but did not meet minimal recommendations of physical activity. Conclusion This study suggests that it is easier to predict an individual’s physical capacity than their actual physical participation. PMID:17596782

Comparative life history and physiology of two understory Neotropical herbs.

PubMed

Mulkey, Stephen S; Smith, Alan P; Wright, S Joseph

1991-10-01

Demography and physiology of two broad-leaved understory tropical herbs (Marantaceae) were studied in gaps and shaded understory in large-scale irrigated and control treatments during the dry season at Barro Colorado Island (BCI), Panama. Because photosynthetic acclimation potential may not predict light environments where tropical species are found, we studied a suite of physiological features to determine if they uniquely reflect the distribution of each species. Calathea inocephala and Pleiostachya pruinosa grow and reproduce in gaps, persist in shade, and have equivalent rates of leaf production. Calathea leaves survived 2 to 3 times as long as leaves of Pleiostachya and plants of Pleiostachya were 6 to 8 times more likely to die as plants of Calathea during 3.5 years of study. Pleiostachya had lowest survival in shade and when not irrigated during the dry season, while Calathea survived well in both habitats and both treatments. Pleiostachya had higher photosynthetic capacity and stomatal conductance than Calathea and acclimated to gaps by producing leaves with higher photosynthetic capacity. Calathea had lower mesophyll CO 2 concentrations than Pleiostachya. Both species had similar dark respiration rates and light compensation points, and water-use and nitrogen-use efficiencies were inversely related between species. Species showed no differences in leaf osmotic potentials at full turgor. Calathea roots were deeper and had tuberous swellings.Leaf-level assimilation and potential water loss are consistent with where these species are found, but photosynthetic acclimation to high light does not reflect both species' abilities to grow and reproduce in gaps. Pleiostachya's gap-dependent, rapid growth and reproduction require high rates of carbon gain in short-lived leaves, which can amortize their cost quickly. High rates of water loss are associated with reduced longevity during drought. Calathea's roots may confer greater capacitance, while its leaves are durable, long-lived and have lower water loss, permitting persistence long after gap closure.

Behavioral and physiological photoresponses to light intensity by intertidal microphytobenthos

NASA Astrophysics Data System (ADS)

Du, Guoying; Yan, Hongmei; Liu, Chunrong; Mao, Yunxiang

2018-03-01

Behavioral and physiological responses to light are the two major mechanisms by which natural microphytobenthic assemblages adapt to the intertidal environment and protect themselves from light stress. The present study investigated these photoresponses with different light intensities over 8 h of illumination, and used a specific inhibitor (Latrunculin A, Lat A) for migration to compare migratory and non-migratory microphytobenthos (MPB). Photosynthetic activity was detected using rapid light curves and induction curves by chlorophyll fluorescence. It showed distinct variation in migratory responses to different light intensities; high light induced downward migration to avoid photoinhibition, and low and medium light (50-250 μmol/(m2·s)) promoted upward migration followed by downward migration after certain period of light exposure. No significant difference in non-photochemical quenching (NPQ) or PSII maximal quantum yield ( F v/ F m) was detected between low and medium light irradiance, possibly indicating that only high light influences the photosynthetic capability of MPB. Decreased photosynthetic activity, indicated by three parameters, the maximum relative electron transport rate (rETR max), minimum saturating irradiance ( E k) and light utilization coefficient ( α), was observed in MPB after exposure to prolonged illumination under low and medium light. Lat A effectively inhibited the migration of MPB in all light treatments and induced lower F v/ F m under high light (500 and 100 μmol/(m2·s)) and prolonged illumination at 250 μmol/(m2·s), but did not significantly influence F v/ F m under low light (0-100 μmol/(m2·s)) or NPQ. The increase of NPQ in Lat A treatments with time implied that the MPB assemblages can recover their physiological photoprotection capacity to adapt to light stress. Non-migratory MPB exhibited lower light use efficiency (lower α) and lower maximum photosynthetic capacity (lower rETR max) than migratory MPB under light intensities above 250 μmol/(m2·s) after 4.0 h illumination.

Altered serotonin physiology in human breast cancers favors paradoxical growth and cell survival.

PubMed

Pai, Vaibhav P; Marshall, Aaron M; Hernandez, Laura L; Buckley, Arthur R; Horseman, Nelson D

2009-01-01

The breast microenvironment can either retard or accelerate the events associated with progression of latent cancers. However, the actions of local physiological mediators in the context of breast cancers are poorly understood. Serotonin (5-HT) is a critical local regulator of epithelial homeostasis in the breast and other organs. Herein, we report complex alterations in the intrinsic mammary gland serotonin system of human breast cancers. Serotonin biosynthetic capacity was analyzed in human breast tumor tissue microarrays using immunohistochemistry for tryptophan hydroxylase 1 (TPH1). Serotonin receptors (5-HT1-7) were analyzed in human breast tumors using the Oncomine database. Serotonin receptor expression, signal transduction, and 5-HT effects on breast cancer cell phenotype were compared in non-transformed and transformed human breast cells. In the context of the normal mammary gland, 5-HT acts as a physiological regulator of lactation and involution, in part by favoring growth arrest and cell death. This tightly regulated 5-HT system is subverted in multiple ways in human breast cancers. Specifically, TPH1 expression undergoes a non-linear change during progression, with increased expression during malignant progression. Correspondingly, the tightly regulated pattern of 5-HT receptors becomes dysregulated in human breast cancer cells, resulting in both ectopic expression of some isoforms and suppression of others. The receptor expression change is accompanied by altered downstream signaling of 5-HT receptors in human breast cancer cells, resulting in resistance to 5-HT-induced apoptosis, and stimulated proliferation. Our data constitutes the first report of direct involvement of 5-HT in human breast cancer. Increased 5-HT biosynthetic capacity accompanied by multiple changes in 5-HT receptor expression and signaling favor malignant progression of human breast cancer cells (for example, stimulated proliferation, inappropriate cell survival). This occurs through uncoupling of serotonin from the homeostatic regulatory mechanisms of the normal mammary epithelium. The findings open a new avenue for identification of diagnostic and prognostic markers, and valuable new therapeutic targets for managing breast cancer.

Load Carriage Capacity of the Dismounted Combatant - A Commanders’ Guide

DTIC Science & Technology

2012-10-01

predictive model has been used throughout this document to predict the physiological burden (i.e. energy cost ) of representative load carriage...scenarios. As a general guide this model indicates that a 10 kg increase in external load is metabolically equivalent (i.e. energy cost ) to an increase...larger increases in energy cost for a load carriage task. The multi-factorial nature of human load carriage capacity makes it difficult to set

Determinants and short-term physiological consequences of PHA immune response in lesser kestrel nestlings.

PubMed

Rodríguez, Airam; Broggi, Juli; Alcaide, Miguel; Negro, Juan José; Figuerola, Jordi

2014-08-01

Individual immune responses are likely affected by genetic, physiological, and environmental determinants. We studied the determinants and short-term consequences of Phytohaemagglutinin (PHA) induced immune response, a commonly used immune challenge eliciting both innate and acquired immunity, on lesser kestrel (Falco naumanni) nestlings in semi-captivity conditions and with a homogeneous diet composition. We conducted a repeated measures analyses of a set of blood parameters (carotenoids, triglycerides, β-hydroxybutyrate, cholesterol, uric acid, urea, total proteins, and total antioxidant capacity), metabolic (resting metabolic rate), genotypic (MHC class II B heterozygosity), and biometric (body mass) variables. PHA challenge did not affect the studied physiological parameters on a short-term basis (<12 hr), except plasma concentrations of triglycerides and carotenoids, which decreased and increased, respectively. Uric acid was the only physiological parameter correlated with the PHA induced immune response (skin swelling), but the change of body mass, cholesterol, total antioxidant capacity, and triglycerides between sessions (i.e., post-pre treatment) were also positively correlated to PHA response. No relationships were detected between MHC gene heterozygosity or resting metabolic rate and PHA response. Our results indicate that PHA response in lesser kestrel nestlings growing in optimal conditions does not imply a severe energetic cost 12 hr after challenge, but is condition-dependent as a rapid mobilization of carotenoids and decrease of triglycerides is elicited on a short-term basis. © 2014 Wiley Periodicals, Inc.

Physiological mechanisms drive differing foliar calcium content in ferns and angiosperms.

PubMed

Funk, Jennifer L; Amatangelo, Kathryn L

2013-09-01

Recent evidence points to ferns containing significantly lower contents of foliar calcium and other cations than angiosperms. This is especially true of more ancient 'non-polypod' fern lineages, which predate the diversification of angiosperms. Calcium is an important plant nutrient, the lack of which can potentially slow plant growth and litter decomposition, and alter soil invertebrate communities. The physiological mechanisms limiting foliar calcium (Ca) content in ferns are unknown. While there is a lot we do not know about Ca uptake and transport in plants, three physiological processes are likely to be important. We measured transpiration rate, cation exchange capacity, and leaching loss to determine which process most strongly regulates foliar Ca content in a range of fern and co-occurring understory angiosperm species from a montane Hawaiian rainforest. We found higher instantaneous and lifetime (corrected for leaf lifespan) transpiration rates in angiosperms relative to ferns. Ferns preferentially incorporated Ca into leaves relative to strontium, which suggests that root or stem cation exchange capacity differs between ferns and angiosperms, potentially affecting calcium transport in plants. There were no differences in foliar Ca leaching loss between groups. Among the physiological mechanisms measured, foliar Ca was most strongly correlated with leaf-level transpiration rate and leaf lifespan. This suggests that inter-specific differences in a leaf's lifetime transpiration may play a significant role in determining plant nutrition.

No Evidence for Emotional Empathy in Chickens Observing Familiar Adult Conspecifics

PubMed Central

Edgar, Joanne L.; Paul, Elizabeth S.; Harris, Lauren; Penturn, Sarah; Nicol, Christine J.

2012-01-01

The capacity of animals to empathise is of high potential relevance to the welfare of group-housed domestic animals. Emotional empathy is a multifaceted and multilayered phenomenon which ranges from relatively simple processes such as emotional matching behaviour to more complex processes involving interaction between emotional and cognitive perspective taking systems. Our previous research has demonstrated that hens show clear behavioural and physiological responses to the mild distress of their chicks. To investigate whether this capacity exists outside the mother/offspring bond, we conducted a similar experiment in which domestic hens were exposed to the mild distress of unrelated, but familiar adult conspecifics. Each observer hen was exposed to two replicates of four conditions, in counterbalanced order; control (C); control with noise of air puff (CN); air puff to conspecific hen (APC); air puff to observer hen (APH). During each test, the observer hens' behaviour and physiology were measured throughout a 10 min pre-treatment and a 10 min treatment period. Despite showing signs of distress in response to an aversive stimulus directed at themselves (APH), and using methodology sufficiently sensitive to detect empathy-like responses previously, observer hens showed no behavioural or physiological responses to the mild distress of a familiar adult conspecific. The lack of behavioural and physiological response indicates that hens show no basis for emotional empathy in this context. PMID:22348100

Swimming performance and physiological responses to exhaustive exercise in radio-tagged and untagged Pacific lampreys

USGS Publications Warehouse

Mesa, M.G.; Bayer, J.M.; Seelye, J.G.

2003-01-01

Populations of Pacific lamprey Lampetra tridentata have declined in the Columbia River basin. One factor that may have contributed to this reduction in population size is an excessive use of energy by adult lampreys as they negotiate fishways at dams during spawning migrations. To gain an understanding of the performance capacity of Pacific lampreys, we estimated the critical swimming speed (Ucrit) and documented physiological responses of radio-tagged and untagged adult lampreys exercised to exhaustion. The mean (??SD) Ucrit of untagged lampreys was 86.2 ?? 7.5 cm/s at 15??C, whereas the Ucrit for radio-tagged lampreys was 81.5 ?? 7.0 cm/s, a speed that was significantly lower than that of untagged fish. The physiological responses of tagged and untagged lampreys subjected to exhaustive exercise included decreases in blood pH of 0.3-0.5 units, a 40% decrease in muscle glycogen levels, a 22% increase in hematocrit for untagged fish only, and a 4- to 5-fold increase in muscle and a 40- to 100-fold increase in plasma lactate concentrations. These physiological changes were significant compared with resting control fish and usually returned to resting levels by 1-4 h after fatigue. Our estimates of Ucrit for Pacific lampreys are the first quantitative measures of their swimming performance and suggest that these fish may have difficulty negotiating fishways at dams on the Columbia River, which can have water velocities approaching 2 m/s. Our physiological results indicate that tagged and untagged Pacific lampreys show similar metabolic dysfunction after exhaustive exercise but recover quickly from a single exposure to such a stressor.

Physiologically tolerable decompression profiles for supersonic transport type certification.

DOT National Transportation Integrated Search

1970-07-01

The Supersonic Transport represents a quantum step in civil aeronautics. It will cruise at altitudes having low ambient gaseous pressures far exceeding human capacities for compensatory respiration. In consideration of this evolutionary step, tentati...

Pulmonary gas exchange efficiency during exercise breathing normoxic and hypoxic gas in adults born very preterm with low diffusion capacity.

PubMed

Duke, Joseph W; Elliott, Jonathan E; Laurie, Steven S; Beasley, Kara M; Mangum, Tyler S; Hawn, Jerold A; Gladstone, Igor M; Lovering, Andrew T

2014-09-01

Adults with a history of very preterm birth (<32 wk gestational age; PRET) have reduced lung function and significantly lower lung diffusion capacity for carbon monoxide (DLCO) relative to individuals born at term (CONT). Low DLCO may predispose PRET to diffusion limitation during exercise, particularly while breathing hypoxic gas because of a reduced O2 driving gradient and pulmonary capillary transit time. We hypothesized that PRET would have significantly worse pulmonary gas exchange efficiency [i.e., increased alveolar-to-arterial Po2 difference (AaDO2)] during exercise breathing room air or hypoxic gas (FiO2 = 0.12) compared with CONT. To test this hypothesis, we compared the AaDO2 in PRET (n = 13) with a clinically mild reduction in DLCO (72 ± 7% of predicted) and CONT (n = 14) with normal DLCO (105 ± 10% of predicted) pre- and during exercise breathing room air and hypoxic gas. Measurements of temperature-corrected arterial blood gases, and direct measure of O2 saturation (SaO2), were made prior to and during exercise at 25, 50, and 75% of peak oxygen consumption (V̇o2peak) while breathing room air and hypoxic gas. In addition to DLCO, pulmonary function and exercise capacity were significantly less in PRET. Despite PRET having low DLCO, no differences were observed in the AaDO2 or SaO2 pre- or during exercise breathing room air or hypoxic gas compared with CONT. Although our findings were unexpected, we conclude that reduced pulmonary function and low DLCO resulting from very preterm birth does not cause a measureable reduction in pulmonary gas exchange efficiency. Copyright © 2014 the American Physiological Society.

A conceptual framework for the emerging discipline of conservation physiology

PubMed Central

Coristine, Laura E.; Robillard, Cassandra M.; Kerr, Jeremy T.; O'Connor, Constance M.; Lapointe, Dominique; Cooke, Steven J.

2014-01-01

Current rates of biodiversity decline are unprecedented and largely attributed to anthropogenic influences. Given the scope and magnitude of conservation issues, policy and management interventions must maximize efficiency and efficacy. The relatively new field of conservation physiology reveals the physiological mechanisms associated with population declines, animal–environment relationships and population or species tolerance thresholds, particularly where these relate to anthropogenic factors that necessitate conservation action. We propose a framework that demonstrates an integrative approach between physiology, conservation and policy, where each can inform the design, conduct and implementation of the other. Each junction of the conservation physiology process has the capacity to foster dialogue that contributes to effective implementation, monitoring, assessment and evaluation. This approach enables effective evaluation and implementation of evidence-based conservation policy and management decisions through a process of ongoing refinement, but may require that scientists (from the disciplines of both physiology and conservation) and policy-makers bridge interdisciplinary knowledge gaps. Here, we outline a conceptual framework that can guide and lead developments in conservation physiology, as well as promote innovative research that fosters conservation-motivated policy. PMID:27293654

Benefits of aerobic exercise after stroke.

PubMed

Potempa, K; Braun, L T; Tinknell, T; Popovich, J

1996-05-01

The debilitating loss of function after a stroke has both primary and secondary effects on sensorimotor function. Primary effects include paresis, paralysis, spasticity, and sensory-perceptual dysfunction due to upper motor neuron damage. Secondary effects, contractures and disuse muscle atrophy, are also debilitating. This paper presents theoretical and empirical benefits of aerobic exercise after stroke, issues relevant to measuring peak capacity, exercise training protocols, and the clinical use of aerobic exercise in this patient population. A stroke, and resulting hemiparesis, produces physiological changes in muscle fibres and muscle metabolism during exercise. These changes, along with comorbid cardiovascular disease, must be considered when exercising stroke patients. While few studies have measured peak exercise capacity in hemiparetic populations, it has been consistently observed in these studies that stroke patients have a lower functional capacity than healthy populations. Hemiparetic patients have low peak exercise responses probably due to a reduced number of motor units available for recruitment during dynamic exercise, the reduced oxidative capacity of paretic muscle, and decreased overall endurance. Consequently, traditional methods to predict aerobic capacity are not appropriate for use with stroke patients. Endurance exercise training is increasingly recognised as an important component in rehabilitation. An average improvement in maximal oxygen consumption (VO2max) of 13.3% in stroke patients who participated in a 10-week aerobic exercise training programme has been reported compared with controls. This study underscored the potential benefits of aerobic exercise training in stroke patients. In this paper, advantages and disadvantages of exercise modalities are discussed in relation to stroke patients. Recommendations are presented to maximise physical performance and minimise potential cardiac risks during exercise.

Space Physiology within an Exercise Physiology Curriculum

ERIC Educational Resources Information Center

Carter, Jason R.; West, John B.

2013-01-01

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

A systems approach to integrative biology: an overview of statistical methods to elucidate association and architecture.

PubMed

Ciaccio, Mark F; Finkle, Justin D; Xue, Albert Y; Bagheri, Neda

2014-07-01

An organism's ability to maintain a desired physiological response relies extensively on how cellular and molecular signaling networks interpret and react to environmental cues. The capacity to quantitatively predict how networks respond to a changing environment by modifying signaling regulation and phenotypic responses will help inform and predict the impact of a changing global enivronment on organisms and ecosystems. Many computational strategies have been developed to resolve cue-signal-response networks. However, selecting a strategy that answers a specific biological question requires knowledge both of the type of data being collected, and of the strengths and weaknesses of different computational regimes. We broadly explore several computational approaches, and we evaluate their accuracy in predicting a given response. Specifically, we describe how statistical algorithms can be used in the context of integrative and comparative biology to elucidate the genomic, proteomic, and/or cellular networks responsible for robust physiological response. As a case study, we apply this strategy to a dataset of quantitative levels of protein abundance from the mussel, Mytilus galloprovincialis, to uncover the temperature-dependent signaling network. © The Author 2014. 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.

Respiratory cooling and thermoregulatory coupling in reptiles.

PubMed

Tattersall, Glenn J; Cadena, Viviana; Skinner, Matthew C

2006-11-01

Comparative physiological research on reptiles has focused primarily on the understanding of mechanisms of the control of breathing as they relate to respiratory gases or temperature itself. Comparatively less research has been done on the possible link between breathing and thermoregulation. Reptiles possess remarkable thermoregulatory capabilities, making use of behavioural and physiological mechanisms to regulate body temperature. The presence of thermal panting and gaping in numerous reptiles, coupled with the existence of head-body temperature differences, suggests that head temperature may be the primary regulated variable rather than body temperature. This review examines the preponderance of head and body temperature differences in reptiles, the occurrence of breathing patterns that possess putative thermoregulatory roles, and the propensity for head and brain temperature to be controlled by reptiles, particularly at higher temperatures. The available evidence suggests that these thermoregulatory breathing patterns are indeed present, though primarily in arid-dwelling reptiles. More importantly, however, it appears that the respiratory mechanisms that have the capacity to cool evolved initially in reptiles, perhaps as regulatory mechanisms for preventing overheating of the brain. Examining the control of these breathing patterns and their efficacy at regulating head or brain temperature may shed light on the evolution of thermoregulatory mechanisms in other vertebrates, namely the endothermic mammals and birds.

Making Olympic lizards: the effects of specialised exercise training on performance.

PubMed

Husak, Jerry F; Keith, Allison R; Wittry, Beth N

2015-03-01

Exercise training is well known to affect a suite of physiological and performance traits in mammals, but effects of training in other vertebrate tetrapod groups have been inconsistent. We examined performance and physiological differences among green anole lizards (Anolis carolinensis) that were trained for sprinting or endurance, using an increasingly rigorous training regimen over 8 weeks. Lizards trained for endurance had significantly higher post-training endurance capacity compared with the other treatment groups, but groups did not show post-training differences in sprint speed. Although acclimation to the laboratory environment and training explain some of our results, mechanistic explanations for these results correspond with the observed performance differences. After training, endurance-trained lizards had higher haematocrit and larger fast glycolytic muscle fibres. Despite no detectable change in maximal performance of sprint-trained lizards, we detected that they had significantly larger slow oxidative muscle fibre areas compared with the other treatments. Treatment groups did not differ in the proportion of number of fibre types, nor in the mass of most limb muscles or the heart. Our results offer some caveats for investigators conducting training research on non-model organisms and they reveal that muscle plasticity in response to training may be widespread phylogenetically. © 2015. Published by The Company of Biologists Ltd.

ORAC and DPPH assay comparison to assess antioxidant capacity of tea infusions: relationship between total polyphenol and individual catechin content.

PubMed

Roy, Molay K; Koide, Motoki; Rao, Theertham P; Okubo, Tsutomu; Ogasawara, Yutaka; Juneja, Lekh R

2010-03-01

Commercially available tea infusions are the major source of catechins for preparing bottled tea beverages and tea supplements available in the market today. In the present study, we analyzed five tea infusions to measure the total antioxidant capacity (TAC) by oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity (DRSC) assays, total polyphenol content by the colorimetric method and individual catechin content by high-performance liquid chromatography. Four major tea catechins were also analyzed for their TAC to reveal differential antioxidant behavior of the tea infusions, resulting in the ORAC and DRSC methods. The correlation coefficients between DRSC and the total polyphenol or total catechin content of the tea infusions were 1.0 and 0.99. However, the values fall to 0.73 and 0.69, respectively, while the ORAC activity was correlated with total polyphenol and total catechin content. Determining the TAC of individual tea catechins showed that ORAC of epicatechin was seven-fold higher than that of epigallocatechin gallate; on the contrary, epigallocatechin gallate showed significantly (P < 0.05) stronger DRSC activity than epicatechin. By evaluating the structure-activity relationship, this study further revealed that OH substitution at the 3' position in pyrogallol moieties contributes to the lower ORAC value of epigallocatechin and epigallocatechin gallate comparing with their non-3'-OH counterparts, such as epicatechin and epicatechin gallate, respectively. Also, numbers of OH substitutions were poorly correlated with the observed ORAC value unlike the DRSC. Overall, results of this study enabled us to hypothesize that substances having a lower TAC value in the ORAC assay compared with that in DPPH assays may pertain to a pro-oxidant effect by generating reactive oxygen species in an aqueous buffer, at a physiological pH. We also propose that substances exhibiting lower TAC value in the ORAC assay compared with that in the DPPH assay are powerful pro-oxidants compared with the substances showing a higher TAC value in the ORAC assay than that in the DPPH assay.

The endomembrane requirement for cell surface repair

NASA Technical Reports Server (NTRS)

McNeil, Paul L.; Miyake, Katsuya; Vogel, Steven S.

2003-01-01

The capacity to reseal a plasma membrane disruption rapidly is required for cell survival in many physiological environments. Intracellular membrane (endomembrane) is thought to play a central role in the rapid resealing response. We here directly compare the resealing response of a cell that lacks endomembrane, the red blood cell, with that of several nucleated cells possessing an abundant endomembrane compartment. RBC membrane disruptions inflicted by a mode-locked Ti:sapphire laser, even those initially smaller than hemoglobin, failed to reseal rapidly. By contrast, much larger laser-induced disruptions made in sea urchin eggs, fibroblasts, and neurons exhibited rapid, Ca(2+)-dependent resealing. We conclude that rapid resealing is not mediated by simple physiochemical mechanisms; endomembrane is required.

Lipidomic and Antioxidant Response to Grape Seed, Corn and Coconut Oils in Healthy Wistar Rats

PubMed Central

Wall-Medrano, Abraham; de la Rosa, Laura A.; Vázquez-Flores, Alma A.; Mercado-Mercado, Gilberto; González-Arellanes, Rogelio; López-Díaz, José A.; González-Córdova, Aarón F.; González-Aguilar, Gustavo A.; Vallejo-Cordoba, Belinda; Molina-Corral, Francisco J.

2017-01-01

Specialty oils differ in fatty acid, phytosterol and antioxidant content, impacting their benefits for cardiovascular health. The lipid (fatty acid, phytosterol) and antioxidant (total phenolics, radical scavenging capacity) profiles of grapeseed (GSO), corn (CO) and coconut (CNO) oils and their physiological (triacylglycerides, total and HDL-cholesterol and antioxidant capacity (FRAP) in serum and fatty acid and phytosterol hepatic deposition) and genomic (HL, LCAT, ApoA-1 and SR-BP1 mRNA hepatic levels) responses after their sub-chronic intake (10% diet for 28 days) was examined in healthy albino rats. Fatty acid, phytosterol and antioxidant profiles differed between oils (p ≤ 0.01). Serum and hepatic triacylglycerides and total cholesterol increased (p ≤ 0.01); serum HDL-Cholesterol decreased (p < 0.05); but serum FRAP did not differ (p > 0.05) in CNO-fed rats as compared to CO or GSO groups. Hepatic phytosterol deposition was higher (+2.2 mg/g; p ≤ 0.001) in CO- than GSO-fed rats, but their fatty acid deposition was similar. All but ApoA-1 mRNA level increased in GSO-fed rats as compared to other groups (p ≤ 0.01). Hepatic fatty acid handling, but not antioxidant response, nor hepatic phytosterol deposition, could be related to a more efficient reverse-cholesterol transport in GSO-fed rats as compared to CO or CNO. PMID:28117688

Functional anatomy of the gibbon forelimb: adaptations to a brachiating lifestyle

PubMed Central

Michilsens, Fana; Vereecke, Evie E; D'Août, Kristiaan; Aerts, Peter

2009-01-01

It has been shown that gibbons are able to brachiate with very low mechanical costs. The conversion of muscle activity into smooth, purposeful movement of the limb depends on the morphometry of muscles and their mechanical action on the skeleton. Despite the gibbon's reputation for excellence in brachiation, little information is available regarding either its gross musculoskeletal anatomy or its more detailed muscle–tendon architecture. We provide quantitative anatomical data on the muscle–tendon architecture (muscle mass, physiological cross-sectional area, fascicle length and tendon length) of the forelimb of four gibbon species, collected by detailed dissections of unfixed cadavers. Data are compared between different gibbon species and with similar published data of non-brachiating primates such as macaques, chimpanzees and humans. No quantitative differences are found between the studied gibbon species. Both their forelimb anatomy and muscle dimensions are comparable when normalized to the same body mass. Gibbons have shoulder flexors, extensors, rotator muscles and elbow flexors with a high power or work-generating capacity and their wrist flexors have a high force-generating capacity. Compared with other primates, the elbow flexors of gibbons are particularly powerful, suggesting that these muscles are particularly important for a brachiating lifestyle. Based on this anatomical study, the shoulder flexors, extensors, rotator muscles, elbow flexors and wrist flexors are expected to contribute the most to brachiation. PMID:19519640

Endurance Exercise in Hypoxia, Hyperoxia and Normoxia: Mitochondrial and Global Adaptations.

PubMed

Przyklenk, Axel; Gutmann, Boris; Schiffer, Thorsten; Hollmann, Wildor; Strueder, Heiko K; Bloch, Wilhelm; Mierau, Andreas; Gehlert, Sebastian

2017-07-01

We hypothesized short-term endurance exercise (EN) in hypoxia (HY) to exert decreased mitochondrial adaptation, peak oxygen consumption (VO 2peak ) and peak power output (PPO) compared to EN in normoxia (NOR) and hyperoxia (PER). 11 male subjects performed repeated unipedal cycling EN in HY, PER, and NOR over 4 weeks in a cross-over design. VO 2peak , PPO, rate of perceived exertion (RPE) and blood lactate (Bla) were determined pre- and post-intervention to assess physiological demands and adaptation. Skeletal muscle biopsies were collected to determine molecular mitochondrial signaling and adaptation. Despite reduced exercise intensity (P<0.05), increased Bla and RPE levels in HY revealed higher metabolic load compared to PER (P<0.05) and NOR (n.s.). PPO increased in all groups (P<0.05) while VO 2peak and mitochondrial signaling were unchanged (P>0.05). Electron transport chain complexes tended to increase in all groups with the highest increase in HY (n.s.). EN-induced mitochondrial adaptability and exercise capacity neither decreased significantly in HY nor increased in PER compared to NOR. Despite decreased exercise intensity, short term EN under HY may not necessarily impair mitochondrial adaptation and exercise capacity while PER does not augment adaptation. HY might strengthen adaptive responses under circumstances when absolute training intensity has to be reduced. © Georg Thieme Verlag KG Stuttgart · New York.

Systemic SMAD7 Gene Therapy Increases Striated Muscle Mass and Enhances Exercise Capacity in a Dose-Dependent Manner.

PubMed

Maricelli, Joseph W; Bishaw, Yemeserach M; Wang, Bo; Du, Min; Rodgers, Buel D

2018-03-01

Striated muscle wasting occurs with a variety of disease indications, contributing to mortality and compromising life quality. Recent studies indicate that the recombinant adeno-associated virus (serotype 6) Smad7 gene therapeutic, AVGN7, enhances skeletal and cardiac muscle mass and prevents cancer-induced wasting of both tissues. This is accomplished by attenuating ActRIIb intracellular signaling and, as a result, the physiological actions of myostatin and other ActRIIb ligands. AVGN7 also enhances isolated skeletal muscle twitch force, but is unknown to improve systemic muscle function similarly, especially exercise capacity. A 2-month-long dose-escalation study was therefore conducted using 5 × 10 11 , 1 × 10 12 , and 5 × 10 12 vg/mouse and different tests of systemic muscle function. Body mass, skeletal muscle mass, heart mass, and forelimb grip strength were all increased in a dose-dependent manner, as was the fiber cross-sectional area of tibialis anterior muscles. Maximal oxygen consumption (VO 2 max), a measure of metabolic rate, was similarly enhanced during forced treadmill running, and although the total distance traveled was only elevated by the highest dose, all doses reduced the energy expenditure rate compared to control mice injected with an empty vector. Such improvements in VO 2 max are consistent with physiological cardiac hypertrophy, which is highly beneficial and a normal adaptive response to exercise. This was particularly evident at the lowest dose tested, which had minimal significant effects on skeletal muscle mass and/or function, but increased heart weight and exercise capacity. These results together suggest that AVGN7 enhances striated muscle mass and systemic muscle function. They also define minimally effective and optimal doses for future preclinical trials and toxicology studies and in turn will aid in establishing dose ranges for clinical trials.

The effect of salinity increase on the photosynthesis, growth and survival of the Mediterranean seagrass Cymodocea nodosa

NASA Astrophysics Data System (ADS)

Sandoval-Gil, José M.; Marín-Guirao, Lázaro; Ruiz, Juan M.

2012-12-01

There are major concerns in the Mediterranean Sea over the effects of hypersaline effluents from seawater desalination plants on seagrass communities. However, knowledge concerning the specific physiological capacities of seagrasses to tolerate or resist salinity increases is still limited. In this study, changes in the photosynthetic characteristics, pigment content, leaf light absorption, growth and survival of the seagrass Cymodocea nodosa were examined across a range of simulated hypersaline conditions. To this end, large plant fragments were maintained under salinities of 37 (control ambient salinity), 39, 41 and 43 (practical salinity scale) in a laboratory mesocosm system for 47 days. At the end of the experimental period, net photosynthesis exhibited a modest, but significant, decline (12-17%) in all tested hypersaline conditions (39-43). At intermediate salinity levels (39-41), the decline in photosynthetic rates was mainly accounted for by substantial increases in respiratory losses (approximately 98% of the control), the negative effects of which on leaf carbon balance were offset by an improved capacity and efficiency of leaves to absorb light, mainly through changes in accessory pigments, but also in optical properties related to leaf anatomy. Conversely, inhibition of gross photosynthesis (by 19.6% compared to the control mean) in the most severe hypersaline conditions (43) reduced net photosynthesis. In this treatment, the respiration rate was limited in order to facilitate a positive carbon balance (similar to that of the control plants) and shoot survival, although vitality would probably be reduced if such metabolic alterations persisted. These results are consistent with the ecology of Mediterranean C. nodosa populations, which are considered to have high morphological and physiological plasticity and a capacity to grow in a wide variety of coastal environments with varying salinity levels. The results from this study support the premise that C. nodosa has a higher tolerance to hypersaline conditions than the highly sensitive Posidonia oceanica, the other dominant Mediterranean seagrass, which is limited to marine environments with stable salinities.

Impact of limited solvent capacity on metabolic rate, enzyme activities, and metabolite concentrations of S. cerevisiae glycolysis.

PubMed

Vazquez, Alexei; de Menezes, Marcio A; Barabási, Albert-László; Oltvai, Zoltan N

2008-10-01

The cell's cytoplasm is crowded by its various molecular components, resulting in a limited solvent capacity for the allocation of new proteins, thus constraining various cellular processes such as metabolism. Here we study the impact of the limited solvent capacity constraint on the metabolic rate, enzyme activities, and metabolite concentrations using a computational model of Saccharomyces cerevisiae glycolysis as a case study. We show that given the limited solvent capacity constraint, the optimal enzyme activities and the metabolite concentrations necessary to achieve a maximum rate of glycolysis are in agreement with their experimentally measured values. Furthermore, the predicted maximum glycolytic rate determined by the solvent capacity constraint is close to that measured in vivo. These results indicate that the limited solvent capacity is a relevant constraint acting on S. cerevisiae at physiological growth conditions, and that a full kinetic model together with the limited solvent capacity constraint can be used to predict both metabolite concentrations and enzyme activities in vivo.

Impact of Limited Solvent Capacity on Metabolic Rate, Enzyme Activities, and Metabolite Concentrations of S. cerevisiae Glycolysis

PubMed Central

Vazquez, Alexei; de Menezes, Marcio A.; Barabási, Albert-László; Oltvai, Zoltan N.

2008-01-01

The cell's cytoplasm is crowded by its various molecular components, resulting in a limited solvent capacity for the allocation of new proteins, thus constraining various cellular processes such as metabolism. Here we study the impact of the limited solvent capacity constraint on the metabolic rate, enzyme activities, and metabolite concentrations using a computational model of Saccharomyces cerevisiae glycolysis as a case study. We show that given the limited solvent capacity constraint, the optimal enzyme activities and the metabolite concentrations necessary to achieve a maximum rate of glycolysis are in agreement with their experimentally measured values. Furthermore, the predicted maximum glycolytic rate determined by the solvent capacity constraint is close to that measured in vivo. These results indicate that the limited solvent capacity is a relevant constraint acting on S. cerevisiae at physiological growth conditions, and that a full kinetic model together with the limited solvent capacity constraint can be used to predict both metabolite concentrations and enzyme activities in vivo. PMID:18846199

The Role of Exercise in Cardiac Aging: From Physiology to Molecular Mechanisms

PubMed Central

Roh, Jason; Rhee, James; Chaudhari, Vinita; Rosenzweig, Anthony

2015-01-01

Aging induces structural and functional changes in the heart that are associated with increased risk of cardiovascular disease and impaired functional capacity in the elderly. Exercise is a diagnostic and therapeutic tool, with the potential to provide insights into clinical diagnosis and prognosis, as well as the molecular mechanisms by which aging influences cardiac physiology and function. In this review, we first provide an overview of how aging impacts the cardiac response to exercise and the implications this has for functional capacity in older adults. We then review the underlying molecular mechanisms by which cardiac aging contributes to exercise intolerance, and conversely how exercise training can potentially modulate aging phenotypes in the heart. Finally, we highlight the potential use of these exercise models to complement models of disease in efforts to uncover new therapeutic targets to prevent or treat heart disease in the aging population. PMID:26838314

Choke or thrive? The relation between salivary cortisol and math performance depends on individual differences in working memory and math-anxiety.

PubMed

Mattarella-Micke, Andrew; Mateo, Jill; Kozak, Megan N; Foster, Katherine; Beilock, Sian L

2011-08-01

In the current study, we explored how a person's physiological arousal relates to their performance in a challenging math situation as a function of individual differences in working memory (WM) capacity and math-anxiety. Participants completed demanding math problems before and after which salivary cortisol, an index of arousal, was measured. The performance of lower WM individuals did not depend on cortisol concentration or math-anxiety. For higher WM individuals high in math-anxiety, the higher their concentration of salivary cortisol following the math task, the worse their performance. In contrast, for higher WM individuals lower in math-anxiety, the higher their salivary cortisol concentrations, the better their performance. For individuals who have the capacity to perform at a high-level (higher WMs), whether physiological arousal will lead an individual to choke or thrive depends on math-anxiety. 2011 APA, all rights reserved

The Role of Exercise in Cardiac Aging: From Physiology to Molecular Mechanisms.

PubMed

Roh, Jason; Rhee, James; Chaudhari, Vinita; Rosenzweig, Anthony

2016-01-22

Aging induces structural and functional changes in the heart that are associated with increased risk of cardiovascular disease and impaired functional capacity in the elderly. Exercise is a diagnostic and therapeutic tool, with the potential to provide insights into clinical diagnosis and prognosis, as well as the molecular mechanisms by which aging influences cardiac physiology and function. In this review, we first provide an overview of how aging impacts the cardiac response to exercise, and the implications this has for functional capacity in older adults. We then review the underlying molecular mechanisms by which cardiac aging contributes to exercise intolerance, and conversely how exercise training can potentially modulate aging phenotypes in the heart. Finally, we highlight the potential use of these exercise models to complement models of disease in efforts to uncover new therapeutic targets to prevent or treat heart disease in the aging population. © 2016 American Heart Association, Inc.

Visual Short-Term Memory Compared in Rhesus Monkeys and Humans

PubMed Central

Elmore, L. Caitlin; Ma, Wei Ji; Magnotti, John F.; Leising, Kenneth J.; Passaro, Antony D.; Katz, Jeffrey S.; Wright, Anthony A.

2011-01-01

Summary Change detection is a popular task to study visual short-term memory (STM) in humans [1–4]. Much of this work suggests that STM has a fixed capacity of 4 ± 1 items [1–6]. Here we report the first comparison of change detection memory between humans and a species closely related to humans, the rhesus monkey. Monkeys and humans were tested in nearly identical procedures with overlapping display sizes. Although the monkeys’ STM was well fit by a 1-item fixed-capacity memory model, other monkey memory tests with 4-item lists have shown performance impossible to obtain with a 1-item capacity [7]. We suggest that this contradiction can be resolved using a continuous-resource approach more closely tied to the neural basis of memory [8,9]. In this view, items have a noisy memory representation whose noise level depends on display size due to distributed allocation of a continuous resource. In accord with this theory, we show that performance depends on the perceptual distance between items before and after the change, and d′ depends on display size in an approximately power law fashion. Our results open the door to combining the power of psychophysics, computation, and physiology to better understand the neural basis of STM. PMID:21596568

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.

Comprehensive Identification of RNA-Binding Proteins by RNA Interactome Capture.

PubMed

Castello, Alfredo; Horos, Rastislav; Strein, Claudia; Fischer, Bernd; Eichelbaum, Katrin; Steinmetz, Lars M; Krijgsveld, Jeroen; Hentze, Matthias W

2016-01-01

RNA associates with RNA-binding proteins (RBPs) from synthesis to decay, forming dynamic ribonucleoproteins (RNPs). In spite of the preeminent role of RBPs regulating RNA fate, the scope of cellular RBPs has remained largely unknown. We have recently developed a novel and comprehensive method to identify the repertoire of active RBPs of cultured cells, called RNA interactome capture. Using in vivo UV cross-linking on cultured cells, proteins are covalently bound to RNA if the contact between the two is direct ("zero distance"). Protein-RNA complexes are purified by poly(A) tail-dependent oligo(dT) capture and analyzed by quantitative mass spectrometry. Because UV irradiation is applied to living cells and purification is performed using highly stringent washes, RNA interactome capture identifies physiologic and direct protein-RNA interactions. Applied to HeLa cells, this protocol revealed the near-complete repertoire of RBPs, including hundreds of novel RNA binders. Apart from its RBP discovery capacity, quantitative and comparative RNA interactome capture can also be used to study the responses of the RBP repertoire to different physiological cues and processes, including metabolic stress, differentiation, development, or the response to drugs.

High efficiency cell-recycle continuous sodium gluconate production by Aspergillus niger using on-line physiological parameters association analysis to regulate feed rate rationally.

PubMed

Lu, Fei; Li, Chao; Wang, Zejian; Zhao, Wei; Chu, Ju; Zhuang, Yingping; Zhang, Siliang

2016-11-01

In this paper, a system of cell-recycle continuous fermentation for sodium gluconate (SG) production by Aspergillus niger (A. niger) was established. Based on initial continuous fermentation result (100.0h) with constant feed rate, an automatic feedback strategy to regulate feed rate using on-line physiological parameters (OUR and DO) was proposed and applied successfully for the first time in the improved continuous fermentation (240.5h). Due to less auxiliary time, highest SG production rate (31.05±0.29gL(-1)h(-1)) and highest yield (0.984±0.067molmol(-1)), overall SG production capacity (975.8±5.8gh(-1)) in 50-L fermentor of improved continuous fermentation increased more than 300.0% compared to that of batch fermentation. Improvement of mass transfer and dispersed mycelia morphology were the two major reasons responsible for the high SG production rate. This system had been successfully applied to industrial fermentation and SG production was greatly improved. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Physiological and biochemical characteristics and capacity for polyhydroxyalkanoates synthesis in a glucose-utilizing strain of hydrogen-oxidizing bacteria, Ralstonia eutropha B8562].

PubMed

Volova, T G; Kozhevnikov, I V; Dolgopolova, Iu B; Trusova, M Iu; Kalacheva, G S; Aref'eva, Iu V

2005-01-01

The physiological, biochemical, genetic, and cultural characteristics of the glucose-utilizing mutant strain Ralstonia eutropha B8562 were investigated in comparison with the parent strain R. eutropha B5786. The morphological, cultural, and biochemical characteristics of strain R. eutropha B8562 were similar to those of strain R. eutropha B5786. Genetic analysis revealed differences between the 16S rRNA gene sequences of these strains. The growth characteristics of the mutant using glucose as the sole carbon and energy source were comparable with those of the parent strain grown on fructose. Strain B8562 was characterized by high yields of polyhydroxyalkanoate (PHA) from different carbon sources (CO2, fructose, and glucose). In batch culture with glucose under nitrogen limitation, PHA accumulation reached 90% of dry weight. In PHA, beta-hydroxybutyrate was predominant (over 99 mol %); beta-hydroxyvalerate (0.25-0.72 mol %) and beta-hydroxyhexanoate (0.008-1.5 mol %) were present as minor components. The strain has prospects as a PHA producer on glucose-containing media.

Use of the International Space Station as an Exercise Physiology Lab

NASA Technical Reports Server (NTRS)

Ploutz-Snyder, Lori

2013-01-01

The International Space Station (ISS) is now in its prime utilization phase with great opportunity to use the ISS as a lab. With respect to exercise physiology there is considerable research opportunity. Crew members exercise for up to 2 hours per day using a cycle ergometer, treadmill, and advanced resistive exercise device (ARED). There are several ongoing exercise research studies by NASA, ESA and CSA. These include studies related to evaluation of new exercise prescriptions (SPRINT), evaluation of aerobic capacity (VO2max), biomechanics (Treadmill Kinematics), energy expenditure during spaceflight (Energy), evaluation of cartilage (Cartilage), and evaluation of cardiovascular health (Vascular). Examples of how ISS is used for exercise physiology research will be presented.

Oxidative stress induces mitochondrial dysfunction in a subset of autistic lymphoblastoid cell lines

PubMed Central

Rose, S; Frye, R E; Slattery, J; Wynne, R; Tippett, M; Melnyk, S; James, S J

2014-01-01

There is an increasing recognition that mitochondrial dysfunction is associated with autism spectrum disorders. However, little attention has been given to the etiology of mitochondrial dysfunction and how mitochondrial abnormalities might interact with other physiological disturbances such as oxidative stress. Reserve capacity is a measure of the ability of the mitochondria to respond to physiological stress. In this study, we demonstrate, for the first time, that lymphoblastoid cell lines (LCLs) derived from children with autistic disorder (AD) have an abnormal mitochondrial reserve capacity before and after exposure to reactive oxygen species (ROS). Ten (44%) of 22 AD LCLs exhibited abnormally high reserve capacity at baseline and a sharp depletion of reserve capacity when challenged with ROS. This depletion of reserve capacity was found to be directly related to an atypical simultaneous increase in both proton-leak respiration and adenosine triphosphate-linked respiration in response to increased ROS in this AD LCL subgroup. In this AD LCL subgroup, 48-hour pretreatment with N-acetylcysteine, a glutathione precursor, prevented these abnormalities and improved glutathione metabolism, suggesting a role for altered glutathione metabolism associated with this type of mitochondrial dysfunction. The results of this study suggest that a significant subgroup of AD children may have alterations in mitochondrial function, which could render them more vulnerable to a pro-oxidant microenvironment as well as intrinsic and extrinsic sources of ROS such as immune activation and pro-oxidant environmental toxins. These findings are consistent with the notion that AD is caused by a combination of genetic and environmental factors. PMID:24690598

A metabolic switch toward lipid use in glycolytic muscle is an early pathologic event in a mouse model of amyotrophic lateral sclerosis

PubMed Central

Palamiuc, Lavinia; Schlagowski, Anna; Ngo, Shyuan T; Vernay, Aurelia; Dirrig-Grosch, Sylvie; Henriques, Alexandre; Boutillier, Anne-Laurence; Zoll, Joffrey; Echaniz-Laguna, Andoni; Loeffler, Jean-Philippe; René, Frédérique

2015-01-01

Amyotrophic lateral sclerosis (ALS) is the most common fatal motor neuron disease in adults. Numerous studies indicate that ALS is a systemic disease that affects whole body physiology and metabolic homeostasis. Using a mouse model of the disease (SOD1G86R), we investigated muscle physiology and motor behavior with respect to muscle metabolic capacity. We found that at 65 days of age, an age described as asymptomatic, SOD1G86R mice presented with improved endurance capacity associated with an early inhibition in the capacity for glycolytic muscle to use glucose as a source of energy and a switch in fuel preference toward lipids. Indeed, in glycolytic muscles we showed progressive induction of pyruvate dehydrogenase kinase 4 expression. Phosphofructokinase 1 was inhibited, and the expression of lipid handling molecules was increased. This mechanism represents a chronic pathologic alteration in muscle metabolism that is exacerbated with disease progression. Further, inhibition of pyruvate dehydrogenase kinase 4 activity with dichloroacetate delayed symptom onset while improving mitochondrial dysfunction and ameliorating muscle denervation. In this study, we provide the first molecular basis for the particular sensitivity of glycolytic muscles to ALS pathology. PMID:25820275

Physiological work performance in chronic low back disability: effects of a progressive activity program.

PubMed

Thomas, L K; Hislop, H J; Waters, R L

1980-04-01

Fifteen patients were tested before and after treatment in a multifaceted inpatient program for chronic low back pain to determine if a gradually progressive activity program affected gait performance and physiological capacity. Before treatment, all patients demonstrated decreased physiological conditioning by higher-than-expected values for oxygen consumption and heart rate and by lower-than-normal gait velocity, stride length, and cadence. After treatment, an increase in mean walking velocity of 19 meters/minute reflected parallel gains in cadence and stride length. Improved mechanical performance resulted in improved "energetics." Energy spent per unit of distance walked decreased by 18 percent after treatment, providing a useful measure of increased physiological efficiency. Results indicated that patients with chronic low back disability can derive significant conditioning effects from an exercise program based on general function.

Physiological and biochemical responses of two keystone polychaete species: Diopatra neapolitana and Hediste diversicolor to Multi-walled carbon nanotubes

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

De Marchi, Lucia

Multi-walled carbon nanotubes (MWCNTs) are one of the most important carbon Nanomaterials (NMs). The production and use of these carbon NMs is increasing rapidly and, therefore, the need to assess their presence in the environment and associated risks has become increasingly important. However, limited literature is available regarding the impacts induced in aquatic organisms by this pollutant, namely in invertebrate species. Diopatra neapolitana and Hediste diversicolor are keystone polychaete species inhabiting estuaries and shallow water bodies intertidal mudflats, frequently used to evaluate the impact of environmental disturbances in these systems. To our knowledge, no information is available on physiological andmore » biochemical alterations on these two species due to MWCNTs exposure. Thus, the present study aimed to assess the toxic effects of different MWCNTs concentrations (0.01; 0.10 and 1.00 mg/L) in both species physiological (regenerative capacity and respiration rate) and biochemical (energy reserves, metabolic activities, oxidative stress related biomarkers and neurotoxicity markers) performance, after 28 days of exposure. The results obtained revealed that exposure to MWCNTs induced negative effects on the regenerative capacity of D. neapolitana. Additionally, higher MWCNTs concentrations induced increased respiration rates in D. neapolitana. MWCNTs altered energy-related responses, with higher values of electron transport system activity, glycogen and protein concentrations in both polychaetes exposed to this contaminant. Furthermore, when exposed to MWCNTs both species showed oxidative stress with higher lipid peroxidation, lower ratio between reduced and oxidized glutathione, and higher activity of antioxidant (catalase and superoxide dismutase) and biotransformation (glutathione-S-transferases) enzymes in exposed organisms. - Highlights: • MWCNTs induced negative effects on the regenerative capacity of Diopatra neapolitana. • Diopatra neapolitana and Hediste diversicolor exposed to MWCNTs showed oxidative stress. • Both species under MWCNTs increased their metabolic capacity. • Inhibition of cholinesterases confirmed neurotoxicity of MWCNTs in both species. • D. neapolitana and H. diversicolor are potential bioindicators to monitor carbon NMs pollution.« less

Physiological tradeoffs may underlie the evolution of hypoxia tolerance and exercise performance in sunfish (Centrarchidae).

PubMed

Crans, Kyle D; Pranckevicius, Nicole A; Scott, Graham R

2015-10-01

Tradeoffs between hypoxia tolerance and aerobic exercise performance appear to exist in some fish taxa, even though both of these traits are often associated with a high O2 transport capacity. We examined the physiological basis for this potential tradeoff in four species of sunfish from the family Centrarchidae. Hypoxia tolerance was greatest in rock bass, intermediate in pumpkinseed and bluegill and lowest in largemouth bass, based on measurements of critical O2 tension (Pcrit) and O2 tension at loss of equilibrium (PO2 at LOE). Consistent with there being a tradeoff between hypoxia tolerance and aerobic exercise capacity, the least hypoxia-tolerant species had the highest critical swimming speed (Ucrit) during normoxia and suffered the greatest decrease in Ucrit in hypoxia. There was also a positive correlation between Ucrit in normoxia and PO2 at LOE, which remained significant after accounting for phylogeny using phylogenetically independent contrasts. Several sub-organismal traits appeared to contribute to both hypoxia tolerance and aerobic exercise capacity (reflected by traits that were highest in both rock bass and largemouth bass), such as the gas-exchange surface area of the gills, the pH sensitivity of haemoglobin-O2 affinity, and the activities of lactate dehydrogenase and the gluconeogenic enzyme phosphoenolpyruvate carboxykinase in the liver. Some other sub-organismal traits were uniquely associated with either hypoxia tolerance (low sensitivity of haemoglobin-O2 affinity to organic phosphates, high pyruvate kinase and lactate dehydrogenase activities in the heart) or aerobic exercise capacity (capillarity and fibre size of the axial swimming muscle). Therefore, the cumulative influence of a variety of respiratory and metabolic traits can result in physiological tradeoffs associated with the evolution of hypoxia tolerance and aerobic exercise performance in fish. © 2015. Published by The Company of Biologists Ltd.

Depth investigation of rapid sand filters for drinking water production reveals strong stratification in nitrification biokinetic behavior.

PubMed

Tatari, K; Smets, B F; Albrechtsen, H-J

2016-09-15

The biokinetic behavior of NH4(+) removal was investigated at different depths of a rapid sand filter treating groundwater for drinking water preparation. Filter materials from the top, middle and bottom layers of a full-scale filter were exposed to various controlled NH4(+) loadings in a continuous-flow lab-scale assay. NH4(+) removal capacity, estimated from short term loading up-shifts, was at least 10 times higher in the top than in the middle and bottom filter layers, consistent with the stratification of Ammonium Oxidizing Bacteria (AOB). AOB density increased consistently with the NH4(+) removal rate, indicating their primarily role in nitrification under the imposed experimental conditions. The maximum AOB cell specific NH4(+) removal rate observed at the bottom was at least 3 times lower compared to the top and middle layers. Additionally, a significant up-shift capacity (4.6 and 3.5 times) was displayed from the top and middle layers, but not from the bottom layer at increased loading conditions. Hence, AOB with different physiological responses were active at the different depths. The biokinetic analysis predicted that despite the low NH4(+) removal capacity at the bottom layer, the entire filter is able to cope with a 4-fold instantaneous loading increase without compromising the effluent NH4(+). Ultimately, this filter up-shift capacity was limited by the density of AOB and their biokinetic behavior, both of which were strongly stratified. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of HB17, an Arabidopsis class II homeodomain-leucine zipper transcription factor, to regulate chloroplast number and photosynthetic capacity.

PubMed

Hymus, Graham J; Cai, Suqin; Kohl, Elizabeth A; Holtan, Hans E; Marion, Colleen M; Tiwari, Shiv; Maszle, Don R; Lundgren, Marjorie R; Hong, Melissa C; Channa, Namitha; Loida, Paul; Thompson, Rebecca; Taylor, J Philip; Rice, Elena; Repetti, Peter P; Ratcliffe, Oliver J; Reuber, T Lynne; Creelman, Robert A

2013-11-01

Transcription factors are proposed as suitable targets for the control of traits such as yield or food quality in plants. This study reports the results of a functional genomics research effort that identified ATHB17, a transcription factor from the homeodomain-leucine zipper class II family, as a novel target for the enhancement of photosynthetic capacity. It was shown that ATHB17 is expressed natively in the root quiescent centre (QC) from Arabidopsis embryos and seedlings. Analysis of the functional composition of genes differentially expressed in the QC from a knockout mutant (athb17-1) compared with its wild-type sibling revealed the over-representation of genes involved in auxin stimulus, embryo development, axis polarity specification, and plastid-related processes. While no other phenotypes were observed in athb17-1 plants, overexpression of ATHB17 produced a number of phenotypes in Arabidopsis including enhanced chlorophyll content. Image analysis of isolated mesophyll cells of 35S::ATHB17 lines revealed an increase in the number of chloroplasts per unit cell size, which is probably due to an increase in the number of proplastids per meristematic cell. Leaf physiological measurements provided evidence of improved photosynthetic capacity in 35S::ATHB17 lines on a per unit leaf area basis. Estimates of the capacity for ribulose-1,5-bisphosphate-saturated and -limited photosynthesis were significantly higher in 35S::ATHB17 lines.

Application of HB17, an Arabidopsis class II homeodomain-leucine zipper transcription factor, to regulate chloroplast number and photosynthetic capacity

PubMed Central

Kohl, Elizabeth A.; Tiwari, Shiv; Lundgren, Marjorie R.; Channa, Namitha; Creelman, Robert A.

2013-01-01

Transcription factors are proposed as suitable targets for the control of traits such as yield or food quality in plants. This study reports the results of a functional genomics research effort that identified ATHB17, a transcription factor from the homeodomain-leucine zipper class II family, as a novel target for the enhancement of photosynthetic capacity. It was shown that ATHB17 is expressed natively in the root quiescent centre (QC) from Arabidopsis embryos and seedlings. Analysis of the functional composition of genes differentially expressed in the QC from a knockout mutant (athb17-1) compared with its wild-type sibling revealed the over-representation of genes involved in auxin stimulus, embryo development, axis polarity specification, and plastid-related processes. While no other phenotypes were observed in athb17-1 plants, overexpression of ATHB17 produced a number of phenotypes in Arabidopsis including enhanced chlorophyll content. Image analysis of isolated mesophyll cells of 35S::ATHB17 lines revealed an increase in the number of chloroplasts per unit cell size, which is probably due to an increase in the number of proplastids per meristematic cell. Leaf physiological measurements provided evidence of improved photosynthetic capacity in 35S::ATHB17 lines on a per unit leaf area basis. Estimates of the capacity for ribulose-1,5-bisphosphate-saturated and -limited photosynthesis were significantly higher in 35S::ATHB17 lines. PMID:24006420

Climate change and temperature-dependent biogeography: oxygen limitation of thermal tolerance in animals.

PubMed

Pörtner, H O

2001-04-01

Recent years have shown a rise in mean global temperatures and a shift in the geographical distribution of ectothermic animals. For a cause and effect analysis the present paper discusses those physiological processes limiting thermal tolerance. The lower heat tolerance in metazoa compared with unicellular eukaryotes and bacteria suggests that a complex systemic rather than molecular process is limiting in metazoa. Whole-animal aerobic scope appears as the first process limited at low and high temperatures, linked to the progressively insufficient capacity of circulation and ventilation. Oxygen levels in body fluids may decrease, reflecting excessive oxygen demand at high temperatures or insufficient aerobic capacity of mitochondria at low temperatures. Aerobic scope falls at temperatures beyond the thermal optimum and vanishes at low or high critical temperatures when transition to an anaerobic mitochondrial metabolism occurs. The adjustment of mitochondrial densities on top of parallel molecular or membrane adjustments appears crucial for maintaining aerobic scope and for shifting thermal tolerance. In conclusion, the capacity of oxygen delivery matches full aerobic scope only within the thermal optimum. At temperatures outside this range, only time-limited survival is supported by residual aerobic scope, then anaerobic metabolism and finally molecular protection by heat shock proteins and antioxidative defence. In a cause and effect hierarchy, the progressive increase in oxygen limitation at extreme temperatures may even enhance oxidative and denaturation stress. As a corollary, capacity limitations at a complex level of organisation, the oxygen delivery system, define thermal tolerance limits before molecular functions become disturbed.

High-altitude physiology: lessons from Tibet

NASA Astrophysics Data System (ADS)

Wagner, Peter D.; Simonson, Tatum S.; Wei, Guan; Wagner, Harrieth; Wuren, Tanna; Yan, Ma; Qin, Ga; Ge, Rili

2013-05-01

Polycythemia is a universal lowlander response to altitude; healthy Andean high-altitude natives also have elevated [Hb]. While this may enhance O2 transport to tissues, studies have shown that acute isovolumic changes in [Hb] do not affect exercise capacity. Many high-altitude Tibetans have evolved sea-level values of [Hb], providing a natural opportunity to study this issue. In 21 young healthy male Tibetans with [Hb] between 15 and 23 g/dl, we measured VO2MAX and O2 transport capacity at 4200m. VO2MAX was higher when [Hb] was lower (P<0.05), enabled by both higher cardiac output and muscle O2 diffusional conductance, but neither ventilation nor the alveolar-arterial PO2 difference (AaPO2) varied with [Hb]. In contrast, Andean high altitude natives remain polycythemic with larger lungs and higher lung diffusing capacity, a smaller exercising AaPO2, and lower ventilation. The challenges now are (1) to understand the different adaptive pathways used by Andeans and Tibetans, and (2) to determine in Tibetans whether, during evolution, reduced [Hb] appeared first, causing compensatory cardiac and muscle adaptations, or if enhanced cardiac function and muscle O2 transport capacity appeared first, permitting secondary reduction in [Hb]. For (2), further research is necessary to determine the basis of enhanced cardiac function and muscle O2 transport, and identify molecular targets of evolution in heart and muscle. Putative mutations can then be timed and compared to appearance of those affecting [Hb].

Yin and yang, or peas in a pod? Individual-sport versus team-sport athletes and altitude training

PubMed Central

Aughey, Robert J; Buchheit, Martin; Garvican-Lewis, Laura A; Roach, Gregory D; Sargent, Charli; Billaut, François; Varley, Matthew C; Bourdon, Pitre C; Gore, Christopher J

2013-01-01

The question of whether altitude training can enhance subsequent sea-level performance has been well investigated over many decades. However, research on this topic has focused on athletes from individual or endurance sports, with scant number of studies on team-sport athletes. Questions that need to be answered include whether this type of training may enhance team-sport athlete performance, when success in team-sport is often more based on technical and tactical ability rather than physical capacity per se. This review will contrast and compare athletes from two sports representative of endurance (cycling) and team-sports (soccer). Specifically, we draw on the respective competition schedules, physiological capacities, activity profiles and energetics of each sport to compare the similarities between athletes from these sports and discuss the relative merits of altitude training for these athletes. The application of conventional live-high, train-high; live-high, train-low; and intermittent hypoxic training for team-sport athletes in the context of the above will be presented. When the above points are considered, we will conclude that dependent on resources and training objectives, altitude training can be seen as an attractive proposition to enhance the physical performance of team-sport athletes without the need for an obvious increase in training load. PMID:24255910

Assessment of breathing patterns and respiratory muscle recruitment during singing and speech in quadriplegia.

PubMed

Tamplin, Jeanette; Brazzale, Danny J; Pretto, Jeffrey J; Ruehland, Warren R; Buttifant, Mary; Brown, Douglas J; Berlowitz, David J

2011-02-01

To explore how respiratory impairment after cervical spinal cord injury affects vocal function, and to explore muscle recruitment strategies used during vocal tasks after quadriplegia. It was hypothesized that to achieve the increased respiratory support required for singing and loud speech, people with quadriplegia use different patterns of muscle recruitment and control strategies compared with control subjects without spinal cord injury. Matched, parallel-group design. Large university-affiliated public hospital. Consenting participants with motor-complete C5-7 quadriplegia (n=6) and able-bodied age-matched controls (n=6) were assessed on physiologic and voice measures during vocal tasks. Not applicable. Standard respiratory function testing, surface electromyographic activity from accessory respiratory muscles, sound pressure levels during vocal tasks, the Voice Handicap Index, and the Perceptual Voice Profile. The group with quadriplegia had a reduced lung capacity (vital capacity, 71% vs 102% of predicted; P=.028), more perceived voice problems (Voice Handicap Index score, 22.5 vs 6.5; P=.046), and greater recruitment of accessory respiratory muscles during both loud and soft volumes (P=.028) than the able-bodied controls. The group with quadriplegia also demonstrated higher accessory muscle activation in changing from soft to loud speech (P=.028). People with quadriplegia have impaired vocal ability and use different muscle recruitment strategies during speech than the able-bodied. These findings will enable us to target specific measurements of respiratory physiology for assessing functional improvements in response to formal therapeutic singing training. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Digestive capacities, inbreeding and growth capacities in juvenile Arctic charr Salvelinus alpinus.

PubMed

Ditlecadet, D; Blier, P U; Le François, N R; Dufresne, F

2009-12-01

Genetic variation in growth performance was estimated in 26 families from two commercial strains of Arctic charr Salvelinus alpinus. Physiological determinants of growth and metabolic capacities were also assessed through enzymatic assays. A relatedness coefficient was attributed to each family using parental genotypes at seven microsatellite loci. After 15 months of growth, faster growing families had significantly lower relatedness coefficients than slower growing families, suggesting their value as indicators of growth potential. Individual fish that exhibited higher trypsin activity also displayed higher growth rate, suggesting that superior protein digestion capacities can be highly advantageous at early stages. Capacities to use amino acids as expressed by glutamate dehydrogenase (GDH) activities were lower in the liver of fast-growing fish (13-20%), whereas white muscle of fast-growing fish showed higher activities than that of slow-growing fish for amino acid metabolism and aerobic capacity [22-32% increase for citrate synthase (CS), aspartate aminotransferase (AAT) and GDH]. The generally higher glycolytic capacities (PK and LDH) in white muscle of fast-growing fish indicated higher burst swimming capacities and hence better access to food.

The Baltimore Therapeutic Equipment work simulator: biomechanical and physiological norms for three attachments in healthy men.

PubMed

Bhambhani, Y; Esmail, S; Brintnell, S

1994-01-01

The Baltimore Therapeutic Equipment (BTE) work simulator is routinely used by occupational therapists in functional capacity evaluation. Currently, there is a lack of normative data for various attachments on this instrument. The purposes of this study were to (a) establish norms for the biomechanical and physiological responses during three tasks on the BTE work simulator, namely, wheel-turn, push-pull, and overhead-reach; (b) compare these responses during the three tasks, and (c) examine the interrelationships of these responses during the tasks. Twenty healthy men completed five testing sessions: (a) task familiarization on the BTE work simulator to identify the work intensity, which was perceived as hard on the Borg scale; (b) an incremental arm ergometer exercise test to determine their peak oxygen uptake (pVO2) and peak heart rate (pHR); and (c) one of the three tasks on the BTE work simulator for 4 min in each of the next three sessions. Analysis of variance indicated that torque, work, and power during the overhead-reach were significantly higher (p = .000) compared with the wheel-turn and push-pull tasks. However, no significant differences (p > .05) were observed among the tasks for the VO2 and HR, which were approximately 50% and 70% of pVO2 and pHR respectively. Although there was a significant relationship (p < .05) among tasks for the torque, work, and power, the common variance ranged only between 38% and 67%. The relative pVO2 was significantly related to work (p = .028) and power (p = .027) only during the push-pull task but not the wheel-turn and overhead-reach tasks. These results suggest that occupational therapists should include as many tasks as possible when designing functional capacity evaluation test batteries, and that there is no consistent relationship between cardiorespiratory fitness and performance of various tasks on the BTE work simulator.

Sex differences in the gastrointestinal tract of rats and the implications for oral drug delivery.

PubMed

Afonso-Pereira, Francisco; Dou, Liu; Trenfield, Sarah J; Madla, Christine M; Murdan, Sudaxshina; Sousa, Jõao; Veiga, Francisco; Basit, Abdul W

2018-03-30

Pre-clinical research often uses rodents as animal models to guide the selection of appropriate oral drug and dose selection in humans. However, traditionally, such research fails to consider the gastrointestinal differences between the sexes of rats and the impact on oral drug delivery. This study aimed to identify and characterise the potential sex-related differences in the gastrointestinal environment of sacrificed male and female Wistar rats. Their gastrointestinal tracts were excised and segmented into the stomach, duodenum, jejunum, ileum, caecum and colon. The respective contents and tissue sections were collected and analysed for pH, buffer capacity, surface tension, osmolality and relative P-glycoprotein (P-gp) expression. The pH in the stomach of females was found to be lower than in males. Female rats also exhibited a higher buffer capacity in the caecum and colon when compared with their male counterparts. Males were found to have a higher osmolality than females in the duodenum, ileum and colon. Significant sex differences (p < 0.05) in surface tension were observed in the ileum, where females exhibited a higher surface tension. Interestingly, female rats displayed significantly higher relative P-gp expression levels (p < 0.05) when compared with male rats in the duodenum (1.24 ± 0.85 vs. 0.36 ± 0.26), jejunum (1.45 ± 0.88 vs. 0.38 ± 0.26) and ileum (0.92 ± 0.43 vs. 0.40 ± 0.18) but not in the colon (0.5 ± 0.32 vs. 0.33 ± 0.16) segments. The work reported has demonstrated the stark physiological differences between male and female rats at a physiological level, indicating how the 'sex of the gut' could influence oral drug delivery. These findings, therefore, are of critical importance in pre-clinical research and drug development. Copyright © 2018 Elsevier B.V. All rights reserved.

Morphological Pulmonary Diffusion Capacity for Oxygen of Burmese Pythons (Python molurus): a Comparison of Animals in Healthy Condition and with Different Pulmonary Infections.

PubMed

Starck, J M; Weimer, I; Aupperle, H; Müller, K; Marschang, R E; Kiefer, I; Pees, M

2015-11-01

A qualitative and quantitative morphological study of the pulmonary exchange capacity of healthy and diseased Burmese pythons (Python molurus) was carried out in order to test the hypothesis that the high morphological excess capacity for oxygen exchange in the lungs of these snakes is one of the reasons why pathological processes extend throughout the lung parenchyma and impair major parts of the lungs before clinical signs of respiratory disease become apparent. Twenty-four Burmese pythons (12 healthy and 12 diseased) were included in the study. A stereology-based approach was used to quantify the lung parenchyma using computed tomography. Light microscopy was used to quantify tissue compartments and the respiratory exchange surface, and transmission electron microscopy was used to measure the thickness of the diffusion barrier. The morphological diffusion capacity for oxygen of the lungs and the anatomical diffusion factor were calculated. The calculated anatomical diffusion capacity was compared with published values for oxygen consumption of healthy snakes, and the degree to which the exchange capacity can be obstructed before normal physiological function is impaired was estimated. Heterogeneous pulmonary infections result in graded morphological transformations of pulmonary parenchyma involving lymphocyte migration into the connective tissue and thickening of the septal connective tissue, increasing thickness of the diffusion barrier and increasing transformation of the pulmonary epithelium into a columnar pseudostratified or stratified epithelium. The transformed epithelium developed by hyperplasia of ciliated cells arising from the tip of the faveolar septa and by hyperplasia of type II pneumocytes. These results support the idea that the lungs have a remarkable overcapacity for oxygen consumption and that the development of pulmonary disease continuously reduces the capacity for oxygen consumption. However, due to the overcapacity of the lungs, this reduction does not result in clinical signs and disease can progress unrecognized for an extended period. Copyright © 2015 Elsevier Ltd. All rights reserved.

Large heat capacity change in a protein-monovalent cation interaction.

PubMed

Guinto, E R; Di Cera, E

1996-07-09

Current views about protein-ligand interactions state that electrostatic forces drive the binding of charged species and that burial of hydrophobic and polar surfaces controls the heat capacity change associated with the reaction. For the interaction of a protein with a monovalent cation the electrostatic components are expected to be significant due to the ionic nature of the ligand, whereas the heat capacity change is expected to be small due to the size of the surface area involved in the recognition event. The physiologically important interaction of Na+ with thrombin was studied over the temperature range from 5 to 45 degrees C and the ionic strength range from 50 to 800 mM. These measurements reveal an unanticipated result that bears quite generally on studies of molecular recognition and protein folding. Binding of Na+ to thrombin is characterized by a modest dependence on ionic strength but a large and negative heat capacity change of -1.1 +/- 0.1 kcal mol-1 K-1. The small electrostatic coupling can be explained in terms of a minimal perturbation of the ionic atmosphere of the protein upon Na+ binding. The large heat capacity change, however, is difficult to reconcile with current views on the origin of this effect from surface area changes or large folding transitions coupled to binding. It is proposed that this change is linked to burial of a large cluster of water molecules in the Na+ binding pocket upon Na+ binding. Due to their reduced mobility and highly ordered structure, water molecules sequestered in the interior of a protein must have a lower heat capacity compared to those on the surface of a protein or in the bulk solvent. Hence, a binding or folding event where water molecules are buried may result in significant heat capacity changes independent of changes in exposed hydrophobic surface or coupled conformational transitions.

Does nebulized fentanyl relieve dyspnea during exercise in healthy man?

PubMed Central

Kotrach, Houssam G.; Bourbeau, Jean

2015-01-01

Few therapies exist for the relief of dyspnea in restrictive lung disorders. Accumulating evidence suggests that nebulized opioids selective for the mu-receptor subtype may relieve dyspnea by modulating intrapulmonary opioid receptor activity. Our respective primary and secondary objectives were to test the hypothesis that nebulized fentanyl (a mu-opioid receptor agonist) relieves dyspnea during exercise in the presence of abnormal restrictive ventilatory constraints and to identify the physiological mechanisms of this improvement. In a randomized, double-blind, placebo-controlled crossover study, we examined the effect of 250 μg nebulized fentanyl, chest wall strapping (CWS), and their interaction on detailed physiological and perceptual responses to constant work rate cycle exercise (85% of maximum incremental work rate) in 14 healthy, fit young men. By design, CWS decreased vital capacity by ∼20% and mimicked the negative consequences of a mild restrictive lung disorder on exercise endurance time and on dyspnea, breathing pattern, dynamic operating lung volumes, and diaphragmatic electromyographic and respiratory muscle function during exercise. Compared with placebo under both unrestricted control and CWS conditions, nebulized fentanyl had no effect on exercise endurance time, integrated physiological response to exercise, sensory intensity, unpleasantness ratings of exertional dyspnea. Our results do not support a role for intrapulmonary opioids in the neuromodulation of exertional dyspnea in health nor do they provide a physiological rationale for the use of nebulized fentanyl in the management of dyspnea due to mild restrictive lung disorders, specifically those arising from abnormalities of the chest wall and not affiliated with airway inflammation. PMID:26031762

Climate variations and the physiological basis of temperature dependent biogeography: systemic to molecular hierarchy of thermal tolerance in animals.

PubMed

Pörtner, H O

2002-08-01

The physiological mechanisms limiting and adjusting cold and heat tolerance have regained interest in the light of global warming and associated shifts in the geographical distribution of ectothermic animals. Recent comparative studies, largely carried out on marine ectotherms, indicate that the processes and limits of thermal tolerance are linked with the adjustment of aerobic scope and capacity of the whole animal as a crucial step in thermal adaptation on top of parallel adjustments at the molecular or membrane level. In accordance with Shelford's law of tolerance decreasing whole animal aerobic scope characterises the onset of thermal limitation at low and high pejus thresholds (pejus=getting worse). The drop in aerobic scope of an animal indicated by falling oxygen levels in the body fluids and or the progressively limited capacity of circulatory and ventilatory mechanisms. At high temperatures, excessive oxygen demand causes insufficient oxygen levels in the body fluids, whereas at low temperatures the aerobic capacity of mitochondria may become limiting for ventilation and circulation. Further cooling or warming beyond these limits leads to low or high critical threshold temperatures (T(c)) where aerobic scope disappears and transition to an anaerobic mode of mitochondrial metabolism and progressive insufficiency of cellular energy levels occurs. The adjustments of mitochondrial densities and their functional properties appear as a critical process in defining and shifting thermal tolerance windows. The finding of an oxygen limited thermal tolerance owing to loss of aerobic scope is in line with Taylor's and Weibel's concept of symmorphosis, which implies that excess capacity of any component of the oxygen delivery system is avoided. The present study suggests that the capacity of oxygen delivery is set to a level just sufficient to meet maximum oxygen demand between the average highs and lows of environmental temperatures. At more extreme temperatures only time limited passive survival is supported by anaerobic metabolism or the protection of molecular functions by heat shock proteins and antioxidative defence. As a corollary, the first line of thermal sensitivity is due to capacity limitations at a high level of organisational complexity, i.e. the integrated function of the oxygen delivery system, before individual, molecular or membrane functions become disturbed. These interpretations are in line with the more general consideration that, as a result of the high level of complexity of metazoan organisms compared with simple eukaryotes and then prokaryotes, thermal tolerance is reduced in metazoans. A similar sequence of sensitivities prevails within the metazoan organism, with the highest sensitivity at the organismic level and wider tolerance windows at lower levels of complexity. However, the situation is different in that loss in aerobic scope and progressive hypoxia at the organismic level define the onset of thermal limitation which then transfers to lower hierarchical levels and causes cellular and molecular disturbances. Oxygen limitation contributes to oxidative stress and, finally, denaturation or malfunction of molecular repair, e.g. during suspension of protein synthesis. The sequence of thermal tolerance limits turns into a hierarchy, ranging from systemic to cellular to molecular levels.

Neurostructural abnormalities associated with axes of emotion dysregulation in generalized anxiety.

PubMed

Makovac, Elena; Meeten, Frances; Watson, David R; Garfinkel, Sarah N; Critchley, Hugo D; Ottaviani, Cristina

2016-01-01

Despite the high prevalence of generalized anxiety disorder (GAD) and its negative impact on society, its neurobiology remains obscure. This study characterizes the neurostructural abnormalities associated with key symptoms of GAD, focusing on indicators of impaired emotion regulation (excessive worry, poor concentration, low mindfulness, and physiological arousal). These domains were assessed in 19 (16 women) GAD patients and 19 healthy controls matched for age and gender, using questionnaires and a low demand behavioral task performed before and after an induction of perseverative cognition (i.e. worry and rumination). Continuous pulse oximetry was used to measure autonomic physiology (heart rate variability; HRV). Observed cognitive and physiological changes in response to the induction provided quantifiable data on emotional regulatory capacity. Participants underwent structural magnetic resonance imaging; voxel-based morphometry was used to quantify the relationship between gray matter volume and psychological and physiological measures. Overall, GAD patients had lower gray matter volume than controls within supramarginal, precentral, and postcentral gyrus bilaterally. Across the GAD group, increased right amygdala volume was associated with prolonged reaction times on the tracking task (indicating increased attentional impairment following the induction) and lower scores on the 'Act with awareness' subscale of the Five Facets Mindfulness Questionnaire. Moreover in GAD, medial frontal cortical gray matter volume correlated positively with the 'Non-react mindfulness' facet. Lastly, smaller volumes of bilateral insula, bilateral opercular cortex, right supramarginal and precentral gyri, anterior cingulate and paracingulate cortex predicted the magnitude of autonomic change following the induction (i.e. a greater decrease in HRV). Results distinguish neural structures associated with impaired capacity for cognitive, attentional and physiological disengagement from worry, suggesting that aberrant competition between these levels of emotional regulation is intrinsic to symptom expression in GAD.

Adaptation of Microplate-based Respirometry for Hippocampal Slices and Analysis of Respiratory Capacity

PubMed Central

Schuh, Rosemary A.; Clerc, Pascaline; Hwang, Hyehyun; Mehrabian, Zara; Bittman, Kevin; Chen, Hegang; Polster, Brian M.

2011-01-01

Multiple neurodegenerative disorders are associated with altered mitochondrial bioenergetics. Although mitochondrial O2 consumption is frequently measured in isolated mitochondria, isolated synaptic nerve terminals (synaptosomes), or cultured cells, the absence of mature brain circuitry is a remaining limitation. Here we describe the development of a method that adapts the Seahorse Extracellular Flux Analyzer (XF24) for the microplate-based measurement of hippocampal slice O2 consumption. As a first evaluation of the technique, we compared whole slice bioenergetics to previous measurements made with synaptosomes or cultured neurons. We found that mitochondrial respiratory capacity and O2 consumption coupled to ATP synthesis could be estimated in cultured or acute hippocampal slices with preserved neural architecture. Mouse organotypic hippocampal slices oxidizing glucose displayed mitochondrial O2 consumption that was well-coupled, as determined by the sensitivity to the ATP synthase inhibitor oligomycin. However stimulation of respiration by uncoupler was modest (<120% of basal respiration) compared to previous measurements in cells or synaptosomes, although enhanced slightly (to ~150% of basal respiration) by the acute addition of the mitochondrial complex I-linked substrate pyruvate. These findings suggest a high basal utilization of respiratory capacity in slices and a limitation of glucose-derived substrate for maximal respiration. The improved throughput of microplate-based hippocampal respirometry over traditional O2 electrode-based methods is conducive to neuroprotective drug screening. When coupled with cell type-specific pharmacology or genetic manipulations, the ability to efficiently measure O2 consumption from whole slices should advance our understanding of mitochondrial roles in physiology and neuropathology. PMID:21520220

Effects of caffeine on endurance capacity and psychological state in young females and males exercising in the heat.

PubMed

Suvi, Silva; Timpmann, Saima; Tamm, Maria; Aedma, Martin; Kreegipuu, Kairi; Ööpik, Vahur

2017-01-01

Acute caffeine ingestion is considered effective in improving endurance capacity and psychological state. However, current knowledge is based on the findings of studies that have been conducted on male subjects mainly in temperate environmental conditions, but some physiological and psychological effects of caffeine differ between the sexes. The purpose of this study was to compare the physical performance and psychological effects of caffeine in young women and men exercising in the heat. Thirteen male and 10 female students completed 2 constant-load walks (60% of thermoneutral peak oxygen consumption on a treadmill until volitional exhaustion) in a hot-dry environment (air temperature, 42 °C; relative humidity, 20%) after caffeine (6 mg·kg -1 ) and placebo (wheat flour) ingestion in a double-blind, randomly assigned, crossover manner. Caffeine, compared with placebo, induced greater increases (p < 0.05) in heart rate (HR) and blood lactate concentrations in both males and females but had no impact on rectal or skin temperatures or on walking time to exhaustion in subjects of either gender. Caffeine decreased (p < 0.05) ratings of perceived exertion and fatigue in males, but not in females. In females, but not in males, a stronger belief that they had been administered caffeine was associated with a shorter time to exhaustion. In conclusion, acute caffeine ingestion increases HR and blood lactate levels during exercise in the heat, but it has no impact on thermoregulation or endurance capacity in either gender. Under exercise-heat stress, caffeine reduces ratings of perceived exertion and fatigue in males but not in females.

Collaborative-group testing improves learning and knowledge retention of human physiology topics in second-year medical students.

PubMed

Vázquez-García, Mario

2018-06-01

The present study examined the relationship between second-year medical students' group performance and individual performance in a collaborative-learning environment. In recent decades, university professors in the scientific and humanistic disciplines have successfully put into practice different modalities of collaborative approaches to teaching. Essentially, collaborative approach refers to a variety of techniques that involves the joint intellectual effort of a small group of students, which encourages interaction and discussion among students and professors. The present results show the efficacy of collaborative learning, which, furthermore, allowed students to participate actively in the physiology class. Average student's grades were significantly higher when they engaged in single-best-response, multiple-choice tests as a student team, compared with taking the same examinations individually. The method improved notably knowledge retention, as learning is more effective when performed in the context of collaborative partnership. A selected subset of questions answered wrongly in an initial test, both individually and collectively, was used on a second test to examine student retention of studied material. Grade averages were significantly improved, both individually and groupwise, when students responded to the subset of questions a second time, 1, 2, or 3 wk after the first attempt. These results suggest that the collaborative approach to teaching allowed a more effective understanding of course content, which meant an improved capacity for retention of human physiology knowledge.

Anemone bleaching increases the metabolic demands of symbiont anemonefish.

PubMed

Norin, Tommy; Mills, Suzanne C; Crespel, Amélie; Cortese, Daphne; Killen, Shaun S; Beldade, Ricardo

2018-04-11

Increased ocean temperatures are causing mass bleaching of anemones and corals in the tropics worldwide. While such heat-induced loss of algal symbionts (zooxanthellae) directly affects anemones and corals physiologically, this damage may also cascade on to other animal symbionts. Metabolic rate is an integrative physiological trait shown to relate to various aspects of organismal performance, behaviour and locomotor capacity, and also shows plasticity during exposure to acute and chronic stressors. As climate warming is expected to affect the physiology, behaviour and life history of animals, including ectotherms such as fish, we measured if residing in bleached versus unbleached sea anemones ( Heteractis magnifica ) affected the standard (i.e. baseline) metabolic rate and behaviour (activity) of juvenile orange-fin anemonefish ( Amphiprion chrysopterus ) . Metabolic rate was estimated from rates of oxygen uptake [Formula: see text], and the standard metabolic rate [Formula: see text] of anemonefish from bleached anemones was significantly higher by 8.2% compared with that of fish residing in unbleached anemones, possibly due to increased stress levels. Activity levels did not differ between fish from bleached and unbleached anemones. As [Formula: see text] reflects the minimum cost of living, the increased metabolic demands may contribute to the negative impacts of bleaching on important anemonefish life history and fitness traits observed previously (e.g. reduced spawning frequency and lower fecundity). © 2018 The Author(s).

Evolved changes in the intracellular distribution and physiology of muscle mitochondria in high-altitude native deer mice.

PubMed

Mahalingam, Sajeni; McClelland, Grant B; Scott, Graham R

2017-07-15

Mitochondrial function changes over time at high altitudes, but the potential benefits of these changes for hypoxia resistance remains unclear. We used high-altitude-adapted populations of deer mice, which exhibit enhanced aerobic performance in hypoxia, to examine whether changes in mitochondrial physiology or intracellular distribution in the muscle contribute to hypoxia resistance. Permeabilized muscle fibres from the gastrocnemius muscle had higher respiratory capacities in high-altitude mice than in low-altitude mice. Highlanders also had higher mitochondrial volume densities, due entirely to an enriched abundance of subsarcolemmal mitochondria, such that more mitochondria were situated near the cell membrane and adjacent to capillaries. There were several effects of hypoxia acclimation on mitochondrial function, some of which were population specific, but they differed from the evolved changes in high-altitude natives, which probably provide a better indication of adaptive traits that improve performance and hypoxia resistance at high altitudes. High-altitude natives that have evolved to live in hypoxic environments provide a compelling system to understand how animals can overcome impairments in oxygen availability. We examined whether these include changes in mitochondrial physiology or intracellular distribution that contribute to hypoxia resistance in high-altitude deer mice (Peromyscus maniculatus). Mice from populations native to high and low altitudes were born and raised in captivity, and as adults were acclimated to normoxia or hypobaric hypoxia (equivalent to 4300 m elevation). We found that highlanders had higher respiratory capacities in the gastrocnemius (but not soleus) muscle than lowlanders (assessed using permeabilized fibres with single or multiple inputs to the electron transport system), due in large part to higher mitochondrial volume densities in the gastrocnemius. The latter was attributed to an increased abundance of subsarcolemmal (but not intermyofibrillar) mitochondria, such that more mitochondria were situated near the cell membrane and adjacent to capillaries. Hypoxia acclimation had no significant effect on these population differences, but it did increase mitochondrial cristae surface densities of mitochondria in both populations. Hypoxia acclimation also altered the physiology of isolated mitochondria by affecting respiratory capacities and cytochrome c oxidase activities in population-specific manners. Chronic hypoxia decreased the release of reactive oxygen species by isolated mitochondria in both populations. There were subtle differences in O 2 kinetics between populations, with highlanders exhibiting increased mitochondrial O 2 affinity or catalytic efficiency in some conditions. Our results suggest that evolved changes in mitochondrial physiology in high-altitude natives are distinct from the effects of hypoxia acclimation, and probably provide a better indication of adaptive traits that improve performance and hypoxia resistance at high altitudes. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Spathaspora passalidarum selected for resistance to AFEX hydrolysate shows decreased cell yield.

PubMed

Su, Yi-Kai; Willis, Laura B; Rehmann, Lars; Smith, David; Jeffries, Thomas W

2018-06-21

This study employed cell recycling, batch adaptation, cell mating and high throughput screening to select adapted Spathaspora passalidarum strains with improved fermentative ability.The most promising candidate, YK208-E11 (E11) showed a 3-fold increase in specific fermentation rate compared to the parental strain and an ethanol yield greater than 0.45 g/g substrate while co-utilizing cellobiose, glucose, and xylose. Further characterization showed that strain E11 also makes 40% less biomass compared to the parental strain when cultivated in rich media under aerobic conditions. A tetrazolium agar overlay assay in the presence of respiration inhibitors, including rotenone, antimycin A, KCN, and salicylhydroxamic acid elucidated the nature of the mutational events. Results indicated that E11 has a deficiency in its respiration system that could contribute to its low cell yield. Strain E11 was subjected to whole genome sequencing and a ∼11 kb deletion was identified; the open reading frames absent in strain E11 code for proteins with predicted functions in respiration, cell division and the actin cytoskeleton, and may contribute to the observed physiology of the adapted strain. Results of the tetrazolium overlay also suggest that cultivation on xylose affects the respiration capacity in the wild-type strain, which could account for its faster fermentation of xylose as compared to glucose. These results support our previous finding that S. passalidarum has highly unusual physiological responses to xylose under oxygen limitation.

Effect of oral arginine supplementation on exhaled nitric oxide concentration in sickle cell anemia and acute chest syndrome.

PubMed

Sullivan, Kevin Joseph; Kissoon, Niranjan; Sandler, Eric; Gauger, Cynthia; Froyen, Melanie; Duckworth, Laurie; Brown, Martha; Murphy, Suzanne

2010-10-01

Decreased exhaled nitric oxide levels (FE(NO)) have been described in patients with sickle cell disease (SCD) and a history of acute chest syndrome (ACS) when compared with non-ACS controls. Oral arginine supplementation has been shown to increase FE(NO) in healthy participants, but its effect in SCD patients is not known. To determine the effect of oral arginine intake on FENO in sickle cell patients with and without history of ACS, and in healthy controls. No differences in the FE(NO) increase were seen in SCD patients with a history of ACS (ACS+) compared with healthy controls (HC) and SCD patients without history of ACS (ACS-). ACS+ (n=6), ACS- (n=9), and HC (n=7) patients were studied. At baseline, and after the administration of escalating doses of oral L-arginine (0.1, 0.2, and 0.4 g/kg), serial measurements were made of the following: FE(NO), plasma concentrations of arginine, ornithine, citrulline, aspartate, glutamate, arginine/ornithine ratio, nitrite, nitrate, heart rate (HR), respiratory rate (RR), blood pressure (BP), oxygen saturation (SpO2), forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC). At baseline, FE(NO) did not differ among the groups. ACS- and ACS+ groups were deficient in arginine, and had decreased FEV1, FVC, and SaO2 when compared with HC patients. After arginine supplementation, FE(NO), arginine, ornithine, citrulline, nitrite, and the arginine/ornithine ratio increased similarly in all groups. Changes from baseline for HR, BP, SpO2, RR, FEV1, and FVC were minimal and similar in all groups. In contrast to our earlier study, ACS+ patients had similar FE(NO) values when compared with ACS- and HC patients. All SCD patients were arginine deficient at baseline and showed impairment in respiratory physiology when compared with HC patients. After arginine supplementation, FE(NO) concentration increased in all groups to a similar degree, and lung function and physiologic parameters were minimally affected. The physiologic significance of alterations in FE(NO) in SCD patients and its relationship to ACS predilection requires further delineation.

Violeta Sanchez i Nogue | NREL

Science.gov Websites

lignocellulosic inhibitors resulting in ethanolic fermentation and growth of Saccharomyces cerevisiae," AMB Scheffersomyces stipitis growth and fermentation capacity in rich and inhibitory media," Bioresources and ;Physiological requirements for growth and competitiveness of Dekkera bruxellensis under oxygen-limited or

What Research Tells the Coach About Swimming.

ERIC Educational Resources Information Center

Faulkner, John A.

This booklet is designed to make research findings about swimming available with interpretations for practical application. Chapter 1, "Physical Characteristics of Swimmers," discusses somatotyping, body composition, and growth. Chapter 2, "Physiological Characteristics of Swimmers," discusses resting rate, vital capacity, effects of water…

The Exercise Capacity of Blind Children.

ERIC Educational Resources Information Center

Jankowski, L. W.; Evans, J. K.

1981-01-01

To determine whether blind children in a well-equipped modern institution are receiving enough physical education activities to maintain good physical condition, the physiological characteristics of 20 institutionalized blind children were measured according to body composition, pulmonary function, and tolerance for exercise. (Author)

Peripheral self-reactivity regulates antigen-specific CD8 T-cell responses and cell division under physiological conditions.

PubMed

Swee, Lee Kim; Tan, Zhen Wei; Sanecka, Anna; Yoshida, Nagisa; Patel, Harshil; Grotenbreg, Gijsbert; Frickel, Eva-Maria; Ploegh, Hidde L

2016-11-01

T-cell identity is established by the expression of a clonotypic T-cell receptor (TCR), generated by somatic rearrangement of TCRα and β genes. The properties of the TCR determine both the degree of self-reactivity and the repertoire of antigens that can be recognized. For CD8 T cells, the relationship between TCR identity-hence reactivity to self-and effector function(s) remains to be fully understood and has rarely been explored outside of the H-2 b haplotype. We measured the affinity of three structurally distinct CD8 T-cell-derived TCRs that recognize the identical H-2 L d -restricted epitope, derived from the Rop7 protein of Toxoplasma gondii We used CD8 T cells obtained from mice generated by somatic cell nuclear transfer as the closest approximation of primary T cells with physiological TCR rearrangements and TCR expression levels. First, we demonstrate the common occurrence of secondary rearrangements in endogenously rearranged loci. Furthermore, we characterized and compared the response of Rop7-specific CD8 T-cell clones upon Toxoplasma gondii infection as well as effector function and TCR signalling upon antigenic stimulation in vitro Antigen-independent TCR cross-linking in vitro uncovered profound intrinsic differences in the effector functions between T-cell clones. Finally, by assessing the degree of self-reactivity and comparing the transcriptomes of naive Rop7 CD8 T cells, we show that lower self-reactivity correlates with lower effector capacity, whereas higher self-reactivity is associated with enhanced effector function as well as cell cycle entry under physiological conditions. Altogether, our data show that potential effector functions and basal proliferation of CD8 T cells are set by self-reactivity thresholds. © 2016 The Authors.

Pirfenidone for Idiopathic Pulmonary Fibrosis: A Systematic Review and Meta-Analysis

PubMed Central

Venegas, Carmen; Arenas, Alex; Rada, Gabriel

2015-01-01

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor prognosis. In the last decades pirfenidone an anti-inflammatory and anti-fibrotic agent has shown benefit in inhibit collagen production and has also demonstrated benefit in decline progression in IPF in physiological outcomes as Forced vital capacity (FVC), in clinical outcomes such as progression free survival (PFS) and a benefit in mortality but no in clinically relevant outcomes as exacerbations or worsening of IPF. Methods: We conducted a systematic review to evaluate the effectiveness of physiological and clinical outcomes of pirfenidone compared to placebo in IPF. We performed a search with no language restriction. Two researchers performed literature search, quality assessment, data extraction and analysis. And was performed a summary of findings table following the GRADE approach. Results: We included 5 RCTs (Randomized controlled trials) in analysis. The meta-analysis resulted in a decrease in all cause-mortality (RR 0.52 IC 0.32–0.88) and IPF related mortality (RR 0.32 IC 0.14–0.75); other outcomes evaluated were worsening of IPF (RR 0.64 IC 0.50–0.83) and acute exacerbation (RR: 0.72 IC 0.30–1.66 respectively). Also there was a decrease in progression free survival (PFS) (RR 0.83 IC 0.74–0.92) compared to placebo. Conclusions: We observed significant differences in physiologic and clinically relevant outcomes such as reduction in all-cause mortality, IPF related mortality, worsening and exacerbation of IPF and PFS. So pirfenidone treatment should be considered not only for its benefits in pulmonary function tests but also by its clinically relevant outcomes. PMID:26308723

Cough physiology in elderly women with nontuberculous mycobacterial lung infections.

PubMed

Tsai, Hsiu-Wen; Fennelly, Kevin; Wheeler-Hegland, Karen; Adams, Sherry; Condrey, Jillian; Hosford, Jennifer L; Davenport, Paul W

2017-05-01

Elderly white, thin, nonsmoking women appear to be more susceptible to lung infections with Mycobacterium avium complex and other nontuberculous mycobacteria (NTM). It has been postulated that such disease in women is related to suppression of their cough. We hypothesized that patients with pulmonary NTM (pNTM) infections may have altered cough physiology compared with unaffected control subjects. We used capsaicin-induced cough to assess the cough reflex in pNTM subjects. Eight elderly white women with stable chronic pNTM infections and six unaffected age-matched control subjects were recruited. There was no significant difference between groups in capsaicin-elicited cough motor response, airflow pattern, or cough frequency. The urge-to-cough (UTC) score at the lowest capsaicin concentration was significantly lower in pNTM than control subjects ( P < 0.05). There were no significant differences in the UTC score between pNTM and control subjects at >50 μM capsaicin. These results suggest lower UTC sensitivity to the lowest concentration of capsaicin in pNTM than control subjects. In other words, the pNTM subjects do not sense a UTC when the stimulus is relatively small. NEW & NOTEWORTHY This study investigates the cough motor response and cough sensitivity in patients with nontuberculous mycobacteria (NTM) infection. In elderly white female pulmonary NTM subjects, we demonstrated a capacity to produce coughs similar to that of age-matched control subjects but decreased cough sensitivity in response to a low dose of capsaicin compared with control subjects. These findings are important to understand the pathophysiological mechanisms resulting in NTM disease in elderly white women and/or the syndrome developing in elderly white female NTM patients. Copyright © 2017 the American Physiological Society.

Genetic and phenotypic differentiation of an Andean intermediate altitude population

PubMed Central

Eichstaedt, Christina A; Antão, Tiago; Cardona, Alexia; Pagani, Luca; Kivisild, Toomas; Mormina, Maru

2015-01-01

Highland populations living permanently under hypobaric hypoxia have been subject of extensive research because of the relevance of their physiological adaptations for the understanding of human health and disease. In this context, what is considered high altitude is a matter of interpretation and while the adaptive processes at high altitude (above 3000 m) are well documented, the effects of moderate altitude (below 3000 m) on the phenotype are less well established. In this study, we compare physiological and anthropometric characteristics as well as genetic variations in two Andean populations: the Calchaquíes (2300 m) and neighboring Collas (3500 m). We compare their phenotype and genotype to the sea-level Wichí population. We measured physiological (heart rate, oxygen saturation, respiration rate, and lung function) as well as anthropometric traits (height, sitting height, weight, forearm, and tibia length). We conducted genome-wide genotyping on a subset of the sample (n = 74) and performed various scans for positive selection. At the phenotypic level (n = 179), increased lung capacity stood out in both Andean groups, whereas a growth reduction in distal limbs was only observed at high altitude. At the genome level, Calchaquíes revealed strong signals around PRKG1, suggesting that the nitric oxide pathway may be a target of selection. PRKG1 was highlighted by one of four selection tests among the top five genes using the population branch statistic. Selection tests results of Collas were reported previously. Overall, our study shows that some phenotypic and genetic differentiation occurs at intermediate altitude in response to moderate lifelong selection pressures. PMID:25948820

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

PubMed

Richards, Jeffrey G

2011-01-15

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

Plasma acylcarnitine profiling indicates increased fatty acid oxidation relative to tricarboxylic acid cycle capacity in young, healthy low birth weight men.

PubMed

Ribel-Madsen, Amalie; Ribel-Madsen, Rasmus; Brøns, Charlotte; Newgard, Christopher B; Vaag, Allan A; Hellgren, Lars I

2016-10-01

We hypothesized that an increased, incomplete fatty acid beta-oxidation in mitochondria could be part of the metabolic events leading to insulin resistance and thereby an increased type 2 diabetes risk in low birth weight (LBW) compared with normal birth weight (NBW) individuals. Therefore, we measured fasting plasma levels of 45 acylcarnitine species in 18 LBW and 25 NBW men after an isocaloric control diet and a 5-day high-fat, high-calorie diet. We demonstrated that LBW men had higher C2 and C4-OH levels after the control diet compared with NBW men, indicating an increased fatty acid beta-oxidation relative to the tricarboxylic acid cycle flux. Also, they had higher C6-DC, C10-OH/C8-DC, and total hydroxyl-/dicarboxyl-acylcarnitine levels, which may suggest an increased fatty acid omega-oxidation in the liver. Furthermore, LBW and NBW men decreased several acylcarnitine levels in response to overfeeding, which is likely a result of an upregulation of fatty acid oxidation due to the dietary challenge. Moreover, C10-OH/C8-DC and total hydroxyl-/dicarboxyl-acylcarnitine levels tended to be negatively associated with the serum insulin level, and the total hydroxyl-/dicarboxyl-acylcarnitine level additionally tended to be negatively associated with the hepatic insulin resistance index. This indicates that an increased fatty acid omega-oxidation could be a compensatory mechanism to prevent an accumulation of lipid species that impair insulin signaling. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Shaping Physiological Indices, Swimming Technique, and Their Influence on 200m Breaststroke Race in Young Swimmers

PubMed Central

Strzala, Marek; Stanula, Arkadiusz; Głab, Grzegorz; Glodzik, Jacek; Ostrowski, Andrzej; Kaca, Marcin; Nosiadek, Leszek

2015-01-01

The aim of this study was to investigate somatic properties and physiological capacity, and analyze kinematic parameters in the 200 m breaststroke swimming race. Twenty-seven male swimmers participated in the study. They were 15.7±1.98 years old. Their average height was 1.80 ± 0.02 m and lean body mass (LBM) was 62.45 ± 8.29 kg. Physiological exercise capacity was measured in two separate 90 sec. all-out tests, one for the arms and second for legs. During the tests total work of arm cranking (TWAR) and cycling (TWLG) as well as peak of VO2 for arm (VO2peakAR) and leg (VO2peakLG) were measured. The underwater swimmers body movements were recorded during the all-out swimming 200m breaststroke speed test using an underwater camera installed on a portable trolley. The swimming kinematic parameters and propulsive or non-propulsive movement phases of the arms and legs as well as average speed (V200), surface speed (V200surface) and swimming speed in turn zones (V200turns) were extracted. V200surface was significantly related to the percentage of leg propulsion and was shown to have large effect on VO2peakLG in the Cohen analysis. V200turns depended significantly on the indicators of physiological performance and body structure: TWAR, VO2peak LG and LBM, LBM, which in turn strongly determined the measured results of TWAR, TWLG, VO2peakAR and VO2peakLG. The V200turns and V200surface were strongly associated with V200, 0.92, p < 0.001 and 0.91, p < 0.001 respectively. In each lap of the 200m swimming there was an increased percentage of propulsion of limb movement observed simultaneously with a reduction in the gliding phase in the breaststroke cycles. Key points This study investigated the influence of the selected indicators of somatic properties and physiological capacity as well kinematic and coordination parameters on breaststroke swimming. In this observations the body’s functional capacity have an important impact on achieving good breaststroke swimming results, the V200 was moderately associated on VO2peakLG, moreover, separate V200turns depended with VO2peakLG and on LBM and TWAR. The speed of surface breaststroke swimming - V200surface similarly as V200turns had a very strong influence on the end result of V200 , 0.91, p<0.001 and 0.92, p<0.001 respectively. The ability to swim fast on the surface (V200surface) was positively and significantly associated with the percentage time of propulsion generation -LP in the breaststroke cycle. PMID:25729298

Myoglobin and the regulation of mitochondrial respiratory chain complex IV.

PubMed

Yamada, Tatsuya; Takakura, Hisashi; Jue, Thomas; Hashimoto, Takeshi; Ishizawa, Rie; Furuichi, Yasuro; Kato, Yukio; Iwanaka, Nobumasa; Masuda, Kazumi

2016-01-15

Mitochondrial respiration is regulated by multiple elaborate mechanisms. It has been shown that muscle specific O2 binding protein, Myoglobin (Mb), is localized in mitochondria and interacts with respiratory chain complex IV, suggesting that Mb could be a factor that regulates mitochondrial respiration. Here, we demonstrate that muscle mitochondrial respiration is improved by Mb overexpression via up-regulation of complex IV activity in cultured myoblasts; in contrast, suppression of Mb expression induces a decrease in complex IV activity and mitochondrial respiration compared with the overexpression model. The present data are the first to show the biological significance of mitochondrial Mb as a potential modulator of mitochondrial respiratory capacity. Mitochondria are important organelles for metabolism, and their respiratory capacity is a primary factor in the regulation of energy expenditure. Deficiencies of cytochrome c oxidase complex IV, which reduces O2 in mitochondria, are linked to several diseases, such as mitochondrial myopathy. Moreover, mitochondrial respiration in skeletal muscle tissue tends to be susceptible to complex IV activity. Recently, we showed that the muscle-specific protein myoglobin (Mb) interacts with complex IV. The precise roles of mitochondrial Mb remain unclear. Here, we demonstrate that Mb facilitates mitochondrial respiratory capacity in skeletal muscles. Although mitochondrial DNA copy numbers were not altered in Mb-overexpressing myotubes, O2 consumption was greater in these myotubes than that in mock cells (Mock vs. Mb-Flag::GFP: state 4, 1.00 ± 0.09 vs. 1.77 ± 0.34; state 3, 1.00 ± 0.29; Mock: 1.60 ± 0.53; complex 2-3-4: 1.00 ± 0.30 vs. 1.50 ± 0.44; complex IV: 1.00 ± 0.14 vs. 1.87 ± 0.27). This improvement in respiratory capacity could be because of the activation of enzymatic activity of respiratory complexes. Moreover, mitochondrial respiration was up-regulated in myoblasts transiently overexpressing Mb; complex IV activity was solely activated in Mb-overexpressing myoblasts, and complex IV activity was decreased in the myoblasts in which Mb expression was suppressed by Mb-siRNA transfection (Mb vector transfected vs. Mb vector, control siRNA transfected vs. Mb vector, Mb siRNA transfected: 0.15 vs. 0.15 vs. 0.06). Therefore, Mb enhances the enzymatic activity of complex IV to ameliorate mitochondrial respiratory capacity, and could play a pivotal role in skeletal muscle metabolism. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Relationship Between Non-invasive Brain Stimulation-induced Plasticity and Capacity for Motor Learning.

PubMed

López-Alonso, Virginia; Cheeran, Binith; Fernández-del-Olmo, Miguel

2015-01-01

Cortical plasticity plays a key role in motor learning (ML). Non-invasive brain stimulation (NIBS) paradigms have been used to modulate plasticity in the human motor cortex in order to facilitate ML. However, little is known about the relationship between NIBS-induced plasticity over M1 and ML capacity. NIBS-induced MEP changes are related to ML capacity. 56 subjects participated in three NIBS (paired associative stimulation, anodal transcranial direct current stimulation and intermittent theta-burst stimulation), and in three lab-based ML task (serial reaction time, visuomotor adaptation and sequential visual isometric pinch task) sessions. After clustering the patterns of response to the different NIBS protocols, we compared the ML variables between the different patterns found. We used regression analysis to explore further the relationship between ML capacity and summary measures of the MEPs change. We ran correlations with the "responders" group only. We found no differences in ML variables between clusters. Greater response to NIBS protocols may be predictive of poor performance within certain blocks of the VAT. "Responders" to AtDCS and to iTBS showed significantly faster reaction times than "non-responders." However, the physiological significance of these results is uncertain. MEP changes induced in M1 by PAS, AtDCS and iTBS appear to have little, if any, association with the ML capacity tested with the SRTT, the VAT and the SVIPT. However, cortical excitability changes induced in M1 by AtDCS and iTBS may be related to reaction time and retention of newly acquired skills in certain motor learning tasks. Copyright © 2015 Elsevier Inc. All rights reserved.

The effect of cooling prior to and during exercise on exercise performance and capacity in the heat: a meta-analysis.

PubMed

Tyler, Christopher James; Sunderland, Caroline; Cheung, Stephen S

2015-01-01

Exercise is impaired in hot, compared with moderate, conditions. The development of hyperthermia is strongly linked to the impairment and as a result various strategies have been investigated to combat this condition. This meta-analysis focused on the most popular strategy: cooling. Precooling has received the most attention but recently cooling applied during the bout of exercise has been investigated and both were reviewed. We conducted a literature search and retrieved 28 articles which investigated the effect of cooling administered either prior to (n=23) or during (n=5) an exercise test in hot (wet bulb globe temperature >26°C) conditions. Mean and weighted effect size (Cohen's d) were calculated. Overall, precooling has a moderate (d=0.73) effect on subsequent performance but the magnitude of the effect is dependent on the nature of the test. Sprint performance is impaired (d=-0.26) but intermittent performance and prolonged exercise are both improved following cooling (d=0.47 and d=1.91, respectively). Cooling during exercise has a positive effect on performance and capacity (d=0.76). Improvements were observed in studies with and without cooling-induced physiological alterations, and the literature supports the suggestion of a dose-response relationship among cooling, thermal strain and improvements in performance and capacity. In summary, precooling can improve subsequent intermittent and prolonged exercise performance and capacity in a hot environment but sprint performance is impaired. Cooling during exercise also has a positive effect on exercise performance and capacity in a hot environment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Running-specific prostheses permit energy cost similar to nonamputees.

PubMed

Brown, Mary Beth; Millard-Stafford, Mindy L; Allison, Andrew R

2009-05-01

Improvements in prosthesis design have facilitated participation in competitive running for persons with lower limb loss (AMP). The purpose of this study was to examine the physiological responses of AMP using a run-specific prosthesis (RP) versus a traditional prosthesis (P) and cross-referenced with nonamputee controls (C) matched by training status, age, gender, and body composition during level treadmill running (TM). Twelve trained runners completed a multistage submaximal TM exercise during which HR and oxygen uptake (VO(2)) were obtained. Steady state measures at 134 m x min(-1) were compared between RP and P in AMP. AMP using RP (AMP-RP) and C also performed a continuous speed-incremented maximal TM test until volitional fatigue. RP elicited lower HR and VO(2) compared with P in AMP. Using RP, AMP achieved similar VO(2max) and peak TM speed compared with C but with higher HR(max). Relative HR (%HR(max)) and oxygen uptake (%VO(2max)), the regression intercept, slope, SEE, and Pearson's r correlation were not different between AMP-RP and C. %HR(max) calculated with the published equation, %HR(max) = 0.73(%VO(2max)) + 30, was not significantly different from actual %HR(max) for AMP-RP or C in any stage. RP permits AMP to attain peak TM speed and aerobic capacity similar to trained nonamputees and significantly attenuates HR and energy cost of submaximal running compared with a P. Use of RP confers no physiological advantage compared with nonamputee runners because energy cost at the set speed was not significantly different for AMP-RP. Current equations on the basis of the relative HR-VO(2) relationship seem appropriate to prescribe exercise intensity for persons with transtibial amputations using RP.

Cardiotrophin 1 stimulates beneficial myogenic and vascular remodeling of the heart.

PubMed

Abdul-Ghani, Mohammad; Suen, Colin; Jiang, Baohua; Deng, Yupu; Weldrick, Jonathan J; Putinski, Charis; Brunette, Steve; Fernando, Pasan; Lee, Tom T; Flynn, Peter; Leenen, Frans H H; Burgon, Patrick G; Stewart, Duncan J; Megeney, Lynn A

2017-10-01

The post-natal heart adapts to stress and overload through hypertrophic growth, a process that may be pathologic or beneficial (physiologic hypertrophy). Physiologic hypertrophy improves cardiac performance in both healthy and diseased individuals, yet the mechanisms that propagate this favorable adaptation remain poorly defined. We identify the cytokine cardiotrophin 1 (CT1) as a factor capable of recapitulating the key features of physiologic growth of the heart including transient and reversible hypertrophy of the myocardium, and stimulation of cardiomyocyte-derived angiogenic signals leading to increased vascularity. The capacity of CT1 to induce physiologic hypertrophy originates from a CK2-mediated restraining of caspase activation, preventing the transition to unrestrained pathologic growth. Exogenous CT1 protein delivery attenuated pathology and restored contractile function in a severe model of right heart failure, suggesting a novel treatment option for this intractable cardiac disease.

Loss of 'complexity' and aging. Potential applications of fractals and chaos theory to senescence

NASA Technical Reports Server (NTRS)

Lipsitz, L. A.; Goldberger, A. L.

1992-01-01

The concept of "complexity," derived from the field of nonlinear dynamics, can be adapted to measure the output of physiologic processes that generate highly variable fluctuations resembling "chaos." We review data suggesting that physiologic aging is associated with a generalized loss of such complexity in the dynamics of healthy organ system function and hypothesize that such loss of complexity leads to an impaired ability to adapt to physiologic stress. This hypothesis is supported by observations showing an age-related loss of complex variability in multiple physiologic processes including cardiovascular control, pulsatile hormone release, and electroencephalographic potentials. If further research supports this hypothesis, measures of complexity based on chaos theory and the related geometric concept of fractals may provide new ways to monitor senescence and test the efficacy of specific interventions to modify the age-related decline in adaptive capacity.

Comparative evaluation of twenty pilot workload assessment measure using a psychomotor task in a moving base aircraft simulator

NASA Technical Reports Server (NTRS)

Connor, S. A.; Wierwille, W. W.

1983-01-01

A comparison of the sensitivity and intrusion of twenty pilot workload assessment techniques was conducted using a psychomotor loading task in a three degree of freedom moving base aircraft simulator. The twenty techniques included opinion measures, spare mental capacity measures, physiological measures, eye behavior measures, and primary task performance measures. The primary task was an instrument landing system (ILS) approach and landing. All measures were recorded between the outer marker and the middle marker on the approach. Three levels (low, medium, and high) of psychomotor load were obtained by the combined manipulation of windgust disturbance level and simulated aircraft pitch stability. Six instrument rated pilots participated in four seasons lasting approximately three hours each.

Action comprehension in non-human primates: motor simulation or inferential reasoning?

PubMed

Wood, Justin N; Hauser, Marc D

2008-12-01

Some argue that action comprehension is intimately connected with the observer's own motor capacities, whereas others argue that action comprehension depends on non-motor inferential mechanisms. We address this debate by reviewing comparative studies that license four conclusions: monkeys and apes extract the meaning of an action (i) by going beyond the surface properties of actions, attributing goals and intentions to the agent; (ii) by using environmental information to infer when actions are rational; (iii) by making predictions about an agent's goal, and the most probable action to obtain the goal given environmental constraints; (iv) in situations in which they are physiologically incapable of producing the actions. Motor theories are, thus, insufficient to account for primate action comprehension in the absence of inferential mechanisms.

Physiological responses of women to simulated weightlessness: A review of the first female bed-rest study

NASA Technical Reports Server (NTRS)

Sandler, H.; Winter, D. L.

1978-01-01

Subjects were exposed to centrifugation, to lower body negative pressure (LBNP), and to exericse stress both before and after bed rest. Areas studied were centrifugation tolerance, fluid electrolyte changes and hematology, tolerance to LBNP, physical working capacity, biochemistries, blood fibrinolytic activity, female metabolic and hormonal responses, circadian alterations, and gynecology. Results were compared with the responses observed in similarly bed-rested male subjects. The bed-rested females showed deconditioning responses similar to those of the males, although with some differences. Results indicate that women are capable of coping with exposure to weightlessness and, moreover, that they may be more sensitive subjects for evaluating countermeasures to weightlessness and developing criteria for assessing applicants for shuttle voyages.

Low capacity of erythrocytes to bind with immune complexes via C3b receptor in patients with systemic lupus erythematosus: correlation with pathological proteinuria

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

Nojima, Y.; Terai, C.; Minota, S.

1985-01-01

Erythrocytes from 51 patients with systemic lupus erythematosus and 75 controls were tested for the capacity to bind aggregated human gamma-globulin labeled with radioiodine in the presence of complement. Both in patients and controls, a trimodal distribution of binding capacity was observed. Low (less than 9% of the added radioactivity), intermediate (9-17%), and high binding (more than 17%) were observed in 13, 58, and 29% in controls and in 49, 43 and 8% in lupus patients. The low binding capacity of erythrocytes persisted even after patients entered remission following steroid therapy. A genetic control of binding capacity was supported bymore » familial surveys. Prevalence of pathological proteinuria was significantly higher in patients with low binding capacity than those with intermediate or high binding capacity (16/25 vs 7/26, P less than 0.01). These results indicate that an impaired physiological disposal of immune complexes via the erythrocyte C3b receptor in lupus patients may contribute to the development of renal involvement.« less

[Functional state of various physiological systems of the human body during respiration of neon-oxygen mixture at depth up to 400 meters].

PubMed

Poleshuk, I P; Genin, A M; Unku, R D; Mikhnenko, A E; Sementsov, V N; Suvorov, A V

1991-01-01

Hyperbaric neon-oxygen mixture has been studied for the effect of its high density under pressure of 41 ata on basic physiological functions of human organism. Typical changes of the cardiorespiratory system and tissue respiration parameters are revealed. Changes in physical working capacity are shown. Exposure to gaseous medium of high pressure and density is accompanied by the development of some compensatory-adaptive reactions. The possibility to perform mid-hard physical work is attained with overstrain of respiration and circulation function.

Human Physiological Responses to Cycle Ergometer Leg Exercise During +Gz Acceleration

NASA Technical Reports Server (NTRS)

Chou, J. L.; Stad, N. J.; Barnes, P. R.; Leftheriotis, G. P. N.; Arndt, N. F.; Simonson, S.; Greenleaf, J. E.

1998-01-01

Spaceflight and bed-rest deconditioning decrease maximal oxygen uptake (aerobic power), strength, endurance capacity, and orthostatic tolerance. In addition to extensive use of muscular exercise conditioning as a countermeasure for the reduction in aerobic power (VO(sub 2max)), stimuli from some form of +Gz acceleration conditioning may be necessary to attenuate the orthostatic intolerance component of this deconditioning. Hypothesis: There will be no significant difference in the physiological responses (oxygen uptake, heart rate, ventilation, or respiratory exchange ratio) during supine exercise with moderate +Gz acceleration.

[The adaptive pharmacological correction of functional disorders in young recruits with hypotrophy].

PubMed

Buchnov, A D; Grechko, A T; Murga, Ia T

2000-04-01

Low level of physical development, physiologic reserves, signs of psychical disadaptation, frequent functional disorders in cardiovascular system and gastrointestinal tract are noted in recruits with hypotrophy. Using of rapidly acting adaptogenes during 1 month (phytopreparation elixir "Altai" and "Vitavis" in tablets) significantly improves body state: increase in the level of physiologic reserves, physical working capacity, IMT, body unspecific resistance; improvement in indices of hemodynamics, metabolism and immunity; decrease in asthenization and psychical disadaptation. The state of adaptation and increased resistance in this recruit group remains during the following months of service.

Physiological and nutritional profile of elite female beach handball players from Brazil.

PubMed

Silva, Alexandre S; Coeli Seabra Marques, Rossana; DE Azevedo Lago, Silvio; Guedes Santos, Débora A; Lacerda, Lavoisiana M; Silva, Douglas C; Soares, Ytalo M

2016-05-01

This study evaluated the anthropometric, physiological and nutritional profiles of elite beach handball athletes. Additionally, the cardiometabolic demands of matches were characterized. Six players (24.7±2 years old, 168±0.08 cm, 63.8±7.1 kg) from Brazilian selection, which ranks first in the world, were characterized in terms of aerobic capacities, speeds, anaerobic capacities, muscle power and dietetic profiles. In an official match, heart rate and lactate production were measured. The athletes exhibited a VO2 max of 44.5±4.7 mL/kg/min, a 20-m speed of 3.214±0.43 seconds, a maximal anaerobic power of 337.3±126.3 watts and a long jump muscle power of 210.1±16.6 cm). The athletes had a mean body fat percentage of 24.9±3.0% and balanced macronutrient intakes. During the match, the lactate concentrations were 13.8 mM and 14.1 mM in the middle and at the end of the first set, respectively, and 11.7 mM and 12.0 mM in the middle and end of the second set, respectively. All players, with the exception of the goalkeeper, maintained a median heart rate of at least 123 bpm and no more than 196 bpm. The athletes exhibited only moderate aerobic capacities and better anaerobic and force capacities and high lactate production during the match.

Physiological Capacities: Estimating an Athlete's Potential.

ERIC Educational Resources Information Center

Lemon, Peter W. R.

1982-01-01

Several simple performance tests are described for assessing an athlete's major energy-producing capabilities. The tests are suitable for mass screening because they are easy to administer, require no sophisticated equipment, and can be done quickly. Information for evaluating test results is included. (PP)

Southern Ocean phytoplankton physiology in a changing climate.

PubMed

Petrou, Katherina; Kranz, Sven A; Trimborn, Scarlett; Hassler, Christel S; Ameijeiras, Sonia Blanco; Sackett, Olivia; Ralph, Peter J; Davidson, Andrew T

2016-09-20

The Southern Ocean (SO) is a major sink for anthropogenic atmospheric carbon dioxide (CO 2 ), potentially harbouring even greater potential for additional sequestration of CO 2 through enhanced phytoplankton productivity. In the SO, primary productivity is primarily driven by bottom up processes (physical and chemical conditions) which are spatially and temporally heterogeneous. Due to a paucity of trace metals (such as iron) and high variability in light, much of the SO is characterised by an ecological paradox of high macronutrient concentrations yet uncharacteristically low chlorophyll concentrations. It is expected that with increased anthropogenic CO 2 emissions and the coincident warming, the major physical and chemical process that govern the SO will alter, influencing the biological capacity and functioning of the ecosystem. This review focuses on the SO primary producers and the bottom up processes that underpin their health and productivity. It looks at the major physico-chemical drivers of change in the SO, and based on current physiological knowledge, explores how these changes will likely manifest in phytoplankton, specifically, what are the physiological changes and floristic shifts that are likely to ensue and how this may translate into changes in the carbon sink capacity, net primary productivity and functionality of the SO. Copyright © 2016 Elsevier GmbH. All rights reserved.

Physiological and genomic characterisation of Saccharomyces cerevisiae hybrids with improved fermentation performance and mannoprotein release capacity.

PubMed

Pérez-Través, Laura; Lopes, Christian A; González, Ramón; Barrio, Eladio; Querol, Amparo

2015-07-16

Yeast mannoproteins contribute to several aspects of wine quality by protecting wine against protein haze, reducing astringency, retaining aroma compounds and stimulating lactic-acid bacteria growth. The selection of a yeast strain that simultaneously overproduces mannoproteins and presents good fermentative characteristics is a difficult task. In this work, a Saccharomyces cerevisiae×S. cerevisiae hybrid bearing the two oenologically relevant features was constructed. According to the genomic characterisation of the hybrids, different copy numbers of some genes probably related with these physiological features were detected. The hybrid shared not only a similar copy number of genes SPR1, SWP1, MNN10 and YPS7 related to cell wall integrity with parental Sc1, but also a similar copy number of some glycolytic genes with parental Sc2, such as GPM1 and HXK1, as well as the genes involved in hexose transport, such as HXT9, HXT11 and HXT12. This work demonstrates that hybridisation and stabilisation under winemaking conditions constitute an effective approach to obtain yeast strains with desirable physiological features, like mannoprotein overproducing capacity and improved fermentation performance, which genetically depend of the expression of numerous genes (multigenic characters). Copyright © 2015. Published by Elsevier B.V.

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

Effects of Deployment on Musculoskeletal and Physiological Characteristics and Balance.

PubMed

Nagai, Takashi; Abt, John P; Sell, Timothy C; Keenan, Karen A; McGrail, Mark A; Smalley, Brian W; Lephart, Scott M

2016-09-01

Despite many nonbattle injuries reported during deployment, few studies have been conducted to evaluate the effects of deployment on musculoskeletal and physiological characteristics and balance. A total of 35 active duty U.S. Army Soldiers participated in laboratory testing before and after deployment to Afghanistan. The following measures were obtained for each Soldier: shoulder, trunk, hip, knee, and ankle strength and range of motion (ROM), balance, body composition, aerobic capacity, and anaerobic power/capacity. Additionally, Soldiers were asked about their physical activity and load carriage. Paired t tests or Wilcoxon tests with an α = 0.05 set a priori were used for statistical analyses. Shoulder external rotation ROM, torso rotation ROM, ankle dorsiflexion ROM, torso rotation strength, and anaerobic power significantly increased following deployment (p < 0.05). Shoulder extension ROM, shoulder external rotation strength, and eyes-closed balance (p < 0.05) were significantly worse following deployment. The majority of Soldiers (85%) engaged in physical activity. In addition, 58% of Soldiers reported regularly carrying a load (22 kg average). The deployment-related changes in musculoskeletal and physiological characteristics and balance as well as physical activity and load carriage during deployment may assist with proper preparation with the intent to optimize tactical readiness and mitigate injury risk. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Rigidification of the autolysis loop enhances Na[superscript +] binding to thrombin

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

Pozzi, Nicola; Chen, Raymond; Chen, Zhiwei

2011-09-20

Binding of Na{sup +} to thrombin ensures high activity toward physiological substrates and optimizes the procoagulant and prothrombotic roles of the enzyme in vivo. Under physiological conditions of pH and temperature, the binding affinity of Na{sup +} is weak due to large heat capacity and enthalpy changes associated with binding, and the K{sub d} = 80 mM ensures only 64% saturation of the site at the concentration of Na{sup +} in the blood (140 mM). Residues controlling Na{sup +} binding and activation have been identified. Yet, attempts to improve the interaction of Na{sup +} with thrombin and possibly increase catalyticmore » activity under physiological conditions have so far been unsuccessful. Here we report how replacement of the flexible autolysis loop of human thrombin with the homologous rigid domain of the murine enzyme results in a drastic (up to 10-fold) increase in Na{sup +} affinity and a significant improvement in the catalytic activity of the enzyme. Rigidification of the autolysis loop abolishes the heat capacity change associated with Na{sup +} binding observed in the wild-type and also increases the stability of thrombin. These findings have general relevance to protein engineering studies of clotting proteases and trypsin-like enzymes.« less

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

PubMed

Enzor, Laura A; Place, Sean P

2014-09-15

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

Composite Physiologic Index, Percent Forced Vital Capacity and Percent Diffusing Capacity for Carbon Monoxide Could Be Predictors of Pirfenidone Tolerability in Patients with Idiopathic Pulmonary Fibrosis.

PubMed

Konishi, Satoshi; Arita, Machiko; Ito, Isao; Tachibana, Hiromasa; Takaiwa, Takuya; Fukuda, Yasushi; Watanabe, Naoki; Tsubouchi, Kazuya; Masuda, Gen; Tanaka, Maki; Kourogi, Youhei; Kunimasa, Kei; Nishiyama, Akihiro; Iwasaku, Masahiro; Ito, Akihiro; Tokioka, Fumiaki; Yoshioka, Hiroshige; Hashimoto, Toru; Ishida, Tadashi

2015-01-01

The goals of this study were to assess the efficacy and tolerability of pirfenidone in patients with idiopathic pulmonary fibrosis (IPF) and to identify predictors of tolerability to pirfenidone. We conducted a retrospective observational study. When the patient showed deterioration in the percent forced vital capacity (%FVC) or experienced acute exacerbations or severe adverse events, treatment of the patient with pirfenidone was discontinued. We classified the patients who did not display progression following six months of pirfenidone treatment as the tolerant group and the patients who did display progression as the intolerant group. We retrospectively analyzed differences between the two groups in terms of baseline characteristics. The efficacy of pirfenidone was evaluated by the changes in vital capacity (VC) and %FVC before and after the start of treatment in the tolerant group. Patients A total of 20 patients who had been diagnosed with IPF were treated with pirfenidone. In the tolerant group, the baseline %FVC (p=0.01) and the percentage diffusing capacity of the lungs for carbon monoxide (DLCO, p=0.02) were significantly higher, and the baseline composite physiologic index (CPI) was significantly lower (p=0.009) than in the intolerant group. In the tolerant group, pirfenidone significantly reduced the decline in VC and %FVC of the patients after treatment. In the intolerant group, five patients discontinued pirfenidone treatment because of anorexia. We found that pirfenidone was better tolerated in patients with milder disease symptoms, as indicated by their baseline CPI, %FVC and %DLCO, and that patients in the tolerant group could benefit from the use of pirfenidone.

The effects of strength training on cognitive performance in elderly women.

PubMed

Smolarek, André de Camargo; Ferreira, Luis Henrique Boiko; Mascarenhas, Luis Paulo Gomes; McAnulty, Steven R; Varela, Karla Daniele; Dangui, Mônica C; de Barros, Marcelo Paes; Utter, Alan C; Souza-Junior, Tácito P

2016-01-01

Aging is a degenerative process marked by recognized functional, physiological, and metabolic impairments, such as dynapenia and diminished cognitive capacity. Therefore, the search for innovative strategies to prevent/delay these physiological and cognitive disorders is essential to guarantee the independence and life quality of an elderly population. The aim of this work is to verify the effect of a 12-week resistance exercise program on the general physical aptitude and cognitive capacities of elderly and sedentary women. Twenty-nine women (65.87±5.69 years) were divided into two groups. The control group was composed of eight elderly women who met the same inclusion criteria of the study and the strength training group was composed of 29 elderly women who were subjected to a resistance exercise program defined by 12 upper and lower limb exercises combined in 3×10 repetitions with 1-minute interval between repetitions and two resting minutes between exercises (three times/week). Weight loads were fixed between 60% and 75% of the apparent 1 repetition maximum, which was estimated by the test of 10 maximum repetitions. The direct curl was performed for upper body strength evaluation with 2.3 kg dumbbells for 30 seconds, whereas the chair test was used for lower body evaluation (total sit-stand movements in 30 seconds). The cognitive capacities of subjects were evaluated by "The Montreal Cognitive Assessment" questionnaire. After 12 weeks, the elderly group showed significant increases in the average upper body strength (58%), lower body strength (68%), and cognitive capacity (19%). The present study demonstrated that regular resistance exercises could provide significant gains on the upper and lower body strength concomitant to positive improvements on cognitive capacities of elderly women, bringing enhanced life quality.

Upper airway muscles awake and asleep.

PubMed

Sériès, Frédéric

2002-06-01

Upper airway (UA) structures are involved in different respiratory and non-respiratory tasks. The coordination of agonist and antagonist UA dilators is responsible for their mechanical function and their ability to maintain UA patency throughout the respiratory cycle. The activity of these muscles is linked with central respiratory activity but also depends on UA pressure changes and is greatly influenced by sleep. UA muscles are involved in determining UA resistance and stability (i.e. closing pressure), and the effect of sleep on these variables may be accounted for by its effect on tonic and phasic skeletal muscle activities. The mechanical effects of UA dilator contraction also depend on their physiological properties (capacity to generate tension in vitro, activity of the anaerobic enzymatic pathway, histo-chemical characteristics that may differ between subjects who may or may not have sleep-related obstructive breathing disorders). These characteristics may represent an adaptive process to an increased resistive loading of these muscles. The apparent discrepancy between the occurrence of UA closure and an increased capacity to generate tension in sleep apnea patients may be due to a reduction in the effectiveness of UA muscle contraction in these patients; such an increase in tissue stiffness could be accounted for by peri-muscular tissue characteristics. Therefore, understanding of UA muscle physiological characteristics should take into account its capacity for force production and its mechanical coupling with other UA tissues. Important research goals for the future will be to integrate these issues with other physiological features of the disease, such as UA size and dimension, histological characteristics of UA tissues and the effect of sleep on muscle function. Such integration will better inform understanding of the role of pharyngeal UA muscles in the pathophysiology of the sleep apnea/hypopnea syndrome.

Physiological and physical characteristics of elite dragon boat paddlers.

PubMed

Ho, Sarah R; Smith, Richard M; Chapman, Philip G; Sinclair, Peter J; Funato, Kazuo

2013-01-01

The objectives of this study were to profile the physiological and physical characteristics of elite dragon boat paddlers, to identify characteristics that predict race performance and to quantify the metabolic energy contributions to simulated 200-m and 500-m dragon boat racing. Eleven, national level, male, Japanese dragon boat paddlers completed a battery of tests on a paddling ergometer including an incremental maximal aerobic capacity test, a 2-minute maximal accumulated oxygen deficit (MAOD) test, and simulated 200-m and 500-m races. A physiological and physical profile of subjects was compiled. Results showed that 200-m race performance correlated with flexed arm girth and excess postexercise oxygen consumption (EPOC) measured in the 30 minutes after the MAOD test, whereas 500-m race performance correlated with body fat percentage, relaxed and flexed arm girth, MAOD, EPOC, and peak power during the MAOD test. Stepwise multiple regression revealed that flexed arm girth was the most powerful predictor of 200-m and 500-m race performance, followed by EPOC with the combination of these 2 factors able to explain 74% and 68% of the variance in 200-m and 500-m race performance, respectively. Aerobic energy contributions for 200-m (50 seconds) and 500-m (1 minute 50 seconds) races were (mean (95% confidence intervals)) 52.1% (range, 47.4-56.8%) and 67.5% (range, 60.1-77.8%), respectively. In conclusion, coaches should develop training programs targeted at developing upper-body musculature and increasing anaerobic capacity because these factors are the strongest predictors of 200-m and 500-m race performance. Given the substantial aerobic energy contributions even for a 200-m race event, coaches should aim to increase the maximal aerobic capacity of the paddler in preparation for both 200-m and 500-m events.

Physiological correlates to spontaneous physical activity variability in obese patients with already treated sleep apnea syndrome.

PubMed

Vivodtzev, Isabelle; Mendelson, Monique; Croteau, Marilie; Gorain, Sandy; Wuyam, Bernard; Tamisier, Renaud; Lévy, Patrick; Maltais, François; Pépin, Jean-Louis

2017-03-01

Physical activity is promoted in patients with sleep disorders and obesity. The aim of the present study was to assess physiological factors influencing objectively measured spontaneous physical activity in already treated patients for obstructive sleep apnea (OSA) by nocturnal continuous positive airway pressure (CPAP). Fifty-five patients (age = 53 ± 3 years; body mass index (BMI) = 38 ± 3 kg/m 2 ; compliance with CPAP >4 h/night) were prospectively included. Measurements were 5-day actigraphy with metabolic equivalent of task (METs) assessment, body composition, pulmonary function, quadriceps and respiratory muscle strength, exercise capacity (6-min walking distance and maximal aerobic capacity), as well as sleep parameters (sleepiness, duration, oxygen saturation, and micro-arousals during sleep) and quality of life (SF-36 questionnaire). As expected, the number of steps per day (6879 ± 2511) and mean intensity of physical activity (1.38 ± 0.15 METs) were below the recommendations for obese population. In age-adjusted stepwise regression models, peak oxygen consumption (VO 2 peak ) and peak dyspnea perception during incremental exercise test were independent predictors of the number of steps per day (r = 0.49, p = 0.001) although VO 2 peak and peak minute ventilation were independent predictors of intensity of physical activity (in METs/day; r = 0.49, p = 0.001). In severe obese patients with OSA, exercise capacity, ventilatory requirement, and dyspnea perception were main physiological components of physical activity. These results emphasize the need to consider specific training interventions that increase ability to perform intense physical activity in obese OSA.

Niche dimensions in fishes: an integrative view.

PubMed

Pörtner, H O; Schulte, P M; Wood, C M; Schiemer, F

2010-01-01

Current shifts in ecosystem composition and function emphasize the need for an understanding of the links between environmental factors and organism fitness and tolerance. The examples discussed here illustrate how recent progress in the field of comparative physiology may provide a better mechanistic understanding of the ecological concepts of the fundamental and realized niches and thus provide insights into the impacts of anthropogenic disturbance. Here we argue that, as a link between physiological and ecological indicators of organismal performance, the mechanisms shaping aerobic scope and passive tolerance set the dimensions of an animal's niche, here defined as its capacity to survive, grow, behave, and interact with other species. We demonstrate how comparative studies of cod or killifish populations in a latitudinal cline have unraveled mitochondrial mechanisms involved in establishing a species' niche, performance, and energy budget. Riverine fish exemplify how the performance windows of various developmental stages follow the dynamic regimes of both seasonal temperatures and river hydrodynamics, as synergistic challenges. Finally, studies of species in extreme environments, such as the tilapia of Lake Magadi, illustrate how on evolutionary timescales functional and morphological shifts can occur, associated with new specializations. We conclude that research on the processes and time course of adaptations suitable to overcome current niche limits is urgently needed to assess the resilience of species and ecosystems to human impact, including the challenges of global climate change.

Physiological and subjective sexual arousal in self-identified asexual women.

PubMed

Brotto, Lori A; Yule, Morag A

2011-08-01

Asexuality can be defined as a lifelong lack of sexual attraction. Empirical research on asexuality reveals significantly lower self-reported sexual desire and arousal and lower rates of sexual activity; however, the speculation that there may also be an impaired psychophysiological sexual arousal response has never been tested. The aim of this study was to compare genital (vaginal pulse amplitude; VPA) and subjective sexual arousal in asexual and non-asexual women. Thirty-eight women between the ages of 19 and 55 years (10 heterosexual, 10 bisexual, 11 homosexual, and 7 asexual) viewed neutral and erotic audiovisual stimuli while VPA and self-reported sexual arousal and affect were measured. There were no significant group differences in the increased VPA and self-reported sexual arousal response to the erotic film between the groups. Asexuals showed significantly less positive affect, sensuality-sexual attraction, and self-reported autonomic arousal to the erotic film compared to the other groups; however, there were no group differences in negative affect or anxiety. Genital-subjective sexual arousal concordance was significantly positive for the asexual women and non-significant for the other three groups, suggesting higher levels of interoceptive awareness among asexuals. Taken together, the findings suggest normal subjective and physiological sexual arousal capacity in asexual women and challenge the view that asexuality should be characterized as a sexual dysfunction.

Impact of bile salt adaptation of Lactobacillus delbrueckii subsp. lactis 200 on its interaction capacity with the gut.

PubMed

Burns, Patricia; Reinheimer, Jorge; Vinderola, Gabriel

2011-10-01

In a previous work, bile-salt-resistant derivatives were obtained from non-intestinal lactobacilli. The aim of this work was to investigate the impact of bile adaptation of Lactobacillus delbrueckii subsp. lactis 200 on morphology, surface properties, in vivo interaction capacity with the gut and ability to activate the gut immune response. Electron microscopy studies, growth kinetics in the presence of bovine and porcine bile, the capacity to deconjugate bile acids, hydrophobicity, autoaggregation and co-aggregation capacities were studied for the parental strain and its bile-resistant derivative in vitro. Additionally, survival in intestinal fluid, the interaction with the gut and the immunomodulating capacities were studied in mice. Bile salt adaptation conferred upon the adapted strain a higher capacity to withstand physiological concentrations of bile salts and greater survival capacity in intestinal fluid. However, bile salt exposure reduced cell hydrophobicity, autoaggregation and adhesion capacities, resulting in reduced persistence in the intestinal lumen and delayed capacity to activate the gut immune response. Insight into the effects of bile salts upon the interaction and immunomodulating capacity of lactobacilli with the gut is provided, relating in vitro and in vivo results. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

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.

The effects of ageing on respiratory muscle function and performance in older adults.

PubMed

Watsford, Mark L; Murphy, Aron J; Pine, Matthew J

2007-02-01

The reduced physiological capacity evident with ageing may affect the ability to perform many tasks, potentially affecting quality of life. Previous research has clearly demonstrated the reduced capacity of the respiratory system with ageing and described the effect that habitual physical activity has upon this decline. This research aimed to examine the influence of age on respiratory muscle (RM) function and the relationship between RM function and physical performance within the Australian population. Seventy-two healthy older adults (50-79 years) were divided into males (n=36) and females (n=36) and examined for pulmonary function, RM strength, inspiratory muscle endurance (IME) and 1.6 km walking performance. There were no significant age by gender effects for any variables; however, ageing was significantly related to reduced RM function and walking capacity within each gender. Furthermore, regression analysis showed that the RM strength could be predicted from age. Partial correlations controlling for age indicated that expiratory muscle strength was significantly related to walking performance in males (p=0.04), whilst IME contributed significantly to walking performance in all participants. These within-gender effects and relationships indicate that RM strength is an important physiological variable to maintain in the older population, as it may be related to functional ability.

Evaluating a Seminar on Stress Management.

ERIC Educational Resources Information Center

Deffenbacher, Jerry L.; Shepard, Jeffrey M.

1989-01-01

Examines a college seminar's capacity to reduce stress by evaluating a psychology seminar on stress management over a six-year period. Students reported significantly less general anxiety, general anger, situational stress reactivity, and stress-related physiological reactivity after taking the class. Follow-ups of two classes indicated…

Investigation of relationships between physical parameters and neuro-physiological response to head impact.

DOT National Transportation Integrated Search

1988-06-01

The aim of this study was to shed some light on brain injuries following blows to the head by means of the methods of both cognitive psychology and electrophysiology. More precisely, boxers' attention mechanisms and their capacity of orienting toward...

Identification of beef heifers with superior uterine capacity for pregnancy

USDA-ARS?s Scientific Manuscript database

Infertility and subfertility represent major problems in domestic animals and humans, and the majority of embryonic loss occurs during the first month of gestation that involves pregnancy recognition and conceptus implantation. The critical genes and physiological pathways in the endometrium that me...

Influence of exercise and aging on extracellular matrix composition in the skeletal muscle stem cell niche.

PubMed

Garg, Koyal; Boppart, Marni D

2016-11-01

Skeletal muscle is endowed with a remarkable capacity for regeneration, primarily due to the reserve pool of muscle resident satellite cells. The satellite cell is the physiologically quiescent muscle stem cell that resides beneath the basal lamina and adjacent to the sarcolemma. The anatomic location of satellite cells is in close proximity to vasculature where they interact with other muscle resident stem/stromal cells (e.g., mesenchymal stem cells and pericytes) through paracrine mechanisms. This mini-review describes the components of the muscle stem cell niche, as well as the influence of exercise and aging on the muscle stem cell niche. Although exercise promotes ECM reorganization and stem cell accumulation, aging is associated with dense ECM deposition and loss of stem cell function resulting in reduced regenerative capacity and strength. An improved understanding of the niche elements will be valuable to inform the development of therapeutic interventions aimed at improving skeletal muscle regeneration and adaptation over the life span. Copyright © 2016 the American Physiological Society.

Eccentric Contraction-Induced Muscle Injury: Reproducible, Quantitative, Physiological Models to Impair Skeletal Muscle’s Capacity to Generate Force

PubMed Central

Call, Jarrod A.; Lowe, Dawn A.

2018-01-01

In order to investigate the molecular and cellular mechanisms of muscle regeneration an experimental injury model is required. Advantages of eccentric contraction-induced injury are that it is a controllable, reproducible, and physiologically relevant model to cause muscle injury, with injury being defined as a loss of force generating capacity. While eccentric contractions can be incorporated into conscious animal study designs such as downhill treadmill running, electrophysiological approaches to elicit eccentric contractions and examine muscle contractility, for example before and after the injurious eccentric contractions, allows researchers to circumvent common issues in determining muscle function in a conscious animal (e.g., unwillingness to participate). Herein, we describe in vitro and in vivo methods that are reliable, repeatable, and truly maximal because the muscle contractions are evoked in a controlled, quantifiable manner independent of subject motivation. Both methods can be used to initiate eccentric contraction-induced injury and are suitable for monitoring functional muscle regeneration hours to days to weeks post-injury. PMID:27492161

Oxygen delivery does not limit thermal tolerance in a tropical eurythermal crustacean.

PubMed

Ern, Rasmus; Huong, Do Thi Thanh; Phuong, Nguyen Thanh; Wang, Tobias; Bayley, Mark

2014-03-01

In aquatic environments, rising water temperatures reduce water oxygen content while increasing oxygen demand, leading several authors to propose cardiorespiratory oxygen transport capacity as the main determinant of aquatic animal fitness. It has also been argued that tropical species, compared with temperate species, live very close to their upper thermal limit and hence are vulnerable to even small elevations in temperature. Little, however, is known about physiological responses to high temperatures in tropical species. Here we report that the tropical giant freshwater shrimp (Macrobrachium rosenbergii) maintains normal growth when challenged by a temperature rise of 6°C above the present day average (from 27°C to 33°C). Further, by measuring heart rate, gill ventilation rate, resting and maximum oxygen uptake, and hemolymph lactate, we show that oxygen transport capacity is maintained up to the critical maximum temperature around 41°C. In M. rosenbergii heart rate and gill ventilation rate increases exponentially until immediately below critical temperatures and at 38°C animals still retained more than 76% of aerobic scope measured at 30°C, and there was no indication of anaerobic metabolism at the high temperatures. Our study shows that the oxygen transport capacity is maintained at high temperatures, and that other mechanisms, such as protein dysfunction, are responsible for the loss of ecological performance at elevated temperatures.

The protocol for the isolation and cryopreservation of osteoclast precursors from mouse bone marrow and spleen.

PubMed

Boraschi-Diaz, Iris; Komarova, Svetlana V

2016-01-01

Osteoclasts are responsible for physiological bone remodeling as well as pathological bone destruction in osteoporosis, periodontitis and rheumatoid arthritis, and thus represent a pharmacological target for drug development. We aimed to characterize and compare the cytokine-induced osteoclastogenesis of bone marrow and spleen precursors. Established protocols used to generate osteoclasts from bone marrow were modified to examine osteoclastogenesis of the spleen cells of healthy mice. Osteoclast formation was successfully induced from spleen precursors using receptor activator of nuclear factor κB ligand (50 ng/ml) and macrophage colony stimulating factor (50 ng/ml). Compared to bone marrow cultures, differentiation from spleen required a longer cultivation time (9 days for spleen, as compared to 5 days for marrow cultures) and a higher plating density of non-adherent cells (75,000/cm(2) for spleen, as compared to 50,000/cm(2) for bone marrow). Osteoclasts generated from spleen precursors expressed osteoclast marker genes calcitonin receptor, cathepsin K and matrix metalloproteinase 9 and were capable of resorbing hydroxyapatite. The differentiation capacity of spleen and bone marrow precursors was comparable for BALB/c, C57BL/6 and FVB mice. We also developed and tested a cryopreservation protocol for the osteoclast precursors. While 70-80 % of cells were lost during the first week of freezing, during the subsequent 5 weeks the losses were within 2-5 % per week. Osteoclastogenesis from the recovered bone marrow precursors was successful up to 5 weeks after freezing. Spleen precursors retained their osteoclastogenic capacity for 1 week after freezing, but not thereafter. The described protocol is useful for the studies of genetically modified animals as well as for screening new osteoclast-targeting therapeutics.

Isolation and characterization of a furfural-degrading bacterium Bacillus cereus sp. strain DS1.

PubMed

Zheng, Dan; Bao, Jianguo; Lu, Jueming; Gao, Chunlei

2015-02-01

Furfural was found to be the main organic pollutant in the wastewater coming from the Diosgenin factory. This substance is derived from acidic pentosan in Dioscorea zingiberensis and is also found in a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust. It is regarded as a toxicant and an inhibitor to the growth of microorganism in both sewage disposal and biological fermentation. A furfural-degrading strain (DS1) was isolated from activated sludge of wastewater treatment plant in a diosgenin factory by continuous enrichment culture. The strain was identified as Bacillus cereus based on morphological, physiological tests, as well as on 16S rDNA sequence and Biolog analyses. The capacity of this strain to grow on a mineral salt medium, utilizing furfural as the sole carbon and energy source to degrade furfural, was investigated in this study. Under the condition of pH 9.0, temperature 35 °C, with rotating speed of 150 rpm, and an inoculum of 6 %, the strain showed that the furfural degradation capacity reaches 35 % in 7 days, as measured by high-performance liquid chromatography. The addition of inorganic carbon sources could bring down the biodegradation efficiency of the furfural. The strain DS1 showed better furfural removal capacity, as compared to other inorganic carbon sources in the media. Furthermore, a furfural concentration of as high as 4,000 mg L(-1) was tolerated by the culture. The capacity to degrade furfural was demonstrated for the first time by using the genus B. cereus. This study suggests the possible application in biodegradation strategies.

Phylogenetic Analysis Supports the Aerobic-Capacity Model for the Evolution of Endothermy.

PubMed

Nespolo, Roberto F; Solano-Iguaran, Jaiber J; Bozinovic, Francisco

2017-01-01

The evolution of endothermy is a controversial topic in evolutionary biology, although several hypotheses have been proposed to explain it. To a great extent, the debate has centered on the aerobic-capacity model (AC model), an adaptive hypothesis involving maximum and resting rates of metabolism (MMR and RMR, respectively; hereafter "metabolic traits"). The AC model posits that MMR, a proxy of aerobic capacity and sustained activity, is the target of directional selection and that RMR is also influenced as a correlated response. Associated with this reasoning are the assumptions that (1) factorial aerobic scope (FAS; MMR/RMR) and net aerobic scope (NAS; MMR - RMR), two commonly used indexes of aerobic capacity, show different evolutionary optima and (2) the functional link between MMR and RMR is a basic design feature of vertebrates. To test these assumptions, we performed a comparative phylogenetic analysis in 176 vertebrate species, ranging from fish and amphibians to birds and mammals. Using disparity-through-time analysis, we also explored trait diversification and fitted different evolutionary models to study the evolution of metabolic traits. As predicted, we found (1) a positive phylogenetic correlation between RMR and MMR, (2) diversification of metabolic traits exceeding that of random-walk expectations, (3) that a model assuming selection fits the data better than alternative models, and (4) that a single evolutionary optimum best fits FAS data, whereas a model involving two optima (one for ectotherms and another for endotherms) is the best explanatory model for NAS. These results support the AC model and give novel information concerning the mode and tempo of physiological evolution of vertebrates.

Clinical, Bronchographic, Radiological, and Physiological Observations in Ten Cases of Asbestosis

PubMed Central

Leathart, G. L.

1960-01-01

Ten cases of asbestosis (eight male, two female), aged 45-65 years have been kept under observation for periods of up to eight years. Bronchiectasis was demonstrated bronchographically in six cases. Clubbing of the fingers and coarse crepitations appeared to be signs of bronchiectasis rather than of uncomplicated asbestosis. It is suggested that the prevalence of bronchiectasis is higher than has been reported previously because the patients survived longer. The radiological findings are tabulated and compared with previous descriptions. In these subjects there was no relationship between radiological and clinical state. Nine patients eventually showed clinical deterioration and it often proceeded rapidly. The radiograph however, usually remained unaltered. Pulmonary function tests, including diffusing capacity, arterial blood analysis and estimation of mechanical properties of the lung, were carried out in these 10 cases, and in 11 asbestos workers (aged 35-64 years) without radiological abnormality. The steady state diffusing capacity for carbon monoxide (Dco) at rest was lower in asbestosis than in the control subjects. The pulmonary compliance was remarkably low in asbestosis and related fairly closely to the vital capacity. The maximum voluntary ventilation was also low and was related to increased pulmonary resistance but it cannot be said whether this is in the airways or in the lung tissue. Indirect evidence of inequalities of ventilation/perfusion ratio was obtained in most cases. There is no convincing evidence that pulmonary fibrosis occurs without radiological abnormality, but a defect of diffusion may occur. There is no test of pulmonary function which is diagnostic, but a low pulmonary compliance, especially if combined with a low diffusing capacity, is confirmatory. It is suggested that the demonstration of a progressive decline in vital capacity, or in diffusing capacity, may enable a diagnosis of asbestosis to be made before radiological abnormality has appeared, but this point has not been proved.

Basketball Performance Is Related to Maturity and Relative Age in Elite Adolescent Players.

PubMed

Torres-Unda, Jon; Zarrazquin, Idoia; Gravina, Leyre; Zubero, Jaime; Seco, Jesús; Gil, Susana M; Gil, Javier; Irazusta, Jon

2016-05-01

During a national championship, the anthropometric, physiological, and maturation characteristics of 13- to 14-year-old players of elite basketball teams and their association with sport performance were analyzed. Body parameters (weight, height, skinfold thicknesses, and lengths) were measured and physiological capacities assessed by sprint (20 m) and jump tests (i.e., countermovement jump with arm swing). Chronological age (CA) and maturity offset (years from age at peak height velocity; YAPHV) were calculated, and then predicted age at peak height velocity, as the difference between CA and YAPHV. Game performance was assessed with point averages and the performance index rating (PIR). The birth-date distribution of players was biased, those born early in the selection year outnumbering those born later. Anthropometric analysis indicated that players who performed better had longer body lengths. Physiological testing showed that semi-finalists had better sprint performance than quarter-finalists and those players with greater jump capacity scored more points. Early maturation and advanced maturity status were also associated with better PIR and scored points per game. Multiple blockwise regression analysis showed that, among the factors analyzed, YAPHV was the best predictor of basketball performance. In conclusion, around puberty, physical and physiological parameters associated with maturity and CA are important in determining the success of elite basketball players. Consequently, boys who are born in the second half of the year and/or late maturing tend to be marginalized or totally excluded, and not given the chance to play under equal conditions; their careers may then be held back by the relative disadvantage associated with inexperience.

Biomedical Results of ISS Expeditions 1-12

NASA Technical Reports Server (NTRS)

Fogarty, Jennifer; Sams, Clarence F.

2007-01-01

A viewgraph presentation on biomedical data from International Space Station (ISS) Expeditions 1-12 is shown. The topics include: 1) ISS Expeditions 1-12; 2) Biomedical Data; 3) Physiological Assessments; 4) Bone Mineral Density; 5) Bone Mineral Density Recovery; 6) Orthostatic Tolerance; 7) Postural Stability Set of Sensory Organ Test 6; 8) Performance Assessment; 9) Aerobic Capacity of the Astronaut Corps; 10) Pre-flight Aerobic Fitness of ISS Astronauts; 11) In-flight and Post-flight Aerobic Capacity of the Astronaut Corps; and 12) ISS Functional Fitness Expeditions 1-12.

Physiological Characteristics of Projected Starters and Non-Starters in the Field Positions from a Division I Women’s Soccer Team

PubMed Central

RISSO, FABRICE G.; JALILVAND, FARZAD; ORJALO, ASHLEY J.; MORENO, MATTHEW R.; DAVIS, DESHAUN L.; BIRMINGHAM-BABAUTA, SAMANTHA A.; STOKES, JOHN J.; STAGE, ALYSSA A.; LIU, TRICIA M.; GIULIANO, DOMINIC V.; LAZAR, ADRINA; LOCKIE, ROBERT G.

2017-01-01

NCAA soccer features different substitution rules compared to FIFA-sanctioned matches, with a greater availability of players who can enter the game. This could influence the physiological characteristics of the field position starters (ST) and non-starters (NST) within a collegiate women’s team, which has not been previously analyzed. Thus, 22 field players from the same Division I women’s soccer squad completed: vertical and standing broad jumps; 30-meter (m) sprint (0–5, 0–10, 0–30 m intervals); pro-agility and 60-yard shuttle; and the Yo-Yo Intermittent Recovery Test Level 1. Players were defined into ST (n=10) and NST (n=12) by the coaching staff. A one-way ANOVA derived any significant (p≤0.05) between-group differences, and effect sizes were used for a magnitude-based inference analysis. Z-scores were also calculated to document worthwhile differences above or below the squad mean for the groups. The results showed no significant between-group differences for any of the performance tests. ST did have a worthwhile difference above the squad mean in the 0–10 and 0–30 m sprint intervals, while NST had a worthwhile difference below the squad mean in the 0–30 m interval. Physiological characteristics between ST and NST from the analyzed Division I squad were similar, although ST were generally faster. The similarities between ST and NST may be a function of the team’s training, in that all players may complete the same workouts. Nonetheless, if all players exhibit similar physiological capacities, with appropriate substitutions by the coach a collegiate team should be able to maintain a high work-rate throughout a match. PMID:28674601

Skeletal Muscle-specific G Protein-coupled Receptor Kinase 2 Ablation Alters Isolated Skeletal Muscle Mechanics and Enhances Clenbuterol-stimulated Hypertrophy*

PubMed Central

Woodall, Benjamin P.; Woodall, Meryl C.; Luongo, Timothy S.; Grisanti, Laurel A.; Tilley, Douglas G.; Elrod, John W.; Koch, Walter J.

2016-01-01

GRK2, a G protein-coupled receptor kinase, plays a critical role in cardiac physiology. Adrenergic receptors are the primary target for GRK2 activity in the heart; phosphorylation by GRK2 leads to desensitization of these receptors. As such, levels of GRK2 activity in the heart directly correlate with cardiac contractile function. Furthermore, increased expression of GRK2 after cardiac insult exacerbates injury and speeds progression to heart failure. Despite the importance of this kinase in both the physiology and pathophysiology of the heart, relatively little is known about the role of GRK2 in skeletal muscle function and disease. In this study we generated a novel skeletal muscle-specific GRK2 knock-out (KO) mouse (MLC-Cre:GRK2fl/fl) to gain a better understanding of the role of GRK2 in skeletal muscle physiology. In isolated muscle mechanics testing, GRK2 ablation caused a significant decrease in the specific force of contraction of the fast-twitch extensor digitorum longus muscle yet had no effect on the slow-twitch soleus muscle. Despite these effects in isolated muscle, exercise capacity was not altered in MLC-Cre:GRK2fl/fl mice compared with wild-type controls. Skeletal muscle hypertrophy stimulated by clenbuterol, a β2-adrenergic receptor (β2AR) agonist, was significantly enhanced in MLC-Cre:GRK2fl/fl mice; mechanistically, this seems to be due to increased clenbuterol-stimulated pro-hypertrophic Akt signaling in the GRK2 KO skeletal muscle. In summary, our study provides the first insights into the role of GRK2 in skeletal muscle physiology and points to a role for GRK2 as a modulator of contractile properties in skeletal muscle as well as β2AR-induced hypertrophy. PMID:27566547

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.

Physiological responses and tolerance of kenaf (Hibiscus cannabinus L.) exposed to chromium.

PubMed

Ding, Han; Wang, Guodong; Lou, Lili; Lv, Jinyin

2016-11-01

Selection of kenaf species with chromium (Cr) tolerance and exploring the physiological mechanisms involved in Cr tolerance are crucial for application of these species to phyto-remediation. In the present study, a hydroponic experiment was conducted to investigate the variation in two kenaf cultivars, K39-2 and Zhe50-3 under Cr stress. At the same Cr concentration, the tolerance index (TI) of K39-2 was higher than that of Zhe50-3, indicating that K39-2 may be more tolerant to Cr than Zhe50-3. It was also observed that high concentration of chromium was accumulated both in the shoots and the roots of Hibiscus cannabinus L. The leaves of K39-2 accumulated 4760.28mgkg(-1) of dry weight under 1.50mM Cr stress, and the roots accumulated 11,958.33mgkg(-1). Physiological response shows that the antioxidant enzymes' superoxide dismutase (SOD), catalase activity (CAT) and peroxidase (POD) activities increased in the leaves and decreased in roots of the Cr-stressed plants nearly compared to the control. Moreover, the variation of antioxidant enzymes activities indicated Zhe50-3 was more vulnerable than K39-2, and the contents of the non-protein thiol pool (GSH, NPT and PCs) were higher in K39-2 than Zhe50-3 with the increased Cr concentration. Based on the observations above, it can be concluded that the well-coordinated physiological changes confer a greater Cr tolerance to K39-2 than Zhe50-3 under Cr exposure, and Hibiscus cannabinus L. has a great accumulation capacity for chromium. Copyright © 2016 Elsevier Inc. All rights reserved.

Physiological basis of genetic variation in leaf photosynthesis among rice (Oryza sativa L.) introgression lines under drought and well-watered conditions

PubMed Central

Yin, Xinyou

2012-01-01

To understand the physiological basis of genetic variation and resulting quantitative trait loci (QTLs) for photosynthesis in a rice (Oryza sativa L.) introgression line population, 13 lines were studied under drought and well-watered conditions, at flowering and grain filling. Simultaneous gas exchange and chlorophyll fluorescence measurements were conducted at various levels of incident irradiance and ambient CO2 to estimate parameters of a model that dissects photosynthesis into stomatal conductance (g s), mesophyll conductance (g m), electron transport capacity (J max), and Rubisco carboxylation capacity (V cmax). Significant genetic variation in these parameters was found, although drought and leaf age accounted for larger proportions of the total variation. Genetic variation in light-saturated photosynthesis and transpiration efficiency (TE) were mainly associated with variation in g s and g m. One previously mapped major QTL of photosynthesis was associated with variation in g s and g m, but also in J max and V cmax at flowering. Thus, g s and g m, which were demonstrated in the literature to be responsible for environmental variation in photosynthesis, were found also to be associated with genetic variation in photosynthesis. Furthermore, relationships between these parameters and leaf nitrogen or dry matter per unit area, which were previously found across environmental treatments, were shown to be valid for variation across genotypes. Finally, the extent to which photosynthesis rate and TE can be improved was evaluated. Virtual ideotypes were estimated to have 17.0% higher photosynthesis and 25.1% higher TE compared with the best genotype investigated. This analysis using introgression lines highlights possibilities of improving both photosynthesis and TE within the same genetic background. PMID:22888131

Physiological characteristics of elite and sub-elite badminton players.

PubMed

Ooi, Cheong Hwa; Tan, Albert; Ahmad, Azwari; Kwong, Kien Weng; Sompong, Ruji; Ghazali, Khairul Aswadi Mohd; Liew, Swee Lee; Chai, Wen Jin; Thompson, Martin William

2009-12-01

The aims of this study were to establish the physical and physiological attributes of elite and sub-elite Malaysian male badminton players and to determine whether these attributes discriminate elite players from sub-elite players. Measurements and tests of basic anthropometry, explosive power, anaerobic recovery capacity, badminton-specific movement agility, maximum strength, and aerobic capacity were conducted on two occasions, separated by at least one day. The elite (n = 12) and sub-elite (n = 12) players' characteristics were, respectively: mean age 24.6 years (s = 3.7) and 20.5 years (s = 0.7); mass 73.2 kg (s = 7.6) and 62.7 kg (s = 4.2); stature 1.76 m (s = 0.07) and 1.71 m (s = 0.05); body fat 12.5% (s = 4.8) and 9.5% (s = 3.4); estimated VO(2max) 56.9 ml . kg(-1) . min(-1) (s = 3.7) and 59.5 ml . kg(-1) . min(-1) (s = 5.2). The elite players had greater maximum absolute strength in one-repetition maximum bench press (P = 0.015) compared with the sub-elite players. There were significant differences in instantaneous lower body power estimated from vertical jump height between the elite and sub-elite groups (P < 0.01). However, there was no significant difference between groups in shuttle run tests and on-court badminton-specific movement agility tests. Our results show that elite Malaysian male badminton players are taller, heavier, and stronger than their sub-elite counterparts. The test battery, however, did not allow us to discriminate between the elite and sub-elite players, suggesting that at the elite level tactical knowledge, technical skills, and psychological readiness could be of greater importance.

SIMULTANEOUS URODYNAMIC AND ANORECTAL MANOMETRY STUDIES IN CHILDREN: INSIGHTS INTO THE RELATIONSHIP BETWEEN THE LOWER GASTROINTESTINAL AND LOWER URINARY TRACTS

PubMed Central

Ambartsumyan, Lusine; Siddiqui, Anees; Bauer, Stuart; Nurko, Samuel

2016-01-01

Background Children with urinary incontinence (UI) have associated functional constipation (FC) and fecal incontinence (FI). The physiology between lower urinary tract (LUT) and anorectum in children has not been elucidated. Aims Observe the effect of rectal distention (RD) on LUT function, and bladder filling and voiding on anorectal function. Methods Children with voiding dysfunction referred to Boston Children’s Hospital were prospectively enrolled for combined urodynamic (UDS) and anorectal manometry (ARM). Anorectal and urodynamic parameters were simultaneously measured. Patients underwent 2 micturition cycles, 1st with rectal balloon deflated and 2nd with it inflated (RD). LUT and anorectal parameters were compared between cycles. Key Results 10 children (7 UI, 4 recurrent UTIs, 9 FC ± FI) were enrolled. Post void residual (PVR) increased (p=0.02) with RD. No differences were observed in percent of bladder filling to expected bladder capacity, sensation, and bladder compliance with and without RD. Bladder and abdominal pressures increased at voiding with RD (p<0.05). Intra-anal pressures decreased at voiding (p<0.05), at 25% (p=0.03) and 50% (p=0.06) of total volume of bladder filling. Conclusions & Inferences The PVR volume increased with RD. Stool in the rectum does not alter filling cystometric capacity but decreases the bladder’s ability to empty predisposing patients with fecal retention to UI and UTIs. Bladder and abdominal pressures increased during voiding demonstrating a physiological correlate of dysfunctional voiding. Intra-anal pressures decreased during bladder filling and voiding. This is the first time intra-anal relaxation during bladder filling and voiding has been described. PMID:27214097

Different Preclimacteric Events in Apple Cultivars with Modified Ripening Physiology

PubMed Central

Singh, Vikram; Weksler, Asya; Friedman, Haya

2017-01-01

“Anna” is an early season apple cultivar exhibiting a fast softening and juiciness loss during storage, in comparison to two mid-late season cultivars “Galaxy” and “GD.” The poor storage capacity of “Anna” was correlated with high lipid oxidation-related autoluminescence, high respiration and ethylene production rates, associated with high expression of MdACO1, 2, 4, 7, and MdACS1. All cultivars at harvest responded to exogenous ethylene by enhancing ethylene production, typical of system-II. The contribution of pre-climacteric events to the poor storage capacity of “Anna” was examined by comparing respiration and ethylene production rates, response to exogenous ethylene, expression of genes responsible for ethylene biosynthesis and response, and developmental regulators in the three cultivars throughout fruit development. In contrast to the “Galaxy” and “GD,” “Anna” showed higher ethylene production and respiration rates during fruit development, and exhibited auto-stimulatory (system II-like) effect in response to exogenous ethylene. The higher ethylene production rate in “Anna” was correlated with higher expression of ethylene biosynthesis genes, MdACS3a MdACO2, 4, and 7 during early fruit development. The expression of negative regulators of ripening (AP2/ERF) and ethylene response pathway, (MdETR1,2 and MdCTR1) was lower in “Anna” in comparison to the other two cultivars throughout development and ripening. Similar pattern of gene expression was found for SQUAMOSA promoter binding protein (SBP)-box genes, including MdCNR and for MdFUL. Taken together, this study provides new understanding on pre-climacteric events in “Anna” that might affect its ripening behavior and physiology following storage. PMID:28928755

Navigating under sea ice promotes rapid maturation of diving physiology and performance in beluga whales.

PubMed

Noren, Shawn R; Suydam, Robert

2016-09-15

Little is known about the postnatal development of the physiological characteristics that support breath-hold in cetaceans, despite their need to swim and dive at birth. Arctic species have the additional demand of avoiding entrapment while navigating under sea ice, where breathing holes are patchily distributed and ephemeral. This is the first investigation of the ontogeny of the biochemistry of the locomotor muscle in a year-round Arctic-dwelling cetacean (beluga whale, Delphinapterus leucas). Compared with what we know about other cetaceans, belugas are born with high myoglobin content (1.56±0.02 g 100 g -1 wet muscle mass, N=2) that matures rapidly. Myoglobin increased by 452% during the first year after birth and achieved adult levels (6.91±0.35 g 100 g -1 wet muscle mass, N=9) by 14 months postpartum. Buffering capacity was 48.88±0.69 slykes (N=2) at birth; adult levels (84.31±1.38 slykes, N=9) were also achieved by 14 months postpartum. As the oxygen stores matured, calculated aerobic dive limit more than doubled over the first year of life, undoubtedly facilitating the movements of calves under sea ice. Nonetheless, small body size theoretically continues to constrain the diving ability of newly weaned 2 year olds, as they only had 74% and 69% of the aerobic breath-hold capacity of larger adult female and male counterparts. These assessments enhance our knowledge of the biology of cetaceans and provide insight into age-specific flexibility to alter underwater behaviors, as may be required with the ongoing alterations in the Arctic marine ecosystem associated with climate change and increased anthropogenic activities. © 2016. Published by The Company of Biologists Ltd.

Altered serotonin physiology in human breast cancers favors paradoxical growth and cell survival

PubMed Central

2009-01-01

Introduction The breast microenvironment can either retard or accelerate the events associated with progression of latent cancers. However, the actions of local physiological mediators in the context of breast cancers are poorly understood. Serotonin (5-HT) is a critical local regulator of epithelial homeostasis in the breast and other organs. Herein, we report complex alterations in the intrinsic mammary gland serotonin system of human breast cancers. Methods Serotonin biosynthetic capacity was analyzed in human breast tumor tissue microarrays using immunohistochemistry for tryptophan hydroxylase 1 (TPH1). Serotonin receptors (5-HT1-7) were analyzed in human breast tumors using the Oncomine database. Serotonin receptor expression, signal transduction, and 5-HT effects on breast cancer cell phenotype were compared in non-transformed and transformed human breast cells. Results In the context of the normal mammary gland, 5-HT acts as a physiological regulator of lactation and involution, in part by favoring growth arrest and cell death. This tightly regulated 5-HT system is subverted in multiple ways in human breast cancers. Specifically, TPH1 expression undergoes a non-linear change during progression, with increased expression during malignant progression. Correspondingly, the tightly regulated pattern of 5-HT receptors becomes dysregulated in human breast cancer cells, resulting in both ectopic expression of some isoforms and suppression of others. The receptor expression change is accompanied by altered downstream signaling of 5-HT receptors in human breast cancer cells, resulting in resistance to 5-HT-induced apoptosis, and stimulated proliferation. Conclusions Our data constitutes the first report of direct involvement of 5-HT in human breast cancer. Increased 5-HT biosynthetic capacity accompanied by multiple changes in 5-HT receptor expression and signaling favor malignant progression of human breast cancer cells (for example, stimulated proliferation, inappropriate cell survival). This occurs through uncoupling of serotonin from the homeostatic regulatory mechanisms of the normal mammary epithelium. The findings open a new avenue for identification of diagnostic and prognostic markers, and valuable new therapeutic targets for managing breast cancer. PMID:19903352

Genetic Influences on Physiological and Subjective Responses to an Aerobic Exercise Session among Sedentary Adults

PubMed Central

Karoly, Hollis C.; Stevens, Courtney J.; Magnan, Renee E.; Harlaar, Nicole; Hutchison, Kent E.; Bryan, Angela D.

2012-01-01

Objective. To determine whether genetic variants suggested by the literature to be associated with physiology and fitness phenotypes predicted differential physiological and subjective responses to a bout of aerobic exercise among inactive but otherwise healthy adults. Method. Participants completed a 30-minute submaximal aerobic exercise session. Measures of physiological and subjective responding were taken before, during, and after exercise. 14 single nucleotide polymorphisms (SNPs) that have been previously associated with various exercise phenotypes were tested for associations with physiological and subjective response to exercise phenotypes. Results. We found that two SNPs in the FTO gene (rs8044769 and rs3751812) were related to positive affect change during exercise. Two SNPs in the CREB1 gene (rs2253206 and 2360969) were related to change in temperature during exercise and with maximal oxygen capacity (VO2 max). The SLIT2 SNP rs1379659 and the FAM5C SNP rs1935881 were associated with norepinephrine change during exercise. Finally, the OPRM1 SNP rs1799971 was related to changes in norepinephrine, lactate, and rate of perceived exertion (RPE) during exercise. Conclusion. Genetic factors influence both physiological and subjective responses to exercise. A better understanding of genetic factors underlying physiological and subjective responses to aerobic exercise has implications for development and potential tailoring of exercise interventions. PMID:22899923

Low birth weight is associated with adiposity, impaired skeletal muscle energetics, and weight loss resistance in mice

PubMed Central

Beauchamp, Brittany; Ghosh, Sujoy; Dysart, Michael; Kanaan, Georges N.; Chu, Alphonse; Blais, Alexandre; Rajamanickam, Karunanithi; Tsai, Eve C.; Patti, Mary-Elizabeth; Harper, Mary-Ellen

2014-01-01

Background In utero undernutrition is associated with obesity and insulin resistance, although its effects on skeletal muscle remain poorly defined. Therefore, in the current study we explored the effects of in utero food restriction on muscle energy metabolism in mice. Methods We used an experimental mouse model system of maternal undernutrition during late pregnancy to examine offspring from undernourished dams (U) and control offspring from ad libitum fed dams (C). Weight loss of 10 wk old offspring on a 4 wk 40% calorie restricted diet was also followed. Experimental approaches included bioenergetic analyses in isolated mitochondria, intact (permeabilized) muscle and at the whole body level. Results U have increased adiposity and decreased glucose tolerance compared to C. Strikingly, when U are put on a 40% calorie restricted diet they lose half as much weight as calorie restricted controls. Mitochondria from muscle overall from U had decreased coupled (state 3) and uncoupled (state 4) respiration and increased maximal respiration compared to C. Mitochondrial yield was lower in U than C. In permeabilized fiber preparations from mixed fiber type muscle U had decreased mitochondrial content and decreased adenylate free leak respiration, fatty acid oxidative capacity, and state 3 respiratory capacity through complex I. Fiber maximal oxidative phosphorylation capacity did not differ between U and C but was decreased with calorie restriction. Conclusions Our results reveal that in utero undernutrition alters metabolic physiology through a profound effect on skeletal muscle energetics and blunts response to a hypocaloric diet in adulthood. We propose that mitochondrial dysfunction links undernutrition in utero with metabolic disease in adulthood. PMID:25091727

Stratification of pediatric heart failure on the basis of neurohormonal and cardiac autonomic nervous activities in patients with congenital heart disease.

PubMed

Ohuchi, Hideo; Takasugi, Hisashi; Ohashi, Hiroyuki; Okada, Yoko; Yamada, Osamu; Ono, Yasuo; Yagihara, Toshikatsu; Echigo, Shigeyuki

2003-11-11

Stratification of pediatric patients with congenital heart disease (CHD) has been based on their hemodynamics and/or functional capacity. Our purpose was to compare cardiac autonomic nervous activity (CANA) and neurohormonal activities (NHA) with postoperative status in stable CHD patients with biventricular physiology. We divided 379 subjects (297 CHD patients, 28 dilated cardiomyopathy patient, and 54 control subjects) into 4 subgroups according to New York Heart Association (NYHA) class (1.3+/-0.7) and measured various CANA and NHA indices. Stepwise decreases in baroreflex sensitivity (BRS), heart rate variability (HRV), adrenergic imaging, and vital capacity (VC) were observed in proportion to functional capacity in normal to NYHA II patients (P<0.001). However, there were no differences in these indices between NYHA II and III+IV groups, whereas a stepwise proportional increase in NHA indices was observed in these groups (P<0.001). Natriuretic peptides differentiated all NYHA classes. BRS, HRV, and VC were greater in the adult patients than in the child patients (P<0.05 to 0.01), although the functional class in adult patients was lower. Cardiac surgeries resulted in low BRS and VC, and the VC reduction independently determined a small HRV. Even if functional class and ejection fraction were comparable, CANA and brain natriuretic peptide were lower in CHD patients than in dilated cardiomyopathy patients (P<0.05 to 0.001). CANA and NHA indices are useful to stratify mild and severe heart failure in stable postoperative CHD patients, respectively. However, careful attention should be paid to age- and surgery-related influences on these indices.

Comparison of Mitochondrial Reactive Oxygen Species Production of Ectothermic and Endothermic Fish Muscle

PubMed Central

Wiens, Lilian; Banh, Sheena; Sotiri, Emianka; Jastroch, Martin; Block, Barbara A.; Brand, Martin D.; Treberg, Jason R.

2017-01-01

Recently we demonstrated that the capacity of isolated muscle mitochondria to produce reactive oxygen species, measured as H2O2 efflux, is temperature-sensitive in isolated muscle mitochondria of ectothermic fish and the rat, a representative endothermic mammal. However, at physiological temperatures (15° and 37°C for the fish and rat, respectively), the fraction of total mitochondrial electron flux that generated H2O2, the fractional electron leak (FEL), was far lower in the rat than in fish. Those results suggested that the elevated body temperatures associated with endothermy may lead to a compensatory decrease in mitochondrial ROS production relative to respiratory capacity. To test this hypothesis we compare slow twitch (red) muscle mitochondria from the endothermic Pacific bluefin tuna (Thunnus orientalis) with mitochondria from three ectothermic fishes [rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio), and the lake sturgeon (Acipenser fulvescens)] and the rat. At a common assay temperature (25°C) rates of mitochondrial respiration and H2O2 efflux were similar in tuna and the other fishes. The thermal sensitivity of fish mitochondria was similar irrespective of ectothermy or endothermy. Comparing tuna to the rat at a common temperature, respiration rates were similar, or lower depending on mitochondrial substrates. FEL was not different across fish species at a common assay temperature (25°C) but was markedly higher in fishes than in rat. Overall, endothermy and warming of Pacific Bluefin tuna red muscle may increase the potential for ROS production by muscle mitochondria but the evolution of endothermy in this species is not necessarily associated with a compensatory reduction of ROS production relative to the respiratory capacity of mitochondria. PMID:28966595

Stabilizing sodium hypochlorite at high pH: effects on soft tissue and dentin.

PubMed

Jungbluth, Holger; Marending, Monika; De-Deus, Gustavo; Sener, Beatrice; Zehnder, Matthias

2011-05-01

When sodium hypochlorite solutions react with tissue, their pH drops and tissue sorption decreases. We studied whether stabilizing a NaOCl solution at a high pH would increase its soft-tissue dissolution capacity and effects on the dentin matrix compared with a standard NaOCl solution of the same concentration and similar initial pH. NaOCl solutions were prepared by mixing (1:1) a 10% stock solution with water (standard) or 2 mol/L NaOH (stabilized). Physiological saline and 1 mol/L NaOH served as the controls. Chlorine content and alkaline capacity of NaOCl solutions were determined. Standardized porcine palatal soft-tissue specimens and human root dentin bars were exposed to test and control solutions. Weight loss percentage was assessed in the soft-tissue dissolution assay. Three-point bending tests were performed on the root dentin bars to determine the modulus of elasticity and flexural strength. Values between groups were compared using one-way analysis of variance with the Bonferroni correction for multiple testing (α < .05). Both solutions contained 5% NaOCl. One milliliter of the standard and the stabilized solution consumed 4.0 mL and 13.7 mL of a 0.1-mol/L HCl solution before they reached a pH level of 7.5, respectively. The stabilized NaOCl dissolved significantly more soft tissue than the standard solution, and the pH remained high. It also caused a higher loss in elastic modulus and flexure strength (P < .05) than the control solutions, whereas the standard solution did not. NaOH-stabilized NaOCl solutions have a higher alkaline capacity and are thus more proteolytic than standard counterparts. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Unaltered radial maze performance and brain acetylcholine of the endothelial nitric oxide synthase knockout mouse.

PubMed

Dere, E; Frisch, C; De Souza Silva, M A; Gödecke, A; Schrader, J; Huston, J P

2001-01-01

Proceeding from previous findings of a beneficial effect of endothelial nitric oxide synthase (eNOS) gene inactivation on negatively reinforced water maze performance, we asked whether this improvement in place learning capacities also holds for a positively reinforced radial maze task. Unlike its beneficial effects on the water maze task, eNOS gene inactivation did not facilitate radial maze performance. The acquisition performance over the days of place learning did not differ between eNOS knockout (eNOS-/-) and wild-type mice (eNOS+/+). eNOS-/- mice displayed a slight and eNOS+/+ mice a more severe working memory deficit in the place learning version of the radial maze compared to the genetic background C57BL/6 strain. Possible differential effects of eNOS inactivation, related to differences in reinforcement contingencies between the Morris water maze and radial maze tasks, behavioral strategy requirements, or to different emotional and physiological concomitants inherent in the two tasks are discussed. These task-unique characteristics might be differentially affected by the reported anxiogenic and hypertensional effects of eNOS gene inactivation. Post-mortem determination of acetylcholine concentrations in diverse brain structures revealed that acetylcholine and choline contents were not different between eNOS-/- and eNOS+/+ mice, but were increased in eNOS+/+ mice compared to C57BL/6 mice in the frontal cortex. Our findings demonstrate that phenotyping of learning and memory capacities should not rely on one learning task only, but should include tasks employing both negative and positive reinforcement contingencies in order to allow valid statements regarding differences in learning capacities between rodent strains.

The impact of red cabbage fermentation on bioavailability of anthocyanins and antioxidant capacity of human plasma.

PubMed

Wiczkowski, Wieslaw; Szawara-Nowak, Dorota; Romaszko, Jerzy

2016-01-01

The effect of red cabbage fermentation on anthocyanin bioavailability and plasma antioxidant capacity in humans was studied. In a randomized crossover study, 13 volunteers consumed fresh and fermented red cabbage. Blood and urine samples were collected before and after consumption. Analyses of anthocyanins by HPLC-MS/MS and plasma antioxidant capacity by photochemiluminescence assay were conducted. Red cabbage products contained 20 different nonacylated and acylated anthocyanins with the main structure of cyanidin triglucosides. The anthocyanins ingested were present in physiological fluids in form of 18 native anthocyanins and 12 metabolites (methylated, glucuronided, sulfated). Among cyanidin metabolites identified, methylated forms were predominant. Bioavailability of anthocyanin from fresh red cabbage was over 10% higher than from fermented red cabbage. Upon fresh cabbage consumption, volunteers plasma showed higher antioxidant capacity than after fermented cabbage intake. The study has shown that fermentation process affects red cabbage anthocyanins bioavailability and human plasma antioxidant capacity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative Genomics Analysis of Streptococcus Isolates from the Human Small Intestine Reveals their Adaptation to a Highly Dynamic Ecosystem

PubMed Central

Van den Bogert, Bartholomeus; Boekhorst, Jos; Herrmann, Ruth; Smid, Eddy J.; Zoetendal, Erwin G.; Kleerebezem, Michiel

2013-01-01

The human small-intestinal microbiota is characterised by relatively large and dynamic Streptococcus populations. In this study, genome sequences of small-intestinal streptococci from S. mitis, S. bovis, and S. salivarius species-groups were determined and compared with those from 58 Streptococcus strains in public databases. The Streptococcus pangenome consists of 12,403 orthologous groups of which 574 are shared among all sequenced streptococci and are defined as the Streptococcus core genome. Genome mining of the small-intestinal streptococci focused on functions playing an important role in the interaction of these streptococci in the small-intestinal ecosystem, including natural competence and nutrient-transport and metabolism. Analysis of the small-intestinal Streptococcus genomes predicts a high capacity to synthesize amino acids and various vitamins as well as substantial divergence in their carbohydrate transport and metabolic capacities, which is in agreement with observed physiological differences between these Streptococcus strains. Gene-specific PCR-strategies enabled evaluation of conservation of Streptococcus populations in intestinal samples from different human individuals, revealing that the S. salivarius strains were frequently detected in the small-intestine microbiota, supporting the representative value of the genomes provided in this study. Finally, the Streptococcus genomes allow prediction of the effect of dietary substances on Streptococcus population dynamics in the human small-intestine. PMID:24386196

Electroencephalogram, circulation, and lung function after high-velocity behind armor blunt trauma.

PubMed

Drobin, Dan; Gryth, Dan; Persson, Jonas K E; Rocksén, David; Arborelius, Ulf P; Olsson, Lars-Gunnar; Bursell, Jenny; Kjellström, B Thomas

2007-08-01

Behind armor blunt trauma (BABT) is defined as the nonpenetrating injury resulting from a ballistic impact on personal body armor. The protective vest may impede the projectile, but some of the kinetic energy is transferred to the body, causing internal injuries and occasionally death. The aim in this study was to investigate changes in electroencephalogram (EEG) and physiologic parameters after high-velocity BABT. Eight anesthetized pigs, wearing body armor (including a ceramic plate) on the right side of their thorax, were shot with a 7.62-mm assault rifle (velocity approximately 800 m/s). The shots did not penetrate the armor and these animals were compared with control animals (n = 4), shot with blank ammunition. EEG and several physiologic parameters were thereafter monitored during a 2-hour period after the shot. All animals survived during the experimental period. Five of the exposed animals showed a temporary effect on EEG. Furthermore, exposed animals displayed decreased cardiac capacity and an impaired oxygenation of the blood. Postmortem examination revealed subcutaneous hematomas and crush injuries to the right lung. The results in our animal model indicate that high-velocity BABT induce circulatory and respiratory dysfunction, and in some cases even transient cerebral functional disturbances.

Variability in larval gut pH regulation defines sensitivity to ocean acidification in six species of the Ambulacraria superphylum.

PubMed

Hu, Marian; Tseng, Yung-Che; Su, Yi-Hsien; Lein, Etienne; Lee, Hae-Gyeong; Lee, Jay-Ron; Dupont, Sam; Stumpp, Meike

2017-10-11

The unusual rate and extent of environmental changes due to human activities may exceed the capacity of marine organisms to deal with this phenomenon. The identification of physiological systems that set the tolerance limits and their potential for phenotypic buffering in the most vulnerable ontogenetic stages become increasingly important to make large-scale projections. Here, we demonstrate that the differential sensitivity of non-calcifying Ambulacraria (echinoderms and hemichordates) larvae towards simulated ocean acidification is dictated by the physiology of their digestive systems. Gastric pH regulation upon experimental ocean acidification was compared in six species of the superphylum Ambulacraria. We observed a strong correlation between sensitivity to ocean acidification and the ability to regulate gut pH. Surprisingly, species with tightly regulated gastric pH were more sensitive to ocean acidification. This study provides evidence that strict maintenance of highly alkaline conditions in the larval gut of Ambulacraria early life stages may dictate their sensitivity to decreases in seawater pH. These findings highlight the importance of identifying and understanding pH regulatory systems in marine larval stages that may contribute to substantial energetic challenges under near-future ocean acidification scenarios. © 2017 The Author(s).

Comparing the Behavioural Effects of Exogenous Growth Hormone and Melatonin in Young and Old Wistar Rats

PubMed Central

Nicolau, Cristina; Gamundí, Antoni; Fiol, Maria A.; Tresguerres, Jesús A. F.; Akaârir, Mourad; Rial, Rubén V.

2016-01-01

Growth hormone (GH) and melatonin are two hormones with quite different physiological effects. Curiously, their secretion shows parallel and severe age-related reductions. This has promoted many reports for studying the therapeutic supplementation of both hormones in an attempt to avoid or delay the physical, physiological, and psychological decay observed in aged humans and in experimental animals. Interestingly, the effects of the external administration of low doses of GH and of melatonin were surprisingly similar, as both hormones caused significant improvements in the functional capabilities of aged subjects. The present report aims at discerning the eventual difference between cognitive and motor effects of the two hormones when administered to young and aged Wistar rats. The effects were tested in the radial maze, a test highly sensitive to the age-related impairments in working memory and also in the rotarod test, for evaluating the motor coordination. The results showed that both hormones caused clear improvements in both tasks. However, while GH improved the cognitive capacity and, most importantly, the physical stamina, the effects of melatonin should be attributed to its antioxidant, anxiolytic, and neuroprotective properties. PMID:28050228

Proteomics of contrasting rice genotypes: Identification of potential targets for raising crops for saline environment.

PubMed

Lakra, Nita; Kaur, Charanpreet; Anwar, Khalid; Singla-Pareek, Sneh Lata; Pareek, Ashwani

2018-05-01

High salinity is one of the major problems in crop productivity, affecting seed germination as well as yield. In order to enhance tolerance of crops towards salinity, it is essential to understand the underlying physiological and molecular mechanisms. In this endeavor, study of contrasting genotypes of the same species differing in their response towards salinity stress can be very useful. In the present study, we have investigated temporal differences in morphological, physiological and proteome profiles of two contrasting genotypes of rice to understand the basis of salt tolerance. When compared to IR64 rice, Pokkali, the salt-tolerant wild genotype, has enhanced capacity to cope with stress, better growth rate and possesses efficient antioxidant system, as well as better photosynthetic machinery. Our proteome studies revealed a higher and an early abundance of proteins involved in stress tolerance and photosynthesis in Pokkali in comparison with IR64, which, in contrast, showed greater changes in metabolic machinery even during early duration of stress. Our findings suggest important differences in physicochemical and proteome profiles of the two genotypes, which may be the basis of observed stress tolerance in the salt-tolerant Pokkali. © 2017 John Wiley & Sons Ltd.

The capacity to maintain ion and water homeostasis underlies interspecific variation in Drosophila cold tolerance

PubMed Central

MacMillan, Heath A.; Andersen, Jonas L.; Davies, Shireen A.; Overgaard, Johannes

2015-01-01

Many insects, including Drosophila, succumb to the physiological effects of chilling at temperatures well above those causing freezing. Low temperature causes a loss of extracellular ion and water homeostasis in such insects, and chill injuries accumulate. Using an integrative and comparative approach, we examined the role of ion and water balance in insect chilling susceptibility/ tolerance. The Malpighian tubules (MT), of chill susceptible Drosophila species lost [Na+] and [K+] selectivity at low temperatures, which contributed to a loss of Na+ and water balance and a deleterious increase in extracellular [K+]. By contrast, the tubules of chill tolerant Drosophila species maintained their MT ion selectivity, maintained stable extracellular ion concentrations, and thereby avoided injury. The most tolerant species were able to modulate ion balance while in a cold-induced coma and this ongoing physiological acclimation process allowed some individuals of the tolerant species to recover from chill coma during low temperature exposure. Accordingly, differences in the ability to maintain homeostatic control of water and ion balance at low temperature may explain large parts of the wide intra- and interspecific variation in insect chilling tolerance. PMID:26678786

Low-Level Laser Therapy (LLLT) in Dystrophin-Deficient Muscle Cells: Effects on Regeneration Capacity, Inflammation Response and Oxidative Stress.

PubMed

Macedo, Aline Barbosa; Moraes, Luis Henrique Rapucci; Mizobuti, Daniela Sayuri; Fogaça, Aline Reis; Moraes, Fernanda Dos Santos Rapucci; Hermes, Tulio de Almeida; Pertille, Adriana; Minatel, Elaine

2015-01-01

The present study evaluated low-level laser therapy (LLLT) effects on some physiological pathways that may lead to muscle damage or regeneration capacity in dystrophin-deficient muscle cells of mdx mice, the experimental model of Duchenne muscular dystrophy (DMD). Primary cultures of mdx skeletal muscle cells were irradiated only one time with laser and analyzed after 24 and 48 hours. The LLLT parameter used was 830 nm wavelengths at 5 J/cm² fluence. The following groups were set up: Ctrl (untreated C57BL/10 primary muscle cells), mdx (untreated mdx primary muscle cells), mdx LA 24 (mdx primary muscle cells - LLLT irradiated and analyzed after 24 h), and mdx LA 48 (mdx primary muscle cells - LLLT irradiated and analyzed after 48 h). The mdx LA 24 and mdx LA 48 groups showed significant increase in cell proliferation, higher diameter in muscle cells and decreased MyoD levels compared to the mdx group. The mdx LA 48 group showed significant increase in Myosin Heavy Chain levels compared to the untreated mdx and mdx LA 24 groups. The mdx LA 24 and mdx LA 48 groups showed significant increase in [Ca2+]i. The mdx group showed significant increase in H2O2 production and 4-HNE levels compared to the Ctrl group and LLLT treatment reduced this increase. GSH levels and GPx, GR and SOD activities increased in the mdx group. Laser treatment reduced the GSH levels and GR and SOD activities in dystrophic muscle cells. The mdx group showed significant increase in the TNF-α and NF-κB levels, which in turn was reduced by the LLLT treatment. Together, these results suggest that the laser treatment improved regenerative capacity and decreased inflammatory response and oxidative stress in dystrophic muscle cells, indicating that LLLT could be a helpful alternative therapy to be associated with other treatment for dystrophinopathies.

Comparison of structured and unstructured physical activity training on predicted VO2max and heart rate variability in adolescents - a randomized control trial.

PubMed

Sharma, Vivek Kumar; Subramanian, Senthil Kumar; Radhakrishnan, Krishnakumar; Rajendran, Rajathi; Ravindran, Balasubramanian Sulur; Arunachalam, Vinayathan

2017-05-01

Physical inactivity contributes to many health issues. The WHO-recommended physical activity for adolescents encompasses aerobic, resistance, and bone strengthening exercises aimed at achieving health-related physical fitness. Heart rate variability (HRV) and maximal aerobic capacity (VO2max) are considered as noninvasive measures of cardiovascular health. The objective of this study is to compare the effect of structured and unstructured physical training on maximal aerobic capacity and HRV among adolescents. We designed a single blinded, parallel, randomized active-controlled trial (Registration No. CTRI/2013/08/003897) to compare the physiological effects of 6 months of globally recommended structured physical activity (SPA), with that of unstructured physical activity (USPA) in healthy school-going adolescents. We recruited 439 healthy student volunteers (boys: 250, girls: 189) in the age group of 12-17 years. Randomization across the groups was done using age and gender stratified randomization method, and the participants were divided into two groups: SPA (n=219, boys: 117, girls: 102) and USPA (n=220, boys: 119, girls: 101). Depending on their training status and gender the participants in both SPA and USPA groups were further subdivided into the following four sub-groups: SPA athlete boys (n=22) and girls (n=17), SPA nonathlete boys (n=95) and girls (n=85), USPA athlete boys (n=23) and girls (n=17), and USPA nonathlete boys (n=96) and girls (n=84). We recorded HRV, body fat%, and VO2 max using Rockport Walk Fitness test before and after the intervention. Maximum aerobic capacity and heart rate variability increased significantly while heart rate, systolic blood pressure, diastolic blood pressure, and body fat percentage decreased significantly after both SPA and USPA intervention. However, the improvement was more in SPA as compared to USPA. SPA is more beneficial for improving cardiorespiratory fitness, HRV, and reducing body fat percentage in terms of magnitude than USPA in adolescent individuals irrespective of their gender and sports activities.

Acute Exercise and Oxidative Stress: CrossFit™ vs. Treadmill Bout

PubMed Central

Kliszczewicz, Brian; Quindry, C. John; Blessing, L. Daniel; Oliver, D. Gretchen; Esco, R. Michael; Taylor, J. Kyle

2015-01-01

CrossFit™, a popular high-intensity training modality, has been the subject of scrutiny, with concerns of elevated risk of injury and health. Despite these concerns empirical evidence regarding physiologic stresses including acute oxidative stress is lacking. Therefore, the purpose of this investigation was to examine the acute redox response to a CrossFit™ bout. Furthermore, these findings were compared to a high-intensity treadmill bout as a point of reference. Ten males 26.4 ± 2.7 yrs having three or more months of CrossFit™ experience participated in the present study. Blood plasma was collected at four time points: Pre-exercise (PRE), immediately-post-exercise (IPE), 1 hr-post (1-HP) and 2 hr-post (2-HP), to examine oxidative damage and antioxidant capacity. Regarding plasma oxidative damage, CrossFit™ and Treadmill elicited a time-dependent increase of lipid peroxides 1-HP (CrossFit™=+143%, Treadmill=+115%) and 2-HP (CrossFit™=+256%, Treadmill+167%). Protein Carbonyls were increased IPE in CF only (+5%), while a time-dependent decrease occurred 1-HP (CrossFit™=−16%, Treadmill=−8%) and 2-HP (CF=−16%, TM=−1%) compared to IPE. Regarding antioxidant capacity, Ferric Reducing Antioxidant Power also demonstrated a time-dependent increase within CrossFit™ and Treadmill: IPE (CrossFit™=+25%, Treadmill=+17%), 1-HP (CrossFit™=+26%, Treadmill=+4.8%), 2-HP (CrossFit™=+20%, Treadmill=+12%). Total Enzymatic Antioxidant Capacity showed a time-dependent decrease in IPE (CrossFit™=−10%, Treadmill=−12%), 1-HP (CrossFit™=−12%, Treadmill=−6%), 2-HP (CrossFit™=−7%, Treadmill=−11%). No trial-dependent differences were observed in any biomarker of oxidative stress. The CrossFit™ bout elicited an acute blood oxidative stress response comparable to a traditional bout of high-intensity treadmill running. Results also confirm that exercise intensity and the time course of exercise recovery influence oxidative responses. PMID:26557192

Acute Exercise and Oxidative Stress: CrossFit(™) vs. Treadmill Bout.

PubMed

Kliszczewicz, Brian; Quindry, C John; Blessing, L Daniel; Oliver, D Gretchen; Esco, R Michael; Taylor, J Kyle

2015-09-29

CrossFit(™), a popular high-intensity training modality, has been the subject of scrutiny, with concerns of elevated risk of injury and health. Despite these concerns empirical evidence regarding physiologic stresses including acute oxidative stress is lacking. Therefore, the purpose of this investigation was to examine the acute redox response to a CrossFit(™) bout. Furthermore, these findings were compared to a high-intensity treadmill bout as a point of reference. Ten males 26.4 ± 2.7 yrs having three or more months of CrossFit(™) experience participated in the present study. Blood plasma was collected at four time points: Pre-exercise (PRE), immediately-post-exercise (IPE), 1 hr-post (1-HP) and 2 hr-post (2-HP), to examine oxidative damage and antioxidant capacity. Regarding plasma oxidative damage, CrossFit(™) and Treadmill elicited a time-dependent increase of lipid peroxides 1-HP (CrossFit(™)=+143%, Treadmill=+115%) and 2-HP (CrossFit(™)=+256%, Treadmill+167%). Protein Carbonyls were increased IPE in CF only (+5%), while a time-dependent decrease occurred 1-HP (CrossFit(™)=-16%, Treadmill=-8%) and 2-HP (CF=-16%, TM=-1%) compared to IPE. Regarding antioxidant capacity, Ferric Reducing Antioxidant Power also demonstrated a time-dependent increase within CrossFit(™) and Treadmill: IPE (CrossFit(™)=+25%, Treadmill=+17%), 1-HP (CrossFit(™)=+26%, Treadmill=+4.8%), 2-HP (CrossFit(™)=+20%, Treadmill=+12%). Total Enzymatic Antioxidant Capacity showed a time-dependent decrease in IPE (CrossFit(™)=-10%, Treadmill=-12%), 1-HP (CrossFit(™)=-12%, Treadmill=-6%), 2-HP (CrossFit(™)=-7%, Treadmill=-11%). No trial-dependent differences were observed in any biomarker of oxidative stress. The CrossFit(™) bout elicited an acute blood oxidative stress response comparable to a traditional bout of high-intensity treadmill running. Results also confirm that exercise intensity and the time course of exercise recovery influence oxidative responses.

Physiologic oxygen concentration enhances the stem-like properties of CD133+ human glioblastoma cells in vitro.

PubMed

McCord, Amy M; Jamal, Muhammad; Shankavaram, Uma T; Shankavarum, Uma T; Lang, Frederick F; Camphausen, Kevin; Tofilon, Philip J

2009-04-01

In vitro investigations of tumor stem-like cells (TSC) isolated from human glioblastoma (GB) surgical specimens have been done primarily at an atmospheric oxygen level of 20%. To determine whether an oxygen level more consistent with in situ conditions affects their stem cell-like characteristics, we compared GB TSCs grown under conditions of 20% and 7% oxygen. Growing CD133(+) cells sorted from three GB neurosphere cultures at 7% O(2) reduced their doubling time and increased the self-renewal potential as reflected by clonogenicity. Furthermore, at 7% oxygen, the cultures exhibited an enhanced capacity to differentiate along both the glial and neuronal pathways. As compared with 20%, growth at 7% oxygen resulted in an increase in the expression levels of the neural stem cell markers CD133 and nestin as well as the stem cell markers Oct4 and Sox2. In addition, whereas hypoxia inducible factor 1alpha was not affected in CD133(+) TSCs grown at 7% O(2), hypoxia-inducible factor 2alpha was expressed at higher levels as compared with 20% oxygen. Gene expression profiles generated by microarray analysis revealed that reducing oxygen level to 7% resulted in the up-regulation and down-regulation of a significant number of genes, with more than 140 being commonly affected among the three CD133(+) cultures. Furthermore, Gene Ontology categories up-regulated at 7% oxygen included those associated with stem cells or GB TSCs. Thus, the data presented indicate that growth at the more physiologically relevant oxygen level of 7% enhances the stem cell-like phenotype of CD133(+) GB cells.

Physiological Characteristics and Production of Folic Acid of Lactobacillus plantarum JA71 Isolated from Jeotgal, a Traditional Korean Fermented Seafood

PubMed Central

Lim, Sang-Dong

2014-01-01

Folic acid, one of the B group of vitamins, is an essential substance for maintaining the functions of the nervous system, and is also known to decrease the level of homocysteine in plasma. Homocysteine influences the lowering of the cognitive function in humans, and especially in elderly people. In order to determine the strains with a strong capacity to produce folic acid, 190 bacteria were isolated from various kinds of jeotgal and chungkuk-jang. In our test experiment, JA71 was found to contain 9.03μg/mL of folic acid after 24 h of incubation in an MRS broth. This showed that JA71 has the highest folic acid production ability compared to the other lactic acid bacteria that were isolated. JA71 was identified as Lactobacillus plantarum by the result of API carbohydrate fermentation pattern and 16s rDNA sequence. JA71 was investigated for its physiological characteristics. The optimum growth temperature of JA71 was 37℃, and the cultures took 12 h to reach pH 4.4. JA71 proved more sensitive to bacitracin when compared with fifteen different antibiotics, and showed most resistance to neomycin and vancomycin. Moreover, it was comparatively tolerant of bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus with restraint rates of 60.4%, 96.7%, and 76.2%, respectively. These results demonstrate that JA71 could be an excellent strain for application to functional products. PMID:26760752

Physiological plasticity, long term resistance or acclimation to temperature, in the Antarctic bivalve, Laternula elliptica.

PubMed

Morley, Simon A; Hirse, Timo; Thorne, Michael A S; Pörtner, Hans O; Peck, Lloyd S

2012-05-01

To further investigate the previously reported limited acclimation capacities of Antarctic marine stenotherms, the Antarctic mud clam, Laternula elliptica (King and Broderip, 1830-1831), was incubated at 3.0°C for 89days. The thermal windows of a suite of biochemical and physiological metrics that characterise tissue aerobic status, were then measured in response to acute temperature elevation (2-2.5°C increase per week). To test if acclimation had occurred at the higher temperature, results were compared with published data, from the preceding year, for L. elliptica which had been incubated at ambient temperature (0.0°C) and then subjected to the same acute temperature treatments. Incubation to 3.0°C led to a temperature induced increase of tissue aerobic status (reduced intracellular cCO(2) with increased O(2) consumption, PLA (phospho-L-arginine) and ATP). At the highest acute temperature (7.5°C) the increase in anaerobic pathways (summed acetate/succinate and propionate) was less after 3.0°C than 0.0°C incubation. No other metric shifted its reaction norm in response to acute temperature elevation and so whole animal acclimation had not occurred, even after 3months at 3.0°C. Combined with the constant mortality throughout the 3.0°C incubation period, these data suggest that the recorded physiological changes were either the early stages of acclimation or, more likely, time limited resistance mechanisms. Copyright © 2012 Elsevier Inc. All rights reserved.

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.

The role of stochastic thermal environments in modulating the thermal physiology of an intertidal limpet, Lottia digitalis.

PubMed

Drake, Madeline J; Miller, Nathan A; Todgham, Anne E

2017-09-01

Much of our understanding of the thermal physiology of intertidal organisms comes from experiments with animals acclimated under constant conditions and exposed to a single heat stress. In nature, however, the thermal environment is more complex. Aerial exposure and the unpredictable nature of thermal stress during low tides may be critical factors in defining the thermal physiology of intertidal organisms. In the fingered limpet, Lottia digitalis , we investigated whether upper temperature tolerance and thermal sensitivity were influenced by the pattern of fluctuation with which thermal stress was applied. Specifically, we examined whether there was a differential response (measured as cardiac performance) to repeated heat stress of a constant and predictable magnitude compared with heat stress applied in a stochastic and unpredictable nature. We also investigated differences in cellular metabolism and damage following immersion for insights into biochemical mechanisms of tolerance. Upper temperature tolerance increased with aerial exposure, but no significant differences were found between predictable treatments of varying magnitudes (13°C versus 24°C versus 32°C). Significant differences in thermal tolerance were found between unpredictable trials with different heating patterns. There were no significant differences among treatments in basal citrate synthase activity, glycogen content, oxidative stress or antioxidants. Our results suggest that aerial exposure and recent thermal history, paired with relief from high low-tide temperatures, are important factors modulating the capacity of limpets to deal with thermal stress. © 2017. Published by The Company of Biologists Ltd.

Identification of proteins involved in desiccation tolerance in the red seaweed Pyropia orbicularis (Rhodophyta, Bangiales).

PubMed

López-Cristoffanini, Camilo; Zapata, Javier; Gaillard, Fanny; Potin, Philippe; Correa, Juan A; Contreras-Porcia, Loretto

2015-12-01

Extreme reduction in cellular water content leads to desiccation, which, if persistent, affects the physiology of organisms, mainly through oxidative stress. Some organisms are highly tolerant to desiccation, including resurrection plants and certain intertidal seaweeds. One such species is Pyropia orbicularis, a rhodophycean that colonizes upper intertidal zones along the Chilean coast. Despite long, daily periods of air exposure due to tides, this alga is highly tolerant to desiccation. The present study examined the proteome of P. orbicularis by 2DE and LC-MS/MS analyses to determine the proteins associated with desiccation tolerance (DT). The results showed that, under natural conditions, there were significant changes in the protein profile during low tide as compared to naturally hydrated plants at high tide. These changes were mainly in newly appeared proteins spots such as chaperones, monodehydroascorbate reductase, and manganese superoxide dismutase, among others. Previously undescribed proteins under desiccation conditions included phycobiliproteins, glyoxalase I, and phosphomannomutase. These changes evidenced that several physiological responses involved in DT are activated during low tide, including decreased photosynthetic activity, increased antioxidant capacity, and the preservation of cell physiology by regulating water content, cell wall structure, and cell volume. Similar responses have been observed in resurrection plants and bryophytes exposed to desiccation. Therefore, the coordinated activation of different desiccation tolerance pathways in P. orbicularis could explain the successful biological performance of this seaweed in the upper intertidal rocky zones. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Locomotion in response to shifting climate zones: not so fast.

PubMed

Feder, Martin E; Garland, Theodore; Marden, James H; Zera, Anthony J

2010-01-01

Although a species' locomotor capacity is suggestive of its ability to escape global climate change, such a suggestion is not necessarily straightforward. Species vary substantially in locomotor capacity, both ontogenetically and within/among populations, and much of this variation has a genetic basis. Accordingly, locomotor capacity can and does evolve rapidly, as selection experiments demonstrate. Importantly, even though this evolution of locomotor capacity may be rapid enough to escape changing climate, genetic correlations among traits (often due to pleiotropy) are such that successful or rapid dispersers are often limited in colonization or reproductive ability, which may be viewed as a trade-off. The nuanced assessment of this variation and evolution is reviewed for well-studied models: salmon, flying versus flightless insects, rodents undergoing experimental evolution, and metapopulations of butterflies. This work reveals how integration of physiology with population biology and functional genomics can be especially informative.

Applied physiology of marathon running.

PubMed

Sjödin, B; Svedenhag, J

1985-01-01

Performance in marathon running is influenced by a variety of factors, most of which are of a physiological nature. Accordingly, the marathon runner must rely to a large extent on a high aerobic capacity. But great variations in maximal oxygen uptake (VO2 max) have been observed among runners with a similar performance capacity, indicating complementary factors are of importance for performance. The oxygen cost of running or the running economy (expressed, e.g. as VO2 15 at 15 km/h) as well as the fractional utilisation of VO2 max at marathon race pace (%VO2 Ma X VO2 max-1) [where Ma = mean marathon velocity] are additional factors which are known to affect the performance capacity. Together VO2 max, VO2 15 and %VO2 Ma X VO2 max-1 can almost entirely explain the variation in marathon performance. To a similar degree, these variables have also been found to explain the variations in the 'anaerobic threshold'. This factor, which is closely related to the metabolic response to increasing exercise intensities, is the single variable that has the highest predictive power for marathon performance. But a major limiting factor to marathon performance is probably the choice of fuels for the exercising muscles, which factor is related to the %VO2 Ma X VO2 max-1. Present indications are that marathon runners, compared with normal individuals, have a higher turnover rate in fat metabolism at given high exercise intensities expressed both in absolute (m/sec) and relative (%VO2 max) terms. The selection of fat for oxidation by the muscles is important since the stores of the most efficient fuel, the carbohydrates, are limited. The large amount of endurance training done by marathon runners is probably responsible for similar metabolic adaptations, which contribute to a delayed onset of fatigue and raise the VO2 Ma X VO2max-1. There is probably an upper limit in training kilometrage above which there are no improvements in the fractional utilisation of VO2 max at the marathon race pace. The influence of training on VO2 max and, to some extent, on the running economy appears, however, to be limited by genetic factors.

Physiological differences in professional basketball players as a function of playing position and level of play.

PubMed

Sallet, P; Perrier, D; Ferret, J M; Vitelli, V; Baverel, G

2005-09-01

The aim of this investigation is to evaluate the physical and physiological characteristics of different first (ProA) and second division (ProB) professional basketball players, and to relate them to playing position and level of play. A total of 58 players were divided into ProA and ProB groups and were assessed for physical characteristics, maximal treadmill test and a 30 s all-out test. The sample included 22 centers, 22 forwards and 14 guards. Centers were significantly taller and heavier (203.9+/-5.3 cm and 103.9+/-12.4 kg) than forwards (195.8+/-4.8 cm and 89.4+/-7.1 kg) and guards (185.7+/-6.9 and 82+/-8.8 kg) and also had higher body fat percentages than the other groups. Forwards were also significantly taller than guards. Centers presented a lower maximal aerobic velocity (kmxh-1) than guards (15.5+/-1.2 vs 16.8+/-1.5, P<0.05) on the maximal treadmill test and a lower maximal velocity (rpm) than forwards (156.5+/-18.4 vs 170.3+/-18.3, P<0.05) on the 30 s all-out test. VO2max (mlxmin-1xkg-1) was significantly lower for ProA (53.7+/-6.7) compared to ProB (56.5+/-7.7) players and the fatigue index on the 30 s all-out test was higher for the ProA group (P<0.05). Many physical differences, most notably size, exist between players as a function of their playing position. But these differences have no relationship to the level of play of professional players. General aerobic capacity is fairly homogeneous between playing position and level of play, even if there are observable VO2max differences due to inter-individual profiles. On the other hand, anaerobic capacity seems to be a better predictor of playing level even though it is not clear whether such capacity comes from specific training in ProA, or from an initial selection criteria.

Success stories and emerging themes in conservation physiology.

PubMed

Madliger, Christine L; Cooke, Steven J; Crespi, Erica J; Funk, Jennifer L; Hultine, Kevin R; Hunt, Kathleen E; Rohr, Jason R; Sinclair, Brent J; Suski, Cory D; Willis, Craig K R; Love, Oliver P

2016-01-01

The potential benefits of physiology for conservation are well established and include greater specificity of management techniques, determination of cause-effect relationships, increased sensitivity of health and disturbance monitoring and greater capacity for predicting future change. While descriptions of the specific avenues in which conservation and physiology can be integrated are readily available and important to the continuing expansion of the discipline of 'conservation physiology', to date there has been no assessment of how the field has specifically contributed to conservation success. However, the goal of conservation physiology is to foster conservation solutions and it is therefore important to assess whether physiological approaches contribute to downstream conservation outcomes and management decisions. Here, we present eight areas of conservation concern, ranging from chemical contamination to invasive species to ecotourism, where physiological approaches have led to beneficial changes in human behaviour, management or policy. We also discuss the shared characteristics of these successes, identifying emerging themes in the discipline. Specifically, we conclude that conservation physiology: (i) goes beyond documenting change to provide solutions; (ii) offers a diversity of physiological metrics beyond glucocorticoids (stress hormones); (iii) includes approaches that are transferable among species, locations and times; (iv) simultaneously allows for human use and benefits to wildlife; and (v) is characterized by successes that can be difficult to find in the primary literature. Overall, we submit that the field of conservation physiology has a strong foundation of achievements characterized by a diversity of conservation issues, taxa, physiological traits, ecosystem types and spatial scales. We hope that these concrete successes will encourage the continued evolution and use of physiological tools within conservation-based research and management plans.

Corynebacterium glutamicum for Sustainable Bioproduction: From Metabolic Physiology to Systems Metabolic Engineering.

PubMed

Becker, Judith; Gießelmann, Gideon; Hoffmann, Sarah Lisa; Wittmann, Christoph

Since its discovery 60 years ago, Corynebacterium glutamicum has evolved into a workhorse for industrial biotechnology. Traditionally well known for its remarkable capacity to produce amino acids, this Gram-positive soil bacterium, has become a flexible, efficient production platform for various bulk and fine chemicals, materials, and biofuels. The central turnstile of all these achievements is our excellent understanding of its metabolism and physiology. This knowledge base, together with innovative systems metabolic engineering concepts, which integrate systems and synthetic biology into strain engineering, has upgraded C. glutamicum into one of the most successful industrial microorganisms in the world.

The Role of Vacuolar Malate-Transport Capacity in Crassulacean Acid Metabolism and Nitrate Nutrition. Higher Malate-Transport Capacity in Ice Plant after Crassulacean Acid Metabolism-Induction and in Tobacco under Nitrate Nutrition1

PubMed Central

Lüttge, Ulrich; Pfeifer, Tanja; Fischer-Schliebs, Elke; Ratajczak, Rafael

2000-01-01

Anion uptake by isolated tonoplast vesicles was recorded indirectly via increased H+-transport by H+-pumping of the V-ATPase due to dissipation of the electrical component of the electrochemical proton gradient, ΔμH+, across the membrane. ATP hydrolysis by the V-ATPase was measured simultaneously after the Palmgren test. Normalizing for ATP-hydrolysis and effects of chloride, which was added to the assays as a stimulating effector of the V-ATPase, a parameter, Jmalrel, of apparent ATP-dependent malate-stimulated H+-transport was worked out as an indirect measure of malate transport capacity. This allowed comparison of various species and physiological conditions. Jmalrel was high in the obligate crassulacean acid metabolism (CAM) species Kalanchoë daigremontiana Hamet et Perrier, it increased substantially after CAM induction in ice plant (Mesembryanthemum crystallinum), and it was positively correlated with NO3− nutrition in tobacco (Nicotiana tabacum). For tobacco this was confirmed by measurements of malate transport energized via the V-PPase. In ice plant a new polypeptide of 32-kD apparent molecular mass appeared, and a 33-kD polypeptide showed higher levels after CAM induction under conditions of higher Jmalrel. It is concluded that tonoplast malate transport capacity plays an important role in physiological regulation in CAM and NO3− nutrition and that a putative malate transporter must be within the 32- to 33-kD polypeptide fraction of tonoplast proteins. PMID:11080309

Combined Training Enhances Skeletal Muscle Mitochondrial Oxidative Capacity Independent of Age

PubMed Central

Lanza, Ian R.; Henderson, Gregory C.; Rao, Rajesh R.; Spiegelman, Bruce M.

2015-01-01

Context: Skeletal muscle from sedentary older adults exhibits reduced mitochondrial abundance and oxidative capacity. Objective: The primary objective was to determine whether 8 weeks of combined training (CT) has a more robust effect than endurance training (ET) or resistance training (RT) on mitochondrial physiology in healthy young (18–30 years) and older (≥65 years) adults. Intervention: Thirty-four young and 31 older adults were randomly assigned to 8 weeks of ET, RT, and control/CT. Control subjects completed 8 weeks of no exercise (control) followed by 8 weeks of CT. Body composition, skeletal muscle strength, and peak oxygen uptake were measured before and after the intervention. Vastus lateralis muscle biopsy samples were obtained before and 48 hours after the intervention. Mitochondrial physiology was evaluated by high-resolution respirometry and expression of mitochondrial proteins and transcription factors by quantitative PCR and immunoblotting. Results: ET and CT significantly increased oxidative capacity and expression of mitochondrial proteins and transcription factors. All training modalities improved body composition, cardiorespiratory fitness, and skeletal muscle strength. CT induced the most robust improvements in mitochondria-related outcomes and physical characteristics despite lower training volumes for the ET and RT components. Importantly, most of the adaptations to training occurred independent of age. Conclusion: Collectively, these results demonstrate that both ET and CT increase muscle mitochondrial abundance and capacity although CT induced the most robust improvements in the outcomes measured. In conclusion, CT provides a robust exercise regimen to improve muscle mitochondrial outcomes and physical characteristics independent of age. PMID:25599385

Workplace heat stress, health and productivity - an increasing challenge for low and middle-income countries during climate change.

PubMed

Kjellstrom, Tord; Holmer, Ingvar; Lemke, Bruno

2009-11-11

Global climate change is already increasing the average temperature and direct heat exposure in many places around the world. To assess the potential impact on occupational health and work capacity for people exposed at work to increasing heat due to climate change. A brief review of basic thermal physiology mechanisms, occupational heat exposure guidelines and heat exposure changes in selected cities. In countries with very hot seasons, workers are already affected by working environments hotter than that with which human physiological mechanisms can cope. To protect workers from excessive heat, a number of heat exposure indices have been developed. One that is commonly used in occupational health is the Wet Bulb Globe Temperature (WBGT). We use WBGT to illustrate assessing the proportion of a working hour during which a worker can sustain work and the proportion of that same working hour that (s)he needs to rest to cool the body down and maintain core body temperature below 38 degrees C. Using this proportion a 'work capacity' estimate was calculated for selected heat exposure levels and work intensity levels. The work capacity rapidly reduces as the WBGT exceeds 26-30 degrees C and this can be used to estimate the impact of increasing heat exposure as a result of climate change in tropical countries. One result of climate change is a reduced work capacity in heat-exposed jobs and greater difficulty in achieving economic and social development in the countries affected by this somewhat neglected impact of climate change.

Exercise capacity is associated with endothelin-1 release during emotional excitement in coronary artery disease patients.

PubMed

Tulppo, Mikko P; Piira, Olli-Pekka; Hautala, Arto J; Kiviniemi, Antti M; Miettinen, Johanna A; Huikuri, Heikki V

2014-08-01

Endothelin-1 (ET-1), a potent vasoconstrictor, IL-6, and catecholamines are increased and heart rate variability [SD of normal to normal R-R intervals (SDNN)] decreased during emotional excitement, but individual responses vary. We tested the hypothesis that exercise capacity is associated with physiological responses caused by real-life emotional excitement. We measured the plasma levels of ET-1, IL-6, catecholamines, heart rate, and SDNN in enthusiastic male ice hockey spectators (n = 51; age, 59 ± 9 years) with stable coronary artery disease (CAD) at baseline and during the Finnish National Ice Hockey League's final play-off matches. Maximal exercise capacity (METs) by bicycle exercise test and left ventricular ejection fraction (LVEF) were measured on a separate day. ET-1 response from baseline to emotional excitement correlated with maximal METs (r = -0.30; P = 0.040). In a linear stepwise regression analysis age, body mass index (BMI), METs, LVEF, basal ET-1, and subjective experience of excitement were entered the model as independent variables to explain ET-1 response. This model explained 27% of ET-1 response (P = 0.003). Maximal METs were most strongly correlated with ET-1 response (β = -0.45; partial correlation r = -0.43; P = 0.002), followed by BMI (β = -0.31; partial correlation r = -0.31; P = 0.033) and LVEF (β = -0.30; partial correlation r = -0.33; P = 0.023). Exercise capacity may protect against further cardiovascular events in CAD patients, because it is associated with reduced ET-1 release during emotional excitement. Copyright © 2014 the American Physiological Society.

Antioxidant capacity contributes to protection of ketone bodies against oxidative damage induced during hypoglycemic conditions.

PubMed

Haces, María L; Hernández-Fonseca, Karla; Medina-Campos, Omar N; Montiel, Teresa; Pedraza-Chaverri, José; Massieu, Lourdes

2008-05-01

Ketone bodies play a key role in mammalian energy metabolism during the suckling period. Normally ketone bodies' blood concentration during adulthood is very low, although it can rise during starvation, an exogenous infusion or a ketogenic diet. Whenever ketone bodies' levels increase, their oxidation in the brain rises. For this reason they have been used as protective molecules against refractory epilepsy and in experimental models of ischemia and excitotoxicity. The mechanisms underlying the protective effect of these compounds are not completely understood. Here, we studied a possible antioxidant capacity of ketone bodies and whether it contributes to the protection against oxidative damage induced during hypoglycemia. We report for the first time the scavenging capacity of the ketone bodies, acetoacetate (AcAc) and both the physiological and non-physiological isomers of beta-hydroxybutyrate (D- and L-BHB, respectively), for diverse reactive oxygen species (ROS). Hydroxyl radicals (.OH) were effectively scavenged by D- and L-BHB. In addition, the three ketone bodies were able to reduce cell death and ROS production induced by the glycolysis inhibitor, iodoacetate (IOA), while only D-BHB and AcAc prevented neuronal ATP decline. Finally, in an in vivo model of insulin-induced hypoglycemia, the administration of D- or L-BHB, but not of AcAc, was able to prevent the hypoglycemia-induced increase in lipid peroxidation in the rat hippocampus. Our data suggest that the antioxidant capacity contributes to protection of ketone bodies against oxidative damage in in vitro and in vivo models associated with free radical production and energy impairment.

[Braking capacity after hip arthroplasty - effect of prosthesis design and preoperative status].

PubMed

Franz, A; Mannel, H; Brüggemann, G-P; Schmidt, J

2012-10-01

Driving a car is an important everyday activity. However, the patients' desire to resume driving at an early stage after hip arthroplasty is often faced by the uncertainty about their driving ability. Only little evidence is available to support the clinical decision-making with regard to driving competence after conventional total hip arthroplasty (THA). However, there is no proof that the results observed after THA can be transferred to hip resurfacing arthroplasty (HRA) patients. Due to physiological advantages, i.e., patient age and activity, as well as the special biomechanical implant characteristics, HRA patients could be expected to achieve normal braking capacity at an earlier stage in the rehabilitation process than THA patients. This could be achieved by an accelerated postoperative recovery or could depend on the preoperative vantage point concerning the patients' braking capacity. To verify this hypothesis HRA and THA patients were compared to healthy subjects concerning their ability to perform an emergency braking manoeuvre in a car simulator before surgery, and at 6 weeks and 3 months after operation. Furthermore, postoperative recovery rates were compared between the two groups of patients. In addition, correlations between pre- and postoperative braking capacity were tested. Reaction time, movement time and force-time integral on the brake pedal were analysed. Except for a deficient preoperative force-time integral, no significant differences were detected in HRA patients compared to healthy controls. In contrast THA patients required, pre- as well as postoperatively, a longer movement time and exhibited a smaller force-time integral. The two patient groups did not show any significant difference in recovery rates of movement time and force-time integral. However, considering the two patient groups as a whole, a significant correlation was detected between existing pre- and postoperative deficits. In conclusion, it can be confirmed that HRA patients resume normal braking capacity at an earlier stage in their rehabilitation process than THA patients. Patients recommended for HRA recover braking capacity at the latest six weeks after surgery. This capacity clearly depends on the better preoperative status of the HRA patients and is not determined by a faster recovery rate. General patient-related advantages as well as biomechanical aspects of HRA have thus no influence on the recovery rates of braking capacity during the first three months after surgery. Due to the increasing outpatient rehabilitation regime after HRA, further studies are necessary to detect the turning point after surgical impairment within the first six weeks after surgery. Concerning the THA patients we recommend a longer safety distance when driving a car for up to three months after the operation. However, patients, especially those assigned to THA, should be made aware of their most likely already existing preoperative deficit. For clinical practice a rough estimation of postoperative braking capacity seems to be possible based on group assignment (HRA/THA). Nevertheless, deviators cannot be detected by this group classification. As driving simulator systems usually are not available in hospitals, a more accurate prognosis, i.e., based on established clinical scores, would be helpful. Georg Thieme Verlag KG Stuttgart · New York.

Dissecting Arabidopsis Gβ Signal Transduction on the Protein Surface1[W][OA

PubMed Central

Jiang, Kun; Frick-Cheng, Arwen; Trusov, Yuri; Delgado-Cerezo, Magdalena; Rosenthal, David M.; Lorek, Justine; Panstruga, Ralph; Booker, Fitzgerald L.; Botella, José Ramón; Molina, Antonio; Ort, Donald R.; Jones, Alan M.

2012-01-01

The heterotrimeric G-protein complex provides signal amplification and target specificity. The Arabidopsis (Arabidopsis thaliana) Gβ-subunit of this complex (AGB1) interacts with and modulates the activity of target cytoplasmic proteins. This specificity resides in the structure of the interface between AGB1 and its targets. Important surface residues of AGB1, which were deduced from a comparative evolutionary approach, were mutated to dissect AGB1-dependent physiological functions. Analysis of the capacity of these mutants to complement well-established phenotypes of Gβ-null mutants revealed AGB1 residues critical for specific AGB1-mediated biological processes, including growth architecture, pathogen resistance, stomata-mediated leaf-air gas exchange, and possibly photosynthesis. These findings provide promising new avenues to direct the finely tuned engineering of crop yield and traits. PMID:22570469

D-camphor-crataegus berry extract combination increases blood pressure and cognitive functioning in the elderly - a randomized, placebo controlled double blind study.

PubMed

Werner, Natalie S; Duschek, Stefan; Schandry, Rainer

2009-12-01

The present study investigated whether the D-camphor-crataegus berry extract combination Korodin elevates blood pressure and enhances cognitive performance in the elderly population. Eighty women aged between 50 and 80 years were examined based on a randomized, placebo controlled double blind design. Blood pressure was measured sphygmomanometrically and through continuous noninvasive recording. Cognitive performance was assessed by means of two tests measuring general information processing capacity and visuomotor speed. The administration of the drug led to a short term increase in blood pressure as well as in cognitive performance as compared to placebo. Potential physiological mechanisms of action mediating this effect, including hemodynamic alterations, sympathetic stimulation as well as improvement of cerebral metabolism are discussed.

Passionate men, emotional women: psychology constructs gender difference in the late 19th century.

PubMed

Shields, Stephanie A

2007-05-01

The author examines British and American scientific psychology's portrayal of natural and ideal masculinity and femininity in the late 19th century to show how purported differences in emotion and reason were critical to explaining the evolutionary foundation of existing social hierarchies. Strong emotion was identified with heterosexual manliness and men's purportedly better capacity to harness the power of emotion in the service of reason. "Feminine" emotion was portrayed as a comparatively ineffectual emotionality, a by-product of female reproductive physiology and evolutionary need to be attractive to men. The author argues that constructions of emotion by psychology served an important power maintenance function. A concluding section addresses the relevance of this history to the politics of emotion in everyday life, especially assertions of emotional legitimacy.

Capacity Building: Evidence-Based Practice and Adolescents on the Autism Spectrum

ERIC Educational Resources Information Center

Rue, Hanna C.; Knox, Maria

2013-01-01

Empirical research in the treatment of autism spectrum disorders (ASDs) has resulted in the identification of numerous evidence-based interventions (EBIs). Adolescents with an ASD are faced with unique academic challenges, complex social environments, and physiological changes. They often require interventions to aid in acclimating to their…

Effects of Trail Information on Physical Activity Enjoyment

Treesearch

Erik Rosegard

2004-01-01

Moderate physical activity (PA) improves physical fitness measures (i.e., aerobic capacity, agility, flexibility, body composition, and muscular endurance and strength). In addition to numerous physiological benefits, PA has been shown to increase cognitive and emotional functioning. These benefits lead to improved immune response and have been associated with...

EEG Based Analysis of Cognitive Load Enhance Instructional Analysis

ERIC Educational Resources Information Center

Dan, Alex; Reiner, Miriam

2017-01-01

One of the recommended approaches in instructional design methods is to optimize the value of working memory capacity and avoid cognitive overload. Educational neuroscience offers novel processes and methodologies to analyze cognitive load based on physiological measures. Observing psychophysiological changes when they occur in response to the…

Building Inner Resilience

ERIC Educational Resources Information Center

Lantieri, Linda

2008-01-01

The capacity to be in control of one's thoughts, emotions, and physiology can form an internal safety net preparing children to face the challenges and opportunities of life. This is the goal of the Inner Resilience Program in the New York City Schools. Teachers in the Inner Resilience Program's intervention are exposed to calming and focusing…

AN IN VIVO MICRODIALYSIS METHOD FOR THE QUALITATIVE ANALYSIS OF HEPATIC PHASE I METABOLITES OF PHENOL IN RAINBOW TROUT (ONCORHYNCHUS MYKISS)

EPA Science Inventory

Development of reliable and accurate methodologies for determination of xenobiotic hepatic biotransformation rate and capacity parameters is important to the derivation of precise physiologically-based toxicokinetic (PB-TK) models. Biotransformation data incorporated into PB-TK m...

Physiological Adaptations to Chronic Endurance Exercise Training in Patients with Coronary Artery Disease.

ERIC Educational Resources Information Center

Physician and Sportsmedicine, 1987

1987-01-01

In a roundtable format, five doctors explore the reasons why regular physical activity should continue to play a significant role in the rehabilitation of patients with coronary artery disease. Endurance exercise training improves aerobic capacity, reduces blood pressure, and decreases risk. (Author/MT)

Bacterial protection of beetle-fungus mutualism

Treesearch

Jarrod J. Scott; Dong-Chan Oh; M. Cetin Yuceer; Kier D. Klepzig; Jon Clardy; Cameron R. Currie

2008-01-01

The pervasiveness of beneficial associations between symbiotic microbes and plants and animals in every ecosystem illustrates how the acquisition of a microbe’s physiological capacity confers substantial fitness benefits to hosts (1). However, dependence on mutualistic microbes becomes a liability if antagonistic microbes attack or outcompete beneficial ones (2)....

What Research Tells the Coach About Soccer.

ERIC Educational Resources Information Center

Reilly, Thomas

A complete profile of the average (male) soccer player is established through the study of ten topflight soccer teams in the United States and abroad. Statistical averages for team age, strength and muscular power, body size and composition, agility and flexibility, lung capacity, and various other physical and physiological characteristics are…

Cardiac Rehabilitation. A Handbook for Vocational Rehabilitation Counselors.

ERIC Educational Resources Information Center

Brammell, H. L.; And Others

Basic information about heart disease and functional capacity assessment and its application to activity/job counseling are presented in this handbook for vocational rehabilitation counselors. Sections include the following: impact of heart disease; basic anatomy and physiology (e.g., the heart, pulmonary circulation, causes of cardiac pain, and…

The Female Athlete: Conditioning, Competition, and Culture.

ERIC Educational Resources Information Center

Klafs, Carl E.; Lyon, M. Joan

The female athlete--her structural, physiological, and psychological characteristics and capacities-- is the main focus of this book. It is designed to provide persons in positions of leadership in girls' and women's athletics greater insights and understanding regarding the nature of women athletes and to help structure wholesome sports programs…

Physiological integration modifies δ15N in the clonal plant Fragaria vesca, suggesting preferential transport of nitrogen to water-stressed offspring.

PubMed

Roiloa, S R; Antelo, B; Retuerto, R

2014-08-01

One of the most striking attributes of clonal plants is their capacity for physiological integration, which enables movement of essential resources between connected ramets. This study investigated the capacity of physiological integration to buffer differences in resource availability experienced by ramets of the clonal wild strawberry plant, Fragaria vesca. Specifically, a study was made of the responses of connected and severed offspring ramets growing in environments with different water availability conditions (well watered or water stressed) and nitrogen forms (nitrate or ammonium). The experimental design consisted of three factors, 'integration' (connected, severed) 'water status' (well watered, water stressed) and 'nitrogen form' (nitrate, ammonium), applied in a pot experiment. The effects of physiological integration were studied by analysing photochemical efficiency, leaf spectral reflectance, photosynthesis and carbon and nitrogen isotope discrimination, the last of which has been neglected in previous studies. Physiological integration buffered the stress caused by water deprivation. As a consequence, survival was improved in water-stressed offspring ramets that remained connected to their parent plants. The nitrogen isotope composition (δ(15)N) values in the connected water-stressed ramets were similar to those in ramets in the ammonium treatment; however, δ(15)N values in connected well-watered ramets were similar to those in the nitrate treatment. The results also demonstrated the benefit of integration for offspring ramets in terms of photochemical activity and photosynthesis. This is the first study in which carbon and nitrogen isotopic discrimination has been used to detect physiological integration in clonal plants. The results for nitrogen isotope composition represent the first evidence of preferential transport of a specific form of nitrogen to compensate for stressful conditions experienced by a member clone. Water consumption was lower in plants supplied with ammonium than in plants supplied with nitrate, and therefore preferential transport of ammonium from parents to water-stressed offspring could potentially optimize the water use of the whole clone. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Stress-Induced Tradeoffs in a Free-Living Lizard across a Variable Landscape: Consequences for Individuals and Populations

PubMed Central

Lucas, LeiLani D.; French, Susannah S.

2012-01-01

Current life history theory suggests that the allocation of energetic resources between competing physiological needs should be dictated by an individual’s longevity and pace of life. One key physiological pathway likely to contribute to the partitioning of resources is the vertebrate stress response. By increasing circulating glucocorticoids the stress response can exert a suite of physiological effects, such as altering immune function. We investigated the effects of stress physiology on individual immunity, reproduction and oxidative stress, across an urban landscape. We sampled populations in and around St. George, Utah, examining corticosterone in response to restraint stress, two innate immune measures, reproductive output, and the presence of both reactive oxygen metabolites and antioxidant binding capacity, in populations of common side-blotched lizards (Uta stansburiana) experiencing variable levels of environmental stress. Additionally, using capture-mark-recapture techniques, we examined the relationships between these physiological parameters and population-level differences. Our results reveal elevated physiological stress corresponds with suppressed immunity and increased oxidative stress. Interestingly, urban populations experiencing the most physiological stress also exhibited greater reproductive output and decreased survival relative to rural populations experiencing less physiological stress, demonstrating a tradeoff between reproduction and life maintenance processes. Our results suggest that environmental stress may augment life history strategy in this fast-paced species, and that shifts in life history strategy can in turn affect the population at large. Finally, the urban environment poses definite challenges for organisms, and while it appears that side-blotched lizards are adjusting physiologically, it is unknown what fitness costs these physiological adjustments accrue. PMID:23185478

Physiological and growth responses of Centaurea maculosa (Asteraceae) to root herbivory under varying levels of interspecific plant competition and soil nitrogen availability.

PubMed

Steinger, Thomas; Müller-Schärer, Heinz

1992-08-01

Centaurea maculosa seedlings were grown in pots to study the effects of root herbivory by Agapeta zoegana L. (Lep.: Cochylidae) and Cyphocleonus achates Fahr. (Col.: Curculionidae), grass competition and nitrogen shortage (each present or absent), using a full factorial design. The aims of the study were to analyse the impact of root herbivory on plant growth, resource allocation and physiological processes, and to test if these plant responses to herbivory were influenced by plant competition and nitrogen availability. The two root herbivores differed markedly in their impact on plant growth. While feeding by the moth A. zoegana in the root cortex had no effect on shoot and root mass, feeding by the weevil C. achates in the central vascular tissue greatly reduced shoot mass, but not root mass, leading to a reduced shoot/root ratio. The absence of significant effects of the two herbivores on root biomass, despite considerable consumption, indicates that compensatory root growth occurred. Competition with grass affected plant growth more than herbivory and nutrient status, resulting in reduced shoot and root growth, and number of leaves. Nitrogen shortage did not affect plant growth directly but greatly influenced the compensatory capacity of Centaurea maculosa to root herbivory. Under high nitrogen conditions, shoot biomass of plants infested by the weevil was reduced by 30% compared with uninfested plants. However, under poor nitrogen conditions a 63% reduction was observed compared with corresponding controls. Root herbivory was the most important stress factor affecting plant physiology. Besides a relative increase in biomass allocation to the roots, infested plants also showed a significant increase in nitrogen concentration in the roots and a concomitant reduction in leaf nitrogen concentration, reflecting a redirection of the nitrogen to the stronger sink. The level of fructans was greatly reduced in the roots after herbivore feeding. This is thought to be a consequence of their mobilisation to support compensatory root growth. A preliminary model linking the effects of these root herbivores to the physiological processes of C. maculosa is presented.

Impact of heat stress and hypercapnia on physiological, hematological, and behavioral profile of Tharparkar and Karan Fries heifers

PubMed Central

Pandey, Priyanka; Hooda, O. K.; Kumar, Sunil

2017-01-01

Aim: The present investigation was undertaken to study the impact of heat stress and hypercapnia on physiological, hematological, and behavioral profile of Tharparkar and Karan Fries (KF) heifers. Materials and Methods: The animals of both the breeds of Tharparkar and KF were exposed at different temperatures and CO2 levels. Exposure conditions of 25°C, 400 ppm CO2 level, and 60% relative humidity (RH) were taken as a control condition. The exposure conditions 40°C with two levels of CO2 500 ppm and 600 ppm with RH 55±5% and exposure conditions 42°C with two levels of CO2 500 ppm and 600 ppm with RH 55±5% were taken as treatments. The exposure period in each condition was 4 h daily for 5 consecutive days. Results: Physiological responses (respiration rate [RR], pulse rate [PR], and rectal temperature [RT]) were significantly (p<0.01) higher and different during all exposure conditions compared to control condition in both the breeds of cattle. KF heifers had higher RR, PR, and RT than Tharparkar heifers. Hematological parameters, namely, red blood cell, hemoglobin, and packed cell volume were significantly higher and different during all exposure condition than control in both the breeds, whereas no significant changes were observed in total leukocyte count and differential leukocyte count. Blood pH increased with increase in temperature and CO2 levels and was significantly higher than control conditions. PCO2 and base excess were significantly (p<0.05) lower, and PO2 was higher during different exposure conditions than control in both breeds. Restlessness and excitement signs were observed in all the exposure conditions as compared to control condition in both the breeds. Conclusion: Changes in physiological responses, behavioral pattern, and hematological parameters reflect the current functional status of the body system, and it can be used as an index for assessing the adaptation capacity of cattle to predict changes occurring in climate variables due to increasing CO2 levels and environmental temperature. PMID:29062208

Jatropha curcas and assisted phytoremediation of a mine tailing with biochar and a mycorrhizal fungus.

PubMed

González-Chávez, Ma Del Carmen A; Carrillo-González, Rogelio; Hernández Godínez, María Isabel; Evangelista Lozano, Silvia

2017-02-01

Soil pollution is an important ecological problem worldwide. Phytoremediation is an environmental-friendly option for reducing metal pollution. A greenhouse experiment was conducted to determine the growth and physiological response, metal uptake, and the phytostabilization potential of a nontoxic Jatropha curcas L. genotype when grown in multimetal-polluted conditions. Plants were established on a mine residue (MR) amended or not amended with corn biochar (B) and inoculated or not inoculated with the mycorrhizal fungus Acaulospora sp. (arbuscular mycorrhizal fungus, AMF). J. curcas was highly capable of growing in an MR and showed no phytotoxic symptoms. After J. curcas growth (105 days), B produced high desorption of Cd and Pb from the MR; however, no increases in metal shoot concentrations were observed. Therefore, Jatropha may be useful for phytostabilization of metals in mine tailings. The use of B is recommended because improved MR chemical properties conduced to plant growth (cation-exchange capacity, organic matter content, essential nutrients, electrical conductivity, water-holding capacity) and plant growth development (higher biomass, nutritional and physiological performance). Inoculation with an AMF did not improve any plant growth or physiological plant characteristic. Only higher Zn shoot concentration was observed, but it was not phytotoxic. Future studies of B use and its long-term effect on MR remediation should be conducted under field conditions.

A systematic review of the effects of different types of therapeutic exercise on physiologic and functional measurements in patients with HIV/AIDS

PubMed Central

Gomes-Neto, Mansueto; Conceição, Cristiano Sena; Carvalho, Vitor Oliveira; Brites, Carlos

2013-01-01

Several studies have reported the benefits of exercise training for adults with HIV, although there is no consensus regarding the most efficient modalities. The aim of this study was to determine the effects of different types of exercise on physiologic and functional measurements in patients with HIV using a systematic strategy for searching randomized controlled trials. The sources used in this review were the Cochrane Library, EMBASE, MEDLINE, and PEDro from 1950 to August 2012. We selected randomized controlled trials examining the effects of exercise on body composition, muscle strength, aerobic capacity, and/or quality of life in adults with HIV. Two independent reviewers screened the abstracts using the Cochrane Collaboration's protocol. The PEDro score was used to evaluate methodological quality. In total, 29 studies fulfilled the inclusion criteria. Individual studies suggested that exercise training contributed to improvement of physiologic and functional parameters, but that the gains were specific to the type of exercise performed. Resistance exercise training improved outcomes related to body composition and muscle strength, with little impact on quality of life. Aerobic exercise training improved body composition and aerobic capacity. Concurrent training produced significant gains in all outcomes evaluated, although moderate intensity and a long duration were necessary. We concluded that exercise training was shown to be a safe and beneficial intervention in the treatment of patients with HIV. PMID:24037014

Brettanomyces bruxellensis evolution and volatile phenols production in red wines during storage in bottles.

PubMed

Coulon, J; Perello, M C; Lonvaud-Funel, A; de Revel, G; Renouf, V

2010-04-01

The presence of Brettanomyces bruxellensis is an important issue during winemaking because of its volatile phenols production capacities. The aim of this study is to provide information on the ability of residual B. bruxellensis populations to multiply and spoil finished wines during storage in bottles. Several finished wines were studied. Brettanomyces bruxellensis populations were monitored during two and a half months, and volatile phenols as well as chemical parameters regularly determined. Variable growth and volatile phenols synthesis capacities were evidenced, in particularly when cells are in a noncultivable state. In addition, the volatile phenol production was clearly shown to be a two-step procedure that could strongly be correlated to the physiological state of the yeast population. This study underlines the importance of minimizing B. bruxellensis populations at the end of wine ageing to reduce volatile phenols production risk once the wine in bottle. Moreover, the physiological state of the yeast seems to have an important impact on ethyl-phenols production, hence demonstrating the importance of taking into account this parameter when analysing wine spoilage risks. Little data exist about the survival of B. bruxellensis once the wine in bottle. This study provides information on the alteration risks encountered during wine storage in bottle and reveals the importance of carrying on further studies to increase the knowledge on B. bruxellensis physiology.

Physiological acclimation dampens initial effects of elevated temperature and atmospheric CO2 concentration in mature boreal Norway spruce.

PubMed

Lamba, Shubhangi; Hall, Marianne; Räntfors, Mats; Chaudhary, Nitin; Linder, Sune; Way, Danielle; Uddling, Johan; Wallin, Göran

2018-02-01

Physiological processes of terrestrial plants regulate the land-atmosphere exchange of carbon, water, and energy, yet few studies have explored the acclimation responses of mature boreal conifer trees to climate change. Here we explored the acclimation responses of photosynthesis, respiration, and stomatal conductance to elevated temperature and/or CO 2 concentration ([CO 2 ]) in a 3-year field experiment with mature boreal Norway spruce. We found that elevated [CO 2 ] decreased photosynthetic carboxylation capacity (-23% at 25 °C) and increased shoot respiration (+64% at 15 °C), while warming had no significant effects. Shoot respiration, but not photosynthetic capacity, exhibited seasonal acclimation. Stomatal conductance at light saturation and a vapour pressure deficit of 1 kPa was unaffected by elevated [CO 2 ] but significantly decreased (-27%) by warming, and the ratio of intercellular to ambient [CO 2 ] was enhanced (+17%) by elevated [CO 2 ] and decreased (-12%) by warming. Many of these responses differ from those typically observed in temperate tree species. Our results show that long-term physiological acclimation dampens the initial stimulation of plant net carbon assimilation to elevated [CO 2 ], and of plant water use to warming. Models that do not account for these responses may thus overestimate the impacts of climate change on future boreal vegetation-atmosphere interactions. © 2017 John Wiley & Sons Ltd.

Distinct physiological and metabolic reprogramming by highbush blueberry (Vaccinium corymbosum) cultivars revealed during long-term UV-B radiation.

PubMed

Luengo Escobar, Ana; Alberdi, Miren; Acevedo, Patricio; Machado, Mariana; Nunes-Nesi, Adriano; Inostroza-Blancheteau, Claudio; Reyes-Díaz, Marjorie

2017-05-01

Despite the Montreal protocol and the eventual recovery of the ozone layer over Antarctica, there are still concerns about increased levels of ultraviolet-B (UV-B) radiation in the Southern Hemisphere. UV-B induces physiological, biochemical and morphological stress responses in plants, which are species-specific and different even for closely related cultivars. In woody plant species, understanding of long-term mechanisms to cope with UV-B-induced stress is limited. Therefore, a greenhouse UV-B daily course simulation was performed for 21 days with two blueberry cultivars (Legacy and Bluegold) under UV-B BE irradiance doses of 0, 0.07 and 0.19 W m -2 . Morphological changes, photosynthetic performance, antioxidants, lipid peroxidation and metabolic features were evaluated. We found that both cultivars behaved differently under UV-B exposure, with Legacy being a UV-B-resistant cultivar. Interestingly, Legacy used a combined strategy: initially, in the first week of exposure its photoprotective compounds increased, coping with the intake of UV-B radiation (avoidance strategy), and then, increasing its antioxidant capacity. These strategies proved to be UV-B radiation dose dependent. The avoidance strategy is triggered early under high UV-B radiation in Legacy. Moreover, the rapid metabolic reprogramming capacity of this cultivar, in contrast to Bluegold, seems to be the most relevant contribution to its UV-B stress-coping strategy. © 2016 Scandinavian Plant Physiology Society.

Effect of water flow and chemical environment on microbiota growth and composition in the human colon.

PubMed

Cremer, Jonas; Arnoldini, Markus; Hwa, Terence

2017-06-20

The human gut harbors a dynamic microbial community whose composition bears great importance for the health of the host. Here, we investigate how colonic physiology impacts bacterial growth, which ultimately dictates microbiota composition. Combining measurements of bacterial physiology with analysis of published data on human physiology into a quantitative, comprehensive modeling framework, we show how water flow in the colon, in concert with other physiological factors, determine the abundances of the major bacterial phyla. Mechanistically, our model shows that local pH values in the lumen, which differentially affect the growth of different bacteria, drive changes in microbiota composition. It identifies key factors influencing the delicate regulation of colonic pH, including epithelial water absorption, nutrient inflow, and luminal buffering capacity, and generates testable predictions on their effects. Our findings show that a predictive and mechanistic understanding of microbial ecology in the gut is possible. Such predictive understanding is needed for the rational design of intervention strategies to actively control the microbiota.

Effect of water flow and chemical environment on microbiota growth and composition in the human colon

PubMed Central

Cremer, Jonas; Arnoldini, Markus; Hwa, Terence

2017-01-01

The human gut harbors a dynamic microbial community whose composition bears great importance for the health of the host. Here, we investigate how colonic physiology impacts bacterial growth, which ultimately dictates microbiota composition. Combining measurements of bacterial physiology with analysis of published data on human physiology into a quantitative, comprehensive modeling framework, we show how water flow in the colon, in concert with other physiological factors, determine the abundances of the major bacterial phyla. Mechanistically, our model shows that local pH values in the lumen, which differentially affect the growth of different bacteria, drive changes in microbiota composition. It identifies key factors influencing the delicate regulation of colonic pH, including epithelial water absorption, nutrient inflow, and luminal buffering capacity, and generates testable predictions on their effects. Our findings show that a predictive and mechanistic understanding of microbial ecology in the gut is possible. Such predictive understanding is needed for the rational design of intervention strategies to actively control the microbiota. PMID:28588144

The effects of gravity on the circadian timing system

NASA Technical Reports Server (NTRS)

Fuller, C. A.

1994-01-01

The physiological system responsible for the temporal coordination of an organism is the circadian timing system (CTS). This system provides two forms of temporal coordination. First, the CTS provides for synchronization of the organism with the 24 hour period of the external environment. This synchronization of the organism with the environment is termed entrainment. Second, this system also provides for internal coordination of the various physiological, behavioral, and biochemical events within the organism. When either of these two temporal relationships are disturbed, various dysfunctions can be manifest within the organism. Homeostatic capacity of other physiological systems may be reduced. Performance is decreased and sleep disorders, mental health impairment (e.g., depression), jet lag syndrome, and shift work maladaptation frequently occur. Over the last several years, several studies have evaluated the potential influence of gravity on this physiological control system by examining changes in rhythmic characteristics of organisms exposed to altered gravitational environments. The altered gravitational environments have included the microgravity of spaceflight as well as hyperdynamic fields produced via centrifugation.

Success stories and emerging themes in conservation physiology

PubMed Central

Madliger, Christine L.; Cooke, Steven J.; Crespi, Erica J.; Funk, Jennifer L.; Hultine, Kevin R.; Hunt, Kathleen E.; Rohr, Jason R.; Sinclair, Brent J.; Suski, Cory D.; Willis, Craig K. R.; Love, Oliver P.

2016-01-01

The potential benefits of physiology for conservation are well established and include greater specificity of management techniques, determination of cause–effect relationships, increased sensitivity of health and disturbance monitoring and greater capacity for predicting future change. While descriptions of the specific avenues in which conservation and physiology can be integrated are readily available and important to the continuing expansion of the discipline of ‘conservation physiology’, to date there has been no assessment of how the field has specifically contributed to conservation success. However, the goal of conservation physiology is to foster conservation solutions and it is therefore important to assess whether physiological approaches contribute to downstream conservation outcomes and management decisions. Here, we present eight areas of conservation concern, ranging from chemical contamination to invasive species to ecotourism, where physiological approaches have led to beneficial changes in human behaviour, management or policy. We also discuss the shared characteristics of these successes, identifying emerging themes in the discipline. Specifically, we conclude that conservation physiology: (i) goes beyond documenting change to provide solutions; (ii) offers a diversity of physiological metrics beyond glucocorticoids (stress hormones); (iii) includes approaches that are transferable among species, locations and times; (iv) simultaneously allows for human use and benefits to wildlife; and (v) is characterized by successes that can be difficult to find in the primary literature. Overall, we submit that the field of conservation physiology has a strong foundation of achievements characterized by a diversity of conservation issues, taxa, physiological traits, ecosystem types and spatial scales. We hope that these concrete successes will encourage the continued evolution and use of physiological tools within conservation-based research and management plans. PMID:27382466

Small Airway Dysfunction and Abnormal Exercise Responses

PubMed Central

Petsonk, Edward L.; Stansbury, Robert C.; Beeckman-Wagner, Lu-Ann; Long, Joshua L.; Wang, Mei Lin

2016-01-01

Rationale Coal mine dust exposure can cause symptoms and loss of lung function from multiple mechanisms, but the roles of each disease process are not fully understood. Objectives We investigated the implications of small airway dysfunction for exercise physiology among a group of workers exposed to coal mine dust. Methods Twenty coal miners performed spirometry, first breathing air and then helium-oxygen, single-breath diffusing capacity, and computerized chest tomography, and then completed cardiopulmonary exercise testing. Measurements and Main Results Six participants meeting criteria for small airway dysfunction were compared with 14 coal miners who did not. At submaximal workload, miners with small airway dysfunction used a higher proportion of their maximum voluntary ventilation and had higher ventilatory equivalents for both O2 and CO2. Regression modeling indicated that inefficient ventilation was significantly related to small airway dysfunction but not to FEV1 or diffusing capacity. At the end of exercise, miners with small airway dysfunction had 27% lower O2 consumption. Conclusions Small airway abnormalities may be associated with important inefficiency of exercise ventilation. In dust-exposed individuals with only mild abnormalities on resting lung function tests or chest radiographs, cardiopulmonary exercise testing may be important in defining causes of exercise intolerance. PMID:27073987

Specific detection of membrane-toxic substances with a conductivity assay.

PubMed

Eich, J; Dürholt, H; Steger-Hartmann, T; Wagner, E

2000-03-01

A conductivity assay that represents a new biotest able to detect the effects of membrane-toxic compounds, e.g., detergents, organic solvents, and radical formers, on various organisms was previously described and developed. The conductivity assay measures ion leakage from cells, tissues, or whole plant and animal organisms whose membrane systems have been damaged by membrane-toxic compounds. In this study the specificity of the conductivity assay for membrane-toxic compounds was tested by comparing the electrolyte efflux from Elodea canadensis leaves during incubation with a well-known detergent (benzalkonium chloride) using different plant physiological and biochemical techniques (photochemical efficiency, plasmolysis capacity, NBT reduction, and electron microscopy of membranes of E. canadensis leaves). The comparison of the different methods proved that the electrolyte loss during benzalkonium chloride incubation determined in the conductivity assay is due to membrane impairment. The observed electrolyte loss correlated with a reduction of photochemical efficiency and a decrease in both plasmolysis and NBT reduction capacity. Furthermore, a disintegration of the plasmalemma could be seen in the electron micrographs. These results indicate that the measured electrolyte loss in the conductivity assay is a specific effect of membrane-toxic compounds. Copyright 2000 Academic Press.

Cadmium uptake and toxicity to water hyacinth: Effect of repeated exposures under controlled conditions

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

Nir, R.; Gasith, A.; Perry, A.S.

1990-01-01

Water hyacinth, Eichornia crassipes has drawn attention as a plant of rapid growth and high biomass production, and capable of removing pollutants from domestic and industrial waste effluents. Most of the studies were static assays of short duration (1 to 3 days) and with a single exposure of the plants to cadmium. The authors presumed that repeated exposures to Cd might change the rate of uptake of the metal as well as the growth and physiological state of the plant. This prompted us to undertake the present study in order to evaluate the potential capacity of water hyacinth to removemore » Cd from solution under conditions of repeated exposures but otherwise favorable growth conditions and without interference from other toxic compounds. Removal of metal from effluents by plants is expected to be compounded by the influence of specific conditions of the medium such as temperature, pH, ionic strength, presence of other metals or complexing ligands. The results of the present study will serve as a comparative reference for evaluating the effect of effluent conditions on CD toxicity to water hyacinth and the plant's capacity for metal removal.« less

Genomic insights into the Acidobacteria reveal strategies for their success in terrestrial environments

PubMed Central

Trojan, Daniela; Roux, Simon; Herbold, Craig; Rattei, Thomas; Woebken, Dagmar

2018-01-01

Summary Members of the phylum Acidobacteria are abundant and ubiquitous across soils. We performed a large‐scale comparative genome analysis spanning subdivisions 1, 3, 4, 6, 8 and 23 (n = 24) with the goal to identify features to help explain their prevalence in soils and understand their ecophysiology. Our analysis revealed that bacteriophage integration events along with transposable and mobile elements influenced the structure and plasticity of these genomes. Low‐ and high‐affinity respiratory oxygen reductases were detected in multiple genomes, suggesting the capacity for growing across different oxygen gradients. Among many genomes, the capacity to use a diverse collection of carbohydrates, as well as inorganic and organic nitrogen sources (such as via extracellular peptidases), was detected – both advantageous traits in environments with fluctuating nutrient environments. We also identified multiple soil acidobacteria with the potential to scavenge atmospheric concentrations of H2, now encompassing mesophilic soil strains within the subdivision 1 and 3, in addition to a previously identified thermophilic strain in subdivision 4. This large‐scale acidobacteria genome analysis reveal traits that provide genomic, physiological and metabolic versatility, presumably allowing flexibility and versatility in the challenging and fluctuating soil environment. PMID:29327410

Ligand Assisted Stabilization of Fluorescence Nanoparticles; an Insight on the Fluorescence Characteristics, Dispersion Stability and DNA Loading Efficiency of Nanoparticles.

PubMed

Rhouati, Amina; Hayat, Akhtar; Mishra, Rupesh K; Bueno, Diana; Shahid, Shakir Ahmad; Muñoz, Roberto; Marty, Jean Louis

2016-07-01

This work reports on the ligand assisted stabilization of Fluospheres® carboxylate modified nanoparticles (FCMNPs), and subsequently investigation on the DNA loading capacity and fluorescence response of the modified particles. The designed fluorescence bioconjugate was characterized with enhanced fluorescence characteristics, good stability and large surface area with high DNA loading efficiency. For comparison purpose, bovine serum albumin (BSA) and polyethylene glycol (PEG) with three different length strands were used as cross linkers to modify the particles, and their DNA loading capacity and fluorescence characteristics were investigated. By comparing the performance of the particles, we found that the most improved fluorescence characteristics, enhanced DNA loading and high dispersion stability were obtained, when employing PEG of long spacer arm length. The designed fluorescence bioconjugate was observed to maintain all its characteristics under varying pH over an extended period of time. These types of bioconjugates are in great demand for fluorescence imaging and in vivo fluorescence biomedical application, especially when most of the as synthesized fluorescence particles cannot withstand to varying in vivo physiological conditions with decreases in fluorescence response and DNA loading efficiency.

The making of giant pumpkins: how selective breeding changed the phloem of Cucurbita maxima from source to sink.

PubMed

Savage, Jessica A; Haines, Dustin F; Holbrook, N Michele

2015-08-01

Despite the success of breeding programmes focused on increasing fruit size, relatively little is known about the anatomical and physiological changes required to increase reproductive allocation. To address this gap in knowledge, we compared fruit/ovary anatomy, vascular structure and phloem transport of two varieties of giant pumpkins, and their smaller fruited progenitor under controlled environmental conditions. We also modelled carbon transport into the fruit of competitively grown plants using data collected in the field. There was no evidence that changes in leaf area or photosynthetic capacity impacted fruit size. Instead, giant varieties differed in their ovary morphology and contained more phloem on a cross-sectional area basis in their petioles and pedicels than the ancestral variety. These results suggest that sink activity is important in determining fruit size and that giant pumpkins have an enhanced capacity to transport carbon. The strong connection observed between carbon fixation, phloem structure and fruit growth in field-grown plants indicates that breeding for large fruit has led to changes throughout the carbon transport system that could have important implications for how we think about phloem transport velocity and carbon allocation. © 2014 John Wiley & Sons Ltd.

Mercury species, selenium, metallothioneins and glutathione in two dolphins from the southeastern Brazilian coast: Mercury detoxification and physiological differences in diving capacity.

PubMed

Kehrig, Helena A; Hauser-Davis, Rachel A; Seixas, Tercia G; Pinheiro, Ana Beatriz; Di Beneditto, Ana Paula M

2016-06-01

In the present study, the concentration of trace elements, total mercury (Hg) and selenium (Se) and mercury forms (MeHg, Hginorg and HgSe) in the vulnerable coastal dolphins Pontoporia blainvillei and Sotalia guianensis were appraised and compared, using metallothioneins (MT) and glutathione (GSH) as biomarkers for trace element exposure. The trace element concentrations varied between muscle and liver tissues, with liver of all dolphin specimens showing higher Hg and Se concentrations than those found in muscle. Hg, MeHg and Hginorg molar concentrations showed a clear increase with Se molar concentrations in the liver of both dolphins, and Se concentrations were higher than those of Hg on a molar basis. Se plays a relevant role in the detoxification of MeHg in the hepatic tissue of both dolphins, forming Hg-Se amorphous crystals in liver. In contrast, MT were involved in the detoxification process of Hginorg in liver. GSH levels in P. blainvillei and S. guianensis muscle tissue suggest that these dolphins have different diving capacities. Muscle Hg concentrations were associated to this tripeptide, which protects dolphin cells against Hg stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gait analysis in anorexia and bulimia nervosa.

PubMed

Cimolin, Veronica; Galli, Manuela; Vismara, Luca; Vimercati, Sara Laura; Precilios, Helmer; Cattani, Laila; Fabris De Souza, Shirley; Petroni, Maria Letizia; Capodaglio, Paolo

2013-09-13

Anorexia (AN) and Bulimia Nervosa (BN) are two common eating disorders, which appear to share some reduced motor capacities, such as a reduced balance. The presence and the extent of other motor disorders have not been investigated in a comprehensive way. The aim of this study was to quantify gait pattern in AN and BN individuals in order to ascertain possible differences from the normality range and provide novel data for developing some evidence-based rehabilitation strategies. Nineteen AN patients (age 30.16+9.73) and 20 BN patients (age 26.8+8.41) were assessed with quantitative 3D computerized Gait Analysis. Results were compared with a group of healthy controls (CG; 30.7+5.6). AN and BN patients were characterized by different gait strategies compared to CG. Spatio-temporal parameters indicated shorter step length, with AN showing the shortest values. AN walked slower than BN and CG. As for kinematics, AN and BN showed a nonphysiologic pattern at pelvis and hip level on the sagittal and frontal plane, with BN yielding the most abnormal values. Both AN and BN patients were characterized by high ankle plantar flexion capacity at toe-off when compared to CG. As for ankle kinetics, both AN and BN showed physiologic patterns. Stiffness at hip level was close to CG in both pathologic groups; at the ankle level, stiffness was significantly decreased in both groups, with AN displaying lower values. Both AN and BN were characterized by an altered gait pattern compared to CG. Biomechanical differences were evident mainly at pelvis and hip level. Loss of lean mass may lead to musculoskeletal adaptation, ultimately causing alterations in the gait pattern.

ANTHROPOMETRIC CHARACTERISTICS AND FUNCTIONAL CAPACITY OF ELITE ROWERS AND HANDBALL PLAYERS.

PubMed

Karaba Jakovljevic, Dea; Jovanovic, Gordana; Eric, Mirela; Klasnja, Aleksandar; Slavic, Danijel; Lukac, Damir

2016-09-01

Anthropometric and anaerobic profile of elite athletes are fundamental for the assessment of their respective performance. The present study was designed to evaluate the anthro- pornetric parameters, body composition and anaerobic characteristics of elite male handball players and rowers, and to compare them in relation to specific sport demands. The study group consisted of 41 elite national level athletes: 20 handball players (aged 23.7±3.72) and 21 rowers (aged 19.7±2.84). Anthropometric characteristics (body mass, body height, skinfold thickness, body circumferences), and body fat mass were evaluated, and Wingate anaerobic test for anaerobic power assessment Iwas applied. The significant differences were noted in chest-upper arm, waist and hip circumferences, and supraspinal and calf skinfolds between the two investigated groups. Rowers showed higher values of fat body mass (13.2±3.76 vs. 10.7±3.76%), but lower body mass index (22.0±1,92 vs. 25.7?2.31 kg/in12) compared to handball players. When analyzing the Wingate test parameters, significantly higher values of absolute anaerobic power (786±127 vs. 691±140 W), absolute explosive power in the handball players compared to the rowers were recorded ( 18±26.3 vs. 105±27.8 W/s), whi le rowers achieved higher relative anaerobic capacity (192±3 1.2 vs. 177±E20.8 J/ kg). Specific body composition and anthropometri- cal assessment as a part of morphological analysis should complement physiological profile of elite athletes. The analysis of the anaerobic performance shows that the handball players have greater alactic anaerobic and explosive power component, compared to the rowers in whom the anaerobic endurance and specific training have the greatest effect on the consumption of dominant metabolic substrate during the race.

Effect of Selective Heart Rate Slowing in Heart Failure With Preserved Ejection Fraction.

PubMed

Pal, Nikhil; Sivaswamy, Nadiya; Mahmod, Masliza; Yavari, Arash; Rudd, Amelia; Singh, Satnam; Dawson, Dana K; Francis, Jane M; Dwight, Jeremy S; Watkins, Hugh; Neubauer, Stefan; Frenneaux, Michael; Ashrafian, Houman

2015-11-03

Heart failure with preserved ejection fraction (HFpEF) is associated with significant morbidity and mortality but is currently refractory to therapy. Despite limited evidence, heart rate reduction has been advocated, on the basis of physiological considerations, as a therapeutic strategy in HFpEF. We tested the hypothesis that heart rate reduction improves exercise capacity in HFpEF. We conducted a randomized, crossover study comparing selective heart rate reduction with the If blocker ivabradine at 7.5 mg twice daily versus placebo for 2 weeks each in 22 symptomatic patients with HFpEF who had objective evidence of exercise limitation (peak oxygen consumption at maximal exercise [o2 peak] <80% predicted for age and sex). The result was compared with 22 similarly treated matched asymptomatic hypertensive volunteers. The primary end point was the change in o2 peak. Secondary outcomes included tissue Doppler-derived E/e' at echocardiography, plasma brain natriuretic peptide, and quality-of-life scores. Ivabradine significantly reduced peak heart rate compared with placebo in the HFpEF (107 versus 129 bpm; P<0.0001) and hypertensive (127 versus 145 bpm; P=0.003) cohorts. Ivabradine compared with placebo significantly worsened the change in o2 peak in the HFpEF cohort (-2.1 versus 0.9 mL·kg(-1)·min(-1); P=0.003) and significantly reduced submaximal exercise capacity, as determined by the oxygen uptake efficiency slope. No significant effects on the secondary end points were discernable. Our observations bring into question the value of heart rate reduction with ivabradine for improving symptoms in a HFpEF population characterized by exercise limitation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02354573. © 2015 The Authors.

The Effects of Crushed Ice Ingestion Prior to Steady State Exercise in the Heat.

PubMed

Zimmermann, Matthew; Landers, Grant; Wallman, Karen E; Saldaris, Jacinta

2017-06-01

This study examined the physiological effects of crushed ice ingestion before steady state exercise in the heat. Ten healthy males with age (23 ± 3 y), height (176.9 ± 8.7 cm), body-mass (73.5 ± 8.0 kg), VO 2peak (48.5 ± 3.6 mL∙kg∙min -1 ) participated in the study. Participants completed 60 min of cycling at 55% of their VO 2peak preceded by 30 min of precooling whereby 7 g∙kg -1 of thermoneutral water (CON) or crushed ice (ICE) was ingested. The reduction in T c at the conclusion of precooling was greater in ICE (-0.9 ± 0.3 °C) compared with CON (-0.2 ± 0.2 °C) (p ≤ .05). Heat storage capacity was greater in ICE compared with CON after precooling (ICE -29.3 ± 4.8 W∙m -2 ; CON -11.1 ± 7.3 W∙m -2 , p < .05). Total heat storage was greater in ICE compared with CON at the end of the steady state cycle (ICE 62.0 ± 12.5 W∙m-2; CON 49.9 ± 13.4 W∙m -2 , p < .05). Gross efficiency was higher in ICE compared with CON throughout the steady state cycle (ICE 21.4 ± 1.8%; CON 20.4 ± 1.9%, p < .05). Ice ingestion resulted in a lower thermal sensation at the end of precooling and a lower sweat rate during the initial stages of cycling (p < .05). Sweat loss, respiratory exchange ratio, heart rate and ratings of perceived exertion and thirst were similar between conditions (p > .05). Precooling with crushed ice led to improved gross efficiency while cycling due to an increased heat storage capacity, which was the result of a lower core temperature.

Oral physiology, nutrition and quality of life in diabetic patients associated or not with hypertension and beta-blockers therapy.

PubMed

Pereira, L J; Foureaux, R C; Pereira, C V; Alves, M C; Campos, C H; Rodrigues Garcia, R C M; Andrade, E F; Gonçalves, T M S V

2016-07-01

The relationship between type 2 diabetes oral physiology, nutritional intake and quality of life has not been fully elucidated. We assessed the impact of type 2 diabetes - exclusive or associated with hypertension with beta-blockers treatment - on oral physiology, mastication, nutrition and quality of life. This cross-sectional study was performed with 78 complete dentate subjects (15 natural teeth and six masticatory units minimum; without removable or fixed prostheses), divided into three groups: diabetics (DM) (n = 20; 45·4 ± 9·5 years), diabetics with hypertension and receiving beta-blockers treatment (DMH) (n = 19; 41·1 ± 5·1 years) and controls (n = 39; 44·5 ± 11·7 years) matched for gender, age and socioeconomic status. Blood glucose, masticatory performance, swallowing threshold, taste, food intake, stimulated and unstimulated salivary flow, pH and buffering capacity of saliva were assessed. Glycemia was higher in DM than in controls (P < 0·01). No differences were observed between DM and controls for nutrition and quality of life. Both stimulated and unstimulated salivary flow rate were lower in DMH (P < 0·01), which also presented the lowest number of teeth and masticatory units (P < 0·0001), and reduction in the number of chewing cycles (P < 0·01). Controls showed lower Decayed Missing Filled Teeth index (DMFT) scores in comparison with DMH (P = 0·021). Masticatory performance and saliva buffering capacity were similar among groups. Exclusive type 2 diabetes did not alter oral physiology, nutrition or quality of life. However, when hypertension and beta-blockers treatment were associated with diabetes, the salivary flow rate, chewing cycles and number of teeth decreased. © 2016 John Wiley & Sons Ltd.

Dysanapsis and the resistive work of breathing during exercise in healthy men and women.

PubMed

Dominelli, Paolo B; Molgat-Seon, Yannick; Bingham, Derek; Swartz, Philippa M; Road, Jeremy D; Foster, Glen E; Sheel, A William

2015-11-15

We asked if the higher work of breathing (Wb) during exercise in women compared with men is explained by biological sex. We created a statistical model that accounts for both the viscoelastic and the resistive components of the total Wb and independently compares the effects of biological sex. We applied the model to esophageal pressure-derived Wb values obtained during an incremental cycle test to exhaustion. Subjects were healthy men (n = 17) and women (n = 18) with a range of maximal aerobic capacities (V̇o2 max range: men = 40-68 and women = 39-60 ml·kg(-1)·min(-1)). We also calculated the dysanapsis ratio using measures of lung recoil and forced expiratory flow as index of airway caliber. By applying the model we found that the differences in the total Wb during exercise in women are due to a higher resistive Wb rather than viscoelastic Wb. We also found that the higher resistive Wb is independently explained by biological sex. To account for the known effect of lung volumes on the dysanapsis ratio we compared the sexes with an analysis of covariance procedures and found that when vital capacity was accounted for the adjusted mean dysanapsis ratio is statistically lower in women (0.17 vs. 0.25 arbitrary units; P < 0.05). Our collective findings suggest that innate sex-based differences may exist in human airways, which result in significant male-female differences in the Wb during exercise in healthy subjects. Copyright © 2015 the American Physiological Society.

Plant Growth under Natural Light Conditions Provides Highly Flexible Short-Term Acclimation Properties toward High Light Stress

PubMed Central

Schumann, Tobias; Paul, Suman; Melzer, Michael; Dörmann, Peter; Jahns, Peter

2017-01-01

Efficient acclimation to different growth light intensities is essential for plant fitness. So far, most studies on light acclimation have been conducted with plants grown under different constant light regimes, but more recent work indicated that acclimation to fluctuating light or field conditions may result in different physiological properties of plants. Thale cress (Arabidopsis thaliana) was grown under three different constant light intensities (LL: 25 μmol photons m−2 s−1; NL: 100 μmol photons m−2 s−1; HL: 500 μmol photons m−2 s−1) and under natural fluctuating light (NatL) conditions. We performed a thorough characterization of the morphological, physiological, and biochemical properties focusing on photo-protective mechanisms. Our analyses corroborated the known properties of LL, NL, and HL plants. NatL plants, however, were found to combine characteristics of both LL and HL grown plants, leading to efficient and unique light utilization capacities. Strikingly, the high energy dissipation capacity of NatL plants correlated with increased dynamics of thylakoid membrane reorganization upon short-term acclimation to excess light. We conclude that the thylakoid membrane organization and particularly the light-dependent and reversible unstacking of grana membranes likely represent key factors that provide the basis for the high acclimation capacity of NatL grown plants to rapidly changing light intensities. PMID:28515734

Abstracts of Review Articles and Educational Materials in Physiology

ERIC Educational Resources Information Center

Physiology Teacher, 1977

1977-01-01

Contained are 99 abstracts of review articles, texts, books, manuals, learning programs, and audiovisual material used in teaching physiology. Specific fields include cell physiology, circulation, comparative physiology, development and aging, endocrinology and metabolism, environmental and exercise physiology, gastrointestinal physiology, muscle…

Designing a dynamic dissolution method: a review of instrumental options and corresponding physiology of stomach and small intestine.

PubMed

Culen, Martin; Rezacova, Anna; Jampilek, Josef; Dohnal, Jiri

2013-09-01

Development of new pharmaceutical compounds and dosage forms often requires in vitro dissolution testing with the closest similarity to the human gastrointestinal (GI) tract. To create such conditions, one needs a suitable dissolution apparatus and the appropriate data on the human GI physiology. This review discusses technological approaches applicable in biorelevant dissolutions as well as the physiology of stomach and small intestine in both fasted and fed state, that is, volumes of contents, transit times for water/food and various solid oral dosage forms, pH, osmolality, surface tension, buffer capacity, and concentrations of bile salts, phospholipids, enzymes, and Ca(2+) ions. The information is aimed to provide clear suggestions on how these conditions should be set in a dynamic biorelevant dissolution test. Copyright © 2013 Wiley Periodicals, Inc.

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

Physiology of Sedentary Behavior and Its Relationship to Health Outcomes

PubMed Central

Thyfault, John P; Du, Mengmeng; Kraus, William E; Levine, James A; Booth, Frank W

2014-01-01

Purpose This paper reports on the findings and recommendations of the “Physiology of Sedentary Behavior and its Relationship to Health Outcomes” group, a part of a larger workshop entitled Sedentary Behavior: Identifying Research Priorities sponsored by the National Heart, and Lung and Blood Institute and the National Institute on Aging, which aimed to establish sedentary behavior research priorities. Methods The discussion within our workshop lead to the formation of critical physiological research objectives related to sedentary behaviors, that if appropriately researched would greatly impact our overall understanding of human health and longevity. Results and Conclusions Primary questions are related to physiological “health outcomes” including the influence of physical activity vs. sedentary behavior on function of a number of critical physiological systems (aerobic capacity, skeletal muscle metabolism and function, telomeres/genetic stability, and cognitive function). The group also derived important recommendations related to the “central and peripheral mechanisms” that govern sedentary behavior and how energy balance has a role in mediating these processes. General recommendations for future sedentary physiology research efforts include that studies of sedentary behavior, including that of sitting time only, should focus on the physiological impact of a “lack of human movement” in contradistinction to the effects of physical movement and that new models or strategies for studying sedentary behavior induced adaptations and links to disease development are needed to elucidate underlying mechanism(s). PMID:25222820

A tree from waste: Decontaminated dredged sediments for growing forest tree seedlings.

PubMed

Ugolini, Francesca; Mariotti, Barbara; Maltoni, Alberto; Tani, Andrea; Salbitano, Fabio; Izquierdo, Carlos García; Macci, Cristina; Masciandaro, Graziana; Tognetti, Roberto

2018-04-01

The sediments dredged from a waterway and decontaminated through a phytoremediation process have been used as substrates alternatively to the traditional forest nursery substrate for pot productions of holm oak (Quercus ilex L.) planting stocks. The substrates, made by mixing decontaminated sediments to agricultural soil at different degrees, were tested in order to evaluate their suitability as growth substrates. The experiment was carried out at the nursery of the Department of Agricultural, Food and Forestry Systems of the University of Florence (Italy). The experimental design consisted of four randomized blocks with six pots as replicates for each of the following treatments: 100% sediments, 66% sediments, 33% sediments, 100% agronomic soil and 100% traditional peat based substrate. In each pot, one holm oak acorn was seeded. Germination and both physiological and morphological traits of the seedlings were analysed during and at the end of the first growing season. Holm oak grown in phytoremediated sediments at higher concentrations showed germination levels comparable to those in the traditional substrate, and survival capacity (especially in 66% sediments) slightly higher than in 100% soil. Physiological performance of seedlings resembled that on the traditional substrate which required the addition of fertilizer, at least for the first growing season. Seedlings grown in mixed substrates with higher sediment concentrations occasionally showed better photosynthetic capacity with improved connectivity between the units of the photosystem II. At the end of the first growing season, height as well as the number of growth flushes of the seedlings grown in sole sediment or soil-sediment substrates were similar to what generally is observed for forest nursery stock of Quercus spp.. Regarding the root-system articulation and growth in depth, results in the mixed substrates were comparable to those for seedlings grown in the traditional forest nursery media, and higher than seedlings grown in 100% agronomic soil. According to our results, the reclamation of dredged sediments can provide appropriate nursery substrate for germination beds for forestry species. Copyright © 2018 Elsevier Ltd. All rights reserved.

A physiological evaluation of professional soccer players.

PubMed

Raven, P B; Gettman, L R; Pollock, M L; Cooper, K H

1976-12-01

The purpose of this study was to evaluate the physiological functions of a professional soccer team in the North American Soccer League (NASL). Eighteen players were evaluated on cardiorespiratory function, endurance performance, body composition, blood chemistry, and motor fitness measures near the end of their competitive season. The following means were observed: age, 26 yrs; height, 176 cm; weight 75.5 kg; resting heart rate, 50 beats/min; maximum heart rate (MHR), 188 beats/min; maximum oxygen intake (VO2 max), 58.4 ml/kg-min-1; maximum ventilation (VEmax BTPS), 154 L/min; body fat, 9.59%; 12-min run, 1.86 miles; and Illinois agility run, 15.6 secs. Results on resting blood pressure, serum lipids, vital capacity, flexibility, upper body strength, and vertical jump tests were comparable to values found for the sedentary population. Comparing the results with previously collected data on professional American Football backs indicated that the soccer players were shorter; lighter in body weight; higher in VO2 max (4 ml/kg-min-1) and body fat (1.8%); and similar in MHR, VE max, and VC. The 12-min run scores were similar to the initial values observed for the 1970 Brazilian World Cup Team. The agility run results were superior to data collected from other groups. Their endurance capabilities, agility, and low percent of body fat clearly differentiate them from the sedentary population and show them to be similar to that of professional American football backs.

A physiological evaluation of professional soccer players.

PubMed Central

Raven, P. B.; Gettman, L. R.; Pollock, M. L.; Cooper, K. H.

1976-01-01

The purpose of this study was to evaluate the physiological functions of a professional soccer team in the North American Soccer League (NASL). Eighteen players were evaluated on cardiorespiratory function, endurance performance, body composition, blood chemistry, and motor fitness measures near the end of their competitive season. The following means were observed: age, 26 yrs; height, 176 cm; weight 75.5 kg; resting heart rate, 50 beats/min; maximum heart rate (MHR), 188 beats/min; maximum oxygen intake (VO2 max), 58.4 ml/kg-min-1; maximum ventilation (VEmax BTPS), 154 L/min; body fat, 9.59%; 12-min run, 1.86 miles; and Illinois agility run, 15.6 secs. Results on resting blood pressure, serum lipids, vital capacity, flexibility, upper body strength, and vertical jump tests were comparable to values found for the sedentary population. Comparing the results with previously collected data on professional American Football backs indicated that the soccer players were shorter; lighter in body weight; higher in VO2 max (4 ml/kg-min-1) and body fat (1.8%); and similar in MHR, VE max, and VC. The 12-min run scores were similar to the initial values observed for the 1970 Brazilian World Cup Team. The agility run results were superior to data collected from other groups. Their endurance capabilities, agility, and low percent of body fat clearly differentiate them from the sedentary population and show them to be similar to that of professional American football backs. PMID:1009297

Effect of floorball training on blood lipids, body composition, muscle strength, and functional capacity of elderly men.

PubMed

Vorup, J; Pedersen, M T; Melcher, P S; Dreier, R; Bangsbo, J

2017-11-01

Floorball training consists of intense repeated exercise and may offer a motivating and social stimulating team activity in elderly individuals. However, the effect of floorball training in elderly adults on physiological adaptations important for health is not known. Thus, this study examined the effect of floorball training on blood lipids, muscle strength, body composition, and functional capacity of men aged 65-76 years. Thirty-nine recreational active men were randomized into a floorball group (FG; n = 22) or petanque group (PG; n = 17), in which training was performed 1 h twice a week for 12 weeks. In FG and PG, average heart rate (HR) during training was 80% and 57%, respectively, of maximal HR. In FG, plasma low-density lipoprotein (LDL) cholesterol and triglycerides were 11% and 8% lower (P < 0.05), respectively. Insulin resistance determined by homeostatic model assessment (HOMA-IR) was reduced (P < 0.05) by 18%. HR during submaximal cycling was 5% lower (P < 0.05), and maximal voluntary contraction force was 8% higher (P < 0.05). Total and visceral fat content was lowered (P < 0.05) by 5% and 14%, respectively, HR at rest was 8% lower (P < 0.05) and performance in four different functional capacity tests were better (P < 0.05) after compared to before the training period. No changes were observed in PG. In conclusion, 12 weeks of floorball training resulted in a number of favorable effects important for health and functional capacity, suggesting that floorball training can be used as a health-promoting activity in elderly men. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

High-intensity exercise training increases the diversity and metabolic capacity of the mouse distal gut microbiota during diet-induced obesity.

PubMed

Denou, Emmanuel; Marcinko, Katarina; Surette, Michael G; Steinberg, Gregory R; Schertzer, Jonathan D

2016-06-01

Diet and exercise underpin the risk of obesity-related metabolic disease. Diet alters the gut microbiota, which contributes to aspects of metabolic disease during obesity. Repeated exercise provides metabolic benefits during obesity. We assessed whether exercise could oppose changes in the taxonomic and predicted metagenomic characteristics of the gut microbiota during diet-induced obesity. We hypothesized that high-intensity interval training (HIIT) would counteract high-fat diet (HFD)-induced changes in the microbiota without altering obesity in mice. Compared with chow-fed mice, an obesity-causing HFD decreased the Bacteroidetes-to-Firmicutes ratio and decreased the genetic capacity in the fecal microbiota for metabolic pathways such as the tricarboxylic acid (TCA) cycle. After HFD-induced obesity was established, a subset of mice were HIIT for 6 wk, which increased host aerobic capacity but did not alter body or adipose tissue mass. The effects of exercise training on the microbiota were gut segment dependent and more extensive in the distal gut. HIIT increased the alpha diversity and Bacteroidetes/Firmicutes ratio of the distal gut and fecal microbiota during diet-induced obesity. Exercise training increased the predicted genetic capacity related to the TCA cycle among other aspects of metabolism. Strikingly, the same microbial metabolism indexes that were increased by exercise were all decreased in HFD-fed vs. chow diet-fed mice. Therefore, exercise training directly opposed some of the obesity-related changes in gut microbiota, including lower metagenomic indexes of metabolism. Some host and microbial pathways appeared similarly affected by exercise. These exercise- and diet-induced microbiota interactions can be captured in feces. Copyright © 2016 the American Physiological Society.

Seasonal and geographical variation in heat tolerance and evaporative cooling capacity in a passerine bird.

PubMed

Noakes, Matthew J; Wolf, Blair O; McKechnie, Andrew E

2016-03-01

Intraspecific variation in avian thermoregulatory responses to heat stress has received little attention, despite increasing evidence that endothermic animals show considerable physiological variation among populations. We investigated seasonal (summer versus winter) variation in heat tolerance and evaporative cooling in an Afrotropical ploceid passerine, the white-browed sparrow-weaver (Plocepasser mahali; ∼ 47 g) at three sites along a climatic gradient with more than 10 °C variation in mid-summer maximum air temperature (Ta). We measured resting metabolic rate (RMR) and total evaporative water loss (TEWL) using open flow-through respirometry, and core body temperature (Tb) using passive integrated transponder tags. Sparrow-weavers were exposed to a ramped profile of progressively higher Ta between 30 and 52 °C to elicit maximum evaporative cooling capacity (N=10 per site per season); the maximum Ta birds tolerated before the onset of severe hyperthermia (Tb ≈ 44 °C) was considered to be their hyperthermia threshold Ta (Ta,HT). Our data reveal significant seasonal acclimatisation of heat tolerance, with a desert population of sparrow-weavers reaching significantly higher Ta in summer (49.5 ± 1.4 °C, i.e. higher Ta,HT) than in winter (46.8 ± 0.9 °C), reflecting enhanced evaporative cooling during summer. Moreover, desert sparrow-weavers had significantly higher heat tolerance and evaporative cooling capacity during summer compared with populations from more mesic sites (Ta,HT=47.3 ± 1.5 and 47.6 ± 1.3 °C). A better understanding of the contributions of local adaptation versus phenotypic plasticity to intraspecific variation in avian heat tolerance and evaporative cooling capacity is needed for modelling species' responses to changing climates. © 2016. Published by The Company of Biologists Ltd.

Selection-, age-, and exercise-dependence of skeletal muscle gene expression patterns in a rat model of metabolic fitness.

PubMed

Ren, Yu-Yu; Koch, Lauren G; Britton, Steven L; Qi, Nathan R; Treutelaar, Mary K; Burant, Charles F; Li, Jun Z

2016-11-01

Intrinsic aerobic exercise capacity can influence many complex traits including obesity and aging. To study this connection we established two rat lines by divergent selection of untrained aerobic capacity. After 32 generations the high capacity runners (HCR) and low capacity runners (LCR) differed in endurance running distance and body fat, blood glucose, other health indicators, and natural life span. To understand the interplay among genetic differences, chronological age, and acute exercise we performed microarray-based gene expression analyses in skeletal muscle with a 2×2×2 design to simultaneously compare HCR and LCR, old and young animals, and rest and exhaustion. Transcripts for mitochondrial function are expressed higher in HCRs than LCRs at both rest and exhaustion and for both age groups. Expression of cell adhesion and extracellular matrix genes tend to decrease with age. This and other age effects are more prominent in LCRs than HCRs, suggesting that HCRs have a slower aging process and this may be partly due to their better metabolic health. Strenuous exercise mainly affects transcription regulation and cellular response. The effects of any one factor often depend on the other two. For example, there are ∼140 and ∼110 line-exercise "interacting" genes for old and young animals, respectively. Many genes highlighted in our study are consistent with prior reports, but many others are novel. The gene- and pathway-level statistics for the main effects, either overall or stratified, and for all possible interactions, represent a rich reference dataset for understanding the interdependence among lines, aging, and exercise. Copyright © 2016 the American Physiological Society.

[Carbon monoxide tests in a steady state. Uptake and transfer capacity, normal values and lower limits].

PubMed

Ramonatxo, M; Préfaut, C; Guerrero, H; Moutou, H; Bansard, X; Chardon, G

1982-01-01

The aim of this study was to establish data which would best demonstrate the variations of different tests using Carbon Monoxide as a tracer gas (total and partial functional uptake coefficient and transfer capacity) to establish mean values and lower limits of normal of these tests. Multivariate statistical analysis was used; in the first stage a connection was sought between the fractional uptake coefficient (partial and total) to other parameters, comparing subjects and data. In the second stage the comparison was refined by eliminating the least useful data, trying, despite a small loss of material, to reveal the most important connections, linear or otherwise. The fractional uptake coefficients varied according to sex, also the variation of the partial alveolar-expired fractional uptake equivalent (DuACO) was largely a function of respiratory rate and tidal volume. The alveolar-arterial partial fractional uptake equivalent (DuaCO) depended more on respiratory frequency and age. Finally the total fractional uptake coefficient (DuCO) and the transfer capacity corrected per liter of ventilation (TLCO/V) were functions of these parameters. The last stage of this work, after taking account of the statistical observations consistent with the facts of these physiological hypotheses led to a search for a better way of approaching the laws linking the collected data to the fractional uptake coefficient. The lower limits of normal were arbitrarily defined, separating those 5% of subjects deviating most strongly from the mean. As a result, the relationship between the lower limit of normal and the theoretical mean value was 90% for the partial and total fractional uptake coefficient and 70% for the transfer capacity corrected per liter of ventilation.

A Microbial Perspective on the Grand Challenges in Comparative Animal Physiology

PubMed Central

2018-01-01

ABSTRACT Interactions with microbial communities can have profound influences on animal physiology, thereby impacting animal performance and fitness. Therefore, it is important to understand the diversity and nature of host-microbe interactions in various animal groups (invertebrates, fish, amphibians, reptiles, birds, and mammals). In this perspective, I discuss how the field of host-microbe interactions can be used to address topics that have been identified as grand challenges in comparative animal physiology: (i) horizontal integration of physiological processes across organisms, (ii) vertical integration of physiological processes across organizational levels within organisms, and (iii) temporal integration of physiological processes during evolutionary change. Addressing these challenges will require the use of a variety of animal models and the development of systems approaches that can integrate large, multiomic data sets from both microbial communities and animal hosts. Integrating host-microbe interactions into the established field of comparative physiology represents an exciting frontier for both fields. PMID:29556549

The Cognitive Neuroscience of the Teacher-Student Interaction

ERIC Educational Resources Information Center

Battro, Antonio M.; Calero, Cecilia I.; Goldin, Andrea P.; Holper, Lisa; Pezzatti, Laura; Shalóm, Diego E.; Sigman, Mariano

2013-01-01

Pedagogy is the science and art of teaching. Each generation needs to explore the history, theory, and practice of the teacher-student interaction. Here we pave the path to develop a science that explores the cognitive and physiological processes involved in the human capacity to communicate knowledge through teaching. We review examples from our…

The influence of physiological status on age prediction of Anopheles arabiensis using near infra-red spectroscopy

USDA-ARS?s Scientific Manuscript database

Determining the age of malaria vectors is essential for evaluating the impact of interventions that reduce the survival of wild mosquito populations and for estimating changes in vectorial capacity. Near infra-red spectroscopy (NIRS) is a simple and non-destructive method that has been used to deter...

Physiological responses of fathead minnow larvae to rice pesticides.

PubMed

Heath, A G; Cech, J J; Brink, L; Moberg, P; Zinkl, J G

1997-08-01

Newly hatched fathead minnow (Pimephales promelas) larvae were exposed for 4 days to two pesticides and ambient receiving waters to simulate conditions in the Sacramento River, California, during the striped bass spawning season which coincides with pesticide use in adjacent rice culture. Carbofuran and molinate were tested at two concentrations: a higher level approximating one-half the LC50 and a level much lower that is similar to that seen in the receiving waters of Colusa Basin Drain. Physiological measurements were made immediately after the exposures and again after a 10-day recovery period in noncontaminated waters. These included growth rate, swimming capacity, response to a mild electric shock, upper and lower lethal temperatures, and activity of acetylcholinesterase in whole-body homogenates. The higher concentrations of carbofuran and molinate caused reductions in swimming capacity, an increased sensitivity to the electric shock, and a reduction in upper lethal temperature. Acetylcholinesterase was reduced in those larvae exposed to the higher levels of carbofuran. In general, the lower levels of pesticide exposure caused no measureable effects nor did exposure to water from Colusa Basin Drain.

The effects of warm temperature acclimation on constitutive stress, immunity, and metabolism in white sturgeon (Acipenser transmontanus) of different ploidies.

PubMed

Leal, Michaiah J; Clark, Brigitte E; Van Eenennaam, Joel; Schreier, Andrea D; Todgham, Anne E

2018-06-01

Previous studies suggest fish with additional copies of their genome (polyploids) underperform in suboptimal conditions and may be more susceptible to stress and disease. The objective of this study was to determine the role ploidy plays in the physiological response of white sturgeon to chronically elevated water temperatures. White sturgeon of two ploidies (8 N and 10 N) were acclimated to ambient (18 °C) and warm (22 °C) water. Bioindices of stress (plasma cortisol, glucose and lactate, total erythrocyte count, hematocrit, hemoglobin, mean erythrocyte volume, mean erythrocyte hemoglobin, and mean erythrocyte hemoglobin concentration), immunity (respiratory burst, plasma lysozyme, and total leukocyte count), and cellular metabolic capacity (lactate dehydrogenase and citrate synthase activity) were measured before and after a 6-week acclimation period. Both ploidies appear comparable in their constitutive immune and stress parameters and respond similarly to warming. Hematological indices suggest 8 N and 10 N sturgeon are similar in oxygen carrying capacity; however, differences in enzyme activity between ploidies indicate that 10 N sturgeon may have a lower cellular aerobic capacity. Our results have implications for the screening and management of ploidy on white sturgeon farms and hatcheries, as the differences between ploidies may affect 10 N sturgeon performance at elevated water temperatures. Further research is needed to elucidate the differences in inducible stress and immune responses and metabolism of white sturgeon of different ploidies. Copyright © 2018. Published by Elsevier Inc.

Use of in vitro assays to assess the potential cytotoxic, genotoxic and antigenotoxic effects of vanillic and cinnamic acid.

PubMed

Taner, Gökçe; Özkan Vardar, Deniz; Aydin, Sevtap; Aytaç, Zeki; Başaran, Ahmet; Başaran, Nurşen

2017-04-01

Vanillic acid (VA) found in vanilla and cinnamic acid (CA) the precursor of flavonoids and found in cinnamon oil, are natural plant phenolic acids which are secondary aromatic plant products suggested to possess many physiological and pharmacological functions. In vitro and in vivo experiments have shown that phenolic acids exhibit powerful effects on biological responses by scavenging free radicals and eliciting antioxidant capacity. In the present study, we investigated the antioxidant capacity of VA and CA by the trolox equivalent antioxidant capacity (TEAC) assay, cytotoxicity by neutral red uptake (NRU) assay in Chinese Hamster Ovary (CHO) cells and also the genotoxic and antigenotoxic effects of these phenolic acids using the cytokinesis-blocked micronucleus (CBMN) and the alkaline comet assays in human peripheral blood lymphocytes. At all tested concentrations, VA (0.17-67.2 μg/ml) showed antioxidant activity but CA (0.15-59.2 μg/ml) did not show antioxidant activity against 2,2-azino-bis (3-ethylbenz-thiazoline-6-sulphonic acid) (ABTS). VA (0.84, 4.2, 8.4, 16.8, 84 and 168 μg/ml) and CA (0.74, 3.7, 7.4, 14.8, 74, 148 μg/ml) did not have cytotoxic and genotoxic effects alone at the studied concentrations as compared with the controls. Both VA and CA seem to decrease DNA damage induced by H 2 O 2 in human lymphocytes.

Trends and missing parts in the study of movement ecology

PubMed Central

Holyoak, Marcel; Casagrandi, Renato; Nathan, Ran; Revilla, Eloy; Spiegel, Orr

2008-01-01

Movement is important to all organisms, and accordingly it is addressed in a huge number of papers in the literature. Of nearly 26,000 papers referring to movement, an estimated 34% focused on movement by measuring it or testing hypotheses about it. This enormous amount of information is difficult to review and highlights the need to assess the collective completeness of movement studies and identify gaps. We surveyed 1,000 randomly selected papers from 496 journals and compared the facets of movement studied with a suggested framework for movement ecology, consisting of internal state (motivation, physiology), motion and navigation capacities, and external factors (both the physical environment and living organisms), and links among these components. Most studies simply measured and described the movement of organisms without reference to ecological or internal factors, and the most frequently studied part of the framework was the link between external factors and motion capacity. Few studies looked at the effects on movement of navigation capacity, or internal state, and those were mainly from vertebrates. For invertebrates and plants most studies were at the population level, whereas more vertebrate studies were conducted at the individual level. Consideration of only population-level averages promulgates neglect of between-individual variation in movement, potentially hindering the study of factors controlling movement. Terminology was found to be inconsistent among taxa and subdisciplines. The gaps identified in coverage of movement studies highlight research areas that should be addressed to fully understand the ecology of movement. PMID:19060194

Influence of mental workload on muscle endurance, fatigue, and recovery during intermittent static work.

PubMed

Mehta, Ranjana K; Agnew, Michael J

2012-08-01

Most occupational tasks involve some level of mental/cognitive processing in addition to physical work; however, the etiology of work-related musculoskeletal disorders (WMSDs) due to these demands remains unclear. The aim of this study was to quantify the interactive effects of physical and mental workload on muscle endurance, fatigue, and recovery during intermittent work. Twelve participants, balanced by gender, performed intermittent static shoulder abductions to exhaustion at 15, 35, and 55% of individual maximal voluntary contraction (MVC), in the absence (control) and presence (concurrent) of a mental arithmetic task. Changes in muscular capacity were determined using endurance time, strength decline, electromyographic (EMG) fatigue indicators, muscle oxygenation, and heart rate measures. Muscular recovery was quantified through changes in strength and physiological responses. Mental workload was associated with shorter endurance times, specifically at 35% MVC, and greater strength decline. EMG and oxygenation measures showed similar changes during fatigue manifestation during concurrent conditions compared to the control, despite shorter endurance times. Moreover, decreased heart rate variability during concurrent demand conditions indicated increased mental stress. Although strength recovery was not influenced by mental workload, a slower heart rate recovery was observed after concurrent demand conditions. The findings from this study provide fundamental evidence that physical capacity (fatigability and recovery) is adversely affected by mental workload. Thus, it is critical to determine or evaluate occupational demands based on modified muscular capacity (due to mental workload) to reduce risk of WMSD development.

Cellular and mitochondrial glutathione redox imbalance in lymphoblastoid cells derived from children with autism

PubMed Central

James, S. Jill; Rose, Shannon; Melnyk, Stepan; Jernigan, Stefanie; Blossom, Sarah; Pavliv, Oleksandra; Gaylor, David W.

2009-01-01

Research into the metabolic phenotype of autism has been relatively unexplored despite the fact that metabolic abnormalities have been implicated in the pathophysiology of several other neurobehavioral disorders. Plasma biomarkers of oxidative stress have been reported in autistic children; however, intracellular redox status has not yet been evaluated. Lymphoblastoid cells (LCLs) derived from autistic children and unaffected controls were used to assess relative concentrations of reduced glutathione (GSH) and oxidized disulfide glutathione (GSSG) in cell extracts and isolated mitochondria as a measure of intracellular redox capacity. The results indicated that the GSH/GSSG redox ratio was decreased and percentage oxidized glutathione increased in both cytosol and mitochondria in the autism LCLs. Exposure to oxidative stress via the sulfhydryl reagent thimerosal resulted in a greater decrease in the GSH/GSSG ratio and increase in free radical generation in autism compared to control cells. Acute exposure to physiological levels of nitric oxide decreased mitochondrial membrane potential to a greater extent in the autism LCLs, although GSH/GSSG and ATP concentrations were similarly decreased in both cell lines. These results suggest that the autism LCLs exhibit a reduced glutathione reserve capacity in both cytosol and mitochondria that may compromise antioxidant defense and detoxification capacity under prooxidant conditions.—James, S. J., Rose, S., Melnyk, S., Jernigan, S., Blossom, S., Pavliv, O., Gaylor, D. W. Cellular and mitochondrial glutathione redox imbalance in lymphoblastoid cells derived from children with autism. PMID:19307255

Differences in energy capacities between tennis players and runners.

PubMed

Novak, Dario; Vucetić, Vlatko; Zugaj, Sanja

2013-05-01

The primary purpose of this study was to determine differences between elite athletes and tennis players in order to provide a clearer picture regarding the energy demands in modern tennis. Forty-eight (48) athletes and 24 tennis players from Croatian national leagues were compared in morphological and physiological parameters of an all-out incremental treadmill test with gas exchange measurements. Tennis players' HRmax (192.96+/-7.75 bpm) shows values that are most different to 400-meters sprinters (200.13+/-6.95 bpm). Maximum running speed of tennis players on the treadmill (vmax) is no different with the speed achieved by sprinters, while there are significant differences among other athletes. Values in running speed at anaerobic threshold (vAnT) show no statistically significant difference with the values for athlete sprinters and 400-m sprinters. Values of RvO2max for tennis players indicate significant similarities with athlete sprinters and 400-m sprinters while the values of RvO2AnT are nearly identical with the values for sprinters and show no statistically significant differences (p<0.05). The results indicate that values achieved by tennis players approximate most different those of the middle and long distance runners. This singles out the possible importance of the anaerobic capacity and the high level of sprint endurance in tennis players. Knowing these characteristics is the basis for planning and implementing training systems that will enable the increase and optimal usage of energy capacities of tennis players in possibly improving sports results.

Kinetic evaluation of chromium(VI) sorption by water lettuce (Pistia).

PubMed

Chakraborty, Rupa; Karmakar, Sukalpa; Mukherjee, Somnath; Kumar, Sunil

2014-01-01

An investigation was performed to evaluate the uptake capacity of Pistia in living condition for adsorptive removal of chromium(VI) from spiked solution for examining a remedial measure for disposal of chrome-laden wastewater in an urban wetland system. Kinetics results show about 78% removal was achieved for 3 mg/L initial concentration of Cr(VI). Experimental data showed that the root portion absorbed more Cr(VI) (28.54 μg/g) compared to accumulation in leaf (5.73 μg/g). It was also noted that the plant could effectively remove Cr(VI) from the solution with minor damage up to an initial Cr(VI) concentration of 3 mg/L, for which the adsorption isotherm studies were conducted. The maximum uptake capacity of the plant was recorded as 0.05 mg/g of Cr(VI) at the equilibrium level after a contact period of 7 days for an initial concentration of 8 mg /L, although severe physiological damage occurred. The experimental results were plotted in Langmuir and Freundlich isotherm models and both were found to be well fitted (r(2) = 0.979 and r(2) = 0.974 respectively). The high value of n (2.16) reveals a strong bond between the plant root and dissolved Cr(VI), which favours the adsorption process. The order of the reaction was also examined on the basis of uptake capacity and it was found that the second order model fitted best.

Lizards infected with malaria: physiological and behavioral consequences.

PubMed

Schall, J J

1982-09-10

In northern California, western fence lizards, Sceloporus occidentalis, are frequently parasitized by Plasmodium mexicanum, which causes malaria. Animals with this naturally occurring malarial infection are anemic: immature erythrocytes in peripheral blood become abundant (1 to 30 percent), and blood hemoglobin concentration decreases 25 percent. Maximal oxygen consumption decreases 15 percent and aerobic scope drops 29 percent in infected lizards; both correlate with blood hemoglobin concentration. Running stamina, but not burst running speed, is reduced in malarious lizards. There is a hierarchical relation between infection with malaria and effects on hematology, physiological function, and behavioral capacity. The results suggest that malarial infection may have significant effects on the ecology of lizard hosts.

Biological properties of extracellular vesicles and their physiological functions

PubMed Central

Yáñez-Mó, María; Siljander, Pia R.-M.; Andreu, Zoraida; Zavec, Apolonija Bedina; Borràs, Francesc E.; Buzas, Edit I.; Buzas, Krisztina; Casal, Enriqueta; Cappello, Francesco; Carvalho, Joana; Colás, Eva; Silva, Anabela Cordeiro-da; Fais, Stefano; Falcon-Perez, Juan M.; Ghobrial, Irene M.; Giebel, Bernd; Gimona, Mario; Graner, Michael; Gursel, Ihsan; Gursel, Mayda; Heegaard, Niels H. H.; Hendrix, An; Kierulf, Peter; Kokubun, Katsutoshi; Kosanovic, Maja; Kralj-Iglic, Veronika; Krämer-Albers, Eva-Maria; Laitinen, Saara; Lässer, Cecilia; Lener, Thomas; Ligeti, Erzsébet; Linē, Aija; Lipps, Georg; Llorente, Alicia; Lötvall, Jan; Manček-Keber, Mateja; Marcilla, Antonio; Mittelbrunn, Maria; Nazarenko, Irina; Hoen, Esther N.M. Nolte-‘t; Nyman, Tuula A.; O'Driscoll, Lorraine; Olivan, Mireia; Oliveira, Carla; Pállinger, Éva; del Portillo, Hernando A.; Reventós, Jaume; Rigau, Marina; Rohde, Eva; Sammar, Marei; Sánchez-Madrid, Francisco; Santarém, N.; Schallmoser, Katharina; Ostenfeld, Marie Stampe; Stoorvogel, Willem; Stukelj, Roman; Van der Grein, Susanne G.; Vasconcelos, M. Helena; Wauben, Marca H. M.; De Wever, Olivier

2015-01-01

In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system. PMID:25979354

Biological properties of extracellular vesicles and their physiological functions.

PubMed

Yáñez-Mó, María; Siljander, Pia R-M; Andreu, Zoraida; Zavec, Apolonija Bedina; Borràs, Francesc E; Buzas, Edit I; Buzas, Krisztina; Casal, Enriqueta; Cappello, Francesco; Carvalho, Joana; Colás, Eva; Cordeiro-da Silva, Anabela; Fais, Stefano; Falcon-Perez, Juan M; Ghobrial, Irene M; Giebel, Bernd; Gimona, Mario; Graner, Michael; Gursel, Ihsan; Gursel, Mayda; Heegaard, Niels H H; Hendrix, An; Kierulf, Peter; Kokubun, Katsutoshi; Kosanovic, Maja; Kralj-Iglic, Veronika; Krämer-Albers, Eva-Maria; Laitinen, Saara; Lässer, Cecilia; Lener, Thomas; Ligeti, Erzsébet; Linē, Aija; Lipps, Georg; Llorente, Alicia; Lötvall, Jan; Manček-Keber, Mateja; Marcilla, Antonio; Mittelbrunn, Maria; Nazarenko, Irina; Nolte-'t Hoen, Esther N M; Nyman, Tuula A; O'Driscoll, Lorraine; Olivan, Mireia; Oliveira, Carla; Pállinger, Éva; Del Portillo, Hernando A; Reventós, Jaume; Rigau, Marina; Rohde, Eva; Sammar, Marei; Sánchez-Madrid, Francisco; Santarém, N; Schallmoser, Katharina; Ostenfeld, Marie Stampe; Stoorvogel, Willem; Stukelj, Roman; Van der Grein, Susanne G; Vasconcelos, M Helena; Wauben, Marca H M; De Wever, Olivier

2015-01-01

In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system.

Online mindfulness as a promising method to improve exercise capacity in heart disease: 12-month follow-up of a randomized controlled trial

PubMed Central

Younge, John O.; Wery, Machteld F.; Utens, Elisabeth M. W. J.; Michels, Michelle; Rizopoulos, Dimitris; van Rossum, Liesbeth F. C.; Roos-Hesselink, Jolien W.; Hunink, Myriam M. G.

2017-01-01

There is increasing evidence that mindfulness can reduce stress, and thereby affect other psychological and physiological outcomes as well. Earlier, we reported the direct 3-month results of an online modified mindfulness-based stress reduction training in patients with heart disease, and now we evaluate the effect at 12-month follow-up. 324 patients (mean age 43.2 years, 53.7% male) were randomized in a 2:1 ratio to additional 3-month online mindfulness training or to usual care alone. The primary outcome was exercise capacity measured with the 6 minute walk test (6MWT). Secondary outcomes were blood pressure, heart rate, respiratory rate, NT-proBNP, cortisol levels (scalp hair sample), mental and physical functioning (SF-36), anxiety and depression (HADS), perceived stress (PSS), and social support (PSSS12). Differences between groups on the repeated outcome measures were analyzed with linear mixed models. At 12-months follow-up, participants showed a trend significant improvement exercise capacity (6MWT: 17.9 meters, p = 0.055) compared to UC. Cohen’s D showed significant but small improvement on exercise capacity (d = 0.22; 95%CI 0.05 to 0.39), systolic blood pressure (d = 0.19; 95%CI 0.03 to 0.36), mental functioning (d = 0.22; 95%CI 0.05 to 0.38) and depressive symptomatology (d = 0.18; 95%CI 0.02 to 0.35). All other outcome measures did not change statistically significantly. In the as-treated analysis, systolic blood pressure decreased significantly with 5.5 mmHg (p = 0.045; d = 0.23 (95%CI 0.05–0.41)). Online mindfulness training shows favorable albeit small long-term effects on exercise capacity, systolic blood pressure, mental functioning, and depressive symptomatology in patients with heart disease and might therefore be a beneficial addition to current clinical care. Trial registration: www.trialregister.nl NTR3453 PMID:28486559

Impact of preoperative change in physical function on postoperative recovery: argument supporting prehabilitation for colorectal surgery.

PubMed

Mayo, Nancy E; Feldman, Liane; Scott, Susan; Zavorsky, Gerald; Kim, Do Jun; Charlebois, Patrick; Stein, Barry; Carli, Francesco

2011-09-01

Abdominal surgery represents a physiologic stress and is associated with a period of recovery during which functional capacity is often diminished. "Prehabilitation" is a program to increase functional capacity in anticipation of an upcoming stressor. We reported recently the results of a randomized trial comparing 2 prehabilitation programs before colorectal surgery (stationary cycling plus weight training versus a recommendation to increase walking coupled with breathing exercises); however, adherence to the programs was low. The objectives of this study were to estimate: (1) the extent to which physical function could be improved with either prehabilitation program and identify variables associated with response; and (2) the impact of change in preoperative function on postoperative recovery. This study involved a reanalysis of data arising from a randomized trial. The primary outcome measure was functional walking capacity measured by the Six-Minute Walk Test; secondary outcomes were anxiety, depression, health-related quality of life, and complications (Clavien classification). Multiple linear regression was used to estimate the extent to which key variables predicted change in functional walking capacity over the prehabilitation and follow-up periods. We included 95 people who completed the prehabilitation phase (median, 38 days; interquartile range, 22-60), and 75 who were also evaluated postoperatively (mean, 9 weeks). During prehabilitation, 33% improved their physical function, 38% stayed within 20 m of their baseline score, and 29% deteriorated. Among those who improved, mental health, vitality, self-perceived health, and peak exercise capacity also increased significantly. Women were less likely to improve; low baseline walking capacity, anxiety, and the belief that fitness aids recovery were associated with improvements during prehabilitation. In the postoperative phase, the patients who had improved during prehabilitation were also more likely to have recovered to their baseline walking capacity than those with no change or deterioration (77% vs 59% and 32%; P = .0007). Patients who deteriorated were at greater risk of complications requiring reoperation and/or intensive care management. Significant predictors of poorer recovery included deterioration during prehabilitation, age >75 years, high anxiety, complications requiring intervention, and timing of follow-up assessment. In a group of patients undergoing scheduled colorectal surgery, meaningful changes in functional capacity can be achieved over several weeks of prehabilitation. Patients and those who care for them, especially those with poor physical capacity, should consider a prehabilitation regimen to enhance functional exercise capacity before colectomy. Copyright © 2011 Mosby, Inc. All rights reserved.

Greater ankle strength, anaerobic and aerobic capacity, and agility predict Ground Combat Military Occupational School graduation in female Marines.

PubMed

Allison, Katelyn Fleishman; Keenan, Karen A; Wohleber, Meleesa F; Perlsweig, Katherine A; Pletcher, Erin R; Lovalekar, Mita; Beals, Kim; Coleman, Lawrence C; Nindl, Bradley C

2017-11-01

Women can serve in all military occupational specialties (MOS); however, musculoskeletal and physiological characteristics that predict successful completion of ground combat MOS schools by female Marines are unknown. To determine which demographic, musculoskeletal, and physiological characteristics predict graduation from infantry and vehicle ground combat MOS schools in female Marines. Prospective cohort study. Prior to MOS school, the following were assessed in 62 female Marines (22.0±3.0yrs, 163.9±5.8cm, 63.4±7.2kg): isokinetic shoulder, trunk, and knee and isometric ankle strength; body composition; anaerobic power (AP)/capacity (AC); maximal oxygen uptake (VO 2 max); and field-based fitness tests (broad jump, medicine ball throw, pro-agility). Both absolute and normalized (%body mass: %BM) values were utilized for strength, AP, AC, and VO 2 max. Select tests from each Marine's most recent Physical Fitness Test (PFT: abdominal crunches, 3-mile run time) and Combat Fitness Test (CFT: Maneuver Under Fire, Movement to Contact) were recorded. Participants were classified as graduated (N=46) or did not graduate (N=16). Simple logistic regression was performed to determine predictors of MOS school graduation. Statistical significance was set a priori at α=0.05. Absolute and normalized ankle inversion and eversion strength, normalized anaerobic capacity, absolute and normalized VO 2 max, right pro-agility, and PFT 3-mile run time significantly predicted MOS school graduation (p<0.05). Greater ankle strength, better agility, and greater anaerobic and aerobic capacity are important for successful completion of ground combat MOS school in female Marines. Prior to entering ground combat MOS school, it is recommended that female Marines should train to optimize these mobility-centric characteristics. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Effect of food restriction on energy budget in warm-acclimated striped hamsters.

PubMed

Zhao, Zhi-Jun; Chi, Qing-Sheng; Zhao, Liang; Zhu, Qiao-Xia; Cao, Jing; Wang, De-Hua

2015-08-01

The capacity of small mammals to sustain periods of food shortage largely depends on the adaptive regulation of energy budget in response to the decrease in food supply. In addition to food availability, ambient temperature (Ta) is an important factor affecting the rates of both energy intake and expenditure. To examine the effect of Ta on energy strategy and the capacity to sustain food shortage, striped hamsters were exposed to a warm condition (30°C) and were then restricted to 70% of ad libitum food intake. Body mass, energy intake and expenditure and physiological markers indicative of thermogenesis were measured. Warm exposure had no effect on body mass and digestibility, but decreased energy intake, basal metabolic rate and maximum nonshivering thermogenesis. The mitochondria protein content, cytochrome c oxidase activity and uncoupling protein 1 level of brown adipose tissue were significantly lower in hamsters at 30°C than at 21°C. Food restriction induced a significant decrease in body mass, but the decreased body mass was attenuated at 30°C relative to 21°C. This suggests that striped hamsters could not compensate for the limited food supply by decreasing daily energy expenditure at 21°C, whereas they could at 30°C. The significant reductions in the rates of metabolism and thermogenesis in warm-acclimated hamsters increase the capacity to cope with food shortage. Although, it remains uncertain whether this response represents some generalized evolutionary adaptation, the Ta-dependent adjustment in the capacity to survive food restriction may reflect that warm acclimation plays an important role in adaptive regulation of both physiology and behavior in response to the variations of food availability. Copyright © 2015 Elsevier Inc. All rights reserved.

Critical role of microbiota within cecal crypts on the regenerative capacity of the intestinal epithelium following surgical stress.

PubMed

Zaborin, Alexander; Krezalek, Monika; Hyoju, Sanjiv; Defazio, Jennifer R; Setia, Namrata; Belogortseva, Natalia; Bindokas, Vytautas P; Guo, Qiti; Zaborina, Olga; Alverdy, John C

2017-02-01

Cecal crypts represent a unique niche that are normally occupied by the commensal microbiota. Due to their density and close proximity to stem cells, microbiota within cecal crypts may modulate epithelial regeneration. Here we demonstrate that surgical stress, a process that invariably involves a short period of starvation, antibiotic exposure, and tissue injury, results in cecal crypt evacuation of their microbiota. Crypts devoid of their microbiota display pathophysiological features characterized by abnormal stem cell activation as judged by leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) staining, expansion of the proliferative zone toward the tips of the crypts, and an increase in apoptosis. In addition, crypts devoid of their microbiota display loss of their regenerative capacity as assessed by their ability to form organoids ex vivo. When a four-member human pathogen community isolated from the stool of a critically ill patient is introduced into the cecum of mice with empty crypts, crypts become occupied by the pathogens and further disruption of crypt homeostasis is observed. Fecal microbiota transplantation restores the cecal crypts' microbiota, normalizes homeostasis within crypts, and reestablishes crypt regenerative capacity. Taken together, these findings define an emerging role for the microbiota within cecal crypts to maintain epithelial cell homeostasis in a manner that may enhance recovery in response to the physiological stress imposed by the process of surgery. This study provides novel insight into the process by which surgical injury places the intestinal epithelium at risk for colonization by pathogenic microbes and impairment of its regenerative capacity via loss of its microbiota. We show that fecal transplant restores crypt homeostasis in association with repopulation of the microbiota within cecal crypts. Copyright © 2017 the American Physiological Society.

[Regulation effect of water storage in deeper soil layers on root physiological characteristics and leaf photosynthetic traits of cotton with drip irrigation under mulch].

PubMed

Luo, Hong-Hai; Zhang, Hong-Zhi; Du, Ming-Wei; Huang, Jian-Jun; Zhang, Ya-Li; Zhang, Wang-Feng

2009-06-01

A soil column culture experiment was conducted under the ecological and climatic conditions of Xinjiang to study the effects of water storage in deeper (> 60 cm) soil layers on the root physiological characteristics and leaf photosynthetic traits of cotton variety Xinluzao 13. Two treatments were installed, i.e., well-watered and no watering. The moisture content in plough layer was controlled at 70% +/- 5% and 55% +/- 5% of field capacity by drip irrigation under mulch during growth season. It was shown that the water storage in deeper soil layers enhanced the SOD activity and the vigor of cotton root, and increased the water use efficiency of plant as well as the leaf water potential, chlorophyll content, and net photosynthesis rate, which finally led to a higher yield of seed cotton and higher water use efficiency. Under well-watered condition and when the moisture content in plough layer was maintained at 55% of field capacity, the senescence of roots in middle and lower soil layers was slower, and the higher root vigor compensated the negative effects of impaired photosynthesis caused by water deficit to some extent. The yield of seed cotton was lower when the moisture content in plough layer was maintained at 55% of field capacity than at 70% of field capacity, but no significant difference was observed in the water use efficiency. Our results emphasized the importance of pre-sowing irrigation in winter or in spring to increase the water storage of deeper soil layers. In addition, proper cultivation practices and less frequent drip irrigation (longer intervals between successive rounds of irrigation) were also essential for conserving irrigation water and achieving higher yield.

Revalidation of the Score for Neonatal Acute Physiology in the Vermont Oxford Network.

PubMed

Zupancic, John A F; Richardson, Douglas K; Horbar, Jeffrey D; Carpenter, Joseph H; Lee, Shoo K; Escobar, Gabriel J

2007-01-01

Our specific objectives were (1) to document the performance of the revised Score for Neonatal Acute Physiology and the revised Score for Neonatal Acute Physiology Perinatal Extension in predicting death in the Vermont Oxford Network, compared with published normative values; (2) to determine whether this performance could be improved through recalibration of the weights for individual score items; (3) to determine the impact of including congenital anomalies in the predictive model; and (4) to compare performance against that of the Vermont Oxford Network risk adjustment, separately and in combination. Fifty-eight Vermont Oxford Network centers collected data prospectively for the revised Score for Neonatal Acute Physiology in the first 12 hours after admission of infants in 2002. Data were collected for 10,469 infants, and analyses were undertaken for 9897 who met inclusion criteria. The median revised Score for Neonatal Acute Physiology was 5, and the mean birth weight was 1951 g. Recalibration of the revised Score for Neonatal Acute Physiology and revised Score for Neonatal Acute Physiology Perinatal Extension resulted in minimal changes in their discriminatory abilities. The Vermont Oxford Network risk adjustment performed similarly, compared with the revised Score for Neonatal Acute Physiology Perinatal Extension. Current score performance was similar to that observed previously, which suggests that the revised Score for Neonatal Acute Physiology and revised Score for Neonatal Acute Physiology Perinatal Extension have not decalibrated over the 7 years since the first cohort was assembled, despite advances in neonatal care during that period. Addition of congenital anomalies to the revised Score for Neonatal Acute Physiology Perinatal Extension improved discrimination significantly, particularly for infants with birth weights of >1500 g. The Vermont Oxford Network risk adjustment performed similarly, compared with the revised Score for Neonatal Acute Physiology Perinatal Extension.

Chronic Obstructive Pulmonary Disease: Lobe-based Visual Assessment of Volumetric CT by Using Standard Images—Comparison with Quantitative CT and Pulmonary Function Test in the COPDGene Study

PubMed Central

Kim, Song Soo; Lee, Ho Yun; Nevrekar, Dipti V.; Forssen, Anna V.; Crapo, James D.; Schroeder, Joyce D.; Lynch, David A.

2013-01-01

Purpose: To provide a new detailed visual assessment scheme of computed tomography (CT) for chronic obstructive pulmonary disease (COPD) by using standard reference images and to compare this visual assessment method with quantitative CT and several physiologic parameters. Materials and Methods: This research was approved by the institutional review board of each institution. CT images of 200 participants in the COPDGene study were evaluated. Four thoracic radiologists performed independent, lobar analysis of volumetric CT images for type (centrilobular, panlobular, and mixed) and extent (on a six-point scale) of emphysema, the presence of bronchiectasis, airway wall thickening, and tracheal abnormalities. Standard images for each finding, generated by two radiologists, were used for reference. The extent of emphysema, airway wall thickening, and luminal area were quantified at the lobar level by using commercial software. Spearman rank test and simple and multiple regression analyses were performed to compare the results of visual assessment with physiologic and quantitative parameters. Results: The type of emphysema, determined by four readers, showed good agreement (κ = 0.63). The extent of the emphysema in each lobe showed good agreement (mean weighted κ = 0.70) and correlated with findings at quantitative CT (r = 0.75), forced expiratory volume in 1 second (FEV1) (r = −0.68), FEV1/forced vital capacity (FVC) ratio (r = −0.74) (P < .001). Agreement for airway wall thickening was fair (mean κ = 0.41), and the number of lobes with thickened bronchial walls correlated with FEV1 (r = −0.60) and FEV1/FVC ratio (r = −0.60) (P < .001). Conclusion: Visual assessment of emphysema and airways disease in individuals with COPD can provide reproducible, physiologically substantial information that may complement that provided by quantitative CT assessment. © RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120385/-/DC1 PMID:23220894

A murine model of a novel surgical architecture for proprioceptive muscle feedback and its potential application to control of advanced limb prostheses

NASA Astrophysics Data System (ADS)

Clites, Tyler R.; Carty, Matthew J.; Srinivasan, Shriya; Zorzos, Anthony N.; Herr, Hugh M.

2017-06-01

Objective. Proprioceptive mechanisms play a critical role in both reflexive and volitional lower extremity control. Significant strides have been made in the development of bionic limbs that are capable of bi-directional communication with the peripheral nervous system, but none of these systems have been capable of providing physiologically-relevant muscle-based proprioceptive feedback through natural neural pathways. In this study, we present the agonist-antagonist myoneural interface (AMI), a surgical approach with the capacity to provide graded kinesthetic feedback from a prosthesis through mechanical activation of native mechanoreceptors within residual agonist-antagonist muscle pairs. Approach. (1) Sonomicrometery and electroneurography measurement systems were validated using a servo-based muscle tensioning system. (2) A heuristic controller was implemented to modulate functional electrical stimulation of an agonist muscle, using sonomicrometric measurements of stretch from a mechanically-coupled antagonist muscle as feedback. (3) One AMI was surgically constructed in the hindlimb of each rat. (4) The gastrocnemius-soleus complex of the rat was cycled through a series of ramp-and-hold stretches in two different muscle architectures: native (physiologically-intact) and AMI (modified). Integrated electroneurography from the tibial nerve was compared across the two architectures. Main results. Correlation between stretch and afferent signal demonstrated that the AMI is capable of provoking graded afferent signals in response to ramp-and-hold stretches, in a manner similar to the native muscle architecture. The response magnitude in the AMI was reduced when compared to the native architecture, likely due to lower stretch amplitudes. The closed-loop control system showed robustness at high stretch magnitudes, with some oscillation at low stretch magnitudes. Significance. These results indicate that the AMI has the potential to communicate meaningful kinesthetic feedback from a prosthetic limb by replicating the agonist-antagonist relationships that are fundamental to physiological proprioception.

Successful Implementation of Inquiry-Based Physiology Laboratories in Undergraduate Major and Nonmajor Courses

ERIC Educational Resources Information Center

Casotti, G.; Rieser-Danner, L.; Knabb, M. T.

2008-01-01

Recent evidence has demonstrated that inquiry-based physiology laboratories improve students' critical- and analytical-thinking skills. We implemented inquiry-based learning into three physiology courses: Comparative Vertebrate Physiology (majors), Human Physiology (majors), and Human Anatomy and Physiology (nonmajors). The aims of our curricular…

Stimulation of the Nonneuronal Cholinergic System by Highly Diluted Acetylcholine in Keratinocytes.

PubMed

Uberti, Francesca; Bardelli, Claudio; Morsanuto, Vera; Ghirlanda, Sabrina; Cochis, Andrea; Molinari, Claudio

2017-01-01

The physiological effects of acetylcholine on keratinocytes depend on the presence of nicotinic and muscarinic receptors. The role of nonneuronal acetylcholine in keratinocytes could have important clinical implications for patients with various skin disorders such as nonhealing wounds. In order to evaluate the efficacy of highly diluted acetylcholine solutions obtained by sequential kinetic activation, we aimed to investigate the effects of these solutions on normal human keratinocytes. Two different concentrations (10 fg/mL and 1 pg/mL) and formulations (kinetically activated and nonkinetically activated) of acetylcholine were used to verify keratinocyte viability, proliferation, and migration and the intracellular pathways involved using MTT, crystal violet, wound healing, and Western blot compared to 147 ng/mL acetylcholine. The activated formulations (1 pg/mL and 10 fg/mL) revealed a significant capacity to increase migration, cell viability, and cell proliferation compared to 147 ng/mL acetylcholine, and these effects were more evident after a single administration. Sequential kinetic activation resulted in a statistically significant decrease in reactive oxygen species production accompanied by an increase in mitochondrial membrane potential and a decrease in oxygen consumption compared to 147 ng/mL acetylcholine. The M1 muscarinic receptor was involved in these effects. Finally, the involvement of ERK/mitogen-activated protein kinases (MAPK) and KI67 confirmed the effectiveness of the single treatment on cell proliferation. The intracellular pathways of calcium were investigated as well. Our results indicate for the first time that highly diluted and kinetically activated acetylcholine seems to play an active role in an in vitro model of wound healing. Moreover, the administration of acetylcholine within the physiological range may not only be effective but is also likely to be safe. © 2016 S. Karger AG, Basel.

Chronic unpredictable stress regulates visceral adipocyte‐mediated glucose metabolism and inflammatory circuits in male rats

PubMed Central

Karagiannides, Iordanes; Golovatscka, Viktoriya; Bakirtzi, Kyriaki; Sideri, Aristea; Salas, Martha; Stavrakis, Dimitris; Polytarchou, Christos; Iliopoulos, Dimitrios; Pothoulakis, Charalabos; Bradesi, Sylvie

2014-01-01

Abstract Chronic psychological stress is a prominent risk factor involved in the pathogenesis of many complex diseases, including major depression, obesity, and type II diabetes. Visceral adipose tissue is a key endocrine organ involved in the regulation of insulin action and an important component in the development of insulin resistance. Here, we examined for the first time the changes on visceral adipose tissue physiology and on adipocyte‐associated insulin sensitivity and function after chronic unpredictable stress in rats. Male rats were subjected to chronic unpredictable stress for 35 days. Total body and visceral fat was measured. Cytokines and activated intracellular kinase levels were determined using high‐throughput multiplex assays. Adipocyte function was assessed via tritiated glucose uptake assay. Stressed rats showed no weight gain, and their fat/lean mass ratio increased dramatically compared to control animals. Stressed rats had significantly higher mesenteric fat content and epididymal fat pad weight and demonstrated reduced serum glucose clearing capacity following glucose challenge. Alterations in fat depot size were mainly due to changes in adipocyte numbers and not size. High‐throughput molecular screening in adipocytes isolated from stressed rats revealed activation of intracellular inflammatory, glucose metabolism, and MAPK networks compared to controls, as well as significantly reduced glucose uptake capacity in response to insulin stimulation. Our study identifies the adipocyte as a key regulator of the effects of chronic stress on insulin resistance, and glucose metabolism, with important ramifications in the pathophysiology of several stress‐related disease states. PMID:24819750

A randomized controlled trial comparing periodic mask CPAP with physiotherapy after abdominal surgery.

PubMed

Denehy, L; Carroll, S; Ntoumenopoulos, G; Jenkins, S

2001-01-01

Physiotherapists use a variety of techniques aimed at improving lung volumes and secretion clearance in patients after surgery. Periodic continuous positive airway pressure (PCPAP) is used to treat patients following elective upper abdominal surgery. However, the optimal method of application has not been identified, more specifically, the dosage of application of PCPAP. The present randomized controlled trial compared the effects of two dosages of PCPAP application and 'traditional' physiotherapy upon functional residual capacity (FRC), vital capacity (VC), oxyhaemoglobin saturation (SpO2), incidence of post-operative pulmonary complications and length of stay with a control group receiving 'traditional' physiotherapy only. Fifty-seven subjects were randomly allocated to one of three groups. All groups received 'traditional' physiotherapy twice daily for a minimum of three post-operative days. In addition, two groups received PCPAP for 15 or 30 minutes, four times per day, for three days. Fifty subjects (39 male; 11 female) completed the study. There were no significant differences in any variables between the three groups. The overall incidence of post-operative pulmonary complications was 22% in the control group, 11% and 6% in the PCPAP 15-minute and PCPAP 30-minute groups, respectively. Length of hospital stay was not significantly different between the groups but for subjects who developed post-operative pulmonary complications, the length of stay was significantly greater (Z = -2.32; p = 0.021). The addition of PCPAP to a traditional physiotherapy post-operative treatment regimen after upper abdominal surgery did not significantly affect physiological or clinical outcomes.

Effects of N-acetylcysteine on semen parameters and oxidative/antioxidant status.

PubMed

Ciftci, Halil; Verit, Ayhan; Savas, Murat; Yeni, Ercan; Erel, Ozcan

2009-07-01

To examine whether a beneficial effect of N-acetylcysteine (NAC) on semen parameters and oxidative/antioxidant status in idiopathic male infertility exists. The production of reactive oxygen species is a normal physiologic event in various organs. However, overproduction of reactive oxygen species can be detrimental to sperm and has been associated with male infertility. Our study included 120 patients who had attended our clinic and were diagnosed with idiopathic infertility according to medical history and physical and seminal examination findings, as initial evaluations. The patients were divided randomly into 2 groups. Those in the study group (60 men) were given NAC (600 mg/d orally) for 3 months; the control group (60 men) received a placebo. The oxidative status was determined by measuring the total antioxidant capacity, total peroxide and oxidative stress index in plasma samples. The sperm parameters were evaluated after NAC treatment and were compared with those in the control group. NAC had significant improving effects on the volume, motility, and viscosity of semen. After NAC treatment, the serum total antioxidant capacity was greater and the total peroxide and oxidative stress index were lower in the NAC-treated group compared with the control group. These beneficial effects resulted from reduced reactive oxygen species in the serum and reduced viscosity of the semen. No significant differences were found in the number or morphology of the sperm between the 2 groups. We believe that NAC could improve some semen parameters and the oxidative/antioxidant status in patients with male infertility.

Physiological and lactation responses of Egyptian dairy Baladi goats to natural thermal stress under subtropical environmental conditions.

PubMed

El-Tarabany, Mahmoud S; El-Tarabany, Akram A; Atta, Mostafa A

2017-01-01

The objective of this study was to evaluate the impact of thermal stress on milk production and physiological traits of Baladi goats under subtropical Egyptian conditions. Sixty dairy Baladi goats were exposed to three different levels of temperature-humidity index (THI), including low (less than 70), moderate (over 70 and up to 80), and high levels (over 80). The influence of THI on the milk composition and physiological, hematological, and biochemical traits was investigated. Rectal temperature and respiration rate were significantly greater at the higher THI than at low and moderate THI (p = 0.016 and 0.002, respectively). Baladi goats had decreased daily milk yield in a rate of 27.3 and 19.3 % at high THI level, compared with low and moderate THI, respectively (p = 0.031). On the contrary, no significant differences have been reported in protein, fat, and total solids percentages at different THI levels. Total leucocyte count, serum glucose, and total protein were significantly reduced at high THI in comparison with low and moderate THI levels (p = 0.043, 0.001, and 0.001, respectively). However, dairy goats maintained relatively stable estimates for erythrocytes count, hemoglobin, serum triglycerides, cholesterol, catalase, total antioxidant capacity, and triiodothyronine at different THI levels. Our results indicate that dairy Baladi goats can tolerate THI levels up to 80; however, variable reduction in milk yield and few biochemical (serum total protein and glucose) and hematological (leucocytes count) parameters have been reported at a THI level higher than 80.

Master of all trades: thermal acclimation and adaptation of cardiac function in a broadly distributed marine invasive species, the European green crab, Carcinus maenas.

PubMed

Tepolt, Carolyn K; Somero, George N

2014-04-01

As global warming accelerates, there is increasing concern about how ecosystems may change as a result of species loss and replacement. Here, we examined the thermal physiology of the European green crab (Carcinus maenas Linnaeus 1758), a globally invasive species, along three parallel thermal gradients in its native and invasive ranges. At each site, we assessed cardiac physiology to determine heat and cold tolerance and acclimatory plasticity. We found that, overall, the species is highly tolerant of both heat and cold, and that it survives higher temperatures than co-occurring native marine crustaceans. Further, we found that both heat and cold tolerance are plastic in response to short-term acclimation (18-31 days at either 5 or 25°C). Comparing patterns within ranges, we found latitudinal gradients in thermal tolerance in the native European range and in the invasive range in eastern North America. This pattern is strongest in the native range, and likely evolved there. Because of a complicated invasion history, the latitudinal pattern in the eastern North American invasive range may be due either to rapid adaptation post-invasion or to adaptive differences between the ancestral populations that founded the invasion. Overall, the broad thermal tolerance ranges of green crabs, which may facilitate invasion of novel habitats, derive from high inherent eurythermality and acclimatory plasticity and potentially adaptive differentiation among populations. The highly flexible physiology that results from these capacities may represent the hallmark of a successful invasive species, and may provide a model for success in a changing world.

Thermal biology of two sympatric gerbil species: The physiological basis of temporal partitioning.

PubMed

Ding, Bo-Yang; Chi, Qing-Sheng; Liu, Wei; Shi, Yao-Long; Wang, De-Hua

2018-05-01

Sympatric species can coexist through ecological resource partitioning as for example for habitat, food or time. However, a detailed understanding of the basic thermal physiology, crucial for temporal partitioning, is currently lacking, especially for the desert rodents. Here, we compare the physiological performance with regard to thermal energetics and morphological traits of two sympatric gerbils from the Gobi desert of Inner Mongolia, China. The diurnally active Meriones unguiculatus and the nocturnally active M. meridianus. The diurnal M. unguiculatus had more brown adipose tissue (BAT) mass and capacity for non-shivering thermogenesis (NST), a higher resting metabolic rate (RMR) at low ambient temperatures (T a ) and a higher upper critical temperature of the thermal neutral zone (TNZ) than the nocturnal M. meridianus. The overall thermal conductance and lower critical temperatures of M. unguiculatus were also higher than that of M. meridianus, permitting the former to maintain a stable body temperature (T b ) when exposed to high T a . Laboratory-bred M. meridianus also showed higher daily water intake. We found no differences in body mass, and total evaporative water loss (TEWL) between the two species captured from the natural environment. These results suggest that the diurnal M. unguiculatus have a higher tolerance of high T a s, whereas M. meridianus can save more energy at low T a s. Therefore, from the view point of energy conservation, our results suggest that the nocturnal ecophenotype in M. meridianus is constrained by a lower ability for heat resistance, but this is not the case for the diurnal M. unguiculatus. Copyright © 2018 Elsevier Ltd. All rights reserved.

The effects of acclimatization on blood clotting parameters in exertional heat stress.

PubMed

Vesić, Zoran; Vukasinović-Vesić, Milica; Dincić, Dragan; Surbatović, Maja; Radaković, Sonja S

2013-07-01

Exertional heat stress is a common problem in military services. Considering the coagulation abnormalities are of major importance in development of severe heat stroke, we wanted to examine changes in hemostatic parameters in soldiers during exertional heat stress test as well as the effects of a 10-day passive or active acclimatization in a climatic chamber. A total of 40 male soldiers with high aerobic capacity performed exertional heat stress test (EHST) either in cool [20 degrees C, 16 degrees C wet bulb globe temperature (WBGT)], or hot (40 degrees C, 29 degrees C, (WBGT) environment, unacclimatized (U) or after 10 days of passive (P) or active (A) acclimatization. Physiological strain was measured by tympanic temperatures (Tty) and heart rates (HR). Platelet count (PC), antithrombin III (AT), and prothrombin time (PT) were assessed in blood samples collected before and immediately after the EHST. EHST in hot conditions induced physiological heat stress (increase in Tty and HR), with a significant increase in prothrombin time in the groups U and A. Platelet counts were significantly higher after the EHST compared to the basic levels in all the investigated groups, regardless environmental conditions and acclimatization state. Antithrombin levels were not affected by EHST whatsoever. In the trained soldiers, physiological heat stress caused mild changes in some serum parameters of blood clotting such as prothrombin time, while others such as antithrombin levels were not affected. Platelet counts were increased after EHST in all groups. A 10-day passive or active acclimatization in climatic chamber showed no effect on parameters investigated.

Ontogeny of intestinal safety factors: lactase capacities and lactose loads.

PubMed

O'Connor, T P; Diamond, J

1999-03-01

We measured intestinal safety factors (ratio of a physiological capacity to the load on it) for lactose digestion in developing rat pups. Specifically, we assessed the quantitative relationships between lactose load and the series capacities of lactase and the Na+-glucose cotransporter (SGLT-1). Both capacities increased significantly with age in suckling pups as a result of increasing intestinal mass and maintenance of mass-specific activities. The youngest pups examined (5 days) had surprisingly high safety factors of 8-13 for both lactase and SGLT-1, possibly because milk contains lactase substrates other than lactose; it also, however, suggests that their intestinal capacities were being prepared to meet future demands rather than just current ones. By day 10 (and also at day 15), increased lactose loads resulted in lower safety factors of 4-6, values more typical of adult intestines. The safety factor of SGLT-1 in day 30 (weanling) and day 100 (adult) rats was only approximately 1.0. This was initially unexpected, because most adult intestines maintain a modest reserve capacity beyond nutrient load values, but postweaning rats appear to use hindgut fermentation, assessed by gut morphology and hydrogen production assays, as a built-in reserve capacity. The series capacities of lactase and SGLT-1 varied in concert with each other over ontogeny and as lactose load was manipulated by experimental variation in litter size.

[K+ channels and lung epithelial physiology].

PubMed

Bardou, Olivier; Trinh, Nguyen Thu Ngan; Brochiero, Emmanuelle

2009-04-01

Transcripts of more than 30 different K(+) channels have been detected in the respiratory epithelium lining airways and alveoli. These channels belong to the 3 main classes of K(+) channels, i.e. i) voltage-dependent or calcium-activated, 6 transmembrane segments (TM), ii) 2-pores 4-TM and iii) inward-rectified 2-TM channels. The physiological and functional significance of this high molecular diversity of lung epithelial K(+) channels is not well understood. Surprisingly, relatively few studies are focused on K(+) channel function in lung epithelial physiology. Nevertheless, several studies have shown that KvLQT1, KCa and K(ATP) K(+) channels play a crucial role in ion and fluid transport, contributing to the control of airway and alveolar surface liquid composition and volume. K(+) channels are involved in other key functions, such as O(2) sensing or the capacity of the respiratory epithelia to repair after injury. This mini-review aims to discuss potential functions of lung K(+) channels.

Bio-logging of physiological parameters in higher marine vertebrates

NASA Astrophysics Data System (ADS)

Ponganis, Paul J.

2007-02-01

Bio-logging of physiological parameters in higher marine vertebrates had its origins in the field of bio-telemetry in the 1960s and 1970s. The development of microprocessor technology allowed its first application to bio-logging investigations of Weddell seal diving physiology in the early 1980s. Since that time, with the use of increased memory capacity, new sensor technology, and novel data processing techniques, investigators have examined heart rate, temperature, swim speed, stroke frequency, stomach function (gastric pH and motility), heat flux, muscle oxygenation, respiratory rate, diving air volume, and oxygen partial pressure (P) during diving. Swim speed, heart rate, and body temperature have been the most commonly studied parameters. Bio-logging investigation of pressure effects has only been conducted with the use of blood samplers and nitrogen analyses on animals diving at isolated dive holes. The advantages/disadvantages and limitations of recording techniques, probe placement, calibration techniques, and study conditions are reviewed.

Flight Capacity of Bactrocera dorsalis (Diptera: Tephritidae) Adult Females Based on Flight Mill Studies and Flight Muscle Ultrastructure

PubMed Central

Chen, Peng; Yuan, Ruiling; Wang, Xiaowei; Xu, Jin

2015-01-01

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is considered a major economic threat in many regions worldwide. To better comprehend flight capacity of B. dorsalis and its physiological basis, a computer-monitored flight mill was used to study flight capacity of B. dorsalis adult females of various ages, and the changes of its flight muscle ultrastructures were studied by transmission electron microscopy. The flight capacity (both speed and distance) changed significantly with age of B. dorsalis female adults, peaking at about 15 d; the myofibril diameter of the flight muscle of test insects at 15-d old was the longest, up to 1.56 µm, the sarcomere length at 15-d old was the shortest, averaging at 1.37 µm, volume content of mitochondria of flight muscle at 15-d old reached the peak, it was 32.64%. This study provides the important scientific data for better revealing long-distance movement mechanism of B. dorsalis. PMID:26450591

[The use of biological age on mental work capacity model in accelerated aging assessment of professional lorry-drivers].

PubMed

Bashkireva, A S

2012-01-01

The studies of biological age, aging rate, mental work capacity in professional drivers were conducted. The examination revealed peculiarities of system organization of functions determining the mental work capacity levels. Dynamics of the aging process of professional driver's organism in relation with calendar age and driving experience were shown using the biological age model. The results point at the premature decrease of the mental work capacity in professional drivers. It was proved, that premature age-related changes of physiologic and psychophysiologic indices in drivers are just "risk indicators", while long driving experience is a real risk factor, accelerating the aging process. The "risk group" with manifestations of accelerating aging was observed in 40-49-year old drivers with 15-19 years of professional experience. The expediency of using the following methods for the age rate estimation according to biologic age indices and necessity of prophylactic measures for premature and accelerated aging prevention among working population was demonstrated.

Burst muscle performance predicts the speed, acceleration, and turning performance of Anna’s hummingbirds

PubMed Central

Segre, Paolo S; Dakin, Roslyn; Zordan, Victor B; Dickinson, Michael H; Straw, Andrew D; Altshuler, Douglas L

2015-01-01

Despite recent advances in the study of animal flight, the biomechanical determinants of maneuverability are poorly understood. It is thought that maneuverability may be influenced by intrinsic body mass and wing morphology, and by physiological muscle capacity, but this hypothesis has not yet been evaluated because it requires tracking a large number of free flight maneuvers from known individuals. We used an automated tracking system to record flight sequences from 20 Anna's hummingbirds flying solo and in competition in a large chamber. We found that burst muscle capacity predicted most performance metrics. Hummingbirds with higher burst capacity flew with faster velocities, accelerations, and rotations, and they used more demanding complex turns. In contrast, body mass did not predict variation in maneuvering performance, and wing morphology predicted only the use of arcing turns and high centripetal accelerations. Collectively, our results indicate that burst muscle capacity is a key predictor of maneuverability. DOI: http://dx.doi.org/10.7554/eLife.11159.001 PMID:26583753

Flight Morphology, Compound Eye Structure and Dispersal in the Bog and the Cranberry Fritillary Butterflies: An Inter- and Intraspecific Comparison.

PubMed

Turlure, Camille; Schtickzelle, Nicolas; Van Dyck, Hans; Seymoure, Brett; Rutowski, Ronald

2016-01-01

Understanding dispersal is of prime importance in conservation and population biology. Individual traits related to motion and navigation during dispersal may differ: (1) among species differing in habitat distribution, which in turn, may lead to interspecific differences in the potential for and costs of dispersal, (2) among populations of a species that experiences different levels of habitat fragmentation; (3) among individuals differing in their dispersal strategy and (4) between the sexes due to sexual differences in behaviour and dispersal tendencies. In butterflies, the visual system plays a central role in dispersal, but exactly how the visual system is related to dispersal has received far less attention than flight morphology. We studied two butterfly species to explore the relationships between flight and eye morphology, and dispersal. We predicted interspecific, intraspecific and intersexual differences for both flight and eye morphology relative to i) species-specific habitat distribution, ii) variation in dispersal strategy within each species and iii) behavioural differences between sexes. However, we did not investigate for potential population differences. We found: (1) sexual differences that presumably reflect different demands on both male and female visual and flight systems, (2) a higher wing loading (i.e. a proxy for flight performance), larger eyes and larger facet sizes in the frontal and lateral region of the eye (i.e. better navigation capacities) in the species inhabiting naturally fragmented habitat compared to the species inhabiting rather continuous habitat, and (3) larger facets in the frontal region in dispersers compared to residents within a species. Hence, dispersers may have similar locomotory capacity but potentially better navigation capacity. Dispersal ecology and evolution have attracted much attention, but there are still significant gaps in our understanding of the mechanisms of dispersal. Unfortunately, for many species we lack detailed information on the role of behavioural, morphological and physiological traits for dispersal. Our novel study supports the existence of inter- and intra-specific evolutionary responses in both motion and navigation capacities (i.e. flight and eye morphology) linked to dispersal.

Impact of ocean acidification on the hypoxia tolerance of the woolly sculpin, Clinocottus analis.

PubMed

Hancock, Joshua R; Place, Sean P

2016-01-01

As we move into the Anthropocene, organisms inhabiting marine environments will continue to face growing challenges associated with changes in ocean pH (ocean acidification), dissolved oxygen (dead zones) and temperature. These factors, in combination with naturally variable environments such as the rocky intertidal zone, may create extreme physiological challenges for organisms that are already performing near their biological limits. Although numerous studies have examined the impacts of climate-related stressors on intertidal animals, little is known about the underlying physiological mechanisms driving adaptation to ocean acidification and how this may alter organism interactions, particularly in marine vertebrates. Therefore, we have investigated the effects of decreased ocean pH on the hypoxia response of an intertidal sculpin, Clinocottus analis . We used both whole-animal and biochemistry-based analyses to examine how the energetic demands associated with acclimation to low-pH environments may impact the fish's reliance on facultative air breathing in low-oxygen environments. Our study demonstrated that acclimation to ocean acidification resulted in elevated routine metabolic rates and acid-base regulatory capacity (Na + ,K + -ATPase activity). These, in turn, had downstream effects that resulted in decreased hypoxia tolerance (i.e. elevated critical oxygen tension). Furthermore, we present evidence that these fish may be living near their physiological capacity when challenged by ocean acidification. This serves as a reminder that the susceptibility of teleost fish to changes in ocean pH may be underestimated, particularly when considering the multiple stressors that many experience in their natural environments.

Joint control of terrestrial gross primary productivity by plant phenology and physiology

PubMed Central

Xia, Jianyang; Niu, Shuli; Ciais, Philippe; Janssens, Ivan A.; Chen, Jiquan; Ammann, Christof; Arain, Altaf; Blanken, Peter D.; Cescatti, Alessandro; Bonal, Damien; Buchmann, Nina; Curtis, Peter S.; Chen, Shiping; Dong, Jinwei; Flanagan, Lawrence B.; Frankenberg, Christian; Georgiadis, Teodoro; Gough, Christopher M.; Hui, Dafeng; Kiely, Gerard; Li, Jianwei; Lund, Magnus; Magliulo, Vincenzo; Marcolla, Barbara; Merbold, Lutz; Olesen, Jørgen E.; Piao, Shilong; Raschi, Antonio; Roupsard, Olivier; Suyker, Andrew E.; Vaccari, Francesco P.; Varlagin, Andrej; Vesala, Timo; Wilkinson, Matthew; Weng, Ensheng; Yan, Liming; Luo, Yiqi

2015-01-01

Terrestrial gross primary productivity (GPP) varies greatly over time and space. A better understanding of this variability is necessary for more accurate predictions of the future climate–carbon cycle feedback. Recent studies have suggested that variability in GPP is driven by a broad range of biotic and abiotic factors operating mainly through changes in vegetation phenology and physiological processes. However, it is still unclear how plant phenology and physiology can be integrated to explain the spatiotemporal variability of terrestrial GPP. Based on analyses of eddy–covariance and satellite-derived data, we decomposed annual terrestrial GPP into the length of the CO2 uptake period (CUP) and the seasonal maximal capacity of CO2 uptake (GPPmax). The product of CUP and GPPmax explained >90% of the temporal GPP variability in most areas of North America during 2000–2010 and the spatial GPP variation among globally distributed eddy flux tower sites. It also explained GPP response to the European heatwave in 2003 (r2 = 0.90) and GPP recovery after a fire disturbance in South Dakota (r2 = 0.88). Additional analysis of the eddy–covariance flux data shows that the interbiome variation in annual GPP is better explained by that in GPPmax than CUP. These findings indicate that terrestrial GPP is jointly controlled by ecosystem-level plant phenology and photosynthetic capacity, and greater understanding of GPPmax and CUP responses to environmental and biological variations will, thus, improve predictions of GPP over time and space. PMID:25730847

Shrinking lung syndrome as a manifestation of pleuritis: a new model based on pulmonary physiological studies.

PubMed

Henderson, Lauren A; Loring, Stephen H; Gill, Ritu R; Liao, Katherine P; Ishizawar, Rumey; Kim, Susan; Perlmutter-Goldenson, Robin; Rothman, Deborah; Son, Mary Beth F; Stoll, Matthew L; Zemel, Lawrence S; Sandborg, Christy; Dellaripa, Paul F; Nigrovic, Peter A

2013-03-01

The pathophysiology of shrinking lung syndrome (SLS) is poorly understood. We sought to define the structural basis for this condition through the study of pulmonary mechanics in affected patients. Since 2007, most patients evaluated for SLS at our institutions have undergone standardized respiratory testing including esophageal manometry. We analyzed these studies to define the physiological abnormalities driving respiratory restriction. Chest computed tomography data were post-processed to quantify lung volume and parenchymal density. Six cases met criteria for SLS. All presented with dyspnea as well as pleurisy and/or transient pleural effusions. Chest imaging results were free of parenchymal disease and corrected diffusing capacities were normal. Total lung capacities were 39%-50% of predicted. Maximal inspiratory pressures were impaired at high lung volumes, but not low lung volumes, in 5 patients. Lung compliance was strikingly reduced in all patients, accompanied by increased parenchymal density. Patients with SLS exhibited symptomatic and/or radiographic pleuritis associated with 2 characteristic physiological abnormalities: (1) impaired respiratory force at high but not low lung volumes; and (2) markedly decreased pulmonary compliance in the absence of identifiable interstitial lung disease. These findings suggest a model in which pleural inflammation chronically impairs deep inspiration, for example through neural reflexes, leading to parenchymal reorganization that impairs lung compliance, a known complication of persistently low lung volumes. Together these processes could account for the association of SLS with pleuritis as well as the gradual symptomatic and functional progression that is a hallmark of this syndrome.

Evaluation of space capacities of the respiratory muscles during hypokinesia

NASA Astrophysics Data System (ADS)

Baranov, V. M.; Aleksandrova, N. P.; Tikhonov, M. A.

2005-08-01

Nowdays, the phenomenon of physical performance degradation after a long period of motor restraint or microgravity is universally interpreted as a result of deconditioning of the cardiovascular system and anti- gravity skeletal muscles.Yet, deconditioning affects not only the skeletal but also respiratory muscles exhaustion of which by relative hypoventilation brings about hypercapnia, hypoxia and pulmonary acidosis conducive to the sensations of painful breathlessness impacting the capacity for physical work. It should be emphasized that these developments are little known in spite of their theoretical and practical significance; therefore, our purpose was to study the functional state and spare capacity of the respiratory muscles in laboratory animals (Wistar rats) following 3-wk tail-suspension.The experiment strengthened the hypothesis according to which simulation of the physiological effects of motor restraint and microgravity leads to fatigue and deconditioning of the respiratory muscles.

Nitrogen fluxes at the root-soil interface show a mismatch of nitrogen fertilizer supply and sugarcane root uptake capacity

NASA Astrophysics Data System (ADS)

Inselsbacher, Erich; Schmidt, Susanne; Näsholm, Torgny; Robinson, Nicole; Guillou, Stéphane; Vinall, Kerry; Lakshmanan, Prakash; Brackin, Richard

2016-04-01

Nitrogen (N) uptake by agricultural crops is a key constituent of the global N cycle, as N captured by roots has a markedly different fate than N remaining in the soil. Global evidence indicates that only approximately 50% of applied N fertilizer is captured by crops, and the remainder can cause pollution via runoff and gaseous emissions. This inefficiency is of global concern, and requires innovation based on improved understanding of which N forms are available for and ultimately taken up by crops. However, current soil analysis methods based on destructive soil sampling provide little insight into delivery and acquisition of N forms by roots. Here, we present the results of a study in sugarcane fields receiving different fertilizer regimes comparing soil N supply rates with potential root N uptake rates. We applied microdialysis, a novel technique for in situ quantification of soil nutrient fluxes, to measure flux rates of inorganic N and amino acid N, and analyzed N uptake capacities of sugarcane roots using 15N labelled tracers. We found that in fertilized sugarcane soils, fluxes of inorganic N exceed the uptake capacities of sugarcane roots by several orders of magnitude. Contrary, fluxes of organic N closely matched roots' uptake capacity. These results indicate root uptake capacity constrains plant acquisition of inorganic N. This mismatch between soil N supply and root N uptake capacity is a likely key driver for low N efficiency in the studied crop system. Our results also suggest that the relative contribution of inorganic N for plant nutrition may be overestimated when relying on soil extracts as indicators for root-available N, and organic N may contribute more to crop N supply than is currently assumed. Overall, we show a new approach for examining in situ N relations in soil in context of crop N physiology, which provides a new avenue towards tailoring N fertilizer supply to match the specific uptake abilities and N demand of crops over the growth cycle.

Benefits of emotional integration and costs of emotional distancing.

PubMed

Roth, Guy; Shahar, Bat-Hen; Zohar-Shefer, Yael; Benita, Moti; Moed, Anat; Bibi, Uri; Kanat-Maymon, Yaniv; Ryan, Richard M

2017-12-09

Three studies explored the consequences of the self-determination theory conception of integrative emotion regulation (IER; Ryan & Deci, 2017), which involves an interested stance toward emotions. Emotional, physiological, and cognitive consequences of IER were compared to the consequences of emotional distancing (ED), in relation to a fear-eliciting film. In Study 1, we manipulated emotion regulation by prompting students' (N = 90) IER and ED and also included a control group. Then we tested groups' defensive versus nondefensive emotional processing, coded from post-film written texts. Study 2 (N = 90) and Study 3 (N = 135) used the same emotion regulation manipulations but exposed participants to the fear-eliciting film twice, 72 hr apart, to examine each style's protection from adverse emotional, physiological, and cognitive costs at second exposure. Participants who had been prompted to practice IER were expected to benefit more than participants in the ED and control groups at second exposure, as manifested in lower arousal and better cognitive capacity. Overall, results supported our hypotheses. The current studies provide some support for the assumption that in comparison to ED, taking interest in and accepting one's negative emotions are linked with less defensive processing of negative experiences and with better functioning. © 2017 Wiley Periodicals, Inc.

Coral Carbonic Anhydrases: Regulation by Ocean Acidification.

PubMed

Zoccola, Didier; Innocenti, Alessio; Bertucci, Anthony; Tambutté, Eric; Supuran, Claudiu T; Tambutté, Sylvie

2016-06-03

Global change is a major threat to the oceans, as it implies temperature increase and acidification. Ocean acidification (OA) involving decreasing pH and changes in seawater carbonate chemistry challenges the capacity of corals to form their skeletons. Despite the large number of studies that have investigated how rates of calcification respond to ocean acidification scenarios, comparatively few studies tackle how ocean acidification impacts the physiological mechanisms that drive calcification itself. The aim of our paper was to determine how the carbonic anhydrases, which play a major role in calcification, are potentially regulated by ocean acidification. For this we measured the effect of pH on enzyme activity of two carbonic anhydrase isoforms that have been previously characterized in the scleractinian coral Stylophora pistillata. In addition we looked at gene expression of these enzymes in vivo. For both isoforms, our results show (1) a change in gene expression under OA (2) an effect of OA and temperature on carbonic anhydrase activity. We suggest that temperature increase could counterbalance the effect of OA on enzyme activity. Finally we point out that caution must, thus, be taken when interpreting transcriptomic data on carbonic anhydrases in ocean acidification and temperature stress experiments, as the effect of these stressors on the physiological function of CA will depend both on gene expression and enzyme activity.

Differential gene expression in senescing leaves of two silver birch genotypes in response to elevated CO2 and tropospheric ozone.

PubMed

Kontunen-Soppela, Sari; Riikonen, Johanna; Ruhanen, Hanna; Brosché, Mikael; Somervuo, Panu; Peltonen, Petri; Kangasjärvi, Jaakko; Auvinen, Petri; Paulin, Lars; Keinänen, Markku; Oksanen, Elina; Vapaavuori, Elina

2010-06-01

Long-term effects of elevated CO(2) and O(3) concentrations on gene expression in silver birch (Betula pendula Roth) leaves were studied during the end of the growing season. Two birch genotypes, clones 4 and 80, with different ozone growth responses, were exposed to 2x ambient CO(2) and/or O(3) in open-top chambers (OTCs). Microarray analyses were performed after 2 years of exposure, and the transcriptional profiles were compared to key physiological characteristics during leaf senescence. There were genotypic differences in the responses to CO(2) and O(3). Clone 80 exhibited greater transcriptional response and capacity to alter metabolism, resulting in better stress tolerance. The gene expression patterns of birch leaves indicated contrasting responses of senescence-related genes to elevated CO(2) and O(3). Elevated CO(2) delayed leaf senescence and reduced associated transcriptional changes, whereas elevated O(3) advanced leaf senescence because of increased oxidative stress. The combined treatment demonstrated that elevated CO(2) only temporarily alleviated the negative effects of O(3). Gene expression data alone were insufficient to explain the O(3) response in birch, and additional physiological and biochemical data were required to understand the true O(3) sensitivity of these clones.

Effects of adjunctive exercise on physiological and psychological parameters in depression: a randomized pilot trial.

PubMed

Kerling, Arno; Tegtbur, Uwe; Gützlaff, Elke; Kück, Momme; Borchert, Luise; Ates, Zeynep; von Bohlen, Anne; Frieling, Helge; Hüper, Katja; Hartung, Dagmar; Schweiger, Ulrich; Kahl, Kai G

2015-05-15

Major depressive disorder (MDD) is associated with decreased physical activity and increased rates of the metabolic syndrome (MetS), a risk factor for the development of type 2 diabetes and cardiovascular disorders. Exercise training has been shown to improve cardiorespiratory fitness and metabolic syndrome factors. Therefore, our study aimed at examining whether patients receiving an exercise program as an adjunct to inpatient treatment will benefit in terms of physiological and psychological factors. Fourty-two inpatients with moderate to severe depression were included. Twenty-two patients were randomized to additional 3x weekly exercise training (EXERCISE) and compared to treatment as usual (TAU). Exercise capacity was assessed as peak oxygen uptake (VO2peak), ventilatory anaerobic threshold (VAT) and workload expressed as Watts (W). Metabolic syndrome was defined according to NCEP ATPIII panel criteria. After 6 weeks of treatment, cardiorespiratory fitness (VO2peak, VAT, Watt), waist circumference and HDL cholesterol were significantly improved in EXERCISE participants. Treatment response expressed as ≥50% MADRS reduction was more frequent in the EXERCISE group. Adjunctive exercise training in depressed inpatients improves physical fitness, MetS factors, and psychological outcome. Given the association of depression with cardiometablic disorders, exercise training is recommended as an adjunct to standard antidepressant treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

Pulmonary arterial enlargement predicts long-term survival in COPD patients.

PubMed

de-Torres, Juan P; Ezponda, Ana; Alcaide, Ana B; Campo, Arantza; Berto, Juan; Gonzalez, Jessica; Zulueta, Javier J; Casanova, Ciro; Rodriguez-Delgado, Luisa Elena; Celli, Bartolome R; Bastarrika, Gorka

2018-01-01

Pulmonary artery enlargement (PAE) is associated with exacerbations in Chronic Obstructive Pulmonary Disease (COPD) and with survival in moderate to severe patients. The potential role of PAE in survival prediction has not been compared with other clinical and physiological prognostic markers. In 188 patients with COPD, PA diameter was measured on a chest CT and the following clinical and physiological parameters registered: age, gender, smoking status, pack-years history, dyspnea, lung function, exercise capacity, Body Mass Index, BODE index and history of exacerbations in year prior to enrolment. Proportional Cox regression analysis determined the best predictor of all cause survival. During 83 months (±42), 43 patients died. Age, pack-years history, smoking status, BMI, FEV1%, six minute walking distance, Modified Medical Research Council dyspnea scale, BODE index, exacerbation rate prior to enrollment, PA diameter and PAE (diameter≥30mm) were associated with survival. In the multivariable analysis, age (HR: 1.08; 95%CI: 1.03-1.12, p<0.001) and PAE (HR: 2.78; 95%CI: 1.35-5.75, p = 0.006) were the most powerful parameters associated with all-cause mortality. In this prospective observational study of COPD patients with mild to moderate airflow limitation, PAE was the best predictor of long-term survival along with age.

Heavy Metal Uptake by Herbs. V. Metal Accumulation and Physiological Effects Induced by Thiuram in Ocimum basilicum L.

PubMed

Adamczyk-Szabela, Dorota; Romanowska-Duda, Zdzisława; Lisowska, Katarzyna; Wolf, Wojciech M

2017-01-01

Basil ( Ocimum basilicum L.) is extensively cultivated as either an important spice and food additive or a source of essential oil crucial for the production of natural phenylpropanoids and terpenoids. It is frequently attacked by fungal diseases. The aim of the study was to estimate the impact of thiuram contact time on the uptake of manganese, cobalt, nickel, copper, zinc, cadmium, and lead by Ocimum basilicum L . The relevant plant physiological parameters were also investigated. Two farmland soils typical for the Polish rural environment were used. Studies involved soil analyses, bioavailable, and total forms for all investigated metals, chlorophyll content, and gas exchange. Atomic absorption spectrometry was used to determine concentration of all elements. Analysis of variance proved hypothesis that thiuram treatment of basil significantly influences metal transfer from soil and their concentration in roots and aboveground parts. This effect is mostly visible on the 14th day after the fungicide administration. Thiuram modifies mycoflora in the rhizosphere zone and subsequently affects either metal uptake from the soil environment or their further migration within the basil plant. Notable, those changes are more evident for basil planted in mineral soil as compared to organic soil with higher buffering capacity.

Effects of a prescribed fire on water use and photosynthetic capacity of pitch pines

Treesearch

Heidi J. Renninger; Kenneth L. Clark; Nicholas Skowronski; Karina V.R. Schäfer

2013-01-01

Although wildfires are important in many forested ecosystems, increasing suburbanization necessitates management with prescribed fires. The physiological responses of overstory trees to prescribed fire has received little study and may differ from typical wildfires due to the lower intensity and timing of prescribed fire in the dormant season. Trees may be negatively...

Effect of ovulatory follicle size on steroidogenic capacity and molecular markers of oocyte competence prior to GnRH-induced ovulation in non-lactating beef cows

USDA-ARS?s Scientific Manuscript database

Gonadotropin releasing hormone (GnRH)-induced ovulation of small dominant follicles decreased pregnancy rates and increased late embryonic/fetal mortality in beef cows. Inadequate oocyte competence, as affected by the physiological status of the dominant follicle, is a potential explanation for the...

Biomedical Results of Apollo

NASA Technical Reports Server (NTRS)

Johnston, R. S. (Editor); Dietlein, L. F. (Editor); Berry, C. A. (Editor); Parker, James F. (Compiler); West, Vita (Compiler)

1975-01-01

The biomedical program developed for Apollo is described in detail. The findings are listed of those investigations which are conducted to assess the effects of space flight on man's physiological and functional capacities, and significant medical events in Apollo are documented. Topics discussed include crew health and inflight monitoring, preflight and postflight medical testing, inflight experiments, quarantine, and life support systems.

Some Thoughts on the Matter of Self-Determination and Will.

ERIC Educational Resources Information Center

Deci, Edward L.

"Will" is defined in this paper as the capacity to decide how to behave based on a processing of relevant information. A sequence of motivated behavior begins with informational inputs or stimuli. These come from three sources: the environment, one's physiology, and one's memory. These inputs lead to the formation of motives or awareness of a…

Lower growth temperature increases alternative pathway capacity and alternative oxidase protein in tobacco.

PubMed

Vanlerberghe, G C; McIntosh, L

1992-09-01

Suspension cells of NT1 tobacco (Nicotiana tabacum L. cv bright yellow) have been used to study the effect of growth temperature on the CN-resistant, salicylhydroxamic acid-sensitive alternative pathway of respiration. Mitochondria isolated from cells maintained at 30 degrees C had a low capacity to oxidize succinate via the alternative pathway, whereas mitochondria isolated from cells 24 h after transfer to 18 degrees C displayed, on average, a 5-fold increase in this capacity (from 7 to 32 nanoatoms oxygen per milligram protein per minute). This represented an increase in alternative pathway capacity from 18 to 45% of the total capacity of electron transport. This increased capacity was lost upon transfer of cells back to 30 degrees C. A monoclonal antibody to the terminal oxidase of the alternative pathway (the alternative oxidase) from Sauromatum guttatum (T.E. Elthon, R.L. Nickels, L. McIntosh [1989] Plant Physiology 89: 1311-1317) recognized a 35-kilodalton mitochondrial protein in tobacco. There was an excellent correlation between the capacity of the alternative path in isolated tobacco mitochondria and the levels of this 35-kilodalton alternative oxidase protein. Cycloheximide could inhibit both the increased level of the 35-kilodalton alternative oxidase protein and the increased alternative pathway capacity normally seen upon transfer to 18 degrees C. We conclude that transfer of tobacco cells to the lower temperature increases the capacity of the alternative pathway due, at least in part, to de novo synthesis of the 35-kilodalton alternative oxidase protein.